JP2008260266A - Displaying material substrate, its production method, and displaying material - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To inexpensively provide a displaying material substrate in which a low steam permeability and thin film making are compatible with each other. <P>SOLUTION: The displaying material substrate comprises an aromatic polyamide layer and a glass layer, and has a whole light transmittance of ≥80%. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a substrate suitable for a display material such as an organic EL display and a liquid crystal display.

  Glass is widely used as a substrate for display materials such as organic EL displays and liquid crystal displays. While glass is excellent in light transmittance and gas barrier properties, there is a limit to reducing the film thickness. As thin film glass, about 0.3 mm thickness is a practical lower limit that can be handled by glass alone, and thickness below this has problems of deterioration in handling properties and cracking. Therefore, in response to the demand for further thinning, for example, a display material such as an organic EL display or a liquid crystal display is made using glass having a thickness of about 0.3 mm, and then the glass is thinned by polishing or etching. Is used. In this method, a glass substrate having a thickness of about 0.1 mm is achieved because it is reinforced by other members, but there is a problem that process costs such as polishing and etching increase.

On the other hand, various plastic substrates have been proposed as display material substrates that are lightweight and do not break with thin films. However, since plastic has a high water vapor transmission rate, there is a problem that the organic EL pigment and the liquid crystal material deteriorate. For example, Patent Document 1 discloses a technique in which a gas barrier layer such as SiO ₂ is formed on a plastic substrate. However, an inorganic gas barrier film such as SiO ₂ has a problem of causing defects such as cracks. For this reason, Patent Document 2 proposes a method in which an inorganic gas barrier film and an organic film are combined. However, not only the lower limit is about 10 ⁻³ g / m ² / day, but the problem is high cost. There is.

  Patent Document 3 discloses a combination of glass and protective film. Although it is an attempt to protect the fragility of glass with excellent gas barrier properties with a protective film, the glass transition temperature is low due to the use of polyethylene terephthalate with adhesive, and it is suitable for the sputtering temperature of ITO, which requires about 250 ° C. I can't stand it. Although ITO film formation at a low temperature is not impossible, in this case, there is a problem that the resistance value of the obtained ITO film becomes large.

  Patent Document 4 discloses a so-called “laminated glass” in which a resin is sandwiched between two glass plates. However, since at least two glass plates are required, the entire thickness is increased, which is not preferable.

Patent Document 5 discloses a glass-plastic composite, but there is no disclosure that an aromatic polyamide is used for the plastic, and since a general plastic is used, the heat resistance is low, and a transparent electrode such as ITO is used. There has been a demand for a glass-plastic composite with high heat resistance that cannot withstand the process of forming and soldering.
JP 2007-15350 A JP 2006-231644 A JP 2002-299041 A JP-A-7-287218 Special Table 2002-542971

  The present invention has been achieved as a result of studying the solution of the problems in the prior art described above as an issue. That is, an object of the present invention is to provide a low-cost display material substrate that achieves both a low water vapor transmission rate and a thin film.

  The present invention for achieving the above object is characterized by the following.

  That is, the display material substrate includes an aromatic polyamide layer and a glass layer, and has a total light transmittance of 80% or more.

  It is possible to provide a low-cost display material substrate that achieves both a low water vapor transmission rate, a thin film, and a high total light transmittance.

  The display material substrate of the present invention includes an aromatic polyamide layer and a glass layer.

  Since the substrate for display material of the present invention is used for display materials such as displays and televisions, the total light transmittance is preferably 80% or more. In the present invention, by laminating thin film glass and a special aromatic polyamide, Achieve this. The total light transmittance is preferably 85% or more, more preferably 90% or more. Ideally, it is 100%, but light rays are reflected by the interface reflection between the air layer and the aromatic polyamide layer and the interface reflection between the aromatic polyamide layer and the glass layer. It becomes. Further, when light of a specific wavelength is absorbed, coloring may be seen when used as a display material. A general aromatic polyamide has a large absorption around 400 nm and is colored yellow, but the substrate for display material of the present invention preferably has a light transmittance at 400 nm of 70% or more. More preferably, it is 80% or more. In addition, the light transmittance of 400 nm here is measured by the following and adopts a value of 400 nm.

Transmittance (%) = (T1 / T0) × 100
However, T1 is the intensity | strength of the light which passed the sample, and T0 is the intensity | strength of the light which passed the air of the same distance except not passing a sample.

Wavelength range: 300 nm to 800 nm
Measurement speed: 120 nm / min Measurement mode: Transmission glass Any of a commercially available glass, a glass manufactured by a known method, or a newly manufactured glass may be used. High surface smoothness, non-alkali glass and quartz glass for display material substrates are preferred. The thickness is preferably 0.5 mm or less, more preferably 0.3 mm or less, further preferably 0.2 mm or less, more preferably 0.1 mm or less, more preferably 0.05 mm or less, more preferably 0.03 mm. Hereinafter, it is most preferably 0.01 mm or less. If the thickness exceeds 0.5 mm, the glass itself has sufficient handling properties, so further laminating an aromatic polyamide layer makes it difficult to improve handling and prevent cracking, and causes cracking against bending. It becomes easy.

