JP7769489B2 - Resin membrane manufacturing method, resin membrane filter - Google Patents

Description

The present invention relates to a resin film manufacturing method and a resin film filter.

In the field of bioscience, porous membrane materials are known for their use in blood filtration, cell separation, and as culture substrates. In recent years, porous membrane materials made of resin have been considered as materials that facilitate the selective permeation or capture of target substances compared to conventional porous membrane materials made of nonwoven fabric.

For example, Patent Document 1 discloses a waterproof, breathable filter that includes a resin film having a bottomed recess with an opening on one main surface and first through holes that connect the surface of the recess to the other main surface, with two or more first through holes connecting to one recess.

Japanese Patent Application Laid-Open No. 2019-166509

Patent Document 1 describes a method of forming recesses and through-holes in a resin film included in a filter, which method involves irradiating an original film with an ion beam and a method involves irradiating an original film with a laser.
The inventors of the present invention have studied resin membranes having multiple through holes by referring to the description in Patent Document 1 and have found that resin membranes in which through holes have been formed by the above-mentioned ion beam irradiation or laser irradiation may have poor separation accuracy.

In view of the above, an object of the present invention is to provide a method for producing a resin film that can provide a resin film with excellent separation accuracy.
Another object of the present invention is to provide a resin film filter.

After extensive research into the above-mentioned problems, the inventors discovered that the following configuration can solve the above-mentioned problems.

[1]
A method for manufacturing a resin film having a first main surface and a second main surface and a plurality of through holes penetrating from the first main surface to the second main surface,
A step P1 of preparing a laminate having a temporary support and a photosensitive composition layer;
a step P2 of pattern-exposing the photosensitive composition layer;
Step P3-a or Step P3-b in this order,
the step P3-a includes, in this order, a step P3-a1 of developing the exposed photosensitive composition layer to form the resin film, and a step P3-a2 of peeling off the temporary support and the resin film;
The method for producing a resin film, wherein the step P3-b includes, in this order, a step P3-b1 of peeling the temporary support and the exposed photosensitive composition layer, and a step P3-b2 of developing the photosensitive composition layer from which the temporary support has been peeled off, to form the resin film.
[2]
the step P3-a2 is a step of physically peeling the temporary support and the resin film,
The method for producing a resin film according to [1], wherein the step P3-b1 is a step of physically peeling the temporary support and the exposed photosensitive composition layer.
[3]
The method for producing a resin film according to [1] or [2], wherein the temporary support and the photosensitive composition layer in the laminate are in direct contact with each other.
[4]
The method for producing a resin film according to any one of [1] to [3], wherein the step P2 is a step of pattern exposure through a photomask.
[5]
The method for producing a resin film according to any one of [1] to [4], wherein the step P2 is a step of pattern exposure through a photomask and a light scattering plate.
[6]
The method for producing a resin film according to [4] or [5], wherein the step P2 is a step of contacting the photosensitive composition layer with the photomask and performing pattern exposure.
[7]
the photomask has a plurality of circular light-shielding portions,
The method for producing a resin film according to any one of [4] to [6], wherein the total area of the light-shielding portions is 20% or less of the total area of the photomask.
[8]
the photomask has a plurality of circular light-shielding portions,
[8] The method for producing a resin film according to any one of [4] to [7], wherein the total area of the light-shielding portions is 10% or less of the total area of the photomask.
[9]
the step P3-a1 is a step of developing the exposed photosensitive composition layer with an alkaline aqueous solution to form the resin film,
[1] to [8], wherein the step P3-b2 is a step of developing the photosensitive composition layer from which the temporary support has been peeled off with an alkaline aqueous solution to form the resin film. The method for producing a resin film according to any one of [1] to [8].
[10]
[10] The method for producing a resin film according to any one of [1] to [9], wherein the photosensitive composition layer has a thickness of 10 μm or more.
[11]
A resin film filter made of a resin film manufactured by the resin film manufacturing method according to any one of [1] to [10].
[12]
The resin membrane filter according to [11], which is used for cell separation.

According to the present invention, it is possible to provide a method for producing a resin film that can obtain a resin film with excellent separation accuracy.
Furthermore, according to the present invention, a resin film filter can be provided.

1 is a schematic diagram showing an example of the configuration of a resin film of the present invention.

The present invention will be described in detail below.
In this specification, a numerical range expressed using "to" means a range that includes the numerical values before and after "to" as the lower and upper limits.
In the present specification, in the numerical ranges described in stages, the upper or lower limit value described in a certain numerical range may be replaced with the upper or lower limit value of another numerical range described in stages. Furthermore, in the numerical ranges described in the present specification, the upper or lower limit value described in a certain numerical range may be replaced with a value shown in the examples.

In this specification, the term "process" refers not only to an independent process, but also to a process that cannot be clearly distinguished from other processes, as long as the intended purpose of that process is achieved.

In this specification, the term "transparent" means that the average transmittance of visible light with a wavelength of 400 to 700 nm is 80% or more, and preferably 90% or more.
In this specification, the transmittance is a value measured using a spectrophotometer, and can be measured using, for example, a spectrophotometer U-3310 manufactured by Hitachi, Ltd.

In this specification, unless otherwise specified, the weight-average molecular weight (Mw) and number-average molecular weight (Mn) are values measured by a gel permeation chromatography (GPC) analyzer using a TSKgel GMHxL, TSKgel G4000HxL, or TSKgel G2000HxL (all trade names manufactured by Tosoh Corporation) as a column, THF (tetrahydrofuran) as an eluent, a differential refractometer as a detector, and polystyrene as a standard substance, and converted using polystyrene as the standard substance.
In this specification, unless otherwise specified, the ratio of constituent units of a polymer (for example, a binder polymer) is a mass ratio.
In this specification, unless otherwise specified, the molecular weight of a compound having a molecular weight distribution is the weight average molecular weight (Mw).
In this specification, unless otherwise specified, the content of metal elements is a value measured using an inductively coupled plasma (ICP) spectroscopic analyzer.

In this specification, "(meth)acrylic" is a concept that encompasses both acrylic and methacrylic, and "(meth)acryloxy group" is a concept that encompasses both acryloxy group and methacryloxy group.

In this specification, "alkali-soluble" means that the solubility in 100 g of a 1% by mass aqueous solution of sodium carbonate at 22°C is 0.1 g or more.

In this specification, unless otherwise specified, "water-soluble" means that the solubility in 100 g of water at a pH of 7.0 and a liquid temperature of 22°C is 0.1 g or more. For example, a water-soluble resin refers to a resin that meets the solubility conditions described above.

In this specification, the "solids" of a photosensitive composition refers to the components that form the photosensitive composition layer formed using the photosensitive composition. In cases where the photosensitive composition contains a solvent (e.g., organic solvent, water, etc.), this refers to all components excluding the solvent. Furthermore, liquid components that form the photosensitive composition layer are also considered to be solids.

[Method of manufacturing resin film]
The method for producing a resin film of the present invention comprises:
A method for manufacturing a resin film (hereinafter also simply referred to as a "resin film") having a first main surface and a second main surface and a plurality of through holes penetrating from the first main surface to the second main surface, comprising:
A step P1 of preparing a laminate having a temporary support and a photosensitive composition layer;
a step P2 of patternwise exposing the photosensitive composition layer;
Step P3-a or Step P3-b in this order,
the step P3-a includes, in this order, a step P3-a1 of developing the exposed photosensitive composition layer to form the resin film, and a step P3-a2 of peeling the temporary support from the resin film;
The process P3-b includes, in this order, a process P3-b1 of peeling the temporary support and the exposed photosensitive composition layer, and a process P3-b2 of developing the photosensitive composition layer from which the temporary support has been peeled off to form the resin film.

The mechanism by which the resin film manufacturing method of the present invention solves the problems of the present invention is not necessarily clear, but the present inventors speculate as follows.
The present inventors have found that resin films obtained by forming through-holes using conventional ion beam or laser irradiation may not achieve the required separation accuracy. Specifically, when forming through-holes using ion beam irradiation, there is variation in the ion beam irradiation direction and/or irradiation position, which is predicted to result in a certain probability of large-diameter through-holes being formed due to overlapping of ion beams, resulting in a decrease in separation accuracy. Furthermore, when forming through-holes using laser irradiation, the temperature near the laser-irradiated area increases, causing the resin constituting the resin film to melt. As a result, the diameter of the through-holes increases, which is predicted to result in a decrease in separation accuracy.
In contrast, after extensive research, the inventors have concluded that the resin film manufacturing method of the present invention can suppress the expansion of the hole diameter of the above-mentioned through holes and form through holes with the desired hole diameter, thereby resulting in superior separation accuracy.
Hereinafter, superior separation accuracy will also be referred to as "superior effects of the present invention."

The resin film produced by the present invention will now be described.
FIG. 1 is a schematic view (perspective view) showing an example of the structure of a resin film according to the present invention.
A plurality of through holes 20 are formed in the resin film 10, penetrating from the first main surface 11 to the second main surface 12. Fig. 1 also shows a cut surface 13 obtained by cutting the resin film 10 along a plane including the in-plane direction in which the plurality of through holes 20 are arranged and the thickness direction of the resin film 10.
Each step in the method for producing a resin film will be described below.

[Process P1]
Step P1 is a step of preparing a laminate having a temporary support and a photosensitive composition layer.
The term "preparation" of a laminate includes the act of producing a laminate, and also refers to a concept that includes the act of procuring a laminate by purchase or the like.

Examples of process P1 include a method of producing the laminate by forming a photosensitive composition layer on a temporary support, and a method of producing the laminate by laminating a temporary support and a photosensitive composition layer together.
The laminate may be a laminate consisting of a temporary support and a photosensitive composition layer, or may be a laminate having layers other than the temporary support and the photosensitive composition layer.
In addition, the temporary support and the photosensitive composition layer in the laminate are preferably in direct contact with each other, in other words, it is preferable that no other layer is present between the temporary support and the photosensitive composition layer in the laminate.

<Method for forming a photosensitive composition layer>
A method for forming a photosensitive composition layer on a temporary support (hereinafter, also simply referred to as a "method for forming a photosensitive composition layer") will be described.
The photosensitive composition layer is preferably formed by a coating method using a photosensitive composition containing components constituting the resin film described below (e.g., a binder polymer, a polymerizable compound, a polymerization initiator, etc.) and a solvent. Specifically, the photosensitive composition is applied to a temporary support to form a coating film, and the coating film is dried at a predetermined temperature to form a photosensitive composition layer on the temporary support.

(Temporary support)
The temporary support used in the method for forming the photosensitive composition layer is not particularly limited, and any member having the function of supporting the formed photosensitive composition layer can be used.
The temporary support may have a single-layer structure or a multi-layer structure.
The temporary support is preferably a film, more preferably a resin film, which is flexible and does not significantly deform, shrink, or stretch under pressure or under pressure and heat.
Examples of the film include polyethylene terephthalate film (such as biaxially stretched polyethylene terephthalate film), polymethyl methacrylate film, cellulose triacetate film, polystyrene film, polyimide film, and polycarbonate film, with polyethylene terephthalate film being preferred.
The film may be subjected to a stretching treatment, and is preferably subjected to a biaxial stretching treatment.
Furthermore, it is preferable that the film used as the temporary support is free from deformations such as wrinkles and scratches.

When pattern exposure is performed through a temporary support, the temporary support preferably has high transparency. Specifically, the transmittance of the temporary support at a wavelength of 365 nm is preferably 60% or more, more preferably 70% or more. There is no particular upper limit, but it is often less than 100%.
In view of the pattern formability during pattern exposure through the temporary support and the transparency of the temporary support, the haze value of the temporary support is preferably small. Specifically, the haze value of the temporary support is preferably 2% or less, more preferably 0.5% or less, and even more preferably 0.1% or less. The lower limit is not particularly limited, but is often more than 0%.
From the viewpoints of pattern formability during pattern exposure through the temporary support and transparency of the temporary support, it is preferable that the total number of fine particles, foreign matter, and defects contained in the temporary support is small. Specifically, the total number of fine particles, foreign matter, and defects having a diameter of 1 μm or more in the temporary support is preferably 50/10 ^mm2 or less, more preferably 10/10 ^mm2 or less, even more preferably 3/10 ^mm2 or less, and particularly preferably 0/10 ^mm2 .

The thickness of the temporary support is not particularly limited, but is preferably 5 to 200 μm, and from the viewpoint of ease of handling and versatility, is more preferably 5 to 150 μm, and even more preferably 5 to 100 μm.
The thickness of the temporary support is calculated as the average value of measurements at any five points measured by cross-section observation using a scanning electron microscope.

In order to improve adhesion between the temporary support and the photosensitive composition layer, the surface of the temporary support that comes into contact with the photosensitive composition layer may be surface-modified by UV irradiation, corona discharge, and/or plasma, etc.

When the surface of the temporary support is modified by UV irradiation, the UV irradiation dose is preferably 10 to 2000 mJ/cm ² , more preferably 50 to 1000 mJ/cm ² .

Light sources for UV irradiation include low-pressure mercury lamps, high-pressure mercury lamps, ultra-high-pressure mercury lamps, carbon arc lamps, metal halide lamps, xenon lamps, chemical lamps, electrodeless discharge lamps, and light-emitting diodes (LEDs), which emit light in the wavelength range of 150 to 450 nm.

Examples of temporary supports include a 50 μm-thick biaxially oriented polyethylene terephthalate film, a 75 μm-thick biaxially oriented polyethylene terephthalate film, and a 100 μm-thick biaxially oriented polyethylene terephthalate film.

Preferred forms of the temporary support include, for example, those described in paragraphs [0017] to [0018] of JP 2014-085643 A, paragraphs [0019] to [0026] of JP 2016-027363 A, paragraphs [0041] to [0057] of WO 2012/081680 A, and paragraphs [0029] to [0040] of WO 2018/179370 A, the contents of which are incorporated herein by reference.

In order to provide ease of handling, the temporary support may have a layer containing fine particles (lubricant layer) on the surface of the temporary support. The lubricant layer may be provided on either one side or both sides of the temporary support. The diameter of the particles contained in the lubricant layer is preferably 0.05 to 0.8 μm. The film thickness of the lubricant layer is preferably 0.05 to 1.0 μm.
Commercially available temporary supports include, for example, Lumirror #50-T60, Lumirror 16KS40, and Lumirror 16FB40 (all manufactured by Toray Industries, Inc.), and Cosmoshine A4100, Cosmoshine A4300, and Cosmoshine A8300 (all manufactured by Toyobo Co., Ltd.).

(Photosensitive composition)
The photosensitive composition used to form the photosensitive composition layer preferably contains components capable of forming the desired resin film and a solvent.
The components contained in the photosensitive composition layer and the components that can constitute the resin film will be described in detail later.
The solvent is preferably an organic solvent, such as methyl ethyl ketone, propylene glycol monomethyl ether, propylene glycol monomethyl ether acetate (also known as 1-methoxy-2-propyl acetate), diethylene glycol ethyl methyl ether, cyclohexanone, methyl isobutyl ketone, ethyl lactate, methyl lactate, caprolactam, n-propanol, and 2-propanol.
Furthermore, an organic solvent having a boiling point of 180 to 250° C. (high boiling point solvent) may be used as the solvent.

The solvents may be used alone or in combination of two or more.
The total solid content of the photosensitive composition is preferably from 5 to 80% by mass, more preferably from 5 to 40% by mass, and even more preferably from 5 to 30% by mass, based on the total mass of the photosensitive composition.
The content of the solvent in the photosensitive composition is preferably from 20 to 95% by mass, more preferably from 60 to 95% by mass, and even more preferably from 70 to 95% by mass, based on the total mass of the photosensitive composition.

Examples of methods for applying the photosensitive composition include printing, spraying, roll coating, bar coating, curtain coating, spin coating, and die coating (slit coating).

