JP2010225329A - Composition for forming dielectric of plasma display panel - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a composition for forming a dielectric of a plasma display panel that prevents the occurrence of cracks even if forming a dielectric having a large film-thickness. <P>SOLUTION: The composition for forming a dielectric of a plasma display panel includes: inorganic particles (A) containing the following particles (A1) and (A2); and an acrylic polymer (B), whose weight average molecular weight is 100,000 to 500,000 in terms of polystyrene. The composition is configured such that the total of contents of the particles (A1) and (A2) is ≥90 mass% based on the whole amount of inorganic particles (A). The particles (A1) are SiO<SB>2</SB>particles whose average particle size is 20-100 nm. The particles (A2) are metal oxide particles whose average particle size is 1-30 nm. The composition for forming a dielectric of a plasma display panel achieves the reduction in power consumption and has high storage stability, while preventing, on an electrode, the occurrence of cracks even when forming a dielectric having a large film-thickness. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

TECHNICAL FIELD The present invention relates to a plasma display panel dielectric composition, and more particularly, for containing a SiO ₂ particle and a metal oxide particle, having high storage stability and being less susceptible to cracking during dielectric formation. Relates to the composition.

  In recent years, flat panel displays (hereinafter also referred to as “FPD”) such as a plasma display and a field emission display (hereinafter also referred to as “FED”) have attracted attention as flat fluorescent displays.

FIG. 1 is a schematic view showing a cross-sectional shape of an AC type plasma display panel (hereinafter also referred to as “PDP”), and FIG. 2 is an explanatory view showing a cross-sectional shape of a panel member of the FED.
In FIG. 1, 1 and 2 are glass substrates, 3 and 11 are partition walls, 4 is a transparent electrode, 5 is a bus electrode, 6 is an address electrode, 7 is a phosphor, 8 and 9 are dielectric layers, and 10 is a protective film. is there.
2, 201 and 202 are glass substrates, 203 is an insulating layer, 204 is a transparent electrode, 205 is an emitter, 206 is a cathode electrode, 207 is a phosphor, 208 is a gate, and 209 is a spacer.

  In a PDP currently mass-produced, a paste containing glass particles and a binder polymer is applied to a substrate and fired at about 500 to 600 ° C. to melt the glass particles to form a dielectric (Patent Document 1). reference).

In recent years, in order to reduce the power consumption of PDPs, studies have been made to form a dielectric using a material such as silica (SiO ₂ ) having a dielectric constant lower than that of glass (see Patent Document 2 and Patent Document 3).

  Since the composition described in Document 2 uses organosilane for curing the film, there is a problem that the storage stability of the composition deteriorates due to the alkoxysilyl group of the organosilane.

In the composition described in Document 3, organosilane is not used as a curable binder, but the organosilane is hydrolyzed to prepare SiO ₂ particles. For this reason, since it is thought that the alkoxysilyl group remains also in this particle | grain, the deterioration of the storage stability of a composition becomes a problem. As pointed out in Document 3, since there is a problem of degassing from the dielectric layer after formation, it is desirable to reduce the organic component of the composition as much as possible.

  The PDP dielectric must be formed to a thickness of several tens of μm so as to cover the electrodes formed on the substrate. The electrodes have a width of about 100 μm and a height of about 100 μm, and many electrodes are formed on the substrate at intervals of about 100 μm. When a dielectric having a large film thickness of several tens of μm is formed on such an electrode with a material as described in Documents 2 and 3, cracks have been a problem.

JP-A-11-1062379 JP 2007-299642 A Japanese Patent Laid-Open No. 2007-087636

  An object of the present invention is to provide a plasma display panel dielectric forming composition that has a low possibility of cracking even when a dielectric having a large thickness is formed.

The present inventors have found that by using SiO ₂ particles having a specific average particle diameter and metal oxide particles in combination, the metal oxide particles can act as a curable binder and can be used for forming a PDP dielectric. In addition, the inventors have found that a dielectric can be formed on the electrode without cracks by using an acrylic polymer having a specific molecular weight, and the present invention has been completed.

That is, the present invention
(A) Inorganic particles containing the following (A1) particles and (A2) particles and (A1) SiO ₂ particles having an average particle size of 20 to 100 nm (A2) Metal oxide particles having an average particle size of 1 to 30 nm (B) Weight average An acrylic polymer having a molecular weight of 100,000 to 500,000 in terms of polystyrene, and the total content of the (A1) particles and (A2) particles is 90% by mass or more based on the whole of the (A) inorganic particles. It is a composition for forming a dielectric material of a plasma display panel.

In the said plasma display panel dielectric material formation composition, it is preferable to contain 2-50 mass parts of said (A2) particle | grains with respect to 100 mass parts of (A1) particle | grains,
It is preferable that the (A2) particles have SiO ₂ or Al ₂ O ₃ on at least a part of the surface thereof,
The (A2) particles preferably have Al ₂ O ₃ on at least a part of the surface thereof,
It is preferable to contain 1 to 15 parts by mass of the polymer (B) with respect to 100 parts by mass of the (A) inorganic particles,
The (B) acrylic polymer preferably has a repeating unit represented by the following formula (1).

