JP2012163735A - Photosensitive resin composition, and protective film and insulating film for touch panel using the composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a photosensitive resin composition that can give a cured film having high hardness of the film, good adhesiveness to a substrate, a base or the like, excellent electric characteristics such as a dielectric constant and a dielectric loss tangent, and high transmittance, particularly high transmittance at a wavelength near 400 nm.SOLUTION: The photosensitive resin composition contains a resin (A), a photopolymerization initiator (B), an antioxidant (C) and a photopolymerizable monomer (D). The resin (A) contains a resin (A1) obtained by copolymerizing (a1), (a2) and (a3) to obtain a copolymer (a6), further reacting the obtained copolymer (a6) with (a4) to obtain a copolymer (a7), and further reacting the obtained copolymer (a7) with (a5).

Description

  The present invention relates to a photosensitive resin composition, a protective film using the same, and an insulating film for a touch panel.

  In recent years, as electronic devices have become more sophisticated, diversified, and smaller and lighter, a transparent touch panel is mounted on the front surface of a display element such as a liquid crystal, and characters, symbols, patterns, etc. displayed on the display element through this transparent touch panel There are an increasing number of devices that perform visual recognition and selection, and switch each function of the device by operating a transparent touch panel.

  The touch panel panel is, for example, a bank ATM, a vending machine, a personal digital assistant (PDA, UMPC), a copier, a facsimile, a portable game machine, a guide board, a car navigation, a multimedia station (multi-function installed in a convenience store) Terminal), mobile phones, railway vehicle monitoring devices, and answering devices such as quiz programs are rapidly spreading.

Existing touch panel systems can be classified into a resistive film system, an optical system, an electrostatic capacity system, an ultrasonic system, a pressure system, an electromagnetic wave induction system, an image recognition system, a vibration detection system, and the like.
Specific examples of a touch panel arranged on a display device such as a liquid crystal include a resistance film method and a capacitance method. The resistance film method is a method of detecting a pressed position by voltage, and a capacitance method. Detects the position by capturing the change in capacitance caused by pressing.
As for the electrostatic capacity method, Patent Documents 1 to 3 and the like are disclosed, and an insulating film and a protective film are provided in the laminated structure in order to prevent erroneous recognition of a contact position.

  The performance required for these insulating films and protective films includes adhesion to substrates, bases, and other layers (glass, inorganic materials, metal materials, transparent electrodes such as ITO, organic materials, etc.), and laminated substrates. For example, low dielectric constant and dielectric loss tangent can be mentioned in order to obtain high transmittance, and further, drive stability and high-speed response as a touch panel.

However, these conventional insulating films and protective films often have insufficient adhesion to a base material or a base, and further to a layer formed thereon. Regarding the transmittance, the film is yellowed in the heating process at the time of film formation, so the transmittance in the low wavelength region, particularly in the vicinity of 400 nm is lowered, which is preferable in view of the structure of the touch panel placed on the display device. Absent. Furthermore, none of the dielectric constant and dielectric loss tangent exhibited desirable characteristics.
In addition, since the hardness of the film is low, the panel may be damaged when transported on the production line.
As described above, the conventional technology has not been able to satisfy all the adhesion, transmittance, electrical characteristics, and film hardness required for the insulating film and the protective film.

JP 2008-65748 A JP 2009-15490 A JP 2010-44453 A

  The object of the present invention is that the film has a high hardness, good adhesion to a substrate or an underlayer, etc., excellent electrical characteristics such as dielectric constant and dielectric loss tangent, and high transmittance, particularly transmittance around a wavelength of 400 nm. It aims at providing the photosensitive resin composition which can obtain a high cured film.

  As a result of intensive studies on new means that can solve the above-mentioned problems, the present inventors have found that a photosensitive resin composition containing the following materials can solve the above-mentioned problems, and have reached the present invention.

That is, the present invention is a photosensitive resin composition containing a resin (A), a photopolymerization initiator (B), an antioxidant (C), and a photopolymerizable monomer (D), A) is obtained by copolymerizing the following (a1), (a2) and (a3) to obtain a copolymer (a6), and the obtained copolymer (a6) and unsaturated monobasic acid (a4) And a resin (A1) obtained by reacting the obtained copolymer (a7) with a polybasic acid anhydride (a5). The present invention relates to a photosensitive resin composition.
(A1); Compound (a2) having an alicyclic skeleton and an ethylenically unsaturated bond in one molecule; Compound (a3) having an epoxy group and an ethylenically unsaturated bond in one molecule; (a1) and Compound (a4) having an ethylenically unsaturated bond other than (a2); Unsaturated monobasic acid (a5); Polybasic acid anhydride Further, in the present invention, the antioxidant (C) is a hindered phenol-based oxidation. The photosensitive resin composition is a compound selected from the group consisting of an inhibitor, a hindered amine antioxidant, and a phosphorus antioxidant.

The present invention also relates to the photosensitive resin composition, wherein the resin (A) further contains a thermosetting resin (A2).
In the present invention, the thermosetting resin (A2) contains a compound having a structure represented by the following general formula (1) and a melamine compound having a weight average polymerization degree of 1.0 to 5.0. The present invention relates to the photosensitive resin composition.
General formula (1):

［一般式（１）中、Ｒ¹〜Ｒ⁶は、それぞれ独立して水素原子、または−ＣＨ₂ＯＨ、−ＣＨ₂ＯＣＨ₃、および−ＣＨ₂ＯＣ₄Ｈ₉からなる群より選ばれるいずれかの置換基を表す。］
また本発明は、酸化防止剤（Ｃ）の重量［Ｃ］と熱硬化性樹脂（Ａ２）の重量［Ａ２］との比率（［Ｃ］／［Ａ２］）が、０．００５〜０．１であることを特徴とする請求項４または５に記載の感光性樹脂組成物。

[In General Formula (1), R ^{1 to} R ⁶ are each independently a hydrogen atom or any one selected from the group consisting of —CH ₂ OH, —CH ₂ OCH ₃ , and —CH ₂ OC ₄ H ₉ . Represents a substituent of ]
In the present invention, the ratio ([C] / [A2]) of the weight [C] of the antioxidant (C) to the weight [A2] of the thermosetting resin (A2) is 0.005 to 0.1. The photosensitive resin composition according to claim 4 or 5, wherein the composition is a photosensitive resin composition.

The present invention also relates to the photosensitive resin composition, wherein the photopolymerization initiator (B) is an acetophenone photopolymerization initiator or an oxime ester photopolymerization initiator.
In the present invention, the photopolymerization initiator (B) is 2-methyl-1- (4-methylthiophenyl) -2-morpholinopropan-1-one or 1,2-octadion-1- [4- (phenylthio). -, 2- (o-benzoyloxime)]. The present invention relates to the photosensitive resin composition.
The present invention also relates to the photosensitive resin composition, wherein the photopolymerizable monomer (D) is a compound represented by the general formula (2).
General formula (2):

［一般式（２）中、ｍは１〜３の整数、ａは２〜６の整数、ｂは０〜４の整数を表す。ただし、ａ＋ｂ＝６である。］
また本発明は、さらに密着促進添加剤（Ｅ）を含むことを特徴とする前記感光性樹脂組成物に関する。

[In General Formula (2), m represents an integer of 1 to 3, a represents an integer of 2 to 6, and b represents an integer of 0 to 4. However, a + b = 6. ]
Moreover, this invention relates to the said photosensitive resin composition characterized by including an adhesion promotion additive (E) further.

Moreover, this invention relates to the protective film formed using the said photosensitive resin composition.
Moreover, this invention relates to the insulating film for touchscreens formed using the said photosensitive resin composition.

  The cured film formed from the photosensitive resin composition of the present invention has good adhesion to a base material, a base, and the like, and has high transmittance, particularly high transmittance around a wavelength of 400 nm, and further has a dielectric constant and Since it has a low dielectric loss tangent and good electrical characteristics, it is suitable for use as an insulating film for a touch panel. Further, since it has a high film hardness, it is also suitable as a protective film for preventing scratches that may occur due to contact with a roller or the like during conveyance in the touch panel manufacturing process.

