JP2015120622A - Glass paste - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a glass paste which can adjust its viscosity to a moderate viscosity without using a binder resin, and can dispense with a binder resin causing sintering prevention and a defect.SOLUTION: There is provided a glass paste which contains glass powder having an average particle size of 10-1,000 nm and a volatile organic solvent, does not substantially contain a binder resin, and has viscosity of 20-600 Pa s that is measured with a rotational viscometer at 25°C and a rotational speed of 10 rpm.

Description

  The present invention relates to a glass paste.

  For applications such as coating on various base materials such as metal substrates, sealing of various electronic parts such as display elements and IC packages, coating, and the like, a powder material composed of glass powder and filler powder, and a vehicle composed of resin and solvent, etc. Widely used are pastes that are uniformly mixed.

  However, in such a conventional glass paste, the components contained in the vehicle, in particular, the binder resin does not decompose sufficiently when the paste is fired, causing sintering inhibition or remaining as defects in the glass. there were.

  As a solution to the above problem, it is conceivable not to use a resin, which is a main cause of glass sintering inhibition and defects, as a vehicle component. And the glass paste which does not contain such binder resin is disclosed by patent document 1, for example. However, glass pastes that do not use a resin are difficult to adjust to an appropriate viscosity and have problems such as separation and precipitation of glass powder.

JP-A-2005-97086

  An object of the present invention is to provide a glass paste that can be adjusted to an appropriate viscosity without using a binder resin, and can eliminate the use of a binder resin that causes sintering inhibition and defects.

  The glass paste according to one embodiment of the present invention contains glass powder having an average particle diameter of 10 to 1000 nm and a volatile organic solvent, does not substantially contain a binder resin, and is 25 in a rotational viscometer. The viscosity measured at a temperature of 10 ° C. and a rotation speed of 10 rpm is 20 to 600 Pa · s.

  ADVANTAGE OF THE INVENTION According to this invention, the glass paste which can be adjusted to a moderate viscosity, without using binder resin and can make use of binder resin which causes a sintering inhibition and a defect unnecessary is provided.

It is a figure which shows roughly an example of the apparatus used for manufacture of the glass powder used for the glass paste of this invention.

Hereinafter, although embodiment of this invention is described, this invention is limited to the following description and is not interpreted.
The glass paste of the present invention contains a glass powder having an average particle diameter of 10 to 1000 nm and a volatile organic solvent, does not substantially contain a binder resin, and is measured using a rotational viscometer. The viscosity at 20 ° C. is 20 to 600 Pa · s. In the present specification, when the viscosity of the glass paste is simply referred to as “viscosity” or “viscosity at 25 ° C.”, the viscosity measured at 25 ° C. using a rotational viscometer (rotation speed: 10 rpm) unless otherwise specified. Say. In the present invention, the spindle (SC4-14) and the sample holder (SC4-6R) are used for the measurement with the rotational viscometer.

[Glass powder]
The glass powder used in the glass paste of the present invention has an average particle diameter of 10 to 1000 nm, and if the average particle diameter is within this range, a glass paste having a viscosity at 25 ° C. of 20 to 600 Pa · s can be obtained. it can. The glass powder preferably has an average particle size of 20 to 800 nm, more preferably 30 to 500 nm, from the viewpoint of ease of production, ease of handling, and the like.
In addition, the average particle diameter of glass powder can be obtained by analyzing the image obtained with the apparatus which can observe fine structures, such as a transmission electron microscope and a scanning electron microscope. It is also possible to measure using a laser diffraction particle size distribution measuring apparatus.

The glass powder used for this invention can be manufactured as follows, for example.
First, a glass material compound is dissolved or dispersed in a solvent to prepare a liquid material. A glass raw material compound is a compound containing an element constituting glass, for example, chloride, nitride, hydrate, organic acid salt (for example, acetate, formate, etc.), organic of each element constituting glass. Compound, oxo acid salt, coordination compound, acid, nitrate, sulfate and the like.

