JPH0911212A - Ceramic slurry, its manufacturing method and use - Google Patents

Abstract

(57) [Abstract] [Purpose] A ceramic slurry that can be obtained as a ceramic slurry with excellent properties such as flexibility, moldability, dispersibility, and mechanical strength of a green sheet. provide. [Constitution] Water or a mixed solution of water and a water-soluble organic solvent is used to copolymerize a vinyl monomer with a liquid in which a vinyl monomer is heated in the presence of a polymerization initiator to coat the ceramic powder as an organic binder. Then, microcapsules containing ceramic powder as a core substance are prepared.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is used for forming so-called ceramics such as alumina from the viewpoints of low pollution, resource saving and safety, that is, for producing a formed body and a green sheet made of a ceramic precursor. The present invention relates to a slurry and a method for producing the same, and particularly to a ceramic slurry used in an aqueous system.

[0002]

2. Description of the Related Art Conventionally, a ceramic molded body is manufactured by mixing ceramic powder, a solvent and an organic binder resin (polymer) into a slurry, which is molded, dried and sintered.

(A) As a ceramic binder, an organic binder such as polyvinyl butyral resin or polyacrylic ester resin is generally used. This binder is dissolved or dispersed in an organic solvent such as alcohol, ketone, chlorine-based solvent or aromatic solvent, mixed with ceramic fine powder, kneaded and dispersed for a long time in a ball mill or the like to form a slip state. Eggplant After defoaming, a sheet having a certain thickness is cast on a substrate such as a polyester film by a doctor blade method or the like, and dried by heating to form a green sheet.

(B) As a water-soluble binder for ceramics, a water-soluble polyvinyl acetal having an acetalization degree of 10 mol% or less is disclosed in JP-A-56-76405, and a cold water-soluble polyvinyl acetal having an acetalization degree of 10 to 30 mol%. Japanese Unexamined Patent Publication No. 29408 / 1989-29408, and a modified polyvinyl alcohol having a hydrophobic group or a specific ionic hydrophilic group in its side chain is used as an aqueous organic binder.
It is known from Japanese Patent No. 156959.

As the water-soluble poly (meth) acrylic acid ester-based binder (c), Japanese Patent Publication No. 1-353233, Japanese Patent Publication No. 1-44686, and Japanese Patent Application Laid-Open No. 1-286955 are known. In these, the copolymer of (meth) acrylic acid ester and (meth) acrylic acid is neutralized (pH adjusted) with ammonia, trialkylamine such as trimethylamine, dimethylamino alcohol, amines such as monoethanolamine. .

Further, (d) emulsion binder obtained by emulsion-polymerizing vinyl monomers using a surfactant, using (meth) acrylic acid, which is neutralized (pH adjusted) with ammonia. JP-A-60-180955, JP-A-60-180956, and JP-A-61-1.
JP-A No. 51060, JP-A No. 1-286955, and JP-A No. 63-260855 are known to have a crosslinked structure.

Further, (e) an α-olefin polymer, a (meth) acrylic acid ester alone or a swelled product composed of a (meth) acrylic acid ester monomer and a styrene monomer, and a polymerization initiator is dispersed for polymerization. A system in which an agent (for example, water-soluble polymer polyvinyl alcohol) is dispersed in an aqueous medium and suspension polymerization is performed is used as a binder.
No. 4 is known.

(F) Japanese Unexamined Patent Publication No. 59-128266 discloses a composite binder for ceramic molding containing 1 to 1000 parts by weight of a hydrophobic polymer component with respect to 100 parts by weight of a water-soluble polymer component. ing.

On the other hand, (g) JP-A-59-995,
Japanese Patent Laid-Open No. 60-254697 discloses a method for manufacturing a ceramic multilayer wiring board, and discloses a polymethacrylic acid ester resin as a binder containing a thermal depolymerization type resin therein.

