JP2007332379A - Photocurable resin composition - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a photocationic-curable resin composition which is excellent in polymerization conversion at low temperatures and forms a cured product having excellent adhesive strength and moisture barrier properties, with good productivity. <P>SOLUTION: This photocationic-curable resin composition comprises (A) a cationic polymerizable compound being a compound having an epoxy group and/or a compound having an oxetane ring, (B) a photocationic initiator and (C) an aromatic ether compound expressed by general formula (I). <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a photocationically curable resin composition, its use, particularly a liquid crystal display sealing material and an electroluminescence display sealing material. More specifically, the present invention relates to a photocationically curable resin composition excellent in adhesiveness, moisture permeability resistance, and photocationic polymerizability at low temperatures and its use.

  In recent years, flat panel displays using various display elements have been developed and manufactured in the electronic and electrical industries. In many of these displays, a display element is sealed in a cell made of a flat panel such as glass or plastic. Typical examples thereof include a liquid crystal (LC) display and an electroluminescence (EL) display.

  The liquid crystal display is usually one in which two glass substrates are sealed and sealed together with a sealing material, and liquid crystal is enclosed therein. Conventionally, a thermosetting epoxy resin has been used as the sealing material. However, such a thermosetting epoxy resin needs to be heated and cured at a high temperature of 150 ° C. to 180 ° C. for about 2 hours, and there is a problem that productivity does not increase.

  On the other hand, EL displays are excellent in terms of high brightness, high efficiency, high-speed response, etc., and are attracting attention as next-generation flat panel displays. The EL element includes an inorganic EL element and an organic EL element. For example, the inorganic EL element is put into practical use in a backlight of a watch or the like. The organic EL element is superior to the inorganic EL element in terms of high brightness, high efficiency, high speed response, and multicolorization, but has low heat resistance, and the heat resistance temperature is usually about 80 to 100 ° C. For this reason, the seal of the organic EL display has a problem that it cannot be sufficiently heated and cured even if a thermosetting epoxy resin is used as a sealant.

  In order to solve these problems, an attempt has been made to develop a photo-curing sealing material that can be cured at a low temperature and a high speed. As the photocurable sealing material, there are usually a photo radical curable sealing material and a photocation curable sealing material.

  Acrylic resin is mainly used as the photo-radical curable sealant, which has the advantage that various acrylate monomers and oligomers can be used. However, it has insufficient moisture permeation resistance, reduces volume shrinkage, and adheres. There was a need for further improvements in power.

  On the other hand, an epoxy resin is mainly used as the photocation curable sealing material, and the adhesiveness is relatively good. However, further improvement in photocurability such as photosensitivity and fast curability has been demanded. . In particular, in photocationic polymerization, although the polymerization temperature can usually be in a relatively low range, the conversion rate of the polymerizable compound is not improved due to the low polymerization temperature, and it is difficult to obtain excellent photosensitivity and fast curability. There was a problem. For this reason, attempts have been made to incorporate a compound having a hydroxyl group in order to improve the photocurability of the polymerizable compound in the photocationic polymerization, but a high molecular weight polymer cannot be obtained due to chain transfer by the hydroxyl group. was there.

  Therefore, a photocationically polymerizable resin composition that provides a cured product having excellent photocurability, such as having a high conversion rate even in a relatively low temperature region, and excellent adhesion to a substrate and moisture resistance. The appearance of was desired.

Accordingly, the present inventors have intensively studied to solve the above problems, and the resin composition comprising a cationically polymerizable compound, a photocationic initiator, and an aromatic ether compound has excellent curability at low temperature, and its curing. It has been found that the product has excellent adhesive strength and moisture permeability resistance and good productivity. Further, the present inventors have found that such a photocation curable resin composition can be suitably used for a flat panel such as a liquid crystal display and an electroluminescence display, and have completed the present invention.

  The present invention seeks to solve the problems associated with the prior art as described above, has excellent polymerization conversion at low temperature, and has excellent adhesive strength and moisture permeation resistance, and good productivity. It aims at providing the photocationic curable resin composition which gives the hardened | cured material which has this.

  The present invention also relates to a sealing material suitable for a flat panel such as a liquid crystal display or an electroluminescence display, a liquid crystal display using the sealing material and an electroluminescence display, a liquid crystal display using the sealing material, and a sealing method for an electroluminescence display. It is intended to provide.

  The photocationically curable resin composition according to the present invention includes (A) a cationically polymerizable compound that is a compound having an epoxy group and / or a compound having an oxetane ring, (B) a photocationic initiator, and (C) the following general formula. It contains an aromatic ether compound represented by (I).

[However, the formula (I), R _1, R ₂ is an alkyl group having 1 to 5 carbon atoms, a glycidyl group or a 3-ethyl-3-oxetanylmethyl group, R ₁ in the formula (I) , R ₂ may be the same as or different from each other. ].

It is preferable that the said aromatic ether compound (C) is contained in the quantity of 0.01-5 weight part with respect to 100 weight part of photocation curable resin compositions.
The photocurable resin compound may further contain (D) a fine particle inorganic filler.

