JP6236885B2 - Method for producing substrate for touch panel with protective film, photosensitive resin composition, photosensitive element, and touch panel - Google Patents

Description

  The present invention relates to a method for producing a substrate for a touch panel with a protective film, particularly a method for forming a protective film suitable for protecting electrodes of a capacitive touch panel, a photosensitive resin composition and a photosensitive element used therefor, and It is related with a touch panel.

  Liquid crystal display elements or touch panels (touch sensors) are used in large electronic devices such as personal computers and televisions, small electronic devices such as car navigation systems, mobile phones, and electronic dictionaries, and display devices such as OA / FA devices. These liquid crystal display elements or touch panels are provided with electrodes made of a transparent conductive electrode material. As the transparent conductive electrode material, indium tin oxide (Indium-Tin-Oxide: ITO), indium oxide or tin oxide is known. Since these materials exhibit high visible light transmittance, they are mainly used as electrode materials used for substrates for liquid crystal display elements.

  Various types of touch panels have already been put to practical use. In recent years, the use of capacitive touch panels has progressed. In a capacitive touch panel, when a fingertip that is a conductor comes into contact with a touch input surface, capacitance is coupled between the fingertip and the conductive film to form a capacitor. For this reason, the capacitive touch panel detects the coordinates by capturing the change in charge at the contact position of the fingertip.

  In particular, a projected capacitive touch panel has a good operability such that a complex instruction can be performed because multiple fingertip detection is possible. Due to its good operability, a projected capacitive touch panel has been used as an input device on a display surface in a device having a small display device such as a mobile phone or a portable music player.

  In general, in a projected capacitive touch panel, a plurality of X electrodes and a plurality of Y electrodes orthogonal to the X electrodes have a two-layer structure in order to express two-dimensional coordinates based on the X axis and the Y axis. Is forming. ITO is used as these electrodes.

  By the way, since the frame region of the touch panel is a region where the touch position cannot be detected, reducing the area of the frame region is an important element for improving the product value. In the frame area, metal wiring is required to transmit a touch position detection signal, but in order to reduce the frame area, it is necessary to reduce the width of the metal wiring. Generally, copper is used for metal wiring.

  However, in the touch panel as described above, corrosive components such as moisture and salt may intrude into the inside from the sensing region when touching the fingertip. When a corrosive component enters the inside of the touch panel, the metal wiring is corroded, and there is a risk of an increase in electrical resistance between the electrode and the driving circuit, or disconnection.

  In order to prevent corrosion of metal wiring, a capacitive projection type touch panel in which an insulating layer is formed on metal is disclosed (for example, Patent Document 1). In this touch panel, a silicon dioxide layer is formed on a metal by a plasma chemical vapor deposition method (plasma CVD method) to prevent corrosion of the metal. However, since this method uses a plasma CVD method, there is a problem that a high temperature treatment is required, a base material is limited, and a manufacturing cost is increased.

  By the way, as a method of providing a resist film at a necessary location, a method is known in which a photosensitive layer made of a photosensitive resin composition is provided on a predetermined substrate, and this photosensitive layer is exposed and developed (for example, a patent). Literature 2-4).

JP 2011-28594 A JP-A-7-253666 JP 2005-99647 A JP-A-11-133617

  The production of the protective film with the photosensitive resin composition can be expected to reduce the cost as compared with the plasma CVD method. However, when forming a protective film on the base material for touch panels, when the thickness of the protective film is large, a step may be conspicuous between a place where the film is present and a place where the film is not present. Therefore, it is necessary to make the protective film as thin as possible. However, there was no example in which the rust prevention property of the protective film formed from the photosensitive resin composition was examined at a thickness of 10 μm or less.

  An object of this invention is to provide the manufacturing method of the base material for touchscreens with a protective film which has a protective film which has sufficient antirust property even if it is a thin film on the predetermined base material for touchscreens. It aims at providing the touch panel provided with the photosensitive resin composition and photosensitive element which can form such a protective film, and the base material for touchscreens with a protective film.

  As a result of intensive studies by the present inventors to solve the above problems, the photosensitive resin composition containing a specific binder polymer, a specific photopolymerizable compound, and a photopolymerization initiator has sufficient developability. The inventors have found that even when the protective film formed by photocuring has a thickness of 10 μm or less, it exhibits sufficient rust prevention properties and can sufficiently prevent the corrosion of metals such as copper, and has completed the present invention.

  The manufacturing method of the base material for touchscreens with a protective film of this invention is the binder polymer which contains 3-20 mass% of structural units derived from (meth) acrylic acid on the base material for touchscreens, and at least 3 ethylenically unsaturated group. A photosensitive layer comprising a photosensitive resin composition containing a photopolymerizable compound having a photopolymerization initiator and a photopolymerization initiator is provided, and a predetermined portion of the photosensitive layer is cured by irradiation with actinic rays after the predetermined portion of the photosensitive layer is cured. The protective film which consists of the hardened | cured material of the said predetermined part of the said photosensitive layer which coat | covers a part or all of the said base material is removed.

  According to the manufacturing method of the base material for touchscreens with a protective film of this invention, it is sufficient even if it is a thin film, ensuring developability and the adhesiveness to a base material by using the said specific photosensitive resin composition. It is possible to form a protective film having excellent rust prevention properties. According to the present invention, it is possible to form a protective film having both good aesthetics and rust prevention properties using a photosensitive resin composition, and thus it is possible to reduce the manufacturing cost in the production of touch panels.

  From the viewpoint of further improving rust prevention, the photopolymerizable compound is a (meth) acrylate compound having a skeleton derived from pentaerythritol, a (meth) acrylate compound having a skeleton derived from dipentaerythritol, or a skeleton derived from trimethylolpropane. It is preferable to include at least one compound selected from the group consisting of a (meth) acrylate compound having a glycerin and a (meth) acrylate compound having a glycerin-derived skeleton.

  From the viewpoint of sufficiently ensuring the visibility of the touch panel, the photosensitive layer preferably has a minimum visible light transmittance of 90% or more at 400 to 700 nm. In this case, it is suitable for forming a protective film that covers the electrodes in the sensing region.

In addition, from the viewpoint of further improving the visibility of the touch panel, the photosensitive layer preferably has a b ^* in the CIELAB color system of −0.2 to 1.0. In this case, it is suitable for forming a protective film that covers the electrodes in the sensing region.

  Furthermore, it is preferable that the photosensitive resin composition further contains at least one compound selected from the group consisting of triazole compounds, thiadiazole compounds, and tetrazole compounds from the viewpoint of achieving both developability and rust prevention properties. . In this case, both developability and rust resistance can be achieved, and a protective film having rust resistance can be formed with a good pattern.

  The photopolymerization initiator preferably contains an oxime ester compound and / or a phosphine oxide compound. By including an oxime ester compound and / or a phosphine oxide compound as a photoinitiator, a pattern can be formed with sufficient resolution even when the photosensitive layer is thin.

  Considering the visibility and aesthetics of the touch panel, it is desirable that the transparency of the protective film is higher. However, on the other hand, the present inventors have found that when patterning a thin photosensitive layer having high transparency, the resolution tends to decrease. The present inventors consider that the reason is that when the thickness of the photosensitive layer is reduced, it is easily affected by light scattering from the base material and halation occurs.

  On the other hand, in the present invention, the photopolymerization initiator contains an oxime ester compound and / or a phosphine oxide compound, thereby enabling pattern formation with sufficient resolution.

  The reason why the above effect can be obtained is that the oxime moiety contained in the oxime ester compound or the phosphine oxide moiety contained in the phosphine oxide compound has a relatively high photolysis efficiency but does not decompose with slight light leakage. The present inventors infer that the influence of leakage light is suppressed because of having a large threshold.

  In the method for producing a base material for a touch panel with a protective film of the present invention, a photosensitive element comprising a support film and a photosensitive layer made of the photosensitive resin composition provided on the support film is prepared, The photosensitive layer can be provided by transferring the photosensitive layer of the photosensitive element onto the substrate. In this case, by using the photosensitive element, a roll-to-roll process can be easily realized, a solvent drying process can be shortened, and the manufacturing process can be greatly shortened and cost can be greatly reduced.

  The present invention also includes a binder polymer containing 3 to 20% by mass of a structural unit derived from (meth) acrylic acid, a photopolymerizable compound having at least three ethylenically unsaturated groups, and a photopolymerization initiator. The photosensitive resin composition used for the protective film formation of the base material for touchscreens is provided.

  According to the photosensitive resin composition of the present invention, a protective film having sufficient antirust property can be formed on a predetermined base material for a touch panel even if it is a thin film.

  From the viewpoint of sufficiently ensuring the visibility of the touch panel, the photosensitive resin composition of the present invention preferably has a minimum visible light transmittance of 90% or more when a protective film is formed.

Moreover, from the viewpoint of further improving the visibility of the touch panel, the photosensitive resin composition of the present invention has a b ^* in the CIELAB color system of -0.2 to 1.0 when a protective film is formed. Is preferred.

  Furthermore, the photosensitive resin composition of the present invention further contains at least one compound selected from the group consisting of triazole compounds, thiadiazole compounds, and tetrazole compounds from the viewpoint of achieving both developability and rust prevention properties. Is preferred.

  Moreover, in the photosensitive resin composition of this invention, it is preferable that the said photoinitiator contains an oxime ester compound and / or a phosphine oxide compound. In this case, it is possible to form a thin protective film having a high resolution and a pattern having sufficient resolution.

  The present invention also provides a photosensitive element comprising a support film and a photosensitive layer made of the photosensitive resin composition according to the present invention provided on the support film.

  According to the photosensitive element of the present invention, a protective film having sufficient antirust property can be formed on a predetermined touch panel substrate even if it is a thin film.

  The thickness of the photosensitive layer can be 10 μm or less.

  This invention also provides a touch panel provided with the base material for touchscreens with a protective film obtained by the method which concerns on the said invention on the base material for touchscreens.

  ADVANTAGE OF THE INVENTION According to this invention, the manufacturing method of the base material for touchscreens with a protective film which has a protective film which has sufficient antirust property even if it is a thin film on the predetermined base material for touchscreens, and such a protective film can be formed. A touch panel provided with a photosensitive resin composition, a photosensitive element, and a base material for a touch panel with a protective film can be provided.

  Moreover, according to this invention, the metal electrode of an electrostatic capacitance type touch panel can be protected. Furthermore, according to the present invention, it is possible to protect the electrode in the frame area of the touch panel in which a metal layer such as copper which is likely to generate rust due to moisture, salt, etc. is formed to improve conductivity.

