Transfer film, laminate, method for manufacturing optical waveguide, photosensitive composition, polymer, and optical waveguide

Abstract

The first problem addressed by the present invention is to provide a transfer film which can be developed in an alkali and with which it is possible to form an optical waveguide capable of achieving a low optical transmission loss. The second problem addressed by the present invention is to provide a laminate, a method for manufacturing an optical waveguide, a photosensitive composition, a polymer, and an optical waveguide.　A transfer film according to the present invention comprises a temporary support and a photosensitive composition layer, wherein the photosensitive composition layer includes a polymer having a repeating unit represented by formula (1), a radical polymerizable group, and a carboxyl group or a salt thereof.

Description

Method for manufacturing transfer films, laminates, and optical waveguides, as well as photosensitive compositions, polymers, and optical waveguides. 【0001】 The present invention relates to a transfer film, a laminate, a method for manufacturing an optical waveguide, a photosensitive composition, a polymer, and an optical waveguide. 【0002】 In recent years, optical transmission has been considered as an alternative to conventional power transmission via electrical wiring in order to further improve high-speed and high-density signal transmission between electronic components and wiring boards. Furthermore, polymer optical waveguides are attracting attention as optical transmission paths connecting electronic components and wiring boards due to their ease of processing, high degree of flexibility in placement, and ability to be mounted at high density. 【0003】 For example, Patent Document 1 discloses a photocurable composition that can be applied to optical waveguide applications, provides high resolution, and forms patterns with high refractive index and high transmittance. 【0004】 International Publication No. 2014 / 084190 【0005】 Incidentally, Patent Document 1 discloses a photocurable composition in which a polymer having polymerizable groups and carboxylic acid groups is provided. The present inventors have now investigated the manufacture of optical waveguides using a polymer having the above configuration and have found that there is room for further improvement in achieving both propagation loss and alkali developability. 【0006】 Therefore, the object of the present invention is to provide a transfer film that can form an optical waveguide that is alkali-developable and capable of achieving low light propagation loss. The object of the present invention is also to provide a laminate, a method for manufacturing an optical waveguide, a photosensitive composition, a polymer, and an optical waveguide. 【0007】 The inventors have found that the above problems can be solved by the following configuration. 【0008】[1] A transfer film comprising a temporary support and a photosensitive composition layer, wherein the photosensitive composition layer comprises a polymer having repeating units represented by formula (1) described later, a radical polymerizable group, and a carboxyl group or a salt thereof. [2] The transfer film according to [1], wherein the polymer further comprises repeating units represented by formula (2) described later. [3] The transfer film according to [1] or [2], wherein the polymer further comprises repeating units represented by formula (3) described later. [4] The transfer film according to [1], wherein the total content of specific repeating units selected from the group consisting of repeating units represented by formula (1), repeating units represented by formula (2) described later, and repeating units represented by formula (3) described later is 50% by mass or more with respect to the total repeating units, and the acid value of the polymer is 0.6 to 2.0 mmol / g. [5] The transfer film according to any one of [1] to [4], wherein the photosensitive composition layer further comprises a compound that reduces the amount of carboxyl groups. [6] The transfer film according to [5], wherein the compound that reduces the carboxyl group is a compound that causes a decarboxylation reaction of the carboxyl group by exposure. [7] The transfer film according to [6], wherein the compound that causes a decarboxylation reaction of the carboxyl group by exposure is one or more selected from the group consisting of quinoline compounds, isoquinoline compounds, and quinoxaline compounds. [8] The transfer film according to [7], wherein the quinoline compound, the isoquinoline compound, and the quinoxaline compound each have at least one radical polymerizable group. [9] The transfer film according to [5], wherein the compound that reduces the carboxyl group is an isocyanate compound.

[10] A laminate having a substrate, a resin layer, and a transfer film according to any one of [1] to [9], wherein the photosensitive composition layer of the transfer film is arranged to face the resin layer.

[11] A method for manufacturing an optical waveguide using a laminate comprising a substrate, a resin layer, and a transfer film according to any one of [1] to [9] arranged such that the photosensitive composition layer faces the resin layer, wherein the refractive index of the resin layer is lower than the refractive index of the cured layer of the photosensitive composition layer, comprising: step 1 of performing an exposure treatment on the photosensitive composition layer in the laminate; step 2 of performing an alkaline development treatment on the photosensitive composition layer that has been exposed to form a core; and step 3 of forming a resin layer on the core so as to cover the core, with a refractive index lower than that of the core, to form an optical waveguide having the core and cladding, wherein step 4 is performed before step 1 or between step 1 and step 2, and a temporary support is peeled off.

[12] A photosensitive composition comprising a polymer having a repeating unit represented by formula (1) described later, a radical polymerizable group, and a carboxyl group or a salt thereof.

[13] The photosensitive composition according to

[12] , wherein the polymer further comprises a repeating unit represented by formula (2) described later.

[14] The photosensitive composition according to

[12] or

[13] , further comprising a compound that reduces the amount of carboxyl groups.

[15] A polymer having a repeating unit represented by formula (1) described later, a radical polymerizable group, and a carboxyl group or a salt thereof.

[16] The polymer according to

[15] , wherein the polymer further comprises a repeating unit represented by formula (2) described later.

[17] The polymer according to

[15] or

[16] , wherein the polymer further comprises a repeating unit represented by formula (3) described later.

[18] The polymer according to

[15] , comprising a repeating unit represented by formula (1), a repeating unit selected from the group consisting of a repeating unit represented by formula (2) described later and a repeating unit represented by formula (4) described later, and a repeating unit represented by formula (5) described later.

[19] An optical waveguide having a core portion and a cladding portion having a lower refractive index than the core portion, wherein the core portion is a layer formed using the photosensitive composition described in any of

[12] to

[14] .

[20] An optical waveguide having a core portion and a cladding portion having a lower refractive index than the core portion, wherein the core portion contains a component derived from the polymer described in any of

[15] to

[18] . 【0009】 According to the present invention, a transfer film can be provided that can form an optical waveguide that is alkali-developable and capable of achieving low light propagation loss. Furthermore, according to the present invention, a laminate, a method for manufacturing an optical waveguide, a photosensitive composition, a polymer, and an optical waveguide can be provided. 【0010】 This is a schematic diagram showing an example of an embodiment of the transfer film of the present invention. This is a schematic diagram showing an example of an embodiment of the laminate of the present invention. This is a schematic diagram for explaining a method for manufacturing an optical waveguide using the laminate of the present invention. This is a schematic diagram showing an example of an embodiment of the optical waveguide of the present invention. 【0011】 The present invention will now be described in detail. The following descriptions of constituent elements may be based on representative embodiments of the present invention, but the present invention is not limited to such embodiments. The present invention will now be described in detail. In this specification, numerical ranges expressed using "~" mean ranges that include the numbers written before and after "~" as the lower and upper limits. In addition, in numerical ranges described stepwise in this specification, the upper or lower limit stated in one numerical range may be replaced with the upper or lower limit of another numerical range described stepwise. In addition, in numerical ranges described in this specification, the upper or lower limit stated in one numerical range may be replaced with the values ​​shown in the examples. 【0012】 Furthermore, the term "process" as used in this specification includes not only independent processes, but also processes that cannot be clearly distinguished from other processes, as long as their intended purpose is achieved. 【0013】 In this specification, unless otherwise specified, the temperature condition may be 25°C. For example, unless otherwise specified, the temperature when performing each of the above steps may be 25°C. 【0014】In this specification, "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. Therefore, for example, "transparent resin layer" refers to a resin layer having an average transmittance of visible light with a wavelength of 400 to 700 nm of 80% or more. The average transmittance of visible light is a value measured using a spectrophotometer, and can be measured using, for example, a Hitachi, Ltd. U-3310 spectrophotometer. 【0015】 In this specification, "active light" or "radiation" means, for example, the emission line spectra of mercury lamps such as g-rays, h-rays, and i-rays, far ultraviolet light represented by excimer lasers, extreme ultraviolet (EUV) light, X-rays, and electron beams (EB). Also, in this invention, "light" means active light or radiation. 【0016】 In this specification, unless otherwise specified, "exposure" includes not only exposure using far ultraviolet, extreme ultraviolet, X-ray, and EUV light represented by mercury lamps and excimer lasers, but also drawing using particle beams such as electron beams and ion beams. 【0017】 In this specification, unless otherwise specified, the refractive index is the value measured by an Abbe refractometer (Abbe method) at a wavelength of 589 nm. In this specification, unless otherwise specified, the refractive index when the object of measurement is a film (e.g., a photosensitive composition layer or its cured layer) is the value measured by ellipsometry. 【0018】 In this specification, unless otherwise specified, molecular weights where a molecular weight distribution exists are weight-average molecular weights. In this specification, the weight-average molecular weight of resins is the weight-average molecular weight obtained by gel permeation chromatography (GPC) on a polystyrene basis. 【0019】 In this specification, "(meth)acrylic" is a concept that encompasses both acrylic and methacrylic, "(meth)acryloyl" is a concept that encompasses both acryloyl and methacryloyl, and "(meth)acrylate" is a concept that encompasses both acrylate and methacrylate. 【0020】In this specification, a compound or a layer constituting a transfer film is said to be "alkali-soluble" if its dissolution rate, as determined by the following method, is 0.01 μm / second or higher. A propylene glycol monomethyl ether acetate solution with a concentration of 25% by mass of the target substance (e.g., resin) is applied to a glass substrate, and then heated in an oven at 100°C for 3 minutes to form a coating film (thickness 2.0 μm) of the target substance. The dissolution rate (μm / second) of the coating film is determined by immersing the coating film in a 1% by mass aqueous solution of sodium carbonate (liquid temperature 30°C). If the target substance does not dissolve in propylene glycol monomethyl ether acetate, the target substance is dissolved in an organic solvent other than propylene glycol monomethyl ether acetate with a boiling point of less than 200°C (e.g., tetrahydrofuran, toluene, or ethanol). 【0021】 In this specification, "water-soluble" means that the solubility in 100 g of water at a temperature of 22°C and pH 7.0 is 0.1 g or more. Therefore, for example, a water-soluble resin refers to a resin that satisfies the above-mentioned solubility conditions. 【0022】 The "solid content" of a composition refers to the components that form the composition layer (e.g., a photosensitive composition layer) formed using the composition. If the composition contains a solvent (e.g., an organic solvent and water), it refers to all components excluding the solvent. Furthermore, any liquid components that form the composition layer are also considered to be solid content. 【0023】 In this specification, unless otherwise specified, the thickness of a layer (film thickness) is the average thickness measured using a scanning electron microscope (SEM) for thicknesses of 0.5 μm or more, and the average thickness measured using a transmission electron microscope (TEM) for thicknesses less than 0.5 μm. The above average thickness is the average thickness obtained by forming a section of the material to be measured using an ultramicrotome, measuring the thickness at any five points, and arithmetically averaging them. 【0024】[Transfer Film] The transfer film of the present invention is a transfer film comprising a temporary support and a photosensitive composition layer, wherein the photosensitive composition layer comprises a polymer having a repeating unit represented by formula (1) described later (hereinafter also referred to as "repeating unit (1)"), a radical polymerizable group, and a carboxyl group or a salt thereof (hereinafter also referred to as "specific polymer"). 【0025】 The photosensitive composition layer transferred from the transfer film of the present invention to the object to be transferred exhibits excellent resolution when subjected to alkaline development, and the cured layer obtained from the photosensitive composition layer has low optical loss. In other words, the transfer film of the present invention having the above configuration is alkaline developable and can form an optical waveguide that can achieve low light propagation loss. The reason for this is not clear, but the inventors speculate as follows: The specific polymer contained in the photosensitive composition layer contained in the transfer film has excellent alkaline developability because it possesses carboxyl groups and polymerizable groups. In addition, in the repeating unit (1) contained in the specific polymer, the hydrogen atom on the benzene ring is replaced with a fluorine atom, thereby reducing the number of C-H bonds that have absorption in the wavelength band typically applied in optical transmission (particularly wavelength 1310 nm and its vicinity) and can be a cause of high optical loss. On the other hand, C-F bonds do not have specific absorption in the above wavelength band. As a result, the cured layer obtained from the photosensitive composition layer containing the specific polymer can have suppressed optical loss. Furthermore, our current studies have revealed that when other components (for example, components other than the specific polymer, such as polymerizable compounds) are introduced into the photosensitive composition layer, the presence of polymerizable groups contained in the specific polymer improves the compatibility between the specific polymer and the other components. As a result, turbidity caused by intralayer separation between the specific polymer and the other components is less likely to occur in the photosensitive composition layer, the alkali developability of the photosensitive composition layer is further improved, and the optical loss of the resulting cured layer is more easily suppressed. 【0026】Furthermore, as described later, it is preferable that the photosensitive composition layer in the transfer film contains, in addition to the specific polymer, a compound that further reduces carboxyl groups (hereinafter also referred to as "compound X"). Carboxyl groups have absorption in the wavelength band typically applied in light transmission (particularly around 1310 nm) and can be a cause of high optical loss (note that carboxyl groups have vibrational absorption in the wavelength region of 1400 to 1700 nm, and the tail of the absorption peak is located around 1310 nm). When the photosensitive composition layer in the transfer film contains compound X, it is possible to reduce the carboxyl group content after alkaline development by the action of compound X. In other words, when the photosensitive composition layer of the transfer film contains compound X, the photosensitive composition layer transferred to the object to be transferred shows good affinity to the alkaline developer during alkaline development due to the presence of carboxyl groups derived from the specific polymer, but after alkaline development, the carboxyl group content is reduced by the action of compound X, making it possible to form an optical waveguide with further reduced light propagation loss. 【0027】 In the following, "superior alkaline developability and / or lower light propagation loss" may also be referred to as "superior effects of the present invention." 【0028】 [Composition of the Transfer Film] The composition of the transfer film will be described below. Figure 1 is a schematic cross-sectional view showing an example of an embodiment of the transfer film. The transfer film 10 shown in Figure 1 has a configuration in which a temporary support 12, a thermoplastic resin layer 14, an intermediate layer 16, a photosensitive composition layer 18, and a cover film (protective film) 20 are laminated in this order. Note that although the transfer film 10 shown in Figure 1 has a cover film 20, the cover film 20 may not be included. Also, although the transfer film 10 shown in Figure 1 has a thermoplastic resin layer 14 and an intermediate layer 16, the thermoplastic resin layer 14 and the intermediate layer 16 may not be included. The individual elements constituting the transfer film will be described below. 【0029】<<Temporary Support>> The transfer film has a temporary support. The temporary support is a component that supports the photosensitive composition layer and is ultimately removed by a peeling process. 【0030】 The temporary support may have either a single-layer or multi-layer structure. The temporary support is preferably a film that is flexible and does not undergo significant deformation, shrinkage, or elongation under pressure, or under pressure and heat. Among these, a resin film is more preferable due to its superior strength and flexibility. Examples of the resin film include polyethylene terephthalate film (e.g., biaxially oriented polyethylene terephthalate film), polymethyl methacrylate film, cellulose triacetate film, polystyrene film, polyimide film, and polycarbonate film, with polyethylene terephthalate film being preferred. Furthermore, the film used as the temporary support is preferably free from deformation such as wrinkles and scratches. The temporary support may also be a glass substrate or paper. 【0031】 The temporary support is preferably transparent in such a way that the photosensitive composition layer can be exposed through the temporary support when pattern exposure of the photosensitive composition layer. More specifically, the transmittance of the temporary support at wavelengths of 313 nm, 365 nm, 313 nm, 405 nm, and 436 nm is preferably 60% or more, more preferably 70% or more, even more preferably 80% or more, and most preferably 90% or more. A method for measuring transmittance is to use the MCPD Series manufactured by Otsuka Electronics Co., Ltd. 【0032】 The thickness of the temporary support is not particularly limited, but is preferably 5 to 200 μm, more preferably 5 to 150 μm, even more preferably 5 to 50 μm, and most preferably 5 to 25 μm, from the viewpoint of ease of handling and versatility. The thickness of the temporary support is calculated as the average value of any five points measured by cross-sectional observation using a Scanning Electron Microscope (SEM). 【0033】To improve adhesion between the temporary support and the photosensitive composition layer, the side of the temporary support that comes into contact with the photosensitive composition layer may be surface-modified by UV irradiation, corona discharge, plasma, or the like. 【0034】 Examples of temporary supports include biaxially oriented polyethylene terephthalate films with a thickness of 16 μm, biaxially oriented polyethylene terephthalate films with a thickness of 12 μm, and biaxially oriented polyethylene terephthalate films with a thickness of 9 μm. Temporary supports may also be recycled materials. Examples of recycled materials include those made by washing and chipping used films, and then forming films from these chips. A specific example of a recycled material is Toray's Ecouse series. 【0035】 Preferred forms of the temporary support are described, for example, in paragraphs

