JP2003327475A - Method of producing foldable ceramic green sheet - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method of advantageouly producing a ceramic green sheet in which cracking and chipping do not occur even when bending operation is repeated for a plurality of times, and cracks do not occur in a bent part and a folded part even when firing is performed and which can be used in a sense of a folded paper or paperwork. <P>SOLUTION: A 5 to 20 pts.wt. polyvinyl butyral resin as a binder, a 1 to 20 pts.wt. plasticizer and a 0.5 to 5 pts.wt. phosphoric ester based dispersant are blended to 100 pts.wt. of ceramic raw material powder, an organic solvent is further added thereto, and they are uniformly mixed and dispersed to obtain slurry. The slurry is made into a sheet by a doctor blade process. Thereafter, the sheet is subjected to natural drying or low temperature drying at ≤50°C, and volatile components are left so that the loss in weight after the drying by heating at 150°C for 5 hr reaches ≥5%. Thus, a green sheet with a thickness of 0.05 to 0.5 mm is formed. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a method for producing a foldable ceramic green sheet, and in particular, it does not cause any problems even when it is folded a plurality of times and can be suitably used as ceramic paper for ceramics and crafts. The present invention relates to a method for advantageously producing a ceramic green sheet that does not require

[0002]

BACKGROUND ART Conventionally, a slurry (slip) prepared by mixing a ceramic raw material powder with an organic binder (binder), a plasticizer, a dispersant, a solvent, etc. is used by a doctor blade method or a calendar. A green sheet obtained by forming a thin plate by a method or the like has been used for various purposes. Among them, in particular, since it is excellent in plasticity and workability, and has characteristics such as being capable of cutting, punching, and adhering, it is advantageously used as an electronic component material such as a material for IC substrates and capacitors. is there.

In order to improve the plasticity and flexibility of such a thin plate-shaped ceramic green sheet, many studies have been conducted on the composition and manufacturing method of the sheet, but Most of them were mainly intended for research and development as electronic component materials. For example, for the purpose of controlling plasticity and flexibility, means for preventing the ceramic green sheet obtained by the doctor blade method or the like from being cracked, cracked, or broken due to shrinkage or distortion in the drying process, or roller stretching is proposed. Methods such as methods for producing thinner sheets and various means for pursuing press working, printing, laminating, and handling are merely proposed.

The ceramic green sheet obtained by the doctor blade method is expected to be used as paper because of its thinness. If it can be used as origami paper, it can be used for paper cranes, turtles, treasure ships, etc. By making origami works such as balloons, windmills, morning glories and cut paper works, and then firing them, it is possible to obtain a new ceramic craft product having a unique taste and taste.

However, the ceramic green sheet obtained by the conventional doctor blade method cannot be folded or bent, let alone 18
It has never been possible to fold it by bending it to 0 degrees (R = 0), and up to now, regarding such a foldable green sheet, in other words, it is not possible to use origami or paperwork. Even if it is folded, bent or folded back, cracks or cracks do not occur, or it does not chip or cut, and even if it is baked, a fired product with no defects such as chips or cracks is obtained. No proposal has been made for ceramic materials such as ceramic green sheets or ceramic paper that can be processed like paper.

[0006]

The present invention has been made in view of such circumstances, and the problem to be solved is that it can be used with a feeling of origami or paperwork and is foldable. Another object of the present invention is to provide an advantageous manufacturing method of a ceramic green sheet, and another object is to perform a bending operation of 180 degrees even if the bending operation is repeated a plurality of times. Even if it is fired, cracks and chips do not occur, and a method that can effectively produce a useful ceramic green sheet that does not have cracks from its bent portion or folded portion is provided. In addition, another issue is to provide a ceramic green sheet having excellent properties for pottery and crafts. By the firing of the work resulting from the green sheet, high craft value, is to provide the craft with the aesthetic texture.

[0007]

In order to solve the above problems, in the present invention, 5 to 20 parts by weight of polyvinyl butyral resin and 1 to 10 parts of plasticizer are added to 100 parts by weight of ceramic raw material powder. 20 parts by weight and 0.5 to 5 parts by weight of a phosphoric acid ester-based dispersant are mixed, an organic solvent is further added, and the resulting slurry is uniformly mixed and dispersed to obtain a sheet by a doctor blade method. After that, air-dry or low-temperature drying at 50 ° C or less is performed at 150 ° C × 5
So that the weight loss after heating and drying for 5 hours is 5% or more,
A method for producing a foldable ceramic green sheet, which is characterized in that it is obtained as a green sheet having a thickness of 0.05 mm to 0.5 mm in which volatile components are retained, is a gist thereof.

