JP2018009092A - Sealing agent for display element and display element - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a sealing agent for display element which can suppress occurrence of out gas and occurrence of a crack and a foreign matter after coating, and to provide a display element using the sealing agent for display element.SOLUTION: There are provided a crosslinkable resin having a water-soluble resin being a copolymer of a segment having -COOX group (X is cation of base having boiling point of 0°C or higher) derived from a carboxyl group of a carboxylic group-containing ethylenically unsaturated monomer, and a segment derived from other ethylenically unsaturated monomers and a crosslinkable functional group crosslinking the water-soluble resin; and a sealing agent for display element containing water.SELECTED DRAWING: None

Description

The present invention relates to a sealant for a display element that can suppress generation of outgas and generation of cracks and foreign matters after application. Moreover, this invention relates to the display element which uses this sealing agent for display elements.

In recent years, liquid crystal display elements, organic EL display elements, and the like are widely used as display elements having features such as thinness, light weight, and low power consumption. In these display elements, a curable resin composition is usually used for sealing a liquid crystal, a color filter layer, and a light emitting layer.

A liquid crystal display element usually has two transparent substrates with electrodes facing each other at a predetermined interval, and the periphery thereof is sealed with a sealant to form a cell, and a liquid crystal injection port provided in a part thereof Then, the liquid crystal is injected into the cell, and the liquid crystal inlet is sealed by using a liquid crystal inlet sealing agent. Conventionally, as a sealing agent for liquid crystal inlets, a one-component or two-component curable epoxy resin composition, a photocurable acrylic resin composition as described in Patent Document 1, and the like have been widely used. Has been used. However, the one-pack type curable epoxy resin composition generally requires a long period of heating at a high temperature, so that the productivity is inferior. It takes time and effort to do this, and after mixing, it must be used within the pot life (pot life). On the other hand, the photo-curable acrylic resin composition is excellent in workability and productivity, but because of its strong interaction with the liquid crystal, it contaminates the liquid crystal and causes color unevenness. There was a problem that a large amount of outgas was generated due to the residual acrylic resin or photoinitiator residue, or the adhesiveness or transparency of the cured product was inferior.

On the other hand, in a color filter which is a constituent member of a liquid crystal display element, a dye which is a colored pixel component is obtained by covering a color filter with a thermosetting resin composition as described in Patent Document 2 and sealing it. It is said that liquid crystal contamination caused by elution of pigments and pigments into liquid crystals can be prevented. However, although the thermosetting resin composition as disclosed in Patent Document 2 contains an organic solvent, in recent years, a volatile organic solvent (VOC) is used from the viewpoint of reducing odor and environmental burden. There is a tendency that those not using the above are preferred. Further, when the organic solvent remains in the resin composition, the outgas is generated to cause serious damage to the liquid crystal. Accordingly, there has been a demand for a curable resin composition that can suppress the generation of outgas and is excellent in transparency.

In addition, in the organic EL display element, when the organic light emitting material layer and the electrode are exposed to the outside air, the performance of the organic EL display element deteriorates rapidly. Therefore, in order to increase the stability and durability of the organic EL display element, There has been proposed a method in which a material layer and an electrode are covered and sealed with a resin protective film via an inorganic material film. For example, Patent Document 3 discloses a method of forming a resin film made of an acrylic resin composition on an inorganic material film, and Patent Document 4 discloses a method of forming a resin film by photocationic polymerization. It is disclosed. However, even in such a case, there are problems such as outgas generation due to residues of acrylic resin and photoinitiator.

JP-A-6-160972 JP, 2015-106032, A JP 2001-307873 A JP 2005-336314 A

An object of this invention is to provide the sealing agent for display elements which can suppress generation | occurrence | production of outgas and the generation | occurrence | production of the crack after application | coating, and a foreign material. Another object of the present invention is to provide a display element using the sealant for display element.

The present invention relates to a segment having a —COOX group (X is a cation of a base having a boiling point of 0 ° C. or higher) derived from a carboxyl group of a carboxyl group-containing ethylenically unsaturated monomer, and other ethylenically unsaturated groups A water-soluble resin that is a copolymer having a segment derived from a monomer, a cross-linkable resin having a cross-linkable functional group capable of cross-linking the water-soluble resin, and a display element seal containing water It is a stopping agent.
The present invention is described in detail below.

In order to suppress the generation of outgas by the sealant for display elements, it is conceivable to use a high molecular weight resin component, and a solvent is used for adjusting the viscosity that is increased by using the high molecular weight resin component. Can be considered.
The present inventors use water as a solvent that hardly generates outgas, and further, as a water-soluble resin that is excellent in transparency and hardly generates outgas, as a carboxyl group-containing ethylenically unsaturated monomer, and The use of a copolymer having a monomer component of another copolymerizable ethylenically unsaturated monomer or a salt of the copolymer was studied. However, the obtained sealant for display elements has a problem that cracks and foreign matters are likely to occur after application.
Therefore, as a result of further intensive studies, the present inventors have found that the salt of the copolymer has a base-derived cation moiety having a boiling point in a specific range, thereby generating outgas and cracking after coating. The present inventors have found that a sealant for a display element that can suppress the generation of foreign matters can be obtained, and have completed the present invention.
Moreover, since the sealing agent for display elements of this invention can be heat-hardened at low temperature, it can prevent damage to the device by light irradiation or high temperature heating.
In the present specification, the above-mentioned “transparent” means that the total light transmittance measured with a haze meter is 85% or more and the haze value (cloudiness value) is 1% or less. To do.

