WO2024181097A1

WO2024181097A1 - Photocurable composition, method for producing cured article, film, optical element, image sensor, solid-state imaging element, image display device, and radical polymerization initiator

Info

Publication number: WO2024181097A1
Application number: PCT/JP2024/004625
Authority: WO
Inventors: 賢鮫島; 雅臣牧野
Original assignee: 富士フイルム株式会社
Priority date: 2023-02-27
Filing date: 2024-02-09
Publication date: 2024-09-06

Abstract

Provided are: a photocurable composition comprising a radical polymerization initiator represented by formula (1) and a radical polymerizable compound; applications of same; and a radical polymerization initiator.　In formula (1), Ar1 represents a (k+m+1)-valent aromatic or heteroaromatic group, and Ar2 represents a (k+2)-valent aromatic or heteroaromatic group; R1 represents an alkyl group, an aryl group, a heteroaryl group, or the like; L represents a single bond or CR11R12, R11 and R12 each independently represent a hydrogen atom, an alkyl group or an aryl group, and k represents 0 or 1; R6 represents an alkyl group optionally substituted by a halogen atom, a cyano group, or the like, or by -C(=O)R2, -NR11R12, or the like, and m represents an integer of 1-4; and Y1 represents a linear alkyl group.

Description

Photocurable composition, method for producing cured product, film, optical element, image sensor, solid-state imaging device, image display device, and radical polymerization initiator

The present disclosure relates to a photocurable composition, a method for producing a cured product, a film, an optical element, an image sensor, a solid-state imaging element, an image display device, and a radical polymerization initiator.

2. Description of the Related Art Optical filters such as color filters are produced using a photocurable composition that contains a colorant, a photopolymerization initiator, and a polymerizable compound.
In recent years, when high definition of recorded images is desired, the number of pixels of color filters and the like is desired to be improved, and patterns are becoming finer. For the purpose of forming fine patterns, a technology is being attempted in which a long light source is replaced by a shorter wavelength KrF excimer laser (248 nm) instead of the conventional i-line (365 nm), thereby improving the optical resolution and transferring finer patterns even with fine mask exposure. However, the exposure amount of KrF is lower than that of the conventional i-line, and there is a concern that sufficient sensitivity cannot be obtained with conventional photopolymerization initiators.
As photopolymerization initiators used in conventional photocurable compositions, the compounds described in WO 2015/036910 and WO 2021/006315 are known.
WO 2015/036910 describes an oxime ester compound having an ether-linked mother nucleus and a heteroaryl group in a side chain as a photopolymerization initiator.
WO 2021/006315 describes a negative photosensitive resin composition using an oxime ester compound having two types of ether-linked mother nuclei having a condensed polycyclic skeleton and a condensed polycyclic heterocyclic skeleton.

According to the inventors' investigations, for example, to form a high-definition cured product using a KrF laser, it is believed that even higher sensitivity is required than the compounds described in WO 2015/036910 and WO 2021/006315.

An object of the present disclosure is to provide a photocurable composition having high sensitivity.
Another problem to be solved by another embodiment of the present disclosure is to provide a method for producing a cured product, a film, an optical element, an image sensor, a solid-state imaging element, or an image display device using the photocurable composition.
Furthermore, a problem to be solved by another embodiment of the present disclosure is to provide a novel radical polymerization initiator.

Means for solving the above problems include the following aspects.
<1> A photocurable composition comprising a radical polymerization initiator represented by formula (1) and a radical polymerizable compound.

In formula (1), Ar ₁ represents a (k+m+1)-valent aromatic group or a (k+m+1)-valent heteroaromatic group, and Ar ₂ represents a (k+2)-valent aromatic group or a (k+2)-valent heteroaromatic group.
R ₁ represents an alkyl group, an aryl group, a heteroaryl group, an alkoxy group, an aryloxy group, or a heteroaryloxy group.
L represents a single bond or CR ₁₁ R ₁₂ , R ₁₁ and R ₁₂ each independently represent a hydrogen atom, an alkyl group or an aryl group, and k represents 0 or 1. When k is 0, L does not exist, and Ar ₁ and Ar ₂ are linked only via an oxygen atom.
R ₆ each independently represents a halogen atom, a cyano group, an alkoxy group, a hydroxy group, a phenoxy group, -C(=O)R ₂ , -C(=O)NHR ₃ , -NHC(=O)R ₄ , -NR ₁₁ R ₁₂ or an alkyl group which may be substituted with -SR ₁₁ ; R ₂ , R ₃ and R ₄ each independently represent an alkyl group or an aryl group; R ₁₁ and R ₁₂ each independently represent a hydrogen atom, an alkyl group or an aryl group; and m represents an integer of 1 to 4.
_Y1 represents a straight chain alkyl group.

<2> The photocurable composition according to <1>, wherein R ₆ is a group represented by the following formula (2):

In formula (2), Ar ₃ represents an alkyl group or an aryl group, and * represents a linking portion with Ar ₁ in formula (1).
<3> The photocurable composition according to <1> or <2>, wherein the radical polymerization initiator is a compound represented by the following formula (3):

In formula (3), _Ar3 represents an alkyl group or an aryl group, _R7 represents an alkyl group or an aryl group, Z represents a linear alkyl group having 1 to 20 carbon atoms, L represents a _single bond or _CR11R12 , _R11 and _R12 each independently represent a hydrogen atom, an alkyl group, or an aryl group, and k represents 0 or 1.

<4> The photocurable composition according to any one of <1> to <3>, further comprising a resin.
<5> The photocurable composition according to <4>, wherein the resin has a graft chain, the graft chain includes at least one selected from the group consisting of a polyether chain, a polyester chain, and a polyacrylic chain, and the graft chain has a weight average molecular weight of 1,000 or more.
<6> The photocurable composition according to <4> or <5>, wherein the resin includes a resin having an acryloyl group, a methacryloyl group, an epoxy group, or an oxetanyl group.

<7> The photocurable composition according to any one of <1> to <6>, further comprising a colorant.
<8> The photocurable composition according to <7>, wherein the content of the colorant is 60 mass% or more based on the total solid content of the photocurable composition.
<9> The photocurable composition according to any one of <1> to <8>, further comprising a pigment derivative.
<10> The photocurable composition according to any one of <1> to <9>, further comprising a chain transfer agent.
<11> The photocurable composition according to any one of <1> to <10>, further comprising a sensitizer.
<12> The photocurable composition according to any one of <1> to <11>, which is for exposure to an excimer laser having a wavelength of 150 nm to 300 nm.

<13> A method for producing a cured product, comprising the step of irradiating the photocurable composition described in any one of <1> to <12> with excimer laser light having a wavelength of 150 nm to 300 nm.

<14> A film that is a cured product of the photocurable composition according to any one of <1> to <12>.
<15> An optical element comprising the film according to <14>.
<16> An image sensor comprising the film according to <14>.
<17> A solid-state imaging device comprising the film according to <14>.
<18> An image display device comprising the film according to <14>.

<19> A radical polymerization initiator represented by formula (1).

According to an embodiment of the present disclosure, a photocurable composition having high sensitivity is provided.
Further, according to other embodiments of the present disclosure, there are provided a method for producing a cured product, a film, an optical element, an image sensor, a solid-state imaging element, or an image display device using the photocurable composition.
Furthermore, according to another embodiment of the present disclosure, a novel radical polymerization initiator is provided.

The contents of the present disclosure will be described in detail below. The following description of the components may be based on a representative embodiment of the present disclosure, but the present disclosure is not limited to such an embodiment.
In the present disclosure, the word "to" is used to mean that the numerical values before and after it are included as the lower limit and upper limit.
In the description of groups (atomic groups) in the present disclosure, descriptions that do not indicate whether they are substituted or unsubstituted include groups (atomic groups) that have no substituents as well as groups (atomic groups) that have a substituent. For example, an "alkyl group" includes not only an alkyl group that has no substituents (unsubstituted alkyl groups) but also an alkyl group that has a substituent (substituted alkyl group).
In the present disclosure, unless otherwise specified, the term "exposure" includes not only exposure using light but also drawing using particle beams such as electron beams and ion beams. Examples of light used for exposure include the bright line spectrum of a mercury lamp, far ultraviolet light represented by an excimer laser, extreme ultraviolet light (EUV light), X-rays, and actinic rays or radiation such as electron beams.
In the present disclosure, "(meth)acrylate" refers to both or either of acrylate and methacrylate, "(meth)acrylic" refers to both or either of acrylic and methacrylic, and "(meth)acryloyl" refers to both or either of acryloyl and methacryloyl.
In the present disclosure, Me in the structural formulae represents a methyl group, Et represents an ethyl group, Bu represents a butyl group, and Ph represents a phenyl group.
In the present disclosure, the weight average molecular weight and the number average molecular weight are values calculated in terms of polystyrene measured by a GPC (gel permeation chromatography) method.
In this disclosure, total solids refers to the total mass of all components of a composition excluding the solvent.
In this disclosure, a pigment means a colorant that is poorly soluble in a solvent.
In the present disclosure, the term "step" refers not only to an independent step, but also to a step that cannot be clearly distinguished from other steps, as long as the intended effect of the step is achieved.
In the present disclosure, for oxime compounds having E- and Z-stereoisomers, unless otherwise specified, either the E- or Z-isomer may be used.
The present disclosure will be described in detail below.

(Photocurable composition)
The photocurable composition according to the present disclosure contains a radical polymerization initiator represented by formula (1) and a radical polymerizable compound.
Furthermore, the photocurable composition according to the present disclosure can be more suitably used as a photocurable composition for exposure to light having a wavelength of 150 nm to 300 nm, and can be particularly suitably used as a photocurable composition for exposure to an excimer laser having a wavelength of 150 nm to 300 nm.

In formula (1), Ar ₁ represents a (k+m+1)-valent aromatic group or a (k+m+1)-valent heteroaromatic group, and Ar ₂ represents a (k+2)-valent aromatic group or a (k+2)-valent heteroaromatic group.
_R1 represents an alkyl group, an aryl group, a heteroaryl group, an alkoxy group, an aryloxy group, or a heteroaryloxy group. When k is 0, L does not exist, and _Ar1 and _Ar2 are linked via only an oxygen atom.
L represents a single bond or CR ₁₁ R ₁₂ , R ₁₁ and R ₁₂ each independently represent a hydrogen atom, an alkyl group or an aryl group, and k represents 0 or 1.
R ₆ each independently represents a halogen atom, a cyano group, an alkoxy group, a hydroxy group, a phenoxy group, -C(=O)R ₂ , -C(=O)NHR ₃ , -NHC(=O)R ₄ , -NR ₁₁ R ₁₂ or an alkyl group which may be substituted with -SR ₁₁ ; R ₂ , R ₃ and R ₄ each independently represent an alkyl group or an aryl group; R ₁₁ and R ₁₂ each independently represent a hydrogen atom, an alkyl group or an aryl group; and m represents an integer of 1 to 4.
_Y1 represents a straight chain alkyl group.

As a result of extensive investigations, the present inventors have found that by employing the above-mentioned configuration, a photocurable composition having high sensitivity can be obtained.
The radical polymerization initiator represented by the above formula (1) has a mother nucleus structure linked by an ether bond (-C-O-C-), i.e., a structure of Ar ₁ -O-Ar ₂ , which makes the light absorption peak sharper and improves the absorption efficiency. Furthermore, by having a specific substituent represented by R ₆ in Ar ₁ and having an unbranched linear alkyl group represented by Y ₁ (the linear alkyl group may have a heteroatom) on the carbon atom of the oxime group, the generation of radicals from the oxime ester structure is promoted, and it is presumed that these structures work together to achieve high sensitivity, although the mechanism of action is not clear. Therefore, it is presumed that a photocurable composition with higher sensitivity can be obtained by using the radical photopolymerization initiator represented by the above formula (1).

The photocurable composition according to the present disclosure is preferably used as a photocurable composition for optical filters. Examples of optical filters include color filters and infrared transmission filters, and color filters are preferred. That is, the photocurable composition according to the present disclosure is preferably used as a photocurable composition for color filters. More specifically, it can be preferably used as a photocurable composition for forming pixels of a color filter. Examples of pixel types include red pixels, green pixels, blue pixels, magenta pixels, cyan pixels, and yellow pixels.

Preferred examples of the infrared transmission filter include filters that satisfy the spectral characteristics of a maximum transmittance of 20% or less (preferably 15% or less, more preferably 10% or less) in the wavelength range of 400 nm to 640 nm and a minimum transmittance of 70% or more (preferably 75% or more, more preferably 80% or more) in the wavelength range of 1,100 nm to 1,300 nm. The infrared transmission filter is preferably a filter that satisfies any of the following spectral characteristics (1) to (5).
(1): A filter having a maximum transmittance of 20% or less (preferably 15% or less, more preferably 10% or less) in the wavelength range of 400 nm to 640 nm, and a minimum transmittance of 70% or more (preferably 75% or more, more preferably 80% or more) in the wavelength range of 800 nm to 1,500 nm.
(2): A filter having a maximum transmittance of 20% or less (preferably 15% or less, more preferably 10% or less) in the wavelength range of 400 nm to 750 nm, and a minimum transmittance of 70% or more (preferably 75% or more, more preferably 80% or more) in the wavelength range of 900 nm to 1,500 nm.
(3): A filter having a maximum transmittance of 20% or less (preferably 15% or less, more preferably 10% or less) in the wavelength range of 400 nm to 830 nm, and a minimum transmittance of 70% or more (preferably 75% or more, more preferably 80% or more) in the wavelength range of 1,000 nm to 1,500 nm.
(4): A filter having a maximum transmittance of 20% or less (preferably 15% or less, more preferably 10% or less) in the wavelength range of 400 nm to 950 nm, and a minimum transmittance of 70% or more (preferably 75% or more, more preferably 80% or more) in the wavelength range of 1,100 nm to 1,500 nm.
(5): A filter having a maximum transmittance of 20% or less (preferably 15% or less, more preferably 10% or less) in the wavelength range of 400 nm to 1,050 nm, and a minimum transmittance of 70% or more (preferably 75% or more, more preferably 80% or more) in the wavelength range of 1,200 nm to 1,500 nm.

The photocurable composition according to the present disclosure is preferably used for solid-state imaging devices. More specifically, it is preferably used as a photocurable composition for optical filters used in solid-state imaging devices, and is more preferably used as a photocurable composition for color filters used in solid-state imaging devices.

The solid content of the photocurable composition according to the present disclosure is preferably 5% by mass to 40% by mass. The lower limit is more preferably 7.5% by mass or more, and even more preferably 10% by mass or more. The upper limit is more preferably 35% by mass or less, and even more preferably 30% by mass or less.
In an embodiment of the photocurable composition according to the present disclosure, the solids concentration is more preferably from 7.5% by mass to 35% by mass, and even more preferably from 10% by mass to 30% by mass.

<Radical Polymerization Initiator Represented by Formula (1)>
The photocurable composition according to the present disclosure contains a radical polymerization initiator represented by the above formula (1) (hereinafter, may be referred to as the polymerization initiator according to the present disclosure). The polymerization initiator according to the present disclosure is preferably a photoradical polymerization initiator that generates radicals when exposed to light having a wavelength of 150 nm to 300 nm.
The exposure wavelength at which the radical polymerization initiator represented by the above formula (1) generates radicals is preferably 150 nm to 460 nm, more preferably 150 nm to 420 nm, even more preferably 150 nm to 380 nm, and particularly preferably 150 nm to 300 nm.

One of the features of the radical polymerization initiator represented by formula (1) is that Ar ₁ and Ar ₂ in formula (1) are linked to each other via an oxygen atom to form a mother nucleus structure.
In formula (1), Ar ₁ represents an aromatic group having a valence of (k+m+1) or a heteroaromatic group having a valence of (k+m+1), and Ar ₂ represents an aromatic group having a valence of (k+2) or a heteroaromatic group having a valence of (k+2). The aromatic group or heteroaromatic group represented by Ar ₁ or Ar ₂ may be a monocyclic structure or a condensed ring structure having two or more rings. Ar ₁ and Ar ₂ may be the same or different from each other.

In formula (1), L represents a single bond or CR ₁₁ R ₁₂ , R ₁₁ and R ₁₂ each independently represent a hydrogen atom, an alkyl group or an aryl group, and k represents 0 or 1.
For example, when k is 0, Ar ₁ and Ar ₂ form a mother nucleus structure in which they are linked only via oxygen atoms. When k is 1, L is a single bond, and Ar ₁ and Ar ₂ are 6-membered aromatic groups, the mother nucleus of the polymerization initiator has the following structure:

When k is 1 and L represents CR ₁₁ R ₁₂ , R ₁₁ and R ₁₂ may be the same or different from each other. From the viewpoint of synthesis suitability, it is preferable that R ₁₁ and R ₁₂ are the same as each other.

Below are specific examples (X-1) to (X-14) of the mother nucleus structure in formula (1). It goes without saying that the mother nucleus structure in formula (1) is not limited to the specific examples below, since other modifications are also included within the scope defined by formula (1). In the mother nucleus structures below, "*" represents a bond.

Among them, from the viewpoint of making the light absorption peak sharper and improving the light absorption efficiency, at least one type of mother structure selected from the group consisting of (X-3) to (X-8) in which k is 1 and L is a single bond in formula (1) is preferred, at least one type of mother structure selected from the group consisting of (X-3), (X-7) and (X-8) is more preferred, and (X-3) is even more preferred.

In formula (1), R ₁ represents an alkyl group, an aryl group, a heteroaryl group, an alkoxy group, an aryloxy group, or a heteroaryloxy group.
The alkyl group includes a straight-chain or branched alkyl group having 1 to 5 carbon atoms, and the aryl group includes an unsubstituted phenyl group.
From the viewpoint of improving sensitivity, R ₁ in formula (1) is preferably at least one group selected from the group consisting of an alkyl group, an aryl group, an alkoxy group, and an aryloxy group, more preferably an alkyl group, still more preferably an alkyl group having 1 to 4 carbon atoms, and particularly preferably a methyl group.

It is presumed that the specific substituent represented by _R6 in formula (1) contributes to the high sensitivity of the polymerization initiator of the present disclosure.
The number of R ₆ in formula (1) may be 1 to 4 depending on m. A plurality of R ₆ may be the same or different.
m represents an integer of 1 to 4, and is preferably 1 from the viewpoints of sensitivity and synthesis suitability.
R ₆ represents an alkyl group which may be substituted with a halogen atom, a cyano group, an alkoxy group, a hydroxy group, a phenoxy group, -C(=O)R ₂ , -C(=O)NHR ₃ , -NHC(=O)R ₄ , -NR ₁₁ R ₁₂ or -SR ₁₁ ; R ₂ , R ₃ and R ₄ each independently represent an alkyl group or an aryl group; R ₁₁ and R ₁₂ each independently represent a hydrogen atom, an alkyl group or an aryl group.
In particular, from the viewpoint of making the light absorption peak sharper, improving the light absorption efficiency, and improving the radical generation efficiency, R ₆ is preferably at least one group selected from the group consisting of -C(=O)R ₂ , -C(=O)NHR ₃ , and -NHC(=O)R ₄ bonded to Ar ₁ via a carbonyl group, and here, a structure in which R ₂ , R ₃ , and R ₄ each have an aryl group is more preferable, and a group represented by the following formula (2) is even more preferable.
That is, R ₆ in formula (1) is preferably a group represented by the following formula (2).

In formula (2), Ar ₃ represents an alkyl group or an aryl group, and * represents a linking portion with Ar ₁ in formula (1).

When _Ar3 represents an aryl group, the aryl group is preferably an aryl group having 6 to 20 carbon atoms, more preferably an aryl group having 6 to 12 carbon atoms, and further preferably a phenyl group.
The aryl group may further have at least one substituent selected from an alkyl group, a halogen atom, a cyano group, an alkoxy group, a hydroxy group, and a phenoxy group. A structure in which the aryl group has an alkyl group and a structure in which the aryl group has a halogen atom are preferred.
Examples of the halogen atom include fluorine, chlorine, boron, and iodine. Among them, it is preferable to have a halogen atom selected from an iodine atom and a boron atom, and it is more preferable to have a boron atom.

