KR20080045609A - Composition for forming dielectric layer, green sheet, substrate having dielectric layer and method of manufacturing the same - Google Patents

Abstract

A composition for forming a dielectric layer is provided to ensure uniform and stable dispersibility and storage stability, and to form a defectless, even, and high-quality dielectric layer. A composition for forming a dielectric layer contains an inorganic component, a thermally labile binder, a dispersant, and a solvent. The inorganic component does not a lead powder. The dispersant is a polycarboxylic acid-based polymer compound. The thermally labile binder is contained in an amount of 55-105 parts by weight based on 100 parts by weight of the inorganic component. The dispersant is contained in an amount of 0.01-5 parts by weight based on 100 parts by weight of the inorganic component.

Description

A composition for forming a dielectric layer, a green sheet, a dielectric layer forming substrate, and a method of manufacturing the same {COMPOSITION FOR FORMING DIELECTRIC LAYER, GREEN SHEET, SUBSTRATE HAVING DIELECTRIC LAYER AND METHOD OF MANUFACTURING THE SAME}

The present invention relates to a dielectric layer forming composition suitable for forming a dielectric layer such as a plasma display panel, a green sheet obtained by molding the composition into a film, and a dielectric layer forming substrate having a dielectric layer obtained from the green sheet, and a manufacturing method thereof. will be.

The display device includes a liquid crystal display device, an electroluminescence display device, a plasma display panel, and the like. Among these, plasma display panels (hereinafter also referred to as "PDPs") are attracting attention as next-generation multimedia displays.

3 is a sectional view of an example of a PDP. The PDP shown in FIG. 3 consists of a pair of glass substrate of the glass substrate 1 for front plates, and the glass substrate 2 for back plates. On the inner surfaces of the glass substrate 1 for the front plate and the glass substrate 2 for the back plate, the display electrodes 3 and the address electrodes 4 that are perpendicular to each other are formed. The display electrode 3 and the address electrode 4 are covered with a dielectric layer 5 (front plate dielectric layer) and 6 (back plate dielectric layer), respectively. In addition, the glass substrates 1 and 2 are separated into the discharge spaces (pixels) by the ribs (bullets) 8 via the protective film 7, and phosphors 9 are formed in each pixel.

As a method of forming the dielectric layer of a PDP, the method of joining the green sheet obtained by shape | molding the composition for dielectric layer formation to a film form with a board | substrate, and baking the green sheet after that is known (patent document 1, 2 etc.). According to this method, a high quality dielectric layer can be efficiently formed.

Such a composition for forming a dielectric layer is required to have excellent dispersibility and long-term storage stability. When using the composition for dielectric layer formation in which dispersibility is inferior or the dispersion state deteriorated during storage, a uniform coating film cannot be formed and the dielectric layer formed has many defects, and it becomes difficult to acquire desired characteristics as a dielectric.

In connection with the present invention, Patent Document 3 proposes to use a polycarboxylic acid-based high molecular compound as the dispersant in a composition for forming a dielectric layer containing an inorganic component (glass component), a thermally decomposable binder, a dispersant, and a solvent. .

Patent Document 1: Japanese Patent Application Laid-Open No. 9-102273

Patent Document 2: Japanese Patent Application Laid-Open No. 10-182919

Patent Document 3: Japanese Unexamined Patent Publication No. 2004-2164

In recent years, from the viewpoint of environmental protection or the like, it has been desired to use one containing no lead (lead compound) as the inorganic component used for forming the dielectric layer.

When the present inventors applied the prescription of patent document 3 to the composition for dielectric layer formation which does not contain a soft powder, it turned out that the dispersibility and storage stability of the obtained dielectric layer formation composition are not enough.

Therefore, the present invention provides a composition for forming a dielectric layer containing an inorganic component, a thermally decomposable binder, a dispersant, and a solvent, even when the inorganic component does not contain a soft powder. An object of the present invention is to provide a composition for forming a dielectric layer, a green sheet, a dielectric layer forming substrate, and a method of manufacturing the same, which can form a uniform and high-quality dielectric layer without defect by coating and firing.

MEANS TO SOLVE THE PROBLEM In order to solve the said subject, the present inventors earnestly researched the composition for dielectric layer formation containing the inorganic component which does not contain a powder, a thermally decomposable binder, a dispersing agent, and a solvent. As a result, when the polycarboxylic acid-based high molecular compound is used as the dispersant and the content of the thermally decomposable binder is 55 to 105 parts by weight based on 100 parts by weight of the inorganic component by solid content, it is for forming a dielectric layer having uniform and stable dispersibility and storage stability. When a composition was obtained and the green sheet formed from this composition was used, it discovered that a high quality dielectric layer was obtained without a fault, and came to complete this invention.

Thus, according to the first aspect of the present invention, a composition for forming a dielectric layer containing an inorganic component, a thermally decomposable binder, a dispersant, and a solvent, wherein the inorganic component does not contain lead, and the dispersant is a polycarboxylic acid polymer compound. Moreover, content of the said thermally-decomposable binder is 55-105 weight part with respect to 100 weight part of inorganic components by solid content, The composition for dielectric layer formation is provided.

In the composition for dielectric layer formation of this invention, it is preferable that content of the said dispersing agent is 0.01-5 weight part with respect to 100 weight part of inorganic components by solid content ratio.

In the composition for forming a dielectric layer of the present invention, the polycarboxylic acid-based high molecular compound is at least one selected from the group consisting of partial esters of α-olefin / maleic anhydride copolymers, aliphatic polycarboxylic acid salts, and aliphatic polycarboxylic acid special silicones. desirable.

In the composition for dielectric layer formation of this invention, it is preferable that an inorganic component contains a glass component and a filler component.

It is preferable that the composition for dielectric layer formation of this invention is a slurry whose average particle diameter is 0.5-4.0 micrometers.

