Classifications

• • 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
• • C—CHEMISTRY; METALLURGY
  • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
  • C09K—MATERIALS FOR MISCELLANEOUS APPLICATIONS, NOT PROVIDED FOR ELSEWHERE
  • C09K3/00—Materials not provided for elsewhere
  • C09K3/10—Materials in mouldable or extrudable form for sealing or packing joints or covers
• • 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
  • G02F1/1303—Apparatus specially adapted to the manufacture of LCDs
• • C—CHEMISTRY; METALLURGY
  • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
  • C09K—MATERIALS FOR MISCELLANEOUS APPLICATIONS, NOT PROVIDED FOR ELSEWHERE
  • C09K2200/00—Chemical nature of materials in mouldable or extrudable form for sealing or packing joints or covers
  • C09K2200/04—Non-macromolecular organic compounds
  • C09K2200/0429—Alcohols, phenols, ethers
• • C—CHEMISTRY; METALLURGY
  • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
  • C09K—MATERIALS FOR MISCELLANEOUS APPLICATIONS, NOT PROVIDED FOR ELSEWHERE
  • C09K2200/00—Chemical nature of materials in mouldable or extrudable form for sealing or packing joints or covers
  • C09K2200/04—Non-macromolecular organic compounds
  • C09K2200/0441—Carboxylic acids, salts, anhydrides or esters thereof

Definitions

• the present invention relates to a sealant for a liquid crystal dropping method and a method for manufacturing a liquid crystal display panel.
• a liquid crystal sealant is applied to form a seal pattern. Then, the liquid crystal is dropped onto the substrate on which the seal pattern is formed or the substrate that is paired with the seal pattern, and the liquid crystals are bonded together in a vacuum. After that, the seal pattern is cured by UV irradiation or heating to form a seal member.
• the liquid crystal sealant since the liquid crystal sealant is dropped in the uncured state, impurities and small molecule components in the liquid crystal sealant may be eluted into the liquid crystal sealant. Then, when the small molecule component or the like elutes into the liquid crystal display, a display defect called an afterimage is likely to occur on the liquid crystal display panel.
• the conventional liquid crystal sealant often contains a UV-curable (meth) acrylic compound and a thermosetting epoxy compound.
• the epoxy compound is usually not cured by UV curing. Therefore, the seal pattern after UV curing still contains a large amount of low molecular weight epoxy compounds. Then, when the seal pattern was heated for thermosetting, the liquid crystal phase transitioned due to the heat, and the epoxy compound in the seal pattern was easily eluted into the liquid crystal.
• Patent Document 1 a compound having a (meth) acrylic group and an epoxy group in one molecule to suppress elution of the epoxy compound into a liquid crystal while ensuring UV curability and thermosetting property.
• Patent Document 2 It has also been proposed to suppress the elution of the epoxy compound into the liquid crystal display by using a crystalline epoxy compound having a melting point of 50 ° C. or higher (Patent Document 2).
• the epoxy group contained in the epoxy compound or the like greatly contributes to the adhesive strength between the sealing member and the substrate.
• a compound having an epoxy group is polymerized by UV curing. Therefore, the epoxy group is difficult to move freely during thermosetting, and the epoxy group cannot sufficiently contribute to the bond with the substrate.
• Patent Document 2 it is difficult to include a large amount of epoxy compound having a high melting point in the liquid crystal sealant because the viscosity of the liquid crystal sealant increases. Therefore, it has been difficult to obtain sufficient adhesive strength even with this technique.
• the present invention has been made in view of the above problems. Specifically, the sealant for the liquid crystal dripping method and the liquid crystal display panel, which can form a sealing member having high adhesive strength to the substrate and which can cope with the narrowing of the frame of the liquid crystal display panel and which is difficult to dissolve in the liquid crystal.
• the purpose is to provide a manufacturing method.
• the present invention provides the following sealant for the liquid crystal dropping method.
• An epoxy compound having no polymerizable functional group other than an epoxy group, a (meth) acrylic / epoxy-containing compound having both a (meth) acrylic group and an epoxy group in one molecule, and no epoxy group ( Meta)
• a sealant for the liquid crystal dropping method which contains an acrylic compound, a heat curing agent, and a photopolymerization initiator, and has a content of the epoxy compound of 22 to 38% by mass.
• the residual DC value measured 30 seconds after heating the mixture of 1:10 by mass ratio at 120 ° C. for 1 hour, applying a voltage at 5 V for 1 second, short-circuiting for 0.1 seconds, is the above-mentioned.
• a liquid crystal dropping method in which only the liquid crystal is heated at 120 ° C. for 1 hour, a voltage is applied at 5 V for 1 second, short-circuited for 0.1 seconds, and then 200% or less of the residual DC value measured 30 seconds later. Sealant for.
• each component contained in the sealant for the liquid crystal dropping method each of the components and the liquid crystal is mixed at a mass ratio of 1:10, heated at 120 ° C. for 1 hour, and a voltage is applied at 5 V for 1 second.
• the residual DC value was measured 30 seconds after the short circuit was performed for 0.1 seconds
• the residual DC value of 98% by mass or more of the sealant for the liquid crystal dropping method was 1 at 120 ° C. for the liquid crystal display only.
• the liquid crystal dropping method according to [1] which is 300% or less of the residual DC value measured 30 seconds after heating for hours, applying a voltage at 5 V for 1 second, short-circuiting for 0.1 seconds.
• Sealant [3] The sealant for a liquid crystal dropping method according to [1] or [2], wherein the proportion of the component having a molecular weight of 500 or more in the epoxy compound is 25% by mass or more.
