JP2011225426A - Sealing material and paste material using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To increase the reliability of an organic EL display or the like by creating a sealing material suitable for laser sealing, concretely, a sealing material easy to absorb a laser beam and also having a low softening point.SOLUTION: The sealing material contains: by mass 80 to 99.7% inorganic powder including SnO-containing glass powder; and 0.3 to 20% pigment, and is also used for laser sealing.

Description

  The present invention relates to a sealing material and a paste material using the same, and more particularly to a sealing material used for a sealing process using laser light (hereinafter referred to as laser sealing) and a paste material using the same.

  In recent years, organic EL displays have attracted attention as flat display panels. Since the organic EL display can be driven by a DC voltage, the driving circuit can be simplified, and there are advantages such as a liquid crystal display that is not dependent on the viewing angle, bright due to self-emission, and has a high response speed. Currently, organic EL displays are mainly used in small portable devices such as mobile phones, but in the future, application to ultra-thin televisions is expected. Note that the organic EL display is mainly driven by disposing an active element such as a thin film transistor (TFT) in each pixel in the same manner as a liquid crystal display.

  The organic EL display is composed of two glass substrates, a negative electrode such as metal, an organic light emitting layer, a positive electrode such as ITO, and an adhesive material. Conventionally, an organic resin adhesive material such as an epoxy resin having a low temperature curability or an ultraviolet curable resin has been used as the adhesive material. However, organic resin adhesive materials cannot completely block gas intrusion. For this reason, when an organic resin adhesive material is used, the airtightness inside the organic EL display cannot be maintained, and as a result, the organic light-emitting layer having low water resistance tends to deteriorate, and the organic EL display There was a problem that the display characteristics of the display deteriorated with time. In addition, the organic resin-based adhesive material has an advantage that glass substrates can be bonded to each other at a low temperature. However, since the water resistance is low, when an organic EL display is used for a long time, the reliability of the display is likely to be lowered.

US Pat. No. 6,416,375 JP 2006-315902 A

  The sealing material containing glass powder is excellent in water resistance as compared with the organic resin adhesive material, and is suitable for ensuring airtightness inside the organic EL display.

  However, since glass powder generally has a softening point of 300 ° C. or higher, it has been difficult to apply it to an organic EL display. More specifically, when glass substrates are sealed with the above-mentioned sealing material, the entire organic EL display is put into an electric furnace and baked at a temperature equal to or higher than the softening point of the glass powder to soften and flow the glass powder. There is a need. However, since the active element used in the organic EL display has only heat resistance of about 120 to 130 ° C., sealing the glass substrates by this method damages the active element due to heat, and the organic EL display. Display characteristics will deteriorate. In addition, since the organic light emitting material also has poor heat resistance, sealing the glass substrates by this method damages the organic light emitting material due to heat and degrades the display characteristics of the organic EL display.

  In view of such circumstances, in recent years, laser sealing has been studied as a method for sealing an organic EL display. According to laser sealing, since only the part to be sealed can be locally heated, the glass substrates can be sealed together while preventing thermal degradation of the active element or the like.

  Patent Documents 1 and 2 describe that a front glass substrate and a rear glass substrate of a field emission display are laser-sealed. However, Patent Documents 1 and 2 do not describe a specific material configuration, and it is unclear what material configuration is suitable for laser sealing. For this reason, even if the sealing material is irradiated with the laser beam, the sealing material cannot absorb the laser beam accurately, and it is difficult to efficiently convert the laser beam into heat energy at the sealing site. If the output of the laser beam is increased, laser sealing can be performed without optimizing the material configuration. However, in this case, the active element or the like may be heated to deteriorate the display characteristics of the organic EL display. is there.

  Further, the lower the softening point of the glass powder, the more efficient the laser sealing. Specifically, as the softening point of the glass powder is lower, laser sealing can be completed in a shorter time, and the sealing strength can be increased during laser sealing.

  Therefore, the present invention improves the reliability of organic EL displays and the like by creating a sealing material suitable for laser sealing, specifically, a sealing material that easily absorbs laser light and has a low softening point. This is a technical issue.

  As a result of intensive studies, the present inventors have found that the above technical problem can be solved by adding a predetermined amount of a pigment that absorbs laser light and adopting SnO glass powder. It is. That is, the sealing material of the present invention contains 80 to 99.7% by mass of inorganic powder containing SnO-containing glass powder and 0.3 to 20% by mass of pigment, and is used for laser sealing. To do. Here, the “SnO-containing glass powder” refers to a glass powder containing 20 mol% or more of SnO as a glass composition. The “inorganic powder” refers to an inorganic material powder other than a pigment, and usually refers to a mixture of glass powder and a refractory filler.