The sealing agent for display elements of this invention contains water-soluble resin.
The water-soluble resin includes a segment having a —COOX group (X is a base cation having a boiling point of 0 ° C. or higher) derived from a carboxyl group of a carboxyl group-containing ethylenically unsaturated monomer, and other ethylenic groups. It is a copolymer having a segment derived from an unsaturated monomer (hereinafter also referred to as “water-soluble resin according to the present invention”). The water-soluble resin according to the present invention may be any of a random copolymer, a block copolymer, and a graft copolymer.
In the present specification, the term “water-soluble” means that an aqueous solution can be obtained in a neutral range of pH 6 to pH 9.

By having the -COOX group-containing segment, the water-soluble resin according to the present invention is excellent in water-solubility and reactivity with the crosslinkable resin, and the obtained sealant for display elements is cracked after application. The generation of foreign matter can be suppressed.

In the segment having the -COOX group, the -COOX group is derived from the carboxyl group of the carboxyl group-containing ethylenically unsaturated monomer.
Examples of the carboxyl group-containing ethylenically unsaturated monomer include acrylic acid, methacrylic acid, 3-acryloyloxypropionic acid, fumaric acid, itaconic acid, maleic acid, and crotonic acid. Of these, acrylic acid and methacrylic acid are preferable from the viewpoint of copolymerization.

In the -COOX group, X is a cation of a base having a boiling point of 0 ° C or higher.
The preferable lower limit of the boiling point of the base is 30 ° C., and the preferable upper limit is 150 ° C. When the boiling point of the base is within this range, the obtained sealant for display elements has a more suitable surface drying property, and is more excellent in the effect of suppressing the generation of cracks and foreign matters after application. . The upper limit with the more preferable boiling point of the said base is 100 degreeC.

The preferable lower limit of the molecular weight of the base having a boiling point of 0 ° C. or higher is 20 and the preferable upper limit is 300. When the molecular weight of the base is within this range, the obtained sealant for a display element has a more suitable surface drying property and is more excellent in the effect of suppressing the generation of cracks and foreign matters after coating. . The more preferable lower limit of the molecular weight of the base is 40, and the more preferable upper limit is 100.

Specific examples of the base having a boiling point of 0 ° C or higher include, for example, ethylamine (boiling point 16.6 ° C, molecular weight 45.08), propylamine (boiling point 48 ° C, molecular weight 59.11), isopropylamine (boiling point 33 ° C). , Molecular weight 59.11), etc., dimethylamine (boiling point 6.9 ° C., molecular weight 45.08), diethylamine (boiling point 55.5 ° C., molecular weight 73.14), dipropylamine (boiling point 109 ° C., molecular weight) Secondary amines such as diisopropylamine (boiling point 84 ° C., molecular weight 101.19), trimethylamine (boiling point 2.9 ° C., molecular weight 59.11), triethylamine (boiling point 89.7 ° C., molecular weight 101.19). ), Tripropylamine (boiling point 156 ° C., molecular weight 143.25), N, N-diisopropylethylamine (boiling point 127 ° C., molecular weight) 29.24) and tertiary amines, such as, sodium hydroxide (boiling point 1388 ° C., molecular weight 39.99) and the like. Especially, since it is excellent in the effect which suppresses generation | occurrence | production of the crack after application | coating, and a foreign material, it is preferable that the said base whose boiling point is 0 degreeC or more is a propylamine, a diethylamine, or a triethylamine.

The preferable lower limit of the content ratio of the segment having the —COOX group in the water-soluble resin according to the present invention is 5% by weight, and the preferable upper limit is 30% by weight. When the content ratio of the segment having the -COOX group is within this range, the obtained water-soluble resin is more excellent in reactivity with water-soluble and cross-linkable resins without deteriorating water resistance and storage stability. It becomes. The more preferable lower limit of the content ratio of the segment having the —COOX group is 10% by weight, the more preferable upper limit is 25% by weight, and the still more preferable upper limit is 20% by weight.

Examples of the other ethylenically unsaturated monomers include, for example, methyl (meth) acrylate, ethyl (meth) acrylate, n-propyl (meth) acrylate, isopropyl (meth) acrylate, (meth) acrylic acid. n-butyl, isobutyl (meth) acrylate, sec-butyl (meth) acrylate, t-butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, hydroxyethyl (meth) acrylate, (meth) acryl Cyclohexyl acid, 2-methylcyclohexyl (meth) acrylate, dicyclopentanyloxyethyl (meth) acrylate, isobornyl (meth) acrylate, dicyclopentanyl (meth) acrylate, benzyl (meth) acrylate, ( 2-hydroxyethyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate (Meth) acrylic acid ester monomers such as pill, 4-hydroxybutyl (meth) acrylate, and aromatic vinyl monomers such as styrene, α-methylstyrene, p-methylstyrene, p-chlorostyrene And vinyl cyanide monomers such as acrylonitrile and methacrylonitrile.
In the present specification, the “(meth) acryl” means acryl or methacryl.