• the thermal curing agent is selected from the group consisting of an organic acid dihydrazide-based thermal latent curing agent, an imidazole-based thermal latent curing agent, an amine adduct-based thermal latent curing agent, and a polyamine-based thermal latent curing agent.
• the sealant for the liquid crystal dropping method according to any one of [1] to [3], which is one or more.
• the step of dropping the liquid crystal in the region of the seal pattern of the one substrate or on the other substrate, and the one substrate and the other substrate are overlapped with each other via the seal pattern.
• a method for manufacturing a liquid crystal display panel which comprises a step of matching and a step of curing the seal pattern.
• the sealant for the liquid crystal dropping method of the present invention is difficult to dissolve in the liquid crystal. Further, the adhesive strength between the sealing member obtained from the sealing agent for the liquid crystal dropping method and the substrate is high. Therefore, in the obtained liquid crystal display panel, liquid crystal leakage and afterimages are unlikely to occur, and a narrower frame can be realized.
• sealing agent for liquid crystal dripping method is a member for producing a sealing member for a liquid crystal display panel, and is a member for manufacturing a sealing member for a liquid crystal display panel. Is preferably used when producing. However, it can also be used to manufacture a liquid crystal display panel by a liquid crystal injection method or the like.
• the conventional sealant has a problem that the liquid crystal display panel is easily contaminated when a large amount of epoxy compound that can contribute to the improvement of the adhesive strength is contained.
• the amount of the epoxy compound is reduced, for example, when the liquid crystal display panel is narrowed, sufficient adhesive strength cannot be obtained, and peeling occurs between the substrate and the cured product (seal member) of the sealant. There was something.
• the amount of the epoxy compound is 22 to 38% by mass with respect to the total amount of the sealant, and the residual DC of the mixture obtained by mixing the sealant and the liquid crystal in a predetermined ratio.
• the residual DC value of the mixture containing the sealant and the liquid crystal display can be measured as follows. First, the sealant and a liquid crystal display (for example, MLC-7026, manufactured by Merck & Co., Inc.) are put into a vial at a mass ratio of 1:10 and mixed. Then, it is heated at 120 ° C. for 1 hour. Then, the mixture is taken out and injected into a glass cell (for example, KSSZ-10 / B111M1NSS05, manufactured by EHC) in which an alignment film and a transparent electrode are formed in advance. Then, a voltage of 5 V is applied to the obtained cell for 1 second and short-circuited for 0.1 second. Then, the remaining voltage (residual DC value) after 30 seconds is measured with a 6254 type measuring device (manufactured by Toyo Corporation).
• a 6254 type measuring device manufactured by Toyo Corporation.
• the liquid crystal when measuring the residual DC value of only the liquid crystal, put only the liquid crystal into a vial and mix. Then, it is heated at 120 ° C. for 1 hour. Next, the liquid crystal is taken out and injected into a glass cell (for example, KSSZ-10 / B111M1NSS05, manufactured by EHC) in which an alignment film and a transparent electrode are formed in advance. A voltage of 5 V is applied to the obtained cell for 1 second and short-circuited for 0.1 second. Then, the voltage (residual DC value) remaining after 30 seconds is measured by, for example, a 6254 type measuring device (manufactured by Toyo Corporation).
• a 6254 type measuring device manufactured by Toyo Corporation.
• the residual DC value of the mixture containing the sealant and the liquid crystal varies slightly depending on the type of the liquid crystal, but it may be 200% or less with respect to the residual DC value of the liquid crystal only, and more preferably 180% or less.
• the residual DC value of the mixture can be adjusted by the type of components constituting the sealant. For example, for many components contained in the sealant, the residual DC value of the mixture can be satisfied by adjusting the individual residual DC value to be 300% or less of the residual DC value of the liquid crystal display alone. .. More specifically, the ratio of the component having an individual residual DC value of 300% or less with respect to the residual DC value of the liquid crystal display alone is preferably 98% by mass or more with respect to the total amount of the sealant.
• each component and a liquid crystal display for example, MLC-7026, manufactured by Merck & Co., Inc.
• a liquid crystal display for example, MLC-7026, manufactured by Merck & Co., Inc.
• the mixture is heated at 120 ° C. for 1 hour.
• this mixture is injected into a glass cell (for example, KSSZ-10 / B111M1NSS05, manufactured by EHC) in which an alignment film and a transparent electrode are formed in advance.
• a voltage of 5 V is applied to the obtained cell for 1 second and short-circuited for 0.1 second.
• the voltage (residual DC value) remaining after 30 seconds is measured by, for example, a 6254 type measuring device (manufactured by Toyo Corporation). It is more preferable that the residual DC value of each component is 280% or less with respect to the residual DC value of the blank liquid crystal display.
• the sealant of the present invention includes an epoxy compound, a (meth) acrylic / epoxy-containing compound, a (meth) acrylic compound, a thermosetting agent, and a photopolymerization initiator.
• an epoxy compound a (meth) acrylic / epoxy-containing compound
• a (meth) acrylic compound a thermosetting agent
• a photopolymerization initiator a photopolymerization initiator
• inorganic particles, organic particles, a silane coupling agent, and the like may be contained, if necessary.
• the description of (meth) acrylic in the present specification includes acrylic, methacryl, or both.
• Epoxide compound is a compound containing at least an epoxy group in one molecule and having no polymerizable functional group other than the epoxy group.
• the polymerizable functional group in the present specification refers to a functional group that is activated by light irradiation or heating, a thermosetting agent, a photopolymerization initiator, a catalyst, or the like to carry out a polymerization reaction.
