JP2013237603A - Glass paste - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a glass paste capable of firing in a short time while preventing pinhole defects from occurring during coating and firing, because pinhole defects occur when coating a conventional glass paste, and sufficient temperature and time of heat treatment are indispensable for a process of firing the coated glass paste, when forming a glass layer as an insulating layer or a protective layer of a substrate or an electrode.SOLUTION: There is provided a glass paste including a glass powder material and an organic vehicle, where the glass paste contains 0.1-5 mass% of an organic binder; the organic binder is a polymer containing a hydroxy group; a monomer having the hydroxy group accounts for 15 mol% or more of monomers constituting the polymer; and viscosity of the glass paste at 25°C is 100-100,000 mPa s.

Description

  The present invention relates to a glass paste, and more particularly to a glass paste used when applied and fired in a sheet form or a film form.

  In displays such as liquid crystal, organic EL, and electronic paper, solar cells, touch panels, and the like, a glass layer that forms a glass paste into a sheet or film is used as an insulating layer or protective layer for the substrate or electrode. Such a glass layer is formed by applying glass paste by various application methods such as screen printing and baking.

  In recent years, improvement in breakage resistance, weight reduction, and flexibility of devices described above have been required, and at present, the use of a plastic substrate film as a base material as these materials has attracted attention. When producing the said flexible display and a solar cell, it is common to use a roll to roll method. The roll-to-roll method (see, for example, Patent Document 1) is a manufacturing method in which a plastic substrate film previously wound in a roll shape is unwound, and various treatments are continuously performed, and finally wound into a roll shape. Since the carrying-in and carrying-out in each process can be omitted, it is widely used when a plastic substrate film is used as a base material.

  Usually, a glass paste is a mixture of a solid component such as glass powder and a solvent, which is baked to remove the solvent and soften the glass powder material for adhesion, sealing, coating, etc. It is. In particular, in the case of a glass paste used to form a sheet-like or film-like glass layer, there is a problem that a crack or crack occurs in the glass layer after firing, or a pinhole defect in which a hole is partially formed occurs. Various studies have been made.

For example, Patent Document 2 discloses a glass paste in which an inorganic powder having a thermal expansion coefficient of 25 × 10 ⁻⁷ / ° C. or less is mixed in order to suppress cracks that occur during firing of glass frit. Further, in Patent Document 2, the firing temperature of the glass paste is targeted to be about 100 ° C. higher than the softening point of the glass frit, and in the embodiment, firing is performed at 800 ° C. for 10 minutes.

  Further, in Patent Document 3, 3,4′-oxydianiline and 4,4 are used in order to obtain a glass film that does not cause cracking or cracking even when fired on the base material using a polyimide film as the base material. A low-melting-point glass paste is disclosed in which a low-melting-point glass is dispersed in a polyimide precursor solution in which a polyimide precursor composed of '-oxydiphthalic acid and / or a derivative thereof is dissolved in a solvent. Moreover, in patent document 3, in order to obtain a glass film, the low melting point glass is melted at a temperature not lower than the melting point of the low melting point glass and not higher than 550 ° C., and in this example, heating is performed at 400 to 450 ° C. for 1 hour. .

  Further, Patent Document 4 contains an acrylic resin having a hydrophilic functional group in order to suppress film defects such as streaky coating marks, craters, and pinholes that occur in the glass film-forming material layer on the transfer film. A glass paste containing a binding resin is disclosed. In the glass paste, when the softening point of the glass powder material is less than 400 ° C., the glass powder material is melted at a stage where an organic substance such as a binder resin is not completely decomposed and removed in the baking process of the film forming material layer. A part of the organic substance remains, and the softening point of the glass powder material is set to 400 ° C. or higher. Moreover, in patent document 4, a calcination temperature is 400-600 degreeC and the baking is performed for 30 minutes at 570 degreeC in the Example.

JP 2011-245625 A JP-A-7-133136 JP 2001-270736 A Japanese Patent Laid-Open No. 10-324541

  When a glass layer is formed using glass paste, various coating methods such as screen printing are used, but there is a problem that pinhole defects occur in the coating and baking processes.

  In addition, the process of removing the solvent contained in the glass paste and firing the glass powder material requires a sufficient heat treatment temperature and time. As described above, the electrodes and substrates of various devices and the plastic substrate film described above are used. Thus, it is required to form a glass layer on a substrate or the like that is easily deformed or altered by heating, and a glass powder material that can be fired in a short time is desired.