First, the photosensitive resin composition of the present invention will be described.
The photosensitive resin composition of the present invention is a photosensitive resin composition containing a resin (A), a photopolymerization initiator (B), an antioxidant (C), and a photopolymerizable monomer (D). (A) includes a resin (A1) having a specific structure.

  In the present application, when expressed as “(meth) acryl”, “(meth) acrylic acid”, “(meth) acrylate”, “acryl and / or methacryl”, “ "Acrylic acid and / or methacrylic acid", "acrylate and / or methacrylate" shall be represented.

<Resin (A)>
The resin (A) includes a resin (A1) having a specific structure, and preferably further includes a thermosetting resin (A2).

[Resin (A1)]
Resin (A1) is obtained by copolymerizing the following (a1), (a2) and (a3) to obtain a copolymer (a6). The obtained copolymer (a6) and unsaturated monobasic acid (a4) ) To obtain a copolymer (a7), and a resin obtained by further reacting the obtained copolymer (a7) with a polybasic acid anhydride (a5). Resin (A1) By including, the adhesiveness with a base material, the foundation | substrate, etc. becomes favorable, and the coating film which has a dielectric constant and a dielectric loss tangent with a favorable electrical property can be obtained.
(A1); Compound (a2) having an alicyclic skeleton and an ethylenically unsaturated bond in one molecule; Compound (a3) having an epoxy group and an ethylenically unsaturated bond in one molecule; (a1) and Compound (a4) having an ethylenically unsaturated bond other than (a2); Unsaturated monobasic acid (a5); Polybasic acid anhydride (a1); Alicyclic skeleton and ethylenically unsaturated bond in one molecule Specifically, the compound having the following: cyclopentyl (meth) acrylate, cyclohexyl (meth) acrylate, methylcyclohexyl (meth) acrylate, cycloheptyl (meth) acrylate, cyclooctyl (meth) acrylate, menthyl (meth) acrylate, di Cyclopentanyl (meth) acrylate, dicyclopentenyl (meth) acrylate, dicyclopentanyloxyethyl (Meth) acrylate, dicyclopentenyloxyethyl (meth) acrylate, cyclohexenyl (meth) acrylate, cycloheptenyl (meth) acrylate, cyclooctenyl (meth) acrylate, mentadienyl (meth) acrylate, isobornyl (meth) acrylate, pinanyl (meth) ) Acrylate, adamantyl (meth) acrylate, norbornenyl (meth) acrylate, pinenyl (meth) acrylate and derivatives having substituents on these alicyclic rings. Examples of the substituent on the alicyclic ring of these monomers include an alkyl group, a hydroxyl group, and a carboxyl group.

  Among these, cyclohexyl (meth) acrylate, dicyclopentanyl (meth) acrylate, dicyclopentenyl (meth) acrylate, dicyclopentanyloxyethyl (meth) acrylate, in particular, because the transmittance near a wavelength of 400 nm can be increased. Dicyclopentenyloxyethyl (meth) acrylate, isobornyl (meth) acrylate, or adamantyl (meth) acrylate is preferred, with dicyclopentanyl (meth) acrylate, dicyclopentenyl (meth) acrylate, isobornyl ( It is meth) acrylate or adamantyl (meth) acrylate. These can be used alone or in combination.

  (A2); As a compound having an epoxy group and an ethylenically unsaturated bond in one molecule, glycidyl (meth) acrylate, β-methylglycidyl (meth) acrylate, β-propylglycidyl (meth) acrylate, β-methyl Glycidyl-α-ethyl acrylate, 3-methyl-3,4-epoxybutyl (meth) acrylate, 4-methyl-4,5-epoxypentyl (meth) acrylate, 5-methyl-5,6-epoxyhexyl (meth) Examples include acrylate and glycidyl vinyl ether, and glycidyl (meth) acrylate is preferred.

Specific examples of compounds having an ethylenically unsaturated bond other than (a3); (a1) and (a2) include methyl (meth) acrylate, ethyl (meth) acrylate, butyl (meth) acrylate, and 2-hydroxyethyl. Unsubstituted or substituted alkyl esters of unsaturated carboxylic acids such as (meth) acrylates, aminoethyl (meth) acrylates;
Ester compounds containing an aromatic ring of an unsaturated carboxylic acid such as benzyl (meth) acrylate and phenoxy (meth) acrylate;
Aromatic vinyl compounds such as styrene, α-methylstyrene, α-phenylstyrene and vinyltoluene;
Carboxylic acid vinyl esters such as vinyl acetate and vinyl propionate;
Vinyl cyanide compounds such as (meth) acrylonitrile and α-chloroacrylonitrile;
And N-substituted maleimide compounds such as N-cyclohexylmaleimide, N-phenylmaleimide, and N-benzylmaleimide. These can be used alone or in combination.

  (A4); As unsaturated monobasic acids, (meth) acrylic acid, crotonic acid, o-, m-, p-vinylbenzoic acid, α-haloalkyl of (meth) acrylic acid, alkoxyl, halogen, nitro, cyano Examples thereof include monocarboxylic acids such as substituted products. Of these, (meth) acrylic acid is preferred.

(A5); As polybasic acid anhydrides, dibasic acid anhydrides such as maleic anhydride, succinic anhydride, itaconic anhydride, phthalic anhydride, tetrahydrophthalic anhydride, hexahydrophthalic anhydride, chlorendic anhydride, etc .: anhydrous Examples thereof include polybasic acid anhydrides such as trimellitic acid, pyromellitic anhydride, benzophenone tetracarboxylic acid anhydride, and biphenyl tetracarboxylic acid anhydride. Of these, tetrahydrophthalic anhydride or succinic anhydride is preferred.
(Production method of resin (A1))
Resin (A1) is obtained by copolymerizing (a1), (a2) and (a3) to obtain a copolymer (a6), and reacting the obtained copolymer (a6) with the following (a4) Thus, a copolymer (a7) is obtained, and the copolymer (a7) obtained is further reacted with a polybasic acid anhydride (a5).

  First, (a1), (a2) and (a3) are copolymerized to obtain a copolymer (a6). This copolymerization is performed under normal conditions. For example, in a flask equipped with a stirrer, a thermometer, a reflux condenser, a dropping funnel and a nitrogen introduction tube, 0.5 to 20 times based on the weight of the total amount of (a1), (a2) and (a3) An amount of solvent is introduced and the atmosphere in the flask is replaced with nitrogen from air. Then, after heating up a solvent to 40-140 degreeC, it is a mass reference | standard with respect to the predetermined amount of (a1), (a2) and (a3), and the total amount of (a1), (a2) and (a3). 0 to 20 times the amount of solvent, and a solution obtained by adding 0.1 to 10 parts of the polymerization initiator with respect to the weight ratio of (a1), (a2) and (a3) (stirred and dissolved at room temperature or under heating) Is added dropwise from the dropping funnel to the flask over 0.1 to 8 hours, and further stirred at 40 to 140 ° C. for 1 to 10 hours.

In the above step, a part or all of the polymerization initiator may be charged to the flask side,
A part or all of (a1), (a2) and (a3) may be charged to the flask side. Moreover, in order to control molecular weight and molecular weight distribution, you may use (alpha) -methylstyrene dimer and a mercapto compound as a chain transfer agent. The amount of α-methylstyrene dimer or mercapto compound used is 0.005 to 5 parts on a mass basis with respect to the total amount of (a1) to (a3). In addition, the above-described polymerization conditions may be appropriately adjusted in the preparation method and the reaction temperature in consideration of the production equipment, the amount of heat generated by the polymerization, and the like.