• the polymerizable functional group includes a photopolymerizable functional group, a thermopolymerizable functional group, a polyadded functional group and the like, and specific examples thereof include a (meth) acrylic group, a vinyl group, an acrylamide group, an epoxy group and an isosia. Nart group, silanol group and the like are included.
• the number of epoxy groups contained in one molecule of the epoxy compound is preferably 2 or more.
• the number of epoxy groups in the epoxy compound is 2 or more, the adhesiveness between the obtained sealing member and the substrate of the liquid crystal display panel becomes good. Further, the moisture resistance of the obtained sealing member is likely to increase.
• the epoxy compound may be liquid at room temperature or solid.
• the softening point of the epoxy compound is preferably 40 to 110 ° C. from the viewpoint of the viscosity of the obtained sealant.
• the epoxy compound may be a monomer, an oligomer, or a polymer.
• the molecular weight (or weight average molecular weight) of the epoxy compound is usually preferably 220 to 3000, more preferably 250 to 2500, and even more preferably 300 to 2000.
• the ratio of the component having a molecular weight of 500 or more to the total amount of the epoxy compound is preferably 25% by mass or more.
• Epoxy compounds with a molecular weight of 500 or more are difficult to dissolve in liquid crystals. Therefore, in such an epoxy compound, the above-mentioned individual residual DC value tends to be 300% or less as compared with the residual DC value of the liquid crystal display alone.
• the weight average molecular weight of the epoxy compound can be specified (in terms of polystyrene) by, for example, gel permeation chromatography (GPC).
• the epoxy compound may partially contain an individual residual DC value of more than 300% of the residual DC value of the liquid crystal display alone.
• the structure of the epoxy compound is not particularly limited, and an example thereof includes an aromatic epoxy compound having an aromatic ring in the main chain.
• aromatic epoxy compounds include aromatic diols typified by bisphenol A, bisphenol S, bisphenol F, bisphenol AD, diols obtained by modifying these with ethylene glycol, propylene glycol, and alkylene glycol AD, and epichlorohydrin.
• Aromatic polyvalent glycidyl ether compound obtained by reaction; obtained by reaction of epichlorohydrin with novolak resin derived from phenol, cresol, etc. and formaldehyde, polyphenols represented by polyalkenylphenol, copolymers thereof, etc.
• novolak-type polyvalent glycidyl ether compounds include novolak-type polyvalent glycidyl ether compounds; glycidyl ether compounds of xylylenephenol resin; naphthalene-type epoxy compounds; diphenyl ether-type epoxy compounds; biphenyl-type epoxy compounds; and the like.
• the aromatic epoxy compound is a cresol novolac type epoxy compound, a phenol novolac type epoxy compound, a bisphenol A type epoxy compound, a bisphenol F type epoxy compound, a triphenol methane type epoxy compound, or a triphenol ethane type epoxy compound.
• Trisphenol type epoxy compound, diphenyl ether type epoxy compound, biphenyl type epoxy compound are preferable.
• the sealant may contain only one type of epoxy compound, or may contain two or more types of sealant.
• the value is preferably 150 mV or less.
• the content of the epoxy compound is preferably 22 to 38% by mass, more preferably 22 to 36% by mass, and even more preferably 23 to 35% by mass with respect to the total amount of the sealant.
• the amount of the epoxy compound is 25% by mass or more, the adhesive strength between the sealing member obtained from the sealing agent and the substrate of the liquid crystal display panel is increased, and the frame of the liquid crystal display panel can be narrowed.
• the amount of the epoxy compound is 38% by mass or less, the residual DC value of the mixture of the sealant and the liquid crystal measured as described above tends to be 200% or less with respect to the residual DC value of the liquid crystal only. , The obtained liquid crystal display panel is unlikely to remain.
• the (meth) acrylic-epoxy-containing compound may be a compound having an epoxy group and a (meth) acrylic group in one molecule.
• the sealing agent only contains the above-mentioned epoxy compound and the later-described (meth) acrylic compound, the compatibility between them may be low.
• the sealing agent further contains a (meth) acrylic / epoxy-containing compound, the compatibility between the epoxy compound and the (meth) acrylic compound is enhanced, and the epoxy compound is less likely to be eluted into the liquid crystal.
• the number of epoxy groups and (meth) acrylic groups contained in one molecule of the (meth) acrylic / epoxy-containing compound is not particularly limited, but may be one, for example. Further, the number of epoxy groups and the number of (meth) acrylic groups may be the same or different.
• the (meth) acrylic-epoxy-containing compound include a (meth) acrylic-modified epoxy compound obtained by reacting an epoxy compound with (meth) acrylic acid in the presence of a basic catalyst.
• the epoxy compound used for preparing the (meth) acrylic-modified epoxy compound may be a bifunctional or higher-functional epoxy compound having two or more epoxy groups in the molecule, and may be bisphenol A type, bisphenol F type, or 2,2'-diallyl.
• Bisphenol type epoxy compounds such as bisphenol A type, bisphenol AD type, and hydrogenated bisphenol type; novolak type epoxy compounds such as phenol novolac type, cresol novolac type, biphenyl novolac type, and trisphenol novolac type; biphenyl type epoxy compounds; naphthalene Type epoxy compounds and the like are included.
• the (meth) acrylic-modified epoxy compound obtained by (meth) acrylic-modifying a polyfunctional epoxy compound such as trifunctional or tetrafunctional has a high crosslink density. Therefore, if the sealing agent contains such a (meth) acrylic-modified epoxy compound, the adhesive strength between the sealing member and the substrate tends to decrease when the liquid crystal display panel is manufactured. Therefore, a (meth) acrylic-modified epoxy compound obtained by modifying a bifunctional epoxy compound with (meth) acrylic is preferable.
