JP2005298281A - Inorganic powder-containing resin composition and transfer sheet - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an inorganic powder-containing resin composition for the purpose of forming the dielectric layer not to cause the brightness non-uniformity owing to an uneven fault (an orange peel), and to provide a transfer sheet having a film forming material layer of this composition and also to provide a manufacturing method for a dielectric layer-formed substrate and also a dielectric layer-formed substrate. <P>SOLUTION: The inorganic powder-containing resin composition which contains an inorganic powder and a binder, is characterized in that this inorganic powder has a viscosity at the sintering temperature in the range of 2-100 Pa s. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an inorganic powder-containing resin composition, a transfer sheet, a method for producing a dielectric layer forming substrate, and a dielectric layer forming substrate. In particular, the inorganic powder-containing resin composition of the present invention is useful as a material for forming a dielectric layer of a plasma display panel.

  In recent years, plasma display panels (hereinafter referred to as “PDP”) have attracted attention as liquid crystal displays as thin flat large displays. A part of the PDP has a structure in which a dielectric layer made of a glass sintered body is formed on the surface of a glass substrate.

  The dielectric layer is formed by preparing a paste-like composition containing an inorganic powder, a resin and a solvent, applying the paste-like composition to the surface of a glass substrate by a screen printing method, and drying the film. A method is known in which a forming material layer is formed, and then the film forming material layer is baked to remove organic substances and sinter inorganic powder.

  In recent years, a film-forming material formed on a support film by forming a film-forming material layer by applying a paste-like composition containing inorganic powder, a resin and a solvent on the support film for the purpose of improving productivity. A method of forming a dielectric layer on the surface of the glass substrate by transferring the layer onto the surface of the glass substrate on which the electrode is fixed and firing the transferred film-forming material layer is disclosed (Patent Document 1). ~ 4).

  The inorganic powder is roughly classified into a melt type and a sintered type. Since the melt type flows relatively easily at the firing temperature, the smoothness of the dielectric layer is better than when the sintered type is used.

In the melting process of the inorganic powder, CO ₂ generated by the decomposition of the binder and gases such as H ₂ O and CO ₂ derived from the inorganic powder are generated. These gases form bubbles in the molten inorganic powder, and the bubbles are further bonded to each other or thermally expanded to increase the bubble diameter. Thereafter, the bubbles are ruptured and defoamed from the melted inorganic powder, but when the bubbles are broken, large irregularities are generated on the surface. This irregularity defect is generally called “skin skin”. Yuzu skin formed on the dielectric layer has a large number of bubble breakage marks of about 0.5 mmφ and a height or depth of several μm, and the size of the bubble breakage marks is the same as the general electrode size. Degree. Therefore, there has been a problem that luminance unevenness due to thickness unevenness occurs.

  In Patent Document 5, based on the total weight of polymethacrylic acid ester and glass powder having an average particle diameter of 0.5 to 30 μm, polymethacrylic acid ester is 10 to 60% by weight and average particle diameter is 0.5 to A composition for a transparent dielectric layer, comprising 40 to 90% by weight of 30 μm glass powder, is disclosed. It is described that a high-quality transparent dielectric layer having a constant thickness can be formed by using the composition for transparent dielectric layer. Moreover, since it is hard to fuse | melt when the average particle diameter of glass powder is 30 micrometers or more, it is described that it becomes a dirty skin after baking.

  However, even when glass powder having an average particle size of 0.5 to 30 μm is used, there is a case where the skin is generated on the dielectric layer.

  Patent Document 6 discloses a dielectric layer forming transfer film in which a film forming material layer made of a glass paste composition is formed on a support film, and the viscosity of the glass paste composition is 1000 to 30000 cp (1 to 30 Pa). -It is described that it is s).

However, even when a glass paste composition having a viscosity of 1000 to 30000 cp is used, there is a case where the skin is generated on the dielectric layer.
JP-A-9-102273 Japanese Patent Laid-Open No. 11-35780 Japanese Patent Laid-Open No. 2001-185024 International Publication No. 00/42622 Pamphlet Japanese Patent Laid-Open No. 10-182919 JP 2001-236888 A

  The present invention solves such a problem of the prior art, and includes an inorganic powder-containing resin composition for forming a dielectric layer or the like that does not cause uneven brightness due to uneven defects (skin skin). The purpose is to provide. It is another object of the present invention to provide a transfer sheet having a film forming material layer made of the composition, a method for producing a dielectric layer forming substrate, and a dielectric layer forming substrate.

