TW201718671A - Sealant for liquid crystal display element, vertical conduction material, and liquid crystal display element - Google Patents

Abstract

The purpose of the present invention is to provide a sealant for a liquid crystal display element, the sealant having excellent adhesion and moisture permeation prevention and being capable of suppressing liquid crystal contamination. The purpose of the present invention is also to provide a vertical conduction material and a liquid crystal display element obtained using the sealant for a liquid crystal display element. The present invention is a sealant for a liquid crystal display element, containing a curable resin, and a polymerization initiator and/or a thermosetting agent, the curable resin containing a compound having three or more polymerizable functional groups and one or more [epsilon]-caprolactone open-ring structures in each molecule thereof and not having a cyclic structure.

Description

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

The present invention relates to a sealant for a liquid crystal display element which is excellent in adhesion and moisture permeability and which can suppress liquid crystal contamination. Moreover, the present invention relates to an upper and lower conductive material and a liquid crystal display element using the sealing agent for a liquid crystal display element.

In recent years, the method of manufacturing a liquid crystal display element such as a liquid crystal display unit is known from the prior art, for example, in the patent document 1 and the patent document 2, from the viewpoints of shortening the production time and optimizing the liquid crystal amount. A liquid crystal dropping method called a dropping method using a photothermal heat and a hardening type sealant is becoming a mainstream.

The dropping method first forms a rectangular seal pattern by dripping on one of the two substrates on which the electrodes are attached. Next, a small droplet of liquid crystal is dropped on the entire surface of the transparent substrate in a state where the sealant is not cured, and the other transparent substrate is immediately superposed, and the sealing portion is temporarily hardened by irradiating light such as ultraviolet rays. Thereafter, it is heated and subjected to main hardening at the time of liquid crystal annealing to produce a liquid crystal display element. When the substrate is bonded under reduced pressure, the liquid crystal display element can be manufactured with extremely high efficiency.

With the popularization of tablet terminals or mobile terminals, liquid crystal display elements are increasingly required to have moisture resistance reliability in driving in a high temperature and high humidity environment, and the sealant is further required to prevent from coming from the sealant. The penetration of external water. In order to improve the moisture resistance reliability of the liquid crystal display element, it is necessary to improve the adhesion between the sealant and the substrate, and to obtain a cured product of the sealant which is excellent in moisture permeability resistance. However, it is difficult to achieve both adhesion and moisture permeability in the sealant.

Prior technical literature

Patent literature

Patent Document 1: Japanese Laid-Open Patent Publication No. 2001-133794

Patent Document 2: Japanese Patent Laid-Open No. Hei 5-295087

An object of the present invention is to provide a sealing agent for a liquid crystal display element which is excellent in adhesion and moisture permeability and which can suppress liquid crystal contamination. Moreover, an object of the present invention is to provide an upper and lower conductive material and a liquid crystal display element using the sealing agent for a liquid crystal display element.

The present invention relates to a sealant for a liquid crystal display device, comprising a curable resin, a polymerization initiator, and/or a thermosetting agent, wherein the curable resin contains a compound having three or more polymerizable functionalities in one molecule. A compound having one or more ring-opening structures of ε-caprolactone and having no cyclic structure.

Hereinafter, the present invention will be described in detail.

The present inventors have found that a compound having three or more polymerizable functional groups and one or more ε-caprolactone ring-opening structures in one molecule and having no cyclic structure is used. The present invention is obtained as a curable resin, and a sealant for a liquid crystal display element which is excellent in adhesion and moisture permeability and which can suppress liquid crystal contamination can be obtained.

The sealing agent for liquid crystal display elements of this invention contains a curable resin.

The curable resin contains a compound having three or more polymerizable functional groups and one or more ring-opening structures of ε-caprolactone in one molecule and having no cyclic structure (hereinafter also It is called "the polymerizable compound of this invention". By containing the polymerizable compound of the present invention, the sealing agent for a liquid crystal display device of the present invention is excellent in adhesion and moisture permeability, and can suppress liquid crystal contamination.

The polymerizable compound of the present invention has three or more polymerizable functional groups in one molecule.

The polymerizable functional group which the polymerizable compound of the present invention has may, for example, be a (meth)acrylonyl group, an epoxy group or an episulfide group. In particular, the polymerizable compound of the present invention preferably has a (meth) acrylonitrile group as a polymerizable functional group, and more preferably all of the polymerizable functional groups are (meth) acrylonitrile groups.

In the present specification, the above "(meth)acryloyl group" means an acryloyl group or a methacrylium group.

The polymerizable compound of the present invention preferably has 4 to 8 polymerizable functional groups per molecule, and preferably has 6 polymerizable properties per molecule, from the viewpoints of both curability and moisture permeability resistance. Functional group.

The polymerizable compound of the present invention has one or more ring-opening structures of ε-caprolactone in one molecule. The polymerizable compound of the present invention is excellent in adhesion by the ring-opening structure of the above ε-caprolactone.

The polymerizable compound of the present invention preferably has a ring-opening structure of two or more ε-caprolactones in one molecule, more preferably an open-ring structure of four or more ε-caprolactones in one molecule. Further, it is preferably an open-ring structure having 4 to 8 ε-caprolactones in one molecule, and most preferably an open-ring structure having 6 ε-caprolactones in one molecule.

When the polymerizable compound of the present invention does not have a cyclic structure, the viscosity increase after the preparation can be suppressed, and the obtained sealing compound for liquid crystal display elements is excellent in workability.

The polymerizable compound of the present invention is more excellent in the effect of suppressing liquid crystal contamination, and preferably has one or more hydrogen bond functional groups in one molecule.

Examples of the hydrogen bond functional group include a hydroxyl group (-OH), a primary amine group (-NH ₂ ), and a secondary amine group (-NHR (R represents an aromatic or aliphatic hydrocarbon, and derivatives thereof). )), carboxyl (-COOH), primary guanamine (-CONH ₂ ), hydroxylamine (-NHOH), guanamine bond (-NHCO-), imine bond (-NH-), sulfhydryl bond ( -CONHCO-), hydrogenated azo bond (-NH-NH-), and the like. Among them, a hydroxyl group is preferred.

