TWI880929B - Sealant for liquid crystal dropping method - Google Patents

Abstract

The present invention relates to a sealing agent for a liquid crystal dropping method, which is a sealing agent for a liquid crystal dropping method that produces a cured product having excellent adhesion to an alignment film and excellent low moisture permeability, and contains a curable resin, a photoinitiator, and a thermosetting agent. The curable resin contains an oligomer A and an oligomer B. The oligomer A is an epoxy resin part (methyl) having an epoxy equivalent of 200 g/epo or more and an aromatic ring weight of 0.43 or more. ) acrylic acid-modified compound, and oligomer B is one or more selected from the group consisting of bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol AD type epoxy resin, a compound in which bisphenol A type epoxy resin is partially modified with (meth) acrylic acid, a compound in which bisphenol F type epoxy resin is partially modified with (meth) acrylic acid, and a compound in which bisphenol AD type epoxy resin is partially modified with (meth) acrylic acid.

Description

Sealant for liquid crystal dropping method

The present invention relates to a sealing agent for a liquid crystal dropping method.

Among the methods for manufacturing liquid crystal display elements, the drip method is a method that can produce a panel by directly dripping liquid crystal into a closed loop of a sealant under vacuum, laminating, and releasing the vacuum. This drip method has many advantages, such as reducing the amount of liquid crystal used and shortening the injection time into the liquid crystal panel. It is currently becoming the mainstream method for manufacturing liquid crystal panels using large substrates. In the method including the drip method, the sealant and liquid crystal are applied, laminated, and then a gap is set to align, and the sealant is mainly cured by ultraviolet curing.

Patent document 1 proposes an epoxy resin obtained by adding an alkyl carbonate or a halogen alcohol compound to a phenol compound having one or more phenolic hydroxyl groups and further etherifying the alkyl carbonate to serve as a raw material for a sealant for a liquid crystal dropping method; and a modified epoxy resin obtained by modifying the epoxy resin with a carboxylic acid, a carboxylic anhydride or a phenol compound (Patent document 1). [Prior art document] [Patent document]

[Patent Document 1] Japanese Patent Application Publication No. 2017-002246

[The problem that the invention is trying to solve]

In recent years, as the bezels of liquid crystal panels have become narrower, there is a tendency for sealants to overlap with alignment films. Therefore, adhesion to the alignment film is required. In addition, there is a tendency for the line width of the sealant to become narrower. Therefore, low moisture permeability is required.

Therefore, the subject of the present invention is to provide a sealing agent for a liquid crystal dropping method, which produces a cured product having excellent adhesion to an alignment film and excellent low moisture permeability. [Means for solving the subject]

The present invention has the following structure. [1] A sealant for a liquid crystal dropping method, which is a sealant for a liquid crystal dropping method containing a curable resin, a photoinitiator and a thermosetting agent, and the curable resin contains an oligomer A and an oligomer B, and the oligomer A is a compound obtained by modifying part of an epoxy resin having an epoxy equivalent of 200 g/epo or more and an aromatic ring weight of 0.43 or more with (meth)acrylic acid, Oligomer B is one or more selected from the group consisting of bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol AD type epoxy resin, a compound obtained by partially modifying bisphenol A type epoxy resin with (meth)acrylic acid, a compound obtained by partially modifying bisphenol F type epoxy resin with (meth)acrylic acid, and a compound obtained by partially modifying bisphenol AD type epoxy resin with (meth)acrylic acid. [2] A sealant for liquid crystal dropping method as described in [1], wherein oligomer A has three or more benzene rings in one molecule. [3] A sealant for liquid crystal dropping method as described in [1] or [2], wherein oligomer A has a bisphenol F type structure. [4] A sealant for a liquid crystal dropping method as described in any one of [1] to [3], wherein the oligomer B is a bisphenol F type epoxy resin or a compound of a bisphenol F type epoxy resin partially modified with (meth) acrylic acid. [Effect of the invention]

According to the present invention, a sealing agent for a liquid crystal dropping method can be provided, which produces a cured product having excellent adhesion to an alignment film and excellent low moisture permeability.

The following is a description of suitable embodiments of the present invention. In the present specification, "glycidyl" means 2,3-epoxypropyl. "Methylglycidyl" means 2,3-epoxy-2-methylpropyl. "Epoxy" includes at least one of glycidyl and methylglycidyl. "(Meth)acryl" includes at least one of acryl ( _CH2 = _CH2 -C(=O)-) and methacryl ( _CH2 =CH( _CH3 )-C(=O)-). "Substituted" means "substituted or unsubstituted".

[Sealing agent for liquid crystal dropping method] The sealing agent for liquid crystal dropping method contains a curable resin, a photoinitiator and a thermosetting agent, the curable resin contains oligomer A and oligomer B, oligomer A is a compound obtained by modifying part of an epoxy resin having an epoxy equivalent of 200 g/epo or more and an aromatic ring weight of 0.43 or more with (meth)acrylic acid, and oligomer B is one or more selected from the group consisting of bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol AD type epoxy resin, a compound obtained by modifying part of a bisphenol A type epoxy resin with (meth)acrylic acid, a compound obtained by modifying part of a bisphenol F type epoxy resin with (meth)acrylic acid, and a compound obtained by modifying part of a bisphenol AD type epoxy resin with (meth)acrylic acid.

(Hardening resin) Hardening resin contains oligomer A and oligomer B.

<Oligomer A> Oligomer A is a compound obtained by partially (meth)acrylic acid-modifying an epoxy resin having an epoxy equivalent of 200 g/epo or more and an aromatic ring weight of 0.43 or more (hereinafter also referred to as "raw material epoxy resin"). Here, "partial (meth)acrylic acid-modifying" the epoxy resin means that a part of the epoxy groups of the epoxy resin are modified with (meth)acrylic acid.

<< Raw material epoxy resin>> <<< Epoxy equivalent>>> The epoxy equivalent of the raw material epoxy resin is 200 g/epo or more. By using a raw material epoxy resin having such an epoxy equivalent, the functional group concentration in one molecule of oligomer A becomes low, and a sealant for a liquid crystal dropping method having excellent adhesion to an alignment film can be obtained. The epoxy equivalent of the raw material epoxy resin is preferably 200 to 400 g/epo, more preferably 230 to 330 g/epo, and particularly preferably 260 to 320 g/epo. In this specification, the epoxy equivalent can be obtained in accordance with JIS K7236: 2001 (corresponding to ISO 3001: 1999).