As a method for drying the coating film of the photosensitive composition, heat drying and vacuum drying are preferred. In this specification, "drying" means removing at least a part of the solvent contained in the photosensitive composition. Examples of the drying method include natural drying, heat drying, and vacuum drying. The above-mentioned drying methods can be applied alone or in combination.
The drying temperature is preferably 80° C. or higher, more preferably 90° C. or higher. There is no particular upper limit, but the drying temperature is preferably 130° C. or lower, more preferably 120° C. or lower. Drying may be performed by continuously changing the drying temperature.
The drying time is preferably 20 seconds or more, more preferably 40 seconds or more, and even more preferably 60 seconds or more. There is no upper limit, but the drying time is preferably 600 seconds or less, and more preferably 300 seconds or less.

Step P1 may be a step of preparing a laminate having a temporary support, a water-soluble resin layer, and a photosensitive composition layer in this order.
An example of the above process is a method of preparing a laminate having a temporary support, a water-soluble resin layer, and a photosensitive composition layer in this order, by applying the photosensitive composition to the surface of the water-soluble resin layer opposite the temporary support to form a coating film, and then performing a drying treatment to form a photosensitive composition layer.
In this specification, the term "water-soluble resin layer" refers to a layer containing a water-soluble resin. In other words, a part or all of the resin constituting the water-soluble resin layer is a water-soluble resin.

Examples of water-soluble resins include polyvinyl alcohol resins, polyvinylpyrrolidone resins, cellulose resins, acrylamide resins, polyethylene oxide resins, gelatin, vinyl ether resins, polyamide resins, and copolymers thereof.
Further, examples of the water-soluble resin include copolymers of (meth)acrylic acid and vinyl compounds. As the copolymer of (meth)acrylic acid and vinyl compounds, a copolymer of (meth)acrylic acid and allyl (meth)acrylate is preferred, and a copolymer of methacrylic acid and allyl methacrylate is more preferred. The composition ratio (mol %) of the copolymer of (meth)acrylic acid and vinyl compounds is preferably 90/10 to 20/80, and more preferably 80/20 to 30/70.

The weight average molecular weight of the water-soluble resin is preferably 5,000 or more, more preferably 7,000 or more, and even more preferably 10,000 or more. There is no upper limit, but it is preferably 200,000 or less, more preferably 100,000 or less, and even more preferably 50,000 or less.
The dispersity (Mw/Mn) of the water-soluble resin is preferably 1 to 10, and more preferably 1 to 5.

The water-soluble resin layer preferably contains polyvinyl alcohol as the water-soluble resin, and more preferably contains both polyvinyl alcohol and polyvinylpyrrolidone.

The water-soluble resins may be used alone or in combination of two or more.
The content of the water-soluble resin is not particularly limited, but is preferably 50% by mass or more, more preferably 70% by mass or more, even more preferably 80% by mass or more, and particularly preferably 90% by mass or more, based on the total mass of the water-soluble resin layer. The upper limit is not particularly limited, but is preferably 99.9% by mass or less, more preferably 99.8% by mass or less.
The water-soluble resin layer may contain known additives such as surfactants, if necessary.

The thickness of the water-soluble resin layer is not particularly limited, but from the standpoint of the time required to remove the water-soluble resin layer (intermediate layer) and the smoothness of the filter, a thickness of 0.1 to 5 μm is preferred, and 0.5 to 3 μm is more preferred.

In order to facilitate the removal (dissolution) of the water-soluble resin layer described below, the dissolution rate of the water-soluble resin layer in water (warm water) at a liquid temperature of 80° C. is preferably 0.5 μm/sec or more, more preferably 1 μm/sec or more, and even more preferably 2 μm/sec or more. There is no particular upper limit, but it is preferably 10 μm/sec or less, more preferably 8 μm/sec or less, and even more preferably 5 μm/sec or less.
The dissolution rate per unit time of the water-soluble resin layer in warm water is measured in accordance with the method for measuring the dissolution rate of the photosensitive composition layer in a 1.0% by mass aqueous sodium carbonate solution, which will be described later.

The method for preparing a temporary support having a water-soluble resin layer (a laminate having a temporary support and a water-soluble resin layer) is not particularly limited, but a method of forming the temporary support by a coating method using a composition (a composition for forming a water-soluble resin layer) containing components such as a water-soluble resin constituting the water-soluble resin layer and a solvent is preferred. Specifically, a method of preparing a temporary support having a water-soluble resin layer includes applying the composition to a temporary support to form a coating film, and then subjecting the coating film to a drying treatment at a predetermined temperature to form a water-soluble resin layer.
Examples of the solvent contained in the composition include the solvent contained in the photosensitive composition. The method for applying the composition and the method for drying the coating film can be performed in accordance with the method for forming the photosensitive composition layer.

Step P1 may be a step of preparing a laminate having a water-soluble temporary support and a photosensitive composition layer in this order. That is, the temporary support used in the method for forming the photosensitive composition layer may be a water-soluble temporary support.
In this specification, the term "water-soluble temporary support" refers to a temporary support containing a water-soluble resin. That is, a part or all of the resin constituting the water-soluble temporary support is a water-soluble resin.
In the above step, it is preferable to prepare a laminate having a water-soluble temporary support and a photosensitive composition layer in this order according to the above-mentioned method for forming a photosensitive composition layer, except that a water-soluble temporary support is used as the temporary support. That is, it is preferable to prepare the laminate by applying the photosensitive composition to a water-soluble temporary support to form a coating film, and then subjecting this coating film to a drying treatment at a predetermined temperature to form a photosensitive composition layer.

Examples of the water-soluble resin contained in the water-soluble temporary support include the resins described above as the water-soluble resin contained in the water-soluble resin layer, including preferred embodiments (for example, the type and content of the water-soluble resin).
The water-soluble temporary support preferably contains polyvinyl alcohol as a water-soluble resin.

In order to facilitate dissolution and removal of the water-soluble temporary support described below, the dissolution rate of the water-soluble temporary support in water (warm water) at a liquid temperature of 80° C. is preferably 0.5 μm/sec or more, more preferably 1 μm/sec or more, and even more preferably 2 μm/sec or more. There is no particular upper limit, but it is preferably 10 μm/sec or less, more preferably 8 μm/sec or less, and even more preferably 5 μm/sec or less.
The dissolution rate per unit time of the water-soluble temporary support in warm water is measured in accordance with the method for measuring the dissolution rate of the photosensitive composition layer in a 1.0% by mass aqueous sodium carbonate solution, which will be described later.

The water-soluble temporary support may be prepared by a known method, or a commercially available product may be purchased. Examples of commercially available water-soluble temporary supports include Solbron (registered trademark) EF (PVA film, manufactured by Aicello Corporation), Hi-Selon (registered trademark) (PVA film, manufactured by Mitsubishi Chemical Corporation), and Kurarea (registered trademark) (PVA film, manufactured by Kuraray Co., Ltd.).

Furthermore, process P1 is not limited to the above-mentioned method for forming a photosensitive composition layer, but may also be a lamination process in which a temporary support and a photosensitive composition layer are laminated together to produce a laminate having the temporary support and the photosensitive composition layer.
The lamination step is carried out, for example, by pressing the temporary support and the surface of the photosensitive composition layer together so that they come into contact with each other. The method of pressing the temporary support is not particularly limited, and includes known transfer methods and lamination methods. Among these, it is preferable to place the surface of the photosensitive composition layer on the temporary support and apply pressure and heat using a roll or the like.
For lamination, known laminators such as a vacuum laminator, an auto-cut laminator, etc. The lamination temperature is not particularly limited, but is often 70 to 130°C.

<Cover film>
The laminate having the temporary support and the photosensitive composition layer prepared in step P1 may further have a cover film. When the laminate further has a cover film, the laminate preferably has the temporary support, the photosensitive composition layer, and the cover film in this order. By disposing the photosensitive composition layer between the temporary support and the cover film, the photosensitive composition layer before exposure can be protected from both sides.

Examples of the cover film include polyolefin films such as polypropylene film and polyethylene film, polyester films such as polyethylene terephthalate film, polycarbonate film, and polystyrene film.
Furthermore, a resin film made of the same material as the temporary support may be used as the cover film.
Among these, the cover film is preferably a polyolefin film, more preferably a polypropylene film or a polyethylene film, and even more preferably a polypropylene film.

The thickness of the cover film is preferably 1 to 100 μm, more preferably 5 to 50 μm, even more preferably 5 to 40 μm, and particularly preferably 15 to 30 μm, from the viewpoints of excellent mechanical strength and relative inexpensiveness.

The method for further laminating a cover film onto a laminate having a temporary support and a photosensitive composition layer is not particularly limited, and examples include a method in which the cover film is attached to the surface of the photosensitive composition layer of the laminate opposite the temporary support.
The lamination method is not particularly limited, and examples thereof include a method in which the cover film and the laminate are laminated together using a known laminator such as a vacuum laminator or an auto-cut laminator.

[Process P2]
Step P2 is a step of pattern-exposing the photosensitive composition layer of the laminate prepared in step P1.
In this specification, the term "pattern exposure" refers to a form of patterned exposure, that is, exposure in a form in which exposed areas and unexposed areas exist.
The positions, shapes and areas of the exposed and unexposed regions in the pattern exposure are adjusted appropriately according to the positions, shapes and areas of the through holes to be formed in the intended resin film.
When the laminate has a cover film, step P2 may be performed after peeling off the cover film, or step P2 may be performed without peeling off the cover film, and it is preferable to peel off the cover film before performing step P2.

When pattern exposure is performed on the laminate having the temporary support and photosensitive composition layer prepared in step P1 above, the exposure light may be irradiated from the surface of the photosensitive composition layer of the laminate opposite the temporary support, or the exposure light may be irradiated from the surface of the temporary support of the laminate opposite the photosensitive composition layer.

Examples of the exposure method used in process P2 include a method of exposure using a photomask and a projection exposure method that does not use a photomask.
Examples of the exposure method using a photomask include a contact exposure method in which the photomask is brought into contact with the photosensitive composition layer and exposure, and a proximity exposure method in which the photomask is not brought into contact with the photosensitive composition layer and exposure.
The step P2 is preferably a step of performing pattern exposure through a photomask, and more preferably a step of performing pattern exposure by contacting the photosensitive composition layer with the photomask. The position of the photomask in the pattern exposure is not particularly limited as long as it is between the light source of the exposure light and the laminate.
The photosensitive composition layer and the photomask may be brought into contact with each other by pressure bonding.
Examples of the pressure bonding method include a method of evacuating the space between the photosensitive composition layer and the photomask, a method of placing auxiliary plates on both sides of the laminate and evacuating the space between the auxiliary plates, a method of blowing gas from one or both sides of the laminate, a method of placing auxiliary plates on one or both sides of the laminate and blowing gas from one or both sides of the laminate, and a combination of these methods.
The method for producing a resin film preferably includes a step of peeling off the photomask between step P2 and step P3-a or step P3-b. Examples of the method for peeling off the photomask include known peeling methods, and may also include a method for peeling off a temporary support, which will be described later.

The photomask used for pattern exposure preferably has a pattern structure corresponding to the position, shape and area of the through-holes to be formed in the target resin film.
The photomask has a light-shielding portion and an opening.
Examples of the shape of the light-shielding part include a circle and a polygon (preferably a regular polygon or an approximately regular polygon). The term "circle" means a perfect circle or an approximately circle, and more specifically, a shape is considered to be circular when the ratio (D2/D1) of the diameter D2 of the circumscribing circle circumscribing the light-shielding part to the diameter D1 of the inscribing circle inscribing the light-shielding part is 1.2 or less.
The photomask may have light-shielding portions arranged regularly or irregularly.
The photomask is preferably a photomask having a plurality of circular or square light-shielding portions, more preferably a photomask having a plurality of circular light-shielding portions. The arrangement of the light-shielding portions can be, for example, a 60° houndstooth check pattern, a 45° houndstooth check pattern, or a square lattice pattern.
When the light-shielding part has a circular shape, the major axis of the light-shielding part is preferably 0.05 to 20 μm, more preferably 1 to 10 μm, and even more preferably 1 to 5 μm.
When the light-shielding part has a polygonal shape, the length of one side of the polygon of the light-shielding part is preferably 0.05 to 20 μm, more preferably 1 to 10 μm, and even more preferably 1 to 5 μm. It is preferable that the longest side of the polygon is within the above range.
The pitch of the light-shielding portions (the distance between the light-shielding portions) is preferably 0.05 to 20 μm, more preferably 1 to 10 μm, and even more preferably 1 to 5 μm.
The total area of the light-shielding portions in a photomask having a plurality of light-shielding portions (for example, circular light-shielding portions) is preferably 20% or less, more preferably 10% or less, of the total area of the photomask. The lower limit is preferably 5% or more.
The area of the light-shielding portion can be measured, for example, by observing a transmitted image under an optical microscope and calculating the area from the observed image.

It is also preferable that the step P2 is a step of pattern exposure through a photomask and a light scattering plate.
In process P2, the light scattering plate (diffusion plate) used when performing pattern exposure via a photomask and a light scattering plate can be a known scattering plate that has the function of scattering the exposure light emitted from the light source uniformly within a predetermined angular width range by passing the exposure light.
The light scattering plate must be transparent and preferably has high UV transmittance. High UV transmittance allows pattern formation with a small amount of exposure light, improving throughput. Examples of materials that transmit UV include quartz glass, alkali-free glass, acrylic resin, UV-transmitting acrylic resin, PET, and polycarbonate.
The scattering characteristics of the light scattering plate are not particularly limited, and a scattering plate having appropriate scattering characteristics is selected depending on the shape of the target through-hole.
Examples of light-scattering plates include light-scattering plates having an uneven shape formed on at least one surface with a size corresponding to the wavelength of the exposure light, light-scattering plates containing a dispersing material having a size corresponding to the wavelength of the exposure light in the base material that constitutes the light-scattering plate, and light-scattering plates having the above uneven shape formed on at least one surface and containing the above-mentioned dispersing material.
The thickness of the light scattering plate is, for example, 50 to 500 μm, and preferably 50 to 150 μm.

Examples of commercially available light scattering plates include Lens Diffuser Plates (registered trademark) manufactured by Optical Solutions Co., Ltd., trade names: (hereinafter the same) LSD5ACUVT10, LSD10ACUVT10, LSD20ACUVT10, LSD30ACUVT10, LSD40ACUVT10, LSD60ACUVT10, LSD80ACUVT10 (all made of ultraviolet-transmitting acrylic resin), Lens Diffuser Plates (registered trademark): LSD5AC10, LSD10AC10, LSD20AC10, LSD30AC10, LSD4 0AC10, LSD60AC10, LSD80AC10 (all made of acrylic resin), Lens Diffuser Plate (registered trademark): LSD5PC10, LSD10PC10, LSD20PC10, LSD30PC10, LSD40PC10, LSD60PC10, LSD80PC10, LSD60x10PC10, LSD60x1PC10, LSD40x1PC10, LSD30x5PC10 (all made of polycarbonate), Lens Diffuser Plate (registered trademark): LSD5U3PS (all made of quartz glass), etc.
Other light scattering plates include the fly-eye lens FE10 manufactured by Nippon Tokushu Kogaku Jushi Co., Ltd., the Diffuser manufactured by Fit Co., Ltd., the SDXK-1FS, SDXK-AFS, and SDXK-2FS manufactured by Suntec Opto Co., Ltd., the light diffusion film MX manufactured by Filplus Co., Ltd., the acrylic diffusion plates ADF901, ADF852, ADF803, ADF754, ADF705, ADF656, ADF607, ADF558, ADF509, and ADF451 manufactured by Shibuya Optical Co., Ltd., and Oji F Nano Buckling (registered trademark) manufactured by Tex Co., Ltd., light diffusion films HDA060, HAA120, GBA110, DCB200, FCB200, IKA130, EDB200 manufactured by Lintec Corporation, Scotchcal (registered trademark) light diffusion diffuser films 3635-30, 3635-70 manufactured by 3M Japan Ltd., Light Up (registered trademark) SDW, EKW, K2S, LDS, PBU, GM7, SXE, MXE, SP6F, Optosay manufactured by Kimoto Co., Ltd. Bar (registered trademark) L-9, L-11, L-19, L-20, L-35, L-52, L-57, STC3, STE3, Chemical Mat (registered trademark) 75PWX, 125PW, 75PBA, 75BLB, 75PBB, Opalus (registered trademark) PBS-689G, PBS-680G, PBS-689HF, PBS-680HG, PBS-670G, UDD-147D2, UDD-148D2, SHBS-227C1, SHBS-228C2, UDD-247 manufactured by Keiwa Co., Ltd. Examples of such products include D2, PBS-630L, PBS-630A, PBS-632A, BS-539, BS-530, BS-531, BS-910, BS-911, and BS-912, and Legenda (registered trademark) PC, CL, HC, OC, TR, MC, SQ, EL, and OE manufactured by Kuraray Co., Ltd., and D120P, D121UPZ, D121UP, D261SIIIJ1, D261IVJ1, D263SIII, S263SIV, D171, D171S, and D174S manufactured by Tsujiden Co., Ltd.