  The inorganic powder according to the present invention includes SnO-containing glass powder. If it does in this way, the softening point of glass powder will fall and the softening point of sealing material will also fall. As a result, laser sealing can be completed in a short time, and the sealing strength can be increased during laser sealing.

The sealing material of the present invention contains 80 to 99.7% by mass of inorganic powder including SnO-containing glass powder. In this way, since the airtightness inside the organic EL display can be secured, it is possible to prevent the situation where H ₂ O, O ₂ or the like that deteriorates the organic light emitting layer enters the inside of the organic EL display. The reliability of the organic EL display can be increased. If the content of the inorganic powder is less than 80% by mass, the softening flow of the sealing material becomes poor during laser sealing, and it becomes difficult to increase the sealing strength.

  The sealing material of this invention contains 0.3-20 mass% of pigments. If the pigment content is regulated to 0.3% by mass or more, the laser light can be efficiently converted into thermal energy, so that only the part to be sealed is easily heated locally. The glass substrates can be laser-sealed together while preventing deterioration. On the other hand, if the pigment content is regulated to 20% by mass or less, it is possible to prevent the glass from devitrifying during laser sealing.

  The sealing material of the present invention is used for laser sealing. Since the sealing material of the present invention can accurately absorb laser light, it can be suitably used for laser sealing. Note that, as described above, according to laser sealing, only the portion to be sealed can be locally heated, so that the glass substrates can be sealed together while preventing thermal degradation of the active element or the like.

Various lasers can be used for laser sealing. In particular, a semiconductor laser, a YAG laser, a CO ₂ laser, an excimer laser, an infrared laser, and the like are preferable in terms of easy handling.

Secondly, the sealing material of the present invention, SnO-containing glass powder, as a glass composition, in mole%, SnO 35 to _70%, preferably contains _P 2 O 5 _10~30%. If it does in this way, it will become easy to raise the water resistance of glass, maintaining the low melting point characteristic of glass.

Thirdly, in the sealing material of the present invention, the SnO-containing glass powder further has a glass composition of mol%, ZnO 1 to 20%, B ₂ O ₃ 1 to 20%, Al ₂ O ₃ 0.1. It is preferable to contain -10%. If it does in this way, it will become easy to raise the thermal stability of glass, while reducing the thermal expansion coefficient of glass.

Fourthly, the sealing material of the present invention has pigments such as C (carbon), Co ₃ O ₄ , CuO, Cr ₂ O ₃ , Fe ₂ O ₃ , MnO ₂ , SnO, and Ti _n O _2n-1 (n Are preferably one or two or more selected from an integer). These pigments have excellent color developability and good laser light absorption.

Fifth, in the sealing material of the present invention, the pigment is preferably carbon. Carbon is inexpensive and has particularly good absorption of laser light. Carbon also has the effect of preventing the SnO-containing glass powder from being altered during laser sealing, that is, the effect of preventing the oxidation of SnO in the glass composition to SnO ₂ during laser sealing.

  Sixth, the sealing material of the present invention preferably contains 0.1 to 60% by volume of a refractory filler in the inorganic powder.

Seventhly, the sealing material of the present invention is such that the refractory filler is selected from cordierite, zircon, tin oxide, niobium oxide, zirconium phosphate, zirconium tungstate phosphate, NbZr (PO ₄ ) ₃ or Two or more are preferable.

  Eighth, the sealing material of the present invention is preferably used for sealing an organic EL device. Here, the “organic EL device” includes an organic EL display, organic EL lighting, and the like.

  Ninthly, the paste material of the present invention is characterized in that, in the paste material containing a sealing material and a vehicle, the sealing material is the sealing material described above, and the vehicle contains an aliphatic polyolefin carbonate.

  Tenth, in the paste material of the present invention, the vehicle has N, N′-dimethylformamide, ethylene glycol, dimethyl sulfoxide, dimethyl carbonate, propylene carbonate, butyrolactone, caprolactone, N-methyl-2-pyrrolidone, It is preferable to include one or more selected from glycol (PhDG), dibutyl phthalate (DBP), benzyl glycol (BzG), benzyl diglycol (BzDG), and phenyl glycol (PhG).

Eleventh, the paste material of the present invention is preferably subjected to a binder removal treatment in an inert atmosphere. Here, the “inert atmosphere” includes a neutral gas atmosphere such as an N ₂ gas atmosphere and an Ar gas atmosphere, and a reduced pressure atmosphere such as a vacuum atmosphere.