[0017] to

[0018] of Japanese Patent Publication No. 2014-085643, paragraphs

[0019] to

[0026] of Japanese Patent Publication No. 2016-027363, paragraphs

[0041] to

[0057] of International Publication No. 2012 / 081680, and paragraphs

[0029] to

[0040] of International Publication No. 2018 / 179370, the contents of which are incorporated herein by reference. 【0036】 To improve handling, a layer containing fine particles (lubricant layer) may be provided on the surface of the temporary support. The lubricant layer may be provided on one side of the temporary support or on both sides. 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. 【0037】 Commercially available temporary supports include Lumirror 16KS40, Lumirror 16FB40, Lumirror #38-U48, Lumirror #75-U34, and Lumirror #25T60 (all manufactured by Toray Industries, Inc.), and Cosmoshine A4100, Cosmoshine A4160, Cosmoshine A4300, Cosmoshine A4360, and Cosmoshine A8300 (all manufactured by Toyobo Co., Ltd.). 【0038】<<Photosensitive Composition Layer>> The transfer film has a photosensitive composition layer. The photosensitive composition layer is preferably a so-called negative photosensitive composition layer. Hereinafter, each component contained in the photosensitive composition layer will be described in detail. 【0039】 <Specific Polymer> The photosensitive composition layer contains a specific polymer. The specific polymer has a repeating unit represented by formula (1) (repeating unit (1)), a radically polymerizable group, and a carboxy group or a salt thereof. The specific polymer is preferably an alkali-soluble resin. 【0040】 《Repeating Unit Represented by Formula (1) (Repeating Unit (1))》 【0041】 In formula (1), R ａ to R ｃ each independently represents a hydrogen atom, a deuterium atom, or a fluorine atom. R ａ to R ｃ are preferably a deuterium atom or a fluorine atom in terms of further reducing optical loss, and a hydrogen atom is preferable in terms of simplicity of synthesis and ease of availability. 【0042】 R １ to R ５ each independently represents a hydrogen atom or a fluorine atom. However, at least one of R １ to R ５ represents a fluorine atom. In terms of further reducing optical loss, it is preferable that all of R １ to R ５ represent fluorine atoms. 【0043】 In the specific polymer, the content of the repeating unit (1) (when a plurality of types are included, the total content thereof) is preferably 30 to 95% by mass, more preferably 40 to 90% by mass, and still more preferably 45 to 80% by mass with respect to all the repeating units of the specific polymer. In the specific polymer, the content of the repeating unit (1) (when a plurality of types are included, the total content thereof) is preferably 25 to 90 mol%, more preferably 30 to 80 mol%, and still more preferably 40 to 70 mol% with respect to all the repeating units of the specific polymer. The repeating unit (1) may be used alone or in combination of two or more. 【0044】 The specific polymer has a radical polymerizable group. The radical polymerizable group of the specific polymer is not particularly limited, but examples include ethylenically unsaturated groups, with (meth)acryloyloxy groups, vinyl groups, allyl groups, or styryl groups being preferred, and (meth)acryloyloxy groups being more preferred. 【0045】 The specific polymer preferably contains repeating units having radical polymerizable groups, as this provides superior effects for the present invention. Examples of repeating units having radical polymerizable groups include the repeating unit represented by formula (2) (hereinafter also referred to as "repeating unit (2)") and the repeating unit represented by formula (4) (hereinafter also referred to as "repeating unit (4)"). Among the repeating units having radical polymerizable groups, the repeating unit represented by formula (2) (repeating unit (2)) is preferred. Repeating unit (2) and repeating unit (4) will be described below. 【0046】 《The repeating unit represented by equation (2) (Repeating unit (2))》 【0047】 In formula (2), R ｄ ~R ｆ Each of these independently represents a hydrogen atom, a deuterium atom, or a fluorine atom. ｄ ~R ｆ In terms of further reducing optical loss, deuterium atoms or fluorine atoms are preferred, while hydrogen atoms are preferred in terms of ease of synthesis and availability. 【0048】 X １ represents an oxygen atom, a sulfur atom, or a single bond, with an oxygen atom or a sulfur atom being preferred, and an oxygen atom being more preferred. 【0049】 L １ This represents a single bond, or a linear or branched n1+1 valent aliphatic hydrocarbon group having 1 to 10 carbon atoms, which may have substituents, and at least one methylene group may be substituted with an oxygen atom or a sulfur atom. The number of carbon atoms is preferably 1 to 6, and more preferably 1 to 3. 【0050】 When n1 represents 1, L １Preferably, represents a linear or branched alkylene group having 1 to 10 carbon atoms, which may have substituents and at least one methylene group may be substituted with an oxygen atom or a sulfur atom; more preferably, represents a linear or branched alkylene group having 1 to 10 carbon atoms, which may have substituents. The number of carbon atoms is preferably 1 to 6, and more preferably 1 to 3. 【0051】 If n1 represents 2, then L １ It is preferable that represents a trivalent linking group represented by formula (L1A), and when n1 represents 3, L １ Preferably, represents a tetravalent linking group represented by formula (L1B). 【0052】 【0053】 In formula (L1A), L １１ ~L １３ Each of these independently represents a linear or branched alkylene group having 1 to 6 carbon atoms, which may have single bonds or substituents, and at least one methylene group may be substituted with an oxygen atom or a sulfur atom. １１ * represents a hydrogen atom or an alkyl group (e.g., a methyl group). １ is, X １ This indicates the connection position with * ２ This indicates the bonding position with P. However, the total number of carbon atoms in the trivalent linking group represented by formula (L1A) is between 1 and 10. 【0054】 In formula (L1B), L １４ ~L １７ Each of these independently represents a linear or branched alkylene group having 1 to 6 carbon atoms, which may have single bonds or substituents, and at least one methylene group may be substituted with an oxygen atom or a sulfur atom. １ is, X １ This indicates the connection point with [the other element]. * ２ The symbol indicates the bonding position with P. However, the total number of carbon atoms in the tetravalent linking group represented by formula (L1B) is between 1 and 10. 【0055】 L １ Examples of substituents that may be present include hydroxyl groups and aromatic hydrocarbon groups (e.g., phenyl groups). 【0056】 P represents an acryloyloxy group or a methacryloyloxy group. When n1 represents 2 or 3, the multiple Ps may be the same or different from each other. 【0057】 n1 represents an integer from 1 to 3. It is preferable that n1 represents 1, as this provides superior effects for the present invention. １ When n1 represents a single bond, then n1 represents 1. 【0058】 《The repeating unit represented by formula (4) (Repeating unit (4))》 【0059】 In the formula, R ８ and R ９ Each of these independently represents either a hydrogen atom or a methyl group. ２ and X ３ These are, independently, -O- or -NR Ｎ Represents -. X ２ and X ３ It is preferable to represent -O-. Ｎ R represents a hydrogen atom or an alkyl group. Ｎ The number of carbon atoms in the alkyl group represented by is preferably 1 to 6, and more preferably 1 to 3. 【0060】 L ２ This represents an unsubstituted divalent hydrocarbon group. ２ The divalent hydrocarbon group represented is preferably a linear or branched alkylene group having 1 to 10 carbon atoms. The number of carbon atoms is preferably 1 to 6, and more preferably 1 to 3. 【0061】In the specified polymer, the content of repeating units having radical polymerizable groups (preferably repeating unit (2) or repeating unit (4), more preferably repeating unit (2)) (if multiple types are included, the total content) is preferably 10 to 60% by mass, more preferably 10 to 50% by mass, and even more preferably 10 to 40% by mass, relative to the total repeating units of the specified polymer. In the specified polymer, the content of repeating units having radical polymerizable groups (preferably repeating unit (2) or repeating unit (4), more preferably repeating unit (2)) (if multiple types are included, the total content) is preferably 10 to 60 mol%, more preferably 10 to 50 mol%, and even more preferably 10 to 35 mol%, relative to the total repeating units of the specified polymer. The repeating units having radical polymerizable groups may be used individually or in combination of two or more types. 【0062】 The specific polymer has a carboxyl group or a salt thereof. The specific polymer preferably contains repeating units having a carboxyl group or a salt thereof, and more preferably contains repeating units having a carboxyl group, in terms of superior effects of the present invention. The countercation of the carboxyl salt may be either an inorganic cation or an organic cation, such as a sodium cation, a potassium cation, and a quaternary ammonium cation. 【0063】 Examples of repeating units having a carboxyl group or a salt thereof include (meth)acrylic acid, crotonic acid, itaconic acid, maleic acid, and fumaric acid, as well as repeating units derived from salts thereof. 【0064】 Among the repeating units having a carboxyl group or a salt thereof, the repeating unit represented by formula (A) (hereinafter also referred to as "repeating unit (A)") is preferred, and the repeating unit represented by formula (5) (hereinafter also referred to as "repeating unit (5)") is more preferred. Repeating units (A) and (5) will be described below. 【0065】 Repeating Unit (A) 【0066】 In formula (A), R Ａ１represents a hydrogen atom, a halogen atom, or an alkyl group. The alkyl group is preferably linear or branched. The alkyl group has 1 to 5 carbon atoms, and more preferably 1 carbon atom. 【0067】 A １ represents a single bond or a divalent linking group. Examples of the above divalent linking groups are -CO-, -O-, -S-, -SO-, and -SO ２ -, -NR Ｎ - (R Ｎ Examples include hydrogen atoms or alkyl groups having 1 to 5 carbon atoms), hydrocarbon groups (for example, alkylene groups, cycloalkylene groups, alkenylene groups, phenylene groups, and other arylene groups), and linked groups formed by linking multiple of these. 【0068】 R Ａ２ R represents a hydrogen atom or a monovalent cation. Ａ２ The monovalent cation represented by may be either a monovalent organic cation or a monovalent inorganic cation. Specific examples of monovalent cations include sodium cations, potassium cations, and quaternary ammonium cations. Ａ２ It is preferable that this represents a hydrogen atom. 【0069】 Repeating Unit (5) 【0070】 In the formula, R １０ represents a hydrogen atom or a methyl group. 【0071】In the specified polymer, the content of repeating units having a carboxyl group or a salt thereof (preferably repeating unit (A) or repeating unit (5)) (if multiple types are included, the total content) is preferably 3 to 30% by mass, more preferably 5 to 20% by mass, and even more preferably 5 to 15% by mass, relative to the total repeating units of the specified polymer. In the specified polymer, the content of repeating units having a carboxyl group or a salt thereof (preferably repeating unit (A) or repeating unit (5)) (if multiple types are included, the total content) is preferably 3 to 40 mol%, more preferably 10 to 35 mol%, and even more preferably 10 to 30 mol%, relative to the total repeating units of the specified polymer. Repeating units having a carboxyl group or a salt thereof may be used individually or in combination of two or more types. 【0072】 Furthermore, the specific polymer may further contain acid groups other than carboxyl groups or salts thereof. Examples of acid groups other than carboxyl groups include phenolic hydroxyl groups, phosphate groups, and sulfonic acid groups. 【0073】 The specified polymer may contain repeating units other than those described above. An example of other repeating units that the specified polymer may contain is the repeating unit represented by formula (3) (hereinafter also referred to as "repeating unit (3)"). When the specified polymer contains repeating unit (3), the hydrophilicity of the specified polymer is further improved without degrading optical loss, and its alkali developability tends to be even better. 【0074】 【0075】 In formula (3), R ６ R represents a hydrogen atom or a cyano group. ７ R represents a hydrogen atom, a methyl group, or a cyanoethyl group. ６ When R represents a cyano group, ７ represents a hydrogen atom. Also, R ６ When R represents a hydrogen atom, ７ represents a hydrogen atom, a methyl group, or a cyanoethyl group. 【0076】In the specified polymer, the content of repeating units (3) (total content if multiple types are included) is preferably 3 to 15% by mass, more preferably 3 to 10% by mass, and even more preferably 3 to 8% by mass, relative to the total repeating units of the specified polymer. In the specified polymer, the content of repeating units (3) (total content if multiple types are included) is preferably 3 to 20 mol%, more preferably 3 to 15 mol%, and even more preferably 3 to 12 mol%, relative to the total repeating units of the specified polymer. Repeating units (3) may be used individually or in combination of two or more types. 【0077】 Other repeating units that may be included in the specific polymer include repeating units derived from alkyl (meth)acrylates. The alkyl group in the alkyl (meth)acrylate is preferably a chain-like structure (linear or branched structure). The number of carbon atoms in the alkyl group is typically 1 to 50, with 1 to 10 being more preferred. Specific examples of alkyl (meth)acrylates include methyl (meth)acrylate. 【0078】 Furthermore, another example of a repeating unit that may be contained in a specific polymer is a repeating unit having an alicyclic structure. The alicyclic structure may be monocyclic or polycyclic. Examples of alicyclic structures include dicyclopentanyl ring structures, dicyclopentenyl ring structures, isobornyl ring structures, adamantane ring structures, and cyclohexyl ring structures. Examples of monomers from which repeating units having an alicyclic structure are derived include dicyclopentanyl (meth)acrylate, dicyclopentenyl (meth)acrylate, isobornyl (meth)acrylate, adamantyl (meth)acrylate, and cyclohexyl (meth)acrylate. 【0079】If the specific polymer contains other repeating units, the content of the other repeating units (total content if multiple types are included) is preferably 30% by mass or less, more preferably 20% by mass or less, and even more preferably 15% by mass or less, relative to the total repeating units of the specific polymer. The other repeating units may be used individually or in combination of two or more types. 【0080】 The lower limit of the weight-average molecular weight of the specific polymer is preferably 5,000 or more, more preferably 8,000 or more, and even more preferably 10,000 or more, in terms of excellent photosensitive composition layer formation (in other words, excellent film-forming ability for forming a photosensitive composition layer). There is no particular upper limit, but it is preferably 50,000 or less in terms of better adhesion (laminate adhesion) when bonding to any substrate (during transfer). 【0081】 The acid value of the specific polymer is preferably 0.2 to 3.0 mmol / g, more preferably 0.6 to 2.0 mmol / g, and even more preferably 0.8 to 1.7 mmol / g, in terms of superior alkali developability. 【0082】 Furthermore, some or all of the carboxyl groups of the specific polymer may be anionized or not anionized in the photosensitive composition layer. In this specification, anionized carboxyl group (-COO － Both the anionized and unanionized carboxyl groups are referred to as carboxyl groups. 【0083】 In order to obtain superior effects from the present invention, the specific polymer preferably contains a total amount of specific repeating units selected from the group consisting of repeating unit (1), repeating unit (2), and repeating unit (3) of 50% by mass or more, and more preferably 70% by mass or more, relative to the total number of repeating units. There is no particular upper limit to the specific repeating units, but 95% by mass or less is preferred. 【0084】An example of a preferred embodiment of the specific polymer is a polymer in which the total content of specific repeating units selected from the group consisting of repeating unit (1), repeating unit (2), and repeating unit (3) is 50% by mass or more (preferably 70% by mass or more) relative to the total number of repeating units, and the acid value is 0.6 to 2.0 mmol / g. There is no particular upper limit to the specific repeating units, but 95% by mass or less is preferred. 【0085】 Another example of a preferred embodiment of a specific polymer is a polymer comprising a repeating unit (1), a repeating unit selected from the group consisting of repeating units (2) and (4) (a repeating unit having a radical polymerizable group), and a repeating unit (5). 【0086】In the photosensitive composition layer, the lower limit of the content of specific polymers (or the total content if multiple types are included) is preferably 25.0% by mass or more, more preferably 40.0% by mass or more, even more preferably 50.0% by mass or more, particularly preferably 60.0% by mass or more, and most preferably 70.0% by mass or more, relative to the total mass of the photosensitive composition layer. The upper limit of the content of specific polymers is preferably 95.0% by mass or less, more preferably 90.0% by mass or less, even more preferably 85.0% by mass or less, and particularly preferably 80.0% by mass or less, relative to the total mass of the photosensitive composition layer. Furthermore, in order to achieve both low optical loss and better resolution, it is also preferable that the content of specific polymers be 70.0% by mass or less, more preferably 40.0 to 70.0% by mass, and even more preferably 50.0 to 70.0% by mass, relative to the total mass of the photosensitive composition layer. The specific polymers may be used individually or in combination of two or more types. Furthermore, from the viewpoint of further reducing optical loss, it is preferable that the content of the specific polymer be 80.0% by mass or more, more preferably 85.0% by mass or more, and even more preferably 90.0% by mass or more, relative to the total mass of the photosensitive composition layer. When the content of the specific polymer is within the above numerical range, it is preferable that the photosensitive composition layer contains a compound (compound X) that reduces the amount of carboxyl groups, as described later, in order to further improve resolution. With the above configuration, when patterning the photosensitive composition layer, the carboxyl groups of the specific polymer are reduced in the exposed area by the action of the compound (compound X) that reduces the amount of carboxyl groups, thereby forming a more hydrophobic film. As a result, the residual film properties in the exposed area tend to be excellent in alkaline development (in other words, a pattern with excellent resolution is more likely to be obtained). 【0087】<Compounds that reduce the amount of carboxyl groups> The photosensitive composition layer preferably contains a compound that reduces the amount of carboxyl groups (hereinafter also referred to as "compound X"). The mechanism by which compound X reduces the amount of carboxyl groups is not particularly limited. For example, compound X may have a crosslinking group that can react with carboxyl groups (especially carboxyl groups derived from a specific polymer) that are present in the photosensitive composition layer, and this crosslinking group may react with the carboxyl groups to reduce the amount of carboxyl groups (hereinafter also referred to as "mechanism A"). Alternatively, compound X may cause a decarboxylation reaction of the carboxyl groups (especially carboxyl groups derived from a specific polymer) present in the photosensitive composition layer (in other words, compound X may cause the carboxyl groups (especially carboxyl groups derived from a specific polymer) to be CO ２ One example is a mechanism (hereinafter also referred to as "mechanism B") that reduces the amount of carboxyl groups by elimination (decarboxylation). 【0088】 Compound X that reduces the amount of carboxyl groups by mechanism A. Examples of the crosslinkable groups mentioned above include isocyanate groups. Among the crosslinkable groups, thermally crosslinkable groups are preferred, and blocked isocyanate groups are more preferred. A blocked isocyanate group refers to a group having a structure in which an isocyanate group is protected (so-called masked) with a blocking agent. The number of crosslinkable groups in compound X is not particularly limited, for example, 1 to 10 is preferred, 1 to 6 is more preferred, and 2 to 6 is even more preferred. 