〔式中、Ｒ¹ は、水素原子またはメチル基を示し、Ｒ² は、炭素数１〜１０の２価の炭化水素基を示し、Ｒ³ は、水素原子または炭素数１〜４のアルキル基を示す。〕

[Wherein, R ¹ represents a hydrogen atom or a methyl group, R ² represents a divalent hydrocarbon group having 1 to 10 carbon atoms, and R ³ represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms. Indicates. ]

The composition for forming a plasma display panel dielectric according to the present invention contains SiO ₂ particles having a dielectric constant lower than that of glass as inorganic particles, so that power consumption can be reduced and organosilane or the like can be contained. The storage stability is high. In addition, since the composition for forming a plasma display panel dielectric of the present invention contains an acrylic polymer having a specific molecular weight, cracks are generated even when a dielectric having a large film thickness is formed on an electrode. Is less likely to

FIG. 1 is a schematic cross-sectional view showing a general PDP. FIG. 2 is an explanatory sectional view showing a general FED.

Hereinafter, the dielectric composition for forming a plasma display panel of the present invention will be described in detail.
The composition for forming a dielectric of a plasma display panel of the present invention comprises an A component composed of inorganic particles containing specific SiO ₂ particles and specific metal oxide particles, and a B component composed of a specific polymer. The composition is used as a dielectric forming material for a plasma display panel (PDP).

[(A) inorganic particles]
The inorganic particles (A) include at least the following (A1) SiO ₂ particles and (A2) metal oxide particles.

((A1) SiO ₂ particles)
The composition for forming a dielectric of a plasma display panel of the present invention can lower the dielectric constant of the dielectric obtained by containing SiO ₂ particles (A1) as inorganic particles (A).

The average particle diameter of the SiO ₂ particles (A1) is 20 to 100 nm, preferably 40 to 100 nm, and more preferably 50 to 100 nm. When the average particle diameter of the SiO ₂ particles (A1) is within the above range, the generation of cracks during film formation for forming the dielectric and when the dielectric is placed at a high temperature can be suppressed.
The average particle diameter of the SiO ₂ particles (A1) is a numerical value measured by a laser diffraction method using a particle size distribution measuring device (for example, Nanotrack particle size distribution measuring device “UPA-150” manufactured by Nikkiso Co., Ltd.).

In the present specification, the particle size distribution of the SiO ₂ particles (A1) is a particle size distribution measuring device (for example, Nanotrack particle size distribution measuring device “UPA-150 manufactured by Nikkiso Co., Ltd.) in a state where the SiO ₂ particles are dispersed in an organic solvent. )) Was measured by the laser diffraction method.

In the SiO ₂ particles (A1), sufficient if the average particle diameter in the range of 20 to 100 nm, may be a mixture of particles having a plurality of particle size distribution within the range satisfying.

Specific examples of commercially available products of SiO ₂ particles (A1) include powder-like ones such as “# 150”, “# 200” and “# 300” manufactured by Nippon Aerosil Co., Ltd. Untreated, "R972", "R974", "R976", "RX200", "RX300", "RY200S", "RY300" and "R106" manufactured by Nippon Aerosil Co., Ltd. SS50A ”,“ Silo Hobic 100 ”manufactured by Fuji Silysia Co., etc., and the like whose surface is subjected to a hydrophobization treatment.

As a material used for blending the SiO ₂ particles (A1) into the composition, an aqueous sol or colloid in which the SiO ₂ particles (A1) are dispersed in water, a polar solvent such as isopropyl alcohol, toluene, or the like A material in the form of a solvent-based sol or colloid dispersed in a nonpolar solvent can be used.

When a solvent-type sol or colloidal material is used, the dispersion state of SiO ₂ particles can be adjusted by further adding water and a solvent to the dispersion to dilute, and SiO ₂ SiO ₂ particles that have been surface-treated for the purpose of improving the dispersibility of the particles can be used. Further, in this solvent-based sol or colloidal material, the solid content concentration is usually more than 0% by mass and 50% by mass or less, preferably 0.01% by mass or more and 40% by mass or less. is there.

When the colloidal silica in which the SiO ₂ particles (A1) are dispersed in an organic solvent is used as a material used when the SiO ₂ particles (A1) are blended in the composition, excellent transparency and heat resistance are obtained. A cured product having the same can be obtained.

Examples of the colloidal silica in which the SiO ₂ particles (A1) are dispersed in a solvent include alcohol-based solvent-dispersed colloidal silica such as isopropyl alcohol manufactured by Nissan Chemical Industries, ketone-based solvent-dispersed colloidal silica such as methylisobutyl, and toluene. Examples include polar solvent-dispersed colloidal silica.

((A2) metal oxide particles)
In the plasma display panel dielectric forming composition of the present invention, the metal oxide particles (A2) are cured by using the metal oxide particles (A2) together with the SiO ₂ particles (A1) as the inorganic particles (A). Works as a sex binder. For this reason, in this composition, even if it does not use organosilane etc. as a sclerosing | hardenable binder, thick film formation is possible and storage stability is high.

Examples of the metal oxide particles (A2) include CeO ₂ , Al ₂ O ₃ , TiO ₂ , ZrO ₂ , SnO ₂ , ZnO, BaTiO _{3 and the} like. Among these, Al ₂ O ₃ , TiO ₂ , ZrO ₂ and ZnO are particularly preferable.

