JPS60195053A - Water-soluble ceramic binder - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a water-soluble organic binder used for forming ceramic sheets and sheets.

One of the ceramic molding methods is a sheet molding method in which fine ceramic powder and a solvent are mixed to form a slurry, which is then drawn into a sheet using a doctor blade, etc., and then heated and dried to obtain a ceramic sheet (green sheet, green sheet). There is. The sheet obtained in this way (
Since the material is then fired after being shaped into the desired shape using a method such as cutting, an organic binder is used to maintain the shape during punching and firing.

For example, in the conventional sheet forming method, an organic binder such as butyral (σ1 fat, vinyl acetate resin, etc.) is dissolved in an organic solvent such as methyl ethyl ketone, butyl acetate, ethyl acetate, toluene, alcohol, etc., and this is combined with fine ceramic powder. The method involves mixing for a long time to form a slurry, defoaming the air in the slurry, then drawing it into a sheet onto a carrier film using a blade with a certain thickness, and heating and drying this to form a ceramic notebook. It has been adopted.

However, in this method using organic solvents, (1) the organic solvent causes harm to human health, (2) there is a risk of explosion due to the use of flammable organic solvents, and (3) there is a risk of using expensive organic solvents. There were problems in terms of economic efficiency, etc.

Other methods have been proposed, such as using water-soluble organic binders such as polyvinyl alcohol and vinyl acetate, and aqueous emulsions such as polyacrylic esters and copolymers of ethylene and organic acids as binders. .

However, in these proposed methods, since water is used as a solvent, the above-mentioned (1), (2), (3)
) problem has been solved, but it cannot be said to be perfect.Due to the presence of water, the ceramic fine powder tends to agglomerate in the slurry during the long mixing stage with the ceramic fine powder, and the viscosity of the slurry decreases. It is difficult to say that all the problems have been solved, such as a marked deviation from Newtonian flow, poor slurry fluidity and poor ceramic dispersibility, and difficulty in obtaining a sheet with high density and a smooth surface.

In other words, regarding ceramic sheet molding, the above (1)
), (2), and (3), (4) The surface of the ceramic sheet after drying must be smooth. (5) The formed sheet must have appropriate flexibility for pressure lamination molding and tape winding. (6) It is required that the formed sheet be easily converted back into slurry.

However, emulsion-type organic binders are difficult to regenerate into slurry, so they are not suitable for sheet molding.

Further, it is preferable to mold the molded product using a water-soluble organic binder and water as a solvent, since it is possible to reproduce the molded product.

However, polymers containing carboxylic acids such as acrylic acid, which are often used as water-soluble organic binders, become water-soluble by neutralizing the carboxylic acid groups (carboxyl groups) with alkali or ammonium such as sodium hydroxide or potassium hydroxide. -1. (This type of neutralization had the disadvantage that a flexible sheet could not be obtained.

In view of the above-mentioned circumstances, an object of the present invention is to provide a water-soluble organic binder that can use water as a solvent and that can yield a high-density, flexible ceramic sheet with a smooth surface free of aggregates. . □That is, the present invention jA)
α,β- consisting of acrylic acid and methacrylic acid
A copolymer containing 5 to 45 moles of at least one unsaturated carbonic acid and 95 to 55 moles of (B) at least one vinyl compound represented by the following formula (1) or (n). and at least 85 molar proportions of the carboxyl groups contained in the copolymer are tertiary, in which the total number of carbon atoms contained in the three substituents thereof is 6 to 9.
The present invention relates to a water-soluble ceramic binder which is neutralized with a grade amine.

General formula (1) CH-C:HR.

0OR2 Formula (ll) Next, the present invention will be further explained.

The α,β-unsaturated carboxylic acid of the present invention is acrylic acid or methacrylic acid, and each may be used alone or as a mixture.

