JP6154303B2 - Sealing agent for display element and method for manufacturing display element - Google Patents

Description

  The present invention relates to a sealant for a display element used for sealing a display element, a method for manufacturing a display element using the sealant, and a display element.

  A manufacturing method of a display element such as a liquid crystal display element (also referred to as a liquid crystal display or an LCD) or an organic EL element is a conventional vacuum from the viewpoint of shortening tact time and optimizing the amount of liquid crystal or organic EL material to be used. The injection method is changing to a liquid crystal dropping method called a dropping method using a photocurable resin, a photopolymerization initiator, a thermosetting resin, and a light containing a thermosetting agent, and a thermosetting sealant. .

  In the dropping method using LCD as an example, first, a rectangular frame-shaped seal pattern is formed on one of two transparent substrates with electrodes by a dispenser, and the liquid crystal micro-droplets are transferred to the transparent substrate with the sealant uncured. Then, the other transparent substrate is immediately overlapped, and the seal portion is irradiated with light such as ultraviolet rays for temporary curing. Thereafter, heating is performed at the time of liquid crystal annealing and main curing is performed to produce an LCD. Also in the organic EL element, since the organic EL material is weak against moisture and oxygen in the environment, sealing is performed by a dropping method.

  A curable resin composition having a thermosetting property and a photo-curing property is known as a sealing agent for a liquid crystal dropping method (see, for example, Patent Documents 1 and 2). A thermosetting agent is added to the conventional composition to enable thermosetting.

JP 2011-102912 A JP 2012-198427 A

  However, when a liquid crystal display element or an organic EL element is produced using a curable resin composition using a thermosetting agent, display unevenness may occur. This is because the thermosetting agent is eluted in a sealing material such as liquid crystal or organic EL in the heating process of the liquid crystal display element or the organic EL element, and the eluted thermosetting agent may cause display unevenness. To do.

  If the blending amount of the thermosetting agent is reduced in order to prevent this, the resulting sealant will have poor adhesion, the liquid crystal and organic EL material will be contaminated, and the resulting device will have poor electrical properties. There is a risk that. Furthermore, since the curing rate of the thermosetting agent is slow, it takes a long time to contact the sealing material, which causes contamination.

  In addition, if the combination of the thermosetting agent is stopped and only the photocuring agent is used, the curability and adhesiveness are not sufficient, and a portion that does not receive light when bonded to the base material is generated, and the above-mentioned elution due to the elution of an inadequate curing component Cause similar problems.

  A problem to be solved by the present invention is that there is no need to add a thermosetting agent, it is possible to sufficiently cure only by photocuring, and it is possible to suppress contamination of the sealing material by the sealing agent. It is providing the sealing agent for elements, the manufacturing method of a display element, and a display element.

In order to solve the above problems, the sealant for display element of the present invention is
A sealant composed of a curable resin composition and used for sealing display elements,
The curable resin composition contains a chain transfer agent,
The chain transfer agent includes (a) a compound containing at least one selected from a urethane bond, a urea bond and an isocyanate group as a component, and a metal-containing compound as a component (b). Is.

  In the sealant for display elements of the present invention, the component (b) of the chain transfer agent is preferably a metal compound containing at least one metal selected from tin, copper, zinc, cobalt, and nickel.

  In the sealant for display elements of the present invention, the content of the chain transfer agent contained in the sealant is preferably 20 to 80% by mass with respect to the total mass of the sealant.

  In the sealant for display element of the present invention, the sealant contains a photocurable monomer, and the content of the photocurable monomer contained in the sealant is 20 to 80% by mass with respect to the total mass of the sealant. It is preferable that

  In the sealant for a display element of the present invention, the photocurable monomer is preferably a compound having at least one hydroxyl group in the molecule.

  The gist of the method for manufacturing a display element of the present invention is that the above-described sealing agent can be used as a sealing agent for the sealing material of the display element to prevent contamination of the sealing material with the sealing agent. is there.

  The gist of the display element of the present invention is that the above-mentioned sealing agent is used as a sealing agent for the sealing material of the display element and can prevent contamination of the sealing material with the sealing agent. .

  The sealant for display elements of the present invention is composed of a curable resin composition containing a chain transfer agent, and the chain transfer agent is at least one selected from a urethane bond, a urea bond and an isocyanate group as the component (a). By having a composition comprising a compound containing one or more species and a metal-containing compound as component (b), it does not require a component such as a thermosetting agent, for example, only by photocuring by irradiation with ultraviolet rays or the like. It is possible to sufficiently cure at normal temperature including a portion not exposed to light, and it is possible to prevent the composition of the sealant from being poorly cured and the uncured sealant from contaminating the sealing material.

