JPH03159949A - Ceramic form and production thereof - Google Patents

Abstract

PURPOSE:To obtain the title form with improved mechanical strength by forming to a desired shape a green sheet containing both inorganic powder and glass powder followed by calcination. CONSTITUTION:A total of 100 pts.wt. of (A) 30-70wt.% of inorganic powder 0.01-5mum in average size (e.g. alumina) and (B) 70-30wt.% of glass powder 1-15mum in average size and, if needed, (C) 1-30wt.% of inorganic fiber and/or whisker 1-200mum in fiber length is incorporated with (D) 10-30 pts.wt. of a (meth)acrylic binder 30000-200000 in weight-average molecular weight and (E) an organic solvent followed by kneading into a slurry. A green sheet 0.03-1mm thick produced by forming this slurry is then formed to a desired shape and then calcined.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention relates to various ceramic molded bodies, particularly ceramic molded bodies used for crafts, pottery, physical science instruments, etc., and a method for producing the same.

[Prior Art] Ceramics such as tea bowls and vases are usually made by kneading clay or the like into shape using a potter's wheel, drying, and firing at a temperature of 1200° C. or lower. Furthermore, glassware is generally made by glasswork in a state where glass is heated to a temperature above its softening point.

Furthermore, in recent years, ceramic substrates have been manufactured by processing and firing ceramic green sheets made of alumina, alumina glass, zirconia, etc., and are used in various electronic components. However, all of these substrates are flat.

On the other hand, as an attempt to manufacture three-dimensional structures by taking advantage of the workability of green sheets, Japanese Patent Application Laid-Open No. 126106/1983 describes a method for manufacturing spherical ceramic plates,
No. 115703 only discloses a method for manufacturing a ceramic substrate having a curved surface.

[Problem B to be solved by the invention] The present inventors have already disclosed zirconia and (meth)acrylic binders with specific particle sizes in JP-A-63-277546, JP-A-1-111769, and JP-A-1-201063. It has been disclosed that a zirconia green sheet containing . However, in order to sinter the zirconia green sheets, a high temperature of 1,400°C or higher is required, and for this purpose the heating element is expensive molybdenum silicide (canthal).
The problem is that an electric furnace must be used and it is not versatile. Therefore, the object of the present invention is to be able to produce ceramic green sheets that are sintered at a temperature below sufficient to use a general-purpose electric furnace (maximum operating temperature of 1200°C, regular use of 1000°C), and that can be produced even after sintering. It is an object of the present invention to provide a complex-shaped molded article having sufficient strength and a method for producing the same.

[Tasks for Solving the Problems] According to the present invention, this object is achieved by combining 30% to 70% by weight of inorganic powder and 30% to 70% by weight of glass powder 10O
Based on parts by weight, or 30% to 60% by weight! % of inorganic powder, 30% to 60% by weight of glass powder, and 1% to 30% by weight of inorganic fibers and/or whiskers, for a total of 10OfE parts, 10 to 30% of (meth)acrylic binder. 3 obtained by molding a ceramic green sheet containing part by weight into a desired shape and then firing the green sheet molded body at a temperature of 1200°C or less.
A ceramic molded body containing 0% to 70% by weight of inorganic powder and 30% to 70% by weight of glass powder,
Or 30% to 60% by weight of inorganic powder, 30% to 60% by weight of glass powder, and 1% to 30% by weight.
This is achieved by a ceramic molded body containing inorganic fibers and/or whiskers.

The inorganic powder contained in the green sheet is, for example, alumina (AI203), forsterite (2Mgo.
Si(h), enstatite (MgO・Si(h),
Spinel (MgO・AI203 etc.), silica (SiO
2), Mullite (AI203/St02), cordierite (2MgO/2AI203/5SiO2), zircon (Zr02/SiOa), aluminum titanate (AI203/TiO2), magnesia (MgO),
Titania (Ti(h), zirconia (Zr02) and talc (MgsSiaO+ll(OH)2) and clay (
One or more clays selected from clays such as AhSi20s(O}I)4) are used. Preferred are alumina, forsterite, and cordierite.

Borosilicate (Si02-8203) as glass powder
The basic composition is alumina, zirconia,
Magnesia, calcia (Cab) and barrier (Bad)
The one containing 1% to 50% by weight of the following is selected.