＜＜＜Aromatic ring weight＞＞＞ The aromatic ring weight of the raw material epoxy resin is 0.43 or more. By combining the oligomer A obtained by using the raw material epoxy resin having such an aromatic ring weight with the oligomer B described later, a sealant for the liquid crystal dropping method having excellent low moisture permeability can be obtained. The aromatic ring weight of the raw material epoxy resin is preferably 0.43 to 0.60, more preferably 0.43 to 0.55, and particularly preferably 0.48 to 0.53.

In this specification, the aromatic ring content means the proportion of aromatic ring structures in the raw material epoxy resin. That is, the aromatic ring content is the value obtained by the following formula (number 1). Aromatic ring content = the total number of molecular weights of aromatic ring structures in one molecule of the raw material epoxy resin ÷ the molecular weight of one molecule of the raw material epoxy resin    (number 1)

In addition, the molecular weight of the aromatic ring structure is calculated based on the weight of the carbon atoms constituting the aromatic ring. For example, for a group having one benzene ring such as phenyl, phenylene, etc., the molecular weight is the sum of the molecular weights of the carbon atoms constituting the benzene ring (ring with 6 carbon atoms) (i.e. 72). In addition, for a group having a condensed ring such as a naphthalene ring (ring with 10 carbon atoms) and anthracene ring (ring with 14 carbon atoms), the molecular weight is the sum of the molecular weights of the carbon atoms constituting the condensed ring (i.e. 120 and 168). Furthermore, in the case where the aromatic ring is a heteroaromatic ring, the molecular weight of the aromatic ring structure is calculated based on the weight of the heteroatoms and carbon atoms constituting the heteroaromatic ring. It is preferred that the aromatic ring group constituting oligomer A does not contain heteroatoms.

＜＜＜Properties of the raw material epoxy resin＞＞＞ The raw material epoxy resin is preferably an epoxy resin represented by the following formula (1).

[wherein, ^G1 and ^G2 are independently glycidyl or methylglycidyl, ^R11 is a hydrogen atom or a methyl group, ^X1 is an aromatic group having 6 to 20 carbon atoms which may be substituted -O-, an aromatic group having 6 to 20 carbon atoms which may be substituted -( ^OR1 ) _n1 -O- (wherein, ^R1 is an alkylene group having 1 to 6 carbon atoms, and n1 is an integer of 1 to 10), or an aromatic group having a total of 5 to 30 atoms which may be substituted, Y ¹ is an arylene group having 6 to 20 carbon atoms, an alkylene group having 1 to 4 carbon atoms-an arylene group having 6 to 20 carbon atoms, an alkylene group having 1 to 4 carbon atoms-an arylene group having 6 to 20 carbon atoms-an alkylene group having 1 to 4 carbon atoms, an arylene group having 6 to 20 carbon atoms-an alkylene group having 1 to 4 carbon atoms-an arylene group having 6 to 20 carbon atoms, or a group: -R ² -(OR ² ) _n2 -(wherein R ² is an alkylene group having 1 to 6 carbon atoms, and n2 is 0 or an integer of 1 to 6), but the number of benzene rings in the molecule is 3 or more]

In formula (1), ^G1 and ^G2 are independently glycidyl or methylglycidyl. From the viewpoint of easy synthesis, it is preferred that ^G1 and ^G2 are both glycidyl.

In formula (1), R ¹¹ is a hydrogen atom or a methyl group. From the viewpoint of ease of synthesis, R ¹¹ is preferably a hydrogen atom.

In formula (1), ^X1 is an aromatic -O- group having 6 to 20 carbon atoms which may be substituted, an aromatic -( ^OR1 ) _n1 -O- group having 6 to 20 carbon atoms which may be substituted (wherein ^R1 is an alkylene group having 1 to 6 carbon atoms and n1 is an integer of 1 to 10), or an aromatic heteroaryl group having a total of 5 to 30 carbon atoms which may be substituted.

The aromatic group having 6 to 20 carbon atoms may include monocyclic or polycyclic aromatic hydrocarbon groups, phenyl, biphenyl, naphthyl, terphenyl, anthracenyl, fluorenyl, etc., with phenyl and biphenyl being preferred.

The substituent of the aromatic group having 6 to 20 carbon atoms is not particularly limited, and examples thereof include alkyl groups having 1 to 4 carbon atoms, alkoxy groups, alkylcarbonyl groups, alkylalkyl groups, and cycloalkyl groups.

Examples of the alkyl group having 1 to 4 carbon atoms include methyl, ethyl, propyl, isopropyl, butyl, isobutyl, sec-butyl and tert-butyl.

Examples of the alkyl moiety in the alkoxy group include the aforementioned examples of the alkyl group having 1 to 4 carbon atoms. Examples of the alkoxy group include methoxy, ethoxy, propoxy, butoxy, isobutoxy, sec-butoxy, tert-butoxy, and the like. Examples of the alkyl group in the alkylcarbonyl group and the alkylalkyl group include the aforementioned examples of the alkyl group having 1 to 4 carbon atoms. Examples of the alkylcarbonyl group include acetyl, propionyl, 2-methylpropionyl, butyryl, and the like. Examples of the alkylalkyl group include methylalkyl, ethylalkyl, propylalkyl, isopropylalkyl, butylalkyl, isobutylalkyl, sec-butylalkyl, tert-butylalkyl, and the like. Examples of the cycloalkyl group include monocyclic or polycyclic aliphatic hydrocarbon groups having 3 to 20 carbon atoms, cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl, cyclodecyl, cyclododecyl, and adamantyl.

The alkylene groups having 1 to 4 carbon atoms include methylene, ethylene, trimethylene, propylene (propylene-1,2-diyl), propylene (propylene-1,1-diyl), isopropylene (propylene-2,2-diyl), tetramethylene, butylene (butylene-1,1-diyl), isobutylene (2-methylpropylene-1,1-diyl), etc. In addition, the alkylene groups having 1 to 6 carbon atoms include, in addition to the aforementioned alkylene groups having 1 to 4 carbon atoms, alkylene groups having 5 and 6 carbon atoms such as pentamethylene, 2-methylpentane-1,5-diyl, and hexamethylene.

