JP2006241367A - Sealing resin composition and sealed structure using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain a sealing resin composition in which outside air and steam do not penetrates into an inner space and which seals a peripheral part between substrates so as not to leak a sealing gas such as an inert gas, etc., from an inner space and a sealed structure such as a display element, etc., using the same. <P>SOLUTION: The sealing resin composition seals a peripheral part between substrates composed of two opposing substrates and forms a sealed structure having an inner space maintained under reduced pressure or in an inert gas atmosphere. The sealing resin composition comprises at least one kind of a thermoplastic resin (a) and a thermosetting resin (b) composed of a polyimide silicone as an essential component and resin layers obtained by sealing are each independently formed so as to constitute a multilayer structure in which the resin layers are mutually adjacent. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a sealing resin composition and a sealing structure using the same, and more specifically, external air does not penetrate into the internal space, and an enclosed gas such as an inert gas does not leak from the internal space. The sealing resin composition which can seal the peripheral part between board | substrates in this way, and sealing structures, such as a display element using the same.

  In recent years, thin display elements such as liquid crystal display elements, PDPs (plasma display panels), FEDs (field emission displays), VFDs (fluorescent display tubes) have attracted attention, and the development of elements with higher functions has been promoted. Yes.

  Since the liquid crystal display element does not require a function of keeping the inside of the element at a reduced pressure, the gas barrier property and the outgas characteristic are usually not required. However, in display elements such as PDP, FED, and VFD, the internal space of the element is maintained in a vacuum state under reduced pressure. Therefore, the sealing material that seals the peripheral edge between the substrates is inactive from the internal space. There is a need for a function for preventing gas leakage, that is, a function for maintaining a reduced pressure.

  In particular, in a PDP or the like, there is a case where a process of keeping the internal space at a high vacuum after sealing is required in order to process impurities generated when the substrate is sealed. For example, when manufacturing a PDP, after sealing the substrate, heating and exhausting at a high temperature of about 300 ° C. or more, and adding a step of introducing a discharge gas after removing impurities such as moisture and carbon. It has been proposed (see, for example, Patent Document 1).

  Until now, lead glass has been mainly used as a sealing material in PDP, FED, VFD and the like. However, since lead glass requires a temperature close to 450 ° C. to fuse and fire it, not only does the loss of the phosphor in the device increase and the performance deteriorates, but also lead that causes environmental problems Since it contains, there are restrictions on use.

  On the other hand, in a liquid crystal display element, an epoxy resin containing a filler such as silica is widely used as a material for sealing between glass substrates. This is because the cured epoxy resin has excellent moisture resistance and mechanical strength. Therefore, it has been proposed to use a low-temperature sealing composition made of a single thermosetting resin such as an epoxy resin even in a sealing structure such as a PDP (see, for example, Patent Document 2).

According to this, the peripheral portion between the substrates can be sealed at a temperature lower than that of lead glass, but it has an effect of shielding the inert gas such as water vapor and He gas, and further outgas generated from the inside of the resin composition over a long period of time. In the case of PDPs, which are small and have a growing need for larger screens and thinner screens in the future, they have been regarded as problematic because they cannot maintain long-term reliability of products.
Under such circumstances, the appearance of a sealing resin composition that does not contain lead, has a long-term shielding effect such as an inert gas such as water vapor or He gas, or outgas, and can ensure long-term reliability such as PDP is eagerly desired. It had been.
JP 2000-243280 A JP 2003-183624 A

  An object of the present invention is to provide a sealing resin composition capable of sealing a peripheral edge portion between substrates so that external air does not permeate into the internal space, and an enclosed gas such as an inert gas does not leak from the internal space, and An object of the present invention is to provide a sealing structure such as a display element using the.

  As a result of intensive studies to solve the above-mentioned problems, the present inventors have found that the conventional sealing resin composition using only a thermosetting resin such as an epoxy resin can overcome the problem of lead. However, it is not possible to sufficiently seal the peripheral portion between the two substrates facing each other while maintaining a predetermined interval, but the thermoplastic resin layer is adjacent to the thermosetting resin layer containing polyimide silicone resin as an essential component. By forming the multi-layered structure, it was found that a peripheral structure between the substrates is substantially sealed, and a sealed structure in which the internal space is maintained in an atmosphere containing reduced pressure or inert gas can be formed. It came to be completed.

  That is, according to the first invention of the present invention, the sealing structure in which the inter-substrate peripheral edge constituted by two opposing substrates is sealed, and the internal space thereof is maintained in a reduced pressure or inert gas atmosphere. It is a resin composition for sealing for forming a resin, and contains at least one thermoplastic resin (a) and a thermosetting resin (b) containing a polyimide silicone resin as essential components, and is obtained by sealing. A resin composition for sealing is provided, wherein the resin layers are formed independently and have a multilayer structure adjacent to each other.

  According to the second invention of the present invention, in the first invention, the thermoplastic resin (a) is a polyolefin resin, a polyvinyl alcohol resin, an ethylene / vinyl alcohol copolymer resin, a polyamide resin, a polyethylene terephthalate resin, Alternatively, a sealing resin composition is provided which is selected from polyethylene naphthalate resins.