  The ratio of the constituent components derived from each is a molar fraction with respect to the total number of moles of the constituent components constituting the copolymer (a6), 2 to 40 mol% of the structural units derived from (a1), The structural unit derived from (a2) is preferably 2 to 95 mol%, the structural unit derived from (a3) is preferably 3 to 65 mol%, and the structural unit derived from (a1) from the balance of flexibility and heat resistance. 5 to 35 mol%, 5 to 80 mol% of structural units derived from (a2), and 15 to 50 mol% of structural units derived from (a3) are more preferable.

  Next, (a4) is added to the copolymer (a6) to impart light and thermosetting properties to the resin (A). The reaction of the copolymers (a6) and (a4) can be performed, for example, under the conditions described in JP-A No. 2001-89533. Specifically, the atmosphere in the flask is replaced from nitrogen to air, and, for example, trisdimethylaminomethylphenol is used as a reaction catalyst for carboxyl groups and epoxy groups based on the total amount of (a1) to (a4). In addition, 0.01 to 5%, and as a polymerization inhibitor, for example, hydroquinone is 0.001 to 5% in a flask based on the total amount of (a1) to (a4), and 60%. By reacting at ˜130 ° C. for 1 to 10 hours, the above copolymers (a6) and (a4) can be reacted. Similar to the polymerization conditions, the charging method and the reaction temperature may be appropriately adjusted in consideration of the production equipment, the amount of heat generated by the polymerization, and the like.

  The amount of (a4) added is 5 to 100 mol%, preferably 10 to 95 mol%, based on the epoxy group in the resin obtained by copolymerizing (a1) to (a3). It is preferable that the composition ratio of (a2) is within the above range because sufficient photocurability and thermosetting can be obtained and the reliability is excellent.

  Next, the copolymer (a7) and (a5) are reacted to impart alkali solubility to the resin (A).

  The reaction of the copolymers (a7) and (a5) can be performed, for example, under the conditions described in JP 2001-89533 A. Specifically, as a reaction catalyst, for example, 0.01 to 5% of triethylamine is placed in a flask on a mass basis with respect to the total amount of (a1) to (a4), and at 60 to 130 ° C., By reacting for 1 to 10 hours, the above copolymers (a7) and (a5) can be reacted. Similar to the polymerization conditions, the charging method and the reaction temperature may be appropriately adjusted in consideration of the production equipment, the amount of heat generated by the polymerization, and the like.

  The amount of (a5) added is 5 to 100 mol%, preferably 10 to 95 mol%, based on the number of moles of the alcoholic hydroxyl group of the copolymer (a7).

  The weight average molecular weight in terms of polystyrene of the resin (A1) is preferably 3000 to 100,000, more preferably 5000 to 50000. When the weight average molecular weight of the resin (A1) is in the above range, the coating property is good, the film is not easily reduced during development, and the developability of the unexposed part tends to be good during development. ,preferable.

  The molecular weight distribution [weight average molecular weight / number average molecular weight] of the resin (A1) is preferably 1.5 to 6.0, and more preferably 1.8 to 4.0. The molecular weight distribution in the above range is preferable because the developability is excellent.

  Content of resin (A1) used for the photosensitive resin composition of this invention is 5-90 weight% normally in solid content of 100 weight% of the photosensitive resin composition, Preferably it is 10-70 weight%. It is preferable for the content of the resin (A1) to be in the above-mentioned range since it is excellent in solubility in a developing solution, hardly causes a development residue, and does not easily reduce the film thickness at the exposed portion during development.

  In addition, as resin which introduce | transduced (meth) acryl group into the side chain of resin like this invention, in addition to resin (A1) of this invention, resin which has a carboxyl group, epoxy group in one molecule ( There is a type in which a compound containing a (meth) acrylic group is reacted. In order to increase the (meth) acrylic group content of the side chain in this type, a resin having a high carboxyl group ratio must be used. However, a resin having a high carboxyl group ratio has a problem that it is difficult to handle because the solution viscosity is high. Since the present invention uses a trunk polymer that does not contain a carboxyl group, there is no problem as described above.

[Thermosetting resin (A2)]
As a thermosetting resin (A2), an epoxy compound and a melamine compound are mentioned, for example.

  The epoxy compound may be a low molecular compound or a high molecular compound, and representative examples include bisphenol A epoxy resin, hydrogenated bisphenol A epoxy resin, bisphenol F epoxy resin, hydrogenated bisphenol F epoxy resin, and novolac epoxy. Resins, cycloaliphatic epoxy resins, heterocyclic epoxy resins, glycidyl ester resins, glycidylamine resins, epoxy resins such as epoxidized oil; brominated derivatives of the above epoxy resins, tris (glycidylphenyl) methane, Triglycidyl isocyanurate etc. are mentioned. Among them, bisphenyl A type epoxy resin, hydrogenated bisphenol A type epoxy resin, novolac type epoxy resin, cycloaliphatic type epoxy resin, glycidyl ester type resin, glycidylamine type resin, tris (glycidylphenyl) methane This is preferable in that the cured density is high and the adverse effect on the developability of the colored composition is small.

Examples of the melamine compound include melamine in which 1 to 6 hydrogens of an amino group (—NH ₂ ) are methylolated, and a water-soluble melamine resin composed of a quantifier thereof, such as Sumitomo Chemical Co., Ltd. “Smitex Resin” or methylol. Melamine whose ester group is esterified with C1-4 aliphatic alcohol, and oil-soluble melamine resin consisting of its quantity, such as Dainippon Ink Chemical Co., Ltd. "Super Becamine", or polyester resin and acrylic resin as melamine resin Cross-linked with

  Among them, the melamine compound includes a thermosetting melamine compound represented by the following general formula (1) or a mixture of partial condensates thereof, and a mixture of the thermosetting melamine compound and the partial condensate thereof, And when both are contained. This melamine compound is preferable because the hardness of the coating film can be increased.

The weight average degree of polymerization of this melamine compound is the weight average molecular weight of the melamine compound including “the thermosetting melamine compound represented by the general formula (1)” and “the mixture of its partial condensates”. It is a value divided by “the weight average molecular weight of the thermosetting melamine compound represented by 1)”. It is preferable that the weight average degree of polymerization preferably includes a compound of 1.0 to 5.0 because the hardness of the coating film can be further increased. More preferably, it is 1.0 to 2.5, and most preferably 1.0 to 2.0.
General formula (1):

［一般式（１）中、Ｒ¹〜Ｒ⁶は、それぞれ独立して水素原子、または−ＣＨ₂ＯＨ、−ＣＨ₂ＯＣＨ₃、および−ＣＨ₂ＯＣ₄Ｈ₉からなる群より選ばれるいずれかの置換基を表す。］
一般式（１）で表される熱硬化性メラミン化合物、またはその部分縮合物の混合物、としては、例えば以下の市販品が挙げられる。

[In General Formula (1), R ^{1 to} R ⁶ are each independently a hydrogen atom or any one selected from the group consisting of —CH ₂ OH, —CH ₂ OCH ₃ , and —CH ₂ OC ₄ H ₉ . Represents a substituent of ]
Examples of the thermosetting melamine compound represented by the general formula (1) or a mixture of partial condensates thereof include the following commercially available products.

The products in which R ^{1 to} R ^{6 are} —CH ₂ OCH ₃ include Nicarak MW-30M, Nicarak MW-30, Nicarac MW-22, Nicarac MW-21 (manufactured by Sanwa Chemical Co., Ltd.), and Cymel 300, Cymel 301, Cymel 303, Cymel 350 (manufactured by Nippon Cytec Industries, Inc.), etc., R ^{1 to} R ^{6 are} —CH ₂ OH, Nicarak MS-11, R ^{1 to} R ^{6 are} —CH ₂ OCH _{3 and} —CH ₂ OC ₄ H ₉ as products, Nicarax MX-45, Nicarax MX-500, Nicarax MX-520, Nicarax MX-43 (manufactured by Sanwa Chemical Co., Ltd.), and Cymel 232, Cymel 235, Cymel 236, Cymel 238 (manufactured by Nippon Cytec Industries, Inc.), etc. As a product of the R ¹ to R ⁶ gar CH ₂ OC ₄ H _9, CYMEL 506 (Nippon Cytec Industries Inc.) Full alkyl ether compound of hexamethylol melamine and the like and / or mixtures of partial condensate (the average degree of polymerization 1-2).

