JP6720815B2 - Photosensitive resin composition, optical element, spacer, insulating film and display device obtained by using the same - Google Patents

Description

The present invention relates to a member for forming an optical element used in a display device or the like, and more particularly to a photosensitive resin composition suitably used for forming a protective layer of an optical film having anisotropy formed on a substrate. .. Furthermore, the present invention resides in an optical element in which an optical film having anisotropy is coated with the protective layer, a display device including the optical element, and the like.

In an LCD (liquid crystal display), a linear polarizing plate or a circular polarizing plate is used to control optical rotation and birefringence in display. A circularly polarizing plate is also used in an OLED (organic EL element) to prevent reflection of external light. Conventionally, in these polarizing plates (optical elements), iodine or an organic dye having dichroism is dissolved or adsorbed in a polymer material such as polyvinyl alcohol, and the film is stretched in one direction in a film shape to obtain iodine or A polarizing plate obtained by aligning an organic dye having dichroism has been widely used. However, the conventional optical film manufactured in this manner has problems that various equipments are required, the cost is high, and the yield of bonding is poor. Further, with the diversification of display devices, there has been a demand for weight reduction and thickness reduction, and in this respect, the conventional film-shaped polarizing plate has a limit.

In order to solve these problems, a solution containing a dichroic dye is applied onto a substrate such as glass or a transparent film while applying a shearing force to orient the dichroic dye to give anisotropy. A method for producing an optical film (hereinafter, abbreviated as “anisotropic optical film”) has been studied, and further, a so-called In-Cell-type polarizer obtained by applying the film to the inside of an LCD cell has been developed. Is being considered.

An anisotropic optical film formed by a wet film formation method using such a dichroic dye has insufficient water resistance, moisture resistance, and chemical resistance. Since the resistance to organic solvents such as N-methylpyrrolidone used when forming a film is insufficient, it is necessary to provide a protective layer for the purpose of protecting them. However, the protective layer for an anisotropic optical film used in this manner has not been sufficiently studied.

As a property required for a protective layer for an anisotropic optical film, it is important that the anisotropic optical film is not deteriorated when the protective layer is first formed. From the viewpoint of heat resistance of the anisotropic optical film, For the protective layer, it is important to form a film capable of sufficiently securing the optical film protective property at a low temperature of 200° C. or lower.
Conventionally, as a member such as a protective layer that is most commonly used for a display device such as an LCD, a radical polymerization type material that radically polymerizes an ethylenically unsaturated group with a photo radical polymerization initiator is mainly used. Finally requires a baking step of about 230° C. to push out the polymerization of the ethylenically unsaturated group, so that when this is used for the anisotropic optical film protective layer, it deteriorates the anisotropic optical film. It is not preferable in that it will end up. On the other hand, as a photolithography material that can be cured at low temperature, a polymer having a side chain such as an epoxy group and an alkali-soluble group such as a carboxylic acid that can cut off a crosslinking reaction at a relatively low temperature is used as a binder resin. Various types have been disclosed (see Patent Documents 1 to 5).

On the other hand, in color filters that include low heat resistance members, such as the adoption of pixels containing dyes for the purpose of high brightness and the adoption of plastic substrates for the purpose of weight reduction and flexibility, do not deteriorate them. It is necessary to form the spacer under the condition that the temperature is limited. However, since the spacer is formed in the liquid crystal layer, a high level of electrical reliability is required even when formed at a low temperature, and sufficient strength as a spacer must be ensured.
In addition, the technology of TFTs using organic semiconductors is approaching practical application along with the development of plastic substrates and printing. When using such materials, there is a temperature-limited condition so as not to deteriorate them. A member such as an interlayer insulating film that can be formed by is required. In this case as well, a high level of electrical reliability and insulation that does not disturb the electrical signal is required.

JP-A-11-133600 JP 2001-64337 A JP-A-2002-90507 JP, 2008-260909, A JP 2012-194290 A

When forming an anisotropic optical film by a wet film formation method, it is efficient to apply it continuously to a large mother substrate, remove the unnecessary part of the optical film, and then divide it into a predetermined size for use. is there. At this time, while patterning the protective layer using a photosensitive resin composition for a protective layer having photolithography property, and removing the optical film of the portion protruding from the pattern of the protective layer, the necessary panel on the mother substrate. It is rational if an optical film with a protective layer divided into sizes can be obtained.

However, as a result of examination by the present inventors, in the photosensitive resin compositions described in Patent Documents 1, 2, 3 and 5, when the anisotropic optical film and the protective layer are collectively patterned with an alkaline developer, There is a problem that the protective layer tends to peel off, and patterning of the optical film is difficult. Further, Patent Documents 2, 3, 4, and 5 are compositions used by baking at a high temperature of 220° C. or higher, and even if they are cured at a low temperature, their electrical reliability and chemical resistance are not sufficient. Documents 4 and 5 have a problem in terms of electrical reliability, and it has been found that it is difficult to apply them to the inside of a liquid crystal cell or the like, which requires a high degree of electrical reliability.

The present invention has been made in view of such conventional techniques. That is, the present invention is capable of patterning by photolithography, has sufficient adhesion and film strength to protect an optical film even after alkali exposure with the lower anisotropic optical film at the same time after exposure, and further 200 It is possible to form a protective layer that has sufficient chemical resistance to protect the lower optical film even at a low temperature baking of ℃ or below and that can secure a high level of electrical reliability that can sufficiently cope with the inside of the liquid crystal cell. It is intended to provide a photosensitive resin composition.

Further, the present invention provides a photosensitive resin composition capable of forming a spacer having sufficient strength even at a low temperature bake of 200° C. or lower, and an insulating film excellent in electrical reliability even at a low temperature bake of 200° C. or lower. It aims at providing the photosensitive resin composition which can form.

MEANS TO SOLVE THE PROBLEM As a result of earnestly studying in order to solve the said subject, this inventor WHEREIN: In the photosensitive resin composition containing (A) polymeric compound, (B) photocationic polymerization initiator, and (C) photoradical polymerization initiator, The polymerizable compound (A) contains a specific copolymer and a specific polymerizable compound, the polymerizable compound (A) contains a cyclic aliphatic group, and the cationic photopolymerization initiator (B) is aromatic. It is a group iodonium salt, and found that the above problem can be solved by setting the content ratio of the cycloaliphatic ring in the total solid content of the photosensitive resin composition to a specific range, and completed the present invention. .. That is, the gist of the present invention is as follows.

[1] A photosensitive resin composition containing a polymerizable compound (A), a cationic photopolymerization initiator (B) and a radical photopolymerization initiator (C),
The polymerizable compound (A) includes (A-1) a copolymer having an epoxy group and a carboxyl group, and (A-2) a polymerizable compound having an ethylenically unsaturated group,
The polymerizable compound (A) contains a cycloaliphatic group,
The cationic photopolymerization initiator (B) contains an aromatic iodonium salt, and
A photosensitive resin composition, wherein the content of the cycloaliphatic ring in the total solid content of the photosensitive resin composition is 7% by mass or more.
[2] The photosensitive resin composition according to [1], wherein the (A-1) copolymer having an epoxy group and a carboxyl group has the cyclic aliphatic group.
[3] The photosensitive resin composition according to [1] or [2], wherein the anion of the aromatic iodonium salt is a hexafluorophosphate anion.
[4] Any of [1] to [3], wherein the total content of the (B) photocationic polymerization initiator and the (C) photoradical polymerization initiator is 10% by mass or less based on the total solid content. The photosensitive resin composition according to item 1.
[5] The photosensitive resin composition according to any one of [1] to [4], which is for a protective layer of an optical film having anisotropy.
[6] An optical element which has an optical film having anisotropy and whose surface is covered with a protective layer composed of the photosensitive resin composition according to any one of [1] to [5].
[7] A display device including the optical element according to [6].
[8] The photosensitive resin composition according to any one of [1] to [4], which is for a spacer and/or for an insulating film.
[9] A spacer and/or an insulating film composed of the photosensitive resin composition according to [8].
[10] A display device including the spacer and/or the insulating film according to [9].

According to the photosensitive resin composition of the present invention, patterning by photolithography is possible, and a film having sufficient adhesiveness and film that can protect the optical film even after being subjected to alkali development together with the underlying anisotropic optical film after exposure. A protective layer that has strength, has sufficient chemical resistance to protect the underlying optical film even when baked at a low temperature of 200° C. or less, and can ensure a high level of electrical reliability that can sufficiently cope with inside a liquid crystal cell. It is possible to provide. Further, it is possible to provide a spacer having sufficient strength even at a low temperature baking of 200° C. or less, an insulating film having excellent electrical reliability, and the like.

1(1) is an anisotropic optical film with a protective layer after coating a photosensitive resin composition, FIG. 1(2) is an anisotropic optical film with a protective layer after exposure and development, and FIG. 1(3) is It is a conceptual diagram explaining the shape of the anisotropic optical film with a protective layer after baking. FIG. 2 is an optical microscope observation result of the anisotropic optical film with a protective layer of Example 4. FIG. 3 is an SEM observation result of the anisotropic optical film with the protective layer of Example 4. FIG. 4 shows the measurement results of the resonance frequency of Example 5 and Comparative Example 7. FIG. 5 is a load-displacement curve of the spacer of Example 6.

Embodiments of the present invention will be described in detail below. However, the following description is an example (representative example) of the embodiment of the present invention, and the present invention is not limited to these contents unless it exceeds the gist.
In the present invention, “(meth)acrylic acid” includes both acrylic acid and methacrylic acid, and “(meth)acrylate”, “(meth)acryloyl” and the like have the same meaning. Moreover, what attached "(poly)" in front of a monomer name means the said monomer and this polymer. In the present invention, the "total solids" means all the components of the photosensitive resin composition of the present invention except the solvent.

[Photosensitive resin composition]
The photosensitive resin composition of the present invention contains (A) a polymerizable compound, (B) a photocationic polymerization initiator and (C) a photoradical polymerization initiator.

[(A) Polymerizable compound]
The photosensitive resin composition of the present invention contains (A) a polymerizable compound, so that the photocurability during photolithography, the protection and adhesion of the lower optical film during the formation of a development pattern, and the resistance after heat curing. It is possible to obtain a protective film having an excellent film quality with suppressed chemical property and permeability.
Further, the polymerizable composition (A) contains a cyclic aliphatic group, and (A) a polymerizable compound, (A-1) a copolymer having an epoxy group and a carboxyl group, and (A-2) And a polymerizable compound having an ethylenically unsaturated group.

[(A-1) Copolymer Having Epoxy Group and Carboxyl Group]
The photosensitive resin composition of the present invention contains (A-1) a copolymer having an epoxy group and a carboxyl group (hereinafter, may be abbreviated as “(A-1) copolymer”). The film strength after exposure, the solubility in an alkali developing solution, and the low temperature curability tend to be achieved. The (A-1) copolymer can be obtained, for example, by polymerizing a vinyl compound having at least an epoxy group and a vinyl compound having a carboxyl group as a copolymerizable component.

For example, by using an epoxy group-containing vinyl compound, the repeating unit structure represented by the following general formula (1) can be introduced into the (A-1) copolymer.

In the general formula (1), R ¹ represents a hydrogen atom or a methyl group.
α represents a direct bond or a divalent linking group. However, the carbon atom of the epoxy group in the formula (1) that is not bonded to α may be bonded to α to form a ring.

Examples of the divalent linking group for α include an alkylene group which may have a substituent, and the methylene group in the alkylene group is an unsaturated bond, an ether bond, a thioether bond, an ester bond, a thioester bond, or an amide. It may be substituted with at least one bond selected from the group consisting of a bond and a urethane bond. For example, a connecting group containing an ester bond or an amide bond can be mentioned.
Although the carbon number of the alkylene group is not particularly limited, it is preferably 1 or more from the viewpoint of easiness of synthesis, and preferably 9 or less from the viewpoint of film-forming property, and 7 or less. Is more preferable, 5 or less is more preferable, and 3 or less is particularly preferable.
Examples of the substituent that the alkylene group may have include a halogen atom, an alkenyl group having 2 to 8 carbon atoms, an alkoxyl group having 1 to 8 carbon atoms, a phenyl group, a mesityl group, a tolyl group, a naphthyl group, and a cyano group. Group, acetyloxy group, alkylcarbonyloxy group having 2 to 9 carbon atoms, sulfamoyl group, alkylsulfamoyl group having 2 to 9 carbon atoms, alkylcarbonyl group having 2 to 9 carbon atoms, phenethyl group, hydroxyethyl group, acetyl An amide group, a dialkylaminoethyl group formed by combining alkyl groups having 1 to 4 carbon atoms, a trifluoromethyl group, a trialkylsilyl group having 1 to 8 carbon atoms, a nitro group, an alkylthio group having 1 to 8 carbon atoms, etc. Of these, preferred are an alkoxyl group having 1 to 8 carbon atoms, a cyano group, an acetyloxy group, an alkylcarboxyl group having 2 to 8 carbon atoms, a sulfamoyl group, an alkylsulfamoyl group having 2 to 9 carbon atoms, and a halogen atom. .. From the viewpoint of ease of synthesis, the alkylene group is preferably unsubstituted.

Among α, from the viewpoint of ease of synthesis, a direct bond, an alkylene group substituted with an ether bond, or an alkylene group substituted with an ester bond is preferable, and an alkylene group substituted with an ester bond is more preferable, - (C = O) -O- CH 2 - and more preferably a group.