  According to the third invention of the present invention, in the first invention, the thermosetting resin (b) is further selected from an epoxy resin, an acrylic resin, an unsaturated polyester resin, a polyimide resin, or a phenol resin. A sealing resin composition comprising at least one kind is provided.

  According to the fourth invention of the present invention, in the first invention, the inorganic fine particles (c) are further added to the total amount of the resin component comprising the thermoplastic resin (a) and the thermosetting resin (b). On the other hand, a sealing resin composition characterized by containing 50 to 95% by mass is provided.

  Furthermore, according to the fifth invention of the present invention, in any one of the first to fourth inventions, the ratio of the thermoplastic resin (a) to the thermosetting resin (b) is 30: 1 to 1 by weight. : 30 is provided. The resin composition for sealing is provided.

  On the other hand, according to the sixth invention of the present invention, there is provided a sealing structure in which the peripheral portion between the substrates is sealed with the resin layer by the sealing resin composition according to any one of the first to fifth inventions. Is done.

  Since the sealing resin composition of the present invention does not contain lead and contains a thermoplastic resin and a specific thermosetting resin as resin components, it is shielded over a long period of time, such as an inert gas such as water vapor or He gas, or an outgas. The effect is large, the inside needs to be maintained at a reduced pressure, and excellent performance is exhibited in a display element such as a PDP that requires heat resistance. Moreover, since it can draw on a board | substrate easily, without using a special apparatus, the industrial value of the sealing resin composition of this invention is very large.

1. Sealing resin composition The sealing resin composition of the present invention seals a peripheral portion between substrates constituted by two opposing substrates, and sealing is performed in which the internal space is maintained in a reduced pressure or inert gas atmosphere. A sealing resin composition for forming a structure, comprising at least one thermoplastic resin (a) and a thermosetting resin (b) having a polyimide silicone resin as essential components, and sealing The resulting resin layers are formed independently and have a multilayer structure adjacent to each other. In addition, inorganic fine particles (c) can be blended in either or both of the thermoplastic resin (a) and the thermosetting resin (b).

(A) Thermoplastic Resin The thermoplastic resin used in the present invention is a synthetic resin having reversible thermal characteristics that exhibit plasticity by heating, cure when cooled, and exhibit plasticity again when heated. The thermoplastic resin includes not only a homopolymer of raw material monomers but also random copolymers with other monomers, block copolymers, graft copolymers, end group-modified products with other substances, and the like.

  For example, polyolefin resin such as polyethylene resin, polypropylene resin, polybutene resin, polymethylpentene resin; polyvinyl alcohol resin, polyvinyl butyral resin, ethylene-vinyl alcohol copolymer resin, ethylene-vinyl acetate copolymer resin, ethylene- (meth) acrylate Polyolefin resins such as copolymer resins, chlorinated polyethylene resins, partially oxidized polyethylene resins, and copolymer resins thereof; polyamide resins; polyethylene terephthalate resins, polyethylene naphthalate resins, polybutylene terephthalate resins, polyacetal resins, polycarbonate resins, polyphenylene oxide resins, Polyarylate resin, polysulfone resin, polyamideimide resin, polyphenylene sulfide resin, cellulose acetate, cellulose butyrate , Polystyrene resin, polybutadiene resin, polyacrylonitrile resin, styrene-butadiene copolymer resin, styrene-acrylonitrile copolymer resin, acrylonitrile-butadiene-styrene copolymer resin, acrylate-styrene-acrylonitrile resin, chlorinated polyethylene-acrylonitrile-styrene copolymer Examples thereof include resins, polyvinyl chloride resins, polyvinylidene chloride resins, polyvinyl acetate resins, polymethyl methacrylate resins, polybutyl methacrylate resins, polytetrafluoroethylene resins, and ethylene-polytetrafluoroethylene copolymer resins. Examples of the polyamide resin include 6 nylon, 6,6 nylon, 11 nylon, 12 nylon, 6,12 nylon, and aromatic nylon.

  Of these, thermoplastic resins selected from polyolefin resins, polyvinyl alcohol resins, ethylene / vinyl alcohol copolymer resins, polyamide resins, polyethylene terephthalate resins, or polyethylene naphthalate resins are preferred.

  A thermoplastic resin is not specifically limited, It can use individually or in mixture of 2 or more types. It is preferable to select and combine several resins having excellent gas barrier properties against inert gas, such as polyethylene terephthalate, aromatic nylon, and ethylene-vinyl alcohol copolymer resin. These resins having excellent gas barrier properties against inert gas are preferably combined with polyolefin resins such as polypropylene having excellent gas barrier properties against water vapor.