• the epoxy compound for preparing the (meth) acrylic-modified epoxy compound is more preferably a biphenyl type epoxy compound, a naphthalene type epoxy compound, and a bisphenol type epoxy compound, and a bisphenol type epoxy compound such as bisphenol A type and bisphenol F type is a sealant. It is more preferable from the viewpoint of coating efficiency.
• the epoxy compound for preparing the (meth) acrylic-modified epoxy compound may be one kind or two or more kinds. Further, the epoxy compound for preparing the (meth) acrylic-modified epoxy compound is preferably highly purified by a molecular distillation method, a washing method or the like.
• reaction between the above epoxy compound and (meth) acrylic acid can be carried out according to a conventional method.
• (meth) acrylic acid reacts with some of the epoxy groups in the epoxy compound to obtain a (meth) acrylic-modified epoxy compound having a (meth) acrylic group and an epoxy group.
• the reaction product not only the (meth) acrylic-modified epoxy compound, but also an unreacted epoxy compound and a (meth) acrylic compound in which (meth) acrylic acid reacts with all the epoxy groups of the epoxy compound. May be included.
• the unreacted epoxy compound is an epoxy compound having no polymerizable functional group other than the above-mentioned epoxy group.
• the (meth) acrylic compound in which (meth) acrylic acid reacts with all the epoxy groups of the epoxy compound corresponds to the (meth) acrylic compound described later. Therefore, the reaction product may be used as it is as a sealant.
• the molecular weight (weight average molecular weight) of the (meth) acrylic / epoxy-containing compound is preferably, for example, 310 to 1000, and more preferably 350 to 900.
• the weight average molecular weight Mw of the (meth) acrylic / epoxy-containing compound can be measured (in terms of polystyrene) by, for example, gel permeation chromatography (GPC).
• GPC gel permeation chromatography
• the amount of the (meth) acrylic / epoxy-containing compound contained in the sealant is preferably 15 to 50% by mass, more preferably 18 to 40% by mass, still more preferably 20 to 35% by mass, based on the total amount of the sealant.
• the amount of the (meth) acrylic / epoxy-containing compound is 15% by mass or more, the adhesive strength between the sealing member obtained from the sealing agent and the substrate of the liquid crystal display panel is increased, and the frame of the liquid crystal display panel can be narrowed. ..
• the amount of the epoxy compound is 50% by mass or less, the residual DC value of the mixture of the sealant and the liquid crystal is likely to be 200% or less with respect to the residual DC value of the liquid crystal alone, and the obtained liquid crystal display panel can be obtained. Afterimages are unlikely to occur.
• the (meth) acrylic compound is a compound containing one or more (meth) acrylic groups in one molecule and does not have an epoxy group.
• the (meth) acrylic compound may be a monomer, an oligomer, or a polymer.
• the number of (meth) acrylic groups contained in one molecule of the (meth) acrylic compound is preferably 2 or more.
• the photocurability of the sealant becomes good.
• examples of the (meth) acrylic compound include di (meth) acrylates such as polyethylene glycol, propylene glycol, and polypropylene glycol; di (meth) acrylates of tris (2-hydroxyethyl) isocyanurate; and 1 mol of neopentyl glycol.
• the glass transition temperature of the (meth) acrylic compound is preferably 25 ° C. or higher and lower than 200 ° C. from the viewpoint that the elastic modulus of the film after photo-curing of the sealant easily falls within a desired range.
• the glass transition temperature is more preferably 40 ° C. to 200 ° C., further preferably 50 to 150 ° C.
• the glass transition temperature is measured by a viscoelasticity measuring device (DMS).
• the molecular weight (or weight average molecular weight) of the (meth) acrylic compound is preferably 310 to 1000, more preferably 400 to 900.
• the weight average molecular weight Mw of the (meth) acrylic compound can be measured (in terms of polystyrene) by, for example, gel permeation chromatography (GPC).
• GPC gel permeation chromatography
• the amount of the (meth) acrylic compound contained in the sealant is preferably 15 to 40% by mass, more preferably 18 to 35% by mass, based on the total amount of the sealant, although it depends on the curability of the desired sealant. 20 to 32% by mass is more preferable.
• the amount of the (meth) acrylic compound is in the above range, the elastic modulus of the sealant after photocuring tends to be good.
• thermosetting agent may be any component capable of curing the epoxy compound by heating.
• thermosetting agents do not cure the above-mentioned epoxy compounds and (meth) acrylic / epoxy-containing compounds under normal storage conditions (room temperature, visible light, etc.), but compounds that cure these compounds by heating. Is preferable.
• the sealing agent containing such a thermosetting agent both storage stability and thermosetting property can be achieved at the same time.
• a compound capable of curing an epoxy compound hereinafter, also referred to as "epoxy curing agent” is preferable.
• the melting point of the epoxy curing agent is preferably 50 ° C. or higher and 250 ° C. or lower, more preferably 100 ° C. or higher and 200 ° C. or lower, and 150 ° C. or higher, from the viewpoint of increasing the viscosity stability of the sealing agent and not impairing the moisture resistance of the obtained sealing member. It is more preferably ° C. or higher and 200 ° C. or lower.
• the sealing agent can be made one-component curable.
• workability is excellent because it is not necessary to mix the main agent and the curing agent at the time of use.
• epoxy curing agents examples include organic acid dihydrazide-based thermal latent curing agents, imidazole-based thermal latent curing agents, amine adduct-based thermal latent curing agents, and polyamine-based thermal latent curing agents.
• epoxy curing agents include organic acid dihydrazide-based thermal latent curing agents, imidazole-based thermal latent curing agents, dicyandiamide-based thermal latent curing agents, amine adduct-based thermal latent curing agents, and polyamine-based thermal latent curing agents. Contains agents.
