Sealant for display element

Abstract

The purpose of the present invention is to provide a sealant for a display element, said sealant being superior in both adhesiveness and moisture permeation prevention. The present invention is a sealant for a display element, said sealant including a curable resin and a polymerization initiator, wherein the curable resin includes at least one type of compound selected from the group consisting of a compound represented by formula (I) and a compound represented by formula (II). In formula (I) and formula (II), R1 represents a hydrogen atom or a methyl group, R2 represents a structure that is derived from an optionally substituted dicarboxylic acid or an anhydride thereof, X represents a ring-opened structure of a lactone, n represents 0 to 2.0 (average value), Y represents an optionally substituted aliphatic cyclic structure, and Ep represents a structure that is derived from an epoxy compound with two or more functional groups.

Description

Display element sealant

[0001] The present invention relates to a sealant for a display element.

[0002] In recent years, liquid crystal display elements and organic EL display elements have become widely used as display elements characterized by their thinness, light weight, and low power consumption. In such display elements, display element sealants are typically used to bond various components and seal the liquid crystal and light-emitting layers. For example, a liquid crystal dripping method using a display element sealant, as disclosed in Patent Documents 1 and 2, is used as a manufacturing method for liquid crystal display elements from the viewpoints of shortening takt time and optimizing the amount of liquid crystal used. In the dripping method, a display element sealant is first applied to one of two electrode-equipped substrates to form a frame-shaped seal pattern. Next, while the sealant is still uncured, minute droplets of liquid crystal are dripped into the seal frame of the substrate. The other substrate is then superimposed under vacuum, and the sealant is cured to produce a liquid crystal display element. This dripping method is currently the mainstream method for manufacturing liquid crystal display elements.

[0003] Japanese Patent Application Laid-Open No. 2001-133794 International Publication No. 02 / 092718

[0004] With the widespread use of tablet devices and mobile terminals, display elements are increasingly required to have moisture-resistant reliability when operated under high-temperature, high-humidity environments. This requires sealants to be more effective at preventing water intrusion from the outside. To improve the moisture-resistant reliability of display elements, it is necessary to improve the adhesion of the sealant to the substrate, etc., to prevent water intrusion from the interface between the sealant and the substrate, and also to improve the moisture-resistant properties of the sealant. While blending fillers such as talc into sealants can improve the moisture-resistant properties of sealants, rigorous moisture-resistant reliability tests can result in uneven display on the display elements. In particular, for display elements with narrow frame designs, even sealants that previously presented no problems have had difficulty achieving both adhesion (especially adhesion to alignment films in the case of sealants for liquid crystal display elements) and moisture-resistant properties.

[0005] An object of the present invention is to provide a sealant for display elements that is excellent in both adhesiveness and moisture permeation prevention properties.

[0006] Disclosure 1 is a sealant for display elements containing a curable resin and a polymerization initiator, wherein the curable resin contains at least one selected from the group consisting of a compound represented by the following formula (I) and a compound represented by the following formula (II). Disclosure 2 is a sealant for display elements of Disclosure 1, wherein the curable resin contains a compound represented by the following formula (1) as the compound represented by formula (I). Disclosure 3 is a sealant for display elements of Disclosure 1, wherein in formula (I) and formula (II), R ２ The present disclosure 4 is a sealant for display elements according to the first or second disclosure, which has a structure represented by the following formula (2-1), (2-2), (2-3), or (2-4): ２ is the sealant for display elements of Disclosure 1, 2, or 3, which has a structure represented by the following formula (3-1), (3-2), (3-3), or (3-4). Disclosure 5 is the sealant for display elements of Disclosure 1, 2, 3, or 4, wherein the total content of the compound represented by Formula (I) and the compound represented by Formula (II) per 100 parts by mass of the curable resin is 5 parts by mass or more and 60 parts by mass or less. Disclosure 6 is the sealant for display elements of Disclosure 1, 2, 3, 4, or 5, wherein the curable resin further contains a bisphenol-type epoxy compound, and the total content of the compound represented by Formula (I) and the compound represented by Formula (II) per 100 parts by mass of the bisphenol-type epoxy compound is 50 parts by mass or more and 600 parts by mass or less. Disclosure 7 is the sealant for display elements of Disclosure 1, 2, 3, 4, 5, or 6, which is used in manufacturing a liquid crystal display element by a liquid crystal dropping method.

[0007]

[0008] In formula (I) and formula (II), R １ represents a hydrogen atom or a methyl group, R ２ represents a structure derived from an optionally substituted dicarboxylic acid or an anhydride thereof, X represents a lactone ring-open structure, n is 0 or more and 2.0 or less (average value), Y represents an optionally substituted aliphatic cyclic structure, and Ep represents a structure derived from a difunctional or higher epoxy compound.

[0009]

[0010] In formula (1), R１ represents a hydrogen atom or a methyl group, R ２ represents a structure derived from an optionally substituted dicarboxylic acid or an anhydride thereof, X represents a lactone ring-open structure, n is 0 or more and 2.0 or less (average value), and Ep represents a structure derived from a difunctional or higher epoxy compound. Some or all of the hydrogen atoms of the two 1,4-cyclohexylene groups in formula (1) may be substituted.

[0011]

[0012] In formulas (2-1) to (2-4), * represents a bonding position, and in formula (2-1), R ３ ~R １２ each independently represents a hydrogen atom or an alkyl group having 1 to 10 carbon atoms, and in formula (2-2), R １３ ~R ２０ each independently represents a hydrogen atom or an alkyl group having 1 to 10 carbon atoms, and in formula (2-3), R ２１ ~R ２４ each independently represents a hydrogen atom or an alkyl group having 1 to 10 carbon atoms, and in formula (2-4), R ２５ ~R ２８ each independently represents a hydrogen atom or an organic group having 1 to 60 carbon atoms, or R ２５ and R ２８ and each independently represent a hydrogen atom or an alkyl group having 1 to 10 carbon atoms, and R ２６ and R ２７ represents a structure in which and are bonded.

[0013]

[0014] In formulas (3-1) to (3-4), * represents a bonding position, and in formula (3-1), R ２９ represents a hydrogen atom or an alkyl group having 1 to 10 carbon atoms, and in formula (3-2), R ３０ represents a hydrogen atom or an alkyl group having 1 to 10 carbon atoms, and in formula (3-3), R ３１ represents a hydrogen atom or an alkyl group having 1 to 10 carbon atoms, and in formula (3-4), R ３２ and R ３３each independently represents a hydrogen atom or an organic group having 1 to 60 carbon atoms, or R ３２ and R ３３ represents a structure in which and are bonded.

[0015] The present invention is described in detail below. The inventors investigated the use of a flexible resin with a long molecular chain as the curable resin used in a sealant for display elements, thereby imparting flexibility to the sealant and exhibiting stress relaxation properties, thereby ensuring high adhesion. However, when the sealant is drawn thinner in a narrow frame design, the adhesion is insufficient, and peeling or the like may occur on the display element substrate. The inventors investigated improving adhesion by using a flexible resin with a longer molecular chain, but the resulting sealant had poor moisture permeation prevention properties, and display defects or the like may occur when the produced display element is exposed to a high-temperature, high-humidity environment. Therefore, as a result of further intensive research, the inventors discovered that a sealant for display elements excellent in both adhesion and moisture permeation prevention properties can be obtained by using a compound having a specific structure as the curable resin, leading to the completion of the present invention.

