WO2021177111A1 - Sealing agent for liquid crystal dropping methods and method for producing liquid crystal display panel - Google Patents

Abstract

The present invention addresses the problem of providing: a sealing agent for liquid crystal dropping methods, said sealing agent being able to be suited to frame narrowing of a liquid crystal display panel and being capable of forming a sealing member that exhibits high bonding strength to a substrate, while being not likely to be dissolved in liquid crystals; and a method for producing a liquid crystal display panel.　A sealing agent for liquid crystal dropping methods, by which the above-described problem is solved, contains an epoxy compound that does not have a polymerizable functional group other than an epoxy group, a (meth)acryl/epoxy-containing compound that has both a (meth)acryl group and an epoxy group in each molecule, a (meth)acrylic compound that does not have an epoxy group, a thermal curing agent and a photopolymerization initiator; and the content of the epoxy compound is from 22 to 38% by mass. The residual DC value as measured in 30 seconds after heating a mixture, in which the sealing agent for liquid crystal dropping methods and liquid crystals are mixed at a mass ratio of 1:10, at 120°C for one hour, applying a voltage thereto at 5V for one second, and short-circuiting for 0.1 second is 200% or less of the residual DC value as measured using only the liquid crystals.

Description

Manufacturing method of sealant for liquid crystal dropping method and liquid crystal display panel

The present invention relates to a sealant for a liquid crystal dropping method and a method for manufacturing a liquid crystal display panel.

When manufacturing a liquid crystal display panel by the liquid crystal dropping method, a liquid crystal sealant is applied to form a seal pattern. Then, the liquid crystal is dropped onto the substrate on which the seal pattern is formed or the substrate that is paired with the seal pattern, and the liquid crystals are bonded together in a vacuum. After that, the seal pattern is cured by UV irradiation or heating to form a seal member. However, in this method, since the liquid crystal sealant is dropped in the uncured state, impurities and small molecule components in the liquid crystal sealant may be eluted into the liquid crystal sealant. Then, when the small molecule component or the like elutes into the liquid crystal display, a display defect called an afterimage is likely to occur on the liquid crystal display panel.

Here, the conventional liquid crystal sealant often contains a UV-curable (meth) acrylic compound and a thermosetting epoxy compound. And the epoxy compound is usually not cured by UV curing. Therefore, the seal pattern after UV curing still contains a large amount of low molecular weight epoxy compounds. Then, when the seal pattern was heated for thermosetting, the liquid crystal phase transitioned due to the heat, and the epoxy compound in the seal pattern was easily eluted into the liquid crystal.

Therefore, it has been proposed to use a compound having a (meth) acrylic group and an epoxy group in one molecule to suppress elution of the epoxy compound into a liquid crystal while ensuring UV curability and thermosetting property. (For example, Patent Document 1). It has also been proposed to suppress the elution of the epoxy compound into the liquid crystal display by using a crystalline epoxy compound having a melting point of 50 ° C. or higher (Patent Document 2).

Japanese Unexamined Patent Publication No. 2015-28184 Japanese Unexamined Patent Publication No. 2006-23583

Here, in recent years, it has been required to increase the liquid crystal display area of the liquid crystal display panel and narrow the width of the area surrounding the liquid crystal display area (hereinafter, also referred to as "narrowing the frame"). In order to realize a narrow frame, it is also indispensable to narrow the width of the seal member. However, with the conventional seal member, if the width is narrowed, the adhesive strength tends to be insufficient, peeling occurs at the interface between the substrate and the seal member, and the liquid crystal display tends to exude.

In addition, the epoxy group contained in the epoxy compound or the like greatly contributes to the adhesive strength between the sealing member and the substrate. In the technique described in Patent Document 1 described above, a compound having an epoxy group is polymerized by UV curing. Therefore, the epoxy group is difficult to move freely during thermosetting, and the epoxy group cannot sufficiently contribute to the bond with the substrate. On the other hand, in the technique described in Patent Document 2, it is difficult to include a large amount of epoxy compound having a high melting point in the liquid crystal sealant because the viscosity of the liquid crystal sealant increases. Therefore, it has been difficult to obtain sufficient adhesive strength even with this technique.

The present invention has been made in view of the above problems. Specifically, the sealant for the liquid crystal dripping method and the liquid crystal display panel, which can form a sealing member having high adhesive strength to the substrate and which can cope with the narrowing of the frame of the liquid crystal display panel and which is difficult to dissolve in the liquid crystal. The purpose is to provide a manufacturing method.

The present invention provides the following sealant for the liquid crystal dropping method.
[1] An epoxy compound having no polymerizable functional group other than an epoxy group, a (meth) acrylic / epoxy-containing compound having both a (meth) acrylic group and an epoxy group in one molecule, and no epoxy group ( Meta) A sealant for the liquid crystal dropping method, which contains an acrylic compound, a heat curing agent, and a photopolymerization initiator, and has a content of the epoxy compound of 22 to 38% by mass. The residual DC value measured 30 seconds after heating the mixture of 1:10 by mass ratio at 120 ° C. for 1 hour, applying a voltage at 5 V for 1 second, short-circuiting for 0.1 seconds, is the above-mentioned. A liquid crystal dropping method in which only the liquid crystal is heated at 120 ° C. for 1 hour, a voltage is applied at 5 V for 1 second, short-circuited for 0.1 seconds, and then 200% or less of the residual DC value measured 30 seconds later. Sealant for.

[2] For each component contained in the sealant for the liquid crystal dropping method, each of the components and the liquid crystal is mixed at a mass ratio of 1:10, heated at 120 ° C. for 1 hour, and a voltage is applied at 5 V for 1 second. When the residual DC value was measured 30 seconds after the short circuit was performed for 0.1 seconds, the residual DC value of 98% by mass or more of the sealant for the liquid crystal dropping method was 1 at 120 ° C. for the liquid crystal display only. For the liquid crystal dropping method according to [1], which is 300% or less of the residual DC value measured 30 seconds after heating for hours, applying a voltage at 5 V for 1 second, short-circuiting for 0.1 seconds. Sealant.
[3] The sealant for a liquid crystal dropping method according to [1] or [2], wherein the proportion of the component having a molecular weight of 500 or more in the epoxy compound is 25% by mass or more.

[4] The thermal curing agent is selected from the group consisting of an organic acid dihydrazide-based thermal latent curing agent, an imidazole-based thermal latent curing agent, an amine adduct-based thermal latent curing agent, and a polyamine-based thermal latent curing agent. The sealant for the liquid crystal dropping method according to any one of [1] to [3], which is one or more.
[5] The sealant for a liquid crystal dropping method according to any one of [1] to [4], which further contains inorganic particles.
[6] The sealant for a liquid crystal dropping method according to any one of [1] to [5], which further contains organic particles.
[7] The sealant for the liquid crystal dropping method according to any one of [1] to [6], which further contains a silane coupling agent.

[8] A step of applying the sealant for the liquid crystal drop method according to any one of [1] to [7] on one of the pair of substrates to form a seal pattern, and the seal pattern. In the uncured state, the step of dropping the liquid crystal in the region of the seal pattern of the one substrate or on the other substrate, and the one substrate and the other substrate are overlapped with each other via the seal pattern. A method for manufacturing a liquid crystal display panel, which comprises a step of matching and a step of curing the seal pattern.

[9] The method for manufacturing a liquid crystal display panel according to [8], wherein the seal pattern is irradiated with light in a step of curing the seal pattern.
[10] The method for manufacturing a liquid crystal display panel according to [9], wherein in the step of curing the seal pattern, the seal pattern is irradiated with light and then heated.

The sealant for the liquid crystal dropping method of the present invention is difficult to dissolve in the liquid crystal. Further, the adhesive strength between the sealing member obtained from the sealing agent for the liquid crystal dropping method and the substrate is high. Therefore, in the obtained liquid crystal display panel, liquid crystal leakage and afterimages are unlikely to occur, and a narrower frame can be realized.

1. 1. Sealing agent for liquid crystal dripping method The sealing agent for liquid crystal dripping method of the present invention (hereinafter, also simply referred to as "seal agent") is a member for producing a sealing member for a liquid crystal display panel, and is a member for manufacturing a sealing member for a liquid crystal display panel. Is preferably used when producing. However, it can also be used to manufacture a liquid crystal display panel by a liquid crystal injection method or the like.

As described above, the conventional sealant has a problem that the liquid crystal display panel is easily contaminated when a large amount of epoxy compound that can contribute to the improvement of the adhesive strength is contained. On the other hand, if the amount of the epoxy compound is reduced, for example, when the liquid crystal display panel is narrowed, sufficient adhesive strength cannot be obtained, and peeling occurs between the substrate and the cured product (seal member) of the sealant. There was something.

On the other hand, as a result of diligent studies by the present inventors, the amount of the epoxy compound is 22 to 38% by mass with respect to the total amount of the sealant, and the residual DC of the mixture obtained by mixing the sealant and the liquid crystal in a predetermined ratio. By adjusting the composition of the sealant so that the value is 200% or less of the residual DC value of the liquid crystal only, the adhesive strength between the obtained seal member and the substrate is greatly increased, while the seal is sealed. It has been found that afterimages caused by elution of components in the agent are less likely to occur.