  On the other hand, the effect of laminating with the aromatic polyamide layer becomes more remarkable as the glass is thinner. Further, although it depends on the kind of glass, a thickness of about 0.1 mm or less is preferable because it does not cause cracking when bent at a curvature radius of 100 cm. Although there is no lower limit to the thickness of the glass, it is considered that about 0.001 mm is a lower limit that can withstand the drying shrinkage during the formation of the aromatic polyamide layer. More preferably, it is 0.005 mm or more.

  Glass may be supplied in the form of a sheet or may be supplied continuously, but a continuous display material substrate can be obtained by using a continuous supply. .

  The thickness of the aromatic polyamide layer is not limited, but is preferably 50 μm or less. When it exceeds 50 μm, a long time is required for extraction and drying of the solvent. The thickness of the aromatic polyamide layer is preferably 30 μm or less, more preferably 20 μm or less, still more preferably 10 μm or less, and most preferably 5 μm or less. There is no lower limit to the thickness of the aromatic polyamide, but about 0.01 μm is considered to be the lower limit at which a uniform film can be formed. More preferably, it is 0.05 μm or more.

  In addition, there is no upper limit to the number of layers for both the glass layer and the aromatic polyamide layer, and a plurality of aromatic polyamide layers, a plurality of glass layers, a combination of a plurality of layers, or as appropriate according to the intended use What is necessary is just to comprise. Among them, from the viewpoint of cost and the like, the combination of one glass layer and one aromatic polyamide layer is most preferable. At this time, the gas barrier property and handling property are sufficient, and the thinning and productivity are most excellent.

  Here, the “aromatic polyamide 1 layer” includes a laminated structure obtained by coextrusion film formation. That is, the aromatic polyamide layer used in the present invention may be a single layer composed of a single aromatic polyamide or a laminate composed of two or more types of aromatic polyamide. By being laminated, an antireflection function can be imparted, or different functions such as “easy adhesion with glass on the glass side and easy adhesion with a transparent conductive film on the surface layer” can be imparted. In the case of stacking, examples include a method of laminating a film forming stock solution using a confluence apparatus such as a feed block and pinol and discharging from a single layer die, and a method of laminating a film forming stock solution using a multilayer die. it can. Laminate film formation is possible by coating multiple times, but productivity may be inferior.

  The aromatic polyamide used in the present invention preferably has a glass transition temperature of 200 ° C. or higher or does not have a glass transition temperature. More preferably, it is 250 ° C. or higher, more preferably 300 ° C. or higher, most preferably 350 ° C. or higher, or no glass transition temperature. By having a high glass transition temperature, it can withstand sputtering and vapor deposition temperatures of metals such as ITO (indium tin oxide), and it is possible to sputter metals such as ITO in the same way as sputtering on a single glass. Become. In addition, the heat treatment after sputtering can be performed at a high temperature. A generally known aromatic polyamide such as PPTA (polyparaphenylene terephthalamide) has a glass transition temperature of 200 ° C. or higher, but is colored yellow and is soluble only in a special solvent such as concentrated sulfuric acid. Therefore, it cannot be applied to the present invention. In order to achieve a total light transmittance of 80% or more when used as a display material substrate, the aromatic polyamide can be dissolved in an organic solvent at 25 ° C. at least 5% by mass. It is preferable not to become.

  All of these characteristics are attributed to the solubility of the aromatic polyamide. When the solubility is insufficient, when the aromatic polyamide concentration becomes high at the time of drying, it cannot be dissolved in the organic solvent and precipitates, or a gel-like material is generated. This causes light scattering, white turbidity, and surface roughening.

In order to improve the solubility of aromatic polyamides, the proportion of rigid para bonds, polycyclic aromatics such as naphthalene and anthracene is reduced, and the proportion of flexible meta structure, ether, -SO ₂ -or methylene structure It is preferable to introduce a bulky substituent such as fluorene, tert-butyl, halogen, and alkyl halide.

  In order for the glass transition temperature to be 200 ° C. or higher and to increase the adhesive strength with glass, it is more preferable that the aromatic polyamide contains a structural unit represented by the chemical formula (I).

R ¹ : Arbitrary group R ² : Arbitrary group R ³ : An aromatic group having 6 to 12 carbon atoms which is directly connected or has a phenyl group as an essential component.

R ⁴ : directly connected or an aromatic group having 6 to 12 carbon atoms having a -phenyl group as an essential component R ⁵ : aromatic group In the chemical formula (I), R ¹ and R ² are not particularly limited, Any group may be used. Preferably, -H, an aliphatic group having 1 to 5 carbon _{atoms, -CF 3, -CCl 3, -OH} , -F, -Cl, -Br, -OCH 3, silyl group, or an aromatic group . Since R ¹ and R ² are side chain substituents, they have a relatively small effect on the physical properties of the polyamide compared to the main chain substituents, but improve optical properties, wettability, solvent solubility, etc. Therefore, it is preferable to introduce appropriately. For example, —OH, silyl group, or —COOH can be introduced for the purpose of improving wettability and adhesion to glass.