[0016] The display element sealant of the present invention contains a curable resin. The curable resin contains at least one selected from the group consisting of the compound represented by formula (I) and the compound represented by formula (II). By containing at least one selected from the group consisting of the compound represented by formula (I) and the compound represented by formula (II), the display element sealant of the present invention is excellent in both adhesion (particularly adhesion to an alignment film) and moisture permeability prevention, and also excellent in low liquid crystal contamination when used as a sealant for a liquid crystal display element. In particular, the curable resin preferably contains the compound represented by formula (I), and more preferably contains the compound represented by formula (1) as the compound represented by formula (I).

[0017] In the above formula (I) and the above formula (II), R ２ represents a structure derived from an optionally substituted dicarboxylic acid or an anhydride thereof. ２When the structure is derived from an optionally substituted dicarboxylic acid or an anhydride thereof, the resulting sealant for a display element has excellent adhesiveness (particularly adhesiveness to an alignment film).

[0018] The optionally substituted dicarboxylic acid may be an aliphatic dicarboxylic acid or an aromatic dicarboxylic acid. When the optionally substituted dicarboxylic acid or anhydride thereof is substituted, examples of the substituent include an unsaturated bond containing an aromatic ring, a carbon chain having 1 to 60 carbon atoms which may have a branched structure, and a hydrocarbon skeleton which includes a cyclic structure.

[0019] Specific examples of the optionally substituted dicarboxylic acid or anhydride thereof include phthalic anhydride, 3-methylphthalic anhydride, 4-methylphthalic anhydride, 4-tert-butylphthalic anhydride, 1,2-naphthalenedicarboxylic anhydride, 2,3-naphthalenedicarboxylic anhydride, 1,8-naphthalenedicarboxylic anhydride, phenylmaleic anhydride, phenylsuccinic anhydride, 1,2-cyclohexanedicarboxylic anhydride, 3-methylcyclohexane-1,2-dicarboxylic anhydride, 4-methylcyclohexane-1,2-dicarboxylic anhydride, 4-cyclohexene-1,2-dicarboxylic anhydride, 3-methyl-4-cyclohexene-1,2-dicarboxylic anhydride, 3,4,5,6-tetrahydrophthalic anhydride, 4-methyl-4-cyclohexene-1,2-dicarboxylic anhydride, tetrapropenylsuccinic anhydride, Succinic anhydride, decylsuccinic anhydride, tetradecylsuccinic anhydride, tetradecenylsuccinic anhydride, hexadecylsuccinic anhydride, allylsuccinic anhydride, isooctadecenylsuccinic anhydride, butylsuccinic anhydride, 4-hexene-1,2-dicarboxylic anhydride, 2-dodecen-1-ylsuccinic anhydride, 2,2-dimethylsuccinic anhydride, 2-hexen-1-ylsuccinic anhydride, 4-methyl-4-pentene 2-(2-carboxyethyl)-3-methylmaleic anhydride, 7-oxabicyclo[2.2.1]hept-5-ene-2,3-dicarboxylic anhydride, and the dicarboxylic acids before conversion into anhydrides.

[0020] The above R ２ From the viewpoint of further improving the adhesiveness (particularly the adhesiveness to the alignment film) of the resulting sealant for display elements, it is preferable that the structure be represented by the above formula (2-1), (2-2), (2-3), or (2-4), and it is more preferable that the structure be represented by the above formula (3-1), (3-2), (3-3), or (3-4).

[0021] Examples of the structure represented by the formula (2-1) include structures derived from 1,2-cyclohexanedicarboxylic anhydride, 3-methylcyclohexane-1,2-dicarboxylic anhydride, 4-methylcyclohexane-1,2-dicarboxylic anhydride, etc. Examples of the structure represented by the formula (2-2) include structures derived from 4-cyclohexene-1,2-dicarboxylic anhydride, 3-methyl-4-cyclohexene-1,2-dicarboxylic anhydride, 3,4,5,6-tetrahydrophthalic anhydride, 4-methyl-4-cyclohexene-1,2-dicarboxylic anhydride, etc. Examples of the structure represented by the formula (2-3) include structures derived from phthalic anhydride, 3-methylphthalic anhydride, 4-methylphthalic anhydride, 4-tert-butylphthalic anhydride, etc. Examples of the structure represented by the formula (2-4) include structures derived from R ２６ and R ２７ and may be unbonded, or R ２６ and R ２７ However, from the viewpoint of improving moisture permeability prevention, R ２６ and R ２７ The structure in which R ２６ and R ２７ Examples of the structure in which R is not bonded include structures derived from tetrapropenylsuccinic anhydride, decylsuccinic anhydride, tetradecylsuccinic anhydride, tetradecenylsuccinic anhydride, hexadecylsuccinic anhydride, isooctadecenylsuccinic anhydride, butylsuccinic anhydride, allylsuccinic anhydride, 4-hexene-1,2-dicarboxylic anhydride, 2-dodecen-1-ylsuccinic anhydride, 2,2-dimethylsuccinic anhydride, 2-hexen-1-ylsuccinic anhydride, 4-methyl-4-pentene-1,2-dicarboxylic anhydride, 2-octenylsuccinic anhydride, 4,9-decadiene-1,2-dicarboxylic anhydride, etc. ２６ and R ２７Examples of the structure in which the above are bonded include structures derived from 5-norbornene-2,3-dicarboxylic anhydride, bicyclo[2.2.2]oct-5-ene-2,3-dicarboxylic anhydride, 7-oxabicyclo[2.2.1]hept-5-ene-2,3-dicarboxylic anhydride, and the like.

[0022] In the formulas (I) and (II), X represents a lactone ring-open structure. Examples of the lactone include γ-undecalactone, ε-caprolactone, γ-decalactone, σ-dodecalactone, γ-nonanolactone, γ-heptanolactone, γ-valerolactone, σ-valerolactone, β-butyrolactone, γ-butyrolactone, β-propiolactone, σ-hexanolactone, and 7-butyl-2-oxepanone. Among these, lactones having a linear main skeleton with 5 to 7 carbon atoms upon ring-opening are preferred. When n is 0 in the formulas (I) and (II), i.e., when there is no lactone ring-open structure represented by X, the resulting sealant for display elements exhibits superior moisture permeability prevention properties. When n is greater than 0 and 2.0 or less (average value), the resulting sealant for display elements exhibits superior adhesion (particularly adhesion to alignment films). When n exceeds 0, n is preferably greater than 0 and not greater than 0.5 (average value). In addition, the "average value" of n means that when the compound represented by formula (I) or the compound represented by formula (II) is a mixture of compounds each having a different number of repetitions of X, n is expressed as the average value of the repetition numbers (molar average value).

[0023] In the above formula (I) and the above formula (II), Ep represents a structure derived from a bifunctional or higher epoxy compound. Examples of the epoxy compound from which Ep is derived include bisphenol A type epoxy compounds, bisphenol F type epoxy compounds, bisphenol E type epoxy compounds, bisphenol S type epoxy compounds, hydrogenated bisphenol A type epoxy compounds, hydrogenated bisphenol F type epoxy compounds, hydrogenated bisphenol E type epoxy compounds, hydrogenated bisphenol S type epoxy compounds, dicyclopentadiene type epoxy compounds, resorcinol type epoxy compounds, naphthalene type epoxy compounds, fluorene type epoxy compounds, rubber-modified epoxy compounds, glycidyl ester compounds, etc. Among these, Ep is preferably a structure derived from a bisphenol A type epoxy compound, a bisphenol F type epoxy compound, or a bisphenol E type epoxy compound. In this specification, the "structure derived from an epoxy compound" refers to the structure of the portion other than the epoxy group in the epoxy compound.