  Examples of the solvent for dissolving or dispersing the glass raw material compound include water, alcohol (for example, methyl alcohol, ethyl alcohol, n-propyl alcohol, isopropyl alcohol, n-butyl alcohol, n-pentyl alcohol), formic acid, acetic acid. , Highly polar solvents such as propionic acid; mineral spirit, mineral thinner, petroleum spirit, white spirit, mineral turpentine, kerosene, n-hexane, hexanoic acid, 2-ethylhexanoic acid, cyclohexane, isoheptane, toluene, benzene And low polar solvents such as xylene.

  The glass raw material compound is preferably selected depending on the solvent to be mixed. For example, when water is used as the solvent, a water-soluble compound such as a chloride, an organic acid salt, or a nitrate is used. Moreover, even if it is insoluble in water, such as an oxide or carbonate, it can be dissolved in an acid or the like.

  Specific examples of the glass raw material compound suitable for the high polar solvent include, for example, sodium silicate, potassium silicate, tetramethoxysilane, tetraethoxysilane, methyltriethoxysilane, boric acid, phosphoric acid, zinc nitrate, zinc acetate, Zinc chloride, lithium nitrate, lithium acetate, lithium chloride, sodium nitrate, sodium acetate, sodium chloride, potassium nitrate, potassium acetate, potassium chloride, bismuth nitrate, magnesium nitrate, magnesium acetate, magnesium chloride, calcium nitrate, calcium acetate, calcium chloride, Strontium nitrate, barium nitrate, barium acetate, barium chloride, aluminum nitrate, aluminum chloride, zirconia nitrate, niobium nitrate, cerium nitrate, cerium chloride, manganese nitrate, manganese acetate, manganese chloride, iron nitrate, acetic acid , Iron chloride, cobalt acetate, cobalt chloride, nickel nitrate, cobalt acetate, nickel chloride, copper nitrate, copper chloride and the like.

  Specific examples of the glass raw material compound suitable for the low-polar dilution solvent include, for example, tetramethoxysilane, tetraethoxysilane, octamethylcyclotetrasiloxane, polydimethylsiloxane, tributyl boride, triphenylphosphine, and triphenylphosphine oxide. , Zinc 2-ethylhexanoate, lithium 2-ethylhexanoate, lithium naphthenate, sodium 2-ethylhexanoate, potassium 2-ethylhexanoate, bismuth 2-ethylhexanoate, magnesium 2-ethylhexanoate, 2-ethyl Calcium hexanoate, strontium 2-ethylhexanoate, barium 2-ethylhexanoate, tris (ethylacetoacetate) aluminum, aluminum-sec-butoxide, aluminum mono-n-butoxydiethyl Acetoacetic acid ester, ethyl acetoacetate aluminum dinormal butyrate, tin (II) octylate, dibutyltin dilaurate, zirconia 2-ethylhexanoate, niobium 2-ethylhexanoate, niobium ethoxide, niobium butoxide, 2-ethylhexanoic acid Bismuth, tungsten (IV) ethoxide, tungsten (IV) isopropoxide, lanthanum 2-ethylhexanoate, yttrium 2-ethylhexanoate, gadolinium 2-ethylhexanoate, tetraisopropoxytitanium, tetra-n-butoxytitanium, tetra (2-ethylhexyl) titanate, cerium 2-ethylhexanoate, chromium 2-ethylhexanoate, manganese 2-ethylhexanoate, iron 2-ethylhexanoate, copper naphthenate, 2-ethylhexanoate co Belt, and a nickel 2-ethylhexanoate and the like

  The concentration of the glass raw material compound in the liquid raw material is preferably in the range of 1 to 30% by mass, more preferably in the range of 2 to 20% by mass as the total amount of the oxide equivalent of the glass raw material compound. When the concentration of the glass raw material compound is less than 1% by mass, the required amount of solvent increases and the environmental load is large. On the other hand, when it exceeds 30 mass%, it becomes difficult to obtain fine glass particles. Moreover, preparation of a uniform concentration solution becomes difficult and the composition of the obtained glass powder may be non-uniform.

