KR20140097355A - Protective film for touch panel electrode, and touch panel - Google Patents

Abstract

The present invention relates to a protective film for a touch panel electrode obtained by curing a predetermined portion of a photosensitive layer comprising a photosensitive polymer composition containing a binder polymer, a photopolymerizable compound and a photopolymerization initiator, Tannonitrile and benzoic acid are detected.

Description

TECHNICAL FIELD [0001] The present invention relates to a protective film for a touch panel,

The present invention relates to a protective film for an electrode for a touch panel, and a touch panel having the same.

2. Description of the Related Art Liquid crystal display elements and touch panels (touch sensors) are used for small electronic apparatuses such as car navigations, mobile phones, electronic dictionaries, and OA / FA apparatuses from large electronic apparatuses of PCs and televisions. Electrodes made of a transparent conductive electrode material are provided on these liquid crystal display elements and the touch panel. As the transparent conductive electrode material, ITO (Indium-Tin-Oxide), indium oxide and tin oxide are known. These materials exhibit high visible light transmittance and thus become mainstream as an electrode material for substrates for liquid crystal display devices and the like.

Various types of touch panels have already been put to practical use. Recently, capacitive touch panels have been used. In the capacitive touch panel, when a fingertip of a conductive chain touches a touch input surface, a finger is electrostatically coupled to the conductive film to form a capacitor. For this reason, the capacitance type touch panel detects the coordinates of the fingertip by grasping the change of the charge at the contact position of the fingertip.

Particularly, since the projection type electrostatic capacitance type touch panel is capable of multi-point detection of the fingertip, it has a good operability that complex instructions can be given, And is used as an input device on a display surface of a device having a small display device.

Generally, in a projection-type capacitive touch panel, a plurality of X electrodes and a plurality of Y electrodes orthogonal to the X electrodes are arranged in a two-layer structure in order to express two-dimensional coordinates by the X axis and the Y axis And ITO (Indium-Tin-Oxide) is used as the electrode.

However, since the frame region of the touch panel is an area where the touch position can not be detected, it is an important factor for improving the product value that the area of the frame region is narrowed. In order to transmit the detection signal of the touch position to the frame region, metal wiring is required. However, in order to narrow the frame area, it is necessary to narrow the width of the metal wiring. Since the conductivity of ITO is not sufficiently high, metal wiring is generally formed of copper.

However, in the above-mentioned touch panel, corrosion components such as moisture and salinity may invade from the sensing area when touching the fingertip. When the corrosion component intrudes into the inside of the touch panel, the metal wiring is corroded, and there is a fear of increasing the electrical resistance between the electrode and the driving circuit, or disconnection.

In order to prevent corrosion of a metal wiring, a capacitance type projection-type touch panel in which an insulating layer is formed on a 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 (plasma CVD) method to prevent corrosion of the metal. However, since this method uses the plasma CVD method, there is a problem that a high-temperature treatment is required, the substrate is limited, and the manufacturing cost is increased.

As a method of providing a resistor film at a required place, there is known a method in which a photosensitive layer composed of a photosensitive resin composition is provided on a predetermined substrate and the photosensitive layer is exposed and developed (for example, refer to Patent Documents 2 to 4) 4). In Patent Documents 5 and 6, According to the above method, a protective film for a touch panel is formed.

Patent Document 1: Japanese Patent Laid-Open Publication No. 2011-28594 Patent Document 2: Japanese Patent Application Laid-Open No. 7-253666 Patent Document 3: Japanese Patent Application Laid-Open No. 2005-99647 Patent Document 4: Japanese Patent Application Laid-Open No. 11-133617 Patent Document 5: Japanese Patent Application Laid-Open No. 2010-27033 Patent Document 6: Japanese Patent Laid-Open Publication No. 2011-232584

Summary of the Invention

Problems to be solved by the invention

The production of the protective film by the photosensitive resin composition can be expected to reduce the cost as compared with the plasma CVD method. However, when a protective film is formed on the electrode for a touch panel, if the thickness of the resin film is large, a step difference may be prominent in a portion having a film and a portion without a film. Therefore, it is necessary to make the protective film as thin as possible.

However, there has been no study on the anti-corrosive property of a film formed from a photosensitive resin composition at a level of 10 탆 or less in thickness.

In consideration of the protection of the sensing region, transparency of the resin cured film is required in the production of the protective film by the photosensitive resin composition.

An object of the present invention is to provide a protective film for an electrode for a touch panel which has a desired shape, is excellent in transparency, and has sufficient rust prevention even if it is a thin film, and a touch panel having such a protective film.

Means for solving the problem

In order to solve the above problems, the present inventors have intensively studied and, as a result, have found that a resin cured film formed from a specific photosensitive resin composition and detecting a specific compound by pyrolysis gas chromatography mass spectrometry can have a desired shape and is excellent in transparency At the same time, has sufficient rustproofing property even if the thickness is 10 μm or less, and has found that it is suitable as a protective film for an electrode for a touch panel. Thus, the present invention has been accomplished.

The present invention is a protective film for an electrode for a touch panel obtained by curing a predetermined portion of a photosensitive layer made of a photosensitive resin composition containing a binder polymer, a photolithium compound, and a photopolymerization initiator, A protective film for an electrode for a touch panel in which nitrile and benzoic acid are detected.

According to the protective film of the electrode for a touch panel of the present invention, it is possible to have a desired shape and to have excellent transparency, and also to have sufficient rust prevention even if a thin film having a thickness of 10 μm or less is provided.

The inventors of the present invention consider the reason why the protective film of the electrode for a touch panel of the present invention can exhibit the above effect. When the thickness of the protective film becomes small. The corrosion component tends to invade the electrode for the touch panel. On the contrary, the photosensitive layer containing a component that is a detection source of heptanonitrile and benzoic acid can be considered to be a composition which has sufficient transparency and pattern forming property and can form a dense cured state. The present inventors presume that by forming the protective film of the electrode for the touch panel as such a photosensitive layer, both the rustproofing property capable of suppressing the penetration of the corrosion component and the transparency and the pattern forming property are achieved.

In the protective film of the electrode for a touch panel of the present invention, the detection peak area of benzoic acid in pyrolysis gas chromatography mass spectrometry is preferably from 1 to 10% based on the detection peak area of the heptanonitrile from the viewpoint of further improving the anti- .

The protective film of the electrode for a touch panel of the present invention preferably has a visible light transmittance of at least 90% at 400 to 700 nm.

From the viewpoint of providing a protective film having a good shape, the binder polymer preferably has a carboxyl group and has an acid value of 75 mgKOH / g or more.

From the viewpoint of further improving the rust-preventive property, the binder polymer preferably has a hydroxyl value of 50 mgKOH / g or less.

The protective film of the electrode for a touch panel of the present invention preferably has a thickness of 10 mu m or less.

The present invention also provides a touch panel having a protective film according to the present invention.

According to the present invention, it is possible to provide a protective film for an electrode for a touch panel which has a desired shape, is excellent in transparency, and has sufficient rust prevention even if it is a thin film, and a touch panel having such a protective film.