[0024] The preferred upper limit of the molecular weight of the epoxy compound from which Ep is derived is 1000. When the molecular weight of the epoxy compound is 1000 or less, the resulting sealant for display elements has better workability. The more preferred upper limit of the molecular weight of the epoxy compound from which Ep is derived is 500.

[0025] In the formulas (I) and (II), Y represents an optionally substituted alicyclic structure. When Y is such an alicyclic structure, the display element sealant of the present invention exhibits excellent adhesion (particularly adhesion to an alignment film) and moisture permeability prevention. Among these, Y is preferably an optionally substituted 1,2-cyclohexylene group, an optionally substituted 1,3-cyclohexylene group, or an optionally substituted 1,4-cyclohexylene group. An optionally substituted 1,4-cyclohexylene group is more preferable, as this provides particularly excellent adhesion (particularly adhesion to an alignment film). Furthermore, from the viewpoint of ease of raw material availability, Y is preferably unsubstituted. When Y is substituted, examples of the substituent include an alkyl group having 1 to 10 carbon atoms. That is, although some or all of the hydrogen atoms of the two 1,4-cyclohexylene groups in the formula (1) may be substituted, from the viewpoint of ease of raw material availability, it is preferable that they are unsubstituted. In the case where the hydrogen atoms of the two 1,4-cyclohexylene groups in the above formula (1) are substituted, examples of the substituent include alkyl groups having 1 to 10 carbon atoms.

[0026] Examples of methods for producing the compound represented by formula (I) include the following: That is, a method comprising the steps of reacting a compound having an alicyclic structure and (meth)acryloyloxymethyl groups and hydroxymethyl groups bonded to the alicyclic structure, or a compound in which some or all of the hydrogen atoms in the alicyclic structure have been substituted, with the optionally substituted dicarboxylic acid or anhydride thereof in the presence of a polymerization inhibitor by heating and stirring, and adding the bifunctional or higher functional epoxy compound to the resulting reaction product and heating and stirring to react all of the epoxy groups. In particular, examples of methods for producing the compound represented by formula (1) include the following: That is, a method comprising the steps of reacting 1,4-cyclohexanedimethanol mono(meth)acrylate or a compound in which some or all of the hydrogen atoms in the cyclohexylene groups have been substituted, with the optionally substituted dicarboxylic acid or anhydride thereof by heating and stirring in the presence of a polymerization inhibitor, and adding the bifunctional or higher functional epoxy compound to the resulting reaction product and heating and stirring to react all of the epoxy groups. The 1,4-cyclohexanedimethanol mono(meth)acrylate or a compound in which some or all of the hydrogen atoms of the cyclohexylene groups have been substituted may be reacted with the lactone before being reacted with the optionally substituted dicarboxylic acid or anhydride thereof. In this specification, the term "(meth)acryloyl" means acryloyl or methacryloyl, and the term "(meth)acrylate" means acrylate or methacrylate.

[0027] Examples of methods for producing the compound represented by formula (II) include the following: That is, a method comprising a step of reacting a compound having an aliphatic cyclic structure and a (meth)acryloyloxymethyl group and a hydroxymethyl group bonded to the aliphatic cyclic structure, or a compound in which some or all of the hydrogen atoms in the aliphatic cyclic structure have been substituted, with the optionally substituted dicarboxylic acid or anhydride thereof by heating and stirring in the presence of a polymerization inhibitor, and a step of adding the bifunctional or higher functional epoxy compound to the resulting reaction product and heating and stirring to react some of the epoxy groups.

[0028] Examples of the polymerization inhibitor include hydroquinone and p-methoxyphenol.

[0029] The curable resin preferably contains at least one selected from the group consisting of the compound represented by formula (I) and the compound represented by formula (II), as well as other curable resins. When the curable resin contains the other curable resins, the preferred lower limit of the total content of the compound represented by formula (I) and the compound represented by formula (II) per 100 parts by mass of the curable resin is 5 parts by mass, and the preferred upper limit is 60 parts by mass. When the total content of the compound represented by formula (I) and the compound represented by formula (II) is 5 parts by mass or more, the resulting display element sealant has better adhesion (particularly adhesion to an alignment film). When the total content of the compound represented by formula (I) and the compound represented by formula (II) is 60 parts by mass or less, the resulting display element sealant has better moisture permeation prevention properties and workability. A more preferred lower limit of the total content of the compound represented by formula (I) and the compound represented by formula (II) is 10 parts by mass, and a more preferred upper limit is 30 parts by mass. In this specification, the above-mentioned "total content of the compound represented by the formula (I) and the compound represented by the formula (II)" means the content of one of the compounds contained when only one of these compounds is contained, and means the total content when both are contained.

[0030] The curable resin preferably contains a bisphenol-type epoxy compound as the other curable resin. By containing the bisphenol-type epoxy compound, the resulting sealant for display elements has better adhesion.

[0031] Examples of the bisphenol-type epoxy compound include bisphenol A-type epoxy compounds, bisphenol F-type epoxy compounds, bisphenol E-type epoxy compounds, bisphenol S-type epoxy compounds, and 2,2'-diallyl bisphenol A-type epoxy compounds. Furthermore, a partially (meth)acrylic-modified bisphenol-type epoxy compound may also be used as the bisphenol-type epoxy compound. Examples of the partially (meth)acrylic-modified bisphenol-type epoxy compound include partially (meth)acrylic-modified bisphenol A-type epoxy compounds, partially (meth)acrylic-modified bisphenol F-type epoxy compounds, and partially (meth)acrylic-modified bisphenol E-type epoxy compounds. In this specification, the term "(meth)acrylic" refers to acrylic or methacrylic. In this specification, the term "partially (meth)acrylic-modified epoxy compound" refers to a compound having one or more epoxy groups and one or more (meth)acryloyl groups per molecule, which is obtained by reacting some of the epoxy groups of an epoxy compound having two or more epoxy groups per molecule with (meth)acrylic acid.

[0032] The preferred lower limit of the content of the bisphenol-type epoxy compound per 100 parts by mass of the total curable resin is 5 parts by mass, and the preferred upper limit is 30 parts by mass. When the content of the bisphenol-type epoxy compound is within this range, the resulting sealant for display elements has superior adhesiveness, and when used as a sealant for liquid crystal display elements, it also has excellent low liquid crystal contamination properties. The more preferred lower limit of the content of the bisphenol-type epoxy compound is 10 parts by mass, and the more preferred upper limit is 20 parts by mass.

[0033] The preferred lower limit of the total content of the compound represented by formula (I) and the compound represented by formula (II) per 100 parts by mass of the bisphenol-type epoxy compound is 50 parts by mass, and the preferred upper limit is 600 parts by mass. When the total content of the compound represented by formula (I) and the compound represented by formula (II) per 100 parts by mass of the bisphenol-type epoxy compound is 50 parts by mass or more, the resulting sealant for display elements has better adhesion (particularly adhesion to alignment films). When the total content of the compound represented by formula (I) and the compound represented by formula (II) per 100 parts by mass of the bisphenol-type epoxy compound is 600 parts by mass or less, the resulting sealant for display elements has better moisture permeation prevention properties and workability. A more preferred lower limit of the total content of the compound represented by formula (I) and the compound represented by formula (II) per 100 parts by mass of the bisphenol-type epoxy compound is 100 parts by mass, and a more preferred upper limit is 300 parts by mass.

