KR20150119213A - Composition, cured product, and display device and method for manufacturing same - Google Patents

Abstract

Disclosure of the Invention An object of the present invention is to provide a composition having a viscosity low enough to embed a minute gap, high photocurability, and little cell deformation after curing. (A) an epoxy resin, (A2) a compound having an oxetanyl group, (B) an acid addition product of a glycidyl group, an oxetanyl group, a vinyloxy group, a vinyloxy group, and a hydroxyl group (C) a photocationic polymerization initiator, and (D) a filler, wherein the content ratio of the component (B) is at least one selected from the group consisting of Is 4 to 40 parts by mass based on 100 parts by mass of the total of the component (A1), the component (A2) and the component (B), and the content of the component (D) 65 parts by mass.

Description

Technical Field [0001] The present invention relates to a composition, a cured product, a display device,

The present invention relates to a composition, a cured product, a display device and a method of manufacturing the same.

2. Description of the Related Art Recently, display devices for various electronic apparatuses include liquid crystal display type devices, organic EL type devices, and electrophoretic type devices. These display devices are generally a laminate having a display element such as a liquid crystal element and a pair of substrates for holding the display element therebetween and have a structure in which the peripheral portion of the display element is sealed with a seal member. The sealing method of the sealing member differs depending on the type of the device.

For example, a liquid crystal display device can be manufactured by: 1) applying a sealant on a transparent substrate to form a frame for filling the liquid crystal, 2) dropping a minute liquid crystal in the frame, and 3) (2) a method of superposing two substrates under a high vacuum in a cured state, and (4) a method of curing the liquid crystal sealing material (ODF method). That is, an encapsulant is disposed on one side of a substrate that supports the display element, and thereafter the substrate on which the encapsulant is not disposed and the substrate on which the encapsulant is disposed are bonded to each other via a sealing agent.

As such a liquid crystal sealing agent, for example, a liquid crystal sealing agent comprising an epoxy resin having low solubility in liquid crystal and an epoxy resin curing agent has been proposed (for example, Patent Document 1).

On the other hand, a display device of an electrophoretic mode or an electric flow mode, for example, a display device having a microcup structure (for example, Patent Document 2) has 1) a display device and a pair of substrates (2) applying or dropping a sealant to a gap (hereinafter also referred to as an end face) between the substrates formed on the periphery of the laminate, and (3) curing the sealant. That is, after the display element is sandwiched between the two substrates, the sealing agent is infiltrated into the gap between the two substrates, and then the sealing agent is cured.

As the sealing agent for the electrophoretic display device, a thermosetting resin composition containing a liquid epoxy resin, a thiol compound, a microcapsule containing a secondary amine or a tertiary amine, a filler and the like is known For example, Patent Document 3).

On the other hand, as a photo-curable resin composition excellent in curability and adhesiveness, an epoxy resin, a monomer having an oxetanyl group, an acrylic resin having a plurality of cationic polymerizable groups (prepolymer), and a photocurable resin composition (For example, Patent Document 4).

Japanese Patent Application Laid-Open No. 2005-018022 Japanese Patent Publication No. 2004-536332 International Publication No. 2012/01499 Japanese Patent No. 4667145

As described above, when a display device such as an electrophoresis method or an electric flow method is manufactured, a laminate having a display element sandwiched between a pair of substrates is assembled, and then a minute gap (The end face) of the substrate. Therefore, a sealing agent having a viscosity lower than that of the liquid crystal sealing agent used in a liquid crystal display device manufactured by the ODF method and capable of intruding into a minute gap is also desired.

In general, the curing method of the encapsulant may be either thermal curing or photo-curing, but when the device is deteriorated by heat, it is desired to be photo-curable. In order to reduce the cured residue upon photocuring, it is effective to contain a prepolymer having a plurality of cationically polymerizable functional groups as shown in Patent Document 4 in the encapsulant. However, such a prepolymer tends to remain stressed in the cured product as compared with a general epoxy resin. As a result, there is a problem that deformation (cell deformation) tends to occur in the resulting laminate.

In view of this, the present inventors have found that by controlling the content of the prepolymer or the content of the filler, the residual stress on the cured product is reduced and cell deformation can be suppressed.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and has as its object to provide a composition having a viscosity low enough to embed a minute gap, less cured residue after photo-curing, And a method for producing the same.

[1] A process for producing a photosensitive resin composition, which comprises the steps of (A1) mixing an epoxy resin (except for an addition polymer of a (meth) acrylate monomer having an epoxy group) and (A2) a compound having an oxetanyl group, (B) a polymer having at least one functional group selected from the group consisting of a glycidyl group, an oxetanyl group, a vinyloxy group, an acid adduct of a vinyloxy group, and a hydroxyl group, (C) a photocationic polymerization initiator and (D) a filler, wherein the content ratio of the component (B) is at least one selected from the group consisting of the components (A1), Is 4 to 40 parts by mass based on 100 parts by mass of the total amount of the component (B), and the content of the component (D) is 3 to 65 parts by mass with respect to 100 parts by mass of the composition.

[2] A composition according to [1], wherein the viscosity at 25 ° C and 2.5 rpm as measured by an E-type viscometer is from 0.5 to 50 Pa · s and is used as an end face encapsulant for a display device.

[3] The composition according to [2], wherein the display device is a device for displaying information by an electrophoresis method.

[4] The display device according to any one of [1] to [4], wherein the display device comprises an electrophoretic display element and a pair of substrates for holding the display element therebetween, wherein the pair of substrates formed on the periphery of the pair of substrates , And the display element is sealed between the pair of substrates by infiltrating the display element.

[5] The composition according to any one of [2] to [4], wherein the display device is an electronic paper.

[6] The composition according to any one of [1] to [5], wherein the (A1) epoxy resin comprises a biphasic liquid epoxy resin.

[7] The composition according to [6], wherein the bifunctional liquid epoxy resin is an aromatic epoxy resin of (A1-1) bifunctional ability.

[8] The composition according to [7], wherein the (A1) epoxy resin further comprises (A1-2) a monofunctional epoxy resin or an aliphatic epoxy resin.

[9] The composition according to [8], wherein the viscosity of the above (A1-2) monofunctional epoxy resin or aliphatic epoxy resin measured at 25 ° C. and 2.5 rpm by an E-type viscometer is 5 to 500 mPa · s .

(B) an addition polymer of the (meth) acrylate monomer having at least one functional group selected from the group consisting of a glycidyl group, an oxetanyl group, a vinyloxy group, an acid adduct of a vinyloxy group, and a hydroxyl group , Wherein the weight average molecular weight of the composition is 1000 to 100000. The composition according to any one of [1] to [9]

[11] The composition according to any one of [1] to [10], wherein the (D) filler comprises an organic filler.

[12] A cured product of the composition according to any one of [1] to [11], wherein the cured product has a water vapor transmission rate of 60 g / m < 2 >

[13] The display device according to any one of [1] to [11], wherein the gap between the pair of substrates formed on the periphery of the pair of substrates is sealed with a pair of substrates for holding the display element therebetween; A display device comprising a cured product of the composition described in one.