When _Ar3 represents an alkyl group, the alkyl group is preferably an unsubstituted alkyl group having a linear, branched or cyclic structure, an aryl group, or an alkyl group having at least one substituent selected from Group A below, more preferably a methyl group or an alkyl group having at least one substituent selected from Group A below, even more preferably an alkyl group having at least one substituent selected from Group A below, particularly preferably an alkyl group having at least one substituent selected from Group B below, and most preferably an alkyl group having at least one substituent selected from Group C below.
- Group A -
Cyano group, alkenyl group, alkynyl group, -N(R _a ) ₂ , -SR _a , -COOH, -OR _a , -O-COR _c , -O-CO-OR _c , -CONR _a R _b , -NR _a -CO-R _b , -O-CO-NR _a R _b , -NR _a -CO-OR _b , -NR _a -CO-NR _a R _b , -SO-R _c , -SO ₂ -R _c , -O-SO ₂ -R _c , -SO ₂ -NR _a R _b , -NR _a -SO ₂ -R _a , -CO-NR _a -COR _b , -CO-NR _a -SO ₂ -R _b , -SO ₂ -NRa _- CO- _Rb , _-SO2 - _NRa - _SO2 - _Rc , -Si( _Ra ) _L ( _ORb ) _K , heterocyclic group, and -O( _RdO ) _J - _Ra
Here, R _a and R _b each independently represent a hydrogen atom, an alkyl group, an aryl group, or a heteroaryl group; R _c each independently represent an alkyl group, an aryl group, or a heteroaryl group; R _d each independently represent an alkylene group, an arylene group, or a group combining two or more of these; L and K each independently represent an integer of 0 to 3, satisfying L+K=3; and J represents an integer of 1 to 100.
- Group B -
Alkenyl groups, -N(R _a ) ₂ , -SR _a , -OR _a
- Group C -
-N(R _a ) ₂ , -SR _a , -OR _a
Here, each R _a independently represents a hydrogen atom, an alkyl group, an aryl group or a heteroaryl group.
Each R _a is preferably an alkyl group, an aryl group or a heteroaryl group, more preferably an alkyl group, and particularly preferably a cycloalkyl group.
Each R _b is preferably a hydrogen atom or an alkyl group, and more preferably an alkyl group.
The above _Rc is preferably an alkyl group or an aryl group, and is preferably an alkyl group.
Each _Rd is preferably an alkylene group, and more preferably an ethylene group or a propylene group.
Two or more of the above R _a to R _c may be bonded to form a ring structure.

Specific examples of R ₆ in formula (1) are (R6-1) to (R6-26) below, but R ₆ is not limited to the following specific examples. In the following specific examples of R ₆ , * represents a linking portion with Ar ₁ .

As _R6 , from the viewpoint of further improving the radical generation efficiency, (R6-1), (R6-12) to (R6-16), (R6-19), (R6-20), (R6-22), and (R6-24) to (R6-26) are preferred, and from the viewpoint of further improving the radical generation efficiency due to the heavy atom effect, (R6-12) to (R6-15), (R6-19), (R6-20), (R6-22), and (R6-24) to (R6-26) are more preferred.

In formula (1), _Y1 represents a linear alkyl group.
In order to further improve the radical generation efficiency, it is preferable that the alkyl chain has an appropriate chain length in the linear alkyl group of Y _1. From the above viewpoint, Y ₁ is preferably a group selected from linear alkyl groups having 1 to 20 carbon atoms, more preferably a group selected from linear alkyl groups having 1 to 12 carbon atoms, and further preferably a group selected from linear alkyl groups having 1 to 6 carbon atoms.
The linear alkyl group may contain a heteroatom in the middle of the alkyl group chain, or may have a heteroatom, aryl group, or the like bonded to the end of the linear alkyl group. Examples of the heteroatom include an oxygen atom, a sulfur atom, and a halogen atom, and examples of the halogen atom include a chlorine atom, a bromine atom, and a fluorine atom. Examples of the aryl group include a phenyl group.
Specific examples of _Y1 in formula (1) are (Y-1) to (Y-27), but _Y1 is not limited to the following specific examples. In the following specific examples of _Y1 , * represents a linkage with -C(=N)- linked to _Ar2 .

From the viewpoint of further improving the radical generation efficiency, _Y1 is preferably at least one group selected from (Y-1) to (Y-5) which are straight-chain alkyl groups and do not contain a heteroatom, (Y-15) to (Y-18) which contain an oxygen atom, a sulfur atom, or the like in the middle, and (Y-20) to (Y-26) which have a halogen atom bonded to the end of a straight-chain alkyl group, and more preferably at least one group selected from (Y-1), (Y-2), (Y-15), (Y-16), (Y-20), and (Y-24).
The reason why the above is preferable is considered to be that the radical generation efficiency is further improved by the appropriate chain length of the alkyl chain in _Y1 , and that the radical generation efficiency is further improved by the heavy electron effect caused by the inclusion of a sulfur atom, a halogen atom, or the like in the alkyl chain.

The polymerization initiator of the present disclosure is not particularly limited except that it is a radical polymerization initiator represented by the above formula (1), and each of the partial structures described above, i.e., the mother structure, R ₁ , k, R ₆ , Y ₁ , and m, is as described above.
Although any combination of these partial structures may be used, it can be said that a compound represented by formula (1) constituted by combining preferred specific examples of each partial structure is a more preferred compound as a radical polymerization initiator.

In the following formula (1-1) in which the mother nucleus structure in formula (1) is represented by X, each partial structure in formula (1-1) is clearly indicated to show exemplary compounds (A-1) to (A-112) of the radical polymerization initiator represented by formula (1). Specific examples of the radical polymerization initiator represented by formula (1) below are preferably (A-1) to (A-112), but needless to say are not limited to these. The polymerization initiator of the present disclosure includes various modified examples within the range defined by formula (1).

Among them, for example, exemplary compounds (A-3) and (A _-26 ) to (A-29) which combine (X-3), which is a preferred embodiment of X as the mother structure, with (Y-1), which is a preferred Y ₁ , and combine (R6-1) and (R6-13) to (R6-16), which are preferred R _{1, and exemplary compounds (A-32) and (A-33) which combine (R6-19) and (R6-20), which are preferred R 1} , are exemplified as preferred initiators.
In addition, exemplary compounds (A-45) to (A-48), (A-58) to (A- ₆₀ ), and (A-63) to (A-69) are exemplified as preferred initiators, which are obtained by combining (X-3), which is a _preferred embodiment of X as the mother structure, with (R6-12), which is a preferred R 1, and combining (Y-2) to (Y-5), (Y-15) to (Y-17), and (Y-20) to (Y-26), which are preferred Y 1.

The polymerization initiator of the present disclosure represented by the above formula (1) is more preferably a compound represented by the following formula (3).

In formula (3), _Ar3 represents an alkyl group or an aryl group, _R7 represents an alkyl group or an aryl group, Z represents a linear alkyl group having 1 to 20 carbon atoms, L represents a _single bond or _CR11R12 , _R11 and _R12 each independently represent a hydrogen atom, an alkyl group or an aryl group, and k represents 0 or 1.
Ar ₃ in formula (3) has the same meaning as Ar ₃ in formula (2) above, and preferred examples are also the same.
_R7 in formula (3) has the same meaning as _R1 in formula (1), and preferred examples are also the same.
Z in formula (3) has the same meaning as _Y1 in formula (1), and preferred examples are also the same.

The radical polymerization initiator represented by the above formula (1) preferably has absorption in any one of the ArF absorption region at a wavelength of 193 nm, the KrF absorption region at a wavelength of 248 nm, and the i-line absorption region at a wavelength of 365 nm, and more preferably has absorption in any one of the ArF absorption region at a wavelength of 193 nm and the KrF absorption region at a wavelength of 248 nm.
The gram absorption coefficient at a wavelength of 248 nm or 365 nm of the radical polymerization initiator represented by the above formula (1) is preferably 1,000 L·g ^-1 ·cm ^-1 or more, more preferably 10,000 L·g ^-1 ·cm- ¹ or more, and even more preferably 20,000 L·g ^-1 ·cm- ¹ or more, from the viewpoint of sensitivity.

The gram absorption coefficient of the radical polymerization initiator represented by formula (1) is measured by the following method.
12.5 mg of polymerization initiator was weighed out and placed in a 100 mL measuring flask. Acetonitrile was added to this to completely dissolve it. 2 mL of this polymerization initiator solution was taken out with a whole pipette and made up into a 25 mL measuring flask. This was used as a measurement sample.
The sample is added to a 5 mL quartz glass cell of 1 cm square, and the absorbance is measured in air to calculate the gram absorption coefficient. The measuring device used is an ultraviolet-visible-near infrared spectrophotometer UH4150 (manufactured by Hitachi High-Tech Science Corporation).

The photocurable composition according to the present disclosure may contain one radical polymerization initiator represented by the above formula (1) alone or two or more radical polymerization initiators. When the photocurable composition contains two or more radical polymerization initiators, the total amount of the two or more radical polymerization initiators is preferably within the following range.
The content of the radical polymerization initiator represented by the above formula (1) is, from the viewpoints of sensitivity and coating film uniformity, preferably from 0.01% by mass to 30% by mass, more preferably from 0.05% by mass to 25% by mass, even more preferably from 0.1% by mass to 20% by mass, and particularly preferably from 1% by mass to 15% by mass, based on the total solid content of the photocurable composition.

Moreover, the radical polymerization initiator represented by the above formula (1) preferably has no absorption at wavelengths of 450 nm or more, more preferably has no absorption at wavelengths of 420 nm or more, and particularly preferably has no absorption in the wavelength range longer than 400 nm. In the present disclosure, "having no absorption" means that the gram absorption coefficient at that wavelength is 100 L·g ^-1 ·cm ^-1 or less. The radical polymerization initiator represented by the above formula (1) is preferably white to light yellow. The above colors are preferable because they have little effect on the spectrum of the color filter.

<Synthesis of radical polymerization initiator>
The method for producing the radical polymerization initiator represented by the above formula (1) is not particularly limited, and the initiator may be produced by a known method or may be produced with reference to a known method.
Exemplary compound (A-3), which is an example of the radical polymerization initiator represented by the above formula (1), can be synthesized, for example, from dibenzofuran as a starting material according to the following scheme.
The details of the synthesis method of the example compounds will be described later.

<Other radical polymerization initiators>
The photocurable composition according to the present disclosure may contain a radical polymerization initiator other than the radical polymerization initiator represented by formula (1) above.
Other radical polymerization initiators include oxime compounds, α-aminoacetophenone compounds, α-hydroxyketone compounds, acylphosphine compounds, and the like.
Of these, oxime compounds are preferred.
By using the radical polymerization initiator represented by the above formula 1 in combination with another radical polymerization initiator, a more well-balanced pattern with good rectangularity can be obtained.

Examples of the oxime compound include the compound described in paragraph 0142 of WO 2022/085485, the polymer described in JP 2020-172619 A, the compound represented by formula 1 described in WO 2020/152120, and the oxime ester compound described in WO 2021/023144. Specific examples of oxime compounds and commercially available products include the compounds described in paragraph 0142 of WO 2022/085485. In addition, an example of a commercially available product is TR-PBG-327 (manufactured by Tronley).
In addition, it is also preferable to use a compound that is not colored or that has high transparency and is not easily discolored as the oxime compound. Commercially available products include ADEKA ARCLES NCI-730, NCI-831, and NCI-930 (all manufactured by ADEKA CORPORATION).
Other radical polymerization initiators include fluorenyl amino ketone photoinitiators described in JP-T-2020-507664, photopolymerization initiators represented by the general formula (1) of JP-A-2021-173858, photopolymerization initiators described in paragraphs 0022 to 0024 of JP-A-2021-173858, photopolymerization initiators represented by the general formula (1) of JP-A-2021-170089, photopolymerization initiators described in paragraphs 0117 to 0120 of JP-A-2021-170089, and JP-A-2021 -181406 described compounds, photopolymerization initiators described in JP-A-2022-013379, compounds represented by formula (1) described in JP-A-2022-015747, fluorine-containing fluorene oxime ester photoinitiators described in JP-T-2021-507058, initiators described in China Patent Application Publication No. 110764367, initiators described in JP-T-2022-518535, initiators described in WO 2021/175855, and the like can also be used.
In addition, as the oxime compound, the compounds described in paragraphs 0143 to 0149 of WO 2022/085485 can be used.

Specific examples of oxime compounds include the compounds described in paragraphs 0083 to 0105 of Japanese Patent No. 4600600.

Furthermore, the following compounds are particularly preferred examples of oxime compounds:

When the radical polymerization initiator represented by the above formula (1) is used in combination with another radical polymerization initiator, the mass ratio of the radical polymerization initiator represented by the above formula (1) to the other radical polymerization initiator is not particularly limited, but in one embodiment, from the viewpoint of sensitivity, the content of the radical polymerization initiator represented by the above formula (1) is preferably 10 mass% or more, more preferably 50 mass% or more, even more preferably 80 mass% or more, and particularly preferably 90 mass% or more, based on the total mass of the polymerization initiator.

<Radical Polymerizable Compound>
The photocurable composition according to the present disclosure includes a radically polymerizable compound.
The radically polymerizable compound may, for example, be a compound having an ethylenically unsaturated group.

Examples of resin-type radically polymerizable compounds include resins containing repeating units having radically polymerizable groups. The weight-average molecular weight (Mw) of the resin-type polymerizable compound is preferably 2,000 to 2,000,000. The upper limit of the weight-average molecular weight is more preferably 1,000,000 or less, and even more preferably 500,000 or less. The lower limit of the weight-average molecular weight is more preferably 3,000 or more, and even more preferably 5,000 or more.

The molecular weight of the monomer-type radically polymerizable compound (polymerizable monomer) is preferably less than 2,000, and more preferably 1,500 or less. The lower limit of the molecular weight of the polymerizable monomer is preferably 100 or more, and more preferably 200 or more.

The compound having an ethylenically unsaturated group as a polymerizable monomer is preferably a trifunctional to 15functional (meth)acrylate compound, and more preferably a trifunctional to 6functional (meth)acrylate compound. Specific examples include the compounds described in paragraph 0128 of WO 2022/085485 and JP 2017-194662 A, the contents of which are incorporated herein by reference.

As a compound having an ethylenically unsaturated group, the compounds described in paragraphs 0129 to 0137 of WO 2022/085485 can also be used. The compound having an ethylenically unsaturated group may be a compound having an acid group such as a carboxy group, a sulfo group, or a phosphate group, a compound having a caprolactone structure, a compound having an alkyleneoxy group, or a compound having a fluorene skeleton.

As compounds having an ethylenically unsaturated group, it is also preferable to use UA-7200 (manufactured by Shin-Nakamura Chemical Co., Ltd.), DPHA-40H (manufactured by Nippon Kayaku Co., Ltd.), UA-306H, UA-306T, UA-306I, AH-600, T-600, AI-600, LINC-202UA (manufactured by Kyoeisha Chemical Co., Ltd.), 8UH-1006, 8UH-1012 (all manufactured by Taisei Fine Chemical Co., Ltd.), Light Acrylate POB-A0 (manufactured by Kyoeisha Chemical Co., Ltd.), etc.

The content of the radical polymerizable compound is preferably 0.1% by mass to 50% by mass based on the total solid content of the photocurable composition. The lower limit is more preferably 0.5% by mass or more, and even more preferably 1% by mass or more. The upper limit is more preferably 45% by mass or less, and even more preferably 40% by mass or less.
In an embodiment, the content of the radical polymerizable compound relative to the total solid content of the photocurable composition is more preferably 0.5% by mass to 45% by mass, and even more preferably 1% by mass to 40% by mass.
In the photocurable composition according to the present disclosure, only one type of radical polymerizable compound may be used, or two or more types may be used. When the photocurable composition contains two or more types of radical polymerizable compounds, it is preferable that the total amount of the two or more types of radical polymerizable compounds is within the above range.

<Coloring Agent>
The photocurable composition according to the present disclosure preferably further comprises a colorant.
Examples of the colorant include a chromatic colorant and a black colorant. Examples of the chromatic colorant include a colorant having a maximum absorption wavelength in the wavelength range of 400 nm to 700 nm. Examples of the chromatic colorant include a green colorant, a red colorant, a yellow colorant, a purple colorant, a blue colorant, and an orange colorant.
The colorant may be a pigment or a dye.
From the viewpoints of coloring property and dispersibility, the colorant is preferably at least one pigment selected from the group consisting of a diketopyrrolopyrrole pigment, a quinacridone pigment, an anthraquinone pigment, a perylene pigment, a phthalocyanine pigment, an isoindoline pigment, a quinophthalone pigment, an azo pigment, an azomethine pigment, and a dioxazine pigment, and more preferably at least one pigment selected from the group consisting of a diketopyrrolopyrrole pigment, a phthalocyanine pigment, and an isoindoline pigment.
In addition, a black pigment can be used, and examples of the black pigment that can be used include carbon black and pigments containing titanium atoms or zirconium atoms.

The average primary particle diameter of the pigment is preferably 1 nm to 200 nm. The lower limit is more preferably 5 nm or more, and even more preferably 10 nm or more. The upper limit is more preferably 180 nm or less, even more preferably 150 nm or less, and particularly preferably 100 nm or less. In the present disclosure, the primary particle diameter of the pigment can be determined from an image photograph obtained by observing the primary particles of the pigment with a transmission electron microscope. Specifically, the projected area of the primary particles of the pigment is determined, and the corresponding circle equivalent diameter is calculated as the primary particle diameter of the pigment. In the present disclosure, the average primary particle diameter is the arithmetic average value of the primary particle diameters of 400 primary particles of the pigment. In addition, the primary particles of the pigment refer to independent particles without aggregation.
The crystallite size of the pigment, determined from the half-width of a peak derived from any crystal plane in an X-ray diffraction spectrum obtained using CuKα radiation as an X-ray source, is preferably 0.1 nm to 100 nm, more preferably 0.5 nm to 50 nm, even more preferably 1 nm to 30 nm, and particularly preferably 5 nm to 25 nm.

Green colorants include phthalocyanine compounds and squarylium compounds, and are preferably phthalocyanine compounds. The green colorant is preferably a pigment. Specific examples of green colorants include green pigments such as C.I. Pigment Green 7, 10, 36, 37, 58, 59, 62, 63, 64, 65, and 66. In addition, compounds described in paragraphs 0143 to 0149 of WO 2022/085485, aluminum phthalocyanine compounds described in JP 2020-070426 A, and diarylmethane compounds described in JP 2020-504758 A can also be used as green colorants.

The green colorant is preferably C.I. Pigment Green 7, 36, 58, 59, 62, or 63, and more preferably C.I. Pigment Green 7, 36, 58, or 59.

Red colorants include diketopyrrolopyrrole compounds, anthraquinone compounds, azo compounds, naphthol compounds, azomethine compounds, xanthene compounds, quinacridone compounds, perylene compounds, and thioindigo compounds, with diketopyrrolopyrrole compounds, anthraquinone compounds, and azo compounds being preferred, and diketopyrrolopyrrole compounds being more preferred. The red colorant is preferably a pigment. Specific examples of red colorants include C.I. (Color Index) Pigment Red 1, 2, 3, 4, 5, 6, 7, 9, 10, 14, 17, 22, 23, 31, 38, 41, 48: 1, 48: 2, 48: 3, 48: 4, 49, 49: 1, 49: 2, 52: 1, 52: 2, 53: 1, 57: 1, 60: 1, 63: 1, 66, 67, 81: 1, 81: 2, 81: 3, 83, 88, 90, 105, 112, 119, 122, 123, 144, 146, 149, Examples of red pigments include 150, 155, 166, 168, 169, 170, 171, 172, 175, 176, 177, 178, 179, 184, 185, 187, 188, 190, 200, 202, 206, 207, 208, 209, 210, 216, 220, 224, 226, 242, 246, 254, 255, 264, 269, 270, 272, 279, 291, 294, 295, 296, and 297. In addition, the compound described in paragraph 0034 of WO 2022/085485 can also be used as a red colorant. Lumogen F Orange 240 (manufactured by BASF, red pigment, perylene pigment) can also be used as a red colorant.

The red colorant is preferably C.I. Pigment Red 122, 177, 179, 254, 255, 264, 269, 272, or 291, and more preferably C.I. Pigment Red 254, 264, or 272.