• organic acid dihydrazide-based thermal latent curing agents include adipic acid dihydrazide (melting point 181 ° C.), 1,3-bis (hydrazinocarboethyl) -5-isopropylhydranthin (melting point 120 ° C.), 7,11-octa. Includes decadien-1,18-dicarbohydrazide (melting point 160 ° C.), dodecanedioic acid dihydrazide (melting point 190 ° C.), sebacic acid dihydrazide (melting point 189 ° C.) and the like.
• imidazole-based thermal latent curing agents examples include 2,4-diamino-6- [2'-ethylimidazolyl- (1')]-ethyltriazine (melting point 215-225 ° C.) and 2-phenylimidazole (melting point). 137 to 147 ° C.) and the like.
• dicyandiamide-based thermal latent curing agents examples include dicyandiamide (melting point 209 ° C.) and the like.
• the amine adduct-based thermal latent curing agent is a thermal latent curing agent composed of an additional compound obtained by reacting an amine-based compound having catalytic activity with an arbitrary compound.
• amine adduct-based thermal latent curing agents are Ajinomoto Fine-Techno's Amicure PN-40 (melting point 110 ° C), Ajinomoto Fine-Techno's Amicure PN-23 (melting point 100 ° C), and Ajinomoto Fine-Techno's Amicure PN.
• the polyamine-based thermal latent curing agent is a thermal latent curing agent having a polymer structure obtained by reacting amine and epoxy, and an example thereof is ADEKA Hardener EH4339S (softening point 120 to 130 ° C.) manufactured by ADEKA Corporation. , And ADEKA Hardener EH4357S (softening point 73 to 83 ° C.) and the like.
• organic acid dihydrazide-based thermal latent curing agent organic acid dihydrazide-based thermal latent curing agent, imidazole-based thermal latent curing agent, amine adduct-based thermal latent curing agent, or polyamine A thermal latent curing agent is preferred.
• the sealant may contain only one type of epoxy curing agent, or may contain two or more types of sealant.
• the content of the thermosetting agent is preferably 1 to 20% by mass, more preferably 2 to 18% by mass, still more preferably 3 to 15% by mass, based on the total amount of the sealing agent.
• the amount of the thermosetting agent is within the above range, the thermosetting property of the sealant becomes good.
• the photopolymerization initiator may be a compound capable of generating an active species by irradiation with light, may be a self-cleaving type photopolymerization initiator, or may be a hydrogen abstraction type photopolymerization. It may be an initiator.
• the sealing agent may contain only one kind of photopolymerization initiator, or may contain two or more kinds of photopolymerization initiators.
• self-cleaving photopolymerization initiators include benzyl dimethyl ketals such as alkylphenone compounds (eg, 2,2-dimethoxy-1,2-diphenylethane-1-one (BASF IRGACURE 651)), 2-. ⁇ -Aminoalkylphenone such as methyl-2-morpholino (4-thiomethylphenyl) propan-1-one (IRGACURE 907 manufactured by BASF), 1-hydroxy-cyclohexyl-phenyl-ketone (IRGACURE 184 manufactured by BASF), etc.
• acylphosphine oxide compounds eg 2,4,6-trimethylbenzoindiphenylphosphine oxide, etc.
• titanosen compounds eg, bis ( ⁇ 5-2,4-cyclopentadiene-1-yl))- Bis (2,6-difluoro-3- (1H-pyrrole-1-yl) -phenyl) titanium, etc.
• acetophenone compounds eg diethoxyacetophenone, 2-hydroxy-2-methyl-1-phenylpropan-1- On, benzyl dimethyl ketal, 1- (4-isopropylphenyl) -2-hydroxy-2-methylpropan-1-one, 4- (2-hydroxyethoxy) phenyl- (2-hydroxy-2-propyl) ketone, 1, -Hydroxycyclohexyl-phenylketone, 2-methyl-2-morpholino (4-thiomethylphenyl) propan-1-one, 2-benzyl-2
• hydrogen abstraction-type photopolymerization initiators examples include benzophenone compounds (eg, benzophenone, o-benzoylmethylbenzoate methyl-4-phenylbenzophenone, 4,4'-dichlorobenzophenone, hydroxybenzophenone, 4-benzoyl-4'-.
• benzophenone compounds eg, benzophenone, o-benzoylmethylbenzoate methyl-4-phenylbenzophenone, 4,4'-dichlorobenzophenone, hydroxybenzophenone, 4-benzoyl-4'-.
• Methyl-diphenylsulfide acrylicized benzophenone, 3,3', 4,4'-tetra (t-butylperoxycarbonyl) benzophenone, 3,3'-dimethyl-4-methoxybenzophenone, etc.
• thioxanthone compounds eg, thioxanthone, 2-Chlorothioxanthone (manufactured by Tokyo Kasei Kogyo Co., Ltd.), 1-chloro-4-propoxythioxanthone, 1-chloro-4-ethoxythioxanthone (Spedcure CPTX manufactured by Lambson Limited), 2-isopropylxantone (Speedcure ITX manufactured by Lambson Limited) , 4-Isopropylthioxanthone, 2,4-dimethylthioxanthone, 2,4-diethylthioxanthone (Speedcure DETX manufactured by Lambson Limited), 2,4-dichlorothioxanthone,
• the absorption wavelength of the photopolymerization initiator is not particularly limited, and for example, a photopolymerization initiator that absorbs light having a wavelength of 360 nm or more is preferable. Among them, it is more preferable to absorb light in the visible light region, a photopolymerization initiator that absorbs light having a wavelength of 360 to 780 nm is more preferable, and a photopolymerization initiator that absorbs light having a wavelength of 360 to 430 nm is particularly preferable.