  The average particle diameter of the metal oxide particles (A2) is 1 to 30 nm, preferably 5 to 30 nm, and more preferably 10 to 30 nm. When the average particle diameter of the metal oxide particles (A2) is within the above range, sufficient transparency can be imparted to the dielectric.

  The average particle diameter of the metal oxide particles (A2) is a numerical value measured by a laser diffraction method using a particle size distribution measuring device (for example, Nanotrack particle size distribution measuring device “UPA-150” manufactured by Nikkiso Co., Ltd.). .

  In the present specification, the particle size distribution of the metal oxide particles (A2) is a particle size distribution measuring apparatus (for example, Nanotrack particle size distribution measuring apparatus “UPA-150” manufactured by Nikkiso Co., Ltd.) in a state where the particles are dispersed in an organic solvent. ) Using a laser diffraction method.

  The metal oxide particles (A2) need only have an average particle size in the range of 1 to 30 nm, and may be a mixture of particles having a plurality of particle size distributions within a range satisfying this condition. .

The metal oxide particles (A2) preferably have SiO ₂ or Al ₂ O ₃ on at least a part of their surfaces, and more preferably have Al ₂ O ₃ . By using such metal oxide particles, the dispersibility of the metal oxide particles in the composition can be improved.

The amount of SiO ₂ or Al ₂ O ₃ present on the surface of the metal oxide particles (A2) is preferably 1 to 40% by mass, more preferably 1 to 30% by mass with respect to the metal oxide particles (A2). .
The metal oxide particles (A2) having SiO ₂ or Al ₂ O ₃ on at least a part of the surface, for example, a SiO ₂ coating agent such as tetramethoxysilane or sodium silicate in a liquid containing metal oxide particles, Alternatively, it can be obtained by adding and reacting an Al ₂ O ₃ coating agent such as triisopropoxyaluminum.

Commercial products of metal oxide particles (A2) having SiO ₂ or Al ₂ O ₃ on at least a part of the surface include NANOFINE-50W-LP2, NANOFINE-50W, NANOFINE-50A, STR-100C-LP, STR- Examples include 100A-LP, STR-100W-LP, STR-60C-LP (manufactured by Sakai Chemical).

In the present invention, the metal oxide particles (A2) may be surface-modified with a dispersant. When the metal oxide particles (A2) whose surface is modified with a dispersant are used, aggregation of the SiO ₂ particles (A1) and the metal oxide particles (A2) can be suppressed, and storage stability can be improved. I can do it. As such a dispersant, a general dispersant such as a silicone-based dispersant such as polydimethylsiloxane, an organic acid, an organic dispersant such as a surfactant or an organic polymer can be used. These may be used in combination.

  The surface modification of the metal oxide particles (A2) with the dispersant is performed, for example, by adding the dispersant to the liquid containing the metal oxide particles (A2) and performing dispersion with a disperser such as a paint shaker. I can do it.

  Commercially available metal oxide particles (A2) surface-modified with silicone dispersants include NANOFINE-50W-LP2, NANOFINE-50S-LP2, NANOFINE-50A, STR-100C-LP, STR-100A-LP, STR-100W-LP, STR-60C-LP (manufactured by Sakai Chemical) and the like can be mentioned.

  As the organic dispersant for modifying the surface of the metal oxide particles, surfactants; organic acids such as formic acid, acetic acid, propionic acid and valeric acid organic acids; organic polymers such as acrylic polymers can be used. .

(Other inorganic particles)
The composition for forming a plasma display panel dielectric of the present invention may contain inorganic particles other than SiO ₂ particles (A1) and metal oxide particles (A2) as inorganic particles (A).

Examples of such inorganic particles include glass particles.
These inorganic particles can be used alone or in combination of two or more, and particles composed of a composite of inorganic compounds can also be used.

(Content of inorganic particles (A), etc.)
In the composition for forming a plasma display panel dielectric according to the present invention, the content of the inorganic particles (A) is preferably 10 to 70% by mass, more preferably 20 to 70%, with the total amount of the composition being 100% by mass. 65% by mass.

The total content of (A1) particles and (A2) particles is 90% by mass or more with respect to the whole inorganic particles (A).
The content of (A2) particles is preferably 2 to 50 parts by mass, more preferably 5 to 30 parts by mass with respect to 100 parts by mass of (A1) particles. (A2) When the content of the particles is within the above range, the occurrence of cracks during film formation for forming the dielectric and when the dielectric is placed at a high temperature can be suppressed.

[(B) polymer]
The composition for forming a dielectric of a plasma display panel according to the present invention forms a dielectric without cracks on an electrode by containing a polymer (B) together with SiO ₂ particles (A1) and metal oxide particles (A2). It becomes possible.

The polymer (B) is an acrylic polymer having a polystyrene-equivalent weight average molecular weight measured by GPC of 100,000 to 500,000, preferably 150,000 to 400,000.
The polymer (B) is preferably a polymer having a structural unit represented by the following formula (1).

式（１）において、Ｒ¹ は、水素原子またはメチル基を示し、Ｒ² は、炭素数１〜１０の２価の炭化水素基を示し、また、Ｒ³ は、水素原子または炭素数１〜４のアルキル基を示す。

In Formula (1), R ¹ represents a hydrogen atom or a methyl group, R ² represents a divalent hydrocarbon group having 1 to 10 carbon atoms, and R ³ represents a hydrogen atom or 1 to carbon atoms. 4 represents an alkyl group.