Here, the residual DC value of the mixture containing the sealant and the liquid crystal display can be measured as follows. First, the sealant and a liquid crystal display (for example, MLC-7026, manufactured by Merck & Co., Inc.) are put into a vial at a mass ratio of 1:10 and mixed. Then, it is heated at 120 ° C. for 1 hour. Then, the mixture is taken out and injected into a glass cell (for example, KSSZ-10 / B111M1NSS05, manufactured by EHC) in which an alignment film and a transparent electrode are formed in advance. Then, a voltage of 5 V is applied to the obtained cell for 1 second and short-circuited for 0.1 second. Then, the remaining voltage (residual DC value) after 30 seconds is measured with a 6254 type measuring device (manufactured by Toyo Corporation).

On the other hand, when measuring the residual DC value of only the liquid crystal, put only the liquid crystal into a vial and mix. Then, it is heated at 120 ° C. for 1 hour. Next, the liquid crystal is taken out and injected into a glass cell (for example, KSSZ-10 / B111M1NSS05, manufactured by EHC) in which an alignment film and a transparent electrode are formed in advance. A voltage of 5 V is applied to the obtained cell for 1 second and short-circuited for 0.1 second. Then, the voltage (residual DC value) remaining after 30 seconds is measured by, for example, a 6254 type measuring device (manufactured by Toyo Corporation).

Here, the residual DC value of the mixture containing the sealant and the liquid crystal varies slightly depending on the type of the liquid crystal, but it may be 200% or less with respect to the residual DC value of the liquid crystal only, and more preferably 180% or less. The residual DC value of the mixture can be adjusted by the type of components constituting the sealant. For example, for many components contained in the sealant, the residual DC value of the mixture can be satisfied by adjusting the individual residual DC value to be 300% or less of the residual DC value of the liquid crystal display alone. .. More specifically, the ratio of the component having an individual residual DC value of 300% or less with respect to the residual DC value of the liquid crystal display alone is preferably 98% by mass or more with respect to the total amount of the sealant.

The individual residual DC value of each component in the sealant can be measured as follows. First, each component and a liquid crystal display (for example, MLC-7026, manufactured by Merck & Co., Inc.) are put into a vial at a mass ratio of 1:10 and mixed. The mixture is heated at 120 ° C. for 1 hour. Then, this mixture is injected into a glass cell (for example, KSSZ-10 / B111M1NSS05, manufactured by EHC) in which an alignment film and a transparent electrode are formed in advance. A voltage of 5 V is applied to the obtained cell for 1 second and short-circuited for 0.1 second. Then, the voltage (residual DC value) remaining after 30 seconds is measured by, for example, a 6254 type measuring device (manufactured by Toyo Corporation). It is more preferable that the residual DC value of each component is 280% or less with respect to the residual DC value of the blank liquid crystal display.

Here, the sealant of the present invention includes an epoxy compound, a (meth) acrylic / epoxy-containing compound, a (meth) acrylic compound, a thermosetting agent, and a photopolymerization initiator. However, in addition to these components, inorganic particles, organic particles, a silane coupling agent, and the like may be contained, if necessary. The description of (meth) acrylic in the present specification includes acrylic, methacryl, or both.
Hereinafter, each component and physical properties of the sealant of the present invention will be described in detail.

(1) Epoxide compound An epoxy compound is a compound containing at least an epoxy group in one molecule and having no polymerizable functional group other than the epoxy group. The polymerizable functional group in the present specification refers to a functional group that is activated by light irradiation or heating, a thermosetting agent, a photopolymerization initiator, a catalyst, or the like to carry out a polymerization reaction. The polymerizable functional group includes a photopolymerizable functional group, a thermopolymerizable functional group, a polyadded functional group and the like, and specific examples thereof include a (meth) acrylic group, a vinyl group, an acrylamide group, an epoxy group and an isosia. Nart group, silanol group and the like are included.

The number of epoxy groups contained in one molecule of the epoxy compound is preferably 2 or more. When the number of epoxy groups in the epoxy compound is 2 or more, the adhesiveness between the obtained sealing member and the substrate of the liquid crystal display panel becomes good. Further, the moisture resistance of the obtained sealing member is likely to increase.

The epoxy compound may be liquid at room temperature or solid. The softening point of the epoxy compound is preferably 40 to 110 ° C. from the viewpoint of the viscosity of the obtained sealant.

Here, the epoxy compound may be a monomer, an oligomer, or a polymer. The molecular weight (or weight average molecular weight) of the epoxy compound is usually preferably 220 to 3000, more preferably 250 to 2500, and even more preferably 300 to 2000. However, the ratio of the component having a molecular weight of 500 or more to the total amount of the epoxy compound is preferably 25% by mass or more. Epoxy compounds with a molecular weight of 500 or more are difficult to dissolve in liquid crystals. Therefore, in such an epoxy compound, the above-mentioned individual residual DC value tends to be 300% or less as compared with the residual DC value of the liquid crystal display alone. The weight average molecular weight of the epoxy compound can be specified (in terms of polystyrene) by, for example, gel permeation chromatography (GPC). However, the epoxy compound may partially contain an individual residual DC value of more than 300% of the residual DC value of the liquid crystal display alone.

Here, the structure of the epoxy compound is not particularly limited, and an example thereof includes an aromatic epoxy compound having an aromatic ring in the main chain. Examples of aromatic epoxy compounds include aromatic diols typified by bisphenol A, bisphenol S, bisphenol F, bisphenol AD, diols obtained by modifying these with ethylene glycol, propylene glycol, and alkylene glycol AD, and epichlorohydrin. Aromatic polyvalent glycidyl ether compound obtained by reaction; obtained by reaction of epichlorohydrin with novolak resin derived from phenol, cresol, etc. and formaldehyde, polyphenols represented by polyalkenylphenol, copolymers thereof, etc. Also included are novolak-type polyvalent glycidyl ether compounds; glycidyl ether compounds of xylylenephenol resin; naphthalene-type epoxy compounds; diphenyl ether-type epoxy compounds; biphenyl-type epoxy compounds; and the like.

More specifically, the aromatic epoxy compound is a cresol novolac type epoxy compound, a phenol novolac type epoxy compound, a bisphenol A type epoxy compound, a bisphenol F type epoxy compound, a triphenol methane type epoxy compound, or a triphenol ethane type epoxy compound. , Trisphenol type epoxy compound, diphenyl ether type epoxy compound, biphenyl type epoxy compound are preferable.

The sealant may contain only one type of epoxy compound, or may contain two or more types of sealant. When the individual residual DC value is measured for each epoxy compound as described above, the value is preferably 150 mV or less.

The content of the epoxy compound is preferably 22 to 38% by mass, more preferably 22 to 36% by mass, and even more preferably 23 to 35% by mass with respect to the total amount of the sealant. When the amount of the epoxy compound is 25% by mass or more, the adhesive strength between the sealing member obtained from the sealing agent and the substrate of the liquid crystal display panel is increased, and the frame of the liquid crystal display panel can be narrowed. On the other hand, when the amount of the epoxy compound is 38% by mass or less, the residual DC value of the mixture of the sealant and the liquid crystal measured as described above tends to be 200% or less with respect to the residual DC value of the liquid crystal only. , The obtained liquid crystal display panel is unlikely to remain.

(2) (Meta) Acrylo-Epoxy-Containing Compound The (meth) acrylic-epoxy-containing compound may be a compound having an epoxy group and a (meth) acrylic group in one molecule.

If the sealing agent only contains the above-mentioned epoxy compound and the later-described (meth) acrylic compound, the compatibility between them may be low. On the other hand, when the sealing agent further contains a (meth) acrylic / epoxy-containing compound, the compatibility between the epoxy compound and the (meth) acrylic compound is enhanced, and the epoxy compound is less likely to be eluted into the liquid crystal.

Here, the number of epoxy groups and (meth) acrylic groups contained in one molecule of the (meth) acrylic / epoxy-containing compound is not particularly limited, but may be one, for example. Further, the number of epoxy groups and the number of (meth) acrylic groups may be the same or different. Examples of the (meth) acrylic-epoxy-containing compound include a (meth) acrylic-modified epoxy compound obtained by reacting an epoxy compound with (meth) acrylic acid in the presence of a basic catalyst.

The epoxy compound used for preparing the (meth) acrylic-modified epoxy compound may be a bifunctional or higher-functional epoxy compound having two or more epoxy groups in the molecule, and may be bisphenol A type, bisphenol F type, or 2,2'-diallyl. Bisphenol type epoxy compounds such as bisphenol A type, bisphenol AD type, and hydrogenated bisphenol type; novolak type epoxy compounds such as phenol novolac type, cresol novolac type, biphenyl novolac type, and trisphenol novolac type; biphenyl type epoxy compounds; naphthalene Type epoxy compounds and the like are included.

