TW202003775A - Sealant for liquid crystal display element, vertical conduction material, and liquid crystal display element - Google Patents

Abstract

A purpose of the present invention is to provide a sealant for a liquid crystal display element, said sealant having superior properties of adhesion to a flexible substrate, moisture permeation prevention, and low liquid crystal staining. Another purpose of the present invention is to provide a vertical conduction material and a liquid crystal display element that are obtained using said sealant for a liquid crystal display element. This sealant for a liquid crystal display element includes a curable resin, a thermoplastic resin, and a polymerization initiator, wherein the curable resin includes a monofunctional (meth)acrylic compound having a five-membered or greater cyclic ether skeleton, and a multifunctional (meth)acrylic compound.

Description

Sealant for liquid crystal display element, upper and lower conduction materials and liquid crystal display element

The present invention relates to a sealant for a liquid crystal display element excellent in adhesion to a flexible substrate, moisture permeability resistance, and low liquid crystal contamination. In addition, the present invention relates to an upper and lower conduction material and a liquid crystal display element formed by using the sealant for liquid crystal display elements.

In recent years, as a method of manufacturing a liquid crystal display element such as a liquid crystal display unit, from the viewpoints of shortening the lead time and optimizing the amount of liquid crystal, etc., the use of a photo-thermal combination curing type as disclosed in Patent Document 1 and Patent Document 2 is used. The liquid crystal dropping method of the sealant is called the dropping method. In the dropping method, first, a frame-shaped sealing pattern is formed on one of the two transparent substrates with electrodes by drop coating. Then, in a state where the sealant is not cured, tiny droplets of liquid crystal are dropped onto the entire surface of the frame of the transparent substrate, immediately attached to another transparent substrate, and temporarily irradiated with ultraviolet light or the like to the sealing portion for temporary curing. Thereafter, the liquid crystal is heated during annealing to perform hardening to produce a liquid crystal display element. If the substrates are bonded under reduced pressure, the liquid crystal display element can be manufactured with extremely high efficiency. At present, the dropping method has become the mainstream of the manufacturing method of the liquid crystal display element.

In the past, glass substrates have been mainly used as substrates for liquid crystal display devices, but in recent years, flexible substrates using polyethylene terephthalate, polyimide, triethylene cellulose, etc. have attracted attention. However, in the conventional sealant, there is a problem that when such a flexible substrate is used, it cannot be sufficiently adhered. In addition, in recent years, curved displays made by bending a panel have attracted attention. However, in the conventional sealant, there is a problem that the sealant cannot follow when the substrate is bent, which may cause display defects. [Prior Technical Literature] [Patent Literature]

Patent Document 1: Japanese Patent Laid-Open No. 2001-133794 Patent Document 2: Japanese Patent Laid-Open No. 5-295087

[Problems to be solved by the invention]

The present invention relates to a sealant for a liquid crystal display element excellent in adhesion to a flexible substrate, moisture permeability resistance, and low liquid crystal contamination. In addition, an object of the present invention is to provide an upper and lower conduction material and a liquid crystal display element using the sealant for a liquid crystal display element. [Technical means to solve the problem]

The present invention is a sealant for a liquid crystal display element, which contains a curable resin, a thermoplastic resin, and a polymerization initiator, and the curable resin includes: a monofunctional (meth)acrylic acid having a cyclic ether skeleton of 5 or more rings Compounds, and multifunctional (meth)acrylic compounds. Hereinafter, the present invention will be described in detail.

The inventors of the present invention conducted research on blending a thermoplastic resin into a sealant to make the sealant for liquid crystal display elements correspond to a flexible substrate. However, although the obtained sealant has a certain degree of improvement in adhesion to a substrate composed of polyethylene terephthalate (PET), etc., it is particularly effective for polyimide. (PI) or triethyl acetyl cellulose (TAC) substrates, the adhesion is still insufficient. Therefore, the present inventors further studied the use of a monofunctional (meth)acrylic compound having a specific structure and a polyfunctional (meth)acrylic compound in combination as a curable resin. As a result, they found that a sealant for liquid crystal display elements excellent in adhesion to a flexible substrate can be obtained, and the present invention has been completed. In addition, the sealant for liquid crystal display elements of the present invention can also be excellent in moisture permeability resistance and low liquid crystal contamination.

The sealing compound for liquid crystal display elements of this invention contains curable resin. The curable resin includes a monofunctional (meth)acrylic compound having a cyclic ether skeleton of 5 or more rings (hereinafter, also referred to as "monofunctional (meth)acrylic compound of the present invention"). By including the monofunctional (meth)acrylic compound of the present invention as the above-mentioned curable resin and containing the following thermoplastic resin, the sealant for a liquid crystal display element of the present invention has excellent adhesion to a flexible substrate, even if the substrate It can also maintain sufficient adhesion when bending. In addition, in this specification, the above-mentioned "(meth)acrylic acid" means acrylic acid or methacrylic acid, and the above-mentioned "(meth)acrylic compound" means a compound having a (meth)acryloyl group. "Acyl) acryloyl" refers to acryloyl or methacryloyl. In addition, the "monofunctional (meth)acrylic compound" refers to a compound having one (meth)acryloyl group in one molecule, and the "multifunctional (meth)acrylic compound" refers to having in one molecule More than 2 (meth)acryloyl compounds.

The monofunctional (meth)acrylic compound of the present invention has a cyclic ether skeleton of 5 or more rings (hereinafter, also simply referred to as "cyclic ether skeleton"). The cyclic ether skeleton is preferably a cyclic ether skeleton having 4 or more carbon atoms. The upper limit of the carbon number of the cyclic ether skeleton does not particularly exist, but the substantial upper limit is 6.

The cyclic ether skeleton is preferably selected from a tetrahydrofuran skeleton, 1,3-dioxane skeleton, 1,4-dioxane skeleton, 1,2-oxathiolane (1,2-oxathiolane) skeleton, At least one of the groups formed by the morpholinic skeleton.