The photocurable resin compound may further contain (E) a silane coupling agent.
The cationically polymerizable compound (A) is 5 to 99.8 parts by weight,
The photocationic initiator (B) is 0.1 to 10 parts by weight,
The aromatic ether compound (C) is 0.01 to 5 parts by weight,
The fine particle inorganic filler (D) is 0 to 70 parts by weight, and the silane coupling agent (E) is 0 to 10 parts by weight (however, an amount relative to 100 parts by weight of the photocationically curable resin composition is shown). It is preferable that it is contained.

The sealing material for liquid crystal displays according to the present invention is characterized by comprising the photocationically curable resin composition.
The sealing method according to the present invention is characterized in that the liquid crystal display sealing material is used as the sealing material in the sealing method of a liquid crystal display in which substrates facing the liquid crystal display are bonded together by a sealing material.

The electroluminescent display sealing material according to the present invention is characterized by comprising the photocationically curable resin composition.
The sealing method according to the present invention is characterized in that the electroluminescent display sealing material is used as the sealing material in an electroluminescent display sealing method in which substrates facing each other of the electroluminescent display are bonded together by a sealing material.

  The photocationically curable resin composition according to the present invention is excellent in conversion at low temperature, and the cured product has excellent adhesive strength and moisture permeability. According to the sealing material comprising the composition, a liquid crystal display or an electroluminescence display having excellent adhesive strength and moisture permeation resistance can be provided with good productivity.

Hereinafter, the present invention will be described in detail.
[(A) Cationic polymerizable compound]
Examples of the cationically polymerizable compound (A) in the present invention include an epoxy compound and an oxetane compound.

  Specific examples of the epoxy compound include phenyl glycidyl ether and butyl glycidyl ether as compounds having one epoxy group, and hexanediol diglycidyl ether and tetraethylene glycol diglycidyl as compounds having two or more epoxy groups. Examples include ether, trimethylolpropane triglycidyl ether, bisphenol A diglycidyl ether, bisphenol F diglycidyl ether, and novolak type epoxy compounds.

  Moreover, as a compound which has an alicyclic epoxy group, the compound etc. which are represented by following General formula (1) and General formula (2) are mentioned, for example.

オキセタン化合物としては、下記一般式（３）

As an oxetane compound, the following general formula (3)

で表されるオキセタン環を少なくとも１つ有する化合物であればいずれも使用することができる。
例えばオキセタン環を好ましくは１〜１５含有する化合物、さらに好ましくは１〜１０含有する化合物、特に好ましくは１〜４含有する化合物が挙げられる。

Any compound having at least one oxetane ring represented by the formula (1) can be used.
For example, a compound containing preferably 1 to 15 oxetane ring, more preferably 1 to 10 compound, and particularly preferably 1 to 4 compound.

<Compound having one oxetane ring>
As a compound having one oxetane ring, the following general formula (4)

で示される化合物等が挙げられる。
前記一般式（４）において、Ｚ、Ｒ¹、Ｒ²は下記の原子又は置換基を意味する。
Ｚは酸素原子または硫黄原子である。

And the like.
In the general formula ^{(4), Z, R 1} , R 2 denotes an atom or a substituent described below.
Z is an oxygen atom or a sulfur atom.

R ¹ is a hydrogen atom, a fluorine atom, a methyl group, an ethyl group, a propyl group, a butyl group or other alkyl group having 1 to 6 carbon atoms;
A fluoroalkyl group having 1 to 6 carbon atoms such as a trifluoromethyl group, a perfluoromethyl group, a perfluoroethyl group, a perfluoropropyl group;
An aryl group having 6 to 18 carbon atoms, such as a phenyl group or a naphthyl group, a furyl group, or a thienyl group;

R ² represents a hydrogen atom, a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group or other alkyl group having 1 to 6 carbon atoms;
2 to 6 carbon atoms such as 1-propenyl group, 2-propenyl group, 2-methyl-1-propenyl group, 2-methyl-2-propenyl group, 1-butenyl group, 2-butenyl group and 3-butenyl group Alkenyl groups;
A substituted or unsubstituted aralkyl group having 7 to 18 carbon atoms such as benzyl group, fluorobenzyl group, methoxybenzyl group, phenethyl group, styryl group, cinnamyl group, ethoxybenzyl group;
Groups having other aromatic rings such as aryloxyalkyl groups such as phenoxymethyl group and phenoxyethyl group;
An alkylcarbonyl group having 2 to 6 carbon atoms such as an ethylcarbonyl group, a propylcarbonyl group, a butylcarbonyl group;
Alkoxycarbonyl groups having 2 to 6 carbon atoms such as ethoxycarbonyl group, propoxycarbonyl group, butoxycarbonyl group;
An N-alkylcarbamoyl group having 2 to 6 carbon atoms, such as an ethylcarbamoyl group, a propylcarbamoyl group, a butylcarbamoyl group, and a pentylcarbamoyl group;