Examples of the yellow colorant include azo compounds, azomethine compounds, isoindoline compounds, pteridine compounds, quinophthalone compounds, and perylene compounds. The yellow colorant is preferably a pigment, more preferably an azo pigment, an azomethine pigment, an isoindoline pigment, a pteridine pigment, a quinophthalone pigment, or a perylene pigment, and more preferably an azo pigment or an azomethine pigment. Specific examples of the yellow colorant include C.I. Pigment Yellow 1, 2, 3, 4, 5, 6, 10, 11, 12, 13, 14, 15, 16, 17, 18, 20, 24, 31, 32, 34, 35, 35:1, 36, 36:1, 37, 37:1, 40, 42, 43, 53, 55, 60, 61, 62, 63, 65, 73, 74, 77, 81, 83, 86, 93, 94, 95, 97, 98, 100, 101, 104, 106, 108, 109, 110, 113, 114, 115, 116, 117, 118, 1
19, 120, 123, 125, 126, 127, 128, 129, 137, 138, 139, 147, 148, 150, 151, 152, 153, 154, 155, 156, 161, 162, 164, 166, 167, 168, 169, 170, 171, 172, 173, 174, 175, 176, 177, 179, 180, 181, 182, 185, 187, 188, 193, 194, 199, 213, 214, 215, 228, 231, 232, 233, 234, 235, 236 and the like.

　Also, azobarbituric acid nickel complex having the following structure can be used as a yellow colorant.

In addition, the compounds described in paragraphs 0031 to 0033 of WO 2022/085485 can also be used as yellow colorants.

The yellow colorant is preferably C.I. Pigment Yellow 117, 129, 138, 139, 150, or 185.

Orange colorants include orange pigments such as C.I. Pigment Orange 2, 5, 13, 16, 17:1, 31, 34, 36, 38, 43, 46, 48, 49, 51, 52, 55, 59, 60, 61, 62, 64, 71, and 73.

Examples of purple colorants include purple pigments such as C.I. Pigment Violet 1, 19, 23, 27, 32, 37, 42, 60, and 61.

Examples of blue colorants include C.I. Pigment Blue 1, 2, 15, 15:1, 15:2, 15:3, 15:4, 15:6, 16, 22, 29, 60, 64, 66, 79, 80, 87, and 88. Aluminum phthalocyanine compounds having phosphorus atoms can also be used as blue colorants. Specific examples include the compounds described in paragraphs 0022 to 0030 of JP-A No. 2012-247591 and paragraph 0047 of JP-A No. 2011-157478.

Dyes can also be used as chromatic colorants. There are no particular limitations on the dyes, and any known dyes can be used. Examples include pyrazole azo, anilino azo, triarylmethane, anthraquinone, anthrapyridone, benzylidene, oxonol, pyrazolotriazole azo, pyridone azo, cyanine, phenothiazine, pyrrolopyrazole azomethine, xanthene, phthalocyanine, benzopyran, indigo, and pyrromethene dyes.

　A dye polymer can also be used as the chromatic colorant. The dye polymer is preferably a dye dissolved in an organic solvent before use. The dye polymer may also form particles. When the dye polymer is in the form of particles, it is usually used in a state of being dispersed in a solvent. A dye polymer in a particulate state can be obtained, for example, by emulsion polymerization, and specific examples of the compound and manufacturing method described in JP-A-2015-214682 include the compound described in paragraph 0048 of WO2022/085485.

Chromatic colorants include diarylmethane compounds described in JP-T-2020-504758, triarylmethane dye polymers described in Korean Patent Publication No. 10-2020-0028160, xanthene compounds described in JP-A-2020-117638, phthalocyanine compounds described in WO-A-2020/174991, and isoindoline compounds described in JP-A-2020-160279. or a salt thereof, a compound represented by formula 1 described in Korean Patent Publication No. 10-2020-0069442, a compound represented by formula 1 described in Korean Patent Publication No. 10-2020-0069730, a compound represented by formula 1 described in Korean Patent Publication No. 10-2020-0069070, a compound represented by formula 1 described in Korean Patent Publication No. 10-2020-0069067, a compound represented by formula 1 described in Korean Patent Publication No. 10 Compounds represented by formula 1 described in JP-A-2020-0069062, halogenated zinc phthalocyanine pigments described in JP-A-6809649, isoindoline compounds described in JP-A-2020-180176, phenothiazine compounds described in JP-A-2021-187913, quinophthalone compounds represented by formula 1 in Korean Patent Publication No. 10-2020-0030759, and Korean Patent Publication No. Polymer dyes described in JP-A-2020-0061793, colorants described in JP-A-2022-029701, isoindoline compounds described in WO 2022/014635, aluminum phthalocyanine compounds described in WO 2022/024926, compounds described in JP-A-2022-045895, and compounds described in WO 2022/050051 can be used. The chromatic colorant may be a rotaxane, and the dye skeleton may be used in the cyclic structure of the rotaxane, in the rod-shaped structure, or in both structures.

Two or more chromatic colorants may be used in combination. When two or more chromatic colorants are used in combination, the combination of two or more chromatic colorants may form a black color.

The black colorant is not particularly limited, and known ones can be used. For example, inorganic black colorants include carbon black, titanium black, zirconium oxynitride, graphite, etc., and carbon black, titanium black, or zirconium oxynitride is preferred, and titanium black or zirconium oxynitride is more preferred. Titanium black is black particles containing titanium atoms, and low-order titanium oxide or titanium oxynitride is preferred. Titanium black can be surface-modified as necessary for the purpose of improving dispersibility and suppressing aggregation.
For example, the surface of titanium black can be coated with silicon oxide, titanium oxide, germanium oxide, aluminum oxide, magnesium oxide, or zirconium oxide. It can also be treated with a water-repellent substance as described in JP-A-2007-302836. Color Index (C.I.) Pigment Black 1, 7 can also be used as a black colorant.
It is preferable that both the primary particle size and the average primary particle size of the titanium black particles are small. Specifically, it is preferable that the average primary particle size is 10 to 45 nm. Titanium black can also be used as a dispersion. For example, a dispersion containing titanium black particles and silica particles, in which the content ratio of Si atoms to Ti atoms in the dispersion is adjusted to a range of 0.20 to 0.50, can be mentioned. For the above dispersion, the description in paragraphs 0020 to 0105 of JP2012-169556A can be referred to, and the contents thereof are incorporated into the present disclosure.

Examples of commercially available titanium black products include Titanium Black 10S, 12S, 13R, 13M, 13M-C, 13R-N, and 13M-T (trade names: manufactured by Mitsubishi Materials Corporation), and Tilack D (trade name: manufactured by Ako Kasei Co., Ltd.). Examples of organic black colorants include bisbenzofuranone compounds, azomethine compounds, perylene compounds, and azo compounds, with bisbenzofuranone compounds and perylene compounds being preferred. Examples of bisbenzofuranone compounds include those described in JP-T-2010-534726, JP-T-2012-515233, JP-T-2012-515234, WO 2014/208348, and JP-T-2015-525260, and are available, for example, as "Irgaphor Black" manufactured by BASF. Examples of perylene compounds include C.I. Pigment Black 31 and 32. Examples of azomethine compounds include compounds described in JP-A-01-170601 and JP-A-02-034664, and are available as "Chromofine Black A1103" manufactured by Dainichi Seika Chemicals Co., Ltd. Examples of organic black colorants include perylene black (Lumogen Black FK4280, etc.) and Paliogen Black S0084 described in paragraphs 0016 to 0020 of JP-A-2017-226821.

The photocurable composition according to the present disclosure may contain one colorant alone or two or more colorants. When two or more colorants are used, the total amount thereof is preferably within the following range.
From the viewpoint of further exerting the effects of the present disclosure, the content of the colorant is preferably 10% by mass to 75% by mass relative to the total solid content of the photocurable composition. The upper limit of the content of the colorant relative to the total solid content of the photocurable compound according to the present disclosure is more preferably 70% by mass or less, and even more preferably 65% by mass or less. The lower limit of the content of the colorant relative to the total solid content of the photocurable compound according to the present disclosure is more preferably 20% by mass or more, even more preferably 30% by mass or more, and particularly preferably 60% by mass or more.
In one embodiment, the content of the colorant is more preferably 20% by mass to 70% by mass, even more preferably 30% by mass to 65% by mass, and particularly preferably 60% by mass to 65% by mass, based on the total solid content of the photocurable composition.

<Resin>
The photocurable composition according to the present disclosure preferably further contains a resin.
The photocurable composition according to the present disclosure can use a resin as the radical polymerizable compound. It is preferable to use a radical polymerizable compound that contains at least a resin. The resin is blended, for example, for dispersing pigments and the like in the photocurable composition, or for use as a binder. Note that a resin that is mainly used for dispersing pigments and the like in the photocurable composition is also called a dispersant. However, the above-mentioned uses of the resin are only examples, and the resin can also be used for purposes other than the uses exemplified above.
The resin having a radically polymerizable group also corresponds to a radically polymerizable compound.
Moreover, the photocurable composition according to the present disclosure more preferably further contains a resin other than the radically polymerizable compound.

The weight average molecular weight of the resin is preferably 3,000 to 2,000,000. The upper limit is preferably 1,000,000 or less, and more preferably 500,000 or less. The lower limit is preferably 4,000 or more, and more preferably 5,000 or more.

The resins include (meth)acrylic resins, epoxy resins, ene-thiol resins, polycarbonate resins, polyether resins, polyarylate resins, polysulfone resins, polyethersulfone resins, polyphenylene resins, polyarylene ether phosphine oxide resins, polyimide resins, polyamide resins, polyamideimide resins, polyolefin resins, cyclic olefin resins, polyester resins, styrene resins, vinyl acetate resins, polyvinyl alcohol resins, polyvinyl acetal resins, polyurethane resins, and polyurea resins. One of these resins may be used alone, or two or more may be mixed and used. As the cyclic olefin resin, norbornene resin is preferred from the viewpoint of improving heat resistance. Commercially available norbornene resins include, for example, the ARTON series (e.g., ARTON F4520) manufactured by JSR Corporation. In addition, examples of the resin include those described in the examples of WO 2016/088645, those described in JP 2017-057265 A, those described in JP 2017-032685 A, those described in JP 2017-075248 A, those described in JP 2017-066240 A, those described in JP 2017-167513 A, those described in JP 2017-173787 A, and those described in paragraphs 0041 to 0060 of JP 2017-206689 A. Resins described in paragraphs 0022 to 0071 of JP 2018-010856 A, blocked polyisocyanate resins described in JP 2016-222891 A, resins described in JP 2020-122052 A, resins described in JP 2020-111656 A, resins described in JP 2020-139021 A, resins containing a structural unit having a ring structure in the main chain and a structural unit having a biphenyl group in the side chain described in JP 2017-138503 A can also be used. In addition, resins having a fluorene skeleton can also be preferably used as the resin. For resins having a fluorene skeleton, the description in U.S. Patent Application Publication No. 2017/0102610 can be referred to, and the contents of this specification are incorporated herein by reference. In addition, as the resin, the resin described in paragraphs 0199 to 0233 of JP 2020-186373 A, the alkali-soluble resin described in JP 2020-186325 A, the resin represented by formula 1 described in Korean Patent Publication No. 10-2020-0078339 A, and the copolymer containing an epoxy group and an acid group described in WO 2022/030445 A can also be used.

It is preferable to use a resin having an acid group as the resin. Examples of the acid group include a carboxy group, a phosphate group, a sulfo group, and a phenolic hydroxy group. These acid groups may be of only one type, or of two or more types. The resin having an acid group can be used, for example, as an alkali-soluble resin. The acid value of the resin having an acid group is preferably 30 to 500 mgKOH/g. The lower limit is preferably 50 mgKOH/g or more, and more preferably 70 mgKOH/g or more. The upper limit is preferably 400 mgKOH/g or less, more preferably 200 mgKOH/g or less, even more preferably 150 mgKOH/g or less, and particularly preferably 120 mgKOH/g or less.

The resin may also be the compound described in paragraphs 0056 to 0059 of WO 2022/085485.

As the resin, it is also preferable to use a resin having a polymerizable group. Examples of the polymerizable group include an ethylenically unsaturated group and a cyclic ether group. In particular, from the viewpoint of outgassing suppression, it is preferable that the photocurable compound according to the present disclosure contains a resin having a (meth)acryloyl group, an epoxy group, or an oxetanyl group.

Furthermore, as the resin, a resin having at least one repeating unit (hereinafter also referred to as repeating unit Ep) selected from the repeating units represented by formula (Ep-1) and the repeating units represented by formula (Ep-2) can be used (hereinafter also referred to as resin Ep). The above resin Ep may contain only one of the repeating units represented by formula (Ep-1) and the repeating units represented by formula (Ep-2), or may contain both the repeating units represented by formula (Ep-1) and the repeating units represented by formula (Ep-2). When both repeating units are contained, the ratio of the repeating units represented by formula (Ep-1) to the repeating units represented by formula (Ep-2) is preferably 5:95 to 95:5 in molar ratio, more preferably 10:90 to 90:10, and even more preferably 20:80 to 80:20.

In formulae (Ep-1) and (Ep-2), L ¹ represents a single bond or a divalent linking group, and R ¹ represents a hydrogen atom or a substituent. Examples of the substituent represented by R ¹ include an alkyl group and an aryl group, and an alkyl group is preferable. The number of carbon atoms of the alkyl group is preferably 1 to 10, more preferably 1 to 5, and even more preferably 1 to 3. R ¹ is preferably a hydrogen atom or a methyl group. Examples of the divalent linking group represented by L ¹ include an alkylene group (preferably an alkylene group having 1 to 12 carbon atoms), an arylene group (preferably an arylene group having 6 to 20 carbon atoms), -NH-, -SO-, -SO ₂ -, -CO-, -O-, -COO-, -OCO-, -S-, and a group formed by combining two or more of these. The alkylene group may be linear, branched, or cyclic, and is preferably linear or branched. In addition, the alkylene group may have a substituent or may be unsubstituted. Examples of the substituent include a hydroxy group and an alkoxy group.

The content of the repeating unit Ep in the resin Ep is preferably 1 mol% to 100 mol% of all repeating units in the resin Ep. The upper limit is more preferably 90 mol% or less, and even more preferably 80 mol% or less. The lower limit is more preferably 2 mol% or more, and even more preferably 3 mol% or more.

The resin Ep may have other repeating units in addition to the repeating unit Ep. Examples of the other repeating units include a repeating unit having an acid group and a repeating unit having an ethylenically unsaturated group.

Examples of the acid group include a phenolic hydroxy group, a carboxy group, a sulfo group, and a phosphate group, with a phenolic hydroxy group or a carboxy group being preferred, and a carboxy group being more preferred.

Examples of ethylenically unsaturated groups include vinyl groups, styrene groups, (meth)allyl groups, and (meth)acryloyl groups.

When the resin Ep contains a repeating unit having an acid group, the content of the repeating unit having an acid group in the resin Ep is preferably 5 mol% to 85 mol% of all repeating units of the resin Ep. The upper limit is more preferably 60 mol% or less, and even more preferably 40 mol% or less. The lower limit is more preferably 8 mol% or more, and even more preferably 10 mol% or more.

When the resin Ep contains a repeating unit having an ethylenically unsaturated group, the content of the repeating unit having an ethylenically unsaturated group in the resin Ep is preferably 1 mol% to 65 mol% of all repeating units of the resin Ep. The upper limit is more preferably 45 mol% or less, and even more preferably 30 mol% or less. The lower limit is more preferably 2 mol% or more, and even more preferably 3 mol% or more.

The resin Ep preferably further contains a repeating unit having an aromatic hydrocarbon ring. The aromatic hydrocarbon ring is preferably a benzene ring or a naphthalene ring, and is preferably a benzene ring. The aromatic hydrocarbon ring may have a substituent. Examples of the substituent include an alkyl group. When the resin having a cyclic ether group contains a repeating unit having an aromatic hydrocarbon ring, the content of the repeating unit having an aromatic hydrocarbon ring is preferably 1 mol% to 65 mol% of the total repeating units of the resin having a cyclic ether group. The upper limit is more preferably 45 mol% or less, and even more preferably 30 mol% or less. The lower limit is more preferably 2 mol% or more, and even more preferably 3 mol% or more. Examples of the repeating unit having an aromatic hydrocarbon ring include repeating units derived from monofunctional polymerizable compounds having an aromatic hydrocarbon ring, such as vinyl toluene and benzyl (meth)acrylate.

As the resin, it is also preferable to use a resin containing a repeating unit derived from a compound represented by formula (X).

In the formula, R ¹ represents a hydrogen atom or a methyl group, R ²¹ and R ²² each independently represent an alkylene group, and n represents an integer of 0 to 15. The number of carbon atoms in the alkylene group represented by R ²¹ and R ²² is preferably 1 to 10, more preferably 1 to 5, even more preferably 1 to 3, and particularly preferably 2 or 3. n represents an integer of 0 to 15, preferably an integer of 0 to 5, more preferably an integer of 0 to 4, and even more preferably an integer of 0 to 3.

Examples of the compound represented by formula (X) include ethylene oxide or propylene oxide modified (meth)acrylate of paracumylphenol. Commercially available products include Aronix M-110 (manufactured by Toagosei Co., Ltd.).

As the resin, it is also preferable to use a resin having an aromatic carboxy group (hereinafter, also referred to as resin Ac). In resin Ac, the aromatic carboxy group may be included in the main chain of the repeating unit, or may be included in the side chain of the repeating unit. It is preferable that the aromatic carboxy group is included in the main chain of the repeating unit. In this disclosure, an aromatic carboxy group refers to a group having a structure in which one or more carboxy groups are bonded to an aromatic ring. In the aromatic carboxy group, the number of carboxy groups bonded to the aromatic ring is preferably 1 to 4, and more preferably 1 to 2.

The resin Ac is preferably a resin containing at least one repeating unit selected from the repeating units represented by formula (Ac-1) and the repeating units represented by formula (Ac-2).

In formula (Ac-1), Ar ¹ represents a group containing an aromatic carboxy group, L ¹ represents --COO-- or CONH--, and L ² represents a divalent linking group.
In formula (Ac-2), Ar ¹⁰ represents a group containing an aromatic carboxy group, L ¹¹ represents --COO-- or CONH--, L ¹² represents a trivalent linking group, and P ¹⁰ represents a polymer chain.

In formula (Ac-1), examples of the group containing an aromatic carboxy group represented by Ar ¹ include a structure derived from an aromatic tricarboxylic acid anhydride, a structure derived from an aromatic tetracarboxylic acid anhydride, etc. Examples of the aromatic tricarboxylic acid anhydride and aromatic tetracarboxylic acid anhydride include compounds having the following structures.

In the above formula, Q ¹ represents a single bond, —O—, —CO—, —COOCH ₂ CH ₂ OCO—, —SO ₂ —, —C(CF ₃ ) ₂ —, a group represented by the following formula (Q-1) or a group represented by the following formula (Q-2).

The group containing an aromatic carboxy group represented by Ar ¹ may have a polymerizable group. The polymerizable group is preferably an ethylenically unsaturated group or a cyclic ether group, and more preferably an ethylenically unsaturated group.
Specific examples of the group containing an aromatic carboxy group represented by Ar ¹ include a group represented by formula (Ar-11), a group represented by formula (Ar-12), and a group represented by formula (Ar-13).

In formula (Ar-11), n1 represents an integer of 1 to 4, preferably 1 or 2, and more preferably 2.
In formula (Ar-12), n2 represents an integer of 1 to 8, preferably an integer of 1 to 4, more preferably 1 or 2, and even more preferably 2.
In formula (Ar-13), n3 and n4 each independently represent an integer of 0 to 4, and are preferably an integer of 0 to 2, more preferably 1 or 2, and further preferably 1. However, at least one of n3 and n4 is an integer of 1 or more.
In formula (Ar-13), Q ¹ represents a single bond, —O—, —CO—, —COOCH ₂ CH ₂ OCO—, —SO ₂ —, —C(CF ₃ ) ₂ —, a group represented by the above formula (Q-1) or a group represented by the above formula (Q-2).
In formulae (Ar-11) to (Ar-13), *1 represents the bonding position to ^L1 .

In formula (Ac-1), ^L1 represents --COO-- or CONH--, and preferably represents --COO--.

In formula (Ac-1), examples of the divalent linking group represented by L ² include an alkylene group, an arylene group, -O-, -CO-, -COO-, -OCO-, -NH-, -S-, and a group obtained by combining two or more of these. The number of carbon atoms in the alkylene group is preferably 1 to 30, more preferably 1 to 20, and even more preferably 1 to 15. The alkylene group may be linear, branched, or cyclic. The number of carbon atoms in the arylene group is preferably 6 to 30, more preferably 6 to 20, and even more preferably 6 to 10. The alkylene group and the arylene group may have a substituent. Examples of the substituent include a hydroxy group. The divalent linking group represented by L ² is preferably a group represented by -L ^2a -O-. L ^2a is an alkylene group; an arylene group;
Examples of the alkylene group include a group obtained by combining an alkylene group with an arylene group; a group obtained by combining at least one selected from an alkylene group and an arylene group with at least one selected from -O-, -CO-, -COO-, -OCO-, -NH- and S-, and the alkylene group is preferable. The number of carbon atoms in the alkylene group is preferably 1 to 30, more preferably 1 to 20, and even more preferably 1 to 15. The alkylene group may be linear, branched, or cyclic. The alkylene group and the arylene group may have a substituent. Examples of the substituent include a hydroxyl group.