The monofunctional (meth)acrylic compound of the present invention may have one of the above-mentioned cyclic ether skeletons in one molecule, or may have two or more, but preferably has one of the above-mentioned cyclics in one molecule Ether skeleton. Furthermore, the monofunctional (meth)acrylic compound of the present invention preferably has the above-mentioned cyclic ether skeleton at the end of the molecular chain.

Specific examples of the monofunctional (meth)acrylic compound of the present invention include tetrahydrofurfuryl (meth)acrylate, compounds represented by the following formula (1), and 5-ethyl-5- ((Meth)acryloyloxymethyl)-1,3-dioxane, etc.

In formula (1), n is an integer of 1 or more and 6 or less.

Among the total 100 parts by weight of the monofunctional (meth)acrylic compound of the present invention and the following polyfunctional (meth)acrylic compound, the lower limit of the content of the monofunctional (meth)acrylic compound of the present invention is preferably 3 parts by weight The preferred upper limit is 95 parts by weight. When the content of the monofunctional (meth)acrylic compound of the present invention is 3 parts by weight or more, the obtained sealant for a liquid crystal display element has more excellent adhesion to a flexible substrate. When the content of the monofunctional (meth)acrylic compound of the present invention is 95 parts by weight or less, the obtained sealant for liquid crystal display elements is more excellent in moisture permeability resistance and low liquid crystal contamination. The lower limit of the content of the monofunctional (meth)acrylic compound of the present invention is more preferably 8 parts by weight, the more preferred upper limit is 80 parts by weight, the further preferred lower limit is 20 parts by weight, and the further preferred upper limit is 65 parts by weight, particularly preferably The upper limit is 60 parts by weight.

The curable resin contains a polyfunctional (meth)acrylic compound. By containing the above-mentioned multifunctional (meth)acrylic compound, the sealing compound for liquid crystal display elements of this invention is excellent in moisture permeability and low liquid crystal contamination.

Examples of the polyfunctional (meth)acrylic compound include polyfunctional meth)acrylate compounds, polyfunctional epoxy (meth)acrylates, and polyfunctional (meth)acrylates (urethane (meth)acrylate). )Wait. Among them, polyfunctional epoxy (meth)acrylate is preferred. In addition, in this specification, the above-mentioned "(meth)acrylate" means acrylate or methacrylate, and the above-mentioned "epoxy (meth)acrylate" means that at least one epoxy of the epoxy compound A compound derived from the reaction of (meth)acrylic acid.

Examples of the two functional groups in the polyfunctional (meth)acrylate compound include 1,3-butanediol di(meth)acrylate and 1,4-butanediol di(meth)acrylate. , 1,6-hexanediol di(meth)acrylate, 1,9-nonanediol di(meth)acrylate, 1,10-decanediol di(meth)acrylate, ethylene glycol di (Meth)acrylate, diethylene glycol di(meth)acrylate, tetraethylene glycol di(meth)acrylate, polyethylene glycol di(meth)acrylate, 2-n-butyl-2 -Ethyl-1,3-propanediol di(meth)acrylate, dipropylene glycol di(meth)acrylate, tripropylene glycol di(meth)acrylate, polypropylene glycol di(meth)acrylate, neopentyl glycol Alcohol di(meth)acrylate, ethylene oxide addition bisphenol A di(meth)acrylate, propylene oxide addition bisphenol A di(meth)acrylate, ethylene oxide addition bisphenol F di(meth)acrylate, dimethylol dicyclopentadienyl di(meth)acrylate, ethylene oxide modified isocyanurate di(meth)acrylate, 2-hydroxy- 3-(meth)acryl oxypropyl (meth)acrylate, carbonate diol di(meth)acrylate, polyether diol di(meth)acrylate, polyester diol di(meth) Group) acrylate, polycaprolactone diol di(meth)acrylate, polybutadiene diol di(meth)acrylate, etc.

In addition, examples of the trifunctional or more of the above-mentioned polyfunctional (meth)acrylate compounds include trimethylolpropane tri(meth)acrylate and ethylene oxide addition trimethylolpropane tri( Methacrylic acid ester, propylene oxide addition trimethylolpropane tri(meth)acrylate, caprolactone modified trimethylolpropane tri(meth)acrylate, ethylene oxide addition isotri Polycyanic acid tri (meth) acrylate, glycerol tri (meth) acrylate, propylene oxide addition glycerol tri (meth) acrylate, neopentaerythritol tri (meth) acrylate, triphosphate (meth) )Acryloyloxyethyl, ditrimethylolpropane tetra (meth) acrylate, neopentaerythritol tetra (meth) acrylate, dipentaerythritol penta (meth) acrylate, dixin Pentaerythritol hexa(meth)acrylate, etc.

Examples of the above-mentioned multifunctional epoxy (meth)acrylate include those obtained by reacting a multifunctional epoxy compound and (meth)acrylic acid in the presence of an alkaline catalyst in accordance with conventional practice.

Examples of the epoxy compound used as a raw material for synthesizing the above-mentioned multifunctional epoxy (meth)acrylate include bisphenol A epoxy compound, bisphenol F epoxy compound, and bisphenol E epoxy compound. , Bisphenol S epoxy compound, 2,2'-diallyl bisphenol A epoxy compound, hydrogenated bisphenol epoxy compound, propylene oxide addition bisphenol A epoxy compound, m-phenylene Phenolic epoxy compound, biphenyl epoxy compound, sulfide epoxy compound, diphenyl ether epoxy compound, dicyclopentadiene epoxy compound, naphthalene epoxy compound, phenol novolac epoxy Compound, o-cresol novolac epoxy compound, dicyclopentadiene novolac epoxy compound, biphenol novolac epoxy compound, naphthol novolac epoxy compound, glycidylamine epoxy compound, Alkyl polyol epoxy compounds, rubber modified epoxy compounds, glycidyl ester compounds, etc.

The above-mentioned polyfunctional (meth)acrylate amine ester can be obtained, for example, by reacting a polyfunctional isocyanate compound with a (meth)acrylic acid derivative having a hydroxyl group in the presence of a catalyst-based tin compound.

