JPH0153233B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a binder used when molding so-called ceramics such as alumina, barium titanate, ferrite, etc., and particularly to a water-based binder for molding ceramics that does not use an organic solvent. Ceramics molding methods include dry press molding,
There are doctor blade methods, extrusion molding methods, etc., but the various binders used in these molding methods have many drawbacks. In the dry press molding method, a mold is filled with a ceramic composition granulated by spray drying a slurry prepared by mixing ceramic powder such as alumina with water, a lubricant, a binder, a plasticizer, etc. This is a method of press forming. As the binder used in this molding method, polyvinyl alcohol, methyl cellulose, and sodium salt of carboxymethyl cellulose are generally used. However, the granules obtained using these binders are hard, and therefore press pressure must be increased, which increases mold wear, shortens the life of the mold, and increases the size of the press machine. There are problems, and it is also difficult to mold a complicated shape. By using a plasticizer such as glycerin or polyethylene glycol in combination with a binder, it is possible to soften the granules slightly and reduce the pressing pressure, but this increases the amount of organic substances other than the binder, making it difficult to remove the binder before firing. When removing the binder, the shrinkage becomes large, causing deformation such as blistering and distortion, and cracking, and the bonding force decreases, resulting in weak mechanical strength, which is undesirable. Furthermore, during storage after molding, the plasticizer may bleed onto the surface or volatilize, causing brittleness. In addition, polyvinyl alcohol, methyl cellulose, carboxymethyl cellulose
Na salt has poor thermal decomposition properties, and leaves a large amount of ash containing carbon and alkali metals such as Na, which cannot be decomposed or burned out in the binder removal process, causing deformations such as blisters, cracks, and cracks during the firing process. When used as electronic components such as IC substrates, IC packages, and dielectric materials, it causes loss of electrical properties such as electrical insulation. Furthermore, these binders have a high hygroscopic property, and moisture absorption after molding reduces mechanical strength, causing breakage during storage and handling before removal of the binder. In the doctor blade method, a slurry prepared by mixing ceramic powder with an organic solvent, a dispersant, a plasticizer, an organic solvent binder, etc. is cast onto a carrier film by adjusting the thickness with a doctor blade, and then dried to form a tape. This is a method of forming green sheets into shaped green sheets. Toluene, trichloroethylene, isopropyl alcohol, ethyl alcohol, etc. are used as organic solvents, but they pose many problems such as explosion due to ignition, fire danger, odor during molding, toxicity to the human body, and pollution problems due to evaporated organic gas during drying. There is a point. Additionally, it will be necessary to install explosion-proof equipment, waste gas treatment equipment, solvent recovery equipment, etc. Polyvinyl butyral is generally used as an organic solvent-based binder, but it has poor thermal decomposition properties and ash content such as carbon and sodium that remains after binder removal causes the same problems as binders for press molding. Furthermore, a plasticizer such as a phthalate ester must be used, and the molded product becomes brittle due to breathing or volatilization of the plasticizer on the surface during storage after molding. The extrusion molding method uses ceramic powder, water, dispersant,
This is a method in which a lubricant, a binder plasticizer, etc. are mixed and the mixture is extruded using an extrusion molding machine. Methyl cellulose, hydroxyethyl cellulose, and polyvinyl alcohol are generally used as binders, but they have poor thermal decomposition properties, and the same problems as binders for press molding occur due to ash content such as carbon and Na remaining after binder removal. . In view of the current situation, the present inventor has developed a press molding method,
As a result of extensive research to solve these problems with binders used in doctor blade methods, extrusion molding methods, etc., we have developed (1) (meth)acrylic acid alkyl esters having alkyl groups of 1 to 20 carbon atoms; 30 to 85% by weight of at least one monomer selected from the group consisting of (meth)acrylic acid alkoxyalkyl esters having 1 to 4 alkylene groups, and (2) general formula (R ₁ , R ₂ , and R ₃ each represent hydrogen or a methyl group, and n represents an integer of 1 or more.) or (R ₄ and R ₅ are each hydrogen or methyl group,
R ₆ is hydrogen or an alkyl group having 1 to 4 carbon atoms,