In this case, the inorganic powder has an average particle diameter of 0.01 to 5.
In the range of μm, the amount added is 30% to 70% by weight (inorganic fibers and/or 60% by weight if whiskers are included).
weight%), the average particle size of the glass powder is 1-15μ
The amount added is preferably 30% by weight to 70% by weight (60% by weight if inorganic fibers and/or whiskers are included). If the inorganic powder is less than 30% by weight and the glass powder is more than 70% by weight (60% by weight if it contains inorganic fibers and/or whiskers), the strength of the ceramic molded body after sintering is insufficient; In addition, if the glass powder is less than 30% by weight and the inorganic powder is 70% by weight (60% by weight if it contains inorganic fibers and/or whiskers)
% by weight), below 1200℃, especially too
It does not sinter sufficiently at temperatures below ℃.

Further, in order to further increase the strength after sintering, it is preferable to add inorganic fibers and/or whiskers, and the amount added is preferably 1% by weight to 30% by weight. If it exceeds 30% by weight, the strength will be weakened and the effect of addition will not be recognized.

Inorganic fibers and/or whiskers can be selected from glass, alumina, carbon, inorganic fibers such as silicon carbide and zirconia, silicon carbide, whiskers such as zinc oxide and potassium titanate, but glass fibers and alumina Fibers are particularly preferred. Fiber diameter is 1-2
00 μm, more preferably in the range of 10 to 100 μm, m
*Length is 0.01-30mms, preferably 0.2-30mms
The range is 3mm.

In addition, pigments such as cobalt blue, chrome green, titanium yellow, and ceramic red are added to the green sheet to give it colorability.Inorganic powder, glass powder, inorganic fiber, and/or pigments are added to the total of whiskers. It may be added in an amount of 1% to 20% by weight.

The binder used in the present invention is based on acrylic acid or methacrylic acid and their esters (meth)
It is an acrylic binder, and is selected from methyl acrylate, ethyl acrylate, n-probyl acrylate, n-butyl acrylate, isobutyl acrylate, cyclohexyl acrylate, 2-ethylhexyl acrylate, etc., and has 1 to 10 carbon atoms. 20 to 60% by weight of acrylic esters having alkyl groups, methyl methacrylate, ethyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, n-octyl methacrylate, n-decyl methacrylate,
1 to 2 carbon atoms selected from n-dodecyl methacrylate, lauryl methacrylate, cyclohexyl methacrylate, 2-ethylhexyl methacrylate, etc.
Methacrylic acid ester with 0 alkyl groups 40
~80% by weight, and 0.01~5% by weight of carboxyl group-containing monomers such as acrylic acid, methacrylic acid, maleic acid, itaconic acid, etc. are optimally selected as the monomer composition of the binder.

Well, these acrylic late esters, methacrylic acid esters, and hydroxyl group-containing monomers such as 2-hydroxyethyl acrylate, 2-hydroxybutyl acrylate, glycerol acrylate, and trimethylolpropane acrylate can be copolymerized with carboxyl group-containing monomers. or aminoethyl (meth)acrylate, aminoethyl (meth)acrylamide, allylamine, N-methylaminoethyl (meth)acrylate, N-phenylaminoethyl (meth)acrylate, or aminoethyl (meth)acrylate containing a basic nitrogen atom in the molecule. ) acrylic}, N. N-dimethylaminoethyl (meth)acrylate, N. Basic unsaturated monomers such as N-dimethylaminobrobyl (meth)acrylamide, N-vinylpyrrolidone, acryloylformoline, and vinylpyridine, or aromatic or fatty acids having unsaturated bonds such as styrene, vinyl acetate, allyl alcohol, allyl ether, etc. Monomers of the above group may be added to the binder composition in an amount not exceeding 10% by weight.

These monomers have a weight average molecular weight (Mv) of 3 by known polymerization methods such as suspension polymerization, solution polymerization, and emulsion polymerization.
0000 to 200000, preferably 5000
0 to 150,000, and the number average molecular weight (Mn) is in the range of 10,000 to 100,000, preferably 3,000.
It is adjusted to a range of 0 to 80,000. In order to maintain the shape of K green sheets formed into complex shapes even after sintering, the weight average molecular weight (Mu) should be in the range of 80,000 to 100,000, and the number average molecular weight (Mn) should be in the range of 50,000 to 6,000.
A range of 0 is particularly preferred.

The binder thus obtained is mixed with the above-selected inorganic powder and glass powder, or inorganic powder, glass powder, inorganic fiber and/or whiskers and an organic solvent, and if necessary, a dispersant, a plasticizer, etc. A slurry is prepared by adding and kneading for a predetermined time using a ball mill or the like, and then a ceramic green sheet is prepared using a known method such as a doctor blade method. ! do.