It is a schematic cross section which shows one Embodiment of the photosensitive element of this invention. It is a schematic cross section for demonstrating one Embodiment of the manufacturing method of the base material for touchscreens with a protective film of this invention. It is a model top view which shows an example of an electrostatic capacitance type touch panel. It is a schematic top view which shows another example of an electrostatic capacitance type touch panel. (A) is the fragmentary sectional view in alignment with the VV line | wire of C part shown by FIG. 3, (b) is a fragmentary sectional view which shows another aspect. It is a top view which shows an example of the electrostatic capacitance type touch panel in which a transparent electrode exists in the same plane. It is a partially cutaway perspective view showing an example of a capacitive touch panel in which transparent electrodes are present on the same plane. It is a fragmentary sectional view in alignment with the VI-VI line in FIG. It is a figure for demonstrating an example of the manufacturing method of the capacitive touch panel in which a transparent electrode exists in the same plane, (a) is a partially notched perspective view which shows the board | substrate provided with a transparent electrode, (b) FIG. 3 is a partially cutaway perspective view showing the obtained capacitive touch panel. It is a figure for demonstrating an example of the manufacturing method of the electrostatic capacitance type touch panel in which a transparent electrode exists in the same plane, (a) is a fragmentary sectional view along the VIIIa-VIIIa line | wire in FIG. ) Is a partial cross-sectional view showing a step of providing an insulating film, and (c) is a partial cross-sectional view taken along line VIIIc-VIIIc in FIG. 9.

  Hereinafter, embodiments for carrying out the present invention will be described in detail. However, the present invention is not limited to the following embodiments. In particular, since the photosensitive resin composition of the present invention is excellent in transparency and rust prevention properties, if it is an object to protect a base material for a touch panel (touch sensor), particularly an electrode or wiring formation site, It can be suitably used regardless of changes in the configuration of the touch panel. Specifically, when the touch panel configuration is changed from the cover glass, touch panel, and liquid crystal panel configuration to the cover glass integrated type or on-cell type, the electrodes or wiring formation parts of the touch panel (touch sensor) are protected. If it is the purpose to do, it can use suitably.

  In this specification, the protective film of the base material for touch panels can be provided in the sensing area | region which has an electrode, the frame area | region which has metal wiring, or another area | region. The protective film of the base material for touch panels may be provided only in one of the regions, or may be provided in a plurality of regions. Furthermore, the position and range of providing the protective film, such as being provided on a part of the electrode formed in the sensing region, can be appropriately selected according to the purpose of use.

  Moreover, in this specification, being excellent in transparency means transmitting visible light of 400 to 700 nm by 90% or more, and is included in the concept of transparency even if light is scattered to some extent.

  In the present specification, “(meth) acrylic acid” means acrylic acid or methacrylic acid, “(meth) acrylate” means acrylate or a corresponding methacrylate, and “(meth) acryloyl”. “Group” means an acryloyl group or a methacryloyl group. Further, “(poly) oxyethylene chain” means an oxyethylene chain or a polyoxyethylene chain, and “(poly) oxypropylene chain” means an oxypropylene chain or a polyoxypropylene chain. Furthermore, “(EO) modification” means having a (poly) oxyethylene chain.

  In addition, in this specification, the term “process” is not limited to an independent process, and even if it cannot be clearly distinguished from other processes, the term “process” is used as long as the intended action of the process is achieved. included. In the present specification, a numerical range indicated by using “to” indicates a range including the numerical values described before and after “to” as the minimum value and the maximum value, respectively.

  Further, in the present specification, the content of each component in the composition is the total amount of the plurality of substances present in the composition unless there is a specific notice when there are a plurality of substances corresponding to each component in the composition. Means.

  FIG. 1 is a schematic cross-sectional view showing an embodiment of the photosensitive element of the present invention. The photosensitive element 1 shown in FIG. 1 is opposite to the support film 10, the photosensitive layer 20 made of the photosensitive resin composition according to the present invention provided on the support film 10, and the support film 10 of the photosensitive layer 20. And a protective film 30 provided on the side.

  The photosensitive element 1 of this embodiment can be used suitably for formation of the protective film of the base material for touchscreens.

  As the support film 10, a polymer film can be used. Examples of the polymer film include films made of polyethylene terephthalate, polycarbonate, polyethylene, polypropylene, polyethersulfone, and the like.

  The thickness of the support film 10 is preferably 5 to 100 μm, preferably 10 to 70 μm, from the viewpoint of ensuring coverage and suppressing a reduction in resolution when irradiating actinic rays through the support film 10. More preferably, it is 15-40 micrometers, It is further more preferable, It is especially preferable that it is 20-35 micrometers.

  The photosensitive resin composition according to the present invention constituting the photosensitive layer 20 includes at least three binder polymers (hereinafter also referred to as the component (A)) containing 3 to 20% by mass of a structural unit derived from (meth) acrylic acid. A photopolymerizable compound having an ethylenically unsaturated group (hereinafter also referred to as (B) component) and a photopolymerization initiator (hereinafter also referred to as (C) component) are contained.

  In the present embodiment, the binder polymer as the component (A) is a polymer having a structural unit derived from (a1) (meth) acrylic acid. As the component (A), a copolymer containing a structural unit derived from (a1) (meth) acrylic acid and a structural unit derived from (a2) (meth) acrylic acid alkyl ester is preferable.

  (A2) Examples of (meth) acrylic acid alkyl ester include (meth) acrylic acid methyl ester, (meth) acrylic acid ethyl ester, (meth) acrylic acid butyl ester, (meth) acrylic acid 2-ethylhexyl ester, and Examples include (meth) acrylic acid hydroxyl ethyl ester.

  The polymer and the copolymer may further contain other monomers that can be copolymerized with the component (a1) and / or the component (a2) in the structural unit.

  Examples of the other monomer that can be copolymerized with the component (a1) and / or the component (a2) include (meth) acrylic acid tetrahydrofurfuryl ester, (meth) acrylic acid dimethylaminoethyl ester, and (meth) acrylic. Acid diethylaminoethyl ester, (meth) acrylic acid glycidyl ester, (meth) acrylic acid benzyl ester, 2,2,2-trifluoroethyl (meth) acrylate, 2,2,3,3-tetrafluoropropyl (meth) acrylate , (Meth) acrylamide, (meth) acrylonitrile, diacetone (meth) acrylamide, styrene, and vinyltoluene. When synthesizing the binder polymer as component (A), the above monomers may be used alone or in combination of two or more.

  The content of the structural unit derived from (meth) acrylic acid in the component (A) is 3 to 20% by mass based on the total mass of the monomers constituting the component (A), but further excellent in rust prevention. Then, it is preferable that it is 19 mass% or less, It is more preferable that it is 18 mass% or less, It is still more preferable that it is 17 mass% or less, It is especially preferable that it is 16 mass% or less. The content is preferably 4% by mass or more, more preferably 5% by mass or more, still more preferably 8% by mass or more, in terms of excellent alkali developability, more preferably 10% by mass. The above is particularly preferable.

  In this embodiment, by using a combination of the component (A) in which the content of the structural unit derived from (meth) acrylic acid is within the above range and the component (B) that satisfies the above conditions, the developability and the group A protective film having a sufficient antirust property can be formed with a thickness of 10 μm or less while ensuring adhesion to the material. Therefore, according to the photosensitive resin composition which concerns on this embodiment, the protective film which can make aesthetics and rust prevention property compatible can be formed.

  In a conventional photosensitive element considering film characteristics, a photosensitive layer is usually formed with a thickness exceeding 10 μm, and (meth) acrylic acid of a binder polymer contained in the photosensitive resin composition in order to ensure developability at this time Adjustment of the content of the structural unit derived from is performed. From the viewpoint of securing developability, the content of structural units derived from (meth) acrylic acid is usually set to a value greater than 20% by mass. When such a photosensitive resin composition was used, when a protective film was formed on the electrode with a thickness of 10 μm or less, sufficient rust prevention properties could not be obtained. The inventors speculate that this is because, in the case of a thin film of 10 μm or less, corrosive components such as moisture and salt are likely to be contained in the film, and this tendency is further increased by the carboxyl group contained in the binder polymer. . If the acid value is too low, it tends to be difficult to ensure sufficient developability or adhesion to the substrate, but in the present embodiment, it contains an appropriate structural unit derived from (meth) acrylic acid. By combining the component (A) having an amount and the component (B) that can further improve rust prevention, it is considered that rust prevention and developability can be achieved at a high level.

The acid value of the binder polymer as the component (A) can be measured as follows.
That is, first, 1 g of the binder polymer that is the object of acid value measurement is precisely weighed. 30 g of acetone is added to the precisely weighed binder polymer and dissolved uniformly. Next, an appropriate amount of phenolphthalein as an indicator is added to the solution, and titration is performed using a 0.1N potassium hydroxide (KOH) aqueous solution. The acid value is determined by calculating the number of mg of KOH required to neutralize the acetone solution of the binder polymer to be measured. When a solution obtained by mixing a binder polymer with a synthetic solvent, a diluting solvent, or the like is an object to be measured, the acid value is calculated by the following formula.
Acid value = 0.1 × Vf × 56.1 / (Wp × I / 100)
In the formula, Vf represents the titration amount (mL) of the aqueous KOH solution, Wp represents the weight (g) of the solution containing the measured binder polymer, and I represents the ratio of the nonvolatile content in the solution containing the measured binder polymer. (Mass%) is shown.
In addition, when blending the binder polymer in a state mixed with volatile components such as a synthetic solvent and a diluting solvent, the mixture is preliminarily heated for 1 to 4 hours at a temperature higher than the boiling point of the volatile components by 1 to 4 hours before being volatile. The acid value can also be measured after removing the component.

  The molecular weight of the binder polymer as the component (A) is not particularly limited, but from the viewpoints of coatability, coating film strength, and developability, it is usually preferable that the weight average molecular weight is 10,000 to 200,000. More preferably, it is 30,000 to 150,000, and very preferably 50,000 to 100,000. In addition, the measurement conditions of a weight average molecular weight shall be the same measurement conditions as the Example of this-application specification.

  Examples of the photopolymerizable compound having at least three ethylenically unsaturated groups as the component (B) include trimethylolpropane tri (meth) acrylate, tetramethylolmethanetri (meth) acrylate, tetramethylolmethanetetra (meta ) Obtained by reacting an α, β-unsaturated carboxylic acid (for example, acrylic acid, methacrylic acid, etc.) with a polyhydric alcohol such as acrylate, dipentaerythritol penta (meth) acrylate, dipentaerythritol hexa (meth) acrylate, etc. And a compound obtained by adding an α, β-unsaturated carboxylic acid to a glycidyl group-containing compound such as trimethylolpropane triglycidyl ether tri (meth) acrylate.