However, the (meth) acrylic-modified epoxy compound obtained by (meth) acrylic-modifying a polyfunctional epoxy compound such as trifunctional or tetrafunctional has a high crosslink density. Therefore, if the sealing agent contains such a (meth) acrylic-modified epoxy compound, the adhesive strength between the sealing member and the substrate tends to decrease when the liquid crystal display panel is manufactured. Therefore, a (meth) acrylic-modified epoxy compound obtained by modifying a bifunctional epoxy compound with (meth) acrylic is preferable.

The epoxy compound for preparing the (meth) acrylic-modified epoxy compound is more preferably a biphenyl type epoxy compound, a naphthalene type epoxy compound, and a bisphenol type epoxy compound, and a bisphenol type epoxy compound such as bisphenol A type and bisphenol F type is a sealant. It is more preferable from the viewpoint of coating efficiency. The epoxy compound for preparing the (meth) acrylic-modified epoxy compound may be one kind or two or more kinds. Further, the epoxy compound for preparing the (meth) acrylic-modified epoxy compound is preferably highly purified by a molecular distillation method, a washing method or the like.

Further, the reaction between the above epoxy compound and (meth) acrylic acid can be carried out according to a conventional method. When this reaction is carried out, (meth) acrylic acid reacts with some of the epoxy groups in the epoxy compound to obtain a (meth) acrylic-modified epoxy compound having a (meth) acrylic group and an epoxy group. However, in the reaction product, not only the (meth) acrylic-modified epoxy compound, but also an unreacted epoxy compound and a (meth) acrylic compound in which (meth) acrylic acid reacts with all the epoxy groups of the epoxy compound. May be included. Only the (meth) acrylic-modified epoxy compound may be isolated from the product and used as a sealant, but the unreacted epoxy compound is an epoxy compound having no polymerizable functional group other than the above-mentioned epoxy group. Corresponds to. Further, the (meth) acrylic compound in which (meth) acrylic acid reacts with all the epoxy groups of the epoxy compound corresponds to the (meth) acrylic compound described later. Therefore, the reaction product may be used as it is as a sealant.

Here, the molecular weight (weight average molecular weight) of the (meth) acrylic / epoxy-containing compound is preferably, for example, 310 to 1000, and more preferably 350 to 900. The weight average molecular weight Mw of the (meth) acrylic / epoxy-containing compound can be measured (in terms of polystyrene) by, for example, gel permeation chromatography (GPC). When the molecular weight of the (meth) acrylic / epoxy compound-containing compound is in the above range, the viscosity of the sealant tends to be in the desired range.

The amount of the (meth) acrylic / epoxy-containing compound contained in the sealant is preferably 15 to 50% by mass, more preferably 18 to 40% by mass, still more preferably 20 to 35% by mass, based on the total amount of the sealant. When the amount of the (meth) acrylic / epoxy-containing compound is 15% by mass or more, the adhesive strength between the sealing member obtained from the sealing agent and the substrate of the liquid crystal display panel is increased, and the frame of the liquid crystal display panel can be narrowed. .. On the other hand, when the amount of the epoxy compound is 50% by mass or less, the residual DC value of the mixture of the sealant and the liquid crystal is likely to be 200% or less with respect to the residual DC value of the liquid crystal alone, and the obtained liquid crystal display panel can be obtained. Afterimages are unlikely to occur.

(3) (Meta) Acryloyl Compound The (meth) acrylic compound is a compound containing one or more (meth) acrylic groups in one molecule and does not have an epoxy group. The (meth) acrylic compound may be a monomer, an oligomer, or a polymer.

The number of (meth) acrylic groups contained in one molecule of the (meth) acrylic compound is preferably 2 or more. When the number of (meth) acrylic groups in the (meth) acrylic compound is 2 or more, the photocurability of the sealant becomes good.

Here, examples of the (meth) acrylic compound include di (meth) acrylates such as polyethylene glycol, propylene glycol, and polypropylene glycol; di (meth) acrylates of tris (2-hydroxyethyl) isocyanurate; and 1 mol of neopentyl glycol. Di (meth) acrylate of diol obtained by adding 4 mol or more of ethylene oxide or propylene oxide to bisphenol A; Di (meth) acrylate of diol obtained by adding 2 mol of ethylene oxide or propylene oxide to 1 mol of bisphenol A; Di or tri (meth) acrylate of triol obtained by adding 3 mol or more of ethylene oxide or propylene oxide to 1 mol of trimethylolpropane; obtained by adding 4 mol or more of ethylene oxide or propylene oxide to 1 mol of bisphenol A. Di (meth) acrylate of diol; tri (meth) acrylate of tris (2-hydroxyethyl) isocyanurate; tri (meth) acrylate of trimethylolpropane or an oligomer thereof; tri (meth) acrylate of pentaerythritol, or an oligomer thereof Poly (meth) acrylate of dipentaerythritol; Tris (acryloxyethyl) isocyanurate; Caprolactone-modified tris (acryloxyethyl) isocyanurate; Caprolactone-modified tris (methacryloxyethyl) isocyanurate; Poly of alkyl-modified dipentaerythritol ( Meta) acrylate; Poly (meth) acrylate of caprolactone-modified dipentaerythritol; Di (meth) acrylate of neopentyl glycol hydroxypivalate; Di (meth) acrylate of caprolactone-modified neopentyl glycol of hydroxypivalate; Ethyleneoxide-modified phosphoric acid ( Meta) acrylates; (meth) acrylates of ethylene oxide-modified alkylated phosphates; oligo (meth) acrylates of neopentylglucol, trimethylolpropane, pentaerythritol; and the like. In addition, a compound obtained by reacting all of the above-mentioned epoxy compounds containing a bifunctional or higher functional epoxy group with (meth) acrylic acid is also included.

Among these, the glass transition temperature of the (meth) acrylic compound is preferably 25 ° C. or higher and lower than 200 ° C. from the viewpoint that the elastic modulus of the film after photo-curing of the sealant easily falls within a desired range. The glass transition temperature is more preferably 40 ° C. to 200 ° C., further preferably 50 to 150 ° C. The glass transition temperature is measured by a viscoelasticity measuring device (DMS).

The molecular weight (or weight average molecular weight) of the (meth) acrylic compound is preferably 310 to 1000, more preferably 400 to 900. The weight average molecular weight Mw of the (meth) acrylic compound can be measured (in terms of polystyrene) by, for example, gel permeation chromatography (GPC). When the molecular weight of the (meth) acrylic compound is in the above range, the viscosity of the sealant tends to be in the desired range.

The amount of the (meth) acrylic compound contained in the sealant is preferably 15 to 40% by mass, more preferably 18 to 35% by mass, based on the total amount of the sealant, although it depends on the curability of the desired sealant. 20 to 32% by mass is more preferable. When the amount of the (meth) acrylic compound is in the above range, the elastic modulus of the sealant after photocuring tends to be good.

(4) Thermosetting agent The thermosetting agent may be any component capable of curing the epoxy compound by heating. However, thermosetting agents do not cure the above-mentioned epoxy compounds and (meth) acrylic / epoxy-containing compounds under normal storage conditions (room temperature, visible light, etc.), but compounds that cure these compounds by heating. Is preferable. According to the sealing agent containing such a thermosetting agent, both storage stability and thermosetting property can be achieved at the same time. Further, as the thermosetting agent, a compound capable of curing an epoxy compound (hereinafter, also referred to as "epoxy curing agent") is preferable.

The melting point of the epoxy curing agent is preferably 50 ° C. or higher and 250 ° C. or lower, more preferably 100 ° C. or higher and 200 ° C. or lower, and 150 ° C. or higher, from the viewpoint of increasing the viscosity stability of the sealing agent and not impairing the moisture resistance of the obtained sealing member. It is more preferably ° C. or higher and 200 ° C. or lower. When the melting point of the epoxy curing agent is in the above range, the sealing agent can be made one-component curable. When the sealing agent is one-component curable, workability is excellent because it is not necessary to mix the main agent and the curing agent at the time of use.

Examples of epoxy curing agents include organic acid dihydrazide-based thermal latent curing agents, imidazole-based thermal latent curing agents, amine adduct-based thermal latent curing agents, and polyamine-based thermal latent curing agents.

Examples of epoxy curing agents include organic acid dihydrazide-based thermal latent curing agents, imidazole-based thermal latent curing agents, dicyandiamide-based thermal latent curing agents, amine adduct-based thermal latent curing agents, and polyamine-based thermal latent curing agents. Contains agents.

Examples of organic acid dihydrazide-based thermal latent curing agents include adipic acid dihydrazide (melting point 181 ° C.), 1,3-bis (hydrazinocarboethyl) -5-isopropylhydranthin (melting point 120 ° C.), 7,11-octa. Includes decadien-1,18-dicarbohydrazide (melting point 160 ° C.), dodecanedioic acid dihydrazide (melting point 190 ° C.), sebacic acid dihydrazide (melting point 189 ° C.) and the like.

Examples of imidazole-based thermal latent curing agents include 2,4-diamino-6- [2'-ethylimidazolyl- (1')]-ethyltriazine (melting point 215-225 ° C.) and 2-phenylimidazole (melting point). 137 to 147 ° C.) and the like.