The method of producing the polymerizable compound of the present invention is, for example, a (meth) acrylate having three or more (meth) acryloyl groups in one molecule and having no cyclic structure. The method of ester modification and the like.

In the present specification, the above "(meth) acrylate" means acrylate or methacrylate, and the above-mentioned "modification of (meth) acrylate by ε-caprolactone means" A ring-opening or ring-opening polymer of ε-caprolactone introduced between an alcohol-derived moiety and a (meth)acryl fluorenyl group of the methyl acrylate.

As a method of modifying the above (meth) acrylate by ε-caprolactone, specifically, for example, the alcohol and ε-caprolactone are reversed at a high temperature in the presence of a catalyst. a method for esterifying an ε-caprolactone-modified alcohol with (meth)acrylic acid using a dehydrating solvent in the presence of an acid catalyst after synthesizing an ε-caprolactone-modified alcohol; or a method in which an acrylic acid is reacted with ε-caprolactone to synthesize ε-caprolactone-modified (meth)acrylic acid, and the ε-caprolactone-modified (meth)acrylic acid is esterified with an alcohol. .

In the present specification, the above "(meth)acrylic acid" means acrylic acid or methacrylic acid.

The polymerizable compound of the present invention preferably has a dendritic polymer structure in which a plurality of molecular chains are regularly branched from a central atom or a central molecule, and specific examples thereof include pentaerythritol tri(methyl). Acrylate, trimethylolpropane tri(meth)acrylate, trimethylolethane tri(meth)acrylate, dipentaerythritol tri(meth)acrylate, pentaerythritol tetra(a) Acrylate, di-trimethylolpropane tetra(meth)acrylate, dipentaerythritol tetra(meth)acrylate, dipentaerythritol penta(meth)acrylate, dipentaerythritol A modified ε-caprolactone such as an alcohol hexa(meth)acrylate. Among them, ε-caprolactone-modified dipentaerythritol hexaacrylate represented by the following formula (1) is preferred.

In the formula (1), l, m, n, o, p, and q each independently represent an integer of 1 to 12.

In the above formula (1), l, m, n, o, p are more excellent in all of the sealants for liquid crystal display elements obtained in terms of adhesiveness, moisture permeability, and low liquid crystal contamination. And q Preferably, they are 1 or 2, respectively, and most preferably 1 each.

The curable resin may contain other polymerizable compounds in addition to the polymerizable compound of the present invention.

In the case where the above-mentioned other polymerizable compound is contained, the content of the polymerizable compound of the present invention is preferably 1 part by weight, more preferably 80 parts by weight, based on 100 parts by weight of the entire curable resin. When the content of the polymerizable compound of the present invention is 1 part by weight or more, the obtained sealing agent for a liquid crystal display element is more excellent in adhesion. When the content of the polymerizable compound of the present invention is 80 parts by weight or less, the obtained sealing agent for a liquid crystal display element is more excellent in moisture permeability resistance. A more preferred lower limit of the content of the polymerizable compound of the present invention is 10 parts by weight, more preferably 70 parts by weight, still more preferably 30 parts by weight, and still more preferably 60 parts by weight.

Examples of the other polymerizable compound include other epoxy compounds or other (meth)acrylic compounds other than those contained in the polymerizable compound of the present invention.

Examples of the other epoxy compound include bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol E type epoxy resin, bisphenol S type epoxy resin, and 2,2'-dienes. Propyl bisphenol A type epoxy resin, hydrogenated bisphenol type epoxy resin, propylene oxide addition bisphenol A type epoxy resin, resorcinol type epoxy resin, biphenyl type epoxy resin, thioether type Epoxy resin, diphenyl ether type epoxy resin, dicyclopentadiene type epoxy resin, naphthalene type epoxy resin, phenolic novolac type epoxy resin, o-cresol novolac type epoxy resin, dicyclopentylene Diene novolak type epoxy resin, biphenyl novolak type epoxy resin, naphthol novolak type epoxy resin, glycidylamine type epoxy resin, alkyl polyol type epoxy resin, rubber modified ring An oxygen resin, a glycidyl ester compound, or the like.

Among the above-mentioned bisphenol A type epoxy resins, for example, jER828EL, jER1004 (all manufactured by Mitsubishi Chemical Corporation), EPICLON 850CRP (manufactured by DIC Corporation), and the like are mentioned.

Among the above-mentioned bisphenol F-type epoxy resins, for example, jER806 and jER4004 (all manufactured by Mitsubishi Chemical Corporation) and the like are mentioned.

Among the above-mentioned bisphenol E-type epoxy resins, for example, R710 (manufactured by Printec Co., Ltd.) or the like can be mentioned.

The bisphenol S-type epoxy resin is commercially available, and examples thereof include EPICLON EXA 1514 (manufactured by DIC Corporation).

In the above-mentioned 2,2'-diallyl bisphenol A type epoxy resin, for example, RE-810NM (manufactured by Nippon Kayaku Co., Ltd.) or the like can be mentioned.

Among the above-mentioned hydrogenated bisphenol type epoxy resins, for example, EPICLON EXA 7015 (manufactured by DIC Corporation) or the like can be mentioned.

In the above-mentioned propylene oxide-added bisphenol A-type epoxy resin, for example, EP-4000S (manufactured by Adeka Co., Ltd.) or the like can be mentioned.

In the above-mentioned resorcinol-type epoxy resin, for example, EX-201 (manufactured by Nagase Chemical Co., Ltd.) or the like can be mentioned.

Among the above-mentioned biphenyl type epoxy resins, for example, jER YX-4000H (manufactured by Mitsubishi Chemical Corporation) or the like can be mentioned.

Among the above-mentioned thioether type epoxy resins, for example, YSLV-50TE (manufactured by Nippon Steel & Sumitomo Chemical Co., Ltd.) and the like are mentioned.

Among the above-mentioned diphenyl ether type epoxy resins, as a commercially available person, for example, YSLV-80DE (new Nippon Steel Sumitomo Chemical Co., Ltd.) and so on.

Among the above-mentioned dicyclopentadiene type epoxy resins, for example, EP-4088S (manufactured by Adeka Co., Ltd.) or the like can be mentioned.

Among the above-mentioned naphthalene type epoxy resins, for example, EPICLON HP4032, EPICLON EXA-4700 (all manufactured by DIC Corporation), and the like are mentioned.