The composition for forming a dielectric layer of the present invention is preferably used for forming a dielectric layer of a plasma display panel.

According to the 2nd of this invention, the green sheet obtained by shape | molding the composition for dielectric layer formation of this invention to a film form is provided.

According to the third aspect of the present invention, there is provided a dielectric layer forming substrate comprising a dielectric layer formed on the substrate using the green sheet of the present invention.

According to the fourth aspect of the present invention, there is provided a method for producing a dielectric layer-forming substrate, comprising the steps of bonding the green sheet of the present invention to a substrate and forming a dielectric layer by firing the green sheet.

Since the composition for dielectric layer formation of this invention uses the inorganic component which does not contain a powder, it is excellent from the viewpoint of environmental protection.

Even if the composition for dielectric layer formation of this invention is preserve | saved or conveyed in the slurry state, an inorganic component does not aggregate or sediment, and it has a uniform and stable dispersion state over a long term.

When using the composition for dielectric layer formation of this invention, since it can apply | coat uniformly, a uniform green sheet can be formed, As a result, a uniform, high quality dielectric layer without a fault can be obtained.

The composition for forming a dielectric layer and the green sheet of the present invention can be suitably used for forming the dielectric layer of a plasma display panel.

The dielectric layer forming substrate of the present invention is uniform and of high quality since it has a dielectric layer formed using the green sheet of the present invention.

According to the method for producing a dielectric layer forming substrate of the present invention, it is possible to efficiently manufacture a uniform and high quality dielectric layer forming substrate having a dielectric layer free of pixel defects.

Hereinafter, the present invention will be described in detail by classifying the present invention into 1) a composition for forming a dielectric layer, 2) a green sheet, and 3) a dielectric layer forming substrate, and a method of manufacturing the same.

1) Dielectric Layer Formation Composition

The composition for forming a dielectric layer of the present invention (hereinafter may be simply referred to as the "composition of the present invention") is a composition for forming a dielectric layer containing an inorganic component, a thermally decomposable binder, a dispersant, and a solvent, wherein the inorganic component is softly powdered. The dispersant is a polycarboxylic acid polymer compound, and the content of the thermally decomposable binder is 55 to 105 parts by weight based on 100 parts by weight of the inorganic component.

(Inorganic ingredient)

The inorganic component used for the composition of this invention does not contain a powder from the viewpoint of environmental protection. As an inorganic component, the mixture which consists of a glass component which does not contain a soft powder, or a glass component which does not contain a soft powder, and a filler component is mentioned.

As an inorganic component, the composition for forming a white dielectric layer excellent in reflectance can be obtained by using the mixture which consists of a glass component and a filler component which does not contain a powder.

There is no particular restriction on the glass component that does not contain the lead, as long as it does not contain the lead. For example, ZnO-B ₂ O ₃ -SiO ₂ (zinc oxide-boron oxide-silicon oxide) -based glass, ZnO-P ₂ O ₅ -SiO ₂ (zinc oxide-phosphorus-silicon oxide) glass, Bi ₂ O ₃ -B ₂ O ₃ -SiO ₂ (bismuth oxide-boron oxide-silicon oxide) glass, ZnO-B ₂ O _3- K ₂ O (zinc oxide-boron oxide-potassium oxide) glass, ZnO-P ₂ O ₅ -TiO ₂ (zinc oxide-phosphorus-titanium oxide) glass, B ₂ O ₃ -SiO ₂ -Al ₂ O ₃ Three-component glass such as (boron oxide-silicon oxide-aluminum oxide) glass and P ₂ O ₅ -B ₂ O ₃ -Al ₂ O ₃ (phosphorus oxide-boron oxide-aluminum oxide) glass; Bi ₂ O ₃ -B ₂ O ₃ -SiO ₂ -Al ₂ O ₃ (bismuth oxide-boron oxide-silicon oxide-aluminum oxide) based glass, ZnO-B ₂ O ₃ -SiO ₂ -Al ₂ O ₃ (zinc oxide -Boron Oxide-Silicon Oxide-Aluminum Oxide Glass, ZnO-P ₂ O ₅ -SiO ₂ -Al ₂ O ₃ (Zinc Oxide-Phosphorus Oxide-Silicon Oxide-Aluminum Oxide) Glass, ZnO-Bi ₂ O _3- Four-component glass such as SiO ₂ -B ₂ O ₃ (zinc oxide, bismuth oxide, silicon oxide, boron oxide) glass; Five-component glass such as ZnO-Bi ₂ O ₃ -SiO ₂ -Al ₂ O ₃ -B ₂ O ₃ (zinc oxide-bismuth oxide-silicon oxide-aluminum oxide-boron oxide) -based glass; Six-component glass such as ZnO-Bi ₂ O ₃ -SiO ₂ -Al ₂ O ₃ -B ₂ O ₃ -BaO (zinc oxide-bismuth oxide-silicon oxide-aluminum oxide-boron oxide-barium oxide) -based glass; Etc. can be mentioned.

Further, these glass component, or may include CaO, Na ₂ O, TiO _2, CuO, Li ₂ O, K ₂ O, BaO, MgO, SrO is added.

Among these, use of ZnO-B ₂ O ₃ -SiO ₂ -Al ₂ O ₃ (zinc oxide-boron oxide-silicon oxide-aluminum oxide) -based glass is preferred, and ZnO-Bi ₂ O ₃ -SiO ₂ -Al ₂ More preferred is the use of O ₃ -B ₂ O ₃ -BaO (zinc oxide-bismuth oxide-silicon oxide-aluminum oxide-boron oxide-barium oxide) glass.

Examples of the filler component include TiO ₂ (titanium oxide), Al ₂ O ₃ (alumina), SiO ₂ (silica), ZrO ₂ (zirconia), and the like. Among these, TiO ₂ and Al ₂ O ₃ are preferable.