The heteroaromatic group having a total number of 5 to 30 atoms is a monocyclic or polycyclic heterocyclic group containing at least one hetero atom selected from the group consisting of oxygen atoms, sulfur atoms and nitrogen atoms in addition to carbon atoms, and examples thereof include phthalimide, imidazolyl, xanthyl, thiazolyl, thienyl, dibenzofuranyl, chromenyl, isothiochromenyl, phenathiothiol, pyrrolyl, pyrazolyl ... The substituents of the heteroaromatic group having a total number of 5 to 30 atoms can be exemplified by the substituents of the aromatic group having a total number of 6 to 20 carbon atoms.

^X1 is preferably a phenoxy group, a 4-tert-butylphenoxy group, a biphenyl-2-yloxy group, a phthalimide group, or a phenyl-(OCH ₂ CH ₂ ) _n1a -O- group (wherein n1a represents an integer of 2 to 10), and more preferably a phenoxy group.

In formula (1), ^Y1 is an arylene group having 6 to 20 carbon atoms, an alkylene group having 1 to 4 carbon atoms-an arylene group having 6 to 20 carbon atoms, an alkylene group having 1 to 4 carbon atoms-an arylene group having 6 to 20 carbon atoms-an alkylene group having 1 to 4 carbon atoms, an arylene group having 6 to 20 carbon atoms-an alkylene group having 1 to 4 carbon atoms-an arylene group having 6 to 20 carbon atoms, or the group: ^-R2- ( ^OR2 ) _n2- (wherein ^R2 is an alkylene group having 1 to 6 carbon atoms, and n2 is 0 or an integer from 1 to 6).

The arylene group having 6 to 20 carbon atoms may be a monocyclic or polycyclic aromatic group, phenylene, naphthylene and anthracenylene, preferably phenylene.

Examples of the alkylene group having 1 to 4 carbon atoms and the arylene group having 6 to 20 carbon atoms in the alkylene group having 1 to 4 carbon atoms-arylene group having 6 to 20 carbon atoms are as described above. The alkylene group having 1 to 4 carbon atoms-arylene group having 6 to 20 carbon atoms is preferably ethylene-1,4-phenylene. The bonding order of each group in the alkylene group having 1 to 4 carbon atoms-arylene group having 6 to 20 carbon atoms may be any, but the arylene group having 6 to 20 carbon atoms in the alkylene group having 1 to 4 carbon atoms-arylene group having 6 to 20 carbon atoms is preferably bonded to the oxygen atom to which the group containing ^X1 is bonded.

Examples of the alkylene groups having 1 to 4 carbon atoms and the arylene groups having 6 to 20 carbon atoms in the alkylene groups having 1 to 4 carbon atoms-arylene groups having 6 to 20 carbon atoms-alkylene groups having 1 to 4 carbon atoms are as described above. Preferably, the alkylene groups having 1 to 4 carbon atoms-arylene groups having 6 to 20 carbon atoms-alkylene groups having 1 to 4 carbon atoms are 1,3-phenylene dimethylene (meta-phenylene) and 1,4-phenylene dimethylene (para-phenylene).

Examples of the alkylene group having 1 to 4 carbon atoms and the arylene group having 6 to 20 carbon atoms in the arylene group having 6 to 20 carbon atoms-alkylene group having 1 to 4 carbon atoms-arylene group having 6 to 20 carbon atoms are as described above. The arylene group having 6 to 20 carbon atoms-alkylene group having 1 to 4 carbon atoms-arylene group having 6 to 20 carbon atoms is preferably the following group: (wherein, R ²¹ and R ²² are independent of each other and are hydrogen atom, methyl, ethyl, trifluoromethyl or phenyl) It is especially good.

In formula (1), ^Y1 is preferably an arylene group having 6 to 20 carbon atoms, an alkylene group having 1 to 4 carbon atoms-an arylene group having 6 to 20 carbon atoms, an alkylene group having 1 to 4 carbon atoms-an arylene group having 6 to 20 carbon atoms-an alkylene group having 1 to 4 carbon atoms, or an arylene group having 6 to 20 carbon atoms-an alkylene group having 1 to 4 carbon atoms-an arylene group having 6 to 20 carbon atoms. In suitable epoxide compounds having ^Y1 , either ^X1 or ^Y1 has an aromatic ring. When an epoxide compound having either ^X1 or ^Y1 has an aromatic ring, the obtained cured product has excellent low moisture permeability.

In formula (1), the total number of benzene rings possessed by ^X1 and ^Y1 is 3 or more. If an epoxy resin in which the total number of benzene rings possessed by ^X1 and ^Y1 is 2 is used, it is impossible to obtain an epoxy resin having an epoxy equivalent of 200 g/epo or more and an aromatic ring weight of 0.43 or more, and the adhesion to the alignment film may be poor and/or the moisture permeability may be increased.

The compound obtained by partially (meth)acryl-modifying the epoxy resin represented by formula (1) is a compound in which a part of ^G1 and/ _{or G2 in the epoxy resin represented by formula (1) is substituted with a group: -CH2CR13(OR31)CH2OZ} ⁽ _wherein ^{R13 is a} hydrogen atom or a methyl group, ^R31 is a hydrogen atom or a (meth)acryl group, and Z is a (meth)acryl group).

The epoxy compound represented by the above formula (1) and the compound in which the epoxy compound represented by the above formula (1) is partially (meth)acrylic-modified can be produced by the method described in Japanese Patent Application Laid-Open No. 2017-002246.

<< Suitable aspect of oligomer A>> From the viewpoint of low moisture permeability, oligomer A preferably has 3 or more benzene rings in one molecule, more preferably 3 to 6 benzene rings in one molecule, and particularly preferably 4 to 6 benzene rings in one molecule. Here, the group having a condensed ring refers to the number of benzene rings in the single ring constituting the condensed ring. For example, the number of benzene rings of a naphthalene ring is 2, and the number of benzene rings of a pyrene ring is 4. In the case where oligomer A has 3 or more benzene rings in one molecule, it is preferred that the benzene rings exist independently (i.e., do not contain a condensed ring).

In addition, from the viewpoint of low moisture permeability, it is preferred that the oligomer A has a bisphenol F type structure, and it is particularly preferred that the oligomer A has three or more benzene rings in one molecule and has a bisphenol F type structure. Here, the bisphenol F type structure refers to the structure shown below: This particularly preferred compound includes, in addition to the bisphenol F structure, compounds having a phenyl group.