In the above-mentioned phenolic novolac type epoxy resin, for example, EPICLON N-770 (manufactured by DIC Corporation) or the like can be mentioned.

In the above-mentioned o-cresol novolac type epoxy resin, for example, EPICLON N-670-EXP-S (manufactured by DIC Corporation) or the like can be mentioned.

In the above-mentioned dicyclopentadiene novolac type epoxy resin, for example, EPICLON HP7200 (manufactured by DIC Corporation) or the like can be mentioned.

In the above-mentioned biphenol novolak type epoxy resin, for example, NC-3000P (manufactured by Nippon Kayaku Co., Ltd.) or the like can be mentioned.

In the above-mentioned naphthol-based novolak-type epoxy resin, for example, ESN-165S (manufactured by Nippon Steel & Sumitomo Chemical Co., Ltd.) or the like can be mentioned.

Among the above-mentioned glycidylamine-type epoxy resins, for example, jER630 (manufactured by Mitsubishi Chemical Corporation), EPICLON 430 (manufactured by DIC Corporation), TETRAD-X (manufactured by Mitsubishi Gas Chemical Co., Ltd.), and the like are mentioned.

In the above-mentioned alkyl polyol type epoxy resin, for example, ZX-1542 (manufactured by Nippon Steel & Sumitomo Chemical Co., Ltd.), EPICLON 726 (manufactured by DIC Corporation), and Epolight 80MFA (manufactured by Kyoeisha Chemical Co., Ltd.) are mentioned. , DENACOL EX-611 (manufactured by Nagase Chemical Co., Ltd.).

Among the above-mentioned rubber-modified epoxy resins, for example, YR-450, YR can be cited. -207 (both manufactured by Nippon Steel & Sumitomo Chemical Co., Ltd.) and Epolead PB (manufactured by DAICEL).

Among the above-mentioned glycidyl ester compounds, for example, DENACOL EX-147 (manufactured by Nagase Chemical Co., Ltd.) or the like can be cited.

Among the above-mentioned epoxy compounds, for example, YDC-1312, YSLV-80XY, YSLV-90CR (all manufactured by Nippon Steel & Sumitomo Chemical Co., Ltd.), XAC4151 (manufactured by Asahi Kasei Co., Ltd.), jER1031, and jER1032 (both of them) are mentioned. It is manufactured by Mitsubishi Chemical Corporation, EXA-7120 (manufactured by DIC Corporation), TEPIC (manufactured by Nissan Chemical Co., Ltd.), and the like.

Moreover, the curable resin may contain a compound having an epoxy group and a (meth) acrylonitrile group in one molecule as the other epoxy compound. As such a compound, for example, a partial (meth)acryl-modified epoxy resin obtained by reacting a partial epoxy group of an epoxy compound having two or more epoxy groups with (meth)acrylic acid is exemplified. Wait.

Among the above-mentioned partial (meth)acrylic-modified epoxy resins, for example, UVACURE 1561 (manufactured by DAICEL-ALLNEX Co., Ltd.) or the like can be mentioned.

Examples of the other (meth)acrylic compound include an epoxy (meth)acrylate obtained by reacting (meth)acrylic acid with an epoxy compound, and (meth)acrylic acid having a hydroxyl group. The (meth) acrylate compound obtained by the reaction of the compound, the (meth) acrylate amine obtained by reacting the isocyanate compound with the (meth)acrylic acid derivative having a hydroxyl group, and the like. Among them, epoxy (meth) acrylate is preferred. Further, the other (meth)acrylic compound is preferably one having two or more (meth) acrylonitrile groups in the molecule in terms of high reactivity.

In the present specification, the above-mentioned "epoxy (meth) acrylate" means A compound obtained by reacting all of the epoxy groups of the epoxy compound with (meth)acrylic acid.

Examples of the epoxy (meth) acrylate include those obtained by reacting an epoxy compound with (meth)acrylic acid in the presence of a basic catalyst according to a conventional practice.

The epoxy compound to be used as a raw material for synthesizing the above epoxy (meth) acrylate is the same as the other polymerizable compound which can be used as the other epoxy compound.

Among the above-mentioned epoxy (meth) acrylates, for example, EBECRYL 860, EBECRYL 3200, EBECRYL 3201, EBECRYL 3412, EBECRYL 3600, EBECRYL 3700, EBECRYL 3701, EBECRYL 3702, EBECRYL 3703, EBECRYL 3708, EBECRYL 3800, EBECRYL 6040, EBECRYL RDX 63182 (both manufactured by DAICEL-ALLNEX), EA-1010, EA-1020, EA-5323, EA-5520, EA-CHD, EMA-1020 (all manufactured by Shin-Nakamura Chemical Industry Co., Ltd.) ), Epoxy Ester M-600A, Epoxy Ester 40EM, Epoxy Ester 70PA, Epoxy Ester 200PA, Epoxy Ester 80MFA, Epoxy Ester 3002M, Epoxy Ester 3002A, Epoxy Ester 1600A, Epoxy Ester 3000M, Epoxy Ester 3000A, Epoxy Ester 200EA, Epoxy Ester 400EA (all manufactured by Kyoeisha Chemical Co., Ltd.), DENACOL Acrylate DA-141, DENACOL Acrylate DA-314, and DENACOL Acrylate DA-911 (all manufactured by Nagase Chemical Co., Ltd.).