【0089】The compound X having a crosslinkable group is preferably a compound having an isocyanate group (isocyanate compound), and more preferably a compound having a blocked isocyanate group (blocked isocyanate compound). The dissociation temperature of the blocked isocyanate compound is not particularly limited, but is preferably 90 to 180°C, and more preferably 100 to 160°C. The dissociation temperature of the blocked isocyanate means "the temperature of the endothermic peak associated with the deprotection reaction of the blocked isocyanate when measured by DSC (Differential Scanning Calorimetry) analysis using a differential scanning calorimetry meter." As the differential scanning calorimetry meter, for example, a differential scanning calorimetry meter (model: DSC6200) manufactured by Seiko Instruments Corporation can be suitably used. However, the differential scanning calorimetry meter is not limited to this. 【0090】 Examples of 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, and di-2-ethylhexyl malonate)] and oxime compounds (e.g., formaldehyde oxime, acetaldehyde oxime, acetoxime, methyl ethyl ketoxime, and cyclohexanone oxime, etc., which have a structure represented by -C(=N-OH)- in the molecule). Among these, for blocking agents with a dissociation temperature of 90 to 160°C, at least one selected from the group consisting of oxime compounds and pyrazole compounds is preferred from the viewpoint of storage stability. 【0091】 Blocked isocyanate compounds are preferably formed by having an isocyanurate structure, which improves the brittleness of the film and enhances adhesion to the transfer material. Blocked isocyanate compounds having an isocyanurate structure are obtained by protecting hexamethylene diisocyanate by isocyanurating it. Among these, as blocked isocyanate compounds having an isocyanurate structure, compounds having an oxime structure obtained by using an oxime compound as a blocking agent are preferred because they make it easier to set the dissociation temperature within a favorable range and reduce development residue compared to compounds without an oxime structure. 【0092】The blocked isocyanate compound may have a polymerizable group. There are no particular restrictions on the polymerizable group, and known polymerizable groups can be used, with radical polymerizable groups being preferred. Examples of polymerizable groups include ethylenically unsaturated groups such as (meth)acryloyl groups, (meth)acrylamide groups, and styryl groups, among which (meth)acryloyl groups are preferred, and acryloyl groups are more preferred. 【0093】 Commercially available blocked isocyanate compounds can be used. Examples of commercially available blocked isocyanate compounds include Karenz® AOI-BM, Karenz® MOI-BM, Karenz® MOI-BP, etc. (all manufactured by Showa Denko Corporation), and the block-type Duranate series (for example, Duranate® TPA-B80E, Duranate® SBN-70D, Duranate® WT32-B75P, etc., manufactured by Asahi Kasei Chemicals Corporation). 【0094】 Compound X that reduces the amount of carboxyl groups by mechanism B. Compound X that reduces the amount of carboxyl groups by mechanism B includes compounds that, upon exposure, cause a decarboxylation reaction of carboxyl groups (particularly carboxyl groups derived from a specific polymer) in the photosensitive composition layer, thereby reducing the amount of carboxyl groups. Compound X transitions from the ground state to an excited state upon exposure, and in the excited state accepts electrons from the carboxyl groups (particularly carboxyl groups derived from a specific polymer) in the photosensitive composition layer, and the carboxyl groups are converted to CO ２ It can be detached as such. 【0095】Examples of compounds X that can cause a decarboxylation reaction of a carboxyl group in an excited state include nitrogen-containing aromatic compounds. Nitrogen-containing aromatic compounds are compounds having an aromatic ring (nitrogen-containing aromatic ring) having one or more (e.g., 1 to 4) nitrogen atoms as ring member atoms. The nitrogen-containing aromatic ring may be monocyclic or polycyclic, with polycyclic being preferred. If the nitrogen-containing aromatic ring is an aromatic ring formed by the fusion of multiple (e.g., 2 to 6) aromatic ring structures, it is sufficient that at least one of the multiple aromatic ring structures contains a nitrogen atom as a ring member atom. Furthermore, the nitrogen-containing aromatic ring may have heteroatoms other than nitrogen atoms (e.g., oxygen atoms and sulfur atoms) as ring member atoms. In addition, the nitrogen-containing aromatic compound may further have substituents. 【0096】 Examples of nitrogen-containing aromatic compounds include quinoline compounds (quinoline and quinoline derivatives), isoquinoline compounds (isoquinoline and isoquinoline derivatives), quinoxaline compounds (quinoxaline and quinoxaline derivatives), acridine compounds (acridine and acridine derivatives), phenanthroline compounds (phenanthroline and phenanthroline derivatives), and phenazine compounds (phenazine and phenazine derivatives), which have a higher molar extinction coefficient at a wavelength of 365 nm and excellent photosensitivity at a wavelength of 365 nm. Quinoline compounds, isoquinoline compounds, or quinoxaline compounds are preferred, and quinoline compounds are more preferred. The substituents that the nitrogen-containing aromatic compounds may have are not particularly limited, and examples include alkyl groups, aryl groups, halogen atoms, acyl groups, alkoxycarbonyl groups, arylcarbonyl groups, carbamoyl groups, cyano groups, nitro groups, and groups represented by the following formula (PB1). 【0097】 Formula (PB1): *-L Ｂ１ - (P Ｂ１ ) ｎＢ１ In the ceremony, L Ｂ１ This represents a single bond or an nB1+1 valent linking group. Ｂ１ represents a polymerizable group. nB1 represents an integer from 1 to 3. Note that P Ｂ１ If multiple P Ｂ１They may be the same or different from one another. 【0098】 L Ｂ１ The nB1+1 valent linking groups represented by these are, for example, -CO-, -O-, -S-, -SO-, -SO ２ -, -NR Ｎ - (R Ｎ Examples of these include hydrogen atoms or C1-C5 alkyl groups, aliphatic hydrocarbon groups, aromatic hydrocarbon groups, and linking groups formed by combining two or more of these. The aliphatic hydrocarbon group and aromatic hydrocarbon group may further have substituents. Examples of substituents include alkyl groups, aryl groups, halogen atoms, acyl groups, alkoxycarbonyl groups, arylcarbonyl groups, carbamoyl groups, cyano groups, and nitro groups. 【0099】 The above L Ｂ１ As for, -(L Ｂ２ ) ｎＢ２ -L Ｂ３ It is also preferable that the group be represented by -. Ｂ２ is an oxygen atom or CH ２ This represents nB2, which represents 0 or 1. Ｂ３ This represents a single bond or an nB1+1 valent linking group. Ｂ３ Specific examples of nB1+1 valent linking groups represented by include, for example, linear, branched, or cyclic nB1+1 valent aliphatic hydrocarbon groups that may have substituents and in which at least one methylene group may be substituted with an oxygen atom (-O-), and nB1+1 valent aromatic hydrocarbon groups that may have substituents. The number of carbon atoms in the aliphatic hydrocarbon group is preferably 1 to 30, more preferably 1 to 20, and even more preferably 1 to 10. A benzene ring group is preferred as the aromatic hydrocarbon group. Examples of substituents that the aliphatic hydrocarbon group and the aromatic hydrocarbon group may have include the substituents mentioned above. When nB2 represents 0, -(L Ｂ２ ) ｎＢ２ The part represented by - indicates a single bond. 【0100】 In formula (PB1), P Ｂ１Examples of the polymerizable group represented by include a radical polymerizable group and a cationic polymerizable group, and a radical polymerizable group is preferred. Examples of the radical polymerizable group include a styryl group, a (meth)acryloyl group, and a vinyl group, etc. Among them, a styryl group or a (meth)acryloyl group is preferred. 【0101】 In the formula (PB1), nB1 is preferably 1 or 2, and more preferably 1. 【0102】 In addition, L in the formula (PB1) Ｂ１ The (nB1 + 1)-valent linking group represented by is also preferably a divalent linking group. L Ｂ１ As an example of the divalent linking group represented by , at least one CH ２ is replaced by -CO-, -O-, -S-, -SO-, -SO ２ -, -NR Ｎ -(R Ｎ is a hydrogen atom or an alkyl group having 1 to 5 carbon atoms) may be substituted alkylene group (the number of carbon atoms is preferably 1 to 30, more preferably 1 to 20, and even more preferably 1 to 12.) and arylene group, etc. are mentioned. In addition, the above alkylene group and arylene group may further have a substituent, and examples of the substituent include the above-mentioned substituents, etc. L Ｂ１ As another example of the divalent linking group represented by , -(L Ｂ４ ) ｎＢ４ -(L Ｂ５ ) ｎＢ５ -represented divalent linking group is also mentioned. The above L Ｂ４ represents an oxygen atom or CH ２ . nB4 represents 0 or 1. L Ｂ５ may have a substituent, and the methylene group may be substituted with an oxygen atom (-O-), a linear, branched or cyclic alkylene group having 1 to 10 carbon atoms, or an arylene group (preferably a phenylene group) which may have a substituent. nB5 represents an integer of 0 to 3. However, the total number of nB4 and nB5 is 1 or more. When there are a plurality of L Ｂ５ , the plurality of L Ｂ５ may be the same as or different from each other. When nB4 represents 0, -(L Ｂ４ )ｎＢ４ The part represented by - represents a single bond. Also, when nB5 represents 0, -(L Ｂ５ ) ｎＢ５ The part represented by - represents a single bond. Examples of substituents that the alkylene group and arylene group may have include the substituents mentioned above. L Ｂ５ As a linear, branched, or cyclic alkylene group having 1 to 10 carbon atoms, which may have substituents and in which the methylene group may be substituted with an oxygen atom, a linear alkylene group having 1 to 10 carbon atoms, which may have substituents and in which the methylene group may be substituted with an oxygen atom, is preferred. - (L Ｂ５ ) ｎＢ５ The number of atoms excluding the hydrogen atoms in the part represented by - is preferably 1 to 30, preferably 1 to 20, and more preferably 1 to 12. 【0103】 The above nitrogen-containing aromatic compound is preferably polymerizable, and more preferably radical polymerizable, in that its volatilization during the optical waveguide manufacturing process is suppressed, thereby resulting in superior effects of the present invention. 【0104】 A suitable example of a nitrogen-containing aromatic compound having the above-mentioned radical polymerizable group is the compound represented by the following formula (B1). 【0105】 【0106】 In the ceremony, L １ is an oxygen atom or CH ２ This represents n1, which represents 0 or 1. ２ P represents a linear, branched, or cyclic n²+1 valent aliphatic hydrocarbon group having 1 to 10 carbon atoms, which may have a single bond or substituents, and at least one methylene group may be substituted with an oxygen atom, or an n²+1 valent aromatic hydrocarbon group which may have substituents. n² represents an integer from 1 to 3. P represents a styryl group, an acryloyl group, or a methacryloyl group. If there are multiple Ps, they may be the same or different from each other. Also, if n1 represents 0, -(L １ ) ｎ１ The part represented by - indicates a single bond. 【0107】 L ２ Among these, a linear n2+1 valent alkylene group having 1 to 10 carbon atoms is preferred, which may have substituents and at least one methylene group may be substituted with an oxygen atom. n2 is preferably 1 or 2, and more preferably 1. 【0108】 Specific examples of compounds represented by formula (B1) include those represented by formulas (B1) to (B3), which will be described later. Compounds represented by formulas (B1) to (B3) can be synthesized by conventional methods. 【0109】 Specific examples of the nitrogen-containing compounds mentioned above include quinoline, 2-methylquinoline, 3-methylquinoline, 4-methylquinoline, 6-methylquinoline, 7-methylquinoline, 8-methylquinoline, 4-methoxyquinoline, 6-methoxyquinoline, 8-methoxyquinoline, 2,4-dimethylquinoline, 2,6-dimethylquinoline, 4-methyl-6-methoxyquinoline, 4-methyl-6,8-dimethoxyquinoline, 4-chloroquinoline, and 4-phenylquinoline. Examples include quinoline compounds such as phosphorus, 4-(4-vinylphenyl)quinoline, and compounds represented by the following formulas (B1) to (B1); quinoxaline compounds such as quinoxaline, 2-methylquinoxaline, 2,3-dimethylquinoxaline, and 5-methylquinoxaline; isoquinoline compounds such as isoquinoline and 1-methylisoquinoline; acridine compounds such as acridine and 9-methylacridine; phenazine compounds such as phenazine; and the like. 【0110】 【0111】Furthermore, examples of compound X include acridinium salts, (iso)quinolinium salts, and iridium complexes. (Iso)quinolinium salts refer to quinolinium salts and isoquinolinium salts. In addition, compound X may be expressed by the action of two compounds. Examples of such two compounds include an aromatic compound (b1) that is unsubstituted or substituted with an electron-donating group (preferably an alkyl group or alkoxy group) and an aromatic compound (b2) that is substituted with an electron-withdrawing group (preferably a cyano group or alkoxycarbonyl group). In this combination, the cation radical of aromatic compound (b1), which is generated by electron transfer from photoexcited aromatic compound (b1) to aromatic compound (b2), accepts electrons from its carboxyl group, thereby expressing the function of compound X. Furthermore, since radicals are generated in this process, they can also be used as polymerization initiators. 【0112】 Compound X may be used alone or in combination of two or more types. When the photosensitive composition layer contains compound X, the content of compound X (or the total content if multiple types are included) is preferably 0.1% by mass or more, and more preferably 1.0% by mass or more, based on the total mass of the photosensitive composition layer. The upper limit is preferably 30.0% by mass or less, more preferably 20.0% by mass or less, even more preferably 15.0% by mass or less, and particularly preferably 10.0% by mass or less, based on the total mass of the photosensitive composition layer. 【0113】 <Polymerizable Compound> The photosensitive composition layer may also preferably contain a polymerizable compound. This polymerizable compound is a different component from the specific polymer and compound X described above. 【0114】 The polymerizable compound is preferably a compound with a molecular weight (or weight-average molecular weight if it has a molecular weight distribution) of less than 5,000, and is also preferably a polymerizable monomer. 【0115】A polymerizable compound is a polymerizable compound having one or more polymerizable groups (for example, 1 to 15 groups) in one molecule. Examples of polymerizable groups include ethylenically unsaturated groups, such as (meth)acryloyl groups, vinyl groups, and styryl groups, with (meth)acryloyl groups being preferred. The polymerizable compound preferably contains two or more polymerizable compounds. Here, two or more polymerizable compounds mean polymerizable compounds having two or more polymerizable groups (for example, 2 to 15 groups) in one molecule. The photosensitive composition layer preferably contains a two-functional polymerizable compound and a three-functional or more polymerizable compound. 【0116】 A preferred embodiment of a bifunctional polymerizable compound is the compound represented by formula (M) (hereinafter also referred to as "compound M"). ２ -R １ -Q １ Formula (M) In formula (M), Q １ and Q ２ Each of these independently represents a (meth)acryloyloxy group. １ This represents a divalent linking group having a chain-like structure. 【0117】 Q １ and Q ２ They may be the same or different, but in terms of ease of synthesis, Q １ and Q ２ It is preferable that they are the same group. １ Examples include divalent hydrocarbon groups and alkylene oxides of divalent hydrocarbon groups (-L １ -O-) Adducts include divalent hydrocarbon groups having 6 to 20 carbon atoms, or alkylene oxides of divalent hydrocarbon groups (-L １ -O-) adducts are preferred. The divalent hydrocarbon group only needs to have a chain-like structure in at least part of it, and the part other than the chain-like structure may be, for example, a branched chain, a cyclic, or a linear alkylene group having 1 to 20 carbon atoms, an arylene group, an ether bond, or a combination thereof, and an alkylene group or a group formed by combining two or more alkylene groups and one or more arylene groups is preferred. As an alkylene oxide adduct of a divalent hydrocarbon group, an alkylene oxyalkylene group (-L１ -O-L １ -), polyalkylene oxyalkylene group (-(L １ -O) ｐ -L １ -), and alkylene oxide adducts of divalent hydrocarbon groups other than polyalkylene oxyalkylene groups are examples. １ Each of these 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 between 10 and 30. 【0118】 Furthermore, Q in compound M １ and Q ２ The number of atoms in the shortest connecting chain between them is preferably 20 to 150, more preferably 30 to 120, and even more preferably 40 to 90. In this specification, "Q １ and Q ２ "The number of atoms in the shortest linking chain connecting the two points" is Q １ R connected to １ From the atom to Q ２ R connected to １ This is the shortest number of atoms required to connect up to the first atom in a given structure. 【0119】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. Other examples include tricyclodecanedimethanol diacrylate, tricyclodecanedimethanol di(meth)acrylate, fluorene structure-containing (meth)acrylate, and epoxy (meth)acrylate. The above ester monomers can also be used as mixtures. 【0120】 More specifically, examples of bifunctional polymerizable compounds include tricyclodecanedimethanol diacrylate (A-DCP, manufactured by Shin-Nakamura Chemical Industry Co., Ltd.), tricyclodecanedimethanol dimethacrylate (DCP, manufactured by Shin-Nakamura Chemical Industry Co., Ltd.), 1,9-nonanediol diacrylate (A-NOD-N, manufactured by Shin-Nakamura Chemical Industry Co., Ltd.), 1,6-hexanediol diacrylate (A-HD-N, manufactured by Shin-Nakamura Chemical Industry Co., Ltd.), and fluorene structure-containing (meth)acrylates (OGSOL EA-F5710, OGSOL EA-0300, and OGSOL GA-2800, all manufactured by Osaka Gas Chemical Co., Ltd.). 【0121】There are no particular restrictions on the polymerizable compounds with three or more functions, and they can be appropriately selected from known compounds. Examples of polymerizable compounds with three or more functions 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 with a glycerin tri(meth)acrylate skeleton. 【0122】 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, while "(tri / tetra)(meth)acrylate" is a concept that encompasses tri(meth)acrylate and tetra(meth)acrylate. 【0123】 Polymerizable compounds include urethane (meth)acrylates. The lower limit of the number of functional groups is more preferably 6 or more, and even more preferably 8 or more. The upper limit of the number of functional groups is, for example, 20 or less. 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. In addition, urethane (meth)acrylates with three or more functional groups are also included. Examples of urethane (meth)acrylates with three or more functionalities include 8UX-015A (manufactured by Taisei Fine Chemical Co., Ltd.), UA-32P, U-15HA, and UA-1100H (all manufactured by Shin Nakamura Chemical Industry Co., Ltd.), AH-600 (product name) manufactured by Kyoeisha Chemical Co., Ltd., UA-306H, UA-306T, UA-306I, UA-510H, and UX-5000 (all manufactured by Nippon Kayaku Co., Ltd.). 【0124】Other preferred embodiments of polymerizable compounds include ethylenically unsaturated compounds having acidic groups. Examples of acidic groups include phosphoric acid groups, sulfo groups, and carboxyl groups, with carboxyl groups being preferred. Examples of ethylenically unsaturated compounds having acidic groups include tri- to tetrafunctional ethylenically unsaturated compounds having acidic groups [pentaerythritol tri- and tetraacrylate (PETA) skeletons with carboxyl groups introduced (acid value: 80-120 mg KOH / g)] and quintuple- to hexafunctional ethylenically unsaturated compounds having acidic groups [dipentaerythritol penta- and hexaacrylate (DPHA) skeletons with carboxyl groups introduced (acid value: 25-70 mg KOH / g)]. These tri- or more functional ethylenically unsaturated compounds having acidic groups may be used in combination with bifunctional ethylenically unsaturated compounds having acidic groups as needed. Examples of bifunctional or ethylenically unsaturated compounds having a carboxyl group include Arronix® TO-2349 (manufactured by Toagosei Co., Ltd.), Arronix® M-520 (manufactured by Toagosei Co., Ltd.), and Arronix® M-510 (manufactured by Toagosei Co., Ltd.). 【0125】 As ethylenically unsaturated compounds having acidic groups, polymerizable compounds having acidic groups as described in paragraphs