  Next, heat treatment is performed on the liquid raw material. The heat treatment of the liquid material is performed by jetting the liquid material into the reaction space together with a flame or hot air. The liquid raw material ejected together with the flame or hot air forms a large number of fine droplets simultaneously with the ejection, and these droplets are all heated instantaneously and uniformly by the heat of the flame or hot air. For this reason, the droplets remain as fine droplets without agglomerating, the solvent is volatilized, and the glass raw material compound dissolved or dispersed in the droplets is uniformly pyrolyzed and vitrified to form a fine and homogeneous glass. Particles are formed. Then, these fine glass particles are solidified as fine and homogeneous particles by the subsequent rapid cooling. Therefore, it is possible to stably obtain a glass powder that is fine and has a high sphericity (sphericity).

  For the generation of the flame, a mixed gas of a combustible gas such as hydrogen gas, propane gas, city gas, and acetylene gas and a combustion-supporting gas such as oxygen gas can be used. The flow rate of the mixed gas varies depending on the type of gas used. For example, in the case of a combination of propane gas and oxygen gas, the flow rate of propane gas is preferably in the range of 0.7 to 1.3 NL (normal liters) / min. The range of 0.8 to 1.2 NL / min is more preferable, and the flow rate of oxygen gas is preferably 3 to 6 NL / min, and more preferably 4 to 6 NL / min.

In the present invention, when a flame is used, it is preferable to supply an oxidizing gas such as oxygen gas or air to the reaction space. By supplying an oxidizing gas, the reaction field (reaction space) of the combustible gas and the combustion-supporting gas can be raised to a higher temperature, and the raw material can be pyrolyzed more quickly to nucleate fine particles. Fine glass particles with high sphericity can be synthesized. The flow rate of the oxidizing gas is preferably in the range of 6 to 18 NL / min, and more preferably in the range of 7 to 15 NL / min.
Moreover, air, nitrogen gas, etc. can be used for a hot air, for example. The flow rate of hot air is preferably in the range of 10 to 28 NL / min, and more preferably in the range of 12 to 26 NL / min.

  The temperature of the flame and hot air, that is, the heat treatment temperature of the liquid raw material is preferably 1500 ° C. or higher. If the heat treatment temperature is less than 1500 ° C., the thermal decomposition reaction of the glass raw material compound is not sufficiently performed, and there is a possibility that vitrification does not occur or the vitrification becomes insufficient. However, if the temperature is too high, an element having a small atomic weight may be volatilized. Therefore, the heat treatment temperature is more preferably 1600 ° C. or higher, and even more preferably 1700 to 2500 ° C.

  Thereafter, the glass particles generated by the heat treatment of the liquid raw material are collected and collected using a collection device such as a bag filter.

The liquid raw material heat treatment step and the glass powder collection / recovery step can be performed using, for example, an apparatus as shown in FIG.
As shown in FIG. 1, this apparatus is connected to a reaction cylinder 1 that forms a reaction space, a burner 2 that is detachably attached to a wall on one end side of the reaction cylinder 1, and the other end side of the reaction cylinder 1. A recovery device 4 having a bag filter 3 for collecting glass particles generated in the reaction cylinder 1 is provided. Around the reaction tube 1, a cooling pipe 5 through which cooling water flows is disposed as a cooling means. The burner 2 is supplied with a liquid raw material, a mixed gas of combustible gas and combustion-supporting gas, and an oxidizing gas. Further, an exhaust port (not shown) is opened on the downstream side of the recovery device 4, and an exhaust device 6 such as an ejector is connected to the exhaust port.

  In the apparatus shown in FIG. 1, a liquid raw material, a mixed gas of combustible gas and combustion-supporting gas, and an oxidizing gas are ejected from the burner 2 into the reaction tube 1. At that time, the mixed gas is burned to form a flame. Thereby, the liquid raw material and the oxidizing gas are ejected into the reaction tube 1 together with the flame formed by burning the mixed gas. The liquid raw material ejected into the reaction cylinder 1 becomes droplets, but is instantaneously heated by the heat of the flame to cause a thermal decomposition reaction. A cooling pipe 5 is disposed around the reaction tube 1, and the pyrolyzate is rapidly cooled and vitrified when it comes out of the flame. Thus, glass powder is produced | generated when droplets vitrify one after another. The generated glass powder is collected and collected by a collection device 4 having a bag filter 3.

