JPH0693020A - Polyvinyl acetal-acetal-based resin, its production and ceramic sheet using the same - Google Patents

Abstract

PURPOSE:To obtain a resin useful as a ceramic binder having improved solubility in clean water, excellent mechanical strength, saving resources without using an organic solvent to cause pollution, comprising specific structural units. CONSTITUTION:A polyvinyl acetal resin comprises structural units of formula I, formula II and formula III [R<1> is H or 1-12C alkyl; R<2> is H, 1-12C alkyl, 1-8C alkyl or aryl; M is H or (organic) ammonium ion]. 5-30mol% unit of formula I is reacted with 1-70mol% unit of formula II and 20-65mol% unit of formula II so as to be 100mol% in total amount to give a carbonxylethylated polyvinylacetal-based resin. Ceramic fine powder having 0.05-2 micron standard deviation value of average particle diameter is blended with the carboxylethylated polyvinylacetal-based resin as a binder.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is a novel carboxyethylated polyacetal resin, and in view of low pollution and resource saving, when forming so-called ceramics such as alumina, that is, a green precursor which is a ceramic precursor. TECHNICAL FIELD The present invention relates to an organic binder used for producing a sheet, and particularly to an excellent organic organic binder for ceramics and a ceramic sheet using the same.

[0002]

(A) Conventionally, as a binder for ceramics, an organic binder such as butyral resin is generally used, and this binder is used as an organic binder such as alcohol, ketone, chlorine-based solvent, aromatic solvent and the like. It is dissolved or dispersed in a system solvent, mixed with ceramic fine powder, kneaded and dispersed in a ball mill for a long time to form a slip state, and after defoaming, a doctor blade method or a reversing method. A method of casting a sheet having a certain thickness by a heating method and heating and drying it on a material such as a polyester film to form a green sheet is used.

(B) As a water-soluble binder for ceramics, a water-soluble polyvinyl acetal having a degree of acetalization of 10 mol% or less is disclosed in JP-A-56-76405, and a degree of acetalization of 10 to 30 mol. % Cold water-soluble polyvinyl acetate as disclosed in JP-A-64-29408, and modified polyvinyl alcohol having a hydrophobic group or a specific ionic hydrophilic group in the side chain as an aqueous organic binder.
No. 156959 is known.

On the other hand, as (c) water-soluble acrylic ester binders, Japanese Patent Publication No. 1-53233 and Japanese Patent Publication No. 1-4.
4668 and JP-A-1-286955 are known. A (meth) acrylic acid type copolymer having these carboxyl groups, that is, a (meth) acrylic acid ester type copolymer obtained by copolymerizing (meth) acrylic acid is ammonia,
Neutralization (pH) is adjusted with trialkylamines such as trimethylamine, dimethylamino alcohol, amines such as monoethanolamine.

[0005]

[Problems to be Solved by the Invention] However, (a)
Butyl alcohol, isopropyl alcohol, trichloroethylene, toluene, etc. are used as the organic solvent, but they are explosive due to ignition, the risk of fire,
There are many problems such as odor during molding and drying, environmental pollution by evaporative gas, pollution problem of harmfulness to human body, etc. Furthermore, it is necessary to install explosion-proof equipment, waste gas treatment equipment, solvent recovery equipment, etc. There is. In the case of (b), since it is a water-soluble polyvinyl acetal, it has a large hygroscopic property and there is a problem that the characteristics of the ceramic green sheet vary.
In the case of (c), the tensile strength of the ceramic green sheet using the (meth) acrylic acid ester-based copolymer having a carboxyl group is weak and the dimensional change of the sheet is large during lamination pressure bonding. There is.

[0006] The present invention provides a water-soluble binder having good properties and not large hygroscopicity when using a water-soluble binder without using an organic solvent which causes pollution problems, and pressure bonding using the same. The purpose of the invention is to provide a ceramic sheet having excellent strength and surface condition.

