WO2012090298A1

WO2012090298A1 - Photocurable resin composition, protective coating agent, hard coating film, liquid crystal display module, and method for manufacturing same

Info

Publication number: WO2012090298A1
Application number: PCT/JP2010/073702
Authority: WO
Inventors: 朋子阿部; 藤井　徹也
Original assignee: 日立化成工業株式会社
Priority date: 2010-12-28
Filing date: 2010-12-28
Publication date: 2012-07-05

Abstract

The present invention provides a photocurable resin composition having properties necessary for protective coating treatment such as repairability, adhesiveness, humidity resistance, and heat cycle properties. When the photocurable resin composition is used as a protective coating agent, it is possible to easily confirm the presence or absence of a protective coating treatment. The photocurable resin composition comprises: (A) urethane oligomer; (B) a polymerizable compound having an ethylenically unsaturated group; (C) a photopolymerization initiator containing 2-methyl-1-[4-(methylthio)phenyl]-2-morpholino-propan-1-one; and (D) a leuco dye.

Description

Photo-curable resin composition, protective coating agent, cured film, liquid crystal display module and method for producing the same

The present invention relates to a photocurable resin composition, a protective coating agent, a cured film, a liquid crystal display module, and a method for producing the same.

In recent years, the demand for mobile communication devices, particularly mobile phones, has increased rapidly, and the demand for LCDs (liquid crystal displays) used therefor has also increased. In addition, for display devices such as televisions and personal computer monitors, the demand for LCDs is expected to increase in the future because LCDs can be increased in size and are light and thin.

LCDs are made by encapsulating a liquid crystal material between two glass substrates and pasting deflecting plates on the front and back of the combined glass, and ITO etc. on the surface encapsulating the liquid crystal material of each glass substrate The electrode is formed.

This LCD is a liquid crystal connected via a connecting member such as an anisotropic conductive film to a flexible wiring board on which a semiconductor chip (hereinafter sometimes referred to as “LCD driver IC”) for controlling driving and display of the LCD is mounted. Used as a display module. Known mounting methods for mounting an LCD driver IC on a flexible wiring board include TAB (Tape Automated Bonding), COF (Chip on Film), and the like. A COG (Chip on Glass) method is also known in which an LCD driver IC is directly mounted on an electrode formed on a glass substrate of an LCD.

The connection part between the lead electrode of the flexible wiring board in the mounting method such as TAB or COF or the bump electrode of the semiconductor chip in the COG mounting method and the electrode of the LCD needs to be protected from moisture, dust, etc. Insulation is performed. As this insulation treatment method, a coating treatment with a protective coating agent such as an acrylic resin or a urethane resin is widely adopted. Such a protective coating agent is generally used in a state dissolved in an organic solvent. The protective coating agent is applied to the connecting portion and dried to form a coating film, and the lead electrode or the bump electrode and the LCD electrode are protected.

However, these protective coating agents can cause air pollution because organic solvents are discharged into the atmosphere during the coating process, and have a high environmental impact. Moreover, since the process of drying an organic solvent is required after apply | coating a protective coating agent, there also existed a problem that work efficiency was inferior.

On the other hand, in the field of electronic components, in order to insulate various electronic components, a method using a photocurable resin composition substantially free of an organic solvent is known. For example, Patent Document 1 discloses a photocurable resin composition that contains an acrylic-modified hydrogenated polybutadiene resin and the like that is capable of moisture-proofing and insulating electronic components and does not substantially contain an organic solvent.

JP 2001-302946 A

However, the photocurable resin composition described in the cited document 1 is used as a protective film for a lead electrode of a flexible wiring board on which the LCD driver IC is mounted or a connection part between a bump electrode of a semiconductor chip and an electrode of an LCD. When used, the present inventors have clarified that it cannot be applied to this field because of insufficient curability.

If the above-mentioned protective coating agent is incomplete or only partially irradiated with light, the part may not be sufficiently cured and reliability such as moisture resistance may be reduced. For this reason, there is a need for a protective coating agent that not only contains substantially no organic solvent but also can clearly identify a portion cured by light irradiation. In addition, LCDs, LCD driver ICs are connected to flexible wiring boards or LCD driver ICs for flexible wiring boards equipped with LCD driver ICs, or connection bodies in which LCD driver ICs are connected to LCDs and the connection portions are coated with a protective coating agent. When a failure occurs, it is desirable to peel off the LCD from the flexible wiring board on which the LCD driver IC is mounted or the LCD driver IC, and replace the defective component with another component. For this reason, the repair property which can peel and remove the protective coating agent in a connection part easily is also calculated | required.

Therefore, an object of the present invention is to provide a material that satisfies these requirements and has performance necessary for protective coating treatment such as adhesion, moisture resistance, and heat cycleability. A further object of the present invention is to provide a protective coating agent, a cured film, a liquid crystal display module and a method for producing the same using the same.

In view of the above circumstances, the present invention provides (A) a urethane oligomer (hereinafter sometimes referred to as “(A) component”), (B) a polymerizable compound having an ethylenically unsaturated group (hereinafter sometimes referred to as “(B ) Component ”), (C) 2-methyl-1- [4- (methylthio) phenyl] -2-morpholino-propan-1-one (hereinafter sometimes referred to as“ component (C) ”), and ( D) A photocurable resin composition containing a leuco dye (hereinafter sometimes referred to as “component (D)”) is provided.

Such a photo-curable resin composition has high repair properties and performance necessary for protective coating treatment such as adhesion, moisture resistance, and heat cycle properties. Furthermore, since the color of the photocurable resin composition of the present invention is changed by irradiating and curing ultraviolet rays, the application of the composition and the confirmation of the curing of the composition can be easily performed. Therefore, when the photocurable resin composition of the present invention is used as a protective coating agent, the presence or absence of the protective coating treatment can be easily confirmed. Furthermore, since the photocurable resin composition of the present invention can be used as a protective coating agent without using an organic solvent, the environmental load is small.

The component (D) is preferably leuco crystal violet from the viewpoint that the color developability upon curing is further improved.

The component (A) is preferably a urethane oligomer having a (meth) acryloyl group from the viewpoint that the adhesiveness, moisture resistance, and heat cycle properties can be further improved.

The above-mentioned photocurable resin composition preferably does not substantially contain an organic solvent from the viewpoint of reducing the environmental load. “Substantially free of organic solvent” means that the content of the organic solvent in the photocurable resin composition is 3000 ppm or less, for example.

The present invention provides a protective coating for a connecting portion in which an electrode of a liquid crystal display and a lead electrode of a flexible wiring board are connected via a connecting member, and an electrode of a liquid crystal display and a bump electrode of a semiconductor chip via a connecting member. A protective coating agent comprising the above-mentioned photo-curable resin composition, which can be suitably used for a protective coating of connected connection parts.

The present invention provides a cured film obtained by photocuring the above-mentioned photocurable resin composition, and having a storage elastic modulus at 25 ° C. of 10 to 200 MPa. According to such a cured film, it is possible to sufficiently protect electrodes such as circuit electrodes, lead electrodes, and bump electrodes from moisture, dust, and the like. In addition, the storage elastic modulus of a cured film can be measured by the method as described in an Example, for example.