The preferable lower limit of the content ratio of the segment derived from the other ethylenically unsaturated monomer in the water-soluble resin according to the present invention is 70% by weight, and the preferable upper limit is 95% by weight. When the content ratio of the segment derived from the other ethylenically unsaturated monomer is within this range, the cured product of the obtained sealant for display element is more excellent in moisture and heat resistance. The more preferable lower limit of the content ratio of the segment derived from the other ethylenically unsaturated monomer is 75% by weight, the more preferable upper limit is 90% by weight, and the still more preferable lower limit is 80% by weight.

The water-soluble resin according to the present invention includes aromatic substituted maleimide monomers such as phenylmaleimide, benzylmaleimide, naphthylmaleimide, o-chlorophenylmaleimide, and alkylmaleimides such as methylmaleimide, ethylmaleimide, propylmaleimide, and isopropylmaleimide. It may have a segment derived from a substituted maleimide monomer or the like.

In particular, the water-soluble resin according to the present invention is preferably a (meth) acrylic copolymer having the -COOX group in the side chain.

The water-soluble resin according to the present invention comprises a copolymer having a segment derived from the carboxyl group-containing ethylenically unsaturated monomer and a segment derived from the other ethylenically unsaturated monomer having the boiling point. It can be suitably obtained by neutralizing with a base at 0 ° C. or higher to give a carboxylate.

As a method for producing a copolymer having a segment derived from the carboxyl group-containing ethylenically unsaturated monomer and a segment derived from the other ethylenically unsaturated monomer, for example, a radical polymerization initiator and If necessary, using a molecular weight regulator, a monomer component constituting a copolymer such as the carboxyl group-containing ethylenically unsaturated monomer and the other ethylenically unsaturated monomer, bulk polymerization, Examples of the polymerization method include conventionally known methods such as solution polymerization, suspension polymerization, dispersion polymerization, and emulsion polymerization. Of these, solution polymerization is preferred.

Examples of the solvent used in the solution polymerization include aliphatic alcohols such as methanol, ethanol, isopropanol and glycol, cellosolves such as cellosolve and butylcellosolve, carbitols such as carbitol and butylcarbitol, and acetic acid. Esters such as cellosolve, carbitol acetate, propylene glycol monomethyl ether acetate, ethers such as diethylene glycol dimethyl ether, cyclic ethers such as tetrahydrofuran, ketones such as cyclohexanone, methyl ethyl ketone, methyl isobutyl ketone, dimethyl sulfoxide, dimethylformamide, etc. And organic solvents having the following polarity.
Examples of the medium used for the suspension polymerization, the dispersion polymerization, the emulsion polymerization, and the like include liquid hydrocarbons such as benzene, toluene, hexane, and cyclohexane, and other nonpolar organic solvents. .

When an organic solvent is used when producing a copolymer having a segment derived from the carboxyl group-containing ethylenically unsaturated monomer and a segment derived from the other ethylenically unsaturated monomer, it is obtained. It is preferable to add an appropriate amount of water to the obtained resin solution and then distill off the organic solvent by decompression or the like.

As a radical polymerization initiator used when producing a copolymer having a segment derived from the carboxyl group-containing ethylenically unsaturated monomer and a segment derived from the other ethylenically unsaturated monomer, for example, , Peroxides, azo initiators, and the like.
Examples of the molecular weight modifier include α-methylstyrene dimer, mercaptan chain transfer agent, and the like.

The minimum with a preferable weight average molecular weight of the water-soluble resin concerning this invention is 5000, and a preferable upper limit is 50,000. When the weight average molecular weight of the water-soluble resin according to the present invention is within this range, generation of outgas can be further reduced, and the obtained sealant for display elements can damage liquid crystal display elements and organic EL display elements. It becomes more excellent in the effect of suppressing odor, and it also becomes more excellent in adhesion. The minimum with a more preferable weight average molecular weight of the water-soluble resin concerning this invention is 10,000, and a more preferable upper limit is 20,000.
In addition, the said weight average molecular weight is a value calculated | required by polystyrene conversion by measuring with a gel permeation chromatography (GPC) in this specification. Examples of the column for measuring the weight average molecular weight in terms of polystyrene by GPC include Shodex LF-804 (manufactured by Showa Denko KK). Moreover, tetrahydrofuran etc. are mentioned as a solvent used by GPC.