1 is a schematic cross-sectional view showing an embodiment of a photosensitive element used for forming a protective film for an electrode for a touch panel according to the present invention.
2 is a schematic cross-sectional view for explaining an embodiment of a method of forming a protective film for a touch panel electrode according to the present invention.
3 is a schematic top view showing an example of a capacitive touch panel.
Fig. 4 is a schematic top view showing another example of a capacitive touch panel. Fig.
[Fig. 5] Fig. 5 (a) is a partial sectional view taken along the line VV in Fig. 3, and Fig. 5 (b) is a partial sectional view showing another embodiment.
6 is a gas chromatogram obtained by pyrolysis gas chromatography mass spectrometry of the protective film obtained in Example 6. FIG.

Carrying out the invention  Form for

Hereinafter, embodiments for carrying out the present invention will be described in detail. However, the present invention is not limited to the following embodiments. Further, in the present specification. (Meth) acrylic acid means acrylic acid or methacrylic acid, (meth) acrylate means acrylate or methacrylate corresponding thereto, and (meth) acryloyl group means acryloyl group or methacryloyl group, It means a diary. Further, the (poly) oxyethylene chain means an oxyethylene group or a polyoxyethylene group, and the (poly) oxypropylene chain means an oxypropylene group or a polyoxypropylene group.

In this specification, the term " process " is included in this term, not only in the independent process but also in the case where the desired operation of the process is achieved even when it can not be clearly distinguished from other processes. Also, in this specification, the numerical range indicated by using " ~ " indicates a range including numerical values before and after "~" as a minimum value and a maximum value, respectively.

In the present specification, the content of each component in the composition means the total amount of the plurality of substances present in the composition, unless otherwise specified, when a plurality of substances corresponding to each component are present in the composition.

A protective film for a touch panel electrode of the present invention is a protective film for a touch panel electrode obtained by curing a predetermined portion of a photosensitive layer composed of a photosensitive resin composition containing a binder polymer, a photopolymerizable compound and a photopolymerization initiator, Characterized in that heptanonitrile and benzoic acid are detected by mass spectrometry.

In the present specification, the pyrolysis gas chromatography mass spectrometric analysis of the protective film is carried out by gas chromatography mass spectrometry on the gas generated by heating the measurement sample at 140 ° C. The heating time of the measurement sample may be in the range of 1 to 60 minutes, preferably 30 minutes. Measurement conditions of pyrolysis gas chromatography mass spectrometry are shown below.

(Measurement conditions of pyrolysis gas chromatography mass spectrometry)

Measurement apparatus: GC / MS QP-2010 (product name, manufactured by Shimadzu Corporation)

Column: HP-5MS (product name manufactured by Agilent Technologies, Inc.)

Oven Temp: After heating at 40 占 폚 for 5 minutes, the temperature was raised to 300 占 폚 at a rate of 15 占 폚 / min

Carrier gas: helium, 1.0 mL / min

Interface temperature: 280 ℃

Ion source temperature: 250 ° C

Sample injection amount: 0.1 mL

The detection peak area of benzoic acid in pyrolysis gas chromatography mass spectrometry of the protective film is preferably 1 to 10%, more preferably 1 to 9%, and most preferably 1 to 7%, based on the detection peak area of heptanonitrile. , More preferably from 1 to 6%, and particularly preferably from 1 to 6%. When the detection peak area of benzoic acid is 1 to 10%, it has a desired shape and is excellent in transparency. The effect of the present invention that the thin film has sufficient rustproofing property can be more reliably obtained.

Next, a photosensitive element and a photosensitive resin composition which can be used for obtaining a protective film for an electrode for a touch panel of the present invention will be described.

1 is a schematic cross-sectional view showing one embodiment of a photosensitive element used for forming a protective film for an electrode for a touch panel according to the present invention. The photosensitive element 1 shown in Fig. 1 comprises a support film 10, a photosensitive layer 20 made of a photosensitive resin composition according to this embodiment provided on the support film 10, And a protective film 30 provided on the side opposite to the film 10.

By using the photosensitive element, a protective film of the electrode for a touch panel of the present invention can be formed.

In the present specification, the electrode for the touch panel includes not only the electrode in the sensing region of the touch panel but also the metal wiring in the frame region. Either one of the electrodes for providing the protective film or both electrodes may be provided.

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 占 퐉, more preferably 10 to 70 占 퐉, from the viewpoint of ensuring coverage and suppressing lowering of resolution when irradiating actinic light rays through the support film 10, More preferably 15 to 40 占 퐉, and particularly preferably 20 to 35 占 퐉.

The photosensitive resin composition according to the present embodiment constituting the photosensitive layer 20 is a photosensitive resin composition containing a binder polymer (hereinafter also referred to as component (A)), a photopolymerizable compound (hereinafter also referred to as component (B) (Hereinafter also referred to as component (C)). The above photosensitive resin composition may contain a component which generates heptanonitrile and benzoic acid upon pyrolysis of the cured product when the cured product is irradiated with an actinic ray. The protective film formed from the photosensitive resin composition containing such components detects heptanonitrile and benzoic acid by pyrolysis gas chromatography mass spectrometry described above.

As the component (A), for example, a polymer having a carboxyl group can be used.

In the present embodiment, the component (A) is preferably a copolymer containing a constituent unit derived from (a) (meth) acrylic acid and (b) alkyl (meth) acrylate.

Examples of the alkyl (meth) acrylate ester include (meth) acrylic acid methyl ester, (meth) acrylic acid ethyl ester, (meth) acrylic acid butyl ester, 2-ethylhexyl (meth) Ethylhexyl ethyl ester.

The copolymer may further contain other monomers copolymerizable with the component (a) and / or the component (b) in the constitutional unit.

Examples of the other monomer copolymerizable with the component (a) and / or the component (b) include (meth) acrylic acid tetrahydrofurfuryl ester, (meth) acrylic acid dimethylaminoethyl ester, (Meth) acrylate, benzyl (meth) acrylate, 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 the component (A), the above monomers may be used singly or in combination of two or more.

The weight average molecular weight of the binder polymer as the component (A) is preferably from 10,000 to 200,000, more preferably from 15,000 to 150,000, even more preferably from 30,000 to 150,000, and particularly preferably from 30,000 to 100,000 And more preferably from 40,000 to 100,000. The measurement conditions of the weight average molecular weight are the same as those in the examples of this specification.

From the viewpoint of easily forming a protective film having a desired shape, the acid value of the binder polymer as the component (A) can be set to 75 mgKOH / g or more, and from the viewpoint 75 To 200 mgKOH / g, more preferably 75 to 150 mgKOH / g, and even more preferably 75 to 120 mgKOH / g.

The acid value of the binder polymer as the component (A) can be measured in the following manner. That is, first, 1 g of a binder polymer to be an acid value measurement object is precisely weighed. 30 g of acetone is added to the above-mentioned binder polymer, and this is uniformly dissolved. Then, an appropriate amount of phenolphthalein as an indicator is added to the solution, and the titration is carried out using a 0.1N KOH aqueous solution. Then, the acid value is calculated by the following formula.