  As a result of intensive studies to solve the above problems, the present inventors have found that the above object can be achieved by the following inorganic powder-containing resin composition, and have completed the present invention.

  That is, the present invention provides an inorganic powder-containing resin composition containing an inorganic powder and a binder, wherein the inorganic powder has a viscosity at a sintering temperature in the range of 2 to 100 Pa · s. The present invention relates to an inorganic powder-containing resin composition.

  The present inventors specify the composition of the inorganic powder, which has been determined from the electrical characteristics such as dielectric characteristics and the optical characteristics, by the viscosity related to the moldability when the inorganic powder is melted, and thereby the surface of the dielectric layer. It has been found that it is possible to effectively suppress the skin. When the inorganic powder having a viscosity at the sintering temperature in the range of 2 to 100 Pa · s is used, the melted inorganic powder has high fluidity, so that the generated bubbles are uneven when the bubbles are broken. It has been found that a dielectric layer that is less prone to defects and thereby has excellent surface smoothness can be obtained.

  When the viscosity at the sintering temperature of the inorganic powder is less than 2 Pa · s, the fluidity becomes too high and it becomes difficult to obtain a dielectric layer having a predetermined thickness. On the other hand, when the viscosity exceeds 100 Pa · s, the fluidity of the molten inorganic powder becomes poor, and the irregular defects generated when the bubbles break are difficult to disappear. As a result, it becomes easy to generate a crushed skin in the dielectric layer. The viscosity is preferably 2.5 to 65 Pa · s, more preferably 3 to 55 Pa · s.

  Although sintering temperature is suitably adjusted with the kind of inorganic powder to be used, it is generally about 400-850 degreeC. In the temperature range, crystallization of the inorganic powder, scattering of metal components in the inorganic powder, and decrease in transparency may occur in rare cases. Therefore, the sintering temperature is set to 550 to avoid these phenomena. It is preferably within the range of 630 ° C, more preferably within the range of 560 to 630 ° C.

  The inorganic powder-containing resin composition is particularly suitably used as a dielectric layer forming material.

  In the present invention, the inorganic powder is preferably a glass powder, and the binder is preferably a (meth) acrylic polymer.

  The transfer sheet of the present invention is formed by coating the inorganic powder-containing resin composition on a support film and drying to form a film-forming material layer. The transfer sheet is preferably provided with a protective film on the film forming material layer. By providing the protective film, it is possible to prevent foreign matters from adhering to the surface of the film forming material layer until the film forming material layer is transferred onto the substrate.

  In addition, the present invention provides a transfer step of transferring the film forming material layer of the transfer sheet to a substrate, and sintering to form a dielectric layer on the substrate by sintering inorganic powder in the transferred film forming material layer The present invention relates to a method for manufacturing a dielectric layer forming substrate including steps, and a dielectric layer forming substrate manufactured by the method.

  In the said manufacturing method, it is preferable that the sintering temperature at the time of sintering inorganic powder is in the range of 550-630 degreeC, More preferably, it exists in the range of 560-630 degreeC.

  Hereinafter, the present invention will be described in detail.

  The inorganic powder-containing resin composition of the present invention contains at least an inorganic powder and a binder.

  As the inorganic powder, those having a viscosity within the range of 2 to 100 Pa · s at the sintering temperature can be used without particular limitation. Specifically, lead oxide, silicon oxide, titanium oxide, aluminum oxide, calcium oxide , Boron oxide, zinc oxide, glass powder and the like. The average particle size of the inorganic powder is preferably 0.1 to 10 μm from the viewpoint of meltability.

In the present invention, glass powder is preferably used as the inorganic powder. Known glass powders can be used without any particular limitation. For example, 1) a mixture of lead oxide, boron oxide and silicon oxide (PbO—B ₂ O ₃ —SiO ₂ system), 2) lead oxide, zinc oxide , Boron oxide, silicon oxide (PbO—ZnO—B ₂ O ₃ —SiO ₂ system), 3) lead oxide, boron oxide, silicon oxide, aluminum oxide (PbO—B ₂ O ₃ —SiO ₂ —Al ₂ O) ₃ ) mixture, 4) lead oxide, barium oxide, boron oxide, silicon oxide (PbO-BaO-B ₂ O ₃ -SiO ₂ system) mixture, 5) lead oxide, zinc oxide, boron oxide, barium oxide, A mixture of silicon oxide (PbO—ZnO—B ₂ O ₃ —BaO—SiO ₂ system) and the like can be given. In consideration of forming the dielectric layer by a sintering process, it is preferable to use glass powder having a softening point of 430 ° C. or higher.

