JP5876994B2 - Manufacturing method of glass substrate for flat panel display - Google Patents

Description

  The present invention relates to a glass substrate used for a flat panel display such as a liquid crystal display device, an organic EL display device, and a plasma display, and a method for producing the glass substrate.

  If scratches such as pits are present on a glass substrate for flat panel displays such as liquid crystal display devices, organic EL display devices, and plasma displays, the quality of the display image on the flat panel display is degraded. It is necessary to take measures. Here, as an example of the glass substrate for flat panel displays, a laminated glass, a cover glass, a glass for a touch panel, and the like can be given.

  If scratches such as pits are present on the surface of the glass substrate, the surface of the glass substrate will vary in light refraction, resulting in distortion of the image displayed on the flat panel display. If there is a visible scratch on the surface of the glass substrate, the distortion of the image displayed by the display device is also visible, resulting in a reduction in the quality of the display image. Even if the scratches on the surface of the glass substrate are not large enough to be visually recognized, if small scratches are adjacent to each other, the distortion of the displayed image is large enough to be visually recognized.

  However, if chemical polishing is performed again in order to suppress scratches on the surface of the glass substrate, the thickness will be reduced again by polishing, so that the uniformity of the thickness of each glass substrate is impaired. There is a possibility that a problem such as a problem occurs, or a problem that the scratches are enlarged due to chemical polishing may occur. In addition, when mechanical polishing is performed on the scratches on the surface of the glass substrate, there is a possibility that cracking may occur due to mechanical stress applied to the thin glass substrate.

  For this reason, conventionally, a technique of filling a scratch present on the glass substrate by injecting a transparent resin into the scratch on the surface of the glass substrate and curing the transparent resin may be employed (see, for example, Patent Documents 1 to 3). . According to these techniques, it is possible to effectively prevent a deterioration in display image quality due to scratches on the glass substrate surface by pinpointing scratches on the glass substrate surface and filling them with resin. It is said that.

JP 2006-045014 A JP 2006-201649 A JP 2007-197236 A

  However, in the techniques according to Patent Documents 1 to 3 described above, it is necessary to specify a visible scratch on the glass substrate surface in the inspection processing step, and to perform a pit repair process each time for the specified scratch. However, there is a disadvantage that it becomes complicated. In addition, it is difficult to identify a scratch on the surface of the glass substrate that is not large enough to be visually recognized, and thus it is difficult to perform a pit repair process.

  An object of the present invention is to provide a glass substrate for a flat panel display capable of preventing the scratches on the surface of the glass substrate from adversely affecting the quality of the display image regardless of the size of the scratches on the surface of the glass substrate with a simple configuration. It is providing the manufacturing method of the glass substrate.

  A glass substrate for a flat panel display according to the present invention includes a raw glass and a translucent polymer film. The raw glass has a surface roughened by etching. Examples of the arithmetic average roughness Ra of the roughened surface include 0.7 nm to 70 nm. The translucent polymer film is applied to the roughened surface of the raw glass. This translucent polymer film is thickly coated so as to fill in pits that may exist on the surface of the raw glass. The translucent polymer film has a thickness of, for example, 0.5 μm or more. Moreover, it is preferable that this translucent polymer film is the range (example: 1.4-1.6) in which the refractive index approximates a bare glass.

  In the above-described configuration, since the arithmetic average roughness Ra of the surface of the raw glass is roughened by etching, reliable adhesion between the raw glass and the translucent polymer film can be achieved. At this time, the arithmetic average roughness Ra of the surface of the raw glass is preferably set to 0.7 nm to 70 nm. The reason is that if Ra <0.7 nm and the glass surface is too flat, the adhesion between the polymer and the glass deteriorates, and in the adhesion test, it is easily peeled off with ethanol or the like. On the other hand, if Ra> 70 nm and the glass surface is too rough, it may be difficult to maintain clear display characteristics as a flat panel display.