Furthermore, in the chemical formula (I), other groups can be introduced at the positions of R ³ and R ⁴ . Of course, it may be directly connected as, for example, -Ph -, - O-Ph -, - C (CF 3) 2 -Ph- , etc. may be introduced. However, the most preferable structure is a directly connected structure.

In the chemical formula (I), R ⁵ is not particularly limited as long as it is an aromatic group. A phenyl group and a chlorophenyl group are preferable. In the chemical formula (I), R ⁵ is preferably a rigid aromatic group such as paraphenylene, 2-substituted paraphenylene, or biphenyl for the purpose of imparting heat resistance and rigidity. On the other hand, polycyclic aromatic groups such as terphenyl and anthracene are rigid but have many π electrons, which may cause the polyamide to be colored. Moreover, when improving transparency in the near ultraviolet region or the ultraviolet region, R ⁵ is preferably a metaphenyl group or a 1,3-hexafluoropropyl-2,2-biphenyl group. Since these groups have flexibility, rigidity may be reduced, but transparency to light having a shorter wavelength is improved.

  The molar fraction of the structural unit of the chemical formula (I) with respect to the aromatic polyamide used in the present invention is preferably 50% or more. More preferably, it is 70% or more, more preferably 90% or more, more preferably 95% or more, and most preferably 100%. When the molar fraction of the structural unit of the chemical formula (I) is less than 50%, the adhesion to glass may be insufficient. In this case, it is preferable to improve the adhesive strength by adding a silane coupling agent.

  As other components of the aromatic polyamide used in the present invention, the structural units represented by the chemical formulas (II) and (III) are preferably contained from the viewpoint of solubility in an organic solvent and light transmittance. In order to reduce the low birefringence and reduce the wavelength dispersion of the retardation, the structural unit represented by the chemical formula (III) is preferable. Here, the wavelength dispersibility is a value obtained by dividing the phase difference at a wavelength of 400 nm by the phase difference at a wavelength of 550 nm.

  Regarding the retardation, for example, when used for a liquid crystal display substrate, the aromatic polyamide film of the present invention preferably has a retardation of light having a wavelength of 550 nm of less than 10 nm. Such a phase difference can be realized by, for example, a technique in which an aromatic polyamide solution is spread on glass and then dried. When used in the above-described applications, this phase difference is more preferably 5 nm or less, further preferably 2 nm or less, and most preferably 0 nm. Since the phase difference of light having a wavelength of 550 nm is as small as less than 10 nm, it can be suitably used, for example, as a protective film for optical discs in addition to display materials.

  On the other hand, there are also applications in which it is preferable to positively impart a phase difference, such as a phase difference substrate in which a function of a phase difference film is added to a display material substrate. In this case, the phase difference of light having a wavelength of 550 nm is preferably 10 to 2,000 nm. When the retardation is within this range, excellent color tone reproducibility can be exhibited when used as an optical retardation film, particularly a wide-range quarter-wave retardation plate. For example, in the method of the present invention in which an aromatic polyamide solution is spread on glass and then dried, such a phase difference may include a liquid crystal structure such as a biphenyl structure represented by the chemical formula (II) in the aromatic polyamide used, When the aromatic polyamide solution is spread on glass, a method of extending the aromatic polyamide solution by increasing the moving speed of the glass plate relative to the discharge amount of the aromatic polyamide solution, or an additive for developing the phase difference Examples thereof include a method of adding to an aromatic polyamide solution. When used in the above-described applications, the phase difference is preferably 100 to 550 nm, and more preferably 130 to 380 nm.

  Examples of the additive include liquid crystalline molecules such as ultraviolet curable liquid crystal and thermosetting liquid crystal, and aromatic polymers or oligomers such as polycarbonate and styrene.

  In the display material substrate of the present invention, the refractive index in the orthogonal axis direction in the plane of the display material substrate with respect to a light beam having a wavelength of 590 nm is nx and ny (where nx ≧ ny), and the display material substrate with respect to a light beam with a wavelength of 590 nm is used. When the refractive index in the thickness direction is nz and the thickness of the substrate for display material is d (nm), the thickness direction retardation Rth defined by the following formula is preferably 10 nm or less, more preferably 8 nm or less, More preferably, it is 5 nm or less, and most preferably 2 nm or less. When the retardation Rth in the thickness direction of the display material substrate is 10 nm or less, the display material substrate is excellent not only in the optical isotropy in the surface of the display material substrate but also in the thickness direction. Can be more suitably used. In applications that require optical isotropy in the thickness direction, it is preferable that the thickness direction retardation Rth is small, but the lower limit is considered to be about 0.01 nm in practice. In order to obtain such a film having a small thickness direction retardation Rth, it is effective not to introduce an additive or a copolymerization component that develops a thickness direction retardation.