  Twelfth, the paste material of the present invention is preferably used for laser sealing in an inert atmosphere.

It is a schematic diagram which shows the softening point of glass powder when it measures with a macro type | mold DTA apparatus. It is data which shows the influence which phenylglycol (PhG) has on the drying rate of a paste material.

  The sealing material of the present invention contains 80 to 99.7% by mass of inorganic powder containing SnO-containing glass powder and 0.3 to 20% by mass of pigment. The content of the inorganic powder is preferably 90 to 99 mass%, 95 to 99 mass%, particularly 97 to 99 mass%. When the content of the inorganic powder is small, the softening flow of the sealing material becomes poor during laser sealing, and it becomes difficult to increase the sealing strength. On the other hand, when the content of the inorganic powder is more than 99.9% by mass, the content of the pigment is relatively reduced, so that it is difficult to convert the laser light into heat energy. The pigment content is preferably 0.4 to 10% by mass, particularly preferably 0.6 to 10% by mass. If the pigment content is too small, it becomes difficult to convert laser light into heat energy. On the other hand, when there is too much content of a pigment, the thermal stability of glass will fall easily.

In the sealing material of the present invention, the average particle diameter D50 of the SnO-containing glass powder is preferably less than 15 μm, 0.5 to 10 μm, particularly preferably 1 to ₅ μm. When regulating the average particle diameter D ₅₀ of the SnO-containing glass powder less than 15 [mu] m, it tends to narrow the gap between the two glass substrates, in this case, along with the time required for the laser sealing is reduced, the glass substrate and the sealing material Even if there is a difference in the thermal expansion coefficient, cracks and the like are less likely to occur in the glass substrate and the sealing part. Here, the “average particle diameter D ₅₀ ” refers to a value measured by the laser diffraction method, and in the volume-based cumulative particle size distribution curve when measured by the laser diffraction method, the accumulated amount is accumulated from the smaller particle. The particle diameter is 50%.

In the sealing material of the present invention, the maximum particle diameter _Dmax of the SnO-containing glass powder is preferably 30 μm or less, 20 μm or less, particularly preferably 10 μm or less. When the average particle diameter _Dmax of the SnO-containing glass powder is regulated to 30 μm or less, the gap between the two glass substrates is easily narrowed. In this case, the time required for laser sealing is reduced, and the glass substrate and the sealing material are also reduced. Even if there is a difference in the thermal expansion coefficient, cracks and the like are less likely to occur in the glass substrate and the sealing part. Here, the “average particle diameter D _max ” refers to a value measured by the laser diffraction method. In the volume-based cumulative particle size distribution curve measured by the laser diffraction method, the accumulated amount is accumulated from the smaller particle. The particle diameter is 99%.

The SnO-containing glass of the present invention preferably contains SnO 35 to 70% and P ₂ O ₅ 10 to 30% as a glass composition in terms of the following oxide%. The reason for limiting the glass composition range as described above is shown below. In the description of the glass composition range, “%” indicates mol% unless otherwise specified.

  SnO is a component that lowers the melting point of glass and is an essential component. Its content is 20% or more, preferably 35 to 70%, 40 to 70%, particularly preferably 50 to 68%. In particular, if the SnO content is 50% or more, the glass tends to soften and flow during laser sealing. When the content of SnO is less than 35%, the viscosity of the glass becomes too high, and it becomes difficult to perform laser sealing with a desired laser output. On the other hand, if the SnO content is more than 70%, vitrification tends to be difficult.

P ₂ O ₅ is a glass-forming oxide and is a component that increases the thermal stability of glass. The content is preferably 10 to 30%, 15 to 27%, particularly preferably 15 to 25%. When the content of P ₂ O ₅ is less than 10%, the thermal stability of the glass tends to be lowered. On the other hand, when the content of P ₂ O ₅ is more than 30%, reduces the weather resistance of the glass, it becomes difficult to ensure long-term reliability of the organic EL device or the like.

  In addition to the above components, the following components can be added.

  ZnO is an intermediate oxide and a component that stabilizes the glass. The content is preferably 0 to 30%, 1 to 20%, particularly preferably 1 to 15%. If the ZnO content is more than 20%, the thermal stability of the glass tends to be lowered.

B ₂ O ₃ is a glass-forming oxide and a component that stabilizes the glass. _Further, B 2 _{O 3} is a component for enhancing the weather resistance of the glass. The content is preferably 0 to 20%, 1 to 20%, particularly preferably 2 to 15%. If the content of B ₂ O ₃ is more than 20%, the viscosity of the glass becomes too high, and it becomes difficult to perform laser sealing with a desired laser output.