  In general, as the film thickness of the light-transmitting polymer film increases, the HAZE rate increases and the transparency decreases. Therefore, the film thickness of the light-transmitting polymer film is set to a thickness of about 0.1 μm to 0.3 μm. Often done. However, in this invention, the pit suppression effect by the translucent polymer film is remarkably improved by using a translucent polymer film having a thickness of 0.5 μm or more. As a result, the glass substrate surface can be flattened with a simple configuration.

  As the material for the light-transmitting polymer film, it is preferable to use a polymer that hardly causes a decrease in the total light transmittance or an increase in the HAZE ratio even when the film thickness is increased. For example, it is preferable that the total light transmittance is 91.85% or more when the thickness of the glass substrate is 0.5 mm. Moreover, it is preferable that a HAZE rate is 4.88% or less in a plate | board thickness of 0.5 mm as a glass substrate. Here, the HAZE rate means diffuse transmittance / total light transmittance × 100, and is a value specified based on JIS K7136. Examples of such a material for the translucent polymer film include, but are not limited to, materials obtained from the pit-suppressing polymer coating described in paragraphs 0019 to 0032.

  According to the present invention, it is possible to prevent the scratch on the glass substrate surface from adversely affecting the quality of the display image regardless of the size of the scratch on the glass substrate surface with a simple configuration.

FIG. 1A and FIG. 1B are diagrams showing an outline of a glass substrate according to an embodiment of the present invention. FIG. 2 is a flowchart illustrating an example of a method for manufacturing a glass substrate. FIG. 3A to FIG. 3C are views showing the formation state of the translucent resin layer. 4A and 4B are diagrams illustrating an example of a structure in which a layer is further provided over the light-transmitting resin layer. 5A and 5B are graphs showing the relationship between the film thickness, the transmittance, and the HAZE rate. FIGS. 6A and 6B are tables showing the relationship between the film thickness, the transmittance, and the HAZE rate.

  1A and 1B show a schematic configuration of a glass substrate 100 according to an embodiment of the present invention. The glass substrate 100 has a base glass 10 and a translucent polymer film 12 applied to the surface of the base glass 10. An example of the raw material of the raw glass 10 is alkali-free glass. Here, a plate-like element glass 10 made of 100 mm × 100 mm × 0.5 mm aluminosilicate glass is used. Single or multiple pits 102 may exist on the surface of the raw glass 10. The translucent polymer film 12 serves to prevent the pits 102 from adversely affecting the quality of the display image of the flat panel display in which the glass substrate 100 is used.

  Then, an example of the manufacturing method of a glass substrate is demonstrated using FIG. When the translucent polymer film 12 is applied to the raw glass 10, a surface roughening treatment is first performed on the surface of the raw glass 10 (S1). In the roughening treatment step of S1, an etching solution comprising 0.5 to 3% by weight hydrofluoric acid, 0 to 10% by weight hydrochloric acid, 0 to 5% by weight sulfuric acid and the remaining water is used. Etching is performed for about 2 minutes. The base glass 10 is immersed in an etching solution after being washed with water. Then, in the roughening treatment step of S1, the surface of the raw glass 10 is etched by about 5 μm (single side: 2.5 μm). As a result, the arithmetic average roughness Ra of the surface of the raw glass 10 is roughened from about 0.3 nm to 0.7 nm to 70 nm.

  Subsequently, the process proceeds to a cleaning process for cleaning the etched glass 10 (S2). In the cleaning process step of S2, each etched glass 10 is washed with water, then immersed in IPA (isopropyl alcohol) to perform a replacement process, and further dried by a drier.

  Then, it transfers to the film-forming process process which apply | coats the translucent polymer film 12 on the surface of the raw glass 10 (S3). Here, the resin component, the silane coupling agent, the solvent, and the additive of the polymer coating for pit suppression used for the translucent polymer film 12 are as follows.