  By further including the thermosetting resin (A2), it is possible to obtain a coating film having high hardness by reacting during the heating step and forming a network-like coating film structure. Therefore, the protective film that requires higher hardness is excellent in the effect of preventing scratches during conveyance in the production line.

  The thermosetting resin (A2) is preferably used in an amount of 3 to 30% by weight in 100% by weight of the solid content of the photosensitive resin composition. When the thermosetting resin (A2) is less than 3% by weight, it is difficult to obtain a sufficient hardness-improving effect. When the thermosetting resin (A2) is more than 30% by weight, the transmittance is significantly reduced due to yellowing of the resin.

[Other resins (A3)]
The photosensitive resin composition of the present invention may further contain other resin (A3).
The other resin is preferably a resin having a transmittance of preferably 80% or more, more preferably 95% or more in the entire wavelength region of 400 to 700 nm. Other resins include thermoplastic resins and active energy ray curable resins, and these can be used alone or in admixture of two or more.

  Examples of the thermoplastic resin include butyral resin, styrene-maleic acid copolymer, chlorinated polyethylene, chlorinated polypropylene, polyvinyl chloride, vinyl chloride-vinyl acetate copolymer, polyvinyl acetate, polyurethane resin, and polyester resin. Acrylic resins, alkyd resins, polystyrene resins, polyamide resins, rubber resins, cyclized rubber resins, celluloses, polyethylene (HDPE, LDPE), polybutadiene, polyimide resins, and the like.

  Active energy ray-curable resins include (meth) acrylic compounds having reactive substituents such as isocyanate groups, aldehyde groups, and epoxy groups on polymers having reactive substituents such as hydroxyl groups, carboxyl groups, and amino groups. Or a resin in which a photocrosslinkable group such as a (meth) acryloyl group or a styryl group is introduced by reacting with or cinnamic acid is used. Further, a linear polymer containing an acid anhydride such as a styrene-maleic anhydride copolymer or an α-olefin-maleic anhydride copolymer is converted into a (meth) acrylic compound having a hydroxyl group such as hydroxyalkyl (meth) acrylate. Half-esterified products are also used.

<Photoinitiator (B)>
As photopolymerization initiator (B), 4-phenoxydichloroacetophenone, 4-t-butyl-dichloroacetophenone, diethoxyacetophenone, 1- (4-isopropylphenyl) -2-hydroxy-2-methylpropan-1-one 1-hydroxycyclohexyl phenyl ketone, 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butan-1-one, 2-methyl-1- [4- (methylthio) phenyl] -2- Acetophenone photopolymerization initiators such as morpholinopropan-1-one, 1,2-octadion-1- [4- (phenylthio)-, 2- (o-benzoyloxime)], ethanone, 1- [9-ethyl -6- (2-methylbenzoyl) -9H-carbazol-3-yl]-, 1- (o-acetyloxime), etc. Oxime ester photoinitiator, benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzoin photopolymerization initiator such as benzyldimethyl ketal, benzophenone, benzoylbenzoic acid, methyl benzoylbenzoate, 4-phenylbenzophenone, Benzophenone photopolymerization initiators such as hydroxybenzophenone, acrylated benzophenone, 4-benzoyl-4'-methyldiphenyl sulfide, thioxanthone, 2-chlorothioxanthone, 2-methylthioxanthone, isopropylthioxanthone, 2,4- Thioxanthone photopolymerization initiators such as diisopropylthioxanthone, 2,4,6-trichloro-s-triazine, 2-phenyl-4,6-bis (trichloromethyl) -s- Riazine, 2- (p-methoxyphenyl) -4,6-bis (trichloromethyl) -s-triazine, 2- (p-tolyl) -4,6-bis (trichloromethyl) -s-triazine, 2-piperonyl -4,6-bis (trichloromethyl) -s-triazine, 2,4-bis (trichloromethyl) -6-styryl-s-triazine, 2- (naphth-1-yl) -4,6-bis (trichloro Methyl) -s-triazine, 2- (4-methoxy-naphth-1-yl) -4,6-bis (trichloromethyl) -s-triazine, 2,4-trichloromethyl- (piperonyl) -6-triazine, Triazine photopolymerization initiators such as 2,4-trichloromethyl (4′-methoxystyryl) -6-triazine, borate photopolymerization initiators, carbazole photopolymerization initiators, imi Tetrazole-based photopolymerization initiator and the like are used, a photopolymerization initiator (B) may be used alone or in admixture of two or more.

Of these, acetophenone-based photopolymerization initiators and oxime ester-based photopolymerization initiators are preferable because of high sensitivity, a small amount of addition, and high transmittance.
Among the acetophenone photopolymerization initiators and oxime ester photopolymerization initiators, 2-methyl-1- (4-methylthiophenyl) -2-morpholinopropan-1-one or 1,2-octadione-1 -[4- (Phenylthio)-, 2- (o-benzoyloxime)] does not turn yellow during the heating step, and therefore provides a photosensitive resin composition having high transmittance, particularly high transmittance in the vicinity of a wavelength of 400 nm. More preferable.

Therefore, it can be more preferably used in an insulating film for a touch panel installed on a display device with a touch panel that requires a higher transmittance.
The photopolymerization initiator (B) is preferably used in an amount of 1 to 30% by weight in 100% by weight of the solid content of the photosensitive resin composition.

  The photosensitive resin composition of the present invention further includes α-acyloxy ester, acylphosphine oxide, methylphenylglyoxylate, benzyl, 9,10-phenanthrenequinone, camphorquinone, and ethylanthraquinone as sensitizers. 4,4′-diethylisophthalophenone, 3,3 ′, 4,4′-tetra (t-butylperoxycarbonyl) benzophenone, 4,4′-diethylaminobenzophenone, and the like can be used in combination. The sensitizer can be used in an amount of 0.1 to 150 parts by weight with respect to 100 parts by weight of the photopolymerization initiator (B).

<Antioxidant (C)>
The photosensitive resin composition of the present invention contains an antioxidant (C) in order to increase the transmittance of the coating film.
Antioxidant (C) is that the photopolymerization initiator (B) and thermosetting resin (A2) contained in the photosensitive resin composition are oxidized and yellowed by a thermal process during thermal curing and ITO annealing. In order to prevent this, the transmittance of the coating film can be increased. That is, the photosensitive resin composition of the present invention contains the antioxidant (C), thereby preventing yellowing due to oxidation during the heating step and obtaining a high coating film transmittance.

  Preferable examples of the antioxidant (C) include hindered phenol-based antioxidants, hindered amine-based antioxidants, phosphorus-based antioxidants, and sulfide-based antioxidants. More preferably, they are hindered phenolic antioxidants, hindered amine antioxidants, or phosphorus antioxidants. These can be used alone or in combination of two or more.

  As the hindered phenol-based antioxidant, 2,4-bis [(laurylthio) methyl] -o-cresol, 1,3,5-tris (3,5-di-t-butyl-4-hydroxybenzyl), 1,3,5-tris (4-t-butyl-3-hydroxy-2,6-dimethylbenzyl) and 2,4-bis- (n-octylthio) -6- (4-hydroxy-3,5- And di-t-butylanilino) -1,3,5-triazine, pentaerythritol tetrakis [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate.