  An object of the present invention is to obtain a glass paste that can be fired in a short time without forming pinhole defects during coating or firing when the glass layer is formed.

  The present invention is a glass paste containing a glass powder material and an organic vehicle, the glass paste containing 0.1 to 5% by mass of an organic binder, the organic binder being a polymer containing a hydroxyl group, It is a glass paste characterized in that a monomer having a hydroxyl group is 15 mol% or more among the constituent monomers, and the viscosity of the glass paste at 25 ° C. is 100 to 100,000 mPa · s.

  As the glass powder material, it is preferable to use a glass powder material having an average particle diameter of about 0.1 to 10 [mu] m, and it melts in a firing step to form a glass layer.

  The organic vehicle is composed of an organic solvent and an organic binder, and disappears by burning, decomposition, and volatilization after heating and baking the glass paste.

  The organic binder is a glass powder material that is dispersed and supported in the glass paste. When the glass paste is baked, it is removed from the paste by heating or the like (hereinafter also referred to as debinding). There is.

  The organic binder is a polymer containing a hydroxyl group, and among the monomers constituting the polymer, the monomer having a hydroxyl group is 15 mol% or more.

  By using an organic binder having a hydroxyl group contained with respect to the total mass of the glass paste, the glass powder material in the glass paste is more dispersed, and the glass powder material is uniformly laminated in the coating film. Later, pinholes are less likely to occur. On the other hand, when there is no hydroxyl group, the glass powder material aggregates in the glass paste, and the glass powder material in the coating film is laminated unevenly. As a result, pinholes are likely to occur in sparsely stacked portions.

  Moreover, in this invention, content of the said organic binder is 0.1-5 mass%. If it is less than 0.1% by mass, the effect of the organic binder is insufficient, and if it exceeds 5% by mass, the time required for the binder removal process becomes long, and the binder removal may be insufficient.

The viscosity of the present invention rheometer (BROOKFIELD Co., RVDV-II + P CP) was used to measure the viscosity of the glass paste composition at a shear rate of 10 sec ^-1 at 25 ° C. conditions.

  In the case of the present invention, as described above, since the content of the organic binder is 5% by mass or less, the glass powder material is likely to aggregate and settle. Therefore, if the viscosity is less than 100 mPa · s, the glass powder material may be difficult to disperse in the organic solvent. Moreover, when it exceeds 100,000 mPa · s, it may be difficult to apply. Moreover, Preferably it is good also as 1000-70000 mPa * s.

  The present invention is particularly effective when using a base material that is easily deformed or damaged by heating, such as a plastic film substrate. For example, if the firing temperature is in the range of 380 to 450 ° C., the binder is removed. It becomes possible to make baking time into the range for 3 to 15 minutes.

  According to the present invention, it is possible to obtain a glass paste that can be fired at a low temperature in a short time without forming pinhole defects during coating or firing when the glass layer is formed.

  The present invention is a glass paste containing a glass powder material and an organic vehicle, the glass paste containing 0.1 to 5% by mass of an organic binder, the organic binder being a polymer containing a hydroxyl group, It is a glass paste characterized in that a monomer having a hydroxyl group is 15 mol% or more among the constituent monomers, and the viscosity of the glass paste at 25 ° C. is 100 to 100,000 mPa · s.

  As described above, the organic vehicle is composed of an organic solvent and an organic binder, and disappears by burning, decomposition, and volatilization after heating and baking the glass paste. In addition, said organic solvent is contained in 5-69 mass% in glass paste.

  For example, organic solvents include N, N′-dimethylformamide (DMF), α-terpineol, γ-butyllactone (γ-BL), tetralin, butyl carbitol acetate, ethyl acetate, isoamyl acetate, diethylene glycol monoethyl ether, diethylene glycol mono Ethyl ether acetate, 2,2,4-trimethyl-1,3-pentanediol mono (2-methylpropanoate), benzyl alcohol, toluene, 3-methoxy-3-methylbutanol, n-pentanol, 4-methyl Pentanol, cyclohexanol, triethylene glycol monomethyl ether, triethylene glycol dimethyl ether, dipropylene glycol monomethyl ether, dipropylene glycol monobutyl ether, tripropylene glycol Monomethyl ether, tripropylene glycol monobutyl ether, propylene carbonate, dimethyl sulfoxide (DMSO), N-methyl-2-pyrrolidone and the like can be used. In particular, α-terpineol is preferable because of its good solubility in resins and the like.