[0025] to

[0030] of Japanese Patent Application Publication No. 2004-239942 are preferred, and the details thereof are incorporated herein. 【0126】 The weight-average molecular weight (Mw) of the polymerizable compound is preferably 200 to 3000, more preferably 250 to 2600, and even more preferably 280 to 2200. 【0127】When the photosensitive composition layer contains polymerizable compounds, the content of polymerizable compounds (total content if multiple types are included) is preferably 3.0 to 60.0% by mass, more preferably 10.0 to 50.0% by mass, and particularly preferably 10.0 to 30.0% by mass, relative to the total mass of the photosensitive composition layer. When the photosensitive composition layer contains polymerizable compounds, the mass ratio of the polymerizable compound to a specific polymer (mass of polymerizable compound / mass of specific polymer) is preferably 0.01 to 2.0, more preferably 0.05 to 1.5, even more preferably 0.05 to 1.0, and particularly preferably 0.05 to 0.8. To achieve both low optical loss and better resolution, it is also preferable to set the lower limit of the mass ratio of the polymerizable compound to a specific polymer (mass of polymerizable compound / mass of specific polymer) to 0.30 or higher. The polymerizable compound may be used alone or in combination of two or more types. 【0128】 <Polymerization Initiator> The photosensitive composition layer may also preferably contain a polymerization initiator (preferably a photopolymerization initiator). The photopolymerization initiator may be a photoradical polymerization initiator, a photocationic polymerization initiator, or a photoanionic polymerization initiator, but it is preferably a photoradical polymerization initiator. 【0129】 There are no particular restrictions on the photopolymerization initiator, and known photopolymerization initiators can be used. The photopolymerization initiator is preferably one or more selected from the group consisting of oxime ester compounds (photopolymerization initiators having an oxime ester structure) and aminoacetophenone compounds (photopolymerization initiators having an aminoacetophenone structure), and it is more preferable to include both compounds. When both compounds are included, the content of the oxime ester compound relative to the total content of both compounds is preferably 5 to 90% by mass, and more preferably 15 to 50% by mass. Furthermore, other photopolymerization initiators may be used in combination, such as hydroxyacetophenone compounds, acylphosphine oxide compounds, and bistriphenylimidazole compounds. 【0130】 Furthermore, as photopolymerization initiators, for example, those described in paragraphs 0031 to 0042 of Japanese Patent Publication No. 2011-095716 and paragraphs 0064 to 0081 of Japanese Patent Publication No. 2015-014783 may be used. 【0131】Specific examples of photopolymerization initiators include the following: Oxime ester compounds include, for example, 1,2-octanedione,1-[4-(phenylthio)phenyl-,2-(O-benzoyl oxime)] (trade name: IRGACURE OXE-01, IRGACURE series are BASF products), etanone,1-[9-ethyl-6-(2-methylbenzoyl)-9H-carbazole-3-yl]-,1-(O-acetyloxime) (trade name: IRGACURE OXE-02, manufactured by BASF), [8-[5-(2,4,6-trimethylphenyl)-11-(2-ethylhexyl)-11H-benzo[a]carbazoyl][2-(2,2,3,3-tetrafluoropropoxy)phenyl]methanone-(O-acetyloxime) (trade name: IRGACURE OXE-03 (manufactured by BASF), 1-[4-[4-(2-benzofuranylcarbonyl)phenyl]thio]phenyl]-4-methylpentanone-1-(O-acetyloxime) (trade name: IRGACURE OXE-04 (manufactured by BASF), and trade name: Lunar 6. Examples include 1-[4-(phenylthio)phenyl]-3-cyclopentylpropane-1,2-dione-2-(O-benzoyl oxime) (product name: TR-PBG-305, manufactured by Changzhou Strong Electronic Materials Co., Ltd.), 1,2-propanedione,3-cyclohexyl-1-[9-ethyl-6-(2-furanylcarbonyl)-9H-carbazole-3-yl]-,2-(O-acetyloxime) (product name: TR-PBG-326, manufactured by Changzhou Strong Electronic Materials Co., Ltd.), and 3-cyclohexyl-1-(6-(2-(benzoyloxyimino)hexanoyl)-9-ethyl-9H-carbazole-3-yl)-propane-1,2-dione-2-(O-benzoyl oxime) (product name: TR-PBG-391, manufactured by Changzhou Strong Electronic Materials Co., Ltd.).Examples of aminoacetophenone compounds include 2-(dimethylamino)-2-[(4-methylphenyl)methyl]-1-[4-(4-morpholinyl)phenyl]-1-butanone (trade name: Omnirad 379EG, the Omnirad series is a product of IGM Resins B.V.), 2-methyl-1-(4-methylthiophenyl)-2-morpholinopropan-1-one (trade name: Omnirad 907), and APi-307 (1-(biphenyl-4-yl)-2-methyl-2-morpholinopropan-1-one, manufactured by Shenzhen UV-ChemTech Ltd.). Other photopolymerization initiators include, for example, 2-hydroxy-1-{4-[4-(2-hydroxy-2-methyl-propionyl)-benzyl]phenyl}-2-methyl-propan-1-one (trade name: Omnirad 127), 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)-butanone-1 (trade name: Omnirad 369), 2-hydroxy-2-methyl-1-phenyl-propan-1-one (trade name: Omnirad 1173), 1-hydroxy-cyclohexyl-phenyl-ketone (trade name: Omnirad 184), 2,2-dimethoxy-1,2-diphenylethane-1-one (trade name: Omnirad 651), and 2,4,6-trimethylbenzoyl-diphenylphosphine oxide (trade name: Omnirad TPO). Examples include H), and bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide (trade name: Omnirad 819). 【0132】 If the photosensitive composition layer contains a polymerization initiator (preferably a photopolymerization initiator), its content (or total content if multiple types are included) is preferably 0.1 to 15.0% by mass, and more preferably 0.5 to 10.0% by mass, relative to the total mass of the photosensitive composition layer. The polymerization initiator may be used alone or in combination of two or more types. 【0133】<Surfactants> The photosensitive composition layer may contain surfactants. Examples of surfactants include anionic surfactants, cationic surfactants, nonionic surfactants, and amphoteric surfactants, with nonionic surfactants being preferred. Examples of nonionic surfactants include polyoxyethylene higher alkyl ethers, polyoxyethylene higher alkylphenyl ethers, higher fatty acid diesters of polyoxyethylene glycol, silicone-based surfactants, and fluorine-based surfactants. 【0134】As surfactants, for example, the surfactants described in paragraphs 0120 to 0125 of International Publication No. 2018 / 179640 can also be used. Furthermore, as surfactants, the surfactants described in paragraph 0017 of Japanese Patent Publication No. 4502784 and paragraphs 0060 to 0071 of Japanese Unexamined Patent Publication No. 2009-237362 can also be used. A commercially available fluorine-based surfactant is, 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-551-A, 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, MFS-578, MFS-579, MFS-586, 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), Florard FC430, FC431, FC171 (all manufactured by Sumitomo 3M Co., Ltd.), 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 Inc.), PolyFox PF636, PF656, PF6320, PF6520, PF7002 (all manufactured by OMNOVA Corporation), Futergent Examples 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). In addition, acrylic compounds having a molecular structure with a functional group containing a fluorine atom, in which the fluorine atom-containing functional group is cleaved and the fluorine atom volatilizes when heated, can also be suitably used as fluorine-based surfactants. Examples of such fluorine-based surfactants include the MegaFac DS series manufactured by DIC Corporation (Chemical Daily (February 22, 2016), Nikkei Sangyo Shimbun (February 23, 2016)), for example, MegaFac DS-21.Furthermore, as a fluorinated 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. Block polymers can also be used as fluorinated surfactants. In addition, fluorinated polymer compounds containing repeating units derived from a (meth)acrylate compound having a fluorine atom and repeating units derived from a (meth)acrylate compound having two or more (preferably five or more) alkylene oxy groups (preferably ethylene oxy groups, propylene oxy groups) can also be used as fluorinated surfactants. Furthermore, fluorinated polymers having ethylenically unsaturated bond-containing groups in their side chains can also be used as fluorinated surfactants. Examples include Megafac RS-101, RS-102, RS-718K, RS-72-K (all manufactured by DIC Corporation). 【0135】As for fluorine-based surfactants, from the viewpoint of improving environmental suitability, it is preferable that the surfactant is derived from a substitute material for compounds having a linear perfluoroalkyl group with 7 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 Solspers. Examples include 20000 (manufactured by Lubrizol Nippon Co., Ltd.), NCW-101, NCW-1001, NCW-1002 (manufactured by Fujifilm Wako Pure Chemical Industries Ltd.), Paionin D-6112, D-6112-W, D-6315 (manufactured by Takemoto Oil & Fat Co., Ltd.), Orfin E1010, Surfinol 104, 400, 440 (manufactured by Nisshin Chemical Industry Co., Ltd.), etc. 【0136】 Examples of silicone-based surfactants include linear polymers composed of siloxane bonds, and modified siloxane polymers in which organic groups have been introduced into the side chains or terminals. 【0137】Specific examples of 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, Toray Silicone SH8400 (all manufactured by Toray Dow Corning Co., Ltd.), as well as X-22-4952, X-22-4272, X-22-6266, KF-351A, K354L, KF-355A, KF- Examples include 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 Silicone Co., Ltd.), F-4440, TSF-4300, TSF-4445, TSF-4460, TSF-4452 (all manufactured by Momentive Performance Materials), BYK307, BYK323, BYK330 (all manufactured by Bic Chemie), etc. 【0138】 The surfactant content (total content if multiple types are included) is preferably 0.0001 to 10.0% by mass, more preferably 0.001 to 5.0% by mass, and even more preferably 0.005 to 3.0% by mass, based on the total mass of the photosensitive composition layer. The surfactant may be used alone or in combination of two or more types. 【0139】 <Other Additives> The photosensitive composition layer may contain other additives as needed. Examples of other additives include polymerization inhibitors, chain transfer agents, antioxidants, plasticizers, sensitizers, heterocyclic compounds, and alkoxysilane compounds. Examples of polymerization inhibitors, plasticizers, sensitizers, heterocyclic compounds, and alkoxysilane compounds are those described in paragraphs 0097 to 0119 of International Publication No. 2018 / 179640. Additives contained in the photosensitive composition layer described in Japanese Patent Publication No. 2024-052274, Japanese Patent Publication No. 2022-185008, Japanese Patent Publication No. 2024-034089, and International Publication No. 2023 / 119998 can also be referenced. 【0140】Furthermore, the photosensitive composition layer may further contain known additives such as rust inhibitors, metal oxide particles, dispersants, acid growth agents, development accelerators, conductive fibers, colorants, thermal radical polymerization initiators, thermal acid generators, ultraviolet absorbers, thickeners, and organic or inorganic precipitation inhibitors. Preferred embodiments of these components are described in paragraphs 0165 to 0184 of Japanese Patent Application Publication No. 2014-085643, and the contents of this publication are incorporated herein by reference. 【0141】 The photosensitive composition layer may contain impurities. Examples of impurities include sodium, potassium, magnesium, calcium, iron, manganese, copper, aluminum, titanium, chromium, cobalt, nickel, zinc, tin, halogens, and their ions. Among these, halide ions, sodium ions, and potassium ions are particularly likely to be mixed in as impurities, so it is especially preferable to have them in the following amounts. 【0142】 The impurity content in the photosensitive composition layer 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 impurity content in the photosensitive composition layer may be 1 ppb by mass or more, or 0.1 ppm by mass or more, relative to the total mass of the photosensitive composition layer. 【0143】 Methods to keep impurities within the above range include, for example, selecting raw materials with low impurity content for the photosensitive material, preventing the incorporation of impurities during the formation of the photosensitive material, and removing them by washing. By such methods, the amount of impurities can be kept within the above range. 【0144】 Impurities can be quantified using known methods such as ICP (Inductively Coupled Plasma) emission spectroscopy, atomic absorption spectroscopy, and ion chromatography. 【0145】Furthermore, it is preferable that the content of compounds such as benzene, formaldehyde, trichloroethylene, 1,3-butadiene, carbon tetrachloride, chloroform, N,N-dimethylformamide, N,N-dimethylacetamide, and hexane in the photosensitive composition layer be low. The content of these compounds in the photosensitive composition layer 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, based on the total mass of the photosensitive composition layer. The lower limit of the above content may be 10 ppb by mass or more, or 100 ppb by mass or more, based on the total mass of the photosensitive composition layer. The content of these compounds can be suppressed in the same way as the metal impurities described above. They can also be quantified by known measurement methods. 【0146】 The water content in the photosensitive composition layer 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, in order to improve patternability. 【0147】 <<Average thickness of the photosensitive composition layer>> The average thickness of the photosensitive composition layer is preferably 1 to 50 μm. The average thickness of the photosensitive composition layer is more preferably 2 to 10 μm, and even more preferably 2 to 5 μm. 【0148】 <<Percentage of remaining carboxyl groups and content of carboxyl groups in the photosensitive composition layer after treatment to reduce the amount of carboxyl groups>> In a photosensitive composition layer that has been treated to reduce the amount of carboxyl groups, the content of carboxyl groups relative to the total mass of the photosensitive composition layer is preferably 0.01 to 4.0% by mass, more preferably 0.01 to 3.0% by mass, and even more preferably 0.01 to 2.5% by mass. That is, for example, when a pattern is formed by applying the pattern forming method described later, the content of carboxyl groups relative to the total mass of the cured photosensitive composition layer obtained through steps X1 to X5 is preferably 0.01 to 4.0% by mass, more preferably 0.01 to 3.0% by mass, and even more preferably 0.01 to 2.5% by mass. 【0149】Furthermore, the residual rate of carboxyl groups after the treatment to reduce the amount of carboxyl groups is preferably 30 mol% or less relative to the initial carboxyl group content (carboxyl group content in the photosensitive composition layer before exposure). The residual rate of carboxyl groups (particularly carboxyl groups derived from a specific polymer) in the photosensitive composition layer is obtained by measuring the IR (infrared) spectra of the carboxyl group content in each layer of the photosensitive composition layer before exposure and the photosensitive composition layer after the treatment to reduce the amount of carboxyl groups, and calculating the residual rate of the peak derived from the carboxyl group. The residual rate of the carboxyl group content is determined by the C=O expansion peak of the carboxyl group (1710 cm⁻¹). －１ This is obtained by calculating the survival rate (of the peak). 【0150】 <<Intermediate Layer>> The transfer film may have an intermediate layer between the temporary support and the photosensitive composition layer. Preferably, the intermediate layer is placed between the thermoplastic resin layer and the photosensitive composition layer, and, if the thermoplastic resin layer is not present, between the temporary support and the photosensitive composition layer. When the intermediate layer is placed between the thermoplastic resin layer and the photosensitive composition layer, layer mixing during the coating and formation of the thermoplastic resin layer and the photosensitive composition layer can be suppressed. Also, if the transfer film does not have a thermoplastic resin layer, placing an intermediate layer between the temporary support and the photosensitive composition layer can suppress surface roughness of the photosensitive composition layer when the temporary support is peeled off, and consequently, can suppress exposure defects during exposure after the temporary support is peeled off. 【0151】 As the intermediate layer, a water-soluble resin layer containing a water-soluble resin can be used. Alternatively, as the intermediate layer, an oxygen-blocking layer with oxygen-blocking function, as described as a "separation layer" in Japanese Patent Publication No. 5-072724, can also be used. The oxygen-blocking layer used as the intermediate layer may be appropriately selected from known layers described in the above publication, etc. Among these, an oxygen-blocking layer that exhibits low oxygen permeability and disperses or dissolves in water or an alkaline aqueous solution (a 1% by mass aqueous solution of sodium carbonate at 22°C) is preferred. 【0152】 The following describes the various components that may be included in the intermediate layer (water-soluble resin layer). 【0153】<Water-soluble resin> The intermediate layer contains a resin. The resin contains a water-soluble resin as part or all of it. Examples of resins that can be used as water-soluble resins include polyvinyl alcohol-based resins, polyvinylpyrrolidone-based resins, cellulose-based resins, acrylamide-based resins, polyethylene oxide-based resins, gelatin, vinyl ether-based resins, polyamide resins, and copolymers thereof. Copolymers of (meth)acrylic acid / vinyl compounds can also be used as water-soluble resins. As the copolymer of (meth)acrylic acid / vinyl compounds, copolymers of (meth)acrylic acid / (meth)acrylate are preferred, and copolymers of methacrylic acid / methacrylate are more preferred. When the water-soluble resin is a copolymer of (meth)acrylic acid / vinyl compounds, the composition ratio (mol%) is preferably, for example, 90 / 10 to 20 / 80, and more preferably 80 / 20 to 30 / 70. 【0154】 The lower limit of 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. The upper limit is preferably 200,000 or less, more preferably 100,000 or less, and even more preferably 50,000 or less. The degree of dispersion (Mw / Mn) of the water-soluble resin is preferably 1 to 10, and more preferably 1 to 5. 【0155】 Furthermore, in order to further improve the ability to suppress interlayer mixing of the intermediate layer, it is preferable that the resin contained in the intermediate layer is different from the resin contained in the layer located on one side of the intermediate layer and the resin contained in the layer located on the other side. That is, for example, if the adjacent layer on one side of the intermediate layer is a thermoplastic resin layer and the adjacent layer on the other side is a photosensitive composition layer, it is preferable that the resin contained in the intermediate layer is different from the resin contained in each of the thermoplastic resin layer and the photosensitive composition layer. 【0156】 The water-soluble resin preferably contains polyvinyl alcohol, and more preferably contains both polyvinyl alcohol and polyvinylpyrrolidone, in order to further improve oxygen barrier properties and interlayer mixing inhibition ability. 【0157】The water-soluble resin may be used alone or in combination of two or more types. The content of the water-soluble resin is not particularly limited, but in order to further improve oxygen barrier properties and interlayer mixing suppression ability, it is preferably 50% by mass or more, and more preferably 70% by mass or more, relative to the total mass of the intermediate layer. There is no particular upper limit, but for example, it is preferably 99.9% by mass or less, and more preferably 99.8% by mass or less. 【0158】 The thickness of the intermediate layer is preferably 3.0 μm or less, more preferably 2.0 μm or less. The lower limit is preferably 0.1 μm or more, more preferably 0.5 μm or more, and even more preferably 1.0 μm or more. 【0159】 <<Thermoplastic Resin Layer>> The transfer film may have a thermoplastic resin layer between the temporary support and the photosensitive composition layer. When the transfer film has a thermoplastic resin layer, when the transfer film is transferred to the material to be transferred and a laminate is formed, air bubbles are less likely to occur in the photosensitive composition layer of the laminate. The following describes the components that the thermoplastic resin layer may contain. 【0160】 <Thermoplastic Resin> The thermoplastic resin layer contains a thermoplastic resin. As the thermoplastic resin, an alkali-soluble resin is preferred. Examples of thermoplastic resins include acrylic resin, polystyrene resin, styrene-acrylic copolymer, polyurethane resin, polyvinyl alcohol, polyvinyl formal, polyamide resin, polyester resin, polyamide resin, epoxy resin, polyacetal resin, polyhydroxystyrene resin, polyimide resin, polybenzoxazole resin, polysiloxane resin, polyethyleneimine, polyallylamine, and polyalkylene glycol. As the alkali-soluble resin, acrylic resin is preferred in terms of developability and adhesion to adjacent layers. Here, "acrylic resin" means a resin containing at least one repeating unit selected from the group consisting of repeating units derived from (meth)acrylic acid, repeating units derived from (meth)acrylic acid ester, and repeating units derived from (meth)acrylamide. 【0161】The alkali-soluble resin is preferably a resin having acid groups, and more preferably a resin containing repeating units having acid groups. Examples of acid groups include carboxyl groups, sulfol groups, phosphoric acid groups, and phosphonic acid groups, with carboxyl groups being preferred. The alkali-soluble resin is also preferably an acrylic resin having repeating units derived from (meth)acrylic acid, as it has better developability and / or better adhesion to adjacent layers. When the alkali-soluble resin contains repeating units having acid groups, the content is preferably 5 to 50% by mass, more preferably 10 to 40% by mass, and even more preferably 12 to 30% by mass, based on the total mass of the acrylic resin. 【0162】 As for the acid value of the alkali-soluble resin, from the viewpoint of developability, 60 mg KOH / g or higher is preferred. The upper limit is preferably 300 mg KOH / g or less, more preferably 250 mg KOH / g or less, and even more preferably 200 mg KOH / g or less. As an acrylic resin having carboxyl groups with an acid value of 60 mg KOH / g or higher, for example, it can be appropriately selected from known resins. Specifically, see paragraph