[14] A display device according to [13], wherein the gap between the pair of substrates is 20 to 500 μm.

[15] A method of manufacturing a display device, comprising the steps of: obtaining a laminate including a display element and a pair of substrates for holding the display element therebetween; 11. A method of manufacturing a display device, comprising the steps of: applying or dropping a composition described in any one of claims 1 to 11; and curing the applied or dropped composition.

According to the present invention, it is possible to provide a composition having a viscosity low enough to embed a minute gap, less cured residue after photo-curing, and less cell deformation after curing.

1 is a schematic diagram showing an embodiment of a display device of the present invention.

1. Composition

The composition of the present invention comprises (A) an epoxy resin, (A2) a compound having an oxetanyl group, (B) an addition polymer of a (meth) acrylate monomer having a cationic polymerizable functional group, (C) An initiator, and (D) a filler.

(A1) epoxy resin

The epoxy resin preferably has two or more epoxy groups in one molecule and further contains an epoxy resin in a liquid state at room temperature. In the present invention, an addition polymer of a (meth) acrylate monomer having an epoxy group to an epoxy resin; That is, it does not include a homopolymer of a (meth) acrylic monomer having an epoxy group and a copolymer of a (meth) acrylic monomer having an epoxy group and another monomer.

Examples of the epoxy resin include bisphenol-type epoxy resins such as bisphenol A type, bisphenol F type, bisphenol E type, bisphenol S type, bisphenol AD type, and hydrogenated bisphenol A type; Diphenyl ether type epoxy resin; Novolak type epoxy resins such as phenol novolac type, cresol novolak type, biphenyl novolac type, bisphenol novolac type, naphthol novolak type, trisphenol novolak type and dicyclopentadiene novolak type; Biphenyl type epoxy resins; Naphthyl type epoxy resin; Triphenolalkane type epoxy resins such as triphenol methane type, triphenol ethane type and triphenolpropane type; Alicyclic epoxy resins; Aliphatic epoxy resins; Polysulfide-modified epoxy resins; Resorcinol type epoxy resin; Glycidylamine type epoxy resins, and the like.

Among these epoxy resins, a bifunctional epoxy resin is preferable from the viewpoints that the crystallinity is relatively low, the coating property and the viscosity stability are good, and a cured product having a crosslinked structure is easily obtained. The bifunctional epoxy resin is preferably an aromatic epoxy resin in view of high moisture resistance of the cured product. That is, the (A1) epoxy resin preferably contains an aromatic epoxy resin of (A1-1) bifunctional ability.

The bifunctional aromatic epoxy resin is more preferably a bisphenol-type epoxy resin such as a bisphenol A type epoxy resin, a bisphenol F type epoxy resin, or a bisphenol E type epoxy resin.

The weight average molecular weight (Mw) of the bifunctional aromatic epoxy resin is preferably 200 to 700, more preferably 300 to 500. The weight average molecular weight of the epoxy resin can be measured by, for example, gel permeation chromatography (GPC) using polystyrene as a standard.

The epoxy equivalent of the bifunctional aromatic epoxy resin is preferably 100 to 250 g / eq, more preferably 110 to 200 g / eq.

(A1) The epoxy resin may contain only one type of epoxy resin, or may include two or more kinds of epoxy resins different in kind and molecular weight. For example, when the epoxy resin (A1) contains an aromatic epoxy resin having a bifunctional (A1-1) functionality, it is preferable to use a monofunctional epoxy resin, aliphatic epoxy resin, or the like (A1-2 ) Another epoxy resin is preferably included.

The monofunctional epoxy resin may be an aromatic epoxy resin, an alicyclic epoxy resin, or an aliphatic epoxy resin. Specific examples thereof include phenyl glycidyl ether, butyl glycidyl ether, and the like.

The aliphatic epoxy resin may be mono-functional or di-functional. The aliphatic epoxy resin is preferably an aliphatic polyglycidyl ether obtained by reacting an aliphatic polyhydric alcohol having 2 to 18 carbon atoms with epichlorohydrin. Specific examples thereof include hexane diol diglycidyl ether, tetraethylene glycol diglycidyl ether, trimethylol propane triglycidyl ether, and the like.

(A1-2) The weight average molecular weight of the other epoxy resin is preferably 60 to 400, more preferably 100 to 300, from the viewpoint of lowering the viscosity of the composition.

The viscosity of other epoxy resin at 25 占 폚 and 2.5 rpm measured by an E-type viscometer is preferably 5 to 500 mPa · s. This is because the epoxy resin having a viscosity in the above range easily adjusts the viscosity of the composition to a range described later.

(A1-2) The content ratio of the (a1-1) dielasticity of the other epoxy resin to the aromatic epoxy resin can be appropriately set according to the viscosity of the composition to be obtained and the moisture resistance of the cured product. For example, the content ratio of the other epoxy resin (A1-2) may be about 1 to 20 mass%, preferably about 5 to 15 mass%, relative to the aromatic epoxy resin having the bifunctional (A1-1). (A1-2) By setting the content ratio of the other epoxy resin to a certain value or more, the viscosity of the composition tends to be lowered; By setting it to a certain value or less, moisture resistance of the cured product can be easily maintained.

Further, in order to increase the heat resistance of the cured product, the (A1) epoxy resin may further include (A1-3) a solid epoxy resin. (A1-3) The solid epoxy resin includes, for example, a solid A-type epoxy resin.

The total content of the (A1) epoxy resin may be about 10 to 70 mass% with respect to the total composition. (A1-1) The content ratio of the aromatic epoxy resin having a bifunctional ability can be set to about 80 to 100 mass% with respect to the total of the (A1) epoxy resin.

(A2) a compound having an oxetanyl group

The compound having an oxetanyl group is a compound having at least one oxetanyl group in one molecule. In the present invention, an addition polymer of a (meth) acrylate monomer having an oxetanyl group to an oxetanyl group-containing compound; That is, it does not include a homopolymer of a (meth) acrylate monomer having an oxetanyl group, or a copolymer of a (meth) acrylate monomer having an oxetanyl group and another monomer.

The compound having an oxetanyl group may be an aromatic compound or an aliphatic compound. From the viewpoint of low viscosity and easy adjustment of viscosity, it is preferably an aliphatic compound. Further, the compound having an oxetanyl group may be monofunctional or may have a bifunctional or higher functionality. From the viewpoint of obtaining a cured product having a crosslinked structure, it is preferably a bifunctional.

Examples of the compound having a monofunctional oxetanyl group include 3-ethyl-3-hydroxymethyloxetane, 3-ethyl-3-phenoxymethyloxetane, 3- ) Oxetane, 3-ethyl (triethoxysilylpropoxymethyl) oxetane, 3-cyclohexyloxymethyl-3-ethyl-oxetane, and the like.

Examples of the compound having an oxetanyl group having a bifunctional or higher functionality include bis (3-ethyl-3-oxetanylmethyl) ether, 1,4-bis {[ }benzene;

Trimethylolpropane tris (3-ethyl-3-oxetanylmethyl) ether, pentaerythritol tris (3-ethyl-3-oxetanylmethyl) ether, pentaerythritol tetrakis (3-ethyl-3-oxetanylmethyl) ether, dipentaerythritol pentaquis (3-ethyl-3-oxetanylmethyl) ether and the like.