[Resin component]
The resin component of the pit-suppressing polymer coating is required to improve the environmental durability and scratch resistance of the translucent polymer film 12 and improve the adhesion to the base glass 10. By doing so, the pencil hardness (JIS K 5400) of the translucent polymer film 12 formed from the pit-suppressing polymer coating can be easily set to HB or higher. That is, the function as the hard coat component is easily exhibited.

  The resin component of the pit suppressing polymer may be a thermosetting resin or a thermoplastic resin. For example, polyesters such as polyethylene terephthalate, polybutylene terephthalate and polyethylene naphthalate; polyimides such as polyimide and polyamideimide; polyamides such as polyamide 6, polyamide 6,6, polyamide 12, and polyamide 11; polyvinylidene fluoride, polyvinyl fluoride, poly Fluorine resins such as tetrafluoroethylene, ethylenetetrafluoroethylene copolymer, polychlorotrifluoroethylene; vinyl resins such as polyvinyl alcohol, polyvinyl ether, polyvinyl butyral, polyvinyl acetate, and polyvinyl chloride; epoxy resins; oxetane resins; aziridine resins: Oxazoline resin: Xylene resin; Aramid resin; Polyimide silicone; Polyurethane; Polyurea; Melamine resin; Ethers, acrylic resins and such copolymers thereof.

  These resin components may be dissolved in an organic solvent, may be provided with a functional group such as a sulfo group or a carboxy group, may be made into an aqueous solution, or may be dispersed in water such as emulsification. Further, if necessary, a curing agent such as a crosslinking agent and a polymerization initiator, a polymerization accelerator, a solvent, a viscosity modifier and the like can be added and used.

  Among the above-described resins, one or more of polyurethane, polyester, acrylic resin, polyamide, polyimide, epoxy resin, oxetane resin, aziridine resin, melamine resin, and polyimide silicone are preferable in terms of transparency, water resistance, and hardness. . Acrylic resins are suitable for applications such as glass substrates because of their high hardness and excellent transparency.

  Moreover, it is preferable that a resin component contains the liquid polymer hardened | cured with a thermal energy and / or light energy. Here, examples of the liquid polymer that is cured by thermal energy include a reactive polymer and a self-crosslinking polymer.

  The reactive polymer is a polymer in which a monomer having a substituent is polymerized, and examples of the substituent include a hydroxy group, a carboxy group, an acid anhydride, an oxetane group, a glycidyl group, and an amino group. Specific monomers include polyfunctional alcohols such as ethylene glycol, diethylene glycol, dipropylene glycol, and glycerin, malonic acid, succinic acid, glutamic acid, pimelic acid, ascorbic acid, phthalic acid, acetylsalicylic acid, adipic acid, and isophthalic acid. Acid anhydrides such as acid, benzoic acid, carboxylic acid compounds such as m-toluic acid, maleic anhydride, phthalic anhydride, dodecyl succinic anhydride, dichloromaleic anhydride, tetrachlorophthalic anhydride, tetrahydrophthalic anhydride, pimelic anhydride , Oxetane compounds such as 3,3-dimethyloxetane, 3,3-dichloromethyloxetane, 3-methyl-3-hydroxymethyloxetane, azidomethylmethyloxetane, bisphenol A diglycidyl ether, bisphenol F diglycidyl Ether, phenol novolac polyglycidyl ether, N, N-diglycidyl-p-aminophenol glycidyl ether, tetrabromobisphenol A diglycidyl ether, hydrogenated bisphenol A diglycidyl ether (ie 2,2-bis (4-glycidyloxycyclohexyl) ) Propane), neopentyl glycol diglycidyl ether, 1,6-hexanediol diglycidyl ether, trimethylolpropane polyglycidyl ether, hexahydrophthalic acid diglycidyl ester, propylene glycol diglycidyl ether, tripropylene glycol diglycidyl ether, polypropylene Glycol diglycidyl ether, fatty acid-modified epoxy, diethylene glycol diglycidyl ether, polyethylene Glycidyl ether compounds such as recall diglycidyl ether, glycerin polyglycidyl ether, diglycerin polyglycidyl ether, polyglycerin polyglycidyl ether, sorbitol polyglycidyl ether, ethylene oxide lauryl alcohol glycidyl ether, ethylene oxide phenol glycidyl ether, adipic acid glycidyl ether, N , N-diglycidylaniline, tetraglycidyldiaminodiphenylmethane, N, N, N, N-tetraglycidyl-m-xylylenediamine, triglycidyl isocyanurate, N, N-diglycidyl-5,5-dialkylhydantoin, etc. Compound, diethylenetriamine, triethylenetetramine, dimethylaminopropylamine, N-aminoethyl Lupiperazine, benzyldimethylamine, tris (dimethylaminomethyl) phenol, DHP30-tri (2-ethylhexoate), metaphenylenediamine, diaminodiphenylmethane, diaminodiphenylsulfone, dicyandiamide, boron trifluoride, monoethylamine, methanediamine, Among the amine compounds such as xylenediamine and ethylmethylimidazole, among the compounds containing two or more oxirane rings in one molecule, glycidyl compounds by epichlorohydrin of bisphenol A, or the like can be mentioned.