[0010]

In the binder (a), butyl alcohol, isopropyl alcohol, trichloroethylene, toluene, etc. are used as the organic solvent. However, these organic solvents are explosive due to ignition,
There is a risk of fire, odors during molding and drying, especially halogen-based solvents have environmental pollution due to evaporative gas and pollution problems such as harmful to humans.To prevent these, explosion-proof equipment, waste gas treatment equipment, solvent There are many problems such as the need to install recovery equipment. In the cases of (b) and (c), since they are water-soluble, they have high hygroscopicity, and there are drawbacks such as variations in the characteristics of the ceramic green sheets. In the case of (d),
Ceramic green sheets using an emulsion having a carboxyl group have weaknesses such as low tensile strength, poor gloss and smoothness. Further, since all binders have poor binder removal properties, there is a problem that the strength of the ceramic sheet and the ceramic substrate after firing is poor. Also,
In the case of (e), the compatibility of the α-olefin polymer with the (meth) acrylic acid ester alone or the (meth) acrylic acid ester monomer and the styrenic monomer is poor, and the mechanical properties of the ceramic precursor composition are high. The characteristics are not good. Further, since a polymer having a poor thermal decomposability such as an α-olefin polymer or polyvinyl alcohol is used, there is a problem that the binder removal property is poor and the strength of the fired ceramic, ceramic sheet and ceramic substrate is poor. In the case of (f), it is a method of adding a hydrophobic polymer latex obtained by emulsion polymerization as an aqueous dispersion to a water-soluble polymer solution dissolved in water. Because there are many molecules,
In order to use the water-soluble polymer as a binder, it is important that the added amount is as small as possible. Further, when a large amount of water-soluble polymer is present, the green sheet is likely to absorb moisture, so that the mechanical properties and the like greatly vary. Further, since the hydrophobic polymer latex obtained by emulsion polymerization contains a surfactant, the workability is not good, such as agglomeration depending on the type of ceramic powder and a large amount of bubbles generated during defoaming.

On the other hand, in order to use the polymethacrylic acid ester used in (g) as an organic binder for ceramic molding, for example, the vapor pressure of a ketone-based solvent such as methyl ethyl ketone or an alcohol-based solvent such as butyl alcohol, etc. Since it uses a high organic solvent, it lacks fire safety.

[0012]

Therefore, as a result of intensive investigations by the present inventors, the ceramic powder was dispersed in an aqueous system, a vinyl monomer and a polymerization initiator were added thereto, and the monomer was heated by heating or the like. A ceramic precursor composition which is formed by a ceramic slurry which is a microcapsule and which is coated with ceramic powder as a core substance while becoming a polymerization or organic binder component, requires only a small amount of an organic binder component and does not drop out of the ceramic powder. The present invention has been completed by finding out that it is excellent in mechanical properties and useful as a water-based ceramic slurry. That is, the present invention relates to the ceramic powder 10
At least one kind of hydrophilic group in water or a mixed solution of water and a water-soluble organic solvent in which 0 part by weight is dispersed; anionic hydrophilic group (carboxyl group, sulfonic acid group, sulfuric acid group, etc.) or a metal thereof, Polymerization of salts of ammonium, amine, etc. and one or more kinds of monomers having an alkyl group having 1 to 18 carbon atoms and / or a cyclic alkyl group and / or aryl group having 3 to 12 carbon atoms The above object is achieved as a ceramic slurry which is characterized in that it is copolymerized in the presence of an agent to form microcapsules coated with ceramic powder.

The ceramic powder is not particularly limited, but it is desirable that the average particle size of the ceramic powder in forming a green sheet is 50.0 μm or less. The ceramic precursor composition comprises 100 ceramic powders.
A predetermined molded body is obtained from a ceramic slurry composed of 1 part by weight, 30 parts by weight of the organic binder 2 and, if necessary, a dispersant and a plasticizer, and the above object is achieved.

The average particle size of the green sheet is 50.0 μm.
By coating the surface of the base material with a ceramic composition slurry comprising 100 parts by weight of ceramic powder of m or less, 30 parts by weight of the above organic binder 2 and, if necessary, a dispersant and a plasticizer in a thin film form. As a result, the above object is achieved.

Further, 100 parts by weight of a ceramic powder having an average particle size of 50.0 μm or less and the organic binder 2 to 30 are used.
It is composed of a ceramic precursor composition consisting of parts by weight and, if necessary, a dispersant and a plasticizer, on which a conductor layer is formed in a pattern, and laminated and adhered to form several layers to several tens of layers. Then, a multilayer ceramic substrate is obtained by sintering. Or, the green sheet layer has an average particle size of 50.0
a ceramic precursor composition comprising 100 parts by weight of ceramic powder having a size of less than or equal to μm, 2 to 30 parts by weight of a ceramic organic binder, and optionally a dispersant and a plasticizer. The above object is achieved by a method of manufacturing a multilayer wiring ceramic substrate which is obtained by sintering a laminated body having layers interposed therebetween.