    Thickness direction retardation Rth (nm) = d × {(nx + ny) / 2−nz}

R ⁶ : aromatic group

R ⁷ : Arbitrary group R ⁸ : Arbitrary group R ⁹ : Aromatic group In the chemical formulas (II) and (III), R ⁶ and R ⁹ are not particularly limited as long as R ⁶ and R ⁹ are aromatic groups. A phenyl group and a chlorophenyl group are preferable. For the purpose of imparting heat resistance and rigidity, a rigid aromatic group such as paraphenylene, 2-substituted paraphenylene, and biphenyl is preferable. On the other hand, polycyclic aromatic groups such as terphenyl and anthracene are rigid but have many π electrons, which may cause the polyamide to be colored. Moreover, when improving transparency in the near-ultraviolet region or the ultraviolet region, R ⁶ and R ⁹ are preferably a metaphenyl group or a 1,3-hexafluoropropyl-2,2-biphenyl group. Since these groups have flexibility, rigidity may be reduced, but transparency to light having a shorter wavelength is improved. In order to impart solubility, in chemical formula (II) and chemical formula (III), R ⁶ and R ⁹ preferably contain a flexible structure such as a metafel group.

In the chemical formula (III), R ⁷ and R ⁸ are not particularly limited and may be any group. Preferably, -H, an aliphatic group having 1 to 5 carbon _{atoms, -CF 3, -CCl 3, -OH} , -F, -Cl, -Br, -OCH 3, silyl group, or an aromatic group . Since R ⁷ and R ⁸ are side chain substituents, they have a relatively small effect on the physical properties of the polyamide compared to the main chain substituents, but improve optical properties, wettability, solvent solubility, etc. Therefore, it is preferable to introduce appropriately. For example, —F can be introduced for the purpose of reducing the moisture absorption rate, or —OH, silyl group, and —COOH can be introduced for the purpose of improving wettability and adhesion to glass.

In addition, the display material substrate of the present invention preferably has a water vapor transmission rate of 10 ⁻⁵ g / m ² / day or less. Although it was difficult to achieve a water vapor transmission rate of 10 ⁻³ g / m ² / day or less with a conventional plastic substrate with a gas barrier layer, the display material substrate of the present invention has at least one glass layer. The rate can achieve the water vapor transmission rate of the glass, ie 0 g / m ² / day. The smaller the value of water vapor transmission rate, the better. There is no lower limit. More preferably, it is 10 < ^-6 > g / m < ² > / day or less, More preferably, it is 10 < ^-7 > g / m < ² > / day or less, Most preferably, it is 10 < ^-10 > g / m < ² > / day or less. In the current measuring apparatus, about 10 ⁻⁵ g / m ² / day is the lower limit of measurement.

  In addition, it is preferable that the display material substrate of the present invention is free from cracking when bent at a radius of curvature of 100 cm. For this purpose, it is preferable to make the glass thinner and tougher. The radius of curvature that does not cause cracking is preferably 50 cm, more preferably 15 cm, more preferably 10 cm, and most preferably 1 cm. Continuous production of display materials and flexible displays can be realized by preventing cracks with a smaller radius of curvature. Further, if the radius of curvature is 15 cm or less, it can be wound around a core having a radius of 6 inches and stored and transported in the form of a roll.

  Although the manufacturing method of the aromatic polyamide in this invention is demonstrated below, of course, this invention is not limited to this.

  Various methods can be used as a method for obtaining a polyamide solution, that is, a film forming stock solution. For example, a low temperature solution polymerization method, an interfacial polymerization method, a melt polymerization method, a solid phase polymerization method, and the like can be used. Further, a polymerization method without using a solvent, for example, a vapor deposition polymerization method may be used. When it is obtained from a low temperature solution polymerization method, that is, from carboxylic acid dichloride and diamine, it is synthesized in an aprotic organic polar solvent.

  Carboxylic acid dichlorides include terephthalic acid dichloride, 2 chloro-terephthalic acid dichloride, isophthalic acid dichloride, naphthalene dicarbonyl chloride, biphenyl dicarbonyl chloride, 4,4′-biphenyl dicarbonyl chloride, terphenyl dicarbonyl chloride, 2 fluoro-terephthale Acid dichloride, 1,4-cyclohexanecarboxylic acid dichloride and the like can be mentioned, and most preferred are terephthalic acid dichloride, 2chloro-terephthalic acid dichloride, 4,4′-biphenyldicarbonyl chloride, and isophthalic acid dichloride.