In the reactive polymer, a crosslinking agent, a catalyst, a cationic polymerization initiator described later, and the like may be used in combination. As a crosslinking agent, a melamine resin, an epoxy resin, a metal oxide etc. are mentioned, for example. Examples of the metal oxide include basic metal compounds Al (OH) ₃ , Al (OOC · CH ₃ ) ₂ (OOCH), Al (OOC · CH ₃ ) ₂ , ZrO (OCH ₃ ), Mg (OOC · CH _3). ), Ca (OH) ₂ , Ba (OH) _{3 and the} like can be used as appropriate.

  Self-crosslinking polymers are those that self-crosslink between functional groups by heating, and examples include those containing a glycidyl group and a carboxy group, and those containing both an N-methylol and a carboxy group.

  Examples of the liquid polymer that is cured by light energy include oligomers or prepolymers such as polyester, epoxy resin, oxetane resin, polyacryl, polyurethane, polyimide, polyamide, polyamideimide, and polyimide silicone.

  Examples of monomer units constituting a liquid polymer that is cured by light energy include bisphenol A / ethylene oxide-modified diacrylate, dipentaerythritol hexa (penta) acrylate, dipentaerythritol monohydroxypentaacrylate, and dipropylene glycol diacrylate. Acrylate, trimethylolpropane triacrylate, glycerin propoxytriacrylate, 4-hydroxybutyl acrylate, 1,6-hexanediol diacrylate, 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate, isobornyl acrylate, polyethylene glycol diacrylate, Pentaerythritol triacrylate, tetrahydrofurfuryl acrylate, trimethylolpropane tria Relates, acrylates such as tripropylene glycol diacrylate, tetraethylene glycol dimethacrylate, alkyl methacrylate, allyl methacrylate, 1,3-butylene glycol dimethacrylate, n-butyl methacrylate, benzyl methacrylate, cyclohexyl methacrylate, diethylene glycol dimethacrylate, 2- Such as ethylhexyl methacrylate, glycidyl methacrylate, 1,6-hexanediol dimethacrylate, 2-hydroxyethyl methacrylate, isobornyl methacrylate, lauryl methacrylate, phenoxyethyl methacrylate, t-butyl methacrylate, tetrahydrofurfuryl methacrylate, trimethylolpropane trimethacrylate, etc. Methacrylates Glycidyl ethers such as allyl glycidyl ether, butyl glycidyl ether, higher alcohol glycidyl edel, 1,6-hexanediol glycidyl ether, phenyl glycidyl ether, stearyl glycidyl ether, diacetone acrylamide, N, N-dimethylacrylamide, dimethylaminopropyl acrylamide , Dimethylaminopropylmethacrylamide, methacrylamide, N-methylolacrylamide, N, N-dimethylacrylamide, acryloylmorpholine, N-vinylformamide, N-methylacrylamide, N-isopropylacrylamide, Nt-butylacrylamide, N-phenyl Acrylics such as acrylamide, acryloylpiperidine, 2-hydroxyethylacrylamide ( Methacryl) amides, 2-chloroethyl vinyl ether, cyclohexyl vinyl ether, ethyl vinyl ether, hydroxybutyl vinyl ether, isobutyl vinyl ether, vinyl ethers such as triethylene glycol vinyl ether, carboxylic acid vinyl esters such as vinyl butyrate, vinyl monochloroacetate and vinyl pivalate And monofunctional monomers as well as polyfunctional monomers.