  The organic binder is a polymer containing a hydroxyl group, and among the monomers constituting the polymer, the monomer having a hydroxyl group is preferably 15 mol% or more. When the amount is less than 15 mol%, the glass powder material tends to aggregate in the glass paste, and the glass powder material in the coating film is laminated unevenly, and pinholes are likely to occur in the loosely laminated portions.

  Moreover, 0.1-5 mass% of organic binders are contained with respect to the mass of the glass paste. Preferably it is good also as 0.5-3 mass%. When the content exceeds 5% by mass, the binder is not sufficiently removed and the formed glass film is colored. When the content is less than 0.1% by mass, the aggregation, sedimentation and coating properties of the glass may be deteriorated.

  The organic binder may be selected from those that can be removed at the time of firing, and the temperature at which the organic binder completely disappears is preferably lower than the softening point of the glass, preferably even at a temperature of 30 ° C. or lower than the softening point of the glass. Those that can completely disappear can be preferably used. When the temperature at which the disappearance of the organic binder is completed is close to the softening point of the glass, there is a high possibility that the organic binder remains in the film, and it is necessary to make the temperature rise rate slow in order to prevent the organic binder from remaining. As a result, firing takes a long time and defects such as pinholes may occur.

  As the kind of the above organic binder, for example, acrylic acid ester, nitrocellulose, ethylcellulose and the like can be suitably used because they have a hydroxyl group. Particularly, among those organic binders, those having a hydroxyl group per monomer unit are 15 mol% or more. Is preferred.

  Among the organic binders described above, the acrylate ester may be a copolymer of an acrylate ester monomer containing a hydroxyl group and an acrylate ester monomer having no hydroxyl group in a desired ratio of hydroxyl groups. This is preferable because the amount can be easily adjusted. Examples of the monomer having a hydroxyl group constituting the acrylate ester include hydroxymethyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, 2 -Hydroxybutyl (meth) acrylate, 3-hydroxybutyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate ethylene glycol monomethyl (meth) acrylate, ethylene glycol monoethyl (meth) acrylate, glycerol (meth) acrylate, etc. It is done.

  In addition, when a monomer containing no hydroxyl group is used in combination with the above monomer, for example, methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, isopropyl (meth) acrylate, butyl methacrylate, isobutyl (meth) Acrylate, t-butyl (meth) acrylate, allyl methacrylate, butyl methacrylate, isobutyl methacrylate, ethylene glycol dimethacrylate, pentyl (meth) acrylate, amyl (meth) acrylate, isoamyl (meth) acrylate, hexyl (meth) acrylate, heptyl ( (Meth) acrylate, octyl (meth) acrylate, isooctyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, nonyl (meth) acrylate , Decyl (meth) acrylate, isodecyl (meth) acrylate, undecyl (meth) acrylate, dodecyl (meth) acrylate, tridecyl (meth) acrylate, lauryl (meth) acrylate, stearyl (meth) acrylate, isostearyl (meth) acrylate Alkyl (meth) acrylate, cyclohexyl (meth) acrylate, 4-butylcyclohexyl (meth) acrylate, dicyclopentanyl (meth) acrylate, dicyclopentenyl (meth) acrylate, dicyclopentadienyl (meth) acrylate, Bornyl (meth) acrylate, isobornyl (meth) acrylate, tricyclodecanyl (meth) acrylate, ethylene glycol di (meth) acrylate, triethylene glycol (Meth) acrylate, tetraethylene glycol di (meth) acrylate, butylene glycol di (meth) acrylate, propylene glycol di (meth) acrylate, and 1,6-hexanediol di (meth) acrylate.

  It is also possible to use polyethylene glycol, polymethylstyrene, polycarbonate, methacrylic acid ester, etc. mixed with the above organic binder having a hydroxyl group so that the TI value satisfies 1.0 to 2.0.

  The glass powder material is preferably contained in the glass paste in an amount of 30 to 90% by mass. If it is less than 30% by mass, pinholes may be generated after heat sintering. Moreover, when exceeding 90 mass%, defects, such as a blur, may be seen visually after application | coating. Preferably it is good also as 60-85 mass%.

