Classifications

• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08K—Use of inorganic or non-macromolecular organic substances as compounding ingredients
  • C08K5/00—Use of organic ingredients
  • C08K5/0008—Organic ingredients according to more than one of the "one dot" groups of C08K5/01 - C08K5/59
  • C08K5/0025—Crosslinking or vulcanising agents; including accelerators
• • G—PHYSICS
  • G02—OPTICS
  • G02F—OPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS
  • G02F1/00—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics
  • G02F1/01—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour 
  • G02F1/13—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour  based on liquid crystals, e.g. single liquid crystal display cells
  • G02F1/133—Constructional arrangements; Operation of liquid crystal cells; Circuit arrangements
  • G02F1/1333—Constructional arrangements; Manufacturing methods
  • G02F1/1339—Gaskets; Spacers; Sealing of cells
• • G—PHYSICS
  • G02—OPTICS
  • G02F—OPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS
  • G02F1/00—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics
  • G02F1/01—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour 
  • G02F1/13—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour  based on liquid crystals, e.g. single liquid crystal display cells
  • G02F1/133—Constructional arrangements; Operation of liquid crystal cells; Circuit arrangements
  • G02F1/1333—Constructional arrangements; Manufacturing methods
  • G02F1/1341—Filling or closing of cells
• • G—PHYSICS
  • G02—OPTICS
  • G02F—OPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS
  • G02F1/00—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics
  • G02F1/01—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour 
  • G02F1/13—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour  based on liquid crystals, e.g. single liquid crystal display cells
  • G02F1/133—Constructional arrangements; Operation of liquid crystal cells; Circuit arrangements
  • G02F1/1333—Constructional arrangements; Manufacturing methods
  • G02F1/1341—Filling or closing of cells
  • G02F1/13415—Drop filling process

Definitions

• the present invention relates to a liquid crystal sealant and a method for producing a liquid crystal display panel using the same.
• liquid crystal display panels have been widely used as image display panels for various electronic devices such as mobile phones and personal computers.
• the liquid crystal display panel has a structure in which a liquid crystal material (hereinafter simply referred to as “liquid crystal”) is sandwiched between two transparent substrates having electrodes provided on the surface, and the periphery thereof is sealed with a liquid crystal sealant. It is.
• liquid crystal sealant has a small influence on the reliability of the liquid crystal display panel because it is in direct contact with the liquid crystal although the amount used is small. Therefore, in order to achieve high image quality of the liquid crystal display panel, liquid crystal sealants are currently required to have advanced and diverse characteristics.
• liquid crystal display panels are mainly manufactured by a liquid crystal injection method.
• the liquid crystal injection method is (1) after applying a liquid crystal sealant on one transparent substrate to form a frame, and (2) drying the liquid crystal sealant by precuring the substrate.
• the other substrate is bonded, (3) the two substrates are heated and pressed, and the substrates are bonded together to form a frame (cell) of the liquid crystal sealant between the substrates, and (4) empty
• This is a method of manufacturing a liquid crystal display panel by injecting an appropriate amount of liquid crystal into a cell and then sealing the liquid crystal injection port.
• liquid crystal dropping method has been studied as a method for manufacturing a liquid crystal display panel, which is expected to improve productivity.
• a liquid crystal sealant is applied on a transparent substrate to form a frame for filling the liquid crystal
• (2) a minute liquid crystal is dropped into the frame
• two substrates are stacked under high vacuum while the sealant is in an uncured state, and then (4) the liquid crystal sealant is cured to produce a panel.
• a light and thermosetting liquid crystal sealant may be used.
• the liquid crystal sealant is preliminarily cured by irradiating light such as ultraviolet rays, it is heated by heating. Curing may be performed.
• liquid crystal sealing agent for the liquid crystal dropping method
• a liquid epoxy resin Patent Document 1
• an agent Patent Document 2.
• a liquid crystal sealant containing resin fine particles having a core-shell structure has been proposed (Patent Document 3).
• an organic filler to the liquid crystal sealant (Patent Document 4).
• liquid crystal sealing agents containing organic fillers such as rubbery components and resin fine particles are known.
• the organic filler plays a role as a stress relaxation agent in the liquid crystal sealant. Therefore, when the organic filler occupies a large proportion in the volume of the liquid crystal sealing agent, the effect as a stress relaxation agent can be expected.
• organic fillers are not compatible with liquid components (such as acrylic resins and (meth) acryl-modified epoxy resins), it is difficult to mix and disperse a large amount of organic fillers. Therefore, the stress relaxation property of the liquid crystal seal obtained from the liquid crystal sealant is not sufficiently increased, and the adhesive strength is not sufficient. Even if a large amount of organic filler could be blended, the viscosity of the liquid crystal sealant was likely to increase, and the applicability was liable to be impaired.
• liquid components such as acrylic resins and (meth) acryl-modified epoxy resins
• the present invention by adding an organic filler having a small specific surface area to the liquid crystal sealant, a large amount of the organic filler is dispersed in the liquid crystal sealant, thereby improving the stress relaxation property and adhesive strength of the liquid crystal seal.
• 1st of this invention is related with the manufacturing method of the liquid-crystal sealing compound and liquid crystal display panel which are shown below.
• At least one resin selected from (1) acrylic resin (1a) or (meth) acryl-modified epoxy resin (1b) having an epoxy group and a (meth) acryl group in one molecule; ) An organic filler, and (3) a radical polymerization initiator, wherein the average specific surface area of the organic filler of (2) is 0.4 m 2 / g or more and 1.5 m 2 / g.