  In this way, a large number of fine droplets are formed simultaneously with the ejection from the liquid raw material ejected into the reaction cylinder 1, and all of these droplets are instantaneously heated by the heat of the flame and emitted the flame. By the way, it is cooled rapidly. For this reason, the droplets are thermally decomposed uniformly and vitrified as fine droplets without agglomeration, and fine and homogeneous glass particles are formed. Further, since the oxidizing gas is ejected from the burner 2 together with the liquid raw material, the reaction field can be raised to a higher temperature, and the raw material can be decomposed more instantly to generate nuclei of fine particles. Therefore, it is possible to stably obtain a glass powder that is fine and has a high sphericity (sphericity).

  In addition, although the apparatus shown in FIG. 1 spouts a liquid raw material in a reaction space with a flame, it replaces with the burner 2 and equips with the apparatus which injects a hot air and a liquid raw material in reaction space (reaction cylinder 1). In addition, the liquid raw material in the form of droplets can be rapidly cooled after being thermally decomposed by the heat of hot air.

  In this apparatus, the liquid raw material ejected into the reaction cylinder 1 forms a large number of fine droplets simultaneously with the ejection, and these droplets are all heated instantaneously with hot air and then rapidly cooled. For this reason, the droplets are thermally decomposed uniformly and vitrified as fine droplets without agglomeration, and fine and homogeneous glass particles are formed. Therefore, it is possible to stably obtain a glass powder that is fine and has a high sphericity (sphericity).

  According to said manufacturing method, the fine glass powder whose average particle diameter is 10-1000 nm is obtained.

[Volatile organic solvent]
The volatile organic solvent used in the glass paste of the present invention can be used without particular limitation as long as it is an organic solvent having volatility at room temperature (5-35 ° C.). Among these, a volatile organic solvent having a boiling point at normal pressure (hereinafter simply referred to as “boiling point”) of 300 ° C. or less is preferable because it is sufficiently volatilized and removed when the glass paste is fired. In addition, when the boiling point is less than 170 ° C., when the layered glass paste layer is formed on the workpiece for forming or sealing the insulating pattern, the organic solvent volatilizes and the viscosity increases, thereby forming a uniform layer. Therefore, the boiling point of the volatile organic solvent is preferably 170 ° C. or higher. As for a volatile organic solvent, it is more preferable that the boiling point is 180-280 degreeC.