[0034] The curable resin may further contain a curable resin other than the bisphenol epoxy compound as the other curable resin, within the scope of not impairing the object of the present invention. Examples of the other curable resin other than the bisphenol epoxy compound include other (meth)acrylic compounds other than the compound represented by formula (I) above, and other epoxy compounds other than the compound represented by formula (II) above and the bisphenol epoxy compound.

[0035] Examples of the other (meth)acrylic compounds include (meth)acrylic acid ester compounds, epoxy (meth)acrylates, and urethane (meth)acrylates. Of these, epoxy (meth)acrylates are preferred. From the viewpoint of reactivity, the other (meth)acrylic compounds preferably have two or more (meth)acryloyl groups in one molecule. In this specification, the term "epoxy (meth)acrylate" refers to a compound in which all epoxy groups in an epoxy compound have reacted with (meth)acrylic acid.

[0036] Examples of the monofunctional (meth)acrylic acid ester compounds include methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, n-butyl (meth)acrylate, isobutyl (meth)acrylate, t-butyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, n-octyl (meth)acrylate, isooctyl (meth)acrylate, isononyl (meth)acrylate, isodecyl (meth)acrylate, lauryl (meth)acrylate, and isononyl (meth)acrylate. Myristyl (meth)acrylate, stearyl (meth)acrylate, 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 2-hydroxybutyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, cyclohexyl (meth)acrylate, isobornyl (meth)acrylate, bicyclopentenyl (meth)acrylate, benzyl (meth)acrylate, 2-methoxyethyl (meth)acrylate, 2-ethoxyethyl (meth)acrylate, 2 -butoxyethyl (meth)acrylate, 2-phenoxyethyl (meth)acrylate, methoxyethylene glycol (meth)acrylate, methoxypolyethylene glycol (meth)acrylate, phenoxydiethylene glycol (meth)acrylate, phenoxypolyethylene glycol (meth)acrylate, tetrahydrofurfuryl (meth)acrylate, ethyl carbitol (meth)acrylate, 2,2,2-trifluoroethyl (meth)acrylate, 2,2,3,3-tetrafluoropropyl Examples of the acrylates include 2-(meth)acryloyloxyethyl succinate, 2-(meth)acryloyloxyethyl hexahydrophthalate, 2-(meth)acryloyloxyethyl 2-hydroxypropyl phthalate, 2-(meth)acryloyloxyethyl phosphate, and glycidyl (meth)acrylate.

[0037] Furthermore, examples of the bifunctional (meth)acrylic acid ester compounds include 1,3-butanediol di(meth)acrylate, 1,4-butanediol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, 1,9-nonanediol di(meth)acrylate, 1,10-decanediol di(meth)acrylate, ethylene glycol di(meth)acrylate, diethylene glycol di(meth)acrylate, tetraethylene glycol di(meth)acrylate, polyethylene glycol di(meth)acrylate, 2-n-butyl-2-ethyl-1,3-propanediol di(meth)acrylate, dipropylene glycol di(meth)acrylate, tripropylene glycol di(meth)acrylate, polypropylene glycol di(meth)acrylate, and propylene glycol di(meth)acrylate. Examples of suitable di(meth)acrylates include butyl di(meth)acrylate, neopentyl glycol di(meth)acrylate, ethylene oxide-added bisphenol A di(meth)acrylate, propylene oxide-added bisphenol A di(meth)acrylate, ethylene oxide-added bisphenol F di(meth)acrylate, dimethyloldicyclopentadienyl di(meth)acrylate, ethylene oxide-modified isocyanuric acid di(meth)acrylate, 2-hydroxy-3-(meth)acryloyloxypropyl (meth)acrylate, carbonate diol di(meth)acrylate, polyether diol di(meth)acrylate, polyester diol di(meth)acrylate, polycaprolactone diol di(meth)acrylate, and polybutadiene diol di(meth)acrylate.

[0038] Furthermore, examples of the (meth)acrylic acid ester compounds having three or more functional groups include trimethylolpropane tri(meth)acrylate, ethylene oxide-added trimethylolpropane tri(meth)acrylate, propylene oxide-added trimethylolpropane tri(meth)acrylate, caprolactone-modified trimethylolpropane tri(meth)acrylate, ethylene oxide-added isocyanuric acid tri(meth)acrylate, glycerin tri(meth)acrylate, propylene oxide-added glycerin tri(meth)acrylate, pentaerythritol tri(meth)acrylate, tris(meth)acryloyloxyethyl phosphate, ditrimethylolpropane tetra(meth)acrylate, pentaerythritol tetra(meth)acrylate, dipentaerythritol penta(meth)acrylate, and dipentaerythritol hexa(meth)acrylate.

[0039] The epoxy (meth)acrylate may be, for example, one obtained by reacting an epoxy compound with (meth)acrylic acid in the presence of a basic catalyst according to a conventional method.

[0040] As the epoxy compound serving as a raw material for synthesizing the epoxy (meth)acrylate, the same epoxy compounds as those from which Ep is derived can be used.

[0041] Among the above-mentioned epoxy (meth)acrylates, commercially available ones include, for example, epoxy (meth)acrylate manufactured by Daicel Allnex Corporation, epoxy (meth)acrylate manufactured by Shin-Nakamura Chemical Co., Ltd., epoxy (meth)acrylate manufactured by Kyoeisha Chemical Co., Ltd., and epoxy (meth)acrylate manufactured by Nagase ChemteX Corporation. Examples of the epoxy (meth)acrylates manufactured by Daicel Allnex Co., Ltd. include EBECRYL860, EBECRYL3200, EBECRYL3201, EBECRYL3412, EBECRYL3600, EBECRYL3700, EBECRYL3701, EBECRYL3702, EBECRYL3703, EBECRYL3708, EBECRYL3800, EBECRYL6040, EBECRYL RDX63182, and KRM8076. Examples of the epoxy (meth)acrylates manufactured by Shin-Nakamura Chemical Co., Ltd. include EA-1010, EA-1020, EA-5323, EA-5520, EA-CHD, and EMA-1020. Examples of the epoxy (meth)acrylates manufactured by Kyoeisha Chemical Co., Ltd. include Epoxy Ester M-600A, Epoxy Ester 40EM, Epoxy Ester 70PA, Epoxy Ester 200PA, Epoxy Ester 80MFA, Epoxy Ester 3002M, Epoxy Ester 3002A, Epoxy Ester 1600A, Epoxy Ester 3000M, Epoxy Ester 3000A, Epoxy Ester 200EA, Epoxy Ester 400EA, etc. Examples of the epoxy (meth)acrylates manufactured by Nagase ChemteX Corporation include Denacol Acrylate DA-141, Denacol Acrylate DA-314, Denacol Acrylate DA-911, etc.

[0042] The urethane (meth)acrylate can be obtained, for example, by reacting an isocyanate compound with a (meth)acrylic acid derivative having a hydroxyl group in the presence of a catalytic amount of a tin compound.