• Liquid crystal sealing agent which is the following.
• the hydrogen bonding functional group equivalent in one molecule of the (1) resin is 1.0 ⁇ 10 ⁇ 4 mol / g or more and 5.0 ⁇ 10 ⁇ 3 mol / g or less.
• the content of the organic filler (2) is 30 to 100 parts by mass with respect to 100 parts by mass of the resin unit including the acrylic resin (1a) and the (meth) acryl-modified epoxy resin (1b).
• the liquid crystal sealing agent according to [1] or [2].
• the organic filler (2) is selected from the group consisting of silicone fine particles, acrylic fine particles, styrene fine particles, urethane fine particles, acrylic / silicone composite fine particles, and polyolefin fine particles having a softening point of 30 to 120 ° C.
• the radical polymerization initiator (3) is added in an amount of 0.01 to 3.0 with respect to 100 parts by mass of the resin unit obtained by combining the acrylic resin (1a) and the (meth) acryl-modified epoxy resin (1b).
• the resin unit further includes 3 to 30 parts by mass of (5) an inorganic filler with respect to 100 parts by mass of the resin unit in which the acrylic resin (1a) and the (meth) acryl-modified epoxy (1b) are combined.
• the liquid crystal sealant according to any one of [8] to [8].
• the liquid crystal sealant of the present invention is preferably used for the production of a liquid crystal display panel by a liquid crystal dropping method.
• the liquid crystal sealant of the present invention is used for forming a liquid crystal seal of a liquid crystal display panel.
• the formed liquid crystal seal effectively suppresses liquid crystal leakage and has high adhesive strength. Also, the gap width between the substrates of the liquid crystal cell can be adjusted appropriately.
• the liquid crystal sealant of the present invention includes (1) at least one kind of resin, (2) an organic filler, and (3) a radical polymerization initiator. Furthermore, (4) an epoxy curing agent and (5) an inorganic filler may be included.
• a liquid-crystal sealing compound contains at least 1 type of resin (1)
• the said resin (1) is an acrylic resin (1a), or an epoxy group and (meth) acryl group in 1 molecule. It contains at least one resin selected from (meth) acryl-modified epoxy resins (1b).
• the resin (1) includes a (meth) acryl-modified epoxy resin (1b). The (meth) acryl-modified epoxy resin (1b) improves the moisture resistance of the cured product.
• Acrylic resin (1a) refers to a compound containing one or more (meth) acrylic groups. However, the acrylic resin (1a) does not contain an epoxy group.
• acrylic resins include diacrylates and / or dimethacrylates such as polyethylene glycol, propylene glycol, polypropylene glycol; diacrylates and / or dimethacrylates of tris (2-hydroxyethyl) isocyanurate; 4 per mole of neopentyl glycol.
• Diacrylate and / or dimethacrylate of diol obtained by adding at least 1 mole of ethylene oxide or propylene oxide; Diacrylate and / or diacrylate of diol obtained by adding 2 mole of ethylene oxide or propylene oxide to 1 mole of bisphenol A Methacrylate: Diol of triol obtained by adding 3 mol or more of ethylene oxide or propylene oxide to 1 mol of trimethylolpropane Diacrylate and / or dimethacrylate of diol obtained by adding 4 mol or more of ethylene oxide or propylene oxide to 1 mol of bisphenol A; tris (2-hydroxyethyl) isocyanurate triacrylate And / or trimethacrylate; trimethylolpropane triacrylate and / or trimethacrylate, or oligomer thereof; pentaerythritol triacrylate and / or trimethacrylate, or oligomer thereof; polyacrylate and / or polymethacrylate of dipentaery
• the content of the acrylic resin (1a) in the liquid crystal sealant is preferably 0 to 80 parts by mass, and preferably 0 to 75 parts by mass with respect to 100 parts by mass of the liquid crystal sealant, although it depends on the required degree of curability. More preferably, it is 0 to 60 parts by mass.
• the weight average molecular weight of the acrylic resin (1a) may be about 310 to 500, for example.
• the weight average molecular weight Mw of the acrylic resin (1a) can be measured, for example, by gel permeation chromatography (GPC).
• the (meth) acryl-modified epoxy resin (1b) is preferably a (meth) acryl-modified epoxy resin obtained by reacting an epoxy resin and (meth) acrylic acid, for example, in the presence of a basic catalyst.
• (Meth) acryl may be either methacryl or acrylic.
• the raw material epoxy resin may be a bifunctional or higher functional epoxy resin having two or more epoxy groups in the molecule, such as bisphenol A type, bisphenol F type, 2,2′-diallyl bisphenol A type, bisphenol AD type, And bisphenol type epoxy resins such as hydrogenated bisphenol type; novolak type epoxy resins such as phenol novolak type, cresol novolak type, biphenyl novolak type, and trisphenol novolak type; biphenyl type epoxy resin; naphthalene type epoxy resin and the like.
• bisphenol A type bisphenol F type
• 2,2′-diallyl bisphenol A type bisphenol AD type
• bisphenol type epoxy resins such as hydrogenated bisphenol type
• novolak type epoxy resins such as phenol novolak type, cresol novolak type, biphenyl novolak type, and trisphenol novolak type
• biphenyl type epoxy resin naphthalene type epoxy resin and the like.