Specific examples of the epoxy group-containing vinyl compound include allyl glycidyl ether, glycidyl (meth)acrylate, 2-methylglycidyl (meth)acrylate, α-ethylglycidyl (meth)acrylate, α-n-propylglycidyl (meth)acrylate. , Α-n-butylglycidyl (meth)acrylate, 3,4-epoxybutyl (meth)acrylate, 6,7-epoxyheptyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate glycidyl ether, glycidyl ether glycidyl crotonate , Glycidyl isocrotonate, crotonyl glycidyl ether, itaconic acid monoalkyl monoglycidyl ester, fumaric acid monoalkyl monoglycidyl ester, maleic acid monoalkyl monoglycidyl ester, o-vinylbenzyl glycidyl ether, m-vinylbenzyl glycidyl ether, p -Glycidyl group-containing vinyl compounds such as vinylbenzyl glycidyl ether. In addition to this, 3,4-epoxycyclohexylmethyl (meth)acrylate, 2-(3,4-epoxycyclohexyl)ethyl (meth)acrylate, 2,3-epoxycyclopentylmethyl (meth)acrylate, 7,8- Examples thereof include alicyclic epoxy group-containing vinyl compounds such as epoxy [tricyclo[5.2.1.0]dec-2-yl]oxymethyl(meth)acrylate.
These may be used alone or in any combination of two or more in any proportion. Among these, from the viewpoint of adhesiveness to the substrate, it is preferable to use an aliphatic epoxy group-containing vinyl compound, more preferable to use a (meth)acrylate compound, and glycidyl (meth)acrylate or 4-hydroxybutyl( It is further preferred to use (meth)acrylate glycidyl ether.

The content of the repeating unit structure represented by the general formula (1) in the (A-1) copolymer is preferably 30 mol% or more, more preferably 40 mol% or more, and 45 mol% or more. Is more preferable, 50 mol% or more is still more preferable, 55 mol% or more is particularly preferable, and 60 mol% or more is most preferable. Further, it is usually 80 mol% or less, preferably 70 mol% or less, more preferably 65 mol% or less, and particularly preferably 60 mol% or less. When it is at least the above lower limit, exposure sensitivity and low-temperature curability will tend to be secured, and when it is at most the above upper limit, excellent film quality and patternability during development will tend to be secured.

In the (A-1) copolymer, for example, by using a carboxyl group-containing vinyl compound, the repeating unit structure represented by the following general formula (2) can be introduced into the (A-1) copolymer. ..

In the general formula (3), R ² represents a hydrogen atom or a methyl group.
β represents a direct bond or a divalent linking group.

Examples of the divalent linking group for β include an ether bond, a thioether bond, an ester bond, a thioester bond, an amide bond, a urethane bond, and an alkylene group which may have a substituent. A part of the methylene groups of the alkylene group may be substituted with at least one bond selected from the group consisting of an unsaturated bond, an ether bond, a thioether bond, an ester bond, a thioester bond, an amide bond and a urethane bond. For example, a connecting group containing an ester bond or an amide bond can be mentioned.
Although the carbon number of the alkylene group is not particularly limited, it is preferably 1 or more from the viewpoint of easiness of synthesis, and preferably 9 or less from the viewpoint of film-forming property, and 7 or less. Is more preferable.
Examples of the substituent that the alkylene group may have include a halogen atom, an alkenyl group having 2 to 8 carbon atoms, an alkoxyl group having 1 to 8 carbon atoms, a phenyl group, a mesityl group, a tolyl group, a naphthyl group, and a cyano group. Group, acetyloxy group, alkylcarbonyloxy group having 2 to 9 carbon atoms, sulfamoyl group, alkylsulfamoyl group having 2 to 9 carbon atoms, alkylcarbonyl group having 2 to 9 carbon atoms, phenethyl group, hydroxyethyl group, acetyl An amide group, a dialkylaminoethyl group formed by combining alkyl groups having 1 to 4 carbon atoms, a trifluoromethyl group, a trialkylsilyl group having 1 to 8 carbon atoms, a nitro group, an alkylthio group having 1 to 8 carbon atoms, etc. Of these, preferred are an alkoxyl group having 1 to 8 carbon atoms, a cyano group, an acetyloxy group, an alkylcarboxyl group having 2 to 8 carbon atoms, a sulfamoyl group, an alkylsulfamoyl group having 2 to 9 carbon atoms, and a halogen atom. .. From the viewpoint of ease of synthesis, the alkylene group is preferably unsubstituted.

Among β, from the viewpoint of ease of synthesis, a direct bond, an ether bond, an ester bond, an alkylene group substituted with an ether bond, or an alkylene group substituted with an ester bond is preferable, and a direct bond or an ester bond is preferable. More preferable, and direct binding is further preferable.

Preferable specific examples of the carboxyl group-containing vinyl compound include unsaturated carboxylic acids such as (meth)acrylic acid, crotonic acid, isocrotonic acid, maleic acid, maleic anhydride, itaconic acid, and citraconic acid.

The content of the repeating unit structure represented by the general formula (2) in the copolymer (A-1) is preferably 5 mol% or more, more preferably 10 mol% or more, and 15 mol% or more. It is more preferable that the content is 18 mol% or more, still more preferably 18 mol% or more, and particularly preferably 20 mol% or more. Further, it is preferably 40 mol% or less, more preferably 35 mol% or less, further preferably 30 mol% or less, and particularly preferably 28 mol% or less. When it is at least the above lower limit, the alkali developability tends to be easily secured, and when it is at most the above upper limit, the production stability of the polymer (A) tends to be easily secured.

In the copolymer (A-1), for example, by using a vinyl compound containing a cycloaliphatic group, the repeating unit structure represented by the following general formula (3) is introduced into the copolymer (A-1). You can By containing the cyclic aliphatic group-containing repeating unit structure represented by the following general formula (3), the exposed part of the resulting protective layer is less likely to swell during development, and the lower optical layer having anisotropy is formed. Adhesion during development is secured, peeling during development is suppressed, and the lower layer tends to be sufficiently protected. Furthermore, by preventing the components of the developing solution from penetrating into the protective layer, deterioration of electric reliability due to alkali development tends to be prevented.

In the general formula (3), R ³ represents a hydrogen atom or a methyl group.
γ represents a direct bond or a divalent linking group.
R ⁴ represents a cycloaliphatic group which may have a substituent.

Examples of the divalent linking group for γ include an ether bond, a thioether bond, an ester bond, a thioester bond, an amide bond, a urethane bond, and an alkylene group which may have a substituent. A part of the methylene groups of the alkylene group may be substituted with at least one bond selected from the group consisting of an unsaturated bond, an ether bond, a thioether bond, an ester bond, a thioester bond, an amide bond and a urethane bond. For example, a connecting group containing an ester bond or an amide bond can be mentioned.
Although the carbon number of the alkylene group is not particularly limited, it is preferably 1 or more from the viewpoint of easiness of synthesis, and preferably 9 or less from the viewpoint of film-forming property, and 7 or less. Is more preferable.
Examples of the substituent that the alkylene group may have include a halogen atom, an alkenyl group having 2 to 8 carbon atoms, an alkoxyl group having 1 to 8 carbon atoms, a phenyl group, a mesityl group, a tolyl group, a naphthyl group, and a cyano group. Group, acetyloxy group, alkylcarbonyloxy group having 2 to 9 carbon atoms, sulfamoyl group, alkylsulfamoyl group having 2 to 9 carbon atoms, alkylcarbonyl group having 2 to 9 carbon atoms, phenethyl group, hydroxyethyl group, acetyl An amide group, a dialkylaminoethyl group formed by combining alkyl groups having 1 to 4 carbon atoms, a trifluoromethyl group, a trialkylsilyl group having 1 to 8 carbon atoms, a nitro group, an alkylthio group having 1 to 8 carbon atoms, etc. Of these, preferred are an alkoxyl group having 1 to 8 carbon atoms, a cyano group, an acetyloxy group, an alkylcarboxyl group having 2 to 8 carbon atoms, a sulfamoyl group, an alkylsulfamoyl group having 2 to 9 carbon atoms, and a halogen atom. .. From the viewpoint of ease of synthesis, the alkylene group is preferably unsubstituted.

Among γ, from the viewpoint of ease of synthesis, a direct bond, an ether bond, an ester bond, an alkylene group substituted with an ether bond, or an alkylene group substituted with an ester bond is preferable, and an ester bond is more preferable.

The carbon number of the cycloaliphatic group in R ⁴ is not particularly limited, but from the viewpoint of the strength of the film, it is preferably 5 or more, more preferably 6 or more, further preferably 7 or more, and 8 Particularly preferably, it is 20 or less, more preferably 15 or less, still more preferably 12 or less, from the viewpoint of reactivity of the vinyl polymer.
Further, the cycloaliphatic group may be monocyclic or polycyclic, but is preferably polycyclic from the viewpoint of film strength. Further, the hydrocarbon constituting the cycloaliphatic ring may contain a hetero atom, but from the viewpoint of ensuring transparency of the optical film and effectively expressing the effect of the cycloaliphatic ring, It is preferably an alicyclic hydrocarbon containing no.
Specific examples of the cycloaliphatic group include a cyclohexyl group, a dicyclopentanyl group, an adamantyl group, a norbornyl group, a tetracyclodecanyl group, and the like. Among these, from the viewpoint of the strength of the film, a dicyclopentanyl group. Or, an adamantyl group is preferable.
The substituent that the cyclic aliphatic group may have is not particularly limited, but examples thereof include an alkyl group having 1 to 15 carbon atoms, a halogen atom, an alkenyl group having 2 to 8 carbon atoms, and an alkoxyl group having 1 to 8 carbon atoms. , Phenyl group, mesityl group, tolyl group, naphthyl group, cyano group, acetyloxy group, alkylcarbonyloxy group having 2 to 9 carbon atoms, sulfamoyl group, alkylsulfamoyl group having 2 to 9 carbon atoms, 2 to 2 carbon atoms 9 alkylcarbonyl group, phenethyl group, hydroxyethyl group, acetylamide group, dialkylaminoethyl group formed by combining alkyl groups having 1 to 4 carbon atoms, trifluoromethyl group, trialkylsilyl group having 1 to 8 carbon atoms , A nitro group, an alkylthio group having 1 to 8 carbon atoms, and the like, preferably an alkoxyl group having 1 to 8 carbon atoms, a cyano group, an acetyloxy group, an alkylcarboxyl group having 2 to 8 carbon atoms, a sulfamoyl group, and a carbon number. 2-9 alkylsulfamoyl groups and halogen atoms. From the viewpoint of achieving both developability and non-swelling property at the time of development, an unsubstituted or alkyl group is preferable, and an unsubstituted or methyl group is particularly preferable.

Specific examples of the cycloaliphatic group-containing vinyl compound include cyclohexyl (meth)acrylate, isobornyl (meth)acrylate, t-butylcyclohexyl (meth)acrylate, norbornyl (meth)acrylate, dicyclopentenyl (meth)acrylate, and dicyclopentenyl (meth)acrylate. Cyclopentenyloxyethyl (meth)acrylate, dicyclopentanyl (meth)acrylate, 1-adamantyl (meth)acrylate, 2-methyl-2-adamantyl (meth)acrylate, 2-ethyl-2-adamantyl (meth)acrylate, etc. Are listed.
These may be used alone or in any combination of two or more in any proportion. Among these, from the viewpoint of the strength of the formed film, it is preferable to use a polycyclic cycloaliphatic group-containing vinyl compound, such as dicyclopentanyl (meth)acrylate or 2-methyl-2-adamantyl (meth). It is further preferred to use acrylates.

The content of the repeating unit structure represented by the general formula (3) in the (A-1) copolymer is preferably 10 mol% or more, preferably 15 mol% or more, and 20 mol% or more. More preferably, it is more preferably 25 mol% or more, and particularly preferably 28 mol% or more. Further, it is preferably 45 mol% or less, more preferably 40 mol% or less, and particularly preferably 35 mol% or less. When the content is at least the lower limit, there is a tendency that adhesion and protection with the lower layer during alkali development, and electrical reliability can be secured, and when it is at most the upper limit, exposure sensitivity and developability tend to be secured. is there.

In obtaining the (A-1) copolymer, other vinyl compounds may be appropriately used as other copolymerization components in addition to the above-mentioned three types of polymerization components, or after the copolymer is formed. Alternatively, for example, a functional group such as a vinyl group may be subjected to an addition reaction. Examples of other vinyl compounds include styryl compounds such as styrene and α-methylstyrene, methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, butyl (meth)acrylate, pentyl (meth)acrylate, and hexyl. (Meth)acrylate, dodecyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, hydroxymethyl (meth)acrylate, hydroxyethyl (meth)acrylate, polyethylene glycol (meth)acrylate, polypropylene glycol (meth)acrylate, benzyl (meth) ) Acrylate, N,N-dimethylaminoethyl(meth)acrylate, N-(meth)acryloylmorpholine, (meth)acrylonitrile, (meth)acrylamide, N-methylol(meth)acrylamide, N,N-dimethyl(meth)acrylamide , (Meth)acrylate compounds such as N,N-dimethylaminoethyl (meth)acrylamide, and vinyl compounds such as vinyl acetate. These may be contained in the (A-1) copolymer in an arbitrary combination and ratio as long as the repeating unit structure derived therefrom has an amount of less than 20 mol %. Among these, it is preferable to use a (meth)acrylate compound from the viewpoint of reactivity. However, among these, since those containing an aromatic group tend to be colored, it is preferable not to use them for member applications requiring high transparency. From such a viewpoint, the content ratio of the aromatic group-containing vinyl compound is 10 mol. % Or less is preferable, and 0 mol% is more preferable.

There is no limitation on the method of polymerizing the epoxy group-containing vinyl compound, the carboxyl group-containing vinyl compound, the cycloaliphatic group-containing vinyl compound, and other vinyl compounds, but it is necessary to use a radical polymerization initiator in an organic solvent, for example. It can be synthesized by a known method such as adding a chain transfer agent according to the above and heating at the activation temperature of the radical polymerization initiator.

The weight average molecular weight of the (A-1) copolymer of the present invention is not particularly limited, but is preferably 3,000 or more, more preferably 5,000 or more. Further, it is preferably 100,000 or less, more preferably 70,000 or less, further preferably 50,000 or less, further preferably 20,000 or less, and particularly preferably 10,000 or less. When it is at least the lower limit, the film strength such as chemical resistance tends to be secured, and when it is at most the upper limit, excellent patterning characteristics tend to be secured.