[0007]

Therefore, as a result of intensive investigations by the present inventors, the organic amine salt or ammonium salt of carboxyethylated polyvinyl acetal which is a hydrolysis product of cyanoethylated polyvinyl acetal. According to the above, it was found that the solubility in water and the mechanical strength can be improved, and it was found to be useful as a water-soluble ceramic binder, and the present invention was completed. That is, the present invention has the general formula

[0008]

[Chemical 5]

[0009] and

[0010]

[Chemical 6]

(Wherein R ¹ is a hydrogen atom or a carbon number 1
To 12 alkyl groups, R ² is a hydrogen atom, and has 1 to 1 carbon atoms.
2 alkyl groups, a cyclic alkyl group having 1 to 8 carbon atoms,
An aryl group or an aryl group having a substituent, M is a hydrogen atom, an ammonium ion or an organic ammonium ion. ) And 5 to 20 mol% of the constitutional unit represented by (1), 1 to 50 mol% of the constitutional unit represented by (2), and (3) A poly (vinyl acetal) resin obtained by reacting 20 to 65 mol% of the structural unit so that the total amount becomes 100 mol%. Yes, this resin is manufactured as follows. That is, (A) an aqueous solution of polyvinyl alcohol having a degree of saponification of 70 mol% or more and an average degree of polymerization of 500 to 2500 and R ¹ COR ² (wherein R ¹ is a hydrogen atom or a carbon number of 1 to 12). Alkyl groups, R ² is a hydrogen atom, an alkyl group having 1 to 12 carbon atoms, a cyclic alkyl group having 1 to 8 carbon atoms, an aryl group or an aryl group having a substituent). With an aqueous solution of a compound at a temperature of 13 to 40 ° C. in the presence of an acid catalyst, and then a temperature of 3
After reacting at 5 to 80 ° C., the reaction product is neutralized, and (B) the obtained polyvinyl acetal is dissolved in a water-soluble solvent, and acrylonitrile is added at 45 ° C. in the presence of an alkaline aqueous solution. A step of reacting at the following temperature, and (C)
A step of hydrolyzing the cyanoethylated polyvinyl acetal obtained in (B) at a temperature of 50 ° C. or higher in the presence of an alkaline aqueous solution, and a carboxylethylated polyvinyl acetal system obtained by purification. By using a water-soluble organic binder prepared by dissolving a resin in water and an organic amine, the above-mentioned object is achieved as a water-soluble organic binder for ceramic green sheets.

(A) The average fine particles have a standard deviation value of 0.05.
100 parts by weight of ceramic fine powder in the range of ˜2 μm, and (B) polyvinyl acetal resin 5 to 4 having a water-soluble carboxyl group as the organic binder.
0 parts by weight and (C) a ceramic precursor composition slurry, which optionally comprises a dispersant and a plasticizer, is coated on the surface of the base material in a thin film to form a ceramic green sheet. The above-mentioned object is achieved by the manufacturing method.

These various purposes are based on the above-mentioned ceramic grease.
It is also achieved by a ceramic sheet obtained by sintering a sheet. , Or the ceramic green sheet layer,
(A) 100 parts by weight of ceramic fine powder having a standard deviation of 0.05 to 2 microns, and (B) 5 to 40 parts by weight of polyvinyl acetal resin having a water-soluble carboxyl group as a binder. Part, and (C) a ceramic precursor composition containing a dispersant and a plasticizer as necessary, and a plurality of conductor layers are sintered through the above ceramic green sheet layer to sinter the laminate. The above object is achieved by the method for producing a multilayer wiring ceramic substrate.

The present invention will be described in detail below.

First, the degree of polymerization of the polyvinyl alcohol used in the present invention is 500 to 4000, preferably 550 to 3000, more preferably 550 to 1700, and the saponification degree is preferably 70 mol% or more. , 88 to 95 mol% is most suitable. If the saponification degree is less than 70 mol%, it becomes insoluble in water, and 95 mol%
If it is larger, the crystallinity of polyvinyl alcohol becomes higher and it becomes difficult to dissolve it in water. The polyvinyl alcohol aqueous solution is prepared by dissolving the polyvinyl alcohol in water, and the solid content concentration of the polyvinyl alcohol dissolved in water is 5
It is desirable to set the content to -15% by weight. The acid catalyst is an inorganic acid such as hydrochloric acid, sulfuric acid or nitric acid, or an organic acid such as paratoluenesulfonic acid, and hydrochloric acid is particularly preferable. The amount of the acid catalyst added is 3 to 12% by weight, preferably 4 to 10% by weight, based on the aqueous solution. If the amount of the acid catalyst added is less than 3% by weight with respect to the aqueous solution, the acetalization reaction does not proceed sufficiently and the production time becomes long. Since the aldehyde derivative and the ketone derivative undergo Aldol condensation by the acid, the obtained polyvinyl acetal is colored and the post-treatment of the neutralization step becomes complicated.