  Further, since the sealing agent of the present invention can be cured in a short time, it is possible to minimize the time for the uncured sealing agent to elute in contact with the sealing material. A problem that the display element may have uneven display due to adverse effects on electrical characteristics, etc. due to contamination of the sealing material by components of the sealing agent, avoiding contact with the sealing material for a long time in a cured state. Can be prevented.

  Since the manufacturing method of the display element of the present invention uses the above sealing agent as a sealing agent for the sealing material of the display element, it is possible to prevent contamination of the sealing material with the sealing agent. Therefore, it is possible to minimize the contamination due to the sealing agent and prevent problems such as display unevenness due to the contamination.

  The display element of the present invention has a configuration in which the above-described sealing agent is used as a sealing agent for the sealing material of the display element and can prevent contamination of the sealing material with the sealing material. It is possible to minimize the contamination of the sealing material by the agent and prevent problems such as display unevenness of the display element due to the contamination.

FIG. 1 is an explanatory view of a curable curing unevenness test method of an example, (a) is a plan view, and (b) is a sectional view taken along line BB of (a). FIG. 2 is an example of an FT-IR chart used for measurement of the curing reaction rate of the example.

  Hereinafter, embodiments of the present invention will be described in detail. The sealant for display elements of the present invention (hereinafter sometimes simply referred to as sealant) is composed of a curable resin composition. In this example, an example in which an ultraviolet curable resin composition (hereinafter sometimes simply referred to as a composition) is used as a sealing agent for liquid crystal sealing of a liquid crystal display panel (referred to as a liquid crystal sealing agent) will be described.

  The composition of the sealing agent can be composed of, for example, (A) a photocurable component, (B) a chain transfer agent, and (C) a photopolymerization initiator. The curing principle of the ultraviolet curable material is that the photopolymerization initiator absorbs ultraviolet rays (ultraviolet light) to generate active species such as radical species, and the active species is a carbon-carbon double layer such as (meth) acrylate. The bond is radically polymerized and cured. However, in the ultraviolet curable material, the portion where the ultraviolet rays are shielded is uncured by ordinary ultraviolet curing. On the other hand, by adding the chain transfer agent (B), the radicals generated by the irradiation of ultraviolet rays are transmitted to the places where the ultraviolet rays are shielded and no radicals are generated, and the polymerization reaction is started and advanced. The dark part where ultraviolet rays are shielded can be cured. That is, by adding the chain transfer agent (B), it is possible to impart dark part curability that can cure a portion that does not reach irradiation light. Therefore, it is possible to cure at a normal temperature for a short time without adding a thermosetting agent or the like. Hereafter, each said component is demonstrated.

  (A) As a photocurable component, the ultraviolet curable material from which hardened | cured material can be obtained by irradiating light, such as an ultraviolet-ray, can be used. In addition to ultraviolet rays, the photocurable component includes those from which a cured product can be obtained by visible light, infrared rays, or the like.

  As the ultraviolet curable material, a photocurable monomer can be used. Specific examples of the photocurable monomer include curable monomers such as (meth) acrylate and oligomers. In the present invention, the description of “(meth) acrylate” means acrylate and / or methacrylate.