The preferable lower limit of the -COOX group equivalent of the water-soluble resin according to the present invention is 220, and the preferable upper limit is 4000. When the —COOX group equivalent of the water-soluble resin according to the present invention is within this range, the water-soluble resin and the reactivity with the cross-linkable resin are excellent. The more preferable lower limit of the —COOX group equivalent of the water-soluble resin according to the present invention is 340, and the more preferable upper limit is 2000.
The -COOX group equivalent of the water-soluble resin according to the present invention is obtained by dividing the weight (g) of the water-soluble resin according to the present invention by the number of moles (mol) of -COOX groups contained in the water-soluble resin according to the present invention. This is the value obtained by

The water-soluble resin according to the present invention may be preliminarily dissolved or dispersed in an aqueous solution or an organic solvent, and may be mixed with a crosslinkable resin or the like after adjusting the amount of water or the amount of organic solvent as necessary.

The sealing agent for display elements of this invention contains the crosslinkable resin which has a crosslinkable functional group which can bridge | crosslink the water-soluble resin concerning this invention.
By cross-linking the water-soluble resin according to the present invention using the cross-linkable resin, the cured product of the sealant for display element of the present invention has adhesion, hardness, and moisture resistance with a glass substrate or an acrylic coating layer. Excellent thermal properties. Moreover, the said crosslinkable resin also has the effect of improving the wettability and adhesiveness at the time of application | coating when coating the hardened | cured material of the sealing agent for display elements of this invention.

Examples of the crosslinkable functional group possessed by the crosslinkable resin include an oxazoline group, an epoxy group, a hydroxy group, an amino group, an isocyanate group, a carbodiimide group, and an aziridine group. Of these, an oxazoline group is preferable.
The crosslinkable resin preferably has two or more crosslinkable functional groups in one molecule.

The preferable lower limit of the crosslinkable functional group equivalent of the crosslinkable resin is 100, and the preferable upper limit is 2000. When the crosslinkable functional group equivalent of the crosslinkable resin is within this range, the cured product of the obtained sealant for display element is more excellent in adhesion, hardness, and wet heat resistance. The more preferable lower limit of the crosslinkable functional group equivalent of the crosslinkable resin is 120, and the more preferable upper limit is 600.
The crosslinkable functional group equivalent of the crosslinkable resin is a value obtained by dividing the weight (g) of the crosslinkable resin by the number of moles (mol) of the crosslinkable functional group contained in the crosslinkable resin.

The crosslinkable resin is preferably water-soluble.
Examples of the resin skeleton of the crosslinkable resin include a polyacryl skeleton, a polyester skeleton, a polyurethane skeleton, a polyamide skeleton, a polyimide skeleton, and a polystyrene skeleton. Of these, a polyacryl skeleton is preferable.

The minimum with a preferable weight average molecular weight of the said crosslinkable resin is 500, and a preferable upper limit is 500,000. When the weight average molecular weight of the crosslinkable resin is within this range, the water-soluble resin according to the present invention can be more uniformly crosslinked.

The crosslinkable resin may be preliminarily dissolved or dispersed in an aqueous solution or an organic solvent, and may be mixed with the water-soluble resin according to the present invention after adjusting the amount of water or the amount of organic solvent as necessary. .
Examples of commercially available solutions and dispersions containing the crosslinkable resin include Epocross K series and Epocross WS series (both manufactured by Nippon Shokubai Co., Ltd.).

The content ratio of the water-soluble resin according to the present invention and the crosslinkable resin is preferably a weight ratio of water-soluble resin according to the present invention: crosslinkable resin = 1: 0.1 to 1: 1.5. . When the content ratio of the water-soluble resin according to the present invention and the crosslinkable resin is within this range, the cured product of the obtained sealant for display elements is more excellent in adhesion, hardness, and moisture and heat resistance. . The content ratio of the water-soluble resin according to the present invention and the crosslinkable resin is more preferably a weight ratio of water-soluble resin according to the present invention: crosslinkable resin = 1: 0.25 to 1: 1.

In addition, the molar ratio of the —COOX group of the water-soluble resin according to the present invention to the crosslinkable functional group of the crosslinkable resin is —COOX group: crosslinkable functional group = 1: 0.1 to 1:10. Preferably there is. When the molar ratio of the —COOX group of the water-soluble resin according to the present invention to the crosslinkable functional group of the crosslinkable resin is within this range, the cured product of the obtained sealant for display elements is adhesive. It becomes more excellent in hardness and heat-and-moisture resistance. The molar ratio of the —COOX group of the water-soluble resin according to the present invention to the crosslinkable functional group of the crosslinkable resin is —COOX group: crosslinkable functional group = 1: 0.2 to 1: 6. Is more preferable.

The sealing agent for display elements of this invention contains water as a solvent.
By using the above water as a solvent, outgassing can be suppressed, and when applying and drying the sealant for display elements, environmental load such as discharge of organic chemicals, and fire hazard And adverse effects on the health of the handler can be reduced.
As described above, the water-soluble resin according to the present invention and the crosslinkable resin having an oxazoline group may be mixed with other components after being previously dissolved or dispersed in an aqueous solution or an organic solvent.

The content of water in the sealant for display element of the present invention is not particularly limited and is appropriately set so as to have a viscosity suitable for a coating method or the like, but the amount of solid content is 1 to 50% by weight. It is preferable that the amount is 10 to 40% by weight.