The aromatic carboxyl-containing group represented by Ar ¹⁰ in formula (Ac-2) has the same meaning as Ar ¹ in formula (Ac-1), and preferred embodiments are also the same.

In formula (Ac-2), L ¹¹ represents —COO— or CONH—, and preferably represents —COO—.

In formula (Ac-2), the trivalent linking group represented by L ¹² includes a hydrocarbon group, -O-, -CO-, -COO-, -OCO-, -NH-, -S-, and a group combining two or more of these. Examples of the hydrocarbon group include an aliphatic hydrocarbon group and an aromatic hydrocarbon group. The carbon number of the aliphatic hydrocarbon group is preferably 1 to 30, more preferably 1 to 20, and even more preferably 1 to 15. The aliphatic hydrocarbon group may be linear, branched, or cyclic. The carbon number of the aromatic hydrocarbon group is preferably 6 to 30, more preferably 6 to 20, and even more preferably 6 to 10. The hydrocarbon group may have a substituent. Examples of the substituent include a hydroxyl group. The trivalent linking group represented by L ¹² is preferably a group represented by formula (L12-1), and more preferably a group represented by formula (L12-2).

In formula (L12-1), L ^12b represents a trivalent linking group, X ¹ represents S, *1 represents the bonding position to L ¹¹ in formula (Ac-2), and *2 represents the bonding position to P ¹⁰ in formula (Ac-2). Examples of the trivalent linking group represented by L ^12b include a hydrocarbon group; and a group in which a hydrocarbon group is combined with at least one selected from -O-, -CO-, -COO-, -OCO-, -NH-, and -S-, and the like. A hydrocarbon group or a group in which a hydrocarbon group is combined with -O- is preferred.

In formula (L12-2), L ^12c represents a trivalent linking group, X ¹ represents S, *1 represents the bonding position to L ¹¹ in formula (Ac-2), and *2 represents the bonding position to P ¹⁰ in formula (Ac-2). Examples of the trivalent linking group represented by L ^12c include a hydrocarbon group; and a group in which a hydrocarbon group is combined with at least one selected from -O-, -CO-, -COO-, -OCO-, -NH-, and -S-, and the like, with a hydrocarbon group being preferred.

In formula (Ac-2), P ¹⁰ represents a polymer chain. The polymer chain represented by P ¹⁰ preferably has at least one repeating unit selected from poly(meth)acrylic repeating units, polyether repeating units, polyester repeating units, and polyol repeating units. The weight average molecular weight of the polymer chain P ¹⁰ is preferably 500 to 20,000. The lower limit is more preferably 1,000 or more. The upper limit is more preferably 10,000 or less, even more preferably 5,000 or less, and particularly preferably 3,000 or less. When the weight average molecular weight of P ¹⁰ is within the above range, the dispersibility of the pigment in the composition is good. When the resin having an aromatic carboxy group is a resin having a repeating unit represented by formula (Ac-2), this resin is preferably used as a dispersant.

The polymer chain represented by P ¹⁰ may contain a polymerizable group. The polymerizable group may be an ethylenically unsaturated group.

The photocurable composition according to the present disclosure preferably contains a resin as a dispersant. Examples of dispersants include acidic dispersants (acidic resins) and basic dispersants (basic resins). Here, the acidic dispersant (acidic resin) refers to a resin in which the amount of acid groups is greater than the amount of basic groups. As the acidic dispersant (acidic resin), a resin in which the amount of acid groups is 70 mol% or more is preferable when the total amount of the acid groups and the amount of the basic groups is 100 mol%. The acid group possessed by the acidic dispersant (acidic resin) is preferably a carboxy group. The acid value of the acidic dispersant (acidic resin) is preferably 10 mgKOH/g to 105 mgKOH/g. In addition, the basic dispersant (basic resin) refers to a resin in which the amount of basic groups is greater than the amount of acid groups. As the basic dispersant (basic resin), a resin in which the amount of basic groups is greater than 50 mol% is preferable when the total amount of the acid groups and the amount of the basic groups is 100 mol%.
The basic group contained in the basic dispersant is preferably an amino group.

The resin used as the dispersant is preferably a graft polymer. For details of the graft polymer, refer to paragraphs 0025 to 0094 of JP2012-255128A, the contents of which are incorporated herein by reference.
From the viewpoint of dispersion stability, it is preferable that the resin is a graft polymer having a graft chain, the graft chain includes at least one chain selected from the group consisting of a polyether chain, a polyester chain, and a polyacrylic chain, and the weight average molecular weight of the graft chain is 1,000 or more.

The resin used as the dispersant is preferably a polyimine-based dispersant containing nitrogen atoms in at least one of the main chain and side chain. The polyimine-based dispersant is preferably a resin having a main chain with a partial structure having a functional group with a pKa of 14 or less, a side chain with an atomic number of 40 to 10,000, and having a basic nitrogen atom in at least one of the main chain and side chain. There are no particular restrictions on the basic nitrogen atom, so long as it is a nitrogen atom that exhibits basicity. For details of polyimine-based dispersants, please refer to the description in paragraphs 0102 to 0166 of JP 2012-255128 A, the contents of which are incorporated herein by reference.

The resin used as the dispersant is preferably one having a structure in which multiple polymer chains are bonded to a core portion. Examples of such resins include dendrimers (including star-shaped polymers). Specific examples of dendrimers include polymer compounds C-1 to C-31 described in paragraphs 0196 to 0209 of JP2013-043962A.

The resin used as the dispersant is also preferably a resin containing a repeating unit having an ethylenically unsaturated group in a side chain. The content of the repeating unit having an ethylenically unsaturated group in a side chain is preferably 10 mol % or more, more preferably 10 mol % to 80 mol %, and even more preferably 20 mol % to 70 mol %, of all repeating units of the resin.
As a resin having an oxetane group, for example, a resin described in WO 2021/182268 or WO 2021/187257 can be used.

Moreover, the resin used as the dispersant is preferably a resin containing an oxetane group on the side chain, and more preferably a resin containing a repeating unit having an oxetane group on the side chain.
Furthermore, the resin containing an oxetane group in the side chain is preferably a graft polymer.
Suitable examples of the resin containing an oxetane group in a side chain include those described in the Examples below. The content of repeating units having an oxetane group in a side chain in the above resin is preferably 10 mol % or more, more preferably 10 mol % to 80 mol %, and even more preferably 20 mol % to 70 mol %, of all repeating units in the resin.

In addition, as dispersants, resins described in JP 2018-087939 A, block copolymers (EB-1) to (EB-9) described in paragraphs 0219 to 0221 of Japanese Patent No. 6,432,077 A, polyethyleneimine having a polyester side chain described in WO 2016/104803 A, block copolymers described in WO 2019/125940 A, block polymers having an acrylamide structural unit described in JP 2020-066687 A, block polymers having an acrylamide structural unit described in JP 2020-066688 A, dispersants described in WO 2016/104803 A, and the like can also be used.

As the dispersant, polyamic acid type dispersing resins and polyimide type dispersing resins can also be used. As such resins, dispersants described in WO 2022/019253, WO 2022/019254, and WO 2022/019255 can also be used.

Dispersants are also available as commercially available products. Specific examples of commercially available dispersants include the Disperbyk series manufactured by BYK-Chemie (e.g., Disperbyk-111, 161, 2001, etc.), the Solsperse series manufactured by Lubrizol Japan Co., Ltd. (e.g., Solsperse 20000, 76500, etc.), and the Ajisper series manufactured by Ajinomoto Fine-Techno Co., Ltd. In addition, the products described in paragraph 0129 of JP 2012-137564 A and the products described in paragraph 0235 of JP 2017-194662 A can also be used as dispersants.

When the photocurable composition according to the present disclosure contains a resin as a radical polymerizable compound, the content of the resin is preferably 1% by mass to 70% by mass based on the total solid content of the photocurable composition. The lower limit is more preferably 2% by mass or more, even more preferably 3% by mass or more, and particularly preferably 5% by mass or more. The upper limit is more preferably 65% by mass or less, and even more preferably 60% by mass or less.
The content of the resin having an acid group is preferably 1% by mass to 70% by mass based on the total solid content of the photocurable composition. The lower limit is more preferably 2% by mass or more, even more preferably 3% by mass or more, and particularly preferably 5% by mass or more. The upper limit is more preferably 65% by mass or less, and even more preferably 60% by mass or less.
The content of the alkali-soluble resin is preferably 1% by mass to 70% by mass based on the total solid content of the photocurable composition. The lower limit is more preferably 2% by mass or more, even more preferably 3% by mass or more, and particularly preferably 5% by mass or more. The upper limit is more preferably 65% by mass or less, and even more preferably 60% by mass or less.
When the photocurable composition according to the present disclosure contains a resin as a dispersant, the content of the resin as a dispersant is preferably 0.1% by mass to 30% by mass with respect to the total solid content of the photocurable composition. The upper limit is more preferably 25% by mass or less, and even more preferably 20% by mass or less. The lower limit is more preferably 0.5% by mass or more, and even more preferably 1% by mass or more. The content of the resin as a dispersant is preferably 1 part by mass to 100 parts by mass with respect to 100 parts by mass of the colorant. The upper limit is more preferably 80 parts by mass or less, even more preferably 70 parts by mass or less, and particularly preferably 60 parts by mass or less. The lower limit is more preferably 5 parts by mass or more, even more preferably 10 parts by mass or more, and particularly preferably 20 parts by mass or more.
The photocurable composition according to the present disclosure may contain only one type of resin or may contain two or more types of resin. When the photocurable composition according to the present disclosure contains two or more types of resin, the total amount of the two or more types of resin is preferably within the above range.

<Solvent>
The photocurable composition according to the present disclosure preferably contains a solvent. Examples of the solvent include organic solvents. The type of solvent is not particularly limited as long as the solubility of each component and the coatability of the composition are satisfied. Examples of the organic solvent include ester-based solvents, ketone-based solvents, alcohol-based solvents, amide-based solvents, ether-based solvents, and hydrocarbon-based solvents. For details of these solvents, reference can be made to paragraph number 0223 of International Publication No. 2015/166779, the contents of which are incorporated herein by reference. In addition, ester-based solvents substituted with a cyclic alkyl group and ketone-based solvents substituted with a cyclic alkyl group can also be preferably used. Specific examples of organic solvents include polyethylene glycol monomethyl ether, dichloromethane, methyl 3-ethoxypropionate, ethyl 3-ethoxypropionate, ethyl cellosolve acetate, ethyl lactate, diethylene glycol dimethyl ether, butyl acetate, methyl 3-methoxypropionate, 2-heptanone, 2-pentanone, 3-pentanone, 4-heptanone, cyclohexanone, 2-methylcyclohexanone, 3-methylcyclohexanone, 4-methylcyclohexanone, cycloheptanone, cyclooctanone, cyclohexyl acetate, cyclopentanone, ethyl carbitol acetate, butyl carbitol acetate, propylene glycol monomethyl ether, propylene glycol dimethyl ether, butyl acetate ... Examples of the ethylene glycol monomethyl ether acetate include 3-methoxy-N,N-dimethylpropanamide, 3-butoxy-N,N-dimethylpropanamide, propylene glycol diacetate, 3-methoxybutanol, methyl ethyl ketone, gamma butyrolactone, sulfolane, anisole, 1,4-diacetoxybutane, diethylene glycol monoethyl ether acetate, butane-1,3-diyl diacetate, dipropylene glycol methyl ether acetate, diacetone alcohol (also known as diacetone alcohol and 4-hydroxy-4-methyl-2-pentanone), 2-methoxypropyl acetate, 2-methoxy-1-propanol, and isopropyl alcohol. However, there are cases where it is better to reduce the amount of aromatic hydrocarbons (benzene, toluene, xylene, ethylbenzene, etc.) used as organic solvents for environmental reasons, etc. (for example, the amount can be 50 ppm (parts per million) by mass or less, 10 ppm by mass or less, or 1 ppm by mass or less, relative to the total amount of organic solvents).

In the present disclosure, it is preferable to use an organic solvent with a low metal content. The metal content of the organic solvent is preferably, for example, 10 parts per billion (ppb) by mass or less. If necessary, an organic solvent with a mass ppt (parts per trillion) level may be used, and such an organic solvent is provided, for example, by Toyo Gosei Co., Ltd. (The Chemical Daily, November 13, 2015).

Methods for removing impurities such as metals from organic solvents include, for example, distillation (molecular distillation, thin-film distillation, etc.) and filtration using a filter. The filter used for filtration preferably has a pore size of 10 μm or less, more preferably 5 μm or less, and even more preferably 3 μm or less. The filter material is preferably polytetrafluoroethylene, polyethylene, or nylon.

The organic solvent may contain isomers (compounds with the same number of atoms but different structures). In addition, the organic solvent may contain only one type of isomer, or multiple types of isomers.

The peroxide content in the organic solvent is preferably 0.8 mmol/L or less, and more preferably substantially free of peroxide.

The content of the solvent in the photocurable composition is preferably 10% by mass to 95% by mass, more preferably 20% by mass to 90% by mass, and even more preferably 30% by mass to 90% by mass.

In addition, from the viewpoint of environmental regulations, the photocurable composition according to the present disclosure preferably does not substantially contain any environmentally regulated substances. In the present disclosure, "substantially does not contain any environmentally regulated substances" means that the content of the environmentally regulated substances in the photocurable composition is 50 ppm by mass or less, preferably 30 ppm by mass or less, more preferably 10 ppm by mass or less, and particularly preferably 1 ppm by mass or less.
Examples of environmentally regulated substances include benzene; alkylbenzenes such as toluene and xylene; and halogenated benzenes such as chlorobenzene. These substances are registered as environmentally regulated substances under the REACH (Registration Evaluation Authorization and Restriction of Chemicals) regulations, the PRTR (Pollutant Release and Transfer Register) Act, and the VOC (Volatile Organic Compounds) regulations, and their usage and handling methods are strictly regulated. These compounds may be used as solvents when producing each component used in the photocurable composition, and may be mixed into the photocurable composition as a residual solvent. From the viewpoint of human safety and environmental consideration, it is preferable to reduce these substances as much as possible. As a method for reducing the environmentally regulated substances, a method of heating or reducing the pressure in the system to a temperature equal to or higher than the boiling point of the environmentally regulated substances and distilling off the environmentally regulated substances from the system can be mentioned. In addition, when a small amount of the environmentally regulated substances is distilled off, it is also useful to perform azeotropy with a solvent having a boiling point equivalent to that of the solvent corresponding to the environmentally regulated substances in order to increase efficiency. In addition, when a compound having radical polymerizability is contained, a polymerization inhibitor or the like may be added and distilled off under reduced pressure in order to suppress the progress of radical polymerization reaction during distillation under reduced pressure and crosslinking between molecules. These distillation methods are possible at any stage, such as the stage of the raw materials, the stage of the product of the reaction of the raw materials (for example, the resin solution or polyfunctional monomer solution after polymerization), or the stage of the photocurable composition prepared by mixing these compounds.

<Pigment Derivatives>
The photocurable composition according to the present disclosure may further include a pigment derivative.
The pigment derivative is used, for example, as a dispersing aid. Examples of the pigment derivative include a compound having a structure in which an acid group or a basic group is bonded to a colorant skeleton.

　Examples of the pigment skeletons that make up the pigment derivatives include a quinoline dye skeleton, a benzimidazolone dye skeleton, a benzisoindole dye skeleton, a benzothiazole dye skeleton, an iminium dye skeleton, a squarylium dye skeleton, a croconium dye skeleton, an oxonol dye skeleton, a pyrrolopyrrole dye skeleton, a diketopyrrolopyrrole dye skeleton, an azo dye skeleton, an azomethine dye skeleton, a phthalocyanine dye skeleton, a naphthalocyanine dye skeleton, an anthraquinone dye skeleton, a quinacridone dye skeleton, a dioxazine dye skeleton, a perinone dye skeleton, a perylene dye skeleton, a thioindigo dye skeleton, an isoindoline dye skeleton, an isoindolinone dye skeleton, a quinophthalone dye skeleton, an iminium dye skeleton, a dithiol dye skeleton, a triarylmethane dye skeleton, and a pyrromethene dye skeleton.

Examples of the acid group include a carboxy group, a sulfo group, a phosphoric acid group, a boronic acid group, a carboxylic acid amide group, a sulfonic acid amide group, an imide acid group, and salts thereof. Examples of atoms or atomic groups constituting the salt include an alkali metal ion (Li ⁺ , Na ⁺ , K ⁺ , etc.), an alkaline earth metal ion (Ca ²⁺ , Mg ²⁺ , etc.), an ammonium ion, an imidazolium ion, a pyridinium ion, and a phosphonium ion. Examples of the carboxylic acid amide group include a group represented by -NHCOR ^X1 . Examples of the sulfonic acid amide group include a group represented by -NHSO ₂ R ^X2 . Examples of the imide acid group include a group represented by -SO ₂ NHSO ₂ R ^X3 , -CONHSO ₂ R ^X4 , -CONHCOR ^X5 , or SO ₂ NHCOR ^X6 , and more preferably -SO ₂ NHSO ₂ R ^X3 . R ^x1 to R ^x6 each independently represent an alkyl group or an aryl group. The alkyl group and aryl group represented by R ^x1 to R ^x6 may have a substituent. The substituent is preferably a halogen atom, and more preferably a fluorine atom.

Basic groups include amino groups, pyridinyl groups and their salts, salts of ammonium groups, and phthalimidomethyl groups. Atoms or atomic groups that make up the salts include hydroxide ions, halogen ions, carboxylate ions, sulfonate ions, and phenoxide ions.

The pigment derivative may be a pigment derivative having excellent visible transparency (hereinafter, also referred to as a transparent pigment derivative). The maximum molar absorption coefficient (εmax) of the transparent pigment derivative in the wavelength region of 400 nm to 700 nm is preferably 3,000 L mol ^-1 cm- ¹ or less, more preferably 1,000 L mol ^-1 cm ^-1 or less, and even more preferably 100 L mol ^-1 cm ^-1 or less. The lower limit of εmax is, for example, 1 L mol ^-1 cm- ¹ or more, and may be 10 L mol ^-1 cm ^-1 or more.

Specific examples of pigment derivatives include the compounds described in paragraph 0124 of WO 2022/085485, the benzimidazolone compounds or salts thereof described in JP 2018-168244 A, and compounds having an isoindoline skeleton described in general formula (1) of Japanese Patent No. 6996282 A.

The content of the pigment derivative is preferably 1 to 30 parts by mass, and more preferably 3 to 20 parts by mass, relative to 100 parts by mass of the colorant. The total content of the pigment derivative and the colorant is preferably 35% by mass or more, more preferably 40% by mass or more, even more preferably 45% by mass or more, and particularly preferably 50% by mass or more, relative to the total solid content of the photocurable composition. The upper limit is preferably 70% by mass or less, and more preferably 65% by mass or less. Only one type of pigment derivative may be used, or two or more types may be used in combination.

<Chain Transfer Agent>
From the viewpoint of adhesion, the photocurable composition according to the present disclosure preferably further contains a chain transfer agent.
Examples of the chain transfer agent include thiol compounds, thiocarbonylthio compounds, and aromatic α-methylalkenyl dimers, and the like. Thiol compounds are preferred because they allow easy adjustment of the line width of the pattern even when used in a small amount. In addition, the chain transfer agent is preferably a compound that causes little coloring.

- Thiol compounds -
The thiol compound is a compound having one or more thiol groups, and is preferably a compound having two or more thiol groups.The upper limit of the number of thiol groups contained in the thiol compound is preferably 20 or less, more preferably 15 or less, even more preferably 10 or less, particularly preferably 8 or less, and most preferably 6 or less.The lower limit of the number of thiol groups contained in the thiol compound is preferably 3 or more.From the viewpoint of adhesion, it is particularly preferable that the thiol compound is a compound having 4 thiol groups.

It is also preferable that the thiol compound is a compound derived from a polyfunctional alcohol.