Plastic molding lubricants and various stabilizers can be added to the thermoplastic resin.
Examples of the lubricant include waxes such as paraffin wax, liquid paraffin, polyethylene wax, polypropylene wax, ester wax, carnauba, and microwax; stearic acid, 1,2-oxystearic acid, lauric acid, palmitic acid, oleic acid, and the like Fatty acids: Fatty acid salts (metal soaps) such as calcium stearate, barium stearate, magnesium stearate, lithium stearate, zinc stearate, aluminum stearate, calcium laurate, zinc linoleate, calcium ricinoleate, zinc 2-ethylhexoate ); Stearic acid amide, oleic acid amide, erucic acid amide, behenic acid amide, palmitic acid amide, lauric acid amide, hydroxystearic acid amide, methylene bis-stear Fatty acid amides such as acid amide, ethylene bis stearic acid amide, ethylene bis lauric acid amide, distearyl adipic acid amide, ethylene bis oleic acid amide, dioleyl adipic acid amide, N-stearyl stearic acid amide; butyl stearate, etc. Fatty acid esters; alcohols such as ethylene glycol and stearyl alcohol; polyethers composed of polyethylene glycol, polypropylene glycol, polytetramethylene glycol, and modified products thereof; polysiloxanes such as dimethylpolysiloxane and silicon grease; fluorine-based oils And fluorine compounds such as fluorine-based grease and fluorine-containing resin powder; inorganic compound powders such as silicon nitride, silicon carbide, magnesium oxide, alumina, silicon dioxide, and molybdenum disulfide.

  As stabilizers, bis (2,2,6,6-tetramethyl-4-piperidyl) sebacate, bis (1,2,2,6,6-pentamethyl-4-piperidyl) sebacate, 1- [2 -{3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionyloxy} ethyl] -4- {3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionyloxy} -2,2,6,6-tetramethylpiperidine, 8-benzyl-7,7,9,9-tetramethyl-3-octyl-1,2,3-triazaspiro [4,5] undecane-2,4- Dione, 4-benzoyloxy-2,2,6,6-tetramethylpiperidine, dimethyl-1- (2-hydroxyethyl) -4-hydroxy-2,2,6,6-tetramethylpiperidine polycondensate Poly [[6- (1,1,3,3-tetramethylbutyl) imino-1,3,5-triazine-2,4-diyl] [(2,2,6,6-tetramethyl-4-piperidyl ) Imino] hexamethylene [[2,2,6,6-tetramethyl-4-piperidyl) imino]], 2- (3,5-di-tert-butyl-4-hydroxybenzyl) -2-n-butyl In addition to hindered amine stabilizers such as bis (1,2,2,6,6-pentamethyl-4-piperidyl) malonate, there may be mentioned antioxidants such as phenols, phosphites and thioethers.

  In the present invention, the mixing method of each component is not particularly limited. For example, a mixer such as a ribbon blender, a tumbler, a nauter mixer, a Henschel mixer, a super mixer, or a banbury mixer, a kneader, a roll, a kneader ruder, a single screw extruder. It is carried out using a kneader such as a twin screw extruder.

  Thus, by mixing each component, the thermoplastic resin (composition) can be obtained in the form of powder, beads, pellets, or a mixture thereof. Pellets are desirable because they are easy to handle. The obtained composition can be applied by various thermoplastic resin molding machines, preferably a hot melt gun.

(B) Thermosetting resin On the other hand, the thermosetting resin used in the present invention forms a three-dimensional network structure once cured, and has an irreversible thermal property that does not soften and melt even when reheated. Is an essential component. The essential component means that it occupies at least 50% by weight or more of the thermosetting resin. The thermosetting resin is used in combination with the thermoplastic resin in order to seal the peripheral portion between the substrates with a multi-layered resin layer.

  The polyimide silicone resin, which is an essential component in the present invention, is characterized by having a silicone polymer and a polyimide skeleton in the molecular chain. For example, there is a resin sold by Shin-Etsu Chemical Co., Ltd. under the trade name: Shin-Etsu Polyimide Silicone. This polyimide silicone resin is a reaction product of tetracarboxylic dianhydride and a diamine having a siloxane bond, and a thermosetting group described later is contained in the structure of the reaction product.

  The polyimide silicone resin is produced by a one-stage polymerization method in which the diamine and tetracarboxylic dianhydride are used in approximately equimolar numbers in the presence of a solvent and polymerized only at a high temperature. First, an amic acid is synthesized at a low temperature. Thereafter, it can also be produced by a two-stage polymerization method in which imidization is performed at a high temperature. The desired ratio and molecular weight of the silicone polymer and the polyimide skeleton can be obtained by controlling the types and reaction conditions of the diamine and tetracarboxylic dianhydride as the raw materials.

  As the thermosetting group, a carboxyl group, an amino group, an epoxy group, a hydroxyl group, etc. are common, but in consideration of the production process of polyimide, a carboxyl group or a phenol group is preferable in that it does not easily react with an amino group. Selected.

  Since the polyimide silicone resin is excellent in solubility in an organic solvent, it can be dissolved in an organic solvent and adjusted to an appropriate viscosity so that it can be easily coated on various substrates. Solvents that can be used are not particularly limited, phenols such as phenol, 4-methoxyphen-4-methoxyphenol, 2,6-dimethylphenol, m-cresol, ethers such as tetrahydrofuran and anisole; cyclohexanone, Ketones such as 2-butanone, methyl isobutyl ketone, 2-heptanone, 2-octanone and acetophenone; esters such as butyl acetate, methyl benzoate and γ-butyrolactone; cellosolves such as butyl cellosolve acetate and propylene glycol monomethyl ether acetate; Examples include amides such as N, N-dimethylformamide, N, N-dimethylacetamide, and N-methyl-2-pyrrolidone.