Acid value = 0.1 x Vf x 56.1 / (Wp x I)

(% By mass) of the non-volatile component in the measured solution containing the binder polymer, Vf represents the amount (ml) of the KOH aqueous solution, Wp represents the weight (g) of the measured solution containing the binder polymer, .

When the binder polymer is blended with volatile components such as a synthetic solvent and a diluting solvent, the mixture is heated for 1 to 4 hours at a temperature higher than the boiling point of the volatile components by 10 ° C or higher before the quenching, .

The hydroxyl value of the binder polymer as the component (A) is preferably 50 mgKOH / g or less, more preferably 45 mgKOH / g or less, from the viewpoint of further improving the rustproofing property.

The hydroxyl value of the component (A) can be measured in the following manner.

First, 1 g of a binder polymer to be measured for hydroxyl value is identified. 10 ml of a 10% by mass anhydrous acetic acid pyridine solution was added to the above-mentioned binder polymer, and the resulting solution was uniformly dissolved and heated at 100 占 폚 for 1 hour. After heating, 10 mL of water and 10 mL of pyridine are added, and the mixture is heated at 100 占 폚 for 10 minutes. Thereafter, measurement is carried out by neutralization titration with an ethanol solution of 0.5 mol / L potassium hydroxide using an automatic titrator (" COM-1700 " manufactured by Hiranuma Kyo Co. Ltd.).

The hydroxyl value can be calculated by the following formula.

Hydroxyl group = (A-B) x f x 28.05 / sample (g) + acid value

Wherein A represents the amount (mL) of a 0.5 mol / L potassium hydroxide ethanol solution used in the blank test, B represents the amount (mL) of a 0.5 mol / L potassium hydroxide ethanol solution properly used, f Represents a factor.

When the binder polymer is mixed with a synthetic solvent or a diluting solvent, the mixture is heated for 1 to 4 hours at a temperature higher than the boiling point of the relevant synthetic solvent or diluting solvent by at least 10 ° C, and the solvent is removed And then measure the hydroxyl value.

As the photopolymerizable compound as the component (B), a photopolymerizable compound having an ethylenic unsaturated group can be used.

Examples of the photopolymerizable compound having an ethylenic unsaturated group include monofunctional vinyl monomers, bifunctional vinyl monomers and polyfunctional vinyl monomers having at least three polymerizable ethylenic unsaturated groups.

Examples of the monofunctional vinyl monomers include (meth) acrylic acid, (meth) acrylic acid alkyl esters and monomers copolymerizable therewith, which are exemplified as monomers used in the synthesis of the copolymer which is a suitable example of the component (A) have.

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 such as 2,2-bis (4- (meth) acryloxypolyethoxypolypropoxyphenyl) propane), bisphenol A diglycidyl ether di (meth) acrylate, Phthalic acid, etc.) with a substance having a hydroxyl group and an ethylenic unsaturated group (? -Hydroxyethyl acrylate,? -Hydroxyethyl methacrylate, etc.).

Examples of the polyfunctional vinyl monomer having at least three polymerizable ethylenic unsaturated groups include trimethylolpropane tri (meth) acrylate, tetramethylol methane tri (meth) acrylate, tetramethylol methane tetra (Meth) acrylate, dipentaerythritol penta (meth) acrylate, dipentaerythritol hexa (metha) acrylate, and the like; a compound obtained by reacting an?,? - unsaturated saturated carboxylic acid with a polyhydric alcohol; Trimethylol propane triglycidyl ether triacrylate, and other compounds obtained by adding an?,? - unsaturated carboxylic acid to a glycidyl group-containing compound.

Among them, it is preferable to contain a polyfunctional vinyl monomer having at least three polymerizable ethylenic unsaturated groups. From the viewpoint of suppressing the electrode erosion and easiness of development, it is preferable to use a (meth) acrylate compound having a skeleton derived from pentaerythritol, a (meth) acrylate compound having a skeleton derived from dipentaerythritol, and a skeleton derived from trimethylolpropane (Meth) acrylate compound having a skeleton derived from dipentane erythritol, and a (meth) acrylate compound having a skeleton derived from trimethyrol propane And at least one kind selected from the group consisting of

Here, (meth) acrylate having skeleton derived from dipentane erythritol means an esterified product of dipentaerythritol and (meth) acrylic acid, and the esterified product thereof also includes a compound modified with an alkyleneoxy group. The number of ester bonds in one molecule is preferably 6, 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 thereof includes a compound modified with an alkyleneoxy group . The number of ester bonds in one molecule is preferably 3, but a compound having 1 to 2 ester bonds may be mixed.

These compounds may be used singly or in combination of two or more.

When a monomer having at least three polymerizable ethylenically unsaturated groups in the molecule is used in combination with a monofunctional vinyl monomer or a bifunctional vinyl monomer, there is no particular limitation on the ratio to be used. However, in view of attaining photocuring property and suppressing ability of electrode corrosion Is preferably 30 parts by mass or more, more preferably 50 parts by mass or more based on 100 parts by mass of the total amount of the photopolymerizable compound contained in the photosensitive resin composition, based on 100 parts by mass of the monomer having at least three polymerizable ethylenically unsaturated groups in the molecule More preferably 75 parts by mass or more.

The content of the component (A) and the component (B) in the photosensitive resin composition according to the present embodiment is preferably 35 to 50 parts by weight, (A) is from 40 to 80 parts by mass, and the component (B) is from 20 to 60 parts by mass, more preferably from 50 to 85 parts by mass, and the component (B) is from 15 to 65 parts by mass, To 70 parts by mass, and the component (B) is more preferably from 30 to 50 parts by mass, particularly preferably from 55 to 65 parts by mass of the component (A) and from 35 to 45 parts by mass of the component (B). Particularly, in terms of maintaining transparency and forming a pattern, the content of the component (A) and the component (B) is preferably such that the content of the component (A) is 100 parts by mass or less, More preferably 35 parts by mass or more, further preferably 40 parts by mass or more, further preferably 50 parts by mass or more, particularly preferably 55 parts by mass or more.

When the content of the component (A) and the content of the component (B) are within the above ranges, sufficient sensitivity can be obtained while satisfying the coating property or the film property in the photosensitive element, and the photocuring property, the developing property, It can be ensured sufficiently.

The photosensitive resin composition according to the present embodiment preferably contains an oxime ester compound as the photopolymerization initiator which is the component (C). By including the oxime ester compound, the resin cured film pattern can be formed with sufficient resolution even when a thin film having a thickness of 10 m or less is formed on the substrate. In addition, a resin cured film pattern excellent in transparency can also be formed.

Examples of the oxime ester compound include compounds represented by the following formula (C-1).

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. Unless the effect of the present invention is impaired, the aromatic ring in the general formula (C-1) may have a substituent.

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, an alkyl group having 4 to 8 carbon atoms, or a cycloalkyl group having 4 to 10 carbon atoms More preferable.

Examples of the compound represented by the above general formula (C-1) include 1,2-octanedione, 1- [4- (phenylthio) -, 2- (O-benzoyloxime) 2-octanedione and 1- [4- (phenylthio) -. 2- (O-benzoyloxime)] are available as IRGACURE OXE O1 (trade name, manufactured by BASF).