[0025] of Japanese Patent Application Publication No. 2011-095716, paragraphs

[0033] to

[0052] of Japanese Patent Application Publication No. 2010-237589, and paragraphs

[0053] to

[0068] of Japanese Patent Application Publication No. 2016-224162. 【0163】 Alkali-soluble resins may have polymerizable groups. These polymerizable groups can be any group involved in the polymerization reaction, such as ethylenically unsaturated groups like vinyl groups, acryloyl groups, methacryloyl groups, styryl groups, and maleimide groups; or cationic polymerizable groups like epoxy groups and oxetane groups. Among these, groups with ethylenically unsaturated properties are preferred as polymerizable groups, with acryloyl groups or methacryloyl groups being more preferred. 【0164】 The weight-average molecular weight of the alkali-soluble resin is preferably 1,000 or more, more preferably 10,000 to 100,000, and even more preferably 20,000 to 50,000. 【0165】The thermoplastic resin may be used alone or in combination of two or more types. The thermoplastic resin content is preferably 10 to 99% by mass, more preferably 20 to 90% by mass, and even more preferably 400 to 90% by mass, relative to the total mass of the thermoplastic resin layer, in terms of developability and adhesion to adjacent layers. 【0166】 <Plasticizer> The thermoplastic resin layer may contain a plasticizer from the viewpoint of resolution, adhesion to adjacent layers, and developability. The molecular weight (weight-average molecular weight) of the plasticizer is preferably 200 to 2,000. The plasticizer is not particularly limited as long as it is a compound that is compatible with the alkali-soluble resin and exhibits plasticity, but it is preferable that it contains a (meth)acrylate compound from the viewpoint of resolution and storage stability. From the viewpoint of compatibility, resolution, and adhesion to adjacent layers, it is more preferable that the alkali-soluble resin is an acrylic resin and the plasticizer contains a (meth)acrylate compound. Examples of (meth)acrylate compounds include polymerizable compounds that can be included in the above photosensitive composition layer. The plasticizer may be used alone or in combination of two or more types. From the viewpoint of resolution of the thermoplastic resin layer, adhesion to adjacent layers, and developability, the plasticizer content is preferably 0.5 to 40% by mass, and more preferably 5 to 40% by mass, relative to the total mass of the thermoplastic resin layer. 【0167】 <Other Additives> The thermoplastic resin layer may contain other additives besides the components listed above. Examples of other additives include dyes; compounds that generate acids, bases, or radicals upon exposure to light (such as acid generators, photobase generators, and photoradical polymerization initiators); sensitizers; polymerization inhibitors; surfactants; and the like. 【0168】 The average thickness (layer thickness) of the thermoplastic resin layer is preferably 3 to 30 μm, more preferably 4 to 25 μm, and even more preferably 5 to 20 μm, from the viewpoint of adhesion with adjacent layers. Furthermore, the thermoplastic resin layer may also be, for example, the thermoplastic resin layer described in paragraphs