The polyimide silicone resin exhibits excellent heat resistance and mechanical strength possessed by polyimide by thermosetting, and exhibits low moisture absorption, flexibility, solvent resistance, and adhesion to various substrates such as glass.
The curing conditions of the polyimide silicone resin are not particularly limited, but are cured by heating in the range of 80 to 300 ° C, preferably 100 to 250 ° C. If it is cured at a temperature lower than 80 ° C., it takes too much time for thermosetting, and it is not practical, and if it is cured at a temperature exceeding 300 ° C., the resin is thermally deteriorated.

  Polyimide silicone resin may be used alone, but in addition, for example, phenol resin, urea resin, melamine resin, diallyl phthalate resin, acrylic resin, epoxy resin, silicone resin, urethane resin, polyimide resin, bis-maleimide triazine resin, or the like It can be used as a mixture of two or more thermosetting resins mainly composed thereof. However, the resin other than the polyimide silicone resin is desirably less than 50% by weight.

  Adhesion and durability can be further improved by using a polyimide silicone resin in combination with a resin having a functional group reactive with a phenol group contained therein, for example, an epoxy resin. The epoxy resin used in combination may be an alicyclic epoxy resin, a hydrogenated epoxy resin, an aromatic epoxy resin, or a mixture thereof.

  The alicyclic epoxy resin is a thermosetting resin having an alicyclic portion such as cyclohexane and an epoxy portion. Examples of the alicyclic epoxy resin include a hydrogenated epoxy resin represented by a hydrogenation reaction of an epoxy resin having a benzene ring, represented by a bisphenol A type epoxy resin, and a double bond of a cyclohexene ring. Aliphatic cyclic epoxy resins oxidized and epoxidized with peracetic acid. For example, hydrogenated bisphenol A type diglycidyl ether, (3,4-4 ', 4'-epoxycyclo) hexylmethylhexanecarboxylate, poly (epoxidized cyclohexene oxide), and the like. These alicyclic epoxy compounds may be used alone or in combination.

  Further, in the case of a hydrogenated epoxy resin, the cyclohexane cyclization rate of the benzene ring is 80% or more, preferably 90% or more, and the content of total chlorine that is an impurity residual component is 0.5% by weight or less, preferably Is preferably 0.1% by weight or less. The cyclohexane cyclization rate can be determined by a nuclear magnetic resonance analyzer or the like at a rate at which a benzene ring is changed to a cyclohexane ring.

  An aromatic epoxy resin is a compound having one or more aromatic nuclei and two or more epoxy groups, and having no alicyclic ring. The epoxy group in the aromatic epoxy resin is preferably a glycidyl group. Typical aromatic epoxy resins are glycidyl ethers of polyphenols, glycidyl esters of aromatic polycarboxylic acids, glycidyl aminated products of aromatic amines, and the like. In addition, oligomerized products of these glycidyl compounds can also be used. Specific examples of the aromatic epoxy resin include bisphenol A diglycidyl ether, bisphenol F diglycidyl ether, novolac polyglycidyl ether, and N, N-diglycidyl aniline.

  The curing agent that can be used in the present invention is not particularly limited as long as it can react with the thermosetting resin to obtain a cured product. For example, various curing agents such as hydrazide-based curing agents, acid anhydrides, dicyandiamide and modified products thereof can be used, and they may be used alone or in combination.

  Examples of such hydrazide-based curing agents include adipic acid dihydrazide, sebacic acid dihydrazide, dodecanedioic acid dihydrazide, isophthalic acid dihydrazide, eicosanedioic acid dihydrazide, 7,11-octadecadien-1,18-dicarbodihydrazide, or 1 , 3-bis (hydrazinocarbonoethyl) -5-isopropylhydantoin, and the like may be used alone or in combination.

  In the case of acid anhydrides, it is desirable that the 6-membered ring portion in the structure is a cyclo ring, such as 4-methylhexahydrophthalic anhydride or hexahydrophthalic anhydride. A hydrazide-based curing agent that acts as an agent and easily obtains a more transparent cured product is desirable.