The concentration of the acid catalyst is weakly acidic in the first reaction,
The second reaction is strongly acidic (pH 2 or less).

Further, the general formula R ¹ CO used in the present invention is
R ² (wherein R ¹ is a hydrogen atom or an alkyl group having 1 to 12 carbon atoms, R ² is a hydrogen atom, an alkyl group having 1 to 12 carbon atoms, a cyclic alkyl group having 1 to 8 carbon atoms, Examples of the compound represented by the aryl group or the aryl group having a substituent include formaldehyde, acetaldehyde,
Propionaldehyde, butyraldehyde, heptylaldehyde, acrolein, crotonaldehyde, cyclohexanealdehyde, benzaldehyde, p-carboxybenzaldehyde, furfural, 4-hydroxybenzaldehyde, acetone, methylethylketone, methylpropylketone, methylbutylketone, methyl acetoacetate, acetoacetate At least one compound can be selected from known compounds such as ethyl acetate, levulinic acid, methyl levulinate, and ethyl levulinate.

The general formula used in the present invention R ¹ COR
² (wherein R ¹ is a hydrogen atom or an alkyl group having 1 to 12 carbon atoms, R ² is a hydrogen atom, an alkyl group having 1 to 12 carbon atoms, a cyclic alkyl group having 1 to 8 carbon atoms, an ari It is preferable that the amount of the compound represented by the formula (1) is a vinyl group or an aryl group having a substituent) is 25 to 75 mol% with respect to 2 mol of the polyvinyl alcohol unit. 30-65 mol% is preferable. When it is less than 25 mol%, the physical properties of the film are poor, and when it is more than 75 mol%, the solubility in water is poor.

Further, in the present invention, a surfactant is used in order to prevent the fine particles of the polyvinyl acetal resin produced during the reaction from adhering to form a lump. The surfactant used is well known and is not particularly limited. For example, nonionic compounds such as polyoxyethylene aryl ether, polyoxyethylene alkyl ether, polyoxyethylene alkyl ester, polyoxyethylene sorbitan fatty acid ester, polyoxyethylene-based surfactant, and polyoxyethylene alkyls. Surfactant (HLB;
6 to 15), polyvalent alcohol-based surfactants such as sorbitan fatty acid ester, and anion-based interfaces such as sodium lauryl sulfate, sodium dodecylbenzenesulfonate, sodium hexadecanesulfonate, and sodium alkylarylethersulfonate. Activator etc. are mentioned. The addition amount is preferably such that the concentration of the polyvinyl acetal in the dispersion liquid system is 0.01 to 3.0% by weight, preferably 0.03 to 1.0% by weight, but not particularly limited. Not something.

The reaction conditions used in the present invention include polyvinyl alcohol and the general formula R ¹ COR ² (wherein R ¹ is a hydrogen atom or an alkyl group having 1 to 12 carbon atoms, R ²
Is a hydrogen atom, an alkyl group having 1 to 12 carbon atoms, and 1 carbon atom
Is an aryl group having 8 to 8 cyclic alkyl groups, aryl groups or substituents. The first reaction temperature with the compound represented by (1) reacts in the range of 13 to 40 ° C. Preferably 13
~ 35 ° C is good. If the temperature is lower than 13 ° C., the reaction product may be difficult to dissolve in the solvent, and if the temperature is higher than 40 ° C., the polymer precipitate particles formed may adhere to each other to form a block. Next, the second reaction temperature is 35
Aging is carried out at -80 ° C to further promote the reaction. The reaction time at the first reaction temperature is 1-2 hours (general formula
It is preferable to continue stirring for 1 to 5 hours at the second reaction temperature, including the dropping period of the R ¹ COR ² compound. still,
In the case of precipitating and precipitating the polymer, bulky (small density) particles can be obtained by lowering the temperature and precipitating and precipitating the polymer after finishing the first reaction.