The oligomer A may be one or a combination of two or more. In addition, the oligomer A is not a component equivalent to the oligomer B described later. That is, the oligomer A is not a compound obtained by modifying a portion of a bisphenol A type epoxy resin with (meth) acrylic acid, a compound obtained by modifying a portion of a bisphenol F type epoxy resin with (meth) acrylic acid, or a compound obtained by modifying a portion of a bisphenol AD type epoxy resin with (meth) acrylic acid.

<Oligomer B> Oligomer B is one or more selected from the group consisting of bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol AD type epoxy resin and partially (meth) acrylic acid modified compounds thereof (i.e., compounds obtained by partially (meth) acrylic acid modified bisphenol A type epoxy resin, compounds obtained by partially (meth) acrylic acid modified bisphenol F type epoxy resin and compounds obtained by partially (meth) acrylic acid modified bisphenol AD type epoxy resin). Here, bisphenol A type epoxy resin is an epoxy resin of a condensation product of bisphenol A (2,2-bis(4-hydroxyphenyl)propane) and epichlorohydrin. Bisphenol F epoxy resin is an epoxy resin of the condensation product of bisphenol F (bis(4-hydroxyphenyl)methane) and epichlorohydrin. Bisphenol AD epoxy resin is an epoxy resin of the condensation product of bisphenol AD (1,1-bis(4-hydroxyphenyl)ethane) and epichlorohydrin.

From the viewpoint of adhesion to the alignment film, it is preferred that oligomer B is one or more selected from the group consisting of bisphenol F epoxy resin and compounds obtained by partially (meth)acrylic acid-modified bisphenol F epoxy resin. Oligomer B may be one or a combination of two or more.

<Other curable resins> The curable resins other than oligomer A and oligomer B (hereinafter also referred to as "oligomer C") are not particularly limited, and examples thereof include conventional resins having ethylenically unsaturated groups and/or epoxy groups that are used as the main agent of the sealant for the liquid crystal dropping method.

The oligomer C of the resin having an epoxy group is not particularly limited as long as it has one or more epoxy groups. Examples of such resins having an epoxy group include raw material epoxy resins and epoxy resins other than raw material epoxy resins. Here, "epoxy resins other than raw material epoxy resins" are epoxy resins having an epoxy equivalent of 200 g/epo or more and an aromatic ring weight of less than 0.43; epoxy resins having an epoxy equivalent of less than 200 g/epo and an aromatic ring weight of more than 0.43; or epoxy resins having an epoxy equivalent of less than 200 g/epo and an aromatic ring weight of less than 0.43. The oligomer C of the resin having an epoxy group is preferably an epoxy resin described in Japanese Patent Application Laid-Open No. 2017-214462 in which an alkyl carbonate or a halogen alcohol is added to a compound having one or more phenolic hydroxyl groups and the resulting compound is further glycidyl etherified.

Examples of the resin oligomer C having an ethylenically unsaturated group include a resin oligomer C having an epoxy group in which all epoxy groups are modified with (meth)acrylic acid.

The oligomer C of the resin having an ethylenically unsaturated group and an epoxy group may include a (meth)acrylic acid-modified compound of a part of an epoxy resin other than the raw material epoxy resin.

In addition to the above, oligomer C is also described in WO2014/057871, Japanese Patent Application Publication No. 2017-002204, etc., and can be appropriately selected. In addition, oligomer C preferably has no silicon atoms.

(Photoinitiator) Photopolymerization initiator refers to a compound that is activated by absorbing light energy and generates free radicals. Photopolymerization initiators are not particularly limited, and examples thereof include benzoins, acetophenones, benzophenones, thioxanthines, α-acyl oxime esters, phenylglyoxylic acid esters, diphenyldiones, azo compounds, diphenyl sulfide compounds, acylphosphine oxide compounds, benzoins, benzoin ethers, and anthraquinones. Photopolymerization initiators preferably have low solubility in liquid crystals and have a reactive group that does not vaporize decomposition products when exposed to light. Examples of such suitable polymerization initiators include EY resin KR-2 (manufactured by KSM Co., Ltd.). In addition, the free radical polymerization initiator is preferably a mixture of a compound obtained by reacting a compound having at least two epoxy groups with dimethylaminobenzoic acid and a compound obtained by reacting a compound having at least two epoxy groups with hydroxythioxanone as described in WO2012/077720.

(Thermohardener) Thermohardeners are not particularly limited. Examples of amine-based hardeners include organic acid dihydrazide compounds, amine adducts, imidazole and its derivatives, dicyandiamides, aromatic amines, epoxy-modified polyamines and polyaminoureas, organic acid dihydrazides such as VDH (1,3-bis(hydrazinocarbonylethyl)-5-isopropylhydantoin), ADH (adipic acid dihydrazide), UDH (7,11-octadecadiene-1,18-dicarbonylhydrazide) and LDH (octadecane-1,18-dicarboxylic acid dihydrazide); Adeka Hardener EH5030S from ADEKA, Ajicure PN-23, Ajicure PN-30, Ajicure MY-24, Ajicure PN-35 from Ajinomoto FineTechno, and Ajicure MY-25. Amine adducts sold under the names of MY-H, MY-H, etc. are preferred. These hardeners may be used alone or in combination.

(Additional ingredients) The sealant for the liquid crystal dropping method may further contain additional ingredients such as fillers and coupling agents. The additional ingredients may be a single ingredient or a combination of two or more.

Fillers are added for the purpose of controlling the viscosity of the sealant for the liquid crystal dropping method, improving the strength of the cured product after the sealant for the liquid crystal dropping method is cured, or improving the adhesiveness reliability of the sealant for the liquid crystal dropping method by suppressing linear expansion, etc. The filler is not particularly limited, and well-known inorganic fillers and organic fillers used for the sealant for the liquid crystal dropping method can be listed.

Inorganic fillers include calcium carbonate, magnesium carbonate, barium sulfate, magnesium sulfate, aluminum silicate, titanium oxide, aluminum oxide, zinc oxide, silicon dioxide, kaolin, talc, glass beads, sericite activated clay, bentonite, aluminum nitride and silicon nitride.