The present invention includes a step of connecting an electrode of a liquid crystal display and a lead electrode of a flexible wiring board via a connecting member, and the above-described photocuring so as to cover the electrode of the liquid crystal display, the lead electrode of the flexible wiring board, and the connecting member. The manufacturing method of a liquid crystal display module including the process of apply | coating an adhesive resin composition and forming a coating film, and the process of irradiating an actinic ray to a coating film is provided.

The present invention also includes a step of connecting the electrode of the liquid crystal display and the bump electrode of the semiconductor chip via a connection member, and the photocurable property described above so as to cover the electrode of the liquid crystal display, the bump electrode of the semiconductor chip and the connection member. Provided is a method for producing a liquid crystal display module, comprising a step of applying a resin composition to form a coating film and a step of irradiating the coating film with actinic rays.

The present invention further provides a liquid crystal display module manufactured by these manufacturing methods.

The photocurable resin composition of the present invention has high repair properties and performance necessary for protective coating treatment such as adhesion, moisture resistance, and heat cycle properties. Furthermore, when the photocurable resin composition of the present invention is used as a protective coating agent, the presence or absence of a protective coating treatment can be easily confirmed. Furthermore, according to this invention, the protective coating agent using this photocurable resin composition, a cured film, a liquid crystal display module, and its manufacturing method are provided.

It is a schematic cross section which shows an example of the liquid crystal display module of this embodiment to which the liquid crystal display and the flexible wiring board (TAB mounting system) were connected. It is a schematic cross section which shows an example of the liquid crystal display module of this embodiment to which the liquid crystal display and the flexible wiring board (COF mounting system) were connected. It is a schematic cross section which shows an example of the liquid crystal display module of this embodiment by which the semiconductor chip was mounted on the glass substrate of a liquid crystal display (COG mounting system).

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings, but the present invention is not limited to the embodiments. In the drawings, the same or corresponding parts are denoted by the same reference numerals, and redundant description is omitted.

In this specification, “(meth) acrylate” means “acrylate” and “methacrylate” corresponding thereto. Similarly, “(meth) acryl” means “acryl” and “methacryl” corresponding thereto, and “(meth) acryloyl” means “acryloyl” and corresponding “methacryloyl”.

The photocurable resin composition of the present embodiment includes (A) a urethane oligomer, (B) a polymerizable compound having an ethylenically unsaturated group, (C) 2-methyl-1- [4- (methylthio) phenyl. ] A photopolymerization initiator containing 2-morpholino-propan-1-one, and (D) a leuco dye. Hereinafter, each component will be described.

<(A) component: Urethane oligomer>
The (A) urethane oligomer can be obtained, for example, by reacting (a1) a diol compound with (a2) a compound having an isocyanate group.

Examples of (a1) diol compounds include polyolefin diols such as polyethylene glycol, polypropylene glycol, polybutadiene diol, polyisoprene diol, hydrogenated polybutadiene diol, hydrogenated polyisoprene diol, polyether diol, polyester diol, polycaprolactone diol, and silicone. Diols are mentioned. Among these, polyolefin diol is preferable from the viewpoints of flexibility (reduction in storage elastic modulus) and adhesiveness.

Some of the polybutadiene diols and polyisoprene diols have “1,4-repeating units” or “1,2-repeating units”.

Here, in the polybutadiene, the “1,4-repeat unit” is a repeat unit represented by the following chemical formula (1t) or (1c), and the “1,2-repeat unit” is the following chemical formula: It is a repeating unit represented by (1d).

Examples of the polybutadiene diol mainly having 1,4-repeating units include Poly bd R-45HT and Poly bd R-15HT (trade name, manufactured by Idemitsu Kosan Co., Ltd.). Examples of the polybutadiene diol mainly having 1,2-repeating units include compounds represented by the following general formula (1a), specifically, G-1000, G-2000, G-3000 (1,2 -Content ratio of repeating unit: 85% or more, Nippon Soda Co., Ltd., trade name). Examples of the polyisoprene diol mainly having 1,2-repeat units include Poly IP (trade name, manufactured by Idemitsu Kosan Co., Ltd.).

[In the formula (1a), n1 represents an integer of 1 to 60. ]

Among these polyolefin diols, particularly from the viewpoint of heat cycleability, hydrogenation mainly having 1,2-repeating units represented by the following general formula (1b) obtained by hydrogenating the polybutadiene polyol of the above general formula (1a). Polybutadiene diol is preferred. In the hydrogenated polybutadiene polyol and hydrogenated polyisoprene polyol, all unsaturated double bonds may not be hydrogenated, and a few unsaturated double bonds may remain (iodine value (I ₂ mg / 100 g) is preferably 21 or less).

[In the formula (1b), n2 represents an integer of 1 to 60. ]

(A2) As a compound which has an isocyanate group, the diisocyanate compound represented by following General formula (2) is mentioned, for example.
OCN-X-NCO (2)
[In formula (2), X represents a divalent organic group. ]

Examples of the divalent organic group represented by X in the general formula (2) include, for example, an alkylene group having 1 to 20 carbon atoms, an unsubstituted or substituted lower alkyl group having 1 to 5 carbon atoms such as a methyl group. And arylene groups such as a phenylene group and a naphthylene group. The number of carbon atoms of the alkylene group is more preferably 1-18. The divalent organic group represented by X has an aromatic ring such as a phenylene group, a xylylene group, a naphthylene group, a diphenylmethane-4,4′-diyl group, a diphenylsulfone-4,4′-diyl group. Groups are preferred. A hydrogenated diphenylmethane-4,4'-diyl group is also preferred.

Examples of the diisocyanates represented by the general formula (2) include diphenylmethane-2,4′-diisocyanate; 3,2′-, 3,3′-, 4,2′-, 4,3 ′. -, 5,2'-, 5,3'-, 6,2'- or 6,3'-dimethyldiphenylmethane-2,4'-diisocyanate; 3,2'-, 3,3'-, 4,2 '-, 4,3'-, 5,2'-, 5,3'-, 6,2'- or 6,3'-diethyldiphenylmethane-2,4'-diisocyanate; 3,2'-, 3, 3'-, 4,2'-, 4,3'-, 5,2'-, 5,3'-, 6,2'- or 6,3'-dimethoxydiphenylmethane-2,4'-diisocyanate; diphenylmethane -4,4'-diisocyanate; diphenylmethane-3,3'-diisocyanate; Diphenylmethane diisocyanate compounds such as rumethane-3,4′-diisocyanate and their hydrogenated products; diphenyl ether-4,4′-diisocyanate; benzophenone-4,4′-diisocyanate; diphenylsulfone-4,4′-diisocyanate; 2,4-diisocyanate; tolylene-2,6-diisocyanate; m-xylylene diisocyanate; p-xylylene diisocyanate; 1,5-naphthalene diisocyanate; 4,4 '-[2,2bis (4-phenoxyphenyl) propane Diisocyanate; Hexamethylene diisocyanate; 2,2,4-trimethylhexamethylene diisocyanate; Isophorone diisocyanate; 4,4'-dicyclohexylmethane diisocyanate; Hexane-1,4-diisocyanate; hydrogenated m- xylylene diisocyanate, aliphatic or alicyclic isocyanates such lysine diisocyanate. Like these diisocyanates, it is preferable to use an aromatic diisocyanate compound in which X in the formula (2) is a group having an aromatic ring. These can be used alone or in combination of two or more. In addition, as a compound which has an isocyanate group, you may use trifunctional or more polyisocyanate with the diisocyanate represented by General formula (2).