  Specific examples of suitable volatile organic solvents include 2,4-diethyl-1,5-pentanediol (boiling point: about 264 ° C.), 1,2-propanediol (boiling point: 187.3 ° C.), 2-methyl -2,4-pentanediol (boiling point: 197.1 ° C), 2-butyl-2-ethyl-1,3-propanediol (boiling point: about 178 ° C), ethylene glycol (boiling point: 197.85 ° C), 2 -Ethyl-1,3-hexanediol (boiling point: 241 to 249 ° C), diethylene glycol (boiling point: 244.8 ° C), triethylene glycol (boiling point: about 288 ° C), benzyl alcohol (boiling point: about 205 ° C), 3 -Methoxy-3-methylbutanol (boiling point: 173 to 175 ° C), glycerin (boiling point: about 290 ° C), pentaerythritol (boiling point: about 276 ° C), α-terpi Alcohol solvents such as all (boiling point: 217-218 ° C); acetyltriethyl citrate (boiling point: 228-229 ° C), benzyl acetate (boiling point: about 212 ° C), 4-t-butylcyclohexyl acetate (boiling point: 228- 230 ° C.), propylene glycol diacetate (boiling point: about 190 ° C.), diethyl succinate (boiling point: about 218 ° C.), 2,2,4-trimethyl-1,3-pentanediol monoisobutyrate (boiling point: about 253) ° C.), 2,2,4-trimethyl-1,3-pentanediol diisobutyrate (boiling point: about 280 ° C.), dimethyl phthalate (boiling point: 283-284 ° C.), diethylene glycol monoethyl ether acetate (boiling point: 217.degree. 4 ° C), diethylene glycol monobutyl ether acetate (boiling point: 246.8 ° C) Diethylene glycol monoacetate (boiling point: 188 ° C), triacetin (boiling point: 258-260 ° C), ethyl benzoate (boiling point: 211-213 ° C), 2,2,4-trimethyl-1,3-pentanediol mono (2 -Ethyl solvent such as methyl propanoate (boiling point: 255-260 ° C); diethylene glycol monomethyl ether (boiling point: 194.1 ° C), diethylene glycol monoethyl ether (boiling point: about 202 ° C), diethylene glycol monobutyl ether (boiling point: 230.4 ° C), diethylene glycol mono-2-ethylhexyl ether (boiling point: about 272 ° C), diethylene glycol diethyl ether (boiling point: 188.4 ° C), diethylene glycol dibutyl ether (boiling point: 254.6 ° C), propylene glycol mono Phenyl ether (boiling point: about 243 ° C.), triethylene glycol dimethyl ether (boiling point: about 216 ° C.), hexyl ether (boiling point: 228-229 ° C.), ethylene glycol mono-2-ethylhexyl ether (boiling point: 228.6 ° C.), tri Ether solvents such as ethylene glycol dimethyl ether (boiling point: about 216 ° C.), dipropylene glycol monobutyl ether (boiling point: 222 to 232 ° C.), tripropylene glycol monobutyl ether (boiling point: 242.4 ° C.), and others, γ-butyl lactone (Boiling point: about 204 ° C), tetralin (boiling point: 206-208 ° C), propylene carbonate (boiling point: about 240 ° C), dimethyl sulfoxide (boiling point: about 189 ° C), N-methyl-2-pyrrolodon (boiling point: about 202) ° C) and the like. All of these organic solvents have a boiling point in the range of 170 to 300 ° C.

As the volatile organic solvent used in the glass paste of the present invention, among the above organic solvents, those having 2 to 3 oxygen atoms in the molecule are used, and the oxygen atom in the molecule is a glass fine particle. It is more preferable from the viewpoint of causing an interaction with organic solvent molecules and allowing the viscosity to fall within an appropriate range. A volatile organic solvent having 2 to 3 oxygen atoms in the molecule is preferred. In particular, selected from ethylene glycol, 1,2-propanediol, diethylene glycol, glycerin, 2-ethyl-1,3-hexanediol, ethylene glycol mono-2-ethylhexyl ether and 2,4-diethyl-1,5-pentanediol. At least one selected from the above is preferred.
From the viewpoint of the viscosity and the thixo ratio described later, 1,2-propanediol and / or 2,4-diethyl 1,5-pentanediol are particularly preferable.
In addition, a volatile organic solvent may be used individually by 1 type, and may use 2 or more types together.

  20-70 mass% is preferable and, as for content of the said volatile organic solvent in the glass paste of this invention, 30-60 mass% is more preferable.

[Optional ingredients]
In the glass paste of the present invention, if necessary, components other than the above components can be blended within a range that does not impair the effects of the present invention. Examples of such optional components include inorganic fillers, color pigments, antifoaming agents, dispersants, thixotropy imparting agents, and the like. In addition, a solvent other than the volatile organic solvent, for example, a non-volatile organic solvent having no boiling point at normal pressure, can be blended within a range that does not impair the effects of the present invention.

Examples of inorganic fillers include silica, alumina, mullite, zirconia, zirconium silicate, aluminum titanate, mullite, cordierite, eucryptite, spodumene, zirconium phosphate compounds, tin oxide compounds, and quartz solid solutions. Examples of the zirconium phosphate-based compound include (ZrO) ₂ P ₂ O ₇ , NaZr ₂ (PO ₄ ) ₃ , KZr ₂ (PO ₄ ) ₃ , Ca _0.5 Zr ₂ (PO ₄ ) ₃ , and NbZr (PO ₄ ). ₃ , Zr ₂ (WO ₃ ) (PO ₄ ) ₂ , and composite compounds thereof. These may be used alone or in combination of two or more.

