TWI471351B - Sealing agent for liquid-crystal-one-drop-filling process and method for manufacturing liquid crystal display - Google Patents

Description

Sealant for liquid crystal dropping process and method for manufacturing liquid crystal display

The present invention relates to a method of manufacturing a liquid crystal display by means of a liquid crystal dropping process, and in particular to a manufacturing method in which a main seal is formed on the outer periphery of a substrate by using a sealant used in combination with photocuring and heat curing. The invention also relates to a sealant for use therewith.

In a conventional method of assembling a liquid crystal display (hereinafter also referred to as LCD) having a relatively small size, two transparent substrates with electrodes are opposed to each other at a given distance, and a periphery thereof is bonded with a sealant to form a unit. The liquid crystal inlet formed at a portion of the periphery introduces liquid crystal into the unit, and finally the sealant seals the entrance of the liquid crystal to manufacture the LCD.

In recent years, with the gradual penetration of large-sized LCDs, the above-described manufacturing method has caused various problems, for example, low productivity due to the extremely long time required for liquid crystal injection.

Previously, a method of manufacturing an LCD called a liquid crystal dropping process (ODF process) has been studied and put into practical use as an efficient method for manufacturing a large-sized LCD. In this process, a rectangular pattern seal is first formed by screen printing and the like on one of two transparent substrates with electrodes. Then, the liquid crystal droplets were dropped into the sealing frame on the transparent substrate, but the sealing agent was not cured. Another transparent substrate was placed thereon, and then the sealant was cured to manufacture an LCD. Low-voltage laminate substrates for efficient LCD manufacturing.

The sealant used in the liquid crystal dropping process is usually a UV curing type or a UV-thermal combination curing type (JP-A-2001-133, 794 (Patent Document 1), JP-A-2006-23, 580 (Patent Document 2), JP- A-2006-23,581 (Patent Document 3), JP-A-2006-23,582 (Patent Document 4), and the like. In the UV-thermal combination curing type application, after the two substrates are placed opposite each other, the sealant is cured to a degree that does not move by short-time UV irradiation, and then further heating is performed to thermally cure the seal. The agent is used to achieve the final strength, so it is considered to be more advantageous.

However, the UV-curable and UV-thermal combination-curing sealants contain a photopolymerization initiator. The residual photoinitiator which is not decomposed during UV irradiation and the material which is decomposed by UV irradiation are in contact with the liquid crystal material, which adversely affects the liquid crystal. The patent documents described above state that the use of a polymerization initiator having an acrylic group can reduce the residual amount (for example, Patent Document 2, paragraphs 0022 to 0024). However, it is believed that photo-fragmentation must produce a decomposing material because the molecule contains a photo-fragmentation site and an acrylic group.

On the other hand, a thermosetting binder and a sealant comprising a maleic imine compound are known to be a curing system which does not require the use of a photopolymerization initiator (see, for example, WO 2003/082,940 (Patent Document 5), WO 2003/107,427 (Patent Document 6), JP-A-2005-532, 678}.

JP-A-2002-338946 (Patent Document 7) discloses a (meth) acrylate-containing oligomer and a maleimide, as an application for a liquid crystal application, which comprises a composition of a maleimide compound. A sealant of a derivative, and JP-A-2003-34708 (Patent Document 8) discloses a resin composition containing an epoxy resin and a maleimide-containing carboxylic acid. However, these are used to form an encapsulant having an empty cell of "liquid crystal inlet", and the application of the liquid crystal dropping process (ODF process) is not explained. JP-A-2005-2015 (Patent Document 9) has proposed a composition containing a maleic imine compound which is derived from a bisphenol-S as a sealing compound for a liquid crystal dropping process (ODF process). section. Further, Patent Document 9 has pointed out the possibility that if the conventional sealant of Patent Document 8 is used as a sealant for the ODF process, the maleic imine compound and other polymerizable components may be eluted.