In this case, the content of the (meth)acrylic binder in the ceramic green sheet is in the range of lθ to 30 parts by weight. When the content of the binder in the green sheet is less than 10 parts by weight, the moldability of the green sheet will be poor, and the strength and flexibility will also be insufficient.
If the green sheet is bent or otherwise processed, cracks and cuts will occur. In addition, when the content exceeds 30 parts by weight, the strength and flexibility of the green sheet can be obtained, but the shrinkage due to sintering is large, especially when manufacturing a three-dimensional complex shaped molded product, and after bending. A problem arises in which the green jeat is not kept in shape and deforms.

In the sheet forming method using the doctor blade method, polyvinyl butyral resin is usually used as the organic binder, but when this is used, cracks and cuts are likely to occur during the bending process even if the amount of binder added is increased. It is not preferable to use polyvinyl butyral resin because it has problems with shape retention after sintering.

As the solvent for the binder, organic solvents such as toluene, methyl ethyl ketone, ethyl acetate, and isobrobanol are preferred, but when the binder is polymerized using water as a solvent, water can of course be used as the solvent.

In the doctor blade method, the thickness of the green sheet is usually 0.
．． The thickness of ceramic green sheets suitable for bending, punching, or pressing is 0.03 to 11.
It is 1 to 0.5 Illm.

When making complex shapes, green sheets can be used as origami by hand to make paper crafts such as cranes, helmets, ships, etc.
Because it can be used to make physical and chemical instruments such as crucibles, trays, Petri dish funnels, beakers and droppers by pressing, etc., it can be made into component materials such as strings, pipes and rings by bonding and adhesive processing, and it can also be colored after sintering. It can be used in a wide variety of methods and applications, such as for pottery and crafts to create complex shapes, using the creator's creative methods (cutting with scissors, gluing, laminating, etc.) -12- [Example below: The present invention will be explained in more detail by reference examples and examples, but the present invention is not limited to these examples.

Reference Example 1 80 parts by weight of toluene and 40 parts by weight of methyl ethyl ketone as solvents were placed 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, and the nitrogen introduction tube was charged. Introduce more nitrogen to create a nitrogen atmosphere in the flask k. Then, the mixed monomer was added dropwise to the funnel, 2% by weight of ethyl acrylate, 2% by weight.
- Ethylhexyl acrylate 38% by weight, methyl methacrylate} 4.94% by weight, cyclohexyl methacrylate 25% by weight, lauryl methacrylate 30% by weight
100 parts by weight of a mixed monomer consisting of % by weight and 0.06% by weight of methacrylic acid were charged, and 0.4 part by weight of a polymerization initiator dropwise added funnel-haired bisisobutyronitrile.

-13- While adjusting the internal temperature of the flask to 60°C, the mixed monomers and polymerization initiator were added dropwise with stirring over 2 hours, heated at 60°C for 2 hours, then at 80°C for 2 hours, and then cooled to form a solid. Min concentration 45%, glass transition temperature -35°C, weight average molecular weight s o o oo, number average molecular weight 500
A binder named 00 was prepared.

Example 1 Alumina powder (A-13-S manufactured by Showa Denko K.K.) 40
Weight% and Si02-Al20a-820a-BaO
To a total of 100 parts by weight of 60% by weight of glass powder consisting of,
1 part by weight of sorbitan triolate as a dispersant and a mixture of toluene/ethyl acetate (50/50) as a solvent 3
After putting 0 parts by weight in a ball mill and mixing for 12 hours, Reference Example 1
18 parts by weight of the binder obtained above was added as a solid content, and then kneaded in a ball mill for 24 hours to prepare a slurry.

This slurry was cast onto a polymer film using a doctor blade method and dried at 80°C to a thickness of 0.
A 3 mm green sheet was obtained.

The obtained green sheet has sufficient strength and flexibility for bending and punching, and has a size of 1.50 mm square = 14
- A crane was folded using a punched sticker and baked at 900°C. The obtained sintered body maintained its shape in a homogeneously contracted state, and exhibited high strength without any cracks or cracks.

Table 1 shows the condition of each part of the crane obtained.

Example 2 In Example 1, instead of 40% by weight of alumina powder and 60% by weight of glass powder, which was a total of 100 parts by weight, 35% by weight of alumina powder (A-13-S manufactured by Showa Denko K.K.),
25% by weight of forsterite powder and Sto2-AI
A green sheet with a thickness of 0.2 mm was obtained in the same manner as in Example 1, except that a total of 100 parts by weight of 40% by weight of glass powder consisting of 203-8203-BaO-Zr02 was used.