m represents an integer of 2 or more. ) (meta)
A monomer component consisting of 5 to 60% by weight of at least one monomer selected from the group consisting of acrylic esters, and (3) 5 to 60% by weight of a carboxyl group-containing monomer, or (1) having 1 to 1 carbon atoms. At least one monomer selected from the group consisting of a (meth)acrylic acid alkyl ester having 20 alkyl groups and a (meth)acrylic acid alkoxyalkyl ester having an alkylene group having 1 to 4 carbon atoms 30
~85% by weight, (2) General formula (R ₁ , R ₂ , and R ₃ each represent hydrogen or a methyl group, and n represents an integer of 1 or more.) or (R ₄ and R ₅ are each hydrogen or methyl group,
R ₆ is hydrogen or an alkyl group having 1 to 4 carbon atoms,
m represents an integer of 2 or more. ) (meta)
5 to 60% by weight of at least one monomer selected from the group consisting of acrylic esters, (3) 5 to 60% by weight of a carboxyl group-containing monomer, and (4) the aforementioned
Other vinyl monomers copolymerizable with (1), (2), and (3) 0
A monomer component consisting of more than 35% by weight (however,
The sum of all monomers is 100% by weight. ) was found to be a binder for ceramic molding obtained by copolymerizing the above requirements, and the present invention was completed. In other words, the present invention reduces press pressure, improves moldability, and moisture absorption in the press molding method, shifts from a solvent-based to a safe and sanitary water-based system in the doctor blade method, and improves thermal decomposition; The object of the present invention is to provide a binder for ceramic molding that provides improved degradability and improved moldability. In the following description, (meth)acrylic acid refers to acrylic acid and/or methacrylic acid, and (meth)acrylate refers to acrylate and/or methacrylate. As the (meth)acrylic acid alkyl ester having an alkyl group having 1 to 20 carbon atoms used in the present invention, methyl (meth)acrylate, ethyl (meth)acrylate, isopropyl (meth)acrylate, n-butyl (meth)acrylate ,
Isobutyl (meth)acrylate, cyclohexyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, n-dodecyl (meth)acrylate, stearyl (meth)acrylate, etc. can be used. Examples of the (meth)acrylic acid alkoxyalkyl ester having an alkylene group having 1 to 4 carbon atoms include methoxymethyl (meth)acrylate, methoxyethyl (meth)acrylate, ethoxymethyl (meth)acrylate, ethoxyethyl (meth)acrylate, Ethoxybutyl (meth)acrylate, butoxyethyl (meth)acrylate, etc. can be used. At least one selected from the group consisting of (meth)acrylic acid alkyl esters having an alkyl group having 1 to 20 carbon atoms and (meth)acrylic acid alkoxyalkyl esters having an alkylene group having 1 to 4 carbon atoms. The seed monomers should be used in proportions ranging from 30 to 85% by weight out of 100% by weight of the total copolymerized monomers. If the ratio is too low (less than 30% by weight), the thermal decomposition property will decrease, the press pressure will increase due to the hardness, and the binding strength as a binder will decrease. If the ratio exceeds 85% by weight, the hydrophilicity decreases, the amount of wetting and adsorption to ceramic powder decreases, and the binding strength as a binder decreases. general formula (R ₁ , R ₂ and R ₃ each represent hydrogen or a methyl group, and n represents an integer of 1 or more.) Examples of the monomer include polypropylene glycol di(meth)acrylate and polyethylene glycol di(meth)acrylate. can be mentioned. general formula (R ₄ and R ₅ are each hydrogen or methyl group,
R ₆ is hydrogen or an alkyl group having 1 to 4 carbon atoms,
m represents an integer of 2 or more. ) Monomers represented by are polypropylene glycol mono(meth)acrylate, polyethylene glycol mono(meth)acrylate, methoxypolypropylene mono(meth)acrylate, methoxypolyethylene glycol mono(meth)acrylate, ethoxypolypropylene glycol mono(meth)acrylate, Ethoxypolyethylene glycol mono(meth)acrylate, n-butoxypolypropylene glycol mono(meth)acrylate, n-
Butoxypolyethylene glycol mono(meth)acrylate and the like can be mentioned. At least one monomer represented by these general formulas must be used in a proportion ranging from 5 to 60% by weight based on 100% by weight of the total copolymerized monomers. If the ratio is less than 5% by weight, the hydrophilicity decreases, and the amount of wetting and adsorption to the ceramic powder decreases, resulting in a decrease in the binding strength as a binder, or the binder becomes hard, requiring increased press pressure. Moreover, if the ratio exceeds 60% by weight, hygroscopicity increases and the mechanical strength of the molded product decreases. As a carboxyl group-containing monomer, (meth)
Maleic acid half esters such as acrylic acid, maleic acid, itaconic acid, monoisopropyl maleate,