Examples of the polyfunctional isocyanate compound include isophorone diisocyanate, 2,4-toluene diisocyanate, 2,6-toluene diisocyanate, hexamethylene diisocyanate, trimethylhexamethylene diisocyanate, Diphenylmethane-4,4'-diisocyanate (MDI), hydrogenated MDI, polymeric MDI, 1,5-naphthalene diisocyanate, norbornanediol diisocyanate, tolidine diisocyanate, xylylene diisocyanate (XDI), hydrogenated XDI, lysine diisocyanate, triphenylmethane triisocyanate, tri(isocyanatophenyl) phosphorothioate, tetramethyl xylylene diisocyanate, 1,6,11- Undecane triisocyanate, etc.

In addition, as the above-mentioned polyfunctional isocyanate compound, a chain-extended polyfunctional isocyanate compound obtained by the reaction of a polyol and an excess of polyfunctional isocyanate compound can also be used. Examples of the above-mentioned polyols include ethylene glycol, propylene glycol, glycerin, sorbitol, trimethylolpropane, carbonate diol, polyether diol, polyester diol, and polycaprolactone diol.

Examples of the (meth)acrylic acid derivatives having hydroxyl groups include hydroxyalkyl mono(meth)acrylates, mono(meth)acrylates of glycols, and mono(meth)acrylic acid of triols. Ester or di(meth)acrylate, epoxy (meth)acrylate, etc. Examples of the hydroxyalkyl mono(meth)acrylate include 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 2-hydroxybutyl (meth)acrylate, 4-Hydroxybutyl (meth)acrylate and the like. Examples of the above-mentioned glycols include ethylene glycol, propylene glycol, 1,3-propanediol, 1,3-butanediol, 1,4-butanediol, and polyethylene glycol. Examples of the triols include trimethylolethane, trimethylolpropane, and glycerin. Examples of the epoxy (meth)acrylate include bisphenol A epoxy acrylate.

In addition, the polyfunctional (meth)acrylic compound preferably has a ring-opening structure of a lactone. Since the above-mentioned multifunctional (meth)acrylic compound has a ring-opening structure of a lactone, the sealant for a liquid crystal display element of the present invention has more excellent adhesion to a flexible substrate.

When the polyfunctional (meth)acrylic compound has a ring-opening structure of lactone, examples of the lactone include γ-undecanolide, ε-caprolactone, γ-decalactone, σ-dodecanolide, γ-nonanolide, γ-nonanolide, γ-valerolactone, σ-valerolactone, β-butyrolactone, γ-butyrolactone, β-propiolactone, σ-hexalactone, 7-butyl-2-oxetanone, etc. Among them, the carbon number of the linear portion of the main skeleton at the time of ring opening is preferably 5 to 7, more preferably ε-caprolactone. The above-mentioned multifunctional (meth)acrylic compound may have a ring-opening structure of one of these lactones, or may have a ring-opening structure of two or more lactones.

In addition, when the above-mentioned multifunctional (meth)acrylic compound has a ring-opening structure of a lactone, the ring-opening structure of the lactone may be only one in one molecule, or may be a repeating structure. In the case where the ring-opening structure of the above lactone becomes a repeating structure, the preferable upper limit of the repeating number is 5.

As the ring-opening structure having a lactone in the polyfunctional (meth)acrylic compound, it is preferable to introduce a ring-opening structure of a lactone into the skeleton of the polyfunctional epoxy (meth)acrylate, more It is preferably caprolactone modified epoxy (meth)acrylate, and more preferably caprolactone modified bisphenol A epoxy (meth)acrylate.

The above polyfunctional (meth)acrylic compound may be used alone or in combination of two or more.

The preferable lower limit of the weight average molecular weight of the above polyfunctional (meth)acrylic compound is 800, and the more preferable upper limit is 2000. When the weight average molecular weight of the polyfunctional (meth)acrylic compound is within this range, the obtained sealant for liquid crystal display elements is more excellent in adhesiveness, coatability, and moisture permeability of the flexible substrate. In addition, in this specification, the said weight average molecular weight is measured by the gel permeation chromatography (GPC) using tetrahydrofuran as a solvent, and it is the value calculated by polystyrene conversion. Examples of the column for measuring the number average molecular weight in terms of polystyrene by GPC include Shodex LF-804 (manufactured by Showa Denko).

The sealant for liquid crystal display elements of the present invention may also contain other hardeners in addition to the monofunctional (meth)acrylic compound of the present invention and the above polyfunctional (meth)acrylic compound within the range that does not impair the object of the present invention. Sexual resin. Examples of the other curable resins include monofunctional (meth)acrylic compounds other than the monofunctional (meth)acrylic compound of the present invention, epoxy compounds, and the like.

Examples of the other monofunctional (meth)acrylic compounds include monofunctional (meth)acrylate compounds and monofunctional (meth)acrylamide compounds.

Examples of the monofunctional (meth)acrylate compound include methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, n-butyl (meth)acrylate, ( Isobutyl meth), tertiary butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, n-octyl (meth) acrylate, isooctyl (meth) acrylate, (A Based) isononyl acrylate, isodecyl (meth)acrylate, lauryl (meth)acrylate, isomyristyl (meth)acrylate, stearyl (meth)acrylate, (meth)acrylic acid 2-hydroxyethyl, 2-hydroxypropyl (meth)acrylate, 2-hydroxybutyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, cyclohexyl (meth)acrylate, (A Group) Isocamphor acrylate, dicyclopentenyl (meth) acrylate, benzyl (meth) acrylate, 2-methoxyethyl (meth) acrylate, 2-ethoxy (meth) acrylate Ethyl acetate, 2-butoxyethyl (meth)acrylate, 2-phenoxyethyl (meth)acrylate, methoxyethylene glycol (meth)acrylate, methoxypolyethylene glycol ( Methacrylate, phenoxydiethylene glycol (meth)acrylate, phenoxypolyethylene glycol (meth)acrylate, tetrahydrofurfuryl (meth)acrylate, ethyl carbitol ( Methacrylic acid ester, (meth)acrylic acid-2,2,2 trifluoroethyl ester, (meth)acrylic acid 2,2,3,3-tetrafluoropropyl ester, (meth)acrylic acid 1H,1H,5H -Octafluoropentyl ester, imido (meth)acrylate, dimethylaminoethyl (meth)acrylate, diethylaminoethyl (meth)acrylate, 2-(meth)acryl Oxyethyl succinic acid, 2-(meth)acryloyloxyethylhexahydrophthalic acid, phthalic acid 2-(meth)acryloyloxyethyl 2-hydroxypropyl ester, phosphoric acid 2 -(Meth)acrylic acid ethyl ester, glycidyl (meth)acrylate, etc.