In addition, the direction in which the exposure light is irradiated onto the photosensitive composition layer in process P2 is not particularly limited. However, in order to form through-holes that extend in a direction more perpendicular to the first main surface of the resin film, the angle between the direction in which the exposure light is irradiated onto the photosensitive composition layer and the normal direction to the surface of the photosensitive composition layer is preferably within 10°, and more preferably within 5°. The lower limit is not particularly limited, and may be 0°.

Examples of the exposure light include light having a wavelength capable of curing the photosensitive composition layer (e.g., wavelengths of 365 nm and 405 nm). The dominant wavelength of the exposure light is preferably 365 nm. The "dominant wavelength" refers to the wavelength with the greatest intensity.
Scattered light is also preferred as the exposure light. Examples of the method of exposure using scattered light include a method of exposure through the above-mentioned light scattering plate.

The dose of exposure light in step P2 (exposure dose) is not particularly limited and is appropriately selected depending on conditions such as the composition and thickness of the photosensitive composition layer, the periodic pattern of the photomask, and the wavelength of the exposure light, so that a desired pattern structure is formed in the resin film. Specifically, the exposure dose is preferably 5 to 200 mJ/ ^cm² , and more preferably 10 to 200 mJ/ ^cm² .
Examples of light sources for the exposure light include various lasers, light-emitting diodes (LEDs), ultra-high pressure mercury lamps, high pressure mercury lamps, and metal halide lamps. If necessary, the wavelength of the irradiated light may be adjusted through a spectral filter such as a long wavelength cut filter, a short wavelength cut filter, or a bandpass filter.

The light source, exposure dose, and exposure method of the exposure light are described, for example, in paragraphs [0146] to [0147] of WO 2018/155193, the contents of which are incorporated herein by reference.

[Process P3-a]
Process P3-a includes, in this order: process P3-a1 of developing the exposed photosensitive composition layer to form a resin film having predetermined through-holes; and process P3-a2 of peeling off the temporary support from the resin film.

<Process P3-a1>
Step P3-a1 is a step of developing the exposed photosensitive composition layer to form a resin film having predetermined through-holes.
The step P3-a1 is preferably a step of developing the exposed photosensitive composition layer with an alkaline aqueous solution to form a resin film having predetermined through-holes.

As the development method, a method using a developer is preferred.
The developer is preferably an alkaline aqueous solution. Examples of alkaline compounds that can be contained in the alkaline aqueous solution include sodium hydroxide, potassium hydroxide, sodium carbonate, potassium carbonate, sodium hydrogen carbonate, potassium hydrogen carbonate, tetramethylammonium hydroxide, tetraethylammonium hydroxide, tetrapropylammonium hydroxide, tetrabutylammonium hydroxide, and choline (2-hydroxyethyltrimethylammonium hydroxide).
The pH of the alkaline aqueous solution at 25° C. is preferably 8 to 13, more preferably 9 to 12. The pH can be measured using a known pH meter according to a method in accordance with JIS Z8802-1984.
The content of the alkaline compound in the alkaline aqueous solution is not particularly limited, but is preferably 0.1 to 5 mass %, more preferably 0.1 to 3 mass %, based on the total mass of the alkaline aqueous solution.
The alkaline aqueous solution preferably contains water in addition to the alkaline compound. The alkaline aqueous solution may contain an organic solvent and/or a known surfactant.

Development methods include, for example, puddle development, shower development, spin development, and dip development.

A suitable developer is, for example, the developer described in paragraph [0194] of WO 2015/093271, and a suitable development method is, for example, the development method described in paragraph [0195] of WO 2015/093271, the contents of which are incorporated herein by reference.

<Process P3-a2>
Step P3-a2 is a step of peeling off the temporary support and the resin film having the predetermined through-holes.
The step P3-a2 is preferably a step of physically peeling the temporary support and the resin film having the predetermined through-holes.

The peeling step can be carried out by, for example, a known method. The peeling step may be a chemical or physical peeling step, with a physical peeling step being preferred.

An example of a physical peeling step is a method of peeling the temporary support from the photosensitive composition layer having through-holes formed therein. The peeling angle is not particularly limited, but is preferably 10 to 190°, and more preferably 85 to 185°, relative to the main surface of the photosensitive composition layer.
Examples of physical peeling methods include the peeling methods described in paragraphs [0161] to [0162] of JP-A No. 2010-072589.

When the laminate has a temporary support, a water-soluble resin layer, and a photosensitive composition layer in this order, step P3-a2 may be a step of dissolving the water-soluble resin layer to remove the water-soluble resin layer and peeling the photosensitive composition layer from the temporary support. Alternatively, when the laminate has a water-soluble temporary support and a photosensitive composition layer, step P3-a2 may be a step of dissolving the water-soluble temporary support to remove the water-soluble temporary support and obtain the photosensitive composition layer.
Furthermore, when the laminate has a water-soluble resin layer or a water-soluble temporary support, the step P3-a2 and the step P3-a1 of forming a resin film having predetermined through-holes may be carried out simultaneously by developing the exposed photosensitive composition layer with an alkaline aqueous solution.

[Process P3-b]
Process P3-b is a process including, in this order, process P3-b1 of peeling the temporary support and the exposed photosensitive composition layer, and process P3-b2 of developing the peeled photosensitive composition layer to form a resin film having predetermined through-holes.

The peeling method in step P3-b1 can be, for example, the peeling method in step P3-a2. Step P3-b1 is preferably a step of physically peeling the exposed photosensitive composition layer from the temporary support.
The developing method in step P3-b2 can be, for example, the same as the developing method in step P3-a1. Step P3-b2 is preferably a step of developing the photosensitive composition layer from which the temporary support has been peeled off with an alkaline aqueous solution to form a resin film having predetermined through-holes.

[Other processes]
The method for producing a resin film may include other steps in addition to the steps described above.
The other steps include, for example, a post-exposure step and a post-bake step.
The post-exposure step is a step of further exposing the film after step P3-a1 or step P3-b2. The exposure conditions in the post-exposure step can be adjusted as appropriate. The exposure dose in the post-exposure step is preferably 100 to 5000 mJ/ ^cm² , more preferably 200 to 3000 mJ/ ^cm² .
The post-baking step is a step of further heating after step P3-a1 or step P3-b2. The heating conditions in the post-baking step can be adjusted as appropriate. The heating temperature in the post-baking step is preferably 80 to 250°C, more preferably 90 to 160°C. The heating time in the post-baking step is preferably 1 to 180 minutes, more preferably 10 to 60 minutes.
When the method for producing a resin film includes both a post-exposure step and a post-bake step, it is preferable to carry out the post-bake step after the post-exposure step.

[Resin film]
The resin film is a film manufactured by the above-described method using a photosensitive composition layer, and has a first main surface and a second main surface, and has a plurality of through holes penetrating from the first main surface to the second main surface.
The resin film may be formed from a negative photosensitive composition layer or a positive photosensitive composition layer, and is preferably formed from a negative photosensitive composition layer in that the toughness of the filter is superior.

When the resin film is formed from a negative photosensitive composition layer, the resin film may contain components contained in the negative photosensitive composition layer and modified products (e.g., decomposition products, cured products, etc.) derived from the negative photosensitive composition layer.
When the resin film is formed from a positive photosensitive composition layer, the resin film may contain components contained in the positive photosensitive composition layer and modified products (e.g., decomposed products, cured products, etc.) derived from the positive photosensitive composition layer.

[Through hole]
1 shows a resin film 10 having a plurality of through holes 20 periodically arranged therein. Specifically, the plurality of through holes 20 are arranged at equal intervals in the in-plane direction of the resin film 10, in a staggered pattern with an angle of 60°. That is, on the first main surface 11 (and the second main surface 12) of the resin film 10, three adjacent through holes 20 form lattice units each consisting of an equilateral triangle with an angle of 60°, and the formed lattice units are arranged in a staggered pattern. By arranging the plurality of through holes at equal intervals in this manner, the resistance to the passage of liquid through the resin film 10 can be reduced, and the formation of through holes with an enlarged opening area due to the overlap of the plurality of through holes can be suppressed.

The plurality of through holes formed in the resin film are not limited to being arranged in a 60° houndstooth pattern, but may be periodically arranged in other houndstooth pattern arrangements, square lattice arrangements, rectangular lattice arrangements, etc. Furthermore, the plurality of through holes are not limited to being periodically arranged, and may not be periodically arranged.
The plurality of through holes are preferably arranged in a staggered or square lattice pattern in the in-plane direction of the resin film, and more preferably arranged in a 60° staggered pattern.

The arrangement of the plurality of through holes in the resin film is designed appropriately depending on the shape of the through holes and the properties (for example, size, shape, properties, elasticity, etc.) of the object to which the resin film is applied.
For example, when a plurality of through holes are periodically arranged at equal intervals in the in-plane direction as shown in FIG. 1, the pitch of the periodic arrangement of the through holes is preferably 1 to 30 μm, more preferably 3 to 15 μm.
In this specification, the term "pitch" refers to the period of the periodic structure of the periodic pattern. When a plurality of through holes are periodically arranged in the in-plane direction of the resin film, the pitch refers to the sum of the diameters of the through holes and the distances between the through holes on a straight line along the direction in which the through holes are periodically arranged (hereinafter also referred to as the "arrangement direction").

The number of through holes formed in the resin film is appropriately designed depending on the shape and arrangement of the through holes and the properties of the object to which the resin film is applied.
The number of through holes per area of the resin film is ^often 1 x ¹⁰ /cm or more, preferably 1 x ¹⁰ /cm or ^more , and more preferably 1 x ¹⁰ /cm or ^more . There is no particular upper limit, but it is ^often 1 x ¹⁰ /cm or less, preferably 1 x ¹⁰ /cm ^or less, and more preferably 1 x ¹⁰ /cm ^or less.

Next, the shape of the through holes in the resin film will be described in detail.
1 has a circular opening, the opening shape of the through-hole 20 is not limited to a circular shape and may be an ellipse or a polygon such as a square or a hexagon. The opening shape of the through-hole in the resin film is preferably a circular or ellipse in terms of superior mechanical strength, and more preferably a circular shape in terms of improved separation accuracy.
In this specification, when the term "shape of the opening" is used to refer to a through hole formed in a resin film, it refers to the shape of the cross section obtained by cutting the through hole along the main surface of the resin film or a plane parallel to the main surface, when viewed from the normal direction of the main surface.

Furthermore, although the through-hole 20 shown in FIG. 1 extends along the normal direction of the first main surface 11 and the second main surface 12 of the resin film 10, the direction in which the through-hole extends is not limited to this direction.

Among the multiple through holes in the resin film, the ratio Rt of the number of through holes whose extension direction forms an angle of 5° or less with the thickness direction of the resin film is preferably 90% or more, more preferably 95% or more, and even more preferably 99.0% or more. There is no particular upper limit, and it may be 100%.

The average pore size of the through-holes is not particularly limited and is selected appropriately depending on the properties of the object to which the resin film is applied (e.g., size, shape, properties, elasticity, etc.). The average pore size of the through-holes is, for example, often 20 μm or less, preferably 10 μm or less, and more preferably 5 μm or less. There is no particular lower limit, but a value of 0.05 μm or more is preferred, and 1 μm or more is more preferred.

Furthermore, the ratio Rr of the number of through holes having a diameter 0.9 to 1.1 times the average diameter of the through holes among the multiple through holes in the resin film is preferably 90% or more, more preferably 95% or more, and even more preferably 99% or more. There is no particular upper limit, and it may be 100%.

Furthermore, in the resin film, the ratio of the standard deviation of the through-hole diameter to the average through-hole diameter is preferably 5% or less, more preferably 3% or less, and even more preferably 1% or less. The lower limit is not particularly limited and may be 0%.

In this specification, the "pore diameter" of a through hole refers to the pore diameter of the cross-section of the opening obtained by cutting the through hole along a plane that is parallel to the main surface of the resin film and passes through a position that is 10% of the thickness of the resin film filter from the first main surface. If the cross-section of the opening is circular, the pore diameter of the through hole is the diameter of the circular cross-section of the opening. If the cross-section of the opening is other than circular, the pore diameter of the through hole is the equivalent circular diameter of the cross-section of the opening.

The through-holes in the resin film preferably have a curved portion formed at an end of at least one of the first and second main surfaces, where the diameter of the through-hole increases as it approaches the open end.
The curved portion has a curvature radius of 0.1 μm or more, more preferably 1 μm or more, in a cross section including the direction in which the through holes extend and the thickness direction of the resin film. There is no upper limit, but the radius is preferably 3 μm or less, more preferably 2 μm or less.

Furthermore, in process P2 described below, when pattern exposure is performed via a photomask and a light scattering plate, the through-holes can have a truncated cone shape (excluding both ends near the opening ends) in which the cross-sectional area and diameter of the opening expand from the first main surface 11 side to the second main surface 12 side.

[Physical properties of resin film]
The thickness of the resin film is not particularly limited, but is preferably 5 μm or more, more preferably 8 μm or more, and even more preferably 10 μm or more, in terms of superior toughness. The upper limit is not particularly limited, but is preferably 100 μm or less, more preferably 50 μm or less, and even more preferably 30 μm or less, in terms of superior separation accuracy.
The thickness of the resin film is calculated as the average value of measurements taken at any five points by cross-sectional observation using a scanning electron microscope.

In the resin film, the contact angle of at least one of the first main surface and the second main surface with water is often 10 to 90°, and from the viewpoint of achieving better separation accuracy and filtration speed, it is preferably 10 to 70°, and more preferably 10 to 50°.
The contact angles of the first and second main surfaces of the resin film with water can be obtained by measuring the static contact angles (°) with water by the sessile drop method using a contact angle meter (Automatic Contact Angle Meter DMo-602, manufactured by Kyowa Interface Science Co., Ltd.).

The swelling ratio of the resin film in a 1.0 mass % aqueous sodium carbonate solution is preferably 100% or less, more preferably 50% or less, and even more preferably 30% or less, from the viewpoint of improving the formability of through holes. The swelling ratio of the resin film in a 1.0 mass % aqueous sodium carbonate solution is measured by the following method.
A photosensitive composition layer (thickness in the range of 1.0 to 10 μm) formed on a glass substrate and from which the solvent has been thoroughly removed is exposed to light at 500 mJ/cm ² (measured with i-line) from an ultra-high pressure mercury lamp. Each glass substrate is immersed in a 1.0 mass % aqueous sodium carbonate solution at 25°C, and the film thickness is measured after 30 seconds. The percentage increase in film thickness after immersion relative to the film thickness before immersion is then calculated. Specific examples include 4%, 13%, and 25%.

[Photosensitive composition layer]
The photosensitive composition layer may be a layer formed from a negative photosensitive composition, or may be a layer formed from a positive photosensitive composition.