Moreover, the diisocyanates represented by the general formula (2) may be those stabilized with a blocking agent necessary to avoid changes over time. Examples of the blocking agent include hydroxy acrylate, alcohol typified by methanol, phenol, and oxime, but are not particularly limited.

The blending ratio when the (a1) diol compound and the diisocyanate represented by the general formula (2) are reacted is the number average molecular weight of the urethane oligomer to be produced and the terminal of the urethane oligomer to be produced is a hydroxyl group. Or an isocyanate group.

When the terminal of the urethane oligomer is a hydroxyl group, the blending ratio is preferably adjusted so that the ratio between the number of hydroxyl groups and the number of isocyanate groups (number of hydroxyl groups / isocyanate groups) is 1.01 or more, and the number average molecular weight is increased. It is preferable to adjust to less than 2 from a viewpoint.

When the terminal of the urethane oligomer is a hydroxyl group, monocarboxylic acids having a (meth) acryloyl group such as acetic acid and (meth) acrylic acid, and a monoisocyanate compound having a (meth) acryloyl group such as 2-isocyanatoethyl (meth) acrylate Alternatively, the terminal of the urethane oligomer may be modified by reacting a terminal hydroxyl group with a compound capable of reacting with a hydroxyl group such as acid anhydrides.

Moreover, when making the terminal of a urethane oligomer into an isocyanate group, it is preferable to adjust so that the ratio (the number of isocyanate groups / number of hydroxyl groups) of the number of isocyanate groups and the number of hydroxyl groups may be 1.01 or more, and a number average molecular weight is enlarged. It is preferable to adjust to less than 2 from a viewpoint. By setting it as such a ratio, it becomes a urethane oligomer by which the terminal is an isocyanate group, and it can make it easy to introduce | transduce various frame | skeletons. Examples of the compound for introducing various skeletons include compounds capable of reacting with isocyanate groups such as monohydroxy compounds, lactams, oximes, monocarboxylic acids, and divalent acid anhydrides.

Examples of the monohydroxy compound include 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, 1,4-cyclohexanedimethanol mono (meth) acrylate, Caprolactone or alkylene oxide adduct of each (meth) acrylate, glycerin di (meth) acrylate, trimethylol di (meth) acrylate, pentaerythritol tri (meth) acrylate, dipentaerythritol penta (meth) acrylate, ditrimethylolpropane tri ( Monohydroxy compounds having a (meth) acryloyl group such as (meth) acrylate and 2-acryloxyethanol, and monohydrides having a carboxylic acid such as glycolic acid and hydroxypivalic acid Alkoxy compounds. These monohydroxy compounds can be used alone or in combination of two or more.

The urethane oligomer preferably has a (meth) acryloyl group from the viewpoint of improving toughness and further improving adhesiveness, moisture resistance, and heat cycle properties. As described above, the urethane oligomer having a (meth) acryloyl group reacts with a monocarboxylic acid having a (meth) acryloyl group or a monoisocyanate compound having a (meth) acryloyl group when the terminal of the urethane oligomer is a hydroxyl group. In addition, when the terminal of the urethane oligomer is an isocyanate group, it can be obtained by reacting a monohydroxy compound having a (meth) acryloyl group.

From the viewpoint of further improving heat cycle properties and curability, urethane oligomers having a (meth) acryloyl group and a hydrogenated polybutadiene structure mainly having 1,2-repeating units are preferred. The urethane oligomer having a hydrogenated polybutadiene structure mainly having a (meth) acryloyl group and 1,2-repeat units is, for example, a hydrogenated polybutadiene diol represented by the above general formula (1b), or a general formula (2). It can be synthesized from the diisocyanate compound represented and a monohydroxy compound having a (meth) acryloyl group.

The reaction of the diol compound in the production of the urethane oligomer used as the component (A) with the diisocyanate represented by the general formula (2) and a compound for introducing various skeletons is an organic solvent, preferably This can be carried out by heat condensation in the presence of a non-nitrogen-containing polar solvent.

Examples of the non-nitrogen-containing polar solvent include ether solvents such as diethylene glycol dimethyl ether, diethylene glycol diethyl ether, triethylene glycol dimethyl ether, and triethylene glycol diethyl ether; sulfur-containing solvents such as dimethyl sulfoxide, diethyl sulfoxide, dimethyl sulfone, and sulfolane; Examples thereof include ester solvents such as γ-butyrolactone and cellosolve acetate; ketone solvents such as cyclohexanone and methyl ethyl ketone; and aromatic hydrocarbon solvents such as toluene and xylene. These can be used alone or in combination of two or more.

Among the above solvents, it is preferable to select and use a solvent capable of dissolving the generated urethane oligomer.

If necessary, the reaction may be carried out in the presence of a catalyst such as a tertiary amine, an alkali metal, an alkaline earth metal, a metal such as tin, zinc, titanium, cobalt, or a metalloid compound.

The number average molecular weight of the urethane oligomer (A) thus obtained is preferably from 500 to 7000, from the viewpoint of curability, flexibility (reduction in storage elastic modulus), and coatability, and preferably from 1,000 to It is more preferably 5,000, particularly preferably 1,500 to 4,000.

In the present specification, the number average molecular weight is a value measured by gel permeation chromatography (GPC) and converted using a standard polystyrene calibration curve. Further, the number average molecular weight, the weight average molecular weight, and the degree of dispersion are defined as follows.
(A) Number average molecular weight (Mn)
Mn = Σ (N _i M _i ) / ΣNi = ΣX _i M _i
(X _i = Mole fraction of molecules with molecular weight M _i = N _i / ΣN _i )
(B) Weight average molecular weight (Mw)
Mw = Σ (N _i M _i ² ) / ΣN _i M _i = ΣW _i M _i
(W _i = weight fraction of molecules of molecular weight M _i = N _i M _i / ΣN _i M _i )
(C) Molecular weight distribution (dispersion degree)
Dispersity = Mw / Mn

The content of the component (A) is based on 100 parts by mass of the total amount of the component (A) and the component (B) from the viewpoint of further improving curability, adhesiveness, and flexibility (reduction in storage elastic modulus). 40 to 70 parts by mass, more preferably 45 to 60 parts by mass, and particularly preferably 50 to 55 parts by mass.

<(B) component: polymerizable compound having an ethylenically unsaturated group>
(B) The polymerizable compound having an ethylenically unsaturated group is preferably liquid at room temperature (25 ° C.) and can dissolve the component (C) described below. For example, (B1) ethylenically unsaturated A polymerizable compound containing a double bond and a cyclic aliphatic group (hereinafter also referred to as “component (B1)”), (B2) a polymerizable compound having 5 to 10 ethylenically unsaturated double bonds in the molecule (Hereinafter also referred to as “component (B2)”), (B3) polymerizable compounds represented by the following general formula (3) (hereinafter also referred to as “component (B3)”).

(In Formula (3), R ¹ represents a hydrogen atom or a methyl group, and R ² represents an alkyl group having 4 to 20 carbon atoms.)

As the component (B1), a monofunctional or polyfunctional polymerizable compound having a vinyl group, an acryloyl group, a methacryloyl group, etc., and a monocyclic or condensed ring made of a saturated or unsaturated hydrocarbon alone or Two or more types can be used in combination. By having an ethylenically unsaturated double bond and a cyclic aliphatic group, the adhesion tends to be further improved.