Among the above (meth) acrylate compounds, examples of the monofunctional ones include methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, and n-butyl (meth)acrylate. Ester, isobutyl (meth)acrylate, tert-butyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, n-octyl (meth)acrylate, isooctyl (meth)acrylate , isodecyl (meth)acrylate, isodecyl (meth)acrylate, lauryl (meth)acrylate, (a) Ethyl myristate, stearyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate, 4-hydroxybutyl (meth)acrylate, cyclohexyl (meth)acrylate, isodecyl (meth)acrylate, dicyclopentenyl (meth)acrylate, isobenzyl (meth)acrylate, ( 2-methoxyethyl (meth)acrylate, 2-ethoxyethyl (meth)acrylate, 2-butoxyethyl (meth)acrylate, 2-phenoxyethyl (meth)acrylate , methoxyethylene glycol (meth) acrylate, methoxy polyethylene glycol (meth) acrylate, phenoxy diethylene glycol (meth) acrylate, phenoxy polyethylene glycol ( Methyl) acrylate, tetrahydrofurfuryl (meth) acrylate, ethyl carbitol (meth) acrylate, 2, 2, 2-trifluoroethyl (meth) acrylate, (meth) acrylate 2 , 2,3,3-tetrafluoropropyl ester, (meth)acrylic acid 1H, 1H, 5H-octafluoropentyl ester, quinone imine (meth) acrylate, dimethylaminoethyl (meth) acrylate, Diethylaminoethyl (meth)acrylate, 2-(methyl)propenyloxyethyl succinate, hexahydrophthalic acid 2-(methyl)propenyloxyethyl ester, 2-(methyl)acryloxyethyl 2-hydroxypropyl phthalate, 2-(methyl) propylene methoxyethyl phosphate, ( Glycidyl methacrylate or the like.

Further, among the above (meth) acrylate compounds, examples of the bifunctional ones 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-nonanediol di(meth)acrylate, ethylene glycol II (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 Alcohol di(meth)acrylate, ethylene oxide addition bisphenol A II Acrylate, propylene oxide addition bisphenol A di(meth) acrylate, ethylene oxide addition bisphenol F di(meth) acrylate, di(methyl) bis(methyl) acrylate Pentadienyl ester, ethylene oxide modified di(meth) acrylate, 2-hydroxy-3-(meth) propylene methoxy propyl (meth) acrylate, carbonate diol Di(meth)acrylate, polyether diol di(meth) acrylate, polyester diol di(meth) acrylate, polycaprolactone diol di(meth) acrylate, polybutadiene Glycol di(meth)acrylate or the like.

In addition, examples of the above-mentioned (meth) acrylate compound include trimethylolpropane tri(meth)acrylate and ethylene oxide addition trimethylolpropane tris(methyl). Acrylate, propylene oxide addition trimethylolpropane tri(meth) acrylate, ethylene oxide addition tris (meth) acrylate, tris (meth) acrylate, Propylene oxide addition glycerol tri(meth) acrylate, neopentyl alcohol tri(meth) acrylate, tris(methyl) propylene methoxyethyl phosphate, di-trimethylolpropane tetra (methyl Acrylate, neopentyltetrakis(meth)acrylate, dipentaerythritol penta(meth)acrylate, dipentaerythritol hexa(meth)acrylate, and the like.

The above (meth)acrylic acid amide can be reacted, for example, by reacting 2 equivalents of a (meth)acrylic acid derivative having a hydroxyl group with an isocyanate compound having 2 isocyanate groups in an amount of a catalyst amount of a tin-based compound. And get.

Examples of the isocyanate compound which is a raw material of the above (meth)acrylic acid amide ester include isophorone diisocyanate, 2,4-toluene diisocyanate, 2,6-toluene diisocyanate, and hexamethylene diisocyanate. Trimethylhexamethylene diisocyanate, diphenylmethane-4,4'-diisocyanate (MDI), hydrogenated MDI, polymeric MDI, 1,5-naphthalene diisocyanate, norbornane diisocyanate, tolidine diisocyanate Benzyl diisocyanate (XDI), Hydrogenated XDI, quaternary acid diisocyanate, triphenylmethane triisocyanate, tris(isocyanate phenyl) thiophosphate, tetramethyl benzene diisocyanate, 1,6,11-undecane triisocyanate, and the like.

Further, as the isocyanate compound which is a raw material of the above (meth)acrylic acid amide, for example, ethylene glycol, propylene glycol, glycerin, sorbitol, trimethylolpropane, carbonate diol or polyether diol can also be used. A chain-extended isocyanate compound obtained by reacting a polyhydric alcohol such as a polyester diol or a polycaprolactone diol with an excess of an isocyanate compound.

Examples of the (meth)acrylic acid derivative having a hydroxyl group which is a raw material of the above (meth)acrylic acid amine ester include 2-hydroxyethyl (meth)acrylate and 2-hydroxypropyl (meth)acrylate. Hydroxyalkyl (meth)acrylate such as 2-hydroxybutyl (meth)acrylate or 4-hydroxybutyl (meth)acrylate; ethylene glycol, propylene glycol, 1,3-propanediol, 1,3-butane a mono (meth) acrylate of a glycol such as an alcohol, 1,4-butanediol or polyethylene glycol; a mono-(methyl) monohydric alcohol such as trimethylolethane, trimethylolpropane or glycerol Epoxy (meth) acrylate such as acrylate or di(meth) acrylate; or bisphenol A epoxy acrylate.

Among the above-mentioned (meth) acrylates, for example, M-1100, M-1200, M-1210, M-1600 (all manufactured by Toagosei Co., Ltd.), EBECRYL 210, EBECRYL 220, EBECRYL 230, EBECRYL 270, EBECRYL 1290, EBECRYL 2220, EBECRYL 4827, EBECRYL 4842, EBECRYL 4858, EBECRYL 5129, EBECRYL 6700, EBECRYL 8402, EBECRYL 8803, EBECRYL 8804, EBECRYL 8807, EBECRYL 9260 (all manufactured by DAICEL-ALLNEX), Artresin UN-330, Artresin SH-500B, Artresin UN-1200TPK, Artresin UN-1255, Artresin UN-3320HB, Artresin UN-7100, Artresin UN-9000A, Artresin UN -9000H (all manufactured by Gensei Industrial Co., Ltd.), U-2HA, U-2PHA, U-3HA, U-4HA, U-6H, U-6HA, U-6LPA, U-10H, U-15HA, U-108 , U-108A, U-122A, U-122P, U-324A, U-340A, U-340P, U-1084A, U-2061BA, UA-340P, UA-4000, UA-4100, UA-4200, UA -4400, UA-5201P, UA-7100, UA-7200, UA-W2A (all manufactured by Shin-Nakamura Chemical Industry Co., Ltd.), AH-600, AI-600, AT-600, UA-101I, UA-101T, UA -306H, UA-306I, UA-306T (all manufactured by Kyoeisha Chemical Co., Ltd.).