Next, an alkaline substance for neutralizing the inorganic or organic acid added to the reaction system as a catalyst to pH 6 to 8, that is, alkali hydroxide such as sodium hydroxide or potassium hydroxide, carbonic acid such as sodium carbonate, etc. The reaction system is neutralized by adding alkali, hydrogencarbonate such as sodium hydrogencarbonate, etc., and aqueous ammonia. In this case, the temperature is 30 to 6
It may be 0 ° C.

The method for producing carboxylethylated polyvinyl acetal used in the present invention is to dissolve polyvinyl acetal in a water-soluble inert organic solvent, and acrylonitrile in the presence of an alkali hydroxide catalyst dissolved in water. To produce cyanoethyl polyvinyl acetal, which is further hydrolyzed at a temperature of 45 ° C. or higher to be neutralized (pH 6 to 7). During this production, polyvinyl acetate
Is adjusted by dissolving it in a water-soluble organic solvent such as dioxane, and the solid content concentration of polyvinyl acetal dissolved in the water-soluble organic solvent is 5 to 15% by weight, preferably 5 to 10% by weight.
It is desirable to set it as the weight%. Examples of the alkali hydroxide catalyst include sodium hydroxide and potassium hydroxide. The amount of the alkali hydroxide catalyst added is 3 mol per 2 to 4 mol of the polyvinyl alcohol constitutional unit of polyvinyl acetal, and the reaction rate of acrylonitrile is 5 to 3 mol.
It may be added so as to be 0 mol%. However, the addition amount of the organic solvent is 1 to 2 times, preferably 1 to 1.5 times the total volume 1 of water, polyvinyl acetal and alkali hydroxide. The reaction temperature of acrylonitrile is 20 to 4
0 ° C. is desirable. If the temperature is lower than 20 ° C., the reaction is slow, and if the temperature is higher than 40 ° C., the CN group may be hydrolyzed. If the reaction rate of acrylonitrile is controlled to be 5 to 30 mol%, the CN group may be hydrolyzed to a carboxyl group at 40 ° C. or higher. In particular, the reaction temperature of acrylonitrile is not limited.

In the method for producing a multilayer ceramic substrate used in the present invention, (A) average fine particles have a standard deviation value of 0.05 to 2
100 parts by weight of fine ceramic powder in the micron range, (B) a solution of polyvinyl acetal resin having a water-soluble carboxyl group as a binder (polymer solid content; 5 to 40 parts by weight), and (C ) If necessary, a ceramic precursor composition selected from a dispersant and a plasticizer is wet-mixed for 24 hours using a ball mill to prepare a ceramic precursor composition slurry, which is then prepared by a doctor blade method. Then create a green sheet. 200 mm x 200
Cut into mm squares and punch through holes in the required layers.
On this punched green sheet, W, Mo, Ag,
A conductor paste mainly composed of many elements such as Au, Pt, Pd, Cu and Ni is printed at a predetermined position by the screen printing method. A green seal printed with conductors in this way
A predetermined circuit is formed on the sheet, 40 layers of the green sheet having the circuit formed thereon are laminated, and hot-pressed. The obtained laminated body is cut into a required shape, and 800 to 16
It was calcined at a temperature of 00 ° C. for 1 hour in air or nitrogen.
During firing, the binder was sufficiently removed in the air at 500 ° C. or in a non-reducing atmosphere during the heating process. This green
A multilayer ceramic substrate was manufactured by the sheet lamination method.

As the ceramic fine powder whose average fine particles used in the present invention have a standard deviation of 0.05 to 2 microns, Al ₂ O ₃ , SiO ₂ , 3Al ₂ O ₃ .SiO ₂ ,
PbO, Al ₂ O ₃ .MgO, B ₂ O ₃ , CaO, BaO,
At least two kinds are selected from SrO, ZnO and the like. Examples of the fine ceramic particles include spherical particles and pulverized particles.

The water-soluble organic binder obtained according to the present invention is a ceramic grease excellent in dispersibility of ceramics, surface smoothness, density, elongation, and strength without using a water-insoluble organic solvent or hardly. -It is possible to generate an engine, which is advantageous from the viewpoint of low pollution and resource saving. Also, by laminating and firing the green sheets, a dense multilayer ceramic substrate having excellent surface smoothness can be obtained.