Examples of the divalent hydrocarbon group having 1 to 10 carbon atoms a group R ^2, for example a methylene group, an ethylene group, a propylene group, and butylene group.
The alkyl group having 1 to 4 carbon atoms a group R ^3, a methyl group, an ethyl group, a propyl group and a butyl group.

  In the polymer (B), the content ratio of the structural unit represented by the formula (1) is preferably 10 to 50% by mass, more preferably 20% with respect to 100% by mass of the entire structural units constituting the polymer. -40 mass%. By containing the structural unit represented by the formula (1) in the above range, a PDP dielectric excellent in crack resistance and optical properties can be obtained.

  As such a polymer, a homopolymer of a (meth) acrylate compound represented by the following formula (2), a copolymer of two or more of a (meth) acrylate compound represented by the formula (2), and Copolymers of (meth) acrylate compounds represented by formula (2) and other copolymerizable monomers are included.

  The polymer constituting the composition for forming a plasma display panel dielectric of the present invention is preferably a copolymer of a (meth) acrylate compound represented by the formula (2) and another copolymerizable monomer.

〔式中、Ｒ¹ は、水素原子またはメチル基を示し、Ｒ² は、炭素数１〜１０の２価の炭化水素基を示し、Ｒ³ は、水素原子または炭素数１〜４のアルキル基を示す。〕
式（２）で表わされる（メタ）アクリレート化合物の具体例としては、ヒドロキシエチル（メタ）アクリレート、２−ヒドロキシプロピル（メタ）アクリレート、４−ヒドロキシブチル（メタ）アクリレート、３−ヒドロキシプロピル（メタ）アクリレート、２−ヒドロキシブチル（メタ）アクリレート、３−ヒドロキシブチル（メタ）アクリレートなどのヒドロキシアルキル（メタ）アクリレート；
２−メトキシエチル（メタ）アクリレート、２−エトキシエチル（メタ）アクリレート、２−プロポキシエチル（メタ）アクリレート、２−ブトキシエチル（メタ）アクリレート、２−メトキシブチル（メタ）アクリレートなどのアルコキシアルキル（メタ）アクリレートなどが挙げられる。

[Wherein, R ¹ represents a hydrogen atom or a methyl group, R ² represents a divalent hydrocarbon group having 1 to 10 carbon atoms, and R ³ represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms. Indicates. ]
Specific examples of the (meth) acrylate compound represented by the formula (2) include hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, and 3-hydroxypropyl (meth). Hydroxyalkyl (meth) acrylates such as acrylate, 2-hydroxybutyl (meth) acrylate, 3-hydroxybutyl (meth) acrylate;
Alkoxyalkyls such as 2-methoxyethyl (meth) acrylate, 2-ethoxyethyl (meth) acrylate, 2-propoxyethyl (meth) acrylate, 2-butoxyethyl (meth) acrylate, 2-methoxybutyl (meth) acrylate, etc. ) Acrylate and the like.

The other copolymerizable monomer used for the copolymerization with the (meth) acrylate compound represented by the formula (2) is not particularly limited as long as it is a compound copolymerizable with the (meth) acrylate compound. For example, methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, isopropyl (meth) acrylate, butyl (meth) acrylate, isobutyl (meth) acrylate, t-butyl (meth) acrylate, pentyl (meth) Acrylate, amyl (meth) acrylate, isoamyl (meth) acrylate, hexyl (meth) acrylate, heptyl (meth) acrylate, octyl (meth) acrylate, isooctyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, nonyl (meth) Acrylate Decyl (meth) acrylate, isodecyl (meth) acrylate, undecyl (meth) acrylate, dodecyl (meth) acrylate, alkyl (meth) acrylates such as lauryl (meth) acrylate, stearyl (meth) acrylate, isostearyl (meth) acrylate;
Phenoxyalkyl (meth) acrylates such as phenoxyethyl (meth) acrylate and 2-hydroxy-3-phenoxypropyl (meth) acrylate;
Polyethylene glycol mono (meth) acrylate, ethoxydiethylene glycol (meth) acrylate, methoxypolyethylene glycol (meth) acrylate, phenoxypolyethylene glycol (meth) acrylate, nonylphenoxypolyethylene glycol (meth) acrylate, polypropylene glycol mono (meth) acrylate, methoxypolypropylene Polyalkylene glycol (meth) acrylates such as glycol (meth) acrylate, ethoxy polypropylene glycol (meth) acrylate, nonylphenoxy polypropylene glycol (meth) acrylate;
Cyclohexyl (meth) acrylate, 4-butylcyclohexyl (meth) acrylate, dicyclopentanyl (meth) acrylate, dicyclopentenyl (meth) acrylate, dicyclopentadienyl (meth) acrylate, bornyl (meth) acrylate, isobornyl ( Cycloalkyl (meth) acrylates such as (meth) acrylate and tricyclodecanyl (meth) acrylate;
Benzyl (meth) acrylate, tetrahydrofurfuryl (meth) acrylate;
Unsaturated carboxylic acids such as (meth) acrylic acid, vinyl benzoic acid, maleic acid and vinyl phthalic acid; vinyl group-containing radical polymerizable compounds such as vinyl benzyl methyl ether, vinyl glycidyl ether, styrene, α-methyl styrene, butadiene and isoprene Is mentioned.