Examples of the monofunctional (meth)acrylamide compound include diethyl(meth)acrylamide.

The epoxy compound as the other curable resin may be the same as the epoxy compound used as a raw material for synthesizing the polyfunctional epoxy (meth)acrylate.

The sealing compound for liquid crystal display elements of this invention contains a thermoplastic resin. By including the monofunctional (meth)acrylic compound of the present invention as the curable resin and using the thermoplastic resin, the sealant for a liquid crystal display element of the present invention has excellent adhesion to a flexible substrate even if the substrate is bent Can also maintain sufficient adhesion.

The thermoplastic resin preferably has a glass transition temperature (hereinafter, also referred to as "Tg") of 30°C or lower. When the Tg of the thermoplastic resin is 30° C. or lower, the obtained sealant for a liquid crystal display element has more excellent adhesion to a flexible substrate. The upper limit of the Tg of the thermoplastic resin is more preferably 25°C, the more preferable upper limit is 21°C, the further more preferable upper limit is 10°C, the more preferable upper limit is 7°C, and the most preferable upper limit is 4°C. In addition, the lower limit of the Tg of the thermoplastic resin is preferably -30°C. In addition, in this specification, the said glass transition temperature means the value measured by the differential scanning calorimetry (DSC) based on "the measurement method of the transition temperature of plastics" based on JISK7121.

The preferred lower limit of the weight average molecular weight of the above thermoplastic resin is 5000, and the preferred upper limit is 100,000. When the weight average molecular weight of the thermoplastic resin is 5000 or more, the obtained sealing compound for liquid crystal display elements is more excellent in moisture permeability resistance. When the weight average molecular weight of the thermoplastic resin is 100,000 or less, the obtained sealant for a liquid crystal display element has more excellent applicability and adhesion to a flexible substrate. The more preferable lower limit of the weight average molecular weight of the above thermoplastic resin is 20,000, and the more preferable upper limit is 80,000.

Examples of the thermoplastic resin include polyolefin, polyester, (meth)acrylic resin, polyamide, polyurethane, ABS resin, AES resin, AAS resin, MBS resin, anionic/styrene copolymer, styrene/ (Meth) methacrylate copolymer, polystyrene, polycarbonate, polyphenylene oxide, phenoxy resin, etc. Examples of the polyolefin include polyethylene, polypropylene, ethylene/vinyl acetate copolymer, ethylene/(meth)acrylic acid copolymer, ethylene/(meth)acrylic acid copolymer, ethylene/(methyl ) Ethyl acrylate copolymer, ethylene/vinyl alcohol copolymer, ethylene/ethyl (meth)acrylate/maleic anhydride copolymer, etc. As said (meth)acrylic resin, polymethyl (meth)acrylate etc. are mentioned, for example. As the above-mentioned thermoplastic resin, among them, polyester and (meth)acrylic resin are preferred, polyester is more preferred, and copolymerized polyester is further preferred, and saturated polyester resin and saturated copolymerized polyester resin are particularly preferred. These thermoplastic resins may be used alone or in combination of two or more.

Regarding the above-mentioned thermoplastic resin, in order to obtain more excellent flexibility and toughness of the cured product of the sealant for liquid crystal display elements, preferably an amorphous resin, the flexibility of the obtained sealant for liquid crystal display elements In terms of better adhesion of the substrate, it is more preferably an amorphous polyester. Examples of commercially available non-crystalline polyesters include Vylon300 (Tg7°C, weight average molecular weight of about 55000), Vylon500 (Tg4°C, weight average molecular weight of about 55000), and Vylon550 (Tg-15°C, weight average Molecular weight about 60,000), Vylon560 (Tg7℃, weight average molecular weight about 40,000), Vylon630 (Tg7℃, weight average molecular weight about 55000), Vylon650 (Tg10℃, weight average molecular weight about 55000), Vylon670 (Tg7℃, weight average molecular weight about 80000) (all manufactured by Toyobo Textile Co., Ltd.), etc. In addition, in this specification, the above-mentioned "amorphism" means that a clear melting point peak has not been confirmed by differential scanning calorimetry (DSC) based on the "Method for Measuring the Transition Temperature of Plastics" based on JIS K 7121.

The lower limit of the content of the thermoplastic resin in the total 100 parts by weight of the curable resin and the thermoplastic resin is preferably 10 parts by weight, and the upper limit is preferably 70 parts by weight. When the content of the thermoplastic resin is 10 parts by weight or more, the obtained sealant for a liquid crystal display element has more excellent adhesion to a flexible substrate. When the content of the thermoplastic resin is 70 parts by weight or less, the obtained sealant for liquid crystal display elements is more excellent in coatability and moisture permeability. The more preferable lower limit of the content of the thermoplastic resin is 20 parts by weight, and the more preferable upper limit is 60 parts by weight.

The sealing agent for liquid crystal display elements of this invention contains a polymerization initiator. Examples of the polymerization initiator include a photoradical polymerization initiator that generates radicals by light irradiation, or a thermal radical polymerization initiator that generates radicals by heating.

