JP2015024645A - Ceramic extrusion molding, method of producing the molding, ceramic fired body and method of producing the fired body - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a ceramic extrusion molding reduced in dents and protrusions of the surface, a method of producing the molding, a ceramic fired body and a method of producing the fired body.SOLUTION: A method of producing a ceramic extrusion molding (9) uses a clay mainly based on a ceramic powder and comprises forming a ceramic extrusion intermediate product (1) by extrusion molding and drying the ceramic extrusion intermediate product (1) to form the ceramic extrusion molding (9). The ceramic extrusion intermediate product (1) is laid on a plurality of rollers (5), and, while the rollers (5) are rotated to rotate the ceramic extrusion molding (9), warm air is blown to the ceramic extrusion intermediate product (1) to dry. In drying, the rollers (5) applied with a non-aqueous organic solution on the surface are used.

Description

  The present invention relates to a ceramic extrusion-molded body and a manufacturing method thereof, and a ceramic fired body and a manufacturing method thereof, which are used for ceramic filters and the like used for exhaust gas purification and solid-liquid separation.

  Conventionally, when drying a long (before firing) ceramic molded body made of clay or the like, two rollers that rotate the ceramic molded body in the same direction in order to suppress warping after drying. Rotational drying is effective in that it is placed in between and dried while rotating (see Patent Documents 1 and 2).

  Moreover, it is disclosed that a coat layer is formed with Teflon (registered trademark) on two roller surfaces on which a ceramic molded body is rotationally dried, and a roller having excellent releasability on the roller surface is used (patent). Reference 2).

JP 2003-26466 A JP 2006-205526 A

  However, when the ceramic molded body is rotationally dried, a part of the clay on the surface of the ceramic molded body may adhere to the roller. For this reason, a dent is generated on the surface of the ceramic molded body, or the deposit is pressed against another part of the ceramic molded body (the surface of the molded body). In some cases, it may stick to the surface of the molded body to form protrusions, resulting in defects in appearance.

  In addition, when a coat layer is provided on the roller surface with Teflon (registered trademark), unexpected unevenness due to wear or crack of the coat layer may occur due to repeated drying. Furthermore, the wear of the coating layer may cause the two rollers to be out of parallel, and the ceramic molded body may be deformed.

  Further, when a ceramic molded body is used as a support for a ceramic filter, a separation membrane is formed on the surface of the support. However, if the irregularities on the surface of the molded body are large, defects may occur in the separation membrane.

  This invention is made | formed in view of such a problem, and it aims at providing the ceramic extrusion-molding body with few dents and protrusions on the surface, its manufacturing method, a ceramic sintered body, and its manufacturing method.

  (1) In the present invention, as a first embodiment (a method for producing a ceramic extrusion molded body), a ceramic extrusion intermediate is produced by extrusion molding using clay mainly composed of ceramic powder, and then the ceramic extrusion intermediate In a method for producing a ceramic extruded body, the ceramic extruded intermediate is placed on a plurality of rollers, and the ceramic extruded intermediate is rotated by rotating the rollers. At the same time, the ceramic extrusion intermediate is dried by blowing hot air, and the roller having a water-insoluble organic solution applied on the surface is used for the drying.

  In the first aspect, the ceramic extrusion intermediate formed by extrusion molding is placed on a plurality of rollers, the ceramic extrusion intermediate is rotated by rotating the rollers, and the ceramic extrusion intermediate is rotated during the rotation. A hot air is blown onto the surface to dry, and a roller having a water-insoluble organic solution applied to the surface is used for the drying.

  In other words, since the surface of the roller is covered with a non-water-soluble organic solution such as wet lubricating oil (different from the water used for clay), even if the roller and the ceramic extrusion intermediate are in contact, Part of the surface clay of the ceramic extrusion intermediate is difficult to peel off and adhere to the roller.

  Therefore, it is possible to suppress the formation of dents on the surface of the ceramic extrusion intermediate due to the peeling of the clay, and the deposits on the roller may form dents on other parts of the molded product surface, or the deposits may stick to the surface. As a result, it is possible to suppress the occurrence of protrusions, so that the occurrence of defects in appearance can be reduced. As a result, a ceramic extruded body can be produced with a high yield.

  Moreover, in the first aspect, unlike the case where a roller having a coat layer formed of Teflon (registered trademark) is used, there is no fear of unevenness due to wear or peeling of the coat layer or parallel shift due to wear. There is an advantage that a ceramic extruded body with less surface irregularities and excellent dimensional accuracy can be produced.

  Moreover, in this 1st aspect, since the unevenness | corrugation of the surface of a ceramic extrusion molding is small, when using a ceramic extrusion molding (specifically the sintered body) as a support body of a ceramic filter, it forms on the surface of a support body. There is an effect that defects are hardly generated in the separation membrane.

That is, in the first aspect, since the surface of the ceramic extruded body (and hence the fired body) is smooth, there is an effect that it is difficult to cause film defects during film formation.
(2) The present invention is characterized in that, as a second aspect, the temperature of the warm air is not higher than the boiling point of the water-insoluble organic solution applied to the roller.

  In the second aspect, since the temperature of the hot air is not higher than the boiling point of the water-insoluble organic solution applied to the roller, the water-insoluble organic solution is difficult to volatilize during the hot-air drying and is sufficiently moistened. An effect is obtained. That is, even during drying, the surface of the roller is sufficiently covered with the water-insoluble organic solution, so that the surface clay of the ceramic extrusion intermediate does not easily adhere to the roller.