In the sealing agent for a liquid crystal display device of the present invention, the content ratio of the (meth)acryl fluorenyl group to the epoxy group in the curable resin is preferably 50:50 to 95:5 in terms of a molar ratio.

The sealing agent for liquid crystal display elements of the present invention contains a polymerization initiator and/or a thermal curing agent.

Examples of the polymerization initiator include a radical polymerization initiator, a cationic polymerization initiator, and the like.

Examples of the radical polymerization initiator include a photoradical polymerization initiator which generates a radical by light irradiation, a thermal radical polymerization initiator which generates a radical by heating, and the like.

Examples of the photoradical polymerization initiator include a benzophenone compound, an acetophenone compound, a fluorenyl phosphine oxide compound, a titanocene compound, an oxime ester compound, and a benzoin ether compound. 9-oxygen sulfur A compound or the like.

Among the above-mentioned photoradical polymerization initiators, for example, IRGACURE 184, IRGACURE 369, IRGACURE 379, IRGACURE 651, IRGACURE 819, IRGACURE 907, IRGACURE 2959, IRGACURE OXE01, Lucirin TPO (both manufactured by BASF Corporation), NCI-930 (manufactured by Adeka Corporation), SPEEDCURE EMK (manufactured by Siber Hegner, Japan), benzoin methyl ether, benzoin ethyl ether, and benzoin isopropyl ether (all manufactured by Tokyo Chemical Industry Co., Ltd.).

Examples of the thermal radical polymerization initiator include those composed of an azo compound, an organic peroxide, and the like. Among them, an initiator (hereinafter also referred to as "polymer azo initiator") composed of a polymer azo compound is preferred.

In the present specification, the term "polymer azo compound" means a compound having an azo group and generating a number average molecular weight of a radical which can cure a (meth) acrylonitrile group by heat of 300 or more.

A preferred lower limit of the number average molecular weight of the above polymer azo initiator is 1000, and a preferred upper limit is 300,000. When the number average molecular weight of the above polymer azo initiator is within this range, liquid crystal contamination can be suppressed and easily mixed with the curable resin. A more preferred lower limit of the number average molecular weight of the above polymer azo initiator is 5,000, more preferably 100,000, and still more preferably a lower limit of 10,000, and further preferably an upper limit of 90,000.

In the present specification, the above-mentioned number average molecular weight is measured by gel permeation chromatography (GPC) and is determined by polystyrene conversion. As a column for measuring the number average molecular weight obtained by polystyrene conversion by GPC, for example, Shodex LF-804 (manufactured by Showa Denko Co., Ltd.) or the like can be mentioned.

The polymer azo initiator is, for example, a structure in which a plurality of units such as polyalkylene oxide or polydimethyl siloxane are bonded via an azo group.

The polymer azo initiator having a structure in which a plurality of units such as polyalkylene oxide are bonded via an azo group is preferably a polyethylene oxide structure. As such a polymer azo The initiator may, for example, be a polycondensate of 4,4'-azobis(4-cyanovaleric acid) and a polyalkylene glycol, or 4,4'-azobis(4-cyanovaleric acid). And a polycondensate of polydimethyl methoxy oxane having a terminal amine group, and the like, specifically, for example, VPE-0201, VPE-0401, VPE-0601, VPS-0501, and VPS-1001 (both and Wako Pure Chemical Industries Co., Ltd.) and so on. In addition, examples of the non-polymer azo compound include V-65 and V-501 (all manufactured by Wako Pure Chemical Industries, Ltd.).

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

As the above cationic polymerization initiator, a photocationic polymerization initiator can be suitably used. The photocationic polymerization initiator is not particularly limited as long as it generates protonic acid or Lewis acid by light irradiation, and may be an ionic photoacid generation type or a nonionic photoacid generation type.

Examples of the photocationic polymerization initiator include an anthracene salt such as an aromatic diazonium salt, an aromatic halosulfonium salt or an aromatic onium salt, an iron-aromatic hydrocarbon complex, a titanocene complex, and an aromatic salt. An organic metal complex such as a ketol-aluminum complex or the like.

Among the above-mentioned photo-cationic polymerization initiators, for example, Adeka Optomer SP-150 and Adeka Optomer SP-170 (all manufactured by ADEKA Co., Ltd.) and the like are mentioned.

The content of the polymerization initiator is preferably 0.01 parts by weight, and preferably 10 parts by weight, based on 100 parts by weight of the curable resin. When the content of the above-mentioned polymerization initiator is within this range, the obtained sealing agent for a liquid crystal display element is excellent in storage stability and hardenability by suppressing liquid crystal contamination. A lower limit of the content of the above polymerization initiator is 0.1 weight. The upper limit is more preferably 5 parts by weight.

Examples of the above-mentioned thermosetting agent include an organic acid hydrazine, an imidazole derivative, an amine compound, a polyhydric phenol compound, and an acid anhydride. Among them, an organic acid hydrazine can be suitably used.

Examples of the organic acid hydrazine include diindole azelaic acid, diterpene isophthalate, diammonium adipate, and diammonium malonate.

Among the above-mentioned organic acid bismuth, for example, SDH, ADH (all manufactured by Otsuka Chemical Co., Ltd.), Amicure VDH, Amicure VDH-J, Amicure UDH, and Amicure UDH-J (all Ajinomoto Fine-Techno) Company manufacturing) and so on.

The content of the above-mentioned thermosetting agent is preferably 1 part by weight, and preferably 50 parts by weight, based on 100 parts by weight of the curable resin. When the content of the above-mentioned heat-hardening agent is in this range, it is possible to make the thermosetting property more excellent without deteriorating the coating property of the obtained sealing compound for liquid crystal display elements. A more preferable upper limit of the content of the above thermal curing agent is 30 parts by weight.

The sealing agent for a liquid crystal display element of the present invention preferably contains a filler in order to improve the viscosity, improve the adhesion obtained by the stress dispersion effect, improve the linear expansion ratio, and improve the moisture permeability of the cured product.

Examples of the filler include cerium oxide, talc, glass beads, asbestos, gypsum, diatomaceous earth, bentonite, bentonite, montmorillonite, sericite, activated clay, alumina, zinc oxide, iron oxide, and the like. Inorganic fillers such as magnesium oxide, tin oxide, titanium oxide, calcium carbonate, magnesium carbonate, magnesium hydroxide, aluminum hydroxide, aluminum nitride, tantalum nitride, barium sulfate, calcium citrate, or polyester microparticles, polyurethane microparticles, An organic filler such as a vinyl polymer microparticle or an acrylic polymer microparticle.