• a (meth) acryl-modified epoxy resin obtained by (meth) acryl modification of a trifunctional or tetrafunctional polyfunctional epoxy resin is preferably a bifunctional epoxy resin because it has a high crosslinking density and is likely to have a low adhesive strength. .
• the bifunctional epoxy resin is preferably a biphenyl type epoxy resin, a naphthalene type epoxy resin, or a bisphenol type epoxy resin, and bisphenol type epoxy resins such as bisphenol A type and bisphenol F type are particularly preferable from the viewpoint of production efficiency. This is because the bisphenol type epoxy resin has advantages such as excellent applicability as compared with the biphenyl ether type epoxy resin.
• the raw material epoxy resin may be one kind or a combination of two or more kinds. Moreover, it is preferable that the epoxy resin used as a raw material is highly purified by a molecular distillation method, a washing method, or the like.
• the weight average molecular weight of the (meth) acryl-modified epoxy resin (1b) may be, for example, about 310 to 500.
• the weight average molecular weight Mw of the (meth) acryl-modified epoxy resin (1b) can be measured, for example, by gel permeation chromatography (GPC).
• the content of the (meth) acryl-modified epoxy resin (1b) in the liquid crystal sealant is preferably 0 to 80 parts by mass, more preferably 0 to 75 parts by mass with respect to 100 parts by mass of the liquid crystal sealant.
• the amount is preferably 0 to 60 parts by mass.
• the (meth) acryl-modified epoxy resin has an epoxy group and a (meth) acryl group in the molecule, it can have both photocuring properties and thermosetting properties. Furthermore, even if the (meth) acryl-modified epoxy resin is an amorphous epoxy resin, since the ratio of the number of hydroxyl groups to the number of epoxy groups is large, dissolution in liquid crystals can be highly suppressed.
• the acrylic resin (1a) and the (meth) acryl-modified epoxy resin (1b) have a hydrogen bonding functional group such as a hydroxyl group, a urethane bond, an amide group, or a carboxyl group.
• a hydrogen bonding functional group such as a hydroxyl group, a urethane bond, an amide group, or a carboxyl group.
• the hydrogen bondable functional group include at least a hydroxyl group generated by the reaction of the epoxy group of the epoxy resin with (meth) acrylic acid, but the acrylic resin (1a) and the (meth) acryl-modified epoxy resin (1b)
• the hydroxyl group, urethane bond, carboxyl group, amide group, and the like contained in (meth) acrylic acid and epoxy resin which are raw materials of Since a resin having a hydrogen bonding functional group has low compatibility with a liquid crystal material that is hydrophobic, dissolution in the liquid crystal material is suppressed. Therefore, a liquid crystal sealing agent suitable for the liquid crystal
• the hydrogen-bonding functional group equivalent of the acrylic resin (1a) and the (meth) acryl-modified epoxy resin (1b) is preferably 1.0 ⁇ 10 ⁇ 4 to 5 ⁇ 10 ⁇ 3 mol / g, ⁇ more preferably 10 -3 ⁇ 4.5 ⁇ 10 -3 mol / g, more preferably from 1.5 ⁇ 10 -3 ⁇ 4.0 ⁇ 10 -3 mol / g.
• the hydrogen bondable functional group equivalent is 1.0 ⁇ 10 ⁇ 4 mol / g or more, the number of hydrogen bondable functional groups in one molecule of the acrylic resin (1a) and the (meth) acryl-modified epoxy resin (1b) Since it is contained sufficiently, an effect of suppressing dissolution in liquid crystal is easily obtained.
• the hydrogen bondable functional group equivalent is 5 ⁇ 10 ⁇ 3 mol / g or less
• the cured product of the acrylic resin (1a) and the (meth) acrylic-modified epoxy resin (1b) is likely to have sufficient moisture resistance.
• familiarity with the organic filler is extremely difficult to be impaired.
• the hydrogen bondable functional group equivalent (mol / g) of the acrylic resin (1a) and the (meth) acryl-modified epoxy resin (1b) is “one molecule acrylic resin (1a) or (meth) acryl-modified epoxy resin (1b)”.
• Mw weight average molecular weight
• the hydrogen bondable functional group equivalent of the (meth) acryl-modified epoxy resin can be adjusted, for example, by adjusting the number of moles of (meth) acrylic acid to be reacted with the raw material epoxy resin; the raw material (meth) acrylic acid or epoxy resin It can be controlled by adjusting the amount of the hydrogen-bonding functional group possessed by.
• the hydroxyl value equivalent of the (meth) acryl-modified epoxy resin obtained by reacting the epoxy resin as a raw material with (meth) acrylic acid is 3 ⁇ 10 ⁇ 3 to 5 ⁇ 10 ⁇ 3 mol / g. preferable.
• the total content of the acrylic resin (1a) and the (meth) acryl-modified epoxy resin (1b) with respect to 100 parts by mass of the liquid crystal sealant is preferably 10 to 75 parts by mass, and preferably 10 to 70 parts by mass. Is more preferably 40 to 60 parts by mass.
• the organic filler contained in the liquid crystal sealant is not particularly limited, but has a melting point or softening point of 30 to 120 from the viewpoint of preventing dripping of the liquid crystal sealant due to melting near the thermosetting temperature. Those having a temperature of ° C are preferred.
• the liquid crystal sealant provided in the gap between the substrates of the liquid crystal cell is reversibly or irreversibly deformed (crushed or crushed), Prevent leaks. By setting the softening point of the organic filler to 30 to 120 ° C., the deformation of the organic filler is facilitated and the sealing ability of the liquid crystal sealing agent is enhanced.