  Examples of the diamine include 4,4′-diaminodiphenylsulfone, 3,3′-diaminodiphenylsulfone, 3,4′-diaminodiphenylsulfone, bis [4- (4-aminophenoxy) phenyl] sulfone, and bis [4- ( 3-aminophenoxy) phenyl] sulfone, 2,2′-ditrifluoromethyl-4,4′-diaminobiphenyl, 9,9-bis (4-aminophenyl) fluorene, 9,9-bis (4-amino-3) -Methylphenyl) fluorene, 9,9-bis (4-amino-3-fluorophenyl) fluorene, 9,9-bis (4-amino-3-chlorophenyl) fluorene, 2,2-bis [4- (4- Aminophenoxy) phenyl] propane, 2,2-bis (4-aminophenyl) hexafluoropropane, and the like. 4,4′-diaminodiphenylsulfone, 3,3′-diaminodiphenylsulfone, 3,4′-diaminodiphenylsulfone, 2,2′-ditrifluoromethyl-4,4′-diaminobiphenyl, 9,9- Bis (4-aminophenyl) fluorene and 9,9-bis (4-amino-3-fluorophenyl) fluorene are mentioned.

  Furthermore, it is preferable to contain Si element in order to improve the adhesiveness with the substrate. Specifically, examples of the diamine component include those obtained by copolymerizing 1 to 10 mol% of bis (3-aminopropyl) tetramethyldisiloxane, bis (p-amino-phenyl) octamethylpentasiloxane, and the like.

  When performing polymerization using two or more kinds of diamines, diamines are added one by one, 10 to 99 mol% of acid dichloride is added to the diamine and reacted, and then another diamine is added, Further, a stepwise reaction method in which acid dichloride is added and reacted, a method in which all diamines are mixed and added, and then acid dichloride is added and reacted can be used. Similarly, when two or more kinds of acid dichlorides are used, a stepwise method, a method of simultaneously adding them, and the like can be used. In any case, the molar ratio of the total diamine to the total acid dichloride is preferably 95 to 105: 105 to 95, and if it is outside this value, it is difficult to obtain a polymer solution suitable for molding.

  Examples of the aprotic polar solvent used in the production of polyamide include sulfoxide solvents such as dimethyl sulfoxide and diethyl sulfoxide, formamide solvents such as N, N-dimethylformamide and N, N-diethylformamide, and N, N. -Acetamide solvents such as dimethylacetamide, N, N-diethylacetamide, pyrrolidone solvents such as N-methyl-2-pyrrolidone, N-vinyl-2-pyrrolidone, phenol, o-, m- or p-cresol, xylenol , Phenolic solvents such as halogenated phenols and catechols, hexamethylphosphoramide, γ-butyrolactone, etc., and these are preferably used alone or as a mixture. Charcoal The use of hydrogen is also possible. Further, for the purpose of promoting the dissolution of the polymer, 50 wt% or less of an alkali metal or alkaline earth metal salt can be added to the solvent.

The polyamide may contain 10% by weight or less of an inorganic or organic additive for the purpose of surface formation and processability improvement. Examples of the additive for the purpose of surface formation include inorganic particles such as SiO ₂ , TiO ₂ , and other metal fine powders.

  In addition, surfactants, esters such as ethyl lactate and propylene glycol monomethyl ether acetate, alcohols such as ethanol, cyclohexanone and methyl isobutyl ketone are used for the purpose of improving the wettability of the interface between the aromatic polyamide and the glass as necessary. Ketones such as, and ethers such as tetrahydrofuran and dioxane may be mixed.

  Further, in order to enhance the adhesion to glass, 0.5 to 10% by weight of a silane coupling agent or the like can be added to the aromatic polyamide solution, or the glass can be pretreated with such a chemical solution.

  When added to an aromatic polyamide solution, 0.5 to 10% by weight of a silane coupling agent such as methylmethacryloxydimethoxysilane or 3-aminopropyltrimethoxysilane or an aluminum chelating agent is added to the polymer in the varnish. Good.

  When processing glass, the coupling agent described above is added to a solvent such as isopropanol, ethanol, methanol, water, tetrahydrofuran, propylene glycol monomethyl ether acetate, propylene glycol monomethyl ether, ethyl lactate, diethyl adipate and the like in an amount of 0.5 to 20. Surface treatment is performed by spin coating, dipping, spray coating, steam treatment, etc. on the solution in which the weight% is dissolved. In some cases, the reaction between the substrate and the coupling agent is allowed to proceed by applying a temperature from 50 ° C. to 300 ° C.

  Moreover, the thermosetting polyamide which provided the thermosetting property to the above-mentioned polyamide of this invention is also preferable. As a method for imparting thermosetting property, for example, there is a method in which the polyamide main chain terminal of the present invention is substituted with a reactive group such as norbornene, acetylene, maleimide, and a thermosetting agent is added.

  Polyamide solution uses acid dichloride and diamine as monomers to produce hydrogen chloride as a by-product. When neutralizing this, inorganic neutralizers such as calcium hydroxide, calcium carbonate, lithium carbonate, and ethylene Organic neutralizers such as oxide, propylene oxide, ammonia, triethylamine, triethanolamine, diethanolamine are used. The reaction between isocyanate and carboxylic acid is carried out in an aprotic organic polar solvent in the presence of a catalyst.