Among these (B1) components, those having an acryloyl group or a methacryloyl group ((meth) acrylate compound) include, for example, cyclohexyl (meth) acrylate, norbornyl (meth) acrylate, isobornyl (meth) acrylate, norbornanyl (meth) ) Acrylate, dicyclopentenyl (meth) acrylate, dicyclopentenyloxyethyl (meth) acrylate, dicyclopentanyl (meth) acrylate, dicyclopentanyloxyethyl (meth) acrylate, tricyclodecane dimethylol di (meth) An acrylate is mentioned. Moreover, what has vinyl groups, such as vinyl norbornene and vinyl norbornane, can also be used. Among these polymerizable compounds, an isobornyl (meth) acrylate compound is preferable from the viewpoint of further improving the strength and adhesiveness of the cured product.

Examples of the component (B2) include dipentaerythritol penta (meth) acrylate, dipentaerythritol hexa (meth) acrylate, dipentaerythritol monohydroxypenta (meth) acrylate, and dipentaerythritol hexahydroxy (meth) acrylate. Can be mentioned.

(B2) By using a component, sclerosis | hardenability can be improved more without impairing adhesiveness.

As the component (B3), in the general formula (3), R ² is preferably an alkyl group having 6 to 18 carbon atoms, and an alkyl group having 8 to 16 carbon atoms from the viewpoint of further improving flexibility (reduction in storage modulus). More preferred are groups of 10 to 14 alkyl groups.

Examples of the polymerizable compound represented by the general formula (3) include n-butyl (meth) acrylate, tert-butyl (meth) acrylate, isobutyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, isodecyl ( Examples include (meth) acrylate, n-hexyl (meth) acrylate, stearyl (meth) acrylate, lauryl (meth) acrylate, and tridecyl (meth) acrylate. These can be used alone or in combination of two or more.

(B3) By using a component, the storage elastic modulus of hardened | cured material can be reduced more.

In addition, as the component (B), a polymerizable compound having an ethylenically unsaturated group other than the above can be used in combination, and has a vinyl group, an acryloyl group, a methacryloyl group, or the like, which is monofunctional or polyfunctional. A polymerizable compound can be used.

Of these, (meth) acrylate compounds having an acryloyl group or a methacryloyl group are preferred. For example, methyl (meth) acrylate, ethyl (meth) acrylate, n-propyl (meth) acrylate, ethoxyethyl (meth) acrylate, methoxyethyl Alkoxyalkyl (meth) acrylates such as (meth) acrylate, butoxyethyl (meth) acrylate, 2-methoxyethoxyethyl (meth) acrylate, 2-ethoxyethoxyethyl (meth) acrylate, glycidyl (meth) acrylate, 2-hydroxyethyl Hydroxyalkyl (meth) acrylates such as (meth) acrylate and 2-hydroxypropyl (meth) acrylate, methoxydiethylene glycol (meth) acrylate, ethoxydiethyl Alkoxy (poly) alkylene glycol (meth) acrylate such as glycol (meth) acrylate, methoxydipropylene glycol (meth) acrylate, fluorinated alkyl (meth) acrylate such as octafluoropentyl (meth) acrylate, N, N-dimethylamino Dialkylaminoalkyl (meth) acrylates such as ethyl (meth) acrylate, N, N-diethylaminoethyl (meth) acrylate, allyl (meth) acrylate, 1,3-butanediol (meth) acrylate, 1,4-butanediol ( Monofunctional (meth) acrylate compounds such as glycol mono (meth) acrylates such as (meth) acrylate, 1,6-hexanediol (meth) acrylate and 3-methylpentanediol (meth) acrylate , Polyethylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, neopentyl glycol di (meth) acrylate, triethylene glycol di (meth) acrylate, tripropylene glycol di (meth) acrylate, hydroxypivalate ester neopentyl glycol Di (meth) acrylate, trimethylolpropane di (meth) acrylate, 1,3-bis (hydroxyethyl) -5,5-dimethylhydantoin di (meth) acrylate, α, ω-di (meth) acrylbisdiethylene glycol phthalate, Trimethylolpropane tri (meth) acrylate, 2-hydroxyethyl (meth) acryloyl phosphate, trimethylolpropane tri (meth) acrylate, ethylene glyco Rudi (meth) acrylate, tetraethylene glycol di (meth) acrylate, polyethylene glycol di (meth) acrylate, 1,4-butanediol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, diacryloxy Multifunctional (meth) acrylates such as ethyl phosphate, dipentaerythritol trihydroxy (meth) acrylate, trimethylolpropane tri (meth) acrylate, pentaerythritol tri (meth) acrylate, pentaerythritol tetra (meth) acrylate .

Further, acrylamide derivatives such as acrylamide, dimethylacrylamide, diethylacrylamide, and (meth) acryloylmorpholine can also be used. Further, those having a vinyl group such as α, ω-tetraallylbistrimethylolpropane tetrahydrophthalate, N-vinylpyrrolidone, N-vinylcaprolactam can also be used.

The content of these components (B) can be adjusted to a viscosity range suitable for the workability of the curable and photocurable resin composition (hereinafter sometimes referred to as “workability”), and the resulting curing is obtained. From the viewpoint of moisture resistance of the film, 30 to 60 parts by weight, preferably 40 to 55 parts by weight, more preferably 45 to 50 parts by weight with respect to 100 parts by weight of the total amount of component (A) and component (B). Particularly preferred.
In the present invention, it is preferable to use the component (B1) and the component (B2) in combination from the viewpoint of further improving adhesion, curability, moisture resistance and workability.

When the component (B1) and the component (B2) are used in combination, the content of the component (B1) is preferably 20 to 55 parts by mass with respect to 100 parts by mass as the total of the components (A) and (B). 25 to 50 parts by mass is more preferable, and 30 to 45 parts by mass is particularly preferable.
When the content of the component (B1) is 20 parts by mass or more, the adhesiveness and workability are excellent, and when it is 55 parts by mass or less, moisture resistance can be further improved.

The content of the component (B2) when the component (B1) and the component (B2) are used together is 100 masses of the total amount of the component (A) and the component (B) from the viewpoint of improving the curability and adhesiveness in a balanced manner. 1 to 20 parts by mass is preferable, 2 to 15 parts by mass is more preferable, and 3 to 10 parts by mass is particularly preferable.

Furthermore, it is preferable to use the component (B3) from the viewpoint of further improving the flexibility (reduction in storage elastic modulus).
When the component (B3) is used, the content is preferably 1 to 10 parts by mass, more preferably 1.5 to 10 parts by mass with respect to 100 parts by mass as the total of the components (A) and (B). 2 to 8 parts by mass is particularly preferred.

<Component (C): 2-methyl-1- [4- (methylthio) phenyl] -2-morpholino-propan-1-one>
(C) 2-Methyl-1- [4- (methylthio) phenyl] -2-morpholino-propan-1-one is a photopolymerization initiator having the following structure.

2-Methyl-1- [4- (methylthio) phenyl] -2-morpholino-propan-1-one is excellent in solubility in the component (B) and has surface curability on the coated surface of the photocurable resin composition. In addition to excellent bottom curability.

The content of the component (C) is preferably 1 to 15 parts by mass with respect to 100 parts by mass of the total amount of the component (A) and the component (B) from the viewpoint of further improving curability, repairability and color developability. Is more preferably from 10 to 10 parts by weight, particularly preferably from 3 to 9 parts by weight, and most preferably from 5 to 8 parts by weight.