• organic filler examples include fine particles selected from the group consisting of silicone fine particles, acrylic fine particles, styrene fine particles such as styrene / divinylbenzene copolymer, urethane fine particles, acrylic / silicone composite fine particles, and polyolefin fine particles.
• the average value of the specific surface area of the organic filler is preferably 0.4 m 2 / g or more and 1.5 m 2 / g or less, and more preferably 0.5 m 2 / g or more and 1.0 m 2 / g or less.
• the specific surface area is measured according to JIS Z8830.
• An organic filler having a small specific surface area (1.5 m 2 / g or less) hardly increases the viscosity of the liquid crystal sealant and does not easily form an aggregate of organic fillers even when added in a large amount to the liquid crystal sealant. .
• the specific surface area of the organic filler can greatly depend not only on the particle diameter of the organic filler but also on the roughness of the particle surface.
• the organic filler is not easily compatible with the resin component contained in the liquid crystal sealant. Therefore, the amount of the organic filler having a large specific surface area (greater than 1.5 m 2 / g) that can be blended in the liquid crystal sealant without causing aggregation becomes low. When there is little content of an organic filler, adhesive strength will fall. This is because the stress caused by curing shrinkage of the liquid crystal sealant is not sufficiently relaxed by the organic filler.
• the organic filler is aggregated in the liquid crystal sealing agent, the organic filler cannot be uniformly distributed in the liquid crystal sealing agent. Therefore, the stress due to curing shrinkage of the liquid crystal sealant is not sufficiently relaxed by the organic filler, and the adhesive strength is reduced.
• the viscosity of the liquid crystal sealant tends to increase.
• the viscosity of the liquid crystal sealant is too high, the liquid crystal sealant is unlikely to be deformed into a predetermined shape when the liquid crystal cell substrate and the substrate are overlapped. This makes it difficult to properly control the gap width between the substrates of the liquid crystal cell.
• the specific surface area of the organic filler within a certain range, the content of the organic filler in the liquid crystal sealing agent is increased, and as a result, while properly controlling the gap width between the substrates of the liquid crystal cell, the liquid crystal sealing agent ( Increasing the adhesive strength of the cured liquid crystal sealant).
• the liquid crystal sealant of the present invention can appropriately control the gap width between the substrates even if the gap width between the substrates of the liquid crystal cell is 1 ⁇ m to 5 ⁇ m.
• the contact area between the resin component contained in the liquid crystal sealant and the organic filler can be reduced, and the thixotropic index (TI value) can be lowered.
• TI value thixotropic index
• the viscosity at a low share is low.
• the liquid crystal sealant is stirred, many bubbles are less likely to be involved, and the bubbles once contained tend to easily escape to the outside. That is, if there are few bubbles contained in the liquid crystal sealant, disconnection due to insufficient defoaming may be less likely to occur when the liquid crystal sealant is applied with a dispenser during liquid crystal cell manufacture.
• the organic filler of the present invention is preferably spherical, more preferably spherical.
• the particle diameter of the organic filler can be measured by microscopy, specifically by image analysis with an electron microscope.
• the surface of the organic filler of the present invention is preferably smooth. If the surface is smooth, the specific surface area decreases, and the amount of the organic filler that can be added increases.
• the organic filler preferably has a spherical shape or a smooth surface in the liquid crystal sealant, but does not have a smooth surface even if it is not spherical in the liquid crystal seal frame in the liquid crystal display panel. May be. This is because the organic filler in the liquid crystal sealant is deformed during the manufacturing process of the liquid crystal display panel.
• the content of the organic filler in the liquid crystal sealing agent is 30 to 100 parts by mass with respect to 100 parts by mass of the resin unit that is the total of the acrylic resin (1a) and the (meth) acryl-modified epoxy resin (1b).
• the amount is preferably 40 to 80 parts by mass, and more preferably 50 to 80 parts by mass.
• the radical polymerization initiator contained in the liquid crystal sealant is a photo radical polymerization initiator for photocuring the acrylic resin (1a), the (meth) acryl-modified epoxy resin (1b), etc.
• a thermal radical polymerization initiator for heat curing reaction is included.
• photo radical polymerization initiators can be used. Examples include alkylphenone compounds, acylphosphine oxide compounds, titanocene compounds, oxime ester compounds, benzoin compounds, acetophenone compounds, benzophenone compounds, thioxanthone compounds, ⁇ -acyloxime ester compounds, Examples include phenyl glyoxylate compounds, benzyl compounds, azo compounds, diphenyl sulfide compounds, organic dye compounds, iron-phthalocyanine compounds, benzoin ether compounds, anthraquinone compounds, and the like.
• alkylphenone compounds include benzyl dimethyl ketals such as 2,2-dimethoxy-1,2-diphenylethane-1-one (IRGACURE 651); 2-methyl-2-morpholino (4-thiomethylphenyl) propane ⁇ -aminoalkylphenones such as -1-one (IRGACURE 907); ⁇ -hydroxyalkylphenones such as 1-hydroxy-cyclohexyl-phenyl-ketone (IRGACURE 184) and the like.
• the acylphosphine oxide compound include 2,4,6-trimethylbenzoyl-diphenyl-phosphine oxide.
• the titanocene-based compound includes bis ( ⁇ 5-2,4-cyclopentadien-1-yl) -bis (2,6-difluoro-3- (1H-pyrrol-1-yl) -phenyl) titanium and the like.