  As said (meth) acrylate compound, if it is a compound which has one or more (meth) acrylate groups in a molecule | numerator, a conventionally well-known thing can be used without being restrict | limited especially. Specific examples of the (meth) acrylate compound include isobornyl (meth) acrylate, bornyl (meth) acrylate, tricyclodecanyl (meth) acrylate, dicyclopentanyl (meth) acrylate, dicyclopentenyl (meth) acrylate, and cyclohexyl. (Meth) acrylate, (meth) acrylic acid, benzyl (meth) acrylate, 4-butylcyclohexyl (meth) acrylate, (meth) acryloylmorpholine, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, isopropyl (meth) acrylate, octyl (meth) acrylate , Isooctyl (meth) acrylate, nonyl (meth) acrylate, decyl (meth) acrylate, isodecyl (meth) acrylate, undecyl (meth) acrylate, dodecyl (meth) acrylate, lauryl (meth) acrylate, stearyl (meth) acrylate, Isostearyl (meth) acrylate, tetrahydrofurfuryl (meth) acrylate, polyethylene glycol mono (meth) acrylate, polypropylene glycol mono (meth) acrylate, methoxyethylene glycol (meth) acrylate, ethoxyethyl (meth) acrylate, methoxypolyethylene glycol ( (Meth) acrylate, methoxypolypropylene glycol (meth) acrylate, polyoxyethylene nonylphenyl ether acrylic , Diacetone (meth) acrylamide, isobutoxymethyl (meth) acrylamide, N, N-dimethyl (meth) acrylamide, t-octyl (meth) acrylamide, dimethylaminoethyl (meth) acrylate, diethylaminoethyl (meth) acrylate, Mono (meth) acrylates such as 7-amino-3,7-dimethyloctyl (meth) acrylate, N, N-diethyl (meth) acrylamide, N, N-dimethylaminopropyl (meth) acrylamide, butanediol di (meth) ) Acrylate, hexanediol di (meth) acrylate, nonanediol di (meth) acrylate, decanediol di (meth) acrylate, 2-butyl-2-ethyl-1,3-propanediol di (meth) acrylate, 2-hydroxy − 3-acryloyloxypropyl methacrylate, dipropylene glycol di (meth) acrylate, tripropylene glycol di (meth) acrylate, triethylene glycol di (meth) acrylate, tetraethylene glycol di (meth) acrylate, tricyclodecane dimethylol Di (meth) acrylate, 1,4-butanepolyol di (meth) acrylate, 1,6-hexanepolyol di (meth) acrylate, neopentyl glycol di (meth) acrylate, polyethylene glycol di (meth) acrylate, polypropylene glycol di (Meth) acrylate, 9,9-bis [4- (2-acryloyloxyethoxy) phenyl] fluorene, polyester di (meth) acrylate, tris (2-hydroxyethyl) iso Anurate tri (meth) acrylate, tris (2-hydroxyethyl) isocyanurate di (meth) acrylate, tricyclodecane dimethylol di (meth) acrylate, EO adduct of bisphenol A di (meth) acrylate, EO of hydrogenated bisphenol A Di (meth) acrylate of polyol of adduct or PO adduct, epoxy (meth) acrylate obtained by adding (meth) acrylate to diglycidyl ether of bisphenol A, triethylene glycol divinyl ether, trimethylolpropane tri (meth) Acrylate, pentaerythritol tri (meth) acrylate, trimethylolpropane EO adduct tri (meth) acrylate, trisacryloyloxyethyl phosphate, pentaerythritol tetra (Meth) acrylate, tetrafurfuryl alcohol oligo (meth) acrylate, ethyl carbitol oligo (meth) acrylate, 1,4-butanediol oligo (meth) acrylate, 1,6-hexanediol oligo (meth) acrylate, trimethylolpropane Examples thereof include poly (meth) acrylates such as oligo (meth) acrylate, pentaerythritol oligo (meth) acrylate, (poly) urethane (meth) acrylate, and (poly) butadiene (meth) acrylate. These may be used alone or in combination of two or more.

  The photocurable monomer is preferably a compound having at least one hydroxyl group in the molecule. A glass substrate is generally used as the substrate used for the display element. The photocurable monomer having a hydroxyl group can improve the adhesion to a glass substrate or the like. Examples of the compound having at least one hydroxyl group in the molecule include 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, and 2-hydroxy-3-acryloyl. Examples include roxypropyl methacrylate and pentaerythritol tri (meth) acrylate.

  The content of the photocurable monomer contained in the sealant is preferably 20 to 80% by mass with respect to the total mass of the sealant. If the photocurable monomer is less than 20% by mass, the curing may be poor and the sealing agent may contaminate the sealing material. If the photocurable monomer exceeds 80% by mass, the physical properties after curing become hard and the adhesion to the substrate is reduced. There is a fear. The more preferable content of the photocurable monomer is in the range of 30 to 70% by mass.

  (B) The chain transfer agent includes a nitrogen-containing compound containing at least one selected from a urethane bond, a urea bond and an isocyanate group in the molecule as the component (a), and a metal-containing compound as the component (b). Is included.

  Specific examples of the nitrogen-containing compound (a) include polyurethane, polyurea, isocyanate and the like. The polyurethane and polyurea can be obtained, for example, by reacting isocyanate with a hydroxyl group-containing compound such as polyether polyol or polyester polyol, an amine-containing compound, or the like.

  Examples of the isocyanate include methylene diisocyanate, ethylene diisocyanate, tetramethylene diisocyanate, hexamethylene diisocyanate (HDI), dodecamethylene diisocyanate, 2,2,4-trimethylhexamethylene diisocyanate, lysine diisocyanate (LDI), 1,3,6. -Aliphatic isocyanates such as hexamethylene triisocyanate, hydrogenated-4,4'-diphenylmethane diisocyanate (hydrogenated MDI), hydrogenated-xylylene diisocyanate (hydrogenated XDI), 1,4-cyclohexane diisocyanate, hydrogenated-2 , 4-tolylene diisocyanate (hydrogenated TDI), isophorone diisocyanate (IPDI), norbornene diisocyanate (NBDI), etc. Naphthalate, xylylene diisocyanate (XDI), araliphatic isocyanate such as tetramethylxylylene diisocyanate (TMXDI), 1,4-diphenyl diisocyanate, 2,4 or 2,6-tolylene diisocyanate (TDI), 2,4 or 4,4-diphenylmethane diisocyanate (MDI), 1,5-naphthalene diisocyanate (NDI), 3,3′-dimethyl-4,4′-diphenylmethane diisocyanate, O-tolidine diisocyanate, polyphenylmethane polyisocyanate (crude MDI), And polyisocyanates such as aromatic isocyanates such as triphenylmethane triisocyanate and tris (isocyanatephenyl) thiophosphate. Isocyanates are biuret-type polyisocyanates obtained by further reacting the above polyisocyanates with water, adduct-type polyisocyanates obtained by reacting with polyhydric alcohols such as trimethylolpropane, and some polyisocyanates such as polyesters and polyether derivatives. And a liquid prepolymer obtained by polymerizing, and a multimer obtained by isocyanuration. These may be used alone or in combination of two or more.