Hereinafter, the present invention will be described in detail.

That is, according to the present invention, the ceramic powder is dispersed in water or a mixed liquid of water and a water-soluble organic solvent, and at least one or more kinds of hydrophilic groups as an organic binder precursor component; anionic hydrophilic A group (carboxyl group, sulfonic acid group, sulfuric acid group, etc.) or a salt thereof such as a metal, ammonium or amine, an alkyl group having 1 to 18 carbon atoms and / or a cyclic alkyl group having 3 to 12 carbon atoms, and And / or at least one vinyl-based monomer having an aryl group is added, and copolymerized in the presence of a polymerization initiator to form an organic binder to form coated microcapsules. The present invention relates to a characteristic ceramic slurry and its manufacturing method.

The organic binder precursor used in the present invention is a vinyl-based monomer, and the organic binder that is a polymer thereof is formed on the surface of the ceramic powder during the polymerization and covers the ceramic powder. That is, these are microcapsules containing ceramic powder as a core substance in the slurry. Further, in the ceramic precursor, the ceramic powder and the ceramic powder are adhered to each other to maintain their shape. As a component which is an organic binder precursor, for example, a monomer having an anionic hydrophilic group; (meth) acrylic acid, monohydroxyethyl (meth) acrylate succinate, monohydroxyethyl (meth) acrylate phthalate, ω- Carboxy-polycaprolactone mono (meth) acrylate, (meth) acrylic acid dimer, maleic acid (monoester), fumaric acid (monoester), itaconic acid (monoester), citraconic acid (monoester), 2-acrylamido-2 -Methyl propane sulfonic acid, also eg methyl (meth)
Acrylate, ethyl (meth) acrylate, n-propyl (meth) acrylate, isopropyl (meth) acrylate, n-butyl (meth) acrylate, isobutyl (meth) acrylate, n-amyl (meth) acrylate, isoamyl (meth) acrylate, n-hexyl (meth) acrylate, n-octyl (meth) acrylate, isooctyl (meth) acrylate, decyl (meth) acrylate, dodecyl (meth) acrylate, lauryl (meth) acrylate, stearyl (meth) acrylate, cyclohexyl (meth) (Meth) such as acrylate, isobornyl (meth) acrylate, phenyl (meth) acrylate, benzyl (meth) acrylate
Unsaturation of acrylate monomers, ethylene monomers such as ethylene and isobutylene, styrene monomers such as styrene and α-methylstyrene, maleic acid diesters, fumaric acid diesters, itaconic acid diesters, citraconic acid diesters, etc. Examples thereof include diester monomers.

The plasticizer used in this slurry is basically difficult to azeotrope with water or an aqueous solvent, and has compatibility with an organic binder which is a polymer obtained from vinyl monomers. It is a good one. For example, dibutyl phthalate (abbreviated as DBP), di-2-ethylhexyl phthalate (DOP), diisononyl phthalate (DINP), diisodecyl phthalate (DIDP), diheptyl phthalate (DHP), di-n-octyl phthalate (ND)
OP) butyl benzyl phthalate (BBP), phthalate ester such as ethyl phthalyl ethyl glycolate, di-2-ethylhexyl adipate (DOA), aliphatic ester such as dibutyl diglycol adipate (BXA), tripropylene glycol methyl Ether (TP
M), propylene glycol ethers such as dipropylene glycol-n-butyl ether (DPnB), tripropylene glycol-n-butyl ether (TPnB) and propylene glycol phenyl ether (PPh). Preferably, DOP, DINP, DI
DP, DHP and N-DOP are good. The plasticizer may be added according to each form and is not particularly limited. That is, the mechanical properties of the ceramic precursor composition molded using the organic binder for ceramics are retained,
It should be good if it is easy to handle. In other words, the mechanical properties of the obtained green sheet can be controlled by adjusting the addition amount of the plasticizer. As one guideline, the elongation is required to be about 5 to 25% in order to obtain the handling property of the green sheet and the drilling accuracy. The plasticizer may be added during or after the polymerization of the vinyl monomer. It is preferable to add it at the time of polymerization in order to prevent adhesion between microcapsules.