• Examples of the oxime ester compounds include 1,2-octanedione-1- [4- (phenylthio) -2- (0-benzoyloxime)] (IRGACURE OXE 01).
• thermal radical polymerization initiator examples include organic peroxide compounds and azo compounds.
• thermal radical polymerization initiator those having a lower limit of 10 hours half-life temperature of 80 ° C. and an upper limit of 150 ° C. are preferably used.
• organic peroxide compound examples include ketone peroxide compounds such as methyl ethyl ketone peroxide, peroxyketal compounds such as 1,1-di (t-butyloxy) cyclohexane, and t-butyl peroxide.
• Alkyl peroxyester compounds such as oxybivalate, diacyl peroxide compounds such as dilauroyl peroxide, peroxydicarbonate compounds such as (2-ethylhexyl) peroxydicarbonate, and t-butylperoxy
• peroxycarbonate compounds such as isopropyl carbonate, dialkyl peroxide compounds such as di-t-butyl peroxide, hydroperoxide compounds such as t-amyl hydroperoxide, and the like.
• the azo compound examples include 1,1′-azobis (2,4-cyclohexane) -1-carbonitrile, 2,2′-azobis [(2-imidazoline-2-el) propane] disulfate.
• water-soluble azo compounds such as dihydrate
• oil-soluble azo compounds such as 1-[(cyano-1-methyl) azo] formamide
• polymer azo compounds examples include 1,1′-azobis (2,4-cyclohexane) -1-carbonitrile, 2,2′-azobis [(2-imidazoline-2-el) propane] disulfate.
• water-soluble azo compounds such as dihydrate
• oil-soluble azo compounds such as 1-[(cyano-1-methyl) azo] formamide, and polymer azo compounds.
• the content of the (3) radical polymerization initiator in the liquid crystal sealant is 0.01 to 100 parts by mass with respect to 100 parts by mass of the resin unit that is the total of the acrylic resin (1a) and the (meth) acryl-modified epoxy resin (1b).
• the amount is preferably 3.0 parts by mass, more preferably 0.1 to 2 parts by mass.
• a liquid crystal sealant containing an epoxy curing agent is excellent in storage stability and thermosetting.
• the epoxy curing agent may be a known one, but from the viewpoint of increasing the viscosity stability of the liquid crystal sealant and maintaining moisture resistance, the melting point is 50 ° C. or more and 250 ° C. or less, depending on the heat curing temperature.
• a certain epoxy curing agent is preferable, an epoxy curing agent having a melting point of 100 ° C. or more and 200 ° C. or less is more preferable, and an epoxy curing agent having a melting point of 150 ° C. or more and 200 ° C. or less is further preferable.
• Preferred examples of such an epoxy curing agent include organic acid dihydrazide compounds, imidazole compounds, dicyandiamide compounds, and polyamine compounds.
• organic acid dihydrazide compounds include adipic acid dihydrazide (melting point 181 ° C.), 1,3-bis (hydrazinocarboethyl) -5-isopropylhydantoin (melting point 120 ° C.), 7,11-octadecadien-1 , 18-dicarbohydrazide (melting point 160 ° C.), dodecanedioic acid dihydrazide (melting point 190 ° C.), sebacic acid dihydrazide (melting point 189 ° C.), and the like.
• imidazole compounds include 2,4-diamino-6- [2′-ethylimidazolyl- (1 ′)]-ethyltriazine (melting point 215 to 225 ° C.) and 2-phenylimidazole (melting point 137 to 147 ° C. ) Etc. are included.
• Examples of the dicyandiamide compound include dicyandiamide (melting point: 209 ° C.).
• the polyamine-based compound is a thermal latent curing agent having a polymer structure obtained by reacting an amine and an epoxy.
• ADEKA Hardener EH4339S softening point 120 to 130 ° C.
• Adeka Hardener EH4357S softening point 73 to 83 ° C. manufactured by ADEKA Corporation is included. These may be used alone or in combination.
• the content of the epoxy curing agent in the liquid crystal sealant is 3 to 30 parts by mass with respect to 100 parts by mass of the resin unit that is the total of the acrylic resin (1a) and the (meth) acryl-modified epoxy resin (1b). Is preferred.
• the liquid crystal sealing agent containing an epoxy curing agent can be a so-called one-part curable resin composition.
• the one-component curable resin composition is excellent in workability because it is not necessary to mix the main agent and the curing agent when used.
• the liquid crystal sealing agent of the present invention may further contain an inorganic filler.
• an inorganic filler By adding the inorganic filler, it is possible to control the viscosity of the liquid crystal sealant, the strength of the cured product, and the linear expansion.
• the inorganic filler is not particularly limited, but examples thereof include calcium carbonate, magnesium carbonate, barium sulfate, magnesium sulfate, aluminum silicate, zirconium silicate, iron oxide, titanium oxide, aluminum oxide (alumina), zinc oxide, silicon dioxide, Inorganic fillers such as potassium titanate, kaolin, talc, glass beads, sericite activated clay, bentonite, aluminum nitride, and silicon nitride are included, and silicon dioxide and talc are preferable.
• the shape of the inorganic filler is not particularly limited, and may be a regular shape such as a spherical shape, a plate shape, or a needle shape, or an irregular shape.
• the inorganic filler preferably has an average primary particle size of 1.5 ⁇ m or less and a specific surface area of 0.5 m 2 / g to 20 m 2 / g.