The weight average molecular weight in the present invention is a value in terms of polystyrene measured by "gel permeation chromatography system LS Solution" manufactured by Shimadzu Corporation using "Column GPC-804" manufactured by Shimadzu Corporation.

The content ratio of the (A-1) copolymer in the photosensitive resin composition of the present invention is preferably 20% by mass or more and 30% by mass or more based on the total solid content of the photosensitive resin composition. Is more preferable, 40% by mass or more is more preferable, 90% by mass or less is preferable, 80% by mass or less is more preferable, 70% by mass or less is further preferable, 60 It is more preferable that the amount is not more than mass%, and it is particularly preferable that the amount is not more than 50% by mass. When it is at least the above lower limit, the patterning property by photolithography tends to be easily secured, while when it is at most the above upper limit, sufficient curability tends to be easily secured.

[(A-2) Polymerizable compound having an ethylenically unsaturated group]
The photosensitive resin composition of the present invention contains (A-2) a polymerizable compound having an ethylenically unsaturated group (hereinafter, may be abbreviated as “(A-2) polymerizable compound”). By containing the polymerizable compound (A-2), the exposure sensitivity can be increased, and patternability by photolithography and stable image formation tend to be facilitated. The polymerizable compound having an ethylenically unsaturated group (A-2) is a compound having at least one ethylenically unsaturated group in the molecule.

The more ethylenically unsaturated groups in the molecule, the finer the network during crosslinking (curing), and the easier it becomes to ensure chemical resistance and electrical reliability. Further, even if the cross-linking ratio in all ethylenically unsaturated groups becomes low due to low temperature baking, it is advantageous in that a reasonable network is secured.
From this, (A-2) the polymerizable compound having an ethylenically unsaturated group is preferably a compound having a large number of ethylenically unsaturated groups, and specifically, it is preferable to have two or more ethylenically unsaturated groups. It is more preferable to have at least 5 and even more preferable to have at least 5. The number of ethylenically unsaturated bonds has no upper limit, but is usually 12 or less, preferably 6 or less. A resin having a large number of ethylenically unsaturated bonds such as a dendrimer may be used, or a resin having an ethylenically unsaturated bond in its side chain may be used.

From the viewpoint of reactivity, the ethylenically unsaturated group contained in the polymerizable compound (A-2) having an ethylenically unsaturated group is preferably an allyl group and/or a (meth)acryloyl group.
As the polymerizable compound having an ethylenically unsaturated group (A-2), only one type may be used, or two or more types may be used in combination with any ratio. In the case of using a plurality of kinds of ethylenically unsaturated group-containing compounds, the number of ethylenically unsaturated groups, the molar average of the number of ethylenically unsaturated groups that this plurality of kinds of ethylenically unsaturated group-containing compound has The value should be in the above-mentioned preferable range.

Hereinafter, among (A-2) the polymerizable compound having an ethylenically unsaturated group, a particularly preferable compound will be described. Specifically, for example, esters of (A-2-1) unsaturated carboxylic acid and polyhydroxy compound, urethane (meth) of (A-2-2) hydroxy(meth)acrylate compound and polyisocyanate compound Examples thereof include acrylates, and epoxy (meth)acrylates of (A-2-3)(meth)acrylic acid or hydroxy(meth)acrylate compound and polyepoxy compound.

Examples of the ester (A-2-1) of an unsaturated carboxylic acid and a polyhydroxy compound include, for example, a reaction product of an unsaturated carboxylic acid and a sugar alcohol, and an alkylene oxide adduct of an unsaturated carboxylic acid and a sugar alcohol. Examples thereof include a reaction product and a reaction product of an unsaturated carboxylic acid and an alcohol amine.
Here, specific examples of the unsaturated carboxylic acid include acrylic acid, methacrylic acid, and itaconic acid.

Specific examples of the sugar alcohol include ethylene glycol, polyethylene glycol (addition number 2 to 14), propylene glycol, polypropylene glycol (addition number 2 to 14), trimethylene glycol, tetramethylene glycol, hexamethylene glycol, trimethylol. Examples thereof include polyhydric alcohols such as propane, glycerol, pentaerythritol, and dipentaerythritol.

Specific examples of the alkylene oxide adduct of sugar alcohol include compounds in which ethylene oxide or propylene oxide is added to the above sugar alcohol.
Specific examples of the alcohol amine include polyhydric alcohol amines such as diethanolamine and triethanolamine.

Then, as the esters of unsaturated carboxylic acid and polyhydroxy compound, specifically, ethylene glycol di(meth)acrylate, diethylene glycol di(meth)acrylate, propylene glycol di(meth)acrylate, trimethylolpropane di( (Meth)acrylate, trimethylolpropane tri(meth)acrylate, trimethylolpropane ethylene oxide-added tri(meth)acrylate, glycerol di(meth)acrylate, glycerol tri(meth)acrylate, glycerol propylene oxide-added tri(meth)acrylate, penta Erythritol di(meth)acrylate, pentaerythritol tri(meth)acrylate, pentaerythritol tetra(meth)acrylate, dipentaerythritol penta(meth)acrylate, dipentaerythritol hexa(meth)acrylate, and their crotonates and isocrotonates. , Maleate, itaconate, citraconate and the like. The esters of unsaturated carboxylic acids and polyhydroxy compounds also include derivatives of these compounds.

The esters of unsaturated carboxylic acids and polyhydroxy compounds include unsaturated carboxylic acids and aromatic polyhydroxy compounds such as hydroquinone, resorcinol, pyrogallol, bisphenol F and bisphenol A, or their ethylene oxide adducts. And the reaction products of Specific examples include bisphenol A di(meth)acrylate, bisphenol A bis[oxyethylene (meth)acrylate], and bisphenol A bis[glycidyl ether (meth)acrylate].

Further, a reaction product of the above unsaturated carboxylic acid and a heterocyclic polyhydroxy compound such as tris(2-hydroxyethyl)isocyanurate, for example, di(meth)acrylate of tris(2-hydroxyethyl)isocyanurate, Tri (meth) acrylate etc. are also mentioned.
Further, a reaction product of an unsaturated carboxylic acid, a polycarboxylic acid and a polyhydroxy compound, for example, a condensate of (meth)acrylic acid, phthalic acid and ethylene glycol, a (meth)acrylic acid, maleic acid and diethylene glycol Examples thereof include condensates, condensates of (meth)acrylic acid, terephthalic acid and pentaerythritol, condensates of (meth)acrylic acid, adipic acid, butanediol and glycerin.

Examples of urethane (meth)acrylates of the (A-2-2) hydroxy(meth)acrylate compound and the polyisocyanate compound include hydroxy(meth)acrylate compounds, aliphatic polyisocyanates, alicyclic polyisocyanates, and aromatics. Examples thereof include a reaction product with a polyisocyanate compound such as a group polyisocyanate or a heterocyclic polyisocyanate.

Specific examples of the hydroxy(meth)acrylate compound include hydroxymethyl(meth)acrylate, hydroxyethyl(meth)acrylate, and tetramethylolethanetri(meth)acrylate. Further, the polyisocyanate compound is an aliphatic polyisocyanate such as hexamethylene diisocyanate, 1,8-diisocyanate-4-isocyanate methyloctane; cyclohexane diisocyanate, dimethylcyclohexane diisocyanate, 4,4-methylenebis(cyclohexyl isocyanate), isophorone diisocyanate, bicyclo Alicyclic polyisocyanates such as heptane triisocyanate; aromatic polyisocyanates such as 4,4-diphenylmethane diisocyanate and tris(isocyanatophenyl)thiophosphate; and heterocyclic polyisocyanates such as isocyanurate.

Examples of commercially available urethane (meth)acrylates of a hydroxy (meth)acrylate compound and a polyisocyanate compound include "U-4HA", "UA-306A", "UA-MC340H" and "U-MC340H" manufactured by Shin Nakamura Chemical Co., Ltd. Examples include UA-MC340H" and "U6LPA".
As urethane (meth)acrylates of a hydroxy (meth)acrylate compound and a polyisocyanate compound, in order to sufficiently secure the chemical resistance of the cured product, four or more urethane bonds [-NH-CO-O- ] And a compound having 4 or more (meth)acryloyloxy groups is preferable. Such compounds include, for example, a compound having 4 or more hydroxyl groups, a diisocyanate compound, a compound having 2 or more hydroxyl groups and a compound having 3 or more isocyanate groups, 4 or more. Can be obtained by a method of reacting the compound having an isocyanate group with the compound having one or more hydroxyl groups and two or more (meth)acryloyloxy groups.

Specific examples include the following compounds. That is, as a compound obtained by reacting a compound having 4 or more hydroxyl groups with a diisocyanate compound, a compound having 4 or more hydroxyl groups such as pentaerythritol and polyglycerin, hexamethylene diisocyanate and trimethylhexamethylene diisocyanate , A compound obtained by reacting with a diisocyanate compound such as isophorone diisocyanate and tolylene diisocyanate.

Examples of the compound obtained by reacting a compound having two or more hydroxyl groups with a compound having three or more isocyanate groups include a compound having two or more hydroxyl groups such as ethylene glycol and "Duranate" manufactured by Asahi Kasei Chemicals Corporation. (Registered trademark) 24A-100", same "Duranate (registered trademark) 22A-75PX", same "Duranate (registered trademark) 21S-75E", same "Duranate (registered trademark) 18H-70B" Three or more adduct types such as "Duranate (registered trademark) P-301-75E", "Duranate (registered trademark) E-402-90T" and "Duranate (registered trademark) E-405-80T" Examples thereof include compounds obtained by reacting with a compound having an isocyanate group.

As a compound obtained by reacting a compound having four or more isocyanate groups with a compound having one or more hydroxyl groups and two or more (meth)acryloyloxy groups, isocyanate ethyl (meth)acrylate or the like is polymerized. Alternatively, a compound having 4 or more, preferably 6 or more isocyanate groups such as a compound obtained by copolymerization, "Duranate (registered trademark) ME20-100" manufactured by Asahi Kasei Chemicals, and pentaerythritol di(meth). One or more hydroxyl groups such as acrylate, dipentaerythritol tri(meth)acrylate, dipentaerythritol tetra(meth)acrylate, dipentaerythritol penta(meth)acrylate and 2 or more, preferably 3 or more (meth)acryloyl Examples thereof include compounds obtained by reacting with a compound having an oxy group.

Examples of the epoxy (meth)acrylates of the (A-2-3) (meth)acrylic acid or hydroxy(meth)acrylate compound and the polyepoxy compound include (meth)acrylic acid or the above hydroxy(meth)acrylate compound. And a compound obtained by reacting with a polyepoxy compound such as an aliphatic polyepoxy compound, an aromatic polyepoxy compound, and a heterocyclic polyepoxy compound.

Specifically, for example, (meth)acrylic acid or the above hydroxy(meth)acrylate compound, (poly)ethylene glycol polyglycidyl ether, (poly)propylene glycol polyglycidyl ether, (poly)tetramethylene glycol polyglycidyl ether. , (Poly)pentamethylene glycol polyglycidyl ether, (poly)neopentyl glycol polyglycidyl ether, (poly)hexamethylene glycol polyglycidyl ether, (poly)trimethylolpropane polyglycidyl ether, (poly)glycerol polyglycidyl ether, ( Aliphatic polyepoxy compounds such as poly) sorbitol polyglycidyl ether; phenol novolac polyepoxy compounds, brominated phenol novolac polyepoxy compounds, (o-, m-, p-) cresol novolac polyepoxy compounds, bisphenol A polyepoxy compounds, Aromatic polyepoxy compounds such as bisphenol F polyepoxy compounds; Reaction with polyepoxy compounds such as sorbitan polyglycidyl ether, triglycidyl isocyanurate, and heterocyclic polyepoxy compounds such as triglycidyl tris(2-hydroxyethyl)isocyanurate And the like.

Examples of the polymerizable compound having an ethylenically unsaturated group other than (A-2-1) to (A-2-3) include (meth)acrylamides such as ethylenebis(meth)acrylamide, diallyl phthalate and the like. Allyl esters, compounds having a vinyl group such as divinyl phthalate, compounds having a thioether bond obtained by sulfidizing the ether bond of an ethylenically unsaturated compound having an ether bond with phosphorus pentasulfide, etc. to a thioether bond. Can be mentioned.
Besides this, a special ethylenically unsaturated group-containing compound such as a macromonomer or a dendrimer acrylate may be used depending on the required characteristics. Examples of dendrimers include STAR-501 and SIRIUS-501 manufactured by Osaka Organic Co., Ltd. Examples of the macromonomer include AA-6, AS-6, AB-6, AN-6S and the like manufactured by Toagosei Co., Ltd.

These (A-2) polymerizable compounds having an ethylenically unsaturated group may be used alone or in combination of two or more, but ensure high electrical reliability and chemical resistance. From the viewpoint of (A-2-1), it is preferable to use an ester of an unsaturated carboxylic acid and a polyhydroxy compound, and an ethylenic ester such as dipentaerythritol hexa(meth)acrylate or dipentaerythritol penta(meth)acrylate. A compound having 5 or more saturated groups is particularly preferable.

Further, as the polymerizable compound (A-2), a compound containing a cycloaliphatic group may be used. The hydrocarbon constituting the cycloaliphatic ring may contain a hetero atom, but from the viewpoint of ensuring the transparency of the optical film and effectively expressing the effect of the cycloaliphatic ring in the present invention, It is preferably an alicyclic hydrocarbon containing no atoms. Examples of the cycloaliphatic ring group include those having the cycloaliphatic ring described as R ^{4 in the} above formula (3). Further, specific examples of the polymerizable compound having a cycloaliphatic group include dimethylol-tricyclodecanedi(meth)acrylate, isobornyl(meth)acrylate, cyclohexyl(meth)acrylate and the like.

The photosensitive resin composition of the present invention can be used by developing with an alkali developer after exposure, but for the purpose of optimizing developability, (A-2) a carboxyl group or a hydroxyl group as the polymerizable compound, A polyethylene glycol or a polypropylene glycol group-introduced ethylenically unsaturated group-containing polymerizable compound may be used.