As described above, in the method for producing a foldable ceramic green sheet according to the present invention, polyvinyl butyral resin is used as a binder with respect to the ceramic raw material powder, and a predetermined amount thereof is blended. In addition to the specified amount of plasticizer, a phosphate ester-based dispersant is used as a dispersant, and the specified amount is further added to form a uniform slurry with an organic solvent, which is then formed into a sheet by the doctor blade method. Further, it is naturally dried or dried at a low temperature of 50 ° C. or lower to give 150
Allow volatile components to remain so that the weight loss after heating and drying at 5 ° C for 5 hours is 5% or more.
A green sheet having a thickness of mm is used, and thus a slurry having a specific composition is used, and after a thin sheet is formed by a doctor blade method, a predetermined natural drying or low temperature drying operation is performed. By allowing a predetermined amount of volatile components to remain, it is possible to advantageously obtain a ceramic green sheet having outstanding folding properties.

That is, according to the present invention, a thin sheet is formed by a doctor blade method using a predetermined slurry, and a green sheet in which a predetermined amount of volatile components is left is formed. (R =
Bending is possible until it reaches 0), and 3 to the other side.
Even if it is bent by 60 degrees or if such a bending operation is repeated a plurality of times, cracks or chips do not occur,
Moreover, even if it is fired, it is possible to advantageously obtain a thin-walled ceramic green sheet that does not crack from the bent portion or the folded back portion, which makes it possible to obtain ceramic green sheets or ceramic paper for ceramics and crafts. Moreover, ceramic origami could be advantageously provided.

In the method for producing a foldable ceramic green sheet according to the present invention, it is preferable that the green sheet has an elongation of 200 to 400% and 1 to 20 kg / cm. It is configured so as to have a tensile strength of ² , whereby the folding property which is the object of the present invention can be further enhanced, and the shape retention can be effectively ensured, which is completed by origami processing. The ability to retain the desired shape is remarkably enhanced, and thus the origami product or craft product having the desired shape can be obtained advantageously.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION When a desired foldable ceramic green sheet is manufactured by the manufacturing method according to the present invention, the ceramic raw material powder has been conventionally used for manufacturing a green sheet. Fine powders may be used as they are, and examples thereof include powders of alumina, zirconia, mullite, and the like, and various ceramic powders such as ceramics, white ceramic materials, borosilicate glass, glass ceramic materials, and dielectric materials such as barium titanate. You can Moreover, even if the particle size of such a ceramic raw material powder is the same as the conventional one, for example, the average particle size of 10 μm or less is used.

In order to obtain a foldable ceramic green sheet from such ceramic raw material powder, polyvinyl butyral resin is used as a binder in the present invention. This polyvinyl butyral resin is a thermoplastic / solvent-soluble resin having excellent adhesiveness and has been conventionally used as a ceramic binder. In particular, in the present invention, it is used as an organic solvent. It is easily dissolved and has good compatibility with plasticizers and dispersants, shape retention in the molding process, bondability,
It is used in order to advantageously obtain a foldable ceramic green sheet by utilizing excellent characteristics such as moldability and coating property.

The polyvinyl butyral resin as such a binder is 100% of the ceramic raw material powder.
It should be used in a proportion of 5 to 20 parts by weight, preferably in a proportion of 8 to 15 parts by weight, relative to parts by weight. Here, when the amount of the polyvinyl butyral resin used is reduced, the moldability, plasticity, and bondability or bond strength of the sheet are reduced, and when the amount is less than the lower limit of 5 parts by weight, The strength of the obtained sheet is insufficient, bending and folding become difficult, and defects such as cracks occur. In addition, the amount of polyvinyl butyral resin compounded increases, and
If it exceeds the weight part, it will be difficult to dissolve the resin, and the viscosity of the slurry will also increase, so it will be necessary to greatly increase the amount of solvent, and the defoaming time will increase significantly. In addition to the above problems and cost problems, there is an inherent problem that cracks (cuts, cracks, cracks) easily occur because the resin burns in a low temperature range and abnormally generates heat during the firing step.