  Examples of the polyether polyol include diols such as polyethylene oxide having a hydroxyl group at both ends, polypropylene oxide, random polyethylene oxide and polypropylene oxide, block copolymer, polyoxyethylene glycol, polyoxypropylene glycol, and polyoxytetramethylene glycol. Examples include triols such as polyoxyalkylene polyols having three hydroxyl groups.

  The polyester polyol is a polyester compound having a hydroxyl group at a terminal obtained by a reaction between a polyhydric alcohol and a polybasic acid. Polyester polyols are carbon alcohol 1-30 dialcohols, terminal diol (poly) ethylene glycol, terminal diol (poly) propylene glycol, terminal diol (poly) hexamethylene glycol, terminal diol (poly) caprolactone, etc. Is mentioned. Examples of the polybasic acid include dibasic acids such as phthalic acid, isophthalic acid, terephthalic acid, and adipic acid.

  Examples of the amine-containing compound include amines having 1 to 30 carbon chains having a primary or secondary amino group at the terminal, (poly) ethylene glycol as a terminal diamine, (poly) propylene glycol as a terminal diamine, ( Poly) hexamethylene glycol, (poly) caprolactone of terminal diamine, (poly) ester (poly) ol of terminal diamine, (poly) amide of terminal diamine, (poly) ester of terminal diamine, and the like.

  In addition, the polyurethane and polyurea compounds may have an alkyl group or a terminal group after polymerization by (thio) ether, (thio) ester, amide, (thio) urethane, (thio) urea, N-alkyl bond, etc., if necessary. Sealed with (meth) acrylic group, epoxy group, oxazolyl group, carbonyl group, thiol group, thioether group, thioester group, phosphoric acid (ester) group, phosphonic acid (ester) group, carboxylic acid (ester) group, etc. May be.

  The urethane bond or urea bond may be contained in the molecule by combining a plurality of types or by combining end groups.

  (B) As the metal of the metal-containing compound as the component (b) constituting the chain transfer agent, one or more kinds of metals selected from tin, copper, zinc, cobalt and nickel are preferably used. The metal-containing compound of component (b) is not particularly limited as long as one or more of the above metals are contained in the constituent molecules in the form of metal salts or complexes, and those conventionally known are used. Can be used.

  Examples of the metal salt include metal salt forms such as carboxylate, phosphate, sulfonate, hydrochloride, bromate, and (per) (sub) chlorate of the metal species.

  The metal complex is not particularly limited as long as it is coordinated and stabilized with an organic ligand capable of forming a coordination bond with the metal species and 1: 1 to 1: 4 (metal: ligand). A well-known thing can be used without this.