When the inorganic component is a mixture consisting of a glass component and a filler component, the blending ratio of the glass component and the filler component is usually glass component: filler component = 50:50 to 99: 1 (weight ratio), preferably 70:30 to 95 : Five.

The inorganic component can be obtained by mixing the powdery glass component and, if desired, the powdery filler component, or melting the glass component, and then cooling and pulverizing to make a fleet, and mixing this with the powdery filler component if desired.

The average particle diameter of the inorganic component to be used becomes like this. Preferably it is 3 micrometers or less, More preferably, it is 0.5-3.0 micrometers. By using the inorganic component which has an average particle diameter in this range, it becomes easy to obtain the composition for dielectric layer formation which has a uniform and stable dispersion state.

The maximum particle diameter of the inorganic component is preferably 20 µm or less in order to obtain a uniform and transparent dielectric layer. When the maximum particle diameter of an inorganic component exceeds 20 micrometers, defects, such as a pinhole, will generate | occur | produce easily on the surface of the dielectric layer obtained, and it will become difficult to acquire desired breakdown voltage characteristics.

The average particle diameter and the maximum particle diameter of the inorganic component can be measured, for example, by a laser diffraction / scattering particle size distribution measuring device or the like.

(Dispersant)

The composition of this invention uses a polycarboxylic acid type high molecular compound as a dispersing agent.

The polycarboxylic acid polymer compound used in the present invention means a polymer compound having a plurality of carboxylic acid groups in a molecule. Such a polycarboxylic acid-based high molecular compound can disperse high specific gravity particles such as glass flits in comparison with known dispersants such as silane coupling agents and general surfactants.

By using a polycarboxylic acid type high molecular compound as a dispersing agent, the dispersibility of the glass flit in the composition for dielectric layers can be improved, and a composition can be maintained in a favorable dispersion state. That is, it is suppressed that glass flits aggregate and form secondary particle. As a result, the imbalance of the dielectric properties in the dielectric layer can be improved, and further, the withstand voltage of the dielectric layer can be improved.

It is preferable to use at least 1 sort (s) chosen from the group which consists of partial ester of (alpha)-olefin / maleic anhydride copolymer, aliphatic polycarboxylic acid salt, and aliphatic polycarboxylic acid special silicone as a polycarboxylic acid type high molecular compound. Among them, partial esters of α-olefin / maleic anhydride copolymers exhibit excellent dispersion effects. The molecular weight of the partial ester of the α-olefin / maleic anhydride copolymer is not particularly limited, but is preferably 10,000 to 50,000.

The compounding quantity of a dispersing agent is solid content ratio, Preferably it is 0.01-5 weight part, More preferably, it is 0.5-3 weight part with respect to 100 weight part of inorganic components. When the compounding quantity of a dispersing agent is less than this range, the dispersion state of the composition for dielectric layer formation obtained will become nonuniform, and there exists a possibility that an inorganic component may become easy to settle or aggregate. On the other hand, when more than this range, a dispersing agent remains in a dielectric layer even after a baking process, and becomes a cause of a breakdown voltage and transparency fall.

(Pyrolytic binder)

The composition of the present invention contains a thermally decomposable binder in addition to the inorganic component and the dispersant.

Content of the thermally decomposable binder in the composition of this invention is 55-105 weight part with respect to 100 weight part of inorganic components by solid content ratio, Preferably it is 65-95 weight part. By setting a thermally decomposable binder in such a range, the composition for dielectric layer formation which is excellent in dispersibility and storage stability which has a uniform and stable dispersion state can be obtained.

The thermally decomposable binder has a function as a binder that can be decomposed and easily removed by firing.

Although it does not restrict | limit especially as a thermally decomposable binder used for this invention, It is an organic polymer which has a function as a binder, and can be decomposed | disassembled and removed easily by baking, and serves as an excellent binder and a pressure-sensitive adhesive with a glass substrate. Use of the acrylic resin to complete is preferable.

As an acrylic resin, the homopolymer of a (meth) acrylate compound, the copolymer obtained from 2 or more types of (meth) acrylate compounds, the copolymer obtained from (meth) acrylate compound and another copolymerizable monomer, etc. are mentioned, for example. Can be mentioned. Among these, the copolymer obtained from 2 or more types of (meth) acrylate compound is preferable. Here, (meth) acrylate represents either an acrylate or a methacrylate (similarly hereafter).

As a specific example of a (meth) acrylate compound, 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, ethylhexyl (meth) acrylate, nonyl (meth) acrylate, decyl (meth) acrylate, isodecyl Alkyl, such as (meth) acrylate, undecyl (meth) acrylate, dodecyl (meth) acrylate, lauryl (meth) acrylate, stearyl (meth) acrylate, and isostearyl (meth) acrylate ( Meth) acrylate;

2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, 2-hydroxybutyl ( Hydroxyalkyl (meth) acrylates such as meth) acrylate and 3-hydroxybutyl (meth) acrylate;

Phenoxyalkyl (meth) acrylates such as phenoxyethyl (meth) acrylate and 2-hydroxy-3-phenoxypropyl (meth) acrylate;

2-methoxyethyl (meth) acrylate, 2-ethoxyethyl (meth) acrylate, 2-propoxyethyl (meth) acrylate, 2-butoxyethyl (meth) acrylate, 2-methoxybutyl ( Alkoxy alkyl (meth) acrylates, such as meth) acrylate;

Polyethylene glycol mono (meth) acrylate, ethoxy diethylene glycol (meth) acrylate, methoxy polyethylene glycol (meth) acrylate, phenoxy polyethylene glycol (meth) acrylate, nonylphenoxy polyethylene glycol (meth) acrylate, Polyalkylene glycols such as polypropylene glycol mono (meth) acrylate, methoxy polypropylene glycol (meth) acrylate, ethoxy polypropylene glycol (meth) acrylate, and nonylphenoxy polypropylene glycol (meth) acrylate ( Meth) acrylate;

Cyclohexyl (meth) acrylate, 4-butylcyclohexyl (meth) acrylate, dicyclopentanyl (meth) acrylate, dicyclopentenyl (meth) acrylate, dicyclopentadienyl (meth) acrylate, bor Cycloalkyl (meth) acrylates such as niel (meth) acrylate, isobornyl (meth) acrylate and tricyclodecanyl (meth) acrylate;

Benzyl (meth) acrylate, tetrahydrofurfuryl (meth) acrylate, etc. are mentioned.