[0043] Examples of the isocyanate compound include isophorone diisocyanate, 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, hexamethylene diisocyanate, trimethylhexamethylene diisocyanate, diphenylmethane-4,4'-diisocyanate (MDI), hydrogenated MDI, polymeric MDI, 1,5-naphthalene diisocyanate, norbornane diisocyanate, tolidine diisocyanate, xylylene diisocyanate (XDI), hydrogenated XDI, lysine diisocyanate, triphenylmethane triisocyanate, tris(isocyanatephenyl)thiophosphate, tetramethylxylylene diisocyanate, and 1,6,11-undecane triisocyanate.

[0044] The isocyanate compound may also be a chain-extended isocyanate compound obtained by reacting a polyol with an excess of an isocyanate compound. Examples of the polyol include ethylene glycol, propylene glycol, glycerin, sorbitol, trimethylolpropane, carbonate diol, polyether diol, polyester diol, and polycaprolactone diol.

[0045] Examples of the (meth)acrylic acid derivatives having a hydroxyl group include hydroxyalkyl mono(meth)acrylates, mono(meth)acrylates of dihydric alcohols, mono(meth)acrylates or di(meth)acrylates of trihydric alcohols, and epoxy (meth)acrylates. Examples of the hydroxyalkyl mono(meth)acrylates include 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 2-hydroxybutyl (meth)acrylate, and 4-hydroxybutyl (meth)acrylate. Examples of the dihydric alcohols include ethylene glycol, propylene glycol, 1,3-propanediol, 1,3-butanediol, 1,4-butanediol, and polyethylene glycol. Examples of the trihydric alcohols include trimethylolethane, trimethylolpropane, and glycerin. Examples of the epoxy (meth)acrylates include bisphenol A-type epoxy acrylate.

[0046] Among the above urethane (meth)acrylates, commercially available ones include, for example, urethane (meth)acrylate manufactured by Toagosei Co., Ltd., urethane (meth)acrylate manufactured by Daicel Allnex Corporation, urethane (meth)acrylate manufactured by Negami Chemical Industrial Co., Ltd., urethane (meth)acrylate manufactured by Shin-Nakamura Chemical Co., Ltd., and urethane (meth)acrylate manufactured by Kyoeisha Chemical Co., Ltd. Examples of the above urethane (meth)acrylate manufactured by Toagosei Co., Ltd. include M-1100, M-1200, M-1210, and M-1600. Examples of the urethane (meth)acrylates manufactured by Daicel Allnex Co., Ltd. include EBECRYL210, EBECRYL220, EBECRYL230, EBECRYL270, EBECRYL1290, EBECRYL2220, EBECRYL4827, EBECRYL4842, EBECRYL4858, EBECRYL5129, EBECRYL6700, EBECRYL8402, EBECRYL8803, EBECRYL8804, EBECRYL8807, and EBECRYL9260. Examples of the urethane (meth)acrylates manufactured by Negami Chemical Industrial Co., Ltd. include Art Resin UN-330, Art Resin SH-500B, Art Resin UN-1200TPK, Art Resin UN-1255, Art Resin UN-3320HB, Art Resin UN-7100, Art Resin UN-9000A, and Art Resin UN-9000H. Examples of the urethane (meth)acrylates manufactured by Shin-Nakamura Chemical Co., Ltd. include U-2HA, U-2PHA, U-3HA, U-4HA, U-6H, U-6HA, U-6LPA, U-10H, U-15HA, U-108, U-108A, U-122A, U-122P, U-324A, U-340A, U-340P, U-1084A, U-2061BA, UA-340P, UA-4000, UA-4100, UA-4200, UA-4400, UA-5201P, UA-7100, UA-7200, and UA-W2A. Examples of the urethane (meth)acrylates manufactured by Kyoeisha Chemical Co., Ltd. include AH-600, AI-600, AT-600, UA-101I, UA-101T, UA-306H, UA-306I, and UA-306T.

[0047] Examples of the other epoxy compounds include resorcinol-type epoxy compounds, biphenyl-type epoxy compounds, sulfide-type epoxy compounds, diphenyl ether-type epoxy compounds, dicyclopentadiene-type epoxy compounds, naphthalene-type epoxy compounds, phenol novolac-type epoxy compounds, ortho-cresol novolac-type epoxy compounds, dicyclopentadiene novolac-type epoxy compounds, biphenyl novolac-type epoxy compounds, naphthalene phenol novolac-type epoxy compounds, glycidylamine-type epoxy compounds, alkyl polyol-type epoxy compounds, rubber-modified epoxy compounds, and glycidyl ester compounds.

[0048] The preferred lower limit of the total content of the curable resin in 100 parts by mass of the sealant for display elements of the present invention is 50 parts by mass, and the preferred upper limit is 95 parts by mass. When the total content of the curable resin is within this range, the resulting sealant for display elements has better curability and adhesiveness. The more preferred lower limit of the total content of the curable resin is 60 parts by mass, and the more preferred upper limit is 85 parts by mass.

[0049] The sealant for display elements of the present invention contains a polymerization initiator. Examples of the polymerization initiator include a photoradical polymerization initiator that generates radicals upon irradiation with light and a thermal radical polymerization initiator that generates radicals upon heating.

[0050] Examples of the photoradical polymerization initiator include benzophenone-based compounds, acetophenone-based compounds, acylphosphine oxide-based compounds, titanocene-based compounds, oxime ester-based compounds, benzoin ether-based compounds, thioxanthone-based compounds, etc. Specific examples of the photoradical polymerization initiator include 1-hydroxycyclohexyl phenyl ketone, 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)-1-butanone, 2-(dimethylamino)-2-((4-methylphenyl)methyl)-1-(4-(4-morpholinyl)phenyl)-1-butanone, 2,2-dimethoxy-1,2-diphenylethan-1-one, bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide, 2-methyl-2-methyl-1 ... methyl-1-(4-methylthiophenyl)-2-morpholinopropan-1-one, 1-(4-(2-hydroxyethoxy)-phenyl)-2-hydroxy-2-methyl-1-propan-1-one, 1-(4-(phenylthio)phenyl)-1,2-octanedione 2-(O-benzoyloxime), 2,4,6-trimethylbenzoyldiphenylphosphine oxide, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, etc. The above photoradical polymerization initiators may be used alone or in combination of two or more.

[0051] Examples of the thermal radical polymerization initiator include those composed of an azo compound, an organic peroxide, and the like. Among these, initiators composed of an azo compound (hereinafter also referred to as "azo initiators") are preferred from the viewpoint of suppressing liquid crystal contamination when the resulting display element sealant is used as a sealant for a liquid crystal display element. The thermal radical polymerization initiators may be used alone or in combination of two or more. Commercially available examples of the azo initiators include VPE-0201, VPE-0401, VPE-0601, VPS-0501, VPS-1001, V-65, and V-501 (all manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.).

[0052] Examples of the organic peroxide include ketone peroxides, peroxyketals, hydroperoxides, dialkyl peroxides, peroxyesters, diacyl peroxides, and peroxydicarbonates.

[0053] The content of the polymerization initiator is preferably 0.01 parts by mass at the lower limit and 10 parts by mass at the upper limit relative to 100 parts by mass of the curable resin. By having the content of the polymerization initiator in this range, the resulting sealant for display elements has better storage stability and curability. The content of the polymerization initiator is more preferably 0.1 parts by mass at the lower limit and 5 parts by mass at the upper limit.

[0054] The sealant for display elements of the present invention preferably further contains a heat curing agent. Examples of the heat curing agent include organic acid hydrazides, imidazole derivatives, amine compounds, polyhydric phenol compounds, and acid anhydrides. Among these, organic acid hydrazides are preferably used. The heat curing agents may be used alone or in combination of two or more.