The molecular weight of the polymerizable compound (A-2) is not particularly limited, but is preferably 100 or more, more preferably 200 or more, further preferably 250 or more, and 2000
The following is preferred, 1500 or less is more preferred, and 1000 or less is even more preferred. When the amount is at least the lower limit, a stronger film tends to be formed, and when the amount is less than the upper limit, sufficient developability tends to be secured.

The content ratio of the polymerizable compound having the compound (A-2) ethylenically unsaturated group in the photosensitive resin composition of the present invention is 10% by mass based on the total solid content of the photosensitive resin composition of the present invention. It is preferably not less than 15% by mass, more preferably not less than 15% by mass, further preferably not less than 20% by mass, further preferably not less than 30% by mass, particularly preferably not less than 40% by mass. preferable. Further, it is preferably 60% by mass or less, more preferably 55% by mass or less, and further preferably 50% by mass or less. When it is at least the above lower limit, high exposure sensitivity tends to be secured, and when it is at most the above upper limit, sufficient low temperature curability tends to be secured easily.

[(A-3) Other polymerizable compound]
The polymerizable compound (A) of the present invention includes (A-1) a copolymer having an epoxy group and a carboxyl group, (A-2) a polymerizable compound other than a polymerizable compound having an ethylenically unsaturated group (hereinafter , "(A-3) other polymerizable compound" may be abbreviated), and in particular, a polymerizable compound containing a cycloaliphatic group is used, whereby A predetermined amount of cycloaliphatic group may be introduced into the resin composition. Examples of other polymerizable compounds include epoxy compounds and oxetane compounds.

Examples of the epoxy compound include JER series of Mitsubishi Chemical Co., Celoxide side series of Daicel (Celoxide is a registered trademark), Epotote series of Nippon Steel & Sumikin Chemical Co., Ltd. (Epototo is a registered trademark), NC-of Nippon Kayaku Co., Ltd. , XD-, EPPN-, EOCN-, RE-, etc., GAN, GOT, SEJ-01R, DIC's EPICLON (registered trademark), Kyoeisha Chemical's Epolite series, and the like. Among these, examples containing a cycloaliphatic group include XD-series, JER series YX-8034, and Epolite 4000. Incidentally, the cycloaliphatic group in the total solid content in the photosensitive resin composition of the present invention, the cycloaliphatic epoxy cyclic fat having a condensed ring in which the ring of the cycloaliphatic group and the ring of the epoxy group are condensed Does not include group groups.

Examples of the oxetane compound include oxetane compounds described in Japanese Patent No. 4367075 and 3-ethyl-3{[(3-ethyloxetane-3-yl)methoxy]methyl}oxetane (OXA-221 manufactured by Toagosei Co., Ltd.), , 4-bis{[(3-ethyloxetane-3-yl)methoxy]methyl}benzene (OXA-121 manufactured by Toagosei Co., Ltd.) and the like, and OXE-10 and 30 of Osaka Organic Co., Ltd. may be mentioned. Further, an oxetane-containing copolymer resin obtained by polymerizing OXE-10 or 30 as a polymerization component also corresponds to this.

When the photosensitive resin composition of the present invention contains (A-3) another polymerizable compound, the content ratio thereof is preferably 3% by mass or more based on the total solid content of the photosensitive resin composition. It is more preferably 5% by mass or more, preferably 40% by mass or less, more preferably 30% by mass or less, and particularly preferably 20% by mass or less. When it is at least the lower limit, the effect of containing other polymerizable compound tends to be obtained, and when it is at most the upper limit, it tends to be easy to secure alkali developability. is there.

As described above, (A) a copolymer having an epoxy group and a carboxyl group, (A-2) a polymerizable compound having an ethylenically unsaturated group, as a constituent that may be contained as a polymerizable compound, (A-3) Other polymerizable compounds and the like can be mentioned, but it is preferable to appropriately select (A) the polymerizable compound so as to contain a cycloaliphatic group. When the polymerizable compound (A) contains a cycloaliphatic group, swelling of the exposed area during development is suppressed, and peeling during development and deterioration of electrical reliability due to development tend to be prevented.
In order to configure the polymerizable compound (A) to contain a cyclic aliphatic group, for example, a compound containing a cyclic aliphatic group as the (A-1) copolymer or (A-2) polymerizable A compound containing a cycloaliphatic group or a compound containing a cycloaliphatic group as (A-3) or another polymerizable compound may be used.

The content ratio of the polymerizable compound (A) of the present invention is preferably 70% by mass or more, more preferably 80% by mass or more, and 85% by mass with respect to the total solid content of the photosensitive resin composition. The amount is more preferably the above, and particularly preferably 90 mass% or more. Further, it is preferably 98% by mass or less, more preferably 97% by mass or less, further preferably 96% by mass or less, and particularly preferably 95% by mass or less. When the photosensitive resin composition of the present invention is mixed with inorganic nanoparticles such as a filler, the content of the polymerizable compound (A) is 65% by mass based on the total solid content of the photosensitive resin composition. % Or more, and more preferably 75% by mass or more. When it is at least the above lower limit value, the effect such as improving hardness tends to be exhibited, and when it is at most the above upper limit value, transparency tends to be secured.

The content ratio of the cycloaliphatic ring contained in the polymerizable compound (A) of the present invention is not particularly limited, but is preferably 3% by mass or more and 6% by mass or more based on the total solid content of the photosensitive composition. More preferably, it is more preferably 9% by mass or more, further preferably 30% by mass or less, more preferably 25% by mass or less, and further preferably 20% by mass or less. When it is at least the above lower limit, peeling during development can be prevented and high electrical reliability after development can be maintained, and when it is at most the above upper limit, exposure sensitivity and developability tend to be secured. In addition, the cycloaliphatic ring in the "content ratio of the cycloaliphatic ring" means a hydrocarbon that constitutes the cycloaliphatic ring, and when the cycloaliphatic ring has a substituent, the content ratio is calculated. In doing so, the calculation is performed without including the substituent. Further, the hydrocarbon constituting the cycloaliphatic ring means an alicyclic hydrocarbon containing no hetero atom.

[Content ratio of cycloaliphatic ring]
The photosensitive resin composition of the present invention has a cycloaliphatic ring content of 7% by mass or more based on the total solid content. By setting the content ratio of the cycloaliphatic ring to 7% by mass or more based on the total solid content, the resulting protective film contains the cycloaliphatic ring in a predetermined amount, and as a result, the developer to be exposed to the exposed portion at the time of development. It is considered that the invasion of particles can be suppressed, peeling at the time of development can be suppressed, and high electrical reliability after development can be maintained.
The content ratio of the cycloaliphatic ring is usually 7% by mass or more based on the total solid content, preferably 8% by mass or more, more preferably 9% by mass or more, and more preferably 10% by mass or more. More preferably, it is more preferably 11% by mass or more, further preferably 12% by mass or more, particularly preferably 35% by mass or less, and more preferably 30% by mass or less. Is more preferably 25% by mass or less, still more preferably 20% by mass or less, particularly preferably 18% by mass or less, and most preferably 15% by mass or less. When it is at least the above lower limit, there is a tendency that peeling at the time of development is suppressed and high electrical reliability after development can be maintained, and when it is at most the above upper limit, exposure sensitivity and developability tend to be secured.

The "content of the cycloaliphatic ring" means the content ratio (% by mass) of hydrocarbons constituting the cycloaliphatic ring contained in the total solid content of the photosensitive resin composition, and the cycloaliphatic When a ring has a substituent that does not form the ring, the mass of the substituent is not included. Further, the hydrocarbon constituting the cycloaliphatic ring means an alicyclic hydrocarbon containing no hetero atom.
For example, when a copolymer having a repeating unit structure represented by the following formula (A-1-a) is used as the (A-1) copolymer, the content ratio of the cyclic aliphatic ring derived from the copolymer is ,% by mass of the cycloaliphatic ring represented by the following formula (A-1-b).

Similarly, when a compound represented by the following formula (A-2-a) is used as the (A-2) polymerizable compound, the content ratio of the cyclic aliphatic ring derived from the polymerizable compound is It is the mass% of the cycloaliphatic ring represented by A-2-b).

Further, the cyclic aliphatic group may be derived from any component, but it is preferable that the cyclic aliphatic group include a derivative derived from the polymerizable compound (A), and the copolymer (A-1) and/or (A-2). It is more preferable to include the one derived from the polymerizable compound having an ethylenically unsaturated group, and it is more preferable to include the one derived from the (A-1) copolymer. The content ratio of the cycloaliphatic ring derived from the (A-1) copolymer is preferably 2% by mass or more and more preferably 5% by mass or more based on the total solid content of the photosensitive resin composition. Is more preferably 8% by mass or more, further preferably 25% by mass or less, more preferably 22% by mass or less, and further preferably 19% by mass or less. Swelling of the exposed portion at the time of alkali development is suppressed by setting the above lower limit or more, and there is a tendency that adhesion and protection with the lower layer during development can be more efficiently ensured, and the above upper limit or less When it is set, the exposure sensitivity and the developability tend to be more efficiently ensured.
The content ratio of the cycloaliphatic ring contained in the photosensitive resin composition includes, for example, a method of analyzing using GC-MS or NMR, but from the viewpoint that it can be confirmed in the film after curing. It is preferable to use GC-MS.

[(B) Cationic cationic polymerization initiator]
The (B) photocationic polymerization initiator contained in the photosensitive resin composition of the present invention is one which generates an acid by irradiation with visible light, ultraviolet light or the like to initiate a polymerization reaction of an epoxy group. The cationic photopolymerization initiator used in the present invention contains an aromatic iodonium salt. Aromatic iodonium salts are inferior in exposure sensitivity to aromatic sulfonium salts, which are generally preferred, but side effects of ionic impurities remaining after curing are small, and high electrical reliability can be secured. It is believed that On the other hand, as compared with the aromatic sulfonium salt, it tends to be more efficiently sensitized by the sensitizer, and therefore the use of the sensitizer can secure the insufficient exposure sensitivity to some extent.

The aromatic iodonium salt is a compound having a diaryliodonium cation. These cations pair with anions (anions) to form a photocationic polymerization initiator.
Examples of the diaryliodonium cation include a diphenyliodonium cation which may have an alkyl group, an ether group, or the like as a substituent, and specifically, (4-methylphenyl)[4-(2-methylpropyl) Phenyl]iodonium cation, (4-methylphenyl)(4-isopropylphenyl)iodonium cation, (4-methylphenyl)(4-isobutyl)iodonium cation, bis(4-tert-butyl)iodonium cation, bis(4-dodecyl) Phenyl)iodonium cation, (2,4,6-trimethylphenyl)[4-(1-methylacetic acid ethyl ether)phenyl]iodonium cation and the like can be mentioned.

Examples of the anion constituting the aromatic iodonium salt include hexafluorophosphate anion PF ⁶⁻ , hexafluoroantimonate anion SbF ⁶⁻ , pentafluorohydroxyantimonate anion SbF ₅ (OH) ⁻ , hexafluoroarsenate anion AsF. ⁶⁻ , tetrafluoroborate anion BF ⁴⁻ , tetrakis(pentafluorophenyl)borate anion B(C ₆ F ₅ ) ⁴⁻ and the like. These anions serve as a source of acid generation, and the higher the acidity of the generated acid, the higher the efficiency of the polymerization reaction, but on the other hand, it tends to deteriorate the electrical reliability. In the photosensitive resin composition of the present invention that requires high electrical reliability, hexafluorophosphate anion (hexafluorophosphate anion) is particularly preferable as the anion component because it can ensure higher electrical reliability.

As the cationic photopolymerization initiator, aromatic sulfonium salts and the like are generally particularly preferred from the viewpoint of high sensitivity. However, since sulfonium salts tend to have poor electrical reliability, aromatic sulfonium salts are used in the present invention. When the iodonium salt and the aromatic sulfonium salt are used in combination, the content ratio of the aromatic sulfonium salt to the total solid content of the photosensitive resin composition is preferably suppressed to 0.2% by mass or less.

As described above, it is preferable to use the hexafluorophosphate salt of aromatic iodonium from the viewpoint of electrical reliability, but the photocurability tends to be improved by appropriately using the sensitizer described later. Further, the photosensitive resin composition of the present invention contains an epoxy group involved in cationic polymerization in the (A-1) copolymer, which tends to have a high molecular weight, so that an aromatic iodonium salt having a low sensitivity is photosensitized. Even when the cross-linking rate of the epoxy group becomes low by using it as a cationic polymerization initiator, it tends to be possible to secure a film strength that does not dissolve during development.

The content ratio of the (B) photocationic polymerization initiator in the photosensitive resin composition of the present invention is preferably 0.5% by mass or more, and more preferably 1% by mass or more, based on the total solid content of the photosensitive resin composition. More preferably, it is more preferably 1.5% by mass or more, further preferably 2.0% by mass or more, particularly preferably 2.5% by mass or more, preferably 9% by mass or less, more preferably 7% by mass or less, 5 The content is more preferably not more than mass%, particularly preferably not more than 4 mass%. By setting the above lower limit or more, it tends to be easy to ensure sufficient photocurability, and by setting the above upper limit or less, it is possible to suppress deterioration of film performance such as deterioration of electrical reliability and coloring. is there.

The content ratio of the aromatic iodonium salt in the photosensitive resin composition of the present invention is preferably 0.5% by mass or more, more preferably 1% by mass or more, based on the total solid content of the photosensitive resin composition. 0.5 mass% or more is more preferable, 2.0 mass% or more is still more preferable, 2.5 mass% or more is especially preferable, 9 mass% or less is preferable, 7 mass% or less is more preferable, and 5 mass% or less is 5 mass% or less. More preferably, 4 mass% or less is particularly preferable. By setting the above lower limit or more, it tends to be easy to ensure sufficient photocurability, and by setting the above upper limit or less, it is possible to suppress deterioration of film performance such as deterioration of electrical reliability and coloring. is there.