Moreover, you may use substituents other than the above in the range which does not inhibit the effect of this invention.
More specific examples of the compound having one oxetane ring include 3-ethyl-3-hydroxymethyloxetane, 3- (meth) allyloxymethyl-3-ethyloxetane, (3-ethyl-3-oxetanylmethoxy) Methylbenzene, 4-fluoro- [1- (3-ethyl-3-oxetanylmethoxy) methyl] benzene, 4-methoxy- [1- (3-ethyl-3-oxetanylmethoxy) methyl] benzene, [1- (3 -Ethyl-3-oxetanylmethoxy) ethyl] phenyl ether, isobutoxymethyl (3-ethyl-3-oxetanylmethyl) ether, isobornyloxyethyl (3-ethyl-3-oxetanylmethyl) ether, isobornyl (3-ethyl) -3-oxetanylmethyl) ether, 2-ethylhexyl (3-ethyl) 3-oxetanylmethyl) ether, ethyldiethylene glycol (3-ethyl-3-oxetanylmethyl) ether, dicyclopentadiene (3-ethyl-3-oxetanylmethyl) ether, dicyclopentenyloxyethyl (3-ethyl-3-oxetanylmethyl) ) Ether, dicyclopentenylethyl (3-ethyl-3-oxetanylmethyl) ether, tetrahydrofurfuryl (3-ethyl-3-oxetanylmethyl) ether, tetrabromophenyl (3-ethyl-3-oxetanylmethyl) ether, 2 -Tetrabromophenoxyethyl (3-ethyl-3-oxetanylmethyl) ether, tribromophenyl (3-ethyl-3-oxetanylmethyl) ether, 2-tribromophenoxyethyl (3-ethyl-3-oxe) Nylmethyl) ether, 2-hydroxyethyl (3-ethyl-3-oxetanylmethyl) ether, 2-hydroxypropyl (3-ethyl-3-oxetanylmethyl) ether, butoxyethyl (3-ethyl-3-oxetanylmethyl) ether, Examples include pentachlorophenyl (3-ethyl-3-oxetanylmethyl) ether, pentabromophenyl (3-ethyl-3-oxetanylmethyl) ether, bornyl (3-ethyl-3-oxetanylmethyl) ether, and the like.

  Examples of the compound having two oxetane rings include compounds represented by the following general formulas (5) and (6).

In the general formulas (5) and (6), R ¹ is a carbon atom such as a hydrogen atom, a fluorine atom, a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, and a hexyl group as in the general formula (4). 1 to 6 alkyl groups;
A fluoroalkyl group having 1 to 6 carbon atoms such as a trifluoromethyl group, a perfluoromethyl group, a perfluoroethyl group, a perfluoropropyl group;
An aryl group having 6 to 18 carbon atoms such as a phenyl group and a naphthyl group;
A furyl group or a thienyl group; R ¹ in the general formulas (5) and (6) may be the same as or different from each other.

In the general formula (5), R ³ is a linear or branched alkylene group having 1 to 20 carbon atoms such as an ethylene group, a propylene group or a butylene group, a poly (ethyleneoxy) group, or a poly (propyleneoxy). Linear or branched poly (alkyleneoxy) groups having 1 to 120 carbon atoms such as groups, propenylene groups, methylpropenylene groups, butenylene groups, etc., linear or branched unsaturated carbon hydrogen groups, carbonyl Group, an alkylene group containing a carbonyl group, and an alkylene group containing a carbamoyl group in the middle of the molecular chain.

R ³ may be a polyvalent group selected from the groups represented by the following general formulas (7), (8), (9) and (10).

In the general formula (7), R ⁴ represents a hydrogen atom, an alkyl group having 1 to 4 carbon atoms such as a methyl group, an ethyl group, a propyl group, or a butyl group, a methoxy group, an ethoxy group, a propoxy group, or a butoxy group. Represents an alkoxy group having 1 to 4 carbon atoms, such as a halogen atom such as a chlorine atom or a bromine atom, a nitro group, a cyano group, a mercapto group, a lower alkyl carboxyl group, a carboxyl group, or a carbamoyl group, and X is 1 It is an integer of ~ 4.

In the general formula (8), R ⁴ represents a hydrogen atom, an alkyl group having 1 to 4 carbon atoms such as a methyl group, an ethyl group, a propyl group, or a butyl group, a methoxy group, an ethoxy group, a propoxy group, or a butoxy group. Represents an alkoxy group having 1 to 4 carbon atoms, such as a halogen atom such as a chlorine atom or a bromine atom, a nitro group, a cyano group, a mercapto group, a lower alkyl carboxyl group, a carboxyl group, or a carbamoyl group, and X is 1 It is an integer of ~ 4.

In the general formula (9), R ⁵ represents an oxygen atom, a sulfur atom, a methylene group, —NH—, —
_{SO -, - SO 2 -,} - C (CF 3) 2 - or -C (CH _{3) 2} - a.
General formula (10) is the following substituents.