(A2) The oxetanyl group-containing compound may have a weight average molecular weight (Mw) of 100 to 500. [

The compound having an oxetanyl group (A2) may lower the viscosity of the composition of the present invention. Further, by combining the epoxy resin (A1) and the compound having an oxetanyl group (A2), the curing rate of the composition tends to be kept constant. As a result, the curing shrinkage of the composition of the present invention is apt to be reduced.

The content of the (A2) oxetanyl group-containing compound is preferably from 20 to 50 mass% with respect to the epoxy resin (A1), from the viewpoint that the viscosity of the composition is kept constant or less and the curing rate is kept constant, , And more preferably from 25 to 40 mass%.

(B) an addition polymer of a (meth) acrylate monomer having a cationic polymerizable functional group

The addition polymer of the (meth) acrylate monomer having a cationic polymerizable functional group may be a homopolymer of a (meth) acrylate monomer having a cationic polymerizable functional group; Or may be a copolymer of a (meth) acrylate monomer having a cationic polymerizable functional group and another radically polymerizable monomer. The addition polymer is preferably a chain addition polymer (having no crosslinking structure). The (meth) acrylate in the present invention is acrylate or the corresponding methacrylate.

The (meth) acrylate monomer in the (meth) acrylate monomer having a cationically polymerizable functional group is preferably methyl acrylate. The number of the radical polymerizable group ((meth) acryloyl group) contained in the (meth) acrylate monomer having a cationic polymerizable functional group is preferably one in view of obtaining a chain addition polymer.

Examples of the cationic polymerizable functional group contained in the (meth) acrylate monomer having a cationic polymerizable functional group include a glycidyl group, an oxetanyl group, a vinyloxy group, an acid adduct of a vinyloxy group, and a hydroxyl group, May be a glycidyl group, an oxetanyl group or a hydroxyl group. The number of cationic polymerizable functional groups in one molecule of the (meth) acrylate monomer may be one, two or more.

Examples of the (meth) acrylate having a glycidyl group include glycidyl (meth) acrylate, 3,4-epoxycyclohexylmethyl (meth) acrylate, methylglycidyl (meth) . Examples of the (meth) acrylate having an oxetanyl group include 3-ethyl-3-oxetanylethyl (meth) acrylate and the like.

Examples of the (meth) acrylate having a vinyloxy group include 2- (vinyloxyethoxy) ethyl (meth) acrylate. The vinyloxy group may be an acid addition product to which an acid such as acetic acid, trifluoroacetic acid or hydrochloric acid is added.

Examples of the (meth) acrylate having a hydroxyl group include 2-hydroxyethyl (meth) acrylate, hydroxypropyl (meth) acrylate, ring-opening portion of? -Caprolactone of 2-hydroxyethyl Water, a (meth) acrylic acid adduct of an epoxy compound (for example, 2-hydroxy-3-phenoxypropyl acrylate), and the like.

Examples of other radically polymerizable monomers copolymerizable with methyl methacrylate having a cationic polymerizable functional group include alkyl (meth) acrylates having an alkyl moiety having 1 to 18 carbon atoms; ?,? - unsaturated acids such as acrylic acid and methacrylic acid; Unsaturated carboxylic acid dicarboxylic acids such as maleic acid, fumaric acid and itaconic acid; Aromatic vinyl compounds such as styrene and? -Methylstyrene; ?,? - unsaturated nitriles such as acrylonitrile and methacrylonitrile; Maleic anhydride, maleimide, N-substituted maleimide, glutaric anhydride, N-vinylpyrrolidone (VP) and the like. These may be used alone or in combination of two or more. For example, an aliphatic compound such as alkyl (meth) acrylate and an aromatic compound such as styrene may be combined.

The content of the (meth) acrylate-derived (meth) acrylate-containing copolymer in the copolymer of (meth) acrylate having a cationic polymerizable functional group with another radically polymerizable monomer is preferably 5 mass % Or more, and more preferably 7 mass% or more. On the other hand, when the content ratio of the (meth) acrylate having a cationic polymerizable functional group is too large, the content ratio of the (meth) acrylate having a cationic polymerizable functional group in the cured product is preferably 40 mass% % Or less.

The cationic polymerizable functional group equivalent of the (meth) acrylate addition polymer having a cationic polymerizable functional group is preferably 5000 g / eq or less from the viewpoint of reducing the cured residue during the photo-curing of the composition containing the cationic polymerizable functional group, Or less. On the other hand, from the viewpoint of reducing the residual stress in the cured product, the cationic polymerizable functional group equivalent is preferably 300 g / eq or more, more preferably 400 g / eq or more.

The weight-average molecular weight (in terms of polystyrene) of the addition polymer of the (meth) acrylate having a cationic polymerizable functional group, as measured by GPC, is generally in the range of from 1,000 to 1,000,000, from the viewpoint of not raising the viscosity of the composition excessively, 100000, preferably 1000 to 50000.

(B) the addition polymer of the (meth) acrylate having a cationic polymerizable functional group has been prepolymerized in advance, so that it is possible not only to shorten the curing time until a predetermined degree of curing is reached, Since it contains a large amount of cationic polymerizable functional groups, it also exhibits good curability. Thereby, the component (B) can reduce the cured residue after the photo-curing, and exhibits good photo-curability, as compared with a composition containing only the compound containing the (A1) epoxy resin or the (A2) oxetanyl group.

On the other hand, in the cured product of the composition containing the component (B), the stress tends to remain, and the resulting laminate (cell) tends to be deformed. In order to suppress such cell deformation, 1) the content ratio of the component (B) to the total of the components (A1) and (A2) is set to a certain value or less; 2) It is preferable that the content ratio of the (D) filler to the whole composition is set to a certain value or more.

Concretely, the content of the component (B) is preferably 4 to 40 parts by mass, more preferably 5 to 37 parts by mass, per 100 parts by mass of the total of the components (A1), (A2) More preferably from 5 to 35 parts by mass, and still more preferably from 5 to 20 parts by mass. When the content ratio of the component (B) is set to a certain value or more, the cured residue at the time of photo-curing can be sufficiently reduced. On the other hand, by reducing the content of the component (B) to a certain value or less, the residual stress in the cured product can be reduced and cell deformation can be reduced.

(C) a photocationic polymerization initiator

The cationic ion polymerization initiator is a compound which generates a cationic species or a Lewis acid by an active energy ray, and is preferably an onium salt compound.