As described above, only a sealant containing a special maleimide compound as a UV-heat combination curing type sealant is known, which is suitable for an ODF process, and does not require a photopolymerization initiator.

document list

Patent Document 1: JP-A-2001-133, 794

Patent Document 2: JP-A-2006-23, 580

Patent Document 3: JP-A-2006-23, 581

Patent Document 4: JP-A-2006-23,582

Patent Document 5: WO2003/082,940

Patent Document 6: WO2003/107,427

Patent Document 7: JP-2002-338946

Patent Document 8: JP-A-2003-34708

Patent Document 9: JP-A-2005-2015

An object of the present invention is to provide a method for manufacturing an LCD by photo-thermal combination curing of a resin by a liquid crystal dropping process which does not adversely affect liquid crystals and which can manufacture an LCD having excellent long-term durability and high precision.

The present invention relates to the following items.

A sealant for manufacturing a liquid crystal display by a liquid crystal dropping process, wherein the sealant comprises at least a maleimide compound and does not contain a photoinitiator; and wherein the sealant can be irradiated by light It is temporarily cured and can be cured by heating to a final cured state after the irradiation of the light.

2. The sealant of item 1 above, which additionally comprises an epoxy resin and a latent epoxy hardener.

3. The sealant according to any one of the above items 1 or 2, which further comprises an additive selected from the group consisting of a filler, a thixotropic agent and a decane coupling agent.

4. The sealant of any one of clauses 2 or 3, wherein the epoxy resin is selected from the group consisting of bisphenol epoxy resins, novolac epoxy resins, and biphenyl epoxy resins.

5. The sealant of any of items 2 to 4 above, wherein the latent epoxy hardener is selected from the group consisting of diterpenoids.

The sealant according to any one of the above items 1 to 5, wherein the maleimide compound is selected from the group consisting of stearin, maleimide, oleyl maleimide, and behenyl A group consisting of quinone imine and 1,10-dimaleimide derivatives of 10,11-dioctylicocosane and combinations thereof.

7. A method of fabricating a liquid crystal display by means of a liquid crystal dropping process, the liquid crystal display having a liquid crystal layer between a first substrate and a second substrate, the method comprising the steps of:

(a) applying a sealant according to any one of the above items 1 to 6 on a sealing region on the outer periphery of the surface of the first substrate;

(b) dropping liquid crystal on a central region surrounded by the sealing region of the surface of the first substrate;

(c) covering the second substrate on the first substrate;

(d) performing temporary fixation by irradiating the sealant with light; and

(e) Final fixing is carried out by heating the sealant.

8. A liquid crystal display having a liquid crystal layer between a first substrate and a second substrate, wherein the liquid crystal display is manufactured by a liquid crystal dropping process, wherein the liquid crystal display is by any one of the above items 1 to 6 The cured product of the sealant is sealed.

The use of the sealant of the present invention for a liquid crystal dropping process allows the manufacture of an LCD that does not move while maintaining precise positioning without adversely affecting the liquid crystal. Then, the manufactured LCD has excellent durability and reliability in its sealed region.

The manufacturing method of the present invention generally comprises the following steps:

(a) applying a liquid sealant on the sealing area on the outer periphery of the surface of the first substrate;

(b) dropping a liquid crystal on a central region surrounded by a sealing region on the surface of the substrate;

(c) covering the second substrate on the first substrate;

(d) performing temporary fixation by irradiating the sealant with light; and

(e) Final fixing is carried out by heating the sealant.

The first substrate and the second substrate used in the present invention are generally transparent glass substrates. Generally, a transparent electrode, an active matrix element (for example, a TFT), an alignment film, a color filter, and the like are formed on at least one opposing surface of two substrates. These configurations can be modified depending on the type of LCD. I believe that the manufacturing method of the present invention can be applied to any type of LCD.