The photocurable resin composition of the present embodiment may contain a photopolymerization initiator other than the component (C) as long as various properties are not impaired. Examples of such a photopolymerization initiator include acridine or an acridine compound having at least one acridinyl group in the molecule, benzophenone, N, N′-tetramethyl-4,4′-diaminobenzophenone (Michler's ketone), and the like. Aromatic ketones such as N, N′-tetraalkyl-4,4′-diaminobenzophenone and 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butanone-1, and quinones such as alkylanthraquinone Benzoin ether compounds such as benzoin alkyl ether, benzoin compounds such as benzoin and alkylbenzoin, benzyl derivatives such as benzyldimethyl ketal, 2- (o-chlorophenyl) -4,5-diphenylimidazole dimer, 2- (o -Chlorophenyl) -4,5-di Methoxyphenyl) imidazole dimer, 2- (o-fluorophenyl) -4,5-diphenylimidazole dimer, 2- (o-methoxyphenyl) -4,5-diphenylimidazole dimer, 2- (p -Methoxyphenyl) -4,5-diphenylimidazole dimer, 2,4,5-triarylimidazole dimer, N-phenylglycine, N-phenylglycine derivatives, coumarin compounds, onium salts.

<(D) component: leuco dye>
(D) As the leuco dye, for example, leuco crystal violet, leucomalachite green, leuco victoria blue BH, leuco victoria pure blue BOH, leuco diamond green, leuco acid violet 5B, leuco solar cyanine 6B, leuco brilliant green, 3, 6 -Bisdiethylamino-9-phenylxanthene. Among these, leuco crystal violet (Tris (4-dimethylaminophenyl) methane) is preferable from the viewpoints of color developability, discoloration, color tone, and the like.

A leuco dye is a reduction-type pigment composed of a colorless or light-colored electron-donating pigment (dye) precursor, and has an action of coloring when mixed with a compound having an acidic group and heated. In addition, it is known that leuco dyes are colored by irradiation with ultraviolet rays in the presence of an organic halogen compound. However, when using a photocurable resin composition as a protective film, it may become a factor which reduces migration resistance when it contains a compound having an acidic group (including a photoacid generator) or an organic halogen compound. In the photocurable resin composition of the present embodiment, the component (C) is used in combination with a leuco dye, particularly leuco crystal violet, even if it does not substantially contain a compound having an acidic group as described above or an organic halogen compound. Thus, excellent color developability is exhibited by irradiating light without heating.
“Substantially free” means that the amount of the compound having an acidic group or the organic halogen compound is small (less than 100 ppm, preferably 50 ppm in the total amount of the photocurable resin composition) as long as the properties of the present invention are not impaired. The following is more preferable), but it is particularly preferably not contained.

The content of the component (D) is 0.01 to 3 parts by mass with respect to 100 parts by mass of the total amount of the component (A) and the component (B) from the viewpoint that the curability and color developability can be further improved. Preferably, 0.05 to 2 parts by mass is more preferable, 0.1 to 1 part by mass is particularly preferable, and 0.2 to 0.5 part by mass is most preferable.

A coupling agent, a filler, a polymerization inhibitor, a modifier, an antifoaming agent, and the like can be arbitrarily added to the photocurable resin composition of the present embodiment as necessary.

Examples of the coupling agent include titanate coupling agents and silane coupling agents. Examples of the titanate coupling agent include a titanate coupling agent having an alkylate group having at least 1 to 60 carbon atoms, a titanate coupling agent having an alkyl phosphite group, and a titanate coupling agent having an alkyl phosphate group. And titanate coupling agents having an alkyl pyrophosphate group. Specifically, isopropyl triisostearoyl titanate, isopropyl trioctanoyl titanate, isopropyl dimethacryl isostearoyl titanate, isopropyl isostearoyl diacryl titanate, isopropyl tris (dioctyl pyrophosphate) titanate, tetraoctyl bis (ditridecyl phosphite) titanate, Examples thereof include tetra (2,2-diallyloxymethyl-1-butyl) bis (ditridecyl) phosphite titanate, bis (dioctylpyrophosphate) oxyacetate titanate, and bis (dioctylpyrophosphate) ethylene titanate.

Examples of silane coupling agents include amino silane coupling agents, ureido silane coupling agents, vinyl silane coupling agents, methacrylic silane coupling agents, epoxy silane coupling agents, and mercapto silane cups. Examples thereof include a ring agent and an isocyanate-based silane coupling agent. Specifically, γ-aminopropyltriethoxysilane, γ-aminopropyltrimethoxysilane, N-β- (aminoethyl) -γ-aminopropyltrimethoxysilane, γ-phenylaminopropyltrimethoxysilane, ureidopropyltrimethoxysilane, Ethoxysilane, vinyltriethoxysilane, vinyltrimethoxysilane, vinyltris (β-methoxyethoxy) silane, γ-methacryloxypropyltrimethoxysilane, γ-methacryloxypropylmethyldimethoxysilane, β- (3,4-epoxycyclohexyl) Examples include ethyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-mercaptopropyltrimethoxysilane, γ-isocyanatopropyltrimethoxysilane, and γ-isocyanatopropyltriethoxysilane. It is. Among these, γ-isocyanatopropyltriethoxysilane is preferable from the viewpoint of further improving adhesiveness. These can be used alone or in combination of two or more. The content of these coupling agents is usually preferably 0.01 to 10 parts by weight, more preferably 0.05 to 5 parts by weight, based on 100 parts by weight of the total amount of the photocurable resin composition. The amount is preferably 0.1 to 2 parts by mass.

Examples of the filler include inorganic fine particles such as fine powdered silicon oxide, magnesium oxide, aluminum hydroxide, and calcium carbonate.

As polymerization inhibitors, for example, hydroquinone, hydroquinone monomethyl ether, benzoquinone, p-tert-butylcatechol, quinones such as 2,6-di-tert-butyl-4-methylphenol, pyrogallol, and other generally used Things can be used.

Examples of the modifier include a leveling agent for improving leveling properties. Examples of the leveling agent include a polyether-modified dimethylpolysiloxane copolymer, a polyester-modified dimethylpolysiloxane copolymer, a polyether-modified methylalkylpolysiloxane copolymer, and an aralkyl-modified methylalkylpolysiloxane copolymer.

Examples of the antifoaming agent include known defoaming agents such as silicon oil, fluorine oil, and polycarboxylic acid polymer.

The photocurable resin composition of the present embodiment can be used by blending the above-described components (A), (B), (C) and (D), and other optional components, and dissolving them by heating. There is no need to use organic solvents.

[Protective coating agent]
The above-mentioned photocurable resin composition can be suitably used as a protective coating agent for a portion that needs to be protected from moisture, dust and the like. Particularly preferably, the protective coating agent comprising the above-mentioned photocurable resin composition is used for protective coating treatment of a connection portion in a liquid crystal display described later.

Protective coating treatment with the photocurable resin composition of the present embodiment can be performed, for example, as follows. First, a photocurable resin composition is applied to a portion to be protected to form a coating film. Next, the coating is irradiated with a necessary amount of ultraviolet rays and cured to form a cured body. The portion to be protected is protected by the cured body.

