JP2017211422A - Sealant for display device and display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a sealant for a display device that can suppress the generation of outgas and is excellent in storage stability, transparency of a cured product, and moisture resistance reliability; and to provide a display device formed by using the sealant for a display device.SOLUTION: There is provided a sealant for a display device containing a butenediol vinylalcohol copolymer, a crosslinking agent that can crosslink the butenediol vinylalcohol copolymer, and water.SELECTED DRAWING: None

Description

The present invention relates to a sealant for a display element that can suppress generation of outgas and is excellent in storage stability, transparency of a cured product, and moisture resistance reliability. 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 the productivity is inferior. The two-pack type curable epoxy resin composition is a mixture of a main agent and a curing agent. 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 the present invention is to provide a sealant for a display element that can suppress the generation of outgas and is excellent in storage stability, transparency of a cured product, and moisture resistance reliability. Another object of the present invention is to provide a display element using the sealant for display element.

The present invention is a sealing element for a display element containing a butenediol-vinyl alcohol copolymer, a crosslinking agent capable of crosslinking the butenediol-vinyl alcohol copolymer, and water.
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 examined the use of water as a solvent that hardly generates outgas, and the use of polyvinyl alcohol resin as a water-soluble resin that is excellent in transparency and hardly generates outgas. However, although the obtained sealant for display elements is excellent in the effect of suppressing the generation of outgas, the polyvinyl alcohol forms crystal nuclei during storage and becomes a foreign substance, and therefore the transparency is inferior. In addition, since the hydroxyl group remains in the cured product of polyvinyl alcohol, there is a problem that the moisture resistance reliability is inferior. When a cross-linking agent capable of cross-linking the polyvinyl alcohol-based resin is used to improve the moisture resistance reliability of the cured product, there is a problem that the obtained sealant for display element is inferior in storage stability. there were.
Therefore, as a result of intensive studies, the present inventors further combined a butenediol-vinyl alcohol copolymer as the polyvinyl alcohol resin with a crosslinking agent capable of crosslinking the butenediol-vinyl alcohol copolymer. By using it, it has been found that an outgas generation can be suppressed, and a sealant for display elements that is excellent in storage stability, transparency of the cured product and moisture resistance reliability can be obtained, and the present invention has been completed. It was.
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 sealant for display elements of the present invention contains a butenediol-vinyl alcohol copolymer as a water-soluble resin.
By using a combination of the above butenediol-vinyl alcohol copolymer and a cross-linking agent described later, the sealant for display element of the present invention can suppress the generation of outgas, storage stability and cured product Excellent transparency and moisture resistance reliability.
The butenediol-vinyl alcohol copolymer 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.

The content ratio of the segment derived from the butenediol and the segment derived from the vinyl alcohol in the butenediol-vinyl alcohol copolymer is a weight ratio, the segment derived from butenediol: the segment derived from vinyl alcohol = 1. : It is preferable that it is 99-30: 70. When the content ratio of the segment derived from the butenediol and the segment derived from the vinyl alcohol is within this range, the obtained sealant for display element suppresses the occurrence of outgas, and the cured product The effect of improving transparency and moisture resistance reliability is excellent. The content ratio of the segment derived from the butenediol and the segment derived from the vinyl alcohol is a weight ratio, the segment derived from the butenediol: the segment derived from the vinyl alcohol = 5: 95 to 20:80. More preferred.

The butenediol-vinyl alcohol copolymer can be obtained by saponifying a butenediol-vinyl ester copolymer.
As the vinyl ester, vinyl acetate is preferably used.

As a method for producing the butenediol-vinyl ester copolymer, for example, a radical polymerization initiator and, if necessary, a molecular weight adjusting agent may be used to form the butenediol and the vinyl ester in bulk polymerization, solution polymerization, suspension. Examples of the polymerization method include conventionally known methods such as turbid 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 in producing the above butenediol-vinyl ester copolymer, 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 manufacturing the said butenediol-vinyl ester copolymer, a peroxide, an azo initiator, etc. are mentioned, for example.
Examples of the molecular weight modifier include α-methylstyrene dimer, mercaptan chain transfer agent, and the like.

A preferable lower limit of the saponification degree of the butenediol-vinyl alcohol copolymer is 70 mol%. When the saponification degree of the butenediol-vinyl alcohol copolymer is 70 mol% or more, the water solubility and the reactivity with the cross-linking agent are improved. The more preferable lower limit of the saponification degree of the butenediol-vinyl alcohol copolymer is 80 mol%, and the more preferable upper limit is 99.9 mol%.
The saponification degree of the butenediol-vinyl alcohol copolymer can be measured by a method according to JIS K6726.