In the step (a), a sealant is applied to the outer peripheral portion of the first substrate surface (opposing surface of the other substrate) of one of the substrates so as to surround the substrate periphery along the shape of the frame. As described herein, the portion of the sealant applied along the shape of the frame is referred to as a sealed region. At this point, the sealant is a fluid so that it can and can be applied by known methods (eg, screen printing and dispensing).

In the step (b), the liquid crystal is then dropped onto the central region surrounded by the sealing region of the frame shape on the surface of the first substrate. This step is preferably carried out at a low pressure.

In step (c), the second substrate is then placed on the first substrate and subjected to light irradiation in step (d). By the irradiation of the light, the sealant can be temporarily cured and exhibiting its strength to such an extent that it does not move by hand, whereby the two substrates can be temporarily fixed.

In the light irradiation of step (d), at least the sealant may be exposed and it is not necessary to irradiate the entire substrate. Generally, the irradiation time is preferably shorter, for example, no longer than 5 minutes, preferably no longer than 3 minutes, and even more preferably no longer than 1 minute.

In step (e), the encapsulant is heated such that the encapsulant achieves a final cure strength (final cure) whereby the two substrates can be finally secured.

The thermal curing in step (e) is typically carried out according to a heating profile comprising a maximum temperature of preferably up to 150 ° C, and more preferably up to 130 ° C. The heating time can be arbitrarily selected, for example, no longer than 3 hours, preferably no longer than 2 hours, still preferably no longer than 1.5 hours (usually 1 hour). The heating device is not particularly limited, and may be a heating device capable of accommodating a temporarily fixed substrate therein.

Through the above process, the main part of the LCD panel is completed.

Next, the sealant to be used in the present invention will be explained. The encapsulant is characterized by comprising at least a maleimide compound and no photoinitiator. In a preferred embodiment of the invention, the encapsulant additionally comprises a thermosetting resin, particularly preferably an epoxy resin and a latent epoxy hardener that cures the epoxy resin. The sealant may additionally contain a (meth) acrylate compound or may not additionally comprise the compound. Satisfactory properties can be achieved even without the (meth) acrylate compound.

The "photoinitiator" as defined in the present invention includes a photoinitiator which is generally used for photopolymerization. The maleimide compound does not mean a photoinitiator. The "photoinitiator" also does not include ordinary (meth) acrylate compounds which can be used as optional components in the present invention. However, the "photoinitiator" includes a compound having a group moiety capable of generating a group other than a (meth) acrylate group even if it has a (meth) acrylate group (ie, (meth) propylene oxime) The same is true for the base. Specifically, a compound having a benzoin (ether) structure and an acrylate group (propylene oxy) is a "photoinitiator" as described in, for example, JP-A-2006-23580. It is speculated that the compound can even produce a decomposition product by performing cutting at the site where the group is generated.

In the present invention, the maleimide compound has a function of initiating polymerization by light irradiation, particularly UV irradiation, and it can be polymerized by itself. The maleimide compound also functions to polymerize (copolymerize) a (meth) acrylate compound when a (meth) acrylate compound is present. The portion that is not reacted during the irradiation of light can be finally cured upon heating.

The maleic imine compound has one or more, preferably one or two substructures represented by part (I) in its molecule: R ¹ and R ² represent H or an alkyl group having 1 to 6 carbons, or R ¹ and R ² together represent an alkylene group having 2 to 6 carbons. Preferably, both R ¹ and R ² represent H, or R ¹ and R ² together represent 1,4-tert-butyl.

The maleic imine compound used in the present invention does not have a moiety derived from bisphenol-S (i.e., a phenyl-SO ₂ -phenyl structure).

The maleimide compound is preferably liquid at room temperature, and thus the moiety (I) is bonded to a group which renders the maleimide compound liquid, for example, comprising a sufficient length and a branch to make the horse The imine compound is a liquid organic group having a branched alkyl group, an alkylene group, an alkylene oxide group, an alkylene group carboxyl group or an alkylamine structure. The maleimide compound may comprise one or two or more substructures (I). A compound having two such groups is a bismaleimide compound. Further, if the sealant becomes a liquid when it is mixed with other maleidin compound or mixed with other components, it can be used even if the maleimide compound is not a liquid.