The method of applying the photocurable resin composition to the protection target can be appropriately changed depending on the shape of the portion to be protected, for example, a coating method using a dispenser device, a dipping method, a brush coating method, a spray method. A wire drawing method or the like can be applied.

Irradiation with ultraviolet rays can be performed using, for example, a high-pressure mercury lamp, a metal halide lamp, an LED, or the like as a light source.

When applied using a dispenser, the viscosity (25 ° C.) of the photocurable resin composition of the present embodiment is preferably 1 to 10 Pa · s, and more preferably 2 to 5 Pa · s. For example, the viscosity of the rotor No. is measured at 25 ° C. using a BL type viscometer (manufactured by Tokimec). 3. It can be measured under the condition that the photocurable resin composition amount is 120 g, the rotation speed is 30 rpm, and the rotation is performed for 3 minutes.

The cured film obtained by curing the photocurable resin composition of the present embodiment preferably has a storage elastic modulus at 25 ° C. of 10 to 200 MPa from the viewpoint of further improving heat cycle properties. Is more preferable.

[LCD module]
Hereinafter, the liquid crystal display module of the present embodiment will be described with reference to FIGS.

FIG. 1 is a schematic cross-sectional view showing an example of a liquid crystal display module of this embodiment in which a liquid crystal display and a flexible wiring board (TAB mounting method) are connected. In the liquid crystal display module 100 of the present embodiment, the connection part in which the electrode 22 in the liquid crystal display and the lead electrode 13 in the flexible wiring board are connected via the connection member 24 is cured by the photocurable resin composition of the present embodiment. The structure is covered with the body 1. In the liquid crystal display, an electrode 22 is formed on a glass substrate (lower glass) 23, and a glass substrate (upper glass) 21 is bonded to the upper surface thereof using a sealing material 25, and is surrounded by the sealing material 25 at a gap between the

glass substrates

21 and 23. This is obtained by injecting liquid crystal (not shown) under reduced pressure into the broken portion. In addition, the flexible wiring board has, for example, an adhesive layer 14 on a polyimide film 15, a lead electrode 13 is formed on the upper layer, a solder resist 16 is applied on the upper layer, and the semiconductor chip 11 and the bump electrode 12 are connected. , And its periphery is obtained by sealing with a liquid sealing material 17.

FIG. 2 is a schematic cross-sectional view showing an example of the liquid crystal display module of the present embodiment in which a liquid crystal display and a flexible wiring board (COF mounting method) are connected. In the liquid crystal display module 200 of the present embodiment, the connection part in which the electrode 42 in the liquid crystal display and the lead electrode 33 in the flexible wiring board are connected via the connection member 44 is cured by the photocurable resin composition of the present embodiment. The structure is covered with the body 2. In the liquid crystal display, an electrode 42 is formed on a glass substrate (lower glass) 43 in the same manner as in the TAB mounting method, and a glass substrate (upper glass) 41 is bonded to the upper surface using a sealing material 45, and

glass substrates

41 and 43 are attached. This is obtained by injecting liquid crystal (not shown) under reduced pressure into a portion surrounded by the sealing material 45 in the gap. Further, the flexible wiring board is formed, for example, by forming a lead electrode 33 on a polyimide film 34, further applying a solder resist 36 on the upper layer, and connecting the semiconductor chip 31 with the bump electrode 32, and sealing the periphery with a connection member 37. Is obtained.

The connection portions between the

electrodes

22 and 42 and the

lead electrodes

13 and 33 in the liquid

crystal display modules

100 and 200 described above can be formed by the following method, for example.

First, the

electrodes

22 and 42 and the

lead electrodes

13 and 33 are connected through the

connection members

24 and 44. Next, a coating film is formed by applying the photocurable resin composition of the present embodiment so as to cover the

electrodes

22 and 42, the

lead electrodes

13 and 33, and the

connection members

24 and 44. The connection portion can be formed by irradiating the coating film with an actinic ray and curing it.

As the

connection members

24 and 44, for example, an anisotropic conductive film (ACF), a non-conductive film (NCF), and a non-conductive paste (NCP) can be suitably used. The above-described connection can be performed under known conditions according to the characteristics of the connection member used.

Formation of the coating film and irradiation with actinic rays can be performed, for example, by the method described in the protective coating process described above.

FIG. 3 is a schematic cross-sectional view showing an example of the liquid crystal display module of the present embodiment in which a semiconductor chip is mounted on a glass substrate of a liquid crystal display (COG mounting method). In the liquid crystal display module 300 of the present embodiment, the connection part in which the electrode 62 in the liquid crystal display and the bump electrode 52 in the semiconductor chip 51 are connected via the connection member 53 is a cured body of the photocurable resin composition of the present embodiment. 3 is covered. In the liquid crystal display, an electrode 62 is formed on a glass substrate (lower glass) 63, a glass substrate (upper glass) 61 is bonded to the upper surface of the electrode 62 using a sealing material 64, and the sealing material 64 is surrounded by a gap between the

glass substrates

61 and 63. This is obtained by injecting liquid crystal (not shown) under reduced pressure into the broken portion.

The connection portion between the electrode 62 and the bump electrode 52 in the liquid crystal display module 300 described above can be formed by, for example, the following method.

First, the electrode 62 and the bump electrode 52 are connected via the connection member 53. Next, a coating film is formed by applying the photocurable resin composition of the present embodiment so as to cover the electrode 62, the bump electrode 52, and the connection member 53. The connection portion can be formed by irradiating the coating film with an actinic ray and curing it.

For connection using the connection member 53, formation of the coating film, and curing, the same method as in the case of the liquid

crystal display modules

100 and 200 described above can be applied.

The case where the photocurable resin composition of the present embodiment is applied to a liquid crystal display module has been described above. However, the photocurable resin composition of the present embodiment includes a microcomputer, a transistor, a capacitor, a resistor, a relay, a transformer, and the like. And a mounting circuit board on which these are mounted, and further, can be applied to protective coating processing for lead wires, harnesses, film substrates and the like that are joined to these electronic components.

Hereinafter, the present invention will be described more specifically with reference to examples and comparative examples, but the present invention is not limited to these examples. “Part” and “%” indicate “part by weight” and “% by weight”, respectively.

Synthesis example 1
After introducing air gas into a reaction vessel equipped with a stirrer, thermometer, cooling pipe and air gas introduction pipe, hydrogenated polybutadiene diol (manufactured by Nippon Soda Co., Ltd., trade name: GI-1000, number average molecular weight: About 1500) 100 parts (about 0.067 mol), hydroquinone monomethyl ether (manufactured by Wako Pure Chemical Industries, Ltd.) 0.01 part and 1,1,3,3-tetramethylguanidine (Wako Pure Chemical Industries, Ltd.) 0.1 parts), heated to 80 ° C., coronate T-65 (manufactured by Nippon Polyurethane Industry Co., Ltd., trade name: 65% by weight of tolylene-2,4-diisocyanate and tolylene-2,6-diisocyanate 20.5 parts (0.118 mol) of a mixture with 35% by mass) was added, and the mixture was kept at 80 to 85 ° C. for 120 minutes. To this was added 13.7 parts (0.118 mol) of 2-hydroxyethyl acrylate (manufactured by Osaka Organic Chemical Industry Co., Ltd., trade name: HEA), the temperature was raised to 80 ° C., and then kept at 80 to 85 ° C. for 120 minutes. The reaction was allowed to proceed.