  The binder is added to make the inorganic powder into a paste, and a known polymer can be used without any particular limitation, but it is particularly preferable to use a (meth) acrylic polymer. The (meth) acrylic polymer can be suitably used as a binder because the amount of decomposition products generated during sintering is smaller than that of other polymers.

  The (meth) acrylic polymer is a polymer of one kind of acrylic monomer or methacrylic monomer, a copolymer of the monomer, or a mixture thereof. Specific examples of the monomer include methyl (meth) acrylate, ethyl (meth) acrylate, propyl (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, ethylhexyl (meth) acrylate, nonyl (meth) acrylate, decyl (meth) acrylate, isodecyl (meth) Alkyl (meth) such as acrylate, undecyl (meth) acrylate, dodecyl (meth) acrylate, lauryl (meth) acrylate, stearyl (meth) acrylate, isostearyl (meth) acrylate Acrylate, phenyl (meth) acrylate, aryl (meth) acrylates such as tolyl (meth) acrylate. Moreover, you may use the (meth) acrylic-type monomer which has polar groups, such as a hydroxyl group and a carboxyl group. Specific examples of the (meth) acrylic monomer having the polar group include (meth) acrylic acid, itaconic acid, (meth) acrylamide, N-methylol (meth) acrylamide, 2-hydroxyethyl (meth) acrylate, 2- Hydroxypropyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate, 3-hydroxybutyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, polyethylene glycol mono (meth) acrylate 2- (meth) acryloyloxyethyl succinic acid, 2- (meth) acryloyloxyethyl phthalic acid, iminol (meth) acrylate and the like. However, when a polar group such as a hydroxyl group or a carboxyl group is introduced into the polymer, the dispersibility of the inorganic powder becomes poor, or it becomes difficult to be decomposed and removed during the sintering process due to the interaction with the surface of the inorganic powder. The optical properties (such as transmittance) of the dielectric layer are degraded. Therefore, the introduction of the polar group-containing monomer is preferably as small as possible, and specifically, it is preferably 5% by weight or less based on the total monomers.

  The weight average molecular weight of the (meth) acrylic polymer can be appropriately adjusted depending on the monomer used, the copolymer composition ratio, and the like. The weight average molecular weight of the (meth) acrylic polymer is preferably 5 to 500,000, more preferably 7 to 350,000. When the weight average molecular weight is less than 50,000, it tends to be a low-strength film-forming material layer with poor cohesive force, whereas when the weight average molecular weight exceeds 500,000, the viscosity becomes too high and the inorganic powder When the inorganic powder-containing resin composition is applied onto a support film, uneven coating or unevenness tends to occur.

  The addition amount of the binder is preferably 5 to 50 parts by weight, more preferably 10 to 30 parts by weight with respect to 100 parts by weight of the inorganic powder. When the added amount of the binder is less than 5 parts by weight, the film forming material layer cannot be provided with sufficient flexibility or the dispersibility of the inorganic powder tends to deteriorate. On the other hand, when the added amount of the binder exceeds 50 parts by weight, the resin component becomes too much, the viscosity of the composition becomes high, and an appropriate dispersion operation tends to be impossible.

  When preparing a transfer sheet on which a film-forming material layer is formed by applying an inorganic powder-containing resin composition on a support film, a solvent is added to the composition so that it can be uniformly applied on the support film. Is preferred.

  The solvent is not particularly limited as long as it has good affinity with the inorganic powder and the binder has good solubility. For example, terpineol, butyl carbitol acetate, butyl carbitol, isopropyl alcohol, benzyl alcohol, turpentine oil, diethyl ketone, methyl butyl ketone, dipropyl ketone, cyclohexanone, n-pentanol, 4-methyl-2-pentanol, Cyclohexanol, diacetone alcohol, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monobutyl ether, propylene glycol monomethyl ether, Propylene glycol monoethyl ether, n-butyl acetate, amyl acetate, methyl cellosolve acetate, ethyl acetate Lucero cellosolve acetate, propylene glycol monomethyl ether acetate, ethyl-3-ethoxy propionate. These may be used alone or in combination of two or more at any ratio.

  The amount of the solvent added is not particularly limited, but is preferably 10 to 50 parts by weight with respect to 100 parts by weight of the inorganic powder.