The maleimide compound in which part (I) is bonded to an alkyl group or an alkyl group (the group may include a double bond and a saturated alicyclic ring) includes the following compounds.

Particularly preferably, including stearin, maleimide, oil-based maleimide, behenyl maleimide, and 1,11-dioctylicosane 1,20-double horse The imine derivatives and combinations thereof. The 1,20-dimaleimide derivative of 10,11-dioctylicosane is commercially available from Henkel under the name X-BMI and can be cited by reference to US 5,973,166 (U.S. Pat. The process described in the specification is synthesized from 1,20-diamino-10,11-dioctylicosane and/or its cyclic isomeric diamine. X-BMI contains 1,20-bismaleimide-10,11-dioctyl-icosane (compound represented by formula (X-1)), 1-heptyl-maleimide -2- octyl madameimine-4-octyl-5-heptylcyclohexane (compound represented by formula (X-2)), 1,2-di-extension imajino One, two or more of amino-3-octyl-4-hexylcyclohexane (a compound represented by the formula (X-3)) and the like. Preferably, the bismaleimide compound represented by the formulae (X-1) to (X-3) can also be used alone.

The maleimide compound in which a part (I) is bonded to a group having an alkylene oxide structure includes the following compounds.

In the formula, R is an alkyl group, preferably an extended ethyl group or a 1,2-extended propyl group, and n is an integer of from 2 to about 40. Preferably, the value and distribution of n are selected such that This compound is shown as a liquid. This compound is commercially available from LUMICURE (registered trademark) MIA200 manufactured by DIC Corporation.

Other examples of useful maleimide compounds include compounds of the formula: (3,4,5,6-tetrahydrophthalic acid imine ethyl acrylate).

The content ratio of the maleimide compound in the sealant can be defined in a wide range, and the maleimide compound can be present in a ratio of 0.1 wt% to 100 wt% throughout the sealant. Even a small amount enables the sealant to be cured (temporarily cured), and the incorporation of a photocurable monomer such as a (meth) acrylate compound generally lowers the ratio. The content ratio of the maleimide compound is preferably not less than 0.5% by weight, more preferably not less than 1% by weight. Although it can be cured even when the content ratio of the maleimide compound is 100 wt%, the ratio is generally less than 100 wt% because the sealant usually contains a filler and the like. When other resins are contained, the sealant preferably contains not more than 90% by weight of the maleimide compound, for example, if it contains a thermosetting resin such as an epoxy resin and/or a photopolymerizable resin such as (meth) acrylate That's it.

In terms of seal strength and the like, the sealant of the present invention may preferably comprise a thermosetting resin, particularly preferably an epoxy resin, in addition to the maleimide compound.

The epoxy resin contained in the sealant preferably contains an epoxy resin having an aromatic ring as a main component, and it is specifically 50% by weight or more, more preferably in the epoxy resin component. 70% or more, and particularly preferably 90% or more, and even 100% is also preferred. If necessary, it may contain an epoxy resin without an aromatic ring.

The aromatic ring-containing epoxy resin includes a bisphenol type epoxy resin, for example, a bisphenol-A type epoxy resin, a bisphenol-F type epoxy resin, and a bisphenol-S type epoxy resin; a novolac type epoxy resin, For example, a phenol-phenolic novolac type epoxy resin and a cresol-phenolic novolac type epoxy resin; and a biphenyl type epoxy resin, for example, a product name YX4000 manufactured by Japan Epoxy Resin Co., Ltd. The aromatic ring-containing epoxy resin generally has one or more epoxy groups in its molecule, and an epoxy equivalent of the resin may be selected as appropriate.