Among the above-mentioned general formula (C-1), 1,2-octanedione, 1- [4- (phenylthio) -, 2- (O-benzoyloxime)] is particularly preferable. In this case, regarding the protective film formed from the resin composition according to the present embodiment, 1,2-octanedione, 1- [4- (phenylthio) -, 2- (O-benzoyloxime) When analysis is performed, it is detected as heptanonitrile and benzoic acid. The detection peak area of the benzoic acid in the pyrolysis gas chromatography mass spectrometry of the protective film obtained in this case is preferably 1 to 10%, more preferably 1 to 9% with respect to the detection peak area of the heptanonitrile , More preferably from 1 to 7%, and particularly preferably from 1 to 6%. When the detection peak area of benzoic acid is 1 to 10%, it has a desired shape and is excellent in transparency. The effect of the present invention that the thin film has sufficient rustproofing property can be more reliably obtained.

The component (C) may be used in combination with a photopolymerization initiator other than the oxime ester compound. As photopolymerization initiators other than oxime ester compounds, For example, benzophenone, 4-methoxy-4'-dimethylaminobenzophenone, 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) 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, Benzidine derivatives such as benzyl dimethyl ketal and the like; acridine derivatives such as 9-phenyl acridine and 1,7-bis (9,9'-acridinyl) heptane; N-phenylglycine, N-phenylglycine derivatives, coumarin-based compounds, and oxazole-based compounds. In addition, a thioxanthone compound and a tertiary amine compound may be combined, such as a combination of diethylthioxanthone and dimethylaminobenzoic acid.

The content of the photopolymerization initiator as the component (C) is preferably from 0.1 to 20 parts by mass, more preferably from 1 to 10 parts by mass, more preferably from 2 to 5 parts by mass based on 100 parts by mass of the total amount of the components (A) Mass part is more preferable.

The content of the component (C) is preferably not less than 0.1 part by mass in view of excellent photosensitivity and resolution, and is preferably not more than 20 parts by mass from the viewpoint of excellent visible light transmittance.

From the viewpoint of further improving the rustproofing property of the protective film, the photosensitive resin composition according to the present embodiment is preferably a triazole compound having a mercapto group, a tetrazole compound having a mercapto group, a thiadiazole compound having a mercapto group, Or a tetrazole compound having an amino group (hereinafter also referred to as a component (D)). As the triazole compound having a mercapto group, for example, 3-mercapto-triazole (manufactured by Wako Pure Chemical Industries, Ltd., trade name: 3MT) can be mentioned. Examples of the thiadiazole compound having a mercapto group include 2-amino-5-mercapto-1,3,4-thiadiazole (trade name: ATT manufactured by Wako Pure Chemical Industries, Ltd.) have.

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

Among these, from the viewpoint of further reducing development residue, it is preferable to include a compound in which an amino group is substituted for a triazole compound containing a mercapto group. Specific examples thereof include 3-amino-5-mercaptotriazole (trade name: AMT, manufactured by BASF Corporation).

Examples of the tetrazole compound having an amino group include a compound represented by the following formula (D-1).

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, and at least one of R ¹¹ and R ¹² is , And an amino group.

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

Among the tetrazole compounds represented by the general formula (D-1), preferred are tetrazole compounds represented by the following general formulas (I) and (II): 5-amino-1H-tetrazole, 1-methyl- Or 1-carboxymethyl-5-amino-tetrazole are preferred.

The tetrazole compound represented by the general formula (D-1) is also a water-soluble salt thereof. Specific examples include alkali metal salts of 1-methyl-5-amino-tetrazole such as sodium, potassium and lithium.

Of these, 5-amino-1H-tetrazole and 1-methyl-5-mercapto-1H-tetrazole are particularly preferable from the viewpoints of suppressing electrode corrosion, adhesion with a metal electrode, ease of development and transparency.

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

From the viewpoint of further improving the rustproofing property when the electrode surface on which the protective film is provided has a metal such as copper, a copper alloy or a nickel alloy, the photosensitive resin composition is preferably a tetrazole compound having an amino group or a triazole compound having a mercapto group It is preferable to further contain a compound in which the amino group is substituted for the compound. in this case. The development residue can be reduced, and it becomes easy to form a protective film with a good pattern. For this reason, it is conceivable that appropriate adhesion of the surface is expressed.

The above effects can be obtained when a triazole compound having an amino group or a triazole compound containing a mercapto group is substituted with an amino group. Thus, the photosensitive resin composition and the photosensitive element according to the present embodiment can be used as a light- Or the like, and is suitable for forming a protective film for protecting electrodes in frame regions of a touch panel having improved conductivity.

The content of the component (D) in the photosensitive resin composition according to the present embodiment is preferably 0.05 to 10.0 parts by mass, more preferably 0.1 to 2.0 parts by mass based on 100 parts by mass of the total amount of the component (A) and the component (B) More preferably from 0.2 to 1.0 part by mass.

However, when a protective film is provided on a part of the ITO electrode of the touch panel, for example, a protective film is not formed in the sensing area. When a protective film is provided on a portion where a metal layer such as copper is formed on the ITO electrode and the ITO electrode in the picture frame region, unnecessary portions can be removed by performing exposure and development after providing the photosensitive layer as a whole. In this case, the photosensitive layer is required to have satisfactory adhesiveness to the protecting electrode, and good developability so as not to cause development residue in an unnecessary portion. The photosensitive resin composition of the present invention preferably contains a phosphate ester (hereinafter also referred to as component (E)) containing a photopolymerizable unsaturated bond from the viewpoint of both achieving both adhesion and developability in such a case.

From the viewpoint of ensuring high adhesion between the ITO electrode and the developing property at a high level while sufficiently ensuring the rust resistance of the protective film to be formed, the phosphoric acid ester containing the photopolymerizable unsaturated bond as the component (E) It is preferable to use a compound. The compound is commercially available such as PM21 (manufactured by Nippon Kayaku Co., Ltd.).

The photosensitive resin composition according to the present embodiment may further contain additives such as a silane coupling agent, a leveling agent, a plasticizer, a filler, a defoaming agent, a flame retardant, a stabilizer, an antioxidant, And the like can be contained in an amount of about 0.01 to 20 parts by mass per 100 parts by mass of the total amount of the component (A) and the component (B). These may be used alone or in combination of two or more.

Here, the visible light transmittance of the photosensitive resin composition can be determined as follows. First, a coating liquid containing a photosensitive resin composition is coated on a support film so that the thickness after drying becomes 10 m or less, and this is dried to form a photosensitive resin composition layer (photosensitive layer). Next, a laminate is laminated on the glass substrate so that the photosensitive resin composition layer (photosensitive layer) is in contact with the laminate. Thus, a measurement sample in which a photosensitive resin composition layer and a support film are laminated is obtained on a glass substrate. Subsequently, ultraviolet rays are irradiated on the obtained measurement sample to cure the photosensitive resin composition layer, and then the transmittance at a measurement wavelength range of 400 to 700 nm is measured using an ultraviolet visible spectrophotometer.