Examples of dicyandiamide-based thermal latent curing agents include dicyandiamide (melting point 209 ° C.) and the like.

The amine adduct-based thermal latent curing agent is a thermal latent curing agent composed of an additional compound obtained by reacting an amine-based compound having catalytic activity with an arbitrary compound. Examples of amine adduct-based thermal latent curing agents are Ajinomoto Fine-Techno's Amicure PN-40 (melting point 110 ° C), Ajinomoto Fine-Techno's Amicure PN-23 (melting point 100 ° C), and Ajinomoto Fine-Techno's Amicure PN. -31 (melting point 115 ° C), Ajinomoto Fine-Techno Amicure PN-H (melting point 115 ° C), Ajinomoto Fine-Techno Amicure MY-24 (melting point 120 ° C), and Ajinomoto Fine-Techno Amicure MY-H (melting point) 131 ° C) and the like are included.

The polyamine-based thermal latent curing agent is a thermal latent curing agent having a polymer structure obtained by reacting amine and epoxy, and an example thereof is ADEKA Hardener EH4339S (softening point 120 to 130 ° C.) manufactured by ADEKA Corporation. , And ADEKA Hardener EH4357S (softening point 73 to 83 ° C.) and the like.

Among the above, from the viewpoint of availability, compatibility with other components, etc., organic acid dihydrazide-based thermal latent curing agent, imidazole-based thermal latent curing agent, amine adduct-based thermal latent curing agent, or polyamine A thermal latent curing agent is preferred. The sealant may contain only one type of epoxy curing agent, or may contain two or more types of sealant.

The content of the thermosetting agent is preferably 1 to 20% by mass, more preferably 2 to 18% by mass, still more preferably 3 to 15% by mass, based on the total amount of the sealing agent. When the amount of the thermosetting agent is within the above range, the thermosetting property of the sealant becomes good.

(5) Photopolymerization Initiator The photopolymerization initiator may be a compound capable of generating an active species by irradiation with light, may be a self-cleaving type photopolymerization initiator, or may be a hydrogen abstraction type photopolymerization. It may be an initiator. The sealing agent may contain only one kind of photopolymerization initiator, or may contain two or more kinds of photopolymerization initiators.

Examples of self-cleaving photopolymerization initiators include benzyl dimethyl ketals such as alkylphenone compounds (eg, 2,2-dimethoxy-1,2-diphenylethane-1-one (BASF IRGACURE 651)), 2-. Α-Aminoalkylphenone such as methyl-2-morpholino (4-thiomethylphenyl) propan-1-one (IRGACURE 907 manufactured by BASF), 1-hydroxy-cyclohexyl-phenyl-ketone (IRGACURE 184 manufactured by BASF), etc. α-Hydroxyalkylphenone, etc.), acylphosphine oxide compounds (eg 2,4,6-trimethylbenzoindiphenylphosphine oxide, etc.), titanosen compounds (eg, bis (η5-2,4-cyclopentadiene-1-yl))- Bis (2,6-difluoro-3- (1H-pyrrole-1-yl) -phenyl) titanium, etc.), acetophenone compounds (eg diethoxyacetophenone, 2-hydroxy-2-methyl-1-phenylpropan-1- On, benzyl dimethyl ketal, 1- (4-isopropylphenyl) -2-hydroxy-2-methylpropan-1-one, 4- (2-hydroxyethoxy) phenyl- (2-hydroxy-2-propyl) ketone, 1, -Hydroxycyclohexyl-phenylketone, 2-methyl-2-morpholino (4-thiomethylphenyl) propan-1-one, 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butanone, etc.), phenyl Glyoxylate compounds (eg, methylphenylgrioxy ester, etc.), benzoin ether compounds (eg, benzoin, benzoin methyl ether, benzoin isopropyl ether, etc.), and oxime ester compounds (eg 1,2-octanedione-1- [ 4- (Phenylthio) -2- (O-benzoyloxime)] (IRGACURE OXE01 manufactured by BASF), Etanone-1- [9-ethyl-6- (2-methylbenzoyl) -9H-carbazole-3-yl]- 1- (0-acetyloxime) (IRGACURE OXE02 manufactured by BASF), etc.) is included.

Examples of hydrogen abstraction-type photopolymerization initiators include benzophenone compounds (eg, benzophenone, o-benzoylmethylbenzoate methyl-4-phenylbenzophenone, 4,4'-dichlorobenzophenone, hydroxybenzophenone, 4-benzoyl-4'-. Methyl-diphenylsulfide, acrylicized benzophenone, 3,3', 4,4'-tetra (t-butylperoxycarbonyl) benzophenone, 3,3'-dimethyl-4-methoxybenzophenone, etc.), thioxanthone compounds (eg, thioxanthone, 2-Chlorothioxanthone (manufactured by Tokyo Kasei Kogyo Co., Ltd.), 1-chloro-4-propoxythioxanthone, 1-chloro-4-ethoxythioxanthone (Spedcure CPTX manufactured by Lambson Limited), 2-isopropylxantone (Speedcure ITX manufactured by Lambson Limited) , 4-Isopropylthioxanthone, 2,4-dimethylthioxanthone, 2,4-diethylthioxanthone (Speedcure DETX manufactured by Lambson Limited), 2,4-dichlorothioxanthone, anthraquinone compounds (for example, 2-methylanthraquinone, 2-ethylanthraquinone, 2-t-butyl anthraquinone, 1-chloroanthraquinone, etc., 2-hydroxyanthraquinone (2-Hydroxyanthraquinone manufactured by Tokyo Kasei Kogyo Co., Ltd.), 2,6-dihydroxyanthraquinone (Anthraquinone manufactured by Tokyo Kasei Kogyo Co., Ltd.), 2-hydroxymethyl anthraquinone (manufactured by Tokyo Kasei Kogyo Co., Ltd.) 2- (Hydroxymethyl) anthraquinone) manufactured by Genuine Chemical Co., Ltd.) and benzyl compounds are included.

The absorption wavelength of the photopolymerization initiator is not particularly limited, and for example, a photopolymerization initiator that absorbs light having a wavelength of 360 nm or more is preferable. Among them, it is more preferable to absorb light in the visible light region, a photopolymerization initiator that absorbs light having a wavelength of 360 to 780 nm is more preferable, and a photopolymerization initiator that absorbs light having a wavelength of 360 to 430 nm is particularly preferable.

Examples of the photopolymerization initiator that absorbs light having a wavelength of 360 nm or more include an alkylphenone-based compound, an acylphosphine oxide-based compound, a titanosen-based compound, an oxime ester-based compound, a thioxanthone-based compound, and an anthraquinone-based compound, and are preferable. It is an oxime ester compound.

The structure of the photopolymerization initiator can be specified by combining high performance liquid chromatography (HPLC) and liquid chromatography mass spectrometry (LC / MS) with NMR measurement or IR measurement.

The molecular weight of the photopolymerization initiator is preferably 200 or more and 5000 or less, for example. When the molecular weight is 200 or more, it is difficult for the photopolymerization initiator to elute into the liquid crystal when the sealant and the liquid crystal come into contact with each other. On the other hand, when the molecular weight is 5000 or less, the compatibility with the above-mentioned (meth) acrylic compound and the like is enhanced, and the curability of the sealant tends to be improved. The molecular weight of the photopolymerization initiator is more preferably 230 or more and 3000 or less, and further preferably 230 or more and 1500 or less.

The molecular weight of the photopolymerization initiator can be determined as the "relative molecular weight" of the molecular structure of the main peak detected when analyzed by high performance liquid chromatography (HPLC: High Performance Liquid Chromatography).

Specifically, a sample solution in which a photopolymerization initiator is dissolved in THF (tetrahydrofuran) is prepared, and high performance liquid chromatography (HPLC) measurement is performed. Then, the area percentage of the detected peak (the ratio of the area of each peak to the total area of all peaks) is obtained, and the presence or absence of the main peak is confirmed. The main peak refers to the peak with the highest intensity (the peak with the highest peak height) among all the peaks detected at the detection wavelength characteristic of each compound (for example, 400 nm in the case of a thioxanthone compound). The relative molecular weight corresponding to the peak peak of the detected main peak can be measured by liquid chromatography-mass spectrometry (LC / MS: Liquid Chromatography Mass Spectrometry).

The amount of the photopolymerization initiator is preferably 0.1 to 8% by mass, more preferably 0.5 to 5% by mass, still more preferably 1 to 3% by mass, based on the total amount of the sealant. When the amount of the photopolymerization initiator is 0.1% by mass or more, the photocurability of the sealant tends to be good. When the amount of the photopolymerization initiator is 8% by mass or less, it becomes difficult for the photopolymerization initiator to elute into the liquid crystal display.

(6) Inorganic Particles The sealant may further contain inorganic particles, if necessary. When the sealing agent contains inorganic particles, the viscosity of the sealing agent, the strength of the obtained sealing member, the linear expansion property, and the like tend to be improved.