[0055] Examples of the organic acid hydrazides include sebacic acid dihydrazide, isophthalic acid dihydrazide, adipic acid dihydrazide, and malonic acid dihydrazide. Commercially available organic acid hydrazides include those manufactured by Otsuka Chemical Co., Ltd. and those manufactured by Ajinomoto Fine-Techno Co., Ltd. Examples of the organic acid hydrazides manufactured by Otsuka Chemical Co., Ltd. include SDH, ADH, and MDH. Examples of the organic acid hydrazides manufactured by Ajinomoto Fine-Techno Co., Ltd. include Amicure VDH, Amicure VDH-J, Amicure UDH, and Amicure UDH-J.

[0056] The content of the thermosetting agent is preferably 1 part by mass at the lower limit and 50 parts by mass at the upper limit relative to 100 parts by mass of the curable resin. By using the thermosetting agent in this range, the resulting sealant for display elements can have excellent thermosetting properties without deteriorating the application properties or storage stability. The more preferred upper limit of the content of the thermosetting agent is 30 parts by mass.

[0057] The sealant for display elements of the present invention preferably further contains a filler for the purposes of adjusting viscosity, further improving adhesion due to a stress dispersion effect, improving the linear expansion coefficient, and further improving moisture permeability prevention.

[0058] The filler may be an inorganic filler or an organic filler. Examples of the inorganic filler include silica, talc, glass beads, asbestos, gypsum, diatomaceous earth, smectite, bentonite, montmorillonite, sericite, activated clay, alumina, zinc oxide, iron oxide, magnesium oxide, tin oxide, titanium oxide, calcium carbonate, magnesium carbonate, magnesium hydroxide, aluminum hydroxide, aluminum nitride, silicon nitride, barium sulfate, and calcium silicate. Examples of the organic filler include polyester fine particles, polyurethane fine particles, vinyl polymer fine particles, and acrylic polymer fine particles.

[0059] The preferred lower limit of the filler content per 100 parts by mass of the curable resin is 10 parts by mass, and the preferred upper limit is 40 parts by mass. By having the filler content within this range, excellent effects such as improved adhesion can be achieved without deteriorating the coating properties, etc. The more preferred lower limit of the filler content is 20 parts by mass, and the more preferred upper limit is 30 parts by mass.

[0060] The sealant for display elements of the present invention preferably further contains a silane coupling agent. The silane coupling agent mainly serves as an adhesion aid for further improving adhesion between the sealant for display elements and a substrate or the like.

[0061] Suitable examples of the silane coupling agent include 3-aminopropyltrimethoxysilane, 3-mercaptopropyltrimethoxysilane, 3-glycidoxypropyltrimethoxysilane, and 3-isocyanatopropyltrimethoxysilane. These are excellent in improving adhesion to substrates and the like, and when the resulting display element sealant is used as a sealant for liquid crystal display elements, they can suppress the outflow of the curable resin into the liquid crystal. The silane coupling agents may be used alone or in combination of two or more.

[0062] The preferred lower limit of the content of the silane coupling agent relative to 100 parts by mass of the curable resin is 0.1 parts by mass, and the preferred upper limit is 5 parts by mass. By having the content of the silane coupling agent in this range, the effect of improving adhesion is more excellent. The more preferred lower limit of the content of the silane coupling agent is 0.3 parts by mass, and the more preferred upper limit is 2 parts by mass.

[0063] The sealant for display elements of the present invention may further contain additives such as a light-shielding agent, a stress relaxation agent, a reactive diluent, a thixotropic agent, a spacer, a curing accelerator, an antifoaming agent, a leveling agent, and a polymerization inhibitor, as necessary.

[0064] Examples of a method for producing the sealant for display elements of the present invention include a method of mixing a curable resin, a polymerization initiator, and additives such as a heat curing agent and, if necessary, a silane coupling agent, using a mixer such as a homodisper, a homomixer, a universal mixer, a planetary mixer, a kneader, or a three-roll mill.

[0065] By blending conductive fine particles into the sealant for display elements of the present invention, a vertically conductive material can be produced. Examples of the conductive fine particles that can be used include metal balls and fine resin particles with a conductive metal layer formed on their surfaces. Among these, fine resin particles with a conductive metal layer formed on their surfaces are preferred because the excellent elasticity of the fine resin particles allows for conductive connection without damaging transparent substrates, etc.

[0066] The sealant for display elements of the present invention is preferably used as a sealant for liquid crystal display elements. Liquid crystal display elements obtained using the sealant for display elements of the present invention are preferably liquid crystal display elements with a narrow frame design. Specifically, the width of the frame portion around the liquid crystal display unit is preferably 2 mm or less. When producing the liquid crystal display element, the application width of the sealant for display elements of the present invention is preferably 1 mm or less.

[0067] The display element sealant of the present invention is suitable for use in the manufacture of liquid crystal display elements by a liquid crystal dropping method. Examples of methods for manufacturing liquid crystal display elements by a liquid crystal dropping method using the display element sealant of the present invention include the following. First, a step is performed in which the display element sealant of the present invention is applied to a substrate by screen printing, dispenser application, or the like to form a frame-shaped seal pattern. Next, a step is performed in which, while the display element sealant of the present invention is still uncured, minute droplets of liquid crystal are dropwise applied to the entire frame of the seal pattern, and another substrate is immediately superimposed thereon. A liquid crystal display element can then be obtained by a method in which the seal pattern portion is irradiated with light such as ultraviolet light to cure the display element sealant. Alternatively, a step of heating the display element sealant may be performed after the step of irradiating the seal pattern portion with light.

[0068] According to the present invention, it is possible to provide a sealant for a display element that is excellent in both adhesiveness and moisture permeation prevention properties.

[0069] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples.

[0070] (Preparation of Curable Resin A) 397 parts by mass of 1,4-cyclohexanedimethanol monoacrylate, 336 parts by mass of 4-methylcyclohexane-1,2-dicarboxylic anhydride, and 0.1 parts by mass of hydroquinone as a polymerization inhibitor were added to a reaction flask, and the mixture was stirred for 5 hours at 90° C. using a mantle heater. Next, 340 parts by mass of bisphenol A diglycidyl ether and 0.5 parts by mass of triphenylphosphine were added to the resulting reaction product, and the mixture was stirred at 110° C. for 5 hours to obtain Curable Resin A. １ H-NMR and １３By C-NMR, it was found that the curable resin A is a compound represented by the formula (1) １ is a hydrogen atom, R ２ is a structure represented by the above formula (3-1) (R ２９ is a methyl group), n is 0, and Ep is a compound having a structure derived from bisphenol A diglycidyl ether.

[0071] (Preparation of curable resin B) Curable resin B was obtained in the same manner as in "(Preparation of curable resin A)" above, except that 397 parts by mass of 1,4-cyclohexanedimethanol monoacrylate was changed to 425 parts by mass of 1,4-cyclohexanedimethanol monomethacrylate. １ H-NMR and １３ By C-NMR, it was found that the curable resin B is a compound represented by the formula (1) １ is a methyl group, R ２ is a structure represented by the above formula (3-1) (R ２９ is a methyl group), n is 0, and Ep is a compound having a structure derived from bisphenol A diglycidyl ether.