In the general formula (10), R ⁶ is an alkyl group having 1 to 4 carbon atoms such as methyl group, ethyl group, propyl group or butyl group, aryl having 6 to 18 carbon atoms such as phenyl group or naphthyl group. And y is an integer of 0 to 200. R ⁷ is an alkyl group having 1 to 4 carbon atoms such as a methyl group, an ethyl group, a propyl group or a butyl group, or an aryl group having 6 to 18 carbon atoms such as a phenyl group or a naphthyl group.

R ⁷ may be a group represented by the following general formula (11).

In the general formula (11), R ⁸ represents an aryl group having 6 to 18 carbon atoms such as an alkyl group having 1 to 4 carbon atoms such as a methyl group, an ethyl group, a propyl group or a butyl group, a phenyl group or a naphthyl group. It is a group. Z is an integer of 0-100.

<Compound having two oxetane rings>
More specific examples of the compound having two oxetane rings include compounds represented by the following formulas (12) and (13).

  Further, examples of the compound having two oxetane rings include 3,7-bis (3-oxetanyl) -5-oxa-nonane and 1,4-bis [(3-ethyl-3-oxetanylmethoxy) methyl]. Benzene, 1,2-bis [(3-ethyl-3-oxetanylmethoxy) methyl] ethane, 1,2-bis [(3-ethyl-3-oxetanylmethoxy) methyl] propane, ethylene glycol bis (3-ethyl- 3-oxetanylmethyl) ether, dicyclopentenylbis (3-ethyl-3-oxetanylmethyl) ether, triethyleneglycolbis (3-ethyl-3-oxetanylmethyl) ether, tetraethyleneglycolbis (3-ethyl-3- Oxetanylmethyl) ether, tricyclodecanediyldimethylenebis (3-ethyl- -Oxetanylmethyl) ether, 1,4-bis [(3-ethyl-3-oxetanylmethoxy) methyl] butane, 1,6-bis [(3-ethyl-3-oxetanylmethoxy) methyl] hexane, polyethylene glycol bis ( 3-ethyl-3-oxetanylmethyl) ether, EO-modified bisphenol A bis (3-ethyl-3-oxetanylmethyl) ether, PO-modified bisphenol A bis (3-ethyl-3-oxetanylmethyl) ether, EO-modified hydrogenated bisphenol A bis (3-ethyl-3-oxetanylmethyl) ether, PO-modified hydrogenated bisphenol A bis (3-ethyl-3-oxetanylmethyl) ether, EO-modified bisphenol F bis (3-ethyl-3-oxetanylmethyl) ether, etc. Is mentioned.

<Compound having 3 or more oxetane rings>
Examples of the compound having three or more oxetane rings include compounds represented by the following formulas (14), (21), and (22).

In the general formula (14), R ¹ has 1 to 6 carbon atoms such as a hydrogen atom, a fluorine atom, a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, and a hexyl group as in the general formula (4). 1 to 6 carbon atoms such as alkyl groups, trifluoromethyl groups, perfluoromethyl groups, perfluoroethyl groups, perfluoropropyl groups, etc., and C 6-18 carbon atoms such as phenyl groups, naphthyl groups, etc. An aryl group, a furyl group or a thienyl group. R ¹ in the general formula (14) may be the same as or different from each other.

R ⁹ represents a trivalent to trivalent organic group, for example, a branched or linear alkylene group having 1 to 30 carbon atoms such as groups represented by the following formulas (15) to (17), Examples thereof include branched poly (alkyleneoxy) groups such as the group represented by (18) or linear or branched polysiloxane-containing groups represented by the following formula (19) or formula (20).

In formula (14), j represents an integer of 3 to 10 equal to the valence of R ⁹ .

In the formula (15), R ¹⁰ is an alkyl group having 1 to 6 carbon atoms such as a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, or a hexyl group.

  In said Formula (18), L is an integer of 1-10 and may mutually be same or different.

  Specific examples of the compound having three or more oxetane rings include compounds represented by the following formula (21) and general formula (22).

  The compound represented by the general formula (22) has 1 to 10 oxetane rings and is as follows.

In the general formula (22), R ¹ has 1 to 6 carbon atoms such as a hydrogen atom, a fluorine atom, a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, and a hexyl group as in the general formula (4). 1 to 6 carbon atoms such as alkyl groups, trifluoromethyl groups, perfluoromethyl groups, perfluoroethyl groups, perfluoropropyl groups, etc., and C 6-18 carbon atoms such as phenyl groups, naphthyl groups, etc. An aryl group, a furyl group or a thienyl group. R ¹ in the general formula (22) may be the same as or different from each other.

R ⁸ is as for formula (11) R ⁸ is a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, an aryl group having 6 to 18 carbon atoms such as a hexyl group. Z is an integer of 0-100. At this time, R ⁸ may be the same or different from each other.