The preferable lower limit of the average degree of polymerization of the butenediol-vinyl alcohol copolymer is 100, and the preferable upper limit is 5000. When the average degree of polymerization of the butenediol-vinyl alcohol copolymer is within this range, the obtained sealant for display element can further reduce the outgassing, and the liquid crystal display element and the organic EL display element The effect of suppressing damage is superior. The more preferable lower limit of the average degree of polymerization of the butenediol-vinyl alcohol copolymer is 300, and the more preferable upper limit is 3000.
The average degree of polymerization of the butenediol-vinyl alcohol copolymer can be measured by a method according to JIS K6726.

Examples of commercially available butenediol-vinyl alcohol copolymers include Nichigo G-Polymer (manufactured by Nippon Synthetic Chemical Co., Ltd.).

The butenediol-vinyl alcohol copolymer may be previously dissolved or dispersed in an aqueous solution or an organic solvent, and may be mixed with a crosslinking agent 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 crosslinking agent which can bridge | crosslink the said butenediol-vinyl alcohol copolymer.
As described above, by using a combination of the butenediol-vinyl alcohol copolymer and a crosslinking agent described later, the sealant for a display element of the present invention can suppress outgassing, and can be stored stably. As well as the transparency and moisture resistance reliability of the cured product. Moreover, the said crosslinking agent also has the effect of improving the adhesiveness of the hardened | cured material of the sealing agent for display elements of this invention, hardness, and heat-and-moisture resistance.

Examples of the crosslinking agent include water-dispersed polyisocyanate compounds, block isocyanate compounds, metal compounds, and carboxyl group-containing resins. Especially, it is preferable that the said crosslinking agent is at least 1 sort (s) selected from the group which consists of a water dispersion polyisocyanate compound, a block isocyanate compound, and a metal compound, a water dispersion polyisocyanate compound, a block isocyanate compound, and More preferably, it is at least one selected from the group consisting of titanate compounds.

As the water-dispersed polyisocyanate compound, for example, a polyisocyanate compound is introduced with a hydrophilic group, and when mixed with water, a part of the oil droplet is formed, and the hydrophilic group is located outside the oil droplet. And those having a structure in which an isocyanate group is located inside the oil droplet.

The preferable lower limit of the molecular weight of the water-dispersed polyisocyanate compound is 50, and the preferable upper limit is 5000. When the molecular weight of the water-dispersed isocyanate compound is within this range, the obtained sealant for display element is excellent in the effect of suppressing the generation of outgas and the moisture resistance reliability of the cured product. The more preferable lower limit of the molecular weight of the water-dispersed isocyanate compound is 100, and the more preferable upper limit is 500.

Examples of commercially available water-dispersed polyisocyanate compounds include Duranate WB40-100, Duranate WB40-80D, Duranate WT20-100, Duranate WT30-100, Duranate WE50-100 (all manufactured by Asahi Kasei Chemicals). Etc.

The minimum with the preferable molecular weight of the said block isocyanate compound is 50, and a preferable upper limit is 5000. When the molecular weight of the blocked isocyanate compound is within this range, the obtained sealant for display element is more excellent in the effect of suppressing the generation of outgas and the moisture resistance reliability of the cured product. The more preferable lower limit of the molecular weight of the blocked isocyanate compound is 100, and the more preferable upper limit is 500.

Examples of the blocked isocyanate compound include 2- (O- (1′-methylpropylideneamino) carboxyamino) ethyl methacrylate, 2-((3,5-dimethylpyrazolyl) carbonylamino) ethyl acrylate, 2-(( 3,5-dimethylpyrazolyl) carbonylamino) ethyl methacrylate and the like.

Examples of commercially available block isocyanate compounds include Karenz AOI-BP, Karenz MOI-BM, Karenz MOI-BP (all manufactured by Showa Denko KK), Duranate MF-K60B, Duranate SBB-70P, Examples include Duranate 17B-60P (all manufactured by Asahi Kasei Chemicals Corporation).

Examples of the metal compound include titanate compounds and zirconate compounds.
Examples of the titanate compound include titanium lactate, titanium triethanolamate, titanium (IV) tetramethoxide, titanium (IV) tetraethoxide, titanium (IV) tetraisopropoxide, titanium (IV) tetrapropoxide, Examples include titanium (IV) tetrabutoxide, titanium (IV) tetraoctoxide, and zirconium (IV) tetrahydroxide.
Examples of the zirconate compound include zirconium (IV) tetramethoxide, zirconium (IV) tetraethoxide, zirconium (IV) tetraisopropoxide, zirconium (IV) tetrapropoxide, zirconium (IV) tetrabutoxide, zirconium ( IV) Tetraoctoxide and the like.
Among these, as the metal compound, a titanate compound is preferable, and titanium (IV) tetraisopropoxide, titanium (IV) tetrabutoxide, and titanium (IV) tetraoctoxide are more preferable.

The cross-linking agent is preliminarily dissolved or dispersed in an aqueous solution or an organic solvent, and after adjusting the amount of water or the amount of organic solvent as necessary, may be mixed with the butenediol-vinyl alcohol copolymer or the like. Good.

