Display element sealant

Abstract

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. The present invention provides a sealant for display elements, which comprises a curable resin and a polymerization initiator, and the curable resin comprises 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, and R 2 represents a structure derived from an optionally substituted dicarboxylic acid or 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. [C1] JPEG0007719989000017.jpg43156

Description

[Technical Field]

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

[0002] In recent years, liquid crystal display elements and organic EL display elements have been widely used as display elements characterized by their thinness, light weight, low power consumption, etc. In such display elements, sealants for display elements are usually used for bonding various members and sealing the liquid crystal and light-emitting layer. For example, a liquid crystal display element manufacturing method known as the "dropping method" using a display element sealant, as disclosed in Patent Documents 1 and 2, is used from the viewpoints of shortening takt time and optimizing the amount of liquid crystal used. In the dropping method, a display element sealant is first applied to one of two electrode-attached substrates to form a frame-shaped seal pattern. Next, while the sealant is still uncured, minute droplets of liquid crystal are dropped into the seal frame of the substrate, and the other substrate is then superimposed under vacuum, and the sealant is cured to produce a liquid crystal display element. This dropping method is currently the mainstream method for manufacturing liquid crystal display elements. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2001-133794 [Patent Document 2] International Publication No. 02 / 092718 Summary of the Invention [Problem to be solved by the invention]

[0004] With the widespread use of tablet devices and mobile devices, display elements are increasingly required to have moisture resistance when operated in high-temperature, high-humidity environments. This requires sealants to be more effective at preventing water intrusion from the outside. To improve the moisture resistance 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 resistance of the sealant. While blending fillers such as talc into sealants can improve the moisture resistance, rigorous moisture resistance tests can result in uneven display on the display element. 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 resistance.

[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. [Means for solving the problem]

[0006] The present disclosure 1 is a sealant for display elements, which contains a curable resin and a polymerization initiator, and 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): Disclosure 2 is the 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). The present disclosure 3 relates to a compound represented by the following formula (I) and the following formula (II): 2 is a sealant for a display element according to Disclosure 1 or 2, which has a structure represented by the following formula (2-1), (2-2), (2-3), or (2-4). The present disclosure 4 relates to a compound represented by the following formula (I) and the following formula (II): 2 is a sealant for a display element according to Disclosure 1, 2 or 3, which has a structure represented by the following formula (3-1), (3-2), (3-3) or (3-4). The present disclosure 5 is a sealant for display elements according to the present disclosure 1, 2, 3, or 4, in which 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. Disclosure 6 is the sealant for display elements according to 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) relative to 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 a sealant for display elements according to Disclosure 1, 2, 3, 4, 5 or 6, which is used in the manufacture of a liquid crystal display element by a liquid crystal dropping method.

[0007] [ka]

[0008] In formula (I) and formula (II), R 1 represents a hydrogen atom or a methyl group, and R 2 represents a structure derived from an optionally substituted dicarboxylic acid or 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] [ka]

[0010] In formula (1), R 1 represents a hydrogen atom or a methyl group, and R 2 represents a structure derived from an optionally substituted dicarboxylic acid or 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. In the two 1,4-cyclohexylene groups in formula (1), some or all of the hydrogen atoms may be substituted.

[0011] [ka]

[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] [ka]

[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 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.

[0015] The present invention will be described in detail below. The present inventors have investigated the use of a flexible resin with a long molecular chain as the curable resin for 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 present inventors have investigated the use of a flexible resin with a longer molecular chain to improve adhesion, but the resulting sealant has poor moisture permeability, 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 present inventors have discovered that a sealant for display elements with excellent both adhesion and moisture permeability can be obtained by using a compound having a specific structure as the curable resin, and have completed the present invention.

[0016] The sealant for a display element 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 sealant for display elements of the present invention is excellent in both adhesion (particularly adhesion to alignment films) and moisture permeability prevention, and also excellent in low liquid crystal contamination when used as a sealant for liquid crystal display elements. 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. Furthermore, 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, Water, 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 Examples of suitable anhydrides include 1,2-dicarboxylic acid anhydride, 2-octenylsuccinic anhydride, 4,9-decadiene-1,2-dicarboxylic acid anhydride, bicyclo[2.2.2]oct-5-ene-2,3-dicarboxylic acid anhydride, 2-(2-carboxyethyl)-3-methylmaleic anhydride, 7-oxabicyclo[2.2.1]hept-5-ene-2,3-dicarboxylic acid anhydride, and the dicarboxylic acids before conversion into anhydrides.