A preferred lower limit of the content of the above filler in 100 parts by weight of the sealant for a liquid crystal display device of the present invention is 10 parts by weight, and preferably the upper limit is 70 parts by weight. When the content of the filler is within this range, the effect of improving the adhesion is not particularly excellent when the coating property or the like is not deteriorated. A more preferred lower limit of the content of the above filler is 20 parts by weight, and a more preferred upper limit is 60 parts by weight.

The sealing agent for liquid crystal display elements of the present invention preferably contains a decane coupling agent. The above decane coupling agent mainly functions as a bonding aid for satisfactorily adhering a sealing agent to a substrate or the like.

The decane coupling agent is excellent in the effect of improving the adhesion to the substrate or the like, and can be used in the liquid crystal by chemically bonding with the curable resin. For example, it can be suitably used. Aminopropyltrimethoxydecane, 3-mercaptopropyltrimethoxydecane, 3-glycidoxypropyltrimethoxydecane, 3-isocyanatepropyltrimethoxydecane, and the like.

A preferred lower limit of the content of the above decane coupling agent in 100 parts by weight of the sealing agent for a liquid crystal display device of the present invention is 0.1 part by weight, preferably 10 parts by weight. When the content of the above decane coupling agent is within this range, the effect of suppressing the occurrence of liquid crystal contamination and improving the adhesion is more excellent. A more preferred lower limit of the content of the above decane coupling agent is 0.3 parts by weight, and a more preferred upper limit is 5 parts by weight.

The sealing agent for liquid crystal display elements of this invention may also contain an opacifier. The sealant for a liquid crystal display element of the present invention can be suitably used as a light-shielding sealant by containing the above-mentioned light-shielding 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 titanium black is a substance having a higher transmittance in the vicinity of the ultraviolet region, particularly at a wavelength of 370 to 450 nm, than the average transmittance of light having a wavelength of 300 to 800 nm. In other words, the titanium black is a light-shielding agent which imparts light-shielding property to the sealing agent for liquid crystal display elements of the present invention and which has a property of transmitting light of a wavelength near the ultraviolet ray region by sufficiently shielding the light of the wavelength of the visible light region. The light-shielding agent contained in the sealing agent for liquid crystal display elements of the present invention is preferably a material having high insulating properties, and is preferably a titanium black as a light-shielding agent having high insulating properties.

Although the above titanium black does not exhibit sufficient effects without surface treatment, it may be treated with an organic component such as a surface coupler or an inorganic material such as cerium oxide, titanium oxide, cerium oxide, aluminum oxide, zirconium oxide or magnesium oxide. Surface treated titanium black, such as component coatings. Among them, those who have been treated with an organic component are preferred in terms of further improving the insulating properties.

In addition, since the liquid crystal display element manufactured by using the sealing agent for liquid crystal display elements of the present invention containing the above-mentioned titanium black as a light-shielding agent has sufficient light-shielding property, it can achieve light-free leakage, has high contrast, and is excellent. The image shows a quality liquid crystal display element.

Among the above-mentioned titanium blacks, for example, 12S, 13M, 13M-C, 13R-N, 14M-C (all manufactured by Mitsubishi Materials Corporation), Tilack D (manufactured by Ako Chemical Co., Ltd.), and the like are exemplified.

A preferred lower limit of the specific surface area of the above titanium black is 13 m ² /g, preferably an upper limit of 30 m ² /g, a more preferred lower limit of 15 m ² /g, and a more preferred upper limit of 25 m ² /g.

Moreover, the preferred lower limit of the volume resistance of the titanium black is 0.5 Ω. Cm, preferably the upper limit is 3Ω. Cm, the lower limit is 1Ω. Cm, the upper limit is better 2.5Ω. Cm.

The primary particle diameter of the above-mentioned sunscreen agent is only the distance between the substrates of the liquid crystal display element The following is not particularly limited, and a preferred lower limit is 1 nm, and a preferred upper limit is 5000 nm. When the primary particle diameter of the above-mentioned light-shielding agent is in this range, it is possible to obtain a light-shielding property more excellently without deteriorating the coating property of the obtained sealing compound for liquid crystal display elements. A more preferred lower limit of the primary particle diameter of the above-mentioned opacifier is 5 nm, more preferably an upper limit of 200 nm, further preferably a lower limit of 10 nm, and further preferably an upper limit of 100 nm.

In addition, the primary particle diameter of the light-shielding agent can be measured by dispersing the light-shielding agent in a solvent (water, organic solvent, etc.) using NICOMP 380ZLS (made by PARTICLE SIZING SYSTEMS).

A preferred lower limit of the content of the above-mentioned sunscreen agent in 100 parts by weight of the sealant for a liquid crystal display device of the present invention is 5 parts by weight, and preferably the upper limit is 80 parts by weight. When the content of the above-mentioned light-shielding agent is in this range, it is possible to exhibit more excellent light-shielding properties without lowering the adhesion to the substrate or the strength or patternability after curing of the obtained sealing agent for liquid crystal display elements. A more preferred lower limit of the content of the above-mentioned opacifier is 10 parts by weight, more preferably 70 parts by weight, still more preferably 30 parts by weight, and still more preferably 60 parts by weight.

Further, the sealant for a liquid crystal display device of the present invention may further contain a stress relieving agent, a reactive diluent, a thixotropic agent, a separator, a curing accelerator, an antifoaming agent, a leveling agent, a polymerization inhibitor, and other additives.

The method for producing the sealant for a liquid crystal display device of the present invention includes, for example, a homomixer, a homomixer, a universal mixer, a planetary mixer, a kneader, a three-roll mill, and the like, and a curable resin, A method of mixing an additive such as a polymerization initiator and/or a thermosetting agent and a decane coupling agent to be added as needed.

The conductive particles are formulated in the sealant for liquid crystal display elements of the present invention The sub-conducting material can be manufactured. Moreover, such a sealing material for a liquid crystal display element of the present invention and a conductive fine particle upper and lower conductive material are also one of the inventions.