  The photopolymerizable compound having at least three ethylenically unsaturated groups preferably has an acid value of 5 mgKOH / g or less from the viewpoint of excellent rust prevention.

  In the photosensitive resin composition of the present embodiment, a (meth) acrylate compound having a skeleton derived from pentaerythritol and a (meth) acrylate having a skeleton derived from dipentaerythritol from the viewpoint of electrode corrosion inhibition power and ease of development. It preferably contains at least one selected from a compound, a (meth) acrylate compound having a skeleton derived from trimethylolpropane, and a (meth) acrylate compound having a glycerin-derived skeleton, and has a skeleton derived from dipentaerythritol ( It is more preferable to include at least one selected from a (meth) acrylate compound and a (meth) acrylate compound having a skeleton derived from trimethylolpropane.

  Here, (meth) acrylate having a skeleton derived from dipentaerythritol means an esterified product of dipentaerythritol and (meth) acrylic acid, and the esterified product is a compound modified with an alkyleneoxy group. Are also included. The esterified product preferably has 6 ester bonds in one molecule, but a compound having 1 to 5 ester bonds may be mixed.

  The (meth) acrylate compound having a skeleton derived from trimethylolpropane means an esterified product of trimethylolpropane and (meth) acrylic acid, and the esterified product is modified with an alkyleneoxy group. Also included are compounds. In the above esterified product, the number of ester bonds in one molecule is preferably 3, but a compound having 1 to 2 ester bonds may be mixed.

  Among the above photopolymerizable compounds having at least three ethylenically unsaturated groups, an alkylene oxide-modified trimethylolpropane (meth) acrylate compound, an alkylene oxide-modified tetra is preferable from the viewpoint of further improving the resistance to electrode corrosion and the ease of development. Methylolmethane (meth) acrylate compound, alkylene oxide modified pentaerythritol (meth) acrylate compound, alkylene oxide modified dipentaerythritol (meth) acrylate compound, alkylene oxide modified glycerin (meth) acrylate compound, and alkylene oxide modified trimethylolpropane triglycidyl It is preferable to include at least one compound selected from ether (meth) acrylate, and alkylene oxide-modified dipenta And more preferably contains Risuritoru (meth) acrylate compound and alkylene oxide-modified trimethylolpropane (meth) at least one compound selected from acrylate compounds.

  As said alkylene oxide modified | denatured tetramethylol methane (meth) acrylate compound, EO modified | denatured pentaerythritol tetraacrylate can be used, for example. EO-modified pentaerythritol tetraacrylate is available as RP-1040 (manufactured by Nippon Kayaku Co., Ltd.).

  Said compound can be used individually by 1 type or in combination of 2 or more types.

  The content of the component (A) and the component (B) in the photosensitive resin composition of the present embodiment is such that the component (A) is 40 to 40 parts by mass with respect to 100 parts by mass of the total amount of the component (A) and the component (B). 80 parts by mass, (B) component is preferably 20-60 parts by mass, (A) component is preferably 50-70 parts by mass, and (B) component is more preferably 30-50 parts by mass, (A More preferably, the component is 55 to 65 parts by mass and the component (B) is 35 to 45 parts by mass.

  By setting the content of the component (A) and the component (B) within the above range, sufficient sensitivity can be obtained while sufficiently ensuring the coating property or the film property in the photosensitive element, and the photocurability and development. And the ability to suppress electrode corrosion can be sufficiently secured.

  The photosensitive resin composition of this embodiment can contain photopolymerizable compounds other than the said (B) component. As the photopolymerizable compound, for example, the component (B) can be used in combination with one or more of a monofunctional monomer and a bifunctional monomer.

  Examples of the monofunctional monomer include (meth) acrylic acid, (meth) acrylic acid alkyl ester, and monomers copolymerizable therewith exemplified as suitable monomers used for the synthesis of the binder polymer of component (A). It is done.

  Examples of the bifunctional vinyl monomer include polyethylene glycol di (meth) acrylate, trimethylolpropane di (meth) acrylate, polypropylene glycol di (meth) acrylate, bisphenol A polyoxyethylene polyoxypropylene di (meth) acrylate (ie, 2,2-bis (4-acryloxypolyethoxypolypropoxyphenyl) propane), bisphenol A diglycidyl ether di (meth) acrylate, a compound having a hydroxyl group and an ethylenically unsaturated group (β-hydroxyethyl acrylate, β-hydroxy And an esterified product of ethyl methacrylate and the like and polyvalent carboxylic acid (phthalic anhydride, etc.).

  When the photopolymerizable compound (B) and a monofunctional vinyl monomer or a bifunctional vinyl monomer are used in combination, there is no particular limitation on the blending ratio of these monomers, but the photocurability and electrode corrosion inhibition power are not limited. From the viewpoint of obtaining, the proportion of the photopolymerizable compound as the component (B) is preferably 30 parts by mass or more with respect to 100 parts by mass of the total amount of the photopolymerizable compound contained in the photosensitive resin composition. The amount is more preferably 50 parts by mass or more, and further preferably 75 parts by mass or more.

  Examples of the photopolymerization initiator (C) include benzophenone, N, N, N ′, N′-tetramethyl-4,4′-diaminobenzophenone (Michler ketone), N, N, N ′, N ′. -Tetraethyl-4,4'-diaminobenzophenone, 4-methoxy-4'-dimethylaminobenzophenone, 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butanone-1, 2-methyl-1- Aromatic ketones such as [4- (methylthio) phenyl] -2-morpholino-propanone-1; benzoin ether compounds such as benzoin methyl ether, benzoin ethyl ether and benzoin phenyl ether; benzoin compounds such as benzoin, methyl benzoin and ethyl benzoin 1,2-octanedione, 1- [4- (phenylthio); -, 2- (O-benzoyloxime)], ethanone, 1- [9-ethyl-6- (2-methylbenzoyl) -9H-carbazol-3-yl]-, 1- (O-acetyloxime), etc. Oxime ester compounds; benzyl derivatives such as benzyldimethyl ketal; acridine derivatives such as 9-phenylacridine and 1,7-bis (9,9′-acridinyl) heptane; N-phenylglycine derivatives such as N-phenylglycine; coumarin compounds Oxazole compounds; phosphine oxide compounds such as 2,4,6-trimethylbenzoyl-diphenyl-phosphine oxide;

  Among these, an oxime ester compound and / or a phosphine oxide compound are preferred from the transparency of the protective film to be formed and the pattern forming ability when the film thickness is 10 μm or less.

  Considering the visibility and aesthetics of the touch panel, it is preferable that the protective film has higher transparency. On the other hand, the present inventors have found that when patterning a thin photosensitive layer having high transparency, the resolution tends to decrease. The present inventors consider that this is because when the thickness of the photosensitive layer is reduced, the photosensitive layer is easily affected by light scattering from the substrate and halation occurs. On the other hand, by containing an oxime ester compound and / or a phosphine oxide compound as the component (C), pattern formation with sufficient resolution becomes possible.

  The reason why the above effect can be obtained is that the oxime moiety contained in the oxime ester compound or the phosphine oxide moiety contained in the phosphine oxide compound has a relatively high photolysis efficiency but does not decompose with slight light leakage. The present inventors infer that the influence of leakage light is suppressed because of having a large threshold.

  Examples of the oxime ester compound include compounds represented by the following general formula (C-1) and general formula (C-2). From the viewpoint of fast curability and transparency, the following general formula (C-1) The compound represented by these is preferable.

In the general formula (C-1), R ¹ represents an alkyl group having 1 to 12 carbon atoms or a cycloalkyl group having 3 to 20 carbon atoms. In addition, unless the effect of this invention is inhibited, you may have a substituent on the aromatic ring in the said general formula (C-1).

In the general formula (C-1), R ¹ is preferably an alkyl group having 3 to 10 carbon atoms, or a cycloalkyl group having 4 to 15 carbon atoms, and an alkyl group having 4 to 8 carbon atoms or carbon. A cycloalkyl group having a number of 4 to 10 is more preferable.

In the general formula (C-2), R ² represents a hydrogen atom or an alkyl group having 1 to 12 carbon atoms, and R ³ represents an alkyl group having 1 to 12 carbon atoms or a cycloalkyl having 3 to 20 carbon atoms. R ⁴ represents an alkyl group having 1 to 12 carbon atoms, and R ⁵ represents an alkyl group or aryl group having 1 to 20 carbon atoms. p1 represents an integer of 0 to 3. When p1 is 2 or more, a plurality of R ⁴ may be the same or different. Note that carbazole may have a substituent as long as the effects of the present invention are not impaired.

In general formula (C-2), R ² is preferably an alkyl group having 1 to 8 carbon atoms, more preferably an alkyl group having 1 to 4 carbon atoms, and still more preferably an ethyl group. .

In the general formula (C-2), R ³ is preferably an alkyl group having 1 to 8 carbon atoms or a cycloalkyl group having 4 to 15 carbon atoms, and an alkyl group having 1 to 4 carbon atoms or a carbon number. More preferably, it is a 4-10 cycloalkyl group.

  Examples of the compound represented by the general formula (C-1) include 1,2-octanedione, 1- [4- (phenylthio)-, 2- (O-benzoyloxime)] and the like. Examples of the compound represented by the general formula (C-2) include ethanone, 1- [9-ethyl-6- (2-methylbenzoyl) -9H-carbazol-3-yl]-, 1- (O-acetyl). Oxime) and the like. 1,2-octanedione, 1- [4- (phenylthio)-, 2- (O-benzoyloxime)] is available as IRGACURE OXE 01 (trade name, manufactured by BASF Corporation). Etanone, 1- [9-ethyl-6- (2-methylbenzoyl) -9H-carbazol-3-yl]-, 1- (O-acetyloxime) is IRGACURE OXE 02 (manufactured by BASF Corporation) (Commercial name) is commercially available. These are used alone or in combination of two or more.

  Of the above general formula (C-1), 1,2-octanedione, 1- [4- (phenylthio)-, 2- (O-benzoyloxime)] is particularly preferable. Among the above general formula (C-2), in particular, ethanone, 1- [9-ethyl-6- (2-methylbenzoyl) -9H-carbazol-3-yl]-, 1- (O-acetyloxime) is extremely preferable.