The other copolymerizable monomer is not particularly limited as long as it is a compound copolymerizable with the (meth) acrylate compound. For example, unsaturated carboxylic acids, such as (meth) acrylic acid, vinyl benzoic acid, maleic acid, and vinyl phthalic acid; Vinyl group-containing radically polymerizable compounds such as vinyl benzyl methyl ether, vinyl glycidyl ether, styrene, α-methyl styrene, butadiene and isoprene; Etc. can be mentioned.

In this invention, what was manufactured by a well-known manufacturing method, or what was obtained as a commercial item can be used as a thermally decomposable binder.

As a manufacturing method of a thermally decomposable binder, it does not specifically limit but a well-known method can be employ | adopted. For example, acrylic resins can be prepared by (co) polymerizing the (meth) acrylate compound and, if desired, other copolymerizable monomers.

A polymerization method is not specifically limited, For example, the radical polymerization method using radical polymerization initiators, such as azobisisobutyronitrile (AIBN), is mentioned.

Although the weight average molecular weight in particular of the thermally decomposable binder used for this invention is not restrict | limited, Usually, it is 15,000-400,000, Preferably it is 50,000-300,000. Molecular weight can be measured by gel permeation chromatography (GPC).

Although the glass transition temperature (Tg) of the thermally decomposable binder used for this invention is not specifically limited, Usually, they are -15 degreeC-+40 degreeC.

Moreover, in this invention, the thermally-decomposable binder can also use the emulsion of the thermally-decomposable binder by which a thermally-decomposable binder is disperse | distributed to an aqueous phase in particulate form.

(solvent)

The composition of this invention contains a solvent in addition to the said inorganic component, a dispersing agent, and a thermally decomposable binder. The solvent imparts suitable fluidity or plasticity and good film formability to the composition.

As a solvent used for this invention, Water; Ethers such as diethyl ether, diisopropyl ether, dibutyl ether, 1,2-dimethoxyethane, tetrahydrofuran and 1,4-dioxane; Esters such as methyl acetate, ethyl acetate, propyl acetate, butyl acetate and methyl lactate; Ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone, diethyl ketone, and cyclohexanone: N, N-dimethylformamide, N, N-dimethylacetamide, hexamethyl phosphate phosphoramide, N-methylpyrroli Amides such as don; lactams such as ε-caprolactam; lactones such as γ-lactone and δ-lactone; Sulfoxides such as dimethyl sulfoxide and diethyl sulfoxide; Aliphatic hydrocarbons such as pentane, hexane, heptane, octane, nonane and decane; Alicyclic hydrocarbons such as cyclopentane, cyclohexane and cyclooctane; Aromatic hydrocarbons such as benzene, toluene and xylene; Halogenated hydrocarbons such as dichloromethane, chloroform, carbon tetrachloride, 1,2-dichloroethane and chlorobenzene; And mixed solvent which consists of 2 or more types of these; Etc. can be mentioned. Among these, in order to obtain efficiently the composition for dielectric layer formation which has a uniform and stable dispersion state, use of ester, ketones, aromatic hydrocarbons, or the mixed solvent which consists of two or more of these is preferable.

Although the usage-amount of a solvent is not specifically limited, Usually, it is 1-55 weight% with respect to the whole composition.

(Other additives)

Other additives, such as a plasticizer, a tackifier, a storage stabilizer, an antifoamer, a thermal decomposition promoter, and antioxidant, may be added to the composition of this invention as needed.

For example, plasticizers are added to improve processability. Examples of the plasticizer to be used include adipic acid ester plasticizers, phthalic acid ester plasticizers and glycol ester plasticizers. The usage-amount of a plasticizer is 0-10 weight part with respect to 100 weight part of inorganic components.

(Preparation of composition)

The composition of this invention can be prepared by premixing raw materials, such as a thermally decomposable binder, an inorganic component, a dispersing agent, and a solvent, then putting into a dispersing machine and mechanically dispersing.

There is no restriction | limiting in particular as a disperser used for dispersion, For example, Media mills, such as a ball mill and a bead mill; Various homogenizers, such as ultrasonic and stirring; Jet mill; Roll mill;

Known dispersers, such as these, are mentioned.

After dispersion | distribution, it prepares so that the average particle diameter (average particle diameter of the total inorganic component after composition preparation) of the slurry of a composition may be 0.5-4.0 micrometers, Preferably it is 1-3.5 micrometers.

The average particle diameter of the slurry can be diluted with methyl isobutyl ketone so that the slurry has a concentration of 0.05% by weight, for example, and can be measured by a laser diffraction / scattering particle size distribution analyzer in accordance with JISZ8825-1.

Since the composition of this invention obtained as mentioned above does not contain a soft powder, it is excellent from a viewpoint of environmental protection.

The composition of the present invention is excellent in dispersibility, there is no secondary aggregation or sedimentation even after long-term storage or transportation, and a good dispersion state immediately after preparing the composition can be maintained for a long time.

Therefore, even after storing the composition for dielectric layer formation of this invention after long term storage for a long term, using this composition can form a uniform green sheet similarly to the case immediately after preparation, and is uniform and high quality without a fault. A dielectric layer can be obtained.