The thiol compound is preferably a compound represented by the following formula (SH-1).
L ¹ - (SH) _n formula (SH-1)
In the formula, SH represents a thiol group, ^L1 represents an n-valent group, and n represents an integer of 1 or more.

In formula (SH-1), examples of the n-valent group represented by L ¹ include a hydrocarbon group, a heterocyclic group, -O-, -S-, -NR-, -CO-, -COO-, -OCO-, -SO ₂ -, or a group consisting of a combination thereof. R represents a hydrogen atom, an alkyl group, or an aryl group, and is preferably a hydrogen atom. The hydrocarbon group may be an aliphatic hydrocarbon group or an aromatic hydrocarbon group. The aliphatic hydrocarbon group may be cyclic or noncyclic. The aliphatic hydrocarbon group may be a saturated aliphatic hydrocarbon group or an unsaturated aliphatic hydrocarbon group. The hydrocarbon group may have a substituent or may not have a substituent. The cyclic aliphatic hydrocarbon group and the aromatic hydrocarbon group may be a monocyclic ring or a condensed ring. The heterocyclic group may be a monocyclic ring or a condensed ring. The heterocyclic group is preferably a 5-membered ring or a 6-membered ring. The heterocyclic group may be an aliphatic heterocyclic group or an aromatic heterocyclic group. Examples of heteroatoms constituting the heterocyclic group include a nitrogen atom, an oxygen atom, a sulfur atom, etc. The number of carbon atoms constituting ^L1 is preferably 3 to 100, and more preferably 6 to 50.

In formula (SH-1), n represents an integer of 1 or more. The upper limit of n is preferably 20 or less, more preferably 15 or less, even more preferably 10 or less, particularly preferably 8 or less, and most preferably 6 or less. The lower limit of n is preferably 2 or more, more preferably 3 or more. It is particularly preferable that n is 4.

Specific examples of thiol compounds include compounds with the following structure. Commercially available thiol compounds include PEMP (manufactured by SC Organic Chemicals, a thiol compound), Suncerer M (manufactured by Sanshin Chemical Industry Co., Ltd., a thiol compound), and Karenz MT BD1 (manufactured by Showa Denko K.K., a thiol compound).

-Thiocarbonylthio compounds-
The thiocarbonylthio compound is a compound having a thiocarbonylthio group (-S-C(=S)-) in the molecule, and examples thereof include bis(thiocarbonyl)disulfide compounds (compounds represented by formula (SC-1) below), dithioester compounds (compounds represented by formula (SC-2) below), trithiocarbonate compounds (compounds represented by formula (SC-3) below), dithiocarbamate compounds (compounds represented by formula (SC-4) below), and xanthate compounds (compounds represented by formula (SC-5) below).

In formulae (SC-1) to (SC-5), Z ¹ to Z ¹¹ each independently represent a substituent.

Examples of the substituents represented by Z ¹ to Z ¹¹ include an alkyl group, an aryl group, a heteroaryl group, -SR ^Z1 , -NR ^Z1 R ^Z2 , -NR ^Z1 -NR ^Z2 R ^Z3 , -COOR ^Z1 , -OCOR ^Z1 , -CONR ^Z1 R ^Z2 , -P(═O)(OR ^Z1 ) ₂ or -O-P(═O)R ^Z1 R ^Z2 (wherein R ^Z1 , R ^Z2 and R ^Z3 are each independently an alkyl group, an aryl group or a heteroaryl group), etc. Among the above groups, one or more hydrogen atoms bonded to the carbon atom may be substituted with a cyano group, a carboxy group, etc.
The number of carbon atoms in the alkyl group is preferably 1 to 30, more preferably 1 to 15, and still more preferably 1 to 8. The alkyl group may be linear, branched, or cyclic, and is preferably linear or branched.
The aryl group preferably has 6 to 30 carbon atoms, more preferably 6 to 20 carbon atoms, and even more preferably 6 to 12 carbon atoms.
The heteroaryl group is preferably a monocyclic heteroaryl group or a heteroaryl group having 2 to 8 condensed rings, more preferably a monocyclic heteroaryl group or a heteroaryl group having 2 to 4 condensed rings. The number of heteroatoms constituting the ring of the heteroaryl group is preferably 1 to 3. The heteroatoms constituting the ring of the heteroaryl group are preferably nitrogen atoms, oxygen atoms, or sulfur atoms. The heteroaryl group is preferably a 5-membered or 6-membered ring. The number of carbon atoms constituting the ring of the heteroaryl group is preferably 3 to 30, more preferably 3 to 18, and even more preferably 3 to 12.

Specific examples of bis(thiocarbonyl) disulfide compounds include tetraethyl thiuram disulfide, tetramethyl thiuram disulfide, bis(n-octyl mercapto-thiocarbonyl) disulfide, bis(n-dodecyl mercapto-thiocarbonyl) disulfide, bis(benzyl mercapto-thiocarbonyl) disulfide, bis(n-butyl mercapto-thiocarbonyl) disulfide, bis(t-butyl mercapto-thiocarbonyl) disulfide, bis(n-heptyl mercapto-thiocarbonyl) disulfide, bis(n- Examples of such disulfides include bis(n-hexylmercapto-thiocarbonyl) disulfide, bis(n-pentylmercapto-thiocarbonyl) disulfide, bis(n-nonylmercapto-thiocarbonyl) disulfide, bis(n-decylmercapto-thiocarbonyl) disulfide, bis(t-dodecylmercapto-thiocarbonyl) disulfide, bis(n-tetradecylmercapto-thiocarbonyl) disulfide, bis(n-hexadecylmercapto-thiocarbonyl) disulfide, and bis(n-octadecylmercapto-thiocarbonyl) disulfide.

Specific examples of dithioester compounds include 2-phenyl-2-propyl benzothioate, 4-cyano-4-(phenylthiocarbonylthio)pentanoic acid, and 2-cyano-2-propyl benzodithioate.

Specific examples of trithiocarbonate compounds include S-(2-cyano-2-propyl)-S-dodecyl trithiocarbonate, 4-cyano-4-[(dodecylsulfanyl-thiocarbonyl)sulfanyl]pentanoic acid, cyanomethyl dodecyl trithiocarbonate, and 2-(dodecylthiocarbonothiolthio)-2-methylpropionic acid.

Specific examples of dithiocarbamate compounds include cyanomethylmethyl(phenyl)carbamodithioate and cyanomethyldiphenylcarbamo-dithioate.

Specific examples of xanthate compounds include xanthogenate esters.

- Aromatic α-methylalkenyl dimer -
An example of the aromatic α-methylalkenyl dimer is 2,4-diphenyl-4-methyl-1-pentene.

As a chain transfer agent, trithiocarbonate compounds such as those used as RAFT agents in RAFT (Reversible Addition-Fragmentation chain Transfer) polymerization, which is a type of living polymerization, can also be preferably used.

The molecular weight of the chain transfer agent is preferably 200 or more, since this can suppress contamination of the apparatus due to sublimation. The upper limit is preferably 1,000 or less, more preferably 800 or less, and even more preferably 600 or less, since this can increase the SH valence per unit mass.

From the viewpoint of adhesion, the content of the chain transfer agent is preferably 0.01% by mass to 10% by mass, more preferably 0.01% by mass to 5% by mass, and even more preferably 0.05% by mass to 1% by mass, based on the total solid content of the photocurable composition. Only one type of chain transfer agent may be used, or two or more types may be used in combination.

<Polyalkyleneimine>
The photocurable composition according to the present disclosure may also contain a polyalkyleneimine. The polyalkyleneimine is used, for example, as a dispersing aid for pigments. The dispersing aid is a material for enhancing the dispersibility of pigments in the photocurable composition. The polyalkyleneimine is a polymer obtained by ring-opening polymerization of an alkyleneimine, and is a polymer having at least a secondary amino group. The polyalkyleneimine may contain a primary amino group or a tertiary amino group in addition to the secondary amino group. The polyalkyleneimine is preferably a polymer having a branched structure containing a primary amino group, a secondary amino group, and a tertiary amino group. The number of carbon atoms of the alkyleneimine is preferably 2 to 6, more preferably 2 to 4, even more preferably 2 or 3, and particularly preferably 2.

The molecular weight of the polyalkyleneimine is preferably 200 or more, more preferably 250 or more. The upper limit is preferably 100,000 or less, more preferably 50,000 or less, even more preferably 10,000 or less, and particularly preferably 2,000 or less. Regarding the molecular weight value of the polyalkyleneimine, if the molecular weight can be calculated from the structural formula, the molecular weight of the polyalkyleneimine is the value calculated from the structural formula. On the other hand, if the molecular weight of the polyalkyleneimine cannot be calculated from the structural formula or is difficult to calculate, the number average molecular weight value measured by the boiling point elevation method is used. If the molecular weight cannot be measured by the boiling point elevation method or is difficult to measure, the number average molecular weight value measured by the viscosity method is used. If the molecular weight cannot be measured by the viscosity method or is difficult to measure, the number average molecular weight value measured in polystyrene equivalent terms by the GPC (gel permeation chromatography) method is used.

The amine value of the polyalkyleneimine is preferably 5 mmol/g or more, more preferably 10 mmol/g or more, and even more preferably 15 mmol/g or more.

Specific examples of alkyleneimines include ethyleneimine, propyleneimine, 1,2-butyleneimine, and 2,3-butyleneimine, with ethyleneimine or propyleneimine being preferred, and ethyleneimine being more preferred. The polyalkyleneimine is particularly preferably polyethyleneimine. Furthermore, the polyethyleneimine preferably contains primary amino groups in an amount of 10 mol% or more, more preferably 20 mol% or more, and even more preferably 30 mol% or more, based on the total of the primary amino groups, secondary amino groups, and tertiary amino groups. Commercially available polyethyleneimines include Epomin SP-003, SP-006, SP-012, SP-018, SP-200, and P-1000 (all manufactured by Nippon Shokubai Co., Ltd.).

The content of polyalkyleneimine in the total solid content of the photocurable composition is preferably 0.1% to 5% by mass. The lower limit is more preferably 0.2% by mass or more, even more preferably 0.5% by mass or more, and particularly preferably 1% by mass or more. The upper limit is more preferably 4.5% by mass or less, even more preferably 4% by mass or less, and particularly preferably 3% by mass or less. The content of polyalkyleneimine is preferably 0.5 parts by mass to 20 parts by mass relative to 100 parts by mass of pigment. The lower limit is more preferably 0.6 parts by mass or more, even more preferably 1 part by mass or more, and particularly preferably 2 parts by mass or more. The upper limit is more preferably 10 parts by mass or less, and even more preferably 8 parts by mass or less. Only one type of polyalkyleneimine may be used, or two or more types may be used. When two or more types are used, it is preferable that the total amount is within the above range.

<Curing accelerator>
The photocurable composition according to the present disclosure may contain a curing accelerator. Examples of the curing accelerator include thiol compounds, methylol compounds, amine compounds, phosphonium salt compounds, amidine salt compounds, amide compounds, base generators, isocyanate compounds, alkoxysilane compounds, and onium salt compounds. Specific examples of the curing accelerator include the compounds described in paragraph 0164 of WO 2022/085485. The content of the curing accelerator in the total solid content of the photocurable composition is preferably 0.3% by mass to 8.9% by mass, more preferably 0.8% by mass to 6.4% by mass.

<Infrared absorber>
The photocurable composition according to the present disclosure may contain an infrared absorbing agent. For example, when an infrared transmission filter is formed using the photocurable composition according to the present disclosure, the wavelength of light transmitted through the film obtained by adding an infrared absorbing agent to the photocurable composition can be shifted to a longer wavelength side. The infrared absorbing agent is preferably a compound having a maximum absorption wavelength on the longer wavelength side than a wavelength of 700 nm. The infrared absorbing agent is preferably a compound having a maximum absorption wavelength in the range of more than 700 nm and not more than 1800 nm. In addition, the ratio A ¹ /A ² between the absorbance A ¹ at a wavelength of 500 nm of the infrared absorbing agent and the absorbance A ² at the maximum absorption wavelength is preferably 0.08 or less, more preferably 0.04 or less.

Infrared absorbers include pyrrolopyrrole compounds, cyanine compounds, squarylium compounds, phthalocyanine compounds, naphthalocyanine compounds, quaterrylene compounds, merocyanine compounds, croconium compounds, oxonol compounds, iminium compounds, dithiol compounds, triarylmethane compounds, pyrromethene compounds, azomethine compounds, anthraquinone compounds, dibenzofuranone compounds, dithiolene metal complexes, metal oxides, metal borides, etc. Specifically, the compounds described in paragraphs 0114 to 0121 of WO 2022/065215, the compounds described in paragraphs 0144 to 0146 of WO 2021/049441, the croconic acid compounds described in JP 2021-195515 A, the near-infrared absorbing dyes described in JP 2022-022070 A, and the croconium compounds described in WO 2019/021767 A can also be used.

The content of the infrared absorber in the total solid content of the photocurable composition is preferably 1% by mass to 40% by mass. The lower limit is more preferably 2% by mass or more, even more preferably 5% by mass or more, and particularly preferably 10% by mass or more. The upper limit is more preferably 30% by mass or less, and even more preferably 25% by mass or less. The photocurable composition according to the present disclosure may contain only one type of infrared absorber, or may contain two or more types. When the photocurable composition according to the present disclosure contains two or more types of infrared absorbers, it is preferable that the total amount of the two or more types of infrared absorbers is in the above range.

<Ultraviolet absorbing agent>
The photocurable composition according to the present disclosure may contain an ultraviolet absorber. Examples of ultraviolet absorbers include conjugated diene compounds, aminodiene compounds, salicylate compounds, benzophenone compounds, benzotriazole compounds, acrylonitrile compounds, hydroxyphenyltriazine compounds, indole compounds, and triazine compounds. Specific examples of such compounds include the compounds described in paragraph 0179 of International Publication No. WO 2022/085485. As the ultraviolet absorber, the reactive triazine ultraviolet absorber described in JP 2021-178918 A and the ultraviolet absorber described in JP 2022-007884 A can be used. The content of the ultraviolet absorber in the total solid content of the photocurable composition is preferably 0.01% by mass to 10% by mass, more preferably 0.01% by mass to 5% by mass. Only one type of ultraviolet absorber may be used, or two or more types may be used. When the photocurable composition according to the present disclosure contains two or more types of ultraviolet absorbers, it is preferable that the total amount of the two or more types of ultraviolet absorbers is within the above range.

<Polymerization inhibitor>
The photocurable composition according to the present disclosure may contain a polymerization inhibitor. Examples of the polymerization inhibitor include hydroquinone, p-methoxyphenol, di-tert-butyl-p-cresol, pyrogallol, tert-butylcatechol, benzoquinone, 4,4'-thiobis(3-methyl-6-tert-butylphenol), 2,2'-methylenebis(4-methyl-6-t-butylphenol), and N-nitrosophenylhydroxyamine salt (ammonium salt, cerous salt, etc.). Among them, p-methoxyphenol is preferred. The content of the polymerization inhibitor in the total solid content of the photocurable composition is preferably 0.0001% by mass to 5% by mass. The polymerization inhibitor may be one type or two or more types. When the photocurable composition according to the present disclosure contains two or more types of polymerization inhibitors, it is preferable that the total amount of the two or more polymerization inhibitors is in the above range.

<Silane coupling agent>
The photocurable composition according to the present disclosure may contain a silane coupling agent. In the present disclosure, the silane coupling agent refers to a silane compound having a hydrolyzable group and other functional groups. The hydrolyzable group refers to a substituent that is directly bonded to a silicon atom and can generate a siloxane bond by at least one of a hydrolysis reaction and a condensation reaction. Examples of the hydrolyzable group include a halogen atom, an alkoxy group, and an acyloxy group, and an alkoxy group is preferred. That is, the silane coupling agent is preferably a compound having an alkoxysilyl group. Examples of functional groups other than the hydrolyzable group include a vinyl group, a (meth)allyl group, a (meth)acryloyl group, a mercapto group, an epoxy group, an oxetanyl group, an amino group, a ureido group, a sulfide group, an isocyanate group, and a phenyl group, and an amino group, a (meth)acryloyl group, and an epoxy group are preferred. Specific examples of the silane coupling agent include the compounds described in paragraph 0177 of International Publication No. WO 2022/085485. The content of the silane coupling agent in the total solid content of the photocurable composition is preferably from 0.01% by mass to 15.0% by mass, and more preferably from 0.05% by mass to 10.0% by mass.
The silane coupling agent may be one type or two or more types. When the photocurable composition according to the present disclosure contains two or more types of silane coupling agents, the total amount of the two or more types of silane coupling agents is preferably within the above range.

<Surfactant>
The photocurable composition according to the present disclosure may contain a surfactant. As the surfactant, various surfactants such as fluorine-based surfactants, nonionic surfactants, cationic surfactants, anionic surfactants, and silicone-based surfactants may be used. The surfactant is preferably a silicone-based surfactant or a fluorine-based surfactant. For the surfactant, reference may be made to the surfactants described in paragraphs 0238 to 0245 of WO 2015/166779, the contents of which are incorporated herein by reference.

The fluorine content in the fluorosurfactant is preferably 3% to 40% by mass, more preferably 5% to 30% by mass, and particularly preferably 7% to 25% by mass. Fluorine surfactants with a fluorine content within this range are effective in terms of uniformity of the coating film thickness and liquid saving, and also have good solubility in the photocurable composition.

As fluorosurfactants, compounds described in paragraphs 0167 to 0173 of WO 2022/085485 and fluorine-containing copolymers described in JP 2022-000494 can also be used.

As a nonionic surfactant, the compounds described in paragraph 0174 of WO 2022/085485 can also be used.

Silicone surfactants include DOWSIL SH8400, SH8400 FLUID, FZ-2122, 67 Additive, 74 Additive, M Additive, SF 8419 OIL (all manufactured by Dow Toray Co., Ltd.), TSF-4300, TSF-4445, TSF-4460, and TSF-4452 (all manufactured by Momen Co., Ltd.). Examples include BYK-307, BYK-322, BYK-323, BYK-330, BYK-333, BYK-3760, and BYK-UV3510 (manufactured by BYK-Chemie), etc.

　Also, the silicone surfactant may be a compound with the following structure, where n is 1 to 200.

The content of the surfactant in the total solid content of the photocurable composition is preferably 0.001% by mass to 5.0% by mass, and more preferably 0.005% by mass to 3.0% by mass. The photocurable composition may contain only one type of surfactant, or may contain two or more types of surfactants. When the photocurable composition according to the present disclosure contains two or more types of surfactants, it is preferable that the total amount of the two or more types of surfactants is in the above range.

<Antioxidants>
The photocurable composition according to the present disclosure may contain an antioxidant. Examples of the antioxidant include phenolic compounds, phosphite compounds, and thioether compounds. As the phenolic compound, any phenolic compound known as a phenolic antioxidant may be used. A preferred phenolic compound is a hindered phenolic compound. A compound having a substituent at the site (ortho position) adjacent to the phenolic hydroxy group is preferred. As the above-mentioned substituent, a substituted or unsubstituted alkyl group having 1 to 22 carbon atoms is preferred. In addition, as the antioxidant, a compound having a phenolic group and a phosphite ester group in the same molecule is also preferred. In addition, as the antioxidant, a phosphorus-based antioxidant can also be suitably used. Examples of phosphorus-based antioxidants include tris[2-[[2,4,8,10-tetrakis(1,1-dimethylethyl)dibenzo[d,f][1,3,2]dioxaphosphepin-6-yl]oxy]ethyl]amine, tris[2-[(4,6,9,11-tetra-tert-butyldibenzo[d,f][1,3,2]dioxaphosphepin-2-yl)oxy]ethyl]amine, and ethylbis(2,4-di-tert-butyl-6-methylphenyl)phosphite. Commercially available antioxidants include, for example, Adeka STAB AO-20, Adeka STAB AO-30, Adeka STAB AO-40, Adeka STAB AO-50, Adeka STAB AO-50F, Adeka STAB AO-60, Adeka STAB AO-60G, Adeka STAB AO-80, and Adeka STAB AO-330 (manufactured by ADEKA Corporation). In addition, the antioxidant may be a compound described in paragraphs 0023 to 0048 of Japanese Patent No. 6268967, a compound described in International Publication No. WO 2017/006600, a compound described in International Publication No. WO 2017/164024, or a compound described in Korean Patent Publication No. 10-2019-0059371. The content of the antioxidant in the total solid content of the photocurable composition is preferably 0.01% by mass to 20% by mass, and more preferably 0.3% by mass to 15% by mass. Only one type of antioxidant may be used, or two or more types may be used. When the photocurable composition according to the present disclosure contains two or more types of antioxidants, the total amount of the two or more types of antioxidants is preferably in the above range.