[0026]

The feature of the present invention is that the carboxylethylated polyvinyl acetate salt is a water-soluble ceramic binder.
The above-mentioned water-soluble binder exerts its function in bonding between the ceramic fine powders, and satisfies various properties of the green sheet, that is, flexibility, moldability, dispersibility, and surface condition. It is a thing. Further, it satisfies various characteristics of the laminated body of the green sheet with circuit patterns, that is, the laminating pressure-bonding property, the mechanical strength and the like.

[0027]

EXAMPLES Examples of the present invention will be shown below, but the present invention is not limited thereto.

The term "%" means "% by weight". Further, in the examples, the respective properties of the binder and the sheet were evaluated as follows. (Moldability) ◯: Good separation of the green sheet from mylar sheet and no crack (brittleness). Δ: The green sheet is slightly fragile when touched. ×: The green sheet is fragile when touched and does not become a green sheet. (Flexibility) ◯: The green sheet obtained can be folded by hand. Δ: When the obtained green sheet is bent by hand, it is slightly fragile. X: When the obtained green sheet is bent by hand, it easily breaks. (Dispersibility) ◯: Secondary aggregation is small in the dispersion state of the ceramic fine particles in the green sheet. B: Secondary aggregation is slightly higher in the state of dispersion of ceramic fine particles in the green sheet. ×: Secondary aggregation is large in the dispersion state of the ceramic fine particles in the green sheet.

The abbreviations of polymers, solvents and amines used in the examples are as follows. PVA: Polyvinyl alcohol IPA: Isopropyl alcohol PM: Propylene glycol monomethyl ether TMA: Trimethylamine DMEA: Dimethylaminoethanolamine MEA: Monoethanolamine TEA: Triethanolamine Hereinafter, examples will be described.

Example 1 (Synthesis of polyvinyl acetal resin) Stirrer, thermometer,
A 2000 ml three-necked flask equipped with a reflux condenser and a dropping funnel was charged with 1092 g of ion-exchanged water, and 200 g of polyvinyl alcohol having a saponification degree of 97% and a polymerization degree of 1000 (polyvinyl alcohol unit 4.46 mo).
l) was dispersed and heated with stirring to obtain a 15% aqueous solution of polyvinyl alcohol. To this aqueous solution was added 13.6 g of concentrated hydrochloric acid with a concentration of 35%, and the nonionic surfactant C ₁₀ H ₂₁ C was added.
_{6 H 4 O (CH 2 CH} 2 O) 6 H19.2g added that dissolved in water 80g and 30 minutes with stirring at 13 ° C. n-butyl aldehyde 86.40g (1.200mol polyvinyl alcohol unit 2 (53.8 mol% with respect to the mole) was added dropwise, and white fine particles of polyvinyl butyral were precipitated. After further adding 101.6 g of 35% concentrated hydrochloric acid to adjust the pH of the reaction system to 0.5 or less, the temperature was raised to 45 ° C. at 25 ° C./hour, and the temperature was kept at this temperature for 4 hours for aging. The reaction system was neutralized by adding sodium hydroxide, and the pH was adjusted to 8.5. The aging time was 3 hours in the strongly acidic region at a temperature of 30 ° C. or higher. The obtained resin was washed with water and dried according to a conventional method to obtain a white fine powder. At this time, the degree of butyralization was 50%.

(Synthesis of Carboxyethylated Polyvinyl Acetal Resin) 200 g of the obtained polyvinyl acetal having a degree of acetalization of 50% (polyvinyl alcohol unit 0.995 mol) was dispersed in 1800 g of 1,4-dioxane and heated with stirring. A 10% solution of polyvinyl acetal was obtained. 20% of 10% sodium hydroxide solution
00g was mixed with 422.8g of acrylonitrile.
(7.97 mol) was mixed with 1,000 g of 1,4-dioxane and stirred at 30 ° C for 6 hours, then a part of the reaction solution was extracted and dried at 100 ° C for 1 hour to give a colorless transparent film. Obtained. The infrared absorption curve of this film is shown in FIG. The presence of a cyanoethyl group was confirmed by C≡N absorption.