  As said phosphine oxide compound, the compound represented by the following general formula (C-3) and general formula (C-4) is mentioned. From the viewpoint of fast curability and transparency, a compound represented by the following general formula (C-3) is preferred.

In said general formula (C-3), R < ⁶ >, R < ⁷ > and R < ⁸ > show a C1-C20 alkyl group or aryl group each independently. In general formula (C-4), R <^9> , R < ¹⁰ > and R < ¹¹ > show a C1-C20 alkyl group or an aryl group each independently.

When R ⁶ , R ⁷ or R ⁸ in the general formula (C-3) is an alkyl group having 1 to 20 carbon atoms, and R ⁹ , R ¹⁰ or R ¹¹ in the general formula (C-4) are In the case of an alkyl group having 1 to 20 carbon atoms, the alkyl group may be linear, branched or cyclic. Moreover, it is more preferable that carbon number of this alkyl group is 5-10.

When R ⁶ , R ⁷ or R ⁸ in the general formula (C-3) is an aryl group, and when R ⁹ , R ¹⁰ or R ¹¹ in the general formula (C-4) is an aryl group, the aryl The group may have a substituent. Examples of the substituent include an alkyl group having 1 to 6 carbon atoms and an alkoxy group having 1 to 4 carbon atoms.

Among these, it is preferable that R < ⁶ >, R < ⁷ > and R < ⁸ > in the said general formula (C-3) are an aryl group. Moreover, it is preferable that R <^9> , R < ¹⁰ > and R < ¹¹ > in the said general formula (C-4) are an aryl group.

  As the compound represented by the general formula (C-3), 2,4,6-trimethylbenzoyl-diphenyl- is used because of the transparency of the protective film formed and the pattern forming ability when the film thickness is 10 μm or less. Phosphine oxide is preferred. 2,4,6-Trimethylbenzoyl-diphenyl-phosphine oxide is commercially available, for example, as LUCIRIN TPO (trade name, manufactured by BASF Corporation).

  The content of the photopolymerization initiator that is the component (C) is preferably 0.1 to 20 parts by mass with respect to 100 parts by mass of the total amount of the component (A) and the component (B), and 1 to 10 parts by mass. More preferably, it is 2-5 mass parts.

  By making the content of the component (C) within the above range, the photosensitivity becomes sufficient, and the absorption on the surface of the composition increases when irradiated with actinic rays, and the internal photocuring is insufficient. That is, it is possible to suppress problems such as a decrease in visible light transmittance.

  The photosensitive resin composition of this embodiment is at least one compound selected from the group consisting of a triazole compound, a thiadiazole compound, and a tetrazole compound (hereinafter referred to as (D)) from the viewpoint of achieving both rust prevention and developability. It is preferable to further contain a component).

  Examples of the triazole compound include triazole containing a mercapto group such as benzotriazole, 1H-benzotriazole-1-acetonitrile, benzotriazole-5-carboxylic acid, 1H-benzotriazole-1-methanol, carboxybenzotriazole, and 3-mercaptotriazole. Examples thereof include triazole compounds containing an amino group such as compounds and 3-amino-5-mercaptotriazole.

  Examples of the thiadiazole compound include 2-amino-5-mercapto-1,3,4-thiadiazole, 2,1,3-benzothiadiazole and the like.

  As said tetrazole compound, the compound represented by the following general formula (D-1) is mentioned.

R ¹¹ and R ¹² in the general formula (D-1) each independently represent hydrogen, an alkyl group having 1 to 20 carbon atoms, an amino group, a mercapto group, or a carboxymethyl group.

  Examples of the alkyl group include a methyl group, an ethyl group, and a propyl group.

  Specific examples of the tetrazole compound represented by the general formula (D-1) include, for example, 1H-tetrazole, 5-amino-1H-tetrazole, 5-methyl-1H-tetrazole, 1-methyl-5-ethyl- Examples include tetrazole, 1-methyl-5-mercapto-tetrazole, and 1-carboxymethyl-5-mercapto-tetrazole.

  As the component (D), a water-soluble salt of a tetrazole compound represented by the general formula (D-1) can be used. Specific examples include alkali metal salts of 1-carboxymethyl-5-mercapto-tetrazole such as sodium, potassium and lithium.

  Among these, (D) component includes 1H-tetrazole, 5-amino-1H-tetrazole, 1-methyl-, from the viewpoints of inhibiting the corrosion of electrodes, adhesion to metal electrodes, easy development, and transparency. 5-mercapto-1H-tetrazole is particularly preferred.

  These tetrazole compounds and water-soluble salts thereof may be used alone or in combination of two or more.

  Further, from the viewpoint of further improving the developability when the electrode surface on which the protective film is provided has a metal such as copper, silver, nickel, etc., the photosensitive resin composition is a tetrazole compound having an amino group among the above compounds. It is preferable to further contain. In this case, development residues can be reduced, and it becomes easy to form a protective film with a good pattern. The reason for this may be that the balance between the solubility in the developer and the adhesion between the metal and the metal is improved by blending the tetrazole compound having an amino group.

  When the tetrazole compound having an amino group is contained, the above effect can be obtained. Therefore, the photosensitive resin composition and the photosensitive element according to the present embodiment form a metal layer such as copper to improve conductivity. It is suitable for forming a protective film for protecting the electrode in the frame region of the touch panel.

  Content of (D) component in the photosensitive resin composition of this embodiment shall be 0.05-10.0 mass parts with respect to 100 mass parts of total amounts of (A) component and (B) component. Preferably, it is more preferable to set it as 0.1-2.0 mass parts, and it is still more preferable to set it as 0.2-1.0 mass part.

  (D) By making content of a component into the said range, the effect which improves the inhibitory force of electrode corrosion, and the adhesiveness with a metal electrode is fully suppressed, suppressing malfunction, such as a developability or a resolution. Can be obtained.

  In addition to the photosensitive resin composition of the present embodiment, if necessary, an adhesion imparting agent such as a silane coupling agent, a leveling agent, a plasticizer, a filler, an antifoaming agent, a flame retardant, a stabilizer, an oxidation agent. An inhibitor, a fragrance, a thermal crosslinking agent, a polymerization inhibitor and the like can be contained in an amount of about 0.01 to 20 parts by mass with respect to 100 parts by mass of the total amount of the component (A) and the component (B). These can be used alone or in combination of two or more.

  In the photosensitive resin composition of the present embodiment, the minimum value of visible light transmittance at 400 to 700 nm when a protective film is formed is preferably 90% or more, more preferably 92% or more, and 95 % Or more is more preferable.

Here, the visible light transmittance of the photosensitive resin composition is determined as follows.
First, the photosensitive resin composition layer (photosensitive layer) is formed by applying a coating solution containing the photosensitive resin composition on the support film so that the thickness after drying is 10 μm or less, and drying it. To do. Next, laminating is performed on the glass substrate so that the photosensitive layer is in contact. Thus, a measurement sample in which the photosensitive layer and the support film are laminated on the glass substrate is obtained. Next, after the photosensitive layer is photocured by irradiating the obtained measurement sample with ultraviolet rays, the obtained protective film (cured product of the photosensitive layer) is measured using a UV-visible spectrophotometer to measure the wavelength range 400. The transmittance at ˜700 nm is measured.

  When the minimum value of the transmittance in the wavelength range of 400 to 700 nm, which is a general visible light wavelength range, is 90% or more, for example, when protecting the transparent electrode in the sensing area of the touch panel (touch sensor), the touch panel (touch When the protective film is visible from the edge of the sensing area when the metal layer (for example, a layer in which a copper layer is formed on the ITO electrode) is protected, the image display quality in the sensing area, It can suppress sufficiently that a hue | tone or a brightness | luminance falls.

The photosensitive resin composition of the present embodiment preferably has a b ^* in the CIELAB color system of −0.2 to 1.0 from the viewpoint of further improving the visibility of the touch panel. It is more preferable that it is -0.7, and it is still more preferable that it is 0.1-0.5. Similarly to the case where the minimum value of the visible light transmittance is 90% or more, b ^* is −0.2 to 1.0 from the viewpoint of image display quality of the sensing area and prevention of deterioration of the hue. preferable. Note that b ^* in the CIELAB color system is, for example, a spectrophotometer “CM-5” manufactured by Konica Minolta, and a photosensitive resin composition layer having a thickness of 10 μm or less is formed on a glass substrate having a thickness of 0.7 mm. It is obtained by forming and irradiating ultraviolet rays to photo-cure the photosensitive resin composition layer, and then setting the D65 light source at a viewing angle of 2 ° for measurement.

  The photosensitive resin composition of the present invention can be used for forming a photosensitive layer on a substrate having a touch panel electrode. For example, a coating solution that can be obtained by uniformly dissolving or dispersing the photosensitive resin composition in a solvent is prepared, and a coating film is formed by coating on a substrate, and then the solvent is removed by drying. A layer can be formed.

  Solvents include ketones, aromatic hydrocarbons, alcohols, glycol ethers, glycol alkyl ethers, glycol alkyl ether acetates, esters, diethylene glycol, chloroform, and chloride from the standpoints of solubility of each component and ease of film formation. Methylene and the like can be used. These solvents may be used alone or as a mixed solvent composed of two or more solvents.

  Among the above solvents, it is preferable to use ethylene glycol monobutyl ether acetate, diethylene glycol monoethyl ether acetate, diethylene glycol diethyl ether, diethylene glycol ethyl methyl ether, diethylene glycol dimethyl ether, propylene glycol monomethyl ether, propylene glycol monomethyl ether acetate and the like.

  The photosensitive resin composition of the present embodiment is preferably used by forming a film on a photosensitive film like the photosensitive element 1 of the present embodiment. Laminating the photosensitive film on the base material 100 having the tapping panel electrode makes it possible to easily realize a roll-to-roll process, shorten the solvent drying process, etc., and greatly contribute to the shortening of the manufacturing process and cost reduction. Can do.

  The photosensitive layer 20 of the photosensitive element 1 can be formed by preparing a coating solution containing the photosensitive resin composition of the present embodiment, and applying and drying the coating solution on the support film 10. The coating solution can be obtained by uniformly dissolving or dispersing each component constituting the photosensitive resin composition of the present embodiment described above in a solvent.