Further, in the present invention, a predetermined amount of a plasticizer is blended with the polyvinyl butyral resin, and as such a plasticizer, dibutyl phthalate, dioctyl phthalate, dibutyl sebacate, Known compounds such as diisooctyl phthalate, dicapryl phthalate and butylbenzyl phthalate can be used. And, as a compounding amount of such a plasticizer, a ratio of 1 to 20 parts by weight, preferably 3 to 15 parts by weight is adopted with respect to 100 parts by weight of the ceramic raw material powder. It should be noted that when the blending amount of the plasticizer is reduced, the plasticity and flexibility are impaired, and in terms of characteristics, the elongation rate decreases, but this elongation rate decrease decreases the flexibility and the sheet bending. It causes a problem that cracks easily occur when folding or folding, while
When the plasticizer is excessively blended, there is a problem that the obtained green sheet has a weak rigidity, low shape retention, and is sticky and has poor handleability. However, there is an inherent problem that cracks such as breaks, cracks, and cracks easily occur due to abnormal heat generation.

Further, in the present invention, a phosphoric acid ester-based dispersant is used as a dispersant, which is mixed with the above-mentioned polyvinyl butyral resin and a plasticizer into the ceramic raw material powder to prepare a slurry. The Rukoto. Such a phosphoric ester dispersant is generally a nonionic anionic activator obtained by phosphorating an ether type nonionic activator, wherein the OH group bonded to the phosphorus atom (P) is RO. -(CH ₂ CH
₂ O) _n -group (in the formula, n is the average number of moles of ethylene oxide added, and R is an alkyl group or an alkylphenol group having 8 to 30 carbon atoms), Depending on the number of the substituted groups, there are monoester type and diester type, and generally, they are used in a single system or a mixed system, but this type of phosphate ester dispersant is already commercially available. Therefore, such a commercially available product is appropriately selected and used. For example, as a mixture consisting of phosphoric acid monoester, diester, and a trace amount of triester, a product commercially available under the name of phosphanol from Toho Chemical Industry Co., Ltd. can be appropriately selected and used. Of.

In particular, such a dispersant mainly promotes dispersion of a slurry containing a ceramic raw material powder and a resin, a plasticizer, a solvent, etc., and maintains appropriate wetting of the ceramic green sheet and improves homogeneity and flexibility. But
In particular, the use of the phosphoric acid ester-based dispersant dramatically improves the elongation rate of the sheet and further provides physical properties with high flexibility, so that it is possible to advantageously improve the folding property and the folding property. is there.

And, such a phosphoric acid ester-based dispersant is
0.5 to 100 parts by weight of the ceramic raw material powder
It will be compounded in a proportion of 5 parts by weight, but if the compounding amount is less than 0.5 parts by weight, the plasticity and flexibility of the obtained sheet will be impaired, and the elongation rate will decrease in terms of characteristics, This causes a problem of poor foldability. On the other hand, when the compounding amount of the dispersant exceeds 5 parts by weight, the elongation rate is not adversely affected, but the elongation rate is not improved in proportion to the compounding amount. However, the properties and handling properties of the green sheet, for example, the strength and feel of the waist, shape retention, workability, etc. will be deteriorated, and, as in the case of increasing the amount of the plasticizer, the firing step There is a problem in that it is necessary to add a preliminary heat treatment step to perform degreasing and the like.

By the way, according to the present invention, in order to obtain a slurry for producing the desired foldable ceramic green sheet, the polyvinyl butyral resin and the plasticizer as described above are added to a predetermined ceramic raw material powder. By mixing a phosphate ester dispersant in a predetermined ratio and further adding an organic solvent to uniformly mix and disperse, a slurry that can be used in the doctor blade method is prepared. As the organic solvent, known ones for preparing ceramic slurries can be appropriately selected and used, and examples thereof include alcohol solvents such as ethanol and butanol, aromatic solvents such as toluene and xylene, acetone, and methyl ethyl ketone. Ketone solvents such as, in a single system or in a mixed system, Need is it to become. The amount of the organic solvent used is appropriately determined so that the viscosity or fluidity of the obtained slurry is suitable for sheet formation by the doctor blade method.

If necessary, the slurry thus prepared may be added with antistatic agents, defoaming agents, and additives such as colorants, pigments, and frits, and the folding characteristics of the resulting ceramic green sheet. It is also possible to add or contain it as long as it does not adversely affect.
In particular, by adding a colorant, a pigment, or a frit, it is possible to obtain a fired product made of a colored ceramic sheet whose base is colored without using a glaze or a glaze.