  Moreover, you may add a plasticizer to the inorganic powder containing resin composition of this invention. By adding a plasticizer, the viscosity of the composition can be easily adjusted. Thereby, the softness | flexibility of the transfer sheet which apply | coated the inorganic powder containing resin composition on the support film, and formed the film forming material layer, the transferability to the board | substrate of a film forming material layer, etc. can be adjusted.

  As the plasticizer, known ones can be used without particular limitation. For example, adipic acid derivatives such as diisononyl adipate, di-2-ethylhexyl adipate, dibutyl diglycol azate, azelaic acid derivatives such as di-2-ethylhexyl azelate, and sebacic acid such as di-2-ethylhexyl sebacate Derivatives, trimellitic acid derivatives such as tri (2-ethylhexyl) trimellitate, triisononyl trimellitate, triisodecyl trimellitate, pyromellitic acid derivatives such as tetra- (2-ethylhexyl) pyromellitate, propylene glycol monooleate, etc. Oleic acid derivatives, and glycol plasticizers such as polyethylene glycol and polypropylene glycol.

  The addition amount of the plasticizer is preferably 20 parts by weight or less, more preferably 10 parts by weight or less with respect to 100 parts by weight of the inorganic powder. When the addition amount of the plasticizer exceeds 20 parts by weight, the cohesive force (strength) of the obtained film forming material layer is lowered, which is not preferable.

  In addition to the above components, various additives such as a dispersant, a silane coupling agent, a tackifier, a leveling agent, a stabilizer, and an antifoaming agent may be added to the inorganic powder-containing resin composition.

  The inorganic powder-containing resin composition of the present invention preferably has a viscosity measured according to JIS K7117 using a B-type rotational viscometer of 3 to 25 Pa · s. By using the inorganic powder-containing resin composition, when the inorganic powder-containing resin composition is coated on a support film, it is possible to effectively suppress the occurrence of coating unevenness and unevenness, and thereby a film having high surface smoothness. Forming material layers and dielectric layers can be formed. A PDP using the dielectric layer is less likely to cause defects such as missing pixels and blurring.

  When the viscosity of the inorganic powder-containing resin composition is less than 3 Pa · s, entrainment of bubbles during application and movement of adhered foreign substances on the application surface are likely to occur. As a result, coating unevenness and irregularities are likely to occur in the film forming material layer, and there is a possibility that defects occur in the dielectric layer. On the other hand, when the viscosity exceeds 25 Pa · s, living streaks, thickness unevenness, voids, cracks, and the like during application tend to occur. As a result, coating unevenness and irregularities are likely to occur in the film forming material layer, and there is a possibility that defects occur in the dielectric layer. The viscosity of the inorganic powder-containing resin composition is more preferably 7 to 25 Pa · s, and particularly preferably 8 to 15 Pa · s.

  The transfer sheet of the present invention is composed of a support film and at least a film forming material layer formed on the support film. In order to collectively transfer the film forming material layer formed on the support film to the substrate surface It is used for.

  The transfer sheet is produced by applying the inorganic powder-containing resin composition onto a support film and drying and removing the solvent to form a film-forming material layer.

  The support film constituting the transfer film is preferably a resin film having heat resistance and solvent resistance and flexibility. Since the support film has flexibility, the paste-like inorganic powder-containing resin composition can be applied by a roll coater or the like, and the film-forming material layer is stored and supplied in a state of being wound into a roll. be able to.

  Examples of the resin that forms the support film include polyethylene terephthalate, polyester, polyethylene, polypropylene, polystyrene, polyimide, polyvinyl alcohol, polyvinyl chloride, polyfluoroethylene, and other fluorine-containing resins, nylon, and cellulose.

  The thickness of the support film is not particularly limited, but is preferably about 25 to 100 μm.

  In addition, it is preferable that the mold release process is performed to the surface of the support film. Thereby, the peeling operation of the support film can be easily performed in the step of transferring the film forming material layer onto the substrate.

  Examples of the method of applying the inorganic powder-containing resin composition on the support film include roll coaters such as gravure, kiss, and comma, die coaters such as slots and phantoms, squeeze coaters, and curtain coaters. However, any method may be used as long as a uniform coating film can be formed on the support film.

  As drying conditions of the apply | coated inorganic powder containing resin composition, it is about 3 to 10 minutes at 100-150 degreeC, for example.