The solid content concentration of the ceramic slurry used in the present invention is 80% by weight or less and 10% by weight or more. 8
If it exceeds 0% by weight, the fluidity of the slurry deteriorates and the sheet cannot be formed. Further, if it is less than 10% by weight, workability is deteriorated.

In the method for producing a ceramic slurry used in the present invention, the ceramic powder is dispersed in water or a mixed liquid of water and a water-soluble organic solvent, and at least one vinyl-based monodisperse is used as the organic binder precursor. Add the quantity,
The component is copolymerized in the presence of a polymerization initiator to form an organic binder. At this time, the coated microcapsules are formed.

As the solvent used in the present invention, water or water and, for example, methanol, ethanol, propanol,
Alcohols such as isopropanol, ethylene glycol methyl ether, ethylene glycol ethyl ether, ethylene glycol derivatives such as ethylene glycol butyl ether, diethylene glycol methyl ether, diethylene glycol ethyl ether, diethylene glycol derivatives such as diethylene glycol butyl ether, propylene glycol methyl ether, propylene glycol ethyl ether, Examples thereof include a mixed solvent with a water-soluble organic solvent selected from at least one selected from propylene glycol derivatives such as propylene glycol butyl ether, acetic acid ester derivatives such as methyl acetate and ethyl acetate, and lactate ester derivatives such as methyl lactate and ethyl lactate. Further, a poorly water-soluble alcohol solvent may be partially added. When water and a water-soluble solvent are used, the mixing ratio is 100 to 50% by weight of water and 0 to 50 of the water-soluble solvent.

Examples of the polymerization initiator include 2,2'-azobis (isobutyronitrile) and 2,2'-azobis (2,2'-azobis (isobutyronitrile).
Azo compounds such as 4-dimethylvaleronitrile) and 2,2′-azobis (isobutylvaleronitrile), peroxides such as tert-butyl hydroperoxide, benzoyl peroxide, t-butyl peroxide, ammonium persulfate and persulfate. A polymerization initiator such as persulfate such as potassium can be used without particular limitation. A water-soluble polymerization initiator is particularly preferable. It is desirable to use 0.01 to 5 parts by weight based on 100 parts by weight of the total amount of the monomers. If necessary, a molecular weight of the polymer can be controlled by using a chain transfer agent such as tashyadedecyl mercaptan or thioglycolic acid.

This reaction can be carried out usually at 40 to 90 ° C., though it depends on the kind of the polymerization initiator.

The weight average molecular weight of the vinyl monomer polymer as the organic binder used in the present invention is 100,000 or more. If it is less than 100,000, it is difficult to obtain sufficient mechanical properties of the green sheet.

The average particle size used in the present invention is 50.0 μ.
Examples of the ceramic powder having m or less include Al ₂ O
₃ , SiO ₂ , 3Al ₂ O ₃ · SiO ₂ , PbO, Al ₂ O _{3
· MgO, B 2 O 3,} CaO, BaO, ZrO 2, Zn
At least one selected from O, Na ₂ O, P ₂ O ₅ , K ₂ O, Li ₂ O and the like. More specifically, alumina (Al ₂ O ₃ ), mullite (Mullit)
e, 3Al ₂ O ₃ .2SiO ₂ ), cordierite (Co
rdierite, 2MgO.2Al ₂ O ₃ .5Si
O ₂ ) at least one ceramic powder, SiO
₂ -B ₂ O ₃ -Na _{2 O-based, SiO 2 -B 2 O 3 -K} 2 O system,
_{SiO 2 -B 2 O 3 -Li 2} O system, SiO ₂ -B ₂ O ₃ -Zn
Among borosilicate glass such as O-based glass, it is selected from at least one or more kinds of ceramic powder and glass powder. Further, when producing a glass-ceramic substrate, it is preferable to use an amorphous or crystalline glass component that can be fired at a temperature lower than the melting point of copper, and a ceramic powder and a glass powder that are less likely to produce cristobalite after sintering. The composition is preferred. The ceramic powder may be spherical or pulverized. When fine through-hole processing is required, the average particle size of the ceramic powder for green sheets is generally 10μ.
m or less, more preferably 5 μm or less is desirable.

The ceramics used in the present invention are B
Examples thereof include high dielectric materials such as aTiO ₃ and resistor materials, and are not particularly limited.

Examples of the dispersion aid for ceramics used in the present invention include salts of polyacrylic acid such as ammonium polyacrylic acid, phosphate esters, polyethylene glycol, polyvinyl-2-pyrrolidone and copolymers, and glycerol trioleate. Etc.