Further, according to the present invention, the slurry prepared as described above is used to form a sheet by the doctor blade method. Such a doctor blade method is used in the present invention. Since the foldable ceramic green sheet intended for (1) has a thin thickness of 0.05 mm to 0.5 mm, it brings a great advantage. That is, a green sheet having a sheet thickness of 0.5 mm or less is produced by the doctor blade method because a thin sheet can be formed with good productivity and mass production, cost reduction, and quality improvement can be realized. For this purpose, the doctor blade method is effective, which makes it possible to obtain a green sheet having high productivity, good production yield, and good quality at a low production cost.

Next, the sheet-like material obtained by forming the slurry according to the present invention into a sheet by the doctor blade method is
Normal drying or 50 ℃ instead of normal high temperature drying operation
The following low-temperature drying operation is performed to finish the green sheet in which volatile components remain so that the weight loss after heating and drying at 150 ° C. for 5 hours is 5% or more. Here, the plasticity or flexibility of the sheet giving effective folding properties and folding properties is determined by the residual amount of the polyvinyl butyral resin and the plasticizer or the phosphate ester-based dispersant after the sheet is dried, and In order to secure such excellent properties, it is necessary to appropriately suppress the scattering of easily volatilized organic solvents, plasticizers, and dispersants. Therefore, 150 ° C x 5 specified in the present invention
In order to achieve a weight loss of 5% or more after heat-drying for a period of time, it is necessary to employ natural drying or low-temperature drying at 50 ° C. or lower, and in general, the drying wind speed is 1. Drying operation is preferably adopted under conditions of 0 m / sec or less and a dry humidity of 20% or more, and among them, windless low temperature drying, particularly natural drying, is advantageously used as one of the simplest methods. Become.

In the drying operation of such a sheet material, when a high temperature heating and drying operation at a drying temperature of more than 50 ° C. is adopted, the speed of scattering of the solvent and volatile components from the sheet material is high. The above mentioned weight loss is 5%
Residual amount of organic volatile substances (residual amount)
It becomes difficult to secure the above-mentioned property, and thus it becomes difficult to obtain sufficient plasticity or flexibility for exhibiting excellent bending properties and folding properties. In addition, the rapid drying operation makes the scattering rate of the volatile components from the sheet-like material faster, reduces the elongation rate of the sheet, and makes it difficult to maintain effective flexibility.

The foldability and foldability of the green sheet are determined mainly by the blending amount of polyvinyl butyral resin and the remaining amount of volatile components (solvent, dispersant, plasticizer, etc.). One such sheet
The weight loss after heating and drying under the condition of 50 ° C. × 5 hours is expressed as the weight loss. By making the weight loss to be 5% or more, excellent bending properties and folding properties can be exhibited. is there. Therefore, the weight reduction is 5
In the case of a green sheet that is lower than%, when it is folded, bent, or folded back, cracks, cracks, chips, breaks, etc. occur, and even after firing, from the bent portion or folded portion, This causes problems such as cracking. Further, increasing the value of the above-mentioned weight reduction of the green sheet leads to increasing the residual amount of the volatile component in the sheet, but when the residual amount of such a volatile component increases, Although the flexibility of the sheet can be remarkably increased, the shape retention of the bent processed product is poor, which causes problems such as deterioration of the shape of the fired product obtained by firing. It is desirable that the upper limit of the decrease is about 10% or less, preferably about 9% or less.

By the way, as described above, the green sheet in which the volatile components (solvent, dispersant, plasticizer) are allowed to remain in a predetermined ratio also has excellent bendability and foldability which are the objects of the present invention. In order to obtain it, the thickness will be 0.05 mm to 0.5 mm. When the thickness of this green sheet exceeds 0.5 mm, 18
This is because it is difficult to bend or fold it at 0 degree, and the foldability is deteriorated, and it is practically difficult to obtain a green sheet thinner than 0.05 mm. In the thickness between 0.05 mm and 0.5 mm, the thickness of the green sheet is appropriately determined according to the intended use of the green sheet. For example, an origami sheet when folding a paper crane or the like. When used as a product, a thickness of 0.1 mm or less, or a thickness of about 0.1 mm to 0.2 mm is selected.
A thickness of ~ 0.5 mm is selected, and in the case of making small objects, from the viewpoint of strength and shape retention, the thickness is thin, for example 0.1 mm or less. Will be preferably adopted.

The green sheet thus obtained is constructed so that its elongation is 200 to 400% and its tensile strength is 1 to 20 kg / cm ^2. It is desirable that, in addition to excellent bendability and foldability, high shape retention is secured, and it is possible to advantageously perform processing and work of crafts. The origami and crafts can be given a precise shape, and their aesthetics can be effectively enhanced.