The storage stability of the composition for forming a dielectric layer is, for example, by putting the composition for forming a dielectric layer immediately after preparation into a sealed container, leaving the container to stand at room temperature for a predetermined period of time, and then visually observing the presence of phase separation between the glass component and the organic component. Can be evaluated

Moreover, the storage stability of the composition for dielectric layer formation measures the height (H) of the liquid surface immediately after putting into a closed container, and the height (Ha) of the phase separation boundary line of the glass component and organic component after a predetermined period, and is represented by the following formula. Sedimentation rate (%) can also be calculated and evaluated.

Sedimentation rate ＝ (H-Ha) / H × 100

The settling rate after leaving the composition of the present invention at room temperature for four weeks is preferably 20% or less, more preferably 15% or less, and the composition of the present invention is excellent in storage stability.

The composition of the present invention can be suitably used for the formation of a dielectric layer of a flat panel display, particularly a dielectric layer of a PDP.

Moreover, the composition of this invention is useful also as a raw material of manufacture of the green sheet of this invention mentioned later.

2) green sheet

The green sheet of the present invention is obtained by molding the composition of the present invention into a film. Specifically, the composition of the present invention can be coated on a carrier film, then dried to form a film.

An example of manufacturing the green sheet of the present invention is shown in FIG. 1.

In Fig. 1, 13 is a carrier film, 14 is a coating device for coating the composition for forming a dielectric layer of the present invention, 18 is a drying device for removing a solvent (removing a solvent) of the composition for forming a dielectric layer, 20a and 20b are green. It is a lamination roll which laminates a protective film on a sheet.

Hereinafter, the manufacturing method of the green sheet of this invention is demonstrated, referring FIG.

First, the carrier film 13 wound in roll shape is sent to the coating apparatus 14. The carrier film 13 is not particularly limited as long as the carrier film 13 is excellent in peelability with a coating film of the dielectric layer forming composition. For example, plastic films, such as a polyethylene terephthalate film, a polyethylene naphthalate film, a polyethylene film, and a polypropylene film, can be used. Moreover, it is preferable to use what apply | coated peeling agents, such as a silicone resin, an alkyd resin, a fluororesin, and a long-chain alkyl resin, to one side of the said plastic film. Moreover, what extruded polyolefin resin on resin which has peelability on the said plastic film, for example, a polyethylene terephthalate film, may be sufficient. The thickness of a carrier film is 10-200 micrometers normally.

Next, the composition is applied onto the carrier film 13 by the coating device 14. The coating device 14 consists of the storage part 15 and the coating part 16. The storage unit 15 stores the slurry-like composition, and delivers the composition to the coating unit 16 by a fixed amount. The coating portion 16 is not particularly limited. For example, well-known coaters, such as a knife coater and a die coater, can be used.

The coating amount of the composition of this invention can be suitably set according to the thickness of the coating film 17a of the composition to form.

Next, the carrier film 13 in which the coating film 17a of the composition was formed in the surface is sent to the drying apparatus 18. By drying the coating film 17a of the composition (i.e., removing volatile components such as solvents) in the drying apparatus 18, the dry coating film of the composition, that is, the green sheet 17, is laminated on the carrier film 13 Obtained laminates can be obtained.

It does not specifically limit as a method of drying the coating film 17a of the said composition, For example, (A) The method of heating the carrier film in which the coating film was formed to predetermined temperature, (B) The method of sending dry air or hot air to the said coating film surface. And (c) a method of combining the above (a) and (b).

The temperature at the time of drying will not be restrict | limited especially if it is below the temperature at which a carrier film is not heat-strained, Usually, it is 150 degreeC from room temperature, Preferably it is 60-130 degreeC, and drying time is 1 to 10 minutes.

The thickness of the coating film 17a after drying is 10-200 micrometers normally, Preferably it is 20-120 micrometers.

Next, the protective film 19 is laminated on the green sheet 17.

In FIG. 1, the protective film 19 is a long film wound by roll shape. As a protective film to be used, the thing similar to the said carrier film can be used. The thickness of a protective film is 10-200 micrometers normally.

In order to laminate the protective film 19 on the green sheet 17, it joins (laminates) between the two lamination rolls 20a and 20b through the green sheet 17 and the protective film 19 in FIG. ). Lamination may be performed by heating both or one of lamination rolls 20a and 20b, for example, roll 20b on the protective film surface side.

Since the green sheet of this invention is excellent in the dispersibility of a composition, it is not limited to the surface which contact | connects a carrier film surface, The surface of the exposed side also becomes smooth. For this reason, the green sheet of this invention is excellent in the easiness of bonding with a carrier film and a protective film, and can perform lamination smoothly (excellent lamination aptitude). Lamination aptitude can visually observe a laminated | multilayer film (carrier film-green sheet-protective film), and can evaluate whether three layers are properly bonded. Since the green sheet of the present invention is in such a laminated state, the dielectric layer obtained by firing can also form a smooth surface without pinhole defects.

As described above, a laminated film 21 composed of three layers of the carrier film 13-green sheet 17-protective film 19 can be obtained.

The obtained laminated | multilayer film 21 can be wound up in a roll shape, collect | recovered, preserve | saved, and can be transported.

Since the green sheet of this invention obtained by making it above is obtained by shape | molding the composition of this invention into a film form, it can form a uniform and high quality dielectric layer.

3) dielectric layer forming substrate and manufacturing method thereof

The dielectric layer formation substrate of this invention has a dielectric layer formed on the board | substrate using the green sheet of this invention.

The dielectric layer formation substrate of this invention can be obtained by the manufacturing method of the dielectric layer formation substrate of this invention which has the process of bonding a green sheet and a board | substrate, and the process of forming a dielectric layer by baking the said green sheet, for example. Specifically, after peeling a protective film from a green sheet, it laminates on a board | substrate, and after peeling a carrier film, this green sheet can be baked and obtained. According to this method, it is possible to produce a uniform and high quality dielectric layer forming substrate even with a large area.