  A liquid polymer that is cured by light energy is cured by a photopolymerization initiator. Examples of the photopolymerization initiator include acetophenones, benzophenones, Michler benzoylbenzoate, α-amyloxime ester, tetramethylthiuram monosulfide, thioxanthones and the like. Furthermore, n-butylamine, triethylamine, tri-n-butylphosphine, or the like can be mixed as a photosensitizer. Examples of the cationic polymerization initiator include aryldiazonium salts, diarylhalonium salts, triphenylsulfonium salts, silanol / aluminum chelates, α-sulfonyloxyketones, and the like.

[Silane coupling agent]
A silane coupling agent may be appropriately added from the viewpoint of improving adhesion to glass. Specific examples of the silane coupling agent include vinyltrichlorosilane, vinyltrimethoxysilane, vinyltriethoxysilane, 2- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3 -Glycidoxypropylmethyldiethoxysilane, 3-glycidoxypropyltriethoxysilane, p-styryltrimethoxysilane, 3-methacryloxypropylmethyldimethoxysilane, 3-methacryloxypropyltrimethoxysilane, 3-methacryloxypropyl Methyldiethoxysilane, 3-methacryloxypropyltriethoxysilane, 3-acryloxypropyltrimethoxysilane, N-2- (aminoethyl) -3-aminopropylmethyldimethoxysilane, N-2- (amino Til) -3-aminopropyltriethoxysilane, N-2- (aminoethyl) -3-aminopropyltrimethoxysilane, 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 3-triethoxysilyl- N- (1,3-dimethyl-butylidene) propylamine, N-phenyl-3-aminopropyltrimethoxysilane, N- (vinylbenzyl) -2-aminoethyl-3-aminopropyltrimethoxysilane hydrochloride, 3 -Ureidopropyltriethoxysilane, 3-chloropropyltrimethoxysilane, 3-mercaptopropylmethyldimethoxysilane, 3-mercaptopropyltrimethoxysilane, bis (triethoxysilylpropyl) tetrasulfide, 3-isocyanatopropyltriethoxysilane Etc., and the like. The content of the silane coupling agent is not particularly limited, and an arbitrary amount can be added as necessary.

[solvent]
The solvent for the polymer coating for pit suppression is not particularly limited. For example, water, N-methyl-2-pyrrolidone, N, N-dimethylformamide, N, N-dimethylacetamide, dimethyl sulfoxide, hexamethylene phosphortriamide, acetonitrile , Polar solvents such as benzonitrile, phenols such as cresol, phenol, xylenol, alcohols such as methanol, ethanol, propanol, butanol, ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone, methyl acetate, ethyl acetate, propyl acetate Esters such as hexane, benzene, toluene, xylene and other hydrocarbons, formic acid, acetic acid and other carboxylic acids, ethylene carbonate, propylene carbonate and other carbonate compounds, dioxane, diethyl ether Ether compounds such as ethylene glycol alkyl ether, propylene glycol alkyl ether, polyethylene glycol alkyl ether, chain ethers such as polypropylene glycol alkyl ether, heterocyclic compounds such as 3-methyl-2-oxazolidinone, acetonitrile, glutarodinitrile , Nitrile compounds such as methoxyacetonitrile, propionitrile, and benzonitrile. These solvents may be used alone, as a mixture of two or more kinds, or as a mixture with other organic solvents.