After confirming that the isocyanate had disappeared by IR measurement, the reaction was terminated to obtain a urethane oligomer (hereinafter simply referred to as “urethane oligomer”, number average molecular weight: about 3500).

Example 1
After introducing air gas into a reaction vessel equipped with a stirrer, thermometer, cooling pipe and air gas introduction pipe, 52 parts of urethane oligomer obtained in Synthesis Example 1 as component (A) and lauryl as component (B) 2 parts acrylate, 42 parts isobornyl acrylate, 4 parts dipentaerythritol hexaacrylate, 6 parts 2-methyl-1- [4- (methylthio) phenyl] -2-morpholino-propan-1-one as component (C) , 0.3 part of leuco crystal violet as component (D) and 1 part of γ-isocyanatopropyltriethoxysilane as silane coupling agent were added and heated and stirred at 60 ° C. for 3 hours to obtain a photocurable resin composition. .

Example 2
Photocurable resin as in Example 1 except that the amount of lauryl acrylate of component (B) in Example 1 was changed from 2 parts to 8 parts and the amount of isobornyl acrylate was changed from 42 parts to 36 parts. A composition was prepared.

Example 3
A photocurable resin composition was prepared in the same manner as in Example 1 except that the amount of the leuco crystal violet component (D) in Example 1 was changed from 0.3 part to 2 parts.

Example 4
Example 1 except that the amount of component (C) 2-methyl-1- [4- (methylthio) phenyl] -2-morpholino-propan-1-one in Example 1 was changed from 6 parts to 9 parts. Similarly, a photocurable resin composition was prepared.

Example 5
Example 1 is the same as Example 1 except that the amount of 2-methyl-1- [4- (methylthio) phenyl] -2-morpholino-propan-1-one as component (C) in Example 1 was changed from 6 parts to 3 parts. Similarly, a photocurable resin composition was prepared.

Example 6
The amount of the urethane oligomer of the component (A) in Example 1 was changed from 52 parts to 48 parts, 2 parts of the lauryl acrylate of the component (B) was not added, and the amount of dipentaerythritol hexaacrylate was changed from 4 parts to 10 parts. A photocurable resin composition was prepared in the same manner as in Example 1 except that.

Comparative Example 1
The urethane oligomer of component (A) in Example 1 was changed to a polybutadiene homopolymer (B-3000, manufactured by Nippon Soda Co., Ltd., number average molecular weight: about 3,000) (hereinafter simply referred to as “polybutadiene homopolymer”). A photocurable resin composition was prepared in the same manner as Example 1 except for the above.

Comparative Example 2
2-methyl-1- [4- (methylthio) phenyl] -2-morpholino-propan-1-one as the component (C) in Example 1 was converted to 2-benzyl-2-dimethylamino- (4-morpholinophenyl). A photocurable resin composition was prepared in the same manner as in Example 1 except that -butan-1-one was used.

Comparative Example 3
Photocurability in the same manner as in Example 1 except that 2-methyl-1- [4- (methylthio) phenyl] -2-morpholino-propan-1-one as the component (C) in Example 1 was changed to benzophenone. A resin composition was prepared.

Comparative Example 4
2-methyl-1- [4- (methylthio) phenyl] -2-morpholino-propan-1-one as the component (C) in Example 1 was converted into 2- (o-chlorophenyl) -4,5-diphenylimidazole A photocurable resin composition was prepared in the same manner as in Example 1 except that the body was changed.

Comparative Example 5
A photocurable resin composition was prepared in the same manner as in Example 1 except that the leuco crystal violet component (D) in Example 1 was not added.

Comparative Example 6
After introducing air gas into a reaction vessel equipped with a stirrer, thermometer, cooling pipe and air gas introduction pipe, 100 parts of urethane oligomer, 2.5 parts of benzyldimethyl ketal, and γ-methacryloxypropyltriethoxysilane 5 A photocurable resin composition was obtained by heating and stirring at 60 ° C. for 3 hours (resin composition described in Example 1 of JP-A-2001-302946 (Patent Document 1)).

The photocurable resin composition obtained above was evaluated for curability, color developability, elastic modulus, adhesiveness, repairability, moisture resistance, and heat cycle properties as follows.

[Curing property]
The photocurable resin compositions obtained in Examples 1 to 6 and Comparative Examples 1 to 6 were applied to a glass plate using an applicator so that the film thickness was 300 μm and the width was 2 mm. For the obtained coating film, an ultraviolet irradiation device (manufactured by Matsushita Electric Works Co., Ltd., output: 330 mW, number of LEDs: 2), irradiation distance 1 cm, lamp moving speed 80 mm / second, irradiation amount about 350 mJ / cm ² A test piece was prepared by irradiating ultraviolet rays under the conditions described above. About the obtained test piece, the coating-film surface was pushed with the finger | toe, and sclerosis | hardenability was evaluated on the following reference | standard.
A: There is no stickiness.
B: There is some stickiness.
C: There is remarkable stickiness.

[Color development]
The photocurable resin compositions obtained in Examples 1 to 6 and Comparative Examples 1 to 6 were applied to a glass plate using an applicator so that the film thickness was 300 μm and the width was 2 cm. Cut the light with a wavelength other than 365 nm using a bandpass filter with a UV irradiation device manufactured by Nippon Batteries Co., Ltd. on the obtained coating film so that the total irradiation amount becomes 350 mJ / cm ² at an irradiation output of 400 mW / cm ^2. A test piece was prepared by irradiating the sample with ultraviolet rays. About the obtained test piece, the color (b *) was measured with Σ90 COLOR MEASURING SYSTEM manufactured by Nippon Denshoku and evaluated according to the following criteria.
A: -50 or less B: -40 to -50
C: 0 to -40
D: Greater than 0 Note that it is difficult to visually recognize colors for C and D.

[Storage modulus]
The photocurable resin compositions obtained in Examples 1 to 6 and Comparative Examples 1 to 6 were applied to a glass plate using an applicator so that the film thickness was 300 μm and the width was 2 cm. Cut the light with a wavelength other than 365 nm using a bandpass filter with a UV irradiation device manufactured by Nippon Batteries Co., Ltd. on the obtained coating film so that the total irradiation amount becomes 350 mJ / cm ² at an irradiation output of 400 mW / cm ^2. A test piece was prepared by irradiating the sample with ultraviolet rays. About the obtained test piece, it measured on the following conditions in tension mode using RS instruments made from TA instruments, and evaluated the storage elastic modulus in 25 degreeC.
Measurement temperature: -60 to 150 ° C
Temperature increase rate: 5 ° C / min
Frequency: 1Hz

〔Adhesiveness〕
The photocurable resin compositions obtained in Examples 1 to 6 and Comparative Examples 1 to 6 were applied to a glass plate using an applicator so that the film thickness was 300 μm and the width was 2 mm. For the obtained coating film, an ultraviolet irradiation device (manufactured by Matsushita Electric Works Co., Ltd., output: 330 mW, number of LEDs: 2), irradiation distance 1 cm, lamp moving speed 80 mm / second, irradiation amount about 350 mJ / cm ² A test piece was prepared by irradiating ultraviolet rays under the conditions described above. The obtained test piece was fixed to a universal tensile tester (manufactured by Shimadzu Corp., Autograph IS-10T) so that the cured film peeled off from the glass plate forms a 90-degree angle, and at 25 ° C., 50 mm / The 90-degree peel strength was measured at a rate of minutes.