<Sensitizer>
The photocurable compound according to the present disclosure preferably further contains a sensitizer.
By including a sensitizer in the photocurable composition according to the present disclosure, the exposure sensitivity to not only i-line (wavelength 365 nm) but also KrF excimer laser (wavelength 248 nm) can be improved.
From the viewpoint of sensitivity, preferred sensitizers include those having absorption at a wavelength of 365 nm.

Sensitizers include aromatic compounds such as benzophenone and derivatives thereof, thioxanthone and derivatives thereof, anthraquinone and derivatives thereof, coumarin and phenothiazine and derivatives thereof, as well as 3-(aroylmethylene)thiazoline, rhodanine, camphorquinone, and the like.
Further, suitable examples of the sensitizer include eosin, rhodamine, erythrosine, xanthene, thioxanthene, acridine such as 9-phenylacridine, 1,7-bis(9-acridinyl)heptane, 1,5-bis(9-acridinyl)pentane, cyanine dyes, and merocyanine dyes.

Specific examples of the sensitizer include the following:
1. Thioxanthones Thioxanthone, 2-isopropylthioxanthone, 2-chlorothioxanthone, 1-chloro-4-propoxythioxanthone, 2-dodecylthioxanthone, 2,4-diethylthioxanthone, 2,4-dimethylthioxanthone, 1-methoxycarbonylthioxanthone, 2-ethoxycarbonylthioxanthone, 3-(2-methoxyethoxycarbonyl)thioxanthone, 4-butoxycarbonylthioxanthone, 3-butoxycarbonyl-7-methyl Thioxanthone, 1-cyano-3-chlorothioxanthone, 1-ethoxycarbonyl-3-chlorothioxanthone, 1-ethoxycarbonyl-3-ethoxythioxanthone, 1-ethoxycarbonyl-3-aminothioxanthone, 1-ethoxycarbonyl-3-phenylsulfurylthioxanthone, 3,4-di-[2-(2-methoxyethoxy)ethoxycarbonyl]thioxanthone, 1,3-dimethyl-2-hydroxy-9H-thioxanthen-9-one 2-Ethylhexyl ether, 1-ethoxycarbonyl-3-(1-methyl-1-morpholinoethyl)thioxanthone, 2-methyl-6-dimethoxymethylthioxanthone, 2-methyl-6-(1,1-dimethoxybenzyl)thioxanthone, 2-morpholinomethylthioxanthone, 2-methyl-6-morpholinomethylthioxanthone, N-allylthioxanthone-3,4-dicarboximide, N-octylthioxanthone-3,4-dicarboximide, N-(1 ,1,3,3-tetramethylbutyl)thioxanthone-3,4-dicarboximide, 1-phenoxythioxanthone, 6-ethoxycarbonyl-2-methoxythioxanthone, 6-ethoxycarbonyl-2-methylthioxanthone, thioxanthone-2-carboxylic acid polyethylene glycol ester, 2-hydroxy-3-(3,4-dimethyl-9-oxo-9H-thioxanthone-2-yloxy)-N,N,N-trimethyl-1-propanaminium chloride;

2. Benzophenones Benzophenone, 4-phenylbenzophenone, 4-methoxybenzophenone, 4,4'-dimethoxybenzophenone, 4,4'-dimethylbenzophenone, 4,4'-dichlorobenzophenone, 4,4'-bis(dimethylamino)benzophenone, 4,4'-bis(diethylamino)benzophenone, 4,4'-bis(methylethylamino)benzophenone, 4,4'-bis(p-isopropylphenoxy)benzophenone, 4-methylbenzophenone, 2,4,6-trimethylbenzophenone, 4-(4-methylthiophenyl)benzophenone, 3,3'-dimethyl-4-methoxybenzophenone, methyl-2-benzoylbenzoate, 4-(2-hydro 4-(4-tolylthio)benzophenone, 1-[4-(4-benzoyl-phenylsulfanyl)phenyl]-2-methyl-2-(toluene-4-sulfonyl)propan-1-one, 4-benzoyl-N,N,N-trimethylbenzenemethanaminium chloride, 2-hydroxy-3-(4-benzoylphenoxy)-N,N,N-trimethyl-1-propanaminium chloride monohydrate, 4-(13-acryloyl-1,4,7,10,13-pentaoxatridecyl)benzophenone, 4-benzoyl-N,N-dimethyl-N-[2-(1-oxo-2-propenyl)oxy]ethyl-benzenemethanaminium chloride;

3. Coumarins Coumarin 1, Coumarin 2, Coumarin 6, Coumarin 7, Coumarin 30, Coumarin 102, Coumarin 106, Coumarin 138, Coumarin 152, Coumarin 153, Coumarin 307, Coumarin 314, Coumarin 314T, Coumarin 334, Coumarin 337, Coumarin 500, 3-benzoylcoumarin, 3-benzoyl-7-methoxycoumarin, 3-benzoyl-5,7-dimethoxycoumarin, 3-benzoyl-5,7-dipropoxycoumarin, 3-benzoyl-6,8- Dichlorocoumarin, 3-benzoyl-6-chlorocoumarin, 3,3'-carbonyl-bis[5,7-di(propoxy)coumarin], 3,3'-carbonyl-bis(7-methoxycoumarin), 3,3'-carbonyl-bis(7-diethylamino-coumarin), 3-isobutyroylcoumarin, 3-benzoyl-5,7-dimethoxycoumarin, 3-benzoyl-5,7-diethoxycoumarin, 3-benzoyl-5,7-dibutoxycoumarin, 3-benzoyl-5,7-di( methoxyethoxy)coumarin, 3-benzoyl-5,7-di(allyloxy)coumarin, 3-benzoyl-7-dimethylaminocoumarin, 3-benzoyl-7-diethylaminocoumarin, 3-isobutyroyl-7-dimethylaminocoumarin, 5,7-dimethoxy-3-(1-naphthoyl)coumarin, 5,7-diethoxy-3-(1-naphthoyl)coumarin, 3-benzoylbenzo[f]coumarin, 7-diethylamino-3-thienoylcoumarin, 3-(4-cyano benzoyl)-5,7-dimethoxycoumarin, 3-(4-cyanobenzoyl)-5,7-dipropoxycoumarin, 7-dimethylamino-3-phenylcoumarin, 7-diethylamino-3-phenylcoumarin, coumarin derivatives disclosed in JP09-179299-A and JP09-325209-A, such as 7-[{4-chloro-6-(diethylamino)-S-triazin-2-yl}amino]-3-phenylcoumarin, 7-diethylamino-4-methylcoumarin;

4. 3-(Aroylmethylene)thiazolines 3-methyl-2-benzoylmethylene-β-naphthothiazoline, 3-methyl-2-benzoylmethylene-benzothiazoline, 3-ethyl-2-propionylmethylene-β-naphthothiazoline;

5. Rhodanines: 4-dimethylaminobenzal rhodanine, 4-diethylaminobenzal rhodanine, 3-ethyl-5-(3-octyl-2-benzothiazolinylidene)rhodanine, and rhodanine derivatives of the formulae [1], [2], and [7] disclosed in JP-A-8-305019;

6. Other compounds suitable as sensitizers: Acetophenone, 3-methoxyacetophenone, 4-phenylacetophenone, benzil, 4,4'-bis(dimethylamino)benzil, 2-acetylnaphthalene, 2-naphthaldehyde, dansylic acid derivatives, 9,10-anthraquinone, anthracene, pyrene, aminopyrene, perylene, phenanthrene, phenanthrenequinone, 9-fluorenone, dibenzosuberone, curcumin, xanthone, thiomichler's ketone, α-(4-dimethylaminobenzylidene) Ketones, such as 2,5-bis(4-diethylaminobenzylidene)cyclopentanone, 2-(4-dimethylaminobenzylidene)indan-1-one, 3-(4-dimethylaminophenyl)-1-indan-5-yl-propenone, 3-phenylthiophthalimide, N-methyl-3,5-di(ethylthio)phthalimide, N-methyl-3,5-di(ethylthio)phthalimide, phenothiazines, methylphenothiazines, amines, such as N-phenylglycine, ethyl 4-dimethylaminobenzoate, butoxyethyl 4-dimethylaminobenzoate, 4-dimethylaminoacetophenone, triethanolamine, methyldiethanolamine, dimethylaminoethanol, 2-(dimethylamino)ethyl benzoate, poly(propylene glycol)-4-(dimethylamino)benzoate, 6-chloro-2-methylthiochroman-4-one.

From the viewpoint of sensitivity, the sensitizer is preferably at least one compound selected from the group consisting of benzophenone and its derivatives, thioxanthone and its derivatives, anthraquinone and its derivatives, and coumarin and its derivatives.

As a sensitizer, an amine compound such as triethanolamine, N-methyldiethanolamine, ethyl-p-dimethylaminobenzoate, 2-(dimethylamino)ethyl benzoate, 2-ethylhexyl-p-dimethylaminobenzoate, octyl-p-N,N-dimethylaminobenzoate, N-(2-hydroxyethyl)-N-methyl-p-toluidine or Michler's ketone can be added to promote photopolymerization. The action of the amine compound can be enhanced by the addition of a benzophenone-type aromatic ketone compound.
Examples of amine compounds which can be used as oxygen scavengers include substituted N,N-dialkylanilines such as those described in EP-A-339841.
Other accelerators, coinitiators and autoxidizers include thiol compounds, thioether compounds, disulfide compounds, phosphonium salt compounds, phosphine oxide compounds or phosphine compounds, which are described, for example, in EP 438123, GB 2180358 and JP-A-6-68309.

The content of the sensitizer in the total solid content of the photocurable composition is preferably 0.01% by mass to 20% by mass, more preferably 0.05% by mass to 10% by mass, and particularly preferably 0.1% by mass to 5% by mass.
The photocurable composition according to the present disclosure may contain only one type of sensitizer, or may contain two or more types. When the photocurable composition according to the present disclosure contains two or more types of sensitizers, it is preferable that the total amount of the two or more sensitizers is within the above range.

<Other ingredients>
The photocurable composition according to the present disclosure may contain, as necessary, a curing accelerator, a filler, a heat curing accelerator, a plasticizer, and other auxiliaries (e.g., conductive particles, defoamers, flame retardants, leveling agents, peeling accelerators, fragrances, surface tension adjusters, etc.). By appropriately incorporating these components, properties such as film properties can be adjusted. As these components, the compounds described in paragraph 0182 of WO 2022/085485, the xanthene type epoxy resins described in JP 2021-195421 A, the xanthene type epoxy resins described in JP 2021-195422 A, and the like can also be used.

The photocurable composition according to the present disclosure may contain a metal oxide in order to adjust the refractive index of the resulting film. Examples of the metal oxide include TiO ₂ , ZrO ₂ , Al ₂ O ₃ , and SiO ₂ . The primary particle size of the metal oxide is preferably 1 nm to 100 nm, more preferably 3 nm to 70 nm, and even more preferably 5 nm to 50 nm. The metal oxide may have a core-shell structure. In this case, the core may be hollow.

The photocurable composition according to the present disclosure may contain a light resistance improver. The light resistance improver may be a compound described in paragraph 0183 of WO 2022/085485.

It is also preferable that the photocurable composition according to the present disclosure is substantially free of terephthalic acid esters. Here, "substantially free" means that the content of terephthalic acid esters in the total amount of the photocurable composition is 1000 ppb by mass or less, more preferably 100 ppb by mass or less, and particularly preferably 0 (zero).

The curable composition according to the present disclosure preferably has a low melamine content. Specifically, the melamine content is preferably 10,000 mass ppm or less in the total amount of the curable composition, and may be 0 (zero).

From the viewpoint of environmental regulations, the use of perfluoroalkylsulfonic acid and its salts, and perfluoroalkylcarboxylic acid and its salts may be restricted. In the photocurable composition according to the present disclosure, when the content of the above-mentioned compounds is reduced, the content of perfluoroalkylsulfonic acid (particularly perfluoroalkylsulfonic acid having 6 to 8 carbon atoms in the perfluoroalkyl group) and its salts, and perfluoroalkylcarboxylic acid (particularly perfluoroalkylcarboxylic acid having 6 to 8 carbon atoms in the perfluoroalkyl group) and its salts is preferably in the range of 0.01 ppb to 1,000 ppb, more preferably in the range of 0.05 ppb to 500 ppb, and even more preferably in the range of 0.1 ppb to 300 ppb, based on the total solid content of the photocurable composition. The photocurable composition according to the present disclosure may be substantially free of perfluoroalkylsulfonic acid and its salts, and perfluoroalkylcarboxylic acid and its salts. For example, a photocurable composition that is substantially free of perfluoroalkylsulfonic acid and its salts, and perfluoroalkylcarboxylic acid and its salts may be selected by using a compound that can be a substitute for perfluoroalkylsulfonic acid and its salts, and a compound that can be a substitute for perfluoroalkylcarboxylic acid and its salts. Examples of compounds that can be a substitute for regulated compounds include compounds that are excluded from regulation due to the difference in the number of carbon atoms in the perfluoroalkyl group. However, the above content does not prevent the use of perfluoroalkylsulfonic acid and its salts, and perfluoroalkylcarboxylic acid and its salts. The photocurable composition according to the present disclosure may contain perfluoroalkylsulfonic acid and its salts, and perfluoroalkylcarboxylic acid and its salts, within the maximum allowable range.

The water content of the photocurable composition according to the present disclosure is preferably 3% by mass or less, more preferably 0.01% by mass to 1.5% by mass, and even more preferably in the range of 0.1% by mass to 1.0% by mass. The water content can be measured by the Karl Fischer method.

The photocurable composition according to the present disclosure can be used by adjusting the viscosity for the purpose of adjusting the film surface state (flatness, etc.), adjusting the film thickness, etc. The value of the viscosity can be appropriately selected as necessary, and is preferably, for example, 0.3 mPa·s to 50 mPa·s, and more preferably 0.5 mPa·s to 20 mPa·s at 25° C. The viscosity can be measured, for example, using a cone-plate type viscometer, with the temperature adjusted to 25° C.
In the photocurable composition according to the present disclosure, the amount of chloride ions in the photocurable composition is preferably 10,000 ppm or less, more preferably 1000 ppm or less, from the viewpoints of environmental friendliness, suppression of foreign matter generation, suppression of equipment contamination, etc. In order to make the chloride ions in the photocurable composition fall within the above range, a raw material with a low chloride ion content may be used, and a method of removing chloride ions by washing with water, ion exchange resin, filter filtration, etc. Known methods may be used to measure chloride ions, and examples of such methods include ion chromatography and combustion ion chromatography.

There are no particular limitations on the uses of the cured product obtained by using the photocurable compound according to the present disclosure described above, but from the standpoint of curing sensitivity, it is preferable that the photocurable compound according to the present disclosure is for use in excimer laser exposure with a wavelength of 150 nm to 300 nm.

<Containment container>
The container for storing the photocurable composition is not particularly limited, and a known container can be used. In addition, the container described in paragraph 0187 of WO 2022/085485 can also be used as the container.

<Method of preparing photocurable composition>
The photocurable composition according to the present disclosure can be prepared by mixing the above-mentioned components. When preparing the photocurable composition, all components may be simultaneously dissolved and/or dispersed in a solvent to prepare the photocurable composition, or, if necessary, each component may be appropriately prepared as two or more solutions or dispersions, which are mixed at the time of use (at the time of application) to prepare the photocurable composition.

In addition, when preparing the photocurable composition, it is preferable to include a process for dispersing the pigment. In the process for dispersing the pigment, mechanical forces used to disperse the pigment include compression, squeezing, impact, shear, and cavitation. Specific examples of these processes include bead mills, sand mills, roll mills, ball mills, paint shakers, microfluidizers, high-speed impellers, sand grinders, flow jet mixers, high-pressure wet atomization, and ultrasonic dispersion. In addition, when grinding the pigment in a sand mill (bead mill), it is preferable to use beads with a small diameter and increase the bead packing rate, thereby increasing the grinding efficiency. In addition, it is preferable to remove coarse particles by filtration, centrifugation, or the like after the grinding process. In addition, the process and dispersing machine for dispersing the pigment may be suitably used as described in "Dispersion Technology Encyclopedia, published by Joho Kika Co., Ltd., July 15, 2005" or "Dispersion Technology and Industrial Application Practice Focusing on Suspension (Solid/Liquid Dispersion System) - Comprehensive Data Collection, published by Management Development Center Publishing Department, October 10, 1978", and in paragraph number 0022 of JP2015-157893A. In addition, in the process for dispersing the pigment, a salt milling process may be performed to refine the particles. For the materials, equipment, processing conditions, etc. used in the salt milling process, the descriptions in, for example, JP2015-194521A and JP2012-046629A may be referred to. As beads used for dispersion, zirconia, agate, quartz, titania, tungsten carbide, silicon nitride, alumina, stainless steel, glass, or a combination thereof may be used. In addition, inorganic compounds with a Mohs hardness of 2 or more can be used. The composition may contain 1 to 10,000 ppm of the above beads.

When preparing the photocurable composition, it is preferable to filter the photocurable composition with a filter for the purpose of removing foreign matter and reducing defects. The filters and filtration methods described in paragraphs 0196 to 0199 of WO 2022/085485 can also be used.

(Cured product and film)
The cured product according to the present disclosure is obtained by curing the photocurable composition according to the present disclosure.
The film according to the present disclosure is a film obtained from the photocurable composition according to the present disclosure, and is preferably a film obtained by curing the photocurable composition according to the present disclosure. The film according to the present disclosure can be used for optical filters such as color filters and infrared transmission filters. In particular, it can be preferably used as a color pixel of a color filter. Examples of the color pixel include a red pixel, a green pixel, a blue pixel, a magenta pixel, a cyan pixel, and a yellow pixel, and the like. The color pixel is preferably a green pixel or a blue pixel, and more preferably a green pixel.

The thickness of the film according to the present disclosure can be appropriately adjusted depending on the purpose, but is preferably 0.1 μm to 20 μm. The thickness of the film according to the present disclosure refers to the thickness after curing, unless otherwise specified.
The upper limit of the film thickness is more preferably 10 μm or less, even more preferably 5 μm or less, particularly preferably 3 μm or less, and most preferably 1.5 μm or less. The lower limit of the film thickness is more preferably 0.2 μm or more, and even more preferably 0.3 μm or more.
In an embodiment, the thickness of the film according to the present disclosure is more preferably 0.2 μm to 10 μm, even more preferably 0.3 μm to 5 μm, and particularly preferably 0.3 μm to 1.5 μm.

(Method for producing a cured product and method for producing a film)
The method for producing a cured product according to the present disclosure and the method for producing a film according to the present disclosure are not particularly limited, but preferably include a step of irradiating the photocurable composition according to the present disclosure with light having a wavelength of 150 nm to 300 nm.
Examples of light with a wavelength of 150 nm to 300 nm include KrF radiation (wavelength 248 nm) and ArF radiation (wavelength 193 nm).
Moreover, the light having a wavelength of 150 nm to 300 nm is preferably an excimer laser.
The shape of the resulting cured product is not particularly limited, but is preferably a film.
The film according to the present disclosure is a cured product of the photocurable compound according to the present disclosure described above.

The film according to the present disclosure can be produced through a process of applying the photocurable composition according to the present disclosure to a support. The film production method preferably further includes a process of forming a pattern (pixels). Methods for forming the pattern (pixels) include photolithography and dry etching, with photolithography being preferred.

Pattern formation by photolithography preferably includes a step of forming a photocurable composition layer on a support using the photocurable composition according to the present disclosure, a step of exposing the photocurable composition layer in a pattern, and a step of developing and removing the unexposed parts of the photocurable composition layer to form a pattern (pixels). If necessary, a step of baking the photocurable composition layer (pre-bake step) and a step of baking the developed pattern (pixels) (post-bake step) may be provided.

In the step of forming a photocurable composition layer, a photocurable composition layer is formed on a support using the photocurable composition according to the present disclosure. The support is not particularly limited and can be appropriately selected depending on the application. For example, a glass substrate, a silicon substrate, etc. can be mentioned, and a silicon substrate is preferable. A charge-coupled device (CCD), a complementary metal oxide semiconductor (CMOS), a transparent conductive film, etc. may be formed on the silicon substrate. A black matrix for isolating each pixel may be formed on the silicon substrate. A base layer may be provided on the silicon substrate to improve adhesion with the upper layer, prevent diffusion of substances, or flatten the substrate surface. The base layer may be formed using a composition obtained by removing the colorant from the photocurable composition described in the present disclosure, or a composition containing the resin, polymerizable compound, surfactant, etc. described in the present disclosure. The surface contact angle of the base layer is preferably 20° to 70° when measured with diiodomethane. It is also preferable that the surface contact angle is 30° to 80° when measured with water.