The rest of the reaction solution was then heated at 60 ° C. for 2 hours, and then 8 hours
The mixture was stirred at 0 ° C for 2 hours and then left to cool to room temperature. The reaction solution was added dropwise to a large amount of water and stirred to generate a white precipitate. This was filtered, washed with water, and dried to obtain a carboxyethylated polyvinyl acetal resin. A part of this precipitate was dissolved in 1,4-dioxane and dried at 100 ° C. for 1 hour to obtain a colorless transparent film. The infrared absorption curve of this film is shown in FIG. Decrease in C≡N absorption compared to FIG.
It was confirmed that the cyanoethyl group was hydrolyzed into a carboxylethyl group due to the increase of OH absorption and the appearance of C = O absorption.

200 g of this resin was dispersed in a mixed solution of 1440 g of water and 360 g of isopropyl alcohol, and N, N-dimethylethanolamine was added and heated to dissolve and neutralize (pH 6 to 7). % Carboxyethylated polyvinyl acetal resin solution was obtained.

(Preparation of green sheet) Alumina powder as a main component, Al ₂ O ₃ 91% as a whole composition, S
100 parts by weight of ceramic powder having a particle size of 5 μm or less, containing 10% of iO ₂ and 3% of MgO, solid content concentration of 10%
70 parts by weight of a solution of carboxyethylated polyvinyl acetal resin (7 parts by weight in terms of solid content), polyethylene glycol (molecular weight 400) 2.3 g as a plasticizer
Were added together to obtain a ceramic precursor composition. This was kneaded for 24 hours in a ball mill using an alumina lining container and alumina balls. After the ceramic precursor composition slurry was prepared in this manner, air was further degassed from the slurry under reduced pressure. The viscosity of the uniform slurry mixture prepared as described above is adjusted to 5,000 to 10,0.
The coating was applied on a polyester film using a doctor blade type casting device at 00 cps and dried at 120 ° C. to produce a green sheet. The physical properties of the sheet were good in terms of moldability, flexibility and dispersibility.

(Preparation of Multilayer Wiring Ceramic Substrate) A green sheet is 200 mm × 200 m in size using a punch die.
It was cut into m-squares and provided with guide holes. 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 punch method. Tungsten powder having a particle size of 5 μm or less: Nitrocellulose: Ethylcellulose: α-Terpineol = 1
A conductor paste of 00: 4: 2: 23 (weight ratio) was filled in the through holes formed in the green sheet, and then a predetermined circuit pattern was printed on the surface of the green sheet by a screen printing method. The conductor was printed in this way, and 40 sheets of the green sheet on which a circuit was formed were laminated by aligning the positions of the guide holes, and hot press bonding was performed at 120 ° C. and a pressure of 100 Kgf / cm ² . The obtained laminated body was cut into a required shape to obtain a 150 mm × 150 mm square green sheet laminated plate, which was fired at 1600 ° C. for 1 hour in a nitrogen-hydrogen-steam mixed atmosphere firing furnace. During firing, the binder was sufficiently removed during the temperature rising process. By this green sheet laminating method, a multilayer wiring ceramic substrate of 120 mm × 120 mm square and 7 mm thick was produced.

Examples 2 to 10 (Synthesis of polyvinyl acetal resin) Table 1 shows the saponification degree, polymerization degree, carbonyl compound and acetalization degree of PVA.
An experiment was conducted in the same manner as in Example 1 except that the polyvinyl acetal resin was changed as shown in FIG.

(Synthesis of Carboxyethylated Polyvinyl Acetal Resin) Experiments were conducted in the same manner as in Example 1 except that acrylonitrile, solvent and amine were changed as shown in Table 1 to obtain a solution of carboxyethylated polyvinyl acetal resin. It was

(Preparation of Green Sheet) An experiment was carried out in the same manner as in Example 1 except that the solution of the carboxyethylated polyvinyl acetal resin was changed to prepare a green sheet, and its various properties are shown in Table 1.

(Production of Multilayer Wiring Ceramic Substrate) An experiment was conducted in the same manner as in Example 1 to produce a multilayer wiring ceramic substrate from a green sheet.