• Examples of the photopolymerization initiator that absorbs light having a wavelength of 360 nm or more include an alkylphenone-based compound, an acylphosphine oxide-based compound, a titanosen-based compound, an oxime ester-based compound, a thioxanthone-based compound, and an anthraquinone-based compound, and are preferable. It is an oxime ester compound.
• the structure of the photopolymerization initiator can be specified by combining high performance liquid chromatography (HPLC) and liquid chromatography mass spectrometry (LC / MS) with NMR measurement or IR measurement.
• HPLC high performance liquid chromatography
• LC / MS liquid chromatography mass spectrometry
• the molecular weight of the photopolymerization initiator is preferably 200 or more and 5000 or less, for example.
• the molecular weight of the photopolymerization initiator is more preferably 230 or more and 3000 or less, and further preferably 230 or more and 1500 or less.
• the molecular weight of the photopolymerization initiator can be determined as the "relative molecular weight" of the molecular structure of the main peak detected when analyzed by high performance liquid chromatography (HPLC: High Performance Liquid Chromatography).
• the main peak refers to the peak with the highest intensity (the peak with the highest peak height) among all the peaks detected at the detection wavelength characteristic of each compound (for example, 400 nm in the case of a thioxanthone compound).
• the relative molecular weight corresponding to the peak peak of the detected main peak can be measured by liquid chromatography-mass spectrometry (LC / MS: Liquid Chromatography Mass Spectrometry).
• the amount of the photopolymerization initiator is preferably 0.1 to 8% by mass, more preferably 0.5 to 5% by mass, still more preferably 1 to 3% by mass, based on the total amount of the sealant.
• the amount of the photopolymerization initiator is 0.1% by mass or more, the photocurability of the sealant tends to be good.
• the amount of the photopolymerization initiator is 8% by mass or less, it becomes difficult for the photopolymerization initiator to elute into the liquid crystal display.
• the sealant may further contain inorganic particles, if necessary.
• the sealing agent contains inorganic particles, the viscosity of the sealing agent, the strength of the obtained sealing member, the linear expansion property, and the like tend to be improved.
• inorganic particle materials include calcium carbonate, magnesium carbonate, barium sulfate, magnesium sulfate, aluminum silicate, zirconium silicate, iron oxide, titanium oxide, titanium nitride, aluminum oxide (alumina), zinc oxide, silicon dioxide, and titanic acid. Includes potassium, kaolin, talc, glass beads, sericite-activated clay, bentonite, aluminum oxide, silicon nitride and the like.
• the sealing agent may contain only one kind of inorganic particles, or may contain two or more kinds of sealing agents. Among the above, silicon dioxide or talc is preferable as the inorganic particles.
• the shape of the inorganic particles may be a fixed shape such as a spherical shape, a plate shape, a needle shape, or a non-fixed shape.
• the average primary particle size of the inorganic particles is preferably 1.5 ⁇ m or less, and the specific surface area is more preferably 0.5 to 20 m 2 / g.
• the average primary particle size of the inorganic particles can be measured by the laser diffraction method described in JIS Z8825-1.
• the specific surface area of the inorganic particles can be measured by the BET method described in JIS Z8830.
• the content of the inorganic particles is preferably 0.1 to 25% by mass, more preferably 3 to 20% by mass, still more preferably 5 to 18% by mass, based on the total amount of the sealant.
• the content of the inorganic particles is 0.1% by mass or more, the moisture resistance of the obtained sealing member tends to increase, and when it is 25% by mass or less, the coating stability of the sealing agent is not easily impaired.
• the organic particle sealant may further contain organic particles, if necessary. When the sealant contains organic particles, it becomes easy to adjust the elastic modulus of the sealant after photocuring.
• organic particles examples include silicone particles, acrylic particles, styrene particles such as a styrene / divinylbenzene copolymer, and polyolefin particles.
• the sealing agent may contain only one kind of organic particles, or may contain two or more kinds of organic particles.
• the average primary particle size of the organic particles is preferably 0.05 to 13 ⁇ m, more preferably 0.1 to 10 ⁇ m, and even more preferably 0.1 to 8 ⁇ m.
• the shape of the organic particles is not particularly limited, but is preferably spherical, and more preferably true spherical.
• the average primary particle size of organic particles can be measured by microscopy, specifically image analysis with an electron microscope.
• it is preferable that the surface of the organic particles is smooth. A smooth surface reduces the specific surface area and increases the amount of organic particles that can be added to the sealant.
• the content of the organic particles is preferably 0.1 to 20% by mass, more preferably 1 to 15% by mass, still more preferably 3 to 12% by mass, based on the total amount of the sealant.
• the amount of organic particles is in the above range, the elastic modulus of the sealant after photocuring tends to be within a desired range.
• the sealant of the present invention includes, if necessary, a thermal radical polymerization initiator, a coupling agent such as a silane coupling agent, an ion trapping agent, an ion exchanger, a leveling agent, a pigment, a dye, a sensitizer, and the like. It may further contain additives such as plasticizers and antifoaming agents.
• a thermal radical polymerization initiator such as a silane coupling agent, an ion trapping agent, an ion exchanger, a leveling agent, a pigment, a dye, a sensitizer, and the like. It may further contain additives such as plasticizers and antifoaming agents.
• silane coupling agents examples include vinyltrimethoxysilane, ⁇ - (meth) acryloxipropyltrimethoxysilane, ⁇ -glycidoxypropyltrimethoxysilane, ⁇ -glycidoxypropyltriethoxysilane, and the like.