  The solvent is not particularly limited and known ones can be used. For example, acetone, methyl ethyl ketone, methyl isobutyl ketone, toluene, methanol, ethanol, propanol, butanol, methylene glycol, ethylene glycol, propylene glycol, ethylene glycol monomethyl ether, Examples include ethylene glycol monoethyl ether, diethylene glycol dimethyl ether, diethylene glycol ethyl methyl ether, diethylene glycol diethyl ether, propylene glycol monomethyl ether, ethylene glycol monobutyl ether acetate, diethylene glycol monoethyl ether acetate, propylene glycol monomethyl ether acetate, chloroform and methylene chloride. These solvents may be used alone or as a mixed solvent composed of two or more solvents.

  Application methods include, for example, doctor blade coating method, Meyer bar coating method, roll coating method, screen coating method, spinner coating method, inkjet coating method, spray coating method, dip coating method, gravure coating method, curtain coating method, die coating Examples thereof include a coating method.

  Although there is no restriction | limiting in particular in drying conditions, It is preferable that drying temperature shall be 60-130 degreeC, and it is preferable that drying time shall be 30 second-30 minutes.

  The thickness of the photosensitive layer 20 exhibits an effect such as rust prevention sufficient to protect the substrate, electrodes, etc., and the step on the touch panel (touch sensor) surface generated by partial protection film formation is minimized. The thickness after drying is preferably 1 μm or more and 10 μm or less, more preferably 1 μm or more and 9 μm or less, further preferably 1 μm or more and 8 μm or less, further preferably 2 μm or more and 8 μm or less, and further preferably 3 μm or more. Particularly preferably, it is 8 μm or less.

In the present embodiment, the minimum value of the visible light transmittance of the photosensitive layer 20 is preferably 90% or more, more preferably 92% or more, and further preferably 95% or more. The photosensitive layer 20 is preferably adjusted so that b ^* in the CIELAB color system is −0.2 to 1.0, more preferably 0.0 to 0.7, and More preferably, it is 1-0.5.

  The viscosity of the photosensitive layer 20 is such that when the photosensitive element 1 is rolled, it prevents the photosensitive resin composition from exuding from the end face of the photosensitive element 1 for more than one month and cuts the photosensitive element 1. It is preferably 15 to 100 mPa · s at 30 ° C. from the viewpoint of preventing exposure failure and residual development when irradiated with actinic rays caused by the fragments of the photosensitive resin composition adhering to the substrate. More preferably, it is 20-90 mPa * s, and it is still more preferable that it is 25-80 mPa * s.

The viscosity is 1.96 × at 30 ° C. and 80 ° C. in the thickness direction of this sample using a circular film of 7 mm in diameter and 2 mm in thickness formed from the photosensitive resin composition as a measurement sample. It is a value obtained by measuring the rate of change of thickness when a load of 10 ⁻² N is applied, and converting it to viscosity from the rate of change assuming a Newtonian fluid.

  A polymer film can be used as the protective film 30 (cover film). Examples of the polymer film include polyethylene, polypropylene, polyethylene terephthalate, polycarbonate, polyethylene-vinyl acetate copolymer, and a film made of a laminated film of polyethylene-vinyl acetate copolymer and polyethylene.

  The thickness of the protective film 30 is preferably about 5 to 100 μm, but from the viewpoint of storing it in a roll shape, it is preferably 70 μm or less, more preferably 60 μm or less, and further preferably 50 μm or less. It is preferably 40 μm or less.

  The photosensitive element 1 can be stored in a roll or stored.

In the present invention, the above-mentioned photosensitive resin composition of the present embodiment and a coating solution containing a solvent are applied onto a substrate having a touch panel electrode, dried, and then a photosensitive layer comprising the photosensitive resin composition. 20 may be provided. Even in this application, the photosensitive layer preferably satisfies the above-mentioned conditions of film thickness, visible light transmittance, and b ^* in the CIELAB color system.

  Next, the manufacturing method of the base material for touchscreens with a protective film which concerns on this invention is demonstrated. FIG. 2 is a schematic cross-sectional view for explaining one embodiment of the method for producing a base material for a touch panel with a protective film of the present invention.

  The manufacturing method of the base material for touchscreens with this embodiment of the protective film WHEREIN: On the base material 100 for touchscreens which has the electrodes 110 and 120 for touchscreens, the photosensitive layer 20 which consists of the photosensitive resin composition which concerns on this embodiment above-mentioned. A first step to be provided; a second step in which a predetermined portion of the photosensitive layer 20 is cured by irradiation with actinic rays; and a portion other than the predetermined portion of the photosensitive layer 20 after irradiation with actinic rays (a portion of the photosensitive layer that is not irradiated with actinic rays) And a third step of forming a protective film 22 made of a cured product of a predetermined portion of the photosensitive layer that covers part or all of the electrode. In this way, the base material for touchscreens with a protective film is obtained. The base material for touchscreens with a protective film obtained can be used for the touchscreen provided with the base material for touchscreens with a protective film, and the touchscreen 200 with the protective film 22 which is a touch input sheet.

  As the base material 100 for touch panels used by this embodiment, substrates, such as a glass plate, a plastic plate, a ceramic plate, generally used for touch panel (touch sensor) are mentioned. On this substrate, a touch panel electrode to be a target for forming a protective film is provided. Examples of the electrode include electrodes such as ITO, Cu, Al, and Mo, and TFT. An insulating layer may be provided on the substrate between the substrate and the electrode.

  The base material 100 for touch panels which has the electrodes 110 and 120 for touch panels shown by FIG. 2 can be obtained in the following procedures, for example. After forming a metal film by sputtering in the order of ITO and Cu on the touch panel substrate 100 such as a PET film, an etching photosensitive film is pasted on the metal film to form a desired resist pattern, which is unnecessary. After removing Cu with an etching solution such as an aqueous iron chloride solution, the resist pattern is peeled off.

  In the first step of the present embodiment, after removing the protective film 30 of the photosensitive element 1 of the present embodiment, the touch panel electrodes 110 and 120 of the substrate 100 are provided while the photosensitive element 1 is heated. The photosensitive layer 20 is transferred onto the surface by pressure bonding and laminated (see FIG. 2A).

  Examples of the pressing means include a pressing roll. The pressure roll may be provided with a heating means so that it can be heat-pressure bonded.

  The heating temperature in the case of thermocompression bonding is the configuration of the photosensitive layer 20 while ensuring sufficient adhesion between the photosensitive layer 20 and the touch panel substrate 100 and adhesion between the photosensitive layer 20 and the touch panel electrodes 110 and 120. The temperature is preferably from 10 to 180 ° C, more preferably from 20 to 160 ° C, and even more preferably from 30 to 150 ° C so that the components are not easily cured or thermally decomposed.

In addition, the pressure at the time of thermocompression bonding is 50 to 1 × 10 ⁵ N / m in terms of linear pressure from the viewpoint of suppressing deformation of the base material 100 while ensuring sufficient adhesion between the photosensitive layer 20 and the base material 100. It is preferable to set it as 2.5 * 10 < ² > -5 * 10 < ⁴ > N / m, and it is still more preferable to set it as 5 * 10 < ² > -4 * 10 < ⁴ > N / m.

  If the photosensitive element 1 is heated as described above, it is not necessary to pre-heat the base material, but the base material 100 is pre-heat-treated in order to further improve the adhesion between the photosensitive layer 20 and the base material 100. It is preferable to do. The preheating temperature at this time is preferably 30 to 180 ° C.

  In this embodiment, instead of using the photosensitive element 1, the coating liquid containing the photosensitive resin composition and the solvent of the present embodiment is prepared, and the touch panel electrodes 110 and 120 of the substrate 100 are provided. The photosensitive layer 20 can be formed by coating on the surface and drying.

The photosensitive layer 20 preferably satisfies the above-described conditions of film thickness, visible light transmittance, and b ^* in the CIELAB color system.

  In the second step of this embodiment, a predetermined portion of the photosensitive layer 20 is irradiated with an actinic ray L in a pattern via a photomask 130 (see FIG. 2B).

  When irradiating actinic light, if the support film 10 on the photosensitive layer 20 is transparent, it can be irradiated with actinic light as it is. From the viewpoint of protecting the photosensitive layer 20, it is preferable to use a transparent polymer film as the support film 10 and to irradiate actinic rays through the polymer film with the polymer film remaining.

  As the light source used for irradiation with the actinic ray L, a known actinic light source can be used, and examples thereof include a carbon arc lamp, an ultra-high pressure mercury lamp, a high-pressure mercury lamp, and a xenon lamp. Not limited.

The irradiation amount of the actinic ray L at this time is usually 1 × 10 ² to 1 × 10 ⁴ J / m ² , and heating can be accompanied during irradiation. If the irradiation amount of actinic rays is less than 1 × 10 ² J / m ² , the effect of photocuring tends to be insufficient, and if it exceeds 1 × 10 ⁴ J / m ² , the photosensitive layer 20 tends to discolor. There is.

  In the third step of this embodiment, the photosensitive layer 20 after irradiation with actinic rays is developed with a developer to remove portions that are not irradiated with actinic rays (that is, other than predetermined portions of the photosensitive layer), A protective film 22 made of a cured product of a predetermined portion of the photosensitive layer of this embodiment that covers a part or the whole is formed (see FIG. 2C). The formed protective film 22 can have a predetermined pattern.

  When the support film 10 is laminated on the photosensitive layer 20 after irradiation with actinic rays, the support film 10 is removed, and then development for removing a portion not irradiated with actinic rays with a developer is performed.

  As a developing method, using a known developer such as an alkaline aqueous solution, an aqueous developer, an organic solvent, etc., development is performed by a known method such as spraying, showering, rocking immersion, brushing, scraping, etc., and unnecessary portions are removed. Among them, it is preferable to use an alkaline aqueous solution from the viewpoint of environment and safety.

  Among the alkaline aqueous solutions, an aqueous solution of sodium carbonate is preferable. For example, a dilute solution of sodium carbonate (0.5 to 5% by mass aqueous solution) at 20 to 50 ° C. is preferably used.

  The development temperature and time can be adjusted according to the developability of the photosensitive resin composition of the present embodiment.

  In addition, a surfactant, an antifoaming agent, a small amount of an organic solvent for promoting development, and the like can be mixed in the alkaline aqueous solution.

  Further, the base of the alkaline aqueous solution remaining in the photosensitive layer 20 after development and photocuring is used by known methods such as spraying, rocking immersion, brushing, and scraping using an organic acid, an inorganic acid, or an acid aqueous solution thereof. Acid treatment (neutralization treatment) can be performed.

  Furthermore, the water washing process can also be performed after an acid treatment (neutralization treatment).