• the average primary particle diameter of the inorganic filler can be measured by a laser diffraction method described in JIS Z8825-1.
• the specific surface area can be measured by the BET method described in JIS Z8830.
• the content of the inorganic filler in the liquid crystal sealant is 3 to 30 parts by mass with respect to 100 parts by mass of the resin unit that is the total of the acrylic resin (1a) and the (meth) acryl-modified epoxy resin (1b). preferable.
• Epoxy resin The liquid crystal sealant may contain an epoxy resin.
• Epoxy resin has low solubility and diffusibility in liquid crystal, and not only good display characteristics of the obtained liquid crystal panel, but also can improve the moisture resistance of the cured product.
• an epoxy resin shall not contain a (meth) acryl group.
• Such an epoxy resin may be an aromatic epoxy resin having a weight average molecular weight of 500 to 10,000, preferably 1000 to 5,000.
• the weight average molecular weight of the epoxy resin can be measured in the same manner as described above.
• aromatic epoxy resins examples include aromatic diols represented by bisphenol A, bisphenol S, bisphenol F, bisphenol AD, and the like, and diols obtained by modifying them with ethylene glycol, propylene glycol, alkylene glycol, and epichlorohydrin.
• Aromatic polyvalent glycidyl ether compounds obtained by the reaction with phenol; novolak resins derived from phenol or cresol and formaldehyde, polyphenols typified by polyalkenylphenol and copolymers thereof, and obtained by the reaction of epichlorohydrin
• novolak-type polyvalent glycidyl ether compounds; glycidyl ether compounds of xylylene phenol resin, and the like are included.
• the above aromatic epoxy resins include, among others, cresol novolac type epoxy resins, phenol novolac type epoxy resins, bisphenol A type epoxy resins, bisphenol F type epoxy resins, triphenolmethane type epoxy resins, triphenolethane type epoxy resins, trisphenol type epoxy resins.
• Resin, dicyclopentadiene type epoxy resin, diphenyl ether type epoxy resin, and biphenyl type epoxy resin are preferable. Furthermore, you may mix and use these.
• the epoxy resin may be liquid or solid.
• the softening point is preferably 40 ° C or higher and 150 ° C or lower.
• the content of the epoxy resin is preferably 1 to 20 parts by mass and more preferably 3 to 10 parts by mass with respect to 100 parts by mass of the liquid crystal sealant. If the epoxy resin content is too high, the viscosity of the liquid crystal sealant will increase and the applicability may decrease. If the epoxy resin content is too low, the liquid crystal sealant will not have sufficient moisture resistance. It may become.
• the liquid crystal sealant may be a thermal radical polymerization initiator, a coupling agent such as a silane coupling agent, an ion trapping agent, an ion exchange agent, a leveling agent, a pigment, a dye, a plasticizer, if necessary.
• An additive such as an antifoaming agent may further be included.
• a spacer or the like may be blended in order to adjust the gap of the liquid crystal panel.
• the viscosity of the liquid crystal sealant of the present invention at 25 ° C. and 2.5 rpm using an E-type viscometer is preferably 200 to 450 Pa ⁇ s, and more preferably 300 to 400 Pa ⁇ s.
• the viscosity is in the above range, the liquid crystal sealing agent is likely to be deformed into a predetermined shape when the substrates of the liquid crystal cell are overlapped. Therefore, the gap width between the substrates of the liquid crystal cell can be controlled appropriately.
• the thixotropy index (TI value) defined by the following formula of the liquid crystal sealant of the present invention is preferably 1.5 or less, and more preferably 1.3 or less.
• TI value When the TI value is below a certain level, the viscosity at a low share is low. Thereby, when the liquid crystal sealant is agitated, it is difficult for air bubbles to be involved, and even if the air bubbles are entrained, the liquid crystal sealant is easily removed to the outside.
• a liquid crystal sealing agent is applied with a dispenser, disconnection due to insufficient defoaming can be highly suppressed.
• the liquid crystal sealant of the present invention is preferably used as a liquid crystal sealant for a liquid crystal dropping method.
• the liquid crystal sealant may be cured by photocuring, thermosetting, or a combination of photocuring and thermosetting, but thermosetting is preferably used.
• the liquid crystal display panel of the present invention is a display substrate, a counter substrate that is paired with the display substrate, a frame-shaped sealing member interposed between the display substrate and the counter substrate, and a display substrate. And a liquid crystal layer filled in a space surrounded by a sealing member between the substrate and the substrate.
• the cured product of the liquid crystal sealant of the present invention can be used as a seal member.
• the display substrate and the counter substrate are both transparent substrates.
• the material of the transparent substrate can be glass or plastic such as polycarbonate, polyethylene terephthalate, polyethersulfone and PMMA.
• a matrix-like TFT, a color filter, a black matrix, or the like can be disposed on the surface of the display substrate or the counter substrate.
• An alignment film is further formed on the surface of the display substrate or the counter substrate.
• the alignment film includes a known organic alignment agent or inorganic alignment agent.
• Such a liquid crystal display panel can be manufactured using the liquid crystal sealant of the present invention.
• a liquid crystal dropping method and a liquid crystal injecting method as a manufacturing method of the liquid crystal display panel, but the liquid crystal dropping method is preferable as the manufacturing method of the liquid crystal display panel of the present invention.