[0072] (Preparation of curable resin C) Curable resin C was obtained in the same manner as in "(Preparation of curable resin A)" above, except that 340 parts by mass of bisphenol A diglycidyl ether was changed to 374 parts by mass of dicyclopentadiene dimethanol diglycidyl ether. １ H-NMR and １３ According to C-NMR, the curable resin C is １ is a hydrogen atom, R ２ is a structure represented by the above formula (3-1) (R ２９ is a methyl group), n is 0, and Ep is a compound having a structure derived from dicyclopentadiene dimethanol diglycidyl ether.

[0073] (Preparation of Curable Resin D) 397 parts by mass of 1,4-cyclohexanedimethanol monoacrylate, 57 parts by mass of ε-caprolactone, and 0.1 parts by mass of hydroquinone as a polymerization inhibitor were added to a reaction flask, and the mixture was stirred at 90°C for 5 hours using a mantle heater. Thereafter, 336 parts by mass of 4-methylcyclohexane-1,2-dicarboxylic anhydride was added, and the mixture was stirred for an additional 5 hours. Next, 340 parts by mass of bisphenol A diglycidyl ether was added to the resulting reaction product, and then 0.5 parts by mass of triphenylphosphine was added, and the mixture was stirred at 110°C for 5 hours, thereby obtaining Curable Resin D. １ H-NMR and １３ By C-NMR, it was found that the curable resin D is a compound represented by the formula (1) １ is a hydrogen atom, R ２ is a structure represented by the above formula (3-1) (R ２９ is a methyl group), X is an open ring structure of ε-caprolactone, n is 0.5 (average value), and Ep is a structure derived from bisphenol A diglycidyl ether.

[0074] (Preparation of curable resin E) Curable resin E was obtained in the same manner as in "(Preparation of curable resin A)" above, except that 336 parts by mass of 4-methylcyclohexane-1,2-dicarboxylic anhydride was changed to 332 parts by mass of 4-cyclohexene-1,2-dicarboxylic anhydride. １ H-NMR and １３ According to C-NMR, the curable resin E is a compound represented by the formula (1), R １ is a hydrogen atom, R ２ is a structure represented by the above formula (3-2) (R ３０ is a hydrogen atom), n is 0, and Ep is a compound having a structure derived from bisphenol A diglycidyl ether.

[0075] (Preparation of curable resin F) Curable resin F was obtained in the same manner as in "(Preparation of curable resin A)" above, except that 336 parts by mass of 4-methylcyclohexane-1,2-dicarboxylic anhydride was changed to 533 parts by mass of tetrapropenyl succinic anhydride. １ H-NMR and １３ By C-NMR, it was found that the curable resin F is a compound represented by the formula (1), １is a hydrogen atom, R ２ is a structure represented by the above formula (3-4) (R ３２ is a hydrogen atom, R ３３ is a 2-dodecenyl group), n is 0, and Ep is a compound having a structure derived from bisphenol A diglycidyl ether.

[0076] (Preparation of curable resin G) Curable resin G was obtained in the same manner as in "(Preparation of curable resin A)" above, except that 336 parts by mass of 4-methylcyclohexane-1,2-dicarboxylic anhydride was changed to 296 parts by mass of phthalic anhydride. １ H-NMR and １３ By C-NMR, it was found that the curable resin G is a compound represented by the formula (1), １ is a hydrogen atom, R ２ is a structure represented by the above formula (3-3) (R ３１ is a hydrogen atom), n is 0, and Ep is a compound having a structure derived from bisphenol A diglycidyl ether.

[0077] (Preparation of curable resin H) Curable resin H was obtained in the same manner as in "(Preparation of curable resin A)" above, except that 397 parts by mass of 1,4-cyclohexanedimethanol monoacrylate was changed to 232 parts by mass of 2-hydroxyethyl acrylate. １ H-NMR and １３ It was confirmed by C-NMR that the curable resin H was a compound represented by the following formula (4).

[0078]

[0079] (Preparation of curable resin I) Curable resin I was obtained in the same manner as in "(Preparation of curable resin A)" above, except that 397 parts by mass of 1,4-cyclohexanedimethanol monoacrylate was changed to 256 parts by mass of 2-hydroxyethyl methacrylate, and 336 parts by mass of 4-methylcyclohexane-1,2-dicarboxylic anhydride was changed to 296 parts by mass of phthalic anhydride. １ H-NMR and １３ It was confirmed by C-NMR that the curable resin I was a compound represented by the following formula (5).

[0080]

[0081] (Preparation of curable resin J) Curable resin J was obtained in the same manner as in "(Preparation of curable resin D)" above, except that 397 parts by mass of 1,4-cyclohexanedimethanol monoacrylate was changed to 232 parts by mass of 2-hydroxyethyl acrylate, and 336 parts by mass of 4-methylcyclohexane-1,2-dicarboxylic anhydride was changed to 296 parts by mass of phthalic anhydride. １ H-NMR and １３ It was confirmed by C-NMR that the curable resin J was a mixture of a compound represented by the following formula (6) and a compound represented by the following formula (7).

[0082]

[0083]

[0084] (Preparation of Curable Resin K) A curable resin K was obtained in the same manner as in "(Preparation of Curable Resin A)" above, except that the blending amount of bisphenol A diglycidyl ether was changed to 680 parts by mass. １ H-NMR and １３ By C-NMR, it was found that the curable resin K is a compound represented by the formula (II), １ is a hydrogen atom, R ２ is a structure represented by the above formula (3-1) (R ２９ is a methyl group), n is 0, Y is a 1,4-cyclohexylene group, and Ep is a compound having a structure derived from bisphenol A diglycidyl ether.

[0085] (Preparation of Curable Resin L) Curable resin L was obtained in the same manner as in "(Preparation of Curable Resin D)" above, except that the blending amount of bisphenol A diglycidyl ether was changed to 680 parts by mass. １ H-NMR and １３ By C-NMR, it was found that the curable resin L is a compound represented by the formula (II) １ is a hydrogen atom, R ２ is a structure represented by the above formula (3-1) (R ２９ is a methyl group), X is an open-ring structure of ε-caprolactone, n is 0.5 (average value), Y is a 1,4-cyclohexylene group, and Ep is a structure derived from bisphenol A diglycidyl ether.

[0086] (Preparation of curable resin M) Curable resin M was obtained in the same manner as in "(Preparation of curable resin A)" above, except that 397 parts by mass of 1,4-cyclohexanedimethanol monoacrylate was changed to 232 parts by mass of 2-hydroxyethyl acrylate and the amount of bisphenol A diglycidyl ether was changed to 680 parts by mass. １ H-NMR and １３ It was confirmed by C-NMR that the curable resin M was a compound represented by the following formula (8).

[0087]

[0088] (Examples 1 to 15, Comparative Examples 1 to 5) Each material was stirred in the blending ratios shown in Tables 1 to 3 using a planetary stirring device (Thinky Corporation's "Awatori Rentaro"), and then uniformly mixed using a ceramic triple roll to obtain sealants for display elements in Examples 1 to 15 and Comparative Examples 1 to 5.

[0089] <Evaluation> The resulting sealants for display elements were evaluated as follows. The results are shown in Tables 1 to 3.