Although it does not specifically limit as a hardening accelerator, For example, tertiary amines, such as benzyldimethylamine, a tris (dimethylaminomethyl) phenol, a dimethyl cyclohexylamine; 1-cyanoethyl-2-ethyl-4-methyl Imidazoles such as imidazole, 2-ethyl-4-methylimidazole, 1-benzyl-2-methylimidazole; organophosphorus compounds such as triphenylphosphine and triphenyl phosphite; tetraphenylphosphonium bromide, tetra-n-butyl Quaternary phosphonium salts such as phosphonium bromide; 1,8-diazabicyclo [5,4,0] undecene-7 etc. and diazabicycloalkenes such as organic acid salts thereof; zinc octylate, tin octylate and aluminum acetylacetone complex Organometallic compounds such as Tetraethylammonium bromide, quaternary ammonium salts such as tetrabutylammonium bromide; boron trifluoride, boron compounds such as triphenyl borate, zinc chloride, metal halides such as stannic chloride.
In addition, high melting point imidazole compounds, dicyandiamide, high melting point dispersion type latent accelerators such as amine addition type accelerators with amines added to epoxy resins, etc., and imidazole, phosphorus and phosphine accelerators are coated with a polymer. Latent curing represented by high temperature dissociation type thermal cationic polymerization type latent curing accelerators such as microcapsule type latent accelerator, amine salt type latent curing accelerator, Lewis acid salt, Bronsted acid salt, etc. Accelerators can also be used. These curing accelerators can be used alone or in admixture of two or more.

  Here, the usage-amount of a thermosetting resin and a hardening | curing agent is not restrict | limited in particular, For example, when a thermosetting resin which requires a hardening agent like an epoxy resin is (a) and a hardening agent is (c). The weight ratio (a) :( c) can be 97: 3 to 80:20, preferably 95: 5 to 85:15. If the curing agent (c) is less than 3, the viscosity remains low and does not become a viscous liquid resin substance. If the curing agent (c) is more than 20, the curing reaction proceeds excessively and may not become liquid.

This thermosetting resin may contain other components in addition to the resin component. For example, a solvent can be blended to lower the viscosity of the composition and improve the coating properties of the composition. Moreover, the mixing property at the time of mixing each said component can be improved by using a solvent.
A normal solvent can be used as the solvent. For example, solvents such as benzene, toluene, xylene, hexane, heptane, tetrahydrofuran, dioxane, N-methylpyrrolidone, diethyl ether, ethanol, propanol, isobutanol, carbon tetrachloride, acetone, dimethylformamide and the like can be used.

  Other solvents that do not react with thermosetting resins and curing agents include 2,2,4-trimethyl-3-hydroxydipentane isobutyrate, 2,2,4-trimethylpentane-1,3-isobutyrate, and isobutyl. Examples include butyrate, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, diethylene glycol monobutyl ether, and ethyl 2-hydroxypropanoate.

  Examples of the solvent capable of reacting with the thermosetting resin and the curing agent during heating include phenyl glycidyl ether, ethylhexyl glycidyl ether, 3-aminopropyltriethoxysilane, and 3-glycidoxypropylmethyldimethoxysilane.

(C) Inorganic fine particles In the thermoplastic resin (a) and / or thermosetting resin (b), which are the resin components, inorganic fine particles can be blended in order to improve the performance of the sealing portion.

  As the inorganic fine particles, metal oxides such as silica, alumina, titania, zirconia having a particle size of 50 μm or less can be used. If the substrate is a glass substrate, silica is preferably used as the inorganic fine particles. The compounding quantity can be 30 to 95 weight% with respect to the whole resin composition, Preferably it can be 40 to 90 weight%. In the present invention, the inorganic fine particle is an optional component, but it can be expected not only to increase the heat resistance of the sealed portion but also to increase the strength and further suppress gas leakage. If the blending amount is less than 30% by weight, the effect is small, and if it exceeds 95% by weight, the coating property deteriorates.

2. Sealing structure The sealing structure of the present invention is a sealing structure in which the peripheral edge portion between the substrates is sealed with the resin layer of the sealing resin composition, that is, two sheets facing each other while maintaining a predetermined interval. This is a sealing structure in which the peripheral portion between the substrates of the substrate is sealed with the resin layer of the sealing resin composition, and the inert gas is sealed in the internal space or maintained at a reduced pressure.

The substrate may be a glass substrate, a heat-resistant substrate such as metal or ceramics as long as it can constitute a display element, and is not particularly limited, but at least one of the two substrates is preferably a glass substrate. When one of the substrates is a glass substrate, the other may be a substrate made of a heat resistant material such as metal or ceramics.
The size of the lower plate and the upper plate as the substrate is not particularly limited, and a substrate having a small area to a large area can be used. For example, the length is 50 to 500 mm, the width is 50 to 800 mm, and the thickness is 3 to 10 mm. Any one of the lower plate and the upper plate having a hole with a diameter (one side) of 3 to 10 mm is suitable for exhaust.

  In the present invention, a spacer can be interposed between the two substrates. The spacer is a frame-like plate-like body in which the central portion of the substrate is cut out. The outer shape (vertical and horizontal length) is the same as the size of the substrate (lower plate and upper plate). For example, the inner shape (hollow part) is 30 to 450 mm in length, 30 to 750 mm in width, and 0.5 mm in thickness. It can be set to -5 mm. Thereby, the width | variety of the peripheral part between board | substrates is ensured 20-50 mm.

  The inter-substrate peripheral edge is sealed with a resin layer having a multilayer structure adjacent to each other. The resin layer having a multilayer structure includes a thermoplastic resin (a) and a thermosetting resin (b) as resin components, and the resin layers obtained by sealing are formed independently, and are adjacent to each other. become. The multilayer structure is not only the case where the thermoplastic resin (a) and the thermosetting resin (b) are each one layer, but either the thermoplastic resin (a) or the thermosetting resin (b) is 2 The case of more than a layer is included.