Al ₂ O ₃ is an intermediate oxide and a component that stabilizes the glass. Al ₂ O ₃ is a component that lowers the thermal expansion coefficient of glass. The content is preferably 0.1 to 10%, particularly preferably 0.5 to 5%. When the content of Al ₂ O ₃ is more than 10%, the softening point of the glass powder is unreasonably raised and it becomes difficult to perform laser sealing with a desired laser output.

SiO ₂ is a glass-forming oxide and is a component that stabilizes the glass. The content is preferably 0 to 15%, particularly preferably 0 to 5%. When the content of SiO ₂ is more than 15%, the softening point of the glass powder is unreasonably raised, and it becomes difficult to perform laser sealing with a desired laser output.

In ₂ O ₃ is a component that enhances the thermal stability of the glass, and its content is preferably 0 to 5%. When the content of In ₂ O ₃ is more than 5%, the batch cost increases.

Ta ₂ O ₅ is a component that enhances the thermal stability of the glass, and its content is preferably 0 to 5%. When the content of Ta ₂ O ₅ is more than 5%, the softening point of the glass powder is unreasonably raised and it becomes difficult to perform laser sealing with a desired laser output.

La ₂ O ₃ is a component that enhances the thermal stability of the glass and is a component that enhances the weather resistance of the glass. The content is preferably 0 to 15%, 0 to 10%, particularly preferably 0 to 5%. When the content of La ₂ O ₃ is more than 15%, batch cost soars.

MoO ₃ is a component that enhances the thermal stability of the glass, and its content is preferably 0 to 5%. When the content of MoO ₃ is more than 5%, the softening point of the glass powder is unreasonably raised, and it becomes difficult to perform laser sealing with a desired laser output.

WO ₃ is a component that enhances the thermal stability of the glass, and its content is preferably 0 to 5%. When the content of WO ₃ is more than 5%, the softening point of the glass powder is unreasonably raised, and it becomes difficult to perform laser sealing with a desired laser output.

Li ₂ O is a component that lowers the melting point of glass, and its content is preferably 0 to 5%. The content of Li 2 _O is more than 5%, the thermal stability of the glass tends to decrease.

Na ₂ O is a component that lowers the melting point of glass, and its content is preferably 0 to 10%, particularly preferably 0 to 5%. When the content of Na 2 _O is greater than 10%, thermal stability of the glass tends to decrease.

K ₂ O is a component that lowers the melting point of glass, and its content is preferably 0 to 5%. When the content of K 2 _O is more than 5%, the thermal stability of the glass tends to decrease.

  MgO is a component that enhances the thermal stability of the glass, and its content is preferably 0 to 15%. When the content of MgO is more than 15%, the softening point of the glass powder rises unreasonably, making it difficult to seal with a desired laser output.

  BaO is a component that enhances the thermal stability of the glass, and its content is preferably 0 to 10%. When the content of BaO is more than 10%, the component balance of the glass composition is impaired, and conversely, the glass is easily devitrified.

F ₂ is a component to lower the melting point of the glass, the content thereof is preferably 0 to 5%. When the content of F ₂ is greater than 5%, the thermal stability of the glass tends to decrease.

In consideration of thermal stability and low melting point characteristics, In ₂ O ₃ , Ta ₂ O ₅ , La ₂ O ₃ , MoO ₃ , WO ₃ , Li ₂ O, Na ₂ O, K ₂ O, MgO, BaO, The total amount of F ₂ is preferably 10% or less.

  In addition to the above components, other components (CaO, SrO, etc.) can be added, for example, up to 10%.

  From the viewpoint of reducing batch cost, the SnO-containing glass powder according to the present invention preferably has a transition metal oxide content of 10% or less, particularly preferably 5% or less, and substantially does not contain a transition metal oxide. It is more preferable. Here, “substantially no transition metal oxide” refers to the case where the content of the transition metal oxide in the glass composition is 3000 ppm (mass) or less, preferably 1000 ppm (mass) or less.

  In addition, it is preferable that the SnO containing glass powder which concerns on this invention does not contain PbO substantially from an environmental viewpoint. Here, “substantially no PbO” refers to the case where the content of PbO in the glass composition is 1000 ppm (mass) or less.

In the sealing material of the present invention, the pigment is preferably an inorganic pigment, and carbon, Co ₃ O ₄ , CuO, Cr ₂ O ₃ , Fe ₂ O ₃ , MnO ₂ , SnO, and Ti _n O _2n-1 (n is an integer) ) Are more preferably selected from one or more selected from carbon, and carbon is particularly preferable. These pigments have excellent color developability and good laser light absorption.