等。 作為上述光自由基聚合起始劑，具體而言，例如可列舉：1-羥基環己基苯基酮、2-苄基-2-二甲胺基-1-(4-N-口末啉基苯基)丁酮、1,2-(二甲胺基)-2-((4-甲基苯基)甲基)-1-(4-(4-口末啉基)苯基)-1-丁酮、2,2-二甲氧基-1,2-二苯基乙烷-1-酮、雙(2,4,6-三甲基苯甲醯基)苯基氧化膦、2-甲基-1-(4-甲基噻吩基)-2-N-口末啉基丙烷-1-酮、1-(4-(2-羥基乙氧基)-苯基)-2-羥基-2-甲基-1-丙烷-1-酮、1-(4-(苯硫基)苯基)-1,2-辛二酮2-(O-苯甲醯基肟)、2,4,6-三甲基苯甲醯基二苯基氧化膦等。 上述光自由基聚合起始劑可單獨使用，亦可組合使用2種以上。Examples of the photo radical polymerization initiator include benzophenone-based compounds, acetophenone-based compounds, acetylphosphine oxide-based compounds, titanocene-based compounds, oxime ester-based compounds, benzoin ether-based compounds, 9-oxikoukoushan

Wait. Specific examples of the above-mentioned photo-radical polymerization initiator include 1-hydroxycyclohexyl phenyl ketone and 2-benzyl-2-dimethylamino-1-(4-N-terminal morpholinyl Phenyl) butanone, 1,2-(dimethylamino)-2-((4-methylphenyl)methyl)-1-(4-(4-ortholinyl)phenyl)-1 -Butanone, 2,2-dimethoxy-1,2-diphenylethane-1-one, bis(2,4,6-trimethylbenzyl)phenylphosphine oxide, 2- Methyl-1-(4-methylthienyl)-2-N-portalolinylpropane-1-one, 1-(4-(2-hydroxyethoxy)-phenyl)-2-hydroxy- 2-methyl-1-propane-1-one, 1-(4-(phenylthio)phenyl)-1,2-octanedione 2-(O-benzoyl oxime), 2,4, 6-Trimethylbenzyl diphenyl phosphine oxide, etc. The above-mentioned photo radical polymerization initiator may be used alone, or two or more kinds may be used in combination.

Examples of the above-mentioned thermal radical polymerization initiator include azo compounds, organic peroxides, and the like. Among them, from the viewpoint of suppressing liquid crystal contamination, an initiator composed of an azo compound is preferred (hereinafter, also referred to as "azo initiator"), and more preferably composed of a polymer azo compound Initiator (hereinafter, also referred to as "polymer azo initiator"). The above-mentioned thermal radical polymerization initiator may be used alone or in combination of two or more. In addition, in this specification, the above-mentioned "polymer azo compound" refers to a compound having an azo group and generating a radical that can harden the (meth)acryloyl group by heat and having a number average molecular weight of 300 or more.

The preferable lower limit of the number average molecular weight of the above polymer azo compound is 1,000, and the preferable upper limit is 300,000. With the number average molecular weight of the above polymer azo compound being in this range, it is possible to prevent adverse effects on the liquid crystal, and it is easy to mix into the curable resin. The more preferable lower limit of the number average molecular weight of the above-mentioned polymer azo compound is 5000, the more preferable upper limit is 100,000, the more preferable lower limit is 10,000, and the more preferable upper limit is 90,000. In addition, in this specification, the said number average molecular weight is measured by the gel permeation chromatography (GPC) using tetrahydrofuran as a solvent, and it is the value calculated by polystyrene conversion. Examples of the column for measuring the number average molecular weight in terms of polystyrene by GPC include Shodex LF-804 (manufactured by Showa Denko).

Examples of the polymer azo compound include those having a structure in which a plurality of units such as polyalkylene oxide or polydimethylsiloxane are bonded via an azo group. The polymer azo compound having a structure in which a plurality of units such as polyalkylene oxide is bonded via the azo group is preferably a polyethylene oxide structure. Specific examples of the polymer azo compound include, for example, a polycondensate of 4,4'-azobis(4-cyanovaleric acid) and polyalkylene glycol, or 4,4'-a Polycondensates of bis(4-cyanovaleric acid) and polydimethylsiloxane with terminal amine groups. Examples of the commercially available polymer azo initiators include VPE-0201, VPE-0401, VPE-0601, VPS-0501, and VPS-1001 (all manufactured by Fujifilm and Koko Pure Chemical Industries). . In addition, examples of azo initiators that are not polymers include V-65 and V-501 (all manufactured by Fujifilm and Koko Pure Chemical Industries, Ltd.).

Examples of the organic peroxides include ketone peroxide, peroxyketal, hydrogen peroxide, dialkyl peroxide, peroxyester, diacyl peroxide, and peroxydicarbonate.

The content of the polymerization initiator relative to 100 parts by weight of the curable resin is preferably a lower limit of 0.01 parts by weight and a preferred upper limit of 10 parts by weight. When the content of the polymerization initiator is within this range, the obtained sealant for liquid crystal display elements suppresses contamination of liquid crystals, and is more excellent in storage stability or curability. The more preferable lower limit of the content of the polymerization initiator is 0.1 part by weight, and the more preferable upper limit is 5 parts by weight.

The sealing compound for liquid crystal display elements of this invention may contain a thermosetting agent. Examples of the thermosetting agent include organic hydrazine, imidazole derivatives, amine compounds, polyphenol compounds, and acid anhydrides. Among them, organic hydrazine is preferably used. The above-mentioned thermosetting agents may be used alone or in combination of two or more.

Examples of the organic hydrazine include sebacic acid dihydrazide, isophthalic acid dihydrazide, adipic acid dihydrazide, and malonic acid dihydrazide. Examples of the commercially available organic hydrazines include organic hydrazines manufactured by Otsuka Chemical Co., Ltd., and organic hydrazines manufactured by Ajinomoto Fine-Techno. Examples of the organic hydrazine manufactured by the above-mentioned Otsuka Chemical Co., Ltd. include SDH and ADH. Examples of the organic hydrazine manufactured by Ajinomoto Fine-Techno include Ajicure VDH, Ajicure VDH-J, Ajicure UDH, Ajicure UDH-J, and the like.