  The thickness of the film forming material layer varies depending on the content of the inorganic powder, the type and size of the panel, etc., but is preferably 10 to 200 μm, more preferably 30 to 100 μm. When this thickness is less than 10 μm, the thickness of the finally formed dielectric layer tends to be insufficient, and desired dielectric characteristics tend not to be ensured. Usually, when the thickness is 30 to 100 μm, a sufficient thickness of the dielectric layer required for a large panel can be secured.

  Also, the thickness of the normal film forming material layer is about 1.5 to 2 times the thickness of the dielectric layer to be formed, taking into account the amount of reduction in film thickness accompanying decomposition and removal of organic substances in the firing step. It is necessary to. For example, in order to set the thickness of the dielectric layer to 20 to 40 μm, it is necessary to form a film forming material layer having a thickness of about 40 to 80 μm. Variations in the film thickness of the film forming material layer cause variations in the thickness of the dielectric layer and variations in dielectric characteristics, resulting in display defects (luminance unevenness) in the PDP. In order to obtain a high-definition display image, the film thickness tolerance of the dielectric layer after firing needs to be within ± 5%. For example, when the thickness of the dielectric layer is 30 μm, the film thickness tolerance needs to be within ± 1.5 μm. When the thickness of the film forming material layer is 70 μm, the film thickness tolerance is ± 3. Must be within 5 μm. In order to perform thickness control with a film thickness tolerance of ± 3.5 μm, it is necessary to use a measuring apparatus for measuring error within ± 0.1 to 0.2 μm.

  Conventionally, as a method of measuring the thickness (thickness tolerance) of the film forming material layer, 1) a method of manually measuring using a dial gauge, 2) a method of measuring using an infrared thickness gauge, 3) Measurement method using laser light 4) β-ray thickness meter and γ-rays that measure the thickness of materials using absorption and scattering of β-rays and γ-rays generated from radioisotopes A method of measuring using a thickness meter and 5) a method of measuring using a surface roughness meter are employed. However, these measurement methods are not practical because of a large measurement error, a safety problem for the human body, or a contact method.

  On the other hand, the X-ray thickness measurement method is a non-contact method and can be continuously measured. The measurement error is as high as ± 0.1 μm and has no adverse effect on the human body. The measurement method will be described below.

First, the principle of the X-ray thickness measurement method will be described. When the X-rays radiated from the X-ray tube (incident signal intensity: I ₀ ) pass through the measurement substance, they are attenuated according to the thickness T of the measurement substance (transmission signal intensity: I). The transmitted X-ray is measured with an X-ray detector (ionization chamber), and the unit area weight and thickness of the measurement substance are obtained from this attenuation. In this case, the following relational expression holds. However, A in a formula is an absorption coefficient peculiar to a substance.

I = I ₀ · EXP (-A · T)
Although the substance whose thickness is to be measured is only the paste layer containing inorganic powder, the thickness of the support film is also measured at the same time on the measurement principle. Usually, the attenuation rate (absorption coefficient) of the inorganic powder (for example, PbO, B ₂ O ₃ , ZnO, BaO, SiO _2, etc.) contained in the inorganic powder-containing paste layer is the organic substance constituting the support film. It is about 10 times the attenuation rate (absorption coefficient). Therefore, in the case of the X-ray thickness measurement method, the variation in the thickness of the support film is detected only with a sensitivity of about 1/10 of the thickness of the paste layer containing inorganic powder. Within the measurement error range.

  Next, an X-ray thickness measurement method will be described. The direct value obtained by the X-ray thickness measurement method is the amount of attenuation of transmitted X-rays, and is converted from the amount of attenuation of transmitted X-rays to the unit area weight and thickness of the measurement substance. The transmitted X-ray attenuation elements are the inorganic powder and organic substance in the inorganic powder-containing paste layer, and the support film. For this reason, a calibration curve is required. Specifically, using the same inorganic powder-containing resin composition on the same support film, an inorganic powder-containing paste layer close to the thickness of the target inorganic powder-containing paste layer is produced. A calibration curve is created from the produced laminated sheet using another highly accurate measurement method (for example, a surface roughness meter measurement method).

  Next, a method for controlling the thickness of the inorganic powder-containing paste layer using the X-ray thickness measurement method will be described. The thickness of the inorganic powder-containing paste layer determined by the X-ray thickness meter is reflected in the coating amount at the coating unit through the coating amount control unit. By adopting this thickness control method, the film thickness variation of the inorganic powder-containing paste layer can be extremely reduced. As a result, variation in film thickness of the film forming material layer, variation in thickness of the dielectric layer, and variation in dielectric characteristics can be suppressed, so that display defects (luminance unevenness) in the PDP can be effectively prevented. Can do.