  The pigment preferably contains substantially no Cr-based oxide from the environmental viewpoint. Here, “substantially free of Cr-based oxide” refers to a case where the content of Cr-based oxide in the pigment is 1000 ppm (mass) or less.

The average particle diameter _{D 50} of the pigment is 0.1 to 3 m, particularly 0.3~1μm is preferred. The maximum particle diameter D _max of the pigment is preferably 0.5 to 10 μm, particularly 1 to 5 μm. When the particle size of the pigment is too large, it is difficult to uniformly disperse the pigment in the sealing material, and the glass may not be locally softened and flowed during laser sealing. Even if the particle size of the pigment is too small, the pigments tend to aggregate together, so that there is a possibility that the glass does not soften and flow locally during laser sealing.

  The inorganic powder according to the present invention preferably contains a refractory filler. In this way, the thermal expansion coefficient of the sealing material can be lowered, and the mechanical strength of the sealing material can be increased. The mixing ratio of the SnO-containing glass powder and the refractory filler in the inorganic powder is preferably 40 to 100%: 0 to 60%, particularly 50 to 90%: 10 to 50% by volume. When there is more content of a refractory filler than 60 volume%, the ratio of SnO containing glass powder will become relatively small, and the efficiency of laser sealing will fall easily.

Zircon, zirconia, tin oxide, quartz, β-spodumene, cordierite, mullite, quartz glass, β-eucryptite, β-quartz, zirconium phosphate, zirconium phosphate tungstate, zirconium tungstate as refractory filler NbZr (PO ₄ ) _{3 and} other compounds having a basic structure of [AB ₂ (MO ₄ ) ₃ ],
A: Li, Na, K, Mg, Ca, Sr, Ba, Zn, Cu, Ni, Mn etc. B: Zr, Ti, Sn, Nb, Al, Sc, Y etc. M: P, Si, W, Mo etc. Alternatively, these solid solutions can be used.

The maximum particle diameter _Dmax of the refractory filler is preferably 30 μm or less, 20 μm or less, and particularly preferably 10 μm or less. When the maximum particle diameter _Dmax of the refractory filler is larger than 30 μm, a portion having a thickness of 30 μm or more is generated in the sealing portion. Therefore, in the organic EL display, the gap between the glass substrates becomes uneven, and the organic EL It becomes difficult to make the display thinner. Further, if the average particle diameter _Dmax of the refractory filler is regulated to 30 μm or less, the gap between the two glass substrates can be easily narrowed. In this case, the time required for laser sealing is shortened, and the glass substrate and the sealing are sealed. Even if there is a difference in the thermal expansion coefficients of the materials, cracks and the like are less likely to occur in the glass substrate and the sealing part.

In the sealing material of the present invention, the softening point is preferably 450 ° C. or lower, 420 ° C. or lower, and particularly preferably 400 ° C. or lower. When the softening point is higher than 450 ° C., the efficiency of laser sealing tends to decrease. The lower limit of the softening point is not particularly limited, but it is preferable to limit the softening point to 300 ° C. or higher in consideration of the thermal stability of the glass. Here, the “softening point” refers to a value measured with a macro-type differential thermal analysis (DTA) apparatus in a nitrogen atmosphere, DTA starts measurement from room temperature, and the rate of temperature rise is 10 ° C./min. . In addition, the softening point measured with the macro type | mold DTA apparatus points out the temperature (Ts) of the 4th bending point shown in FIG.

Currently, an active matrix drive in which an active element such as a TFT is arranged and driven in each pixel is adopted as an organic EL display as a drive method. In this case, non-alkali glass (for example, OA-10G manufactured by Nippon Electric Glass Co., Ltd.) is used for the glass substrate for organic EL display. The thermal expansion coefficient of the alkali-free glass is usually 40 × 10 ⁻⁷ / ° C. or less. The thermal expansion coefficient of the sealing material is often 76 to 83 × 10 ⁻⁷ / ° C. For this reason, it has been difficult to strictly match the thermal expansion coefficient of the sealing material with that of the alkali-free glass. However, the SnO-containing glass powder according to the present invention has good compatibility with a low expansion refractory filler, particularly NbZr (PO ₄ ) ₃ , zirconium phosphate. It becomes possible to significantly reduce the thermal expansion coefficient of the material. In the sealing material of the present invention, the thermal expansion coefficient is preferably 75 × 10 ⁻⁷ / ° C. or less, 65 × 10 ⁻⁷ / ° C. or less, 55 × 10 ⁻⁷ / ° C. or less, particularly 49 × 10 ⁻⁷ / ° C. or less. . If it does in this way, the stress concerning a sealing part will become small and the stress fracture of a sealing part can be prevented. Here, the “thermal expansion coefficient” refers to an average value measured in a temperature range of 30 to 250 ° C. by a push rod type thermal expansion coefficient measurement (TMA) apparatus.