The above-mentioned appropriate transmittance means the minimum value of the transmittance in the wavelength range.

When the transmittance in a wavelength range of 400 to 700 nm, which is a light ray in a general visible light wavelength range, is 90% or more, the transparent electrode in the sensing area of the touch panel (touch sensor) The color tone and the luminance in the sensing area can be suppressed sufficiently when the protective film is seen from the end of the sensing area when the metal layer of the sensing area (for example, the layer on which the copper layer is formed on the ITO electrode) can do.

The photosensitive resin composition according to the present embodiment can be used for forming a photosensitive layer on a substrate. For example, a coating liquid which can be obtained by uniformly dissolving or dispersing the photosensitive resin composition in a solvent is prepared, and the coating liquid is applied onto the substrate to form a coating film, and the solvent is removed by drying to form the photosensitive layer.

As the solvent, ketones, aromatic hydrocarbons, alcohols, glycol ethers, glycol alkyl ethers, glycol alkyl ether acetates, esters, or diethylene glycols can be used from the viewpoints of solubility of each component and easiness of forming a coating film. These solvents may be used singly or as a mixed solvent comprising two or more kinds of solvents.

Of these solvents, preferred are 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 or the like is preferably used.

The photosensitive resin composition according to the present embodiment is preferably used as a film on a photosensitive film like the photosensitive element 1. By laminating the photosensitive film on a substrate having an electrode for a touch panel, it is possible to shorten the manufacturing process and reduce the cost, for example, by shortening the solvent drying process which can easily realize the roll-to-roll process.

The photosensitive layer 20 of the photosensitive element 1 can be formed by preparing a coating liquid containing the photosensitive resin composition according to the present embodiment, applying the coating liquid onto the supporting film 10, and drying the coating liquid. The coating liquid can be obtained by uniformly dissolving or dispersing each component constituting the photosensitive resin composition according to the present embodiment in the solvent.

The solvent is not particularly limited and a known solvent can be used and examples thereof include acetone, methyl ethyl ketone, methyl isobutyl ketone, toluene, methanol, ethanol, propanol, butanol, methylene glycol, ethylene glycol, propylene glycol, ethylene Ethylene glycol monoethyl ether, 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 singly or as a mixed solvent comprising two or more kinds of solvents.

Examples of the application method include a doctor blade coating method, a Meyer bar coating method, a roll coating method, a screen coating method, a spinner coating method, an inkjet coating method, a spray coating method, a dip coating method, a gravure coating method, Die coating method.

The drying conditions are not particularly limited, but the drying temperature is preferably 60 to 130 DEG C, and the drying time is preferably 0.5 to 30 minutes.

The thickness of the photosensitive layer is preferably 1 mu m or more and 9 mu m or less in thickness after drying so as to exhibit a sufficient effect for electrode protection and to reduce the step on the surface of the touch panel (touch sensor) More preferably 1 μm or more and 8 μm or less, still more preferably 2 μm or more and 8 μm or less, and particularly preferably 3 μm or more and 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 even more preferably 95% or more.

The viscosity of the photosensitive layer 20 is set so as to prevent the photosensitive resin composition from leaking out from the end face of the photosensitive element 1 for at least one month when the photosensitive element is rolled, It is preferably 15 to 100 mPa · s at 30 ° C and more preferably 20 to 90 mPa · s at 30 ° C. because fragments of the resin composition prevent exposure defects and development residue when irradiating actinic light rays caused by adhering to the substrate , More preferably from 25 to 80 mPa · s.

The viscosity was measured by using a circular film having a diameter of 7 mm and a thickness of 2 mm formed of a photosensitive resin composition as a sample for measurement and a load of 1.96 x 10 ^-2 N at 30 캜 and 80 캜 in the thickness direction of the sample The velocity of change of the thickness of the test specimen was measured.

As the protective film 30 (cover film), for example, a film comprising a polyethylene, a polypropylene, a polyethylene terephthalate, a polycarbonate, a polyethylene-vinyl acetate copolymer, and a laminated film of a polyethylene-vinyl acetate copolymer and polyethylene .

The thickness of the protective film 30 is preferably about 5 to 100 mu m, but is preferably 70 mu m or less, more preferably 60 mu m or less, still more preferably 50 mu m or less, And particularly preferably 40 m or less.

The photosensitive element 1 can be rolled up and stored or used.

In this embodiment, the photosensitive resin composition and the coating liquid containing the solvent according to the present embodiment described above are applied on a substrate having a touch panel electrode and dried to form a photosensitive layer 20 made of a photosensitive resin composition, May be installed. Also in this case, it is preferable that the photosensitive layer satisfies the above-described film thickness and visible light transmittance.

Next, a method of forming the protective film of the electrode for a touch panel according to the present invention will be described. 2 is a schematic cross-sectional view for explaining an example of a method of forming a protective film for an electrode for a touch panel according to the present invention.

The method for forming a protective film for a touch panel electrode according to the present embodiment is a method for forming a protective film on a substrate 100 having touch panel electrodes 110 and 120 by using a photosensitive layer 20 made of a photosensitive resin composition according to the present embodiment, A second step of curing a predetermined portion of the photosensitive layer 20 by irradiation of an actinic ray including ultraviolet rays; and a step of removing the photosensitive layer other than a predetermined portion after irradiation of the active ray, And a protective film (22) comprising a cured film pattern of the photosensitive resin composition covering at least a part of the protective film (22). Thus, a touch panel (touch sensor) 200 with a protective film as a touch input sheet can be obtained.

As the substrate 100 used in the present embodiment, a substrate such as a glass plate, a plastic plate, and a ceramic plate which is generally used for a touch panel (touch sensor) can be mentioned. On this substrate, an electrode for a touch panel to be a target of forming a resin cured film to be a protective film is provided. Examples of the electrode include electrodes such as ITO, Cu, Al, and Mo, and TFTs. An insulating layer may be provided between the substrate and the electrode on the substrate.

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

In the first step, after the protective film 30 of the photosensitive element 1 according to the present embodiment is removed, the electrodes 110 and 120 for the touch panels of the substrate 100 are provided while heating the photosensitive element And the photosensitive layer 20 is pressed on the surface of the photosensitive layer 20 to be laminated (see Fig. 2 (a)).

As the pressing means, a pressing roll can be mentioned. The pressing roll may be provided with a heating means so as to be capable of being heated and pressed.

The heating temperature in the case of hot pressing is set to be a temperature in which the photosensitive layer 20 is adhered to the substrate 100 while sufficiently ensuring the adhesion between the photosensitive layer 20 and the substrate 100 and the adhesion between the photosensitive layer 20 and the electrodes 110 and 120 for the touch panels. 20 to 150 deg. C is more preferable, and 30 to 150 deg. C is more preferable.

From the viewpoint of suppressing the deformation of the base material 100 while ensuring sufficient adhesion between the photosensitive layer 20 and the base material 100, the compression pressure during hot pressing is 50 to 1 x 10 < to a ⁵ N / m is more preferable, and preferably, to a ^{2.5 × 10 2 ~ 5 × 10} 4 N / m is preferable, and than ^{5 × 10 2 ~ 4 × 10} 4 N / m to a.