[0020] 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 above formula (2-1) include structures derived from 1,2-cyclohexanedicarboxylic anhydride, 3-methylcyclohexane-1,2-dicarboxylic anhydride, 4-methylcyclohexane-1,2-dicarboxylic anhydride, and the like. Examples of the structure represented by the above 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 above formula (2-3) include structures derived from phthalic anhydride, 3-methylphthalic anhydride, 4-methylphthalic anhydride, 4-tert-butylphthalic anhydride, and the like. The structure represented by the above formula (2-4) includes 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 A structure in which the and are bonded is preferred. Above R 26 and R 27 Examples of the structure in which the and are 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, and the like. Above R 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, etc.

[0022] In the above formula (I) and formula (II), X represents an open-ring structure of a lactone. 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, 7-butyl-2-oxepanone, etc. Among these, lactones having a linear main skeleton with 5 to 7 carbon atoms when ring-opened are preferred. In addition, when n is 0 in the above formula (I) and formula (II), that is, when there is no open-ring structure of lactone represented by X, the resulting sealant for display elements has better moisture permeation prevention properties. When n is more than 0 and not more than 2.0 (average value), the resulting sealant for display elements has better adhesion (particularly adhesion to alignment films). When n is more than 0, n is preferably more than 0 and not more than 0.5 (average value). Furthermore, the "average value" of n means that when the compound represented by formula (I) and the compound represented by formula (II) are mixtures of compounds each having a different number of repetitions of X, n is expressed as the average value of the number of repetitions (molar average value).

[0023] In the above formula (I) and formula (II), Ep represents a structure derived from a difunctional or higher functional epoxy compound. Examples of epoxy compounds from which the above 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 type epoxy compounds, and glycidyl ester compounds. Among these, the Ep preferably has a structure derived from a bisphenol A epoxy compound, a bisphenol F epoxy compound, or a bisphenol E epoxy compound. In this specification, the "structure derived from an epoxy compound" means 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 above formulas (I) and (II), Y represents an optionally substituted alicyclic structure. When Y is such an alicyclic structure, the sealant for a display element of the present invention is excellent in both adhesion (particularly adhesion to an alignment film) and moisture permeability. 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, and is more preferably an optionally substituted 1,4-cyclohexylene group, since this provides particularly excellent adhesion (particularly adhesion to an alignment film). Moreover, from the viewpoint of easy availability of raw materials, etc., it is preferable that the above Y is unsubstituted. When the above Y is substituted, examples of the substituent include an alkyl group having 1 to 10 carbon atoms. That is, the two 1,4-cyclohexylene groups in the above formula (1) may have some or all of their hydrogen atoms substituted, but are preferably unsubstituted from the viewpoint of ease of raw material availability, etc. Examples of the substituent when the hydrogen atoms of the two 1,4-cyclohexylene groups in the above formula (1) are substituted include alkyl groups having 1 to 10 carbon atoms.

[0026] Examples of methods for producing the compound represented by the above formula (I) include the following methods. That is, examples of the method include 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 all of the epoxy groups. In particular, examples of methods for producing the compound represented by the above formula (1) include the following methods. That is, examples of the method include a process including a step of reacting 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 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 all of the epoxy groups. The above-mentioned 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 above-mentioned lactone before being reacted with the above-mentioned 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 the above formula (II) include the following methods. That is, examples of the method include 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), and further contains another curable resin. When the curable resin contains the other curable resin, 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 sealant for display elements has better adhesiveness (particularly adhesiveness to alignment films). 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 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) 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 either compound 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'-diallylbisphenol A type epoxy compounds. Furthermore, as the bisphenol type epoxy compound, a partially (meth)acrylic modified bisphenol type epoxy compound may be used. 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 addition, 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 in one molecule, which is obtained by reacting some of the epoxy groups of an epoxy compound having two or more epoxy groups in one molecule with (meth)acrylic acid.

[0032] The preferred lower limit of the content of the bisphenol-type epoxy compound in 100 parts by mass of the total curable resin is 5 parts by mass, and the preferred upper limit is 30 parts by mass. By ensuring that the content of the bisphenol-type epoxy compound is within this range, the resulting sealant for display elements will have superior adhesive properties, and when used as a sealant for liquid crystal display elements, will also have 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 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 epoxy compound is 50 parts by mass or more, the resulting sealant for display elements has better adhesiveness (particularly adhesiveness 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 epoxy compound is 600 parts by mass or less, the resulting sealant for display elements has better moisture permeation prevention properties and workability. The 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 epoxy compound is 100 parts by mass, and the 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 curable resin other than the bisphenol-type epoxy compound include (meth)acrylic compounds other than the compound represented by formula (I) above, and epoxy compounds other than the compound represented by formula (II) above and the bisphenol-type 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 been 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, Examples of suitable bisphenol A 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 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, and Epoxy Ester 400EA. Examples of the epoxy (meth)acrylates manufactured by Nagase ChemteX Corporation include Denacol Acrylate DA-141, Denacol Acrylate DA-314, and Denacol Acrylate DA-911.