  In the aromatic polyamide solution thus obtained, a salt is formed by a neutralization reaction between hydrogen chloride generated from acid dichloride and a neutralizing agent. This ratio becomes 5 to 20% by weight, and when this film-forming stock solution is dried as it is, a salt is deposited. Therefore, it is preferable to remove the salt before the film formation or in the film formation process. The method for removing the salt is not particularly limited. For example, water is added to the polymer stock solution, and the polymer is reprecipitated and washed by stirring with a stirrer equipped with a cutter. The obtained polymer can be dried and dissolved in a solvent at an arbitrary concentration to obtain a film-forming stock solution.

  Next, the display material substrate formation will be described. The film-forming stock solution prepared as described above is thinned by a solution film-casting method cast on glass. The solution casting method includes a dry-wet method, a dry method, a wet method, etc., and any method may be used, but here, the dry method will be described as an example.

  When forming a film by a dry method, the stock solution is extruded onto a glass from a die, or developed on a glass by a method such as spin coating, bar coating, comma coating, printing, and then the solvent is scattered from the thin film layer. Remove and dry until the film is self-retaining. The glass used here may be one that has been subjected to cleaning or easy adhesion treatment. Examples of cleaning include functional water such as water and ultrasonic water, and organic solvents. Examples of the easy adhesion treatment include plasma treatment, corona treatment, and etching treatment. When the glass is supplied by a roll, methods such as extrusion from a die, bar coating, comma coating, and printing are preferable. Further, when glass is supplied as a single sheet, intermittent coating using a slit die, spin coating, or the like is preferable. The glass to be supplied may be a glass with a protective film. The protective film affixed to the glass is useful for withstanding the drying shrinkage of the aromatic polyamide solution and the tension during handling. Here, the “protective film” refers to a film that is peeled off after completion of the manufacturing process of the display material substrate or after the manufacturing process of the display material.

  Drying conditions can be performed in the range of room temperature to 220 ° C. and within 60 minutes, for example. Although the drying time and the heating rate are controlled by the composition and film thickness of the aromatic polyamide, since the drying is performed only from the other side with the glass in close contact with one side, the solvent is gently dried up to the boiling point + 10 ° C. In addition, stepwise temperature rise is preferable. If heated rapidly, it may foam.

  Next, heat treatment is performed at a temperature of 200 ° C. to 500 ° C., preferably 250 ° C. to 400 ° C. for several seconds to several minutes, to obtain a display material substrate. Furthermore, it is effective to cool slowly after the heat treatment, and it is effective to cool at a rate of 50 ° C./second or less.

  The glass substrate obtained by removing the organic solvent as described above is preferably continuously wound around a cylindrical core. In this case, it is preferable that the glass is continuously supplied from the melting furnace through a glass film forming process or is supplied by a roll and has a length of at least 5 m in the transport direction. Moreover, it is preferable that the radius of the cylindrical core used for winding is 100 cm or less. The cylindrical core preferably has a radius of 50 cm or less, more preferably a radius of 30 cm or less, and even more preferably a radius of 15 cm or less. When the radius is 15 cm or less, it can be wound and stored and transported on a generally used 6-inch diameter cylindrical core, which is extremely economical compared to the conventional method of individually packaging and transporting each sheet individually. It will be advantageous. In addition, a method of transporting a single glass to a display manufacturing factory using a robot arm and conveyor without packaging from the glass factory has been proposed, but in this method, the glass factory and the display manufacturing factory are constructed adjacent to each other. Although there is a great limitation, the method of the present invention for continuously winding around a cylindrical core does not have such a limitation. A weakly adhesive or non-adhesive protective film may be laminated on the glass substrate for the purpose of preventing breakage of the glass due to the conveyance tension during conveyance of the glass substrate or winding around the cylindrical core. Examples of the weakly adhesive protective film include films containing polypropylene, PET, and the like as constituent components. Examples of the non-adhesive protective film include films having PET as a constituent component.

  The substrate for display material of the present invention can be suitably used as a substrate for display material such as an organic EL display and a liquid crystal display.

  The present invention will be described more specifically with reference to the following examples.

  In addition, the measuring method of a physical property and the evaluation method of an effect were performed in accordance with the following method.

(1) Total light transmittance It measured using the following measuring device.

Apparatus: Direct reading haze meter HGM-2DP (for C light source) (manufactured by Suga Test Instruments Co., Ltd.)
Light source: halogen lamp 12V, 50W
Light receiving characteristics: 395 to 745 nm
Optical conditions: Conforms to JIS-K7105-1981 (2) Light transmittance at 400 nm The light transmittance at 400 nm is measured as follows, and a value of 400 nm is adopted.

Transmittance (%) = (T1 / T0) × 100
However, T1 is the intensity | strength of the light which passed the sample, and T0 is the intensity | strength of the light which passed the air of the same distance except not passing a sample.