  The sealing material of the present invention and a vehicle are preferably kneaded and processed into a paste material. If it does in this way, workability | operativity etc. can be improved. Note that the vehicle usually includes a resin binder and a solvent.

  In the paste material of the present invention, the resin binder is preferably an aliphatic polyolefin carbonate, particularly polyethylene carbonate or polypropylene carbonate. These resin binders have the characteristic that it is difficult to alter the SnO-containing glass powder during laser sealing.

  In the paste material of the present invention, N, N′-dimethylformamide, ethylene glycol, dimethyl sulfoxide, dimethyl carbonate, propylene carbonate, butyrolactone, caprolactone, N-methyl-2-pyrrolidone, phenyl diglycol (PhDG) One or more selected from dibutyl phthalate (DBP), benzyl glycol (BzG), benzyl diglycol (BzDG), and phenyl glycol (PhG) are preferred. These solvents have the characteristic that it is difficult to alter the SnO-containing glass powder during laser sealing. In particular, among these solvents, one or two selected from propylene carbonate, phenyl diglycol (PhDG), dibutyl phthalate (DBP), benzyl glycol (BzG), benzyl diglycol (BzDG), and phenyl glycol (PhG). The above is preferable. These solvents have a boiling point of 240 ° C. or higher. For this reason, when these solvents are used, it becomes easy to suppress the volatilization of the solvent during the application work such as screen printing, and as a result, the paste material can be used stably over a long period of time. Furthermore, phenyl diglycol (PhDG), dibutyl phthalate (DBP), benzyl glycol (BzG), benzyl diglycol (BzDG), and phenyl glycol (PhG) have high affinity with pigments. For this reason, even if the addition amount of these solvents is small, the situation where a pigment separates in the paste material can be suppressed.

  As described above, propylene carbonate, phenyl diglycol (PhDG), dibutyl phthalate (DBP), benzyl glycol (BzG), benzyl diglycol (BzDG), and phenyl glycol (PhG) suppress the volatilization of the solvent and paste It has the effect of increasing the long-term stability of the material. Taking phenyldiglycol (PhDG) as an example, this effect will be specifically described. First, as shown in FIG. 2, phenyldiglycol (PhDG) was extrapolated to propylene carbonate to prepare various solvents. Next, after a certain amount of this solvent was dropped onto a glass substrate (OA-10G manufactured by Nippon Electric Glass Co., Ltd.), the glass substrate was left as shown in FIG. Finally, the influence of phenyl diglycol (PhDG) on the drying rate of the paste material was evaluated by measuring the weight loss rate of the solvent. The result is shown in FIG. According to FIG. 2, as the content of phenyldiglycol (PhDG) increases, the solvent weight loss rate decreases. Therefore, it can be seen that if phenyldiglycol (PhDG) is added, the drying speed of the paste material is decreased, and as a result, the long-term stability of the paste material is improved.

The paste material of the present invention is preferably subjected to a binder removal treatment in an inert atmosphere, and particularly preferably subjected to a binder removal treatment in an N ₂ atmosphere. If it does in this way, it will become easy to prevent the situation which SnO containing glass powder changes in the case of binder removal.

The paste material of the present invention is preferably used for laser sealing in an inert atmosphere, and particularly preferably used for laser sealing in an N ₂ atmosphere. If it does in this way, it will become easy to prevent the situation which SnO containing glass powder changes in the case of laser sealing.

  Hereinafter, based on an Example, this invention is demonstrated in detail. The following examples are merely illustrative. The present invention is not limited to the following examples.

  Table 1 shows SnO-containing glass powders (Sample Nos. 1 to 7) according to the present invention.

Each glass powder was prepared as follows. First, after preparing the raw materials so as to have the glass composition shown in Table 1, the prepared raw materials were put in an alumina crucible and melted at a melting temperature shown in the table for 1 to 2 hours in a nitrogen atmosphere. Next, the obtained molten glass was formed into a film shape with a water-cooled roller. Then, after grinding the glass film by a ball mill and then classified, the average particle diameter _{D 50} of 2.5 [mu] m, maximum particle diameter _{D max} to obtain a glass powder 7 [mu] m.

  Sample No. About 1-7, the glass transition point, the softening point, and the thermal expansion coefficient were evaluated. The results are shown in Table 1.

  The glass transition point was determined with a TMA apparatus.