[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] Furthermore, as the isocyanate compound, a chain-extended isocyanate compound obtained by reacting a polyol with an excess amount of an isocyanate compound can also be used. 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 derivative having a hydroxyl group include hydroxyalkyl mono(meth)acrylate, mono(meth)acrylate of a dihydric alcohol, mono(meth)acrylate or di(meth)acrylate of a trihydric alcohol, and epoxy(meth)acrylate. Examples of the hydroxyalkyl mono(meth)acrylate include 2-hydroxyethyl(meth)acrylate, 2-hydroxypropyl(meth)acrylate, 2-hydroxybutyl(meth)acrylate, and 4-hydroxybutyl(meth)acrylate. Examples of the dihydric alcohol include ethylene glycol, propylene glycol, 1,3-propanediol, 1,3-butanediol, 1,4-butanediol, and polyethylene glycol. Examples of the trihydric alcohol include trimethylolethane, trimethylolpropane, and glycerin. Examples of the epoxy (meth)acrylate include bisphenol A type epoxy acrylate.

[0046] Among the above-mentioned 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 Industries, Ltd., urethane (meth)acrylate manufactured by Shin-Nakamura Chemical Co., Ltd., and urethane (meth)acrylate manufactured by Kyoeisha Chemical Co., Ltd. Examples of the urethane (meth)acrylates 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 include EBECRYL210, EBECRYL220, EBECRYL230, EBECRYL270, EBECRYL1290, EBECRYL2220, EBECRYL4827, EBECRYL4842, EBECRYL4858, EBECRYL5129, EBECRYL6700, EBECRYL8402, EBECRYL8803, EBECRYL8804, EBECRYL8807, and EBECRYL9260. Examples of 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 a display element 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, and thioxanthone-based compounds. 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, and the like. The 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, etc. Among them, an initiator composed of an azo compound (hereinafter also referred to as "azo initiator") is preferred from the viewpoint of suppressing liquid crystal contamination when the resulting sealant for display elements is used as a sealant for liquid crystal display elements. The thermal radical polymerization initiators may be used alone or in combination of two or more. Among the above azo initiators, commercially available ones include, for example, 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 using the polymerization initiator in this range, the resulting sealant for display elements has better storage stability and curability. The more preferred lower limit of the content of the polymerization initiator is 0.1 parts by mass, and the more preferred upper limit is 5 parts by mass.

[0054] The sealant for a display element 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, acid anhydrides, etc. Among these, organic acid hydrazides are preferably used. The above-mentioned heat curing agents may be used alone or in combination of two or more kinds.

[0055] Examples of the organic acid hydrazide include sebacic acid dihydrazide, isophthalic acid dihydrazide, adipic acid dihydrazide, and malonic acid dihydrazide. Among the above organic acid hydrazides, commercially available ones include, for example, organic acid hydrazides manufactured by Otsuka Chemical Co., Ltd. and organic acid hydrazides 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., Inc. 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] As the filler, inorganic fillers and organic fillers can be used. 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, the effect of improving adhesion can be achieved without impairing application 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, etc., and can also suppress outflow of the curable resin into the liquid crystal when the resulting sealant for display elements is used as a sealant for liquid crystal display elements. The above silane coupling agents may be used alone or in combination of two or more kinds.

[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 within 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 methods 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. The conductive fine particles may be metal balls, fine resin particles with a conductive metal layer formed on the surface thereof, etc. Among these, fine resin particles with a conductive metal layer formed on the surface thereof are preferred because they have excellent elasticity and can provide conductive connection without damaging transparent substrates, etc.

[0066] The sealant for display elements of the present invention is suitably used as a sealant for liquid crystal display elements. The liquid crystal display element obtained by using the sealant for display elements of the present invention is preferably a liquid crystal display element with a narrow frame design, specifically, the width of the frame part around the liquid crystal display unit is preferably 2 mm or less. When the above liquid crystal display element is produced, the application width of the sealant for a display element of the present invention is preferably 1 mm or less.