  Specific examples of the metal-containing compound of the component (b) include bis (2,4-pentanedionato) tin, dibutyltin bis (trifluoromethanesulfonate), dibutyltin diacetate, dibutyltin dilaurate, dibutyltin maleate, phthalocyanine tin (IV) Dichloride, tetrabutylammonium difluorotriphenyltin, phthalocyanine tin (II), tributyl (2-pyridyl) tin, tributyl (2-thienyl) tin, tributyltin acetate, tributyl (trimethylsilylethynyl) tin, trimethyl (2-pyridyl) ) Tin, bis (hexafluoroacetylacetonato) copper (II), bis (2,4-pentanedionato) copper (II), bis (1,3-propanediamine) copper (II) dichloride, bis (8- Quinolinolato) copper (II), bis (trifluoro-2,4-pentanedionato) copper (II), bis (2-hydroxyethyl) dithiocarba Copper (II) phosphate, copper diethyldithiocarbamate, copper (II) dimethyldithiocarbamate, disodium ethylenediaminetetraacetate (II), copper (II) phthalocyanine, dichloro (1,10-phenanthroline) copper (II), phthalocyanine Copper, tetra-4-tert-butylphthalocyanine copper, tetrakis (acetonitrile) copper (I) hexafluorophosphate, copper naphthenate, bis [2- (2-benzothiazolyl) phenolato] zinc (II), bis [2- ( 2-Benzoxazolyl) phenolato] zinc (II), zinc (II) bis (2-hydroxyethyl) dithiocarbamate, bis (2,4-pentanedionato) zinc (II), bis (8-quinolinolato) zinc (II), bis (tetrabutylammonium) bis (1,3-dithiol-2-thione-4,5-dithiolato) zinc complex, disodium zinc ethylenediaminetetraacetate, zinc dibenzyldithiocarbamate (II), dibutyl Zinc rudithiocarbamate (II), zinc diethyldithiocarbamate, zinc dimethyldithiocarbamate, zinc phthalocyanine, zinc naphthenate, bis (cyclopentadienyl) cobalt (III) hexafluorophosphate, [1,1'-bis (diphenyl) Phosphino) ferrocene] cobalt (II) dichloride, bis (hexafluoroacetylacetonato) cobalt (II), (1R, 2R) -N, N'-bis [3-oxo-2- (2,4,6- Trimethylbenzoyl) butylidene] -1,2-diphenylethylenediaminatocobalt (II), (1S, 2S) -N, N'-bis [3-oxo-2- (2,4,6-trimethylbenzoyl) butylidene] -1,2-diphenylethylenediaminatocobalt (II), bis (2,4-pentanedionato) cobalt (II), bis (trifluoro-2,4-pentandionato) cobalt (II), phthalocyanine cobalt ( II), disodium cobalt ethylenediaminetetraacetate , Hexaamminecobalt (III) chloride, N, N'-disalicylic ethylenediaminecobalt (II), [5,10,15,20-tetrakis (4-methoxyphenyl) porphyrinato] cobalt (II), tris (2 , 4-Pentandionato) cobalt (III), cobalt naphthenate, [1,2-bis (diphenylphosphino) ethane] nickel (II) dichloride, bis (dithiobenzyl) nickel (II), bis (hexafluoroacetyl Acetonato) nickel (II), bis (2,4-pentanedionato) nickel (II), bis (tetrabutylammonium) bis (maleonitriledithiolato) nickel (II) complex, bis (tricyclohexylphosphine) nickel ( II) Dichloride, bis (triphenylphosphine) nickel (II) dichloride, bromo [(2,6-pyridindiyl) bis (3-methyl-1-imidazolyl-2-ylidene)] nickel bromide, ethylenediamine And tetrasodium acetic acid disodium nickel (II), nickel dibutyldithiocarbamate (II), nickel diethyldithiocarbamate and the like. These may be used individually by 1 type and may use 2 or more types together.

  As the form of the metal-containing compound of the component (b), it is not always necessary to have high solubility in an organic substance, but it is an organic acid salt or a metal complex because it is easy to mix and prevents precipitation during storage. It is preferable.

  The metal-containing compound as the component (b) can be combined with the nitrogen-containing compound as the component (a) to constitute a chain transfer agent.

  The method of combining the component (a) and the component (b) is not particularly limited as long as both components are mixed at room temperature or under heating conditions. It is preferable to use a method in which the mixture is sufficiently stirred or kneaded and dissolved or uniformly dispersed in an active gas atmosphere at an appropriate temperature using a mixing apparatus such as a mixing mixer.

  The content of the chain transfer agent contained in the sealant is preferably 20 to 80% by mass with respect to the total mass of the sealant. If the chain transfer agent is less than 20% by mass, the dark part curability may be insufficient, and if it exceeds 80% by mass, the adhesiveness after curing may be insufficient. A more preferable content of the chain transfer agent is in the range of 30 to 70% by mass.

  (C) As a photoinitiator, if it is a compound which absorbs an ultraviolet-ray and starts radical polymerization, a conventionally well-known thing can be used without being restrict | limited especially.

  Specific examples of the photopolymerization initiator include 1-hydroxycyclohexyl phenyl ketone, 2,2-dimethoxy-2-phenylacetophenone, xanthone, fluorenone, benzaldehyde, fluorene, anthraquinone, ethyl anthraquinone, triphenylamine, carbazole, 3 -Methylacetophenone, 4-chlorobenzophenone, 4,4'-dimethoxybenzophenone, 4,4'-diaminobenzophenone, Michler's ketone, benzoin propyl ether, benzoin ethyl ether, benzyl dimethyl ketal, 1- (4-isopropylphenyl) -2- Hydroxy-2-methylpropan-1-one, 2-hydroxy-2-methyl-1-phenylpropan-1-one, thioxanthone, diethylthioxanthone, 2-isopropylthiol Xanthone, 2-chlorothioxanthone, 2-methyl-1- [4- (methylthio) phenyl] -2-morpholino-propan-1-one, 2,4,6-trimethylbenzoyldiphenylphosphine oxide, bis- (2, 6-dimethoxybenzoyl) -2,4,4-trimethylpentylphosphine oxide and the like. These may be used individually by 1 type and may use 2 or more types together.