[0090] (Adhesion to Alignment Film) An imide resin was spin-coated onto a glass substrate with an ITO thin film, pre-baked at 80°C, and then baked at 230°C to prepare a substrate with an alignment film. SE7492 (manufactured by Nissan Chemical Industries, Ltd.) was used as the imide resin. 1 part by mass of spacer particles ("Micropearl SP-2050" manufactured by Sekisui Chemical Co., Ltd.) with an average particle size of 5 μm was uniformly dispersed in 100 parts by mass of the resulting sealant for display elements using a planetary stirrer. A very small amount of the sealant for display elements with the spacer particles dispersed therein was placed in the center of a substrate with an alignment film, and another substrate with the same type of alignment film was superimposed on top of it. The sealant for display elements was spread, and a metal halide lamp was used to measure the wavelength of 365 nm and the illuminance of 100 mW / cm. ２The adhesive test specimen was irradiated with ultraviolet light for 30 seconds, and then heated at 120°C for 1 hour to cure the sealant for display elements, thereby obtaining an adhesive test specimen. The adhesive strength of the obtained adhesive test specimen was measured using a tension gauge. The adhesive strength to the alignment film was evaluated as follows: an adhesive strength of 3.0 kg / cm or more was marked "◎", an adhesive strength of 2.5 kg / cm or more but less than 3.0 kg / cm was marked "◯", an adhesive strength of 2.0 kg / cm or more but less than 2.5 kg / cm was marked "△", and an adhesive strength of less than 2.0 kg / cm was marked "X".

[0091] (Moisture Permeability Prevention) The obtained sealant for display elements was applied to a smooth release film using a coater to a thickness of 200 to 300 μm. Then, using a metal halide lamp, the sealant was irradiated with light having a wavelength of 365 nm and an illuminance of 100 mW / cm. ２ After irradiating the sealant for display elements with ultraviolet light of 1000 W for 30 seconds, the sealant was cured by heating at 120°C for 1 hour to obtain a film for measuring moisture permeability. A cup for measuring moisture permeability was prepared according to the method for testing moisture permeability of moisture-proof packaging materials (cup method) of JIS Z 0208, and the obtained film for measuring moisture permeability was attached to the cup. The cup was then placed in a constant temperature and humidity oven at 80°C and 90% RH to measure the moisture permeability. The obtained moisture permeability value was 60 g / m ２ - If it was less than 24 hours, it was marked as "○", and if it was 60 g / m ２ ・70g / m for 24hr or more ２ - Less than 24 hours: "△", 70 g / m ２ If it was 24 hours or more, it was rated as "X" and the moisture permeability was evaluated.

[0092] (Workability) One part by mass of spacer particles ("Micropearl SP-2050" manufactured by Sekisui Chemical Co., Ltd.) having an average particle size of 5 μm was uniformly dispersed in 100 parts by mass of the obtained sealant for display elements using a planetary stirrer. Next, the sealant for display elements with the spacer particles dispersed therein was filled into a syringe ("PSY-10EU-OR" manufactured by Musashi Engineering Co., Ltd.), degassed, and then applied to one of two transparent substrates using a dispenser ("SHOTMASTER 300" manufactured by Musashi Engineering Co., Ltd.) so as to draw a frame-shaped seal pattern. Thereafter, the other transparent substrate was bonded to the resulting cell under a reduced pressure of 5 Pa using a vacuum bonding device. A metal halide lamp was used to irradiate the resulting cell with a wavelength of 365 nm and an illuminance of 100 mW / cm. ２ After irradiating the sealant for display elements with ultraviolet light for 30 seconds, the sealant was cured by heating at 120° C. for 1 hour to obtain a test piece. The sealant for display elements in the obtained test piece was observed, and the workability was evaluated by assigning "◯" to a case where there was no noticeable coating unevenness in the line width, "Δ" to a case where there was noticeable coating unevenness in the line width, and "×" to a case where disconnection defects occurred.

[0093]

[0094]

[0095]

[0096] According to the present invention, it is possible to provide a sealant for a display element that is excellent in both adhesiveness and moisture permeation prevention properties.

Claims

1. A sealant for display elements, comprising a curable resin and a polymerization initiator, wherein the curable resin contains at least one compound selected from the group consisting of a compound represented by the following formula (I) and a compound represented by the following formula (II): In formula (I) and formula (II), R １ represents a hydrogen atom or a methyl group, R ２ represents a structure derived from an optionally substituted dicarboxylic acid or an anhydride thereof, X represents a lactone ring-open structure, n is 0 or more and 2.0 or less (average value), Y represents an optionally substituted aliphatic cyclic structure, and Ep represents a structure derived from a difunctional or higher epoxy compound.

2. The sealant for display elements according to claim 1, wherein the curable resin contains a compound represented by the following formula (1) as the compound represented by formula (I): In formula (1), R １ represents a hydrogen atom or a methyl group, R ２ represents a structure derived from an optionally substituted dicarboxylic acid or an anhydride thereof, X represents a lactone ring-open structure, n is 0 or more and 2.0 or less (average value), and Ep represents a structure derived from a difunctional or higher epoxy compound. Some or all of the hydrogen atoms of the two 1,4-cyclohexylene groups in formula (1) may be substituted.

3. In the formula (I) and the formula (II), R ２ The sealant for display elements according to claim 1 or 2, wherein the compound represented by the formula (2-1), (2-2), (2-3), or (2-4) below is a structure represented by the formula (2-1), (2-2), (2-3), or (2-4). In formulas (2-1) to (2-4), * represents a bonding position, and in formula (2-1), R ３ ~R １２ each independently represents a hydrogen atom or an alkyl group having 1 to 10 carbon atoms, and in formula (2-2), R １３ ~R ２０ each independently represents a hydrogen atom or an alkyl group having 1 to 10 carbon atoms, and in formula (2-3), R ２１ ~R ２４ each independently represents a hydrogen atom or an alkyl group having 1 to 10 carbon atoms, and in formula (2-4), R ２５ ~R ２８ each independently represents a hydrogen atom or an organic group having 1 to 60 carbon atoms, or R ２５ and R ２８ and each independently represent a hydrogen atom or an alkyl group having 1 to 10 carbon atoms, and R ２６ and R ２７ represents a structure in which and are bonded.

4. In the formula (I) and the formula (II), R ２ The sealant for display elements according to claim 1, 2 or 3, wherein the compound (I) is a compound represented by the following formula (3-1), (3-2), (3-3) or (3-4): In formulas (3-1) to (3-4), * represents a bonding position, and in formula (3-1), R ２９ represents a hydrogen atom or an alkyl group having 1 to 10 carbon atoms, and in formula (3-2), R ３０ represents a hydrogen atom or an alkyl group having 1 to 10 carbon atoms, and in formula (3-3), R ３１ represents a hydrogen atom or an alkyl group having 1 to 10 carbon atoms, and in formula (3-4), R ３２ and R ３３ each independently represents a hydrogen atom or an organic group having 1 to 60 carbon atoms, or R ３２ and R ３３ represents a structure in which and are bonded.

5. A sealant for display elements according to claim 1, 2, 3 or 4, wherein the total content of the compound represented by formula (I) and the compound represented by formula (II) in 100 parts by mass of the curable resin is 5 parts by mass or more and 60 parts by mass or less.

6. A sealant for display elements according to claim 1, 2, 3, 4 or 5, wherein the curable resin further contains a bisphenol-type epoxy compound, and the total content of the compound represented by formula (I) and the compound represented by formula (II) per 100 parts by mass of the bisphenol-type epoxy compound is 50 parts by mass or more and 600 parts by mass or less.

7. The sealant for display elements according to claim 1, 2, 3, 4, 5 or 6, which is used in the manufacture of liquid crystal display elements by a liquid crystal dropping method.

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