The elongation percentage (%) of the green sheet is obtained by dividing the sum of the length and the elongation amount of the dumbbell-shaped test piece by the length of the test piece in the tensile test. It is obtained by multiplying the value obtained by 100, and when the value is less than 200%, it becomes difficult to bend or fold, and there is a problem that cracks easily occur, while it exceeds 400%. In such a case, although the bending / folding property is good, the shape retention property and the tensile strength are lowered and the material is easily deformed, which causes a problem in processing and crafting of the craft.

Further, even if the tensile strength of the green sheet is a small value of less than 1 kg / cm ² , the shape retention property, in other words, the ability to hold the finished shape, is deteriorated and the green sheet is It causes a problem that it is difficult to maintain the work used and the imparted modeling shape. On the other hand, when the tensile strength is increased, the shape retention is improved, which is advantageous for manufacturing, but too large tensile strength It is desirable to keep the tensile strength at 20 kg / cm ² or less, since it will adversely affect the bending and folding properties.

The green sheet thus obtained can be bent up to a bending angle of 180 ° (R = 0), and can be further bent 360 ° to the opposite side.
Even if this is repeated multiple times, cracks and chips do not occur, and even if it is further fired, it does not cause defects such as cracks (cuts, cracks, cracks) from the bent parts and folded parts. As a ceramic green sheet or a ceramic paper that can be processed like paper, it is a useful sheet as a pottery material that can be suitably used for origami and paperwork.

In addition, the ceramic green sheet according to the present invention is used for the work obtained by origami processing and paperworking, in the same manner as in the conventional case, firing suitable for the ceramic raw material powder material constituting each sheet. The firing is performed in the atmosphere and the firing profile (the firing temperature and the firing time), so that a novel ceramic origami or ceramic craft having an excellent appearance can be advantageously formed.

[0030]

The present invention will be described in more detail below by showing examples of the present invention, but the present invention is subject to any restrictions due to the description of such examples. Not to mention that. In addition to the following embodiments, the present invention further includes various changes and modifications based on the knowledge of those skilled in the art, in addition to the above specific description, without departing from the spirit of the present invention. It should be understood that improvements and the like can be added.

Example 1 First, alumina powder (average particle size 0.5 μm) was used as the ceramic raw material powder, while polyvinyl butyral resin (PVB) was used as the binder, dioctyl phthalate (DOP) and dibutyl sebacate (D) were used as the plasticizer.
BS), sorbitan trioleate as a dispersant (ST
O) or a commercially available phosphoric acid ester-based dispersant: phosphanol RE-610 (RE-610: Toho Chemical Industry Co., Ltd.) and toluene / ethanol = 7/3 mixed solvent (M-SOL) as a solvent, respectively. Slurries for doctor blades were prepared by uniformly mixing and dispersing them at the blending ratios shown in Table 1.

[0032]

[Table 1]

Then, each of the thus-obtained slurries was formed into a sheet by a doctor blade method according to a conventional method, and then naturally dried and / or low temperature dried at 50 ° C. or lower to carry out volatile component removal. Various green sheets having different residual ratios were obtained in the thicknesses shown in Table 2 below.

The elongation (%) and tensile strength (kg / cm ² ) of the various green sheets thus obtained were determined, and the residual amount of volatile components was determined for each green sheet. The weight reduction rate (%) after being subjected to a heat drying operation of 150 ° C. × 5 hours [= (weight before drying−weight after drying) × 100 / weight before drying] was evaluated, and each result is shown in Table 2 below. It was shown to.

The various green sheets thus obtained were each subjected to a bending test at 180 degrees, and those having extremely good bending properties were marked with ⊚, those with good bending properties were marked with ○, and cracks in the bending test. In addition to the evaluation with ×, the folded paper crane or turtle was folded from each green sheet and the origami workability was evaluated. The green sheet that could not be folded was marked with x, and the results are also shown in Table 2 below.

Further, regarding the prototype obtained by folding the origami crane (turtle) in such a manner, in an oxidizing atmosphere,
Firing was carried out at a firing temperature of 1560 ° C. Among the obtained fired products, ○ was given for good fired products retaining their initial shape, and Δ for those whose initial shape was slightly broken.
The results are also shown in Table 2 below.