After development, the cured product may be further cured by irradiation with actinic rays (for example, 5 × 10 ³ to 2 × 10 ⁴ J / m ² ) as necessary. The photosensitive resin composition of the present embodiment exhibits excellent adhesion to a metal without a heating step after development, but if necessary, instead of irradiation with actinic light after development or an active A heat treatment (80 to 250 ° C.) may be performed in combination with the irradiation of light.

  As described above, the photosensitive resin composition and the photosensitive element of the present embodiment are suitable for use for forming a protective film on a touch panel substrate. About the said use of the photosensitive resin composition, a protective film can be formed using the coating liquid mixed with the solvent.

  Moreover, this invention can provide the formation material of the protective film of the base material for touchscreens which is the hardened | cured material of the photosensitive layer which consists of the photosensitive resin composition which concerns on this invention. The protective film-forming material for the electrode for a touch panel can contain the photosensitive resin composition of the present embodiment described above, and is preferably a coating solution containing the solvent described above.

  Next, with reference to FIGS. 3, 4, and 5, an example of a place where the protective film according to the present invention is used will be described. FIG. 3 is a schematic top view illustrating an example of a capacitive touch panel. The touch panel shown in FIG. 3 has a touch screen 102 for detecting touch position coordinates on one surface of the transparent substrate 101, and the transparent electrode 103 and the transparent electrode 104 for detecting a change in capacitance in this region are the substrate 101. It is provided above. The transparent electrode 103 and the transparent electrode 104 detect a change in electrostatic capacitance at the touch position, respectively, and set it as an X position coordinate and a Y position coordinate.

  On the transparent substrate 101, a lead-out wiring 105 for transmitting a touch position detection signal from the transparent electrode 103 and the transparent electrode 104 to an external circuit is provided. The lead-out wiring 105 is connected to the transparent electrode 103 and the transparent electrode 104 by a connection electrode 106 provided on the transparent electrode 103 and the transparent electrode 104. A connection terminal 107 for connecting to an external circuit is provided at the end of the lead-out wiring 105 opposite to the connection portion between the transparent electrode 103 and the transparent electrode 104. The photosensitive resin composition of this embodiment can be suitably used for forming the protective film 122 for the lead wiring 105, the connection electrode 106, and the connection terminal 107. At this time, the electrodes in the sensing area (touch screen 102) can be protected at the same time. In FIG. 3, the lead-out wiring 105, the connection electrode 106, a part of the sensing region electrode, and a part of the connection terminal 107 are protected by the protective film 122. For example, as shown in FIG. 4, a protective film 123 may be provided so as to protect the entire touch screen 102.

  With reference to FIG. 5, a cross-sectional structure of a connection portion between the transparent electrode and the lead-out wiring in the touch panel shown in FIG. 3 will be described. FIG. 5 is a partial cross-sectional view taken along the line VV of the portion C shown in FIG. 3 and is a diagram for explaining a connection portion between the transparent electrode 104 and the lead-out wiring 105. As shown in FIG. 5A, the transparent electrode 104 and the lead wiring 105 are electrically connected via the connection electrode 106. As shown in FIG. 5A, a part of the transparent electrode 104 and all of the lead-out wiring 105 and the connection electrode 106 are covered with a protective film 122. Similarly, the transparent electrode 103 and the lead wiring 105 are electrically connected via the connection electrode 106. As shown in FIG. 5B, the transparent electrode 104 and the lead-out wiring 105 may be directly electrically connected. The photosensitive resin composition and photosensitive element of this embodiment are suitable for use for forming a protective film for the above-mentioned structural portion.

  A method for manufacturing a touch panel according to the present embodiment will be described. First, the transparent electrode (X position coordinate) 103 is formed on the transparent electrode 101 provided on the substrate 100. Subsequently, a transparent electrode (Y position coordinate) 104 is formed through an insulating layer (not shown). The transparent electrode 103 and the transparent electrode 104 can be formed by a method of etching a transparent electrode layer formed on the transparent substrate 100.

  Next, on the surface of the transparent substrate 101, a lead-out wiring 105 for connecting to an external circuit and a connection electrode 106 for connecting the lead-out wiring with the transparent electrode 103 and the transparent electrode 104 are formed. The lead-out wiring 105 and the connection electrode 106 may be formed after the transparent electrode 103 and the transparent electrode 104 are formed, or may be formed at the same time as each transparent electrode is formed. The lead-out wiring 105 and the connection electrode 106 can be formed using an etching method or the like after metal sputtering. The lead-out wiring 105 can be formed at the same time as the connection electrode 106 is formed by screen printing using a conductive paste material containing flaky silver, for example. Next, a connection terminal 107 for connecting the lead wiring 105 and an external circuit is formed.

  The photosensitive element 1 according to this embodiment is pressure-bonded so as to cover the transparent electrode 103 and the transparent electrode 104, the lead-out wiring 105, the connection electrode 106, and the connection terminal 107 formed by the above-described process, and the photosensitive element 1 is exposed on the electrode. Layer 20 is provided. Next, the actinic ray L is irradiated to the transferred photosensitive layer 20 in a desired shape through a photomask. After irradiating the actinic ray L, development is performed to remove portions other than the predetermined portion of the photosensitive layer 20, thereby forming a protective film 122 made of a cured product of the predetermined portion of the photosensitive layer 20. In this manner, a touch panel including the protective film 122, that is, a touch panel including the touch panel base material (transparent substrate 101) with the protective film 122 can be manufactured.

  Next, the use place of the protective film according to the present invention will be described with reference to FIGS. The protective film of the present invention can be suitably used, for example, as the protective film (insulating film) 124 in FIGS.

  FIG. 6 is a plan view showing an example of a capacitive touch panel in which the transparent electrode (X position coordinates) 103 and the transparent electrode (Y position coordinates) 104 exist on the same plane, and FIG. FIG. FIG. 8 is a partial cross-sectional view taken along line VI-VI in FIG. The capacitive touch panel includes a transparent electrode 103 that detects a change in capacitance and uses X position coordinates, and a transparent electrode 104 uses Y position coordinates on a transparent substrate 101. Each of the transparent electrode 103 and the transparent electrode 104 having the X and Y position coordinates has a lead-out wiring 105a and a lead-out connected to a control circuit of a driver element circuit (not shown) for controlling an electric signal as a touch panel. A wiring 105b is provided.

  An insulating film 124 is provided at a portion where the transparent electrode (X position coordinate) 103 and the transparent electrode (Y position coordinate) 104 intersect.

  A method of manufacturing a capacitive touch panel in which the transparent electrode (X position coordinates) 103 and the transparent electrode (Y position coordinates) 104 are present on the same plane will be described.

  A method for manufacturing a capacitive touch panel is, for example, a known method using a transparent conductive material, and a part of a transparent electrode that becomes a transparent electrode (X position coordinate) 103 and a transparent electrode 104 that later detects a Y position coordinate. Alternatively, a substrate formed in advance on the transparent substrate 101 may be used. FIG. 9 is a diagram for explaining an example of a method for manufacturing a capacitive touch panel in which transparent electrodes are present on the same plane, and (a) is a partially cutaway perspective view showing a substrate provided with transparent electrodes. (B) is a partially cutaway perspective view showing the obtained capacitive touch panel. FIG. 10 is a diagram for explaining an example of a method for manufacturing a capacitive touch panel in which transparent electrodes exist on the same plane.

  First, as shown in FIG. 9A and FIG. 10A, a substrate on which a transparent electrode (X position coordinate) 103 and a part 104a of the transparent electrode are formed in advance is prepared. An insulating film 124 is provided on a part (a part sandwiched by a part 104a of the transparent electrode) ((b) of FIG. 10). Thereafter, a conductive pattern is formed by a known method. With this conductive pattern, the bridge portion 104b of the transparent electrode can be formed (FIG. 10C). By this transparent electrode bridge portion 104 b, a part of the transparent electrodes 104 a formed in advance can be connected to each other, and a transparent electrode (Y position coordinate) 104 is formed.

  The previously formed transparent electrode may be formed by, for example, a known method using ITO or the like. The lead-out wirings 105a and 105b can be formed by a known method using a metal such as Cu or Ag in addition to the transparent conductive material. Further, a substrate on which the lead wirings 105a and 105b are formed in advance may be used.

  Hereinafter, the present invention will be described more specifically with reference to examples. However, the present invention is not limited to the following examples.

[Preparation of binder polymer solution (A1)]
A flask equipped with a stirrer, a reflux condenser, an inert gas inlet and a thermometer was charged with (1) shown in Table 1, heated to 80 ° C. in a nitrogen gas atmosphere, and the reaction temperature was 80 ° C. ± 2 While maintaining the temperature, (2) shown in Table 1 was added dropwise uniformly over 4 hours. After the dropwise addition of (2), stirring is continued at 80 ° C. ± 2 ° C. for 6 hours. A binder having a constitutional unit derived from (meth) acrylic acid of 12% by mass, a weight average molecular weight of about 65,000 and an acid value of 78 mgKOH / g. A polymer solution (solid content: 45% by mass) (A1) was obtained.

[Preparation of binder polymer solution (A2)]
As in (A1) above, a solution of a binder polymer having a structural unit derived from (meth) acrylic acid of 17.5% by mass, a weight average molecular weight of about 80,000, and an acid value of 115 mgKOH / g (solid content: 45% by mass) ) (A2) was obtained.

[Preparation of binder polymer solution (A3)]
In the same manner as in the above (A1), a binder polymer solution (solid content: 45% by mass) having a structural unit derived from (meth) acrylic acid of 24% by mass, a weight average molecular weight of about 35,000 and an acid value of 156 mgKOH / g ( A3) was obtained.

[Preparation of binder polymer solution (A4)]
In the same manner as (A1) above, a solution of a binder polymer having a structural unit derived from (meth) acrylic acid of 30% by mass, a weight average molecular weight of about 45,000 and an acid value of 195 mgKOH / g (solid content: 45% by mass) ( A4) was obtained.

[Preparation of binder polymer solution (A5)]
In the same manner as in the above (A1), a binder polymer solution (solid content: 45% by mass) having a structural unit derived from (meth) acrylic acid of 24% by mass, a weight average molecular weight of about 45,000 and an acid value of 155 mgKOH / g ( A5) was obtained.