Monomers having at least one carboxyl group in one molecule can be used, such as itaconic acid half ester. These carboxyl group-containing monomers may be used in an acid state, or may be partially or completely neutralized with ammonia or an organic amine. Such organic amines include monoethylamine, diethylamine, mono-n-propylamine, di-n-propylamine, mono-
Low molecular weight amines such as n-butylamine, di-n-butylamine, monoethanolamine, diethanolamine, triethanolamine, triethylenediamine, triethylenetetramine, hexamethylenediamine, hexamethylenetetramine, pyridine, piperidine, and polydimethylaminoethyl Polymer amines such as methacrylate and a condensate of alkylene dichloride and alkylene polyamine can be used. Such carboxyl group-containing monomers should be used in a proportion ranging from 5 to 60% by weight based on 100% by weight of the total copolymerized monomers. If the ratio is less than 5% by weight, the hydrophilicity decreases, the amount of wetting and adsorption to ceramic powder decreases, and the binding strength as a binder decreases. If the ratio exceeds 60% by weight, the thermal decomposition property will decrease, the press pressure will increase due to the hardness, and the binding strength as a binder will decrease. Hygroscopicity also increases. Other vinyl monomers that can be copolymerized with these (1), (2), and (3) include 2-hydroxyethyl (meth)acrylate, glycerol (meth)acrylate, trimethylolpropane (meth)acrylate, and pentaerythritol. (meth)acrylate, glycidyl (meth)acrylate, dimethylaminoethyl (meth)acrylate, diethylaminoethyl (meth)acrylate, (meth)acrylonitrile, acrylamide, N-methylolacrylamide, styrene, α-methylstyrene, ethylene, vinyl chloride, Vinyl acetate etc. can be used. Such copolymerizable monomers are used as necessary, and their proportion is 20% by weight or less based on 100% by weight of all copolymerizable monomers. If the ratio exceeds 20% by weight, the above-mentioned disadvantages (decreased thermal decomposability, binding strength as a binder, or increased press pressure) will occur. The polymerization method for obtaining the binder for ceramic molding of the present invention is not particularly limited, and conventionally known polymerization methods can be used. The thus obtained binder for ceramic molding of the present invention may be used as a binder as it is, or may be used after being appropriately neutralized with ammonia, the above-mentioned organic amine, or the like. The ceramic molding binder of the present invention reduces press pressure, improves moldability, and hygroscopicity in the press molding method; transitions from a solvent-based to a safe and sanitary water-based system and improves thermal decomposition properties in the doctor blade method; and improves thermal decomposition properties in the doctor blade method. The molding method can improve both thermal decomposition properties and moldability. The present invention will be explained in more detail by examples.
The present invention is not limited to these examples. In addition, all parts in the examples indicate parts by weight, and all percentages indicate weight %. Example 1 (Synthesis of binder) In a separable flask equipped with a stirrer, a thermometer, a cooling tube, a nitrogen introduction tube, a mixing monomer dropping funnel, and a polymerization initiator dropping funnel, 150 parts of distilled water and polyoxyethylene nonylphate as an emulsifier were added. Three parts of enyl ether (HLB18.2 manufactured by Kao Soap Co., Ltd.) was charged, and nitrogen was introduced from the nitrogen introduction tube to create a nitrogen atmosphere inside the flask. Next, the mixed monomers were added dropwise to the funnel, 60 parts of ethyl acrylate, and polyethylene glycol monomethacrylate.

[Formula] Bremmer PE-200, manufactured by Nippon Oil & Fats Co., Ltd., 100 parts of mixed monomer consisting of 20 parts of m=4-5) and 20 parts of methacrylic acid
20 parts of a 2% aqueous t-butyl hydroperoxide solution was charged into the polymerization initiator dropping funnel.
The mixed monomers and polymerization initiator were added dropwise over 2 hours while adjusting the internal temperature of the flask to 80°C, and then
After heating at 80℃ for 1 hour, cool and adjust the pH with ammonia water.
8.0 to obtain an aqueous binder for ceramic molding with a solid content concentration of 35%. The ash content and Na content of this binder were measured and the results are shown in Table 1. The ash content was determined by placing the dried binder in a platinum crucible, incinerating it in an electric furnace at 650°C in an air atmosphere for 2 hours, and then measuring its weight. The Na content was measured by dissolving a part of the above ash with mineral acid and using an atomic absorption spectrophotometer. Example 2 (Molding of ceramics) 100 parts of alumina (AL-160SG, purity 99.0%, average particle size 0.4μ, manufactured by Showa Light Metal Co., Ltd.), 40 parts of distilled water,
Dispersant (Aquarik NL, Nippon Shokubai Chemical Co., Ltd.)