The sealant for display elements of the present invention may contain other solvents such as organic solvents in addition to the above water, but does not contain other solvents for the purpose of the present invention of suppressing the generation of outgas. It is preferable. When it contains the said other solvent, it is preferable that the content is 30 weight% or less of the whole solvent, and it is more preferable that it is 10 weight% or less.
When the content of the other solvent is excessive, it is preferable to remove the other solvent by an appropriate method such as azeotropy. The removal of the other solvent may be performed before mixing with the water-soluble resin and the crosslinkable resin according to the present invention.

As said other solvent, organic solvents with low toxicity, such as propylene glycols, such as propylene glycol monomethyl ether acetate, alcohols, such as ethyl alcohol and isopropyl alcohol, are mentioned, for example.

The sealant for a display element of the present invention is a pH adjuster such as aqueous ammonia and sodium hydroxide, a thickener, a drying inhibitor, an antiseptic, an ultraviolet absorber, and an antioxidant within a range not impairing the object of the present invention. Various known additives such as agents, antifoaming agents, leveling agents, coupling agents, pigments and dyes may be contained.

As a method for producing the sealant for display elements of the present invention, for example, the water-soluble resin according to the present invention, the crosslinkable resin, the water, the additive used as necessary, and the like are stirred. And a method of mixing using a machine. Moreover, it is preferable to filter using a filter after stirring so that it may become a uniform mixture.

As a method for applying the sealant for display elements of the present invention, for example, a known coating method such as spin coating, slit coating, screen printing, ink jet coating, electrostatic coating, bar coating, die coating, roll coating or the like is used. It can be used by adjusting the concentration and viscosity suitable for a desired film thickness and a predetermined coating method.

The sealant for display elements of the present invention can be cured by heating at a low temperature. The heating temperature at the time of curing the sealant for display elements of the present invention is not particularly limited, but is usually 80 ° C. to 250 ° C., and preferably 100 ° C. or more to reduce the heat treatment time. In order to suppress, it is preferably 200 ° C. or lower.

The display element which has the hardened | cured material of the sealing agent for display elements of this invention is also one of this invention.
Since the sealant for display element of the present invention is excellent in the effect of suppressing the generation of outgas, and the cured product is excellent in transparency, adhesion, hardness, and heat and moisture resistance, the display element of the present invention is In particular, the display performance is excellent.

ADVANTAGE OF THE INVENTION According to this invention, the sealing agent for display elements which can suppress generation | occurrence | production of an outgas, and the generation | occurrence | production of the crack after application | coating and a foreign material can be provided. Moreover, according to this invention, the display element which uses this sealing agent for display elements can be provided.

Hereinafter, the present invention will be described in more detail with reference to examples. However, the present invention is not limited to these examples.

(Preparation of water-soluble resin A)
A reactor equipped with a stirrer, a reflux condenser, a thermometer, a nitrogen gas inlet tube, and a dropping funnel was prepared in a four-neck separable flask having a capacity of 1000 mL. 50 parts by weight of tetrahydrofuran was placed in the flask, and nitrogen gas was introduced and bubbled to remove dissolved oxygen. 20 parts by weight of methacrylic acid as a carboxyl group-containing ethylenically unsaturated monomer, 50 parts by weight of methyl methacrylate as another ethylenically unsaturated monomer, and t-butylperoxy-2-ethyl as a radical polymerization initiator A monomer solution was prepared by previously mixing 1.3 parts by weight of hexanoate, 2 parts by weight of n-dodecyl mercaptan as a chain transfer agent, and 50 parts by weight of tetrahydrofuran as a solvent, and the inside of the flask containing the tetrahydrofuran was stirred. The monomer solution was added dropwise over 1 hour, and then refluxed at 80 ° C. for 3 hours to carry out a copolymerization reaction, thereby obtaining a resin solution. The copolymer resin was isolated with methanol from the obtained resin solution, purified, and then dried under reduced pressure to obtain a resin solid.
Next, 37 parts by weight of an aqueous solution of 1 mol / L propylamine (boiling point 48 ° C., molecular weight 59.11) and 43 parts by weight of water are added to 20 parts by weight of the obtained resin solids and neutralized at 80 ° C. And dissolved by heating and stirring to obtain an aqueous solution (solid content rate 20% by weight) of water-soluble resin A (weight average molecular weight 12000, -COOX group equivalent 339, -COOX group-containing segment ratio 20% by weight).

(Preparation of water-soluble resin B)
A water-soluble resin B (weight average molecular weight) was prepared in the same manner as in “(Preparation of water-soluble resin A)” except that a diethylamine (boiling point 55.5 ° C., molecular weight 73.14) aqueous solution was used instead of the propylamine aqueous solution. 12000, -COOX group equivalent 339, -COOX group-containing segment ratio 20% by weight) (solid content 20% by weight).