[0067] The sealant for display elements of the present invention is suitably used for producing a liquid crystal display element by a liquid crystal dropping method. Examples of the method for producing a liquid crystal display element by a liquid crystal dropping method using the sealant for display elements of the present invention include the following methods. First, a process 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, while the display element sealant of the present invention is still in an uncured state, minute droplets of liquid crystal are dropwise applied to the entire surface within the frame of the seal pattern, and another substrate is immediately superimposed on the substrate. 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 process of heating the display element sealant may be performed after the process of irradiating the seal pattern portion with light. [Effects of the Invention]

[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. DETAILED DESCRIPTION OF THE INVENTION

[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) To a reaction flask were added 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, 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 13 By C-NMR, the curable resin A was found to be 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 with 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) R 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 with 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 By C-NMR, the curable resin C was found to be 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 with 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 stirred at 90°C for 5 hours using a mantle heater. 336 parts by mass of 4-methylcyclohexane-1,2-dicarboxylic anhydride were then added and stirred for an additional 5 hours. 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 D. 1 H-NMR and 13 By C-NMR, the curable resin D was found to be 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 By C-NMR, the curable resin E was found to be 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 with 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, the curable resin F was found to be 1 is a hydrogen atom, R 2 is a structure represented by the above formula (3-4) (R 32 is a hydrogen atom, R 33 It was confirmed that the compound has a structure in which Ep is derived from bisphenol A diglycidyl ether, n is 0, and Ep is 2-dodecenyl group.

[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, the curable resin G was found to be 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 with a structure derived from bisphenol A diglycidyl ether.

[0077] (Preparation of hardening 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] [ka]

[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] [ka]

[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] [ka]

[0083] [ka]

[0084] (Preparation of curable resin K) 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) R 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 with 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), R 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] [ka]

[0088] (Examples 1 to 15, Comparative Examples 1 to 5) Each material was stirred in accordance with the compounding ratios shown in Tables 1 to 3 using a planetary stirring device (Thinky Corporation, "Awatori Rentaro"), and then mixed uniformly 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 sealant for a display element was evaluated as follows, and 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. One 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 was placed in the center of a substrate with an alignment film, and another substrate with the same type of alignment film was placed on top of it. The sealant for display elements was spread, and a metal halide lamp was used to illuminate the surface at a wavelength of 365 nm and an illuminance of 100 mW / cm. 2After irradiating the sealant for a display element with ultraviolet light for 30 seconds, the sealant was cured by heating at 120°C for 1 hour to obtain an adhesion test piece. The adhesion strength of the obtained adhesion test piece was measured using a tension gauge. The adhesive strength to the alignment film was evaluated as follows: when the adhesive strength was 3.0 kg / cm or more, it was marked "◎", when it was 2.5 kg / cm or more but less than 3.0 kg / cm, it was marked "○", when it was 2.0 kg / cm or more but less than 2.5 kg / cm, it was marked "△", and when it was less than 2.0 kg / cm, it was marked "×".

[0091] (Moisture-proof) The obtained sealant for display elements was applied to a smooth release film using a coater to a thickness of 200 to 300 μm, and then irradiated with a metal halide lamp at 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 film for measuring moisture permeability. A cup for the moisture permeability test 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 - Less than 24 hours: "○"; 60g / m 2 ·70g / m over 24hr 2 - Less than 24 hours is marked "△", 70g / m 2 If it lasted for 24 hours or more, it was rated as "×" and the moisture permeability was evaluated.

[0092] (Workability) One 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. The sealant for display elements with the spacer particles dispersed therein was then 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 (SHOTMASTER300, manufactured by Musashi Engineering Co., Ltd.) to form a frame-shaped seal pattern. The other transparent substrate was then bonded to the resulting cell using a vacuum bonding device under a reduced pressure of 5 Pa, yielding a cell. A metal halide lamp was used to illuminate the resulting cell at 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 "○" if there was no noticeable unevenness in the coating in the line width, "△" if there was noticeable unevenness in the coating in the line width, and "×" if there was a disconnection defect.

[0093] [Table 1]

[0094] [Table 2]

[0095] [Table 3] [Industrial Applicability]

[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. Contains a curable resin and a polymerization initiator, 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): A sealant for a display element characterized by: 【Chemical 1】 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. 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): 【Chemistry 2】 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). 【Chemistry 3】 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 or 2, wherein the compound (3-1), (3-2), (3-3), or (3-4) is a structure represented by the following formula (3-1), (3-2), (3-3), or (3-4): 【Chemistry 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. 3. A sealant for display elements according to claim 1 or 2, 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. the curable resin further contains a bisphenol-type epoxy compound, 3. A sealant for display elements according to claim 1 or 2, wherein the total content of the compound represented by formula (I) and the compound represented by formula (II) is 50 parts by mass or more and 600 parts by mass or less per 100 parts by mass of the bisphenol type epoxy compound.

7. 3. The sealant for display elements according to claim 1, which is used in the production of liquid crystal display elements by a liquid crystal dropping method.

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