  The positional relationship between the thermoplastic resin (a) and the thermosetting resin (b) is not particularly limited in the peripheral portion between the substrates. When the thermoplastic resin (a) and the thermosetting resin (b) are each in one layer, either the thermoplastic resin (a) or the thermosetting resin (b) may be located on the inner space side. . However, it is preferable that the central part of the peripheral part between the substrates is sealed with a resin layer of a thermosetting resin, and the thermoplastic resin layer is adjacent to both sides of the thermosetting resin layer. This is because, among the resin components, the thermoplastic resin (a) mainly has a function of suppressing gas leakage, whereas the thermosetting resin (b) mainly has a function of bonding substrates together. is there.

Inorganic fine particles (c) can be blended in either or both of the thermoplastic resin (a) and the thermosetting resin (b). Inorganic fine particles are optional components. As described above, the inorganic fine particles not only increase the heat resistance of the sealed portion, but also increase the mechanical strength of the resin layer and further suppress gas leakage.
The ratio of the thermoplastic resin (a) and the thermosetting resin (b) is not particularly limited, but is preferably 30: 1 to 1:30 by weight. When the amount of the thermosetting resin (b) is smaller than that of the thermoplastic resin (a) and less than 30: 1, the mechanical strength of the sealing portion is reduced, while on the other hand, it is hotter than the thermoplastic resin (a). If the amount of the curable resin (b) is more than 1:30, gas leakage may not be sufficiently suppressed, which is not preferable.

  The sealing structure of the present invention is useful as a display element such as a PDP, FED, or VFD in which an inner space formed by sealing the peripheral portion between two substrates is maintained at a reduced pressure to a vacuum. PDP is particularly preferable as the display element.

3. Manufacturing method of sealing structure In the present invention, (1) In a state where two substrates are stacked and a spacer is interposed as necessary, the two substrates are maintained at a predetermined interval (2 ) Applying a thermoplastic resin and a thermosetting resin, which are the resin composition for sealing of the present invention, to the periphery of the substrate, pressurizing and holding for a predetermined time to form a multi-layered resin layer; (3) The internal structure between the substrates is depressurized and evacuated, and then the sealing structure is manufactured by closing the exhaust hole of the substrate.

(1) Arrangement of Materials such as Substrate That is, if the sealing method of the present invention is described with reference to the drawings, two substrates of FIG. 1 and a spacer are prepared and overlapped as shown in FIG. The thermoplastic resin and thermosetting resin can be applied to the top and bottom of the spacer.

The size of the substrate is as described above and is not particularly limited. A frame-shaped middle plate 3 can be inserted as a spacer between the lower plate 1 and the upper plate 2 which are substrates, but the thickness of the spacer is either a thermoplastic resin or a thermosetting resin which is a resin component. If the ceramic particle having a particle size corresponding to is contained, the frame-shaped intermediate plate 3 can be omitted.
In the following procedure, for the sake of convenience, a method for manufacturing a sealing structure will be described without using a spacer (intermediate plate).

(2) Application and sealing of sealing resin composition Next, the sealing resin composition is applied to the peripheral edge of the substrate. For this purpose, the sealing resin composition is discharged from the dispenser to the peripheral portion between the two substrates, and is in close contact with the resin composition in a state where the two substrates are maintained at a predetermined interval.

The sealing resin composition contains a thermoplastic resin and a thermosetting resin resin component as resin components, but each resin component may be discharged simultaneously to the periphery of the substrate, or either one may be discharged first. Also good. That is, the thermoplastic resin may be applied first, and then the thermosetting resin may be applied, or vice versa.
Alternatively, the resin component may be applied to one of the two substrates and sealed, and then the resin component may be applied to another substrate and sealed. Alternatively, the resin component may be discharged and injected between the two substrates to be sealed at a time. That is, after removing the overlapped substrate (upper plate), the sealing composition is discharged to the periphery of the substrate (lower plate), and then the substrate (upper plate) is overlapped and pressed to increase the distance between the two substrates. A method of curing the thermosetting resin of the sealing resin composition after the predetermined interval; discharging and injecting the sealing resin composition into the peripheral gap between the two substrates stacked at intervals; A method of curing the thermosetting resin of the sealing resin composition after pressurizing between the substrates and keeping the gap at a predetermined interval can be employed.

  At this time, if only the thermoplastic resin is used as the sealing resin composition, the airtightness is insufficient. Further, if only the thermosetting resin is used as in the prior art, bubbles are generated in the seal portion and the airtightness is insufficient.

The means for applying the sealing resin composition is not particularly limited, but it is advantageous to apply a hot gun to discharge the thermoplastic resin and apply the thermosetting resin onto the substrate using a dispenser or the like.
In the hot gun, a thermoplastic resin is heated to a melting temperature or higher in a hot melt apparatus, and a molten member is directly discharged onto a substrate to be sealed using an extrusion mechanism. Here, a thermoplastic resin, which is a raw material, is filled in the hot melt apparatus and discharged to a predetermined position on the substrate while being heated to the melting temperature of the thermoplastic resin.