As a board | substrate used here, a glass substrate, a ceramic substrate, etc. are mentioned, A glass substrate is preferable. As a glass substrate, the glass substrate for front plates etc. in which the display electrode was formed in the surface are mentioned, for example. Although the thickness in particular of a board | substrate is not restrict | limited, Usually, it is about 1-10 mm.

An example of manufacturing a transparent dielectric layer used for the glass substrate for a front plate of a PDP as a dielectric layer forming substrate of this invention is shown in FIG. 2 is an example in which the transparent dielectric layer 5 is formed on the glass substrate 1 for front plates in FIG.

First, as shown to Fig.2 (a), peeling removal of the protective film 19 of the single side | surface of the laminated | multilayer film 21 is carried out.

Next, as shown in FIG.2 (b), the green sheet 17 is heat-processed on the glass substrate 1 for front plates in which the display electrode 3 was formed in the surface (side in which the display electrode 3 is formed). Squeeze. Thermocompression bonding can be performed on the conditions of 50 degreeC-130 degreeC of heating temperature, and the pressure of 0.05 MPa-2.0 MPa using a heating roller, for example. Since the thermally decomposable binder in the composition of the present invention is a binder and can have a function as a pressure-sensitive adhesive, the green sheet 17 can be uniformly adhered to the glass substrate 1 by a simple operation.

Next, as shown to FIG.2 (c), the carrier film 13 is peeled off from the green sheet 17, and the glass substrate 1 with which the green sheet 17 was thermocompression-bonded is baked. In this process, the pyrolytic binder in the composition is pyrolyzed to completely remove the organic components.

As a method of baking the glass substrate by which the green sheet 17 was thermocompression-bonded, the method of putting the glass substrate by which the green sheet 17 was thermocompression-bonded in the baking furnace and heating the whole, for example is mentioned.

The firing temperature is a temperature at which the thermally decomposable binder is thermally decomposed to completely remove the organic component, and the inorganic component is brought into a uniform molten state to be melted and uniformized. This baking temperature is the temperature of the softening point vicinity of the inorganic component in a green sheet normally. Specifically, it is 500-650 degreeC normally, Preferably it is 520-620 degreeC.

The firing time is usually 1 minute to 3 hours, preferably 5 minutes to 120 minutes.

After baking, as shown in FIG.2 (d), the glass substrate 1 in which the transparent dielectric layer 5 of thickness 5-100 micrometers, Preferably 5-90 micrometers is laminated | stacked can be obtained.

The transparent dielectric layer 5 obtained as mentioned above is uniform and high quality without pinhole defect, and is excellent in transparency.

The surface roughness Ra (µm) of the dielectric layer is usually 0.2 or less. Surface roughness Ra (micrometer) can be measured using a contact surface roughness meter, for example.

In addition, in this embodiment, the case where the transparent dielectric layer 5 used for the glass substrate 1 for a front plate of a PDP was formed was described, but the white dielectric layer 6 and the ceramic substrate with respect to the glass substrate 2 for a back plate were demonstrated. A dielectric layer or the like on the circuit board or the circuit board can also be formed in the same manner.

By using the dielectric layer forming substrate of the present invention, a high quality flat panel display can be manufactured. As a flat panel display, a PDP, a field emission display (FED), a liquid crystal display, an electroluminescent display, etc. are mentioned, A PDP is especially preferable.

Example

Next, although an Example and a comparative example demonstrate this invention further in detail, this invention is not limited to the following Example.

The following components were used for the inorganic component, the thermally decomposable binder, the dispersant, the solvent, and the plasticizer.

1) inorganic components

ZnO-Bi ₂ O ₃ -SiO ₂ -Al ₂ O ₃ -B ₂ O ₃ -BaO-based glass (80 wt%), TiO ₂ , SiO ₂ (TiO ₂ / SiO ₂ ＝ Glass fleet having an average particle diameter of 1.4 μm, which is composed of a filler component (20 wt%) containing 75/25 (wt%) as a main component

2) pyrolytic binder

Copolymer obtained by polymerizing 0.5 weight part of azobisisobutyronitrile as a radical polymerization initiator, and polymerizing 100 weight part of 2-ethylhexyl methacrylates and 1 weight part of acrylic acid at 70 degreeC for 16 hours in toluene (weight average molecular weight (Mw) = 50% by weight solution of 170,000, glass transition temperature (Tg) = -11 ° C.

3) dispersant

(1) Dispersant A: Polycarboxylic acid-based high molecular compound (partial ester of α-olefin / maleic anhydride copolymer, trade name: Floren G700, manufactured by Kyoisha Chemical Co., Ltd.), concentration 100%

(2) Dispersant B: Polyether-based dispersant (trade name: Floren NC-500, manufactured by Kyoisha Chemical Co., Ltd.), concentration 50%

(3) Dispersant C: Nonionic non-silicone compound (trade name: Polyflo KL505, manufactured by Kyoeisha Chemical Co., Ltd.), concentration 100%

4) solvent

toluene

5) plasticizer

Adipic dibutyl

Moreover, the evaluation method regarding the dispersion state of the composition prepared by each Example and the comparative example and the characteristic of a dielectric layer is as follows.

(i) Determination of average particle diameter and maximum particle diameter

The average particle diameter (µm) and the maximum particle diameter of the slurry were diluted with methyl isobutyl ketone so that the slurry had a concentration of 0.05% by weight, and a laser diffraction / scattering particle size distribution measuring device in accordance with JISZ8825-1 (Model: LA-920 , Manufactured by Horiba, Ltd.).

(Ii) measurement of sedimentation rate

The composition for dielectric layer formation immediately after preparation was put into the container, this container was sealed, and the height (H) of the liquid surface was measured. After the container was allowed to stand at room temperature for a predetermined period, it was visually observed to examine the presence or absence of phase separation between the glass component and the organic component. When the glass component and the organic component were phase separated, the height Ha of the phase separation boundary was measured. Sedimentation rate (%) was computed by the formula shown below.