The onium salt compound which generates a cationic species or Lewis acid by an active energy ray includes an onium ion and an anion. Examples of onium ions include diphenyliodonium, 4-methoxydiphenyliodonium, bis (4-methylphenyl) iodonium, bis (4-tert- (Diphenylsulfonium) -phenyl] sulfide, bis [4- (di (4- (2- Phenyl] sulfide, [eta] 5-2,4- (cyclopentadienyl) [1,2,3,4,5,6-.eta .- (methylethyl) benzene] Iron (1+), and the like. Examples of anions include tetrafluoroborate, hexafluorophosphate, hexafluoroantimonate, hexafluoroarsenate, hexachloroantimonate, and the like. Examples of commercially available onium salt compounds which generate cationic species or Lewis acids by an active energy ray include Uvacure 1590, 1591 (trade name, manufactured by Daicel UCB Co., Ltd.), Sun Aid SI-110, SI- SP-100, SP-172, SP-170 and SP-152 (trade names, manufactured by SANSHIN KAGAKU KOGYO CO., LTD. 2074 (trade name, manufactured by Rhodia), and the like. These photocationic polymerization initiators may be used singly or in combination of two or more.

The composition of the present invention may further contain a sensitizer such as thioxanthone or 2-ethyl anthraquinone, if necessary.

The content of the photocationic polymerization initiator (C) is preferably 0.5 to 10 parts by mass based on 100 parts by mass of the total of the components (A1), (A2) and (B) in order to obtain a curing property of a certain level or more.

(D) a filler

The filler may be an inorganic filler, an organic filler, or a mixture thereof. The filler preferably includes an organic filler to increase the impact resistance of the cured product. The filler may contain two or more kinds of inorganic fillers, two or more kinds of organic fillers, or both of inorganic fillers and organic fillers. Further, a filler having a different specific gravity may be included.

The inorganic filler is not particularly limited and examples thereof include calcium carbonate, magnesium carbonate, barium sulfate, magnesium sulfate, aluminum silicate, zirconium silicate, iron oxide, titanium oxide, aluminum oxide (alumina), zinc oxide, , Kaolin, talc, glass beads, cerite active clay, bentonite, aluminum nitride, silicon nitride, and the like, preferably silicon dioxide and talc.

Examples of the organic filler include fine particles selected from the group consisting of silicon fine particles, acrylic fine particles, styrene fine particles such as styrene · divinylbenzene copolymer and polyolefin fine particles; And waxes selected from the group consisting of carnauba wax, microcrystalline wax, modified microcrystalline wax, Fischer-Tropsch wax, and modified Fischer-Tropsch wax.

The shape of the filler is not particularly limited and may be any of a regular shape such as a spherical shape, a plate shape, a needle shape, or an irregular shape. However, it is preferable that the shape of the filler is spherical in view of enhancing the filling property into a minute gap. The average primary particle diameter of the filler is preferably 0.1 to 20 占 퐉, more preferably 0.1 to 10 占 퐉, and still more preferably 0.5 to 5 占 퐉. The average primary particle diameter of the filler can be measured by the laser diffraction method described in JIS Z8825. In order to increase the filler filling rate in the composition, it is preferable to include two or more kinds of fillers having different particle diameters.

The filler is preferably a light dispersion rather than a monodisperse from the viewpoint of enhancing the filling property into a minute gap. The composition containing the filler having a high dispersibility is liable to have a high viscosity, and the filling property with respect to a minute gap tends to decrease.

The surface treatment may be applied to the filler in order to suppress the viscosity increase of the composition due to agglomeration of the filler. Specifically, since the agglomeration of the filler is likely to occur due to the mutual action of the fillers, it is preferable that a treatment for inactivating (non-polarizing) the surface of the filler is performed in order to prevent the fillers from interacting with each other.

Examples of the treatment for inactivating (non-polarizing) the surface of the filler include a method capable of introducing a hydrophobic group into the surface of the filler, and a treatment with a cyclic siloxane, a silane coupling agent, a titanate coupling agent or hexaalkyldisilazane Method.

The filler can increase the moisture resistance of the cured product of the composition containing it or adjust the linear expansion property. In addition, by containing the filler, the content of the curing component in the composition can be reduced, so that it is possible to make it difficult to generate stress at the time of curing. The thixotropic property of the composition may also be adjusted.

The content of the filler is preferably 3 to 65 parts by mass, more preferably 5 to 60 parts by mass, and still more preferably 20 to 60 parts by mass with respect to 100 parts by mass of the composition of the present invention. When the composition contains both an inorganic filler and an organic filler, the content of the filler means the total content of the inorganic filler and the organic filler. By setting the content of the filler to a certain level or more, the moisture resistance of the cured product can be increased and it becomes difficult to generate stress during curing. By setting the content of the filler to a certain level or less, the viscosity of the composition can be easily reduced to a certain level or less, and the applicability can be maintained.

(E) Other components

The composition of the present invention may further contain other curable resin as required. In addition, the composition of the present invention may further comprise a heat curing agent if necessary in order to allow both light curing and thermal curing to be used together. Examples of the thermosetting agent include an acid anhydride, an amine compound and the like.

The composition of the present invention may further contain additives such as a coupling agent such as a silane coupling agent, a rubber agent, an ion trap agent, an ion exchanger, a leveling agent, a pigment, a dye, a plasticizer and a defoaming agent. These additives may be used singly or in combination of plural kinds. Examples of the silane coupling agent include 3-glycidoxypropyltrimethoxysilane and the like.

Among them, the composition of the present invention preferably further comprises a rubber agent for enhancing the impact resistance of the end face of the display device or enhancing the adhesion with the substrate as described later. Examples of the rubber include silicone rubber, acrylic rubber, olefin rubber, polyester rubber, and urethane rubber.

As described above, in the present invention, in order to suppress cell deformation, it is preferable to use an addition polymer of the (A) epoxy resin, the (A2) oxetanyl group-containing compound and the (B) (Meth) acrylate monomer to the total amount of the addition polymer is preferably set to a predetermined value or less ", and the content ratio of (D) the filler to the entire composition is set to a predetermined value or more. On the other hand, the total amount of the addition polymer of the (A) epoxy resin, (A2) oxetanyl group-containing compound and (B) (meth) acrylate monomer addition polymer of the (B) (A1), the content ratio of the aromatic epoxy resin having a relatively high viscosity (A1-1) dielasticity contained in the epoxy resin is high, so that the viscosity of the composition may be increased. Further, when the content of the " (D) filler in the entire composition is at least a certain level, " the viscosity of the composition tends to be further increased.

On the contrary, the content ratio of the compound having (A2) oxetanyl group / (A1) epoxy resin; (A1-2) The viscosity of the composition can be kept low by increasing the content ratio of the aromatic epoxy resin of the other epoxy resin / (A1-1) transitionable. As described above, the content of the (A2) oxetanyl group-containing compound in the (A1) epoxy resin is preferably 20 to 50% by mass. (A1-2) The content ratio of (A2-1) bifunctional component of the other epoxy resin to the aromatic epoxy resin is preferably 1 to 20% by mass.

The water content of the composition of the present invention is preferably 0.5% by weight or less, more preferably 0.2% by weight or less. The composition of the present invention is preferably used as an end face sealant of a display device as described later. When the moisture content in the sealing agent is large, moisture tends to invade from the sealing agent in the device sealed by the sealing agent, and the display device may be affected. Particularly, a device displaying information by an electrophoresis method is susceptible to polar molecules such as water. Therefore, in the present invention, the moisture content of the composition is preferably 0.5 wt% or less.