  In the hindered amine antioxidant, bis (2,2,6,6-tetramethyl-4-piperidyl) sebacate, bis (N-methyl-2,2,6,6-tetramethyl-4-piperidyl) sebacate, N , N'-bis (2,2,6,6-tetramethyl-4-piperidyl) -1,6-hexamethylenediamine, 2-methyl-2- (2,2,6,6-tetramethyl-4- Piperidyl) amino-N- (2,2,6,6-tetramethyl-4-piperidyl) propionamide, tetrakis (2,2,6,6-tetramethyl-4-piperidyl) (1,2,3,4 -Butanetetracarboxylate, poly [{6- (1,1,3,3-tetramethylbutyl) imino-1,3,5-triazine-2,4-diyl} {(2,2,6,6- Tetramethyl-4-piperidyl) Mino} hexamethyl {(2,2,6,6-tetramethyl-4-piperidyl) imino}], poly [(6-morpholino-1,3,5-triazine-2,4-diyl) {(2,2 , 6,6-tetramethyl-4-piperidyl) imino} hexamethine {(2,2,6,6-tetramethyl-4-piperidyl) imino}], dimethyl succinate and 1- (2-hydroxyethyl) -4 Polycondensate with -hydroxy-2,2,6,6-tetramethylpiperidine, N, N'-4,7-tetrakis [4,6-bis {N-butyl-N- (1,2,2, 6,6-pentamethyl-4-piperidyl) amino} -1,3,5-triazin-2-yl] -4,7-diazadecane-1,10-diamine and the like are preferable, and these include one or more. Can be used.

  As the phosphorus-based antioxidant, tris [2-[[2,4,8,10-tetrakis (1,1-dimethylethyl) dibenzo [d, f] [1,3,2] dioxaphosphine- 6-yl] oxy] ethyl] amine, tris [2-[(4,6,9,11-tetra-tert-butyldibenzo [d, f] [1,3,2] dioxaphosphin-2- Yl) oxy] ethyl] amine, ethylbisphosphite (2,4-ditert-butyl-6-methylphenyl), and is preferably at least one compound selected from the group consisting of these, Can use 1 type (s) or 2 or more types.

  As sulfide-based antioxidants, 2,2-thio-diethylenebis [3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate], 2,4-bis [(octylthio) methyl]- o-cresol and 2,4-bis [(laurylthio) methyl] -o-cresol are mentioned.

  The antioxidant (C) is preferably used in an amount of 0.1 to 5% by weight in a total of 100% by weight of the solid content of the photosensitive resin composition. When the amount of the antioxidant (C) is less than 0.1% by weight, the effect of increasing the transmittance is small, and when it is more than 5% by weight, the hardness is greatly lowered and the sensitivity of the photosensitive resin composition is greatly decreased.

Further, the ratio ([C] / [A2]) of the weight [C] of the antioxidant (C) and the weight [A2] of the thermosetting resin (A2) is in the range of 0.005 to 0.1. preferable.
If it is less than 0.005, the effect of increasing the transmittance by the antioxidant (C) is small, and if it exceeds 0.1, the hardness is greatly lowered, and the sensitivity of the photosensitive resin composition may be greatly lowered. In the range of 0.005 to 0.1, a synergistic effect of the photocurability improvement effect by reducing the photopolymerization inhibition by the antioxidant and the hardness improvement effect by the thermosetting resin can be expected, which is preferable.

<Photopolymerizable monomer (D)>
As the photopolymerizable monomer (D), a monofunctional monomer, a bifunctional monomer, and other polyfunctional monomers can be used.
Specific examples of the monofunctional monomer include nonylphenyl carbitol acrylate, 2-hydroxy-3-phenoxypropyl acrylate, 2-ethylhexyl carbitol acrylate, N-vinyl pyrrolidone, and the like.

  Specific examples of the bifunctional monomer include 1,6-hexanediol di (meth) acrylate, ethylene glycol di (meth) acrylate, neopentyl glycol di (meth) acrylate, triethylene glycol di (meth) acrylate, 3-methyl Examples include pentanediol di (meth) acrylate.

  Specific examples of other polyfunctional monomers include trimethylolpropane tri (meth) acrylate, pentaerythritol tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, dipentaerythritol pentaacrylate, dipentaerythritol hexa (meth) acrylate. And a reaction product of pentaerythritol tri (meth) acrylate and an acid anhydride, a reaction product of dipentaerythritol penta (meth) acrylate and an acid anhydride, and the like.

Among these, the use of a compound represented by the following general formula (2) is preferable because adhesion to a base material or a base is improved.
General formula (2):

［一般式（２）中、ｍは１〜３の整数、ａは２〜６の整数、ｂは０〜４の整数を表す。ただし、ａ＋ｂ＝６である。］
光重合性モノマー（Ｄ）の含有量としては、感光性樹脂組成物の固形分１００重量％中、１０〜５０重量％の量で用いることが好ましい。

[In General Formula (2), m represents an integer of 1 to 3, a represents an integer of 2 to 6, and b represents an integer of 0 to 4. However, a + b = 6. ]
The content of the photopolymerizable monomer (D) is preferably used in an amount of 10 to 50% by weight in 100% by weight of the solid content of the photosensitive resin composition.

<Adhesion promoting additive (E)>
Further, when it contains an adhesion promoting additive (E), the adhesion with a glass substrate, ITO or the like is improved, which is preferable.
Adhesion promoting additives include vinyltrichlorosilane, vinyltrimethoxysilane, vinyltriethoxysilane, 2- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-glycid Xylpropylmethyldiethoxysilane, 3-glycidoxypropyltriethoxysilane, p-styryltrimethoxysilane, 3-methacryloxypropylmethyldimethoxysilane, 3-methacryloxypropyltrimethoxysilane, 3-methacryloxypropylmethyldiethoxy Silane, 3-methacryloxypropyltriethoxysilane, 3-acryloxypropyltrimethoxysilane, N-2- (aminoethyl) -3-aminopropylmethyldimethoxysilane, N-2- (aminoethyl) -3- Minopropyltrimethoxysilane, N-2- (aminoethyl) -3-aminopropyltriethoxysilane, 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 3-triethoxysilyl-N- (1, 3-dimethyl-butylidene) propylamine, N-phenyl-3-aminopropyltrimethoxysilane, N- (vinylbenzyl) -2-aminoethyl-3-aminopropyltrimethoxysilane hydrochloride, 3-ureidopropyltriethoxy Examples include silane, 3-chloropropyltrimethoxysilane, 3-mercaptopropylmethyldimethoxysilane, 3-mercaptopropyltrimethoxysilane, bis (triethoxysilylpropyl) tetrasulfide, and 3-isocyanatopropyltriethoxysilane. .

Among them, the silane-based adhesion promoting additive (E) is preferable because adhesion to a glass substrate, ITO, or the like is improved, and 3-glycidoxypropyltrimethoxysilane is particularly preferable.
The adhesion promoting additive (E) is preferably used in an amount of 0.1 to 5% by weight in 100% by weight of the solid content of the photosensitive resin composition.

<Other ingredients>
A solvent, surfactant, storage stability, etc. can also be used for the photosensitive resin composition of this invention as needed.