(Preparation of water-soluble resin C)
A water-soluble resin C (weight average molecular weight) was prepared in the same manner as in “Preparation of water-soluble resin A” except that a triethylamine (boiling point 89.7 ° C., molecular weight 101.19) aqueous solution was used instead of the propylamine aqueous solution. 12000, -COOX group equivalent 339, -COOX group-containing segment ratio 20% by weight) (solid content 20% by weight).

(Preparation of water-soluble resin D)
A water-soluble resin D (weight average molecular weight) was prepared in the same manner as in “(Preparation of water-soluble resin A)” except that a tripropylamine (boiling point: 156 ° C., molecular weight: 143.25) aqueous solution was used instead of the propylamine aqueous solution. 12000, -COOX group equivalent 339, -COOX group-containing segment ratio 20% by weight) (solid content 20% by weight).

(Preparation of water-soluble resin E)
A water-soluble resin E was prepared in the same manner as the above-mentioned “(Preparation of water-soluble resin A)” except that a 1 mol / L sodium hydroxide (boiling point: 1388 ° C., molecular weight: 39.99) aqueous solution was used instead of the propylamine aqueous solution. An aqueous solution (solid content rate 20% by weight) of (weight average molecular weight 12000, -COOX group equivalent 339, -COOX group-containing segment ratio 20% by weight) was obtained.

(Preparation of water-soluble resin F)
A water-soluble resin was prepared in the same manner as “(Preparation of water-soluble resin A)” except that a 1 mol / L ammonia (boiling point−33.34 ° C., molecular weight 17.03) aqueous solution was used instead of the propylamine aqueous solution. An aqueous solution (solid content rate 20% by weight) of F (weight average molecular weight 12000, -COOX group equivalent 339, -COOX group-containing segment ratio 20% by weight) was obtained.

(Examples 1-6, Comparative Example 1)
According to the compounding ratio described in Table 1, each material was mixed with a stirrer for 30 minutes, and then filtered through a membrane filter having a pore size of 5 μm, whereby sealants for display elements of Examples 1 to 6 and Comparative Example 1 were used. Was prepared.

<Evaluation>
The following evaluation was performed about each sealing agent for display elements obtained by the Example and the comparative example. The results are shown in Table 1.

(1) Crack and foreign matter prevention properties Each sealant for a display element obtained in Examples and Comparative Examples has a thickness of 0.7 mm, a width of 50 mm, and a length of 50 mm in an environment of 23 ° C. and 50% RH. After coating on an alkali glass substrate with a spin coater, the number of cracks generated within 15 seconds was measured. “O” indicates that no cracks and foreign matter are confirmed, “Δ” indicates that five or fewer cracks and / or foreign matters are confirmed, and “×” indicates that more than five cracks and / or foreign matters are confirmed. The crack and foreign matter prevention properties were evaluated.

(Production of evaluation substrate)
Each sealant for display elements obtained in Examples and Comparative Examples was applied on a non-alkali glass substrate having a thickness of 0.7 mm, a width of 50 mm, and a length of 50 mm using a spin coater, and then dried at 120 ° C. for 10 minutes. . Next, by post-baking at 140 ° C. for 30 minutes, an evaluation substrate on which a coating film having a thickness of about 10 μm was formed on a glass substrate was converted into transparency, adhesion, hardness, wet heat resistance, low outgassing property, liquid crystal It produced about each evaluation of the voltage holding rate and the display performance of a liquid crystal display element.

(2) Transparency About the board | substrate for evaluation obtained by said "(preparation of board | substrate for evaluation)", the total light transmittance and haze value (haze value) were measured using the haze meter. When the transmittance was 85% or more, “◯”, when it was less than 85%, “x”, and when the haze value was 1% or less, “◯” exceeded 1%. Transparency was evaluated with “x” as the case.

(3) Adhesiveness For the evaluation substrate obtained in the above-mentioned “(Production of evaluation substrate)”, a cross-cut peel test with 100 mm squares at 1 mm intervals was performed in accordance with JIS K5400.
When the remaining rate of the coated film after peeling off the tape is 95% or more, “○”, when it is 80% or more and less than 95%, “△”, and when it is less than 80%, “×” is adhered. Sex was evaluated.

(4) Hardness Pencil hardness was measured in accordance with JIS K5400 with respect to the evaluation substrate obtained in the above-mentioned "(Production of evaluation substrate)".

(5) Moisture and heat resistance The substrate for evaluation obtained in the above-mentioned "(Production of substrate for evaluation)" is subjected to a high-temperature and high-humidity test held for 240 hours in a constant temperature and humidity oven adjusted to a temperature of 85 ° C and a humidity of 85% RH. The state of the coating film before and after the high temperature and high humidity test was visually observed.
“○” indicates no change in the coating film before and after the high-temperature and high-humidity test, and “△” indicates a slight change such as dissolution, peeling, cracking, and whitening in the coating film after the high-temperature and high-humidity test. ”, The case where changes such as dissolution, peeling, cracking, and whitening were clearly seen in the coating film after the high temperature and high humidity test was evaluated as“ x ”, and the heat and moisture resistance was evaluated.