The aromatic ring-free epoxy resin includes an alicyclic epoxy resin having an epoxy group and having a ring deformation in the molecule (for example, an epoxycyclohexane structure and an epoxycyclopentane structure) (for example, by the following formula ( 1) to the compound represented by (5): Hydrogenated bisphenol type epoxy resins (the benzene rings of which are bisphenol type epoxy resins such as bisphenol-A type epoxy resin, bisphenol-F type epoxy resin, and bisphenol-S type epoxy resin) Hydrogenated); dicyclopentadiene type epoxy resin such as dicyclopentadiene phenol novolac glycidyl ether; such as cyclohexane dimethanol diglycidyl ether, butyl glycidyl ether, 2-ethylhexyl An aliphatic alkyl mono or diglycidyl ether such as glycidyl ether or allyl glycidyl ether; alkyl glycidyl esters such as glycidyl methacrylate and tricarboxylic acid glycidyl ester; styrene oxide; such as benzene An aromatic alkyl monoglycidyl ether such as glycidyl ether, cresyl glycidyl ether, p-second-butylphenyl glycidyl ether, and nonylphenyl glycidyl ether; and tetrahydrofurfuryl glycidyl ether.

The epoxy resin component may also contain other known diluents.

The latent epoxy hardener to be used in the present invention cures the epoxy resin upon heating. The latent hardener may be one or more potential hardeners suitably selected from commercially available latent hardeners, and the amount of latent hardener to be added is preferably determined after considering the epoxy equivalent of the epoxy resin.

In particular, the latent curing agent to be preferably used in the present invention is preferably a thermosetting latent curing agent, and includes an amine-based compound hardener, a fine powder-modified amino group, and a modified imidazole-based latent curing agent. Modified amine-based and modified imidazolium-based latent hardeners include core-shell type hardeners in which the amine compound (or amine adduct) core is coated with a modified amine product (surface addition and the like) and a masterbatch type A shell of a hardener, which is a blend of a core-shell type hardener and an epoxy resin.

Examples of the amine compound hardener include aromatic primary amines such as diaminodiphenylmethane and diaminodiphenyl hydrazine; imidazoles such as 2-heptadecylimidazole, trimellitic acid 1-cyanoethyl-2 -undecyl imidazolium, 2,4-diamino-6-[2-methylimidazolyl-(1)]-ethyl-S-triazine, 1-dodecyl-2-chloride Methyl-3-benzylimidazolium, 2-phenylimidazolium isocyanurate, 2-phenyl-4-methyl-5-hydroxymethylimidazole; boron trifluoride-amine complex; dicyandiamide Amine derivatives such as dicyandiamide, o-methylphenyl biguanide and α-2,5-methyl biguanide; organic acid hydrazines such as carbonium, bismuth succinate, dioxane adipate, hydrazine Dioxalate dihydrate, dioxonium dodecanoate and dioxonium isophthalate; and diaminomaleonitrile and its derivatives; and melamine derivatives such as melamine and diallyl melamine.

The modified amine-based latent curing agent is obtained by finely pulverizing an amine compound with a solid reaction product of an epoxy compound, an isocyanate compound or a urea compound. The modified imidazole-based latent curing agent is obtained by finely pulverizing a solid reaction product generally obtained by an addition reaction of an imidazole compound and an epoxy compound.

Representative commercially available modified amine-based latent curing agents include, for example, "Adeca hardener EH-3615S" (trademark of Adeka), "Adeca hardener EH-4070S" (trademark of Adeka), and "Adeca hardener EH-4357S" (Adeka brand), "Ajicure MY-24" (trademark of Ajinomoto), "FujiCureFXE-1000" (trademark of Fuji Chemicals Co., Ltd.), "FujiCureFXR-1036" (trademark of Fuji Chemicals Co., Ltd.), Aradur 939 (Huntsman Advanced) Materials company logo) and the like.