Examples of organic fillers include polymethyl methacrylate, polystyrene, copolymers obtained by copolymerizing monomers constituting these polymers with other monomers, polyester microparticles, polyurethane microparticles, rubber microparticles, and core-shell particles composed of a shell containing a copolymer having a high glass transition temperature and a core containing a copolymer having a low glass transition temperature.

Commercially available fillers can be used. Commercially available inorganic fillers include glass fillers ("CF0023-05C" manufactured by Japan Frit Co., Ltd.), amorphous silica ("SEAHOSTAR KE-P250" manufactured by Japan Catalyst Co., Ltd.), fuming silica (volatile property imparting agent) ("TG-308F" manufactured by Cabot Specialty Chemicals Co., Ltd.), and spherical silica ("CF0018-WB15C" manufactured by Japan Frit Co., Ltd.). Silica particles (SEAHOSTAR KE series (KE-C50, etc.)) and the like. In addition, commercially available organic fillers include core-shell type particles ZEFIAC series (F-351, etc., manufactured by AICA Industries Co., Ltd.) and the like. The fillers can be one or a combination of two or more.

The coupling agent is added for the purpose of improving the adhesion of the liquid crystal display substrate. The coupling agent is not particularly limited, and examples thereof include γ-aminopropyl trimethoxysilane, γ-isocyanate propyl trimethoxysilane, 3-glycidyloxypropyl methyl diethoxy silane and 3-glycidyloxypropyl trimethoxy silane. The silane coupling agent may be one or a combination of two or more.

The additional components other than the filler and the coupling agent are additives added to the sealing agent for a liquid crystal dropping method, and well-known components or commercially available products can be mentioned.

(Composition) Relative to 100 parts by weight of the total of oligomer A and oligomer B, the content of oligomer A is preferably 1 to 99 parts by weight, more preferably 10 to 95 parts by weight, and particularly preferably 40 to 90 parts by weight.

The content of oligomer A is preferably 1 to 100 parts by weight, more preferably 50 to 99 parts by weight, and particularly preferably 90 to 95 parts by weight, relative to 100 parts by weight of the total oligomer A.

The content of oligomer B is preferably 1 to 100 parts by weight, more preferably 50 to 99 parts by weight, and particularly preferably 90 to 95 parts by weight, relative to 100 parts by weight of the total oligomer B.

The total content of oligomer A and oligomer B is preferably 50 to 100 parts by weight, particularly preferably 70 to 100 parts by weight, based on 100 parts by weight of the curable resin. In the curable resin, the component other than oligomer A and oligomer B is oligomer C.

The content of the photopolymerization initiator is preferably 0.1 to 10 parts by weight, more preferably 1 to 5 parts by weight, based on 100 parts by weight of the curable resin.

The content of the thermosetting agent is preferably 1 to 50 parts by weight, more preferably 5 to 40 parts by weight, based on 100 parts by weight of the total curable resin.

The content of the filler is preferably 1 to 50 parts by weight, more preferably 5 to 30 parts by weight, relative to 100 parts by weight of the total curable resin.

The content of the coupling agent is preferably 0.1 to 10 parts by weight, more preferably 0.5 to 5 parts by weight, based on 100 parts by weight of the curable resin.

When the total amount of the sealing agent for a liquid crystal dropping method is 100 parts by weight, the content of the curable resin is preferably 40 parts by weight or more and less than 100 parts by weight, and more preferably 60 parts by weight or more and less than 100 parts by weight.

(Application) The cured product of the sealant for the liquid crystal dropping method is used to seal a liquid crystal display. The liquid crystal display is not particularly limited, and a liquid crystal display to which the conventional sealant for the liquid crystal dropping method is applicable can be used. The sealant for the liquid crystal dropping method is cured by irradiating energy rays such as ultraviolet rays, by heating, or by heating before, after, or simultaneously with irradiating energy rays such as ultraviolet rays. [Example]

Next, the specific aspects of the present invention are further described in detail through embodiments, but the present invention is not limited to these examples.

(Products used) The components used in the examples and comparative examples are as follows. The sealing agent for the liquid crystal dropping method in the examples and comparative examples is prepared by mixing the following components into the composition described in the table. In addition, the values in the table are parts by weight.

1. Oligomer A (1) Compound 1 Compound 1 can be obtained by the following method.

(Production of Compound 1) 166 g of phenyl glycidyl ether (EX-141, manufactured by Nagase Chemtex), 200 g of RESITOP BPF-SG (bisphenol F) (manufactured by Gunei Chemical Industry Co., Ltd.), 10 g of benzyltrimethylammonium chloride (manufactured by Tokyo Chemical Industry Co., Ltd.), and 600 g of toluene (manufactured by Kanto Chemical Industry Co., Ltd.) were added to a flask equipped with a thermometer and a stirrer, and stirred at 120°C for 8 hours. After the reaction was completed, the mixture was cooled to room temperature and washed once with 2000 g of a 1% sodium hydroxide aqueous solution and twice with 2000 mL of water. The solvent of the obtained organic phase was removed by distillation under reduced pressure to obtain 336 g of a yellow transparent viscous ring-opened body (EX-141-bisphenol F ring-opened body).

330 g of EX-141-bisphenol F ring-opened body, 1742 g of epichlorohydrin (manufactured by Wako Junyaku Co., Ltd.), and 35 g of benzyltrimethylammonium chloride (manufactured by Tokyo Chemical Industry Co., Ltd.) were added to a 2L three-necked round-bottom flask equipped with a thermometer, a condenser, a Dean-Stark separator, a dropping funnel, and a stirrer. Next, the mixture was stirred under a reduced pressure of 50 torr, and heated to about 50°C, and 282 g of a 48% aqueous sodium hydroxide solution (manufactured by Kanto Chemical Co., Ltd.) was dripped over 3 hours. The epichlorohydrin in the azeotropically distilled water/epichlorohydrin mixture was returned to the reaction system while stirring was continued. After the addition was completed, stirring was continued for 3 hours. Next, the reaction mixture was cooled to room temperature, 900 g of toluene and 300 g of methyl isobutyl ketone were added, and the mixture was washed four times with 1500 mL of water. The solvent of the obtained organic phase was removed by distillation under reduced pressure to obtain 395 g of a yellow transparent viscous glycidyl ether (compound 1a, raw material epoxy resin).