The moisture content in the composition can be measured by the Karl Fischer method. In order to keep the water content in the composition within the above-mentioned range, a raw material having a low moisture content is selected and a composition is prepared under a condition of low water content. It is also preferable to dewater each raw material before preparing the composition.

The viscosity of the composition of the present invention measured by an E-type viscometer at 25 캜 and 2.5 rpm is preferably from 0.5 to 50 Pa s, and more preferably from 1 to 20 Pa s. When the viscosity of the composition is less than 0.5 Pa s s, it is difficult to maintain the shape of the seal pattern when the sealant is used, and liquid run-down tends to occur. On the other hand, when the viscosity of the composition is more than 50 Pa s, it can not be filled in a minute gap, and the sealing property tends to be lowered.

The viscosity of the composition is, as described above, the content ratio of the compound containing (A2) oxetanyl group / (A1) epoxy resin; (A1) the content ratio of the aromatic epoxy resin of (A1-2) other epoxy resin / (A1-1) bifunctional in the epoxy resin; (D) the shape and particle diameter of the filler and the content ratio thereof. Specifically, in order to reduce the viscosity of the composition, the ratio of (A2) the compound containing an oxetanyl group / (A1) epoxy resin is increased; (A1-2) the content ratio of other epoxy resin / (A1-1) bifunctional aromatic epoxy resin is increased; (D) the content of the filler in the entire composition may be reduced.

The cured product of the composition of the present invention preferably has a certain degree of heat resistance so as to maintain the bonding strength with the substrate at a high temperature when the composition is used as a sealing agent of a display device. The preferable heat resistance is determined depending on the type of the display device substrate. For example, in a display device in which a display element is sandwiched between a resin sheet having a coefficient of linear expansion close to the linear expansion coefficient of the composition and a glass substrate, the composition of the present invention is used as a sealant for sealing the gap between a pair of substrates When used, the glass transition temperature of the cured product obtained by photo-curing the composition of the present invention by irradiation with ultraviolet rays under the condition of 1 J / cm 2 is in the above range, the possibility of occurrence of interface separation between each substrate and the sealing agent is low, It becomes possible to provide a high display device.

The glass transition temperature of the cured product is obtained by irradiating ultraviolet light to the composition of the present invention under the condition of 1 J / cm 2 to photo-cure the film to give a cured film having a thickness of 100 탆. And the glass transition temperature of the obtained cured film is measured at a heating rate of 5 DEG C / minute by DMS.

The cured product of the composition of the present invention preferably has a moisture resistance of a certain level or higher in order to suppress deterioration of the device due to permeated water when the composition is used as a sealing agent of a display device. For example, the cured product of the composition of the present invention preferably has a moisture permeability (water vapor permeability) at 60 ° C and 80% RH of 200 g / (m 2 · 100 μm · 24h) or less and 150 g / (m 2 · 100 μm · 24h ) Or less.

The moisture permeability of the cured product can be measured by a moisture-permeable cup method conforming to JIS Z0208. Specifically, the composition of the present invention is irradiated with ultraviolet rays under the condition of 1 J / cm 2 to be photo-cured to obtain a cured film having a thickness of 100 탆. Using the cured film, an aluminum cup is produced by the method according to JIS Z0208, and the amount of moisture permeation is calculated from the weight before and after being left in a high temperature and high humidity bath at 60 DEG C and 80% RH for 24 hours.

(G / m < 2 >, 100 mu m, 24 h) = [weight of aluminum cup after leaving for 24 hours (g)

The method for producing the composition of the present invention is not particularly limited. For example, the composition of the present invention can be prepared by mixing the above-described components. The means for mixing the respective components is not particularly limited and includes, for example, a twin-screw type stirrer, a roll kneader, a twin screw extruder, a ball mill kneader and a planetary stirrer. The composition of the present invention can be obtained by mixing the above-mentioned components and then filtering them with a filter to remove impurities and further performing a vacuum degassing treatment.

The composition of the present invention is preferably used as a sealant for end faces of a display device for sealing end faces of various display devices.

The composition of the present invention has high applicability because of suitably low viscosity, has good curability, and has high humidity resistance of the cured product. Therefore, a sealing agent for various display devices having a liquid crystal element, an EL element, an LED element, an electrophoretic display element, or the like; And is preferably used as a sealing agent for sealing the end face of the display device having the electrophoretic display element. Examples of electrophoretic display devices include electronic paper and the like.

2. Display device and its manufacturing method

The display device of the present invention includes a display element such as an electrophoresis method, a pair of substrates for holding the display element therebetween, and a seal member sealing the gap between the substrates formed on the periphery of the pair of substrates. The seal member may be a cured product of the composition of the present invention.

1 is a schematic diagram showing an embodiment of a display device of the present invention. The display device 10 includes an electrophoretic display element 12, a pair of substrates 14 and 16 for holding the display element 12 therebetween, and a pair of substrates 14 and 16, And a seal member 20 for sealing the gap 18 formed in the seal member 20.

The display element 12 has an electrophoretic display layer 12A and transparent electrodes 12B and 12C for driving the display layer 12A.

The substrates 14 and 16 may be a glass plate, a resin sheet, or the like, but it is preferable that at least a display surface of the substrates 14 and 16 is a transparent glass plate or a resin sheet. Examples of the transparent resin sheet include polyester resins such as polyethylene terephthalate; Acrylic resin; And a sheet composed of a polycarbonate resin or the like. The thickness of the substrates 14 and 16 may vary depending on the application, but may be about 0.1 to 3 mm, preferably 0.5 to 1.5 mm.

The gap (gap) 18 between the substrate 14 and the substrate 16 may vary depending on the application, but is, for example, 20 to 500 mu m, and more preferably 25 mu m or less in an electronic paper or the like.

The seal member 20 may be a cured product of the composition of the present invention, as described above.

The display device of the present invention is characterized in that it comprises, for example: 1) obtaining a laminate having a display element and a pair of substrates for supporting and supporting the display element; 2) a gap between a pair of substrates formed on the periphery of the laminate , A step of applying or dropping the composition of the present invention, and 3) a step of curing the composition of the present invention.

The means for applying or dropping the composition of the present invention to the periphery of the laminate is not particularly limited and may be dispenser, screen printing, or the like.

The curing method of the composition of the present invention may be thermosetting or photo-curing, but when the element is liable to be deteriorated by heat, photo-curing is preferable.

The irradiation light in the photo-curing is not particularly limited, but it is preferably ultraviolet ray. The light irradiation amount may be, for example, 0.5 to 5 J / m 2.

When the composition of the present invention further contains a thermosetting agent, photo-curing and thermal curing may be used in combination. In this case, the heat curing temperature in the heat curing is preferably 60 to 80 占 폚, more preferably 60 to 70 占 폚, from the viewpoint of reducing the damage to the display element. The heat curing time varies depending on the heat curing temperature and the amount of the sealant, but can be, for example, about 30 to 90 minutes.

As described above, the composition of the present invention can be photocured in a short time in that it contains a certain amount or more of the component (B). On the other hand, the composition containing the component (B) tends to cause deformation (cell deformation) in the laminate obtained after curing since stresses remain in the cured product. In a laminate having such a deformation, a part of the seal member is peeled off from the substrate, and there is a fear that the sealability is lowered.