Examples of inorganic particle materials include calcium carbonate, magnesium carbonate, barium sulfate, magnesium sulfate, aluminum silicate, zirconium silicate, iron oxide, titanium oxide, titanium nitride, aluminum oxide (alumina), zinc oxide, silicon dioxide, and titanic acid. Includes potassium, kaolin, talc, glass beads, sericite-activated clay, bentonite, aluminum oxide, silicon nitride and the like. The sealing agent may contain only one kind of inorganic particles, or may contain two or more kinds of sealing agents. Among the above, silicon dioxide or talc is preferable as the inorganic particles.

The shape of the inorganic particles may be a fixed shape such as a spherical shape, a plate shape, a needle shape, or a non-fixed shape. When the inorganic particles are spherical, the average primary particle size of the inorganic particles is preferably 1.5 μm or less, and the specific surface area is more preferably ^{0.5 to 20 m 2 / g.} The average primary particle size of the inorganic particles can be measured by the laser diffraction method described in JIS Z8825-1. The specific surface area of the inorganic particles can be measured by the BET method described in JIS Z8830.

The content of the inorganic particles is preferably 0.1 to 25% by mass, more preferably 3 to 20% by mass, still more preferably 5 to 18% by mass, based on the total amount of the sealant. When the content of the inorganic particles is 0.1% by mass or more, the moisture resistance of the obtained sealing member tends to increase, and when it is 25% by mass or less, the coating stability of the sealing agent is not easily impaired.

(7) The organic particle sealant may further contain organic particles, if necessary. When the sealant contains organic particles, it becomes easy to adjust the elastic modulus of the sealant after photocuring.

Examples of organic particles include silicone particles, acrylic particles, styrene particles such as a styrene / divinylbenzene copolymer, and polyolefin particles. The sealing agent may contain only one kind of organic particles, or may contain two or more kinds of organic particles. The average primary particle size of the organic particles is preferably 0.05 to 13 μm, more preferably 0.1 to 10 μm, and even more preferably 0.1 to 8 μm.

The shape of the organic particles is not particularly limited, but is preferably spherical, and more preferably true spherical. The spherical shape means that the ratio of the minimum value (b) to the maximum value (a) of the diameter of each particle is b / a = 0.9 to 1.0. The average primary particle size of organic particles can be measured by microscopy, specifically image analysis with an electron microscope. Moreover, it is preferable that the surface of the organic particles is smooth. A smooth surface reduces the specific surface area and increases the amount of organic particles that can be added to the sealant.

The content of the organic particles is preferably 0.1 to 20% by mass, more preferably 1 to 15% by mass, still more preferably 3 to 12% by mass, based on the total amount of the sealant. When the amount of organic particles is in the above range, the elastic modulus of the sealant after photocuring tends to be within a desired range.

(8) Others The sealant of the present invention includes, if necessary, a thermal radical polymerization initiator, a coupling agent such as a silane coupling agent, an ion trapping agent, an ion exchanger, a leveling agent, a pigment, a dye, a sensitizer, and the like. It may further contain additives such as plasticizers and antifoaming agents.

Examples of silane coupling agents include vinyltrimethoxysilane, γ- (meth) acryloxipropyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropyltriethoxysilane, and the like. The amount of the silane coupling agent is preferably 0.01 to 6% by mass, more preferably 0.1 to 5% by mass, still more preferably 0.5 to 3% by mass, based on the total amount of the sealing agent. When the content of the silane coupling agent is 0.01% by mass or more, the obtained sealing member tends to have sufficient adhesiveness. However, many silane coupling agents have a high residual DC value. Therefore, the amount of the silane coupling agent is preferably 6% by mass or less.

The sealant may further contain a spacer or the like for adjusting the gap of the liquid crystal display panel.

The total amount of other components is preferably 1 to 50% by mass with respect to the total amount of the sealant. When the total amount of the other components is 50% by mass or less, the viscosity of the sealant is unlikely to increase excessively, and the coating stability of the sealant is unlikely to be impaired.

(9) Physical Characteristics of Sealing Agent The viscosity of the E-type viscometer of the sealing agent at 25 ° C. and 2.5 rpm is preferably 200 to 450 Pa · s, more preferably 300 to 400 Pa · s. When the viscosity is in the above range, when a pair of substrates are superposed on each other via a sealant (seal pattern), the sealant is likely to be deformed so as to fill these gaps. Therefore, the gap between the pair of substrates of the liquid crystal display panel can be appropriately controlled.

The thixotropy index (TI value) of the sealant is preferably 1.0 to 1.5, more preferably 1.1 to 1.3, from the viewpoint of the coatability of the sealant. The TI value is determined by using an E-type viscometer, the viscosity of the sealant at room temperature (25 ° C.) and 0.5 rpm is η1, and the viscosity of the sealant at 5 rpm is η2. It is a value obtained by applying to.
TI value = (viscosity η1 (25 ° C) at 0.5 rpm) / (viscosity η2 (25 ° C) at 5 rpm) ... (1)

The residual DC value measured by mixing the sealant and the liquid crystal as described above is preferably 100 mV or less. In this case, as the liquid crystal, it is preferable to measure using MLC-7026 manufactured by Merck & Co., Ltd.

2. Liquid crystal display panel The liquid crystal display panel of the present invention includes a pair of substrates, a frame-shaped seal member arranged between the substrates, and a liquid crystal filled between the pair of substrates and inside the frame-shaped seal member. Has. In the liquid crystal display panel, the sealing member is a cured product of the above-mentioned sealing agent. The sealing member obtained from the above-mentioned sealing agent has high adhesive strength with the substrate, and even if the sealing member is thinned, liquid crystal leakage or the like is unlikely to occur. Further, the sealing agent is less likely to contaminate the liquid crystal display. Therefore, afterimages and the like are unlikely to occur when the liquid crystal display panel is used.

The pair of substrates (also referred to as "display substrate and opposed substrate") are both transparent substrates. Examples of materials for the transparent substrate include glass or polycarbonate, polyethylene terephthalate, polyether sulfone, PMMA and the like.

A matrix-shaped TFT, a color filter, a black matrix, etc. are arranged on the surface of the display board or the facing board. An alignment film is further formed on the surface of the display substrate or the facing substrate. The alignment film includes known organic alignment agents, inorganic alignment agents, and the like. Further, a known liquid crystal can be used as the liquid crystal.

The liquid crystal display panel manufacturing method generally includes a liquid crystal dropping method and a liquid crystal injection method, but the liquid crystal display panel manufacturing method of the present invention is preferably the liquid crystal dropping method.

The method for manufacturing a liquid crystal display panel by the liquid crystal dropping method is as follows: 1) a seal pattern forming step of applying the above-mentioned sealant to one substrate to form a frame-shaped seal pattern, and 2) a state in which the seal pattern is uncured. Then, the liquid crystal is dropped on one substrate and in the region surrounded by the seal pattern, or on the other substrate and in the region surrounded by the seal pattern when the other substrate and one substrate are opposed to each other. It includes a step, 3) a superposition step of superimposing one substrate and the other substrate via a seal pattern, and 4) a curing step of curing the seal pattern.

1) In the seal pattern forming step, the above-mentioned sealant is applied to one of the substrates. The method of applying the sealant is not particularly limited, and is not particularly limited as long as it is a method capable of forming a seal pattern with a desired thickness and width, such as screen printing or application with a dispenser, and a known method of applying the sealant. Is similar to.

Further, the shape of the seal pattern to be formed may be appropriately selected according to the application of the liquid crystal display panel, etc., and may be a shape in which the liquid crystal does not leak. For example, it may have a rectangular frame shape, but is not limited to the shape. The line width of the seal pattern is preferably 0.2 to 1.0 mm, more preferably 0.2 to 0.5 mm.

2) In the liquid crystal dropping step, the pair of substrates are opposed to each other with the seal pattern uncured. Here, the state in which the seal pattern is uncured means a state in which the curing reaction of the sealant has not progressed to the gel point. Before the liquid crystal dropping step, the seal pattern may be semi-cured by irradiating or heating the seal pattern in order to suppress the dissolution of the sealant in the liquid crystal. The method of dropping the liquid crystal is the same as the known method of dropping the liquid crystal, and the liquid crystal may be dropped on the substrate on which the seal pattern is formed, and the liquid crystal may be dropped on the substrate on which the seal pattern is not formed (the other substrate). May be dropped.

3) In the superposition process, one substrate and the other substrate are superposed so as to face each other via a seal pattern. At this time, the gap between the substrates is controlled to be within a desired range.

4) In the curing process, the seal pattern is cured. The method for curing the seal pattern is not particularly limited, but it is preferable that the seal pattern is temporarily cured by irradiation with light having a predetermined wavelength and then finally cured by heating. By light irradiation, the seal pattern can be instantly cured, and the components in the sealant can be suppressed from being dissolved in the liquid crystal display.

The wavelength of the light to be irradiated is appropriately selected according to the type of the photopolymerization initiator, and ultraviolet light is preferable. The light irradiation time is, for example, about 10 minutes, although it depends on the composition of the sealant. The amount of energy to be irradiated at this time may be an amount of energy sufficient to cure the (meth) acrylic compound or the (meth) acrylic / epoxy-containing compound.