One of the monomers to be copolymerized with the α,β-unsaturated carboxylic acid is a vinyl compound which is an acrylate or methacrylate represented by the above formula (1). This acrylate or methacrylate is an ester of acrylic or methacrylic acid and an alcohol from 01 to CI8. Such alcohols include methanol, ethanol, iso70ronoyanor, n-propanol, 5eC-phthanol, 1so-butanol, n-butanol, iso-7myl alcohol, n-amyl alcohol, 1SO-hexyl alcohol, n- Hexyl alcohol, 2-ethylhexyl alcohol, octyl alcohol, octadecyl alcohol natonoalkane monool, ethylene glycol, 2-hydroxy 70
These include alkanols such as lovanol. These acrylates and methacrylates can be used alone,
They may also be mixed. □ Furthermore, the monomer to be copolymerized with the above α,β-unsaturated carboxylic acid is a ruhinyl compound represented by the above formula (n). This vinyl compound can be used to produce styrenes such as styrene, α-methylstyrene, β-methylstyrene, α-ethylstyrene, β-ethylstyrene, a,β-dimethylstyrene/, vinyltoluene, ethylstyrene, vinylky/lene, etc. It is a vinyl compound substituted with methyl or ethyl groups. These vinyl compounds may be used alone or in combination.

In the present invention, the α,β-unsaturated carboxylic acid is 5
~/I5 molar ratio, it is necessary to include it in the copolymer.

If the content of α, β-unsaturated carboxylic acid is less than 5 molar ratios, it is difficult to obtain a uniform slurry in which the ceramic binder is completely water-soluble, and when the ceramic sheet molded body once formed is regenerated into slurry. Does not return to a uniform slurry.

If it exceeds 45 mole percent, the ionicity of the ceramic binder will increase, causing agglomeration of the fine ceramic powder during long-term pulverization and mixing with the fine ceramic powder, making it impossible to obtain a uniform slurry and making it difficult to form a ceramic sheet. The flexibility of the body is completely lost.

The copolymer of the present invention is obtained by copolymerizing the α,β-unsaturated carboxylic acid and a vinyl compound using a polymerization initiator.

Copolymerization of these raw materials is carried out in 2. Although a conventional polymerization method can be selected as appropriate, it is preferable to use a polymerization solvent in consideration of the fact that the viscosity increases as the copolymerization progresses, the removal of the polymerization heat generated by the copolymerization, and the like. These solvents may be selected as appropriate, but include methanol, ethanol, 1so-7' lovanol,
Lower alcohols such as n-pronognol, lower ketones such as acetone, methyl ethyl ketone, methyl iso-butyl ketone, noethyl ketone, lower esters such as methyl acetate and ethyl acetate, and 1,4-no'oxane, 1,3-dioxane, tetrahydrofuran, etc. Considering the usage form of the organic binder, it is more preferable to use one that is itself water-soluble, such as a cyclic ether. That is, in the case of the above-mentioned water-soluble solvent, the polymerization solvent and binder are mixed completely and uniformly when mixed with the fine ceramic powder to form a slurry, so that it can be used without removing the polymerization solvent in advance.

The polymerization initiator may be any commonly used so-called ranocal polymerization initiator. For example, ketone ie-oxides such as methyl ethyl peroxide, methylcyclohexanone/peroxide, 1,1-bisCt-#tylperoxy)cyclohex'')-7,2,2-bis(1-butylperoxy)butane, etc. Hydroperoxides such as ye-oxyketal, t-butyl hydroperoxide, and cumene hydroperoxide; noalkyl peroxides such as not-t-butyl-P-oxide, 7-butyl-cumyl peroxide, and no-gymyl peroxide; In addition to peroxides such as acetyl and monooxides, pen/yl peroxides, and other peroxides, azobisisobutyronitrile and the like can also be used.

Polymerization can be carried out at any temperature from room temperature to 150°C, but it is industrially preferable to carry out the polymerization at a temperature below the boiling point of the polymerization solvent since there is no need for pressurization. In addition, for the polymerization operation, the raw materials and the solvent to be used as necessary are placed in a polymerization reactor in advance.
This can be carried out by a method of gradually adding a polymerization initiator, or a method of charging only a solvent into a polymerization reactor and gradually adding raw materials and a polymerization initiator. Although the polymerization time depends on the polymerization temperature and initiator concentration, 6 hours to addition time is usually sufficient.