  Examples of the color pigment include white pigments such as titania, black pigments such as Fe—Mn complex oxide, Fe—Co—Cr complex oxide, and Fe—Mn—Al complex oxide. These may be used alone or in combination of two or more.

  Inorganic fillers and colored pigments are usually used in the form of powder. The shape of the powder particles is not particularly limited and may be spherical, plate-like, crushed, whisker-like, etc., but the particle size is in the range of 0.01 to 100 μm at 50% particle size (D50). Is preferred. The 50% particle diameter (D50) of the inorganic filler and the color pigment can be measured using a laser diffraction particle size distribution measuring apparatus, as with the glass powder.

  The glass paste of the present invention sufficiently stirs a glass powder, a volatile organic solvent, and an inorganic filler, which is an optional component, by a known method using a rotary mixer equipped with a stirrer, a roll mill, a ball mill, or the like. It can be prepared by mixing.

  The viscosity of the glass paste of the present invention is 20 to 600 Pa · s as measured at 25 ° C. and a rotation speed of 10 rpm using a rotational viscometer. When the viscosity is less than 20 Pa · s, the glass paste tends to flow on the substrate, and it becomes difficult to apply the glass paste to the substrate. The viscosity of the glass paste at 25 ° C. is preferably 50 Pa · s or more, and more preferably 80 Pa · s or more. On the other hand, when the viscosity exceeds 600 Pa · s, the viscosity is too high to be handled. The viscosity of the glass paste at 25 ° C. is preferably 400 Pa · s or less, and more preferably 300 Pa · s or less. The glass paste of the present invention can maintain the viscosity in the above range during long-term storage.

The glass paste of the present invention preferably has a thixotropy index (hereinafter also referred to as a thixo ratio) TI obtained from the following formula (1) of 0.8 to 3.8.
TI = η10 / η50 (1)
In Formula (1), η10 is a viscosity (unit: Pa · s) measured at 25 ° C. and a rotational speed of 10 rpm using a rotational viscometer, and η50 is 25 ° C. and a rotational speed of 50 rpm using a rotational viscometer. Viscosity (unit: Pa · s) measured at
The thixotropy index TI is an index indicating the ease of sag of the glass paste when the glass paste is applied onto the substrate and the smoothness of the layer surface after coating (presence of unevenness). On the contrary, the larger the value, the more difficult it is to sag, but unevenness is likely to occur on the surface. If the thixotropy index TI is 0.8 to 3.8, it is possible to balance the sag of the glass paste at the time of application and the smoothness of the layer surface after application, and a desired thickness with less surface irregularities. The glass paste layer can be formed. As for the glass paste of this invention, it is more preferable that the said thixotropy index TI is 1.3-3.2.

  Examples of the material of the substrate for forming the insulating pattern on the substrate using the glass paste of the present invention and the sealing member for sealing various members include glass, metal, ceramics, and the like. . Specific examples of the glass include soda lime glass, borosilicate glass, alkali-free glass, and quartz glass. Specific examples of the metal include copper, aluminum, and stainless steel. Examples of the ceramic include alumina, zirconia, aluminum nitride, silicon carbide, silicon nitride and the like.

  For example, in order to form a glassy layer such as an insulating pattern or a sealing layer using the glass paste of the present invention, first, the glass paste is applied onto a substrate in a required shape and thickness, and then the glass paste layer Form. Next, when the obtained base material with a glass paste layer is used as it is or for sealing, another base material is laminated and subjected to heat treatment in the sintering temperature region of the vitreous material in the sealing paste. Layer.

  To form a glass paste layer on a substrate using glass paste, for example, it is applied on the substrate by applying a printing method such as screen printing, gravure printing or metal mask printing, or is applied using a dispenser or the like. Or the like is used. The thickness and shape of the sealing paste layer are adjusted such that the glass layer finally obtained has a predetermined thickness and shape.

  Next, heat treatment is performed in the sintering temperature region of a glassy material such as glass powder and inorganic filler in the glass paste, but before that, a step of drying the glass paste layer may be provided. This drying step is performed to remove the volatile organic solvent in the glass paste layer. By removing the volatile organic solvent in advance, the component to be eliminated can be surely and sufficiently removed in the heating step.