After irradiation with light, the epoxy compound and (meth) acrylic / epoxy-containing compound are cured by heating. The heating temperature depends on the composition of the sealant, but is, for example, 100 to 150 ° C., and the heating time is preferably about 2 hours.

The present invention will be described in detail based on examples, but the present invention is not limited to these examples.

<Synthesis Example 1> Preparation of Photocurable Composition 1 (Preparation of Composition Containing Methacrylic Acid Modified Epoxy Compound)
Liquid bisphenol F type epoxy compound (EPICLON830-S, manufactured by DIC, epoxy equivalent 160 g / eq) 160 g, polymerization inhibitor (p-methoxyphenol) 0.1 g, catalyst (triethanolamine) 0.2 g, and methacrylic acid 43 0.0 g was charged in a flask, dry air was sent in, and the reaction was carried out at 90 ° C. with reflux stirring for 5 hours. The obtained composition was washed with ultrapure water 20 times to obtain a methacrylic acid-modified epoxy compound-containing composition (photocurable compound-containing composition 1). When the composition of the obtained composition was identified by NMR, 25 mol% of epoxy compounds had epoxy groups at both ends, 50 mol% of methacrylic-modified epoxy compounds had epoxy groups and methacryl groups at the ends, and both ends had epoxy groups. The proportion of (meth) acrylic compounds modified to methacrylic groups was 25 mol%. The obtained composition was separated by a column, and the value of each residual DC was measured by the method described later. The results are shown in Table 1.

<Synthesis Example 2> Preparation of Photocurable Composition 2 (Preparation of Acrylic Acid-Modified Epoxy Compound-Containing Composition)
Liquid bisphenol A type epoxy compound (EPICLON850-S, DIC epoxy equivalent 190 g / eq) 190 g, polymerization inhibitor (p-methoxyphenol) 0.1 g, catalyst (triethanolamine) 0.2 g, and acrylic acid 36. 0 g was charged in a flask, dry air was sent in, and the reaction was carried out at 90 ° C. with reflux stirring for 5 hours. The obtained composition was washed with ultrapure water 20 times to obtain an acrylic acid-modified epoxy composition (photocurable composition 2). When the composition of the obtained composition was identified by NMR, 25 mol% of the epoxy compound had an epoxy group at both ends, and 50 mol% of the (meth) acrylic compound having an epoxy group and an acrylic group at the ends, respectively. The proportion of (meth) acrylic compounds whose terminals were modified to acrylic groups was 25 mol%. The obtained composition was separated by a column, and the value of each residual DC was measured by the method described later. The results are shown in Table 1.

[Example 1]
400 parts by mass of photocurable composition 1, 100 parts by mass of epoxy compound (EP-4010S, manufactured by ADEKA (bisphenol A type, residual DC value = 64 mV)), epoxy compound (850-S, manufactured by DIC (bisphenol)) Type A, residual DC value = 133 mV) 50 parts by mass, (meth) acrylic compound (Ebeclyl3700, manufactured by Daicel Cytec (residual DC value = 52 mV)) 50 parts by mass, (meth) acrylic compound (2CL, Shin-Nakamura) 80 parts by mass of chemical industry (residual DC value = 73 mV)), 50 parts by mass of thermal curing agent (adipate dihydrazide, Otsuka Chemical (residual DC value = 53 mV)), photopolymerization initiator (OXE-01) , BASF Japan (residual DC value = 68 mV)) 20 parts by mass, inorganic particles (silica particles: S-100, Nippon Catachemical Chemicals (residual DC value = 51 mV)) 150 parts by mass, organic particles (fine particles) 90 parts by mass of polymer F351, manufactured by Aika Kogyo Co., Ltd. (residual DC value = 55 mV)) and 10 parts by mass of a silane coupling agent (KBM-403, manufactured by Shin-Etsu Chemical Co., Ltd. (residual DC value = 431 mV)) were mixed. Then, these were sufficiently mixed with three rolls so as to be a uniform liquid to obtain a sealant.

[Example 2]
A sealant was prepared in the same manner as in Example 1 except that the photocurable composition 1 was changed to the photocurable composition 2.

[Example 3]
400 parts by mass of the photocurable composition 2, 50 parts by mass of the epoxy compound (EP-4010S, manufactured by ADEKA, bisphenol A type (residual DC value = 64 mV)), the epoxy compound (Epicoat 1004AF, manufactured by Mitsubishi Chemical Co., Ltd., bisphenol) 50 parts by mass of A type (residual DC value = 57 mV), 50 parts by mass of epoxy compound (850-S, manufactured by DIC, bisphenol A type (residual DC value = 133 mV)), (meth) acrylic compound (Ebeclyl3700, 50 parts by mass of Daicel Cytec (residual DC value = 52 mV)), 80 parts by mass of (meth) acrylic compound (2CL, manufactured by Shin-Nakamura Chemical Industry Co., Ltd. (residual DC value = 73 mV)), thermosetting agent (azipin) Acid dihydrazide, manufactured by Otsuka Chemical Co., Ltd. (residual DC value = 53 mV)) by 50 parts by mass, photopolymerization initiator (OXE-01, manufactured by BASF Co., Ltd. (residual DC value = 68 mV)) by 20 parts by mass, inorganic particles (silica particles) : S-100, manufactured by Nippon Catalytic Chemical Co., Ltd. (residual DC value = 51 mV)) by 150 parts by mass, organic particles (fine particle polymer F351, manufactured by Aika Kogyo Co., Ltd. (residual DC value = 55 mV)) by 90 parts by mass, and silane cup. A ring agent (KBM-403, manufactured by Shin-Etsu Chemical Industry Co., Ltd. (residual DC value = 431 mV)) was mixed in an amount of 10 parts by mass. Then, these were sufficiently mixed with three rolls so as to be a uniform liquid to obtain a sealant.

[Example 4]
500 parts by mass of photocurable composition 1, 80 parts by mass of epoxy compound (EP-4010S, manufactured by ADEKA, bisphenol A type (residual DC value = 64 mV)), epoxy compound (Epicoat 1004AF, manufactured by Mitsubishi Chemical Co., Ltd., bisphenol) 50 parts by mass of A type (residual DC value = 57 mV), 50 parts by mass of epoxy compound (850-S, manufactured by DIC, bisphenol A type (residual DC value = 133 mV)), (meth) acrylic compound (2CL, 40 parts by mass of Shin-Nakamura Chemical Industry Co., Ltd. (residual DC value = 73 mV), 50 parts by mass of thermal curing agent (adipate dihydrazide, Otsuka Chemical Co., Ltd. (residual DC value = 53 mV)), photopolymerization initiator (OXE) -01, 20 parts by mass of BASF (residual DC value = 68 mV)), 130 parts by mass of inorganic particles (silica particles: S-100, manufactured by Nippon Catalytic Chemicals (residual DC value = 51 mV)), organic particles (remaining DC value = 51 mV) 70 parts by mass of fine particle polymer F351, manufactured by Aika Kogyo Co., Ltd. (residual DC value = 55 mV), and 10 parts by mass of silane coupling agent (KBM-403, manufactured by Shinetsu Chemical Industry Co., Ltd. (residual DC value = 431 mV)) are mixed. bottom.

[Example 5]
430 parts by mass of photocurable composition 2, epoxy compound (EP-4010S, manufactured by ADEKA, bisphenol A type (residual DC value = 64 mV), 150 parts by mass, (meth) acrylic compound (Ebecryl3700, manufactured by Daicel Cytec), 100 parts by mass of bisphenol A type (residual DC value = 52 mV), 40 parts by mass of (meth) acrylic compound (2CL, manufactured by Shin-Nakamura Chemical Industry Co., Ltd. (residual DC value = 73 mV)), thermosetting agent (dihydrazide adipate) , Otsuka Chemical Co., Ltd. (residual DC value = 53 mV)) by 50 parts by mass, photopolymerization initiator (OXE-01, manufactured by BASF (residual DC value = 68 mV)) by 20 parts by mass, inorganic particles (silica particles: S) -100, 130 parts by mass of Nippon Catalytic Chemical Co., Ltd. (residual DC value = 51 mV)), 70 parts by mass of organic particles (fine particle polymer F351, manufactured by Aika Kogyo Co., Ltd. (residual DC value = 55 mV)), and a silane coupling agent. (KBM-403, manufactured by Shin-Etsu Chemical Industry Co., Ltd. (residual DC value = 431 mV)) was mixed in an amount of 10 parts by mass. Got

[Example 6]
600 parts by mass of photocurable composition 1, 80 parts by mass of epoxy compound (Epicoat 1004AF, manufactured by Mitsubishi Chemical Co., Ltd., bisphenol A type (residual DC value = 57 mV)), epoxy compound (850-S, manufactured by DIC, bisphenol) 30 parts by mass of type A (residual DC value = 133 mV), 50 parts by mass of thermal curing agent (adipate dihydrazide, manufactured by Otsuka Chemical Co., Ltd. (residual DC value = 53 mV)), photopolymerization initiator (OXE-01, BASF) 20 parts by mass (residual DC value = 68 mV)), 130 parts by mass of inorganic particles (silica particles: S-100, manufactured by Nippon Catalytic Chemical Co., Ltd. (residual DC value = 51 mV)), organic particles (fine particle polymer F351, Aika) 70 parts by mass of an industrial product (residual DC value = 55 mV) and 20 parts by mass of a silane coupling agent (KBM-403, manufactured by Shinetsu Chemical Industry Co., Ltd. (residual DC value = 431 mV)) were mixed. Was sufficiently mixed with three rolls so as to be a uniform liquid to obtain a sealant.