  As the polymer (B), a substance that is completely oxidized and removed by the baking treatment temperature (400 to 600 ° C.) at the time of forming the cured body (dielectric) is particularly preferable. ) A polymer is preferred.

  Specific examples of the preferred (co) polymer as the polymer (B) include, for example, a copolymer of hydroxyethyl (meth) acrylate and isobutyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate and isobutyl (meth). Examples thereof include copolymers with acrylates and copolymers of 2-ethoxyethyl (meth) acrylate, 2-methoxyethyl (meth) acrylate and isobutyl (meth) acrylate.

  The content ratio of the polymer (B) in the plasma display panel dielectric forming composition of the present invention is preferably 1 to 30 parts by mass, more preferably 3 to 15 parts per 100 parts by mass of the inorganic particles (A). Part by mass.

  When the content ratio of the polymer (B) is smaller than 1 part by mass, cracks may occur during film formation for forming the dielectric and when the dielectric is placed at a high temperature. On the other hand, when it is larger than 15 parts by mass, there is a possibility that sufficient transparency cannot be obtained for the dielectric.

[Other ingredients]
The composition for forming a plasma display panel dielectric of the present invention may contain, for example, the following components in addition to the inorganic particles (A) and the polymer (B) as necessary.

((C) Silane compound)
The composition for forming a plasma display panel dielectric of the present invention can contain the following silane compound (C) as required. When the composition for forming a dielectric of a plasma display panel of the present invention contains a silane compound (C), the occurrence of cracks during film formation for forming the dielectric and when the dielectric is placed at a high temperature is suppressed. I can do it.

  The silane compound (C) is an organosilane represented by the following formula (3) (hereinafter also referred to as “component (c1)”), a hydrolyzate of the organosilane represented by the formula (3), and the organo It is a compound selected from the group consisting of silane condensates (hereinafter, these hydrolysates and condensates are also collectively referred to as “component (c2)”).

〔式中、Ｒ⁴は、炭素数１〜８の１価の有機基を示し、Ｒ⁴ が２個以上存在する場合には、それらは互いに同一であっても異なっていてもよい。Ｒ⁵ は、それぞれ独立に炭素数１〜５のアルコキシル基、炭素数１〜６のアシルオキシル基、またはハロゲン原子を示す。ｎは０〜３の整数である。〕

[Wherein, R ⁴ represents a monovalent organic group having 1 to 8 carbon atoms, and when two or more R ⁴ are present, they may be the same as or different from each other. R ⁵ each independently represents an alkoxyl group having 1 to 5 carbon atoms, an acyloxyl group having 1 to 6 carbon atoms, or a halogen atom. n is an integer of 0-3. ]

  The silane compound (C) only needs to contain at least the component (c1) or the component (c2), and even if the organosilane constituting the component (c1) is one, In addition, the hydrolyzate and condensate constituting the component (c2) may each be one type or two or more types.

((C1) component)
(C1) In the formula (3) showing the organosilane constituting the component, R ⁴ is a monovalent organic group having 1 to 8 carbon atoms, and specifically includes, for example, a methyl group, an ethyl group, and n-propyl. Group, i-propyl group, n-butyl group, i-butyl group, sec-butyl group, t-butyl group, n-hexyl group, n-heptyl group, n-octyl group, 2-ethylhexyl group and other alkyl groups Acyl groups such as acetyl group, propionyl group, butyryl group, valeryl group, benzoyl group, trioyl group, caproyl group;
Examples thereof include a vinyl group, an allyl group, a cyclohexyl group, a phenyl group, an epoxy group, a glycidyl group, a (meth) acryloxy group, a ureido group, an amide group, a fluoroacetamide group, and an isocyanate group.

Furthermore, examples of R ⁴ include substituted derivatives of these organic groups.
Examples of the substituent of the substituted derivative representing R ⁴ include a halogen atom, an unsubstituted or substituted amino group, hydroxyl group, mercapto group, isocyanate group, glycidoxy group, 3,4-epoxycyclohexyl group, (meth) acryloxy Group, ureido group, ammonium base and the like. However, when R ¹ is composed of a substituted derivative having these substituents, the number of carbon atoms of the substituted derivative is preferably 8 or less including the carbon atoms constituting the substituent.

In Formula (3), when there are a plurality of R ⁴ (specifically, 2 or 3), these may be the same as or different from each other.
In Formula (3), R ⁵ represents an alkoxyl group having 1 to 5 carbon atoms, an acyloxy group having 1 to 6 carbon atoms, or a halogen atom.

In formula (1), there are a plurality of R ⁵ (specifically, 2 to 4) R ⁵ , which may all be the same or different.
Examples of the alkoxyl group having 1 to 5 carbon atoms representing R ⁵ include a methoxy group, an ethoxy group, an n-propoxy group, an i-propoxy group, an n-butoxy group, a sec-butoxy group, a t-butoxy group, and an n-pentoxy group. Groups and the like.

Examples of the acyloxy group having 1 to 6 carbon atoms representing R ⁵ include an acetoxy group, a propionyloxyl group, a butyryloxy group, a valeryloxy group, and a caproyloxy group.