  As the photopolymerization initiator, commercially available products such as IRGACURE184, 369, 651, 500, 907, CGI1700, CGI1750, CGI1850, CG24-61; Etc.) can be used.

  It is preferable that the addition amount of the photoinitiator added to a sealing agent exists in the range of 0.1-10 mass parts with respect to 100 mass parts of the whole sclerosing | hardenable component of a sealing agent. If the addition amount of the photopolymerization initiator is less than 0.1 parts by mass, the curability may be insufficient, and if it exceeds 10 parts by mass, the physical properties after curing may be reduced. Furthermore, the addition amount of a preferable photoinitiator exists in the range of 0.2-5 mass parts.

  The composition can contain various additives as required. Examples of the additive include stabilizers, softeners, pigments, dyes, antistatic agents, flame retardants, sensitizers, dispersants, solvents, antibacterial and antifungal agents. Each additive can be used in combination as appropriate.

  The composition can be obtained by mixing the above components. The mixing method is not particularly limited, and is sufficiently stirred or kneaded using a stirring device such as a mixing mixer under a reduced pressure or in an inert gas atmosphere such as nitrogen, and dissolved or uniformly dispersed. The method of making it preferable is.

  The sealing agent of this invention is used as a liquid crystal sealing agent for sealing sealing materials, such as a liquid crystal of display elements, such as a liquid crystal display panel. To seal the sealing material means to seal the sealing material in a predetermined space. For example, a liquid crystal sealant has a function as an adhesive for sealing liquid crystal between two substrates and bonding the two substrates together in a liquid crystal display panel. The liquid crystal sealant can be used in a liquid crystal dropping method.

  Hereinafter, the manufacturing method of the liquid crystal display panel using the said liquid-crystal sealing compound is demonstrated. In the liquid crystal display panel, two opposing substrates are bonded to each other through a sealant composition. In the bonding step, the following steps (1) to (4) are sequentially performed.

(1) A sealant is applied to a rectangular frame-shaped seal pattern by a dispenser on an image display region of one substrate (first substrate) to prepare a substrate on which a frame-shaped display region is arranged.
(2) With the sealing agent in an uncured state, liquid crystal microdroplets are dropped on the entire surface of the display area frame on the surface of the first substrate.
(3) Immediately superimpose the second substrate on the first substrate so as to face each other.
(4) By irradiating the composition of the sealing agent with ultraviolet rays and curing the composition, the liquid crystal is sealed, and the first substrate and the second substrate are bonded. A liquid crystal display panel in which liquid crystal is sealed is obtained.

  As the substrate used in the step (1), two sheets of glass are usually used. As the glass substrate, an array substrate in which elements such as TFTs are formed in a matrix on the surface, or a CF substrate in which a color filter, a black matrix, or the like is formed on the surface is used. In addition to glass, the substrate material may be plastic such as polyester, polycarbonate, PMMA, polysulfone, or the like. An alignment film for aligning the liquid crystal may be formed on the opposite surface of the substrate.

  As a method of applying the sealing agent on the substrate in the step (2), application by screen printing may be used in addition to application by a dispenser. Application by a dispenser is used when liquid crystal is filled by a liquid crystal dropping method.

  According to the above-mentioned panel bonding step, it is possible to cure the sealing agent at room temperature only by irradiation with ultraviolet rays without performing thermosetting. Furthermore, curing of the sealant by irradiation with ultraviolet rays can be completed in a short time compared to thermal curing. For this reason, since the liquid crystal which is the sealing agent and the composition of the uncured sealant are in contact with each other in a short time, the composition of the uncured sealant migrates into the liquid crystal and becomes contaminated. Can be minimized.

  In particular, since the sealing agent can be cured even in a portion where ultraviolet rays do not reach directly during curing, such as a light shielding area, the portion is contaminated with the composition of the sealing agent. It is possible to obtain a liquid crystal display panel that is prevented well and the occurrence of display unevenness or the like in the portion is suppressed.

  In the method for producing a display element of the present invention, the sealing agent composition is used for sealing a display element such as a liquid crystal panel, and the sealing agent is sealed by curing the composition only by photocuring. There is a feature that it is possible to prevent contamination of the material.

  In the display element of the present invention, the sealing composition is used as a sealing agent for sealing a sealing material such as liquid crystal of a liquid crystal display panel, and the composition is cured only by photocuring. In this case, it is possible to prevent the sealing material from being contaminated by shortening the time for curing the composition of the sealing agent in a short time.

  The conditions of ultraviolet irradiation when the sealing agent composition is cured can be appropriately selected according to the composition of the composition. As an irradiation apparatus used for ultraviolet irradiation, a known apparatus can be used. As the irradiation apparatus, for example, a light source such as a bulb-type UV lamp or LED-UV lamp in which Hg, Hg / Xe, a metal halide compound, or the like is sealed can be used. Further, the ultraviolet irradiation device may use a condensing UV irradiation device that collects and irradiates light from the light source with a reflection mirror.