The content of the above-mentioned thermosetting agent is preferably 1 part by weight with respect to 100 parts by weight of the above-mentioned curable resin, and the preferred upper limit is 50 parts by weight. When the content of the above-mentioned thermosetting agent is in this range, the coating properties of the obtained sealing compound for liquid crystal display elements are not deteriorated, and the thermosetting properties can be more excellent. The preferable upper limit of the content of the above-mentioned thermosetting agent is 30 parts by weight.

The sealing agent for liquid crystal display elements of the present invention preferably contains a filler for the purpose of improving the viscosity, further improving the adhesiveness of the stress dispersion effect, improving the linear expansion rate, and improving the moisture resistance of the cured product.

As the above-mentioned filler, an inorganic filler or an organic filler can be used. Examples of the inorganic fillers include silica, talc, glass beads, asbestos, gypsum, diatomaceous earth, bentonite, bentonite, montmorillonite, sericite, activated clay, alumina, and oxidation. Zinc, iron oxide, magnesium oxide, tin oxide, titanium oxide, calcium carbonate, magnesium carbonate, magnesium hydroxide, aluminum hydroxide, aluminum nitride, silicon nitride, barium sulfate, calcium silicate, etc. Examples of the organic filler include polyester fine particles, polyurethane fine particles, ethylene polymer fine particles, acrylic polymer fine particles, and the like. These fillers may be used alone or in combination of two or more.

The lower limit of the content of the filler in 100 parts by weight of the sealing compound for liquid crystal display elements of the present invention is preferably 10 parts by weight, and the upper limit is preferably 70 parts by weight. When the content of the filler is within this range, the coating properties and the like are not deteriorated, and the effect of improving the adhesiveness and the like is more excellent. The more preferable lower limit of the content of the filler is 20 parts by weight, and the more preferable upper limit is 60 parts by weight.

The sealing agent for liquid crystal display elements of this invention may contain a silane coupling agent. The above-mentioned silane coupling agent mainly has a role as an adhesion aid for good adhesion of the sealant and the substrate.

As the silane coupling agent, for example, 3-aminopropyltrimethoxysilane, 3-mercaptopropyltrimethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-isocyanic acid are preferably used Propyl trimethoxy silane and so on. Such an effect of improving the adhesion to the substrate and the like is excellent, and chemical bonding with the curable resin can suppress the outflow of the curable resin into the liquid crystal. The aforementioned silane coupling agent may be used alone or in combination of two or more.

The preferable lower limit of the content of the silane coupling agent in 100 parts by weight of the sealing compound for liquid crystal display elements of the present invention is 0.1 part by weight, and the preferable upper limit is 10 parts by weight. When the content of the silane coupling agent falls within this range, the effect of suppressing the generation of liquid crystal contamination and improving the adhesion is more excellent. The lower limit of the content of the silane coupling agent is more preferably 0.3 part by weight, and the upper limit is more preferably 5 parts by weight.

The sealing compound for liquid crystal display elements of this invention may contain a light-shielding agent. By containing the above-mentioned light-shielding agent, the sealing agent for liquid crystal display elements of this invention can be used suitably as a light-shielding sealing agent.

Examples of the light-shielding agent include iron oxide, titanium black, aniline black, cyanine black, fullerene, carbon black, and resin-coated carbon black. Among them, titanium black is preferred.

The above-mentioned titanium black is compared with the average transmittance of light with a wavelength of 300 nm or more and 800 nm or less, and it has a high transmittance in the vicinity of the ultraviolet region, especially light with a wavelength of 370 nm or more and 450 nm or less. . That is, the above-mentioned titanium black has the property of imparting light-shielding properties to the sealant for liquid crystal display elements of the present invention while sufficiently blocking light of wavelengths in the visible light region, and of transmitting light of wavelengths near the ultraviolet region on the one hand Sunscreen. Therefore, by using a lighter that can use the light of a wavelength (370 nm or more and 450 nm or less) with a higher penetration rate of the titanium black as the photo radical polymerization initiator or the photo cationic polymerization initiator, The photocurability of the sealing compound for liquid crystal display elements of this invention can be further increased. On the other hand, the light-shielding agent contained in the sealant for liquid crystal display elements of the present invention is preferably a material with high insulation, and the light-shielding agent with high insulation is preferably titanium black. The titanium black preferably has an optical density (OD value) of 3 or more per 1 μm, and more preferably 4 or more. The higher the light-shielding property of the titanium black, the better. The upper limit of the OD value of the titanium black does not particularly exist, but it is usually 5 or less.

Even if the above-mentioned titanium black is not surface-treated, it still exerts sufficient effects, but it is also possible to use a surface treated with an organic component such as a coupling agent, or silicon oxide, titanium oxide, germanium oxide, aluminum oxide, zirconium oxide, and magnesium oxide Titanium black after surface treatment such as those coated with inorganic components. Among them, in terms of further improvement in insulation properties, those treated with organic components are preferred. In addition, the liquid crystal display element manufactured using the sealing agent for liquid crystal display elements of the present invention blended with the above titanium black as a light-shielding agent has sufficient light-shielding properties, so it can achieve matt leakage, has high contrast, and is excellent Liquid crystal display element of image display quality.

Examples of the commercially available titanium black mentioned above include titanium black manufactured by Mitsubishi Materials Corporation and titanium black manufactured by Ako Chemical Corporation. Examples of the titanium black manufactured by Mitsubishi Materials Corporation include 12S, 13M, 13M-C, 13R-N, and 14M-C. Examples of the titanium black manufactured by Ako Chemical Co., Ltd. include Tilack D and the like.

The preferable lower limit of the specific surface area of the above titanium black is 13 m ² /g, the preferable upper limit is 30 m ² /g, the more preferable lower limit is 15 m ² /g, and the more preferable upper limit is 25 m ² /g. In addition, the preferable lower limit of the volume resistance of the titanium black is 0.5 Ω·cm, the preferable upper limit is 3 Ω·cm, the more preferable lower limit is 1 Ω·cm, and the more preferable upper limit is 2.5 Ω·cm.