Examples of the halogen atom representing R ⁵ include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom.
These can be used alone or in combination of two or more.

(Component (c2))
As described above, the component (c2) is a hydrolyzate of an organosilane represented by the above formula (3) and a condensate of the organosilane.

  The weight average molecular weight (Mw) of the component (c2) is preferably 800 to 50,000, more preferably 1,000 to 40,000 in terms of polystyrene measured by gel permeation chromatography.

  Examples of the component (c2) having such a structure include “MKC silicate” manufactured by Mitsubishi Chemical Corporation, ethyl silicate manufactured by Colcoat, silicone resin manufactured by Toray Dow Corning Silicone Co., and Momentive Performance. A commercially available product (polysiloxane) such as a terminal hydroxypolysiloxane resin (for example, trade name “YR3370”) manufactured by Materials Japan GK, or a silicone resin manufactured by Shin-Etsu Chemical Co., Ltd. can be used.

  Preferable specific examples of the silane compound (C) include hydrolyzate and condensate of dimethyldimethoxysilane, hydrolyzate and condensate of methyltrimethoxysilane, and cohydrolyzate of dimethyldimethoxysilane and methyltrimethoxysilane, and Examples include condensates.

(Content of silane compound (C))
When the composition for forming a plasma display panel dielectric of the present invention contains a silane compound (C), the content ratio of the silane compound (C) is 0 to 10 mass in terms of complete hydrolysis condensate with respect to the total amount of the composition. % Is preferred.

In this specification, the complete hydrolysis-condensation product according to the silane compound (C) includes the OR ⁵ group according to the formula (3) and the OR ⁷ group according to the formula (4) contained in the silane compound (C). And all of Y groups (100%) are hydrolyzed to form Si—OH groups, and the Si—OH groups are completely condensed to form a siloxane structure.

((D) Organic solvent)
The composition for forming a plasma display panel dielectric of the present invention includes an organic solvent (D) for the purpose of adjusting the total solid content concentration and viscosity of the composition, or adjusting the thickness of the cured body (dielectric). ) May be contained.

Moreover, by containing the organic solvent (D), the dispersion stability and the storage stability of the plasma display panel dielectric forming composition are further improved.
The amount of the organic solvent (D) used can be appropriately set according to desired conditions. For example, the total solid concentration of the obtained composition for forming a plasma display panel dielectric is preferably 5 to 99% by mass. The amount is more preferably 7 to 95% by mass, and particularly preferably 10 to 90% by mass.

The “solid content concentration” indicates the concentration of components other than the organic solvent in the plasma display panel dielectric forming composition.
Examples of the organic solvent (D) include alcohols, aromatic hydrocarbons, ethers, ketones, esters and the like. These can be used alone or in combination of two or more.

  In the organic solvent (D), the boiling point at 1 atm is preferably 100 ° C. or higher and 300 ° C. or lower, particularly preferably 150 ° C. or higher and 250 ° C. or lower.

  When the boiling point at 1 atm is less than 100 ° C., the dried product is covered due to the rapid drying of the composition applied in the coating operation (the composition for forming a plasma display panel dielectric). There is a risk of adhesion to the coated surface or uneven coating. On the other hand, when the boiling point at 1 atm exceeds 300 ° C., the organic solvent tends to remain in the cured body (dielectric body) obtained through the baking treatment, resulting in a decrease in strength of the cured body. There is a risk of surface roughness.

  Examples of the alcohols include 1-pentanol, 2-pentanol, 2-methyl-2-butanol, 3-methyl-1-butanol, 2-ethylbutanol, n-hexanol (n-hexyl alcohol), 2- Ethylhexanol, 2-octanol, terpineol, i-butyl alcohol, n-butyl alcohol, n-octyl alcohol, 2-heptyl alcohol, ethylene glycol, ethylene glycol diacetate, ethylene glycol diethyl ether, ethylene glycol dimethyl ether, diethylene glycol, triethylene Glycol, ethylene glycol monobutyl ether (2-butoxyethanol), ethylene glycol monobutyl ether acetate, ethylene glycol monohexyl ether, ethyl Glycol monoethyl ether acetate, ethylene glycol monomethyl ether acetate, diethylene glycol monoethyl ether, diethylene glycol diethyl ether, diethylene glycol dibutyl ether, diethylene glycol monobutyl ether, propylene glycol, propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol monobutyl ether, propylene Examples thereof include monomethyl ether acetate and diacetone alcohol.

  Examples of the aromatic hydrocarbons include toluene and xylene. Examples of the ethers include diethyl acetal, dibutyl ether, dioxane, and the like. Examples of the ketones include acetylacetone, ethyl-n-butylketone, dioxane. Acetone alcohol, methyl isobutyl ketone, methyl-n-butyl ketone, methyl-n-propyl ketone, diethyl ketone, diisobutyl ketone, diisopropyl ketone, and the like. Examples of the esters include ethyl acetoacetate, methyl acetoacetate, ethyl benzoate. Methyl benzoate, amyl acetate, isoamyl acetate, propyl acetate, butyl acetate, diethyl carbonate, methyl lactate, ethyl lactate, dibutyl maleate, and the like. These can be used alone or in combination of two or more.