[0189] to

[0193] of Japanese Patent Application Publication No. 2014-085643, and these details are incorporated herein. 【0169】<<Cover film (protective film)>> The transfer film may have a cover film (protective film). 【0170】 The cover film contains 5 fisheyes with a diameter of 80 μm or more per square meter. ２ The following is preferable. Note that "fish eye" refers to foreign matter, undissolved material, and / or oxidized degradation products incorporated into the film when the material is heated and melted, kneaded, extruded, and / or manufactured by methods such as biaxial stretching and casting. 【0171】 The cover film contains 30 particles / mm² with a diameter of 3 μm or larger. ２ The following is preferable: 10 pieces / mm ２ The following is more preferable: 5 pieces / mm ２ The following is even more preferable: This makes it possible to suppress defects caused by the transfer of irregularities resulting from particles contained in the cover film to the photosensitive composition layer. 【0172】 The arithmetic mean roughness Ra of the cover film surface is preferably 0.01 μm or more, more preferably 0.02 μm or more, and even more preferably 0.03 μm or more. If Ra is within this range, for example, when the transfer film is in a long form, the winding performance when winding the transfer film can be improved. Furthermore, from the viewpoint of suppressing defects during transfer, Ra is preferably less than 0.50 μm, more preferably 0.40 μm or less, and even more preferably 0.30 μm or less. 【0173】 Examples of cover films include polyethylene terephthalate film, polypropylene film, polystyrene film, and polycarbonate film. For example, the cover film described in paragraphs 0083 to 0087 and 0093 of Japanese Patent Application Publication No. 2006-259138 may be used. 【0174】As the cover film, for example, Alphan® FG-201 or Alphan® E-201F manufactured by Oji F-Tex Co., Ltd., Therapyle® 25WZ manufactured by Toray Film Processing Co., Ltd., or Lumirror® 16QS62 (16KS40) manufactured by Toray Industries, Inc. may be used. 【0175】 [Method for Manufacturing Transfer Film] The method for manufacturing the transfer film is not particularly limited, and known manufacturing methods can be applied. Preferably, the method for manufacturing the transfer film involves forming a thermoplastic resin layer, an intermediate layer, and a photosensitive composition layer, which can be placed on a temporary support, by a coating method. For example, an example of a method for manufacturing the transfer film 10 shown in Figure 1 includes the steps of: applying a thermoplastic resin composition to the surface of a temporary support to form a coating film, and then drying this coating film to form a thermoplastic resin layer; applying a water-soluble resin composition to the surface of the thermoplastic resin layer to form a coating film, and then drying this coating film to form an intermediate layer; and applying a photosensitive composition to the surface of the intermediate layer to form a coating film, and then drying this coating film to form a photosensitive composition layer. 【0176】 The transfer film 10 shown in Figure 1 is produced by pressing a cover film onto the photosensitive composition layer of the laminate produced by the manufacturing method described above. Alternatively, the transfer film 10 shown in Figure 1 may be wound up after production and stored as a roll of transfer film. The roll of transfer film can be provided in its original form for the lamination process with the substrate using the roll-to-roll method described later. 【0177】<<Thermoplastic Resin Composition and Method for Forming a Thermoplastic Resin Layer>> The method for forming the thermoplastic resin layer is not particularly limited, and known methods can be used. For example, a method of forming it by coating and drying the thermoplastic resin composition can be used. The coating means is not particularly limited, but examples include slit coating, spin coating, curtain coating, and inkjet coating. The thermoplastic resin composition preferably contains the various components for forming the thermoplastic resin layer described above and a solvent. In the thermoplastic resin composition, the preferred range of the content of each component relative to the total solid content of the composition is the same as the preferred range of the content of each component relative to the total mass of the thermoplastic resin layer described above. The solvent is not particularly limited as long as it can dissolve or disperse each component other than the solvent, and known solvents can be used. As the solvent, the solvents listed as solvents for photosensitive compositions described later can be used. The solvent content is preferably 50 to 1,900 parts by mass, and more preferably 100 to 900 parts by mass, per 100 parts by mass of the total solid content of the composition. 【0178】<<Method for forming a water-soluble resin composition and intermediate layer (water-soluble resin layer)>> The method for forming the intermediate layer is not particularly limited, and known methods can be used. For example, a method of forming it by coating and drying a water-soluble resin composition can be used. The coating means is not particularly limited, but examples include slit coating, spin coating, curtain coating, and inkjet coating. The water-soluble resin composition preferably contains the various components that form the intermediate layer described above and a solvent. In the water-soluble resin composition, the preferred range of the content of each component relative to the total solid content of the composition is the same as the preferred range of the content of each component relative to the total mass of the intermediate layer described above. The solvent is not particularly limited as long as it can dissolve or disperse the water-soluble resin. At least one selected from the group consisting of water and water-miscible organic solvents is preferred, and water or a mixed solvent of water and a water-miscible organic solvent is more preferred. Examples of water-miscible organic solvents include C1-C3 alcohols, acetone, ethylene glycol, and glycerin, with C1-C3 alcohols being preferred, and methanol or ethanol being more preferred. The solvent may be used alone or two or more. The solvent content is preferably 50 to 2,500 parts by mass, more preferably 50 to 1,900 parts by mass, and even more preferably 100 to 900 parts by mass, per 100 parts by mass of the total solids content of the composition. 【0179】<<Photosensitive Composition and Method for Forming a Photosensitive Composition Layer>> The method for forming the photosensitive composition layer is not particularly limited, and known methods can be used. For example, a method of forming it by coating and drying the photosensitive composition can be used. The coating means is not particularly limited, but examples include slit coating, spin coating, curtain coating, and inkjet coating. Examples of photosensitive compositions include photosensitive compositions containing a specific polymer, and among these, it is preferable to contain various components including the specific polymer that forms the above-mentioned photosensitive composition layer and a solvent. In the photosensitive composition, the preferred range of the content of each component relative to the total solid content of the composition is the same as the preferred range of the content of each component relative to the total mass of the above-mentioned photosensitive composition layer. The solvent is not particularly limited as long as it can dissolve or disperse each component other than the solvent, and known solvents can be used. Specifically, examples include water, alkylene glycol ether solvents, alkylene glycol ether acetate solvents, alcohol solvents (methanol and ethanol, etc.), ketone solvents (acetone and methyl ethyl ketone, etc.), aromatic hydrocarbon solvents (toluene, etc.), aprotic polar solvents (N,N-dimethylformamide, etc.), cyclic ether solvents (tetrahydrofuran, etc.), ester solvents (n-propyl acetate, etc.), amide solvents, lactone solvents, and mixed solvents containing two or more of these. 【0180】 The solvent may be used alone or in combination of two or more types. The solvent content is preferably 50 to 1,900 parts by mass, more preferably 100 to 1,200 parts by mass, and even more preferably 100 to 900 parts by mass, per 100 parts by mass of the total solids content of the composition. 【0181】 The coating films of the thermoplastic resin layer-forming composition, the intermediate layer-forming composition, and the photosensitive composition may be dried as needed. Heat drying and vacuum drying are preferred drying methods. 【0182】In order to form optical waveguides with lower light propagation loss, it is preferable that the photosensitive composition layer in the transfer film substantially does not contain scatterers that may contribute to light propagation loss. In the method for manufacturing the transfer film, in order to reduce scatterers in the photosensitive composition layer in the transfer film, it is preferable to apply methods such as not using raw materials containing impurity components that may become scatterers such as aggregates and structures in the formation of the photosensitive composition layer, thoroughly dissolving each component in the solvent in the photosensitive composition (coating solution) that forms the photosensitive composition layer, selecting a combination of compounds that are easily compatible in order to suppress the generation of aggregates in the photosensitive composition, and / or applying a filtration treatment to the photosensitive composition to remove aggregates and dust that have been unintentionally mixed in. In particular, the method for manufacturing the transfer film preferably includes a step of applying a filtration treatment to the photosensitive composition that forms the photosensitive composition layer to remove aggregates and dust that have been unintentionally mixed in. 【0183】 The pore size of the filter is preferably 1 mm or less, more preferably 0.1 mm or less, even more preferably 0.01 mm or less, and particularly preferably 0.001 mm or less. The filter is preferably made of polytetrafluoroethylene, polyethylene, or nylon. 【0184】 [Pattern Forming Method Using Transfer Film] The pattern forming method using the transfer film of the present invention preferably comprises steps X1 to X4. If the photosensitive composition layer contains compound X, the pattern forming method using the transfer film of the present invention more preferably comprises steps X1 to X5. Step X1: A step of bonding the transfer film and the substrate by bringing the surface of the photosensitive composition layer in the transfer film opposite to the temporary support side into contact with the substrate. Step X2: A step of exposing the photosensitive composition layer in a pattern (pattern exposure). Step X3: A step of developing the photosensitive composition layer after exposure using an alkaline developer. Step X4: A step of peeling off the temporary support between steps X1 and X2, or between steps X2 and X3. Step X5: A step of performing a treatment to reduce the amount of carboxyl groups in the photosensitive composition layer (cured layer) that has undergone alkaline development after step X3. 【0185】In the pattern formation method described above, step X1 involves bonding the photosensitive composition layer of a transfer film to an arbitrary substrate to form a laminate having a substrate and a photosensitive composition layer disposed on the substrate. Next, when the photosensitive composition layer of the obtained laminate is exposed in step X2, a polymerization reaction of polymerizable components proceeds in the exposed areas, and in the subsequent developing step X3, the unexposed areas of the photosensitive composition layer are dissolved and removed by an alkaline developer to form a negative-type patterned photosensitive composition layer (cured layer). If the photosensitive composition layer contains compound X, the pattern formation method preferably further includes step X5. In step X5, compound X is activated by subjecting the patterned photosensitive composition layer obtained in step X3 to exposure and / or heating, and the amount of carboxyl groups (particularly carboxyl groups derived from a specific polymer) in the photosensitive composition layer can be reduced by the action of compound X. Typically, even in step X2, depending on the exposure conditions, some of the carboxyl groups contained in the photosensitive composition layer may be removed by the action of compound X. For example, if the specific polymer contains many highly hydrophilic repeating units such as the repeating unit (3) described above, by setting the irradiation dose in step X2 to be stronger, some of the carboxyl groups (especially those derived from the specific polymer) in the photosensitive composition layer can be removed by the action of compound X, thereby reducing the solubility of the exposed area in the alkaline developer during alkaline development in step X3, and thus obtaining better resolution. In the above pattern formation method, if the transfer film has a cover film, it is preferable to include a step of peeling off the cover film from the transfer film before carrying out step X1. The method of peeling off the cover film is not particularly limited, and known methods can be applied. 【0186】 The following describes each step in the pattern formation method using the transfer film of the present invention. 【0187】 <<<Process X1>>> Process X1 involves bringing the surface of the photosensitive composition layer in the transfer film that is opposite to the temporary support side into contact with the substrate, thereby bonding the transfer film and the substrate together. 【0188】<<Substrate>> The substrate is not particularly limited, and for example, substrates such as quartz substrates, silicon substrates, and printed circuit boards (e.g., FR4 substrates, glass epoxy substrates, polyimide substrates, etc.) can be selectively used depending on the application of the optical waveguide. A resin layer having a refractive index lower than that of the cured layer of the photosensitive composition (the photosensitive composition layer (cured layer) obtained by performing the predetermined processing of steps X1 to X4 (preferably steps X1 to X5) described above using a transfer film) may be formed on the substrate. 【0189】 <<Procedure for Process X1>> Process X1 is preferably a bonding process using pressure and heat from a roll or the like. Known laminators such as laminators, vacuum laminators, and auto-cut laminators can be used for bonding. Process X1 is also preferably carried out in a roll-to-roll manner. A roll-to-roll manner is a method in which a substrate that can be wound up and unwound is used as the substrate, and a process of unwinding the substrate (also called the "unwinding process") is performed before any of the processes included in the pattern forming method using a transfer film, and a process of winding the substrate (also called the "winding process") is performed after any of the processes, and at least one of the processes (preferably all processes, or all processes except the heating process) is performed while the substrate is being transported. The unwinding method in the unwinding process and the winding method in the winding process are not particularly limited, and known methods may be used in a manufacturing method to which the roll-to-roll manner is applied. 【0190】<<Step X2>> Step X2 is a step of pattern exposure of the photosensitive composition layer. When the photosensitive composition layer is subjected to Step X2, the polymerization reaction of the polymerization components proceeds. In Step X2, the light source used for exposure can be appropriately selected as long as it emits light in a wavelength range that can cause the reaction of radical polymerizable groups in the specific polymer in the photosensitive composition layer (if the photosensitive composition layer contains a polymerization initiator, preferably light of a wavelength that exposes the polymerization initiator to light. For example, light with wavelengths of 254 nm, 313 nm, 365 nm, 405 nm, etc.). Specifically, examples include ultra-high pressure mercury lamps, high-pressure mercury lamps, metal halide lamps, and LEDs (Light Emitting Diodes). The exposure amount is 5 to 1000 mJ / cm ２ Preferably, 10 to 500 mJ / cm² ２ This is preferable. 【0191】 <<Step X3>> Step X3 is a process in which the photosensitive composition layer, which has been pattern-exposed after step X2, is developed using an alkaline developer. In the photosensitive composition layer after step X2, a polymerization reaction proceeds in the exposed areas, creating a difference in solubility in the developer (dissolution contrast) between the exposed and unexposed areas. The formation of dissolution contrast in the photosensitive composition layer makes it possible to form a pattern in step X3. Furthermore, by performing step X3, the unexposed areas are removed and a negative pattern is formed. 【0192】(Alkaline Developer) The alkaline developer is not particularly limited as long as it can remove the unexposed portion of the photosensitive composition layer. For example, known developers such as the developer described in Japanese Patent Publication No. 5-072724 can be used. As the alkaline developer, for example, an alkaline aqueous solution containing a compound with pKa = 7 to 13 at a concentration of 0.05 to 5 mol / L (liter) is preferred. The alkaline developer may also further contain a water-soluble organic solvent and a surfactant. As the alkaline developer, for example, the developer described in paragraph 0194 of International Publication No. 2015 / 093271 is preferred. The concentration of water in the alkaline developer is preferably 50% by mass or more, more preferably 60% by mass or more, even more preferably 85% by mass or more, particularly preferably 90% by mass or more, and most preferably 95% by mass or more. The upper limit is, for example, less than 100% by mass. 【0193】 There are no particular restrictions on the development method; any of the following may be used: paddle development, shower development, spin development, and dip development. In shower development, unwanted portions can be removed by spraying the developer onto the photosensitive composition layer after exposure. Alternatively, after development, it is preferable to spray a cleaning agent or the like onto the surface with a shower and remove the development residue by scrubbing with a brush or the like. The developer solution temperature is preferably 20 to 40°C. 【0194】<<Step X4>> Step X4 is the step of peeling off the temporary support. The temporary support is peeled off between steps X1 and X2, or between steps X2 and X3. In other words, the pattern exposure in step X2 may be performed after peeling off the temporary support from the photosensitive composition layer, or the pattern exposure in step X2 may be performed through the temporary support before peeling off the temporary support, and then the temporary support may be peeled off before performing the alkaline development in step X3. From the viewpoint of preventing mask contamination due to contact between the photosensitive composition layer and the mask, and avoiding the influence of foreign matter adhering to the mask on exposure, it is preferable to perform the pattern exposure in step X2 without peeling off the temporary support. From the viewpoint of further suppressing exposure blur and further improving resolution, it is preferable to perform the pattern exposure in step X2 after peeling off the temporary support from the photosensitive composition layer. The pattern exposure may be exposure through the mask, or direct exposure using a laser or the like. 【0195】 <<Step X5>> Step X5 is a step in which the amount of carboxyl groups in the photosensitive composition layer (patterned cured layer) that has been subjected to alkaline development in Step X3 is reduced. The treatment to reduce the carboxyl groups (especially carboxyl groups derived from a specific polymer) in the photosensitive composition layer in Step X5 is preferably an exposure treatment or a heat treatment. Alternatively, both an exposure treatment and a heat treatment may be performed as the treatment to reduce the carboxyl groups (especially carboxyl groups derived from a specific polymer) in the photosensitive composition layer in Step X5. 【0196】(Exposure Treatment) The exposure treatment may be either full-surface exposure or pattern exposure, but full-surface exposure is preferred. The light source used for exposure can be appropriately selected as long as it emits light in a wavelength range that can reduce the content of carboxyl groups (particularly carboxyl groups derived from specific polymers) in the photosensitive composition layer (light with a wavelength that excites compound B in the photosensitive composition layer; for example, light in the wavelength range of 254 nm, 313 nm, 365 nm, 405 nm, etc.). Specifically, examples include ultra-high pressure mercury lamps, high-pressure mercury lamps, metal halide lamps, xenon lamps, and LEDs (Light Emitting Diodes). The exposure amount should be 1 to 10 J / cm². ２ Preferably, 2 to 10 J / cm ２ More preferably, 2 to 5 J / cm ２ That is even more preferable. 【0197】 (Heat Treatment) Heat treatment can be carried out, for example, using an oven. Heat treatment is preferably carried out in an environment of 8.1 to 121.6 kPa, and more preferably in an environment of 50.66 kPa or higher. On the other hand, it is more preferably carried out in an environment of 111.46 kPa or lower, and even more preferably in an environment of 101.3 kPa or lower. Heat treatment may be carried out in an air environment or in a nitrogen-purged environment. The heat treatment temperature is preferably 80 to 250°C, more preferably 110 to 170°C, and even more preferably 130 to 150°C. The heat treatment time is preferably 1 to 120 minutes, more preferably 2 to 90 minutes, and even more preferably 5 to 60 minutes. 【0198】[Laminates Using Transfer Film] Laminates using transfer film (hereinafter also referred to as "laminateds") will be described below. The laminate comprises a substrate, a resin layer, and a transfer film, with the photosensitive composition layer of the transfer film facing the resin layer. The configuration of the laminate will be described below. Figure 2 is a schematic cross-sectional view showing an example of an embodiment of the laminate. The laminate 30 shown in Figure 2 comprises a substrate 22, a resin layer 24, and a transfer film 10A in which the photosensitive composition layer 18 is positioned facing the resin layer 24. The transfer film 10A has the same configuration as the transfer film 10 shown in Figure 1, but without the protective film 20. In addition, the transfer film 10A shown in Figure 2 has a thermoplastic resin layer 14 and an intermediate layer 16, but the thermoplastic resin layer 14 and the intermediate layer 16 do not need to be arranged. 【0199】 The following describes each element that makes up the laminate. The composition of the transfer film is as previously described. 【0200】 <Substrate> The substrate is not particularly limited, and substrates such as quartz substrates, silicon substrates, and printed circuit boards (e.g., FR4 substrates, glass epoxy substrates, polyimide substrates, etc.) can be selectively used depending on the application of the optical waveguide. 【0201】<Resin Layer> The resin layer preferably has a refractive index lower than that of the cured layer of the photosensitive composition (the photosensitive composition layer (cured layer) obtained by performing the predetermined processes X1 to X4 (preferably X1 to X5) described above using a transfer film). The difference in refractive index between the resin layer and the cured layer of the photosensitive composition is preferably 0.01 or more, and more preferably 0.02 or more. There is no particular upper limit, but it is preferably 0.50 or less. The refractive index is the refractive index at a wavelength of 589 nm or the refractive index at the wavelength of light to be guided (for example, a wavelength of 1310 nm). Examples of resins constituting the resin layer include ultraviolet-curable fluorinated acrylate resins, polymethacrylate resins, fluorinated polyimide resins, and epoxy resins. The thickness of the resin layer is preferably 5 to 200 μm. A laminate in which the refractive index of the resin layer is lower than that of the cured layer of the photosensitive composition can be suitably used as a material component for manufacturing optical waveguides. 【0202】 The resin layer may be a layer formed by a transfer film. In other words, the resin layer may be a photosensitive composition layer (cured layer) obtained by performing the predetermined processes of steps X1 to X4 (preferably steps X1 to X5) described above using a transfer film. 【0203】 [Method for Manufacturing Optical Waveguides Using Laminates] The method for manufacturing optical waveguides using laminates is preferably a manufacturing method comprising the following steps 1 to 4. When the photosensitive composition layer in the laminate contains compound X, the method for manufacturing optical waveguides using laminates is preferably a manufacturing method comprising the following steps 1 to 5. Step 1: A step of performing an exposure treatment (preferably pattern exposure) on the photosensitive composition layer in the laminate. Step 2: A step of performing an alkaline development treatment on the photosensitive composition layer that has been exposed to form a core. Step 3: A step of forming an optical waveguide having a core and a cladding portion by forming a resin layer on the core so as to cover the core, with a refractive index lower than that of the core. Step 4: A step of peeling off a temporary support before step 1, or between step 1 and step 2. Step 5: A step of performing a treatment to reduce the amount of carboxyl groups between step 2 and step 3, or after step 3. 【0204】The following describes each step in the manufacturing process of optical waveguides. 【0205】 <<Steps 1, 2, and 4>> The procedures for Steps 1, 2, and 4 are the same as the procedures for Steps X2, X3, and X4 described in the upper section, and the preferred embodiment is also the same. 【0206】 <<Step 3>> Step 3 is a step of forming a resin layer (second resin layer) on the core portion (a layer formed by curing the cured components of the photosensitive composition layer) so as to cover the core portion (a layer formed by curing the cured components of the photosensitive composition layer), which is obtained after alkaline development in Step 2, or after Step 5 if Step 5, a process to reduce the amount of carboxyl groups, is performed after Step 2. By going through Step 3, an optical waveguide 40 having a first resin layer 32, a core portion 34, and a second resin layer 36 is formed on the substrate 22 as shown in Figure 3. The first resin layer 32 is the same as the resin layer (resin layer 24 in Figure 2) provided in the laminate used in Step 1, and the second resin layer 36 is a resin layer that is arranged in Step 3 so as to cover the core portion. The first resin layer and the second resin layer function as a cladding portion. The difference in refractive index between the core portion and the cladding portion (first resin layer and second resin layer) is preferably 0.01 or more, and more preferably 0.02 or more. There is no particular upper limit, but 0.5 or less is preferred. The refractive index mentioned above is the refractive index at a wavelength of 589 nm, or the refractive index at the wavelength of light to be guided (for example, a wavelength of 1310 nm). Examples of resins constituting the second resin layer include ultraviolet-curable fluorinated acrylate resins, polymethacrylate resins, fluorinated polyimide resins, and epoxy resins. The method for forming the second resin layer is not particularly limited, but examples include forming a coating film by a known coating method using a composition containing the resin or its precursor, and then photocuring or thermocuring the coating film. The thickness of the second resin layer is preferably, for example, 5 to 200 μm. 【0207】 Furthermore, the second resin layer may be a layer formed from a transfer film. In other words, the second resin layer may be a photosensitive composition layer (cured layer) obtained by performing predetermined processes X1 to X4 (preferably X1 to X5) using a transfer film. 【0208】Methods for adjusting the refractive index of the first and second resin layers to a high refractive index include selectively using components selected from the group consisting of high refractive index polymers and high refractive index monomers, increasing the content ratio of components selected from the group consisting of high refractive index polymers and high refractive index monomers, and / or increasing the crosslinking density. It is also easier to adjust to a high refractive index by using compounds containing heterocyclic and fused ring structures and / or compounds containing heavy elements such as sulfur atoms. Methods for adjusting the refractive index of the first and second resin layers to a low refractive index include selectively using components selected from the group consisting of low refractive index polymers and low refractive index monomers, increasing the content ratio of components selected from the group consisting of low refractive index polymers and low refractive index monomers, and / or decreasing the crosslinking density. 【0209】 <<Step 5>> Step 5 is a process to reduce the amount of carboxyl groups. Step 5 is performed between Step 2 and Step 3, or after Step 3. The procedure for Step 5 is the same as the procedure for Step X5 described above, and the preferred embodiment is also the same. 【0210】 In the core portion subjected to the treatment to reduce the amount of carboxyl groups in step 5, the content of carboxyl groups relative to the total mass of the core portion is preferably 0.01 to 4.0% by mass, more preferably 0.01 to 3.0% by mass, and even more preferably 0.01 to 2.5% by mass. Furthermore, the remaining percentage of carboxyl groups after the treatment to reduce the amount of carboxyl groups in step 5 is preferably 30 mol% or less relative to the content of carboxyl groups in the photosensitive composition layer before the exposure treatment in step 1. 