  Although the glass powder material of this invention should just have a softening point of the grade which a board | substrate does not deteriorate when heat-baking glass paste, Preferably it is 500 degrees C or less, It is good also as less than 400 degreeC. Moreover, a bismuth-type glass composition and a lead-type glass composition can be suitably selected as a glass powder material having the above softening point.

The bismuth-based glass composition contains Bi ₂ O ₃ , B ₂ O ₃ , and a ZnO component. Among these components, the total of Bi ₂ O ₃ , B ₂ O ₃ and ZnO exceeds 80% by mass with respect to the total amount of the bismuth-based glass composition, preferably 85% by mass or more, more preferably It is good also as 90 mass% or more. Moreover, you may contain various arbitrary components according to the objective so that said 3 components may become said range.

The bismuth glass composition, for example, 65 to 95 and _Bi 2 _{O 3} in _mass%, B 2 _{O 3} 1-20, include compositions comprising 1-20 a ZnO.

Bi ₂ O ₃ lowers the softening point of the glass, imparts fluidity, and is desirably contained in the range of 65 to 95% (hereinafter, mass% may be described as%). If it is less than 65%, the above effect cannot be exhibited, and if it exceeds 95%, the stability of the glass is lowered. More preferably, it is 70 to 85% of range.

B ₂ O ₃ is a glass-forming component, facilitates glass melting, suppresses an excessive increase in the linear expansion coefficient of the glass, and imparts moderate fluidity to the glass during baking. It is preferable to make it contain in 1 to 20% of range in glass. If it is less than 1%, depending on the relationship with other components, the fluidity of the glass may be insufficient, and the sinterability may be impaired. On the other hand, if it exceeds 20%, the softening point of the glass rises, and the formability and workability become difficult. More preferably, it is 5 to 10% of range.

  ZnO lowers the softening point of the glass and adjusts the linear expansion coefficient to an appropriate range, and is preferably contained in the range of 1 to 20% in the glass. If it is less than 1%, the above action cannot be exhibited depending on the relationship with other components. If it exceeds 20%, the glass becomes unstable and devitrification tends to occur. More preferably, it is 5 to 10% of range.

In addition to the above, MgO, CaO, In ₂ O ₃ , SnO ₂ , TeO _{2 and the} like represented by general oxides may be added as appropriate within the range not impairing the above properties.

The lead-based glass composition contains PbO, B ₂ O ₃ , and a ZnO component. Among these components, the total of PbO, B ₂ O ₃ and ZnO exceeds 80% by mass with respect to the total amount of the lead-based glass composition, preferably 85% by mass or more, more preferably 90% by mass. It is good also as above. Moreover, you may contain various arbitrary components according to the objective so that said 3 components may become said range.

The lead-based glass composition includes, for example, a composition containing 65 to 85 PbO, 10 to 25 B ₂ O ₃ , and 1 to 10 ZnO by mass%.

  PbO lowers the softening point of the glass and imparts fluidity, and is preferably contained in the range of 65 to 85%. If it is less than 65%, the above effect cannot be exhibited, and if it exceeds 85%, the stability of the glass is lowered. More preferably, it is 70 to 80% of range.

B ₂ O ₃ is a glass-forming component, facilitates glass melting, suppresses an excessive increase in the linear expansion coefficient of the glass, and imparts moderate fluidity to the glass during baking. It is preferable to make it contain in 10 to 25% in glass. If it is less than 10%, depending on the relationship with other components, the fluidity of the glass may be insufficient, and the sinterability may be impaired. On the other hand, if it exceeds 25%, the softening point of the glass rises, and the formability and workability become difficult. More preferably, it is 10 to 22% of range.

  ZnO lowers the softening point of the glass and adjusts the linear expansion coefficient to an appropriate range, and is preferably contained in the range of 1 to 10% in the glass. If it is less than 1%, the above action cannot be exhibited depending on the relationship with other components. If it exceeds 10%, the glass becomes unstable and devitrification tends to occur. More preferably, it is 6 to 8% of range.

In addition to the above, MgO, CaO, In ₂ O ₃ , SnO ₂ , TeO _{2 and the} like represented by general oxides may be added as appropriate within the range not impairing the above properties.