The primary particle diameter of the light-shielding agent is not particularly limited as long as the distance between the substrates of the liquid crystal display element is not exceeded, but the lower limit is preferably 1 nm, and the upper limit is preferably 5000 nm. When the primary particle diameter of the light-shielding agent is within this range, it is possible to achieve a more excellent light-shielding property without deteriorating the coating properties of the obtained sealing compound for liquid crystal display elements. The preferred lower limit of the primary particle size of the above-mentioned opacifier is 5 nm, the more preferred upper limit is 200 nm, the further preferred lower limit is 10 nm, and the further preferred upper limit is 100 nm. In addition, the primary particle diameter of the said sunscreen agent can be measured using NICOMP 380ZLS (made by PARTICLE SIZING SYSTEMS) to disperse the said sunscreen agent in a solvent (water, organic solvent, etc.).

The lower limit of the content of the light-shielding agent in 100 parts by weight of the sealing compound for liquid crystal display elements of the present invention is preferably 5 parts by weight, and the upper limit is preferably 80 parts by weight. When the content of the light-shielding agent is within this range, the adhesion, the strength after curing, and the drawability of the obtained sealant for liquid crystal display elements are not significantly reduced, and more excellent light-shielding properties can be exerted. The more preferable lower limit of the content of the above-mentioned opacifier is 10 parts by weight, the more preferable upper limit is 70 parts by weight, the more preferable lower limit is 30 parts by weight, and the more preferable upper limit is 60 parts by weight.

The sealing agent for liquid crystal display elements of this invention may further contain a stress relaxation agent, a reactive diluent, a thixotropic agent, a spacer, a hardening accelerator, a defoaming agent, a leveling agent, a polymerization inhibitor, etc. as needed. additive.

As a method of manufacturing the sealing agent for liquid crystal display elements of the present invention, for example, a method of mixing additives such as a curable resin, a thermoplastic resin, a polymerization initiator, and a silane coupling agent to be used as needed, etc. can be mentioned. Examples of the above-mentioned mixer include a homogenous disperser, a homomixer, a universal mixer, a planetary mixer, a kneader, and a three-roll mill.

By blending conductive fine particles in the sealant for liquid crystal display elements of the present invention, a vertical conduction material can be manufactured. Moreover, the upper and lower conduction materials containing the sealing compound for liquid crystal display elements of this invention and conductive fine particles are also one of this invention.

As the conductive fine particles, a metal ball, a conductive metal layer formed on the surface of the resin fine particles, or the like can be used. Among them, those having a conductive metal layer formed on the surface of the resin microparticles are preferred because the excellent elasticity of the resin microparticles does not damage the transparent substrate or the like and enables conductive connection.

Moreover, the liquid crystal display element using the sealing compound for liquid crystal display elements of this invention or the upper-lower conduction material of this invention is also one of this invention.

The sealing agent for liquid crystal display elements of this invention can be used suitably for the manufacture of a liquid crystal display element by the liquid crystal dropping method. As a method of manufacturing the liquid crystal display element of the present invention by the liquid crystal dropping method, for example, the following methods can be cited. First, a step of forming a frame-shaped seal pattern by applying the sealant for liquid crystal display elements of the present invention to a substrate by screen printing, dispenser coating, or the like. Then, the following steps are carried out: the liquid crystal display element sealant for the present invention is uncured, and fine droplets of liquid crystal are applied dropwise to the entire surface of the frame of the seal pattern, and immediately another substrate is overlapped. Thereafter, a liquid crystal display element can be obtained by performing a step of photo-curing the sealant by irradiating ultraviolet light or the like to the seal pattern portion. In addition to the step of photo-curing the sealant, a step of heating the sealant to harden it may be performed.

As the above substrate, a flexible substrate is preferred. Examples of the flexible substrate include polyethylene terephthalate (PET), polyimide (PI), triethylene cellulose (TAC), polyester, and poly(meth)acrylate. , Polycarbonate, polyether ballast and other substrates. The sealing agent for liquid crystal display elements of the present invention has excellent adhesion even to a flexible substrate composed of polyimide (PI) or triethyl cellulose (TAC). Moreover, the sealing compound for liquid crystal display elements of this invention can also be used when adhering to a normal glass substrate. Generally, a transparent electrode made of indium oxide or the like, an alignment film made of polyimide or the like, an inorganic ion shielding film, etc. are usually formed on the substrate. [Effect of invention]

According to the present invention, it is possible to provide a sealant for a liquid crystal display element excellent in adhesion to a flexible substrate, moisture permeability resistance, and low liquid crystal contamination. In addition, according to the present invention, it is possible to provide an upper and lower conduction material and a liquid crystal display element using the sealant for a liquid crystal display element.

Hereinafter, the present invention will be described in more detail with examples, but the present invention is not limited to these examples.

(Examples 1 to 13, Comparative Examples 1 to 4) Using a planetary mixer (Thinky Corporation, "Defoaming and Mixing Taro") to mix the materials according to the blending ratios described in Tables 1 and 2, a three-roll mill was further used for mixing to prepare Examples 1 to 13. And the sealing compound for liquid crystal display elements of Comparative Examples 1-4.

<Evaluation> The following evaluation was performed about the sealing compound for liquid crystal display elements obtained in the Example and the comparative example. The results are shown in Tables 1 and 2.

(Adhesion to PET substrate) Each sealant for liquid crystal display elements obtained in Examples and Comparative Examples was applied to a 25 mm×60 mm polyethylene terephthalate (PET) film so as to have a width of 25 mm and a thickness of 40 μm (Manufactured by Lintec, "PET5011") to produce test pieces. Using a tensile tester (manufactured by Shimadzu Corporation, "EZ Graph"), the 180-degree peel strength was measured on the obtained test piece at 25°C and a peel speed of 300 mm/min. Set 180 degree peel strength to 10 N/cm or more as "◎", set 5 N/cm or more but not more than 10 N/cm to "○", and set 2 N/cm or more but not to 5 N/ The one with cm is set to "Δ", and the one with less than 2 N/cm is set to "×" to evaluate the adhesion to the PET substrate.