  The transfer sheet of the present invention may have a protective film on the surface of the film forming material layer. Examples of the material for forming the protective film include resin films such as polyethylene terephthalate, polyester, polyethylene, and polypropylene. The transfer sheet covered with the protective film can be stored and supplied in a state of being wound into a strip shape or a roll shape.

  The dielectric layer forming substrate manufacturing method of the present invention includes a transfer step of transferring the film forming material layer of the transfer sheet to the substrate, and sintering the transferred film forming material layer to form a dielectric layer on the substrate. Including a firing step.

  Examples of the substrate include ceramic and metal substrates, and in particular, when a PDP is manufactured, a glass substrate on which appropriate electrodes are fixed is used.

  An example of the transfer process will be described below. However, the method is not particularly limited as long as the film forming material layer is transferred onto the substrate surface and brought into close contact with the substrate surface.

  After peeling off the protective film of the transfer sheet to be used as appropriate, the transfer sheet is overlaid on the surface of the glass substrate on which the electrode is fixed so that the surface of the film forming material layer is in contact, and this transfer sheet is heated roll type laminator Then, the support film is peeled off from the film forming material layer. As a result, the film forming material layer is transferred and adhered to the surface of the glass substrate.

  The transfer conditions are, for example, a laminator surface temperature of 25 to 100 ° C., a roll linear pressure of 0.5 to 15 kg / cm, and a moving speed of 0.1 to 5 m / min, but are not limited to these conditions. Moreover, the glass substrate may be preheated, and in that case, the preheating temperature is about 50 to 100 ° C.

  An example of the film forming material layer firing step is shown below, but the method is not particularly limited as long as the inorganic powder in the film forming material layer is sintered to form a dielectric layer on the substrate. For example, by placing the glass substrate on which the film forming material layer is formed in a high temperature atmosphere at 550 to 630 ° C., organic substances (binder, residual solvent, various additives, etc.) in the film forming material layer are The inorganic powder (glass powder) is softened and melted and sintered after being decomposed and removed. The sintering time is not particularly limited, but is preferably 15 to 90 minutes. If it is less than 15 minutes, the inorganic powder in the film-forming material layer may not be sufficiently melted. If it exceeds 90 minutes, the metal component in the inorganic powder may evaporate or crystallize. This is not preferable.

  By the firing step, a dielectric layer made of an inorganic sintered body (glass sintered body) is formed on the glass substrate, and a dielectric layer forming substrate is manufactured.

  The thickness of the dielectric layer varies depending on the thickness of the film forming material layer to be used, but is about 15 to 50 μm.

  Since the dielectric layer-formed substrate of the present invention has no irregularities (scratch skin) in the dielectric layer and has extremely high surface smoothness, luminance unevenness caused by the defect in the dielectric layer does not occur. Therefore, a PDP using the dielectric layer forming substrate has excellent optical characteristics.

  Hereinafter, the present invention will be specifically described by way of examples, but the present invention is not limited thereto.

(Measurement of weight average molecular weight)
The produced polymer was dissolved in THF at 0.1 wt%, and the weight average molecular weight was measured by polystyrene conversion using GPC (gel permeation chromatography). Detailed measurement conditions are as follows.
GPC device: manufactured by Tosoh Corporation, HLC-8220GPC
Column: Tosoh Corporation, TSKgel SuperHZM-H, H-RC, HZ-H
Flow rate: 0.6ml / min
Concentration: 0.2 wt%
Injection volume: 20 μl
Column temperature: 40 ° C
Eluent: THF

(Measurement of viscosity of inorganic powder)
The viscosity of the inorganic powder was measured using a parallel plate deformation / rotary viscometer (WRVM-313 modified, manufactured by Agne Technology Center), which is a kind of glass viscosity measuring apparatus. First, the inorganic powder was melted at 1000 ° C., and it was put into a platinum cylindrical container and cooled to prepare a cylindrical measurement sample.
The viscosity at the sintering temperature was measured using each measurement sample.

Example 1
[Preparation of methacrylic polymer]
A four-necked flask equipped with a stirring blade, thermometer, nitrogen gas inlet tube, cooler, and dropping funnel was charged with 100 parts by weight of lauryl methacrylate, 100 parts by weight of ethyl acetate, and 0.2 part by weight of benzoyl peroxide, and gently Nitrogen gas was introduced while stirring, and the polymerization temperature was kept at around 70 ° C. for about 6 hours to conduct a polymerization reaction, and methacrylic polymer A (weight average molecular weight: 300,000, glass transition temperature: −65 ° C.) Prepared.