[Example 7]
500 parts by mass of photocurable composition 1, epoxy compound (EP-4010S, manufactured by ADEKA, bisphenol A type (residual DC value = 64 mV)), 200 parts by mass, epoxy compound (850-S, manufactured by DIC, bisphenol A) 40 parts by mass of mold (residual DC value = 133 mV), 50 parts by mass of thermal curing agent (adipate dihydrazide, manufactured by Otsuka Chemical Co., Ltd. (residual DC value = 53 mV)), photopolymerization initiator (OXE-01, BASF) 20 parts by mass of manufactured (residual DC value = 68 mV)), 130 parts by mass of inorganic particles (silica particles: S-100, manufactured by Nippon Catalytic Chemical Co., Ltd. (residual DC value = 51 mV)), organic particles (fine particle polymer F351, Aika) 50 parts by mass of an industrial product (residual DC value = 55 mV) and 10 parts by mass of a silane coupling agent (KBM-403, manufactured by Shinetsu Chemical Industry Co., Ltd. (residual DC value = 431 mV)) were mixed. Then, these were sufficiently mixed with three rolls so as to be a uniform liquid to obtain a sealant.

[Comparative Example 1]
400 parts by mass of photocurable compound 2, epoxy compound (850-S, manufactured by DIC, bisphenol A type (residual DC value = 133 mV)) by 50 parts, epoxy compound (Epogosei NPG, manufactured by Yokkaichi Synthetic Co., Ltd., 1, 100 parts by mass of 4-butanediol diglycidyl ether (residual DC value = 300 mV), 50 parts by mass of (meth) acrylic compound (Ebecryl3700, manufactured by Daicel Cytec (residual DC value = 52 mV)), (meth) acrylic. 80 parts by mass of compound (2CL, manufactured by Shin-Nakamura Chemical Industry Co., Ltd. (residual DC value = 73 mV)), 50 parts by mass of thermosetting agent (adipate dihydrazide, manufactured by Otsuka Chemical Co., Ltd. (residual DC value = 53 mV)), photopolymerization 20 parts by weight of initiator (OXE-01, manufactured by BASF Japan (residual DC value = 68 mV)), 150 mass of inorganic particles (silica particles: S-100, manufactured by Nippon Catalytic Chemical Co., Ltd. (residual DC value = 51 mV)) 90 parts by mass of organic particles (fine particle polymer F351, manufactured by Aika Kogyo Co., Ltd. (residual DC value = 55 mV)), and silane coupling agent (KBM-403, manufactured by Shin-Etsu Chemical Co., Ltd. (residual DC value = 431 mV)). 10 parts by mass were mixed. Then, these were sufficiently mixed with three rolls so as to be a uniform liquid to obtain a sealant.

[Comparative Example 2]
600 parts by mass of photocurable compound 1, 80 parts by mass of (meth) acrylic compound (2CL, manufactured by Shin-Nakamura Chemical Industry Co., Ltd. (residual DC value = 73 mV)), thermosetting agent (dihydrazide adipate, manufactured by Otsuka Chemical Co., Ltd.) Residual DC value = 53 mV)) by 50 parts by mass, photopolymerization initiator (OXE-01, manufactured by BASF Japan, Inc. (residual DC value = 68 mV)) by 20 parts by mass, inorganic particles (silica particles: S-100, Japanese catalyst) 150 parts by mass of chemicals (residual DC value = 51 mV)), 90 parts by mass of organic particles (fine particle polymer F351, Aika Kogyo (residual DC value = 55 mV)), and silane coupling agent (KBM-403, 10 parts by mass of Shinetsu Chemical Industry Co., Ltd. (residual DC value = 431 mV) was mixed. Then, these were sufficiently mixed with three rolls so as to be a uniform liquid to obtain a sealant.

[Comparative Example 3]
400 parts by mass of photocurable compound 2, epoxy compound (EP-4010S, manufactured by ADEKA, bisphenol A type (residual DC value = 64 mV)) 100 parts by mass, epoxy compound (Epogosei NPG, manufactured by Yokkaichi Synthetic Co., Ltd., 1,4 -50 parts by mass of butanediol diglycidyl ether (residual DC value = 300 mV), 50 parts by mass of (meth) acrylic compound (Ebecryl3700, manufactured by Daicel Cytec (residual DC value = 52 mV)), (meth) acrylic compound (2CL, manufactured by Shin-Nakamura Chemical Industry Co., Ltd. (residual DC value = 73 mV)) by 80 parts by mass, thermosetting agent (adipate dihydrazide, manufactured by Otsuka Chemical Co., Ltd. (residual DC value = 53 mV)) by 50 parts by mass, photopolymerization started 20 parts by mass of the agent (OXE-01, manufactured by BASF (residual DC value = 68 mV)), 150 parts by mass of inorganic particles (silica particles: S-100, manufactured by Nippon Catalytic Chemical Co., Ltd. (residual DC value = 51 mV)), 90 parts by mass of organic particles (fine particle polymer F351, manufactured by Aika Kogyo Co., Ltd. (residual DC value = 55 mV)) and 10 parts by mass of silane coupling agent (KBM-403, manufactured by Shinetsu Chemical Industry Co., Ltd. (residual DC value = 431 mV)). Part, mixed. Then, these were sufficiently mixed with three rolls so as to be a uniform liquid to obtain a sealant.

[Comparative Example 4]
200 parts by mass of photocurable compound 1, epoxy compound (EP-4010S, manufactured by ADEKA, bisphenol A type (residual DC value = 64 mV), 40 parts by mass, epoxy compound (850-S, manufactured by DIC, bisphenol A type) 200 parts by mass of (residual DC value = 133 mV), 130 parts by mass of (meth) acrylic compound (Ebeclyl3700, manufactured by Daicel Cytec (residual DC value = 52 mV)), (meth) acrylic compound (2CL, Shin-Nakamura Chemical Industry Co., Ltd.) (Residual DC value = 73 mV)) 100 parts by mass, thermosetting agent (adipic acid dihydrazide, manufactured by Otsuka Chemical Co., Ltd. (residual DC value = 53 mV)) 50 parts by mass, photopolymerization initiator (OXE-01, BASF) 20 parts by mass of manufactured (residual DC value = 68 mV)), 150 parts by mass of inorganic particles (silica particles: S-100, manufactured by Nippon Catalytic Chemical Co., Ltd. (residual DC value = 51 mV)), organic particles (fine particle polymer F351, Aika) 90 parts by mass of an industrial product (residual DC value = 55 mV) and 20 parts by mass of a silane coupling agent (KBM-403, manufactured by Shinetsu Chemical Industry Co., Ltd. (residual DC value = 431 mV)) were mixed. Was sufficiently mixed with three rolls so as to be a uniform liquid to obtain a sealant.

[Comparative Example 5]
340 parts by mass of photocurable compound 1, epoxy compound (EP-4010S, manufactured by ADEKA, bisphenol A type (residual DC value = 64 mV), 130 parts by mass, epoxy compound (850-S, manufactured by DIC, bisphenol A type) Residual DC value = 133 mV) by 200 parts by mass, thermosetting agent (adipate dihydrazide, manufactured by Otsuka Chemical Co., Ltd. (residual DC value = 53 mV)) by 50 parts by mass, photopolymerization initiator (OXE-01, manufactured by BASF) (residual) 20 parts by mass of inorganic particles (silica particles: S-100, manufactured by Nippon Catalytic Chemical Co., Ltd. (residual DC value = 51 mV)), 150 parts by mass of organic particles (fine particle polymer F351, manufactured by Aika Kogyo Co., Ltd.) (Residual DC value = 55 mV)) was mixed in an amount of 90 parts by mass, and a silane coupling agent (KBM-403, manufactured by Shinetsu Chemical Industry Co., Ltd. (residual DC value = 431 mV)) was mixed in an amount of 20 parts by mass. The mixture was sufficiently mixed with a roll so as to have a uniform liquid to obtain a sealant.

[evaluation]
The sealants obtained in Examples and Comparative Examples were evaluated as follows.

<Measurement of residual DC value between sealant and liquid crystal display>
The above-mentioned sealing agent was mixed with the liquid crystal display, and the residual DC value was measured. 0.1 g of the liquid crystal sealant and 1 g of the liquid crystal (MLC-7026, manufactured by Merck & Co., Inc.) were put into a vial and heated at 120 ° C. for 1 hour to obtain a liquid crystal mixture. Next, this liquid crystal mixture was taken out and injected into a glass cell (KSSZ-10 / B111M1NSS05, manufactured by EHC) in which an alignment film and a transparent electrode were formed in advance. A voltage of 5 V was applied to the obtained cell for 1 second, short-circuited for 0.1 seconds, and then the remaining voltage (residual DC value) after 30 seconds was measured with a 6254 type measuring device (manufactured by Toyo Corporation). bottom. When the residual DC value of the liquid crystal display alone was measured in the same manner, the residual DC value of the liquid crystal display alone was 50 mV.