[Additive]
The light-transmitting polymer preferably has a refractive index that approximates the refractive index of the base glass 10 to be used, and particularly preferably has a refractive index in the range of 1.4 to 1.6. For this reason, in order to adjust the refractive index, the pit-suppressing polymer paint may contain inorganic oxide particles. Inorganic oxide particles include SiO ₂ , Al ₂ O ₃ , ZrO ₂ , SnO ₂ , TiO ₂ , SnO ₂ , InO ₂ , Sb ₂ O ₂ , MgO and other oxide particles and one or more of these. And composite oxide particles. The inorganic oxide particles preferably have an average particle size in the range of 1 to 300 nm, more preferably 2 to 200 nm. The refractive index is preferably in the range of 1.15 to 1.50, more preferably 1.30 to 1.45.

  Furthermore, the boiling point of the solvent is preferably 200 ° C. or less, and more preferably 180 ° C. or less, because it is necessary to dry and cure the pit-inhibiting polymer coating at a low temperature. However, the boiling point of the solvent is preferably 50 ° C. or higher, and more preferably 70 ° C. or higher, from the viewpoints of workability during coating of a slit coater, leveling properties, and prevention of brushing.

In the film forming treatment step of S3, the above-mentioned polymer coating for pit suppression is applied with the number No. The translucent polymer film 12 having a thickness of about 5 μm to 10 μm is applied using a 22 bar coater. Here, a pit-suppressing polymer coating “NCP-2”, which will be described later, is used as the translucent polymer film 12. The refractive index of the translucent polymer film 12 is measured with a high-speed spectroscopic ellipsometer M-2000U (manufactured by JA Woollam) under the conditions of a measurement wavelength of 245 nm to 1000 nm and measurement angles of 50 degrees, 60 degrees, and 70 degrees As a result, a value of 1.50 to 1.53 was shown.
Needless to say, the coating can be performed by means other than the bar coater. For example, the film forming process may be performed using a slit coater. Here, the thickness of the translucent polymer film 12 can be appropriately increased or decreased according to the expected value of the pit depth on the surface of the raw glass 10. For example, when the pits on the surface of the raw glass 10 are shallow, it is possible to fill the pits on the surface of the raw glass 10 even if the translucent polymer film 12 has a thickness of about 0.5 μm. On the other hand, when the pits on the surface of the raw glass 10 are deep, the film thickness of the translucent polymer film 12 may be increased as necessary.

  Then, it transfers to the drying process process which dries the apply | coated translucent polymer film 12 in a furnace (S4). In the drying process step of S4, the drying process is performed by placing the glass substrate 10 for about 30 minutes in a hot-air circulating furnace configured to circulate hot air at about 120 ° C.

  As shown in FIGS. 3A to 3C, the translucent polymer film 12 applied to the surface of the raw glass 10 has a pit 102 inside when the pit 102 exists on the surface of the raw glass 10. Get in. Since the translucent polymer film 12 has a sufficient thickness of 5 μm to 10 μm, the pits 102 are usually completely filled with the translucent polymer film 12 as shown in FIG. Thereafter, as shown in FIG. 3C, the surface of the translucent polymer film 12 is naturally unified by the behavior as a liquid, and the entire surface thereof is flattened.

  As described above, the pits 102 that may exist on the surface of the base glass 10 are filled with the light-transmitting polymer film 12 having a refractive index similar to that of the base glass 10, and the surface of the light-transmitting polymer film 12. The surface of the glass substrate 100 is flattened by flattening. For this reason, when the glass substrate 100 is used for a flat panel display as it is or after performing predetermined processing, the quality of the display image of the flat panel display is deteriorated due to the pits 102 on the surface of the raw glass 10. There is no.