[(C) Photoradical polymerization initiator]
The (C) photo-radical polymerization initiator contained in the photosensitive resin composition of the present invention is a polymerizable compound having an ethylenically unsaturated group (A-2) which generates radicals by irradiation with visible light, ultraviolet rays or the like. It initiates the polymerization reaction of ethylenic groups.

Examples of the photoradical polymerization initiator include metallocene compounds containing titanocene derivatives described in JP-A-59-152396 and JP-A-61-151197; and hexaaryl described in JP-A-2000-56118. Rubiimidazole derivatives; N-aryl-α-amino acids such as halomethylated oxadiazole derivatives, halomethyl-s-triazine derivatives, N-phenylglycine, N-aryl-α-amino acids described in JP-A No. 10-39503. Radical activators such as salts and N-aryl-α-amino acid esters, α-aminoalkylphenone derivatives; oxime ester derivatives and the like described in JP 2000-80068 A, JP 2006-36750 A, etc. Can be mentioned. Among these, the radical polymerization initiator preferably contains oxime ester derivatives and/or α-aminoalkylphenone derivatives.

Specifically, for example, as titanocene derivatives, dicyclopentadienyl titanium dichloride, dicyclopentadienyl titanium bisphenyl, dicyclopentadienyl titanium bis(2,3,4,5,6-pentafluoro Phenyl-1-yl), dicyclopentadienyl titanium bis(2,3,5,6-tetrafluorophen-1-yl), dicyclopentadienyl titanium bis(2,4,6-trifluorophenyl- 1-yl), dicyclopentadienyl titanium di(2,6-difluorophen-1-yl), dicyclopentadienyl titanium di(2,4-difluorophen-1-yl), di(methylcyclopenta) Dienyl)titanium bis(2,3,4,5,6-pentafluorophen-1-yl), di(methylcyclopentadienyl)titanium bis(2,6-difluorophen-1-yl), dicyclo Pentadienyl titanium [2,6-di-fluoro-3-(pyr-1-yl)-phen-1-yl] and the like can be mentioned.

Further, as the biimidazole derivatives, 2-(2'-chlorophenyl)-4,5-diphenylimidazole dimer, 2-(2'-chlorophenyl)-4,5-bis(3'-methoxyphenyl)imidazole are used. Dimer, 2-(2'-fluorophenyl)-4,5-diphenylimidazole dimer, 2-(2'-methoxyphenyl)-4,5-diphenylimidazole dimer, (4'-methoxyphenyl) )-4,5-Diphenylimidazole dimer and the like.

In addition, halomethylated oxadiazole derivatives include 2-trichloromethyl-5-(2'-benzofuryl)-1,3,4-oxadiazole and 2-trichloromethyl-5-[β-(2'- Benzofuryl)vinyl]-1,3,4-oxadiazole, 2-trichloromethyl-5-[β-(2′-(6″-benzofuryl)vinyl)]-1,3,4-oxadiazole, 2 -Trichloromethyl-5-furyl-1,3,4-oxadiazole and the like can be mentioned.

Further, as halomethyl-s-triazine derivatives, 2-(4-methoxyphenyl)-4,6-bis(trichloromethyl)-s-triazine and 2-(4-methoxynaphthyl)-4,6-bis( Trichloromethyl)-s-triazine, 2-(4-ethoxynaphthyl)-4,6-bis(trichloromethyl)-s-triazine, 2-(4-ethoxycarbonylnaphthyl)-4,6-bis(trichloromethyl) -S-triazine and the like can be mentioned.

Further, as α-aminoalkylphenone derivatives, 2-methyl-1[4-(methylthio)phenyl]-2-morpholinopropan-1-one, 2-benzyl-2-dimethylamino-1-(4- Morpholinophenyl)-butanone-1,2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)butan-1-one, 4-dimethylaminoethylbenzoate, 4-dimethylaminoisoamylbenzoe -, 4-diethylaminoacetophenone, 4-dimethylaminopropiophenone, 2-ethylhexyl-1,4-dimethylaminobenzoate, 2,5-bis(4-diethylaminobenzal)cyclohexanone, 7-diethylamino-3-(4 -Diethylaminobenzoyl)coumarin, 4-(diethylamino)chalcone and the like can be mentioned.

Further, for example, oxime and ketooxime ester compounds described in JP-A-2000-80068 and JP-A-2006-36750 can be mentioned.
In addition, benzoin alkyl ethers such as benzoin methyl ether, benzoin phenyl ether, benzoin isobutyl ether and benzoin isopropyl ether; anthraquinone derivatives such as 2-methylanthraquinone, 2-ethylanthraquinone, 2-t-butylanthraquinone and 1-chloroanthraquinone Benzophenone, Michler's ketone, 2-methylbenzophenone, 3-methylbenzophenone, 4-methylbenzophenone, 2-chlorobenzophenone, 4-bromobenzophenone, 2-carboxybenzophenone and other benzophenone derivatives; 2,2-dimethoxy-2-phenyl Acetophenone, 2,2-diethoxyacetophenone, 1-hydroxycyclohexylphenyl ketone, α-hydroxy-2-methylphenylpropanone, 1-hydroxy-1-methylethyl-(p-isopropylphenyl)ketone, 1-hydroxy Acetophenone such as -1-(p-dodecylphenyl)ketone, 2-methyl-(4'-methylthiophenyl)-2-morpholino-1-propanone, 1,1,1-trichloromethyl-(p-butylphenyl)ketone Derivatives; thioxanthone derivatives such as thioxanthone, 2-ethylthioxanthone, 2-isopropylthioxanthone, 2-chlorothioxanthone, 2,4-dimethylthioxanthone, 2,4-diethylthioxanthone, and 2,4-diisopropylthioxanthone; p-dimethylamino Benzoic acid ester derivatives such as ethyl benzoate and ethyl p-diethylaminobenzoate; acridine derivatives such as 9-phenylacridine and 9-(p-methoxyphenyl)acridine; phenazine derivatives such as 9,10-dimethylbenzphenazine And anthrone derivatives such as benzanthrone.

Among these photoradical polymerization initiators, oxime ester derivatives are preferable, ketooxime ester derivatives are more preferable, and ketooxime derivatives having a benzoyl group are particularly preferable, from the viewpoint of sensitivity. Further, α-aminoalkylphenone derivatives are preferable in terms of excellent surface curability.

The photo-radical polymerization initiator may be used alone or in combination of two or more. The combination of two or more photo radical polymerization initiators is not particularly limited.

The content ratio of the photoradical polymerization initiator in the photosensitive resin composition of the present invention is preferably 0.5% by mass or more based on the total solid content of the photosensitive resin composition of the present invention, and 1% by mass. % Or more, more preferably 1.5% by mass or more, further preferably 9% by mass or less, more preferably 7% by mass or less, and 5% by mass or less. Is more preferable and 3% by mass or less is particularly preferable. When it is at least the above lower limit, photocurability tends to be exhibited sufficiently, and it is used in combination with (b) the photocationic polymerization initiator of the present invention, which has excellent electrical reliability but insufficient photocurability. Therefore, both electrical reliability and physical strength tend to be compatible. On the other hand, when the content is not more than the above upper limit, there is a tendency that deterioration of developability and electrical reliability can be suppressed.

The total content of the (B) photocationic polymerization initiator and (C) photoradical polymerization initiator used in the present invention is preferably 10% by mass or less based on the total solid content of the photosensitive resin composition, It is more preferably 8% by mass or less, and particularly preferably 6% by mass or less. By setting the content to the upper limit or less, there is a tendency that it is possible to suppress contamination of the device due to sublimation and deterioration of electrical reliability.

[Sensitizer]
In the photosensitive resin composition of the present invention, an aromatic iodonium salt having relatively low sensitivity is used as the (B) photocationic polymerization initiator as described above, but a sensitizer or an accelerator is used for the purpose of promoting sensitivity. Is preferred. The sensitizer has a role of efficiently absorbing the light of the exposure light source and transferring the energy to the initiator to efficiently excite the initiator. Examples of the sensitizer include pamphlets of International Publication No. 2006/073021, and anthracene compounds and naphthalene compounds described in JP2007-39475A. Among the anthracene compounds and naphthalene compounds, from the viewpoint of sensitivity, 1,4-dimethoxynaphthalene, 1,4-diethoxynaphthalene, 9,10-di(n-butoxy)anthracene, 9,10-bis(n-octanoyl) Oxy)anthracene and the like are preferable.

These sensitizers may be used alone or in combination of two or more. When the sensitizer is used, the content ratio is preferably 0.1% by mass or more, more preferably 0.5% by mass or more, and more preferably 1% by mass or less with respect to the total solid content of the photosensitive resin composition. It is more preferably at least mass%, particularly preferably at least 1.5 mass%. Further, it is preferably 6% by mass or less, more preferably 4% by mass or less, still more preferably 3% by mass or less. When it is at least the above lower limit, sufficient photocurability tends to be ensured, and when it is at most the above upper limit, adverse effects such as coloring tend to be suppressed.

[Leveling agent]
The photosensitive resin composition of the present invention can be applied onto a substrate by wet application or printing, but it is preferable to use a leveling agent for the purpose of avoiding defects such as cissing and uneven film thickness. As the leveling agent, various kinds of surfactants can be mentioned, but it is preferable to use a silicon and/or fluorine type surfactant in order to secure electric reliability.

Examples of the fluorinated surfactant include BM series of Big Chemie, Megafac series of DIC (Megafac is a registered trademark), Florard series of 3M Japan, and Surflon series of AGC (Surflon is a registered trademark). Examples include Neos's footergent series (footergent is a registered trademark).

Examples of the silicone-based surfactant include BYK series manufactured by BYK Chemie, series such as SH/SZ/DC manufactured by Toray Dow Corning, and TSF series manufactured by Momentive Performance Materials.

The content ratio of the leveling agent in the photosensitive resin composition of the present invention is preferably 0.01% by mass or more and preferably 0.02% by mass or more based on the total solid content of the photosensitive resin composition. Is more preferable, 0.05% by mass or more is further preferable, 0.07% by mass or more is particularly preferable, 5% by mass or less is preferable, and 3% by mass or less is preferable. It is more preferably 2% by mass or less. By the above lower limit or more, a sufficient leveling effect tends to be easily obtained, and by setting the above upper limit or less, it is easy to suppress foaming and suppress the appearance of coating defects such as cissing. is there.

[Organic solvent]
The photosensitive resin composition of the present invention is preferably diluted with an organic solvent from the viewpoint of handleability.
When an organic solvent is used, it is preferably used so that the total solid content in the photosensitive resin composition of the present invention is 3% by mass or more, and more preferably 5% by mass or more. It is more preferably used in an amount of 10% by mass or more, further preferably in an amount of 15% by mass or more, particularly preferably in an amount of 20% by mass or more, and 40% by mass. It is preferably used so as to be the following amount, more preferably 35% by mass or less, and further preferably 30% by mass or less. When the content is at least the lower limit, the film thickness tends to be easily controlled, and when it is at most the upper limit, the pot life of the photosensitive resin composition tends to be easily maintained. There is. The total solid content indicates the total of components other than the organic solvent.

Examples of the organic solvent used in the present invention include glycol monoalkyl ethers; glycol dialkyl ethers; glycol diacetates; alkyl acetates; ethers; ketones; monohydric or polyhydric alcohols; aliphatic hydrocarbons; Alicyclic hydrocarbons; aromatic hydrocarbons; chain or cyclic esters; alkoxycarboxylic acids; halogenated hydrocarbons; ether ketones; nitriles and the like, and specific examples include isopropyl alcohol and ethylene glycol. Dimethyl ether, propylene glycol dimethyl ether, 1,4-dioxane, methyl isobutyl ketone, propylene glycol monomethyl ether, ethylene glycol monomethyl ether, ethylene glycol monomethyl ether acetate, propylene glycol monomethyl ether acetate, methyl lactate), dimethylformamide, ethyl lactate, cyclohexanone, Diethylene glycol dimethyl ether, diethylene glycol methyl ethyl ether, diisobutyl ketone, diacetone alcohol, 3-ethoxy propionate, dipropylene glycol dimethyl ether, butyl cellosolve, 3-methoxy-3-methyl-1-butanol, diethylene glycol ethyl methyl ether, diethylene glycol isopropyl methyl ether , Dipropylene glycol monomethyl ether, diethylene glycol diethyl ether, diethylene glycol monomethyl ether, and the like. Suitable organic solvents include propylene glycol monomethyl ether acetate, ethylene glycol monomethyl ether acetate, propylene glycol monomethyl ether and diethylene glycol methyl ethyl ether. These organic solvents may be used alone or in combination of two or more, and may be determined in consideration of balance such as coatability, surface tension and boiling point.

[Inorganic nanoparticles]
If necessary, the photosensitive resin composition of the present invention may contain inorganic nanoparticles. Examples of the inorganic nanoparticles include fillers and metal oxide nanoparticles. Examples of the filler include kaolinite and calcium carbonate. Since they have the effect of improving the physical strength of the cured member, they are preferably used when hard coat properties are desired.
The content ratio of the inorganic nanoparticles that may be contained in the photosensitive resin composition of the present invention is not particularly limited, but from the viewpoint of sufficiently exhibiting the effect of addition, it is preferably 0.5% by mass or more, and more preferably 1%. It is preferably 30% by mass or less, more preferably 3% by mass or more, and preferably 30% by mass or less, and more preferably from the viewpoint of sufficiently securing optical properties and coverability as an optical film protective layer having anisotropy. It is 20 mass% or less, more preferably 15 mass% or less.

[Liquid repellent]
A liquid repellent may be used in the photosensitive resin composition of the present invention, if necessary. The effect of adding a liquid repellent is to prevent swelling of the exposed area during development, or to form a protective layer for the optical film having anisotropy, and then protect it from chemicals or solvents that come into contact with it in subsequent steps. Is possible. Examples of the liquid repellent include fluorine-containing compounds and silicon-containing compounds.