The negative photosensitive composition layer is a photosensitive composition layer in which the solubility in a developer is reduced in the exposed region (exposed portion).
The positive photosensitive composition layer is a photosensitive composition layer in which the solubility in a developer increases in the exposed area (exposed portion).
The photosensitive composition layer preferably contains at least one binder polymer selected from the group consisting of (meth)acrylic resins and alkali-soluble resins, which will be described later, and a polymerizable compound, which will be described later.
The resin film also preferably contains a resin having a structural unit having an acid group protected by an acid-decomposable group, which will be described later, and a photoacid generator, which will be described later.

The components contained in the photosensitive composition layer are described below.

<Binder polymer>
The photosensitive composition layer may contain a binder polymer.
Examples of binder polymers include (meth)acrylic resins, styrene resins, epoxy resins, amide resins, amide epoxy resins, alkyd resins, phenolic resins, ester resins, urethane resins, epoxy acrylate resins obtained by reacting an epoxy resin with (meth)acrylic acid, and acid-modified epoxy acrylate resins obtained by reacting an epoxy acrylate resin with an acid anhydride.

A preferred embodiment of the binder polymer is, for example, a (meth)acrylic resin, which has excellent alkaline developability and film formability.
In this specification, the term "(meth)acrylic resin" refers to a resin having structural units derived from a (meth)acrylic compound. The content of the structural units derived from a (meth)acrylic compound may be 30% by mass or more, preferably 50% by mass or more, more preferably 70% by mass or more, and even more preferably 90% by mass or more, based on the total structural units of the (meth)acrylic resin.
The (meth)acrylic resin may be composed solely of structural units derived from (meth)acrylic compounds, or may contain structural units derived from polymerizable monomers other than (meth)acrylic compounds. That is, the upper limit of the content of structural units derived from (meth)acrylic compounds is not particularly limited, but is 100% by mass or less of all structural units of the (meth)acrylic resin.

Examples of the (meth)acrylic compound include (meth)acrylic acid, (meth)acrylic acid esters, (meth)acrylamides, and (meth)acrylonitrile.
Examples of the (meth)acrylic acid ester include (meth)acrylic acid alkyl ester, (meth)acrylic acid tetrahydrofurfuryl ester, (meth)acrylic acid dimethylaminoethyl ester, (meth)acrylic acid diethylaminoethyl ester, (meth)acrylic acid glycidyl ester, (meth)acrylic acid benzyl ester, 2,2,2-trifluoroethyl (meth)acrylate, and 2,2,3,3-tetrafluoropropyl (meth)acrylate, and (meth)acrylic acid alkyl ester is preferred.
Examples of (meth)acrylamides include acrylamides such as diacetone acrylamide.

The alkyl group of the (meth)acrylic acid alkyl ester may be linear or branched. Specific examples include (meth)acrylic acid alkyl esters having an alkyl group having 1 to 12 carbon atoms, such as methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, butyl (meth)acrylate, pentyl (meth)acrylate, hexyl (meth)acrylate, heptyl (meth)acrylate, octyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, nonyl (meth)acrylate, decyl (meth)acrylate, undecyl (meth)acrylate, and dodecyl (meth)acrylate.
As the (meth)acrylic acid ester, a (meth)acrylic acid alkyl ester having an alkyl group having 1 to 4 carbon atoms is preferred, and methyl (meth)acrylate or ethyl (meth)acrylate is more preferred.

The (meth)acrylic resin may have other structural units in addition to the structural units derived from the (meth)acrylic compound.
The polymerizable monomer that forms the other structural unit is not particularly limited as long as it is a compound other than a (meth)acrylic compound that is copolymerizable with a (meth)acrylic compound, and examples thereof include styrene compounds that may have a substituent at the α-position or on the aromatic ring, such as styrene, vinyltoluene, and α-methylstyrene; vinyl alcohol esters such as acrylonitrile and vinyl-n-butyl ether; maleic acid, maleic anhydride, maleic acid monoesters such as monomethyl maleate, monoethyl maleate, and monoisopropyl maleate; fumaric acid, cinnamic acid, α-cyanocinnamic acid, itaconic acid, and crotonic acid.
These polymerizable monomers may be used alone or in combination of two or more.

In order to improve alkaline developability, the (meth)acrylic resin preferably contains a structural unit having an acid group, such as a carboxy group, a sulfo group, a phosphate group, or a phosphonate group.
In particular, the (meth)acrylic resin preferably has a structural unit having a carboxy group, and more preferably has a structural unit derived from the above-mentioned (meth)acrylic acid.

The content of structural units having an acid group in the (meth)acrylic resin (preferably structural units derived from (meth)acrylic acid) is preferably 10% by mass or more, relative to the total mass of the (meth)acrylic resin, in terms of excellent developability. There is no particular upper limit, but in terms of excellent alkali resistance, it is preferably 50% by mass or less, and more preferably 40% by mass or less.

Furthermore, the (meth)acrylic resin more preferably has a structural unit derived from the above-mentioned alkyl (meth)acrylate ester.
When the (meth)acrylic resin has a structural unit derived from an alkyl (meth)acrylate ester, the content of the structural unit derived from an alkyl (meth)acrylate ester in the (meth)acrylic resin is preferably 1 to 90 mass%, more preferably 1 to 50 mass%, and even more preferably 1 to 30 mass%, based on the total structural units of the (meth)acrylic resin.

The (meth)acrylic resin is preferably a resin having both a structural unit derived from (meth)acrylic acid and a structural unit derived from a (meth)acrylic acid alkyl ester.
Furthermore, as the (meth)acrylic resin, an acrylic resin having a structural unit derived from methacrylic acid, a structural unit derived from methyl methacrylate, and a structural unit derived from ethyl acrylate is also preferred.

Furthermore, the (meth)acrylic resin preferably has at least one selected from the group consisting of a structural unit derived from methacrylic acid and a structural unit derived from a methacrylic acid alkyl ester, and preferably has both a structural unit derived from methacrylic acid and a structural unit derived from a methacrylic acid alkyl ester.
The total content of the structural units derived from methacrylic acid and the structural units derived from alkyl methacrylate in the (meth)acrylic resin is preferably 40% by mass or more, more preferably 60% by mass or more, based on the total structural units of the (meth)acrylic resin. The upper limit is not particularly limited, and may be 100% by mass or less, preferably 80% by mass or less.

It is also preferable that the (meth)acrylic resin has at least one type selected from the group consisting of structural units derived from methacrylic acid and structural units derived from methacrylic acid alkyl esters, and at least one type selected from the group consisting of structural units derived from acrylic acid and structural units derived from acrylic acid alkyl esters.

The (meth)acrylic resin preferably has an ester group at the end, in view of excellent developability of the photosensitive composition layer when producing a resin film.
The terminals of the (meth)acrylic resin are composed of moieties derived from the polymerization initiator used in the synthesis. A (meth)acrylic resin having an ester group at its terminal can be synthesized by using a polymerization initiator that generates a radical having an ester group.

Another preferred embodiment of the binder polymer is an alkali-soluble resin.
From the viewpoint of developability, the binder polymer is preferably an alkali-soluble resin having an acid value of 60 mgKOH/g or more.
The alkali-soluble resin is more preferably a resin having a carboxy group with an acid value of 60 mgKOH/g or more (so-called carboxy group-containing resin), and even more preferably a (meth)acrylic resin having a carboxy group with an acid value of 60 mgKOH/g or more (so-called carboxy group-containing (meth)acrylic resin), because it is likely to be thermally crosslinked with the crosslinking component by heating and form a strong film.
When the binder polymer is a resin having a carboxy group, the three-dimensional crosslinking density can be increased by, for example, adding a thermally crosslinkable compound such as a blocked isocyanate compound to cause thermal crosslinking. Furthermore, when the carboxy group of the resin having a carboxy group is dehydrated and made hydrophobic, the wet heat resistance can be improved.

The carboxyl group-containing (meth)acrylic resin having an acid value of 60 mgKOH/g or more is not particularly limited as long as it satisfies the above-mentioned acid value condition, and can be appropriately selected from known (meth)acrylic resins.
For example, among the polymers described in paragraph [0025] of JP-A No. 2011-095716, carboxyl group-containing acrylic resins having an acid value of 60 mgKOH/g or more, and among the polymers described in paragraphs [0033] to [0052] of JP-A No. 2010-237589, carboxyl group-containing acrylic resins having an acid value of 60 mgKOH/g or more can be preferably used.

Another preferred embodiment of the alkali-soluble resin is a styrene-acrylic copolymer.
In this specification, the term "styrene-acrylic copolymer" refers to a resin having structural units derived from a styrene compound and structural units derived from a (meth)acrylic compound. The total content of the structural units derived from the styrene compound and the structural units derived from the (meth)acrylic compound is preferably 30% by mass or more, and more preferably 50% by mass or more, based on the total structural units of the copolymer.
The content of the structural units derived from the styrene compound is preferably 1% by mass or more, more preferably 5% by mass or more, and even more preferably 5 to 80% by mass, based on the total structural units of the copolymer.
The content of the structural units derived from the (meth)acrylic compound is preferably 5% by mass or more, more preferably 10% by mass or more, and even more preferably 20 to 95% by mass, based on the total structural units of the copolymer.

The alkali-soluble resin is not limited to the above-mentioned embodiments, so long as it is a resin with alkali-solubility. Other suitable alkali-soluble resins include alkali-soluble urethane resins (e.g., "PH-9001" manufactured by Taisei Fine Chemical Co., Ltd.), polyester urethane resins (e.g., "Vylon UR-3500" manufactured by Toyobo Co., Ltd.), and organic-inorganic hybrid resins (e.g., "COMPOCERAN SQ109" manufactured by Arakawa Chemical Industries, Ltd.).

Another preferred embodiment of the binder polymer is a polymer having an aromatic ring structure, and a polymer having a structural unit having an aromatic ring structure is more preferred.
Examples of monomers that form structural units having an aromatic ring structure include monomers having an aralkyl group, styrene, and polymerizable styrene derivatives (e.g., methylstyrene, vinyltoluene, tert-butoxystyrene, acetoxystyrene, 4-vinylbenzoic acid, styrene dimer, and styrene trimer). Of these, monomers having an aralkyl group or styrene are preferred. Examples of aralkyl groups include substituted or unsubstituted phenylalkyl groups (excluding benzyl groups) and substituted or unsubstituted benzyl groups, with substituted or unsubstituted benzyl groups being preferred.

An example of a monomer having a phenylalkyl group is phenylethyl (meth)acrylate.

Examples of monomers having a benzyl group include (meth)acrylates having a benzyl group, such as benzyl (meth)acrylate and chlorobenzyl (meth)acrylate; and vinyl monomers having a benzyl group, such as vinylbenzyl chloride and vinylbenzyl alcohol. Of these, benzyl (meth)acrylate is preferred.

When the binder polymer has a structural unit having an aromatic ring structure, the content of the structural unit having an aromatic ring structure is preferably from 5 to 90 mass%, more preferably from 10 to 70 mass%, and still more preferably from 20 to 60 mass%, based on the total structural units of the binder polymer.
The content of the structural unit having an aromatic ring structure in the binder polymer is preferably 5 to 70 mol %, more preferably 10 to 60 mol %, and even more preferably 20 to 60 mol %, based on the total structural units of the binder polymer.
In this specification, when the content of a "structural unit" is specified by a molar ratio, the "structural unit" is considered to have the same meaning as a "monomer unit." In addition, in this specification, the "monomer unit" may be modified after polymerization by a polymer reaction or the like. The same applies hereinafter.

Another preferred embodiment of the binder polymer is a polymer having an aliphatic hydrocarbon ring structure. In other words, the binder polymer preferably has a structural unit having an aliphatic hydrocarbon ring structure. The aliphatic hydrocarbon ring structure may be monocyclic or polycyclic. In particular, it is more preferred that the binder polymer have a ring structure in which two or more aliphatic hydrocarbon rings are condensed.

Examples of the ring that constitutes the aliphatic hydrocarbon ring structure in the structural unit having an aliphatic hydrocarbon ring structure include a tricyclodecane ring, a cyclohexane ring, a cyclopentane ring, a norbornane ring, and an isoborone ring.
Among these, a ring formed by condensing two or more aliphatic hydrocarbon rings is preferred, and a tetrahydrodicyclopentadiene ring (tricyclo[5.2.1.0 ^2,6 ]decane ring) is more preferred.
Examples of monomers that form structural units having an aliphatic hydrocarbon ring structure include dicyclopentanyl (meth)acrylate, cyclohexyl (meth)acrylate, and isobornyl (meth)acrylate.

When the binder polymer has a structural unit having an aliphatic hydrocarbon ring structure, the content of the structural unit having an aliphatic hydrocarbon ring structure is preferably 5 to 90 mass %, more preferably 10 to 80 mass %, and even more preferably 20 to 70 mass %, based on the total structural units of the binder polymer.
The content of the structural unit having an aliphatic hydrocarbon ring structure in the binder polymer is preferably 5 to 70 mol %, more preferably 10 to 60 mol %, and even more preferably 20 to 50 mol %, based on the total structural units of the binder polymer.

When the binder polymer has a structural unit having an aromatic ring structure and a structural unit having an aliphatic hydrocarbon ring structure, the total content of the structural units having an aromatic ring structure and the structural units having an aliphatic hydrocarbon ring structure is preferably 10 to 90 mass%, more preferably 20 to 80 mass%, and even more preferably 40 to 75 mass%, based on all structural units of the binder polymer.
Furthermore, the total content of the structural units having an aromatic ring structure and the structural units having an aliphatic hydrocarbon ring structure in the binder polymer is preferably 10 to 80 mol %, more preferably 20 to 70 mol %, and even more preferably 40 to 60 mol %, based on all structural units of the binder polymer.

The binder polymer preferably has a structural unit having an acid group.
The acid group includes a carboxy group, a sulfo group, a phosphonic acid group, and a phosphoric acid group, and the carboxy group is preferred.
As the structural unit having an acid group, a structural unit derived from (meth)acrylic acid is preferred, and a structural unit derived from methacrylic acid is more preferred.

When the binder polymer has a structural unit having an acid group, the content of the structural unit having an acid group is preferably 5 to 50 mass %, more preferably 5 to 40 mass %, and even more preferably 10 to 30 mass %, based on the total structural units of the binder polymer.
The content of the structural unit having an acid group in the binder polymer is preferably 5 to 70 mol %, more preferably 10 to 50 mol %, and even more preferably 20 to 40 mol %, based on the total structural units of the binder polymer.
Furthermore, the content of the structural units derived from (meth)acrylic acid in the binder polymer is preferably 5 to 70 mol %, more preferably 10 to 50 mol %, and even more preferably 20 to 40 mol %, based on the total structural units of the binder polymer.

The binder polymer preferably has a reactive group, and more preferably has a structural unit having a reactive group.
The reactive group is preferably a radically polymerizable group, more preferably an ethylenically unsaturated group. When the binder polymer has an ethylenically unsaturated group, the binder polymer preferably has a structural unit having an ethylenically unsaturated group in a side chain.
In this specification, the term "main chain" refers to the relatively longest bond chain in the molecule of the polymer compound that constitutes the resin, and the term "side chain" refers to an atomic group branching off from the main chain.
The ethylenically unsaturated group is more preferably an allyl group or a (meth)acryloxy group.
Examples of structural units having a reactive group include, but are not limited to, those shown below.

When the binder polymer has a structural unit having a reactive group, the content of the structural unit having a reactive group is preferably 5 to 70 mass %, more preferably 10 to 50 mass %, and even more preferably 20 to 40 mass %, based on the total structural units of the binder polymer.
The content of the structural unit having a reactive group in the binder polymer is preferably 5 to 70 mol %, more preferably 10 to 60 mol %, and even more preferably 20 to 50 mol %, based on the total structural units of the binder polymer.