　A known method can be used to apply the photocurable composition. For example, the method described in paragraph 0207 of WO 2022/085485 can be used.

The photocurable composition layer formed on the support may be dried (prebaked). When a film is produced by a low-temperature process, prebaking may not be performed. When prebaking is performed, the prebaking temperature is preferably 150°C or less, more preferably 120°C or less, and even more preferably 110°C or less. The lower limit can be, for example, 50°C or more, and can also be 80°C or more. The prebaking time is preferably 10 seconds to 300 seconds, more preferably 40 seconds to 250 seconds, and even more preferably 80 seconds to 220 seconds. Prebaking can be performed using a hot plate, an oven, etc.

Next, the photocurable composition layer is exposed to light in a pattern (exposure step). For example, the photocurable composition layer can be exposed to light in a pattern by using a stepper exposure machine or a scanner exposure machine through a mask having a predetermined mask pattern. This allows the exposed parts to be cured.

Radiation (light) that can be used for exposure includes g-line and i-line. Light with a wavelength of 300 nm or less (preferably light with a wavelength of 150 nm to 300 nm) can also be used. Examples of light with a wavelength of 300 nm or less include KrF line (wavelength 248 nm) and ArF line (wavelength 193 nm), with KrF line (wavelength 248 nm) being preferred. Long-wavelength light sources of 300 nm or more can also be used.

In addition, during exposure, light may be applied continuously or in pulses (pulse exposure). Pulse exposure is an exposure method in which light is applied and paused repeatedly in short cycles (e.g., milliseconds or less).

The irradiation amount (exposure amount) is, for example, preferably 0.03 J/cm ² to 2.5 J/cm ² , more preferably 0.05 J/cm ² to 1.0 J/cm ^2. The oxygen concentration during exposure can be appropriately selected, and in addition to being performed under air, for example, exposure may be performed under a low-oxygen atmosphere with an oxygen concentration of 19 volume% or less (e.g., 15 volume%, 5 volume%, or substantially oxygen-free), or exposure may be performed under a high-oxygen atmosphere with an oxygen concentration of more than 21 volume% (e.g., 22 volume%, 30 volume%, or 50 volume%). The exposure illuminance can be appropriately set, and can usually be selected from the range of 1000 W/m ² to 100,000 W/m ² (e.g., 5000 W/m ² , 15000 W/m ² , or 35000 W/m ² ). The oxygen concentration and exposure illuminance may be appropriately combined. For example, an oxygen concentration of 10% by volume and an illuminance of 10,000 W/m ² , and an oxygen concentration of 35% by volume and an illuminance of 20,000 W/m ² , can be used.

Next, the unexposed parts of the photocurable composition layer are developed and removed to form a pattern (pixels). The unexposed parts of the photocurable composition layer can be developed and removed using a developer. As a result, the photocurable composition layer in the unexposed parts in the exposure step dissolves into the developer, and only the photocured parts remain. The temperature of the developer is preferably, for example, 20°C to 30°C. The development time is preferably 20 seconds to 180 seconds. In addition, to improve residue removal, the process of shaking off the developer every 60 seconds and then supplying new developer may be repeated several times.

The developer may be an organic solvent or an alkaline developer, with an alkaline developer being preferred. The developer and development method described in paragraph 0214 of WO 2022/085485 may also be used.

After development and drying, it is preferable to perform additional exposure processing or heating processing (post-baking). Additional exposure processing and post-baking are curing processing after development to complete curing. The heating temperature in post-baking is, for example, preferably 100°C to 240°C, more preferably 200°C to 240°C. Post-baking can be performed continuously or batchwise using a heating means such as a hot plate, a convection oven (hot air circulation dryer), or a high-frequency heater to achieve the above conditions for the developed film. When additional exposure processing is performed, it is preferable that the light used for exposure has a wavelength of 400 nm or less. In addition, additional exposure processing may be performed by the method described in Korean Patent Publication No. 10-2017-0122130.

　The pattern formation by dry etching can also be performed using the method described in paragraph 0216 of WO 2022/085485.

(Optical elements)
An optical element according to the present disclosure includes a film according to the present disclosure.
Examples of the optical element include an optical filter, a lens, a prism, a reflecting mirror, a diffraction grating, etc. Among these, an optical filter is preferable.
The types of optical filters include color filters and infrared transmission filters, and are preferably color filters. The color filter preferably has the film according to the present disclosure as its colored pixels.

The film thickness of the film disclosed herein in an optical filter can be adjusted as appropriate depending on the purpose. The film thickness is preferably 20 μm or less, more preferably 10 μm or less, and even more preferably 5 μm or less. The lower limit of the film thickness is preferably 0.1 μm or more, more preferably 0.2 μm or more, and even more preferably 0.3 μm or more.

The width of the pixels included in the optical filter is preferably 0.4 μm to 10.0 μm. The lower limit is more preferably 0.4 μm or more, even more preferably 0.5 μm or more, and particularly preferably 0.6 μm or more. The upper limit is more preferably 5.0 μm or less, even more preferably 2.0 μm or less, particularly preferably 1.0 μm or less, and most preferably 0.8 μm or less. The Young's modulus of the pixels is preferably 0.5 GPa to 20 GPa, and more preferably 2.5 GPa to 15 GPa.

Each pixel included in the optical filter preferably has high flatness. Specifically, the surface roughness Ra of the pixel is preferably 100 nm or less, more preferably 40 nm or less, and even more preferably 15 nm or less. Although there is no lower limit, it is preferable that the surface roughness Ra is, for example, 0.1 nm or more.
The surface roughness of the pixel can be measured, for example, using a Veeco AFM (atomic force microscope) Dimension 3100. The contact angle of water on the pixel can be set to an appropriate preferred value, but is typically in the range of 50° to 110°. The contact angle can be measured, for example, using a contact angle meter CV-DT-A type (Kyowa Interface Science Co., Ltd.). The pixel preferably has a high volume resistance. Specifically, the pixel preferably has a volume resistance of 10 ⁹ Ω·cm or more, more preferably 10 ¹¹ Ω·cm or more. Although no upper limit is specified, it is preferable that the pixel has a volume resistance of 10 ¹⁴ Ω·cm or less. The pixel can be measured using an ultra-high resistance meter 5410 (Advantest Corporation).

In the optical filter, a protective layer may be provided on the surface of the film according to the present disclosure. By providing a protective layer, various functions such as oxygen blocking, low reflection, hydrophilicity/hydrophobicity, and shielding of light of a specific wavelength (ultraviolet rays, near infrared rays, etc.) can be imparted. The thickness of the protective layer is preferably 0.01 μm to 10 μm, more preferably 0.1 μm to 5 μm. Methods for forming the protective layer include a method of forming the protective layer by applying a composition for forming the protective layer, a chemical vapor deposition method, and a method of attaching a molded resin with an adhesive. The components constituting the protective layer include (meth)acrylic resin, ene-thiol resin, polycarbonate resin, polyether resin, polyarylate resin, polysulfone resin, polyethersulfone resin, polyphenylene resin, polyarylene ether phosphine oxide resin, polyimide resin, polyamideimide resin, polyolefin resin, cyclic olefin resin, polyester resin, styrene resin, polyol resin, polyvinylidene chloride resin, melamine resin, urethane resin, aramid resin, polyamide resin, alkyd resin, epoxy resin, modified silicone resin, fluorine resin, polycarbonate resin, polyacrylonitrile resin, cellulose resin, Si, C, W, Al ₂ O ₃ , Mo, SiO ₂ , Si ₂ N ₄ , etc., and may contain two or more of these components. For example, in the case of a protective layer intended for oxygen blocking, the protective layer preferably contains a polyol resin, SiO ₂ , and Si ₂ N ₄ . In the case of a protective layer intended to reduce reflection, the protective layer preferably contains a (meth)acrylic resin and a fluorine resin.

The protective layer may contain additives such as organic or inorganic particles, absorbents for light of specific wavelengths (e.g., ultraviolet light, near infrared light, etc.), refractive index adjusters, antioxidants, adhesion agents, and surfactants, as necessary. Examples of organic or inorganic particles include polymer particles (e.g., silicone resin particles, polystyrene particles, melamine resin particles), titanium oxide, zinc oxide, zirconium oxide, indium oxide, aluminum oxide, titanium nitride, titanium oxynitride, magnesium fluoride, hollow silica, silica, calcium carbonate, and barium sulfate. Known absorbents can be used as absorbents for light of specific wavelengths. The content of these additives can be adjusted as appropriate, but is preferably 0.1% by mass to 70% by mass, and more preferably 1% by mass to 60% by mass, based on the total mass of the protective layer.

The protective layer may also be the one described in paragraphs 0073 to 0092 of JP2017-151176A.

The optical filter may have a structure in which each pixel is embedded in a space partitioned by partitions, for example in a grid pattern.

(Image Sensor)
An image sensor according to the present disclosure includes a membrane according to the present disclosure.
Examples of the image sensor include a solid-state imaging element, an X-ray imaging element, an organic thin-film imaging element, etc. Among them, the present disclosure can be suitably used for a solid-state imaging element. That is, the solid-state imaging element of the present disclosure includes a film that is a cured product of the photocurable compound according to the present disclosure.
The solid-state imaging device according to the present disclosure includes the film according to the present disclosure. The configuration of the solid-state imaging device is not particularly limited as long as it functions as a solid-state imaging device, and examples thereof include the following configurations.

The configuration has a plurality of photodiodes constituting a light receiving area of a solid-state imaging element (such as a CCD (charge-coupled device) image sensor or a CMOS (complementary metal-oxide semiconductor) image sensor) on a substrate, a light-shielding film on the photodiodes and the transfer electrodes with only the light receiving parts of the photodiodes open, a device protection film made of silicon nitride or the like formed on the light-shielding film so as to cover the entire light-shielding film and the light receiving parts of the photodiodes, and a color filter on the device protection film.Furthermore, the configuration may have a light-collecting means (e.g., a microlens, etc., the same below) on the device protection film and below the color filter (on the side closer to the substrate), or a configuration may have a light-collecting means on the color filter.
The color filter may have a structure in which each colored pixel is embedded in a space partitioned, for example, in a lattice shape, by partitions. In this case, the partitions preferably have a lower refractive index than each colored pixel. Examples of imaging devices having such a structure include those described in JP 2012-227478 A, JP 2014-179577 A, and WO 2018/043654 A. In addition, as shown in JP 2019-211559 A, an ultraviolet absorbing layer may be provided in the structure of the solid-state imaging element to improve light resistance. An imaging device equipped with a solid-state imaging element according to the present disclosure can be used for digital cameras, electronic devices having an imaging function (such as mobile phones), as well as vehicle-mounted cameras and surveillance cameras.

(Image display device)
The image display device according to the present disclosure includes the film according to the present disclosure. Examples of the image display device include a liquid crystal display device and an organic electroluminescence display device. The definition of the image display device and details of each image display device are described, for example, in "Electronic Display Devices (by Akio Sasaki, published by Kogyo Chosakai Co., Ltd. in 1990)" and "Display Devices (by Junsho Ibuki, published by Sangyo Tosho Co., Ltd. in 1989)". In addition, the liquid crystal display device is described, for example, in "Next Generation Liquid Crystal Display Technology (edited by Tatsuo Uchida, published by Kogyo Chosakai Co., Ltd. in 1994)". There is no particular limitation on the liquid crystal display device to which the present disclosure can be applied, and the present disclosure can be applied to various types of liquid crystal display devices described in the above "Next Generation Liquid Crystal Display Technology".

(Radical polymerization initiator represented by formula (1))
The radical polymerization initiator according to the present disclosure is a radical polymerization initiator represented by the following formula (1).
The radical polymerization initiator according to the present disclosure is preferably a photoradical polymerization initiator, and more preferably a photoradical polymerization initiator that generates radicals when exposed to light with a wavelength of 150 nm to 300 nm.

The radical polymerization initiator according to the present disclosure, which is represented by formula (1), is the same as the radical polymerization initiator represented by formula (1) described above in the photocurable composition, and the preferred embodiments are also the same.

The present disclosure will be described in more detail below with reference to examples. The materials, amounts used, ratios, processing contents, processing procedures, etc. shown in the following examples can be changed as appropriate without departing from the spirit of the present disclosure. Therefore, the scope of the present disclosure is not limited to the specific examples shown below. In the present examples, "%" and "parts" mean "% by mass" and "parts by mass", respectively, unless otherwise specified.
The radical polymerization initiators A-1 to A-112 used in the examples are the same compounds as the radical polymerization initiators (A-1) to (A-112) described above as the exemplary compounds of the radical polymerization initiator represented by formula (1), respectively.

<<Synthesis Example 1: Synthesis of radical polymerization initiator A-3>>
A radical polymerization initiator (A-3) was synthesized according to the following scheme.

<<Synthesis of Intermediate A-3-a>>
Into a three-neck flask, 25.0 g of dibenzofuran and 60 mL of chlorobenzene were added, and the mixture was cooled to 0° C. under a nitrogen atmosphere to obtain reaction liquid 1. To this reaction liquid 1, 20.6 g of aluminum chloride was added, and 23.7 g of o-toluoyl chloride was added dropwise, followed by stirring at room temperature for 2 hours to obtain reaction liquid 2. Reaction liquid 2 was cooled again to 0° C., and 20.8 g of aluminum chloride was added, followed by dropwise addition of 12.3 g of acetyl chloride.
This reaction solution 2 was stirred at room temperature for 2 hours, added to ice water, and separated and extracted with ethyl acetate. The extract was concentrated, and the concentrate was washed with methanol under heating, and the precipitated solid was collected by filtration to obtain 15.0 g of intermediate A-3-a.
The product was confirmed to be intermediate A-3-a by NMR spectrum. Intermediate A-3-a was analyzed by ¹ H-NMR. The results are shown below.
^1H -NMR (deuterated chloroform, 400MHz, internal standard: tetramethylsilane) δ = 2.37 (s, 3H), 2.70 (s, 3H), 7.29-7.39 (m, 3H), 7.45 (m, 1H), 7.62-7.65 (m, 2H), 8.06 (dd, 1H), 8.15 (dd, 1H), 8.42 (m, 1H), 8.56 (m, 1H)

<<Synthesis of radical polymerization initiator A-3>>
Into a three-neck flask were added 7.96 g of hydroxylamine hydrochloride, 9.39 g of sodium acetate, 30 mL of distilled water, and 70 mL of tetrahydrofuran to obtain reaction solution 3.
To reaction solution 3, 12.5 g of intermediate A-3-a obtained above was added at room temperature under a nitrogen atmosphere, and then the mixture was heated and stirred at 50° C. for 6 hours to obtain reaction solution 4. The obtained reaction solution 4 was separated into ethyl acetate and water, and the organic layer was dried over sodium sulfate and then concentrated. The concentrate contains intermediate A-3-b in the above scheme.
Next, this concentrate was dissolved in 30 mL of tetrahydrofuran, added to a three-neck flask, and cooled to 0° C. under a nitrogen atmosphere. 4.15 g of pyridine was added to this reaction liquid, and 3.30 g of acetyl chloride was added dropwise, followed by stirring at room temperature for 2 hours to obtain reaction liquid 5. Reaction liquid 5 was extracted with ethyl acetate and washed with water. The organic layer was dried over sodium sulfate and then concentrated. The obtained solid was reslurried and purified with methanol, and then filtered to obtain 13.0 g of radical polymerization initiator A-3 having the following structure.
It was confirmed from the NMR spectrum that the product was radical polymerization initiator A-3. Radical polymerization initiator A-3 was analyzed by ¹ H-NMR. The results are shown below.
^1H -NMR (deuterated chloroform, 400MHz, internal standard: tetramethylsilane) δ = 2.29 (s, 3H), 2.36 (s, 3H), 2.49 (s, 3H), 7.29-7.38 (m, 3H), 7.45 (m, 1H), 7.61-7.66 (m, 2H), 7.91 (dd, 1H), 8.08 (dd, 1H), 8.34 (m, 1H), 8.38 (m, 1H)

<<Synthesis Example 2: Synthesis of radical polymerization initiator A-1>>
A radical polymerization initiator A-1 was obtained in the same manner as in the synthesis of the radical polymerization initiator A-3, except that in the synthesis of the intermediate A-3-a, dibenzofuran was changed to diphenyl ether.
It was confirmed from the NMR spectrum that the product was the radical polymerization initiator A-1 having the following structure. The radical polymerization initiator A-1 was analyzed by ¹ H-NMR. The results are shown below.
^1H -NMR (deuterated chloroform, 400MHz, internal standard: tetramethylsilane) δ = 2.29 (s, 3H), 2.36 (s, 3H), 2.49 (s, 3H), 7.00-7.20 (m, 5H), 7.28 (m, 1H), 7.45 (m, 1H), 7.71 (m, 2H), 7.86 (m, 2H), 8.34 (m, 1H)

<<Synthesis Example 3: Synthesis of radical polymerization initiator A-8>>
A radical polymerization initiator A-8 was obtained in the same manner as in the synthesis of the radical polymerization initiator A-3, except that in the synthesis of the intermediate A-3-a, dibenzofuran was changed to 4,6-dibromodibenzofuran.
It was confirmed from the NMR spectrum that the product was radical polymerization initiator A-8 having the following structure. Radical polymerization initiator A-8 was analyzed by ¹ H-NMR. The results are shown below.
^1H -NMR (deuterated chloroform, 400MHz, internal standard: tetramethylsilane) δ = 2.29 (s, 3H), 2.36 (s, 3H), 2.49 (s, 3H), 7.29-7.38 (m, 3H), 7.45 (m, 1H), 7.80 (m, 1H), 7.93 (m, 1H), 8.00 (dd, 1H), 8.34 (m, 1H)

<<Synthesis Example 4: Synthesis of radical polymerization initiator A-10>>
A radical polymerization initiator A-10 was obtained in the same manner as in the synthesis of the radical polymerization initiator A-3, except that in the synthesis of the intermediate A-3-a, dibenzofuran was changed to 9,9-dimethylxanthene.
It was confirmed from the NMR spectrum that the product was radical polymerization initiator A-10 having the following structure. Radical polymerization initiator A-10 was analyzed by ¹ H-NMR. The results are shown below.
^1H -NMR (deuterated chloroform, 400MHz, internal standard: tetramethylsilane) δ = 1.69 (s, 6H), 2.29 (s, 3H), 2.36 (s, 3H), 2.49 (s, 3H), 7.29-7.38 (m, 3H), 7.45 (m, 1H), 7.61-7.66 (m, 2H), 7.86 (dd, 1H), 8.06 (dd, 1H), 8.11 (m, 1H), 8.24 (m, 1H)

<<Synthesis Example 5: Synthesis of radical polymerization initiator A-45>>
A radical polymerization initiator A-45 was obtained in the same manner as in the synthesis of the radical polymerization initiator A-3, except that in the synthesis of the intermediate A-3-a, o-toluoyl chloride was changed to 2-bromobenzoyl chloride and acetyl chloride was changed to propionyl chloride.
The product was confirmed to be radical polymerization initiator A-45 having the following structure by NMR spectrum. Radical polymerization initiator A-45 was analyzed by ¹ H-NMR. The results are shown below.
^1H -NMR (deuterated chloroform, 400MHz, internal standard: tetramethylsilane) δ = 1.10 (t, 3H), 2.28 (s, 3H), 2.93-2.97 (m, 2H), 7.39-7.51 (m, 3H), 7.62-7.72 (m, 3H), 7.85 (dd, 1H), 8.08 (dd, 1H), 8.34 (m, 1H), 8.39 (m, 1H)

<<Synthesis Example 6: Synthesis of radical polymerization initiator A-93>>
A radical polymerization initiator A-93 was obtained in the same manner as in the synthesis of the radical polymerization initiator A-3, except that in the synthesis of the intermediate A-3-a, o-toluoyl chloride was changed to 2,6-dibromobenzoyl chloride and acetyl chloride was changed to 3-(methylthio)propionyl chloride.
It was confirmed from the NMR spectrum that the product was radical polymerization initiator A-93 having the following structure. Radical polymerization initiator A-93 was analyzed by ¹ H-NMR. The results are shown below.
^1H -NMR (deuterated chloroform, 400MHz, internal standard: tetramethylsilane) δ = 2.07 (s, 3H), 2.28 (s, 3H), 2.64-2.68 (m, 2H), 2.93-2.97 (m, 2H), 7.27 (m, 1H), 7.62-7.70 (m, 4H), 7.84 (dd, 1H), 8.12 (m, 1H), 8.36-8.39 (m, 2H)