The dispersion aid for ceramics makes it difficult for the ceramic powders to agglomerate during the preparation of the ceramic powder dispersion and facilitates the flow of the slurry. The dispersion aid for ceramics is used by adding ceramic powder to a solution obtained by dissolving or dispersing in a solvent (water, water and a water-soluble solvent). If used, wet mixing is performed for 1 to 5 hours using a ball mill.

The method for producing the ceramic precursor composition used in the present invention is a ceramic dispersion comprising 100 parts by weight of ceramic powder and, if necessary, a dispersant selected from among various ceramic dispersion aids. Wet mix for at least 5 hours or more to obtain organic binder precursor (vinyl monomer)
2 to 30 parts by weight, a polymerization initiator, and, if necessary, a plasticizer are added, and heated to perform polymerization to obtain a ceramic slurry, which is subjected to a defoaming step, and then an extrusion molding method, an injection molding method, a doctor blade method. , A calendar roll method or the like. The production method is not particularly limited.

In the method for producing the ceramic molded body used in the present invention, the ceramic precursor composition obtained by the above-mentioned production method is fired at a temperature of 350 to 1800 ° C. for at least 5 hours in air or in a non-reducing atmosphere. Can be obtained by

The multilayer ceramic substrate used in the present invention is obtained by the following manufacturing method. Ceramic powder 100
Wet-mix a ceramic dispersion liquid containing at least 1 part by weight and, if necessary, a dispersant selected from among various dispersion aids for ceramics, for at least 1 hour to initiate polymerization with 2 to 30 parts by weight of the organic binder precursor. Agent and plasticizer if necessary, and heating to polymerize to make ceramic slurry, and after defoaming step, green sheet is formed at room temperature to 120 ° C at cast temperature by doctor blade method etc. To be done. In order to improve the mechanical properties of the obtained green sheet, if necessary, further 100 to 180 ° C
It may be dried for 30 to 90 minutes. The obtained green sheet having a thickness of 0.05 to 2 mm is cut into a predetermined size (for example, 10 to 200 mm × 10 to 200 mm square), and a necessary layer and a through hole are punched at predetermined positions.
The diameter of the through hole is not limited, but can be up to 40 microns. This punched green
On the sheet, for example, W (melting point 3410 ° C), Mo
(Melting point 2620 ° C.), Ag (melting point 961.9), Au
(Melting point 1064 ° C.), Pt (melting point 1769 ° C.), Pd
(Melting point 1554 ° C.), Cu (melting point 1083.4 ° C.), N
A conductor paste mainly composed of one or more conductors such as i (melting point 1453 ° C.) is printed at a predetermined position by a screen printing method. In this way, a predetermined circuit is formed on the green sheet on which the conductor is printed through the screen mask, and several to several tens of layers of the green sheet on which the circuit is formed are laminated, and the temperature is 80 to 150 ° C. and the pressure is 0.98 MPa to 29. Four
Hot press bonding is performed at MPa (10 to 300 kgf / cm ² ). The obtained laminated body is cut into a predetermined shape and size. The firing temperature varies depending on the type of conductor (generally, the firing temperature is below the melting point of the conductor).
A ceramic substrate is obtained by firing at a temperature of 00 ° C. for at least 5 hours in air or in a non-reducing atmosphere.

The ceramic slurry obtained according to the present invention is composed of water alone or water and a water-soluble organic solvent, and is unnecessary without using a water-insoluble organic solvent or hardly. Further, in the ceramic precursor composition, the ceramic powder does not fall off, the dispersibility of the ceramic,
A ceramic green sheet excellent in surface smoothness, density, elongation, and strength can be produced, which is advantageous from the viewpoint of low pollution and resource saving. Further, by stacking and firing the green sheets, it is possible to obtain a dense multilayer ceramic substrate having excellent surface smoothness and strength.

[0034]

The features of the present invention are that the ceramic slurry is useful as an aqueous ceramic slurry, and the organic binder component exerts its function for binding between the ceramic powders, and various characteristics of the green sheet, that is, flexibility and molding. Sex, dispersibility,
It satisfies the surface condition. Further, it satisfies various characteristics of the laminated body of the green sheet with a circuit pattern, that is, laminating pressure-bonding property, mechanical strength and the like.