200 g of compound 1a, 35 g of methacrylic acid (manufactured by Tokyo Chemical Industry Co., Ltd.), 212 mg of triphenylphosphine (manufactured by Tokyo Chemical Industry Co., Ltd.) as a catalyst, and 50 mg of BHT (dibutylhydroxytoluene, manufactured by Kanto Chemical Industry Co., Ltd.) were added to a flask equipped with a thermometer and a stirrer, and stirred at 100° C. for 8 hours. After the reaction was completed, a partially methacrylated epoxy compound (Compound 1) was obtained.

(2) Compound 2 Compound 2 was obtained according to the method described in paragraphs 106 to 111 of JP-A-2017-002246.

(3) Compound 3 Compound 3 was obtained by the following method.

(Production of Compound 3) 50 g of phenyl glycidyl ether (EX-141, manufactured by Nagase Chemtex), 116 g of BisP-AP (manufactured by Honshu Chemical Industry Co., Ltd.), 3.1 g of benzyltrimethylammonium chloride (manufactured by Tokyo Chemical Industry Co., Ltd.), and 200 g of toluene (manufactured by Kanto Chemical Co., Ltd.) were added to a flask equipped with a thermometer and a stirrer, and stirred at 120°C for 8 hours. After the reaction was completed, the mixture was cooled to room temperature, 200 g of methyl isobutyl ketone (manufactured by Kanto Chemical Co., Ltd.) was added, and the mixture was washed 4 times with 500 g of a 1% sodium hydroxide aqueous solution and 4 times with 500 mL of water. The solvent of the obtained organic phase was removed by distillation under reduced pressure to obtain 124 g of a yellow transparent viscous ring-opened form (EX-141-BisP-AP ring-opened form).

100 g of EX-141-BisP~AP ring-opened form, 421 g of epichlorohydrin (manufactured by Wako Junyaku Co., Ltd.), and 8.4 g of benzyltrimethylammonium chloride (manufactured by Tokyo Chemical Industry Co., Ltd.) were added to a 1L three-necked round-bottom flask equipped with a thermometer, condenser, Dean-Stark separator, dropping funnel, and stirrer. Next, the mixture was stirred under reduced pressure of 50 torr, and heated to about 50°C, and 68 g of 48% sodium hydroxide aqueous solution (manufactured by Kanto Chemical Co., Ltd.) was dripped over 3 hours. The epichlorohydrin in the azeotropically distilled water/epichlorohydrin mixture was returned to the reaction system while stirring was continued. After the addition was completed, stirring was continued for 3 hours. Next, the reaction mixture was cooled to room temperature, 250 g of toluene and 250 g of methyl isobutyl ketone were added, and the mixture was washed four times with 500 mL of water. The solvent of the obtained organic phase was removed by distillation under reduced pressure to obtain 120 g of a yellow transparent viscous glycidyl ether (compound 3a, raw material epoxy resin).

50 g of compound 3a, 7.2 g of methacrylic acid (manufactured by Tokyo Chemical Industry Co., Ltd.), 22 mg of triphenylphosphine (manufactured by Tokyo Chemical Industry Co., Ltd.) as a catalyst, and 11 mg of BHT (dibutylhydroxytoluene, manufactured by Kanto Chemical Industry Co., Ltd.) were added to a flask equipped with a thermometer and a stirrer, and stirred at 100° C. for 8 hours. After the reaction was completed, a partially methacrylated epoxy compound (compound 3) was obtained.

(4) Compound 4 Compound 4 was obtained by the following method.

(Production of Compound 4) 75 g of biphenyl-type monofunctional epoxy resin (OPP-G, manufactured by Sanko Co., Ltd.), 91 g of 2,2-bis(4-hydroxyphenyl)propane (bisphenol A) (manufactured by Kanto Chemical Co., Ltd.), 3.1 g of benzyltrimethylammonium chloride (manufactured by Tokyo Chemical Co., Ltd.), and 200 g of toluene (manufactured by Kanto Chemical Co., Ltd.) were added to a flask equipped with a thermometer and a stirrer, and stirred at 120°C for 8 hours. After the reaction was completed, the mixture was cooled to room temperature, 200 g of methyl isobutyl ketone (manufactured by Kanto Chemical Co., Ltd.) was added, and the mixture was washed twice with 1000 g of a 1% sodium hydroxide aqueous solution and twice with 1000 mL of water. The solvent of the obtained organic phase was removed by distillation under reduced pressure to obtain 135 g of a yellow transparent viscous ring-opened body (OPP-G-bisphenol A ring-opened body).

100 g of OPP-G-bisphenol A ring-opening body, 406 g of epichlorohydrin (manufactured by Wako Junyaku Co., Ltd.), and 8.2 g of benzyltrimethylammonium chloride (manufactured by Tokyo Chemical Industry Co., Ltd.) were added to a 1L three-necked round-bottom flask equipped with a thermometer, a condenser, a Dean-Stark separator, a dropping funnel, and a stirrer. Next, the mixture was stirred under a reduced pressure of 50 torr, and heated to about 50°C, and 66 g of a 48% aqueous sodium hydroxide solution (manufactured by Kanto Chemical Co., Ltd.) was dripped over 3 hours. The epichlorohydrin in the azeotropically distilled water/epichlorohydrin mixture was returned to the reaction system while stirring was continued. After the addition was completed, stirring was continued for 3 hours. Next, the reaction mixture was cooled to room temperature, 250 g of toluene and 250 g of methyl isobutyl ketone were added, and the mixture was washed four times with 500 mL of water. The solvent of the obtained organic phase was removed by distillation under reduced pressure to obtain 113 g of a yellow transparent viscous glycidyl ether (compound 4a, raw material epoxy resin).

50 g of compound 4a, 7.0 g of methacrylic acid (manufactured by Tokyo Chemical Industry Co., Ltd.), 21 mg of triphenylphosphine (manufactured by Tokyo Chemical Industry Co., Ltd.) as a catalyst, and 11 mg of BHT (dibutylhydroxytoluene, manufactured by Kanto Chemical Industry Co., Ltd.) were added to a flask equipped with a thermometer and a stirrer, and stirred at 100° C. for 8 hours. After the reaction was completed, a partially methacrylated epoxy compound (compound 4) was obtained.