A copolymer is obtained as described above and then neutralized with a tertiary amine to make it water-soluble.

The amine to be treated is a tertiary amine having a total of 6 to 9 carbon atoms in its three substituents.

These amines include not only simple alkylamines such as triethylamine, noethylbutylamine, and trimethylbexylamine, but also those with a hydroxyl group introduced into the alkyl group such as hydroxyalkylamines such as triethanolamine and triisono-gunolamine. can. The ceramic binder of the present invention can be changed by neutralizing with these amines. If the total number of carbon atoms is less than 5, the resulting ceramic binder may have a strong amine odor and may be practically unusable, and the ceramic sheet molded product obtained by drying may not have the flexibility to withstand winding. When the number is 10 or more, the resulting ceramic binder has poor water solubility, making it difficult to form a uniform slurry during pulverization and mixing.

It is important that the amine used for neutralization neutralizes 85 or more moles of carboxylic acid groups present in the resin.

If more than 15 molar carboxylic acid groups remain, the ceramic molded product will be completely assimilated and exhibit no flexibility, making it completely unsuitable for sheet molding. Although there is no problem in using a large excess of amine in the neutralization process, there are limits to its practical use due to economics, operability, the odor peculiar to amines, etc. In practical use of amines, J] is 1 of the neutralization equivalent of the desired carboxylic acid group.
．． It is preferably 2 equivalents or less. Neutralization treatment can be easily carried out by adding a predetermined amount of amine to the obtained resin solution. Normally, complete neutralization can be carried out in 30 minutes to 3 hours at the polymerization temperature.

Although the binder 1d of the present invention can sufficiently exhibit its performance by itself, it is possible to combine high boiling point water-soluble polyols such as ethylene glycol, noropylene glycol, triethylene glycol, noropylene glycol, and glycerin with water-soluble water-soluble polyols. It is also possible to change the flexibility of the obtained ceramic sheet molded product by adding it as an agent.

The present invention will be explained below with reference to Examples.

In the following, all parts refer to parts by weight.

Example 1 In boiling innorobil alcohol (112.5 parts),
A mixture of n-butyl acrylate (73.1 parts), methacrylic acid (28.1 parts), styrene (11.25 parts) and peroxide (0.1 parts) (trade name Perbutyl O [manufactured by NOF Corporation]) dropwise over 2 hours. After completion of the dropwise addition, stirring was continued at the same temperature for 5 hours. After the reaction solution was cooled to room temperature, triethanolamine (48.7 parts) was added to neutralize it. Thereafter, inzolobil alcohol is distilled out from this solution under reduced pressure to obtain a water-soluble resin.

100 parts of alumina powder (manufactured by Sumitomo Aluminum Refining, trade name: AM-21), 4 parts of the above resin, and iodine.

45 parts of exchanged water was added and kneaded in a peel mill for about 10 hours to form a slurry, which was then defoamed.

A kneaded sheet was made from the slurry by the doctor blade method, and after air drying for 2 hours,
After drying for a while, a sheet with a smooth surface was obtained.

This sheet had elasticity that allowed it to be punched out, and its density was measured to be 2.40.

Further, 23 parts of ion-exchanged water was added to 50 parts of the sheet obtained above, and the mixture was kneaded in a ball mill for about 8 hours to form a slurry again. After defoaming treatment, a sheet was produced by the above method. This sheet was also smooth and had the same flexibility as shown in Table 1. It was found that the density was 2.38 and that the sheet could be recycled.

Example 2 A water-soluble resin was obtained in the same manner as in Example 1. However, the polymerization solvent, isopropyl alcohol, was not removed, and the mixing operation with alumina powder was performed using the following recipe.

100 parts of alumina powder 7 parts of the above resin solution (4.1 parts as resin content) 45 parts of ion-exchanged water were kneaded in the same manner as in Example 1 to make a sheet. I got a flexible sheet. Yes, I was able to reproduce it.

Examples 3 to 6 Sheets were prepared in the same manner as in Example 1 using 1,4-dioxane (112.5 parts) as the polymerization solvent and acrylic acid (23.5 parts) instead of methacrylic acid, and Regeneration was performed in a similar manner. In each case, good sheets were obtained as shown in the table below.