[0037]

[Table 2]

As is clear from the results shown in Tables 1 and 2, the ceramic green sheet has a large thickness (Sample No. 5), or a dispersant other than the phosphate ester type is used (Sample No. 8). In such a case, sufficient folding characteristics cannot be imparted, which makes it difficult to carry out origami processing of cranes and turtles, whereas sample No. The green sheets 1 to 4 and 6 and 7 had excellent bending properties of 180 degrees, and it was possible to make a folded crane (turtle) on a trial basis. Sample No. 7
In the green sheet of, the polyvinyl butyral resin, the plasticizer, and the phosphoric acid ester-based dispersant were blended in a large amount, so that the green sheet had excellent flexibility. We admitted that it was inferior to the folded crane (turtle) prototype obtained from the sheet.

Example 2 Sample No. 1 of Example 1 A sheet-like material was formed by the doctor blade method using the common slurry in 2 to 5, and the obtained sheet-like material was air-dried or air-dried at a low temperature of 50 ° C. for 1 hour. A combination of drying, or a heat drying operation of 130 ° C x 30 minutes,
Ceramic green sheets having various sheet thicknesses with different residual volatile components were obtained.

Then, for each of the various ceramic green sheets thus obtained, the weight reduction rate (%) after heating and drying at 150 ° C. for 5 hours was obtained, and a 180 ° bending test was conducted to evaluate the quality of the bending characteristics. The results are also shown in Table 3 below.

[0041]

[Table 3]

As is clear from the results shown in Table 3, the sample No. subjected to the high temperature drying operation was used. The green sheets of 11 and 13 had a small amount of residual volatile components, and therefore the bendability was impossible, and defects such as cutting and chipping of the green sheets occurred in the 180-degree bending test. On the other hand, the sample No. The weight reduction rate is 5% for 9, 10 and 12 green sheets
As described above, it was able to withstand a bending process of 180 degrees.

Example 3 Sample No. 1 in Example 1 Under the same conditions as in 2, the phosphoric acid ester-based dispersant alone was used as another commercial product [Toho Chemical Industry Co., Ltd., phosphanol RS-710,
In place of RH-610H or RS-610CS (both are mixtures consisting of phosphoric acid monoester, diester and a trace amount of triester), a 0.1 mm-thick green sheet was produced by the doctor blade method, and the obtained sheet was obtained. As a result of performing a bending test on each of the various green sheets, it was confirmed that all of them had good folding characteristics, and it was confirmed that the sheets can be suitably used for origami processing and paperwork.

Example 4 Sample No. 1 of Example 1 After adding 3 parts by weight of a pigment (chromium oxide or cobalt carbonate) or a commercially available pigment or glaze to the slurry used in Nos. 2 to 5 to make a uniform mixture, the same procedure as in Example 1 was conducted. After being formed into a sheet by the doctor blade method, it is naturally dried or at 50 ° C.
Various colored green sheets were manufactured by performing the following low temperature drying.

Next, a 180-degree bending test was carried out using the various colored green sheets thus obtained, and it was confirmed that all of the green sheets had excellent bending characteristics. In addition, each green sheet was
When baked at a temperature of 60 ° C., it became clear that a color ceramic sheet of red, blue or pink could be obtained.

[0046]

As is apparent from the above description, according to the method for manufacturing a foldable ceramic green sheet according to the present invention, it is possible to fold up to a bending angle of 180 degrees, and further to the opposite side 360. Bend it once
Even when repeating such a folding operation a plurality of times, a ceramic green sheet that does not generate cracks or chips and has excellent bending properties and folding properties can be produced with good productivity.
Moreover, even if such a ceramic green sheet is fired, it is also possible to prevent cracks from being generated from the bent portion and the folded portion of the ceramic green sheet. By firing the work that has been subjected to such processing, it is possible to advantageously provide ceramic origami and ceramic crafts with excellent aesthetics.

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Claims (2)

[Claims] 1. A polyvinyl butyral resin in an amount of 5 to 20 parts by weight per 100 parts by weight of the ceramic raw material powder,
1 to 20 parts by weight of a plasticizer and 0.5 to 5 parts by weight of a phosphoric acid ester-based dispersant are mixed, and an organic solvent is further added,
The slurry obtained by uniformly mixing and dispersing is used to form a sheet by the doctor blade method, and then natural drying or low temperature drying at 50 ° C. or lower is performed, and the weight loss after heating drying at 150 ° C. × 5 hours is 5 % To obtain a foldable ceramic green sheet, which is obtained as a green sheet having a thickness of 0.05 mm to 0.5 mm in which volatile components remain. 2. The green sheet is 200-400.
The method for producing a foldable ceramic green sheet according to claim 1, which has an elongation percentage of 1% and a tensile strength of 1 to ²⁰ kg / cm ² .