<Solvent>
Examples of the solvent include 1,2,3-trichloropropane, 1,3-butanediol, 1,3-butylene glycol, 1,3-butylene glycol diacetate, 1,4-dioxane, 2-heptanone, and 2-methyl. -1,3-propanediol, 3,5,5-trimethyl-2-cyclohexen-1-one, 3,3,5-trimethylcyclohexanone, ethyl 3-ethoxypropionate, 3-methyl-1,3-butanediol 3-methoxy-3-methyl-1-butanol, 3-methoxy-3-methylbutyl acetate, 3-methoxybutanol, 3-methoxybutyl acetate, 4-heptanone, m-xylene, m-diethylbenzene, m-dichlorobenzene N, N-dimethylacetamide, N, N-dimethylformamide, n-butylal N-butylbenzene, n-propyl acetate, N-methylpyrrolidone, o-xylene, o-chlorotoluene, o-diethylbenzene, o-dichlorobenzene, p-chlorotoluene, p-diethylbenzene, sec-butylbenzene, tert-butylbenzene, γ-butyrolactone, isobutyl alcohol, isophorone, ethylene glycol diethyl ether, ethylene glycol dibutyl ether, ethylene glycol monoisopropyl ether, ethylene glycol monoethyl ether, ethylene glycol monoethyl ether acetate, ethylene glycol monotertiary butyl ether, Ethylene glycol monobutyl ether, ethylene glycol monobutyl ether acetate, ethylene glycol monopropyl ether Ether, ethylene glycol monohexyl ether, ethylene glycol monomethyl ether, ethylene glycol monomethyl ether acetate, diisobutyl ketone, diethylene glycol diethyl ether, diethylene glycol dimethyl ether, diethylene glycol monoisopropyl ether, diethylene glycol monoethyl ether acetate, diethylene glycol monobutyl ether, diethylene glycol monobutyl ether acetate, diethylene glycol Monomethyl ether, cyclohexanol, cyclohexanol acetate, cyclohexanone, cyclopentanone, dipropylene glycol dimethyl ether, dipropylene glycol methyl ether acetate, dipropylene glycol monoethyl acetate Dipropylene glycol monobutyl ether, dipropylene glycol monopropyl ether, dipropylene glycol monomethyl ether, diacetone alcohol, triacetin, tripropylene glycol monobutyl ether, tripropylene glycol monomethyl ether, propylene glycol diacetate, propylene glycol phenyl ether, propylene Glycol monoethyl ether, propylene glycol monoethyl ether acetate, propylene glycol monobutyl ether, propylene glycol monopropyl ether, propylene glycol monomethyl ether, propylene glycol monomethyl ether acetate, propylene glycol monomethyl ether propionate, benzyl alcohol Methyl isobutyl ketone, methyl cyclohexanol, acetic acid n- amyl acetate n- butyl, isoamyl acetate, isobutyl acetate, propyl acetate, include dibasic acid esters such as, used these alone or in mixtures.

In consideration of the drying property of the solvent, it is preferable to include a high boiling point solvent of 160 ° C. or higher in die coating or printing methods. For example, 3-methoxy-3-methyl-1-butanol (bp 174 ° C.), 1, 3 -Butanediol (bp 203 ° C.), 3-methyl-1,3-butanediol (bp 203 ° C.), 2-methyl-1,3-propanediol (bp 213 ° C.), diisobutyl ketone (bp 168.1 ° C.), ethylene glycol mono Butyl ether (bp 171.2 ° C.), ethylene glycol monohexyl ether (bp 208.1 ° C.), ethylene glycol monobutyl ether acetate (bp 191.5 ° C.), ethylene glycol dibutyl ether (bp 203.3 ° C.), diethylene glycol monomethyl ether (bp 194.0) ℃), Diechi Glycol monoethyl ether (bp 202.0 ° C.), diethylene glycol diethyl ether (bp 188.4 ° C.), diethylene glycol monoisopropyl ether (bp 207.3 ° C.), propylene glycol monobutyl ether (bp 170.2 ° C.), propylene glycol diacetate (bp 190 0.0 ° C.), dipropylene glycol monomethyl ether (bp 187.2 ° C.), dipropylene glycol monoethyl ether (bp 197.8 ° C.), dipropylene glycol monopropyl ether (bp 212.0 ° C.), dipropylene glycol dimethyl ether (bp 175 ° C.) ), Tripropylene glycol monomethyl ether (bp 206.3 ° C.), ethyl 3-ethoxypropionate (bp 169.7 ° C.), 3-methoxybutene Ruacetate (bp 172.5 ° C.), 3-methoxy-3-methylbutyl acetate (bp 188 ° C.), γ-butyrolactone (bp 204 ° C.), N, N-dimethylacetamide (bp 166.1 ° C.), N-methylpyrrolidone (bp 202 ° C), p-chlorotoluene (bp162.0 ° C), o-diethylbenzene (bp183.4 ° C), m-diethylbenzene (bp181.1 ° C), p-diethylbenzene (bp183.8 ° C), o-dichlorobenzene (bp180) 0.5 ° C), m-dichlorobenzene (bp 173.0 ° C), n-butylbenzene (bp183.3 ° C), sec-butylbenzene (bp178.3 ° C), tert-butylbenzene (bp169.1 ° C), cyclo Hexanol (bp 161.1 ° C), cyclohexyl acetate (bp 73 ° C.), include such methylcyclohexanol (bp174 ℃), high-boiling solvent or 160 ° C. during 100 wt% total amount of the solvent is preferably 5 to 50 wt%.
A solvent can be used in the quantity of 200-4000 weight part with respect to a total of 100 weight part of solid content of the photosensitive resin composition.

<Surfactant>
Surfactants include polyoxyethylene alkyl ether sulfate, sodium dodecylbenzenesulfonate, alkali salt of styrene-acrylic acid copolymer, sodium stearate, sodium alkylnaphthalene sulfonate, sodium alkyldiphenyl ether disulfonate, monododecyl sulfate. Anionic properties such as ethanolamine, triethanolamine dodecyl sulfate, ammonium dodecyl sulfate, monoethanolamine stearate, sodium stearate, sodium dodecyl sulfate, monoethanolamine of styrene-acrylic acid copolymer, polyoxyethylene alkyl ether phosphate Surfactant: Polyoxyethylene oleyl ether, polyoxyethylene dodecyl ether, polyoxyethylene nonylphenyl ether Nonionic surfactants such as tellurium, polyoxyethylene alkyl ether phosphate ester, polyoxyethylene sorbitan monostearate and polyethylene glycol monolaurate; chaotic surfactants such as alkyl quaternary ammonium salts and their ethylene oxide adducts Agent: Examples include amphoteric surfactants such as alkylbetaines such as alkyldimethylaminoacetic acid betaine and alkylimidazolines, which can be used alone or in admixture of two or more.

<Storage stabilizer>
Examples of the storage stabilizer include quaternary ammonium chlorides such as benzyltrimethyl chloride and diethylhydroxyamine, organic acids such as lactic acid and oxalic acid, and organic acids such as methyl ether, t-butylpyrocatechol, triethylphosphine, and triphenylphosphine. Examples thereof include phosphine and phosphite. The storage stabilizer can be used in an amount of 0.1 to 5% by weight in a total of 100% by weight of the photosensitive resin composition.

<Production method of photosensitive resin composition>
The photosensitive resin composition of the present invention includes a resin (A) containing a resin (A1), a photopolymerization initiator (B), an antioxidant (C), a photopolymerizable monomer (D), and a necessity. Accordingly, the thermosetting resin (A2), the adhesion promoting additive (E) and the solvent can be obtained by stirring and mixing.

<Removal of coarse particles>
The photosensitive resin composition of the present invention is a coarse particle having a size of 5 μm or more, preferably a coarse particle having a size of 1 μm or more, more preferably a coarse particle having a size of 0.5 μm or more, by means of centrifugation, sintered filter, membrane filter or the like. It is preferable to remove the mixed dust and foreign matter.

<Protective film>
The protective film of the present invention is obtained by applying the photosensitive resin composition according to the present invention on a glass substrate, ITO, metal film, organic film, etc. by spin coating such as spin coating, casting coating such as die coating, and coating by roll coating. It can be obtained by forming a coating film by coating by a roll transfer method or the like. The pattern may be formed by photolithography. The protective film formed by the photosensitive resin composition of the present invention has high hardness and is excellent in the effect of preventing scratches during transportation on the production line.

<Insulating film for touch panel>
The insulating film for a touch panel of the present invention is obtained by applying the photosensitive resin composition according to the present invention on a glass substrate, ITO, metal film, organic film, spin coating such as spin coating, casting coating such as die coating, roll coating. It can be obtained by forming a coating film by coating by a roll, coating by a roll transfer method or the like. The pattern may be formed by photolithography. Since the insulating film for a touch panel is placed on a display device with a touch panel, the insulating film formed from the photosensitive resin composition of the present invention has high transmittance and can be preferably used.