  Specific examples of such an organic solvent include propylene glycol monomethyl ether, n-hexanol, 2-ethyl-1-hexanol, and 2-butoxyethanol.

[Production Method of Plasma Display Panel Dielectric Forming Composition]
The composition for forming a dielectric of the plasma display panel of the present invention comprises SiO ₂ particles (A1) and metal oxide particles (A2) which are inorganic particles (A) and a polymer (B), or these and, if necessary. The silane compound (C) and the organic solvent (D) can be mixed.

In such a method for producing a composition for forming a plasma display panel dielectric, depending on the dispersibility of SiO ₂ particles and the like, for example, a ball mill, a sand mill (bead mill, a high shear bead mill), a homogenizer, an ultrasonic homogenizer, a nanomizer, a propeller It is preferable to use a known disperser such as a mixer, a high shear mixer, or a paint shaker. Particularly, a fine particle dispersion ball mill and a sand mill (bead mill, high shear bead mill) having high dispersion performance are preferably used.

There is no particular limitation on the order of mixing the components may be mixed simultaneously all components were mixed with SiO ₂ particles (A1) and the metal oxide particles (A2), the polymer (B) Then, if necessary, other components may be mixed. For example, after the SiO ₂ particles (A1) or the metal oxide particles (A2) are dispersed in the polymer (B) in advance, the other components are mixed. May be mixed.

[Plasma display panel dielectric manufacturing method]
A dielectric can be obtained by applying the film for forming a plasma display panel dielectric of the present invention on a substrate and forming a film thereon.

Moreover, the dielectric material which has a pattern can also be formed by patterning the coating film formed on the board | substrate into the predetermined shape according to the dielectric material which should be formed.
As a method for applying the composition for forming a plasma display panel dielectric of the present invention, for example, a brush, a slit coater, a roll coater, a bar coater, a flow coater, a centrifugal coater, an ultrasonic coater, a (micro) gravure coater or the like is used. Application methods; dip coating method; flow coating method; spray method; screen process method; electrodeposition method;

  Specifically, for example, by using a slit coater or the like, the plasma display panel dielectric forming composition is applied to the surface of a glass substrate to form a coating film, and the coating film is dried to form a film forming material layer. Then, the obtained film-forming material layer is baked to decompose and remove the organic substance (solvent, etc.) and sinter, thereby forming a dielectric made of a cured body.

The drying conditions of the coating film are, for example, 40 to 150 ° C. for 1 to 60 minutes. The thickness of the film forming material layer is, for example, 5 to 250 μm.
Moreover, as for the baking conditions of the film forming material layer, the heating temperature (baking temperature) is, for example, 400 to 650 ° C., and the baking time is, for example, 1 to 360 minutes.

According to the composition for forming a plasma display panel dielectric of the present invention, a cured body (FPD member) having a thickness (fired film thickness) of 40 μm or more can also be formed by a single coating.
“One-time coating” means that when the composition for forming a plasma display panel dielectric is applied on a substrate, the coating operation and the drying operation of the coating film obtained by the coating operation are performed only for one cycle. means.

As described above, since the composition for forming a plasma display panel dielectric of the present invention contains a specific polymer together with specific SiO ₂ particles and specific metal oxide particles, a dielectric having a large thickness is formed. When cracking, cracks are unlikely to occur.

  Specifically, a large number of electrodes having a width of about 100 μm and a height of about 100 μm are formed on a substrate at intervals of about 100 μm, and the electrodes are covered so that the number of film thicknesses is increased by the plasma display panel dielectric forming composition of the present invention. Even when a 10 μm dielectric is formed, the possibility of cracks occurring in the dielectric is low.

The reason why the plasma display panel dielectric forming composition of the present invention can suppress the occurrence of cracks is thought to be because the film becomes strong due to electrostatic interaction between the SiO ₂ particle surface and the metal oxide particle surface. .

  Specific examples of the present invention will be described below, but the present invention is not limited to these examples. In the following examples and comparative examples, “parts” are based on mass unless otherwise specified. Various measurements and evaluations in Examples and Comparative Examples were performed by the following methods.

(1) Optical property evaluation:
After applying the plasma display panel dielectric forming composition on quartz glass so that the dry film thickness is 15 μm, the insulating film is dried at 100 ° C. for 20 minutes and then baked at 500 ° C. for 1 hour. Formed. About the obtained insulating film, the transmittance | permeability was measured using the haze tester (touch panel type haze computer HZ-2S) by Suga Test Instruments Co., Ltd., and the following reference | standard evaluated.
A: When the transmittance exceeds 80% B: When the transmittance is 70% or more and 80% or less C: When the transmittance is less than 70%

(2) Critical film thickness evaluation The obtained composition was applied onto a glass substrate using an applicator having a gap of 100 to 300 μm to form a coating film, and this coating film was dried at 100 ° C. for 20 minutes. Then, a cured film having a film thickness of 2 to 40 μm was produced by further baking at 500 ° C. for 1 hour. By visually observing these cured films, the presence or absence of peeling and cracks was confirmed, and in the range of 2 to 40 μm thickness, the maximum film thickness that does not cause peeling and cracking was defined as the limit film thickness, The critical film thickness was measured.
A: When the limit film thickness exceeds 20 μm B: When the limit film thickness is 10 μm or more and 20 μm or less C: When the limit film thickness is less than 10 μm