It is not necessary to preheat the base material when the photosensitive element 1 is heated as described above. However, in order to further improve the adhesion between the photosensitive layer 20 and the base material 100, desirable. The preheating temperature at this time is preferably 30 to 150 占 폚.

In the method according to the present embodiment, instead of using the photosensitive element, a coating liquid containing the photosensitive resin composition and the solvent according to the present embodiment is prepared to form the electrode for touch panels 110 and 120 And the photosensitive layer 20 can be formed by drying.

The photosensitive layer 20 preferably satisfies the conditions of the above-mentioned film thickness and visible light transmittance.

In the second step, an active ray L is irradiated in a pattern on a predetermined portion of the photosensitive layer 20 through a photomask 130 (see FIG. 2 (b)).

When the support film 10 on the photosensitive layer 20 is transparent when irradiating an actinic ray, the actinic ray can be irradiated as it is. If the support film 10 is opaque, the actinic ray is irradiated after the support film 10 is removed. From the point of view of protection of the photosensitive layer 20, it is preferable to use a transparent polymer film as the supporting film 10, and to irradiate an actinic ray through the polymer film while remaining the polymer film.

As a light source used for irradiation of the actinic ray L, a known active light source can be used. Examples of the light source include a carbon arc lamp, an ultrahigh pressure mercury lamp, a high pressure mercury lamp, and a xenon lamp. And is not particularly limited.

The irradiation amount of the active ray L at this time is usually 1 × 10 ² to 1 × 10 ⁴ J / m 2, and may be accompanied by heating at the time of irradiation. If the dose of the active rays is less than 1 x 10 ² J / m ² , the effect of photocuring tends to become insufficient. If the dose of the active ray exceeds 1 x 10 ⁴ J / m 2, the photosensitive layer 20 tends to discolor.

In the third step, the photosensitive layer after the irradiation of the actinic ray is developed with a developing solution to remove the portion not irradiated with the active ray (i.e., the predetermined portion of the photosensitive layer), and a thickness covering the whole or part of the electrode A protective film 22 composed of a cured film pattern of the photosensitive resin composition according to the present embodiment of 10 탆 or less is formed (see FIG. 2 (c)). The protective film 22 formed may have a predetermined pattern.

When the support film 10 is laminated on the photosensitive layer 20 after irradiation with the actinic ray, a phenomenon occurs in which the portion where the active ray is not irradiated by the developer is removed after removing it.

Examples of the developing method include a method of performing development by a known method such as spraying, shower, swinging dipping, brushing, and scrapping using a known developer such as an aqueous alkali solution, an aqueous developing solution, or an organic solvent to remove unnecessary portions Among them, the use of an aqueous alkali solution is preferable from the viewpoints of environment and safety.

Examples of the base of the alkali aqueous solution include alkali hydroxides such as lithium hydroxide, sodium or potassium hydroxide, alkali carbonates such as lithium carbonate, (Sodium pyrophosphate, potassium pyrophosphate, etc.), tetramethylammonium hydroxide, triethanolamine and the like. Among them, tetramethylammonium hydroxide and the like are preferable.

An aqueous solution of sodium carbonate is also preferably used, for example, a dilute solution (0.5 to 5 mass% aqueous solution) of sodium carbonate at 20 to 50 캜 is suitably used.

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

In addition, a surfactant, defoaming agent, and a small amount of an organic solvent for promoting development may be mixed in the aqueous alkali solution.

After the development, the base of the alkali aqueous solution remaining in the photosensitive layer 20 after photocuring is removed by a known method such as spraying, swinging dipping, brushing, scrapping or the like using an organic acid, (Neutralization treatment).

Furthermore, after the acid treatment (neutralization treatment), a washing step may be carried out.

After the development, the cured film pattern may be further cured by irradiation of an actinic ray (for example, 5 x 10 ³ to 2 x 10 ⁴ J / m 2), if necessary. The photosensitive resin composition according to the present embodiment exhibits excellent adhesion to a metal even without a heating step after development, but may be subjected to heat treatment in accordance with need, instead of irradiation with actinic rays after development, (80 to 160 DEG C) may be performed.

As described above, the protective film for the electrode for a touch panel according to the present invention can be formed.

Examples of the protective film to be detected as the heptanonitrile and the benzoic acid by pyrolysis gas chromatography mass spectrometry include a method in which the photosensitive resin composition constituting the photosensitive layer contains 1,2-octanedione, 1- And [4- (phenylthio) -, 2- (O-benzoyloxime)].

Next, an example of the use position of the protective film of the present invention will be described with reference to Figs. 3, 4, and 5. Fig. 3 is a schematic top view showing 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 a transparent substrate 101, a transparent electrode 103 for detecting a capacitance change in the touch screen 102, A transparent electrode 104 is provided on the substrate 101. The transparent electrode 103 and the transparent electrode 104 respectively detect the X coordinate and the Y coordinate of the touch position.

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

The cross-sectional structure of the connection portion between the transparent electrode and the lead-out wiring in the touch panel shown in Fig. 3 will be described with reference to Fig. 5 is a partial cross-sectional view taken along the line V-V of the portion C shown in Fig. 3, and is a view for explaining the connection portion between the transparent electrode 104 and the lead wiring 105. Fig. The transparent electrode 104 and the lead wiring 105 are electrically connected to each other through the connection electrode 106 as shown in Fig. A part of the transparent electrode 104 and all of the lead wiring 105 and the connection electrode 106 are covered with the protective film 122 as shown in Fig. Similarly, the transparent electrode 103 and the lead-out wiring 105 are electrically connected through the connection electrode 106. 5 (b), the transparent electrode 104 and the lead wiring 105 may be directly and electrically connected to each other. The photosensitive resin composition and the photosensitive element according to the present embodiment described above are suitable for use for forming a resin cured film pattern as a protective film of the structural portion.

A manufacturing method of the touch panel in this embodiment will be described. First, a transparent electrode (X position coordinate) 103 is formed on a transparent electrode 101 provided on a substrate 100. Subsequently, a transparent electrode (Y position coordinate) 104 is formed. The transparent electrode 103 and the transparent electrode 104 may be formed by a method of etching a transparent electrode layer formed on the transparent substrate 100 or the like.

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

The photosensitive element 1 according to the present embodiment is formed so as to cover the transparent electrode 103, the transparent electrode 104, the lead wiring 105, the connection electrode 106, and the connection terminal 107 formed by the above- And a photosensitive layer 20 is provided on the electrode. Next, the transferred photosensitive layer 20 is irradiated with the actinic ray L in a desired pattern through a photomask in a desired shape. A protective film 122 made of a cured product of a predetermined portion of the photosensitive layer 20 is formed by irradiating the active ray L with development and removing the portion other than the predetermined portion of the photosensitive layer 20. In this way, a touch panel including the protective film 122 can be manufactured.