0.2 parts of ammonium polyacrylate (M.D., Ammonium Polyacrylate) and 20 parts of the aqueous binder for 35% ceramic molding obtained in Example 1 were mixed in a ball mill for 24 hours, and the resulting slurry was spray-dried to form a slurry with an average particle size of 100μ. Granules were obtained. The granules were filled into a mold and pressed at press pressures of 500Kg/cm ² , 1000Kg/cm ² , and 1500Kg/cm ² to a thickness of 3 mm, width of 10 mm, and length of 30 mm.
A molded product of mm was obtained. The releasability from the mold and the surface smoothness of the molded product were good. The green density, bending strength, and hygroscopicity of these molded articles were measured, and the results are shown in Table 1. The bending strength was measured using an Instron strength testing machine model 1102 at a span width of 20 mm and a head speed of 0.5 cm/min. The evaluation of hygroscopicity was based on the weight increase rate after humidifying a molded product obtained at a press pressure of 1000 kg/cm ² at 20°C and 65% relative humidity for 24 hours, and the weight increase rate after humidifying the molded product at 20°C and 95% relative humidity for 24 hours.
This was done by measuring the weight increase rate when humidified for a period of time. Comparative Example 1 A molding product was obtained in the same manner as in Example 2, except that 7 parts of polyvinyl alcohol (GL-05, manufactured by Nippon Gosei Kagaku Co., Ltd.) was used as a binder for 100 parts of alumina (AL-160SG). The green density, bending strength, and hygroscopicity of the molded products were measured. In addition, the ash content and Na content of polyvinyl alcohol were also measured. ash,
The Na content is considerably higher than that of the ceramic molding binder of Example 1. Furthermore, the pressing pressure had to be higher than in Example 2 to obtain the same green density. Furthermore, the bending strength was low and the hygroscopicity was high at the same green density.
These results are shown in Table 1. Comparative Example 2 Polymerization and molding were carried out in the same manner as in Example 1 and Example 2, except that 100 parts of a mixed monomer consisting of 25 parts of ethyl acrylate, 10 parts of polyethylene glycol monomethacrylate (PE-200) and 65 parts of methacrylic acid was used. The ash content and sodium content of the resulting binder, as well as the green density, bending strength, and hygroscopicity of the molded articles were measured, and the results are shown in Table 1. Compared to Example 1, the ash content was higher, the hygroscopicity was higher, the pressing pressure was higher, and the bending strength was lower. Example 3 (Synthesis of binder) Polymerization was carried out using the same apparatus as in Example 1. First, add 100 parts of distilled water and ammonium salt of polyoxyethylene sulfate (Hitenol N) to a flask.
-0.8, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.). Next, 10 parts of stearyl methacrylate, 10 parts of ethyl acrylate, 20 parts of 2-methoxyethyl acrylate, and methoxypolyethylene glycol monomethacrylate (

[Formula] NK Ester M-90G, manufactured by Shin Nakamura Chemical Industry Co., Ltd., m = 9) 40
and 20 parts of methacrylic acid.
Pour 100 parts and add 2% t to the polymerization initiator dropping funnel.
-20 parts of a butyl hydroperoxide aqueous solution was charged. While adjusting the internal temperature of the flask to 80°C, the mixed monomer and polymerization initiator were added dropwise over 2 hours each, heated at 80°C for 1 hour, cooled, and adjusted to pH 8.0 with aqueous ammonia to reduce the solid content concentration. A 45% water-based binder for ceramic molding was obtained. The ash and sodium contents of this binder are shown in Table 2. Example 4 (Molding of ceramics) 100 parts of alumina (AL-160SG), 40 parts of distilled water,
0.2 parts of the dispersant (Aquarik NL) and 30 parts of the aqueous binder for 45% ceramic molding obtained in Example 3 were mixed in a ball mill for 24 hours, and the resulting slurry was unwrapped under reduced pressure and placed on silicone-coated release paper. Casting was carried out at a thickness of 1.5m/m. Next, the mixture was heated from 60°C to 120°C at a heating rate of 1°C/min, and dried to a moisture content of 0.1% or less to produce a flexible green sheet in the form of a tape.