The weight average molecular weight (Mw) was measured by gel permeation chromatography (GPC), and was derived by conversion using a standard polystyrene calibration curve. The GPC conditions are shown below.
GPC conditions Pump: Hitachi L-6000 type (manufactured by Hitachi, Ltd., product name)
Column: Gelpack GL-R420, Gelpack GL-R430, Gelpack GL-R440 (above, manufactured by Hitachi Chemical Co., Ltd., product name)
Eluent: Tetrahydrofuran Measurement temperature: 40 ° C
Sample concentration: 120 mg of NV (non-volatile content) 50% by mass resin solution was collected and dissolved in 5 mL of THF Injection amount: 200 μL
Pressure: 4.9 MPa
Flow rate: 2.05 mL / min Detector: Hitachi L-3300 type RI (manufactured by Hitachi, Ltd., product name)

[Measurement method of acid value]
The acid value was measured as follows. First, the binder polymer solution was heated at 130 ° C. for 1 hour to remove volatile components to obtain a solid content. Then, after precisely weighing 1.0 g of the polymer whose acid value is to be measured, the precisely weighed polymer was put in an Erlenmeyer flask, 30 g of acetone was added to this polymer, and this was uniformly dissolved. Next, an appropriate amount of an indicator, phenolphthalein, was added to the solution, and titration was performed using a 0.1N aqueous KOH solution. And the acid value was calculated | required by calculating mg number of KOH required in order to neutralize the acetone solution of a binder polymer.

Example 1
[Preparation of Coating Solution (V-1) Containing Photosensitive Resin Composition]
The materials shown in Table 2 were mixed for 15 minutes using a stirrer to prepare a coating liquid (V-1) containing a photosensitive resin composition for forming a protective film.

[Production of Photosensitive Element (E-1)]
Using a polyethylene terephthalate film having a thickness of 50 μm as the support film, the coating solution (V-1) containing the photosensitive resin composition and the solvent prepared above was uniformly applied on the support film using a comma coater, The solvent was removed by drying with a hot air convection dryer at 100 ° C. for 3 minutes to form a photosensitive layer (photosensitive resin composition layer) made of the photosensitive resin composition. The resulting photosensitive layer had a thickness of 5 μm.

  Next, a polyethylene film having a thickness of 25 μm was further laminated as a cover film on the obtained photosensitive layer to produce a photosensitive element (E-1).

[Measurement of transmittance of protective film]
Laminator (manufactured by Hitachi Chemical Co., Ltd., trade name HLM-3000) so that the photosensitive layer is in contact with a 1 mm thick glass substrate while peeling the polyethylene film which is the cover film of the obtained photosensitive element (E-1). A roll temperature of 120 ° C., a substrate feed rate of 1 m / min, and a pressure bonding pressure (cylinder pressure) of 4 × 10 ⁵ Pa (thickness of 1 mm, length of 10 cm × width of 10 cm). The laminate was laminated under the condition of a pressure of 9.8 × 10 ³ N / m), and a photosensitive layer and a support film were laminated on a glass substrate.

Next, a parallel light exposure machine (EXM1201 manufactured by Oak Manufacturing Co., Ltd.) is used for the photosensitive layer of the obtained laminate, and the exposure amount is 5 × 10 ² J / m ² from the upper side of the photosensitive layer (i line). (Measurement value at a wavelength of 365 nm) After irradiation with ultraviolet rays, the support film was removed to obtain a transmittance measurement sample having a protective film made of a cured film of a photosensitive layer having a thickness of 5.0 μm.

  Next, the minimum value of the visible light transmittance was measured for the obtained sample using a UV-visible spectrophotometer (U-3310) manufactured by Hitachi, Ltd. in a measurement wavelength range of 400 to 700 nm. The transmittance of the obtained protective film at a wavelength of 400 nm is 97% at a wavelength of 700 nm, 96% at a wavelength of 550 nm, and 94% at a wavelength of 400 nm, and the minimum value of the transmittance at 400 to 700 nm is 94%. The transmittance was secured.

[Measurement of b ^* of protective film]
Laminator (manufactured by Hitachi Chemical Co., Ltd., trade name: HLM-) so that the photosensitive layer is in contact with a 0.7 mm-thick glass substrate while peeling the cover film polyethylene film of the obtained photosensitive element (E-1) 3000 type), a roll temperature of 120 ° C., a substrate feed speed of 1 m / min, a pressure bonding pressure (cylinder pressure) of 4 × 10 ⁵ Pa (thickness of 1 mm, length of 10 cm × width of 10 cm) was used. The substrate was laminated under the condition of a linear pressure of 9.8 × 10 ³ N / m) to prepare a substrate in which a photosensitive layer and a support film were laminated on a glass substrate.

Next, the obtained photosensitive layer was subjected to an exposure amount of 5 × 10 ² J / m ² (i-line (wavelength 365 nm) from the upper side of the photosensitive layer side using a parallel light exposure machine (EXM1201 manufactured by Oak Manufacturing Co., Ltd.). )), After irradiating with ultraviolet rays, the support film is removed and further irradiated with ultraviolet rays (measured value at i-line (wavelength 365 nm)) with an exposure amount of 1 × 10 ⁴ J / m ² from above the photosensitive layer side. Thus, a b ^* measurement sample having a protective film made of a cured film of a photosensitive layer having a thickness of 5.0 μm was obtained.

Next, b ^* in the CIELAB color system was measured for the obtained sample using a spectrocolorimeter (CM-5) manufactured by Konica Minolta Co., Ltd. with a light source setting of D65 and a viewing angle of 2 °.

The b ^* of the protective film was 0.44, and it was confirmed that the protective film had a good b ^* .

[Salt spray test of protective film (artificial sweat resistance evaluation test)]
Laminator (Hitachi Chemical Co., Ltd.) so that the photosensitive layer is in contact with a polyimide film with sputtered copper (manufactured by Toray Film Processing Co., Ltd.) while peeling off the polyethylene film which is the cover film of the obtained photosensitive element (E-1). Using a company-made product name: HLM-3000 type, a roll temperature of 120 ° C., a substrate feed rate of 1 m / min, and a pressure (cylinder pressure) of 4 × 10 ⁵ Pa (thickness of 1 mm, length 10 cm × width 10 cm) Since the substrate was used, lamination was performed under the condition that the linear pressure at this time was 9.8 × 10 ³ N / m), and a laminate in which the photosensitive layer and the support film were laminated on the sputtered copper was produced.

Next, a parallel light exposure machine (EXM1201 manufactured by Oak Manufacturing Co., Ltd.) is used for the photosensitive layer of the obtained laminate, and the exposure amount is 5 × 10 ² J / m ² from the upper side of the photosensitive layer (i line). (Measured value at wavelength 365 nm), after irradiating with ultraviolet rays, the support film is removed, and further at an exposure amount of 1 × 10 ⁴ J / m ² from above the photosensitive layer side (measured value at i-line (wavelength 365 nm)) And a sample for evaluation of artificial sweat resistance having a protective film made of a cured film of a photosensitive layer having a thickness of 5.0 μm was obtained.

Next, referring to the JIS standard (Z 2371), using the salt spray tester (STP-90V2 manufactured by Suga Test Instruments Co., Ltd.), the above-described sample was placed in the test tank, and the salt water having a concentration of 50 g / L. (PH = 6.7) was sprayed for 48 hours at a test bath temperature of 35 ° C. and a spray amount of 1.5 mL / h. After spraying, the salt water was wiped off, the surface state of the sample for evaluation was observed, and evaluation was performed according to the following scores.
A: No change on the surface of the protective film.
B: Slight traces are visible on the surface of the protective film, but copper remains unchanged.
C: Traces are visible on the surface of the protective film, but copper is unchanged.
D: There is a trace on the surface of the protective film, and copper is discolored.
When the surface state of the sample for evaluation was observed, a very slight trace was seen on the surface of the protective film, but copper was unchanged and the evaluation was B.

[Development residue test of photosensitive layer]
Laminator (manufactured by Hitachi Chemical Co., Ltd., trade name) so that the photosensitive layer is in contact with the polyimide film with sputtered copper (manufactured by Toray Film Processing Co., Ltd.) while peeling off the polyethylene film which is the cover film of the obtained photosensitive element. HLM-3000 type), a roll temperature of 120 ° C., a substrate feed rate of 1 m / min, a pressure bonding pressure (cylinder pressure) of 4 × 10 ⁵ Pa (thickness of 1 mm, length of 10 cm × width of 10 cm) was used. The laminate was laminated with the photosensitive layer and the support film laminated on the sputtered copper under the condition that the linear pressure at that time was 9.8 × 10 ³ N / m).

After the laminate obtained above was prepared, it was stored for 24 hours at 23 ° C. and 60%, and then the actinic ray transmitting portion and the actinic ray shielding portion were alternately patterned, and a photo with a line / space of 300 μm / 300 μm. Using a mask, a photomask is placed on a support film, and using a parallel light exposure machine (EXM1201 manufactured by Oak Manufacturing Co., Ltd.), the exposure amount is 5 × 10 ² J / m ² from above the photomask surface. (Measured value at i-line (wavelength 365 nm)), ultraviolet rays were imagewise irradiated.

Next, the support film laminated on the photosensitive layer is removed, and spray development is performed at 30 ° C. for 40 seconds using a 1.0% by mass aqueous sodium carbonate solution, and the photosensitive layer is selectively removed to form a pattern. A protective film was obtained. The substrate surface state of the portion of the obtained substrate with the protective film where the photosensitive layer was selectively removed was observed with a microscope, and the development residue was evaluated according to the following ratings.
A: No change on the substrate surface.
B: Copper on the substrate surface is slightly discolored, but there is no development residue.
C: Copper on the surface of the substrate is slightly discolored, and a development residue is slightly generated.
D: Development residue is generated.
When the surface state of the sample for evaluation was observed, the copper on the surface of the substrate was slightly discolored, a slight amount of development residue was generated, and the evaluation was C.

[Crosscut adhesion test of protective film]
Laminator (manufactured by Hitachi Chemical Co., Ltd., trade name) so that the photosensitive layer is in contact with the polyimide film with sputtered copper (manufactured by Toray Film Processing Co., Ltd.) while peeling off the polyethylene film which is the cover film of the obtained photosensitive element. : HLM-3000 type), a roll temperature of 120 ° C., a substrate feed speed of 1 m / min, a pressure bonding pressure (cylinder pressure) of 4 × 10 ⁵ Pa (thickness 1 mm, length 10 cm × width 10 cm), The linear pressure at this time was laminated under the condition of 9.8 × 10 ³ N / m) to produce a laminate in which the photosensitive layer and the support film were laminated on the sputtered copper.