• the amount of the silane coupling agent is preferably 0.01 to 6% by mass, more preferably 0.1 to 5% by mass, still more preferably 0.5 to 3% by mass, based on the total amount of the sealing agent.
• the content of the silane coupling agent is 0.01% by mass or more, the obtained sealing member tends to have sufficient adhesiveness.
• many silane coupling agents have a high residual DC value. Therefore, the amount of the silane coupling agent is preferably 6% by mass or less.
• the sealant may further contain a spacer or the like for adjusting the gap of the liquid crystal display panel.
• the total amount of other components is preferably 1 to 50% by mass with respect to the total amount of the sealant.
• the viscosity of the sealant is unlikely to increase excessively, and the coating stability of the sealant is unlikely to be impaired.
• the viscosity of the E-type viscometer of the sealing agent at 25 ° C. and 2.5 rpm is preferably 200 to 450 Pa ⁇ s, more preferably 300 to 400 Pa ⁇ s.
• the viscosity is in the above range, when a pair of substrates are superposed on each other via a sealant (seal pattern), the sealant is likely to be deformed so as to fill these gaps. Therefore, the gap between the pair of substrates of the liquid crystal display panel can be appropriately controlled.
• the thixotropy index (TI value) of the sealant is preferably 1.0 to 1.5, more preferably 1.1 to 1.3, from the viewpoint of the coatability of the sealant.
• the TI value is determined by using an E-type viscometer, the viscosity of the sealant at room temperature (25 ° C.) and 0.5 rpm is ⁇ 1, and the viscosity of the sealant at 5 rpm is ⁇ 2. It is a value obtained by applying to.
• TI value (viscosity ⁇ 1 (25 ° C) at 0.5 rpm) / (viscosity ⁇ 2 (25 ° C) at 5 rpm) ... (1)
• the residual DC value measured by mixing the sealant and the liquid crystal as described above is preferably 100 mV or less.
• the liquid crystal it is preferable to measure using MLC-7026 manufactured by Merck & Co., Ltd.
• the liquid crystal display panel of the present invention includes a pair of substrates, a frame-shaped seal member arranged between the substrates, and a liquid crystal filled between the pair of substrates and inside the frame-shaped seal member.
• the sealing member is a cured product of the above-mentioned sealing agent.
• the sealing member obtained from the above-mentioned sealing agent has high adhesive strength with the substrate, and even if the sealing member is thinned, liquid crystal leakage or the like is unlikely to occur. Further, the sealing agent is less likely to contaminate the liquid crystal display. Therefore, afterimages and the like are unlikely to occur when the liquid crystal display panel is used.
• the pair of substrates are both transparent substrates.
• Examples of materials for the transparent substrate include glass or polycarbonate, polyethylene terephthalate, polyether sulfone, PMMA and the like.
• a matrix-shaped TFT, a color filter, a black matrix, etc. are arranged on the surface of the display board or the facing board.
• An alignment film is further formed on the surface of the display substrate or the facing substrate.
• the alignment film includes known organic alignment agents, inorganic alignment agents, and the like. Further, a known liquid crystal can be used as the liquid crystal.
• the liquid crystal display panel manufacturing method generally includes a liquid crystal dropping method and a liquid crystal injection method, but the liquid crystal display panel manufacturing method of the present invention is preferably the liquid crystal dropping method.
• the method for manufacturing a liquid crystal display panel by the liquid crystal dropping method is as follows: 1) a seal pattern forming step of applying the above-mentioned sealant to one substrate to form a frame-shaped seal pattern, and 2) a state in which the seal pattern is uncured. Then, the liquid crystal is dropped on one substrate and in the region surrounded by the seal pattern, or on the other substrate and in the region surrounded by the seal pattern when the other substrate and one substrate are opposed to each other. It includes a step, 3) a superposition step of superimposing one substrate and the other substrate via a seal pattern, and 4) a curing step of curing the seal pattern.
• the above-mentioned sealant is applied to one of the substrates.
• the method of applying the sealant is not particularly limited, and is not particularly limited as long as it is a method capable of forming a seal pattern with a desired thickness and width, such as screen printing or application with a dispenser, and a known method of applying the sealant. Is similar to.
• the shape of the seal pattern to be formed may be appropriately selected according to the application of the liquid crystal display panel, etc., and may be a shape in which the liquid crystal does not leak. For example, it may have a rectangular frame shape, but is not limited to the shape.
• the line width of the seal pattern is preferably 0.2 to 1.0 mm, more preferably 0.2 to 0.5 mm.
• the pair of substrates are opposed to each other with the seal pattern uncured.
• the state in which the seal pattern is uncured means a state in which the curing reaction of the sealant has not progressed to the gel point.
• the seal pattern may be semi-cured by irradiating or heating the seal pattern in order to suppress the dissolution of the sealant in the liquid crystal.
• the method of dropping the liquid crystal is the same as the known method of dropping the liquid crystal, and the liquid crystal may be dropped on the substrate on which the seal pattern is formed, and the liquid crystal may be dropped on the substrate on which the seal pattern is not formed (the other substrate). May be dropped.
• the seal pattern is cured.
• the method for curing the seal pattern is not particularly limited, but it is preferable that the seal pattern is temporarily cured by irradiation with light having a predetermined wavelength and then finally cured by heating. By light irradiation, the seal pattern can be instantly cured, and the components in the sealant can be suppressed from being dissolved in the liquid crystal display.
• the wavelength of the light to be irradiated is appropriately selected according to the type of the photopolymerization initiator, and ultraviolet light is preferable.
• the light irradiation time is, for example, about 10 minutes, although it depends on the composition of the sealant.