(6) Low outgassing About the substrate for evaluation obtained in the above-mentioned “(Preparation of substrate for evaluation)”, using a thermal analyzer (“TG / DTA6200” manufactured by Seiko Instruments), the temperature rising rate is 10 ° C. / The weight loss rate when heated to 130 ° C. for min was measured, and this was taken as the outgas generation amount.
When the outgas generation amount was less than 0.1%, “◯”, when the outgas generation amount was 0.1% or more and less than 0.3%, “△”, and the outgas generation amount was 0.3% or more. The low outgassing property was evaluated as “x”.

(Preparation of pollution evaluation liquid crystal)
About the evaluation board | substrate obtained by said ("preparation of evaluation board | substrate"), after scraping off the coating film on a glass substrate with a spatula, 10 mg of the scraped coating films were measured to the screw tube. Next, 0.5 g of liquid crystal (Merck, “ZLI-4792”) was weighed into the screw tube, covered with the screw tube, heated in an oven at 120 ° C. for 30 minutes, and then the liquid crystal was A liquid crystal for contamination evaluation was produced by gradually cooling to room temperature.

(Preparation of substrate for liquid crystal contamination evaluation)
By applying an alignment film on the surface with a spin coater on a glass substrate (thickness 0.7 mm, width 50 mm, length 50 mm) on which an ITO transparent electrode (length 10 mm, width 10 mm) is formed, and firing. A liquid crystal contamination evaluation substrate in which an alignment film having a thickness of 800 mm was formed on a glass substrate was produced.

(7) Voltage holding ratio of liquid crystal A UV curable sealant (manufactured by Sekisui Chemical Co., Ltd.) is drawn in a square frame on the liquid crystal contamination evaluation substrate obtained in the above "(Preparation of liquid crystal contamination evaluation substrate)". A seal pattern was formed by coating with a dispenser. Inside the formed seal pattern, each sealant for display element obtained in Examples and Comparative Examples was finely spotted and then applied with a spin coater, and dried at 120 ° C. for 10 minutes to obtain a film thickness of about A 5 μm coating film was obtained. Subsequently, fine droplets of the contamination evaluation liquid crystal obtained in “(Preparation of contamination evaluation liquid crystal)” above are dropped onto the entire surface of the liquid crystal contamination evaluation substrate, and aligned with another ITO transparent electrode in a vacuum. The substrate on which the film was formed was overlaid. After releasing the vacuum, the outer frame seal part was irradiated with 100 mW / cm ² of ultraviolet rays for 30 seconds using a metal halide lamp. Thereafter, liquid crystal annealing was performed at 120 ° C. for 60 minutes to obtain a liquid crystal cell for evaluating the voltage holding ratio of the liquid crystal.
About the obtained liquid crystal cell, the voltage holding | maintenance voltage of a liquid crystal is measured by applying the alternating voltage of 5V and 60Hz and measuring the holding voltage after 16.7 milliseconds with a voltage holding ratio measuring apparatus (made by Toyo Technica Co., Ltd.). The rate was measured. The case where the voltage holding ratio is 99.0% or more is “◯”, the case where it is 95.0% or more and less than 99.0% is “△”, and the case where it is less than 95.0% is “×”. As a result, the voltage holding ratio of the liquid crystal was evaluated.

(8) Display performance of liquid crystal display element A square frame of UV curable sealant (manufactured by Sekisui Chemical Co., Ltd.) is drawn on the liquid crystal contamination evaluation substrate obtained in the above-mentioned "(Preparation of liquid crystal contamination evaluation substrate)". Thus, a seal pattern was formed by applying with a dispenser. Inside the formed seal pattern, each sealant for display element obtained in Examples and Comparative Examples was finely spotted and then applied with a spin coater, and dried at 120 ° C. for 10 minutes to obtain a film thickness of about A 5 μm coating film was obtained. Subsequently, fine droplets of liquid crystal (manufactured by Merck & Co., "ZLI-4792") are dropped on the entire surface of the liquid crystal contamination evaluation substrate, and a substrate on which another ITO transparent electrode and an alignment film are formed in a vacuum. Are superimposed. After releasing the vacuum, the outer frame seal part was irradiated with 100 mW / cm ² of ultraviolet rays for 30 seconds using a metal halide lamp. Thereafter, liquid crystal annealing was performed at 120 ° C. for 60 minutes to obtain a liquid crystal display element.
The obtained liquid crystal display element was driven with a voltage of AC 3.5 V, and the periphery of the sealant for the display element was visually observed with a halftone voltage. “○” indicates no color unevenness around the sealant for display elements, “△” indicates a slight color unevenness, and “×” indicates a clear dark color unevenness. The display performance of the liquid crystal display element was evaluated.