(Adhesion to TAC substrate) Each sealant for liquid crystal display elements obtained in Examples and Comparative Examples was applied to a 25 mm × 60 mm triacetyl cellulose (TAC) film (Fuji film) so as to have a width of 25 mm and a thickness of 40 μm Manufactured by the company, "TD80UL") to produce test pieces. Using a tensile tester (manufactured by Shimadzu Corporation, "EZ Graph"), the 180-degree peel strength was measured on the obtained test piece at 25°C and a peel speed of 300 mm/min. Set 180 degree peel strength to 10 N/cm or more as "◎", set 5 N/cm or more but not more than 10 N/cm to "○", and set 2 N/cm or more but not to 5 N/ The one with cm is set to "Δ", and the one with less than 2 N/cm is set to "×" to evaluate the adhesion to the TAC substrate.

(Moisture resistance) The sealants for liquid crystal display elements obtained in Examples and Comparative Examples were applied to a smooth release film so as to have a thickness of 200 to 300 μm using a coater. Next, the film for moisture permeability measurement was obtained by irradiating 100 mW/cm ² of ultraviolet light for 30 seconds using a metal halogen lamp. A cup for moisture permeability test is prepared by the method of moisture permeability test method (cup method) of JIS Z 0208, and the obtained membrane for moisture permeability measurement is installed and put into 60℃, 90%RH The moisture permeability is measured in a constant temperature and humidity oven. Set the value of the obtained moisture permeability to less than 500 g/m ² ·24hr to "○", and set the condition to 500 g/m ² ·24hr or more and less than 800 g/m ² ·24hr to "Δ"", the case where 800 g/m ² ·24hr or more is set to "×" to evaluate the moisture permeability resistance.

(Low liquid crystal contamination) 1 part by weight of spacer fine particles (manufactured by Sekisui Chemical Industry Co., Ltd., "Micropearl SI-H050") was dispersed in 100 parts by weight of the sealant for each liquid crystal display element obtained in Examples and Comparative Examples. Next, a syringe for dispensing (manufactured by Musashi Hi-Tech Co., Ltd., "PSY-10E") was filled with a sealant dispersed with spaced fine particles and defoamed. Using a dispenser (manufactured by Musashi Hi-Tech Co., Ltd., "SHOTMASTER300"), the defoamed sealant was applied to two rubbed alignment films and a transparent TAC film (Fuji) with a line width of 1 mm. One film made by the film company, "TD80UL"). Then, tiny droplets of liquid crystal (manufactured by Chisso Corporation, "JC-5004LA") were dropped onto the entire surface of the frame of the sealant of the TAC film, and immediately another TAC film was attached. Thereafter, a metal halogen lamp was used to irradiate 100 mW/cm ² of ultraviolet light to the sealant portion for 30 seconds to obtain a liquid crystal display element. The obtained liquid crystal display device was visually confirmed that the alignment of the liquid crystal in the vicinity of the sealant after being placed in the voltage application state for 24 hours under an environment of 60°C and 90% RH was disturbed (display unevenness). When the display unevenness is not observed at all in the liquid crystal display element, set to "○", and when the display unevenness is observed near the sealant (peripheral part) of the liquid crystal display element, set to "Δ", and the display unevenness Not only the peripheral part but also the central part is set to "×" to evaluate the low liquid crystal contamination. Furthermore, the liquid crystal display element evaluated as "○" is a level that is practically free of problems, the "Δ" liquid crystal display element is a level that may become a problem according to the display design, and the "×" liquid crystal display element is insufficient Practical level.

[Table 1]

[產業上之可利用性][Table 2]

[Industry availability]

According to the present invention, it is possible to provide a sealant for a liquid crystal display element excellent in adhesion to a flexible substrate, moisture permeability resistance, and low liquid crystal contamination. In addition, according to the present invention, it is possible to provide an upper and lower conduction material and a liquid crystal display element using the sealant for a liquid crystal display element.

no

no

Claims (9)

A sealant for liquid crystal display elements, which contains a hardening resin, a thermoplastic resin and a polymerization initiator, and The curable resin includes a monofunctional (meth)acrylic compound having a cyclic ether skeleton of 5 or more rings and a multifunctional (meth)acrylic compound. The sealant for a liquid crystal display element according to claim 1, wherein the cyclic ether skeleton having 5 or more members is selected from the group consisting of tetrahydrofuran skeleton, 1,3-dioxane skeleton, 1,4-dioxane skeleton, At least one of the group consisting of 1,2-oxathiolane (1,2-oxathiolane) skeleton and morpholin skeleton. The sealant for a liquid crystal display element according to claim 1 or 2, wherein the cyclic ether skeleton having 5 or more members is a cyclic ether skeleton having 4 or more carbon atoms. The sealant for liquid crystal display elements according to 2 or 3, wherein the total amount of the monofunctional (meth)acrylic compound having a cyclic ether skeleton of 5 or more members and the polyfunctional (meth)acrylic compound is 100 parts by weight In the above, the content of the monofunctional (meth)acrylic compound having a cyclic ether skeleton of 5 or more rings is 3 parts by weight or more and 95 parts by weight or less. 2. The sealant for liquid crystal display elements according to 2, 3 or 4, wherein the polyfunctional (meth)acrylic compound has a ring-opening structure of a lactone. 2. The sealing compound for liquid crystal display elements according to 2, 3, 4 or 5, wherein the thermoplastic resin is an amorphous polyester. 2. The sealing compound for a liquid crystal display element according to 2, 3, 4, 5 or 6, wherein the content of the thermoplastic resin is 100 parts by weight or more and 70 parts by weight in a total of 100 parts by weight of the curable resin and the thermoplastic resin the following. A top-to-bottom conductive material containing the sealing compound for liquid crystal display elements described in claim 1, 2, 3, 4, 5, 6, or 7 and conductive fine particles. A liquid crystal display element is obtained by using the sealant for liquid crystal display elements described in claim 1, 2, 3, 4, 5, 6 or 7 or the top-to-bottom conductive material described in claim 8.