Representative commercially available modified imidazolium-based latent curing agents include "Adeca hardener EH-3293S" (trademark of ADEKA), "Adeca hardener EH-4344S" (trademark of ADEKA), and "Ajicure PN-23" (trademark of Ajinomoto) ), "Cureduct P-505" (trademark of Shikoku Chemicals Co., Ltd.) and "Sanmide LH-210" (trademark of Air Products and Chemicals).

Further, the core-shell type hardener is one in which the amine compound (or amine adduct) core surface is further subjected to, for example, an acid compound (for example, a carboxylic acid compound and a sulfonic acid compound), an isocyanate compound, and an epoxy compound. The treatment forms a modified product (adduct or the like) on the surface thereof. Further, the masterbatch type hardener is a blend of a core-shell type hardener and an epoxy resin.

Commercially available masterbatch type hardeners include, for example, "Novacure HX-3722" (trademark of Asahi Kasei Epoxy Co., Ltd.), "Novacure HX-3742" (trademark of Asahi Kasei Epoxy Co., Ltd.), and "Novacure HX-3613" (Asahi Kasei Epoxy Co., Ltd.) Trademarks) and the like.

Among the above-mentioned latent hardeners in the present invention, an organic acid lanthanum is preferred. The organic acid bismuth can be arbitrarily selected by considering the melting point and the like.

The ratio of epoxy resin to latent hardener can be suitably selected depending on the type of latent hardener. For example, for 100 parts by weight of the epoxy resin, the amount of the latent hardener is from 0.5 to 500 parts by weight, preferably from 2 to 200 parts by weight.

The content ratio of the epoxy resin can be arbitrarily set, for example, from 0 to 98% by weight, preferably from 10 to 90% by weight based on the total weight of the sealant. The ratio of the epoxy resin to the maleimide compound is from 0 to 980 times, preferably from 0.1 to about 100 times, by weight.

The sealant of the present invention may optionally contain a photopolymerizable component such as a (meth) acrylate compound and/or a vinyl ether compound. However, it is also preferred that the sealant does not contain such compounds.

In particular, (meth) acrylates include, for example, methyl methacrylate, tetrahydrofurfuryl methacrylate, benzyl methacrylate, isodecyl (meth)acrylate, (methyl) 2-hydroxyethyl acrylate, glycidyl ether (meth) acrylate, (poly)ethylene glycol di(meth) acrylate, 1,4-butanediol di(meth) acrylate, 1,6 - hexanediol dimethacrylate, trimethylolpropane tri(meth) acrylate, pentaerythritol tri(meth) acrylate, glycerol di(meth) acrylate, and the like. Here, as used conventionally, "(meth)acrylate" means both a methacrylate and an acrylate.

Further, the epoxy (meth) acrylate is preferably also used as an acrylate compound, and includes, for example, a ring derived from an epoxy resin (for example, bisphenol-A type epoxy resin) and propylene glycol diglycidyl ether. Oxy (meth) acrylate and (meth) acrylic acid.

The blending ratio of the photopolymerizable component (for example, a (meth) acrylate compound and/or a vinyl ether compound) can be arbitrarily set, preferably not more than 90% by weight, more preferably not more than 70% by weight based on the total weight of the sealant. %. When the component is contained, it preferably contains, for example, not less than 3% by weight. Further, the ratio of the photopolymerizable component to the maleimide compound is 0 to 900 times, preferably not more than 100 times, more preferably not more than 20 times by weight. When the component is contained, it preferably contains not less than 0.1 times by weight based on the weight ratio of the maleimide compound. However, in a preferred aspect of the invention, the sealant comprises a maleic imide compound and preferably an epoxy resin, and preferably does not contain other photopolymerizable components, such as (meth)acrylate compounds and/or Vinyl ether compound.

The sealant may additionally contain additives, resin components, and the like to improve or change properties such as fluidity, application properties, corrosion resistance properties, curing properties, and physical properties after curing.