  Moreover, by introducing ceramic powder as a filler into the present glass paste as necessary, it is possible to obtain a glass layer having an adjusted coefficient of thermal expansion, improved film strength, and improved water / acid resistance.

The content of the ceramic powder is preferably 20% by mass or less. When it exceeds 20 mass%, sinterability will be impaired and the compactness of a glass layer will fall. More preferably, it is the range of 0-10 mass%. As the ceramic powder, general inorganic fillers such as Al ₂ O ₃ , ZrO ₂ and TiO ₂ can be used.

  In the present invention, a glass powder material having an average particle diameter of about 0.1 to 10 μm is used. When a glass layer is produced using a glass powder material exceeding 10 μm, the glass layer becomes thick, so that it may be easily damaged when a flexible base material such as a plastic film substrate is used.

  The average particle diameter is a value measured by a laser diffraction / scattering method using a Microtrack MT3000 manufactured by Nikkiso Co., Ltd. In the measurement, after the glass powder material was dispersed in a solvent, laser light was irradiated to obtain scattered / diffracted light, and the particle size distribution was calculated from the light intensity distribution data of the diffracted / scattered light. Note that the scattering phenomenon that occurs when light strikes particles suspended in a solvent varies depending on the size, refractive index, wavelength of incident light, etc., but in this study, the amount of scattered light and the number of occurrences were measured. From the value, the particle size of the particles was calculated according to the program set in the apparatus.

  The average particle size is obtained by multiplying the measured particle size value by the relative particle amount (difference%) and dividing by the total relative particle amount (100%). The average particle diameter is the average particle diameter, and means the particle diameter at an integrated value of 50% (median diameter) in the particle size distribution determined by the laser diffraction / scattering method.

  The glass powder material as described above is obtained by weighing and mixing glass raw materials to prepare a raw material batch, heating and melting the raw material batch in a melting furnace such as a platinum crucible, and cooling and pulverizing. In the heating and melting, heating is performed using a heating device such as a burner or electricity in order to raise the temperature in the furnace and maintain the temperature, and the above raw material batch is melted and vitrified to obtain molten glass. In the above step, the inside of the furnace is maintained at a temperature equal to or higher than the melting temperature of the glass so that the molten glass becomes homogeneous, and is allowed to flow for a predetermined time. The method for cooling the obtained molten glass is not particularly limited, and it is preferably formed into a thin plate shape or a flake shape so as to be easily pulverized. After cooling the glass, it is pulverized by using a molding machine such as a ball mill or a roll molding machine, and a glass powder material is obtained by removing those having significantly different particle sizes by classification.

  One preferred embodiment of the glass paste of the present invention is a glass paste characterized in that the glass paste has a TI value of 1.0 to 2.0.

  The TI value is a value representing the dispersibility of the glass powder material. When the TI value is in the range of 1.0 to 2.0, the dispersibility is good and pinholes are hardly generated. On the other hand, if the TI value exceeds 2.0, pinholes are likely to occur due to aggregation of the glass powder material. When the TI value is less than 1.0, the viscosity becomes remarkably high, and it becomes difficult to apply uniformly.

The TI value is a value calculated using the viscosity measured with a rotary viscometer. In the present invention, the TI value was measured using a rheometer (manufactured by BROOKFIELD, RVDV-II + PCP). At this time, the measurement condition of the TI value may change depending on the viscosity of the glass paste, and select a suitable one of the following two measurement conditions so that the torque value of the viscometer falls within the range of 10 to 90%. And measured.
Condition A: When the rotational speed is 1 to 10 and the torque value falls within the range of 10 to 90% under the condition of 25 ° C., the viscosity at the time of one rotation is divided by the viscosity at the time of 10 rotations. Calculated.
Condition B: When the rotational speed is 10 to 100 and the torque value falls within the range of 10 to 90% under the condition of 25 ° C., the viscosity at 10 revolutions is divided by the viscosity at 100 revolutions. Calculated.

  As described above, when the TI value representing the dispersibility of the glass powder material is in the range of 1.0 to 2.0, the glass paste of the present invention has good dispersibility and is unlikely to generate pinholes. On the other hand, if the TI value exceeds 2.0, pinholes are likely to occur due to aggregation of the glass powder material. When the TI value is less than 1.0, it is when the solid content exceeds 90% by mass and the viscosity is extremely high, so that it is difficult to apply uniformly. As a condition for obtaining an even better glass paste, the TI value may preferably be in the range of 1.0 to 1.5. More preferably, it may be in the range of 1.0 to 1.3.