[0035]

EXAMPLES Examples of the present invention will be described below, but the present invention is not limited to these examples.

The term "%" means "% by weight".

100 parts by weight of ceramic powder and water or water and an organic solvent were added and kneaded with a ball mill to obtain a ceramic dispersion liquid. This was transferred to a flask. A ceramics slurry was obtained by adding 2 to 30 parts by weight of a vinyl monomer, a polymerization initiator, and a plasticizer if necessary, and heating and stirring the mixture. Further, air was degassed from this slurry under reduced pressure. The viscosity of the slurry thus prepared was adjusted by concentration, and the slurry was applied onto a polyester film using a doctor blade type casting device and dried to prepare a green sheet. Various physical properties of the sheet were evaluated with respect to moldability, flexibility and dispersibility.

(Moldability) After coating on a polyester film, drying, and visual evaluation.

◯: Good peeling of the green sheet from the polyester sheet and no cracking.

Δ: A green sheet with some cracks.

X: Do not crack to form a green sheet.

(Flexibility) A central portion of the green sheet was restrained by each of five kinds of glass core rods having different diameters, and a bending test of 180 ° centered on the core rod was conducted. Flexibility was indicated by the diameter (mmφ) of the core rod immediately before the sheet cracked. The diameter of the core rod is 2, 3, 4, 6, 8 mm.

(Dispersibility) ◯: There is little aggregation in the dispersed state of the ceramic fine particles in the green sheet.

Δ: There is a little agglomeration in the dispersed state of the ceramic fine particles in the green sheet.

X: A large amount of agglomeration occurs in the dispersed state of the ceramic fine particles in the green sheet.

Example 1 Alumina powder as a main component, Al ₂ O ₃ 91% in total composition, SiO ₂ 6
%, MgO 3%, 5 kg of a ceramic powder having a particle size of 5 μm or less, and 3.6 kg of water are added together in an alumina lining container, and then mixed with a ball mill using alumina balls.
Kneading for a period of time gave a ceramic dispersion. This ceramic dispersion was transferred to a 10 liter flask equipped with a stirrer, thermometer, reflux condenser, dropping funnel and gas inlet tube. Under a nitrogen gas stream, 100 g of methacrylic acid, which is an organic binder precursor, and 40 n-butyl methacrylate.
In addition to 0 g, a mixed solution of 75 g of a plasticizer, dioctyl phthalate, was uniformly added dropwise over 1 hour, 5 g of ammonium persulfate was added, and the mixture was further heated and stirred at 60 ° C. for 4 hours. This was cooled to room temperature to obtain a ceramic slurry in which the ceramic powder was coated with an organic binder and the solid content concentration was 60%.

After the ceramic precursor composition slurry was prepared in this manner, the slurry was further degassed under reduced pressure.
With respect to the physical properties of the thus prepared uniform slurry mixed liquid, as shown in Table 1, the moldability, flexibility and dispersibility were good.

[0048]

[Table 1]

After the ceramic slurry was prepared, the pressure was reduced from this slurry to 133.3 Pa to 6665 Pa (1 mm).
It was degassed under Hg-50 mmHg). Furthermore, the viscosity is adjusted while scattering water under reduced pressure to 3 Pa · s to 10 Pa ·
s, a doctor blade type casting device was used to cast on a polyester film and dried at 120 ° C. to produce a green sheet having a thickness of 0.2 mm. As shown in Table 1, the physical properties of the sheet were good in moldability, flexibility and dispersibility.

The green sheet is punched with a die 2
It was cut into a piece of 00 mm × 200 mm square and a hole for guide was formed.
Then, the green sheet was fixed using the holes for the guide, and a through hole having a diameter of 0.1 mm was punched out at a predetermined position by a punching method. A tungsten powder having a particle diameter of 5 μm or less: nitrocellulose: ethylcellulose: α-terpineol = 100: 4: 2: 23 (weight ratio) was filled in the through holes formed in the green sheet, and then the screen printing method was used. A predetermined circuit pattern was printed on the surface of the green sheet. The conductor is printed in this way, and 40 sheets of green sheets with a circuit formed are stacked with the positions of the guide holes aligned, and at 120 ° C, 100 kgf /
Hot press bonding was performed at a pressure of cm ² . The obtained laminated body is cut into a required shape to form a 150 mm × 150 mm square green sheet laminated plate, and a mixed atmosphere of nitrogen / hydrogen / steam (pressure ratio; 0.6 atm: 0.2 atm: 0.2 atm) ) Was fired at 1600 ° C. for 2 hours in the firing furnace. During firing, the binder was sufficiently removed during the temperature rising process. 120mm x 120mm square, thickness 7mm by this green sheet lamination method
A multilayer wiring ceramic substrate was manufactured.