  On the other hand, the thermosetting resin is applied on the substrate using, for example, a dispenser or the like, and the viscosity of the composition in the syringe or the discharge part of the dispenser is preferably 10 Pas to 70 Pas. It is preferable to discharge while maintaining at 100 ° C. or higher. The curing temperature of the thermosetting resin is preferably 150 to 250 ° C, particularly 180 to 220 ° C. The curing time under these temperature conditions is preferably about 1 to 20 hours.

After applying the resin component, the pressure is quickly applied, and the resin layer is heated stepwise in the range of 150 to 250 ° C. for 1 to 20 hours. Although heating conditions change with kinds of thermosetting resin to be used, for example, 150-180 degreeC is 0.1-5 hours, 180-210 degreeC is 0.3-5 hours, 200-220 degreeC is 0.3- The thermosetting resin can be cured by heating for 5 hours at 210 to 250 ° C. for 0.3 to 5 hours. Then, it deaerates from the hole of the center part of a board | substrate (upper board) using a vacuum pump, and internal space is evacuated to ¹⁰ < ^-8 > ^-10 < ^-10 > Torr.

(3) Exhaust of the internal space The internal space between the two substrates sealed as described above is depressurized, and after the outgas is substantially exhausted, the exhaust hole used for depressurization is finally used. close.

In this step, a gas other than air may be sealed in the internal space between the substrates. In order to enclose the normal gas, air is sufficiently exhausted from the internal space between the substrates, and then a gas other than air is introduced to close the exhaust hole. Examples of the inert gas to be sealed include discharge gases such as neon, xenon, helium, and argon when the sealing structure is a PDP. The degree of reduced pressure in the internal space of the sealing structure is not particularly limited, and is preferably 0.5 atm or less, particularly preferably 0.1 atm or less. This range is also preferable for the degree of vacuum when the inert gas is filled.
As a result, the sealing structure sealed with the sealing resin composition, that is, the peripheral portion between the two substrates facing each other while maintaining a predetermined interval is sealed, and the internal space is reduced in pressure. A maintained sealing structure is produced.

The sealing structure of the present invention thus obtained is characterized by high airtightness and low air permeation and inert gas leakage. When the sealing resin composition in the present invention is evaluated with, for example, a helium (He) leak detector, the value of He leak of the sealing resin layer can be 10 ⁻¹⁰ [Pa · m ³ / s] or less.

  Examples of the present invention and comparative examples will be specifically described below, but the present invention is not limited to these examples without departing from the spirit of the present invention. The raw materials and evaluation methods used in the examples and comparative examples are shown below.

[raw materials]
A Thermoplastic resin Resin a1: Aromatic nylon (Nylon MXD6)
(Product name: MX nylon 6001, manufactured by Mitsubishi Gas Chemical Co., Ltd.)
Resin a2: Polyethylene terephthalate (PET)
(Product name: Byron GM480, manufactured by Toyobo Co., Ltd.)
B Thermosetting resin Resin b1: Polyimide silicone resin (trade name: Shin-Etsu polyimide silicone SMP-2001, manufactured by Shin-Etsu Chemical Co., Ltd.)
Resin b2: bisphenol type epoxy resin (trade name: Epicoat 828, manufactured by Japan Epoxy Resin Co., Ltd.)
Curing agent: acid anhydride curing agent (trade name: YH307, manufactured by Japan Epoxy Resin Co., Ltd.)
C Inorganic fine particles: Glass frit
(Product name: Lead-free P type, manufactured by Toago Material Technology Co., Ltd.), average particle size 10 μm

[Evaluation method]
(1) Pot life: The viscosity was measured while heating the resin at a predetermined temperature (150 ° C.) at which the thermosetting resin composition was cured. The result was evaluated relative to the time to reach a certain viscosity as follows.
○: The time until the viscosity increase starts is long.
X: The time until the viscosity increase starts is short.
(2) Presence / absence of bubbles: Evaluation was performed as follows by visual observation and observation with an optical microscope.
○: There are no bubbles in the cured resin.
X: Air bubbles are present in the cured resin.
(3) Airtightness: After deaeration using a vacuum pump from the hole in the center of the substrate (upper plate) with the peripheral edge sealed, the internal space was evacuated to 10 ⁻¹⁰ Torr and the presence or absence of leakage was measured. .
The presence or absence of leakage was measured by a hood method using ULVAC helium leak detector HELIOT. First, after evacuating the sample until the background value becomes 1.5 × 10 ⁻¹¹ [Pa · m ³ / s], helium gas is introduced into the hood, and the leak rate of helium gas is measured for 10 minutes. Then, the maximum value of the leak rate of helium gas was recorded to confirm the presence or absence of leak.
○: When He gas was injected into the hood and the He leak rate was observed for 24 hours, the value was almost unchanged, and the He leak rate after 24 hours was below the background value.
X: When He gas was injected into the hood and the He leak rate was observed for 24 hours, the value fluctuated, and the He leak rate after 24 hours was higher than the background value.