On the other hand, the composition of the present invention is adjusted so that the "content ratio of component (B) is less than or equal to a certain value" and the content ratio of "component (D) Thereby, the residual stress in the cured product of the composition of the present invention can be reduced, and cell deformation can be reduced.

On the other hand, if the content ratio of the component (D) is set to a certain value or more, the viscosity of the composition tends to increase. When the content ratio of the component (B) to the total of the component (A1), the component (A2) and the component (B) is set to a certain value or less, the content of the component (A1- 1) component is increased, there is a possibility that the viscosity of the composition is increased. On the contrary, the composition of the present invention contains the component (A2) / component (A1); By adjusting the content ratio of the (A1-2) component / (A1-1) component in the component (A1), low viscosity can be maintained. Thereby, the composition of the present invention can be embedded at a minute gap formed at the periphery of the pair of substrates with high accuracy.

Example

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

1. Materials of composition

(A1) epoxy resin

(A1-1) a bifunctional aromatic epoxy resin

Bisphenol A type epoxy resin: JER828 manufactured by Mitsubishi Kagaku Co., Ltd., epoxy equivalent 184 to 194 g / eq

Hydrogenated bisphenol A type epoxy resin: EP-4080S manufactured by ADEKA, epoxy equivalent 215 g / eq

(A1-2) Other epoxy resin

P-glycidyl ether: PGE, manufactured by Sakamoto Yakuhin Kogyo Co., Ltd., epoxy equivalent: 148 to 155 g / eq, molecular weight: 150, E-type viscosity at 25 DEG C and 2.5 rpm measured by the method described later,

1,6-hexanediol diglycidyl ether: SR-16H manufactured by Sakamoto Yakuhin Kogyo Co., Ltd., epoxy equivalent 150 to 165 g / eq, molecular weight 230, E at 25 ° C and 2.5 rpm, Viscosity 25 mPa · s

(A1-3) solid shape epoxy resin

Bisphenol A type solid epoxy resin: JER1001 manufactured by Mitsubishi Chemical Corporation, epoxy equivalent: 450 to 500 g / eq, softening point: 64 DEG C

(A2) a compound having an oxetanyl group

3-ethyl-3-hydroxymethyloxetane (oxetane alcohol): OXT-101 manufactured by Doagosei Co., Ltd., molecular weight of 116.2

OXT-221, manufactured by Toagosei Co., Ltd., a molecular weight of 214.3

(B) addition polymer of (meth) acrylate monomer

[Production Example 1]

340.0 g of xylene was charged into an acrylic resin composition production apparatus having an internal volume of 2 L and equipped with a stirrer, a thermometer, a reflux condenser and a dropping tank under nitrogen, and then the temperature was raised to the polymerization temperature of 135 캜. A mixture of 400 g of methyl methacrylate, 50 g of styrene, 50 g of glycidyl methacrylate, and 20 g of tert-butyl 2-ethylhexanoate as a radical initiator was added dropwise to this solution over 4 hours. After completion of the dropwise addition, stirring was continued at 135 캜 for 1 hour. Subsequently, by making the apparatus vacuum, the xylene and the remaining monomer were distilled off to obtain an addition polymer A (GMA-modified) of the (meth) acrylate monomer. The weight average molecular weight (Mw) of the obtained addition polymer A was 3000. The cationic polymerizable functional group equivalent of the addition polymer A was 1422 g / eq.

[Production Example 2]

340.0 g of xylene was charged into an acrylic resin composition production apparatus having an internal volume of 2 L and equipped with a stirrer, a thermometer, a reflux condenser and a dropping tank under nitrogen, and then the temperature was raised to the polymerization temperature of 135 캜. A mixture of 400 g of methyl methacrylate, 50 g of styrene, 50 g of 3-ethyl-3-oxetanylethyl methacrylate, and 20 g of tert-butyl 2-ethylhexanoate as a radical initiator was added to this, , And the mixture was added dropwise over 4 hours. After completion of the dropwise addition, stirring was continued at 135 캜 for 1 hour. Subsequently, by making this production apparatus vacuum, the xylene and the remaining monomer were distilled off to obtain an addition polymer B (OXT modified) of a (meth) acrylate monomer. The weight average molecular weight of the obtained addition polymer B was 3000. The cationic polymerizable functional group equivalent of the addition polymer B was 1842 g / eq.

[Production Example 3]

340.0 g of xylene was charged into an acrylic resin composition production apparatus having an internal volume of 2 L and equipped with a stirrer, a thermometer, a reflux condenser and a dropping tank under nitrogen, and then the temperature was raised to the polymerization temperature of 135 캜. Water mixed with 400 g of methyl methacrylate, 50 g of styrene, 50 g of 2-hydroxyethyl methacrylate, and 20 g of tert-butyl 2-ethylhexanoate as a radical initiator was added dropwise over 4 hours as a radical polymerizable monomer Respectively. Stirring was continued at 135 캜 for 1 hour after completion of dropwise addition. Subsequently, by making this production apparatus vacuum, the xylene and the remaining monomer were distilled off to obtain an addition polymer C (HEMA modified) of a (meth) acrylate monomer. The weight average molecular weight (Mw) of the obtained addition polymer C was 3000.

(C) Gwangyang ion initiator

(tolylcumyl) iodonium tetrakis (pentafluorophenyl) borate: manufactured by Rhodia R2074

Diphenyl [4- (phenylthio) phenyl] sulfonium hexafluorophosphate: CPI-110P manufactured by SAN-A PRO

Triarylsulfonium salt: CPI-210S manufactured by San A Pro Co., Ltd.

Diethyl thioxanthone (DETX): DETX-S manufactured by Nippon Kayaku Co., Ltd.

Dibutoxyanthracene (DBA): UVS-1331 manufactured by Kawasaki Seiko Kogyo Co., Ltd.

(D) a filler

Inorganic filler:

Silicon dioxide (FUSELEX (registered trademark) RD-8 manufactured by Tatsumori Co., Ltd., average primary particle diameter 15 mu m, specific surface area 2.2 m < 2 &

Silicon dioxide (manufactured by Tokuyama Corporation: Ekusera UF-725, mass average particle diameter d50: 7 mu m, specific surface area: 1.6 m2 / g, spherical shape)

Organic filler:

Acrylic fine particles (F325G, manufactured by Aika Corporation) having an average primary particle diameter of 0.5 占 퐉, spherical)

Acrylic fine particles (F351G manufactured by Aikogyo KK, average primary particle diameter 0.3 탆, spherical)

(E) Silane coupling agent

3-glycidoxypropyltrimethoxysilane: KBM403 (trade name, manufactured by Shinetsugaku Kogyo Co., Ltd.)

(F) Trifunctional acrylic resin

Trimethylolpropane triacrylate: A-TMPT manufactured by Shin Nakamura Kagakukogyo Co., Ltd.

(G) Radical system photopolymerization initiator

2-dimethylamino-1- (4-morpholinophenyl) -butanone-1: Irgacure369 manufactured by BASF Japan Ltd.