  The softening point was measured with a DTA apparatus. The measurement was performed at a heating rate of 10 ° C./min in a nitrogen atmosphere, and the measurement was started from room temperature.

  The thermal expansion coefficient was determined with a TMA apparatus. The measurement temperature range was 30 to 250 ° C.

As is clear from Table 1, sample No. 1 to 7 had a glass transition point of 295 to 334 ° C., a softening point of 365 to 407 ° C., and a thermal expansion coefficient of 96 to 125 × 10 ⁻⁷ / ° C.

  Next, a sealing material was produced. Glass powder No. 1 of Table 1 was set so that the mixing ratio shown in Table 2 was obtained. Sealing materials (samples A to G) were prepared by mixing 1 to 7, a refractory filler, and a pigment.

As the refractory filler, zirconium phosphate powder and NbZr (PO ₄ ) ₃ powder were used. The particle sizes of the zirconium phosphate powder and the NbZr (PO ₄ ) ₃ powder were an average particle diameter D ₅₀ : 2 μm and a maximum particle diameter D _max : 8 μm, respectively. Further, as the pigment, carbon powder having an average particle diameter D ₅₀ : 0.5 μm and a maximum particle diameter D _max : 3 μm was used.

  Samples A to G were evaluated for glass transition point, softening point, thermal expansion coefficient, flow diameter, weather resistance, and laser sealing property. The results are shown in Table 2.

  The glass transition point was determined with a TMA apparatus. In addition, as a measurement sample, a sample in which each sample was densely sintered was used.

  The softening point was measured with a DTA apparatus. The measurement was performed at a heating rate of 10 ° C./min in a nitrogen atmosphere, and the measurement was started from room temperature.

  The thermal expansion coefficient was determined with a TMA apparatus. The measurement temperature range was 30 to 250 ° C. In addition, as a measurement sample, a sample in which each sample was densely sintered was used.

  The flow diameter was evaluated as follows. First, each sample having a mass corresponding to the density was dry-pressed into a button shape having an outer diameter of 20 mm using a mold. Next, this button is placed on an alkali-free glass substrate (OA-10G manufactured by Nippon Electric Glass Co., Ltd.), and the temperature is raised at a rate of 10 ° C./min up to the firing temperature in the table under a nitrogen atmosphere. After maintaining at the firing temperature for 10 minutes, it was cooled to room temperature. Finally, the diameter of the button after firing was measured. In addition, if a flow diameter is 20 mm or more, it means that fluidity | liquidity is favorable at the baking temperature. The better the fluidity, the more efficient the laser sealing.

  The weather resistance was evaluated as follows. First, 1 g of each sample was dry-pressed into a button shape having an outer diameter of 10 mm using a mold. Next, this button is placed on a high strain point glass substrate, heated in air to a temperature of [softening point of each sample + 30 ° C.] at a rate of 10 ° C./min, and held at that temperature for 10 minutes. Then, the temperature was lowered to room temperature at a rate of 10 ° C./min. Then, the pressure cooker test (henceforth PCT) was done with respect to the button after baking. Specifically, it was held for 48 hours in an atmosphere of a temperature of 121 ° C., a humidity of 95%, and 2 atmospheres. Finally, visually observe the button surface after PCT. If the button surface is all glossy, “○” indicates that part of the button surface is not glossy. “△” indicates that all button surfaces are not glossy. Was evaluated as “×”.

The laser sealing property was evaluated as follows. First, each sample and the vehicle were kneaded so that the paste viscosity was about 150 Pa · s, and further kneaded with a three-roll mill until uniform, to form a paste. A vehicle in which 15% by mass of polyethylene carbonate (PEC, molecular weight: 80000) was dissolved in propylene carbonate was used. Next, an alkali-free glass substrate obtained by processing the prepared paste into a strip shape (manufactured by Nippon Electric Glass Co., Ltd .: OA-10G, dimensions: 10 mm × 50 mm × 0.7 mm thickness, thermal expansion coefficient in a temperature range of 30 to 380 ° C. : 38 × 10 ⁻⁷ / ° C.) was printed and applied so as to have a line width of 0.8 mm × length of 4 mm × thickness of 20 μm, and then dried at 120 ° C. for 30 minutes in a drying oven. Subsequently, the binder removal treatment was performed by firing at a softening point shown in Table 2 for 20 minutes in a nitrogen atmosphere. The temperature raising / lowering speed was 10 ° C./min. Furthermore, the non-alkali glass substrate processed into the same shape on the non-alkali glass substrate on which the glaze film is formed (manufactured by Nippon Electric Glass Co., Ltd .: OA-10G, dimensions: 10 mm × 50 mm × 0.7 mm thickness, 30˜ After accurately overlapping the thermal expansion coefficient in the temperature range of 380 ° C .: 38 × 10 ⁻⁷ / ° C., a semiconductor laser having a wavelength of 808 nm (output: 5 W) along the dry film from the glass substrate side on which the glaze film is not formed 10 W, 15 W, scanning speed 10 mm / s). Finally, the sample that was softened by the laser beam and the glass substrates were bonded together was evaluated as “◯”, and the sample that was not softened and the glass substrates were not bonded was evaluated as “x”.