  In the above embodiment, the liquid crystal panel of the liquid crystal display element has been described as an example of the display element, but the present invention uses the sealing agent as a sealing agent for sealing the organic EL element to manufacture an organic organic EL element. You can also.

  Examples of the present invention and comparative examples are shown below. In addition, this invention is not limited by these Examples. Tables 1 and 2 show preparation examples of compositions of sealing agents of Examples and Comparative Examples.

  Each component of (A) photocurable monomer, (B) chain transfer agent, and (C) photopolymerization initiator is blended in the composition (parts by mass) shown in Tables 1 and 2, and mixed using a stirrer. It melt | dissolved or disperse | distributed and obtained each sealing agent of Examples 1-9 (Table 1) and Comparative Examples 1-3 (Table 2).

  Abbreviations in the table are as follows, and those not specifically labeled by the manufacturer were reagent grades manufactured by Tokyo Kasei Co., Ltd.

(A) Photocurable monomer: (meth) acrylate, IBA: isobornyl acrylate, HPA: hydroxypropyl acrylate, HEA: hydroxyethyl acrylate

(B) Chain transfer agent <urethane-containing compound>
UP-1: synthetic product (Synthesis Example 1 will be described later)
<Urea-containing binding compound>
UP-2: synthetic product (Synthesis Example 2 will be described later)
<Isocyanate-containing compound>
・ N3600: Sumika Bayer Urethane Co., Ltd., trade name “Death Module N3600”
<Metal-containing compounds>
BPDZ: Bis (2,4-pentandiona 卜) zinc (II)
CDEDTC: Diethyldithiocarbamate copper (II)
DBTDL: dibutyltin dilaurate BPDC: bis (2,4-pentandiona ジ オ) cobalt (II)
BTCN: dibutyldithio force nickel rubamate (II)

(Synthesis Example 1) Synthesis of UP-1 In a reaction vessel equipped with a stirrer, 80 g (200 mmol) of polypyrene glycol having a number average molecular weight of 400, 40 g (238 mmol) of hexamethylene diisocyanate
And 0.05 g of dibutyltin dilaurate were added, and the liquid temperature was raised from room temperature to 50 ° C. over 1 hour with stirring. Thereafter, a small amount was sampled and FT-IR was measured, and stirring was continued at 50 ° C. while confirming the absorption of the isocyanate group near 2300 cm ⁻¹ . The content of residual isocyanate groups was calculated from the absorption area of FT-IR, and the reaction was terminated when it decreased to about 15% compared to before the reaction and disappeared, and a colorless transparent viscous liquid was obtained. . Further, 9.84 g (84.8 mmol) of 2-hydroxyethyl acrylate, 0.05 g of dibutyltin dilaurate, and 0.02 g of pentaerythritol tetrakis [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate] were added. The liquid temperature was raised from room temperature to 50 ° C. over 1 hour with stirring. Thereafter, a small amount was sampled and FT-IR was measured, and stirring was continued at 50 ° C. while confirming the absorption of the isocyanate group near 2300 cm ⁻¹ . The content of residual isocyanate groups was estimated from the absorption area of FT-IR, and when the absorption was burnt down, the reaction was terminated, and a colorless transparent viscous liquid was obtained. This is UP-1. UP-1 is a urethane-containing bonded compound having a number average molecular weight of 3200 and an acrylate group at the end.

(Synthesis Example 2) Synthesis of UP-2 A reaction vessel equipped with a stirrer was charged with 40 g (208 mmol) of 1,11-diamino-3,6,9-trioxaundecane and 42 g (250 mmol) of hexamethylene diisocyanate and stirred. The liquid temperature was raised from room temperature to 50 ° C. over 1 hour. Thereafter, a small amount was sampled, FT-IR was measured, and stirring was continued at 50 ° C. while confirming the absorption of isocyanate near 2300 cm ⁻¹ . The content of residual isocyanate groups was calculated from the absorption area of FT-IR, and the reaction was terminated when it decreased to about 15% compared to before the reaction and disappeared, and a colorless transparent viscous liquid was obtained. This is designated as UP-2. UP-2 is a urea-containing binding compound having a molecular weight of about 2000 and an isocyanate group at the end.

(C) Photopolymerization initiator / HCHPK: 1-hydroxy hexyl phenyl ketone

  The following evaluation was performed about the composition of the sealing agent of an Example and a comparative example. An evaluation result is combined with Table 1 and Table 2, and is shown.