Sedimentation rate ＝ (H-Ha) / H × 100

(Iii) Laminate Aptitude

Lamination aptitude was visually observed for the resulting laminated film (PET film-green sheet-PET film) and evaluated as to whether or not the three layers were properly bonded. The case where it was joined was evaluated by × with the case where it was not properly bonded by presence of (circle) and aggregates.

(iv) film thickness

The film thickness was measured by the surface roughness measuring instrument (model: SVP-3000S4, Mitsutoyo Corporation).

(v) pinhole defects

The presence or absence of the pinhole on the dielectric layer (95 mm x 95 mm) was observed under a microscope. (Circle) and the case where there existed one pinhole defect were evaluated as the case where there is no pinhole defect as x.

(vi) surface roughness (Ra)

The surface of the dielectric layer is subjected to a surface roughness measuring instrument for the dielectric layer formed by adhering the green sheet obtained from the composition for the dielectric layer on the glass substrate with an electrode onto the glass substrate, and then firing the surface roughness measuring instrument (Model: SVP-3000S4, Mitsutoyo Corp.) (Manufacture) to evaluate the product.

(Example 1)

100 parts by weight of the inorganic component, 160 parts by weight of the thermally decomposable binder (80 parts by weight of solid content relative to 100 parts by weight of inorganic component), 1 part by weight of dispersant A (1 part by weight of solid content based on 100 parts by weight of inorganic component), solvent 25 By weight part and 1 weight part of plasticizers are disperse | distributed using the bead mill type disperser, the composition 1 for dielectric layer formation (henceforth "slurry 1") of Example 1 was prepared.

The average particle diameter (micrometer) of the slurry (1), the largest particle diameter (micrometer), and the sedimentation rate (%) after 4 days, 2 weeks, and 4 weeks after the slurry (1) were measured. Table 1 shows the measurement results.

As a carrier film, the elongate polyethylene terephthalate (PET) film of 50 micrometers in thickness which single side | surface was peeled by 0.1 micrometer in thickness was prepared. On the peeled surface of this film, the slurry (1) obtained above was apply | coated using the knife coater. Next, it dried for 2 minutes at 100 degreeC, and obtained the green sheet 1 of thickness 35micrometer on the PET film.

Subsequently, on the green sheet 1 obtained above, one side of the same long film as the said PET film was crimped | bonded between rolls of the peeling process surface of the protective PET film by which the peeling process was carried out with silicone resin at 0.1 micrometer in thickness, PET film- The laminated | multilayer film which three layers of green sheet-PET film are laminated | stacked was obtained. At this time, laminate aptitude was evaluated by the said method. The evaluation results are shown in Table 1.

The PET film for protection on the green sheet 1 was peeled off. Obtained Carrier Film (PET Film)-The laminated film (95 mm x 95 mm) of the green sheet was laid down on the green sheet surface, and was superimposed on the surface of the glass substrate (100 mm x 100 mm x 2.8 mm) having a display electrode formed thereon. And thermocompression bonding (80 ° C., 0.5 MPa) using a heating roller.

Subsequently, the carrier film was peeled off and placed in a firing furnace, the temperature was raised to 400 ° C. at 10 ° C./min from room temperature, held at 400 ° C. for 20 minutes, further elevated to 575 ° C. at 10 ° C./min, and 20 minutes at 575 ° C. Pyrolysis and removal were carried out by baking the resin of the green sheet 1 under the conditions of holding to obtain a dielectric layer-forming substrate 1 having a dielectric layer having a thickness of 10 µm.

The presence or absence of the pinhole defect of the dielectric layer on the obtained dielectric layer formation board | substrate 1 was observed under the microscope, and surface roughness Ra (micrometer) was measured. Table 1 shows the measurement results.

(Example 2)

In Example 1, it carried out similarly to Example 1 except having changed the usage-amount of a thermally-decomposable binder from 160 weight part to 140 weight part (70 weight part by solid content with respect to 100 weight part of inorganic components), The composition for dielectric layer formation (2) (henceforth "slurry (2)") was obtained. In addition, the green sheet 2 and the dielectric layer forming substrate 2 were manufactured so that the thickness of the dielectric layer after baking became 10 micrometers.

Average particle diameter (µm) of slurry (2), maximum particle diameter (µm), sedimentation rate (%) after 4 days, after 2 weeks and after 4 weeks of slurry (2), laminate aptitude of green sheet (2), Table 1 shows the presence or absence of pinhole defects and the surface roughness (Ra (µm)) of the dielectric layer on the dielectric layer-forming substrate 2.

(Comparative Example 1)

The composition for forming a dielectric layer in the same manner as in Example 1, except that 2 parts by weight of dispersant B (1 part by weight based on 100 parts by weight of inorganic components) was used instead of 1 part by weight of dispersant A ( 3) (hereinafter, referred to as "slurry (3)"). In addition, the green sheet 3 and the dielectric layer forming substrate 3 were manufactured so that the thickness of the dielectric layer after baking became 10 micrometers.

Average particle diameter (µm) of the slurry (3), maximum particle diameter (µm), sedimentation rate (%) after 4 days, 2 weeks and 4 weeks after the slurry 3, laminate aptitude of the green sheet 3, Table 1 shows the presence or absence of pinhole defects and the surface roughness (Ra (µm)) of the dielectric layer on the dielectric layer-forming substrate 3.

(Comparative Example 2)

A composition for forming a dielectric layer in the same manner as in Example 1, except that 3.3 parts by weight of dispersant C (1 part by weight based on 100 parts by weight of inorganic components) was used instead of 1 part by weight of dispersant A (4 ) (Hereinafter referred to as "slurry (4)"). In addition, the green sheet 4 and the dielectric layer forming substrate 4 were manufactured so that the thickness of the dielectric layer after baking became 10 micrometers.