This sheet was punched out into 1501 squares, folded into a crane, and heated to 950°C.
It was fired in The obtained sintered body maintained its shape in a homogeneously contracted state, and exhibited high strength without any cracks or cracks.

Table 1 shows the condition of each part of the crane obtained.

Example 3 In Example 1, Ar-15 was used instead of 40% by weight of alumina powder and 60% by weight of glass powder, which was a total of 100 parts by weight.
= Lumina powder (A-13-S manufactured by Showa Denko K.K.) 45% by weight, Si02-AI203-820s-BaO-Ca
53% by weight of glass powder consisting of O and glass fiber (Asahi Fiberglass Co., Ltd. $!MF-TIO, diameter 0.
01 mm, length 0.2 mm) 5% by weight, a total of 100 parts by weight, in the same manner as in Example 1 except for k, and the thickness was 0.01 mm.
Obtained a 5I green sheet k. This sheet is 150mm
The squares were punched out, folded into cranes, and fired at 850°C. The obtained sintered body maintained its shape in a homogeneously contracted state, and exhibited high strength without any cracks or cracks.

Table 1 shows the condition of each part of the crane obtained.

Comparative Example 1 Alumina powder (Showa Denko Co., Ltd. & lA-13-S) 1
00 parts by weight, sorbitan triolate l as a dispersant
parts by weight, toluene/ethyl acetate mixture (5 parts by weight) as solvent
0/50) 30 parts by weight were placed in a ball mill and mixed for 12 hours, then 18 parts by weight of the K binder obtained in Reference Example 1 was added as a solid content, and then kneaded in a ball mill for 24 hours to prepare a slurry. This slurry was cast onto a polymer film using a doctor blade method and dried at 80°C to obtain a green sheet with a thickness of 0.31.

Punch out this sheet into 100mm squares, fold it into a crane, 1 2
The fired body obtained by firing at 00°C was insufficiently sintered and had low strength, and broke when held by the crane's head or tail.

Table 1 shows the condition of each part of the crane obtained.

[Effect of the invention] According to the present invention, 30% to 70% by weight of inorganic powder and 3
For a total of 100 parts by weight of 0% to 70% by weight of glass powder, or 30% to 60% by weight of inorganic powder and 30% to 60% by weight of glass powder and 1% by weight to
By using a ceramic green sheet containing 10 to 30 parts by weight of a (meth)acrylic binder to a total of 100 parts by weight of 30% by weight of inorganic fibers and/or whiskers, it is possible to bend, punch, It has sufficient strength and flexibility for press processing, etc., and can be processed into three-dimensional complex shapes, and can be used at temperatures below 1200°C, especially at temperatures below 1000°C.
A sintered body having high strength and retaining its shape was obtained at the following firing temperature.

= 17- Table 1 ■ 3 tables of Yakishi Tomari blasphemy 0 Wakachi /) th 1 catch is ゛ha rumor l 臥 type Aa3Xth
ri, νber, force IK

Claims (7)

[Claims] (1) 30% to 70% by weight of inorganic powder and 30% by weight
A ceramic molded body containing ~70% by weight of glass powder. (2) 30% to 60% by weight of inorganic powder and 30% by weight
A ceramic molded body containing ~60% by weight of glass powder and 1% to 30% by weight of inorganic fibers and/or whiskers. (3) The method for producing a ceramic molded body according to claim 1 or (2), which is obtained by molding a ceramic green sheet into a desired shape and then firing the green sheet molded body. (4) The green sheet according to claim (3) is 30% by weight.
The claim is a ceramic green sheet containing 10 to 30 parts by weight of a (meth)acrylic binder to a total of 100 parts by weight of ~70% by weight of inorganic powder and 30% to 70% by weight of glass powder. A method for producing a ceramic molded body according to item (1). (4) The green sheet according to claim (3) is 30% by weight.
For a total of 100 parts by weight of ~60% by weight inorganic powder, 30% by weight ~ 60% by weight glass powder, and 1% by weight ~ 30% by weight inorganic fibers and/or whiskers, (meth)
The method for producing a ceramic molded body according to claim 2, wherein the ceramic green sheet contains 10 to 30 parts by weight of an acrylic binder. (5) The firing temperature of the green sheet molded body is 1200°C
The method for manufacturing a ceramic molded body according to claim 3, wherein the temperature is as follows. (6) The ceramic molded article according to claim (1) or (2), which is used for crafts or pottery. (7) Claim (1) or (
2) The ceramic molded body described above.