Example 1
Prepare three soda lime glass plates shown in FIG. 1, and seal resin between the lower plate 1 and the middle plate (spacer) 3 and between the upper plate 2 and the middle plate 3 as shown in FIG. The composition was sandwiched and pressed so as to form a multilayer structure of resin layers (three layers a2, b1, and a1 as viewed from the inner space side). The size of the glass plate is: lower plate 1; 100 mm × 200 mm × 5 mm, upper plate 2 having holes 4; 100 mm × 200 mm × 5 mm, hole diameter 5 mm, frame-shaped middle plate 4; outer shape 100 mm × 200 mm, inner The shape was 70 mm × 170 mm and the thickness was 5 mm. In addition, 50 mass% of inorganic fine particles were mix | blended with respect to each resin component in the thermoplastic resin and the thermosetting resin component among the resin compositions for sealing.
The thermoplastic resins a1 and a2 were applied simultaneously on the substrate using a hot gun, and the thermosetting resin b1 was simultaneously applied on the substrate using a dispenser or the like, and quickly pressed (total seal width 6 mm). The thermoplastic resins a1 and a2 and the thermosetting resin b1 were discharged so that the weight ratio was 10: 1. Next, this laminate was heated at 180 ° C. for 2 hours, 200 ° C. for 4 hours, 210 ° C. for 4 hours, and 220 ° C. for 4 hours to cure the thermosetting resin b1. Thereafter, the hole 4 at the center of the upper plate was deaerated using a vacuum pump, the internal space was evacuated to 10 ⁻¹⁰ Torr, and the leak was measured.
The pot life, presence / absence of bubbles, and airtightness were evaluated as described above, and the results are shown in Table 1.

(Examples 2 to 7)
Example 1 except that the type of thermoplastic resin is changed, or the type and composition of the thermosetting resin (resin b2, curing agent) and the discharge position to the peripheral edge of the substrate are changed as shown in Tables 1 and 2. And experimented.
The pot life, presence / absence of bubbles, and airtightness were evaluated as described above, and the results are shown in Tables 1 and 2.

(Comparative Examples 1 and 2)
An experiment was conducted in the same manner as in the example except that only the thermosetting resin was used as the sealing resin composition without using the thermoplastic resin. The pot life, presence / absence of air bubbles, and airtightness were evaluated as described above, and the results are shown in Table 3.

(Comparative Example 3)
An experiment was conducted in the same manner as in the example except that only a thermoplastic resin was used and a resin composition for sealing was used without using a thermosetting resin. The pot life, presence / absence of air bubbles, and airtightness were evaluated as described above, and the results are shown in Table 3.

"Evaluation"
Since Examples 1-7 used a sealing resin composition containing polyimide silicone as a thermosetting resin by combining a thermoplastic resin and a thermosetting resin, all of pot life, presence of air bubbles, and airtightness were good. A simple sealing structure is obtained. On the other hand, in Comparative Examples 1 and 2, since only the thermosetting resin was used as the sealing resin composition, the pot life was good, but the presence of air bubbles and the airtightness were insufficient. Moreover, since the comparative example 3 used only the thermoplastic resin as a sealing resin composition, although there was no bubble, airtightness was inadequate.

It is a top view of the board | substrate etc. which comprise the sealing structure. It is a fragmentary sectional view which shows the state which discharged the sealing resin composition of this invention to the board | substrate.

Explanation of symbols

1 Substrate (lower plate)
2 Substrate (upper plate)
3 Spacer (medium plate)
4 hole a1, a2 thermoplastic resin b1 thermosetting resin

Claims (6)

A sealing resin composition for sealing a peripheral portion between substrates constituted by two opposing substrates, and forming a sealing structure in which the internal space is maintained in a reduced pressure or inert gas atmosphere. ,
A multilayer structure including at least one thermoplastic resin (a) and a thermosetting resin (b) having a polyimide silicone resin as essential components, and resin layers obtained by sealing are formed independently and adjacent to each other A resin composition for sealing.   The thermoplastic resin (a) is selected from polyolefin resin, polyvinyl alcohol resin, ethylene / vinyl alcohol copolymer resin, polyamide resin, polyethylene terephthalate resin, or polyethylene naphthalate resin. Sealing resin composition.   The sealing resin according to claim 1, wherein the thermosetting resin (b) further contains at least one selected from an epoxy resin, an acrylic resin, an unsaturated polyester resin, a polyimide resin, or a phenol resin. Composition.   Furthermore, 30 to 95 mass% of inorganic fine particles (c) are mix | blended with respect to the total amount of the resin component which consists of a thermoplastic resin (a) and a thermosetting resin (b), It is characterized by the above-mentioned. The resin composition for sealing as described in 2.   The sealing resin according to any one of claims 1 to 4, wherein the ratio of the thermoplastic resin (a) and the thermosetting resin (b) is 30: 1 to 1:30 by weight. Composition.   The sealing structure by which the peripheral part between board | substrates is sealed with the resin layer with the sealing resin composition in any one of Claims 1-5.

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