The conductive fine particles can be used for forming a conductive metal layer on the surface of a metal ball or resin fine particles. Among them, the conductive metal layer formed on the surface of the resin fine particles can be electrically connected without damaging the transparent substrate by the excellent elasticity of the resin fine particles, and is therefore suitable.

Further, the liquid crystal display element having the sealing agent for a liquid crystal display element of the present invention or the upper conductive material of the present invention is also one of the inventions.

As a method of producing the liquid crystal display element of the present invention, a liquid crystal dropping method can be suitably used. Specifically, for example, a method having the following steps: printing on a substrate of one of two substrates, such as an ITO film or the like, a glass substrate with an electrode or a polyethylene terephthalate substrate; a step of applying a sealant for a liquid crystal display element of the present invention to form a frame-like seal pattern, and a sealant for a liquid crystal display element of the present invention is a seal pattern of a substrate in an uncured state. a step of dropping a small droplet of liquid crystal in a frame and superposing another substrate under vacuum; and irradiating the sealing pattern portion of the sealing agent for a liquid crystal display element of the present invention with light such as ultraviolet rays to temporarily harden the sealing agent; The step of temporarily hardening the sealant by heating to form it hard.

According to the present invention, it is possible to provide a sealant for a liquid crystal display element which is excellent in adhesion and moisture permeability and which can suppress liquid crystal contamination. Moreover, according to the present invention, it is possible to provide an upper and lower conductive material and a liquid crystal display element using the sealing agent for a liquid crystal display element.

Hereinafter, the present invention will be described in more detail by way of examples, but the invention is not limited to the examples.

(Production of ε-caprolactone-modified dipentaerythritol hexaacrylate A)

25.4 parts by weight (0.1 mol) of dipentaerythritol was reacted with 68.4 parts by weight (0.6 mol) of ε-caprolactone and 43.2 parts by weight (0.6 mol) of acrylic acid, and a pair as a polymerization inhibitor was added to the flask. 0.01 parts by weight of benzenediol, 0.1 parts by weight of p-toluenesulfonic acid as a catalyst, and 200 parts by weight of propylene glycol methyl ether acetate (PGMEA) as a solvent were heated while flowing nitrogen gas.

After reacting for 6 hours in an oil bath of 120 ° C, it was left to cool to room temperature, thereby obtaining ε-caprolactone-modified dineopentaerythritol hexaacrylate A as a polymerizable compound of the present invention.

According to ¹ H-NMR, ¹³ C-NMR, and FT-IR analysis, it was confirmed that the obtained ε-caprolactone-modified dipentaerythritol hexaacrylate A was in the above formula (1), m, n , o, p, and q are compounds of 1.

(Production of ε-caprolactone-modified dipentaerythritol hexaacrylate B)

25.4 parts by weight (0.1 mol) of dipentaerythritol was reacted with 137 parts by weight (1.2 mol) of ε-caprolactone and 43.2 parts by weight (0.6 mol) of acrylic acid, and a pair as a polymerization inhibitor was added to the flask. 0.01 parts by weight of benzenediol, 0.1 parts by weight of p-toluenesulfonic acid as a catalyst, and 200 parts by weight of propylene glycol methyl ether acetate (PGMEA) as a solvent were heated while flowing nitrogen gas.

After reacting for 6 hours in an oil bath of 120 ° C, it was left to cool to room temperature, thereby obtaining as the present hair. The ε-caprolactone-modified dipentaerythritol hexaacrylate B of the polymerizable compound of the present invention.

According to ¹ H-NMR, ¹³ C-NMR, and FT-IR analysis, it was confirmed that the obtained ε-caprolactone-modified dipentaerythritol hexaacrylate B is a l, m, n in the above formula (1) , o, p, and q are compounds of 2.

(Production of carboxylic acid addition ε-caprolactone modified neopentyl alcohol triacrylate)

Adding ε-caprolactone-modified neopentyl alcohol triacrylate to the flask (reaction of pentaerythritol 1 mol with ε-caprolactone 8 mol, and then esterification with 3 mol of acrylic acid) Compound) 20 parts by weight (16.8 mmol), 1.98 parts by weight (16.8 mmol) of succinic anhydride as an acid anhydride, 0.01 parts by weight of hydroquinone as a polymerization inhibitor, and propylene glycol methyl ether acetate (PGMEA) as a solvent 20 parts by weight of the mixture was heated while flowing nitrogen gas.

Next, when succinic anhydride was completely dissolved, 0.02 parts by weight of triethylamine as a catalyst was added, and then reacted in an oil bath at 120 ° C for 6 hours in a nitrogen atmosphere, and then left to cool to room temperature, thereby obtaining the present invention. The carboxylic acid of the polymerizable compound is added to ε-caprolactone-modified neopentyl alcohol triacrylate.

(Examples 1 to 10, and Comparative Examples 1 to 5)

According to the mixing ratios shown in Tables 1 and 2, each material was mixed by a planetary mixer ("Thining Stirring Taro" manufactured by Thinky Co., Ltd.), and further mixed by a three-roll mill to prepare Example 1 ~10, and the sealing agent for liquid crystal display elements of the comparative examples 1-5.

<evaluation>

The following evaluations were performed on the sealants for liquid crystal display elements obtained in the examples and the comparative examples. The results are shown in Tables 1 and 2.

(save stability)

The sealant for each liquid crystal display element obtained in the examples and the comparative examples was measured for the initial viscosity immediately after the production and the viscosity at the time of storage at 25 ° C for one week, and the viscosity was maintained at 25 ° C for one week. / (initial viscosity) is the viscosity change rate, and the viscosity change rate is less than 1.1, and it is rated as "○". If it is less than 1.1, it is rated as "△", and if it is 2.0 or higher, it is rated as "X". To evaluate the preservation stability.

Further, the viscosity of the sealant was measured using an E-type viscometer ("DV-III" manufactured by BROOK FIELD) at a rotation speed of 1.0 rpm at 25 °C.