Example

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

[Preparation of binder polymer solution (A1)] [

(1) shown in Table 1 was added to a flask equipped with a stirrer, a reflux condenser, an inert gas inlet and a thermometer, and the temperature was raised to 80 DEG C in a nitrogen gas atmosphere. While maintaining the reaction temperature at 80 DEG C +/- 2 DEG C, (2) shown in Fig. 1 was uniformly added dropwise over 4 hours. (Solid content: 45% by mass) having a weight average molecular weight of about 65,000, an acid value of 78 mgKOH / g and a hydroxyl value of 2 mgKOH / g was continuously stirred at 80 ° C ± 2 ° C for 6 hours A1).

The weight average molecular weight (Mw) was determined by gel permeation chromatography (GPC) and calculated by using a standard polystyrene calibration curve. The conditions of GPC are shown below.

GPC conditions

Pump: Hitachi L-6000 (manufactured by Hitachi, Ltd., product name)

Column: Gelpack GL-R420, Gelpack GL-R430, Gelpack GL-R440 (trade name, product of Hitachi Seiko Kogyo Co., Ltd.)

Eluent: tetrahydrofuran

Measuring temperature: 40 ° C

Flow rate: 2.05 mL / min

Detector: Hitachi L-3300 Model RI (product name, manufactured by Hitachi, Ltd.)

[Determination of acid value]

The acid value was measured in the following manner. First, the binder polymer solution was heated at 130 占 폚 for 1 hour to remove volatile components to obtain a solid content. After 1 g of the polymer to be measured for acid value was determined, 30 g of acetone was added to this polymer, and this was uniformly dissolved. Then, an appropriate amount of phenolphthalein as an indicator was added to the solution, and titration was performed using a 0.1N KOH aqueous solution. Then, the acid value was calculated by the following formula.

Acid value = 0.1 x Vf x 56.1 / (Wp x I)

In the formula, Vf represents the appropriate amount (mL) of the KOH aqueous solution, Wp represents the weight (g) of the measured resin solution, and I represents the ratio (mass%) of the nonvolatile content in the measured resin solution.

[Method for measuring hydroxyl value]

The hydroxyl value was measured as follows. First, the solution of the binder polymer was heated at 130 占 폚 for 1 hour to remove volatile components to obtain a solid content. After 1 g of the polymer to be measured for hydroxyl value was determined, 10% by mass of a 10% by mass anhydrous acetic acid pyridine solution was added to the Erlenmeyer flask, which was uniformly dissolved and heated at 100 DEG C for 1 hour Respectively. After heating, 10 mL of water and 10 mL of pyridine were added, and the mixture was heated at 100 캜 for 10 minutes. Then, an ethanol solution of 0.5 mol / L potassium hydroxide was prepared using an automatic titrator ("COM-1700" And the neutralization titration was carried out. Then, the hydroxyl value was calculated by the following equation.

Hydroxyl group = (A-B) x f x 28.05 / sample (g) + acid value

In the formula, A represents the amount (mL) of a 0.5 mol / L potassium hydroxide ethanol solution used in the blank test, B represents the amount (mL) of a 0.5 mol / L potassium hydroxide ethanol solution used for titration, and f represents a factor .

(Examples 1 to 8 and Comparative Examples 1 to 8)

[Production of Coating Liquid Containing Photosensitive Resin Composition]

The materials shown in Table 2 were mixed using a stirrer for 15 minutes to prepare a coating liquid containing a photosensitive resin composition for forming a protective film.

[Production of photosensitive element]

Using a polyethylene terephthalate film having a thickness of 50 탆 as a support film, a coating liquid containing the photosensitive resin composition prepared above was uniformly coated on a supporting film using a comma coater, followed by drying in a hot air convection type drier at 100 캜 Dried for a minute to remove the solvent to form a photosensitive layer (photosensitive resin composition layer) comprising a photosensitive resin composition. The thickness of the obtained photosensitive layer was 5 占 퐉.

Subsequently, a polyethylene film having a thickness of 25 mu m was further adhered as a cover film on the obtained photosensitive layer to prepare a photosensitive element for forming a protective film.

[Measurement of transmittance of protective film]

Using a laminator (trade name: HLM-3000, manufactured by Hitachi Kasei Kogyo Co., Ltd.) so that the photosensitive layer was brought into contact with a glass substrate having a thickness of 1 mm while peeling the polyethylene film as the cover film of the obtained photosensitive element, , A substrate transfer rate of 1 m / min, and a compression pressure (cylinder pressure) of 4 × 10 ⁵ Pa (a substrate having a thickness of 1 mm and a length of 10 cm × width of 10 cm was used, the line pressure at this time was 9.8 × 10 ³ N / m) To prepare a laminate in which a photosensitive layer and a supporting film were laminated on a glass substrate.

Subsequently, the photosensitive layer of the obtained laminate was irradiated with light of 5 x 10 < ² > J / m < ² > (i-line (wavelength: 365 nm)) from above the photosensitive layer side using a parallel light exposure device (EXM1201, After the ultraviolet rays were irradiated, the supporting film was removed and the film was allowed to stand in a box type dryer (model number: NV50-CA, manufactured by Mitsubishi Denki Kagaku Co., Ltd.) heated at 140 캜 for 30 minutes , And a protective film having a thickness of 5 mu m was obtained.

Subsequently, the visible light transmittance was measured at a measurement wavelength range of 400 to 700 nm using a spectrophotometer (U-3310) manufactured by Hitachi High Technologies, Ltd., and a minimum value was calculated. Table 4 and Table 5 show the measurement results.

[Salt spray test of protective film (artificial liquid resistance evaluation test)]

(HLM-3000 type, manufactured by Hitachi Seiko Kogyo Co., Ltd.) so that the photosensitive layer was contacted with a sputtered copper-clad polyimide film (manufactured by Toray Industries, Inc.) while peeling the polyethylene film of the obtained photosensitive element. ), A substrate temperature of 120 DEG C, a substrate transfer rate of 1 m / min, a compression pressure (cylinder pressure) of 4 x 10 < ⁵ > Pa (a thickness of 1 mm and a length of 10 cm x 10 cm) 9.8 x 10 < ³ > N / m) to prepare a laminate in which a photosensitive layer and a supporting film were laminated on the sputter copper.

Subsequently, the photosensitive layer of the obtained laminate was irradiated with light having an exposure amount of 5 x 10 < ² > J / m < ² > (i-line (wavelength: 365 nm)) using a parallel light exposure apparatus (EXM1201, After irradiating ultraviolet rays, the support film was removed. Further, ultraviolet light was irradiated from the upper side of the photosensitive layer to an exposure amount of 1 x 10 ⁴ J / m 2 (measurement value at i-line (wavelength 365 nm) And left for 30 minutes in a box-type dryer (model number: NV50-CA, manufactured by Mitsubishi Denki K.K.). Thereby obtaining a sample for artificial liquid resistance evaluation in which a protective film having a thickness of 5.0 mu m was formed.