(3) Evaluation of crack occurrence:
A composition for forming a plasma display panel dielectric is formed on a substrate on which a plurality of reverse-tapered silver electrodes having a top surface width of 100 μm, a bottom surface width of 80 μm, and a height of 12 μm are provided with a spacing of 100 μm. A coating film was formed by coating using an applicator. The coating film was dried at 100 ° C. for 20 minutes, and then baked at 500 ° C. for 1 hour using an oven to form an insulating film. The obtained insulating film was cut into 2 cm squares to prepare test pieces, and the surface of the test pieces was observed with an electron microscope at a magnification of 600 times, so that the presence or absence of cracks on the surface of the test pieces was observed. Were evaluated according to the following criteria.
AA: When the number of cracks generated near the electrode in the whole test piece is 0 to 4 A: When the number of cracks generated near the electrode in the whole test piece is 5 to 10 B: Electrode in the whole test piece When the number of cracks occurring in the vicinity is 11 or more C: When a cured film is not obtained

[Example 1]
In a mixed solvent composed of 292.5 parts of 2-ethylhexanol and 7.5 parts of 2-butoxyethanol, 70 parts of silica particles having an average particle diameter of 80 nm (hereinafter referred to as “silica particles (A1-1)”) and , 30 parts of metal oxide particles (zinc oxide; NANOFINE-50W-LP2) (A2-1) and iso-butyl methacrylate (hereinafter “i-BMA”). ) And hydroxypropyl methacrylate (hereinafter referred to as “HPMA”) (with a monomer mass ratio of i-BMA / HPMA = 80/20 and a weight average molecular weight of 400,000). i-BMA) ₈₀ (HPMA) ₂₀ ")) 9 parts were mixed with stirring to prepare a composition for forming a plasma display panel dielectric. The results of optical property evaluation, critical film thickness evaluation and crack generation evaluation of the obtained plasma display panel dielectric forming composition are shown in Table 1 below.

[Examples 2 to 20, Comparative Examples 1 and 2]
For Examples 2 to 20 and Comparative Examples 1 and 2, the same operation as in Example 1 was performed except that the compositions having the compositions shown in Table 1 were used. Prepared. In Table 1, the numerical values of (A1), (A2), (B) and (D) indicate parts by mass. The results of optical property evaluation, critical film thickness evaluation and crack generation evaluation of the obtained plasma display panel dielectric forming composition are shown in Table 1 below. About composition (21) and (22), since it did not harden | cure, evaluation of the optical characteristic was impossible.

In addition, A1-1 to A1-3 in Table 1 represent silica particles having the average particle diameter shown in Table 2. A2-1 to A2-7 represent the metal oxide particles shown in Table 3. B-1 represents poly (i-BMA) ₈₀ (HPMA) ₂ , D-1 represents 2-ethylhexanol, and D-2 represents 2-butoxyethanol. In Table 3, “surface oxide” indicates that the oxide displayed in this column is attached to the surface of the metal oxide particles. “Surface treatment” indicates that the metal oxide particles have been surface-treated with the dispersant shown in Table 3 below corresponding to the numbers displayed in this column.

DESCRIPTION OF SYMBOLS 1 Glass substrate 2 Glass substrate 3 Partition 4 Transparent electrode 5 Bus electrode 6 Address electrode 7 Phosphor 8 Dielectric layer 9 Dielectric layer 10 Protective film 11 Partition 201 Glass substrate 202 Glass substrate 203 Insulating layer 204 Transparent electrode 205 Emitter 206 Cathode electrode 207 Phosphor 208 Gate 209 Spacer

Claims (6)

(A) Inorganic particles containing the following (A1) particles and (A2) particles and (A1) SiO ₂ particles having an average particle size of 20 to 100 nm (A2) Metal oxide particles having an average particle size of 1 to 30 nm (B) Weight average An acrylic polymer having a molecular weight of 100,000 to 500,000 in terms of polystyrene, and the total content of the (A1) particles and (A2) particles is 90% by mass or more based on the whole of the (A) inorganic particles. A composition for forming a dielectric of a plasma display panel, characterized in that:   2. The composition for forming a dielectric of a plasma display panel according to claim 1, comprising 2 to 50 parts by mass of the (A2) particles with respect to 100 parts by mass of the (A1) particles. The composition for forming a plasma display panel dielectric according to claim 1, wherein the (A2) particles have SiO ₂ or Al ₂ O ₃ on at least a part of a surface thereof. Wherein (A2) particles plasma display panel dielectric-forming composition according to claim 1, characterized in that with Al ₂ O ₃ at least a portion of its surface.   5. The composition for forming a dielectric of a plasma display panel according to claim 1, comprising 1 to 30 parts by mass of the polymer (B) with respect to 100 parts by mass of the inorganic particles (A). object. The said (B) acrylic polymer has a repeating unit represented by following formula (1), The composition for plasma display panel dielectric formation in any one of Claims 1-5 characterized by the above-mentioned.

[Wherein, R ¹ represents a hydrogen atom or a methyl group, R ² represents a divalent hydrocarbon group having 1 to 10 carbon atoms, and R ³ represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms. Indicates. ]

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