• the manufacturing method of the liquid crystal display panel by the liquid crystal dropping method is a1) a first step of forming a seal pattern of the liquid crystal sealant of the present invention on one substrate; a2) a second step of dropping liquid crystal in a region surrounded by the seal pattern of the substrate or a region of the other substrate facing the region surrounded by the seal pattern in an uncured state of the seal pattern; a3) a third step of superimposing one substrate and the other substrate via a seal pattern; a4) a fourth step of curing the seal pattern.
• the state in which the seal pattern is uncured in step a2) means a state in which the curing reaction of the liquid crystal sealant has not progressed to the gel point. For this reason, in step a2), the seal pattern may be semi-cured by light irradiation or heating in order to suppress dissolution of the liquid crystal sealant in the liquid crystal.
• One substrate and the other substrate are a display substrate or a counter substrate, respectively.
• the organic filler contained in the liquid crystal sealant deforms reversibly or irreversibly. Deformation means being crushed or crouched. That is, the organic filler in the liquid crystal sealant is preferably spherical; however, the organic filler in the liquid crystal seal of the liquid crystal display panel does not need to be spherical and is crushed.
• the liquid crystal sealant has a high organic filler content, and the liquid crystal seal in the liquid crystal display panel is crushed, so liquid crystal leaks (liquid crystal enters the liquid crystal seal or breaks through the liquid crystal seal and leaks. Is effectively suppressed. Moreover, the adhesive strength between the substrates increases.
• the specific surface area of the organic filler contained in the liquid crystal sealant is small, the viscosity of the liquid crystal sealant is moderately low. Therefore, when the substrates of the liquid crystal cell are overlapped, it is easy to appropriately control the gap width between the substrates.
• step a4) only curing by heating may be performed, but it is preferable to perform curing by heating (main curing) after curing by light irradiation (temporary curing). This is because the liquid crystal sealant can be instantly cured by temporary curing by light irradiation to suppress dissolution in the liquid crystal.
• the photocuring time is, for example, about 10 minutes although it depends on the composition of the liquid crystal sealant.
• the light irradiation energy may be energy that can cure an acrylic resin or a (meth) acryl-modified epoxy resin.
• the light is preferably ultraviolet light.
• the thermosetting temperature is 120 ° C., for example, although it depends on the composition of the liquid crystal sealant, and the thermosetting time is about 2 hours.
• the liquid crystal display panel of the present invention provides a high-quality display device because liquid crystal leakage is suppressed and the gap width between the substrates is appropriately controlled.
• Resin (1-1) Bifunctional acrylic monomer Bisphenol A type epoxy resin-modified diacrylate (3002A, manufactured by Kyoeisha Chemical Co., Ltd., hydrogen bonding functional group equivalent: 3.3 ⁇ 10 ⁇ 3
• (1-2) Acrylic Modified Epoxy Resin In a 500 mL four-necked flask equipped with a stirrer, gas inlet tube, thermometer, and cooling tube, 160 g of bisphenol F type epoxy resin (EXA-835LV DIC), 36 g of acrylic acid, tri Ethanolamine 0.2g was prepared and heated and stirred under a dry air stream at 110 ° C. for 5 hours to obtain an acrylic-modified epoxy resin. The obtained acrylic-modified epoxy resin was washed 12 times with ultrapure water. The hydrogen-bonding functional group equivalent of the acrylic-modified epoxy resin was 2.1 ⁇ 10 ⁇ 3 .
• thermoplastic polymer particles (A) having a water content of 0.1% by mass or less. It was 80 degreeC when the softening point of the obtained thermoplastic polymer particle (A) was measured based on JISK2207 (ring ball method). It was 28 m ⁇ 2 > / g when the specific surface area of the thermoplastic polymer particle (A) was measured based on JIS Z8830. The average particle size was 0.18 ⁇ m.
• the average particle size of the organic filler was measured by the following method. That is, the cured film of the liquid crystal sealant was observed at a magnification of 10,000 with a transmission electron microscope (TEM) (JEM-2200FS (manufactured by JEOL Ltd.)). The obtained image was analyzed, 50 organic fillers were selected, and their particle sizes were measured. The average value of the measured values obtained was defined as “average particle diameter of organic filler”.
• TEM transmission electron microscope
• the specific surface area of the organic filler was measured by the BET method from the amount of nitrogen adsorbed according to JIS Z8830. Specifically, the specific surface area of 100 organic fillers was measured by the above method, and the average value thereof was defined as “the average value of the specific surface area of the organic filler”.
• Radical polymerization initiator (3-1) Thermal radical polymerization initiator: 1,1′-azobis (2,4-cyclohexane) -1-carbonitrile (V-40: manufactured by Wako Pure Chemical Industries, Ltd.) (3-2) Photoradical polymerization initiator: 2,2-dimethoxy-1,2-diphenylethane-1-one (IRGACURE 651, manufactured by BASF)
• Epoxy resin (1) Epicron 850CRP (Bisphenol A type epoxy resin: manufactured by DIC)
• Example 1 (1-1) bifunctional acrylic monomer 60 parts by mass, (2-1) filler 30 parts by mass, (3-1) thermal radical polymerization initiator 1 part by mass, (4-1) epoxy resin 5 parts by mass, (4 -2) A resin composition comprising 3 parts by mass of a thermal latent curing agent and (4-3) 1 part by mass of an additive is sufficiently mixed using a three-roll mill so as to form a uniform liquid, and a liquid crystal seal An agent was obtained.