(Examples 2 to 20) Except that the types and amounts of organic binder precursors, the compounding ratios, the types and amounts of polymerization initiators, and the types and amounts of dispersion media were changed as shown in Tables 1 and 2. The same experiment as in Example 1 was performed to obtain a ceramic slurry.

[0052]

[Table 2]

An experiment was conducted in the same manner as in Example 1 to produce a green sheet, and its various properties are shown in Table 1.

An experiment was conducted in the same manner as in Example 1 to prepare a multilayer wiring ceramic substrate from a green sheet.

Comparative Example 1 A polyvinyl acetate copolymer containing 4.0 mol% of octyl acrylamide and 2.0 mol% of trimethyl-3- (1-methacrylamido-propyl) ammonium chloride. A modified PVA in which 88.7 mol% of the vinyl component was saponified and the viscosity of a 4% aqueous solution at 20 ° C. was 34 centipoise was used as the binder.

100 parts by weight of a ceramic powder having a particle size of 5 μm or less, containing alumina powder as a main component, and having a composition of Al ₂ O ₃ 33%, SiO ₂ 33%, and borosilicate glass 34%, and a binder resin. 6 parts, 1 part of polyoxyethylene nonylphenol ether as a dispersant,
50 parts of ion-exchanged water was added to obtain a ceramic precursor composition. This was kneaded for 24 hours in a ball mill using an alumina lining container and alumina balls. An experiment was conducted in the same manner as in Example 1 to produce a green sheet, and its various properties are shown in Table 3.

[0057]

[Table 3]

Comparative Example 2 Acrylic acid, butyl acrylate, ethyl acrylate Polymerization ratio (50/25/25) 20 g of a monoethanolamine salt of a copolymer having a weight average molecular weight of about 100,000 was used as a dispersant in water / methanol. Polymerization ratio (5 /
5) Emulsion polymerization of ethyl acrylate in a mixed solvent of 80 g using 0.4 g of ammonium persulfate as a polymerization initiator to obtain a latex having a solid content of 50%.

An experiment was conducted in the same manner as in Comparative Example 1 except that 24 parts of latex and 18 parts of ion-exchanged water were used to prepare a green sheet, and its various properties are shown in Table 3.

Comparative Example 3 Nonionic surfactant as a dispersant, butyl acrylate, acrylic acid as an emulsifier,
A latex having a composition of methacrylic acid polymerization ratio (70/15/15) was obtained.

An experiment was conducted in the same manner as in Comparative Example 1 except that 10 parts of latex (solid content), 25 parts of monoethanolamine as a neutralizing agent and ion-exchanged water were used to prepare a green sheet, and its various characteristics. Is shown in Table 3.

Comparative Example 4 4 parts by weight of glycine betaine chloride of polyoxyethylene octyl phenyl ether and 4 parts by weight of dimethacrylic acid ester of polyoxypropylene polyoxyethylene glycol were used as emulsifiers and 2,2 'as a polymerization initiator. -Azobis (N, N'-dimethyleneisobutylamidine) hydrochloride was used to obtain a latex having a composition of 75 parts by weight of ethyl acrylate, 75 parts by weight of methyl methacrylate, and 4.5 parts by weight of N-methylol acrylate. .

An experiment was conducted in the same manner as in Comparative Example 1 except that 10 parts of latex (solid content), 3 parts of polyethylene glycol (molecular weight 200) and 2 parts of ethyl carbitol as the plasticizer, and 25 parts of ion-exchanged water were used. , A green sheet was prepared, and its various properties are shown in Table 3.