Average particle diameter (µm) of slurry (4), maximum particle diameter (µm), sedimentation rate (%) after 4 days, 2 weeks and 4 weeks after slurry 4, laminate aptitude of green sheet 4, Table 1 shows the presence or absence of pinhole defects and the surface roughness (Ra (µm)) of the dielectric layer on the dielectric layer-forming substrate 4.

(Comparative Example 3)

In Example 1, instead of using 160 parts by weight (solid content; 80 parts by weight) of the thermally decomposable binder, 100 parts by weight (solid content; 50 parts by weight) was used, and the composition for forming a dielectric layer was formed in the same manner as in Example 1. (5) (hereinafter, referred to as "slurry (5)") was obtained. In addition, the green sheet 5 and the dielectric layer forming substrate 5 were manufactured so that the thickness of the dielectric layer after baking became 10 micrometers.

Average particle diameter (µm) of slurry (5), maximum particle diameter (µm), sedimentation rate (%) after 4 days, 2 weeks and 4 weeks after slurry 5, laminate aptitude of green sheet 5, Table 1 shows the presence and absence of pinhole defects and the surface roughness Ra (µm) of the dielectric layer on the dielectric layer-forming substrate 5.

(Comparative Example 4)

In Example 1, instead of using 160 parts by weight (solid content; 80 parts by weight) of the thermally decomposable binder, 220 parts by weight (solid content; 110 parts by weight) was used, and the composition for forming a dielectric layer was formed in the same manner as in Example 1. (6) (hereinafter, referred to as "slurry (6)") was obtained. Furthermore, the green sheet 6 and the dielectric layer forming substrate 6 were manufactured so that the thickness of the dielectric layer after baking might be set to 10 micrometers.

Average particle diameter (µm) of slurry 6, maximum particle diameter (µm), sedimentation rate (%) after 4 days, 2 weeks and 4 weeks after slurry 6, laminate aptitude of green sheet 6, Table 1 shows the presence and absence of pinhole defects and the surface roughness Ra (µm) of the dielectric layer on the dielectric layer-forming substrate 6.

From Table 1, the composition (slurry) (1, 2) for dielectric layer formation of Examples 1 and 2 has a stable dispersibility (excellent storage stability) over a long term, and the green sheet (1, 2) obtained from this composition ) Is excellent in lamination aptitude, and it can be seen that by firing, a uniform dielectric layer without pinhole defects with small surface roughness Ra can be formed.

On the other hand, in the dielectric layer forming compositions (slurry) (3, 4) of Comparative Examples 1 and 2 obtained by using dispersants B and C other than the polycarboxylic acid-based high molecular compound, the storage stability is inferior, and the dielectric layer obtained by coating and firing is a pinhole. There existed a fault and surface roughness Ra fell.

Dielectric layer forming composition (slurry) 5 of Comparative Example 3 using a thermally decomposable binder having a solid content of 55 parts by weight or less with respect to 100 parts by weight of the inorganic component was inferior in storage stability as compared with the dielectric layer forming composition (1). . Moreover, the green sheet 5 obtained from this composition was inferior in lamination aptitude, and the dielectric layer obtained by baking had pinhole defect, and surface roughness Ra fell.

In addition, in Comparative Example 4 in which a pyrolytic binder of 105 parts by weight or more was used in solid content with respect to 100 parts by weight of the inorganic component, pinhole defects were observed in the resulting dielectric layer-forming substrate 6.

1 is a process schematic diagram of manufacturing the green sheet of the present invention.

2 is a cross-sectional view showing the method for forming the dielectric layer forming substrate of the present invention.

3 is a structural sectional view of an example of a plasma display panel.

Explanation of symbols for the main parts of the drawings

One … Glass substrate for front panel,

2 … Glass substrate for back plate,

3…. Display electrodes,

4 … Address electrodes,

5…. Dielectric layer (faceplate dielectric layer),

6. Dielectric layer (backplate dielectric layer),

7. Shield,

８… Rib (bulk),

9... Phosphor,

13. Carrier film,

14. Coating device,

15... Reservoir,

16. Pottery,

17a... Coating film of the composition for forming a dielectric layer,

17. Green Sheet,

18. Drying device,

19. Protective film,

20a, 20b... Laminated rolls,

21. Laminated film

Claims (9)

A composition for forming a dielectric layer containing an inorganic component, a thermally decomposable binder, a dispersant, and a solvent, wherein the inorganic component does not contain lead, the dispersant is a polycarboxylic acid polymer compound, and the content of the thermally decomposable binder is a solid content. It is 55-105 weight part with respect to 100 weight part of inorganic components by ratio, The composition for dielectric layer formation characterized by the above-mentioned. The method of claim 1, Content of the said dispersing agent is 0.01-5 weight part with respect to 100 weight part of inorganic components by solid content ratio, The composition for dielectric layer formation characterized by the above-mentioned. The method according to claim 1 or 2, The polycarboxylic acid-based high molecular compound is at least one member selected from the group consisting of partial esters of α-olefin / maleic anhydride copolymers, aliphatic polycarboxylic acid salts, and aliphatic polycarboxylic acid special silicones. The method according to any one of claims 1 to 3, The composition for dielectric layer formation in which the said inorganic component contains a glass component and a filler component. The method according to any one of claims 1 to 4, An average particle diameter is a slurry of 0.5-4.0 micrometers, The composition for dielectric layer formation characterized by the above-mentioned. The method according to any one of claims 1 to 5, A composition for forming a dielectric layer, which is used for forming a dielectric layer of a plasma display panel. The green sheet obtained by shape | molding the composition for dielectric layer formation as described in any one of Claims 1-6 to film form. A dielectric layer forming substrate comprising a dielectric layer formed on the substrate using the green sheet according to claim 7. A method for producing a dielectric layer-forming substrate, comprising the step of bonding the green sheet and the substrate according to claim 8 and a step of forming a dielectric layer by firing the green sheet.

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