Examples 11 to 16 (Synthesis of polyvinyl acetal resin) Table 2 shows the degree of saponification, degree of polymerization, carbonyl compound and degree of acetalization of PVA.
An experiment was conducted in the same manner as in Example 1 except that the polyvinyl acetal resin was changed as shown in FIG.

(Synthesis of Carboxyethylated Polyvinyl Acetal Resin) A carboxyethylated polyvinyl acetal resin solution was obtained in the same manner as in Example 1 except that acrylonitrile, solvent and amine were changed as shown in Table 2. It was

(Preparation of Green Sheet) Alumina powder as a main component, Al ₂ O ₃ 56%, S
100 parts by weight of ceramic powder having a particle size of 5 μm or less and having a composition of 43% io ₂ and 1% MgO, a solid content concentration of 10
% Carboxyethylated polyvinyl acetal resin solution 100 parts by weight (10 parts by weight in terms of solid content), polyethylene glycol as a plasticizer (molecular weight 400)
2.3 g were added together 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 2.

(Production of Multilayer Wiring Ceramic Substrate) An experiment was conducted in the same manner as in Example 1 to produce a multilayer wiring ceramic substrate from a green sheet.

Comparative Examples 1 and 2 (Synthesis of Polyvinyl Acetal Resin) Table 2 shows the saponification degree, polymerization degree, carbonyl compound and acetalization degree of PVA.
An experiment was conducted in the same manner as in Example 1 except that the polyvinyl acetal resin was changed as shown in FIG.

(Preparation of green sheet) Alumina powder as a main component, Al ₂ O ₃ 56% as a whole composition, S
100 parts by weight of ceramic powder having a particle size of 5 μm or less and having a composition of 43% io ₂ and 1% MgO, a solid content concentration of 10
% Polyvinyl acetal resin solution (5 parts by weight in terms of solid content) and polyethylene glycol (molecular weight 400) 2.3 g as a plasticizer were 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 2.

Comparative Example 3 (Binder Resin) Octyl acrylamide was 4.0
A polyvinyl acetate-based copolymer containing 2.0% by mole of trimethyl-3- (1-methacrylamido-propyl) ammonium chloride and 8% of the vinyl acetate component.
A modified PVA in which 8.7 mol% was saponified and the viscosity of a 4% aqueous solution at 20 ° C. was 34 centipoise was used as a binder.

(Preparation of Green Sheet) An experiment was conducted in the same manner as in Example 1 except that 6 parts of the binder resin, 1 part of polyoxyethylene nonylphenol ether as a dispersant, and 50 parts of ion-exchanged water were used. A green sheet was prepared, and its characteristics are shown in Table 2.

Comparative Example 4 (Binder Resin) Acrylic Acid, Butyl Acrylate,
Polymerization ratio of water / methanol (5/5) using ethyl acrylate polymerization ratio (50/25/25) and 20 g of monoethanolamine salt of a copolymer having a weight average molecular weight of about 100,000 as a dispersant.
Emulsion polymerization of ethyl acrylate using 0.4 g of ammonium persulfate as a polymerization initiator in 80 g of a mixed solvent gave a latex having a solid content of 50%.

(Production of Green Sheet) Example 1 was repeated except that 24 parts of the latex and 18 parts of ion-exchanged water were used.
Perform an experiment in the same manner as above to make a green sheet,
The various characteristics are shown in Table 2.

Next, Examples 1, 4, 6, 9, 12, 14
16 and 16 and the green sheets 5 obtained in Comparative Examples 2 to 4.
The sheets were hot press bonded at 120 ° C. and 100 kgf / cm ² . The number of peelings at this time was visually observed. Further, this laminate was fired at 1,600 ° C. to obtain a ceramic sheet. The density of these sheets was measured, and the surface condition was visually observed.

The results are shown in Table 3.

[0052]

[Table 1]

[0053]

[Table 2]

[0054]

[Table 3]

[0055]

The aqueous solution of the polyacetal resin obtained by the present invention is excellent in the dispersibility of ceramics, the smoothness of the surface, the density, and the mechanical strength without using a water-insoluble organic solvent or hardly. Ceramic green
It 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 has excellent properties such as improved mechanical strength, and is useful as a binder for ceramics.