• Viscosity The viscosity of the obtained liquid crystal sealant was measured with an E-type viscometer at 25 ° C. and 2.5 rpm.
• Adhesive strength After applying a circular seal pattern with a diameter of 1 mm on an alkali-free glass of 25 mm x 45 mm x 5 mm in thickness using a screen plate, and pasting the same pair of glasses together A test piece was prepared by fixing with a jig. Specifically, for Examples 2 and 3 and Comparative Example 2, a test piece fixed with a jig was irradiated with 100 mW / cm 2 of ultraviolet rays using an ultraviolet irradiation device (USHIO INC.), The liquid crystal sealant was cured. At this time, the illuminance energy of ultraviolet rays was set to 2000 mJ / cm 2 .
• test piece for curing the liquid crystal sealant by light was heat-treated at 120 ° C. for 60 minutes using an oven to prepare a test piece for measuring adhesive strength.
• test pieces fixed with a jig were heat-treated at 120 ° C. for 60 minutes using an oven, and the test pieces for measuring the adhesive strength were used.
• the tensile rate was 2 mm / min, and the cured liquid crystal sealant was peeled off in a direction parallel to the glass bottom surface, thereby measuring the plane tensile strength.
• the adhesive strength was evaluated in four stages according to the magnitude of the plane tensile strength. That is, when the tensile strength is 25 MPa or more, the adhesive strength is very good (A), and when the tensile strength is 20 MPa or more and less than 25 MPa, the adhesive strength is good (B), and the tensile strength is 10 MPa.
• the case where the bond strength is less than 20 MPa is regarded as moderate (C)
• the case where the tensile strength is less than 10 MPa is regarded as low and inferior (D).
• a dispenser (Hitachi Plant Technology Co., Ltd.) was filled with the obtained composition, and a rectangular frame of 35 mm ⁇ 40 mm and a line width of 0.7 mm on an alkali-free glass substrate of 40 mm ⁇ 50 mm ⁇ thickness 0.7 mm.
• the seal pattern was drawn with a cross-sectional area of 3500 ⁇ m 2 .
• a liquid crystal material (MLC-11900-000: Merck) corresponding to the panel internal volume after bonding was precisely dropped into the seal pattern of the substrate using a dispenser (Hitachi Plant Technology Co., Ltd.).
• a vacuum bonding apparatus Shin-Etsu Engineering Co., Ltd.
• the glass substrate facing the above glass substrate was superposed under a reduced pressure of 10 Pa, and fixed under a load.
• Example 2 For Examples 2 and 3 and Comparative Example 2, a test piece fixed with a jig was irradiated with 100 mW / cm 2 of ultraviolet rays using an ultraviolet irradiation device (USHIO INC.), And a liquid crystal sealant was applied. Cured. At this time, the illuminance energy of ultraviolet rays was set to 2000 mJ / cm 2 . After the liquid crystal sealant was cured by light, a liquid crystal display panel was produced by heat treatment at 120 ° C. for 60 minutes using an oven.
• an ultraviolet irradiation device USHIO INC.
• liquid crystal display panels were produced by heat-treating test pieces fixed with a jig at 120 ° C. for 60 minutes using an oven.
• a cell gap inspection device manufactured by Otsuka Electronics Co., Ltd. was used to measure the in-plane distribution of the gap interval in the main seal in the sample. Then, the case where neither the maximum value nor the minimum value of the interval was within the range of 5 ⁇ m ⁇ 0.2 ⁇ m was evaluated as x, and the case where it was within the range of 5 ⁇ m ⁇ 0.2 ⁇ m was evaluated in two stages.
• TI value Thixotropic index (TI value) Using an E-type viscometer, the viscosity ⁇ 1 of the liquid crystal sealant at room temperature (25 ° C.) and 0.5 rpm, and the viscosity ⁇ 2 of the liquid crystal sealant at 5 rpm were measured. These measured values were applied to the following formula (1) to obtain a TI value.
• TI value (viscosity ⁇ 1 at 0.5 rpm (25 ° C.)) / (Viscosity ⁇ 2 at 5 rpm (25 ° C.)) (1)
• composition and evaluation results of the liquid crystal sealant of each example are shown in Table 1; the composition and evaluation result of the liquid crystal sealant of each comparative example are shown in Table 2.
• Examples 1 to 13 including the organic filler (2) having a specific surface area in the range of 0.4 to 1.5 m 2 / g have high adhesive strength and can control the gap width of the panel. You can see that Moreover, TI value is 1.5 or less, and defoaming property is also favorable.
• Comparative Examples 1 to 7 include an organic filler (2) having a large specific surface area.
• Comparative Examples 1, 2, 4, 6 and 7, 30 parts by mass of an organic filler having a large specific surface area was added in the same manner as in the Examples. Therefore, the viscosity of the liquid crystal sealant is increased, and the gap controllability of the panel is lowered. Moreover, TI value exceeds 1.5 and defoaming property is also falling. In Comparative Examples 1, 2, and 4, a decrease in adhesive strength was also observed. This is thought to be because the organic filler aggregated.
• the content of the organic filler in Comparative Examples 3 and 5 is 15 parts by mass, which is half the content of the organic filler in Examples, and the adhesive strength is not sufficiently increased. This is probably because the stress due to curing shrinkage is not sufficiently relaxed.
• the present invention can provide a high-quality liquid crystal display device in which liquid crystal leakage is suppressed and the panel gap width of the liquid crystal panel is appropriately controlled.

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