The fluorine-containing compound is not particularly limited and may be a low molecular weight compound or a high molecular weight compound. For example, it has a crosslinking group such as an ethylenically unsaturated double bond or an epoxy group, and a fluoroalkyl group. And compounds containing a fluoropolyether group and the like. Specific examples include RS series manufactured by DIC, Optool DAC and Optoace series manufactured by Daikin Industries, Ltd.

The silicon-containing compound is not particularly limited, and may be a low-molecular compound or a high-molecular compound, and examples thereof include a silicon-modified polyacryl, a silicon-based block copolymer, and a graft polymer having a silicon resin in a side chain. Specific examples thereof include BYK-SILCLEAN 3700 manufactured by BYK Chemie, Modiper FS series manufactured by NOF CORPORATION, and Soken Chemical Co., Ltd. Chemistry LSI-60.
The liquid repellents may be used alone or in combination of two or more.

When the photosensitive resin composition of the present invention contains a liquid repellent, the content ratio thereof is usually 0.01% by mass or more, preferably 0.1% by mass or more, based on the total solid content of the photosensitive resin composition, and usually It is 3 mass% or less, preferably 2 mass% or less. When it is at least the above lower limit, the effect due to the addition of a liquid repellent tends to be easily exhibited, and when it is at most the above upper limit, it becomes difficult to form a film by poorly developing or repelling the coating liquid of the alignment film. Such side effects tend to be avoided.

[Other resins]
The photosensitive resin composition of the present invention may optionally contain other resins that do not correspond to (A). The effects expected of other resins include the control of film quality and the imparting of thermal softening properties useful in closing the side surface of an optical film having anisotropy.

Preferred examples of other resins include acrylic resins, urethane resins, and novolac resins. When the photosensitive resin composition of the present invention contains another resin, the content ratio is preferably 3% by mass or more and more preferably 5% by mass or more based on the total solid content of the photosensitive resin composition. Moreover, 30 mass% or less is preferable and 20 mass% or less is more preferable. When it is at least the above lower limit, the effect of adding other resin tends to be obtained, while when it is at most the above upper limit, curability tends to be easily ensured.

[Other ingredients]
The photosensitive resin composition of the present invention may contain other components, if necessary, unless the excellent effects of the present invention are significantly impaired. Examples of other components include thermal polymerization initiators, melamine crosslinking agents, adhesion improvers such as silane coupling agents, and development accelerators such as acids.

[Physical Properties of Photosensitive Resin Composition]
When the photosensitive resin composition of the present invention is used as an optical member, its transparency is desired to be high. From this point of view, the maximum absorbance at a wavelength of 380 to 750 nm is preferably 0.1 or less, more preferably 0.05 or less, and further preferably 0.03 or less. When it is at most the above upper limit, the light transmittance in the visible region tends to be good.
The method of measuring the maximum absorbance at a wavelength of 380 to 750 nm is not particularly limited, but a method of measuring using a cured film formed to have a film thickness of 1 μm can be mentioned.

[Preparation of photosensitive resin composition]
The method for preparing the photosensitive resin composition of the present invention is not particularly limited, but it can be prepared, for example, by mixing the above-mentioned components with an organic solvent and dissolving or dispersing by stirring or application of ultrasonic waves.

During the preparation, the components may be added and mixed at the same time, but they may be sequentially added and mixed in any order. The order of sequential addition is not particularly limited. For example, there is a procedure in which (B) a photocationic polymerization initiator and (C) a photoradical polymerization initiator are mixed with an organic solvent to obtain a mixture, and then (A) a polymerizable compound is added and mixed. Can be mentioned.

Further, the photosensitive resin composition of the present invention, after mixing the above components with an organic solvent, by filtration using a filter, insoluble matter, gel components that may occur during synthesis of resin, dust It is preferable to remove trace metals and the like. As the filter, for example, Entegris Optimizer, CUNO Nano Shield, Zeta Plus EC or the like can be used. Since insoluble matters, gel components, dust, trace metals, and the like cause cissing when a thin film is formed, it is necessary to select the roughness of the filter eye according to the film thickness. When it is desired to form a thick layer and does not contain inorganic nanoparticles or the like, a fine particle of 0.02 μm or less is preferable.
The chemical structure of each component contained in the photosensitive resin composition of the present invention can be confirmed by analysis by NMR, GPC, IR, MS or the like.

[Protective layer composed of photosensitive resin composition]
The photosensitive resin composition of the present invention can be preferably used for the purpose of forming a protective layer of an optical film having anisotropy. In particular, by forming the film on an optical film having anisotropy and also removing the optical film located under the portion removed by the development when patterning by the photolithography method by removing it with an alkali developing solution at the same time, it is possible to protect the film. An optical film having anisotropy can be used by forming a layer and patterning it into a shape similar to that of the protective layer.

[Optical film having anisotropy]
An optical film having anisotropy has anisotropy in electromagnetic properties in any two directions selected from a total of three directions in a three-dimensional coordinate system in the thickness direction of the film and two orthogonal in-plane directions. It is an optical film. Electromagnetic properties include optical properties such as absorption and refraction, and electrical properties such as resistance and capacitance.
Examples of the film having optical anisotropy such as absorption and refraction include a linear polarization layer, a circular polarization layer, a retardation film, and a conductive anisotropic film. The optical film having anisotropy in the present invention can be preferably used as a polarizing layer, a retardation film, and a conductive anisotropic film, and is particularly useful as a polarizing layer.

The film thickness of the optical film having anisotropy is not particularly limited, but the dry film thickness is preferably 10 nm or more, more preferably 50 nm or more. On the other hand, it is preferably 3 μm or less, more preferably 1 μm or less. When the film thickness of the optical film having anisotropy is within the above range, when patterning the optical film having anisotropy, a range in which the optical film having anisotropy is dissolved is secured, and dissolution control can be performed. Tends to be easier. Furthermore, there is a tendency that a uniform orientation of the dye and a uniform film thickness can be obtained within the film.

The anisotropic material used for the optical film having anisotropy of the present invention is not particularly limited as long as it is a material exhibiting anisotropy. In addition, since an optical film having anisotropy is prepared by wet coating on a substrate, a composition containing an anisotropic material and a solvent (hereinafter referred to as “composition for forming an optical film having anisotropy”). It is preferable).
The composition of the optical film-forming composition having anisotropy may be in the form of a solution, a gel, or a state in which an anisotropic material is dispersed in a solvent. Good. Further, in addition to these, a binder resin, a monomer, a curing agent, an additive, etc. may be contained, if necessary.

Here, the composition for forming an optical film having anisotropy should be in a liquid crystal phase state as a composition to form an optical film having anisotropy with a high degree of orientation, which is formed after the solvent is evaporated. It is preferable from the viewpoint. In this specification, the state of the liquid crystal phase means the state described on pages 1 to 16 of “Basics and Applications of Liquid Crystals” (Shoichi Matsumoto, Ichiyo Tsunoda, 1991). Say. The nematic phase described on page 3 is particularly preferable.
Here, the anisotropic material may be any one that can form an optical film having anisotropy, and examples thereof include a dye. An anisotropic dye film may be used as the anisotropic optical film using a dye as the anisotropic material. By using a dye, an optical film having anisotropy excellent in electromagnetic properties tends to be obtained, and it can be used particularly as a polarizing layer.

The method for coating the optical film having anisotropy of the present invention is not particularly limited, and continuous coating is preferable. In the present invention, continuous coating does not mean intermittent coating for each pattern but continuous coating of regions that should form a plurality of patterns (sections). Even when a plurality of patterns are provided on the substrate, continuous coating can be performed once, and it is not necessary to separately coat a plurality of patterns.
The method for continuously applying the composition for forming an optical film having anisotropy to form the optical film having anisotropy is not particularly limited, and examples include Yuji Harasaki, "Coating Engineering" (stock Asakura Shoten Co., Ltd., published on March 20, 1971) Method described on pages 253 to 277, "Creation and application of molecular cooperation materials" supervised by Kunihiro Ichimura (CMC Publishing Co., Ltd., published March 3, 1998) The methods described on pages 118 to 149, the slot die coating method, the spin coating method, the spray coating method, the bar coating method, the roll coating method, the blade coating method, the curtain coating method, the fountain method, the dipping method and the like can be mentioned. To be Among them, the slot die coating method is preferable because an optical film having highly anisotropic anisotropic anisotropy tends to be obtained.

After forming the anisotropic optical film on the substrate, it is preferable to carry out insolubilization treatment so that the anisotropic optical film is not dissolved in water by salt exchange. The insolubilization treatment lowers the solubility of the dye in the anisotropic optical film, suppresses the elution of the dye from the anisotropic optical film, and enhances the stability of the anisotropic optical film. be able to. Specifically, for example, a process of replacing ions having a low valence with ions having a higher valence (for example, replacing monovalent ions with polyvalent ions) can be mentioned.

[Method for producing protective layer and patterning of optical film having anisotropy]
As a method of applying the photosensitive resin composition of the present invention on the optical film having anisotropy, for example, spinner method, wire bar method, flow coating method, die coating method, blade coating method, rod coating method, roll A coating method, a spray coating method, an inkjet method, an electrospray deposition method and the like can be mentioned. Among them, the die coating method is preferable because it can be applied in a small amount, has less risk of mist adhesion, and is less likely to generate foreign matter, as compared with methods such as the spin coating method.

When the photosensitive resin composition of the present invention contains an organic solvent, it is usually dried after coating or printing. Drying can be performed by heating using a heating device such as a clean oven, a hot plate, infrared rays, a halogen heater, or microwave irradiation. Of these, a clean oven and a hot plate are preferable because they can easily uniformly heat the entire film. The drying conditions may be appropriately selected according to the type of organic solvent. It is preferable to dry at a high temperature for a long time from the viewpoint that it is easier to obtain stable curability if it is sufficiently dried, but on the other hand, the time required for drying is short and the productivity is excellent. In order to prevent the dark reaction of the composition from proceeding, it is preferable to dry it at a low temperature for a short time. Therefore, the drying temperature is usually 40° C. or higher, preferably 50° C. or higher, while it is usually 120° C. or lower, preferably 100° C. or lower. The drying time is preferably 15 seconds or longer, more preferably 30 seconds or longer, but is preferably 5 minutes or shorter, more preferably 3 minutes or shorter. Further, the drying may be performed by a reduced pressure drying method, or the heating method and the reduced pressure drying method may be used in combination.

The photosensitive resin composition layer that has been applied and dried is exposed through an exposure mask or directly drawn with a laser to insolubilize the exposed portion, and then the portion where light irradiation is blocked by the exposure mask or laser irradiation is performed. A development process is performed to remove the photosensitive resin composition layer in the portion that did not exist.

The light source used for exposure is not particularly limited as long as it can insolubilize the photosensitive resin composition of the present invention. Specifically, for example, a xenon lamp, a halogen lamp, a tungsten lamp, a high-pressure mercury lamp, an ultra-high-pressure mercury lamp, a metal halide lamp, a medium-pressure mercury lamp, a low-pressure mercury lamp, a carbon arc, a fluorescent lamp, a lamp light source such as an LED and an argon ion laser, YAG. Examples thereof include laser light sources such as lasers, excimer lasers, nitrogen lasers, helium cadmium lasers, blue-violet semiconductor lasers, and near infrared semiconductor lasers.
Here, when using the light of a specific wavelength, you may use an optical filter.
Exposure is usually 0.01 mJ / cm ² or more, preferably 0.1 mJ / cm ² or more, more preferably 1 mJ / cm ² or more, whereas, typically 1000 mJ / cm ² or less, preferably 800 mJ / cm ^{It is 2} or less, more preferably 500 mJ/cm ² or less.

The photosensitive resin composition of the present invention may be used by adjusting the light curing degree by changing the light transmittance depending on the site using a halftone exposure mask and adjusting the film thickness after development depending on the site. it can. For example, it is possible to obtain the protective layer and the column spacer on the protective layer in a single exposure and development step. As described above, by using the halftone exposure mask, it is possible to obtain a cured member having one or more convex portions. The height difference between the convex portion and the other portion is not particularly limited, but is preferably 1 μm or more. The upper limit is not particularly limited, but is usually 20 μm or less.

The photosensitive resin composition of the present invention can be used by patterning by removing the portion which was not irradiated with light during exposure by a developing treatment. An alkaline developer is used as the developer used for the development.
Examples of alkaline developers include inorganic alkalis such as sodium hydroxide, potassium hydroxide, sodium carbonate, potassium carbonate, sodium silicate, and sodium metasilicate; aliphatic secondary amines such as ethylamine and n-propylamine; trimethylamine; Aliphatic tertiary amines such as methyldiethylamine, dimethylethylamine and triethylamine, aromatic tertiary amines such as pyridine, collidine, lutidine and quinoline, alkanolamines such as ethanoldimethylamine, methyldiethanolamine and triethanolamine, tetra An aqueous solution of an alkaline compound such as a quaternary ammonium salt such as methylammonium hydroxide or tetraethylammonium hydroxide can be used.

The developer used in the present invention may further contain a surfactant, a defoaming agent, a buffer, a complexing agent and the like. Examples of the surfactant include nonionic surfactants such as polyoxyethylene alkyl ethers, polyoxyethylene alkylaryl ethers, polyoxyethylene alkyl esters, sorbitan alkyl esters, and monoglyceride alkyl esters; alkylbenzene sulfonic acid. Examples thereof include anionic surfactants such as salts, alkylnaphthalene sulfonates, alkyl sulfates, alkyl sulfonates, and sulfosuccinic acid ester salts; amphoteric surfactants such as alkyl betaines and amino acids. The developing method and its conditions are not particularly limited.

Examples of the developing method include immersion development, paddle development, spray development, brush development and ultrasonic development. Of these, immersion development and spray development are preferable because stains are less likely to occur, damage is less likely to occur, and uniform development is easy, and paddle development is preferable because the amount of developer used can be suppressed. The developing temperature is usually 10° C. or higher, preferably 15° C. or higher, while it is usually 50° C. or lower, preferably 45° C. or lower.
After development, it is washed with water and dried.
After development, if necessary, additional exposure may be performed to promote photopolymerization. The additional exposure may be performed by the same method as the above exposure method. However, in the case of additional exposure, the entire surface may be exposed without using a mask.