The content ratio of the butenediol-vinyl alcohol copolymer and the crosslinking agent is preferably a weight ratio of the butenediol-vinyl alcohol copolymer: crosslinking agent = 1: 0.01 to 1: 2. . When the content ratio of the butenediol-vinyl alcohol copolymer and the cross-linking agent is within this range, the resulting sealant for a display element has an effect of suppressing the generation of outgas, storage stability, and curing. It is superior due to transparency and moisture resistance reliability. It is more preferable that the content ratio of the butenediol-vinyl alcohol copolymer and the crosslinking agent is a weight ratio of the butenediol-vinyl alcohol copolymer: crosslinking agent = 1: 0.1 to 1: 1. 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 butenediol-vinyl alcohol copolymer and the cross-linking agent may be mixed with other components after being previously dissolved or dispersed in an aqueous solution or an organic solvent, respectively.

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 butenediol-vinyl alcohol copolymer and the crosslinking agent.

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.

Examples of the method for producing the sealant for display elements of the present invention include the butenediol-vinyl alcohol copolymer, the cross-linking agent, the water, and additives used as necessary. The method of mixing using a stirrer etc. is mentioned. 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 can suppress the generation of outgas and is excellent in storage stability, transparency of cured product and moisture resistance reliability, the display element of the present invention is particularly excellent in display performance. It will be a thing.

According to this invention, generation | occurrence | production of outgas can be suppressed and the sealing agent for display elements which is excellent in storage stability, transparency of cured | curing material, and moisture resistance reliability 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 aqueous solution of butenediol-vinyl alcohol copolymer)
Butenediol-vinyl alcohol copolymer (manufactured by Nippon Synthetic Chemical Co., Ltd., “Nichigo G-Polymer AZF8035Q”, saponification degree 98.0 mol%, average polymerization degree 300) was mixed with water in a Teflon (registered trademark) container. The mixture was stirred to obtain an aqueous solution of butenediol-vinyl alcohol copolymer (solid content: 10% by weight).

(Preparation of aqueous polyvinyl alcohol solution)
Polyvinyl alcohol (manufactured by Denka Co., “K-05”, saponification degree 98.0 mol%, average polymerization degree 500) was mixed and stirred with water in a Teflon (registered trademark) container, and an aqueous polyvinyl alcohol solution (solid content ratio 10 % By weight).

(Examples 1 to 5, Comparative Examples 1 and 2)
According to the mixing 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 diameter of 5 μm, whereby the display element seals of Examples 1 to 5 and Comparative Examples 1 and 2 were used. A stop agent 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) Storage Stability For each sealant for display elements obtained in Examples and Comparative Examples, the initial viscosity immediately after production and the viscosity when stored at 25 ° C. for 1 week are measured (25 ° C., Viscosity after storage for 1 week) / (initial viscosity) is defined as the rate of change in viscosity. The storage stability was evaluated with “×” being 2.0 or more.
The viscosity of the sealant for display element was measured using an E-type viscometer (manufactured by BROOK FIELD, “DV-III”) at 25 ° C. under a rotation speed of 1.0 rpm.

(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, the evaluation substrate on which the coating film having a film thickness of about 10 μm was formed on the glass substrate was made transparent, adhesive, moist heat resistance, low outgas resistance, and liquid crystal voltage holding. It produced about each evaluation of the 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 less than 95% is 80% or more, “△”, and when less than 80%, “×” is adhered. Sex was evaluated.

(4) 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 humidity test that is maintained 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.

(5) Low outgassing About the substrate for evaluation obtained in the above-mentioned “(Production of substrate for evaluation)”, using a thermal analyzer (“TG / DTA6200” manufactured by Seiko Instruments Inc.), 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.

(6) Voltage holding ratio of liquid crystal 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)". 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.

(7) 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.

(8) Display performance of organic EL display element (8-1) Fabrication of a substrate on which a laminate including an organic light emitting material layer is disposed An ITO electrode is applied to a 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.

(8-2) 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 laminate on which the laminate 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.

(8-3) 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.

(8-4) 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.

(8-5) Light-emitting state of the organic EL display element The prepared organic EL display element was exposed for 500 hours under conditions of 85 ° C. and 85% RH, respectively, and then a voltage of 3 V was applied, so that the light-emitting state (light emission and dark spot) was obtained. 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.

According to this invention, generation | occurrence | production of outgas can be suppressed and the sealing agent for display elements which is excellent in storage stability, transparency of cured | curing material, and moisture resistance reliability can be provided. Moreover, according to this invention, the display element which uses this sealing agent for display elements can be provided.

Claims (3)

A sealing agent for a display element, comprising a butenediol-vinyl alcohol copolymer, a crosslinking agent capable of crosslinking the butenediol-vinyl alcohol copolymer, and water. The sealant for display elements according to claim 1, wherein the crosslinking agent is at least one selected from the group consisting of a water-dispersed polyisocyanate compound, a blocked isocyanate compound, and a titanate compound. A display element comprising a cured product of the sealant for display elements according to claim 1.