2. Preparation of composition

(Example 1)

40 parts by mass of the addition polymer A of (meth) acrylate obtained in Production Example 1 and 360 parts by mass of bisphenol A type epoxy resin (manufactured by Mitsubishi Chemical Corp.) as the component (A1) were added to a light- JER828) and 50 parts by weight of phenylglycidyl ether (PGE manufactured by Sakamoto Yakuhin Kogyo Co., Ltd.), 125 parts by weight of 3-ethyl-3 {[(3-ethyloxetan- 400 parts by mass of an inorganic filler (FUSELEX (registered trademark) RD-8 manufactured by Tatsumori Co., Ltd., silicon dioxide) and (E) 400 parts by mass of (E) 10 parts by mass of 3-glycidoxypropyltrimethoxysilane (KBM403, manufactured by Shinetsu Kagaku Kogyo Co., Ltd.) was added as a component, and the mixture was heated and stirred to completely dissolve it. Then, 10 parts by mass of (tolylcumyl) iodonium tetrakis (pentafluorophenyl) borate (Rh204, manufactured by Rhodia) and 5 parts by mass of diethyl thioxanthone (manufactured by Nippon Kayaku Co., Ltd. ) Preparation DETX-S) was further added and stirred to obtain a composition.

(Examples 2 to 21 and Comparative Examples 1 to 7)

A composition was obtained in the same manner as in Example 1 except that the composition of the composition was changed as shown in Tables 1 to 3.

(evaluation)

4) cell deformation test, 5) gap penetration test, 6) high temperature and high humidity reliability, 7) glass transition temperature, 8) element deterioration test, and 9) 80% RH The amount of moisture permeation was evaluated by the following method.

1) Viscosity

The viscosity of the obtained composition was measured by an E-type viscometer at 25 DEG C and 2.5 rpm.

2) UV curing test

The obtained composition was applied on a polycarbonate plate and a polyethylene terephthalate (PET) plate (4.5 cm x 2.0 cm x 0.2 cm) with a thickness of 100 mu m using an applicator, and ultraviolet rays were irradiated with a metal halide lamp at 1 J / Cm < 2 >. The degree of curing of the coating film on the polycarbonate plate immediately after the irradiation was visually evaluated. The degree of curing was evaluated as " Good " Δ indicates that the surface is hardened only, or that the surface has stickiness (tack) Δ; And those which were not cured at all were evaluated as x.

3) Adhesive strength

To the obtained composition, 1% of spherical silica having an average particle diameter of 50 탆 as a spacer was added, mixed and defoamed. The composition containing the spacer was drawn on a non-alkali glass substrate of 25 mm x 45 mm x 0.7 mm thick through a screen plate to form a circular seal pattern having a diameter of 1 mm.

An alkali-free glass substrate on which a seal pattern was drawn was superimposed and fixed on a pair of alkali-free glass substrates, and then irradiated with ultraviolet rays under a condition of 1 J / cm 2 to be photo-cured to obtain test pieces. The obtained test pieces were stored in a constant temperature bath at 25 캜 and a humidity of 50% for 24 hours. Thereafter, the plane tensile strength of the test piece taken out from the thermostatic chamber was measured with a tensile tester (manufactured by Tesco) under the condition of a tensile speed of 2 mm / min.

4) Cell deformation test

A spherical spacer having an average particle diameter of 50 mu m was sprayed (placed) on a non-alkali glass substrate of 50 mm x 50 mm x 0.7 mm thick. On this substrate, a pair of non-alkali glass substrates of 40 mm x 40 mm x 0.7 mm thick was superimposed, and then the obtained composition was applied to a gap (50 mu m) between the substrates formed on the periphery by the dispenser. Thereafter, the applied composition was irradiated with ultraviolet rays under the condition of 1 J / cm < 2 >

Whether a Newton ring occurred in the center of the obtained cell was observed, and the presence or absence of deformation was evaluated.

○: Newton ring was not visible in the center of the cell (no deformation)

C: One Newton ring occurred in the center of the cell (slight deformation)

X: Two or more Newton rings were formed in the center of the cell (with deformation)

5) Clearance penetration test

(Registered trademark) having a size of 30 mm x 30 mm x thickness 50 mu m was placed between a non-alkali glass substrate of 50 mm x 50 mm x 0.7 mm thick and a 40 mm x 40 mm x 0.7 mm thick non-alkali glass substrate. The sheet was sandwiched therebetween to form a peripheral portion having a width of 5 mm including a gap (50 mu m) between the glass substrates on the outer periphery of the Teflon (registered trademark) sheet. At the periphery thereof, the obtained composition was applied by a dispenser. Thereafter, the coated composition was irradiated with ultraviolet rays under the condition of 1 J / cm < 2 > It was observed whether or not the composition had permeated into the periphery of the obtained measuring cell.

&Amp; cir &: The composition penetrated to the outer periphery of Teflon (registered trademark) sheet

DELTA: Part of the portion where the composition did not penetrate to the outer periphery of the Teflon (registered trademark) sheet

X: No penetration of the composition to the outer periphery of the Teflon (registered trademark) sheet

6) High temperature and high humidity reliability test

10 mg of dried fine calcium carbonate fine powder was placed on a 50 mm x 50 mm x 0.7 mm thick non-alkali glass substrate, and then a pair of 40 mm x 40 mm x 0.7 mm thick non-alkali glass substrates were superimposed , And the obtained composition was applied to a gap (100 mu m) between the glass substrates formed on the periphery with a dispenser. Thereafter, the coated composition was irradiated with ultraviolet rays under the condition of 1 J / cm < 2 >

The cell for measurement was measured for cell weights before and after being allowed to stand when (1) the cells were allowed to stand at 60 ° C and 95% RH for 1000 hours and (2) at 85 ° C and 85% RH for 1000 hours, respectively. The smaller the change in the cell weight before and after leaving, the higher the humidity resistance.

?: The weight of the cell after being left is not less than 100% and not more than 102%

?: The weight of the cell after being left is not less than 102 but not more than 105%

X: The weight of the cell after being left exceeds 105% of the weight of the cell before being left to stand

7) Glass transition temperature (Tg)

The composition containing the spacer prepared in 1) above was coated on a release paper with a thickness of 100 mu m by using an applicator. The coating film was photocured by irradiating ultraviolet rays to the coating film formation side of the release paper on which the coating film of the composition was formed under the condition of 1 J / cm 2. Thereafter, the coating film was peeled off from the release paper to obtain a film having a thickness of 100 mu m. The glass transition temperature (Tg) of the obtained film was measured at a heating rate of 5 占 폚 / min using DMS-6100 manufactured by Seiko Instruments Inc.