During development, not only the non-exposed portion of the protective layer formed of the photosensitive resin composition is removed, but the lower optical film having anisotropy is also patterned into a shape similar to that of the protective layer. The development time is set so that the contour of the optical film having anisotropy, such as -1(2), can be removed to the inside of the contour of the protective film.

The photosensitive resin composition of the present invention is baked after development to promote curing to increase the film strength, and melt flow to remove the side surface of the lower optical film having anisotropy as shown in FIG. Can be used by blocking.

The baking temperature is preferably 100° C. or higher, more preferably 120° C. or higher, and preferably 200° C. or lower, more preferably 180° C. or lower. If the temperature is lower than this, there is a tendency that the time required for curing is long and the productivity is deteriorated or it is not sufficiently cured, and if the temperature is higher than this, the optical film having anisotropy tends to be deteriorated. There is. Further, it is more preferable that the baking time is shorter, but it is suitable for 3 minutes to 2 hours, and particularly 10 minutes to 1 hour, from the viewpoint of ensuring sufficient curability.

The substrate used as the support of the photosensitive resin composition of the present invention is not particularly limited, but a substrate having good surface properties, contact angle characteristics and water absorption characteristics is preferable. As a base material for forming such a substrate, for example, an inorganic material such as glass; triacetate resin, acrylic resin, polyester resin, polycarbonate resin, polyethylene terephthalate resin, triacetyl cellulose resin, norbornene resin Examples thereof include polymeric materials such as cyclic polyolefin resin, polyimide resin, and urethane resin. These may be used alone or in combination of two or more.

[Optical element]
The optical element of the present invention has an optical film having anisotropy, and its surface is covered with a protective layer composed of the photosensitive resin composition of the present invention. It is an element.

[spacer]
INDUSTRIAL APPLICABILITY The photosensitive resin composition of the present invention can be suitably used for the purpose of forming a spacer because it has a sufficient strength even at low temperature baking and can form a pattern having a high level of electrical reliability. The spacer is for ensuring a uniform space of the liquid crystal layer sandwiched between the two substrates, and fine particles such as silica may be mixed with the liquid crystal, but the spacer of the present invention is It is a so-called photo spacer, which is formed into a column or a column by photolithography using the photosensitive resin composition of the invention. It is necessary to have sufficient compression resistance to withstand the pressure at the time of laminating the substrates and the load after the panel is made, and since it is formed in the liquid crystal layer, high electrical reliability is required so as not to adversely affect the operation of the liquid crystal.

[Insulation film]
INDUSTRIAL APPLICABILITY The photosensitive resin composition of the present invention can form a pattern having a high level of electrical reliability even when it is baked at a low temperature, and thus can be preferably used for the purpose of forming an insulating film. The insulating film of the present invention broadly means a member for which an insulating property is required in a display device such as a liquid crystal display, an organic EL display, and ink paper. For the purpose of insulating between a TFT element array substrate and a color filter substrate, for example. An interlayer insulating film to be formed is mentioned. High insulation is required to avoid malfunction.

[Display device]
The display device of the present invention includes at least the optical element of the present invention, at least the spacer of the present invention, and at least the insulating film of the present invention. A specific example is a liquid crystal display device. As a configuration example of the liquid crystal display device, a TFT element array substrate having an interlayer insulating film, an ITO wiring and a polarizing element, a color filter substrate having an alignment film and an optical element with a protective layer of the present invention as a polarizing film sandwiches a spacer. The liquid crystal is injected into the gap. Further, there is a structure in which a backlight is arranged outside the TFT element array substrate. The display device of the present invention is not limited to this, and other examples include organic EL display devices.

Hereinafter, the present invention will be described in detail with reference to examples. However, the present invention is not limited to the following embodiments, and can be implemented with various modifications without departing from the scope of the invention.

[Examples 1 to 3 and Comparative Examples 1 to 6]
Details of each component used in Examples 1 to 3 and Comparative Examples 1 to 6 are as follows.

<Synthesis of Polymer (A-1)-1>
A flask equipped with a reflux condenser, a stirrer, and a nitrogen blowing tube was charged with 4 g of 2,2′-azobis(2,4-dimethylvaleronitrile), 50 g of propylene glycol monomethyl ether acetate, and 200 g of propylene glycol monomethyl ether, and dissolved. After that, 15.6 g of methacrylic acid, 43.0 g of glycidyl methacrylate and 43.5 g of dicyclopentanyl methacrylate were added, and after nitrogen substitution while stirring, the temperature was heated to 70° C. and polymerization was performed for 5 hours, A copolymer (A-1)-1 solution was obtained. The weight average molecular weight (Mw) of this resin was about 7,100.

The weight average molecular weight was measured by "gel permeation chromatograph system LS Solution" manufactured by Shimadzu Corporation using "Column GPC-804" manufactured by Shimadzu Corporation.
The structure of the repeating unit contained in the polymer (A-1)-1 is as follows. The content ratio of the repeating unit structure derived from the carboxyl group-containing vinyl compound (methacrylic acid) in the polymer (A-1)-1 was 24 mol %, and the content of the repeating unit structure derived from the epoxy group-containing vinyl compound (glycidyl methacrylate) was included. The ratio is 46 mol %, and the content ratio of the repeating unit structure derived from the vinyl compound containing a cycloaliphatic group (dicyclopentanyl methacrylate) is 30 mol %.

<Synthesis of Polymer (A-1)-2>
A flask equipped with a reflux condenser, a stirrer, and a nitrogen blowing tube was charged with 4 g of 2,2′-azobis(2,4-dimethylvaleronitrile), 50 g of propylene glycol monomethyl ether acetate, and 200 g of propylene glycol monomethyl ether, and dissolved. After that, 13.9 g of methacrylic acid, 48.9 g of glycidyl methacrylate, and 37.2 g of dicyclopentanyl methacrylate were added, and after nitrogen substitution with stirring, the temperature was heated to 70° C. and polymerized for 5 hours, A copolymer (A-1)-2 solution was obtained. The weight average molecular weight (Mw) of this resin was about 7,400.
The structure of the repeating unit contained in the polymer (A-1)-2 is the same as that of the polymer (A-1)-1. The content ratio of the repeating unit structure derived from the carboxyl group-containing vinyl compound (methacrylic acid) in the polymer (A-1)-2 was 24 mol %, and the content of the repeating unit structure derived from the epoxy group-containing vinyl compound (glycidyl methacrylate) was included. The ratio is 51 mol %, and the content ratio of the repeating unit structure derived from the cyclic aliphatic group-containing vinyl compound (dicyclopentanyl methacrylate) is 25 mol %.

<Synthesis of Polymer (A-1)-3>
A flask equipped with a reflux condenser, a stirrer, and a nitrogen blowing tube was charged with 4 g of 2,2′-azobis(2,4-dimethylvaleronitrile), 50 g of propylene glycol monomethyl ether acetate, and 200 g of propylene glycol monomethyl ether, and dissolved. After that, 13.7 g of methacrylic acid, 68.8 g of glycidyl methacrylate, and 17.5 g of dicyclopentanyl methacrylate were added, and the atmosphere was replaced with nitrogen while stirring. Then, the temperature was heated to 70° C. to polymerize for 5 hours, A copolymer (A-1)-3 solution was obtained. The weight average molecular weight (Mw) of this resin was about 8,000.
The structure of the repeating unit contained in the polymer (A-1)-3 is the same as that of the polymer (A-1)-1. The content ratio of the repeating unit structure derived from the carboxyl group-containing vinyl compound (methacrylic acid) in the polymer (A-1)-3 was 22 mol %, and the content of the repeating unit structure derived from the epoxy group-containing vinyl compound (glycidyl methacrylate) was included. The ratio is 67 mol %, and the content ratio of the repeating unit structure derived from the cycloaliphatic group-containing vinyl compound (dicyclopentanyl methacrylate) is 11 mol %.

<Light acrylate DPE-6A (manufactured by Kyoeisha Chemical Co., Ltd.)>

<DCP (Shin Nakamura Chemical Co., Ltd.)>

<BPE-200 (Shin Nakamura Chemical Co., Ltd.)>

<Irg-250 (manufactured by BASF)>

<CPI-110P (manufactured by San-Apro)>

<SP-171 (made by ADEKA)>
Triarylsulfonium antimonate salt <CPI-310B (manufactured by San-Apro)>
Triarylsulfonium borate salt <Irg907 (manufactured by BASF)>

<UVS-1331 (manufactured by Kawasaki Kasei)>

<ET-2201 (Kawasaki Kasei Co.)>

<BYK-330 (manufactured by Big Chemie)>
Polyether modified polymethylalkyl siloxane

[Examples 1 to 3 and Comparative Examples 1 to 6]
<Preparation of Photosensitive Resin Compositions 1-9>
Each of the components shown in Table 1 was weighed out, stirred using a magnetic stirrer to completely dissolve the components, and the stirring was continued for further 10 minutes. Next, it was filtered using Optimizer V47 0.02 μm FD5A XFR manufactured by Entegris to obtain photosensitive resin compositions 1 to 9.

<Production of Optical Film Forming Composition Having Anisotropy>
20 parts by mass of a lithium salt of a dye represented by the following formula (1) and 1 part by mass of a dye represented by the following formula (2) are dissolved in 79 parts by weight of water with stirring to have anisotropy. An optical film forming composition was prepared.

<Preparation of insolubilized liquid>
75.6 parts by mass of 6N sulfuric acid was added to 24.4 parts by mass of bis(hexamethylene)triamine (manufactured by Tokyo Chemical Industry Co., Ltd.) and dissolved by stirring to prepare an insolubilized solution. The viscosity of the insolubilized liquid was 50 cP.

<Creation of optical film having anisotropy>
An alignment film (polyimide film, film thickness of about 60 nm) was formed on a glass substrate (10×10 cm, thickness 0.7 mm), and the end face was rubbed in the horizontal direction to prepare a substrate. The composition for forming an optical film having anisotropy is continuously coated on this alignment film with a die coater (wet film thickness 2 μm, head speed 15 mm/s) and naturally dried to give a film thickness of about 0.4 μm. An optical film having anisotropy was formed. The environmental conditions during coating were 23° C. and 50 RH%.

Next, the insolubilizing solution was impregnated with the substrate having the optical film having anisotropy for 3 seconds. After taking out the substrate, in order to wash away the excess insolubilizing solution, wash it thoroughly with demineralized water, and then air-dry the substrate to obtain a substrate in which the anisotropic optical film is insolubilized in water. It was

<Cross-cut test after development>
Approximately 1 cc of each of the photosensitive resin compositions 1 to 9 was dropped on the substrate obtained by the above method, the rotation speed of the spin coater was adjusted so that the film thickness after development was 2 μm, and the coating was performed by rotating for 1 minute. did. Then, it was heated and dried at 120° C. for 90 seconds on a hot plate to form a protective layer. The entire surface of this sample was exposed using a 3 kW high pressure mercury lamp at an exposure dose of 50 mJ/cm ² .
Next, this sample was developed for 100 seconds by a shower developing machine using an alkaline developer containing 0.04% by mass of KOH and 0.07% by mass of Emulgen A-60 (manufactured by Kao Corporation). Then, it was washed with running water for 30 seconds and dried with compressed air.
Thirty minutes later, using a cutter guide with a 1 mm interval on the surface of the substrate, 6 horizontal and vertical slits were made with a cutter knife to form a 25-square grid. Next, a piece of Cellotape (registered trademark) CT-24 (manufactured by Nichiban Co., Ltd.) was attached to the cross board, and the top surface was rubbed 10 times with an eraser to strongly press it, and then the tape was peeled off at an angle of 45°. Was observed. Table 1 shows the number of squares remaining out of the 25 squares without destruction or peeling of the protective layer.

<Measurement of UV-Vis absorbance>
Approximately 0.2 cc of each of the photosensitive resin compositions 1 to 9 was dropped onto a 5 cm square glass substrate, the spin coater rotation speed was adjusted so that the film thickness after baking was 1 μm, and rotation was performed for 1 minute for coating. did. Then, it heat-dried on a hot plate and 120 degreeC for 90 second(s), and formed the photosensitive resin composition layer. The entire surface of this sample was exposed using a 3 kW high pressure mercury lamp at an exposure dose of 50 mJ/cm ² . Next, this sample was baked in a 180° C. clean oven for 30 minutes, and the UV-Vis absorbance of the obtained sample was measured at a wavelength of 350 to 800 nm. The maximum absorbance in the visible light region of 380 to 750 nm is shown in Table 1.

<Evaluation of voltage holding ratio (VHR)>
A 2.5 cm square non-alkali glass substrate (“AN-100” manufactured by Asahi Glass Co., Ltd.) with an ITO film formed on the entire one side, and a 2.5 cm square glass substrate with a central portion on one side. A substrate B having a 1 cm-square ITO film connected to a 2 mm wide extraction electrode was prepared.
On the surface of the substrate A on which the ITO film was formed, the photosensitive resin composition was applied by adjusting with a spin coater so that the film thickness after baking would be 2 μm, and was applied on a hot plate at 120° C. It was dried for 90 seconds. After that, the contact portion of the electrode was shielded from light with an exposure amount of 50 mJ/cm ² using a 3 kW high-pressure mercury lamp, exposed, and developed by a shower developing machine for 100 seconds. The developer used was an alkaline developer composed of an aqueous solution containing 0.04% by mass of KOH and 0.07% by mass of Emulgen A-60 (manufactured by Kao Corporation). After that, the substrate was washed with running water for 30 seconds, dried with compressed air, and then baked at 180° C. for 30 minutes in a clean oven to obtain a substrate A on which the photosensitive resin composition was formed.