【0211】Optical waveguides obtained by a manufacturing method using laminates can be applied as optical transmission lines in optical modules. Examples of optical module forms include optical waveguides with optical fibers connected to both ends of the optical waveguide, optical waveguides with connectors connected to both ends of the optical waveguide, optoelectronic composite substrates that combine optical waveguides and printed circuit boards, optoelectronic conversion modules that combine optical waveguides with optical / electrical conversion elements that mutually convert optical signals and electrical signals, and wavelength multiplexers / demultiplexers that combine optical waveguides with wavelength division filters. 【0212】 [Photosensitive Composition] The photosensitive composition of the present invention comprises a polymer (specific polymer) having a repeating unit (repeating unit (1)) represented by the above formula (1), a radical polymerizable group, and a carboxyl group or a salt thereof. The specific polymer contained in the photosensitive composition is the same as the specific polymer contained in the photosensitive composition layer in the transfer film, and the preferred embodiment is also the same. 【0213】 The photosensitive composition preferably contains, in addition to the specific polymer, various components that can be used to form the photosensitive composition layer in the transfer film described above (for example, compound X, polymerizable compounds, and polymerization initiators). In the photosensitive composition, the preferred range of content of each component relative to the total solid content of the composition is the same as the preferred range of content of each component relative to the total mass of the photosensitive composition layer described above. 【0214】The photosensitive composition may also preferably contain a solvent. The solvent is not particularly limited as long as it can dissolve or disperse each component other than the solvent, and known solvents can be used. Specifically, examples include water, alkylene glycol ether solvent, alkylene glycol ether acetate solvent, alcohol solvent (methanol and ethanol, etc.), ketone solvent (acetone and methyl ethyl ketone, etc.), aromatic hydrocarbon solvent (toluene, etc.), aprotic polar solvent (N,N-dimethylformamide, etc.), cyclic ether solvent (tetrahydrofuran, etc.), ester solvent (n-propyl acetate, etc.), amide solvent, lactone solvent, and mixed solvents containing two or more of these. The solvent may be used alone or in combination of two or more. When the composition contains a solvent, the solvent content is preferably 50 to 1,900 parts by mass, more preferably 100 to 1,200 parts by mass, and even more preferably 100 to 900 parts by mass, per 100 parts by mass of the total solids of the composition. 【0215】 [Specific Polymer] The specific polymer of the present invention has a repeating unit represented by the above formula (1) (repeating unit (1)), a radical polymerizable group, and a carboxyl group or a salt thereof. The specific polymer of the present invention is the same as the specific polymer contained in the photosensitive composition layer of the transfer film, and the preferred embodiments are also the same. 【0216】 [First Optical Waveguide] The first optical waveguide of the present invention is an optical waveguide having a core portion and a cladding portion having a lower refractive index than the core portion, which is arranged to cover the periphery of the core portion, wherein the core portion is a layer formed using the photosensitive composition of the present invention described above. 【0217】 The first optical waveguide can be formed by the optical waveguide manufacturing method using the laminate described above. Figure 4 shows a schematic diagram of an example of the first optical waveguide. 【0218】 As shown in Figure 4, the first optical waveguide 50 is composed of a core portion 42 and a cladding portion 44 arranged to cover the periphery of the core portion 42. The refractive index of the cladding portion 44 is lower than that of the core portion 42. In the first optical waveguide, the core portion 42 is a layer formed using the photosensitive composition of the present invention described above. 【0219】 The difference in refractive index between the core and cladding is preferably 0.01 or more, and more preferably 0.02 or more. There is no particular upper limit, but it is preferably 0.5 or less. The refractive index is the refractive index at a wavelength of 589 nm, or the refractive index at the wavelength of the light to be guided (for example, a wavelength of 1310 nm). Examples of resins constituting the cladding include UV-curable fluorinated acrylate resins, polymethacrylate resins, fluorinated polyimide resins, and epoxy resins. The thickness of the cladding is preferably 5 to 200 μm. 【0220】 [Second Optical Waveguide] The second optical waveguide of the present invention is an optical waveguide having a core portion and a cladding portion having a lower refractive index than the core portion and arranged to cover the periphery of the core portion, wherein the core portion contains a component derived from a specific polymer. 【0221】 The second optical waveguide has the same configuration as the first optical waveguide. The second optical waveguide has the same configuration as the first optical waveguide, except that the core is a layer formed using the photosensitive composition of the invention described above. The core of the second optical waveguide contains components derived from a specific polymer. The specific polymer is as previously described. The core of the second optical waveguide can be formed using the photosensitive composition of the invention described above. 【0222】 The present invention will be described in more detail below based on the following examples. The materials, amounts used, proportions, processing content, and processing procedures shown in the following examples can be modified as appropriate without departing from the spirit of the present invention. Therefore, the scope of the present invention should not be interpreted as being limited by the following examples. 【0223】 [Polymers A-K, Comparative Polymers X1-X2] Polymers A-K and comparative polymers X1-X2 are shown below. 【0224】[Synthesis of Polymer A] To 26.8 g of 2-methoxy-1-methylethyl acetate, heated to 90°C under a nitrogen stream, a solution containing the monomer (iii-1) (10.59 g), acrylic acid (4.32 g), 2,3,4,5,6-pentafluorostyrene (25.62 g), polymerization initiator V-601 (Fujifilm Wako Chemical Co., Ltd., 1.49 g), and 2-methoxy-1-methylethyl (20.7 g) was added dropwise over 2 hours. After the addition of the solution was complete, 0.2 g of V-601 was added three times at 1-hour intervals. The mixture was reacted at 90°C for 3 hours and then cooled to room temperature. The reaction solution was diluted with 2-methoxy-1-methylethyl (41.9 g), triethylamine (15.8 g) and 4-methoxyphenol (0.02 g) were added, and the mixture was stirred at 60°C for 4 hours. The reaction solution was diluted with methanol (50 mL), and then the diluted solution was added dropwise to a mixture of concentrated hydrochloric acid (22 g) and distilled water (1050 g). The precipitated powder was collected by filtration. The powder was stirred in distilled water (1000 g), and then the filtration process was repeated three times until the filtrate was neutral. The obtained powder was dried in a forced-air dryer at 50°C to obtain polymer A. 【0225】 • Monomer (ii-1) 【0226】 [Synthesis of Polymer B] <Synthesis of Monomer iii-1> 【0227】 【0228】Potassium-tert-butoxide (11.56 g) was dissolved in ethylene glycol (200 g) heated to 50°C, then cooled to 10°C, and 2,3,4,5,6-pentafluorostyrene (20 g) was added dropwise over 30 minutes. The mixture was reacted at 100°C for 3 hours, and after repeating the liquid-liquid extraction procedure three times with ethyl acetate and water, the aqueous layer was removed, and the ethyl acetate in the organic layer was concentrated to obtain 24.3 g of the intermediate of monomer iii-1. Next, ethyl acetate (200 mL), dimethylacetamide (17.95 g), and 4-methoxyphenol (0.13 g) were added, and after lowering the temperature to below 10°C, 3-chloropropionic acid chloride (15.7 g) was added dropwise over 30 minutes. The mixture was reacted at room temperature for 2 hours, and after liquid-liquid extraction with ethyl acetate and water, the aqueous layer was removed, and the ethyl acetate in the organic layer was concentrated. Next, monomer iii-1 (29.5 g) was obtained by purification using column chromatography. 【0229】 <Synthesis of Polymer B> To 2-methoxy-1-methylethyl acetate (30.9 g), heated to 90°C under a nitrogen stream, a solution containing monomer (iii-1) (15.68 g), acrylic acid (4.32 g), 2,3,4,5,6-pentafluorostyrene (25.62 g), polymerization initiator V-601 (Fujifilm Wako Chemical Co., Ltd., 1.49 g), and 2-methoxy-1-methylethyl (23.4 g) was added dropwise over 2 hours. After the addition of the solution was complete, 0.2 g of V-601 was added three times at 1-hour intervals. The mixture was reacted at 90°C for 3 hours and then cooled to room temperature. The reaction solution was diluted with 2-methoxy-1-methylethyl (35.67 g), triethylamine (15.8 g) and 4-methoxyphenol (0.02 g) were added, and the mixture was stirred at 60°C for 4 hours. The reaction solution was diluted with methanol (50 mL), and then the diluted solution was added dropwise to a mixture of concentrated hydrochloric acid (22 g) and distilled water (1050 g). The precipitated powder was collected by filtration. The powder was stirred in distilled water (1000 g), and then the filtration process was repeated three times until the filtrate was neutral. The obtained powder was dried in a forced-air dryer at 50°C to obtain polymer B. 【0230】[Synthesis of polymers C to K and polymers X1 to X2] Polymers C to K are obtained by the same method as the synthesis of polymers A and B, except that the type and amount of monomer added are appropriately changed according to the structure of the target polymer. 【0231】 The structures of polymers A to K and comparative polymers X1 to X2 are shown below. (Note that in the polymers shown below, the numerical values ​​attached to each repeating unit represent the content (mol%) of each repeating unit relative to the total number of repeating units.) 【0232】 【0233】 【0234】 【0235】 Table 1 shows the weight-average molecular weight (Mw), content of specific repeating units (mass%), presence or absence of radical polymerizable groups, presence or absence of carboxyl groups or their salts, and acid value of polymers A to K and comparative polymers X1 to X2. The content of specific repeating units (mass%) represents the total content (mass%) of specific repeating units selected from the group consisting of repeating units represented by formula (1), formula (2), and formula (3) above, relative to the total repeating units of the polymer. In the table, "k" in the "Weight-average molecular weight (Mw)" column means "×1000". 【0236】 【0237】[Preparation of Photosensitive Composition] [Preparation of Photosensitive Composition 1] Photosensitive composition 1 is prepared based on the components and formulations shown in Table 2. The values ​​listed in each component column in Table 2 represent the content (unit: mass%). The photosensitive composition is adjusted so that the solid content concentration is 27% by mass. In the preparation of the photosensitive composition, the polymer that will become the binder polymer is dissolved in an organic solvent (a mixed solvent of propylene glycol monomethyl ether and methyl ethyl ketone (mass ratio 43 / 57)). The photosensitive composition is prepared by mixing the above-mentioned binder polymer solution with the various components in Table 2. The binder polymer content shown in Table 2 represents the solid content of the binder polymer (excluding the solvent). 【0238】 [Preparation of Photosensitive Composition 2] Photosensitive composition 2 was prepared using the same procedure as for photosensitive composition 1, based on the components and formulation shown in Table 2. 【0239】 [Preparation of photosensitive compositions 3-16, R1, and R2] Photosensitive compositions 3-16, R1, and R2 are prepared according to the same procedure as for photosensitive composition 1, based on the components and formulations shown in Table 2. 【0240】 [Various Components of the Photosensitive Composition] The details of each component of the photosensitive composition shown in Table 2 are described below. <Binder Polymer> As the binder, polymers A to K described above, as well as comparative polymers X1 and X2, are used. 【0241】 <Polymerizable Compounds> A-NOD-N: 1,9-nonanediol diacrylate (manufactured by Shin Nakamura Chemical Industry Co., Ltd.) DPHA: Dipentaerythritol hexaacrylate (manufactured by Toshin Oil & Fat Co., Ltd.) TO-2349: Aronics TO-2349 (manufactured by Toagosei Co., Ltd.) OGSOL EA-F5710: Fluorene structure-containing (meth)acrylate (manufactured by Osaka Gas Chemical Co., Ltd.) 【0242】 <Polymerization initiator> B-CIM: 2,2'-bis(2-chlorophenyl)-4,4',5,5'-tetraphenyl-1,2'-biimidazole (manufactured by Kurogane Chemical Co., Ltd.). 【0243】<Sensitizer> SB-PI 701: 4,4'-bis(diethylamino)benzophenone (Sanyo Trading Co., Ltd.) 【0244】 <Chain Transfer Agent> N-phenylcarbamoylmethyl-N-carboxymethylaniline: Manufactured by Fujifilm Wako Pure Chemical Corporation 【0245】 <Polymerization Inhibitor> TDP-G: Phenothiazine (manufactured by Kawaguchi Chemical Industry Co., Ltd.) 【0246】 <Compound that reduces the amount of carboxyl groups (Compound X)> The following compound is used as the compound that reduces the amount of carboxyl groups (Compound X): Duranate WT32-B75P: A thermally crosslinkable compound, manufactured by Asahi Kasei Chemicals Corporation 9-Methylacridine: (Manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) B1: A compound with the following structure (a synthetic product synthesized by the synthesis method shown later) 【0247】 【0248】 (Synthesis of Compound X-1) In a three-necked flask equipped with a condenser, 60 g, 0.461 mol of 4-hydroxyethyl methacrylate, 390 ml of ethyl acetate, and 51.3 g, 0.5072 mol of triethylamine were added and mixed, then cooled to 5°C. While stirring the contents of the flask, 55.5 g, 0.4841 mol of methanesulfonic acid chloride was added dropwise over 30 minutes, and the mixture was allowed to react at room temperature for a further 1 hour. 300 ml of pure water was added, and the aqueous layer was removed by liquid-liquid extraction. Then, 30 mg of BHT (butylated hydroxytoluene) was added to the organic layer. By distilling off the ethyl acetate in the organic layer under reduced pressure, 90 g of compound (B1-1A) with the following structure was obtained. 【0249】 【0250】Next, 15 g, 0.1153 mol of 4-hydroxyquinoline, 27.7 g, 0.1268 mol of B1-1A, 3.72 g, 0.01153 mol of tetrabutylammonium bromide, 56.33 g, 0.1729 mol of cesium carbonate, 75 μL of nitrobenzene, and 150 mL of THF (Tetrahydrofuran) were added to a three-necked flask with a condenser, and the mixture was reacted at 70°C with stirring for 1 hour. After the reaction was complete, 180 mL each of ethyl acetate and pure water were added and the mixture was thoroughly stirred. The aqueous layer was removed by liquid-liquid extraction, and the organic layer was dried over magnesium sulfate. After removing the magnesium sulfate by filtration, the mixture was purified by silica gel column chromatography using hexane / ethyl acetate as the developing solvent to obtain 14.5 g of compound (B1). 【0251】 [Preparation of Intermediate Layer Forming Composition] An intermediate layer forming composition was prepared with the following composition: --------------------------------------------------- ・PVA 67.5 parts by mass ・PVP 31.5 parts by mass ・HPMC 1.0 part by mass ・Fluorine-based surfactant 0.1 parts by mass ・Methanol 630 parts by weight ・Water 270 parts by mass --------------------------------------------------- 【0252】 The following details each component of the intermediate layer forming composition: PVA (Polyvinyl Alcohol): Kuraray Poval PVA-205 (manufactured by Kuraray Co., Ltd.) PVP (Polypyrrolidone): Polyvinylpyrrolidone K-30 (manufactured by Nippon Shokubai Co., Ltd.) HPMC (Hydroxypropyl Methylcellulose): Metroze 60SH-03 (manufactured by Shin-Etsu Chemical Co., Ltd.) Fluorine-based surfactant: Megafac F-444 (manufactured by DIC Corporation) 【0253】[Preparation of Composition for Thermoplastic Resin Layer] A composition for thermoplastic resin layer with the following composition was prepared. ------------------- 【0254】 The following details each component of the thermoplastic resin layer forming composition. <Binder A> Aromatex FM601 (manufactured by Mitsui Chemicals, Inc., weight-average molecular weight = 90,000, solid content concentration 21% by mass, methyl methacrylate / 2-ethylhexyl acrylate / benzyl methacrylate / methacrylic acid copolymer (molar ratio = 55 / 11.7 / 4.5 / 28.2): 21 parts by mass, methyl ethyl ketone: 26 parts by mass, 1-methoxy-2-propyl acetate: 13 parts by mass, methanol: 40 parts by mass) 【0255】 Binder B: Alloset 7055 (manufactured by Nippon Shokubai Co., Ltd., weight-average molecular weight = 8,000, solid content concentration 41% by mass, styrene / acrylic acid copolymer (molar ratio 63 / 37): 41 parts by mass, methyl ethyl ketone: 50 parts by mass, 1-methoxy-2-propyl acetate: 9 parts by mass) 【0256】[Preparation and Evaluation of Transfer Film 1] [Preparation of Transfer Film 1] A transfer film 1 having a temporary support, a thermoplastic resin layer, an intermediate layer, and a photosensitive composition layer in this order is prepared according to the following procedure. The specific preparation procedure is described below. The above thermoplastic resin layer forming composition is applied to a temporary support (a polyethylene terephthalate film having a thickness of 25 μm) using a slot die to form a coating film, and then dried in an oven at 100°C for 3 minutes to form a thermoplastic resin layer with a thickness of 5.0 μm. Next, the above intermediate layer forming composition is applied to the thermoplastic resin layer using a bar coater to form a coating film with a thickness of 2.0 μm after drying, and then dried in an oven at 100°C to form an intermediate layer. Next, the photosensitive composition 1 is applied to the intermediate layer using a bar coater to form a coating film with a thickness of 4.0 μm after drying, and then dried in an oven at 100°C to form a photosensitive composition layer 1. A protective film (polyethylene terephthalate, 16KS40, Toray Industries, Inc., with a thickness of 16 μm) is pressed onto the photosensitive composition layer 1. 【0257】 <Pattern Formation> (Laminate Fabrication) The transfer film 1 is cut into 50 cm squares, and the protective film is peeled off after cutting. The photosensitive composition layer 1 of the transfer film 1 and the glass substrate are bonded together under the conditions of a roller temperature of 100°C, a linear pressure of 0.6 MPa, and a linear speed of 1.0 m / min. The laminate obtained by bonding the transfer film 1 and the glass substrate has the structure of glass substrate / photosensitive composition layer 1 / intermediate layer / thermoplastic resin layer / temporary support. 【0258】 (Pattern Formation) - Exposure Treatment Next, the temporary support is peeled off from the laminate to expose the thermoplastic resin layer, and the exposed thermoplastic resin layer is brought into close contact with the photomask (a photomask with a line and space pattern of 4 μm line width and 125 μm space width is used). Light is irradiated onto the photosensitive composition layer 1 through the photomask using a high-pressure mercury lamp exposure machine (MAP-1200L, Dainippon Kaken Co., Ltd., main wavelength: 365 nm). During exposure, the exposure amount is adjusted so that the line width of the pattern corresponding to the 4 μm lines formed on the photomask is 4 μm. 【0259】 - Alkaline development and washing treatment: Next, the exposed laminate is subjected to a 90-second shower treatment (alkaline development treatment) using a 1.0% sodium carbonate aqueous solution (pH 11.8) at 30°C as the developer. After alkaline development, the developer is removed by AirKnife treatment, and then a 30-second shower treatment (washing treatment) is performed using pure water as the washing solution, and the washing solution is removed by AirKnife treatment. 【0260】 - Treatment to reduce the amount of carboxyl groups (carboxyl group reduction treatment) The laminate obtained after the above treatment is treated with a xenon lamp at a rate of 2 J / cm². ２ The sample is exposed to light with the specified exposure level, and then further heated in an oven at 150°C for 30 minutes after exposure. 【0261】 [Measurement and Evaluation] <Carboxy group content> (Remaining amount of carboxyl groups (ratio to initial content, IR measurement)) Photosensitive composition 1 is applied to a silicon wafer using a bar coater to form a coating film with a thickness of 4.0 μm after drying, and then dried in an oven at 100°C to form a photosensitive composition layer (hereinafter, the photosensitive composition layer formed at this stage is also called the "uncured photosensitive composition layer"). Next, the entire surface of the photosensitive composition layer is irradiated with light using a high-pressure mercury lamp exposure machine (MAP-1200L, Dainippon Kaken Co., Ltd., main wavelength: 365 nm) at the same exposure amount as in the exposure process for pattern formation shown in the upper section. Next, the photosensitive composition layer after exposure is exposed with a xenon lamp at 2 J / cm². ２ The entire surface is exposed to light with the specified exposure level, and then heated in an oven at 150°C for 30 minutes (hereinafter, the photosensitive composition layer formed at this stage will also be referred to as the "post-treatment photosensitive composition layer"). 【0262】 The IR spectra of the uncured photosensitive composition layer and the treated photosensitive composition layer were measured, and the peak of C=O stretching of the carboxyl group (1710 cm⁻¹) was identified. －１For the peak, the residual rate of carboxyl groups [(amount of carboxyl groups in the photosensitive composition layer after treatment / amount of carboxyl groups in the uncured photosensitive composition layer) × 100 (mol%)] is calculated. A lower residual amount of carboxyl groups indicates that the decarboxylation reaction has progressed. The results are shown in the "Carboxyl Group Residue (Ratio to Initial Value)" column of Table 2. 【0263】 <Optical Loss> A photosensitive composition 1 is applied to a silicon wafer using a bar coater to form a coating film with a thickness of 10.0 μm after drying. This coating is then dried in an oven at 100°C to form a photosensitive composition layer. Next, the entire surface of the photosensitive composition layer is irradiated with light using a high-pressure mercury lamp exposure machine (MAP-1200L, Dainippon Kaken Co., Ltd., main wavelength: 365 nm) at the same exposure amount as in the exposure process for pattern formation shown in the upper section. Subsequently, the photosensitive composition layer after exposure is exposed with a xenon lamp at 2 J / cm². ２ The entire surface is exposed with the specified exposure dose. Then, the same procedure is repeated on the exposed surface to form a 100 μm photosensitive composition layer. After that, the surface is heated in an oven at 150°C for 30 minutes. The transmittance (%) and reflectance (%) of the resulting film are measured using a spectrophotometer equipped with an integrating sphere, and the absorptance (%) is determined by subtracting the transmittance (%) and reflectance (%) values ​​from 100%. Next, the optical loss (dB / cm) at a wavelength of 1310 nm is determined based on the following formula (OP1). Formula (OP1): Optical loss (dB / cm) = {-10 × log} １０ The results for (absorption rate (%) / 100) / film thickness are shown in Table 2. Note that the smaller the optical loss, the easier it is to form an optical waveguide with low light propagation loss. 【0264】 <Maximum Resolution> The minimum line width of the pattern formed without development residue or distortion was determined and defined as the maximum resolution. The results are shown in Table 2. 【0265】 [Preparation and Evaluation of Transfer Film 2] Transfer film 2 was prepared using the same procedure as for transfer film 1, except that photosensitive composition 2 was used instead of photosensitive composition 1. Transfer film 2 was also evaluated using the same procedure as for transfer film 1. 【0266】[Preparation and Evaluation of Transfer Films 3-16, R1, and R2] Transfer films 3-16, R1, and R2 are prepared using the same procedure as for transfer film 1, except that photosensitive compositions 3-16, R1, and R2 are used instead of photosensitive composition 1. Transfer films 3-16, R1, and R2 are also evaluated using the same procedure as for transfer film 1. Even if the photosensitive composition does not contain a compound that reduces the amount of carboxyl groups (compound X) (for example, composition 14), a carboxylic acid group reduction treatment is performed during pattern formation and the formation of evaluation samples. 【0267】 Table 2 is shown below. 【0268】 【0269】 【0270】 【0271】 【0272】 The results in the table clearly show that the transfer film of the example is alkali-developable and capable of forming an optical waveguide that achieves low light propagation loss. 【0273】Furthermore, it has been shown that when the photosensitive composition layer of the transfer film contains a compound (compound X) that reduces carboxyl groups, the resulting cured layer has low optical loss and can form an optical waveguide with lower light propagation loss (see, for example, the comparison between transfer film 13 (transfer film using composition 13) and transfer film 14 (transfer film using composition 14)). Also, when a specific polymer in the photosensitive composition layer of the transfer film contains repeating unit (2) as a repeating unit containing radical polymerizable groups, it has been shown that the resulting cured layer has low optical loss and can form an optical waveguide with lower light propagation loss (see, for example, the results for transfer films 1 to 12 (transfer films using compositions 1 to 12). In particular, see the comparison between transfer films 1, 2, 4, 5, 10 to 12 (transfer films using compositions 1, 2, 4, 5, 10 to 12) and transfer films 3, 6 to 9 (transfer films using compositions 3, 6 to 9)). Furthermore, it has been shown that when a specific polymer in the photosensitive composition layer of the transfer film contains repeating unit (3) as a repeating unit containing a radical polymerizable group, the alkali developability is excellent (in other words, the maximum resolution of the formed pattern is small) (see, for example, the results for transfer films 1 to 12 (transfer films using compositions 1 to 12). In particular, see the comparison between transfer films 1 to 3, 8, 10 to 12 (transfer films using compositions 1 to 3, 8, 10 to 12) and transfer films 4 to 7, 9 (transfer films using compositions 4 to 7, 9)). Also, it has been shown that when the acid value of the specific polymer in the photosensitive composition layer of the transfer film is 0.6 to 2.0 mmol / g, the alkali developability is excellent (in other words, the maximum resolution of the formed pattern is small) (see, for example, the results for transfer films 1 to 12 (transfer films using compositions 1 to 12). In particular, see the comparison between transfer film 2 (transfer film using composition 2) and transfer films 10 to 11 (transfer films using compositions 10 to 11)). Furthermore, when the acid value of a specific polymer in the photosensitive composition layer of the transfer film is 2.0 mmol / g or less, the cured layer obtained by subjecting it to a treatment to reduce the amount of carboxyl groups has a small amount of residual carboxyl groups, resulting in lower optical loss and the formation of an optical waveguide with lower light propagation loss (see, for example, the results for transfer films 1 to 12 (transfer films using compositions 1 to 12)).In particular, see the comparison between transfer film 2 (transfer film using composition 2) and transfer film 11 (transfer film using composition 11). Furthermore, it is clear that when the total content of specific repeating units selected from the group consisting of repeating units (1), repeating units (2), and repeating units (3) in the specific polymer in the photosensitive composition layer of the transfer film is 50% by mass or more relative to the total number of repeating units, the optical loss of the resulting cured layer is reduced, and an optical waveguide with lower light propagation loss can be formed (see, for example, the results for transfer films 1 to 12, 15, and 16 (transfer films using compositions 1 to 12, 15, and 16). In particular, see the comparison between transfer film 2 (transfer film using composition 2) and transfer film 12 (transfer film using composition 12)). Furthermore, it is clear that when the content of the specific polymer in the photosensitive composition layer of the transfer film is 70% by mass or more relative to the total mass of the photosensitive composition layer, the optical loss of the resulting cured layer is reduced, and an optical waveguide with lower light propagation loss can be formed. On the other hand, because the content of polymerizable compounds is relatively low, the resolution tends to deteriorate slightly (see, for example, the comparison between transfer film 9 (transfer film using composition 9) and transfer film 13 (transfer film using composition 13)). 【0274】 10, 10A Transfer film 12 Temporary support 14 Thermoplastic resin layer 16 Intermediate layer 18 Photosensitive composition layer 20 Cover film 22 Substrate 24 Resin layer 30 Laminate 32 First resin layer 34, 42 Core portion 36 Second resin layer 40, 50 Optical waveguide 44 Cladding portion