The green density and tensile properties of the sheet were measured. The tensile properties were determined by punching out the sheet into dumbbell size 3 (JISK6301), pulling it at a pulling speed of 0.5 cm/min, and measuring the elongation and strength at break. These results are shown in Table 2. Comparative Example 3 100 parts of alumina (AL-160SG), 13.5 parts of polyvinyl butyral (3000K, manufactured by Denki Kagaku Kogyo Co., Ltd.) as a binder, 5 parts of n-octyl phthalate as a plasticizer, 0.5 parts of glyceryl trioleate as a dispersant, and a solvent. as trichlorethylene 40
and 20 parts of ethyl alcohol were mixed in a ball mill for 24 hours to prepare a green sheet in the same manner as in Example 4, and its green density and tensile properties were measured. The ash and sodium contents of polyvinyl butyral were also measured.
These results are shown in Table 2. Both the ash content and the sodium content were considerably higher than those of the binder for ceramic molding of Example 3. Comparative Example 4 30 parts of stearyl methacrylate, 13 parts of ethyl acrylate, 25 parts of 2-methoxyethyl acrylate
Polymerization was carried out in the same manner as in Example 3, except that 100 parts of a mixed monomer consisting of 30 parts of methoxypolyethylene glycol monomethacrylate and 2 parts of methacrylic acid was used, and the pH was adjusted to 8.0 with aqueous ammonia to obtain a binder. An attempt was made to obtain a green sheet using this binder in the same manner as in Example 4, but cracks appeared in the sheet due to drying. Example 5 (Synthesis of binder) Polymerization was carried out using the same apparatus as in Example 1. Add n-butyl methacrylate to the mixing monomer dropping funnel.
30 parts, polyethylene glycol diacrylate ( NK ester A-4G, manufactured by Shin Nakamura Chemical Industry Co., Ltd., n=
4) 5 parts, polypropylene glycol monomethacrylate (

[Formula] Blenmar PP-1000, manufactured by Nippon Oil & Fats Co., Ltd., n = 5-6)
30 parts of styrene, 100 parts of a mixed monomer consisting of 15 parts of styrene and 20 parts of acrylic acid were charged, and 20 parts of a 5% ammonium persulfate aqueous solution was charged into the initiator dropping funnel. Next, while adjusting the internal temperature of the flask to 95℃, the mixed monomer and polymerization initiator were added dropwise over 2 hours each, heated at 95℃ for another 30 minutes, cooled, and adjusted to pH 7.0 with aqueous ammonia to solidify. An aqueous binder for ceramic molding with a concentration of 20% was obtained. Example 6 (Molding of ceramics) 100 parts of barium titanate (KYORIX A, manufactured by Kyoritsu Ceramic Materials Co., Ltd.), 40 parts of distilled water, 0.2 parts of a dispersant (Aquarik NL), 2 parts of stearic acid as a lubricant, and Example 5 15 parts of the aqueous binder for ceramic molding with a concentration of 20% obtained in step 1 was mixed with a universal mixer (Model 5DMV, manufactured by Sanei Seisakusho). Next, the mixture was extruded into a rod shape with a diameter of about 5 mm using a container kneader (manufactured by Kurimoto Iron Works). The obtained extrusion molded product was heated from 60°C to 120°C at a heating rate of 1°C/min, and further heated at 120°C for 30 minutes to dry to a water content of 0.1% or less. After drying, cut it and polish the top and bottom circular planes with sandpaper to a length of 10 mm.
It was made into a cylinder shape of mm, and the crushing strength in the longitudinal direction was measured. The results are shown in Table 3. The crushing strength was measured using a Kiya hardness tester (manufactured by Kiya Seisakusho). Comparative Example 5 Extrusion molding was carried out in the same manner as in Example 6 using 3 parts of methyl cellulose (Marporose M-600, manufactured by Matsumoto Yu Seiyaku Co., Ltd.) as a binder to 100 parts of barium titanate (KYORIX A). The crushing strength was then measured. The ash and sodium contents of methylcellulose were also measured, and the results are shown in Table 3. Compared to the binder for ceramic molding of Example 5, both the ash content and the sodium content were higher. Comparative Example 6 10 parts of n-butyl methacrylate, polyethylene glycol diacrylate (NK ester A-
46) Mixed monomer consisting of 5 parts, 18 parts of polypropylene glycol monomethacrylate (Blenmar PP-1000), 65 parts of styrene, and 2 parts of acrylic acid.