Next, a parallel light exposure machine (EXM1201 manufactured by Oak Manufacturing Co., Ltd.) is used for the photosensitive layer of the obtained laminate, and the exposure amount is 5 × 10 ² J / m ² from the upper side of the photosensitive layer (i line). (Measured value at wavelength 365 nm), after irradiating with ultraviolet rays, the support film is removed, and further at an exposure amount of 1 × 10 ⁴ J / m ² from above the photosensitive layer side (measured value at i-line (wavelength 365 nm)) And a cross-cut adhesion test sample having a protective film made of a cured film of a photosensitive layer having a thickness of 5.0 μm was obtained.

Next, a cross cut test of 100 squares was performed with reference to JIS standard (K5400). Using a cutter knife on the test surface, make a 1 x 1 mm square cut on the grid, and firmly press Mending Tape # 810 (manufactured by 3M Co., Ltd.) on the grid, so that the end of the tape is approximately 0 °. After slowly peeling off at an angle, the cross-cut state was observed, and cross-cut adhesion was evaluated according to the following score.
A: Almost 100% of the entire area is in close contact.
B: 95% or more and less than 100% of the entire area remains adhered.
B to C: 85% or more and less than 95% of the total area remains adhered.
C: 65% or more and less than 85% of the total area remains adhered.
C to D: 35% or more and less than 65% of the total area remains adhered.
D: 0% or more and less than 35% of the total area remains adhered.
When the cross section of the evaluation sample was observed, 95% or more of the total area remained adhered to the sputtered copper, and the evaluation was B.

(Examples 2 to 12)
A photosensitive element was prepared in the same manner as in Example 1 except that the photosensitive resin composition shown in Tables 3 and 4 (the unit of numerical values in the table is part by mass) and a solution containing a solvent were used. Measurement, salt spray test, development residue test, and cross-cut adhesion test were performed. As shown in Table 5, in Examples 1 to 12, all of the measurements of transmittance, salt spray resistance evaluation, and cross-cut adhesion were good results.

(Comparative Examples 1-8)
A photosensitive element was prepared in the same manner as in Example 1 except that the photosensitive resin composition shown in Tables 6 and 7 (the unit of numerical values in the table is part by mass) and a solution containing a solvent were used. Measurement, b ^* measurement, salt spray test, development residue test, and cross-cut adhesion test were performed.

  As shown in Table 8, in Comparative Examples 1 and 2 using the binder polymers (A3) and (A4), the salt spray resistance (artificial sweat resistance) was inferior. In addition, as photopolymerizable compounds, ethoxylated bisphenol A dimethacrylate (BPE-500, manufactured by Shin-Nakamura Chemical Co., Ltd.), polyethylene glycol # 400 dimethacrylate (9G, manufactured by Shin-Nakamura Chemical Co., Ltd.), urethane diacrylate In Comparative Examples 3 to 6 using (UA-11, Shin-Nakamura Chemical Co., Ltd.), the salt spray resistance was inferior.

The symbol of the component in Table 2-Table 4, Table 6, and Table 7 shows the following meaning.
(A) Component (A1): Propylene glycol monomethyl ether / toluene solution of copolymer having a monomer blending ratio (methacrylic acid / methyl methacrylate / ethyl acrylate = 12/58/30 (mass ratio)), weight average molecular weight 65,000, acid value 78mgKOH / g
(A2): monomer blending ratio (methacrylic acid / methyl methacrylate / ethyl acrylate = 17.5 / 52.5 / 30 (mass ratio)) in a propylene glycol monomethyl ether / toluene solution of a copolymer, weight average molecular weight 80,000, acid value 115mgKOH / g
Other binder polymer (A3): propylene of a copolymer having a monomer blending ratio (methacrylic acid / methyl methacrylate / butyl acrylate / butyl methacrylate = 24 / 43.5 / 15 / 17.5 (mass ratio)) Glycol monomethyl ether / toluene solution, weight average molecular weight 35,000, acid value 156 mgKOH / g
(A4): a monomer blending ratio (methacrylic acid / methyl methacrylate / butyl methacrylate = 30/35/35 (mass ratio)) in a propylene glycol monomethyl ether / toluene solution of a copolymer, a weight average molecular weight of 45,000, Acid value 195mgKOH / g
(A5): Propylene glycol monomethyl ether / toluene solution of a copolymer having a monomer blending ratio (methacrylic acid / methyl methacrylate / ethyl acrylate = 24/46/30 (mass ratio)), weight average molecular weight 45,000, Acid value 155mgKOH / g

(B) Component A-TMMT: Pentaerythritol tetraacrylate (manufactured by Shin-Nakamura Chemical Co., Ltd.)
TMPTA: Trimethylolpropane triacrylate (manufactured by Nippon Kayaku Co., Ltd.)
RP-1040: EO-modified pentaerythritol tetraacrylate (manufactured by Nippon Kayaku Co., Ltd.)
DPHA: Dipentaerythritol hexaacrylate (Nippon Kayaku Co., Ltd.)
Other photopolymerizable compound BPE-500: ethoxylated bisphenol A dimethacrylate (manufactured by Shin-Nakamura Chemical Co., Ltd.)
9G: Polyethylene glycol # 400 dimethacrylate (manufactured by Shin-Nakamura Chemical Co., Ltd.)
UA-11: Urethane diacrylate (manufactured by Shin-Nakamura Chemical Co., Ltd.)

(C) Component IRGACURE OXE 01: 1,2-octanedione, 1- [4- (phenylthio)-, 2- (O-benzoyloxime)] (manufactured by BASF Corporation)
Lucirin TPO: 2,4,6-trimethylbenzoyl-diphenyl-phosphine oxide (manufactured by BASF Corporation)

(D) Component 1HT: 1H-tetrazole (manufactured by Toyobo Co., Ltd.)
MMT: 1-methyl-5-mercapto-1H-tetrazole (manufactured by Toyobo Co., Ltd.)
HAT: 5-amino-1H-tetrazole (manufactured by Toyobo Co., Ltd.)
3MT: 3-mercapto-triazole (manufactured by Wako Pure Chemical Industries, Ltd.)
ATT: 2-amino-5-mercapto-1,3,4-thiadiazole (manufactured by Wako Pure Chemical Industries, Ltd.)
AMT: 3-amino-5-mercaptotriazole (manufactured by Wako Pure Chemical Industries, Ltd.)

Other components Antage W-500: 2,2′-methylene-bis (4-ethyl-6-tert-butylphenol) (manufactured by Kawaguchi Chemical Co., Ltd.)
Methyl ethyl ketone: manufactured by Tonen Chemical Corporation

  DESCRIPTION OF SYMBOLS 1 ... Photosensitive element, 10 ... Support film, 20 ... Photosensitive layer, 22 ... Protective film, 30 ... Protective film, 100 ... Base material for touch panels, 101 ... Transparent substrate, 102 ... Touch screen, 103 ... Transparent electrode (X position) Coordinates), 104 ... transparent electrode (Y position coordinates), 104a ... part of the transparent electrode, 104b ... bridge portion of the transparent electrode, 105, 105a, 105b ... lead wiring, 106 ... connection electrode, 107 ... connection terminal, 110, DESCRIPTION OF SYMBOLS 120 ... Electrode for touch panels, 122, 123, 124 ... Protective film, 130 ... Photomask, 200 ... Touch panel.

Claims (14)

On a base material for a touch panel, a binder polymer containing 3 to 20% by mass of a structural unit derived from (meth) acrylic acid, a photopolymerizable compound having at least three ethylenically unsaturated groups, a photopolymerization initiator, and a mercapto A photosensitive layer comprising a photosensitive resin composition containing a triazole compound having a group or an amino group, and curing a predetermined portion of the photosensitive layer by irradiation with actinic rays, and then excluding the predetermined portion of the photosensitive layer A method for manufacturing a base material for a touch panel with a protective film, comprising removing a protective film made of a cured product of the predetermined portion of the photosensitive layer covering a part or all of the base material.   The photopolymerizable compound is a (meth) acrylate compound having a skeleton derived from pentaerythritol, a (meth) acrylate compound having a skeleton derived from dipentaerythritol, a (meth) acrylate compound having a skeleton derived from trimethylolpropane, and glycerin The manufacturing method of the base material for touchscreens with a protective film of Claim 1 containing the at least 1 sort (s) of compound selected from the group which consists of a (meth) acrylate compound which has skeleton derived from.   The said photosensitive layer is a manufacturing method of the base material for touchscreens with a protective film of Claim 1 or 2 whose minimum value of the visible light transmittance in 400-700 nm is 90% or more. The said photosensitive layer is a manufacturing method of the base material for touchscreens with a protective film as described in any one of Claims 1-3 whose b ^* in CIELAB color system is -0.2-1.0. The manufacturing method of the base material for touchscreens with a protective film as described in any one of Claims 1-4 in which the said photoinitiator contains an oxime ester compound and / or a phosphine oxide compound. Preparing a photosensitive element comprising a support film and a photosensitive layer made of the photosensitive resin composition provided on the support film, transferring the photosensitive layer of the photosensitive element onto the substrate, and The manufacturing method of the base material for touchscreens with a protective film as described in any one of Claims 1-5 which provides a photosensitive layer. A binder polymer containing 3 to 20% by mass of a structural unit derived from (meth) acrylic acid, a photopolymerizable compound having at least three ethylenically unsaturated groups, a photopolymerization initiator, and a triazole having a mercapto group or an amino group. And a photosensitive resin composition used for forming a protective film on a touch panel substrate. The photopolymerizable compound is a (meth) acrylate compound having a skeleton derived from pentaerythritol, a (meth) acrylate compound having a skeleton derived from dipentaerythritol, a (meth) acrylate compound having a skeleton derived from trimethylolpropane, and glycerin The photosensitive resin composition of Claim 7 containing the at least 1 sort (s) of compound selected from the group which consists of a (meth) acrylate compound which has skeleton derived from. The photosensitive resin composition according to claim 7 or 8 , wherein the minimum value of visible light transmittance when a protective film having a thickness of 5 µm is formed is 90% or more. The photosensitive resin composition according to claim 7 , wherein b ^* in the CIELAB color system when a protective film having a thickness of 5 μm is formed is −0.2 to 1.0. The photosensitive resin composition as described in any one of Claims 7-10 in which the said photoinitiator contains an oxime ester compound and / or a phosphine oxide compound. A photosensitive element comprising: a support film; and a photosensitive layer made of the photosensitive resin composition according to any one of claims 7 to 11 provided on the support film. The photosensitive element of Claim 12 whose thickness of the said photosensitive layer is 10 micrometers or less.   A touch panel provided with the base material for touchscreens with a protective film obtained by the method as described in any one of Claims 1-6.

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