The components which may be contained in the composition may include, for example, organic or inorganic fillers, thixotropic agents, decane coupling agents, diluents, modifiers, colorants (for example, pigments and dyes), and surfactants. Preservatives - stabilizers, plasticizers, lubricants, defoamers, leveling agents, and the like; however, are not limited to such components. Specifically, the composition preferably comprises an additive selected from the group consisting of a filler, a thixotropic agent, and a decane coupling agent.

The filler includes (without particular limitation), for example, an inorganic filler such as cerium oxide, diatomaceous earth, alumina, zinc oxide, iron oxide, magnesium oxide, tin oxide, titanium oxide, magnesium hydroxide, aluminum hydroxide, carbonic acid Magnesium, barium sulfate, gypsum, calcium citrate, talc, glass beads, sericite-activated clay, bentonite, aluminum nitride, tantalum nitride, and the like.

The thixotropic agent includes (without particular limitation) (for example) talc, fine particle cerium oxide, ultrafine surface treated calcium carbonate, fine alumina, platy alumina; layered compound such as montmorillonite; Needle-like compounds such as aluminum borate whiskers and the like. Among them, talc, fine cerium oxide, fine alumina, and the like are preferred.

The decane coupling agent includes, but is not particularly limited to, γ-aminopropyltriethoxydecane, γ-mercaptopropyltrimethoxydecane, γ-methacryloxypropyltrimethoxydecane, γ-glycidol Oxypropyltrimethoxydecane, SH6062, SZ6030 (mainly manufactured by Toray-Dow Corning Silicone Co., Ltd.), KBE903, KBM803 (mainly manufactured by Shin-Etsu Silicone Co., Ltd.), and the like.

The sealant of the present invention obtained above can be temporarily cured by irradiation of light having a UV irradiation energy of not more than 5,000 mJ/cm ² , preferably not more than 2,000 mJ/cm ² , followed by final curing by heating. Therefore, the sealant of the present invention can be adapted to manufacture a liquid crystal display by means of a liquid crystal dropping process.

Further, the sealant of the present invention is a liquid at an application temperature, preferably an ambient temperature (working ambient temperature), and the material to be formulated, especially all resin materials, is not necessarily a liquid.

As described above, the sealant of the present invention is less likely to cause contamination of the liquid crystal because the sealant does not contain a photoinitiator, so that no decomposition material or the like is produced. As shown in the working examples, the decomposition material and the like can be evaluated using the amount of gas (degassing) generated from the sealant at the time of curing.

The sealant to be used in the present invention can also be used in other applications than the liquid crystal dropping process, in which accurate assembly without movement is required.

Instance

<Evaluation of sealing properties>

The materials shown in Table 1 were thoroughly mixed by means of a three-roll mill, and 1 wt% of 5 μm spacers were further mixed to give the sealants of Examples 1 to 4 and Comparative Examples 1 to 3. 2 mg of the obtained sealant was applied to the periphery of the glass substrate of 2 cm × 7 cm size by a dispenser in the shape of a frame. Approximately 7 mg of liquid crystal material was dropped around the center of the glass substrate and allowed to completely degas in a vacuum. Cover another glass substrate and adjust its position. The two sealed substrates were placed in a UV irradiation apparatus (100 mW/cm ² ) and irradiated with UV for 10 seconds. After the UV irradiation, an external force was applied to confirm whether the glass substrate was moved and the quality of the temporary fixation achieved by the UV irradiation was evaluated. It has been confirmed that good fixation can be achieved in the examples of the present invention.

Further, after UV irradiation, the glass substrate was placed in an oven at 120 ° C for 1 hour to complete the manufacture of the dummy liquid crystal cell. The completed liquid crystal cell is visually inspected to confirm the conditions of the liquid crystal cell (there are cracks and the like), the maintenance of the sealed form, and the like. Good conditions for sealing have been demonstrated in the examples of the invention. Table 1 shows the results of the sealants of Examples 1 to 4 and Comparative Examples 1 to 3 together.