  One of the preferred embodiments of the glass paste of the present invention is a step of applying the glass paste described above on a substrate, the applied glass paste, and the softening point of the glass powder material contained in the glass paste +20 to + 100 ° C. Is a method for forming a glass layer, comprising a step of heating and baking within the range.

  For the application of the glass paste, a general coating machine such as a bar coat, a gravure coater, a reverse roll coater, a curtain flow coater, or a die coater can be used. Moreover, it can also be used in screen printing, intaglio printing, relief printing, flat printing, etc., which are general printing methods. In particular, by using a die coater, a gravure coater, a comma coater, and intaglio printing, it becomes possible to apply with uniform and various film thicknesses.

  The substrate on which the glass paste is applied by the method described above is preferably heated and fired through a drying process. The drying step volatilizes the organic solvent of the applied glass paste with hot air or IR. Further, the temperature at this time is preferably heated to such an extent that the organic solvent volatilizes and does not adversely affect the substrate.

  In the heating and baking step after the drying step, the organic solvent and the organic binder are completely removed by hot air or IR, and at the same time, the softened glass powder material forms a glass layer. In the heating and baking step, the temperature in the apparatus used for heating and baking is gradually heated from a temperature below the softening point of the glass, and finally reaches or above the softening point of the glass, preferably +20 to + 100 ° C. It is better to heat. More preferably, the softening point may be +20 to + 40 ° C. At this time, as described above, heating at a temperature not higher than the softening point of the glass and raising the temperature is preferable because the organic solvent and the organic binder can be efficiently removed.

  The substrate is not particularly limited, but as one preferred embodiment of the present invention, it is preferable to use a film material having a 5% weight loss temperature equal to or higher than the softening point of the glass powder. If the 5% weight loss temperature is less than the above, the film material may deteriorate when the glass is fired. Examples of the film material as described above include polyimide, polyamide, and silicone.

  One of the preferred embodiments of the glass paste of the present invention is a film in which the substrate is installed in a roll-to-roll apparatus, and the glass layer is formed while unwinding and winding the substrate. Is preferred.

  The roll-to-roll device unwinds a plastic substrate film previously wound in a roll shape, conveys the plastic film substrate as a base material while applying a constant tension, forms a glass layer on the base material, and then cools it. This is a manufacturing method in which the product is finally wound up again in a roll shape, and it is preferable because loading and unloading in each step can be omitted. When the roll-to-roll apparatus is used, particularly when the time required for the baking process is long, deformation due to the tension applied to the film is generated, and since the unwinding and winding are always performed, it is necessary to enlarge the apparatus itself. Since the glass paste of the present invention can be baked in a short time of 3 to 15 minutes at a temperature of 380 to 450 ° C. or less, it can be particularly preferably used when forming a glass layer using the apparatus.

  Hereinafter, the present invention will be specifically described with reference to Examples and Comparative Examples. Hereinafter, “mass%” may be described as “%”.

<Preparation of bismuth-based glass powder material>
Various inorganic raw materials are weighed and mixed so that the glass powder material is Bi ₂ O ₃ : 84 mass%, B ₂ O ₃ : 6 mass%, ZnO: 10 mass%, and a raw material batch is prepared. After putting in a platinum crucible, it was heated and melted in an electric heating furnace at 1200 ° C. for 1 to 2 hours to obtain a bismuth glass having a softening point of 380 ° C. The obtained glass was pulverized with a quenching twin roll molding machine to obtain a glass powder material. The obtained glass powder material was used in the following Examples and Comparative Examples. Moreover, the softening point was calculated | required from the inflection point using the DTA measuring apparatus (made by Rigaku).

<Production of lead-based glass powder material>
A raw material batch is prepared by weighing and mixing various inorganic raw materials so that the glass powder material is PbO ₂ : 76% by mass, B ₂ O ₃ : 15% by mass, ZnO: 7% by mass, and SiO ₂ : 2% by mass. The raw material batch was put into a platinum crucible and then heated and melted in an electric heating furnace at 1100 ° C. for 1 to 2 hours to obtain a lead-based glass having a softening point of 390 ° C. The obtained glass was pulverized with a quenching twin roll molding machine to obtain a glass powder material. The obtained glass powder material was used in the following Examples and Comparative Examples. Moreover, the softening point was calculated | required from the inflection point using the DTA measuring apparatus (made by Rigaku).