• the amount of energy to be irradiated at this time may be an amount of energy sufficient to cure the (meth) acrylic compound or the (meth) acrylic / epoxy-containing compound.
• the epoxy compound and (meth) acrylic / epoxy-containing compound are cured by heating.
• the heating temperature depends on the composition of the sealant, but is, for example, 100 to 150 ° C., and the heating time is preferably about 2 hours.
• the obtained composition was washed with ultrapure water 20 times to obtain a methacrylic acid-modified epoxy compound-containing composition (photocurable compound-containing composition 1).
• a methacrylic acid-modified epoxy compound-containing composition photocurable compound-containing composition 1
• the proportion of (meth) acrylic compounds modified to methacrylic groups was 25 mol%.
• the obtained composition was separated by a column, and the value of each residual DC was measured by the method described later. The results are shown in Table 1.
• Example 2 A sealant was prepared in the same manner as in Example 1 except that the photocurable composition 1 was changed to the photocurable composition 2.
• thermosetting agent azipin
• Acid dihydrazide manufactured by Otsuka Chemical Co., Ltd.
• photopolymerization initiator OXE-01, manufactured by BASF Co., Ltd.
• inorganic particles siliconca particles: S-100, manufactured by Nippon Catalytic Chemical Co., Ltd.
• organic particles fine particle polymer F351, manufactured by Aika Kogyo Co., Ltd.
• epoxy compound 850-S, manufactured by DIC, bisphenol
• thermal curing agent adipate dihydrazide, manufactured by Otsuka Chemical Co., Ltd.
• fine particle polymer F351 manufactured by Aika Kogyo Co., Ltd.
• 90 parts by mass of organic particles fine particle polymer F351, manufactured by Aika Kogyo Co., Ltd.
• the sealant was applied to a 40 mm ⁇ 45 mm glass substrate (RT-DM88-PIN, manufactured by EHC) in which a transparent electrode and an alignment film were previously formed using a dispenser (shot master: manufactured by Musashi Engineering Co., Ltd.). Specifically, a 35 mm ⁇ 40 mm quadrangular seal pattern (cross-sectional area 3500 ⁇ m 2 ) (main seal) and a similar seal pattern (38 mm ⁇ 43 mm quadrangular seal pattern) were formed on the outer circumference thereof.
• a liquid crystal display (MLC-7026-000, manufactured by Merck & Co., Inc.) corresponding to the capacity of the panel after bonding was precisely dropped into the frame of the main seal using a dispenser.
• the paired glass substrates were bonded under reduced pressure, and then opened to the atmosphere for bonding.
• the two laminated glass substrates were held in a light-shielding box for 3 minutes , then irradiated with light having a wavelength of 370 to 450 nm at 100 mJ / cm 2 and further heated at 120 ° C. for 1 hour.
• Polarizing plates were attached to both sides of the obtained substrate to prepare an evaluation substrate.
• Electrodes were connected so as to drive only one side of the portion of the evaluation substrate filled with the liquid crystal display, and the mixture was energized at 65 ° C. for 24 hours while applying a voltage of 10 V. After that, the entire surface was driven by 4 V, and the boundary line between the half-side drive and the full-surface drive was observed with a microscope.
• the afterimage was evaluated as follows from the state on the boundary line of the substrate. When narrowing the frame, only ⁇ can be said to be a range where there is no practical problem.
• ⁇ No difference is seen on the boundary line of the substrate and no afterimage is seen
• ⁇ An image is seen on the boundary line of the substrate within a range of less than 1 mm from the end of the sealing material
• ⁇ A part of 1 mm or more from the end of the sealing material Afterimage is seen on the board boundary line
• ⁇ Adhesive strength evaluation> Using a screen plate, the sealant was printed on 25 mm ⁇ 45 mm ⁇ 1 mm thick non-alkali glass. The seal pattern was a circle with a diameter of 1 mm. Then, a pair of non-alkali glass was placed on the seal pattern and fixed with a jig. The test piece was irradiated with ultraviolet light of 500 mW / cm 2 with an ultraviolet light irradiation device (manufactured by Ushio, Inc.) to cure the sealant. At this time, the illuminance energy of the ultraviolet light was set to 3.0 J / cm 2 . The test piece obtained by curing the sealant with light was heat-treated at 120 ° C. for 60 minutes using an oven to prepare a sample for measuring adhesive strength.
• the tensile strength of the flat surface of the sample was measured by using a tensile tester (manufactured by Intesco) at a tensile speed of 2 mm / min and peeling the cured sealant in a direction parallel to the bottom surface of the glass. ..
• the adhesive strength was evaluated as follows according to the magnitude of the planar tensile strength. When narrowing the frame, ⁇ or more is preferable. ⁇ : Tensile strength is 15 MPa or more ⁇ : Tensile strength is 10 MPa or more and less than 15 MPa ⁇ : Tensile strength is less than 10 MPa
• the epoxy compound contains an epoxy compound, a (meth) acrylic / epoxy-containing compound, a (meth) acrylic compound, a heat curing agent, and a photopolymerization initiator, and the content of the epoxy compound is 22 to 38% by mass.
• the afterimage evaluation is good and the adhesive strength evaluation is also good. (Examples 1 to 7). It is considered that sufficient adhesiveness was obtained by the predetermined amount of the epoxy compound. Further, it can be said that the components in the sealant are difficult to elute into the liquid crystal display in the sealant having a low residual DC value when mixed with the liquid crystal display.
• the sealant of the present invention a seal member having high adhesiveness to the substrate can be obtained.
• the sealant does not easily contaminate the liquid crystal display. Therefore, the sealant is very useful as a sealant or the like for producing a seal member for various liquid crystal display panels.

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