R ¹¹ represents an alkyl group having 1 to 4 carbon atoms such as a methyl group, an ethyl group, a propyl group, or a butyl group, or a trialkylsilyl group having 3 to 12 carbon atoms (in the trialkylsilyl group, the alkyl groups are the same as each other). However, they may be different, for example, trimethylsilyl group, triethylsilyl group, tripropylsilyl group, tributylsilyl group).

r shows the integer of 1-10.
More specifically, compounds having three or more oxetane rings include trimethylolpropane tris (3-ethyl-3-oxetanylmethyl) ether, pentaerythritol tris (3-ethyl-3-oxetanylmethyl) ether, penta Erythritol tetrakis (3-ethyl-3-oxetanylmethyl) ether, dipentaerythritol hexakis (3-ethyl-3-oxetanylmethyl) ether, dipentaerythritol pentakis (3-ethyl-3-oxetanylmethyl) ether, dipenta Erythritol tetrakis (3-ethyl-3-oxetanylmethyl) ether, caprolactone-modified dipentaerythritol hexakis (3-ethyl-3-oxetanylmethyl) ether, ditrimethylolpropane tetrakis (3 Ethyl-3-oxetanylmethyl) ether, and the like.

(High molecular weight compound)
Furthermore, examples of the compound (A) having an oxetane ring include compounds having a high molecular weight of about 1000 to 5000 in terms of polystyrene measured by gel permeation chromatography, in addition to the above-described examples.

  Examples thereof include compounds represented by the following general formulas (23), (24), and (25).

(Here, p is an integer of 20 to 200.)

(Here, q is an integer of 15 to 200.)

(Here, s is an integer of 20 to 200.)
These compounds having an oxetane ring can be used singly or in combination of two or more.

  The content ratio of the cationic polymerizable compound (A) in the resin composition of the present invention is preferably 5 to 99.8 parts by weight, more preferably 5 to 99. parts by weight in 100 parts by weight of the photocationically curable resin composition. 6 parts by weight, more preferably 10 to 90 parts by weight, particularly preferably 30 to 90 parts by weight, and most preferably 50 to 90 parts by weight.

It is preferable that the cationic polymerizable compound (A) is 30 parts by weight or more because of excellent photosensitivity and fast curability.
Examples of other cationically polymerizable compounds include oxolane compounds, cyclic acetal compounds, cyclic lactone compounds, thiirane compounds, thietane compounds, spiro orthoester compounds, vinyl ether compounds, ethylenically unsaturated compounds, cyclic ether compounds, cyclic thioether compounds, A vinyl compound etc. are mentioned.

These may be used alone or in combination of two or more.
[(B) Photocationic initiator]
The photocationic initiator (B) of the present invention is not particularly limited as long as it is a compound that initiates cationic polymerization of the resin of the component (A) by light, and any of them can be used.

Preferable examples of the photocation initiator include onium salts having a structure represented by the following general formula (26).
This onium salt is a compound that photoreacts and releases a Lewis acid.

^{_{[R 12 a R 13 b R}} 14 c R 15 d W] m + [MX n + m] m- (26)
In the above formula, the cation is an onium ion, W is S, Se, Te, P, As, Sb, Bi, O, I, Br, Cl, or N≡N, and R ¹² , R ¹³ , R ¹⁴ and R ¹⁵ are the same or different organic groups, a, b, c and d are each an integer of 0 to 3, and (a + b + c + d) is equal to ((valence of W) + m).

M is a metal or metalloid constituting the central atom of the halogenated complex [MX _{n + m} ], for example, B, P, As, Sb, Fe, Sn, Bi, Al, Ca, In, Ti, Zn, Sc, V, Cr, Mn, Co and the like.

X is a halogen atom such as F, Cl, Br, etc., m is the net charge of the halide complex ion, and n is the valence of M.
Specific examples of the onium ion in the general formula (26) include diphenyliodonium, 4-methoxydiphenyliodonium, bis (4-methylphenyl) iodonium, bis (4-tert-butylphenyl) iodonium, bis (dodecylphenyl) iodonium, Triphenylsulfonium, diphenyl-4-thiophenoxyphenylsulfonium, bis [4- (diphenylsulfonio) -phenyl] sulfide, bis [4- (di (4- (2-hydroxyethyl) phenyl) sulfonio) -phenyl] And sulfide, η5-2,4- (cyclopentagenyl) [1,2,3,4,5,6-η- (methylethyl) benzene] -iron (1+) and the like.

  Specific examples of the anion in the general formula (26) include tetrafluoroborate, hexafluorophosphate, hexafluoroantimonate, hexafluoroarsenate, hexachloroantimonate and the like.

In the formula (26), a perchlorate ion, a trifluoromethanesulfonate ion, a toluenesulfonate ion, a trinitrotoluenesulfonate ion, or the like may be used instead of the halogenated complex [MX _{n + m} ] as an anion. Good.

Furthermore, in the general formula (26), the anion may be an aromatic anion instead of the halogenated complex [MX _{n + m} ]. Specifically, for example, tetra (fluorophenyl) borate, tetra (difluorophenyl) borate, tetra (trifluorophenyl) borate, tetra (tetrafluorophenyl) borate, tetra (pentafluorophenyl) borate, tetra (perfluorophenyl) ) Borate, tetra (trifluoromethylphenyl) borate, tetra (di (trifluoromethyl) phenyl) borate and the like.