Apparatus: UV measuring instrument U-3410 (manufactured by Hitachi Instruments)
Wavelength range: 300 nm to 800 nm
Measurement speed: 120 nm / min Measurement mode: Transmission (3) Water vapor transmission rate
Device: Permeability measuring device PERMATRAN-W3 / 30 (manufactured by Mocon)
Measurement lower limit: 0.01 g / m ² / day
Measurement temperature: 40 ° C
Measurement humidity: 90% RH
Measurement area: 5 cm ² (using aluminum mask foil (MC025-493 (Hitachi Instrument Service Co., Ltd.))
(4) Glass transition temperature (Tg) DMA measurement device: Viscoelasticity measuring device EXSTAR6000 DMS (manufactured by Seiko Instruments Inc.)
Measurement frequency: 1Hz
Temperature rising rate: 2 ° C./min Glass transition temperature (Tg): In accordance with ASTM E1640-94, the inflection point of E ′ was Tg.

(5) Phase difference at a wavelength of 550 nm Using an automatic birefringence meter (KOBRA-21ADH) manufactured by Oji Scientific Co., Ltd., in a chromatic dispersion measurement mode, a phase difference with respect to a light beam having a wavelength of 480.4 nm, a wavelength of 548.3 nm The phase difference with respect to the light beam, the phase difference with respect to the light beam with a wavelength of 628.2 nm, and the phase difference with respect to the light beam with a wavelength of 752.7 nm are measured, and the Cauchy wavelength dispersion formula (R (Λ) = a + b / λ ² + c / λ ⁴ + d / λ ⁶ ) coefficients a to d were obtained, and obtained by substituting the wavelength of 550 nm (λ = 550) into the Cauchy wavelength dispersion formula. The measurement was performed once.

(6) Solubility 5 mass% of the polymer was dissolved in N-methyl-2-pyrrolidone, and the one that maintained fluidity after being allowed to stand at 25 ° C. for 2 weeks was evaluated as solubility “◯”. “Maintaining fluidity” means a state in which 50 ml or more flows out within one hour when 100 ml of a polymer solution is placed in a 100 ml beaker at 25 ° C. and tilted 90 °.

Example 1
In a 200 ml four-necked flask equipped with a stirrer, 2.483 g of 4,4′-diaminodiphenylsulfone, 2.483 g of 3,3′-diaminodiphenylsulfone and 63.1 ml of N-methyl-2-pyrrolidone were placed under a nitrogen atmosphere. The mixture was stirred under ice cooling. After 10 to 30 minutes, 4.060 g of terephthalic acid dichloride was added in 5 portions. After further stirring for 1 hour, hydrogen chloride generated by the reaction was neutralized with 1.426 g of lithium carbonate to obtain a transparent polymer solution. The obtained polymer solution was ground in water using a mixer, filtered and dried to isolate the polymer. The isolated polymer was dissolved in N, N-dimethylacetamide so that the solid content concentration was 20% by weight to obtain a polymer solution. The obtained polymer solution was applied to a glass having a thickness of 0.15 mm with a bar coater so as to have a coating thickness of 50 μm, and dried at 120 ° C. for 20 minutes and 280 ° C. for 3 minutes to obtain an aromatic polyamide film having a thickness of 10 μm. The overall thickness was 0.16 mm.

(Example 2)
A display material substrate was obtained in the same manner as in Example 1 except that the glass used was 0.03 mm in thickness. The physical properties are shown in Table 2.

(Examples 3 to 10)
A display material substrate was obtained in the same manner as in Example 1 except that the diamine, acid dichloride and glass used were changed to those shown in Table 1. The physical properties are shown in Table 2.

(Example 11)
In a 200 ml four-necked flask equipped with a stirrer, 3.725 g of 4,4′-diaminodiphenylsulfone, 3.352 g of 3,3′-diaminodiphenylsulfone, 0.373 g of bis (3-aminopropyl) tetramethyldisiloxane, N -94 ml of methyl-2-pyrrolidone was added and stirred under ice-cooling in a nitrogen atmosphere. After 10 to 30 minutes, 6.091 g of terephthalic acid dichloride was added in five portions. After further stirring for 1 hour, hydrogen chloride generated by the reaction was neutralized with 2.246 g of lithium carbonate to obtain a transparent polymer solution. The obtained polymer solution was ground in water using a mixer, filtered and dried to isolate the polymer. The polymer was obtained by dissolving the isolated polymer in N, N-dimethylacetamide so that the solid content concentration was 5% by mass, so that the solubility was judged as “◯”. Another polymer isolated was dissolved in N, N-dimethylacetamide so that the solid content concentration was 15% by mass to obtain a polymer solution. The obtained polymer solution was coated on a 0.03 mm thick glass (D263T manufactured by Shot Corp.) with a bar coater so as to have a coating thickness of 100 μm, dried at 120 ° C. for 10 minutes and 280 ° C. for 3 minutes, and an aromatic having a thickness of 10 μm A polyamide film was obtained. The total thickness of the obtained display material substrate was 0.04 mm.