Claims

A transfer film comprising a temporary support and a photosensitive composition layer, A transfer film in which the photosensitive composition layer comprises a polymer having a repeating unit represented by formula (1), a radical polymerizable group, and a carboxyl group or a salt thereof. In the formula, R ａ ~R ｃ Each of these independently represents a hydrogen atom, a deuterium atom, or a fluorine atom. １ ~R ５ Each of these independently represents a hydrogen atom or a fluorine atom. However, R １ ~R ５ At least one of them represents a fluorine atom. 　 The transfer film according to claim 1, wherein the polymer further comprises a repeating unit represented by formula (2). In the formula, R ｄ to R ｆ each independently represents a hydrogen atom, a deuterium atom, or a fluorine atom. X １ represents an oxygen atom, a sulfur atom, or a single bond. L １ represents a single bond or a linear or branched C1-10 n1+1-valent aliphatic hydrocarbon group which may have a substituent and in which at least one methylene group may be substituted with an oxygen atom or a sulfur atom. P represents an acryloyloxy group or a methacryloyloxy group. n1 represents an integer of 1 to 3. When L １ represents a single bond, n1 represents 1. When n1 represents 2 or 3, the plurality of Ps may be the same as or different from each other. 　 The transfer film according to claim 1 or 2, wherein the polymer further comprises a repeating unit represented by formula (3). In the formula, R ６ R represents a hydrogen atom or a cyano group. ７ R represents a hydrogen atom, a methyl group, or a cyanoethyl group. ６ When R represents a cyano group, ７ represents a hydrogen atom. Also, R ６ When R represents a hydrogen atom, ７ represents a hydrogen atom, a methyl group, or a cyanoethyl group. 　 The transfer film according to claim 1, wherein the polymer contains a total content of specific repeating units selected from the group consisting of repeating units represented by formula (1), repeating units represented by formula (2), and repeating units represented by formula (3), which is 50% by mass or more relative to the total number of repeating units, and the acid value of the polymer is 0.6 to 2.0 mmol / g. In the formula, R ｄ ~R ｆ Each of these independently represents a hydrogen atom, a deuterium atom, or a fluorine atom. １ L represents an oxygen atom, a sulfur atom, or a single bond. １ represents a single bond, or a linear or branched n1+1 valent aliphatic hydrocarbon group having 1 to 10 carbon atoms, which may have substituents, and at least one methylene group may be substituted with an oxygen or sulfur atom. P represents an acryloyloxy group or a methacryloyloxy group. n1 represents an integer from 1 to 3. Note that L １ When n1 represents a single bond, n1 represents 1. When n1 represents 2 or 3, the multiple Ps may be the same or different from each other. In the formula, R ６ R represents a hydrogen atom or a cyano group. ７ R represents a hydrogen atom, a methyl group, or a cyanoethyl group. ６ When R represents a cyano group, ７ represents a hydrogen atom. Also, R ６ When R represents a hydrogen atom, ７ represents a hydrogen atom, a methyl group, or a cyanoethyl group. 　 The transfer film according to claim 1 or 2, wherein the photosensitive composition layer further comprises a compound that reduces the amount of carboxyl groups. 　 The transfer film according to claim 5, wherein the compound that reduces the carboxyl groups is a compound that causes a decarboxylation reaction of carboxyl groups upon exposure. 　 The transfer film according to claim 6, wherein the compound that causes a decarboxylation reaction of a carboxyl group by exposure is one or more selected from the group consisting of quinoline compounds, isoquinoline compounds, and quinoxaline compounds. 　 The transfer film according to claim 7, wherein the quinoline compound, the isoquinoline compound, and the quinoxaline compound each have at least one radical polymerizable group. 　 The transfer film according to claim 5, wherein the compound that reduces the carboxyl group is an isocyanate compound. 　 A laminate comprising a substrate, a resin layer, and a transfer film according to claim 1 or 2, wherein the photosensitive composition layer of the transfer film is arranged to face the resin layer. 　 A method for manufacturing an optical waveguide using a laminate comprising a substrate, a resin layer, and a transfer film according to claim 1 or 2, wherein the photosensitive composition layer is arranged to face the resin layer, and the refractive index of the resin layer is lower than that of the cured layer of the photosensitive composition layer, Step 1 involves performing an exposure treatment on the photosensitive composition layer in the laminate, Step 2 involves performing an alkaline development treatment on the photosensitive composition layer that has been exposed to light to form a core, The process includes step 3, which involves forming a resin layer on the core portion so as to cover the core portion, with a lower refractive index than that of the core portion, thereby forming an optical waveguide having the core portion and the cladding portion. A method for manufacturing an optical waveguide, comprising step 4 of peeling off a temporary support before step 1, or between step 1 and step 2. A photosensitive composition comprising a polymer having a repeating unit represented by formula (1), a radical polymerizable group, and a carboxyl group or a salt thereof. In the formula, R ａ ~R ｃ Each of these independently represents a hydrogen atom, a deuterium atom, or a fluorine atom. １ ~R ５ Each of these independently represents a hydrogen atom or a fluorine atom. However, R １ ~R ５ At least one of them represents a fluorine atom. 　 The photosensitive composition according to claim 12, wherein the polymer further comprises a repeating unit represented by formula (2). In the formula, R ｄ ~R ｆ Each of these independently represents a hydrogen atom, a deuterium atom, or a fluorine atom. １ L represents an oxygen atom, a sulfur atom, or a single bond. １ represents a single bond, or a linear or branched n1+1 valent aliphatic hydrocarbon group having 1 to 10 carbon atoms, which may have substituents, and at least one methylene group may be substituted with an oxygen or sulfur atom. P represents an acryloyloxy group or a methacryloyloxy group. n1 represents an integer from 1 to 3. Note that L １ When n1 represents a single bond, n1 represents 1. When n1 represents 2 or 3, the multiple Ps may be the same or different from each other. Furthermore, the photosensitive composition according to claim 12 or 13, comprising a compound that reduces the amount of carboxyl groups. A polymer having a repeating unit represented by formula (1), a radical polymerizable group, and a carboxyl group or a salt thereof. In the formula, R ａ ~R ｃ Each of these independently represents a hydrogen atom, a deuterium atom, or a fluorine atom. １ ~R ５ Each of these independently represents a hydrogen atom or a fluorine atom. However, R １ ~R ５ At least one of them represents a fluorine atom. 　 The polymer according to claim 15, wherein the polymer further comprises a repeating unit represented by formula (2). In the formula, R ｄ ~R ｆ Each of these independently represents a hydrogen atom, a deuterium atom, or a fluorine atom. １ L represents an oxygen atom, a sulfur atom, or a single bond. １ represents a single bond, or a linear or branched n1+1 valent aliphatic hydrocarbon group having 1 to 10 carbon atoms, which may have substituents, and at least one methylene group may be substituted with an oxygen or sulfur atom. P represents an acryloyloxy group or a methacryloyloxy group. n1 represents an integer from 1 to 3. Note that L １ When n1 represents a single bond, n1 represents 1. When n1 represents 2 or 3, the multiple Ps may be the same or different from each other. 　 The polymer according to claim 15 or 16, wherein the polymer further comprises a repeating unit represented by formula (3). In the formula, R ６ R represents a hydrogen atom or a cyano group. ７ R represents a hydrogen atom, a methyl group, or a cyanoethyl group. ６ When R represents a cyano group, ７ represents a hydrogen atom. Also, R ６ When R represents a hydrogen atom, ７ represents a hydrogen atom, a methyl group, or a cyanoethyl group. 　 The repeating unit represented by the above formula (1), A repeating unit selected from the group consisting of repeating units represented by formula (2) and repeating units represented by formula (4), The polymer according to claim 15, comprising a repeating unit represented by formula (5). In the formula, R ｄ ~R ｆ Each of these independently represents a hydrogen atom, a deuterium atom, or a fluorine atom. １ L represents an oxygen atom, a sulfur atom, or a single bond. １ represents a single bond, or a linear or branched n1+1 valent aliphatic hydrocarbon group having 1 to 10 carbon atoms, which may have substituents, and at least one methylene group may be substituted with an oxygen or sulfur atom. P represents an acryloyloxy group or a methacryloyloxy group. n1 represents an integer from 1 to 3. Note that L １ When n1 represents a single bond, n1 represents 1. When n1 represents 2 or 3, the multiple Ps may be the same or different from each other. In the formula, R ８ and R ９ Each of these independently represents either a hydrogen atom or a methyl group. ２ and X ３ These are, independently, -O- or -NR Ｎ Represents -. R Ｎ L represents a hydrogen atom or an alkyl group. ２ This represents an unsubstituted divalent hydrocarbon group. In the formula, R １０ represents a hydrogen atom or a methyl group. 　 An optical waveguide having a core portion and a cladding portion having a lower refractive index than the core portion, which is arranged to cover the periphery of the core portion. An optical waveguide in which the core portion is a layer formed using the photosensitive composition described in claim 12 or 13. 　 An optical waveguide having a core portion and a cladding portion having a lower refractive index than the core portion, which is arranged to cover the periphery of the core portion. The core portion comprises a component derived from the polymer described in claim 15 or 16, wherein the optical waveguide.

Images