As is clear from Table 2, Samples A to E were able to bond glass substrates to each other under all laser irradiation conditions. This result indicates that the energy of the laser beam can be efficiently converted into heat. Moreover, since samples A to E have a thermal expansion coefficient of 50 × 10 ⁻⁷ / ° C. or less, they are consistent with the thermal expansion coefficient of the glass substrate, and no abnormalities such as cracks were observed at the bonding sites.

  On the other hand, the sample F was not able to join the glass substrates under all laser irradiation conditions. Sample G could be bonded when the laser output was 15 W, but could not be bonded when the laser output was 5 W or 10 W. This result indicates that the energy of the laser beam could not be efficiently converted into heat.

Further, as apparent from Table 2, samples A to E have a glass transition point of 300 to 342 ° C., a softening point of 385 to 425 ° C., and a thermal expansion coefficient of 41 to 47 × 10 ⁻⁷ / ° C. The flow diameter was 20 mm or more at the inside firing temperature. In addition, samples A to E had good weather resistance evaluation. On the other hand, Samples F and G had no gloss on part of the button surface after PCT, and were inferior in weather resistance. This cause is considered due to the contents of P ₂ O ₅ and B ₂ O _{3 in} the SnO-containing powder. Specifically, it is considered that the weather resistance of the sample F was lowered because the content of P ₂ O ₅ in the SnO-containing powder was 32%. In Sample G, although the content of _P 2 _{O 5} of SnO-containing powder is 30% or _less, since the content of B 2 _{O 3} is 0.9%, is considered to weather resistance is lowered .

  The sealing material of the present invention is suitable not only for organic EL devices, but also for laser sealing of solar cells such as dye-sensitized solar cells, laser sealing of MEMS packages, and laser sealing of lithium ion secondary batteries. is there.

Claims (12)

  A sealing material comprising 80 to 99.7% by mass of inorganic powder containing SnO-containing glass powder and 0.3 to 20% by mass of pigment, and used for laser sealing. The sealing material according to claim 1, wherein the SnO-containing glass powder contains SnO 35 to 70% and P ₂ O ₅ 10 to 30% in terms of glass composition. The SnO-containing glass powder further contains, as a glass composition, in terms of mol%, ZnO 1 to 20%, B ₂ O ₃ 1 to 20%, Al ₂ O ₃ 0.1 to 10%. Item 3. The sealing material according to Item 2. The pigment is _one or more selected from C (carbon), Co ₃ O ₄ , CuO, Cr ₂ O ₃ , Fe ₂ O ₃ , MnO ₂ , SnO, and Ti _n O _2n-1 (n is an integer). The sealing material according to claim 1, wherein the sealing material is provided.   The sealing material according to any one of claims 1 to 4, wherein the pigment is C (carbon).   The sealing material according to any one of claims 1 to 5, wherein the inorganic powder contains 0.1 to 60% by volume of a refractory filler. The refractory filler is one or more selected from cordierite, zircon, tin oxide, niobium oxide, zirconium phosphate, zirconium phosphate tungstate, and NbZr (PO ₄ ) _3. The sealing material in any one of 1-6.   The sealing material according to claim 1, which is used for sealing an organic EL device. In paste materials including sealing materials and vehicles,
The sealing material is the sealing material according to any one of claims 1 to 8, and the vehicle contains an aliphatic polyolefin carbonate.   Vehicle is N, N'-dimethylformamide, ethylene glycol, dimethyl sulfoxide, dimethyl carbonate, propylene carbonate, butyrolactone, caprolactone, N-methyl-2-pyrrolidone, phenyl diglycol (PhDG), dibutyl phthalate (DBP) The paste material according to claim 9, comprising one or more selected from benzyl glycol (BzG), benzyl diglycol (BzDG), and phenyl glycol (PhG).   The paste material according to claim 9 or 10, which is subjected to a binder removal treatment in an inert atmosphere.   The paste material according to any one of claims 9 to 11, which is used for laser sealing in an inert atmosphere.