[Repairability]
The photocurable resin compositions obtained in Examples 1 to 6 and Comparative Examples 1 to 6 were applied to a glass plate using an applicator so that the film thickness was 300 μm and the width was 2 mm. For the obtained coating film, an ultraviolet irradiation device (manufactured by Matsushita Electric Works Co., Ltd., output: 330 mW, number of LEDs: 2), irradiation distance 1 cm, lamp moving speed 80 mm / second, irradiation amount about 350 mJ / cm ² A test piece was prepared by irradiating ultraviolet rays under the conditions described above. About the obtained test piece, peeling of the cured film was tried and the repair property was evaluated according to the following criteria.
A: The cured film can be peeled off quickly and beautifully without any resin residue from the glass plate. B: The cured film can be peeled off beautifully without resin residue by slowly peeling off the cured film from the glass plate C: Even if the cured film is slowly peeled off from the glass plate, the cured film is cut during the peeling. D: Cannot be peeled off

[Moisture resistance]
The moisture resistance was evaluated by migration resistance.
The photocurable resin compositions obtained in Examples 1 to 6 and Comparative Examples 1 to 6 were used with an ITO electrode substrate (L / S (line width / line width) so that the film thickness was 300 μm and the width was 2 mm using an applicator. (Space width) = 35/15 μm). For the obtained coating film, an ultraviolet irradiation device (manufactured by Matsushita Electric Works Co., Ltd., output: 330 mW, number of LEDs: 2), irradiation distance 1 cm, lamp moving speed 80 mm / second, irradiation amount about 350 mJ / cm ² The test piece was produced by irradiating ultraviolet rays under the conditions described above. The obtained test piece was subjected to a high-temperature and high-humidity bias test for 500 hours under the conditions of 60 ° C., 90% RH, and DC 5 V, and evaluated for migration resistance (insulation resistance maintenance rate, corrosion resistance). With respect to the insulation resistance maintenance ratio, an insulation resistance maintenance ratio was calculated by the following formula using an ion migration tester (IMV, MIG-8600). The higher the insulation resistance maintenance rate, the better.
Insulation resistance maintenance ratio (%) = (resistance value after 500 hours / resistance value before high temperature and high humidity bias test) × 100
Corrosion resistance was evaluated based on the following criteria by visually observing the ITO electrode substrate at an observation magnification of substantially 100 times using a 10-times eyepiece and 10-times objective lens using a transmission type optical microscope.
A: Corrosion is not observed at all. B: Corrosion in a very small range is generated in a dotted manner. C: Corrosion is generated on the wire and conduction is made.

[Heat cycle properties]
Two ITO electrode substrates having a size of 2 × 5 cm and a thickness of 300 μm were bonded to each other with a shift of 1 cm, and the photocurable resin compositions obtained in Examples 1 to 6 and Comparative Examples 1 to 6 were applied to the shifted portions. Cut the light with a wavelength other than 365 nm using a bandpass filter with a UV irradiation device manufactured by Nippon Batteries Co., Ltd. on the obtained coating film so that the total irradiation amount becomes 350 mJ / cm ² at an irradiation output of 400 mW / cm ^2. A test piece was prepared by irradiating the sample with ultraviolet rays. The obtained test piece was held at −20 ° C. for 0.5 hour, then heated to 60 ° C., and held at 60 ° C. for 0.5 hour as 200 cycles (200 hours). The film appearance (cracks, peeling from the substrate, etc.) was evaluated according to the following criteria.
A: No change B: There is a crack in a part of the cured film, or there is peeling at the end of the cured film C: There is a crack in the entire cured film, or the entire cured film is peeled off

In the photocurable resin composition in which the component (A) of Comparative Example 1 was not a urethane oligomer but a polybutadiene homopolymer, the curability was poor and the back surface of the coating film was uncured. The component (C) of Comparative Example 2 was not 2-methyl-1- [4- (methylthio) phenyl] -2-morpholino-propan-1-one but 2-benzyl-2-dimethylamino- (4-morpholinophenyl) ) The photocurable resin composition having 2-butan-1-one had low color developability and it was difficult to visually confirm the presence or absence of coloring. Regarding repairability, the film was cut during peeling. The component (C) of Comparative Examples 3 and 4 was replaced with benzophenone and 2- (o-chlorophenyl) -4, respectively, instead of 2-methyl-1- [4- (methylthio) phenyl] -2-morpholino-propan-1-one, The photocurable resin composition made into 5-diphenylimidazole dimer had poor curability and the back surface of the coating film was uncured. The cause of the poor curability of the photocurable resin composition made from 2- (o-chlorophenyl) -4,5-diphenylimidazole dimer was the dimer of 2- (o-chlorophenyl) -4,5-diphenylimidazole. This is probably due to insufficient body solubility.

1, 2, 3... Cured body of photocurable resin composition, 11, 31, 51... Semiconductor chip, 12, 32, 52... Bump electrode, 13, 33. Lead electrode, 14. ... polyimide film, 16, 36 ... solder resist, 17 ... liquid sealing material, 21, 23, 41, 43, 61, 63 ... glass substrate, 22, 42, 62 ... electrode, 24, 37, 44, 53 ... connection Member, 25, 45, 64 ... Sealing material, 100, 200, 300 ... Liquid crystal display module.

Claims

(A) urethane oligomer,
(B) a polymerizable compound having an ethylenically unsaturated group,
A photocurable resin composition comprising (C) 2-methyl-1- [4- (methylthio) phenyl] -2-morpholino-propan-1-one, and (D) a leuco dye.
The photocurable resin composition according to claim 1, wherein the component (D) is leuco crystal violet.
The photocurable resin composition according to claim 1 or 2, wherein the component (A) is a urethane oligomer having a (meth) acryloyl group.
The photocurable resin composition according to any one of claims 1 to 3, which is substantially free of an organic solvent.
The photocurable resin composition according to any one of claims 1 to 4, wherein the liquid crystal display electrode and the lead electrode of the flexible wiring board are protectively coated on a connection portion where the connection portion is connected via a connection member. Protective coating agent.
5. The photocurable resin composition according to claim 1, wherein the liquid crystal display electrode and the bump electrode of the semiconductor chip are provided with a protective coating on a connection portion where the electrode is connected via a connection member. Protective coating agent.
A cured film obtained by photocuring the photocurable resin composition according to any one of claims 1 to 4,
A cured film having a storage elastic modulus at 25 ° C. of 10 to 200 MPa.
Connecting the electrode of the liquid crystal display and the lead electrode of the flexible wiring board via a connecting member;
The coating film is formed by applying the photocurable resin composition according to any one of claims 1 to 4 so as to cover the electrode of the liquid crystal display, the lead electrode of the flexible wiring board, and the connection member. Process,
Irradiating the coating film with an actinic ray;
A method for manufacturing a liquid crystal display module, comprising:
Connecting the electrode of the liquid crystal display and the bump electrode of the semiconductor chip via a connecting member;
A step of forming a coating film by applying the photocurable resin composition according to any one of claims 1 to 4 so as to cover the electrode of the liquid crystal display, the bump electrode of the semiconductor chip, and the connection member. When,
Irradiating the coating film with an actinic ray;
A method for manufacturing a liquid crystal display module, comprising:
A liquid crystal display module manufactured by the method for manufacturing a liquid crystal display module according to claim 8 or 9.