8) Device degradation test

Three dryness test specimens (12 mm x 40 mm) manufactured by Advantech Co., Ltd. were arranged side by side on a 50 mm x 50 mm x 0.7 mm thick alkali-free glass substrate. On this substrate, a pair of 45 mm x 45 mm x 0.7 mm thick non-alkali glass substrates were superimposed, and then the resulting composition was placed in a gap (gap distance: 100 m) between the substrates formed on the periphery Respectively. Thereafter, the coated composition was irradiated with ultraviolet rays under the condition of 1 J / cm < 2 >

The degree of discoloration of the drying test paper after being left for 60 hours at 80 ° C under a condition of 60 ° C and 80% RH was evaluated on the basis of a standard discoloration chart (moisture content of 1.0 to 10.0 marks) .

?: Drying degree of the end face of the cell after left standing The color of the test paper corresponds to a water content of 1.0 to 3.0

: Drying degree of the end face of the cell after being left to stand The color of the test paper corresponds to a water content of 4.0 to 5.0

X: Drying degree of the end face of the cell after leaving the color The color of the test paper corresponds to a water content of 5.5 to 10.0

9) Measurement of the amount of moisture permeation by the method of moisture-permeation cup

An aluminum cup was prepared by the method according to JIS Z0208 using the 100 탆 film obtained in the item 6), and the amount of moisture permeation was calculated from the weight before and after leaving in a high temperature and high humidity tank of 60 캜 80% RH for 24 hours Respectively.

(G / m < 2 >, 100 mu m, 24 h) = [weight of aluminum cup after leaving for 24 hours (g)

The evaluation results of Examples 1 to 11 are shown in Table 1, the evaluation results of Examples 12 to 21 are shown in Table 2, and the evaluation results of Comparative Examples 1 to 7 are shown in Table 3. In addition, the numerical values in the composition column in Tables 1 to 3 are all " parts by mass ".

[Table 1]

[Table 2]

[Table 3]

It can be seen that the compositions of Examples 1 to 21 exhibit low viscosity and good gap permeability. Further, it can be seen that the compositions of Examples 1 to 21 have good UV curability, less cell deformation, and low moisture permeability of cured products. Further, when the content ratio of the component (B) is a specific value or more, it is found that the cured residue is small and the curability is high. On the other hand, if the content of the component (B) is less than a specific value, it is difficult to cause deformation of the cell, which is considered to be caused by the residual stress in the cured product. Further, it is considered that it is difficult to lower the moisture resistance of the cured product, which is considered to be caused by cell deformation. And the content of the component (B) is in a more preferable range, the effect is more remarkable. When the content of the component (D) is 3 to 65 parts by mass, the moisture permeability is lowered and the cell deformation is less likely to occur because the cured product becomes hard. It is considered that cell deformation is likely to occur when the content ratio of the component (D) is small and the proportion of the component (B) or the like which easily generates residual stress in the cured product increases.

On the other hand, it can be seen that the compositions of Comparative Examples 1 to 7 do not satisfy these characteristics at the same time.

Specifically, it can be seen that the composition of Comparative Examples 1 and 4, in which the content of the component (B) is small, is large in cured residue and low in curability. On the other hand, it can be seen that the compositions of Comparative Examples 2, 3 and 5, in which the content of the component (B) is large, cause cell deformation which appears to be caused by the residual stress in the cured product. In addition, it is considered that the compositions of Comparative Examples 2, 3, and 5 also lowered the moisture resistance of the cured product, which is believed to be caused by cell deformation.

Further, it can be seen that the composition of Comparative Example 6, which contains the component (D) in excess, has a high viscosity and a low penetration into the gap. Furthermore, even in the case of photo-curing, the composition of Comparative Example 7 was poor in moisture resistance and the result of the device deterioration test was not good.

From the comparison of Examples 1, 9 and 10, it was found that (A1-2) the use of a different epoxy resin as the monofunctional epoxy resin or the aliphatic epoxy resin makes it possible to reduce the viscosity of the composition as compared with an aromatic epoxy resin .

[Industrial applicability]

According to the present invention, it is possible to provide a composition which has a viscosity low enough to embed a minute gap and has high photo-curability and little cell deformation after curing. Therefore, the composition of the present invention is preferably used as a sealing member in a display device such as an electronic paper.

10: Display device
12: Display element
14, 16: substrate
18: clearance
20: Seal member

Claims (15)

(A1) an epoxy resin (except for an addition polymer of a (meth) acrylate monomer having an epoxy group)
(A2) a compound having an oxetanyl group (provided that the addition polymer of the (meth) acrylate monomer having an oxetanyl group is excluded)
(B) an addition polymer of a (meth) acrylate monomer having at least one functional group selected from the group consisting of a glycidyl group, an oxetanyl group, a vinyloxy group, an acid adduct of a vinyloxy group, and a hydroxyl group,
(C) a photocationic polymerization initiator,
(D) a filler,
The content of the component (B) is 4 to 40 parts by mass based on 100 parts by mass of the total of the component (A1), the component (A2) and the component (B)
Wherein the content of the component (D) is 3 to 65 parts by mass relative to 100 parts by mass of the composition. The method according to claim 1,
A composition used as an end face sealant for a display device, wherein the viscosity at 25 占 폚 and 2.5 rpm as measured by an E-type viscometer is from 0.5 to 50 Pa 占 퐏. 3. The method of claim 2,
Wherein the display device is a device for displaying information by an electrophoretic method. 3. The method of claim 2,
Wherein the display device comprises an electrophoretic display element and a pair of substrates for holding the display element therebetween,
And penetrating the gap between the pair of substrates formed on the periphery of the pair of substrates to seal the display device between the pair of substrates. 3. The method of claim 2,
Wherein the display device is an electronic paper. The method according to claim 1,
Wherein the (A1) epoxy resin comprises a biphasic liquid epoxy resin. The method according to claim 6,
Wherein the bifunctional liquid epoxy resin is an aromatic epoxy resin of (A1-1) bifunctional ability. 8. The method of claim 7,
The above-mentioned (A1) epoxy resin further comprises (A1-2) a monofunctional epoxy resin or an aliphatic epoxy resin. 9. The method of claim 8,
Wherein the viscosity of the (A1-2) monofunctional epoxy resin or the aliphatic epoxy resin at 25 占 폚 and 2.5 rpm as measured by an E-type viscometer is 5 to 500 mPa s. The method according to claim 1,
The weight average of (B) the addition polymer of the (meth) acrylate monomer having at least one functional group selected from the group consisting of a glycidyl group, an oxetanyl group, a vinyloxy group, an acid adduct of a vinyloxy group and a hydroxyl group A composition having a molecular weight of from 1000 to 100000. The method according to claim 1,
Wherein the (D) filler comprises an organic filler. A cured product of the composition according to claim 1,
The cured product has a water vapor transmission rate of 200 g / m < 2 > day or less at a temperature of 60 DEG C and 80% RH per 100 mu m of the cured product. A display element,
A pair of substrates for holding the display element therebetween,
A display device comprising a cured product of the composition according to claim 1, which seals the gap between the pair of substrates formed on the periphery of the pair of substrates. 14. The method of claim 13,
And the gap between the pair of substrates is 20 to 500 mu m. A step of obtaining a laminate including a display element and a pair of substrates for holding the display element therebetween;
Applying or dropping the composition according to claim 1 onto a gap between the pair of substrates formed on the periphery of the laminate,
And curing the applied or dropped composition.

Images