[Brief description of drawings]

FIG. 1 shows an infrared absorption spectrum of a cyanoethylated polyvinyl butyral resin.

FIG. 2 shows an infrared absorption spectrum of a carboxylethylated polyvinyl butyral resin.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Takeshi Fujita No. 1 Horiyamashita, Hadano City, Kanagawa Prefecture Hiritsu Manufacturing Co., Ltd. Kanagawa Plant

Claims (7)

[Claims] 1. A general formula: And (However, in the formula, R ¹ is a hydrogen atom or an alkyl group having 1 to 12 carbon atoms, R ² is a hydrogen atom, an alkyl group having 1 to 12 carbon atoms, a cyclic alkyl group having 1 to 8 carbon atoms, and Group, or an aryl group having a substituent, and M is a hydrogen atom, an ammonium ion or an organic ammonium ion.) A polyvinyl acetal resin. 2. A general formula: And (However, in the formula, R ¹ is a hydrogen atom or an alkyl group having 1 to 12 carbon atoms, R ² is a hydrogen atom, an alkyl group having 1 to 12 carbon atoms, a cyclic alkyl group having 1 to 8 carbon atoms, and Group or an aryl group having a substituent, M is a hydrogen atom, an ammonium ion or an organic ammonium ion), and the structural unit represented by (1) is 5 to 30 mol%. And the structural unit represented by (2) is 1
-70 mol% and the structural unit represented by (3) is 20-6.
A polyvinyl acetal-based resin comprising a carboxylethylated polyvinyl acetal-based resin obtained by reacting 5 mol% with 100 mol% as a whole. 3. (A) An aqueous polyvinyl alcohol solution having a saponification degree of 70 mol% or more and an average degree of polymerization of 500 to 2500 and a general formula R ¹ COR ² (wherein R ¹ is a hydrogen atom or a carbon number). 1 to 12 alkyl groups, R ² is a hydrogen atom,
An alkyl group having 1 to 12 carbon atoms, a cyclic alkyl group having 1 to 8 carbon atoms, an aryl group or an aryl group having a substituent. ) Is reacted with an aqueous solution of a compound represented by the formula (1) in the presence of an acid catalyst at a temperature of 13 to 40 ° C.
After reacting at 80 ° C. to 80 ° C., the reaction product is neutralized, and (B) the obtained polyvinyl acetal is dissolved in a water-soluble solvent, and acrylonitrile is heated to 45 ° C. or lower in the presence of an alkaline aqueous solution. Reacting at the temperature of (C),
And a step of hydrolyzing the resulting cyanoethylated polyvinyl acetal at a temperature of 50 ° C. or higher in the presence of an alkaline aqueous solution, a method for producing a polyvinyl acetal resin. 4. The average deviation of (A) average fine particles is from 0.05 to 0.05.
A ceramic precursor comprising 100 parts by weight of a ceramic fine powder in the range of 2 microns and 5 to 40 parts by weight of the polyvinyl acetal resin (B) as a binder as defined in claim 1 or 2. Body composition. 5. (A) The average fine particles have a standard deviation value of 0.05 to
A thin film of a ceramic precursor composition comprising 100 parts by weight of a ceramic fine powder in the range of 2 microns and 5 to 40 parts by weight of the polyvinyl acetal resin (B) as a binder in (1) or (2). A ceramic green sheet. 6. (A) The average fine particles have a standard deviation value of 0.05 to
A ceramic green sheet comprising 100 parts by weight of a ceramic fine powder having a size of 2 microns and (B) a binder comprising 5 to 40 parts by weight of the polyvinyl acetal resin 5 according to claim 1 or 2. Ceramic sheet made by sintering. 7. A ceramic green sheet layer comprises (A) 100 parts by weight of fine ceramic powder having a standard deviation of 0.05 to 2 microns in average fine particles, and (B) a binder.
3. A ceramic precursor composition selected from 5 to 40 parts by weight of the polyvinyl acetal-based resin according to claim 1 or 2, wherein a plurality of conductor layers are provided in the ceramic green layer.
A multilayer wiring ceramic substrate obtained by sintering a laminate through a sheet layer.