(adhesive)

For 100 parts by weight of each of the sealants for liquid crystal display elements obtained in the examples and the comparative examples, spacer particles having an average particle diameter of 5 μm (manufactured by Sekisui Chemical Co., Ltd., "Micropearl SP-2050") were obtained by a planetary stirring device. 1 part by weight was uniformly dispersed, and a very small amount was placed in the center portion of Corning glass 1737 (20 mm × 50 mm × thickness 0.7 mm), and the same type of glass was superposed thereon to develop a sealing agent for a liquid crystal display element, using a metal halide After the lamp was irradiated with ultraviolet rays of 100 mW/cm ^{2 for} 30 seconds, it was heated at 120 ° C for 1 hour to cure the sealant, and a test piece was obtained.

For the obtained test piece, the tensile strength was measured using a tensiometer. The bonding strength is ² or more of the circumstances 330N / cm as "◎", followed by strength of 300N / cm ² or more and less than 330N / cm ² of the case as "○", followed by strength of 270N / cm ² and no more than of 300N / cm ² of the case as "△", and then the strength of the case of less than 270N / cm ² of the rated "×", to evaluate the adhesive property.

(water permeability)

Each of the sealing agents for liquid crystal display elements obtained in the examples and the comparative examples was applied to a smooth release film in a thickness of 200 to 300 μm by a coater, and then irradiated with ultraviolet rays of 100 mW/cm ^{2 for} 30 seconds using a metal halide lamp. Thereafter, the film was heated at 120 ° C for 1 hour to obtain a cured film for moisture permeability measurement. A moisture permeability test cup is prepared by a moisture permeability test method (cup type method) of a moisture-proof packaging material according to JIS Z 0208, and the obtained cured film for moisture permeability measurement is installed and put into a temperature of 80 ° C and a humidity of 90%. The moisture permeability was measured in a constant temperature and humidity oven of RH. The obtained moisture permeability value is less than 50 g/m ² . The case of 24hr was rated as "○" and was 50g/m ² . More than 24hr and less than 70g/m ² . In the case of 24 hr, it was rated as "△" and was 70 g/m ² . The case of 24 hr or more was evaluated as "X" to evaluate the moisture permeability.

(Display performance of liquid crystal display element (low liquid crystal contamination))

For 100 parts by weight of each of the sealants for liquid crystal display elements obtained in the examples and the comparative examples, spacer particles having an average particle diameter of 5 μm (manufactured by Sekisui Chemical Co., Ltd., "Micropearl SP-2050") were obtained by a planetary stirring device. 1 part by weight was uniformly dispersed, and the obtained sealant was filled in a syringe for dripping ("PSY-10E" manufactured by Takeo High-Tech Co., Ltd.), and defoaming treatment was carried out, and then a dispenser was used (Wuyi High-Tech Co., Ltd.) Manufactured, "SHOTMASTER 300") A sealant was applied in a frame shape on one of two substrates of a transparent electrode substrate with an ITO film. Then, a small droplet of TN liquid crystal ("JC-5001LA" manufactured by Chisso Co., Ltd.) was dropped by a liquid crystal dropping device and applied to a frame of a sealant, and another transparent electrode was bonded under a vacuum of 5 Pa by a vacuum bonding device. The substrate is obtained while the unit is obtained. The obtained unit was irradiated with ultraviolet rays of 100 mW/cm ^{2 for} 30 seconds using a metal halide lamp, and then heated at 120 ° C for 1 hour to cure the sealant to obtain a liquid crystal display element.

The liquid crystal display element obtained was visually observed for display unevenness on the liquid crystal (especially the corner portion) around the sealing portion, and the case where the display unevenness was not confirmed was evaluated as "○", and it was confirmed that the display was uneven. The case was evaluated as "△", and the case where the display was severely uneven was evaluated as "X", thereby evaluating the display performance of the liquid crystal display element (low liquid crystal contamination).

[Industrial availability]

According to the present invention, it is possible to provide a sealant for a liquid crystal display element which is excellent in adhesion and moisture permeability and which can suppress liquid crystal contamination. Moreover, according to the present invention, it is possible to provide an upper and lower conductive material and a liquid crystal display element using the sealing agent for a liquid crystal display element.

Claims (9)

A sealant for a liquid crystal display element, comprising a curable resin, a polymerization initiator, and/or a thermosetting agent, wherein the curable resin contains a compound having three or more polymerizable groups in one molecule. A compound having a functional group and one or more ring-opening structures of ε-caprolactone and having no cyclic structure. The sealant for a liquid crystal display element according to the first aspect of the invention, which has three or more polymerizable functional groups and one or more open-loop structures of ε-caprolactone in one molecule, and has no ring-shaped structure. The polymerizable functional group of the compound of the structure is a (meth) acrylonitrile group. The sealant for a liquid crystal display element according to the first or second aspect of the invention, which has a ring-opening structure of three or more polymerizable functional groups and one or more ε-caprolactone in one molecule, and does not have The compound having a cyclic structure has an open-ring structure of two or more ε-caprolactones in one molecule. The sealant for a liquid crystal display device of claim 3, which has three or more polymerizable functional groups and one or more open-loop structures of ε-caprolactone in one molecule, and has no ring-shaped structure. The compound of the structure has an open-ring structure of 4 or more ε-caprolactones in one molecule. The sealant for a liquid crystal display element of the first, second, third or fourth aspect of the invention, which has three or more polymerizable functional groups and one or more open-loop structures of ε-caprolactone in one molecule. The compound having no cyclic structure has one or more hydrogen bond functional groups in one molecule. The sealant for liquid crystal display elements of the first, second, third, fourth or fifth aspect of the invention, which has three or more polymerizable functional groups and one or more ε-caprolactones in one molecule. The compound having a ring structure and having no cyclic structure has a dendritic polymer structure. The sealant for a liquid crystal display element of the first, second, third, fourth, fifth or sixth aspect of the invention, wherein the curable resin has three or more polymerizable functional groups in one molecule per 100 parts by weight of the curable resin and The content of the compound having more than one ring-opening structure of ε-caprolactone and having no cyclic structure is from 1 to 80 parts by weight. A top-bottom conductive material containing a sealant for a liquid crystal display element and conductive fine particles of the first, second, third, fourth, fifth, sixth or seventh aspect of the patent application. A liquid crystal display element having a sealant for a liquid crystal display element of the first, second, third, fourth, fifth, sixth or seventh aspect of the patent application or a lower conductive material of the eighth aspect of the patent application.