[Preparation of inorganic powder-containing resin composition]
As inorganic powder, PbO / B ₂ O ₃ / ZnO / SiO ₂ / Al ₂ O ₃ / Ce ₂ O ₃ glass powder A (YFT094, manufactured by Asahi Glass Co., Ltd.) 100 parts by weight, methacrylic polymer A 26 parts by weight, plasticizer As an inorganic powder, 5 parts by weight of trioctyl trimellitic acid and 42.86 parts by weight of α-terpineol / carbitol (weight ratio: 9/1) as a solvent are mixed and dispersed using a three-roll disperser. Containing resin composition A was prepared.

[Production of transfer sheet]
An inorganic powder-containing resin composition A is applied onto a support film obtained by subjecting a polyethylene terephthalate (PET) film (thickness: 75 μm) to a release agent treatment using a doctor blade type film applicator, and the coating film is 150 ° C. Then, the solvent was removed by drying for 5 minutes to form a film-forming material layer (thickness: 75 μm). Thereafter, a protective sheet (PET, thickness: 25 μm) was covered on the film-forming material layer to produce a transfer sheet A, which was wound up in a roll shape.

[Production of dielectric layer-formed glass substrate]
After peeling off the protective film of the transfer sheet A, the surface of the film forming material layer of the transfer sheet A is superposed so as to contact the surface of the glass substrate for panels (fixing surface of the bus electrode), and heat is applied using a heating roll laminator. Crimped. The pressure bonding conditions were a heating roll surface temperature of 80 ° C., a roll linear pressure of 1 kg / cm, and a roll moving speed of 1 m / min. After the thermocompression treatment, when the support film was peeled and removed from the film forming material layer, the film forming material layer was transferred and adhered to the glass substrate surface.

  The glass substrate onto which the film forming material layer has been transferred is placed in a firing furnace, and the temperature in the furnace is increased from room temperature to 420 ° C. at a temperature increase rate of 6.5 ° C./min. Hold for 30 minutes. Furthermore, the dielectric is made of a glass sintered body on the surface of the glass substrate by raising the temperature from 420 to 600 ° C. at a rate of 3 ° C./min and holding and sintering in a 600 ° C. temperature atmosphere for 60 minutes. A layer was formed to produce a dielectric layer-formed glass substrate. The dielectric layer had a thickness of about 30 μm.

Example 2
[Production of dielectric layer-formed glass substrate]
In Example 1, the temperature was increased from 420 to 630 ° C. at a rate of 3.5 ° C./min, and held in a temperature atmosphere of 630 ° C. for 60 minutes, followed by sintering in the same manner as in Example 1. A dielectric layer-formed glass substrate was produced. The dielectric layer had a thickness of about 30 μm.

Example 3
[Preparation of inorganic powder-containing resin composition]
In Example 1, an inorganic powder-containing resin composition was used in the same manner as in Example 1 except that 100 parts by weight of PbO / B ₂ O ₃ glass powder B (ASF1330, manufactured by Asahi Glass Co., Ltd.) was used as the inorganic powder. B was prepared.

[Production of transfer sheet]
In Example 1, except that the inorganic powder-containing resin composition B was used instead of the inorganic powder-containing resin composition A, a transfer sheet B was prepared in the same manner as in Example 1, and wound into a roll. .

[Production of dielectric layer-formed glass substrate]
In Example 1, a dielectric layer-formed glass substrate was produced in the same manner as in Example 1 except that transfer sheet B was used instead of transfer sheet A. The dielectric layer had a thickness of about 30 μm.

Example 4
[Production of dielectric layer-formed glass substrate]
In Example 3, the temperature was increased from 420 to 560 ° C. at a rate of 3.5 ° C./min, and the sample was held and sintered in a temperature atmosphere at 560 ° C. for 60 minutes in the same manner as in Example 3. A dielectric layer-formed glass substrate was produced. The dielectric layer had a thickness of about 30 μm.

Comparative Example 1
[Preparation of inorganic powder-containing resin composition]
In Example 1, inorganic powder was used in the same manner as in Example 1 except that 100 parts by weight of glass powder C of PbO / B ₂ O ₃ / SiO ₂ (ASF1340, manufactured by Asahi Glass Co., Ltd.) was used as the inorganic powder. Containing resin composition C was prepared.