  For example, as shown in FIG. 4A, the glass substrate 100 may be further coated with an organic conductive film 14 having a thickness of about 100 to 300 nm on the surface of the translucent polymer film 12. Examples of the material of the organic conductive film 14 include a polythiophene conductive polymer. As described above, the adhesion of the organic conductive film 14 can be improved by applying the organic conductive film 14 to the surface of the raw glass 10 via the translucent polymer film 12. In addition, as shown in FIG. 4B, the effect of the pits 102 on the display image quality of the flat panel display is remarkably compared with the case where the transparent electrode film 16 made of ITO is directly deposited on the raw glass 10. It becomes possible to decrease.

FIGS. 5A and 5B are graphs showing the relationship between the film thickness of the translucent polymer film 12, the total light transmittance, and the HAZE rate.
In the experiment, the wire No. 2, no. No. 22 and No. 65 bar coaters were used to form translucent polymer films 12 having a thickness of 0.5 μm to 60 μm with respect to the plurality of raw glasses 10. Moreover, as a polymer coating for pit suppression used for the translucent polymer film 12, 1 part by weight of 3-glycidoxypropyltrimethoxysilane, average primary particles with respect to 100 parts by weight of a polyester resin aqueous dispersion having a solid content of 10% Pit-suppressing polymer coating “NCP-1” formed by mixing 0.2 parts by weight of silica having a diameter of 15 nm and a refractive index of 1.42 and 20 parts by weight of ethanol, and 100 parts by weight of a polyester resin aqueous dispersion having a solid content of 10% On the other hand, a pit-suppressing polymer coating “NCP-2” obtained by mixing 1 part by weight of 3-glycidoxypropyltrimethoxysilane and 20 parts by weight of ethanol was used. And the total light transmittance of only the translucent polymer film | membrane 12, the total light transmittance of the whole glass substrate 100, a HAZE rate, a film thickness, etc. were measured. Here, the transmittance was measured based on JIS K 7316-1 using a spectral colorimeter SD-5000 (Nippon Denshoku Industries Co., Ltd.). The HAZE rate was measured based on JIS K 7136 using a turbidimeter NDH5000 (Nippon Denshoku Industries Co., Ltd.). Further, the arithmetic average roughness of the raw glass was measured by an AFM (Atomic Force Microscope) manufactured by Seiko Instruments Inc. Furthermore, the surface resistance was measured based on JIS K 7194 by Loresta MCP-T250 (Mitsubishi Chemical) as needed.

  6 (A) and 6 (B) show the number No. 2 are coated with a plurality of glass substrates 10 (first group), No. 2 The total light transmittance of each group (only the film) for the plurality of glass substrates 10 (second group) coated using No. 22 and the plurality of glass substrates 10 (third group) coated using a No. 65 bar coater ), The total light transmittance at the plate thickness of 0.5 mm (the whole glass substrate), the HAZE rate at the plate thickness of 0.5 mm, and the average value of the thickness (μm) of the translucent polymer film 12. In the above experiment, the raw glass 10 has a total light transmittance of 92.38%, a HAZE ratio of 0.25%, a thickness of 0.5 mm, and an arithmetic average roughness Ra of 0.8 nm. FIG. 6A shows the result related to the pit-suppressing polymer paint “NCP-1”, and FIG. 6B shows the result related to the pit-suppressing polymer paint “NCP-2”.

  As shown in FIG. 5 and FIG. 6, the pit-suppressing polymer coating “NCP-1” and the pit-suppressing polymer coating “NCP-2” are all good in the film thickness range of 0.5 to 10 μm. Results of light transmittance and HAZE rate are obtained. For this reason, even if the surface of the raw glass 10 is coated with the light-transmitting polymer film 12 to a thickness of about 10 μm, the transmittance of the glass substrate 100 is lowered to an extent that cannot be practically used, and the HAZE rate cannot be practically used. There is no inconvenience such as rising to the extent.