Examples of means for introducing a reactive group into a binder polymer include a method of reacting a functional group such as a hydroxy group, a carboxy group, a primary amino group, a secondary amino group, an acetoacetyl group, or a sulfo group with a compound such as an epoxy compound, a blocked isocyanate compound, an isocyanate compound, a vinyl sulfone compound, an aldehyde compound, a methylol compound, or a carboxylic acid anhydride.
A preferred example of a method for introducing a reactive group into a binder polymer is to synthesize a polymer having a carboxy group by polymerization, and then react some of the carboxy groups of the resulting polymer with glycidyl (meth)acrylate by a polymer reaction to introduce a (meth)acryloxy group into the polymer. By this method, a binder polymer having a (meth)acryloxy group in its side chain can be obtained.
The polymerization reaction is preferably carried out at a temperature of 70 to 100°C, and more preferably at a temperature of 80 to 90°C. The polymerization initiator used in the polymerization reaction is preferably an azo-based initiator, and more preferably, for example, V-601 (trade name) or V-65 (trade name) manufactured by Fujifilm Wako Pure Chemical Industries, Ltd. The polymerization reaction is preferably carried out at a temperature of 80 to 110°C. In the polymerization reaction, it is preferable to use a catalyst such as an ammonium salt.

Another suitable binder polymer is an epoxy resin having two or more thermally crosslinkable groups. Examples of such epoxy resins include epoxy resins having two or more epoxy groups or oxetanyl groups in the molecule. More specific examples include bisphenol A epoxy resins, bisphenol F epoxy resins, phenol novolac epoxy resins, cresol novolac epoxy resins, and aliphatic epoxy resins.

(Resin Having a Structural Unit Having an Acid Group Protected by an Acid-Decomposable Group)
When the resin film is formed from a positive photosensitive composition layer, the positive photosensitive composition layer preferably contains a resin having an acid group protected by an acid-decomposable group.
The resin having an acid group protected by an acid-decomposable group is preferably a polymer (hereinafter also referred to as "polymer A") having a structural unit having an acid group protected by an acid-decomposable group (hereinafter also referred to as "structural unit A").
The resin film may contain other polymers in addition to the polymer A. In this specification, the polymer A and other polymers are collectively referred to as "polymer components."
The acid-decomposable groups in the polymer A are deprotected by the action of a catalytic amount of an acidic substance generated by exposure to light, exposing the acid groups and improving the solubility in an alkaline developer.

It is preferable that all of the polymers contained in the above polymer component have structural units having an acid group, as described below. The above polymer component in this specification is not particularly limited and includes other polymers that are added as needed.

Polymer A is preferably an addition polymerization type polymer, and more preferably a polymer having structural units derived from (meth)acrylic acid or an ester thereof. Note that structural units other than structural units derived from (meth)acrylic acid or an ester thereof may include, for example, structural units derived from styrene and structural units derived from a vinyl compound.

-Structural unit A-
The structural unit A is a structural unit having an acid group protected by an acid-decomposable group.
Examples of the acid group protected with an acid-decomposable group include known acid groups and known acid-decomposable groups.
Examples of the acid group include a carboxy group and a phenolic hydroxyl group. Examples of the acid group protected with an acid-decomposable group include groups that are relatively easily decomposed by acid (e.g., acetal functional groups such as a tetrahydropyranyl ester group and a tetrahydrofuranyl ester group), and groups that are relatively difficult to decompose by acid (e.g., tertiary alkyl groups such as a tert-butyl ester group, and tertiary alkyl carbonate groups such as a tert-butyl carbonate group).
Among these, the acid-decomposable group is preferably a group having a structure protected by an acetal-based functional group.

The content of structural unit A is preferably 20% by mass or more, more preferably 20 to 90% by mass, and even more preferably 30 to 70% by mass, relative to the total mass of polymer A.

-Structural unit B-
The polymer A may contain a structural unit B having an acid group.
The structural unit B is, for example, a structural unit containing an acid group that is not protected by an acid-decomposable group, i.e., an acid group that does not have a protecting group. When the polymer A contains the structural unit B, the polymer A becomes more soluble in an alkaline developer in the development step after patterned exposure, and the development time can be shortened.
Examples of the structural unit B include the structural units contained in the alkali-soluble resins described above.

The content of structural unit B is preferably 0.1 to 20% by mass, more preferably 0.5 to 15% by mass, and even more preferably 1 to 10% by mass, relative to the total mass of polymer A.

-Other structural units-
In addition to the structural units A and B described above, polymer A may also contain another structural unit (hereinafter also referred to as "structural unit C").
Examples of monomers that form the structural unit C include styrenes, (meth)acrylic acid alkyl esters, (meth)acrylic acid cyclic alkyl esters, (meth)acrylic acid aryl esters, unsaturated dicarboxylic acid diesters, bicyclounsaturated compounds, maleimide compounds, unsaturated aromatic compounds, conjugated diene compounds, unsaturated monocarboxylic acids, unsaturated dicarboxylic acids, unsaturated dicarboxylic acid anhydrides, groups having an aliphatic cyclic skeleton, and other unsaturated compounds.

As the structural unit C, a structural unit having an aromatic ring or a structural unit having an aliphatic cyclic skeleton is preferred.
Furthermore, as the monomer that forms the structural unit C, a (meth)acrylic acid alkyl ester is also preferred, and a (meth)acrylic acid alkyl ester having an alkyl group having 4 to 12 carbon atoms is more preferred.

The content of the structural unit C is preferably 70% by mass or less, more preferably 60% by mass or less, and even more preferably 50% by mass or less, relative to the total mass of the polymer A. There is no particular lower limit, but it is preferably 1% by mass or more, and more preferably 5% by mass or more.
It is also preferable that polymer A contains, as structural unit C, a structural unit having an ester of the acid group in structural unit B, from the viewpoint of optimizing solubility in a developer and the physical properties of the photosensitive composition layer.

The method for producing the polymer A is not particularly limited, and a known method may be used.
For example, the structural unit A1 can be synthesized by polymerizing a monomer for forming the structural unit B, a monomer for forming the structural unit C in an organic solvent using a polymerization initiator.

The weight-average molecular weight (Mw) of the binder polymer is preferably 10,000 or more, more preferably 30,000 or more, and even more preferably 30,000 to 100,000, in order to achieve superior toughness of the resin film.

The acid value of the binder polymer is preferably from 10 to 200 mgKOH/g, more preferably from 60 to 200 mgKOH/g, and even more preferably from 100 to 200 mgKOH/g.
The acid value of the binder polymer is a value measured according to the method described in JIS K0070:1992.
From the viewpoint of developability, the dispersity of the binder polymer is preferably from 1.0 to 6.0, more preferably from 1.0 to 5.0, even more preferably from 1.0 to 4.0, and particularly preferably from 1.0 to 3.0.

The binder polymers may be used alone or in combination of two or more.
The content of the binder polymer is preferably from 10 to 90% by mass, more preferably from 20 to 80% by mass, and even more preferably from 30 to 80% by mass, based on the total mass of the photosensitive composition layer.
When the binder polymer contains polymer A, the content of polymer A is preferably from 50 to 99% by mass, more preferably from 70 to 98% by mass, based on the total mass of the photosensitive composition layer.

<Polymerizable compound>
The photosensitive composition layer may contain a polymerizable compound.
The polymerizable compound is a compound having a polymerizable group. Examples of the polymerizable group include a radically polymerizable group and a cationic polymerizable group, and the radically polymerizable group is preferred.

The polymerizable compound preferably contains a radical polymerizable compound having an ethylenically unsaturated group (hereinafter also simply referred to as "ethylenically unsaturated compound").
The ethylenically unsaturated group is preferably a (meth)acryloxy group.
The ethylenically unsaturated compound in this specification is a compound other than the binder polymer, and preferably has a molecular weight of less than 5,000.

A preferred embodiment of the polymerizable compound is a compound represented by formula (M) (hereinafter also referred to as "compound M").
Q ² -R ¹ -Q ¹ formula (M)
In formula (M), ^Q1 and ^Q2 each independently represent a (meth)acryloyloxy group, and ^R1 represents a divalent linking group having a chain structure.

Q ¹ and Q ² may be the same or different, but from the viewpoint of ease of synthesis, it is preferred that Q ¹ and Q ² are the same group.
Examples of R ¹ include hydrocarbon groups and alkylene oxide (-L ¹ -O-) adducts of hydrocarbon groups, and hydrocarbon groups having 6 to 20 carbon atoms or alkylene oxide (-L ¹ -O-) adducts of hydrocarbon groups are preferred.
The hydrocarbon group may have a chain structure at least in part, and the portion other than the chain structure may be, for example, a branched, cyclic, or linear alkylene group having 1 to 20 carbon atoms, an arylene group, an ether bond, or a combination thereof, and is preferably an alkylene group or a group in which two or more alkylene groups and one or more arylene groups are combined.
Examples of alkylene oxide adducts of hydrocarbon groups include alkyleneoxyalkylene groups (-L ¹ -OL ¹ -), polyalkyleneoxyalkylene groups (-(L ¹ -O) _p -L ¹ -), and alkylene oxide adducts of hydrocarbon groups other than polyalkyleneoxyalkylene groups.
Each ^L1 independently represents an alkylene group, preferably an ethylene group, a propylene group, or a butylene group, and more preferably an ethylene group or a 1,2-propylene group. p represents an integer of 2 or more, preferably an integer of 10 to 30.

Furthermore, the number of atoms in the shortest linking chain connecting Q ¹ and Q ² in compound M is preferably 20 to 150, more preferably 30 to 120, and even more preferably 40 to 90.
In this specification, "the number of atoms in the shortest linking chain connecting ^Q1 and ^Q2 " refers to the shortest number of atoms connecting from the atom in ^R1 that links to ^Q1 to the atom in ^R1 that links to ^Q2 .

Examples of compound M include 1,6-hexanediol di(meth)acrylate, 1,7-heptanediol di(meth)acrylate, 1,8-octanediol di(meth)acrylate, 1,9-nonanediol di(meth)acrylate, 1,10-decanediol di(meth)acrylate, 1,4-cyclohexanediol di(meth)acrylate, di(meth)acrylate of bisphenol A or hydrogenated bisphenol A and its ethylene oxide/propylene oxide adduct, di(meth)acrylate of bisphenol F or hydrogenated bisphenol F and its ethylene oxide/propylene oxide adduct, polyethylene glycol di(meth)acrylate, polypropylene glycol di(meth)acrylate, poly(ethylene glycol/propylene glycol) di(meth)acrylate, and polybutylene glycol di(meth)acrylate. The above ester monomers can also be used as mixtures.

Another preferred embodiment of the polymerizable compound is a di- or higher functional ethylenically unsaturated compound.
In this specification, the term "difunctional or higher functional ethylenically unsaturated compound" means a compound having two or more ethylenically unsaturated groups in one molecule.
The ethylenically unsaturated group in the ethylenically unsaturated compound is preferably a (meth)acryloyl group, that is, the ethylenically unsaturated compound is preferably a (meth)acrylate compound.

The difunctional ethylenically unsaturated compound is not particularly limited and can be appropriately selected from known compounds.
Examples of the difunctional ethylenically unsaturated compound other than the compound M include tricyclodecane dimethanol di(meth)acrylate, dioxane glycol di(meth)acrylate, and 1,4-cyclohexanediol di(meth)acrylate.

Commercially available bifunctional ethylenically unsaturated compounds include tricyclodecane dimethanol diacrylate (trade name: NK Ester A-DCP, manufactured by Shin-Nakamura Chemical Co., Ltd.), tricyclodecane dimethanol dimethacrylate (trade name: NK Ester DCP, manufactured by Shin-Nakamura Chemical Co., Ltd.), 1,9-nonanediol diacrylate (trade name: NK Ester A-NOD-N, manufactured by Shin-Nakamura Chemical Co., Ltd.), 1,6-hexanediol diacrylate (trade name: NK Ester A-HD-N, manufactured by Shin-Nakamura Chemical Co., Ltd.), ethoxylated bisphenol A dimethacrylate (trade name: NK Ester BPE-500 and 900, manufactured by Shin-Nakamura Chemical Co., Ltd.), polyethylene glycol dimethacrylate (trade name: NK Ester 23G, manufactured by Shin-Nakamura Chemical Co., Ltd.), and dioxane glycol diacrylate (KAYARAD R-604, manufactured by Nippon Kayaku Co., Ltd.).

The tri- or higher functional ethylenically unsaturated compound is not particularly limited and can be appropriately selected from known compounds.
Examples of tri- or higher functional ethylenically unsaturated compounds include dipentaerythritol (tri/tetra/penta/hexa)(meth)acrylate, pentaerythritol (tri/tetra)(meth)acrylate, trimethylolpropane tri(meth)acrylate, ditrimethylolpropane tetra(meth)acrylate, isocyanuric acid (meth)acrylate, and (meth)acrylate compounds having a glycerin tri(meth)acrylate skeleton.

Here, "(tri/tetra/penta/hexa)(meth)acrylate" is a concept that encompasses tri(meth)acrylate, tetra(meth)acrylate, penta(meth)acrylate, and hexa(meth)acrylate, and "(tri/tetra)(meth)acrylate" is a concept that encompasses tri(meth)acrylate and tetra(meth)acrylate.

The polymerizable compound also includes a urethane (meth)acrylate compound.
Examples of urethane (meth)acrylates include urethane di(meth)acrylates, such as propylene oxide-modified urethane di(meth)acrylates and ethylene oxide and propylene oxide-modified urethane di(meth)acrylates.
Further, the urethane (meth)acrylate may also be a tri- or higher functional urethane (meth)acrylate. Examples of tri- or higher functional urethane (meth)acrylates include 8UX-015A (manufactured by Taisei Fine Chemical Co., Ltd.), NK Oligo UA-32P, U-15HA, UA-122P, UA-160TM, and UA-1100H (all manufactured by Shin-Nakamura Chemical Co., Ltd.), AH-600 (manufactured by Kyoeisha Chemical Co., Ltd.), and UA-306H, UA-306T, UA-306I, UA-510H, and UX-5000 (all manufactured by Nippon Kayaku Co., Ltd.).

Another preferred embodiment of the polymerizable compound is an ethylenically unsaturated compound having an acid group.
Examples of the acid group include a phosphate group, a sulfo group, and a carboxy group, with the carboxy group being preferred.
Examples of the ethylenically unsaturated compound having an acid group include a tri- or tetrafunctional ethylenically unsaturated compound having an acid group [a compound having a carboxy group introduced into a pentaerythritol tri- or tetraacrylate (PETA) skeleton (acid value: 80 to 120 mgKOH/g)], and a penta- or hexafunctional ethylenically unsaturated compound having an acid group [a compound having a carboxy group introduced into a dipentaerythritol penta- or hexaacrylate (DPHA) skeleton (acid value: 25 to 70 mgKOH/g)].
These tri- or higher functional ethylenically unsaturated compounds having an acid group may be used in combination with a difunctional ethylenically unsaturated compound having an acid group, if necessary.

Preferred ethylenically unsaturated compounds having an acid group are polymerizable compounds having an acid group described in paragraphs [0025] to [0030] of JP-A No. 2004-239942, the contents of which are incorporated herein by reference.

Examples of polymerizable compounds include compounds obtained by reacting a polyhydric alcohol with an α,β-unsaturated carboxylic acid, compounds obtained by reacting a glycidyl group-containing compound with an α,β-unsaturated carboxylic acid, urethane monomers such as (meth)acrylate compounds having a urethane bond, phthalic acid compounds such as γ-chloro-β-hydroxypropyl-β'-(meth)acryloyloxyethyl-o-phthalate, β-hydroxyethyl-β'-(meth)acryloyloxyethyl-o-phthalate, and β-hydroxypropyl-β'-(meth)acryloyloxyethyl-o-phthalate, and (meth)acrylic acid alkyl esters. These may be used alone or in combination of two or more.