These photocationic initiators can be used alone or in combination of two or more.
The content ratio of the photocationic initiator (B) in the resin composition of the present invention is preferably 0.1 to 10 parts by weight, more preferably 0.3 to 4 parts by weight, in 100 parts by weight of the photocationic curable resin composition. Parts, particularly preferably 0.3 to 3 parts by weight. By setting the content ratio of the photocationic initiator (B) to 0.1 parts by weight or more, the curing state of the resin composition becomes favorable, and from the viewpoint of preventing the photocationic initiator from eluting after curing. It is preferable that it is below the weight part.

[(C) aromatic ether compound]
The photocationically curable resin composition according to the present invention contains an aromatic ether compound (C).

  Examples of the aromatic ether compound (C) include at least one aromatic ether compound selected from the group consisting of compounds represented by the following general formulas (I), (II), and (III). It is preferable.

However, the formula (I), (II) in and _{(III), R 1, R} 2 is an alkyl group, a glycidyl group or a 3-ethyl-3-oxetanylmethyl group having 1 to 5 carbon atoms, wherein In the formulas (I) and (III), R ₁ and R ₂ may be the same as or different from each other.

Wherein R _1, among R _2, as the R _1, R _2, can be preferably used an alkyl group, a glycidyl group or a 3-ethyl-3-oxetanylmethyl group having 1 to 3 carbon atoms.
Of the aromatic ether compounds represented by the formula (I), compounds in which the two substituents —OR ₁ and —OR ₂ are para to each other are preferable.

R ₁ and R ₂ are preferably the same functional group.
In addition, the aromatic ether compound (C) is represented by the above (I) to (III), and other aromatic ether compounds having a substituent represented by the above -OR ₁ (or -OR ₂ ). It may be. As the other aromatic ether compounds, benzene having one substituent represented by -OR _1, hydro anthraquinone dialkyl ethers having a substituent represented by -OR _1, anthracene, pyrene, and the like .

  In the polymerization of the cationic polymerizable compound (A) using the photocationic initiator (B), when the aromatic ether compound (C) having such a substituent is used in combination, a low temperature region, for example, preferably 0 to 100 ° C., More preferably, the conversion of the cationically polymerizable compound at 20 to 100 ° C. is improved, and the cured product can exhibit excellent adhesive strength and moisture permeability.

These aromatic ether compound (I) ~ (III) and other aromatic ether compound is represented by a range which does not inhibit the effect according to the present invention, the -OR ₁ (or -OR ₂₎ In addition to the substituent, it may have another substituent different from these. Examples of such a substituent include an alkyl group having 1 to 5 carbon atoms, preferably 1 to 3 carbon atoms, an ester group, and a hydroxyl group.

These aromatic ether compounds (C) can be used singly or in combination of two or more.
The content of the aromatic ether compound (C) is preferably 0.01 to 5 parts by weight, more preferably 0.05 to 3 parts by weight, with respect to 100 parts by weight of the photocationically curable resin composition. Particularly preferred is 0.1 to 3 parts by weight.

When the aromatic ether compound (C) is used in such a range, the conversion rate is further improved, and the curability can be further increased.
[(D) Fine particle inorganic filler]
The resin composition of the present invention preferably contains a fine particle inorganic filler (D). The fine particle inorganic filler is an inorganic filler having an average primary particle diameter of 0.005 to 10 μm.

  Specific examples include silica, talc, alumina, unmo, calcium carbonate, and the like. The fine particle inorganic filler can be used both untreated and treated. Examples of the surface-treated fine particle inorganic filler include methoxy group, trimethylsilyl group, octylsilyl group, or fine particle inorganic filler surface-treated with silicone oil.

These fine particle inorganic fillers (D) can be used singly or in combination of two or more.
The content ratio of the fine particle inorganic filler (D) in the resin composition of the present invention is preferably 0 to 70 parts by weight, more preferably 0.1 to 70 parts by weight, and particularly preferably 1 to 30 parts by weight.

When the fine particle inorganic filler is added in such a range, moisture permeation resistance, adhesive force, thixotropic imparting and the like are improved.
[(E) Silane coupling agent]
The photocationically curable resin composition according to the present invention may contain a silane coupling agent (E) as necessary. Examples of the silane coupling agent (E) include silane compounds having reactive groups such as epoxy groups, carboxyl groups, methacryloyl groups, and isocyanate groups.

  Specifically, trimethoxysilyl benzoic acid, γ-methacryloxypropyltrimethoxysilane, vinyltriacetoxysilane, vinyltrimethoxysilane, γ-isocyanatopropyltriethoxysilane, γ-glycidoxypropyltrimethoxysilane, β -(3,4-epoxycyclohexyl) ethyltrimethoxysilane and the like.

These silane coupling agents (E) can be used singly or in combination of two or more.
The amount of the silane coupling agent (E) to be used is preferably 0 to 10 parts by weight, more preferably 0.1 to 10 parts by weight, and particularly preferably 0.1 to 10 parts by weight with respect to 100 parts by weight of the photocationically curable resin composition. 3-8 parts by weight is desirable.