  Hereinafter, the present invention will be described based on examples, but the present invention is not limited thereto. In the examples, “parts” and “%” represent “parts by weight” and “% by weight”, respectively.

Moreover, the measuring method of the weight average molecular weight of a resin and an acid value is as follows.
(Weight average molecular weight of resin)
It measured by polystyrene conversion using the gel permeation chromatograph measuring apparatus ("Shodex GPC System-21H" Showa Denko make).
(Acid value)
80 ml of acetone and 10 ml of water are added to 0.5 to 1 g of the resin solution and stirred to dissolve uniformly, and an automatic titrator ("COM-555" manufactured by Hiranuma Sangyo Co., Ltd.) is used with a 0.1 mol / L KOH aqueous solution as a titrant ) And the acid value of the resin solution was measured. Then, the acid value per solid content of the resin was calculated from the acid value of the resin solution and the solid content concentration of the resin solution.

First, the manufacturing method of the resin solution used for the Example and the comparative example is demonstrated.
<Method for producing resin solution>
(Preparation of resin solution A1-1)
Place 100 parts of propylene glycol monomethyl ether acetate in a reaction vessel equipped with a thermometer, cooling tube, nitrogen gas inlet tube and stirrer in a separable four-necked flask, and heat to 120 ° C while injecting nitrogen gas into the vessel. A mixture of 5.2 parts of styrene, 35.5 parts of glycidyl methacrylate, 41.0 parts of dicyclopentanyl methacrylate, and 1.0 part of azobisisobutyronitrile was dropped over 2.5 hours from the dropping tube at a temperature to polymerize. Reaction was performed.
Next, the inside of the flask was purged with air, 0.3 parts of trisdimethylaminomethylphenol and 0.3 part of hydroquinone were added to 17.0 parts of acrylic acid, and the reaction was continued at 120 ° C. for 5 hours. The reaction was terminated when it reached 0.8, and a resin solution having a weight average molecular weight of about 12000 (measured by GPC) was obtained.
Further, 30.4 parts of tetrahydrophthalic anhydride and 0.5 part of triethylamine were added and reacted at 120 ° C. for 4 hours, and propylene glycol monomethyl ether acetate was added so that the non-volatile content was 40% to prepare a resin solution A1-1. did.

(Preparation of resin solution A1-2)
Resin solution A1-2 was prepared by performing a synthetic reaction in the same manner as resin solution A1-1 except that dicyclopentanyl methacrylate in resin solution A1-1 was changed to dicyclopentenyl methacrylate. The weight average molecular weight was 12500.

(Preparation of resin solution A1-3)
Resin solution A1-3 was prepared by conducting a synthetic reaction in the same manner as resin solution A1-1 except that dicyclopentanyl methacrylate in resin solution A1-1 was changed to dicyclopentanyloxyethyl methacrylate. The weight average molecular weight was 12500.

(Preparation of resin solution A1-4)
Resin solution A1-4 was prepared by performing a synthetic reaction in the same manner as resin solution A1-1 except that dicyclopentanyl methacrylate in resin solution A1-1 was changed to dicyclopentenyloxyethyl methacrylate. The weight average molecular weight was 12500.

(Preparation of resin solution A3-1)
Put 40 parts of cyclohexanone in a reaction vessel equipped with a thermometer, cooling tube, nitrogen gas inlet tube, and stirrer in a separable four-necked flask, and heat to 100 ° C. while injecting nitrogen gas into the vessel. A mixture of 9.0 parts of styrene, 9.0 parts of methacrylic acid, 9.5 parts of methyl methacrylate, 9.5 parts of butyl methacrylate, and 1.5 parts of azobisisobutyronitrile was added dropwise over 1 hour to conduct a polymerization reaction. Went.
After the dropwise addition, the mixture was further reacted at 100 ° C. for 3 hours, 0.2 part of azobisisobutyronitrile dissolved in 5 parts of cyclohexanone was added, and the reaction was further continued at 100 ° C. for 1 hour to obtain a weight average molecular weight. Of about 40000 (measured by GPC).
After cooling to room temperature, about 2 g of the resin solution was sampled and heated and dried at 180 ° C. for 20 minutes to measure the nonvolatile content. Then, cyclohexanone was added to the previously synthesized resin solution so that the nonvolatile content was 40%. Resin solution A3-1 was prepared.

(Preparation of resin solution A3-2)
560 parts of cyclohexanone was placed in a reaction vessel, heated to 80 ° C. while injecting nitrogen gas into the vessel, and a mixture of the following monomer and thermal polymerization initiator was added dropwise at the same temperature over 1 hour to carry out a polymerization reaction. After completion of dropping, 34.0 parts of methacrylic acid, 23.0 parts of methyl methacrylate, 45.0 parts of n-butyl methacrylate, 47.0 parts of glycerol monomethacrylate, and 4.0 parts of 2,2′-azobisisobutyronitrile Further, after reacting at 80 ° C. for 3 hours, 1.0 part of azobisisobutyronitrile dissolved in 55 parts of cyclohexanone was added, and the reaction was further continued at 80 ° C. for 1 hour to obtain a copolymer solution. Got.
Next, with respect to 338 parts of the obtained copolymer solution, the mixture of the following compound was dripped at 70 degreeC over 3 hours. After cooling 22.0 parts of 2-methacryloylethyl isocyanate, 0.4 parts of dibutyltin laurate, and 120.0 parts of cyclohexanone to room temperature, about 2 g of the resin solution was sampled, heated and dried at 180 ° C. for 20 minutes, and nonvolatile. The photosensitive resin solution A3-2 was prepared by adding cyclohexanone to the previously synthesized resin solution so that the nonvolatile content was 20% by weight. The obtained photosensitive resin had a weight average molecular weight of 12,000.

[Example 1]
(Photosensitive resin composition 1)
A mixture having the following composition was stirred and mixed so as to be uniform, and then filtered through a 1 μm filter to obtain a photosensitive resin composition 1.

Resin solution A1-1 36.7 parts 0.7 parts of photopolymerization initiator (“Irgacure 907” manufactured by Ciba Specialty Chemicals)
7.0 parts of photopolymerizable monomer (in general formula (2), m = 1, a = 3, b = 3 monomer)
3-glycidoxypropyltrimethoxysilane 0.6 part propylene glycol monomethyl ether acetate 55.0 parts

[Examples 2 to 20, Comparative Examples 1 to 3]
(Photosensitive resin composition 2-23)
Except having changed into the composition shown in Table 1, and the compounding quantity, it carried out similarly to the photosensitive resin composition 1, and obtained the photosensitive resin compositions 2-23.

Abbreviations in Table 1 and Table 2 are shown below.
<Photoinitiator (B)>
・ Irgacure 907; “Irgacure 907” (manufactured by Ciba Japan)
2-methyl-1- (4-methylthiophenyl) -2-morpholinopropan-1-one Irgacure 369; “Irgacure 369” (manufactured by Ciba Japan)
2-Benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butan-1-one Irgacure OXE-01; “Irgacure OXE-01” (manufactured by Ciba Japan)
1,2-octadione-1- [4- (phenylthio)-, 2- (o-benzoyloxime)]
・ Irgacure OXE-02; “Irgacure OXE-02” (manufactured by Ciba Japan)
Ethanone, 1- [9-ethyl-6- (2-methylbenzoyl) -9H-carbazol-3-yl]-, 1- (o-acetyloxime

<Thermosetting resin (A2)>
MW-30; “Nikarak MW-30” (manufactured by Sanwa Chemical Co., Ltd.)
A mixture containing a compound in which R ^{1 to} R ⁶ of the general formula (2) are —CH ₂ OCH ₃ ; EX4931; epoxy resin represented by the following formula (3) (manufactured by Nagase Chemtech)
Formula (3)