  The retardation of the obtained display material substrate at a wavelength of 550 nm was 0.4 nm. Further, no cracks were produced when bending at a curvature radius of 30 cm. As a result of making 100 1 mm grids by the method of JIS D0202-1988 4.15 and conducting a cello tape (registered trademark) peel test, all 100 squares were not peeled off.

(Example 12)
A display material substrate was obtained in the same manner as in Example 11 except that the diamine, acid dichloride and glass used were changed to those shown in Table 1. The physical properties are shown in Table 2.

(Comparative Example 1)
In a 200 ml four-necked flask equipped with a stirrer, 2.483 g of 4,4′-diaminodiphenylsulfone, 2.483 g of 3,3′-diaminodiphenylsulfone and 63.1 ml of N-methyl-2-pyrrolidone were placed under a nitrogen atmosphere. The mixture was stirred under ice cooling. After 10 to 30 minutes, 4.060 g of terephthalic acid dichloride was added in 5 portions. After further stirring for 1 hour, hydrogen chloride generated by the reaction was neutralized with 1.426 g of lithium carbonate to obtain a transparent polymer solution.

A part of the obtained polymer solution was taken on a glass plate, and a uniform film was formed using a bar coater. This was heated at 120 ° C. for 7 minutes to obtain a self-holding film. The obtained film was peeled off from the glass plate and fixed to a metal frame, washed with running water for 10 minutes, and further heat treated at 280 ° C. for 1 minute to obtain an aromatic polyamide film having a thickness of 14 μm. The water vapor transmission rate was 231 g / m ² / day.

Diamine 1: 4,4′-diaminodiphenyl sulfone (manufactured by Wakayama Seika Co., Ltd.),
Diamine 2: 3,3′-diaminodiphenyl sulfone (manufactured by Mitsui Chemicals Fine),
Diamine 3: bis [4- (4-aminophenoxy) phenyl] sulfone (manufactured by Wakayama Seika Co., Ltd.),
Diamine 4: 9,9-bis (4-aminophenyl) fluorene (manufactured by Wakayama Seika Co., Ltd.),
Diamine 5: 2,2′-ditrifluoromethyl-4,4′-diaminobiphenyl (manufactured by Wakayama Seika Co., Ltd.),
Diamine 6: Bis [4- (3-aminophenoxy) phenyl] sulfone (manufactured by Wakayama Seika Co., Ltd.)
Diamine 7: Bis (3-aminopropyl) tetramethyldisiloxane acid dichloride 1 (acid 1): Terephthalic acid dichloride (manufactured by Tokyo Chemical Industry Co., Ltd.)
Acid dichloride 2 (acid 2): 2 chloro-terephthalic acid dichloride acid dichloride 3 (acid 3): Isophthalic acid dichloride (manufactured by Tokyo Chemical Industry Co., Ltd.)
Acid dichloride 4 (acid 4): 4,4'-biphenyldicarbonyl chloride (manufactured by Tokyo Chemical Industry Co., Ltd.)

Claims (13)

A display material substrate comprising an aromatic polyamide layer and a glass layer and having a total light transmittance of 80% or more. The display material substrate according to claim 1, wherein a retardation in a film plane with respect to light having a wavelength of 550 nm is 0 nm or more and less than 10 nm. The display material substrate according to claim 1, wherein a retardation in a film plane with respect to light having a wavelength of 550 nm is 10 nm or more and 2,000 nm or less. The display material substrate according to claim 1, wherein the thickness is 0.35 mm or less. The display material substrate according to claim 1, wherein the water vapor transmission rate is 10 ⁻⁵ g / m ² / day or less. The substrate for display material according to any one of claims 1 to 5, which does not cause cracking when bent at a curvature radius of 100 cm. The substrate for display materials according to claim 1, wherein the glass transition temperature of the aromatic polyamide is 200 ° C. or higher or does not have a glass transition temperature. The display material substrate according to claim 1, wherein the aromatic polyamide can be dissolved in an N-methyl-2-pyrrolidone solution by at least 5 mass%. The display material substrate according to claim 1, wherein the aromatic polyamide contains an Si element. The display material substrate according to claim 1, wherein the aromatic polyamide includes a structural unit represented by the chemical formula (I).

R ¹ : Arbitrary group R ² : Arbitrary group R ³ : An aromatic group having 6 to 12 carbon atoms which is directly connected or has a phenyl group as an essential component.
R ⁴ : directly connected or an aromatic group having 6 to 12 carbon atoms having a phenyl group as an essential component R ⁵ : aromatic group The substrate for display materials according to claim 1, comprising a step of applying an organic solvent solution of an aromatic polyamide to a glass having a thickness of 0.3 mm or less, and a step of removing the organic solvent from the organic solvent solution. Manufacturing method. The manufacturing method of the substrate for display materials of Claim 11 which winds up continuously the glass substrate which removed the organic solvent apply | coated to glass around a cylindrical core. The display material using the board | substrate for display materials in any one of Claims 1-10.