Examples of polymerizable compounds include caprolactone-modified ethylenically unsaturated compounds (e.g., KAYARAD (registered trademark) DPCA-20 manufactured by Nippon Kayaku Co., Ltd., A-9300-1CL manufactured by Shin-Nakamura Chemical Co., Ltd.), alkylene oxide-modified ethylenically unsaturated compounds (e.g., KAYARAD RP-1040 manufactured by Nippon Kayaku Co., Ltd., ATM-35E and A-9300 manufactured by Shin-Nakamura Chemical Co., Ltd., EBECRYL (registered trademark) 135 manufactured by Daicel-Allnex Corporation), and ethoxylated glycerin triacrylate (e.g., A-GLY-9E manufactured by Shin-Nakamura Chemical Co., Ltd.).

As the polymerizable compound (particularly the ethylenically unsaturated compound), one containing an ester bond is also preferred, as it provides excellent developability of the photosensitive composition layer when producing a resin film.
The ethylenically unsaturated compound containing an ester bond is not particularly limited as long as it contains an ester bond in the molecule, but is preferably an ethylenically unsaturated compound having a tetramethylolmethane structure or a trimethylolpropane structure, and more preferably tetramethylolmethane tri(meth)acrylate, tetramethylolmethane tetra(meth)acrylate, trimethylolpropane tri(meth)acrylate, or di(trimethylolpropane)tetraacrylate.
From the viewpoint of providing reliability, the ethylenically unsaturated compound preferably contains an ethylenically unsaturated compound having an aliphatic group having 6 to 20 carbon atoms and the above-mentioned ethylenically unsaturated compound having a tetramethylolmethane structure or a trimethylolpropane structure.
Examples of ethylenically unsaturated compounds having an aliphatic structure with 6 or more carbon atoms include 1,9-nonanediol di(meth)acrylate, 1,10-decanediol di(meth)acrylate, and tricyclodecane dimethanol di(meth)acrylate.

The molecular weight of the polymerizable compound is preferably from 200 to 3,000, more preferably from 250 to 2,600, still more preferably from 280 to 2,200, and particularly preferably from 300 to 2,200.
Among the polymerizable compounds contained in the photosensitive composition layer, the content of polymerizable compounds having a molecular weight of 300 or less is preferably 30% by mass or less, more preferably 25% by mass or less, and even more preferably 20% by mass or less, based on the total content of all polymerizable compounds contained in the photosensitive composition layer. The lower limit is often 0% by mass or more.

The photosensitive composition layer preferably contains a di- or higher functional ethylenically unsaturated compound, and more preferably contains a difunctional ethylenically unsaturated compound.
The photosensitive composition layer more preferably contains a compound represented by formula (M) and a blocked isocyanate compound described below.

The photosensitive composition layer may contain a monofunctional ethylenically unsaturated compound as the ethylenically unsaturated compound.
The content of the difunctional or higher functional ethylenically unsaturated compound in the ethylenically unsaturated compound is preferably 60 to 100 mass %, more preferably 80 to 100 mass %, and even more preferably 90 to 100 mass %, based on the total content of all ethylenically unsaturated compounds contained in the photosensitive composition layer.

The polymerizable compounds (particularly ethylenically unsaturated compounds) may be used alone or in combination of two or more.
The content of the polymerizable compound (particularly the ethylenically unsaturated compound) is preferably 1 to 70 mass %, more preferably 5 to 70 mass %, still more preferably 5 to 60 mass %, and particularly preferably 5 to 50 mass %, relative to the total mass of the photosensitive composition layer.

In order to achieve more uniform through-hole size and improved separation accuracy, the mass ratio of the polymerizable compound content to the binder polymer content in the photosensitive composition layer (100 x polymerizable compound content/binder polymer content) is preferably 40% or more, more preferably 50% or more, and even more preferably 60% or more. There is no particular upper limit, but in order to achieve improved flexibility and superior toughness in the resin film, it is preferably 150% or less, more preferably 120% or less, and even more preferably 100% or less.

<Polymerization initiator>
The photosensitive composition layer may contain a polymerization initiator.
The polymerization initiator is preferably a photopolymerization initiator.
The photopolymerization initiator is not particularly limited, and any known photopolymerization initiator can be used.
Examples of the photopolymerization initiator include a photopolymerization initiator having an oxime ester structure (hereinafter also referred to as an "oxime-based photopolymerization initiator"), a photopolymerization initiator having an α-aminoalkylphenone structure (hereinafter also referred to as an "α-aminoalkylphenone-based photopolymerization initiator"), a photopolymerization initiator having an α-hydroxyalkylphenone structure (hereinafter also referred to as an "α-hydroxyalkylphenone-based polymerization initiator"), a photopolymerization initiator having an acylphosphine oxide structure (hereinafter also referred to as an "acylphosphine oxide-based photopolymerization initiator"), and a photopolymerization initiator having an N-phenylglycine structure (hereinafter also referred to as an "N-phenylglycine-based photopolymerization initiator").

The photopolymerization initiator preferably includes at least one selected from the group consisting of oxime-based photopolymerization initiators, α-aminoalkylphenone-based photopolymerization initiators, α-hydroxyalkylphenone-based photopolymerization initiators, and N-phenylglycine-based photopolymerization initiators, and more preferably includes at least one selected from the group consisting of oxime-based photopolymerization initiators, α-aminoalkylphenone-based photopolymerization initiators, and N-phenylglycine-based photopolymerization initiators.

Furthermore, as the photopolymerization initiator, for example, the polymerization initiators described in paragraphs [0031] to [0042] of JP 2011-95716 A and paragraphs [0064] to [0081] of JP 2015-014783 A may be used.

Commercially available photopolymerization initiators include 1-[4-(phenylthio)phenyl]-1,2-octanedione-2-(O-benzoyloxime) [trade name: IRGACURE® OXE-01, manufactured by BASF], 1-[9-ethyl-6-(2-methylbenzoyl)-9H-carbazol-3-yl]ethanone-1-(O-acetyloxime) [trade name: IRGACURE® OXE-02, manufactured by BASF Corporation], IRGACURE (registered trademark) OXE03 (manufactured by BASF Corporation), IRGACURE (registered trademark) OXE04 (manufactured by BASF Corporation), IRGACURE (registered trademark) 307 (manufactured by BASF Corporation), IRGACURE (registered trademark) 379 (manufactured by BASF Corporation), 2-(dimethylamino)-2-[(4-methylphenyl)methyl]-1-[4-(4-morpholinyl)phenyl]-1-butanone (trade name: Omnirad (registered trademark) 379EG, manufactured by IGM Resins B.V.), 2-methyl-1-(4-methylthiophenyl)-2-morpholinopropan-1-one (trade name: Omnirad (registered trademark) 907, manufactured by IGM Resins B.V.) IGM Resins B.V], 2-hydroxy-1-{4-[4-(2-hydroxy-2-methylpropionyl)benzyl]phenyl}-2-methylpropan-1-one [trade name: Omnirad (registered trademark) 127, IGM Resins B.V], 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)butanone-1 [trade name: Omnirad (registered trademark) 369, IGM Resins B.V], 2-hydroxy-2-methyl-1-phenylpropan-1-one [trade name: Omnirad (registered trademark) 1173, IGM Resins B.V], 1-hydroxycyclohexyl phenyl ketone [trade name: Omnirad (registered trademark) 184, IGM Resins B.V] 2,2-dimethoxy-1,2-diphenylethan-1-one (trade name: Omnirad (registered trademark) 651, manufactured by IGM Resins B.V.), oxime ester-based compounds (trade name: Lunar (registered trademark) 6, manufactured by DKSH Japan Co., Ltd.), 1-[4-(phenylthio)phenyl]-3-cyclopentylpropane-1,2-dione-2-(O-benzoyloxime) (trade name: TR-PBG-305, manufactured by Changzhou Strong Electronic New Materials Co., Ltd.), 1,2-propanedione, 3-cyclohexyl-1-[9-ethyl-6-(2-furanylcarbonyl)-9H-carbazol-3-yl]-, 2-(O-acetyloxime) (trade name: TR-PBG- 326, Changzhou Strong Electronic New Materials Co., Ltd.), 3-cyclohexyl-1-(6-(2-(benzoyloxyimino)hexanoyl)-9-ethyl-9H-carbazol-3-yl)-propane-1,2-dione-2-(O-benzoyloxime) (trade name: TR-PBG-391, Changzhou Strong Electronic New Materials Co., Ltd.), APi-307 (1-(biphenyl-4-yl)-2-methyl-2-morpholinopropan-1-one, Shenzhen UV-ChemTech Ltd.), and 2,2'-bis(2-chlorophenyl)-4,4',5,5'-tetraphenyl-1,2'-biimidazole (HABI).

The photopolymerization initiator may be used alone or in combination of two or more. When two or more types are used, it is preferable to use an oxime-based photopolymerization initiator and at least one selected from the group consisting of an α-aminoalkylphenone-based photopolymerization initiator and an α-hydroxyalkylphenone-based photopolymerization initiator.
When the photosensitive composition layer contains a photopolymerization initiator, the content of the photopolymerization initiator is preferably 0.1% by mass or more, more preferably 0.5% by mass or more, and even more preferably 1.0% by mass or more, relative to the total mass of the photosensitive composition layer. Although there is no particular upper limit, the content is preferably 10% by mass or less, more preferably 5% by mass or less, relative to the total mass of the photosensitive composition layer.

<Photoacid generator>
The photosensitive composition layer may contain a photoacid generator.
When the photosensitive composition layer contains the above-mentioned resin having a structural unit having an acid group protected by an acid-decomposable group, the photosensitive composition layer preferably contains a photoacid generator.

A photoacid generator (photocationic polymerization initiator) is a compound that generates an acid when exposed to actinic rays. The photoacid generator is preferably a compound that responds to actinic rays with a wavelength of 300 nm or more (preferably 300 to 450 nm) and generates an acid, but its chemical structure is not particularly limited. Furthermore, even photoacid generators that are not directly sensitive to actinic rays with a wavelength of 300 nm or more can be used in combination with a sensitizer, as long as they respond to actinic rays with a wavelength of 300 nm or more and generate an acid when used in combination with a sensitizer.
The photoacid generator is preferably a photoacid generator that generates an acid having a pKa of 4 or less, more preferably a photoacid generator that generates an acid having a pKa of 3 or less, and even more preferably a photoacid generator that generates an acid having a pKa of 2 or less. There is no particular lower limit, but a lower limit of −10.0 or more is preferred.

Photoacid generators include ionic photoacid generators and nonionic photoacid generators.
Examples of the ionic photoacid generator include onium salt compounds such as diaryliodonium salts and triarylsulfonium salts, and quaternary ammonium salts. Furthermore, the ionic photoacid generators described in paragraphs [0114] to [0133] of JP-A-2014-085643 may also be used.

Examples of nonionic photoacid generators include trichloromethyl-s-triazines, diazomethane compounds, imide sulfonate compounds, and oxime sulfonate compounds. The trichloromethyl-s-triazines, diazomethane compounds, and imide sulfonate compounds may be those described in paragraphs [0083] to [0088] of JP 2011-221494 A. Furthermore, the oxime sulfonate compounds may be those described in paragraphs [0084] to [0088] of WO 2018/179640 A.

From the viewpoints of sensitivity and resolution, the photoacid generator preferably contains at least one compound selected from the group consisting of onium salt compounds and oxime sulfonate compounds, and from the viewpoints of sensitivity, resolution, and adhesion, it is more preferable that the photoacid generator contain an oxime sulfonate compound.

The photoacid generators may be used alone or in combination of two or more.
When the photosensitive composition layer contains a photoacid generator, the content of the photoacid generator is preferably 0.1 to 30 mass %, more preferably 0.1 to 20 mass %, and still more preferably 0.5 to 15 mass %, relative to the total mass of the photosensitive composition layer.

<Thermal crosslinkable compound>
The photosensitive composition layer preferably contains a thermally crosslinkable compound from the viewpoints of the strength of the resin film to be obtained and the adhesiveness of the unresined film to be obtained. Note that in this specification, a thermally crosslinkable compound having an ethylenically unsaturated group, which will be described later, is not considered to be an ethylenically unsaturated compound but is considered to be a thermally crosslinkable compound.
Examples of the thermally crosslinkable compound include epoxy compounds, oxetane compounds, methylol compounds, and blocked isocyanate compounds. Among these, blocked isocyanate compounds are preferred in terms of the strength of the resulting resin film and the adhesiveness of the resulting photosensitive composition layer.
Since the blocked isocyanate compound reacts with a hydroxy group and a carboxy group, for example, when at least one of the binder polymer and the radically polymerizable compound having an ethylenically unsaturated group has at least one of a hydroxy group and a carboxy group, the hydrophilicity of the formed film tends to decrease and the function as a resin film tends to be enhanced.
The blocked isocyanate compound means a compound having a structure in which the isocyanate group of an isocyanate is protected (so-called masked) with a blocking agent.

The dissociation temperature of the blocked isocyanate compound is not particularly limited, but is preferably from 90 to 160°C, more preferably from 100 to 150°C.
The dissociation temperature of the blocked isocyanate means "the temperature of the endothermic peak accompanying the deprotection reaction of the blocked isocyanate when measured by DSC (Differential Scanning Calorimetry) analysis using a differential scanning calorimeter."
As the differential scanning calorimeter, for example, a differential scanning calorimeter (model: DSC6200) manufactured by Seiko Instruments Inc. can be suitably used, although the differential scanning calorimeter is not limited to this.

Blocking agents with a dissociation temperature of 100 to 160°C include active methylene compounds [malonic acid diesters (e.g., dimethyl malonate, diethyl malonate, di-n-butyl malonate, di-2-ethylhexyl malonate, etc.)] and oxime compounds (e.g., compounds having a -C(=N-OH)- structure in the molecule, such as formaldoxime, acetaldoxime, acetoxime, methyl ethyl ketoxime, and cyclohexanone oxime). Among these, blocking agents with a dissociation temperature of 90 to 160°C are preferably at least one selected from the group consisting of oxime compounds and pyrazole compounds, in terms of storage stability.

The blocked isocyanate compound preferably has an isocyanurate structure in order to improve the brittleness of the film and the adhesive strength to the transfer target.
A blocked isocyanate compound having an isocyanurate structure can be obtained by protecting hexamethylene diisocyanate through isocyanuration.
Among these, as the blocked isocyanate compound having an isocyanurate structure, a compound having an oxime structure in which an oxime compound is used as a blocking agent is preferred because it is easier to adjust the dissociation temperature to a preferred range and to reduce development residues than a compound not having an oxime structure.

The blocked isocyanate compound may have a polymerizable group.
The polymerizable group is not particularly limited, and any known polymerizable group can be used, with a radical polymerizable group being preferred.
Examples of the polymerizable group include ethylenically unsaturated groups such as a (meth)acryloxy group, a (meth)acrylamide group, and a styryl group, as well as groups having an epoxy group such as a glycidyl group.
Of these, the polymerizable group is preferably an ethylenically unsaturated group, more preferably a (meth)acryloxy group, and even more preferably an acryloxy group.

As the blocked isocyanate compound, commercially available products can be used.
Commercially available blocked isocyanate compounds include, for example, Karenz (registered trademark) AOI-BM, Karenz (registered trademark) MOI-BM, Karenz (registered trademark) MOI-BP, and the like (all manufactured by Showa Denko K.K.), and the blocked Duranate series (for example, Duranate (registered trademark) TPA-B80E, Duranate (registered trademark) SBN-70D, Duranate (registered trademark) WT32-B75P, and the like, manufactured by Asahi Kasei Chemicals Corporation).
The NCO value of the blocked isocyanate compound is preferably 4.5 mmol/g or more, more preferably 5.0 mmol/g or more, and even more preferably 5.3 mmol/g or more. The upper limit of the NCO value of the blocked isocyanate compound is not particularly limited, but is preferably 8.0 mmol/g or less, more preferably 6.0 mmol/g or less, even more preferably less than 5.8 mmol/g, and particularly preferably 5.7 mmol/g or less.
The NCO value of a blocked isocyanate compound means the number of moles of isocyanate groups contained in 1 g of the blocked isocyanate compound, and is a value calculated from the structural formula of the blocked isocyanate compound.