<Measurement of average particle diameter>
The average particle diameter of the produced glass powder material was measured using a laser diffraction type particle diameter measuring device (manufactured by Nikkiso Co., Ltd., Microtrack). Measurement is performed by dispersing the glass powder material in water and then irradiating the laser beam to obtain scattered / diffracted light. From the light intensity distribution, the particle size of the glass powder material is determined according to the program set in the device. And the average particle diameter was determined. In the following Examples and Comparative Examples, glass powder materials having an average particle diameter of 1 μm were used.

<Adjustment of glass paste>
Glass pastes shown in the following Examples and Comparative Examples were prepared using a mixed solvent composed of α-terpineol and butyl carbitol acetate, an organic binder, and the glass powder material (average particle diameter of 1 μm) described above. Moreover, it showed in Table 1 about each glass paste.

Example 1
30% of a mixed solvent, 3% of an ethyl cellulose binder (EC vehicle (Nisshin Kasei Co., Ltd.)) and 67% of a bismuth glass powder material were mixed to prepare a glass paste having a viscosity of 6000 mPa · s. The TI value was 1.1.

Example 2
A glass paste having a viscosity of 1200 mPa · s was prepared by mixing 22.3% of a mixed solvent, 0.7% of an ethyl cellulose binder (EC vehicle (Nisshin Kasei Co., Ltd.)) and 67% of a bismuth glass powder material. The TI value was 1.5.

Example 3
A glass paste having a viscosity of 2000 mPa · s was prepared by mixing 47% of a mixed solvent, 3% of an acrylic binder and 50% of a bismuth glass powder material. The TI value was 1.1.

Example 4
A glass paste having a viscosity of 50000 mPa · s was prepared by mixing 13% of a mixed solvent, 2% of an acrylic binder, and 85% of a lead glass powder material having an average particle diameter of 1 μm. The TI value was 1.1.

Comparative Example 1
A glass paste having a viscosity of 20000 mPa · s was prepared by mixing 43% of a mixed solvent, 7% of an ethyl cellulose binder (EC vehicle (Nisshin Kasei Co., Ltd.)) and 50% of a bismuth glass powder material. The TI value was 1.1.

Comparative Example 2
A glass paste having a viscosity of 100000 mPa · s or more was prepared by mixing 8.5% of a mixed solvent, 0.5% of an ethyl cellulose binder (EC vehicle (Nisshin Kasei Co., Ltd.)) and 91% of a bismuth glass powder material. The TI value was smaller than 1 and an accurate value could not be measured.

Comparative Example 3
A glass paste having a viscosity of 1000 mPa · s was prepared by mixing 31.5% of a mixed solvent, 1.5% of an acrylic binder, and 67% of a bismuth glass powder material. The TI value was 1.4.

Comparative Example 4
A glass paste was prepared by mixing 30% of a mixed solvent and 70% of a bismuth glass powder material. Note that the glass powder material immediately settled, and the viscosity and TI value could not be measured.

Comparative Example 5
A glass paste having a viscosity of 50 mPa · s was prepared by mixing 69% of a mixed solvent, 1% of an acrylic binder, and 30% of a bismuth glass powder material. The TI value was 1.1.

<Measurement of TI value>
The TI value was measured by appropriately selecting the following conditions A and B using a rheometer (manufactured by BROOKFIELD, RVDV-II + PCP).
Condition A: When the rotational speed is 1 to 10 and the torque value falls within the range of 10 to 90% under the condition of 25 ° C., the viscosity at the time of one rotation is divided by the viscosity at the time of 10 rotations. Calculated.
Condition B: When the rotational speed is 10 to 100 and the torque value falls within the range of 10 to 90% under the condition of 25 ° C., the viscosity at 10 revolutions is divided by the viscosity at 100 revolutions. Calculated.

<Measurement of viscosity>
The viscosity of the glass paste composition was measured using a rheometer (BROOKFIELD, RVDV-II + PCP). The viscosity at a shear rate of 10 sec ⁻¹ was measured at 25 ° C. In Comparative Example 4, the glass powder material immediately settled, and the viscosity could not be measured.