(1) Curability The curability was measured using an instrument simulating a liquid crystal panel. That is, as shown in FIGS. 1 (a) and 1 (b), a sealing frame 10 is attached to the surface of the first glass slide 11 using a sealing tape 10, and the sealing agent composition 1 is applied to the inside of the frame. Worked. The second slide glass 12 was placed on the sealant so that the composition 1 of the sealant was sandwiched between the two slide glasses 11 and 12. The distance between the two slide glasses 11 and 12 was set to 0.2 mm. Further, a light shielding material 13 made of a strip-shaped black resin having a width of 1 mm is placed on the upper surface of the second glass slide 12, and further 100mW / cm ² of ultraviolet rays is irradiated from the upper surface for 30 seconds to cure the composition 1 of the sealing agent. I let you. Then, the light shielding object 13 and the slide glass 12 on the upper surface were removed, and curing unevenness and curing reaction rate were evaluated by the following methods.

<Hardening unevenness>
Curing of the irradiated part and the non-irradiated part (the part on which the light shielding material was placed) was confirmed by touch, and the unevenness of curing was evaluated according to the following criteria.
A: There is no curing unevenness. O: There is almost no curing unevenness. X: Curing unevenness was confirmed.

<Curing reaction rate>
The curing reaction rate of the non-irradiated part on which the light shield was placed was measured. The curing reaction rate was calculated by the FT-IR method. Note the calculation of the curing reaction rate is performed based on the residual acrylic groups unreacted, as shown in FIG. 2, with a peak area Aa around 810 cm ^-1 for quantitation of acrylic group, the peak area of the 775cm ^-1 Aa / Ab was calculated with reference peak area Ab, and the curing reaction rate was calculated by comparing with Aa / Ab ratio of 0% curing and 100% curing measured in advance, and evaluated according to the following criteria: .
A: Acrylic group reaction rate of 95% or more B: Acrylic group reaction rate of 90% or more and less than 95% Δ: Acrylic group reaction rate of 80% or more and less than 90% X: Acrylic group reaction rate of less than 80%

(2) Adhesiveness The composition of each sealing agent obtained in Examples and Comparative Examples is sandwiched between two glass slides used in FIG. 1, and 100 mW / cm ² ultraviolet rays are used without a light shielding plate. Irradiation for 30 seconds gave an adhesion test piece. About the obtained adhesion test piece, adhesive strength was measured using the tension gauge, and the following references | standards evaluated.
◎: Adhesive strength is 2000 N / m or more ○: Adhesive strength is 1500 N / m or more and less than 2000 N / m Δ: Adhesive strength is 1000 N / m or more and less than 1500 N / m ×: Adhesive strength is less than 1000 N / m

<Evaluation results>
In the examples, the unevenness of curing, the curing reaction rate, and the adhesiveness are all good, and it can be seen that the curing of the portion that is not exposed to light, which is a problem at the time of FPD creation, is sufficiently achieved only by light irradiation. Therefore, this embodiment can be used as a sealant with high adhesive strength only by light irradiation, and the non-light-irradiated part caused by shadows such as substrates and wirings can also be cured, so that a sealing material that causes display unevenness It is possible to prevent elution of the cured material into the inside.

  On the other hand, in the comparative example, the presence of a portion where the curing reaction was insufficient and the adhesiveness were insufficient, and the function as a sealing agent could not be achieved only by light irradiation.

  Although the embodiments of the present invention have been described in detail above, the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the gist of the present invention.

DESCRIPTION OF SYMBOLS 1 Composition of sealing agent 11 First glass slide 12 Second glass slide 13 Light shielding material

Claims (7)

A sealing agent composed of a curable resin composition not containing a thermosetting agent and used for sealing a display element,
The curable resin composition contains a chain transfer agent,
The chain transfer agent includes a compound containing at least one selected from urethane bonds, urea bonds and isocyanate groups as component (a) and a metal-containing compound as component (b). Sealant for display elements.
  2. The display element seal according to claim 1, wherein the component (b) of the chain transfer agent is a metal compound containing at least one metal selected from tin, copper, zinc, cobalt, and nickel. Agent.   The sealant for a display element according to claim 1 or 2, wherein the content of the chain transfer agent contained in the sealant is 20 to 80% by mass with respect to the total mass of the sealant.   The said sealing agent contains a photocurable monomer, and content of the photocurable monomer contained in the said sealing agent is 20-80 mass% with respect to the whole mass of a sealing agent, The 1st characterized by the above-mentioned. The sealing agent for display elements of any one of -3.   The sealant for a display element according to claim 4, wherein the photocurable monomer is a compound having at least one hydroxyl group in the molecule.   A display using the sealing agent according to any one of claims 1 to 5 as a sealing agent for a sealing material of a display element, and preventing contamination of the sealing material with the sealing agent. Device manufacturing method.   The sealing agent according to any one of claims 1 to 5 is used as a sealing agent for a sealing material of a display element, and can prevent contamination of the sealing material with the sealing agent. Display element to be used.