Polymerization was carried out in the same manner as in Example 5 except that 100 parts was used, and the pH was adjusted to 7.0 with aqueous ammonia and used for extrusion molding. In addition, the ash content and sodium content of this binder and the crushing strength of the molded product were measured. The results are shown in Table 3. Compared to Example 6, the ash content was higher and the crushing strength was lower. Example 7 (Synthesis of binder) Polymerization was carried out using the same apparatus as in Example 1. First, 150 parts of distilled water was added to the flask. Next, add 35 parts of methyl methacrylate to the mixing monomer dropping funnel.
Methoxypolyethylene glycol monomethacrylate (

[Formula] NK Ester M-90G, manufactured by Shin-Nakamura Chemical Industry Co., Ltd., m-9)
50 parts of monomer mixture consisting of 5 parts of methacrylic acid and 10 parts of 2-hydroxyethyl methacrylate.
20 parts of a 2% ammonium persulfate aqueous solution was charged into the polymerization initiator dropping funnel. The mixed monomers and polymerization initiator were added dropwise over 2 hours while adjusting the internal temperature of the flask to 80°C. After further heating at 80°C for 1 hour, the mixture was cooled, and the pH was adjusted with monoethanolamine.
7.0 to obtain an aqueous binder for ceramic molding with a solid content concentration of 38%. As a result of measuring the ash content and Na content of this binder in the same manner as in Example 1, the ash content and Na content were 0.0018% and 0.0003%, respectively, based on the binder solid content, which were obtained in Examples 1, 3, and 5. As with the binder, the amount was very small. Example 8 (Molding of ceramics) Sheet molding was carried out in the same manner as in Example 4. 100 parts of alumina (AL-16OSG), 35 parts of distilled water,
0.2 parts of a dispersant (Aquarik NL) and 35 parts of the aqueous binder for ceramic molding with a concentration of 38% obtained in Example 7 were mixed in a ball mill for 24 hours.
The obtained slurry was degassed under reduced pressure and then casted onto silicone-coated release paper to a thickness of 1.5 m/m. Next, the mixture was heated from 60°C to 120°C at a heating rate of 1°C/min, and dried to a moisture content of 0.1% or less to produce a flexible green sheet in the form of a tape.
The green density and tensile properties of the sheet were measured. In addition,
Tensile properties were determined using dumbbell type 3 (JIS
K6301) was punched, pulled at a pulling speed of 0.5cm/min,
The elongation and strength at break were measured. As a result, the green density of the sheet was 2.65 g/cm ³ , and the elongation and breaking strength of the sheet were 14.1% and 32.8 Kg/cm ² , respectively. As is clear from the results, like the green sheet obtained in Example 4, a uniform green sheet was obtained that was flexible and strong, and had no cracks.

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Claims (1)

[Scope of Claims] 1 (1) Consisting of a (meth)acrylic acid alkyl ester having an alkyl group having 1 to 20 carbon atoms and a (meth)acrylic acid alkoxyalkyl ester having an alkylene group having 1 to 4 carbon atoms At least one monomer selected from the group 30~
85% by weight, (2) General formula (R ₁ , R ₂ and R ₃ each represent hydrogen or a methyl group, and n represents an integer of 1 or more.) Or, (R ₄ and R ₅ are each hydrogen or a methyl group, R ₆ is hydrogen or an alkyl group having 1 to 4 carbon atoms, and m is an integer of 2 or more.) A monomer component consisting of 5 to 60% by weight of at least one selected monomer and (3) 5 to 60% by weight of a carboxyl group-containing monomer (however, the total of all monomers is 100% by weight). A binder for ceramic molding obtained by copolymerization. 2 (1) At least one selected from the group consisting of (meth)acrylic acid alkyl esters having an alkyl group having 1 to 20 carbon atoms and (meth)acrylic acid alkoxyalkyl esters having an alkylene group having 1 to 4 carbon atoms. 1 type of monomer 30~
85% by weight, (2) General formula (R ₁ , R ₂ and R ₃ each represent hydrogen or a methyl group, and n represents an integer of 1 or more.) Or, (R ₄ and R ₅ are each hydrogen or a methyl group, R ₆ is hydrogen or an alkyl group having 1 to 4 carbon atoms, and m is an integer of 2 or more.) 5-60% by weight of at least one selected monomer, and (3) 5-60% by weight of a carboxyl group-containing monomer.
and (4) a monomer component consisting of more than 0 and 20% by weight of other vinyl monomers copolymerizable with the above (1), (2), and (3) (however, the total of all monomers is 100% by weight) %) is a binder for ceramic molding obtained by copolymerizing.