As the thermally crosslinkable compound, it is also preferable to use an epoxy-based thermally crosslinkable compound from the viewpoints of hydrophilicity and flexibility. Examples of epoxy-based thermally crosslinkable compounds include compounds having two or more epoxy groups or oxetanyl groups in the molecule. Specific examples include bisphenol A-type epoxy resins, bisphenol F-type epoxy resins, phenol novolac-type epoxy resins, cresol novolac-type epoxy resins, and aliphatic epoxy resins.

As the epoxy-based thermally crosslinkable compound, commercially available products can be used.
Examples of commercially available epoxy-based thermally crosslinkable compounds include JER152, JER157S70, JER157S65, JER806, JER828, and JER1007 (manufactured by Mitsubishi Chemical Holdings Corporation), the commercially available products described in paragraph 0189 of JP 2011-221494 A, the Denacol (registered trademark) EX series, and the Denacol (registered trademark) DLC series (all manufactured by Nagase Chemtec), and YH-300, YH-301, YH-302, YH-315, YH-324, and YH-325 (all manufactured by Nippon Steel Chemical Co., Ltd.).

The thermally crosslinkable compounds may be used alone or in combination of two or more.
When the photosensitive composition layer contains a thermally crosslinkable compound, the content of the thermally crosslinkable compound is preferably from 1 to 50% by mass, more preferably from 5 to 30% by mass, based on the total mass of the photosensitive composition layer.

<Surfactants>
The photosensitive composition layer may contain a surfactant.
Examples of the surfactant include those described in paragraph [0017] of Japanese Patent No. 4502784 and paragraphs [0060] to [0071] of JP-A No. 2009-237362.

The surfactant is preferably a nonionic surfactant, a fluorine-based surfactant, or a silicone-based surfactant.
Commercially available fluorine-based surfactants include, for example, Megafac F-171, F-172, F-173, F-176, F-177, F-141, F-142, F-143, F-144, F-437, F-475, F-477, F-479, F-482, F-551A, F-552, F-554, F-555-A, F-556, F-557, F-558, F-559, F-560, F-561, F-565, F-563, F-568, F-575, F-780, EXP. MFS-330, EXP. MFS-578, EXP. MFS-579, EXP. MFS-586, EXP. MFS-587, R-41, R-41-LM, R-01, R-40, R-40-LM, RS-43, TF-1956, RS-90, R-94, RS-72-K, DS-21 (all manufactured by DIC Corporation), Fluorard FC430, FC431, FC171 (all manufactured by Sumitomo 3M Limited), Surflon S-382, SC-101, SC-103, SC-104, SC-105, SC-1068, SC-381, SC-383, S-393, KH-40 (all manufactured by AGC), PolyFox PF636, PF656, PF6320, PF6520, PF7002 (all manufactured by OMNOVA), Ftergent Examples of such products include 710FL, 710FM, 610FM, 601AD, 601ADH2, 602A, 215M, 245F, 251, 212M, 250, 209F, 222F, 208G, 710LA, 710FS, 730LM, 650AC, 681, and 683 (all manufactured by NEOS Corporation).
Furthermore, as the fluorosurfactant, an acrylic compound having a molecular structure with a functional group containing a fluorine atom, which cleaves the functional group when heated, causing the fluorine atom to volatilize, can also be suitably used. Examples of such a fluorosurfactant include the Megafac DS series manufactured by DIC Corporation (The Chemical Daily (February 22, 2016), The Nikkei Business Daily (February 23, 2016)), such as Megafac DS-21.
As the fluorine-based surfactant, it is also preferable to use a polymer of a fluorine atom-containing vinyl ether compound having a fluorinated alkyl group or a fluorinated alkylene ether group and a hydrophilic vinyl ether compound.
Furthermore, a block polymer can also be used as the fluorine-based surfactant.
Furthermore, as the fluorine-based surfactant, a fluorine-containing polymer compound containing a constituent unit derived from a (meth)acrylate compound having a fluorine atom and a constituent unit derived from a (meth)acrylate compound having two or more (preferably five or more) alkyleneoxy groups (preferably ethyleneoxy groups or propyleneoxy groups) can also be preferably used.
As the fluorine-based surfactant, a fluorine-containing polymer having an ethylenically unsaturated bond-containing group in the side chain can also be used, specifically Megafac RS-101, RS-102, RS-718K, and RS-72-K (all manufactured by DIC Corporation).

From the perspective of improving environmental friendliness, it is preferable that the fluorine-based surfactant be a surfactant derived from an alternative material to compounds having a linear perfluoroalkyl group with seven or more carbon atoms, such as perfluorooctanoic acid (PFOA) and perfluorooctanesulfonic acid (PFOS).

Nonionic surfactants include glycerol, trimethylolpropane, trimethylolethane, and their ethoxylates and propoxylates (e.g., glycerol propoxylate, glycerol ethoxylate, etc.), polyoxyethylene lauryl ether, polyoxyethylene stearyl ether, polyoxyethylene oleyl ether, polyoxyethylene octylphenyl ether, polyoxyethylene nonylphenyl ether, polyethylene glycol dilaurate, polyethylene glycol distearate, sorbitan fatty acid esters, Pluronic L10, L31, L61, L62, 10R5, 17R2, 25R2 (all manufactured by BASF), Tetronic 304, 701, 704, 901, 904, 150R1 (all manufactured by BASF), and Solsperse 20000 (all manufactured by Lubrizol Japan Corporation), NCW-101, NCW-1001, NCW-1002 (all manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.), Paionin D-6112, D-6112-W, D-6315 (all manufactured by Takemoto Yushi Co., Ltd.), Olfine E1010, Surfynol 104, 400, 440 (all manufactured by Nissin Chemical Industry Co., Ltd.).

Examples of silicone surfactants include linear polymers consisting of siloxane bonds and modified siloxane polymers in which organic groups have been introduced into the side chains or ends.

Examples of silicone surfactants include DOWSIL 8032 ADDITIVE, Toray Silicone DC3PA, Toray Silicone SH7PA, Toray Silicone DC11PA, Toray Silicone SH21PA, Toray Silicone SH28PA, Toray Silicone SH29PA, Toray Silicone SH30PA, and Toray Silicone SH8400 (all manufactured by Dow Corning Toray Co., Ltd.), as well as X-22-4952, X-22-4272, X-22-6266, KF-351A, K354L, KF-355A, and KF -945, KF-640, KF-642, KF-643, X-22-6191, X-22-4515, KF-6004, KP-341, KF-6001, KF-6002 (all manufactured by Shin-Etsu Silicones Co., Ltd.), F-4440, TSF-4300, TSF-4445, TSF-4460, TSF-4452 (all manufactured by Momentive Performance Materials), BYK307, BYK323, BYK330 (all manufactured by BYK-Chemie).

The surfactants may be used alone or in combination of two or more.
When the photosensitive composition layer contains a surfactant, the content of the surfactant is preferably 0.01 to 3.0 mass %, more preferably 0.01 to 1.0 mass %, and still more preferably 0.05 to 0.80 mass %, relative to the total mass of the photosensitive composition layer.

<Polymerization inhibitor>
The photosensitive composition layer may contain a polymerization inhibitor.
The polymerization inhibitor means a compound having the function of delaying or inhibiting a polymerization reaction. As the polymerization inhibitor, for example, a known compound used as a polymerization inhibitor can be used.
The resin film preferably contains a polymerization inhibitor, since this makes the opening areas of the through-holes formed in the resin film more uniform and improves the separation accuracy of the resin film.

Examples of polymerization inhibitors include phenothiazine compounds such as phenothiazine, bis-(1-dimethylbenzyl)phenothiazine, and 3,7-dioctylphenothiazine; bis[3-(3-tert-butyl-4-hydroxy-5-methylphenyl)propionic acid][ethylenebis(oxyethylene)]2,4-bis[(laurylthio)methyl]-o-cresol, 1,3,5-tris(3,5-di-t-butyl-4-hydroxybenzyl), 1,3,5-tris(4-t-butyl-3-hydroxy-2,6-dimethylbenzyl), 2,4-bis-(n-octylthio)-6-(4-hydroxy-3,5-di-t-butylanilino)-1,3,5-triazine, and pentaerythritol tetrakis 3-(3,5-di- tert-butyl-4-hydroxyphenyl)propionate; nitroso compounds or salts thereof such as 4-nitrosophenol, N-nitrosodiphenylamine, N-nitrosocyclohexylhydroxylamine, and N-nitrosophenylhydroxylamine; quinone compounds such as methylhydroquinone, t-butylhydroquinone, 2,5-di-t-butylhydroquinone, and 4-benzoquinone; phenolic compounds such as 4-methoxyphenol, 4-methoxy-1-naphthol, and t-butylcatechol; and metal salt compounds such as copper dibutyldithiocarbamate, copper diethyldithiocarbamate, manganese diethyldithiocarbamate, and manganese diphenyldithiocarbamate.

The polymerization inhibitor may be used alone or in combination of two or more.
When the photosensitive composition layer contains a polymerization inhibitor, the content of the polymerization inhibitor is preferably 0.001 to 5.0 mass%, more preferably 0.01 to 3.0 mass%, and even more preferably 0.02 to 2.0 mass%, relative to the total mass of the photosensitive composition layer. The content of the polymerization inhibitor is preferably 0.005 to 5.0 mass%, more preferably 0.01 to 3.0 mass%, and even more preferably 0.01 to 1.0 mass%, relative to the total mass of the polymerizable compounds.

<Hydrogen donor compound>
The photosensitive composition layer may contain a hydrogen donating compound.
The hydrogen donor compound has the effect of further improving the sensitivity of the photopolymerization initiator to actinic rays and suppressing inhibition of polymerization of the polymerizable compound by oxygen.

Examples of hydrogen donor compounds include amines and amino acid compounds.

Examples of amines include compounds described in M. R. Sander et al., "Journal of Polymer Society," Vol. 10, p. 3173 (1972), JP-B No. 44-020189, JP-A No. 51-082102, JP-A No. 52-134692, JP-A No. 59-138205, JP-A No. 60-084305, JP-A No. 62-018537, JP-A No. 64-033104, and Research Disclosure No. 33825. Specific examples include 4,4'-bis(diethylamino)benzophenone (EAB-F), tris(4-dimethylaminophenyl)methane (also known as leuco crystal violet), triethanolamine, p-dimethylaminobenzoic acid ethyl ester, p-formyldimethylaniline, and p-methylthiodimethylaniline.
Among these, the amines are preferably at least one selected from the group consisting of 4,4'-bis(diethylamino)benzophenone and tris(4-dimethylaminophenyl)methane.

Examples of amino acid compounds include N-phenylglycine, N-methyl-N-phenylglycine, and N-ethyl-N-phenylglycine.

Examples of hydrogen donor compounds include organometallic compounds (e.g., tributyltin acetate) described in JP-B 48-042965, hydrogen donors described in JP-B 55-034414, and sulfur compounds (e.g., trithiane) described in JP-A 6-308727.

The hydrogen donor compounds may be used alone or in combination of two or more.
When the photosensitive composition layer contains a hydrogen donor compound, the content of the hydrogen donor compound is preferably 0.01 to 10.0 mass %, more preferably 0.01 to 8.0 mass %, and even more preferably 0.03 to 5.0 mass %, relative to the total mass of the photosensitive composition layer, from the viewpoint of improving the curing rate through a balance between the polymerization growth rate and chain transfer.

<Impurities etc.>
The photosensitive composition layer may contain a certain amount of impurities.
Examples of impurities include sodium, potassium, magnesium, calcium, iron, manganese, copper, aluminum, titanium, chromium, cobalt, nickel, zinc, tin, halogens, and ions thereof. Among these, halide ions (e.g., chloride ions, bromide ions, iodide ions, etc.), sodium ions, and potassium ions are easily mixed in as impurities, so the following contents are preferred.

The content of impurities is preferably 80 ppm by mass or less, more preferably 10 ppm by mass or less, and even more preferably 2 ppm by mass or less, relative to the total mass of the photosensitive composition layer. The lower limit is preferably 1 ppb by mass or more, more preferably 0.1 ppm by mass or more, relative to the total mass of the photosensitive composition layer. Specifically, the total content of the impurities listed above is 0.6 ppm by mass or less, relative to the total mass of the photosensitive composition layer.

Methods for keeping the impurity content within the above range include selecting raw materials for the photosensitive composition layer that contain low impurities, and preventing impurities from being mixed in and removing them by washing when forming the photosensitive composition layer and resin film.

Methods for measuring the content of impurities include known methods such as ICP emission spectroscopy, atomic absorption spectroscopy, and ion chromatography.

The content of at least one compound X selected from the group consisting of benzene, formaldehyde, trichloroethylene, 1,3-butadiene, carbon tetrachloride, chloroform, N,N-dimethylformamide, N,N-dimethylacetamide, and hexane in the photosensitive composition layer is preferably low. Specifically, the content is preferably 100 ppm by mass or less, more preferably 20 ppm by mass or less, and even more preferably 4 ppm by mass or less, relative to the total mass of the photosensitive composition layer. There is no particular lower limit, but it is often 10 ppb by mass or more, and preferably 100 ppb by mass or more, relative to the total mass of the photosensitive composition layer.
The content of compound X can be adjusted, for example, by the above-mentioned method for adjusting the content of impurities. The content of compound X can be measured, for example, by known measurement methods.

The water content in the photosensitive composition layer is preferably low. Specifically, the water content is preferably 0.01 to 1.0% by mass, and more preferably 0.05 to 0.5% by mass, relative to the total mass of the photosensitive composition layer.

<Other ingredients>
The photosensitive composition layer may contain other components (hereinafter also referred to as "other components") in addition to the components described above.
Examples of other components include colorants, antioxidants, and other additives described in paragraphs [0058] to [0071] of JP-A No. 2000-310706.

When the photosensitive composition layer contains particles, it may contain two or more types of particles different in metal type, size, etc.
The photosensitive composition layer does not contain particles, or if the photosensitive composition layer contains particles, the particle content is preferably more than 0 mass % and not more than 35 mass %, relative to the total mass of the photosensitive composition layer. If the photosensitive composition layer does not contain particles or if the photosensitive composition layer contains particles, the particle content is more preferably more than 0 mass % and not more than 10 mass %, relative to the total mass of the photosensitive composition layer. If the photosensitive composition layer does not contain particles or if the photosensitive composition layer contains particles, the particle content is even more preferably more than 0 mass % and not more than 5 mass %, relative to the total mass of the photosensitive composition layer. If the photosensitive composition layer does not contain particles or if the photosensitive composition layer contains particles, the particle content is particularly preferably more than 0 mass % and not more than 1 mass %, relative to the total mass of the photosensitive composition layer. It is most preferred that the photosensitive composition layer does not contain particles.

- Coloring agent -
The photosensitive composition layer may contain a small amount of a colorant (for example, a pigment or a dye), or may be substantially free of a colorant.
When the photosensitive composition layer contains a colorant, the content of the colorant is preferably less than 1% by mass, more preferably less than 0.1% by mass, based on the total mass of the photosensitive composition layer.

-Antioxidants-
Examples of antioxidants include 3-pyrazolidones such as 1-phenyl-3-pyrazolidone (also known as phenidone), 1-phenyl-4,4-dimethyl-3-pyrazolidone, and 1-phenyl-4-methyl-4-hydroxymethyl-3-pyrazolidone; polyhydroxybenzenes such as hydroquinone, catechol, pyrogallol, methylhydroquinone, and chlorohydroquinone; paramethylaminophenol, paraaminophenol, parahydroxyphenylglycine, and paraphenylenediamine.