<Evaluation of degassing generation>

The sealed doses of 100 mg working examples and comparative examples were measured in glass vials and capped, and then irradiated with 100 mW/cm ² UV irradiation for 30 seconds, the bottles were placed in JEOL Co., Ltd. The gas chromatography mass spectrometer JMS-AM II 120 was heated at 120 ° C for 1 hour. The generated gas is automatically collected and subjected to quantitative analysis.

Table 1 shows the results.

In the table:

- the blending values are in wt%,

-ZX-1059: Made of Tohto Kasei Co., Ltd. blended with bisphenol-A and -F epoxy resins,

-EP828US: bisphenol-A epoxy resin manufactured by Epoxy Resins Co., Ltd., Japan.

-X-BMI: a bismaleimide resin manufactured by Henkel Corporation,

-Lumicure MIA-200: Bismaleimide resin manufactured by DIC Corporation,

-Ajicure VDH-J: 1,3-bis(decylcarbonylethyl)-isopropylhydantoin, a dimercapto epoxy curing agent manufactured by Ajinomoto Fine-Techno Co., Ltd., and

- Uvacure 1561: epoxy acrylate manufactured by Cytek Surface Specialties; acrylate of bisphenol-A epoxy resin.

It is apparent from Table 1 that the sealants of the examples do not produce gas and the fixation and final sealing after UV irradiation are satisfactory. Further, as shown in Examples 1 and 2, even a sealant which does not contain a photopolymerizable component other than the maleimide compound (for example, (meth) acrylate) can be well fixed after UV irradiation. .

Numerous modifications may be made without departing from the spirit and scope of the invention. Therefore, the embodiments illustrated herein are by way of example, and are not intended to limit the scope of the invention as claimed.

Industrial applicability

The use of the sealant of the present invention for a liquid crystal dropping process allows the manufacture of an LCD that does not move while maintaining precise positioning without adversely affecting the liquid crystal. The manufactured LCD has excellent durability and reliability in its sealed area. Accordingly, the present invention can be used as a sealant in a method for fabricating an LCD.

Claims (7)

A sealant for manufacturing a liquid crystal display by a liquid crystal dropping process, wherein the sealant comprises at least a maleic imine compound and does not contain a photoinitiator and a (meth) acrylate compound, wherein the Malay The quinone imine compound is selected from the group consisting of stearin, maleic imine, oleyl maleimide, behenyl maleimide, and 10,11-dioctylhexadecane 1,20- a group of bismaleimide derivatives and combinations thereof; and wherein the sealant is temporarily cured by light irradiation and can be cured by heating to a final cured state after the light irradiation. The sealant of claim 1 additionally comprising an epoxy resin and a latent epoxy hardener. The sealant of claim 1 or 2, which additionally comprises an additive selected from the group consisting of a filler, a thixotropic agent, and a decane coupling agent. The sealant of claim 2, wherein the epoxy resin is selected from the group consisting of bisphenol epoxy resins, novolac epoxy resins, and biphenyl epoxy resins. The sealant of claim 2, wherein the latent epoxy hardener is selected from the group consisting of diterpene organic acids. A method for manufacturing a liquid crystal display by a liquid crystal dropping process, the liquid crystal display having a liquid crystal layer between a first substrate and a second substrate, the method comprising the steps of: (a) applying a sealing region on an outer circumference of the surface of the first substrate a sealant as claimed in claim 1 or 2; (b) in a central region surrounded by a sealed area of the surface of the first substrate (c) covering the second substrate on the first substrate; (d) performing temporary fixation by irradiating the sealant with light; and (e) performing by heating the sealant Finally fixed. A liquid crystal display having a liquid crystal layer between a first substrate and a second substrate, wherein the liquid crystal display is manufactured by a liquid crystal dropping process, wherein the liquid crystal display is performed by a cured product of the sealant of claim 1 or 2. seal.