2. Oligomer B (1) Compound 5 Compound 5 was obtained by the following method.

(Production of Compound 5) 200 g of bisphenol F epoxy resin (EXA-830CRP, manufactured by DIC Corporation), 54 g of methacrylic acid (manufactured by Tokyo Chemical Industry Co., Ltd.), 328 mg of triphenylphosphine (manufactured by Tokyo Chemical Industry Co., Ltd.) as a catalyst, and 50 mg of BHT (dibutylhydroxytoluene, manufactured by Kanto Chemical Industry Co., Ltd.) were added to a flask equipped with a thermometer and a stirrer, and stirred at 100°C for 8 hours. After the reaction was completed, a partially methacrylated epoxy compound (Compound 5) was obtained.

(2) Compound 6 Compound 6 was obtained according to the method described in paragraph 92 of WO2014/057871.

3. Oligomer C (1) Compound 7 Compound 7 was obtained according to the method described in paragraphs 131 to 135 of JP-A-2017-214462.

4. Photoinitiator (1) Photoinitiator 1 Photoinitiator 1 was obtained according to the method described in paragraph 58 of WO2012/077720.

(2) Photoinitiator 2 Photoinitiator 2 was obtained according to the method described in paragraph 60 of WO2012/077720.

5. Thermosetting agent Polyamine compound (EH-5030S, manufactured by ADEKA, active hydrogen equivalent 105g/eq)

6. Other ingredients (1) Fillers ・Organic filler; core-shell particles (ZEFIAC F-351, manufactured by AICA Industries) ・Inorganic filler; silica particles (SEAHOSTAR KE-C50, manufactured by Nippon Catalyst Co., Ltd.) ・Inorganic filler; fuming silica (mutation-imparting agent) (TG-308F, manufactured by Cabot Specialty Chemicals) (2) Coupling agent ・Silane coupling agent; 3-glycidyloxypropylmethyldiethoxysilane (KBM-403, manufactured by Shin-Etsu Chemical Industries, Ltd.)

(Measurement of epoxy equivalent) The epoxy equivalent of the epoxy resins (raw material epoxy resins) before methacrylic acid modification of compounds 1 to 7 was measured according to JIS K7236:2001.

(Aromatic ring content) The aromatic ring content of the epoxy resins of compounds 1 to 7 before methacrylic acid modification was calculated based on the structural formula of the corresponding raw material epoxy resin.

(Next, strength) After washing with pure water and drying, polyimide-based alignment liquid (SUNEVER SE-7492, manufactured by Nissan Chemical Industries, Ltd.) was dripped onto an ITO substrate (403005XG-10SQ1500A, manufactured by GEOMATEC) using a pneumatic dispenser (0.4MPa, 5.0 seconds), and then evenly applied using a rotary coater at 5000 rpm for 10 seconds and then maintained for 20 seconds. After evenly applying, pre-baking on a hot plate at 85°C (1 minute) and post-baking in an oven at 230°C (60 minutes) produced a polyimide alignment film-attached substrate.

The sealant for the liquid crystal drop method was dotted on the ITO substrate with 6μm spacers and the substrate with polyimide alignment film (30mm×30mm×0.5mmt) at 15mm×3mm and 15mm×21mm positions, and the diameter of the sealant for the liquid crystal drop method after bonding was in the range of 1.5 to 2.5mmφ. Then, the same substrate (23mm×23mm×0.5mmt) was bonded, and ultraviolet rays (irradiation device: UVX- ^01224S1 , manufactured by Ushio Electric Co., Ltd.) were irradiated with a cumulative light amount of 3,000mJ/cm2 to cure it, and heat-cured in an oven at 120℃ for 1 hour to produce a test piece. The test piece was fixed using a universal testing machine (TG-2kN, manufactured by MINEBEA) and pressed at a speed of 5 mm/min at a position of 15 mm×25 mm on the substrate to measure the bonding strength between ITO substrates (ITO/ITO) and between polyimide substrates (PI/PI(TN)).

(Moisture permeability) The liquid crystal drop method was sandwiched with a sealant using a 100mm×100mm PET film with a thickness of 0.1mm to obtain a diameter of 3.6mm to 3.8mm and a thickness of 0.28mm to 0.32mm. The film was irradiated with a UV irradiation illumination of 100mW/ ^cm2 and a light energy of 1,500mJ/ ^cm2 on both sides. The film was heat-cured in a hot air oven at 120℃ for 1 hour to prepare a sample for moisture permeability measurement. The moisture permeability measurement was based on JISK0208:1976, using a 65℃/95% constant temperature and humidity chamber, and the moisture permeability was calculated from the weight change measured by the moisture permeability cup method. The unit of moisture permeability is g/( ^m2 ･24h).

(Seal leak test in liquid crystal test tank) On an ITO glass substrate (thickness 0.7mm) with an alignment film (SE-5662, manufactured by Nissan Chemical Industries, Ltd.), a sealant for the liquid crystal drop method was dispensed in a 25mm×25mm frame pattern using a seal dispenser. Then, liquid crystal (MLC-6609, manufactured by Merck Co., Ltd.) was dropped onto the substrate using the liquid crystal drop method, and the upper and lower substrates were bonded together. After 3 minutes, ultraviolet light (UV irradiation device: UVX-01224S1, manufactured by Ushio Electric Co., Ltd., cumulative light amount: 3,000mJ/ ^cm2 ) was irradiated to photoharden, and then heat-hardened in a hot air oven at 120°C for 60 minutes to make a test tank. Regarding the manufactured liquid crystal test cells, the case where there was a sealing leak was rated as ×, and the case where no sealing leak was observed was rated as ○.

The results are summarized in Tables 1 and 2.

The sealing agent for the liquid crystal dropping method of the embodiment produces a cured product with excellent adhesion to the alignment film and excellent low moisture permeability. In addition, in the sealing leak test, no sealing leak was observed for the sealing agent for the liquid crystal dropping method of the embodiment, and the liquid crystal sealing was completed. From the comparison of Examples 1 and 2, it can be seen that when oligomer B has a bisphenol F-type structure, it has excellent low moisture permeability. From the comparison of Examples 1 and 3, it can be seen that when oligomer A has a bisphenol F-type structure, it has excellent low moisture permeability. From the comparison of Examples 1 and 4, it can be seen that when the content of oligomer A decreases relative to 100 parts by weight of the total of oligomer A and oligomer B, it has excellent low moisture permeability. From the comparison of Examples 4 to 6, it can be seen that when the epoxy equivalent and aromatic ring weight of the raw material epoxy resin of oligomer A are in a preferred range, low moisture permeability is excellent. In particular, from the comparison of Examples 5 and 6, it can be seen that when the epoxy equivalent of the raw material epoxy resin of oligomer A becomes larger, low moisture permeability is excellent.