When such a silane coupling agent (E) is added in the above range, the adhesive force is preferably improved.
Therefore, the photocationically curable resin composition according to the present invention is:
5-99.8 parts by weight of the cationic polymerizable compound (A),
0.1 to 10 parts by weight of the photocationic initiator (B),
0.01 to 5 parts by weight of the aromatic ether compound (C),
The fine particle inorganic filler (D) is 0 to 70 parts by weight, and the silane coupling agent (E) is 0 to 10 parts by weight (however, the amount is shown based on 100 parts by weight of the photocationically curable resin composition). It is preferable that it is contained.

In the case where the fine particle inorganic filler (D) and the silane coupling agent (E) are used in combination,
5-99.6 parts by weight of the cationic polymerizable compound (A),
0.1 to 10 parts by weight of the photocationic initiator (B),
0.01 to 5 parts by weight of the aromatic ether compound (C),
0.1 to 70 parts by weight of the fine particle inorganic filler (D) and 0.1 to 10 parts by weight of the silane coupling agent (E) (however, the amount relative to 100 parts by weight of the photocationically curable resin composition) It is preferable that it is contained.

[Other ingredients]
The resin composition of the present invention may contain other components such as other resin components, fillers, modifiers, stabilizers, antioxidants and the like within a range not impairing the effects of the present invention.

<Other resin components>
Examples of the other resin components include polyamide, polyamideimide, polyurethane, polybutadiene, polychloroprene, polyether, polyester, styrene-butadiene-styrene block copolymer, petroleum resin, xylene resin, ketone resin, cellulose resin, fluorine. System oligomer, silicon oligomer, polysulfide oligomer and the like.

These may be used alone or in combination of two or more.
<Filler>
Examples of the filler include glass beads, styrene polymer particles, methacrylate polymer particles, ethylene polymer particles, and propylene polymer particles.

These may be used alone or in combination of two or more.
<Modifier>
Examples of the modifier include a polymerization initiation aid, an antiaging agent, a leveling agent, a wettability improver, a surfactant, a plasticizer, and an ultraviolet absorber.

These may be used alone or in combination of two or more.
<Antioxidant>
Examples of the antioxidant include phenol compounds. Specific examples of the phenol compound include hydroquinone, resorcin, 2,6-di-tert-butyl-P-cresol, 4,4′-thiobis- (6-tert-butyl-3-methylphenol), 4, 4'-butylidenebis- (6-tert-butyl-3-methylphenol), 2,2'-methylenebis- (4-methyl-6-tert-butylphenol), 2,6-di-tert-butyl-4-ethyl Phenol, 1,1,3-tris (2-methyl-4hydroxy-5-tert-butylphenyl) butane, n-octadecyl-3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate, Tetrakis [methylene-3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate] methane, triethyl Glycol bis [3- (3-tert- butyl-4-hydroxy-5-methylphenyl) propionate] and the like.

These can be used alone or in combination of two or more.
[Preparation of Photocationic Curable Resin Composition]
The photocationically curable resin composition according to the present invention is prepared so that the respective compositions are mixed uniformly. A viscosity range of 0.01 to 300 Pa · s allows the coating operation to be carried out more efficiently, and the mixing stability of each composition is good. The viscosity range is more preferably 0.1 to 100 Pa · s.

The viscosity may be adjusted by adding a resin compounding ratio or other components.
Further, when the viscosity is high, kneading may be performed by a conventional method using three rolls or the like.
[Sealing material, sealing method, manufacturing method, liquid crystal display and electroluminescence display]
The sealing material which concerns on this invention consists of the said photocation curable resin composition.

  Such a sealing material is suitable as a sealing material for a liquid crystal display or an electroluminescent display because it has a high polymerization conversion rate of the cationic polymerizable compound, is excellent in productivity, and is excellent in adhesive strength and moisture permeability. is there.

A display sealing method using a sealing material made of such a photocationically curable resin composition is as follows.
First, the sealing material for liquid crystal displays or the sealing material for electroluminescent displays according to the present invention is applied onto a liquid crystal display substrate or an electroluminescent display substrate, respectively.

The application method is not limited as long as the sealing material can be applied uniformly.
For example, it may be carried out by a known method such as a screen printing method or a coating method using a dispenser.

After applying the sealing material according to the present invention on the base material of the display, the display base material is bonded, irradiated with light, and the applied sealing material is cured.
Any light source may be used here as long as it can be cured within a predetermined working time. Usually, light in the range of ultraviolet light and visible light can be irradiated.

More specifically, a low-pressure mercury lamp, a high-pressure mercury lamp, a xenon lamp, a metal halide lamp, and the like can be given.
In general, the irradiation light amount can be appropriately selected within the range where the uncured portion of the resin composition does not remain or the range where adhesion failure does not occur when the irradiation light amount is too small, but usually 500 to 3000 mJ / cm ^2. It is.

There is no particular upper limit on the irradiation amount, but an excessive amount is not preferable because unnecessary energy is wasted and productivity is lowered.
Thus, the opposing board | substrate in a liquid crystal display or an electroluminescent display can be bonded together by the said sealing material which concerns on this invention.