Examples 7 to 11 Organic binders were synthesized in the same manner as in Example 1 using the reaction solvents shown in Table IK, α, β-unsaturated carboxylic acids, and vinyl compounds, and ceramic sheets were evaluated. In both cases, recyclable smooth and flexible sheets were obtained.

Examples 12 to 16 and Comparative Examples 1 to 2 A mixture of n-butyl acrylate, methacrylic acid, and a combination initiator azobisisobutyronitrile (0.1 parts) was added to boiling isopropyl alcohol (100 parts). 5 at the same temperature after the completion of the dropwise addition over 2 hours.
After stirring for a while, the reaction solution was heated to room temperature, and triethanolamine was added for neutralization.

The thus obtained resin solution was evaluated in the same manner as in Example 2. The results are shown in Table 2.

Examples 17 to 19 Copolymerization was carried out in the same manner as in Example 15, various amine treatments were carried out, and the resulting resin solutions were used in the same manner as in Example 2 to produce ceramic sheets.

■ Number of amine parts used for neutralization treatment. Neutralize section 100.

Examples 20 to 22, Comparative Example 3 Copolymerization was performed in the same manner as in Example 15, triethanolamine treatment was performed, and the resin solution was used in the same manner as in Example 2 to prepare sheets.

Patent Applicant: Japan Petrochemical Co., Ltd. Masaaki Taneichi; October 19, 2001, Commissioner of the Japan Patent Office, ■ 1, 1, 1, 'i 8'1, Application No. 4162
2. Name of the invention: Water-soluble Hiramix binder 3. Relationship with the person making the amendment: Bamboo ff Applicant name: Japan Petrochemical Co., Ltd. 4. Agent address: 1M1, Minami-Aoyama-chome, Minato-ku, Tokyo. (Delivery port) Showa year, month, day 6, subject of amendment ■ 1 patent' Correct as shown below.

(2), page 7 of the specification, lines 1 to 4 [General formula ('I) “General formula (I) ” and correct it.

(3) "Ceramic Sheet 1~" on page 5, line 5, line 7 of the specification - page 12, line 2 from the bottom is corrected to "ceramic sheet J."

(4) "Ceramic J" on page 5, line 2 of the specification is corrected to "Semmic 2."

Above 2, Claim (1) (A) 5 to 45 mol% of at least 51 types of α, β-unsaturated carboxylic acids consisting of acrylic acid and methacrylic acid, and (B) the following general formula (I ) or (I) in an amount of 95 to 55 mol %, and at least 85 mol % of the carboxyl groups contained in the copolymer contain three substituent groups on the right side of the copolymer. The third whose total number of carbon atoms is 6 to 9
A water-soluble ceramic binder characterized by having a middle phase of grade amine.

(2) The water-soluble ceramic binder according to claim 1, wherein the vinyl compound of the general formula (II) is styrene, α-methylstyrene, or vinyltoluene.

(3) The tertiary amine is 1-ethylamine, dimethylhexylamine, 1-liethanolamine, or triisopropanolamine, as set forth in claims 1 J5 and 2. The water-soluble ceramic binder described in any one of the above.

Claims (3)

[Claims] (1) (A) α,β-unsaturated power consisting of acrylic acid and methacrylic acid? and (B) the following general formula (1) or (II) c) (2=
A copolymer containing 95 to 55 mol of at least one vinyl compound represented by OHR, (+) 0OR2, in which at least 85 mol of carboxyl groups contained in the copolymer is 3 A water-soluble ceramic binder characterized by being neutralized with a tertiary amine whose substituents have a total of 6 to 9 carbon atoms. (2) The water-soluble ceramic binder according to claim 1, wherein the vinyl compound of general formula (II) is styrene, α-methylstyrene, or vinyltoluenteal. (3) The tertiary amine according to any one of claims 1 and 2, characterized in that the tertiary amine is triethylamine, trimethylbexylamine, triethanolamine, or triisozolopanolamine. water-soluble ceramic binder.