(Comparative Example 5) Aqueous dispersion of hydrophobic polymer:
Methacrylic acid ester (MMA / n-BMA / LMA /
CHMA = 10/60/10/20, solid content 48%) and 10% water-soluble polymer PVA (polymerization 500, saponification degree 88.5 mol%) were mixed in a 1/1 weight ratio, for green sheet An organic binder (composite binder) was obtained. (Production of green sheet) Alumina powder as a main component and Al ₂ as a whole composition
O ₃ 33%, SiO ₂ 33%, borosilicate glass 34%
Ceramic powder 100 having a particle size of 5 μm or less
Parts by weight, latex 16 parts (solid content) 50 parts by weight of water, 0.3 parts of polyacrylic acid ammonium salt dispersion aid are mixed in a ball mill for 2 hours, and then 10 parts by weight of a composite binder is added to obtain a powder. An experiment was conducted in the same manner as in Comparative Example 1 except that the mixture was uniformly mixed, and a green sheet was prepared, and its various properties are shown in Table 3.

However, the abbreviations in the table are as follows.

MA: methacrylic acid, n-BMA: n-butyl methacrylate, MMA: methyl methacrylate,
EtMA: ethyl methacrylate, BAA: n-butyl acrylate, St: styrene, MalADM: dimethyl maleate, i-BMA: isobutyl methacrylate, MAA: methyl acrylate, IADM: dimethyl itaconic acid, MA-EA: monoethanolamine of methacrylic acid. Salt, HOMS: 2-methacryloyloxyethyl succinic acid, HOMP-NH ₃ : ammonium salt of 2-methacryloyloxyethyl phthalic acid, MalA: maleic acid, E
tAA: ethyl acrylate, IA-DEA: diethanolamine salt of itaconic acid, AA-DMEA: dimethylaminoethanol salt of acrylic acid, TBAS: 2-acrylamido-2-methylpropanesulfonic acid, TBAS: 2-acrylamido-2-methylpropane Ammonium salt of sulfonic acid, MA-TEA: Triethanolamine salt of methacrylic acid, DOP: Dioctyl phthalate, DBP: Dibutyl phthalate, DIDP: Diisodecyl phthalate,
DINP: diisononyl phthalate, DOA: dioctyl adipate, DIDA: diisodecyl adipate, A
PS: ammonium persulfate, KPS: potassium persulfate,
ABAH: 2,2'-azobis (2-amidinopropane)
Dihydrochloride, BHPO: tertiary butyl hydroperoxide, AIBN: 2,2'-azobis (isobutyronitrile), ACVA: 4,4'-azobis-
4-Cyanovvaleric acid, IPA: Isopropyl alcohol, PGM: Propylene glycol monomethyl ether

[0067]

The ceramic slurry obtained according to the present invention is a ceramic green sheet excellent in dispersibility of ceramics, surface smoothness, density and mechanical strength, without using a water-insoluble organic solvent or hardly. It can be generated, and is advantageous from the viewpoint of low pollution and resource saving. Especially in the doctor blade method, it is possible to transfer from an organic solvent system to a safe and hygienic water system, and also having excellent properties such as improvement of mechanical strength, which is useful as a ceramic slurry. is there.

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Claims (10)

[Claims] 1. A ceramic powder having an average particle size of 50.0 μm or less, and 100 parts by weight of an organic binder precursor,
A ceramic slurry comprising 2 to 30 parts by weight of at least one kind of vinyl-based monomer, a polymerization initiator, and water or water and a water-soluble organic solvent. 2. A ceramic slurry for polymerizing the organic binder precursor according to claim 1 to obtain an organic binder. 3. The method for producing a ceramic slurry according to claim 2. 4. The vinyl-based monomer according to claim 1,
Have at least one kind of hydrophilic group and have 1 to 1 carbon atoms
One or more kinds of (meth) acrylic acid ester monomers having 8 alkyl groups and / or cyclic alkyl groups and / or aryl groups having 3 to 12 carbon atoms, and / or styrene-based monomers, and Ceramic slurry which is an unsaturated diester monomer. 5. The component of the vinyl-based monomer having at least one kind of hydrophilic group according to claim 4, wherein the hydrophilic group is an anionic hydrophilic group or a metal or ammonium thereof,
Ceramic slurries, which are monomers with amine salts. 6. A ceramic precursor composition obtained by molding and drying the slurry according to claim 2. 7. A ceramic green sheet formed by molding the slurry according to claim 2 into a thin film. 8. A ceramic obtained by sintering the ceramic precursor composition according to claim 6. 9. A ceramic sheet obtained by sintering the ceramic green sheet according to claim 6. 10. A ceramic multilayer wiring board obtained by forming a laminate of a plurality of conductor layers with the ceramic green sheet layer according to claim 6 interposed therebetween and sintering the laminate.