<Measurement of residual DC value of raw materials>
Each of the above-mentioned raw materials and a liquid crystal display were mixed, and the residual DC value was measured. 0.1 g of the compound and 1 g of liquid crystal (MLC-7026, manufactured by Merck & Co., Inc.) were put into a vial and heated at 120 ° C. for 1 hour to obtain a liquid crystal mixture. Next, this liquid crystal mixture was taken out and injected into a glass cell (KSSZ-10 / B111M1NSS05, manufactured by EHC) in which an alignment film and a transparent electrode were formed in advance. A voltage of 5 V was applied to the obtained cell for 1 second, short-circuited for 0.1 seconds, and then the residual voltage (residual DC value) after 30 seconds was measured with a 6254 type measuring device.

<Afterimage evaluation>
The sealant was applied to a 40 mm × 45 mm glass substrate (RT-DM88-PIN, manufactured by EHC) in which a transparent electrode and an alignment film were previously formed using a dispenser (shot master: manufactured by Musashi Engineering Co., Ltd.). Specifically, a 35 mm × 40 mm quadrangular seal pattern (cross-sectional area 3500 μm ² ) (main seal) and a similar seal pattern (38 mm × 43 mm quadrangular seal pattern) were formed on the outer circumference thereof.

Next, a liquid crystal display (MLC-7026-000, manufactured by Merck & Co., Inc.) corresponding to the capacity of the panel after bonding was precisely dropped into the frame of the main seal using a dispenser. Next, the paired glass substrates were bonded under reduced pressure, and then opened to the atmosphere for bonding. Then, the two laminated glass substrates were held in a light-shielding box for 3 minutes ^{, then irradiated with light having a wavelength of 370 to 450 nm at 100 mJ / cm 2} and further heated at 120 ° C. for 1 hour. Polarizing plates were attached to both sides of the obtained substrate to prepare an evaluation substrate.

Electrodes were connected so as to drive only one side of the portion of the evaluation substrate filled with the liquid crystal display, and the mixture was energized at 65 ° C. for 24 hours while applying a voltage of 10 V. After that, the entire surface was driven by 4 V, and the boundary line between the half-side drive and the full-surface drive was observed with a microscope. The afterimage was evaluated as follows from the state on the boundary line of the substrate. When narrowing the frame, only ○ can be said to be a range where there is no practical problem.
◯: No difference is seen on the boundary line of the substrate and no afterimage is seen Δ: An image is seen on the boundary line of the substrate within a range of less than 1 mm from the end of the sealing material ×: A part of 1 mm or more from the end of the sealing material Afterimage is seen on the board boundary line

<Adhesive strength evaluation>
Using a screen plate, the sealant was printed on 25 mm × 45 mm × 1 mm thick non-alkali glass. The seal pattern was a circle with a diameter of 1 mm. Then, a pair of non-alkali glass was placed on the seal pattern and fixed with a jig. The test piece was irradiated with ultraviolet light of 500 mW / cm ² with an ultraviolet light irradiation device (manufactured by Ushio, Inc.) to cure the sealant. At this time, the illuminance energy of the ultraviolet light was set to 3.0 J / cm ² . The test piece obtained by curing the sealant with light was heat-treated at 120 ° C. for 60 minutes using an oven to prepare a sample for measuring adhesive strength.

The tensile strength of the flat surface of the sample was measured by using a tensile tester (manufactured by Intesco) at a tensile speed of 2 mm / min and peeling the cured sealant in a direction parallel to the bottom surface of the glass. .. Here, the adhesive strength was evaluated as follows according to the magnitude of the planar tensile strength. When narrowing the frame, Δ or more is preferable.
〇: Tensile strength is 15 MPa or more Δ: Tensile strength is 10 MPa or more and less than 15 MPa ×: Tensile strength is less than 10 MPa

As shown in Table 1, the epoxy compound contains an epoxy compound, a (meth) acrylic / epoxy-containing compound, a (meth) acrylic compound, a heat curing agent, and a photopolymerization initiator, and the content of the epoxy compound is 22 to 38% by mass. In addition, with a sealant in which the residual DC value of the mixture of the sealant and the liquid crystal is 200% or less with respect to the residual DC value of the liquid crystal alone, the afterimage evaluation is good and the adhesive strength evaluation is also good. (Examples 1 to 7). It is considered that sufficient adhesiveness was obtained by the predetermined amount of the epoxy compound. Further, it can be said that the components in the sealant are difficult to elute into the liquid crystal display in the sealant having a low residual DC value when mixed with the liquid crystal display.

On the other hand, when the amount of the epoxy compound was less than 22% by mass, the result of the afterimage evaluation was good, but the result of the adhesiveness test was low (Comparative Example 2). On the other hand, when the amount of the epoxy compound exceeded 38% by mass, the adhesiveness was good, but the value of the afterimage residual DC was likely to increase, and the afterimage evaluation was poor (Comparative Example 5).

Further, even if the content of the epoxy compound was 22 to 38% by mass, the afterimage evaluation was poor in all cases when the residual DC value when the sealant and the liquid crystal were mixed was high (Comparative Example 1, 3 and 4).

This application claims priority based on Japanese Patent Application No. 2020-034974 filed on March 2, 2020. All the contents described in the application specification are incorporated in the application specification.

According to the sealant of the present invention, a seal member having high adhesiveness to the substrate can be obtained. In addition, the sealant does not easily contaminate the liquid crystal display. Therefore, the sealant is very useful as a sealant or the like for producing a seal member for various liquid crystal display panels.

Claims (10)

1. Epoxy compounds that do not have polymerizable functional groups other than epoxy groups,
   A (meth) acrylic-epoxy-containing compound having both a (meth) acrylic group and an epoxy group in one molecule,
   (Meta) acrylic compounds without epoxy groups,
   A sealant for a liquid crystal dropping method, which contains a thermosetting agent and a photopolymerization initiator and has a content of the epoxy compound of 22 to 38% by mass.
   A mixture of the sealant for the liquid crystal dropping method and liquid crystal at a mass ratio of 1:10 was heated at 120 ° C. for 1 hour, a voltage was applied at 5 V for 1 second, short-circuited for 0.1 seconds, and then 30 seconds later. The measured residual DC value is based on the residual DC value measured 30 seconds after heating only the liquid crystal at 120 ° C. for 1 hour, applying a voltage at 5 V for 1 second, short-circuiting for 0.1 seconds. 200% or less,
   Sealing agent for liquid crystal dripping method.
2. For each component contained in the sealant for the liquid crystal dropping method, each of the components and the liquid crystal was mixed at a mass ratio of 1:10, heated at 120 ° C. for 1 hour, and a voltage was applied at 5 V for 1 second. When the residual DC value is measured 30 seconds after short-circuiting for 1 second,
   After the residual DC value of 98% by mass or more of the sealant for the liquid crystal dropping method is such that only the liquid crystal is heated at 120 ° C. for 1 hour, a voltage is applied at 5 V for 1 second, and the liquid crystal display is short-circuited for 0.1 second. , 300% or less of the residual DC value measured after 30 seconds.
   The sealant for the liquid crystal dropping method according to claim 1.
3. The proportion of the component having a molecular weight of 500 or more in the epoxy compound is 25% by mass or more.
   The sealant for the liquid crystal dropping method according to claim 1 or 2.
4. One or more selected from the group consisting of an organic acid dihydrazide-based thermal latent curing agent, an imidazole-based thermal latent curing agent, an amine adduct-based thermal latent curing agent, and a polyamine-based thermal latent curing agent. Is,
   The sealant for the liquid crystal dropping method according to any one of claims 1 to 3.
5. Including more inorganic particles,
   The sealant for the liquid crystal dropping method according to any one of claims 1 to 4.
6. Including additional organic particles,
   The sealant for the liquid crystal dropping method according to any one of claims 1 to 5.
7. Further containing a silane coupling agent,
   The sealant for the liquid crystal dropping method according to any one of claims 1 to 6.
8. A step of applying the sealant for the liquid crystal dropping method according to any one of claims 1 to 7 onto one of the pair of substrates to form a seal pattern.
   A step of dropping a liquid crystal display in the region of the seal pattern on one of the substrates or on the other substrate in a state where the seal pattern is uncured.
   A step of superimposing the one substrate and the other substrate via the seal pattern, and
   The process of curing the seal pattern and
   A method for manufacturing a liquid crystal display panel, including.
9. In the step of curing the seal pattern, the seal pattern is irradiated with light.
   The method for manufacturing a liquid crystal display panel according to claim 8.
10. In the step of curing the seal pattern, it is heated after being irradiated with light.
    The method for manufacturing a liquid crystal display panel according to claim 9.