On the other hand, the sealing agent for the liquid crystal dropping method of Comparative Example 1 contains only oligomer A, so the cured product obtained by using the sealing agent for the liquid crystal dropping method of Comparative Example 1 has high moisture permeability. The sealing agent for the liquid crystal dropping method of Comparative Example 2 contains only oligomer B, so the sealing agent for the liquid crystal dropping method of Comparative Example 2 has poor adhesion to the alignment film, and the cured product obtained by using the sealing agent for the liquid crystal dropping method of Comparative Example 2 has high moisture permeability. The sealing agent for the liquid crystal dropping method of Comparative Example 3 contains two types of oligomers B. In addition, the sealing agent for the liquid crystal dropping method of Comparative Example 3 contains compound 5, which is "an oligomer with an epoxy equivalent of less than 200 g/epo and an aromatic ring weight of 0.43 or more", instead of oligomer A. Therefore, the sealing agent for the liquid crystal dropping method of Comparative Example 3 has poor adhesion to the alignment film, and the cured product obtained by using the sealing agent for the liquid crystal dropping method of Comparative Example 3 has high moisture permeability. The sealing agent for the liquid crystal dropping method of Comparative Example 4 contains compound 7, which is "an oligomer with an epoxy equivalent of more than 200 g/epo and an aromatic ring weight of less than 0.43", instead of oligomer A. Therefore, the cured product obtained by using the sealing agent for the liquid crystal dropping method of Comparative Example 4 has high moisture permeability.

Claims (3)

A sealing agent for a liquid crystal dropping method, which is a sealing agent for a liquid crystal dropping method containing a curable resin, a photoinitiator and a thermosetting agent, wherein the curable resin contains an oligomer A and an oligomer B, wherein the oligomer A is a compound obtained by modifying a part of a raw material epoxy resin 1 by (meth)acrylic acid and having a bisphenol F type structure, wherein the epoxy resin 1 has an epoxide equivalent of 200 g/epo or more and an aromatic ring weight of 0.43 or more, or the oligomer A is a compound obtained by modifying a part of a raw material epoxy resin 2 by (meth)acrylic acid, wherein the epoxy equivalent of the raw material epoxy resin 2 has an epoxide equivalent of 200 g/epo or more and an aromatic ring weight of 0.43 or more, and wherein the oligomer A is a compound obtained by modifying a part of a raw material epoxy resin 2 by (meth)acrylic acid, wherein the epoxy equivalent of the raw material epoxy resin 2 has an epoxide equivalent of 200 g/epo or more and an aromatic ring weight of 0.43 or more, and wherein the oligomer B ... oligomer B is a compound obtained by modifying a part of a raw material epoxy resin 2 by (meth)acrylic acid, wherein the oligomer B is a compound obtained by modifying a part of a raw material epoxy resin 2 by (meth)acrylic acid, wherein the oligomer B is a compound obtained by modifying a part of a raw material epoxy resin 2 by (meth)acrylic acid, wherein the oligomer B is a compound obtained by modifying a part of a raw material epoxy resin 2 by (meth)acrylic acid,

[wherein, ^G1 and ^G2 are independently glycidyl or methylglycidyl, ^R11 is a hydrogen atom or a methyl group, ^X1 is an aromatic group having 6 to 20 carbon atoms which may be substituted -O-, an aromatic group having 6 to 20 carbon atoms which may be substituted -( ^OR1 ) _n1 -O- (wherein, ^R1 is an alkylene group having 1 to 6 carbon atoms, and n1 is an integer of 1 to 10), or an aromatic group having a total of 5 to 30 atoms which may be substituted, Y ^Y1 is an arylene group having 6 to 20 carbon atoms, an alkylene group having 1 to 4 carbon atoms-an arylene group having 6 to 20 carbon atoms, an alkylene group having 1 to 4 carbon atoms-an arylene group having 6 to 20 carbon atoms, an alkylene group having 1 to 4 carbon atoms-an arylene group having 6 to 20 carbon atoms-an alkylene group having 1 to 4 carbon atoms, an arylene group having 6 to 20 carbon atoms-an alkylene group having 1 to 4 carbon atoms-an arylene group having 6 to 20 carbon atoms, or a group: ^-R2- ( ^OR2 ) _n2- (wherein ^R2 is an alkylene group having 1 to 6 carbon atoms, and n2 is 0 or an integer of 1 to 6), but the alkylene group having 1 to 4 carbon atoms in the arylene group having 6 to 20 carbon atoms-an alkylene group having 1 to 4 carbon atoms-an arylene group having 6 to 20 carbon atoms is unsubstituted or substituted with trifluoromethyl or phenyl, but the number of benzene rings in the molecule is 3 or more, and ^Y1 is not the following

[0043] As shown in the base, the oligomer B is selected from the group consisting of bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol AD type epoxy resin, a compound in which a bisphenol A type epoxy resin is partially (meth) acrylic acid-modified, a compound in which a bisphenol F type epoxy resin is partially (meth) acrylic acid-modified, and a compound in which a bisphenol AD type epoxy resin is partially (meth) acrylic acid-modified. One or more of the group consisting of acrylic acid-modified compounds, wherein the bisphenol A type epoxy resin is an epoxy resin of a condensation product of bisphenol A and epichlorohydrin, the bisphenol F type epoxy resin is an epoxy resin of a condensation product of bisphenol F and epichlorohydrin, and the bisphenol AD type epoxy resin is an epoxy resin of a condensation product of bisphenol AD and epichlorohydrin. As in claim 1, the sealing agent for liquid crystal dropping method, wherein oligomer A is a compound having 3 or more benzene rings in one molecule and having a bisphenol F type structure. As in claim 1 or 2, the sealant for liquid crystal dropping method, wherein the oligomer B is a compound obtained by modifying a bisphenol F type epoxy resin or a portion of a bisphenol F type epoxy resin with (meth) acrylic acid.