  Next, heat treatment is performed in the sintering temperature region of the glassy material in the glass paste. It is necessary to sinter the vitreous material at a temperature equal to or higher than the glass softening point (Ts) of the glass powder constituting the vitreous material. The sintering temperature is preferably a glass softening point (Ts) + 5 ° C. to a glass softening point (Ts) + 120 ° C., and a glass softening point (Ts) + 10 ° C. to a glass softening point (Ts) + 100 ° C. is more preferable. preferable.

  The method for the heat treatment is not particularly limited as long as at least the temperature of the glass paste layer becomes the above temperature. Specifically, heat radiation heating, infrared heating, laser light irradiation, induction heating and the like can be mentioned. From the viewpoint of temperature stability, manufacturing cost, etc., heat radiation heating and laser beam irradiation are preferred.

  When performing heat radiation heating with an electric furnace or the like for the above heat treatment, if the binder resin is contained in the glass paste layer as in the past, debinding and heating to remove it (temporary firing), Although it is preferable to carry out in two stages of the main firing for sintering the vitreous material, since the binder resin is not used in the present invention, only the main firing is required and the processing time can be shortened.

  The glass paste of the present invention is printed on a printed circuit board and then baked to form an insulating pattern made of a sintered body of a vitreous material contained therein, or a sealing region of a sealing member is made of such a vitreous material This is useful for applications such as manufacturing a sealed product sealed with a vitreous layer made of a sintered material. Such sealed products include plasma display panels (PDP), field emission displays (FED), flat display devices such as fluorescent display tubes (VFD), optical components such as lens caps and LD caps, semiconductor packages, and crystal vibrations. Examples thereof include electronic parts such as a piezoelectric vibrator such as a child or a surface acoustic wave element.

  EXAMPLES Next, although an Example demonstrates this invention further in detail, this invention is not limited to these Examples at all.

[Examples 1 to 7]
(Manufacture of glass powder)
In mass% notation oxide _{basis, B 2 O 3 21.8%,} ZnO 49.2%, SiO 2 9.9%, Al 2 O 3 1.9%, Na2O 3.3%, K2O 4.1 %, CaO 3.3, BaO 5.8 and CuO 0.7% so that the glass composition is tributyl borate, zinc 2-ethylhexanoate, mineral spirits solution (zinc content: 15.0% by mass), Octamethylcyclotetrasiloxane, tris (ethylacetoacetate) aluminum, sodium 2-ethylhexanoate mineral spirits solution (sodium content: 2.8% by mass), potassium 2-ethylhexanoate isopropyl alcohol solution (potassium content: 8. 4 mass%), calcium 2-ethylhexanoate mineral spirits solution (calcium content: 4.1 mass%), 2-ethyl After barium hexanoate mineral spirits solution (barium content: 15.0% by mass) and copper naphthenate mineral spirits solution (copper content: 8.0% by mass) were weighed out and added, 186 ml of mineral spirit was added as a solvent for 15 hours. The liquid raw material was prepared by stirring and completely dissolving.

  Next, the obtained liquid raw material was supplied to the apparatus shown in FIG. 1, and was jetted from a burner to a reaction tube together with a flame to cause a thermal decomposition reaction, and then rapidly cooled to produce glass powder. That is, oxygen gas was supplied to the burner as a combustion-supporting gas at 5 NL / min and propane gas as a flammable gas was supplied at 1 NL / min, and the tip of the burner was ignited to generate a flame (about 1800 ° C.). After this burner was inserted into the reaction cylinder, the liquid raw material was injected at 2.5 g / min, and oxygen gas as an oxidizing gas was injected at 9 NL / min from the center of the burner where the flame was jetted. During the reaction, cooling water was always flowed through a cooling pipe disposed so as to surround the reaction cylinder so that at least the outlet of the reaction cylinder was kept at a low temperature. Then, the produced | generated glass powder was collect | recovered from the collection apparatus.