<<Synthesis Example 7: Synthesis of radical polymerization initiator A-102>>
A radical polymerization initiator A-102 was obtained in the same manner as in the synthesis of the radical polymerization initiator A-3, except that in the synthesis of the intermediate A-3-a, o-toluoyl chloride was changed to 2-methyl-4-bromobenzoyl chloride and acetyl chloride was changed to methoxyacetyl chloride.
It was confirmed from the NMR spectrum that the product was the radical polymerization initiator A-102 having the following structure. Radical polymerization initiator A-102 was analyzed by ¹ H-NMR. The results are shown below.
^1H -NMR (deuterated chloroform, 400MHz, internal standard: tetramethylsilane) δ = 2.28 (s, 3H), 2.34 (s, 3H), 4.80-4.84 (m, 2H), 3.31 (s, 3H), 7.25 (m, 1H), 7.52 (m, 1H), 7.46 (m, 1H), 7.64 (t, 2H), 7.86 (dd, 1H), 8.05 (dd, 1H), 8.34-8.36 (dd, 2H)

<<Synthesis Example 8: Synthesis of radical polymerization initiator A-105>>
A radical polymerization initiator A-105 was obtained in the same manner as in the synthesis of the radical polymerization initiator A-3, except that in the synthesis of the intermediate A-3-a, o-toluoyl chloride was changed to 2-iodobenzoyl chloride and acetyl chloride was changed to chloroacetyl chloride.
It was confirmed from the NMR spectrum that the product was radical polymerization initiator A-105 having the following structure. Radical polymerization initiator A-105 was analyzed by ¹ H-NMR. The results are shown below.
^1H -NMR (deuterated chloroform, 400MHz, internal standard: tetramethylsilane) δ = 2.29 (s, 3H), 4.79-4.83 (m, 2H), 7.25 (m, 1H), 7.38 (m, 1H), 7.52 (m, 1H), 7.62-7.67 (dd, 2H), 7.86 (m, 1H), 7.98 (m, 1H), 8.07 (m, 1H), 8.34-8.39 (m, 2H)

<<Synthesis Example 9: Synthesis of radical polymerization initiator A-111>>
A radical polymerization initiator A-111 was obtained in the same manner as in the synthesis of the radical polymerization initiator A-3, except that in the synthesis of the intermediate A-3-a, o-toluoyl chloride was changed to 2,5-dibromobenzoyl chloride and acetyl chloride was changed to bromoacetyl chloride.
It was confirmed by NMR spectrum that the product was radical polymerization initiator A-111 having the following structure. Radical polymerization initiator A-111 was analyzed by ¹ H-NMR. The results are shown below.
^1H -NMR (deuterated chloroform, 400MHz, internal standard: tetramethylsilane) δ = 2.29 (s, 3H), 4.71-4.75 (m, 2H), 7.52-7.58 (m, 3H), 7.64 (d, 1H), 7.67 (d, 1H), 7.86 (dd, 1H), 8.06 (dd, 1H), 8.37-8.39 (m, 2H)

<Preparation of Dispersion>
A mixture of the raw materials shown in Tables 1 and 2 below was mixed and dispersed for 3 hours using a bead mill (zirconia beads 0.1 mm in diameter). Next, a dispersion treatment was carried out using a high-pressure disperser equipped with a pressure reducing mechanism, NANO-3000-10 (manufactured by Japan BEE Co., Ltd.), under conditions of a pressure of 2,000 kg/ ^cm2 and a flow rate of 500 g/min. This dispersion treatment was repeated a total of 10 times to obtain a dispersion.
The amounts of dispersants in the following Tables 1 and 2 are in parts by mass. The amounts of dispersants are calculated as solids. In the tables, "-" indicates that the component is not included.

Details of the materials indicated by the abbreviations in the table showing the formulation of the above dispersion are as follows:

<Coloring Agent>
PR264: C.I. Pigment Red 264 [diketopyrrolopyrrole compound, red pigment (R pigment)]
PR254: C.I. Pigment Red 254 [diketopyrrolopyrrole compound, red pigment (R pigment)]
PR291: C.I. Pigment Red 291 [brominated diketopyrrolopyrrole compound, red pigment (R pigment)]
PO71: C.I. Pigment Orange 71 [diketopyrrolopyrrole compound, orange pigment (O pigment)]
PG36: C.I. Pigment Green 36 [copper phthalocyanine complex, green pigment (G pigment)]
PG58: C.I. Pigment Green 58 [zinc phthalocyanine complex, green pigment (G pigment)]
PY129: C.I. Pigment Yellow 129 [azomethine copper complex, yellow pigment (Y pigment)]
PY139: C.I. Pigment Yellow 139 [isoindoline compound, yellow pigment (Y pigment)]
PY185: C.I. Pigment Yellow 185 [isoindoline compound, yellow pigment (Y pigment)]
PY215: C.I. Pigment Yellow 215 [pteridine compound, yellow pigment (Y pigment)]
PB16: C.I. Pigment Blue 16 [metal-free phthalocyanine compound, blue pigment (B pigment)]
PB15:6: C.I. Pigment Blue 15:6 [copper phthalocyanine complex, blue pigment (B pigment)]
IR dye: a compound having the following structure (near infrared absorbing pigment (colorant, also absorbing in the visible light region); in the following structural formula, Me represents a methyl group, and Ph represents a phenyl group).

TiBk: Titanium black [black pigment (Bk pigment)]
Zr oxynitride: Zirconium oxynitride [black pigment (Bk pigment)]

<Pigment Derivatives>
S-1 to S-4: The following compounds

<Dispersant>
P-1: 30% by mass propylene glycol monomethyl ether acrylate (PGMEA) solution of a resin having the following structure. The number attached to the main chain is the molar ratio, and the number attached to the side chain is the number of repeating units. Mw: 20,000.

P-2: 30% by weight PGMEA solution of the resin with the following structure. The number attached to the main chain is the molar ratio, and the number attached to the side chain is the number of repeating units. Mw: 28,000. In the formula, r = 15, s = 63, t = 5, u = 17, n = 9.

P-3: 30% by weight PGMEA solution of the resin with the following structure. The number attached to the main chain is the molar ratio, and the number attached to the side chain is the number of repeating units. Mw: 21,000.

P-4: 30% by weight PGMEA solution of the resin with the following structure. The numbers added to the side chains are the number of repeating units. Mw: 9,000.

P-5: 30% by weight PGMEA solution of the resin with the following structure. The numbers added to the side chains are the number of repeating units. Mw: 10,000.

<Solvent>
S-1: Propylene glycol monomethyl ether acetate (PGMEA)
S-2: Propylene glycol monomethyl ether (PGME)
S-3: Cyclohexanone

<Preparation of Photocurable Composition>
Photocurable compositions were prepared using the following components in the amounts shown in Tables 3 to 6 below.
A dispersion, a resin, a radical polymerizable compound, a radical polymerization initiator, a chain transfer agent, and a solvent.
The above components were further mixed with 1 part by mass of an epoxy compound (EHPE-3150, manufactured by Daicel Corporation), 1 part by mass of an ultraviolet absorber (TINUVIN326, manufactured by BASF Corporation), 1 part by mass of a surfactant 1 shown below, and 0.1 part by mass of a polymerization inhibitor (p-methoxyphenol) to prepare photocurable compositions for each of the Examples and Comparative Examples.

Surfactant 1: 1% by mass solution of KF-6001 (polydimethylsiloxane modified with carbinol at both ends, manufactured by Shin-Etsu Chemical Co., Ltd.) in PGMEA.

　Details of the materials indicated by the abbreviations in Tables 3 to 6, which show the formulations of the photocurable compositions, other than those mentioned above, are as follows:

<Resin>
Ba-1: Resin having the following structure (the numbers attached to the main chain are molar ratios. Weight average molecular weight: 11,000)

Ba-2: Resin with the following structure (numbers attached to the main chain are molar ratios. Weight average molecular weight 15,000)

Ba-3: Resin with the following structure (the numbers attached to the main chain are molar ratios. The sum of x, y, and z is 50. Mw = 15,000)

<Radical Polymerizable Compound>
D-1: KAYARAD DPHA (a mixture of dipentaerythritol pentaacrylate and dipentaerythritol hexaacrylate, manufactured by Nippon Kayaku Co., Ltd.)
D-2: NK Ester A-DPH-12E (ethylene oxide (EO) modified hexafunctional acrylate compound, manufactured by Shin-Nakamura Chemical Co., Ltd.)
D-3: NK Ester A-TMMT (pentaerythritol tetraacrylate, manufactured by Shin-Nakamura Chemical Co., Ltd.)
D-4: Aronix M-510 (a tri- to tetra-functional acrylate compound, manufactured by Toagosei Co., Ltd.)
D-5: Light Acrylate DCP-A (bifunctional alicyclic acrylate compound, manufactured by Kyoeisha Chemical Co., Ltd.)

<Other radical polymerization initiators used in combination>
a-1: Compound having the following structure

a-2: Compound with the following structure:

a-3: Compound with the following structure

a-4: Compound with the following structure

a-5: Api-307, manufactured by YOUWEI, an aminoacetophenone-based polymerization initiator a-6: a compound having the following structure

<Radical Polymerization Initiator for Comparison>
CA-1: The following compound CA-2: The following compound

<Chain Transfer Agent>
F-1: Tetrafunctional thiol compound [compound with the following structure]

F-2: Bifunctional thiol compound [compound with the following structure]

F-3: Compound with the following structure (4-cyano-4-[(dodecylsulfanylthiocarbonyl)sulfanyl]pentanoic acid), manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.

<Sensitizer>
G-1: 2-isopropylthioxanthone (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.)
G-2: 4,4'-bis(diethylamino)benzophenone (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.)
G-3: 7-diethylamino-4-methylcoumarin (Tokyo Chemical Industry Co., Ltd.)
G-4: 6-chloro-2-methylthiochroman-4-one (Tokyo Chemical Industry Co., Ltd.)

<Performance evaluation>
<<Exposure sensitivity>>
Each of the obtained photocurable compositions was applied by spin coating onto an 8-inch (203.2 mm) silicon wafer with an undercoat layer in an amount such that the film thickness after curing would be 0.4 μm, and then heated at 100° C. for 2 minutes using a hot plate to form a photocurable composition layer.
Next, the obtained photocurable composition layer was exposed to light (KrF rays) having a wavelength of 248 nm through a mask having a 0.5 μm square pattern using a KrF scanner exposure machine at an illuminance of 35,000 W/m ² and an exposure dose of 20 mJ/cm ² to 200 mJ/cm ² .
The exposure dose required to reach a pattern line width of 0.7 μm was calculated, and the exposure sensitivity was evaluated according to the following criteria: A smaller value of the exposure dose indicates a higher sensitivity.

- Exposure sensitivity evaluation criteria -
A: The exposure amount is 60 mJ/ ^cm2 or less.
B: The exposure amount is more than 60 mJ/ ^cm2 and is 100 mJ/ ^cm2 or less.
C: The exposure amount is more than 100 mJ/ ^cm2 and is 150 mJ/ ^cm2 or less.
D: The exposure amount is more than 150 mJ/ ^cm2 and is 200 mJ/ ^cm2 or less.
E: The exposure amount exceeds 200 mJ/ ^cm2 .

<<Film adhesion>>
The photocurable composition layer after the pattern exposure was subjected to shower development using a 0.3 mass% aqueous solution of tetramethylammonium hydroxide (TMAH) as a developer at 23° C. for 60 seconds, followed by rinsing with pure water by spin shower to form pixels.
The obtained pixels were observed at a magnification of 20,000 times using a scanning electron microscope (S-4800H, manufactured by Hitachi High-Technologies Corporation). Based on the observed images, adhesion was evaluated according to the following criteria.
The resulting pixels were observed under an optical microscope in 1,071 × 1,071 areas exposed to an exposure dose of 100 mJ/ ^cm2 , and the number of peeled pixels was counted. The adhesion was evaluated based on the number of peeled pixels according to the following criteria.

- Adhesion evaluation criteria -
A: The number of peeled pixels is 10 or less.
B: The number of peeled pixels is more than 10 and 20 or less.
C: The number of peeled pixels is more than 20 and 50 or less.
D: The number of peeled pixels is more than 50 and 200 or less.
E: The number of peeled pixels exceeds 200.

<<Development Residue>>
The obtained pixels were observed at a magnification of 20,000 times in the non-patterned region (unexposed region) using a scanning electron microscope (S-4800H, Hitachi High-Technologies Corporation). The residues in the non-patterned region (unexposed region) after development were observed, and the development residues were evaluated according to the following evaluation criteria.

- Evaluation criteria for development residue -
A: No residue was observed outside the pattern forming area (unexposed area).
B: A small amount of residue was observed outside the pattern forming region (unexposed area), but it was not of any practical concern.
C: Significant residue was observed outside the pattern forming region (unexposed area).

The evaluation results are shown in Tables 7 and 8 above.

As shown in Tables 7 and 8 above, the photocurable compositions of the Examples were superior in sensitivity to the photocurable compositions of the Comparative Examples. That is, even if the radical polymerization initiators had the same mother nucleus structure, the photocurable compositions using the comparative radical polymerization initiators in which at least one of R ₆ and Y ₁ in formula (1) was outside the range specified in the present disclosure were inferior in sensitivity.
Furthermore, as shown in Tables 7 and 8 above, the photocurable compositions of the Examples have good adhesion between the formed film and the substrate, and also leave little development residue in the unexposed areas.

The photocurable compositions of each example also produced similar results when exposed to i-line (365 nm) using an i-line stepper exposure system FPA-3000iS+ (Canon Inc.) instead of KrF line.

In addition, the amount of coating in each of Examples 1 to 112 was changed to an amount that resulted in a film thickness after curing of 0.2 μm or 2.0 μm, and evaluation was performed in the same manner except that a cured film thickness of 0.2 μm or 2.0 μm was formed. The same evaluation results as those above were obtained for each example.

(Example 301: Fabrication of solid-state imaging device)
On a silicon wafer, the photocurable composition of Example 1 was applied by spin coating in an amount such that the film thickness after film formation was 0.4 μm. Then, a hot plate was used to heat at 100° C. for 2 minutes to obtain a coating film. Next, the obtained coating film was exposed to light through a mask of a 1.0 μm square dot pattern at 1,000 mJ/cm ² using an i-line stepper exposure device FPA-3000i5+ (Canon Inc.). Next, paddle development was performed for 60 seconds at 23° C. using a 0.3 mass% aqueous solution of tetramethylammonium hydroxide (TMAH). Thereafter, rinsing was performed with a spin shower, and further washing was performed with pure water. Next, a red pattern was formed on the silicon wafer by curing the photocurable composition of Example 1 by heating at 200° C. for 5 minutes using a hot plate. Similarly, the photocurable composition of Example 6 (green) and the photocurable composition of Example 11 (blue) were sequentially patterned to form red, green, and blue colored patterns (Bayer patterns).
The Bayer pattern is a repeated 2×2 array of color filter elements having one red element, two green elements, and one blue element, as disclosed in U.S. Pat. No. 3,971,065.
The obtained color filter was incorporated into a solid-state imaging device according to a known method. It was confirmed that the solid-state imaging device had excellent adhesion in the cured film and favorable image recognition ability, regardless of which photocurable composition prepared in the Examples was used.

The disclosure of Japanese Patent Application No. 2023-028863, filed on February 27, 2023, is incorporated by reference into this disclosure.
All publications, patent applications, and standards mentioned in this disclosure are incorporated by reference into this disclosure to the same extent as if each individual publication, patent application, or standard was specifically and individually indicated to be incorporated by reference.

Claims

A radical polymerization initiator represented by formula (1),
A photocurable composition comprising: a radical polymerizable compound.

In formula (1),
Ar 1 represents a (k+m+1)-valent aromatic group or a (k+m+1)-valent heteroaromatic group, and Ar 2 represents a (k+2)-valent aromatic group or a (k+2)-valent heteroaromatic group.
R 1 represents an alkyl group, an aryl group, a heteroaryl group, an alkoxy group, an aryloxy group, or a heteroaryloxy group.
L represents a single bond or CR 11 R 12 , R 11 and R 12 each independently represent a hydrogen atom, an alkyl group or an aryl group, and k represents 0 or 1. When k is 0, L does not exist, and Ar 1 and Ar 2 are linked only via an oxygen atom.
R 6 each independently represents a halogen atom, a cyano group, an alkoxy group, a hydroxy group, a phenoxy group, -C(=O)R 2 , -C(=O)NHR 3 , -NHC(=O)R 4 , -NR 11 R 12 or an alkyl group which may be substituted with -SR 11 ; R 2 , R 3 and R 4 each independently represent an alkyl group or an aryl group; R 11 and R 12 each independently represent a hydrogen atom, an alkyl group or an aryl group; and m represents an integer of 1 to 4.
Y1 represents a straight chain alkyl group.
The photocurable composition according to claim 1 , wherein R 6 is a group represented by the following formula (2):

In formula (2), Ar 3 represents an alkyl group or an aryl group, and * represents a linking portion with Ar 1 in formula (1).
The photocurable composition according to claim 1 , wherein the radical polymerization initiator is a compound represented by the following formula (3):

In formula (3),
Ar3 represents an alkyl group or an aryl group;
R7 represents an alkyl group or an aryl group;
Z represents a linear alkyl group having 1 to 20 carbon atoms;
L represents a single bond or CR 11 R 12 , R 11 and R 12 each independently represent a hydrogen atom, an alkyl group or an aryl group, and k represents 0 or 1.
The photocurable composition of claim 1 further comprising a resin.
The photocurable composition according to claim 4, wherein the resin has a graft chain, the graft chain includes at least one selected from the group consisting of a polyether chain, a polyester chain, and a polyacrylic chain, and the weight average molecular weight of the graft chain is 1,000 or more.
The photocurable composition according to claim 4, wherein the resin includes a resin having an acryloyl group, a methacryloyl group, an epoxy group, or an oxetanyl group.
The photocurable composition according to claim 1, further comprising a colorant.
The photocurable composition according to claim 7, wherein the content of the colorant is 60% by mass or more based on the total solid content of the photocurable composition.
The photocurable composition according to claim 1, further comprising a pigment derivative.
The photocurable composition according to claim 1, further comprising a chain transfer agent.
The photocurable composition according to claim 1, further comprising a sensitizer.
The photocurable composition according to claim 1, which is intended for exposure to an excimer laser having a wavelength of 150 nm to 300 nm.
A method for producing a cured product, comprising the step of irradiating the photocurable composition according to any one of claims 1 to 12 with excimer laser light having a wavelength of 150 nm to 300 nm.
A film that is a cured product of the photocurable composition according to any one of claims 1 to 12.
An optical element comprising the film according to claim 14.
An image sensor including the film according to claim 14.
A solid-state imaging device including the film according to claim 14.
An image display device including the film according to claim 14.
A radical polymerization initiator represented by formula (1):

In formula (1),
Ar 1 represents a (k+m+1)-valent aromatic group or a (k+m+1)-valent heteroaromatic group, and Ar 2 represents a (k+2)-valent aromatic group or a (k+2)-valent heteroaromatic group.
R 1 represents an alkyl group, an aryl group, a heteroaryl group, an alkoxy group, an aryloxy group, or a heteroaryloxy group.
L represents a single bond or CR 11 R 12 , R 11 and R 12 each independently represent a hydrogen atom, an alkyl group or an aryl group, and k represents 0 or 1. When k is 0, L does not exist, and Ar 1 and Ar 2 are linked only via an oxygen atom.
R 6 each independently represents a halogen atom, a cyano group, an alkoxy group, a hydroxy group, a phenoxy group, -C(=O)R 2 , -C(=O)NHR 3 , -NHC(=O)R 4 , -NR 11 R 12 or an alkyl group which may be substituted with -SR 11 ; R 2 , R 3 and R 4 each independently represent an alkyl group or an aryl group; R 11 and R 12 each independently represent a hydrogen atom, an alkyl group or an aryl group; and m represents an integer of 1 to 4.
Y1 represents a straight chain alkyl group.