(9) Display performance of organic EL display element (9-1) Preparation of substrate on which laminated body including organic light emitting material layer is arranged ITO electrode is applied to glass substrate (length 25 mm, width 25 mm, thickness 0.7 mm) A substrate having a thickness of 1000 mm was used as a substrate. The substrate was ultrasonically washed with acetone, an aqueous alkali solution, ion-exchanged water, and isopropyl alcohol for 15 minutes each, then washed with boiled isopropyl alcohol for 10 minutes, and further UV-ozone cleaner (manufactured by Nippon Laser Electronics Co., Ltd., The last treatment was performed with “NL-UV253”).
Next, this substrate is fixed to the substrate folder of the vacuum deposition apparatus, and 200 mg of N, N′-di (1-naphthyl) -N, N′-diphenylbenzidine (α-NPD) is put into an unglazed crucible in other different ways. 200 mg of tris (8-quinolinolato) aluminum (Alq ₃ ) was put in an unglazed crucible, and the inside of the vacuum chamber was depressurized to 1 × 10 ⁻⁴ Pa. Thereafter, the crucible containing α-NPD was heated and α-NPD was deposited on the substrate at a deposition rate of 15 Å / s to form a 600 正 孔 hole transport layer. Next, the crucible containing Alq ₃ was heated to form an organic light emitting material layer having a thickness of 600 で at a deposition rate of 15 Å / s. Thereafter, the substrate on which the hole transport layer and the organic light emitting material layer are formed is transferred to another vacuum vapor deposition apparatus, and 200 mg of lithium fluoride is added to a tungsten resistance heating boat in the vacuum vapor deposition apparatus, and aluminum is added to another tungsten boat. 1.0 g of wire was added. Then, after reducing the pressure in the vapor deposition unit of the vacuum vapor deposition apparatus to 2 × 10 ⁻⁴ Pa and depositing 5 μm of lithium fluoride at a deposition rate of 0.2 kg / s, deposit 1000 μm of aluminum at a rate of 20 kg / s. did. The inside of the vapor deposition apparatus was returned to normal pressure with nitrogen, and the substrate on which the laminate including the organic light emitting material layer of 10 mm × 10 mm was arranged was taken out.

(9-2) Coating with inorganic material film A A mask having an opening of 13 mm × 13 mm is installed so as to cover the whole of the laminated body of the substrate on which the laminated body including the obtained organic light emitting material layer is arranged. Then, an inorganic material film A was formed by plasma CVD.
In the plasma CVD method, SiH ₄ gas and nitrogen gas are used as source gases, the flow rates of each are SiH ₄ gas 10 sccm, nitrogen gas 200 sccm, RF power 10 W (frequency 2.45 GHz), chamber temperature 100 ° C., chamber The test was performed under the condition that the internal pressure was 0.9 Torr.
The thickness of the formed inorganic material film A of silicon nitride was about 0.2 μm.

(9-3) Formation of Resin Protective Film Sealing for each display element obtained in Examples and Comparative Examples by a spin coater on the substrate on which the laminate covered with the inorganic material film A obtained above was arranged After the agent was applied, it was dried at 120 ° C. for 10 minutes and then post-baked at 140 ° C. for 30 minutes to form a resin protective film having a thickness of about 10 μm.

(9-4) Coating with inorganic material film B A mask having an opening of 12 mm × 12 mm is installed so as to cover the entire resin protective film of the substrate on which the resin protective film obtained above is formed, and plasma CVD is performed. An inorganic material film B was formed by the method to obtain a display element (organic EL display element).
In the plasma CVD method, SiH ₄ gas and nitrogen gas are used as source gases, the flow rates of each are SiH ₄ gas 10 sccm, nitrogen gas 200 sccm, RF power 10 W (frequency 2.45 GHz), chamber temperature 100 ° C., chamber The test was performed under the condition that the internal pressure was 0.9 Torr.
The thickness of the formed inorganic material film B of silicon nitride was about 1 μm.

(9-5) Light-emitting state of the organic EL display element The prepared organic EL display element was exposed for 500 hours under the conditions of 85 ° C. and 85% RH, respectively, and then a voltage of 3 V was applied to the light-emitting state (light emission and dark spot). The presence or absence of pixel peripheral quenching) is visually observed, and “○” indicates that there is no dark spot or peripheral quenching, and “△” indicates that dark spot or peripheral quenching is observed. The display performance of the organic EL display element was evaluated with “×” as the enlarged case.

ADVANTAGE OF THE INVENTION According to this invention, the sealing agent for display elements which can suppress generation | occurrence | production of an outgas, and the generation | occurrence | production of the crack after application | coating and a foreign material can be provided. Moreover, according to this invention, the display element which uses this sealing agent for display elements can be provided.

Claims (4)

A segment having a —COOX group (X is a cation of a base having a boiling point of 0 ° C. or higher) derived from the carboxyl group of the carboxyl group-containing ethylenically unsaturated monomer, and other ethylenically unsaturated monomers A display element comprising a water-soluble resin that is a copolymer having a segment derived therefrom, a cross-linkable resin having a cross-linkable functional group capable of cross-linking the water-soluble resin, and water Sealant. The sealing agent for display elements according to claim 1, wherein the base having a boiling point of 0 ° C or higher has a molecular weight of 20 to 300. 3. The sealant for a display element according to claim 1, wherein the base having a boiling point of 0 ° C. or higher is propylamine, diethylamine, or triethylamine. A display element comprising a cured product of the sealant for display elements according to claim 1, 2 or 3.