  When the obtained glass powder was imaged with the transmission electron microscope (TEM, the JEOL Co., Ltd. product, JEM-1230) and the average particle diameter was calculated | required from the captured photograph, it was 110 nm. Moreover, when the glass transition point Tg and the glass softening point Ts (degreeC) were measured, they were 484 degreeC and 558 degreeC, respectively. The measuring method is shown below.

[Average particle size]
Using an image analysis software (WinRoof, Mitani Shoji Co., Ltd.), any 50 particles of a photograph taken with a TEM are binarized and then the diameter of an equivalent circle having the same area as the binarized area Was determined as the particle diameter (Li), and the average particle diameter (L) was calculated from the following formula.

[Glass transition point Tg]
Using a differential thermal analyzer (TG8110 manufactured by Rigaku Corporation), about 20 mg of glass powder was heated from room temperature to 800 ° C. at a rate of 5 ° C./min.
[Glass softening point Ts]
About 20 mg of glass powder is put in a platinum pan, measured at a heating rate of 10 ° C./min with a thermogravimetric / suggested thermal analyzer (TG8110 manufactured by Rigaku Corporation), and softening appears on the higher temperature side than the glass transition point Tg. The temperature at the inflection point of the DTA curve accompanying the flow was defined as the glass softening point Ts.

(Preparation of glass paste)
The glass powder and various organic solvents were mixed at a ratio as shown in Table 1, and kneaded with three rolls to prepare a glass paste.
The obtained glass paste was used in a digital rotational viscometer (HBDV-II) manufactured by Brookfield, using a spindle (SC4-14) and a sample holder (SC4-6R), and a rotational speed of 10 rpm at 25 ° C. The viscosity (η10) at 50 and the viscosity (η50) at 50 rpm were measured, and the thixo ratio was calculated from the measured values.
The results are also shown in Table 1.

  As is apparent from Table 1, the glass paste of the present invention has an appropriate viscosity and thixotropy that can be applied by screen printing or the like, even though no binder resin is used. Therefore, a glass coating layer and a glass sealing layer having no defect can be formed using the glass paste of the present invention.

  According to the glass paste of the present invention, the use of a binder resin that causes sintering inhibition and defects can be eliminated, and a glass layer having good characteristics can be formed using this. Therefore, as a material for forming an insulating pattern on a printed substrate, sealing of flat display devices such as a plasma display panel (PDP), a field emission display (FED), a fluorescent display tube (VFD), a lens cap, an LD cap It can be suitably used as a material used for sealing optical parts such as semiconductor packages, and electronic parts such as semiconductor vibrators, piezoelectric vibrators such as crystal vibrators and surface acoustic wave elements.

  DESCRIPTION OF SYMBOLS 1 ... Reaction cylinder, 2 ... Burner, 4 ... Recovery apparatus, 5 ... Cooling pipe.

Claims (7)

  A glass powder having an average particle diameter of 10 to 1000 nm, a volatile organic solvent, a binder resin substantially not contained, and a viscosity measured with a rotational viscometer at 25 ° C. and a rotational speed of 10 rpm. A glass paste characterized by being 20 to 600 Pa · s.   The glass paste according to claim 1, wherein the volatile organic solvent is an organic solvent having a boiling point of 300 ° C. or lower.   The glass paste according to claim 1 or 2, wherein the volatile organic solvent is at least one selected from an ester organic solvent, an ether organic solvent, and an alcohol organic solvent.   The volatile organic solvent is ethylene glycol, 1,2-propanediol, diethylene glycol, glycerin, 2-ethyl-1,3-hexanediol, ethylene glycol mono-2-ethylhexyl ether and 2,4-diethyl 1,5- The glass paste according to any one of claims 1 to 3, comprising at least one selected from pentanediol.   The glass paste according to any one of claims 1 to 4, wherein the volatile organic solvent contains 1,2-propanediol and / or 2,4-diethyl 1,5-pentanediol.   The glass paste according to any one of claims 1 to 5, wherein the glass powder has an average particle size of 20 to 800 nm.   The glass paste according to any one of claims 1 to 6, which has a viscosity of 50 to 400 Pa · s measured at 25 ° C and a rotation speed of 10 rpm with a rotational viscometer.

Images