<Creation of glass layer>
The glass paste produced in the above Examples 1 to 4 and Comparative Examples 1 to 5 and 5% weight reduction temperature obtained by thermogravimetric analysis is 450 ° C. polyimide film (Arakawa Chemical Industries), roll to Application was performed using a die coater in a roll method, and a firing experiment was performed. After coating, drying was performed at 200 ° C. or less with hot air, and then heating was performed while continuously raising the temperature from the temperature below the softening point of the glass powder by IR to perform debinding and firing of the glass layer (370 to 700). 420 minutes at 420 ° C). In Comparative Example 4, since the glass powder material settled and application was impossible, no examination after application was conducted. The results are shown in Table 2.

  In Table 2, “sedimentation” was observed by visually observing the glass paste, and “present” was indicated when the solid content was observed, and “absence” was indicated when no particular change was observed.

  In addition, “applicability” was visually observed after application, and “◯” indicates that no particular problem was observed, and “×” indicates that a problem occurred.

  In addition, “pinhole” was visually observed after firing, and “no” was indicated when no pinhole was observed, and “present” when pinhole was observed. In Comparative Example 2, pinholes were already observed before firing, and firing was not performed because it was not suitable for the purpose of the present invention.

  In addition, “coloring” was visually observed after firing, and “present” was indicated when the glass layer was colored, and “absent” when the glass layer was not colored.

  From Table 2, Examples 1-4 were good in applicability | paintability, and the glass paste which a pinhole, coloring, etc. do not arise in a glass layer after baking was obtained. Moreover, when there is too much content of the organic binder in glass paste, binder removal will become inadequate and coloring will be seen by a glass layer (comparative example 1). On the other hand, when the content of the organic binder was set to 0, the glass powder material settled, and the coating itself became impossible (Comparative Example 4).

  Furthermore, when the TI value of the glass paste is low, the viscosity becomes high and the coating property is lowered (Comparative Example 2). If the hydroxyl group contained in the organic binder is small, pinhole defects occur after sintering, and a suitable glass layer is formed. It cannot be formed (Comparative Example 3). In addition, when the viscosity is low even if the hydroxyl group and TI value contained in the organic binder are the same as in the examples, it is difficult to form a uniform glass layer because the glass powder material settles between drying and baking after coating. (Comparative Example 5) Therefore, it is not suitable for the purpose of the present invention.

  From the above, it has been shown that when the glass layer is formed in the present invention, pinhole defects do not occur at the time of coating or firing, and firing is possible at a low temperature in a short time. Further, it can be suitably used in a roll-to-roll method.

Claims (8)

A glass paste containing a glass powder material and an organic vehicle, wherein the glass paste contains 0.1 to 5% by mass of an organic binder, the organic binder is a polymer containing a hydroxyl group, and a monomer constituting the polymer A glass paste characterized in that the monomer having a hydroxyl group is 15 mol% or more, and the viscosity of the glass paste at 25 ° C. is 100 to 100,000 mPa · s. The glass paste according to claim 1, wherein the glass paste has a TI value of 1.0 to 2.0. The glass paste according to claim 1 or 2, wherein a softening point of the glass powder material is 500 ° C or lower. The glass powder material, 65 to 95 and _Bi 2 _{O 3} in _mass%, the B 2 _{O 3} 1-20, of claims 1 to 3, characterized in that a composition comprising 20 to ZnO The glass paste in any one. The glass powder material, a PbO mass% of 65 to _85, the B 2 _{O 3} 10 to 25, in any one of claims 1 to 3, characterized in that a composition comprising 1 to 10 of ZnO The glass paste as described. The step of applying the glass paste according to any one of claims 1 to 5 on a substrate, and the applied glass paste within a softening point +20 to + 100 ° C of the glass powder material contained in the glass paste. A method for forming a glass layer, comprising a step of heating and baking at a temperature. The method for forming a glass layer according to claim 6, wherein the substrate is a film having a 5% weight loss temperature obtained by thermogravimetric analysis that is equal to or higher than a softening point of the glass powder material. The glass according to claim 6 or 7, wherein the substrate is a film installed in a roll-to-roll apparatus, and the glass layer is formed while unwinding and winding the substrate. Layer formation method.