<Adhesion promoting additive (E)>
Adhesion promoting additive a; 3-glycidoxypropyltrimethoxysilane Adhesion promoting additive b; 3-methacryloxypropyltrimethoxysilane <Antioxidant (C)>
Antioxidant a: hindered phenolic antioxidant 1,3,5-tris (4-t-butyl-3-hydroxy-2,6-dimethylbenzyl)
Antioxidant b: hindered amine antioxidant bis (2,2,6,6-tetramethyl-4-piperidyl) sebacate Antioxidant c; phosphorus antioxidant ethyl bisphosphite (2,4-di tert-butyl-6-methylphenyl)
Antioxidant d: sulfide antioxidant 2,2-thio-diethylenebis [3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate]
<Solvent>
・ PGMAc: Propylene glycol monomethyl ether acetate

The transmittance | permeability of the photosensitive coloring composition obtained by the Example and the comparative example, the adhesiveness with respect to glass and ITO, film | membrane hardness, and an electrical property evaluation were performed with the following method.
<Transmissivity>
The photosensitive resin composition was applied to a 100 mm × 100 mm, 1.1 mm thick glass substrate (Corning Glass Eagle 2000) using a spin coater to obtain a substrate. Next, after drying under reduced pressure, ultraviolet exposure was performed using an ultrahigh pressure mercury lamp with an integrated light quantity of 200 mJ. The coated substrate was heated at 230 ° C. for 20 minutes and allowed to cool, and then the transmittance (T) of the obtained coating film was determined using a microspectrophotometer (“OSP-SP100” manufactured by Olympus Optical Co., Ltd.). It was evaluated with.
Transmission evaluation criteria:
○: Transmittance 95.0% or more / good level Δ; Transmittance 90.0% or more and less than 95.0% / practical level although inferior to ○ ×: Transmittance less than 90.0% / practical Is not suitable level

<Adhesion to glass and ITO>
The adhesiveness of the coating film was evaluated by a cross-cut adhesion test method according to JIS K5400 on a photosensitive resin composition-coated substrate obtained by the same method as that prepared for the measurement of transmittance. The number of peels was counted and evaluated according to the following criteria.
As the substrate, Corning Glass Eagle 2000 and Santo Vacuum Industry ITO film were used.
Adhesion evaluation criteria:
○: Number of cross-cuts <3 △; 3 ≦ Number of cross-cuts ≦ 10 ×; Number of cross-cuts> 10

<Film hardness>
About the photosensitive resin composition coated substrate obtained by the same method as that prepared for the measurement of transmittance, the pencil hardness is measured by the 8.4.1 pencil scratch test of JIS K-5400-1990, and the surface of the protective film Hardness was evaluated according to the following criteria. When this value is 6H or higher, the surface hardness is good.
Film hardness evaluation criteria:
○: 6H or more △; 5H
×: 4H or less

<Electrical characteristics>
The photosensitive resin composition was applied on a 100 mm × 100 mm, 0.7 mm thick glass substrate on which aluminum was vapor-deposited for electrodes at a rotation speed of 2.0 μm using a spin coater to obtain a coated substrate. Next, after drying under reduced pressure, ultraviolet exposure was performed using an ultra-high pressure mercury lamp with an integrated light amount of 300 mJ and an illuminance of 30 mW. After alkali development, the coated substrate was heated at 230 ° C. for 1 hour and allowed to cool, and then aluminum for an electrode with an area of 3.464 × 10 ⁻⁴ m ² was vapor-deposited on the obtained cured coating film. A sample sandwiched between aluminum electrodes was prepared. A dielectric loss tangent of 10 Hz to 1 MHz of the obtained sample was obtained by using an impedance analyzer (“1260 type” manufactured by Solartron) with a relative dielectric constant at 1 kHz at an applied voltage of 100 mV and a dielectric loss tangent at 20 Hz. The electrical characteristics of the coating film were evaluated according to the following criteria based on dielectric constant values.
Electrical property evaluation criteria:
[Relative permittivity (1 kHz)]
○: Less than 3.6 ×: 3.6 or more [dielectric loss tangent (20 Hz)]
○: Less than 0.012 ×; 0.012 or more

The results are shown in Tables 3 and 4 below.

The cured film formed from the photosensitive resin composition of the present invention containing the resin (A1) and the antioxidant (C) not only has high transmittance, but also has high film hardness and adhesion. Was also good. Furthermore, the relative dielectric constant (1 kHz) also satisfied all of less than 3.6, which is generally desirable for protective films and insulating films for touch panels, and was excellent in electrical characteristics such as dielectric constant and dielectric loss tangent.

In addition, when used for an insulating film, the dielectric constant (20 Hz) also satisfied all less than 0.012, which is considered preferable.
Furthermore, when the photopolymerizable monomer (D) having the structure of the general formula (2) is included or when the adhesion promoter a is included, the adhesion to the glass substrate and the ITO layer is particularly excellent.

  Moreover, the photosensitive resin composition containing a hindered phenolic antioxidant, a hindered amine antioxidant, or a phosphorus antioxidant as an antioxidant has particularly excellent transmittance, and the thermosetting resin (A2) The photosensitive resin composition contained had good results in film hardness.

Claims (11)

A photosensitive resin composition containing a resin (A), a photopolymerization initiator (B), an antioxidant (C), and a photopolymerizable monomer (D), wherein the resin (A) is: (A1), (a2) and (a3) are copolymerized to obtain a copolymer (a6), and the obtained copolymer (a6) is reacted with an unsaturated monobasic acid (a4) to form a copolymer. A photosensitive resin composition comprising a resin (A1) obtained by obtaining a polymer (a7) and further reacting the obtained copolymer (a7) with a polybasic acid anhydride (a5) object.
(A1); Compound (a2) having an alicyclic skeleton and an ethylenically unsaturated bond in one molecule; Compound (a3) having an epoxy group and an ethylenically unsaturated bond in one molecule; (a1) and Compound (a4) having an ethylenically unsaturated bond other than (a2); Unsaturated monobasic acid (a5); Polybasic acid anhydride   The antioxidant (C) is any compound selected from the group consisting of a hindered phenol-based antioxidant, a hindered amine-based antioxidant, and a phosphorus-based antioxidant. Photosensitive resin composition.   Resin (A) contains thermosetting resin (A2) further, The photosensitive resin composition of Claim 1 or 2 characterized by the above-mentioned. The thermosetting resin (A2) includes a melamine compound having a structure represented by the following general formula (1) and having a weight average polymerization degree of 1.0 to 5.0. Item 4. The photosensitive resin composition according to Item 3.
General formula (1):

[In General Formula (1), R ^{1 to} R ⁶ are each independently a hydrogen atom or any one selected from the group consisting of —CH ₂ OH, —CH ₂ OCH ₃ , and —CH ₂ OC ₄ H ₉ . Represents a substituent of ]   The ratio ([C] / [A2]) of the weight [C] of the antioxidant (C) and the weight [A2] of the thermosetting resin (A2) is 0.005 to 0.1. The photosensitive resin composition according to claim 3 or 4.   6. The photosensitive resin composition according to claim 1, wherein the photopolymerization initiator (B) is an acetophenone photopolymerization initiator or an oxime ester photopolymerization initiator.   When the photopolymerization initiator (B) is 2-methyl-1- (4-methylthiophenyl) -2-morpholinopropan-1-one or 1,2-octadion-1- [4- (phenylthio)-, 2- ( The photosensitive resin composition according to claim 6, wherein: o-benzoyloxime)]. 8. The photosensitive resin composition according to claim 1, wherein the photopolymerizable monomer (D) is a compound represented by the general formula (2).
General formula (2):

[In General Formula (2), m represents an integer of 1 to 3, a represents an integer of 2 to 6, and b represents an integer of 0 to 4. However, a + b = 6. ]   Furthermore, the adhesion promotion additive (E) is contained, The photosensitive resin composition of any one of Claims 1-8 characterized by the above-mentioned.   The protective film formed using the photosensitive resin composition of any one of Claims 1-9.   The insulating film for touchscreens formed using the photosensitive resin composition of any one of Claims 1-9.