[Production of transfer sheet]
In Example 1, except that the inorganic powder-containing resin composition C was used instead of the inorganic powder-containing resin composition A, a transfer sheet C was prepared in the same manner as in Example 1, and wound into a roll. .

[Production of dielectric layer-formed glass substrate]
In Example 1, a dielectric layer-formed glass substrate was produced in the same manner as in Example 1 except that the transfer sheet C was used instead of the transfer sheet A. The dielectric layer had a thickness of about 30 μm.

Comparative Example 2
[Preparation of inorganic powder-containing resin composition]
In Example 1, inorganic powder was used in the same manner as in Example 1 except that 100 parts by weight of PbO / B ₂ O ₃ / SiO ₂ glass powder D (ASF1390, manufactured by Asahi Glass Co., Ltd.) was used as the inorganic powder. A containing resin composition D was prepared.

[Production of transfer sheet]
In Example 1, except that the inorganic powder-containing resin composition D was used instead of the inorganic powder-containing resin composition A, a transfer sheet D was prepared in the same manner as in Example 1, and wound into a roll. .

[Production of dielectric layer-formed glass substrate]
In Example 1, the transfer sheet D was used in place of the transfer sheet A, the temperature was increased from 420 to 560 ° C. at a temperature increase rate of 3.5 ° C./min, and held at a temperature atmosphere of 560 ° C. for 60 minutes for baking. A dielectric layer-formed glass substrate was produced in the same manner as in Example 1 except that it was tied. The dielectric layer had a thickness of about 30 μm.

  The following evaluation was performed about the dielectric material layer of the dielectric material layer formation glass substrate produced by the Example and the comparative example.

[Measurement of surface roughness of dielectric layer]
The maximum cross-sectional height (Rt) of the dielectric layer was measured after performing surface inclination correction using a non-contact surface roughness measuring device (manufactured by Nippon Beco Co., Ltd., WYKO) in accordance with JIS B0601.

[Surface evaluation of dielectric layer]
The surface of the dielectric layer was visually observed for the presence or absence of irregularities (skin skin) and evaluated according to the following criteria. The observation was performed by irradiating the surface of the dielectric layer (10 × 10 cm) with a fluorescent lamp and confirming the fluctuation of the reflected light at the regular reflection position.
○: Not recognized as an uneven defect (skin skin) (reflected image of fluorescent lamp is not distorted).
X: Recognized as an uneven defect (skin skin) (reflected image of fluorescent lamp is greatly distorted).

表１の結果から明らかなように、焼結温度における粘度が２〜１００Ｐａ・ｓの範囲内にある無機粉体を含有する無機粉体樹脂組成物を用いることより、凹凸欠陥（ユズ肌）のない表面平滑性の高い誘電体層が得られる。該誘電体層を用いたＰＤＰは、輝度ムラが生じにくい。

As is apparent from the results in Table 1, by using an inorganic powder resin composition containing an inorganic powder having a viscosity at a sintering temperature in the range of 2 to 100 Pa · s, unevenness defects (skin skin) A dielectric layer with high surface smoothness is obtained. The PDP using the dielectric layer is less likely to cause luminance unevenness.

Claims (10)

An inorganic powder-containing resin composition comprising an inorganic powder and a binder, wherein the inorganic powder has a viscosity at a sintering temperature in the range of 2 to 100 Pa · s. Stuff. The inorganic powder-containing resin composition according to claim 1, wherein the sintering temperature is within a range of 550 to 630 ° C. The inorganic powder-containing resin composition according to claim 1 or 2, which is used as a material for forming a dielectric layer. The inorganic powder-containing resin composition according to any one of claims 1 to 3, wherein the inorganic powder is a glass powder. The inorganic powder-containing resin composition according to any one of claims 1 to 4, wherein the binder is a (meth) acrylic polymer. A transfer sheet formed by coating the inorganic powder-containing resin composition according to claim 1 on a support film and drying to form a film-forming material layer. The transfer sheet according to claim 6, wherein a protective film is provided on the film forming material layer. A transfer step for transferring the film forming material layer of the transfer sheet according to claim 6 or 7 to the substrate, and firing for sintering the inorganic powder in the transferred film forming material layer to form a dielectric layer on the substrate A method for manufacturing a dielectric layer-formed substrate including the steps. The method for producing a dielectric layer-formed substrate according to claim 8, wherein a sintering temperature when sintering the inorganic powder is within a range of 550 to 630 ° C. A dielectric layer forming substrate produced by the method according to claim 8 or 9.