Subsequently, the above-mentioned sample was placed in a test tank using a salt water spray tester (STP-90V2, manufactured by Suga Test Instruments Co., Ltd.) with reference to JIS standard (Z 2371) ) Was sprayed for 48 hours at a test bath temperature of 35 DEG C and a spray amount of 1.5 mL / h. After completion of the spraying, the brine was wiped off and the surface state of the sample for evaluation was observed and evaluated according to the following ratings. Table 4 and Table 5 show the measurement results.

A: No change on the surface of the protective film.

B: Very little traces are seen on the surface of the protective film, but no change in copper.

C: Traces appear on the surface of the protective film, but no change in copper.

D: There was a trace on the surface of the protective film, and the copper discolored.

[Measurement of generated gas after heating at 140 占 폚 for 30 minutes (pyrolysis gas chromatography mass spectrometry)]

While the resulting photosensitive element was peeled off from the polyethylene film, a laminator (manufactured by Hitachi Seiko Kogyo Co., Ltd., product name: Nitto Furon Film No. 900U, manufactured by Nitto Denko Co., using HLM-3000 type), a roll temperature of 120 ℃, a substrate transport speed 1m / min, the contact pressure (cylinder pressure) of the laminate under the condition of 4 × 10 ⁵ Pa.

Subsequently, a photosensitive layer of the obtained laminate was irradiated with light of 5 x 10 < ² > J / m < ² > (i-line (wavelength: 365 nm)) using a parallel light exposure apparatus (EXM1201, After irradiating ultraviolet rays, the support film was removed, and ultraviolet rays were further irradiated from the upper side of the photosensitive layer at an exposure amount of 1 x 10 ⁴ J / m 2 (measurement value at i-line (wavelength 365 nm)) to obtain a pyrolysis gas chromatographic mass A measurement sample for analysis was obtained.

The measurement sample was heated at 140 占 폚 for 30 minutes using a Tekmar 7000HT headspace sampler and the generated gas was analyzed by GC / MS (model number: GC / MS QP-2010, carrier gas: helium, Min., Column: HP-5MS, oven: heating at 40 占 폚 for 5 minutes and then raising the temperature to 300 占 폚 at a rate of 15 占 폚 / minute; interface temperature: 280 占 폚; ion source temperature: 250 占 폚; And analyzed. Table 4 and Table 5 show the measurement results. The gas chromatogram obtained by pyrolysis gas chromatography mass spectrometry of the protective film obtained in Example 6 is shown in Fig. In Fig. 6, A indicates the detection peak of benzoic acid, and B indicates the detection peak of heptanonitrile.

The symbols in Table 2 and Table 3 indicate the following meanings.

(A) Component

(A1): a propylene glycol monomethyl ether / toluene solution of a copolymer having a monomer content ratio (methacrylic acid / methyl methacrylate / ethyl acrylate = 12/58/30 (mass ratio)), a weight average molecular weight of 65,000, an acid value of 78 mgKOH / g , A hydroxyl value of 2 mgKOH / g, a Tg of 60 DEG C

Component (B)

A-TMMT: pentaerythritol tetraacrylate (manufactured by Shin-Nakamura Chemical Co., Ltd.)

DPHA: dipentaerythritol hexaacrylate (manufactured by Nippon Kayaku Co., Ltd.)

TMPTA: trimethylol propane triacrylate (manufactured by Nippon Kayaku Co., Ltd.)

UX-3204: urethane acrylate (manufactured by Nippon Kayaku Co., Ltd.) containing hydroxyethyl acrylate, polyester diol and hexane methylene diisocyanate as raw materials,

PET-30: Pentaerythritol triacrylate (manufactured by Nippon Kayaku Co., Ltd.)

(C) Component

IRGACURE OXE 01: 1,2-octanedione, 1 - [(4-phenylthio) -, 2- (O-benzoyloxime)] (manufactured by BASF)

IRGACURE 184: 1-Hydroxy-cyclohexyl-phenyl-ketone (from BASF)

IRGACURE 651: 2,2-dimethoxy-1,2-diphenylethane-1-one (manufactured by BASF)

IRGACURE 369: 2-Benzyl-2-dimethylamino-1- (morpholinophenyl) -butanone-1 (manufactured by BASF)

IRGACURE 907: 2-methyl-1- [4- (methylthio) phenyl] -2-morpholinopropane-1-one (manufactured by BASF)

IRGACURE 2959: 1- [4- (2-Hydroxyethoxy) -phenyl] -2-hydroxy-2-methyl-

DETX: 2,4-diethylthioxanthone (manufactured by Nippon Kayaku Co., Ltd.)

N-1717: 1,7-bis (9-acridinyl) heptane (manufactured by ADEKA)

EAB: 4,4'-bis (diethylamino) benzophenone (manufactured by Hodogaya Chemical Co., Ltd.)

(D) Component

HAT: 5-Amino-1H-tetrazole (manufactured by Toyobo Co., Ltd.)

AMT: 3-amino-5-mercaptotriazole (manufactured by Wako Pure Chemical Industries, Ltd.)

ATT: 2-amino-5-mercapto-1,3,4-thiadiazole (manufactured by Wako Pure Chemical Industries, Ltd.)

Other components

Antage W-500: 2,2'-methylene-bis (4-ethyl-6-tert-butylphenol) (Kawaguchi Kagaku Co.,

PM21: Phosphoric ester containing photopolymerizable unsaturated bond (manufactured by Nippon Kayaku Co., Ltd.)

SH-30: Octamethylcyclotetrasiloxane (manufactured by Toray Dow Corning Co., Ltd.)

Methyl ethyl ketone: manufactured by DONENGAGAKU CO., LTD.

One… Photosensitive element, 10 ... Support film, 20 ... Photosensitive layer, 22 ... Shield, 30 ... Protective film, 100 ... Substrate, 101 ... Transparent substrate, 102 ... Touch screen, 103 ... Transparent electrode (X position coordinate), 104 ... Transparent electrode (Y position coordinate), 105 ... Drawing wiring, 106 ... Connecting electrode, 107 ... Connection terminals 110, 120 ... Electrode for touch panel, 122, 123 ... Shield, 130 ... Photomask, 200 ... Touch panel.

Claims (7)

As a protective film for a touch panel electrode obtained by curing a predetermined portion of a photosensitive layer comprising a photosensitive polymer composition containing a binder polymer, a photopolymerizable compound and a photopolymerization initiator,
Heptanonitrile and benzoic acid are detected by pyrolysis gas chromatography mass spectrometry. The method according to claim 1,
Wherein the detection peak area of the benzoic acid in the analysis is 1 to 10% with respect to the detection peak area of the heptanonitrile. 3. The method according to claim 1 or 2,
And the minimum value of the visible light transmittance at 400 to 700 nm is 90% or more. 4. The method according to any one of claims 1 to 3,
Wherein the binder polymer has a carboxyl group and has an acid value of 75 mgKOH / g or more. 5. The method according to any one of claims 1 to 4,
Wherein the binder polymer has a hydroxyl value of 50 mgKOH / g or less. 6. The method according to any one of claims 1 to 5,
Wherein the thickness of the protective film is 10 占 퐉 or less. A touch panel having the protective film according to any one of claims 1 to 6.

Images