When the photosensitive composition layer contains an antioxidant, the content of the antioxidant is preferably 0.001% by mass or more, more preferably 0.005% by mass or more, and even more preferably 0.01% by mass or more, relative to the total mass of the photosensitive composition layer. There is no particular upper limit, but a content of 1% by mass or less is preferred.

<Characteristics of the Photosensitive Composition Layer>
(dissolution rate)
From the viewpoint of suppressing residues during development, the dissolution rate of the photosensitive composition layer (having a film thickness in the range of 1.0 to 10 μm) in a 1.0 mass % aqueous sodium carbonate solution is preferably 0.01 μm/sec or more, more preferably 0.10 μm/sec or more, and even more preferably 0.20 μm/sec or more. There is no particular upper limit, but it is preferably 5.0 μm/sec or less, more preferably 4.0 μm/sec or less, and even more preferably 3.0 μm/sec or less. Specific examples include 1.8 μm/sec, 1.0 μm/sec, and 0.7 μm/sec.
The dissolution rate of the photosensitive composition layer in a 1.0% by mass aqueous sodium carbonate solution is measured by the following method.
The photosensitive composition layer (film thickness: in the range of 1.0 to 10 μm) formed on the glass substrate and from which the solvent has been thoroughly removed is subjected to shower development at 25° C. using a 1.0 mass % aqueous sodium carbonate solution until the photosensitive composition layer is completely dissolved (however, this is limited to a maximum of 2 minutes).
The thickness of the photosensitive composition layer is determined by dividing the film thickness by the time required for the photosensitive composition layer to completely dissolve. If the photosensitive composition layer does not completely dissolve within 2 minutes, the thickness is calculated in the same manner from the amount of film thickness change up to that point.

(Foreign matter content)
The number of foreign particles having a diameter of 1.0 μm or more in the photosensitive composition layer is preferably 10 particles/ ^mm2 or less, more preferably 5 particles/ ^mm2 or less, from the viewpoint of forming through holes. There is no particular lower limit, but it is often 0 particles/ ^mm2 .
The number of foreign particles is measured as follows: Five randomly selected regions (1 mm x 1 mm) on the surface of the photosensitive composition layer are visually observed using an optical microscope from the normal direction to the surface of the photosensitive composition layer, and the number of foreign particles with a diameter of 1.0 μm or more in each region is counted and calculated as the arithmetic average. Specific examples include 0 particles/ ^mm2 , 1 particle/ ^mm2 , 4 particles/ ^mm2 , and 8 particles/ ^mm2 .

[Uses of resin film]
The resin film according to the present invention can be used in a variety of applications.
Examples of uses of the resin membrane include resin membranes, cell separation, selectively permeable membranes, microsensors, drug delivery films, and cell culture substrates. Among these, the resin membrane according to the present invention is preferably used as a resin filter for cell separation.

The present disclosure will be explained in more detail below with reference to the following examples. The materials, amounts used, ratios, processing details, processing procedures, etc. shown in the following examples can be modified as appropriate without departing from the spirit of this disclosure. Therefore, the scope of this disclosure is not limited to the specific examples shown below.

[Raw materials]
In the examples and comparative examples, the raw materials used to produce the resin films are shown below.

[Binder polymer]
B1: Copolymer of St/MMA/MAA = 52/19/29 (mass ratio) (acid value 189 mg KOH/g, Mw = 70,000)
B2: Copolymer of St/MMA/MAA = 52/19/29 (mass ratio) (acid value 189 mg KOH/g, Mw = 100,000)
B3: Copolymer of St/MMA/MAA = 52/19/29 (mass ratio) (acid value 189 mg KOH/g, Mw = 30,000)
B4: Copolymer of St/MMA/MAA/MAA-GMA = 47/2/19/32 (mass ratio) (acid value 124 mg KOH/g, Mw = 42,000)
B5: DCPMA/MMA/MAA = 52/19/29 (mass ratio) copolymer (acid value 189 mg KOH/g, Mw = 70,000)
B6: BnMA/MMA/MAA = 52/19/29 (mass ratio) copolymer (acid value 189 mg KOH/g, Mw = 70,000)
B7: Copolymer of St/MMA/MAA/HEMA = 52/19/19/10 (mass ratio) (acid value 124 mg KOH/g, Mw = 70,000)
B8: Copolymer of St/MMA/MAA/2EHA = 42/19/29/10 (mass ratio) (acid value 189 mg KOH/g, Mw = 70,000)
B9: Copolymer of St/MMA/MAA/AM-90G = 42/19/29/10 (mass ratio) (acid value 189 mg KOH/g, Mw = 70,000)

The symbols in the above resins indicate the following:
St: Styrene, MAA: Methacrylic acid, MMA: Methyl methacrylate, MMA-GMA: Glycidyl methacrylate added to methacrylic acid, DCPMA: Dicyclopentanyl methacrylate, BnMA: Benzyl methacrylate, HEMA: 2-hydroxyethyl methacrylate, 2EHA: 2-ethylhexyl methacrylate, AM-90G: Methoxypolyethylene glycol acrylate

[Polymerizable compound]
"BPE-500": Ethoxylated bisphenol A dimethacrylate (NK Ester BPE-500, manufactured by Shin-Nakamura Chemical Co., Ltd.)
"BPE-900": Ethoxylated bisphenol A dimethacrylate (NK Ester BPE-900, manufactured by Shin-Nakamura Chemical Co., Ltd.)
・ "23G": polyethylene glycol dimethacrylate (NK Ester 23G, manufactured by Shin-Nakamura Chemical Co., Ltd.)
"UA-160TM": urethane (meth)acrylate (NK Oligo UA-160TM, manufactured by Shin-Nakamura Chemical Co., Ltd.)
"UA-122P": urethane (meth)acrylate (NK Oligo UA-122P, manufactured by Shin-Nakamura Chemical Co., Ltd.)
"A-NOD-N": 1,9-nonanediol diacrylate (NK ester A-NOD-N, manufactured by Shin-Nakamura Chemical Co., Ltd.)
"A-DPH": Dipentaerythritol hexaacrylate (NK Ester A-DPH, manufactured by Shin-Nakamura Chemical Co., Ltd.)
"AM-30G": Methoxypolyethylene glycol acrylate (NK Ester AM-30G, manufactured by Shin-Nakamura Chemical Co., Ltd.)

[Polymerization initiator]
"HABI": 2,2'-bis(2-chlorophenyl)-4,4',5,5'-tetraphenyl-1,2'-biimidazole;"EAB-F":4,4'-bis(diethylamino)benzophenone (manufactured by Tokyo Chemical Industry Co., Ltd.)
"Irgacure OXE-02": manufactured by BASF Corporation "Irgacure 379": manufactured by BASF Corporation

[Polymerization inhibitor]
Phenothiazine

[Additives]
Duranate (registered trademark) SBN-70D: manufactured by Asahi Kasei Chemicals Corporation (blocked isocyanate-based thermal crosslinking compound)
"JER828": manufactured by Mitsubishi Chemical Holdings Corporation (epoxy-based thermal crosslinking compound)

[Surfactant]
"F-551A": Megafac (registered trademark) F-551A, manufactured by DIC Corporation, fluorine-based surfactant

〔solvent〕
1-Methoxy-2-propyl acetate, methyl ethyl ketone, propylene glycol monomethyl ether

[Preparation of Photosensitive Composition]
Photosensitive compositions having the compositions shown in Tables 1 and 2 were prepared by mixing and stirring the raw materials listed in Tables 1 and 2. In the tables below, the numerical values listed in the component columns indicate the content (parts by mass) of each component. Note that the binder polymer content values are all the amounts added of solutions containing each binder polymer alone (solid concentration 30% by mass).

[Preparation of Water-Soluble Layer-Forming Composition]
A water-soluble layer-forming composition 1 was prepared using the components and formulation shown below.
Kuraray Poval PVA-205 (Kuraray Co., Ltd.): 227 parts by weight Polyvinylpyrrolidone K-30 (Nippon Shokubai Co., Ltd.): 105 parts by weight Megafac F-444 (DIC Corporation): 0.1 parts by weight Ion-exchanged water: 401 parts by weight Methanol: 267 parts by weight

[Examples 1, 5 to 28]
[Preparation of Laminate]
A coating film was formed using the photosensitive composition N1 on a polyethylene terephthalate (PET) film (thickness 50 μm, Lumirror #50-T60, manufactured by Toray Industries, Inc.) serving as a temporary support, and then dried to prepare a photosensitive composition layer (thickness 15 μm). Furthermore, a cover film (thickness 25 μm, Torayfan #25A-KW37 (polypropylene film), manufactured by Toray Industries, Inc.) was overlaid on the surface of the obtained photosensitive composition layer opposite the temporary support, to prepare a laminate used in Example 1.

[Preparation of resin film]
A photomask was prepared having a plurality of circular light-shielding portions arranged in a 60° houndstooth pattern (light-shielding portion diameter 3 μm, light-shielding portion pitch 20 μm, 60° houndstooth pattern). The cover film was peeled off between the photosensitive composition layer of the laminate and the cover film, and the exposed photosensitive composition layer was brought into contact with the photomask. The photomask was then subjected to pattern exposure with ultraviolet light at an exposure dose of 100 mJ/cm ² (i-line equivalent) using an ultra-high pressure mercury lamp proximity exposure device. The exposure angle was 90° relative to the photosensitive composition layer. In addition, in the photomask, three adjacent light-shielding portions formed a lattice unit consisting of an equilateral triangle with a side length of 20 μm and an angle of 60°, and the formed lattice units constituted a houndstooth pattern.
The exposed photosensitive composition layer was immersed in a 1% by mass aqueous solution of sodium carbonate at 25°C for 60 seconds, and then washed with pure water at 25°C for 60 seconds. Furthermore, a portion of the edge of the resulting resin film was tape-peeled from the temporary support. Using a Tensilon universal material testing machine RTF-2430 (manufactured by A&D Co., Ltd.), the temporary support was peeled from the resin film at a peel angle of 180° to the temporary support and a peel speed of 1 m/min, while the edge of the peeled and exposed resin film was fixed, to obtain the resin film of Example 1.
Resin films of Examples 5 to 28 were prepared with reference to the above preparation procedure.

[Example 2]
The resin film of Example 2 was produced in the same manner as in Examples 1 and 5 to 28 above, except that a photomask having a plurality of square-shaped light-shielding portions arranged in a 60° houndstooth pattern (light-shielding portions each having a side length of 3 μm, a pitch of 20 μm, and a 60° houndstooth pattern) was used. In the photomask, three adjacent light-shielding portions formed lattice units each consisting of an equilateral triangle with a side length of 20 μm and an angle of 60°, and the formed lattice units constituted a houndstooth pattern.

[Example 3]
A water-soluble layer (thickness: 1 μm) was formed between the temporary support and the photosensitive composition layer using the composition 1 for forming a water-soluble layer, and the temporary support was further peeled off by immersion in water at 80° C. instead of peeling with tape (chemical peeling). Except for this, the resin film of Example 3 was produced in the same manner as in the above [Examples 1, 5 to 28].

[Example 4]
The resin film of Example 4 was prepared in the same manner as in Examples 1 and 5 to 28 above, except that the thickness of the photosensitive composition layer was changed to 9 μm.

The average pore size of the through-holes in the resin film in each example was 3 μm, and the pore density was 1.3×10 ⁵ /cm ² .

[Comparative Example 1]
A PET film (thickness: 15 μm) was placed in an irradiation chamber located downstream of the beamline connected to the AVF cyclotron, and the pressure inside the irradiation chamber was reduced to 1.0 × 10 ⁻⁴ Pa. Next, the PET film was irradiated with a xenon ion beam (energy: 350 MeV). The xenon ion beam was irradiated in a direction perpendicular to the main surface of the PET film at an irradiation density of 3 × ¹⁰ ions/cm ^2. Next, the PET film was removed from the irradiation chamber and subjected to chemical etching. A resin membrane (average pore diameter: 3.0 μm, pore density: 1.3 × ¹⁰ ions/cm ² ) with through-holes corresponding to the ion tracks of the xenon ions was obtained. For chemical etching, the PET film irradiated with the xenon ion beam was immersed in an aqueous sodium hydroxide solution (concentration: 1.0 M, temperature: 60°C) for 30 minutes.

[evaluation]
[Separation accuracy]
The resin films produced in each Example and Comparative Example were cut to prepare circular samples with a diameter of 47 mm. A dispersion containing silica particles with a particle size of 1 to 20 μm was passed over the surface of the obtained samples. The particle size distribution of the silica particles contained in the dispersion before and the filtrate after the passage was measured using a laser diffraction particle distribution analyzer "SALD-2300" manufactured by Shimadzu Corporation. The presence or absence of residues derived from the resin film was also confirmed.

[Toughness]
The resin membranes produced in each example and comparative example were cut to prepare circular samples with a diameter of 47 mm. A certain amount of pure water was passed through these samples at a pressure of 150 mmHg. After the passing process, the surfaces of the samples were observed visually and under an optical microscope to check for any tearing. In the optical microscope observation, an area of 1 ^mm2 on the surface of the sample was observed.

It has been confirmed that the method for producing a resin film having through holes according to the present invention can achieve the desired effects.
It was confirmed that the effects of the present invention are more excellent when step P3-a2 and step P3-b1 include a step of physically peeling the layers off (e.g., comparison of Examples 1 to 3). Furthermore, from similar comparisons, it was confirmed that the effects of the present invention are more excellent when the temporary support and the photosensitive composition layer in the laminate are in direct contact with each other.
It was confirmed that when the thickness of the photosensitive composition layer was 10 μm or more, the toughness was superior (comparison of Examples 1, 2 and 4, etc.).
It was confirmed that when the photomask has a circular light-shielding portion, the separation accuracy is superior (comparison between Examples 1 and 2, etc.).

10 Resin film 11 First main surface 12 Second main surface 13 Cross section 20 Through hole

Claims (7)

A method for manufacturing a resin film having a first main surface and a second main surface, and having a plurality of through holes penetrating from the first main surface to the second main surface, comprising:
A step P1 of preparing a laminate having a temporary support and a photosensitive composition layer;
a step P2 of bringing the photosensitive composition layer of the laminate into contact with a photomask and pattern-exposing the photosensitive composition layer from a surface of the photosensitive composition layer of the laminate opposite to the temporary support ;
Step P3-a or Step P3-b in this order,
the photosensitive composition layer is a negative-type photosensitive composition layer containing a radical polymerizable compound,
the step P3-a includes, in this order, a step P3-a1 of developing the exposed photosensitive composition layer with an alkaline aqueous solution to form the resin film, and a step P3-a2 of peeling off the resin film from the temporary support;
The method for producing a resin film, wherein the step P3-b includes, in this order, a step P3-b1 of peeling the temporary support and the exposed photosensitive composition layer, and a step P3-b2 of developing the photosensitive composition layer from which the temporary support has been peeled off with an alkaline aqueous solution to form the resin film. the step P3-a2 is a step of physically peeling the temporary support and the resin film,
2. The method for producing a resin film according to claim 1, wherein the step P3-b1 is a step of physically peeling the temporary support and the exposed photosensitive composition layer. The method for producing a resin film according to claim 1 or 2, wherein the temporary support and the photosensitive composition layer in the laminate are in direct contact with each other. 4. The method for producing a resin film according to claim 1 , wherein the step P2 is a step of pattern exposure through a photomask and a light scattering plate. the photomask has a plurality of circular light-shielding portions,
5. The method for producing a resin film according to claim 1 , wherein the total area of the light-shielding portions is 20% or less of the total area of the photomask. the photomask has a plurality of circular light-shielding portions,
6. The method for producing a resin film according to claim 1 , wherein the total area of the light-shielding portions is 10% or less of the total area of the photomask. The method for producing a resin film according to any one of claims 1 to 6 , wherein the photosensitive composition layer has a thickness of 10 µm or more.