  Such a sealing method of a liquid crystal display or an electroluminescence display is a sealing method that provides a liquid crystal display or an electroluminescence display having a high polymerization conversion rate of the cationic polymerizable compound, excellent productivity, and excellent adhesion strength and moisture resistance. is there.

  Moreover, the manufacturing method of the liquid crystal display or electroluminescent display which concerns on this invention is the method of bonding the board | substrate which opposes in a liquid crystal display or an electroluminescent display with the sealing material of this invention.

  Furthermore, the liquid crystal display according to the present invention uses the sealing material according to the present invention as a seal for bonding the substrates facing the liquid crystal display, and the electroluminescent display according to the present invention uses the sealing material according to the present invention as an electroplate. It is used as a sealing material for bonding substrates facing the luminescence display.

Examples of the present invention will be described below, but the present invention is not limited to these examples.
<Measurement method>
The following evaluation was performed about the obtained resin composition and hardened | cured material.

(Conversion rate)
The conversion rate was calculated from the absorption reduction rate of the epoxy group or oxetane ring in the IR spectrum.
(Adhesive strength)
Adhesion strength was measured by sandwiching two glass plates with a resin composition (thickness: 100 μm), irradiating with light, adhering them, and peeling off these two glass plates at a pulling speed of 2 mm / min. .

(Film moisture permeability)
The moisture permeation amount of a resin composition film (thickness: 100 μm) photocured according to JIS Z0208 was measured under the conditions of 40 ° C. and 90% RH.

<Raw materials>
(Cationically polymerizable compound (A))
Epoxy compound a-1: bisphenol F diglycidyl ether oxetane compound a-2: 1,4-bis [(3-ethyl-3-oxetanylmethoxy) methyl] benzene (photocation initiator (B))
Photoinitiator b-1: A compound represented by the following formula.

  (Aromatic ether compound (C))

(Fine particle inorganic filler (D))
Fine particle silica d-1: Untreated surface fine particle silica having an average primary particle diameter of 12 nm.
[Example 1]

(Preparation of resin composition)
According to the formulation shown in Table 1, 96.9 parts by weight of a-1 (bisphenol F diglycidyl ether) as the compound (A) component and photoinitiator b-1 (formula (26) as the photocationic initiator (B) component )) And 3 parts by weight of c-1 as an aromatic ether compound (C) component were mixed and stirred for 1 hour to obtain a transparent liquid composition.

(Light curing)
It was cured by irradiating light of 3000 mJ / cm ^{2 with} a metal halide lamp.
The evaluation results are shown in Table 2.
[Examples 2 and 3]

A resin composition was prepared and evaluated in the same manner as in Example 1 except that the components having the compositions shown in Table 1 were used. The results are shown in Table 2.
[Comparative Examples 1-3]

  A resin composition was prepared and evaluated in the same manner as in Example 1 except that the components having the compositions shown in Table 1 were used. The results are shown in Table 2.

Claims (9)

(A) a cationically polymerizable compound that is a compound having an epoxy group and / or a compound having an oxetane ring, (B) a photocationic initiator, and (C) an aromatic ether compound represented by the following general formula (I) A photocationically curable resin composition characterized by:

[However, the formula (I), R _1, R ₂ is an alkyl group having 1 to 5 carbon atoms, a glycidyl group or a 3-ethyl-3-oxetanylmethyl group, R ₁ in the formula (I) , R ₂ may be the same as or different from each other. ].   2. The photocationic curing according to claim 1, wherein the aromatic ether compound (C) is contained in an amount of 0.01 to 5 parts by weight with respect to 100 parts by weight of the photocationic curable resin composition. Type resin compound.   The photocationic curable resin composition according to claim 1 or 2, wherein the photocurable resin compound further contains (D) a fine particle inorganic filler.   The photocationic curable resin composition according to any one of claims 1 to 3, wherein the photocurable resin compound further contains (E) a silane coupling agent. 5-99.8 parts by weight of the cationic polymerizable compound (A),
0.1 to 10 parts by weight of the photocationic initiator (B),
0.01 to 5 parts by weight of the aromatic ether compound (C),
The fine particle inorganic filler (D) is 0 to 70 parts by weight, and the silane coupling agent (E) is 0 to 10 parts by weight (however, the amount is shown based on 100 parts by weight of the photocationically curable resin composition). The photocationically curable resin composition according to any one of claims 1 to 4, wherein the photocationically curable resin composition is contained.   The sealing material for liquid crystal displays which consists of a photocationic curable resin composition in any one of Claims 1-5.   In the sealing method of the liquid crystal display which bonds the board | substrate which opposes a liquid crystal display with a sealing material, the sealing material for liquid crystal displays of Claim 6 is used as the said sealing material.   The sealing material for electroluminescent displays which consists of a photocationic curable resin composition in any one of Claims 1-5.   In the sealing method of the electroluminescent display which bonds the board | substrate which opposes an electroluminescent display with a sealing material, the sealing material for electroluminescent displays of Claim 8 is used as the said sealing material.