Next, a UV curable sealant containing silica beads having a diameter of 5 μm was applied on the outer periphery of the surface of the substrate B on which the ITO film was formed, and then the photosensitive resin composition of the substrate A was applied. The surfaces on which the film was formed were opposed to each other so that the outer edge portion was displaced by 3 mm, they were pressure-bonded, and ultraviolet rays were irradiated.
Liquid crystal (MLC-6846-000 manufactured by Merck Japan Co., Ltd.) was injected into the empty cell thus obtained, and the peripheral portion was sealed with a UV-curable sealant to complete a liquid crystal cell for measuring voltage holding ratio.

The liquid crystal cell was annealed (heated in a hot-air circulation furnace at 105° C. for 2.5 hours), and then pulse voltages of 60 Hz, 2 Hz and 0.6 Hz were applied at a voltage of 5 V to obtain a voltage holding ratio of Co., Ltd. It was measured by "VHR-1" manufactured by Toyo Technica, and the results are shown in Table 1. The larger the value, the better the condition. The smaller the frequency of the applied pulse voltage, the more severe the condition.

From Table 1, it can be seen from the comparison between Examples 1 and 2 and Comparative Examples 1 and 2 that when the amount of the cycloaliphatic group in the (A-1) copolymer is small, the anisotropy between the protective layer and the developed layer is small. While the adhesion of the optical film that it has is poor and the VHR is also deteriorated, when the amount of the cycloaliphatic group is large, the adhesion between the protective layer and the optical film is good, and the VHR is also good. I understand. This is because if the content of the cycloaliphatic group in the polymerizable compound (A) is low, the protective layer swells during development, and the protective film tends to float from the lower optical film or absorb components of the developer. It is considered that the result is that the ionic developer component remains in the protective layer.
Further, from the comparison between Example 3 and Comparative Examples 1 and 2, even when the amount of the (A-1) copolymer-derived cycloaliphatic group was small, (A-2) the cyclic compound as the polymerizable compound was cyclic. It can be seen that the same effect can be seen by increasing the amount of cycloaliphatic group in the total solid content by using the one having an aliphatic group.

Furthermore, it is understood from the results of Example 1 and Comparative Examples 3 to 5 that even if the cycloaliphatic group is sufficiently contained, if the photocationic polymerization initiator is a sulfonium salt, VHR is deteriorated. This suggests that the sulfonium cation of the photocationic polymerization initiator deteriorates the electrical reliability.

Further, from the comparison between Example 1 and Comparative Example 6, it can be seen that when the photoradical polymerization initiator is not contained, the photocuring is insufficient and the film is completely dissolved during development, and the film is not formed. It is considered that this is because the photocationic polymerization initiation system used in the present invention has excellent electrical reliability, but the strength of the acid generated is weak, resulting in insufficient exposure sensitivity. On the other hand, it is considered that sufficient exposure sensitivity can be secured by using the photocationic polymerization initiation system and the radical polymerization initiation system in combination. In the present invention, the role of the polymerization initiation system is shared in this way, thereby making it possible to achieve both sufficient electrical reliability during low temperature baking and exposure sensitivity. Further, in all the examples, the maximum absorbance value was 0.0, and it was confirmed that the transparency was good.

[Example 4]
After the development, the protective layer of the photosensitive resin composition 1 was formed on the substrate on which the optical film having anisotropy was formed by the same method as the crosscut test. This sample was exposed using a 3 kW high-pressure mercury lamp at an exposure dose of 50 mJ/cm ² through a pattern mask (aperture width: 300 μm line).
Next, this sample was developed for 100 seconds by a shower developing machine using an alkaline developer containing 0.04% by mass of KOH and 0.07% by mass of Emulgen A-60 (manufactured by Kao Corporation). Then, it was washed with running water for 30 seconds and dried with compressed air. Then, it was baked in a clean oven at 180° C. for 30 minutes to cover the surface and the side surface of the optical film with the protective layer. FIG. 2 shows the state of the obtained anisotropic optical film with a protective layer observed by an optical microscope, and FIG. 3 shows the section observed by SEM. From FIG. 2, it was confirmed that the contour of the optical film having anisotropy was removed to the inside of the contour of the patterned protective layer. Further, from FIG. 3, it was confirmed that the protective layer located outside the contour of the optical film melted and blocked the side surface of the patterned optical film.

<Evaluation of polarization characteristics>
The substrate having the optical film with the protective layer of Example 4 was divided into halves, and the states when the optical films were stacked so as to be orthogonal to each other or parallel to each other were observed. It could be shielded or transmitted, and it was confirmed that the film was a good polarizing film.

<Chemical resistance (protective film characteristics)>
Regarding the optical film with a protective layer of Example 4, NMP (N-methylpyrrolidone) was dropped on the protective layer and left for 15 minutes, and then NMP was wiped off and observed with an optical microscope, and no damage was observed. In addition, when this was superposed with another optical film and observed in a state where they were stacked orthogonally or parallel to each other, it was possible to uniformly block or transmit light, which was good. It was confirmed that there was no abnormal polarization performance.

As described above, by using the photosensitive resin composition of the present invention as the protective layer, it is possible to perform patterning without damaging the optical film having anisotropy, and the formation condition is as low as 180° C. It can be seen that there is sufficient chemical resistance to have NMP resistance despite the existence. Furthermore, it can be seen from the result of the cross-sectional SEM photograph that the protective layer also seals the side surface of the optical film.

[Example 5, Comparative Example 7]
SEIKO EG&G Quartz Crystal QA-A9M-Au 6 μl of photosensitive resin composition 1 and 4 was dripped on the electrode, fixed to the motor using a jig and rotated for 3 seconds to apply, then hot plate It was dried at 90° C. for 2 minutes to form a photosensitive resin composition layer having a film thickness of about 500 nm. This sample was exposed with a 3 kW high-pressure mercury lamp at an exposure dose of 50 mJ/cm ² to obtain a QCM measurement sample. Using a QCM922 manufactured by SEIKO EG&G, the obtained sample was composed of an aqueous solution containing 4% by mass of KOH and 7% by mass of Emulgen A-60 (manufactured by Kao Corporation) at a concentration 100 times that of the developer used in Example 1 or the like. The resonance frequency in the alkaline developer was measured. The results are shown in Fig. 4. The vertical axis represents how much the frequency of the vibrator decreased from 9 MHz, and the resonance frequency in a 100 times concentrated developer of a vibrator in which nothing was applied on the electrode was about -2700 Hz. is there.

From this result, the resonance frequency of the cured film of Example 5 does not show a remarkable decrease in the vibration frequency after the immersion in the 100 times concentration developing solution is observed, and nothing is rapidly applied after 120 seconds from the immersion. You can see it approaching the frequency of the oscillator. The resonance frequency does not particularly decrease and approaches the frequency of the oscillator to which nothing is applied, which means that the applied film does not become heavier than before immersion in the 100 times concentrated alkaline developer, which means that the film has decreased. In other words, it means that there is almost no swelling behavior including the developer.

On the other hand, in the case of the cured film of Comparative Example 7, nothing was applied after a significant decrease in the resonance frequency was observed from immediately after immersion in the 100 times concentrated alkaline developer (0 seconds) to around 80 seconds later. The behavior is such that it approaches the frequency of the oscillator. That is, it means that the film coated on the electrode becomes heavy once and becomes difficult to resonate immediately after immersion until after about 80 seconds, and the film is reduced after swelling containing the 100 times concentration alkaline developer. It means that you are going.

Since the exposed and cured film does not dissolve in an alkaline developer having a normal concentration, a 100 times concentration of an alkaline developer was intentionally used in this experiment. However, even in the exposed film, radical polymerization by oxygen on the outermost surface was performed. It is generally known that the blocked portion dissolves in a small amount in an alkaline developer of normal concentration to reduce the development film, and this experiment can model the phenomenon occurring on the outermost surface. I think that there is. This difference in behavior is due to the difference in the content of the cyclic aliphatic group in the polymerizable compound (A), and the photosensitive resin composition of the present invention contains a predetermined amount of the cyclic aliphatic group and thus does not swell during development. Since it has excellent adhesion to the underlying layer after development and does not hold various components contained in the alkaline developer, excellent electrical reliability can be maintained.

[Example 6]
About 0.2 cc of the photosensitive resin composition 1 was dropped on a 5 cm square glass substrate, the rotation speed of the spin coater was adjusted so that the film thickness after baking was 4 μm, and the coating was performed by rotating for 1 minute. Then, it heat-dried on a hot plate and 120 degreeC for 90 second(s), and formed the photosensitive resin composition layer. This sample was exposed with an ultraviolet ray having an intensity of 25 mW/cm ² at a wavelength of 365 nm at an exposure dose of 50 mJ/cm ² by opening a 200 μm gap using an exposure mask having a circular pattern opening with a diameter of 25 μm. did. Next, this sample was developed for 1 minute using the same developing solution and developing machine as in Example 1, and then baked in an oven at 180° C. for 30 minutes.

When the circular pattern of the obtained sample was observed by SEM, it was confirmed that the circular cone pattern was a good truncated cone as a spacer. As a result of measuring the length, the truncated cone had a height of 3.8 μm, a bottom diameter of 30.7 μm, and a top diameter of 21.0 μm.

Next, Shimadzu Corporation (Shimadzu dynamic ultra-micro hardness meter DUH-W201S) was used as a micro hardness meter for the load-unload test, a measurement temperature was 23° C., a flat indenter with a diameter of 50 μm was used, and a constant speed (10 mN/ The load is applied to the spacer (cured material of the above truncated cone) until it reaches 100 mN in sec), and the load is held for 10 seconds when the load reaches 100 mW, and then unloading at the same speed, and the load-displacement curve (Fig. 5) was obtained. From this load-displacement curve, the maximum displacement H[max] and the final displacement H[Last] were measured.
Next, when the elastic recovery rate was calculated by the following formula, the elastic recovery rate was 100%, and since it is a spacer that can withstand a compression of 100 mN, it is a spacer that is sufficiently resistant to the pressure and physical load during the substrate bonding. I understood it. The elastic recovery rate of 100% means that the height of the spacer does not change before and after the compression, that is, it is not broken or crushed and contracted. This means that a certain space of the liquid crystal layer can be maintained even if a load is applied.

Elastic recovery rate (%)={(maximum displacement H[max]-final displacement H[Last])/maximum displacement H[max]}×100.

[Example 7]
About 0.2 cc of the photosensitive resin composition 1 was dropped on a 5 cm square chromium substrate, and the spin coater was adjusted so that the film thickness after baking was 2 μm. Then, it heat-dried on a hot plate and 120 degreeC for 90 second(s), and formed the photosensitive resin composition layer. The entire surface of this sample was exposed to ultraviolet rays having an intensity of 25 mW/cm ² at a wavelength of 365 nm at an exposure dose of 50 mJ/cm ² . Next, this sample was developed for 1 minute using the same developing solution and developing machine as in Example 1, and then baked in an oven at 180° C. for 30 minutes.

Next, chromium was vapor-deposited with a film thickness of 100 μm using a vapor deposition mask having a circular pattern opening having a diameter of 2 mm to form an upper electrode, and a sample for measuring volume resistance was obtained. The volume resistance was calculated by measuring the current value when a voltage was applied to the obtained sample under conditions of 5 V, 10 V, and 15 V. The obtained results were 5V: 1.9×10 ¹⁴ Ω, 10V: 2.8×10 ¹⁴ Ω, and 15V: 1.9×10 ¹⁴ Ω, which were good results as an insulating film. It means that even if it is baked at a low temperature, it can be sufficiently cured, and because the invasion of the developing solution during development was suppressed, there is no effect of ionic impurities that move in the film even when high voltage is applied. I think I am doing it.

The photosensitive resin composition of the present invention makes it difficult for the exposed part to swell during development, so that the developing solution is allowed to penetrate into the lower-layer anisotropic optical film without peeling from the lower-layer anisotropic optical film. It is possible to perform patterning at once at the time of photolithography of the protective layer, and it is possible to form a protective layer with good electrical reliability and chemical resistance at low temperature without damaging the lower layer. It is possible to manufacture a polarizing film, and it is also effective for weight reduction and flexibility. In addition, since it is possible to provide a spacer having sufficient strength even at a low temperature baking of 200°C or less, an insulating film having excellent electric reliability such as voltage holding ratio and volume resistance, it is possible to provide a dye-based color filter or an organic TFT having weak heat resistance. It can be expected to be applied to

1: Photosensitive resin composition layer for an optical film protective layer having anisotropy 2: Optical film having anisotropy 3: Substrate 4: Protective layer

Claims (10)

A photosensitive resin composition containing (A) a polymerizable compound, (B) a photocationic polymerization initiator, and (C) a photoradical polymerization initiator,
The polymerizable compound (A) includes (A-1) a copolymer having an epoxy group and a carboxyl group, and (A-2) a polymerizable compound having an ethylenically unsaturated group,
The polymerizable compound (A) contains a cycloaliphatic group,
The cationic photopolymerization initiator (B) contains an aromatic iodonium salt, and
A photosensitive resin composition, wherein the content of the cycloaliphatic ring in the total solid content of the photosensitive resin composition is 7% by mass or more. The photosensitive resin composition according to claim 1, wherein the (A-1) copolymer having an epoxy group and a carboxyl group has the cycloaliphatic group. The photosensitive resin composition according to claim 1 or 2, wherein the anion of the aromatic iodonium salt is a hexafluorophosphate anion. The total of the content ratios of the (B) photocationic polymerization initiator and the (C) photoradical polymerization initiator is 10% by mass or less based on the total solid content. Photosensitive resin composition. The photosensitive resin composition according to any one of claims 1 to 4, which is for a protective layer of an optical film having anisotropy. An optical element having an optical film having anisotropy and having a surface covered with a protective layer made of the photosensitive resin composition according to claim 1. A display device comprising the optical element according to claim 6. The photosensitive resin composition according to any one of claims 1 to 4, which is for a spacer and/or for an insulating film. A spacer and/or an insulating film composed of the photosensitive resin composition according to claim 8. A display device comprising the spacer and/or the insulating film according to claim 9.