  Furthermore, the pit-inhibiting polymer coating “NCP-2” exhibited a remarkable effect that even when the film thickness exceeded 10 μm, a decrease in transmittance and an increase in the HAZE rate were hardly observed. For this reason, even when deep pits exist on the surface of the raw glass 10 and the translucent polymer film 12 must be thickly coated by several tens to several hundreds of μm, the transmittance of the glass substrate 100 is increased. However, it is expected that there will be no inconveniences such as a drop to the extent that it cannot withstand practical use and a rise in the HAZE rate to an extent that cannot withstand practical use.

  Moreover, the adhesion test of the translucent polymer film 12 with respect to the raw glass 10 was performed as follows. First, the plurality of base glasses 10 were washed with water and chemically polished with an etching solution. At this time, various compositions were prepared as etching solutions, and the polishing time was also changed appropriately. When the composition of the etching solution and the polishing time change, the arithmetic average roughness Ra of the etched glass 10 changes. In general, the longer the polishing time is, and the higher the hydrofluoric acid concentration is, the more the arithmetic average roughness Ra of the surface of the raw glass 10 tends to increase. Here, a peel test was performed on the dried glass substrate 100 using a cellophane tape, and the relationship with the arithmetic average roughness Ra after chemical polishing of each elementary glass 10 was verified. As a result, it was confirmed that the adhesiveness between the base glass 10 and the translucent polymer film 12 is maintained when the arithmetic average roughness Ra is about 0.7 nm to 70 nm. Specifically, as described above, using an etching solution comprising 0.5 to 3 wt% hydrofluoric acid, 0 to 10 wt% hydrochloric acid, 0 to 5 wt% sulfuric acid, and remaining water, It has been found that it is preferable to etch the surface of the raw glass 10 by about 5 μm (single side: 2.5 μm) over a period of about 2 minutes.

  As described above, even if there are a plurality of pits on the surface of the raw glass 10, it is possible to appropriately prevent the display image quality of the flat panel display to which the glass substrate 100 is applied from being deteriorated. Moreover, since the translucent polymer film 12 also functions as a transparent protective film for the base glass 10, it also has a secondary effect of improving the strength of the base glass 10.

  The above description of the embodiment is to be considered in all respects as illustrative and not restrictive. The scope of the present invention is shown not by the above embodiments but by the claims. Furthermore, the scope of the present invention is intended to include all modifications within the meaning and scope equivalent to the scope of the claims.

10-element glass 12-translucent polymer film 14-conductive film 16-transparent electrode film 100-glass substrate 102-pit

Claims (4)

A method for producing a glass substrate used in a flat panel display,
A roughening treatment step of bringing the etching solution into contact with the surface of the raw glass and roughening the surface;
A film forming process step of thickly coating the light-transmitting polymer film so as to fill pits that may be present on the surface of the raw glass after the roughening process step;
Applying an organic conductive film to the surface of the translucent polymer film; and
Of manufacturing a glass substrate for a flat panel display. The roughening treatment step is a step of subjecting the surface of the raw glass to a surface treatment by etching such that an arithmetic average roughness Ra is 0.7 nm to 70 nm, and the film forming treatment step is the light-transmitting property. 2. The production of a glass substrate for a flat panel display according to claim 1, wherein the film is formed to have a thickness of 5 μm to 10 μm, and the thickness of the organic conductive film is 100 to 300 nm. Method. The manufacturing method of the glass substrate for flat panel displays of Claim 1 or 2 whose refractive index of the said translucent polymer film is 1.4-1.6.   The etching solution according to any one of claims 1 to 3, comprising 0.5 to 3 wt% hydrofluoric acid, 0 to 10 wt% hydrochloric acid, and 0 to 5 wt% sulfuric acid. The manufacturing method of the glass substrate for flat panel displays of description.

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