(3) The present invention is characterized in that, as a third aspect, the maximum height roughness Rz of the concavo-convex portion found on the surface of the ceramic extruded body is 30 μm or less.
In the third aspect, since the maximum height roughness Rz of the uneven portion on the surface of the ceramic extruded body is 30 μm or less, the unevenness on the surface is small.

Here, the maximum height roughness Rz is measured in accordance with JISB0601 2013.
Therefore, when manufacturing a ceramic filter, there is an advantage that membrane defects (such as pores in the membrane) are less likely to occur when a separation membrane is formed on the surface of a ceramic extruded body (and thus a fired body).

The maximum height roughness Rz between the ceramic extruded body and the fired body is substantially the same.
(4) As a fourth aspect of the present invention, the clay includes at least four kinds of the ceramic powder, an organic binder, an aqueous solvent, and a water-insoluble organic solution solvent.

The fourth aspect exemplifies a material preferable as a clay material.
(5) In the present invention, as a fifth aspect, the clay includes 5 to 20 parts by weight of an organic binder, 10 to 40 parts by weight of an aqueous solvent, and a water-insoluble organic solution with respect to 100 parts by weight of the ceramic powder. Includes 0.5 to 20 parts by weight.

The fifth aspect exemplifies a preferable composition as a clay material. Thereby, extrusion molding can be suitably performed without causing cracks or deformation.
Specifically, in the fifth aspect, since the organic binder is 5 parts by weight or more, it is easy to crease, and since it is 20 parts by weight or less, the addition amount of the organic binder is moderate, and after firing A suitable porous body having a predetermined pore diameter can be obtained. Moreover, since an aqueous solvent is 10 weight part or more, an organic binder can fully melt | dissolve, and since it is 40 weight part or less, clay has moderate hardness and sufficient moldability. Further, since the water-insoluble organic solution is 0.5 parts by weight or more, a sufficient wetting effect is obtained at the time of extrusion, and since it is 20 parts by weight or less, the wetting effect is moderate, and the clay after passing through the mold High adhesiveness is preferable.

  In particular, in the case of clay having the above-described composition, extrusion can be suitably performed. However, when performing rotary drying on a roller, the clay easily adheres to the roller. When manufacturing a ceramic extruded body, it is preferable to use a roller having a surface coated with a water-insoluble organic solution because the above-described excellent product can be obtained.

(6) As a sixth aspect of the present invention, the water-insoluble organic solution contained in the clay and the water-insoluble organic solution applied to the roller are the same type of solution.
In the sixth aspect, since the water-insoluble organic solution contained in the clay and the water-insoluble organic solution applied to the roller are the same type of solution, the work process can be simplified, and different solutions are used. It is possible to prevent unexpected reactions.

(7) As a seventh aspect of the present invention, the temperature of the hot air is 35 ° C to 80 ° C.
In the seventh aspect, since the temperature of the hot air is 35 ° C. or higher, the drying rate is high and it is 80 ° C. or lower, so that the water-insoluble organic solution is hardly volatilized and a sufficient wetting effect is obtained.

(8) The present invention, as an eighth aspect, is characterized in that the ceramic extruded body is a long shaped body having a dimension in the axial direction longer than a dimension in the radial direction.
The eighth aspect exemplifies a preferable shape of the ceramic extruded body (for example, a long shaped body such as a cylindrical shape).

  (9) In the present invention, as a ninth aspect, the ceramic extruded body has at least one or more through holes formed in the longitudinal direction, and the shape thereof is a tube shape, a honeycomb shape, or a monolith shape. It is characterized by being.

  The ninth aspect exemplifies a preferable shape of the ceramic extruded body. Here, the honeycomb shape indicates a honeycomb shape with a thin wall surface (for example, the cross-sectional area of the wall surface is less than 1/2 of the total cross-sectional area), and the monolith shape indicates a lotus shape with a thick wall surface (for example, The cross-sectional area of the wall is 1/2 or more of the total cross-sectional area).

In addition, as a cross-sectional shape of the through hole (a cross section perpendicular to the longitudinal direction), a circular shape, an elliptical shape, and a polygonal shape can be given.
(10) As a tenth aspect, the present invention is characterized in that the ceramic extruded body dried by the warm air is further post-dried at a temperature higher than the temperature at the time of drying.

  The ceramic extruded body that is rotationally dried by a roller is dried at a relatively low temperature (for example, 35 to 80 ° C.) so that the water-insoluble organic solution does not volatilize. In some cases, the moisture in the ceramic extrusion may not be removed sufficiently.

  Therefore, in the present tenth aspect, since the ceramic extruded body dried by hot air (on the roller) is further post-dried at a temperature higher than the temperature at the time of drying, sufficient moisture is retained in the ceramic extruded body. Can be removed.

Therefore, when firing thereafter, defects such as cracks are unlikely to occur, which is preferable.
(11) The present invention is an eleventh aspect (ceramic extrusion molding) obtained by the method for producing a ceramic extrusion molding according to any one of the first to tenth aspects. .

Since the ceramic extruded body of the eleventh aspect is obtained by the above-described manufacturing method, there are few surface depressions and protrusions on the surface, and there are few appearance problems.
In addition, since the unevenness of the surface of the ceramic extruded body (and thus the fired body) is small, when the fired body is used as a support for a ceramic filter, there is an effect that a defect is hardly generated in the separation film on the surface of the support. .

  (12) In the present invention, as a twelfth aspect (a method for producing a ceramic fired body), the ceramic extrudate is produced by the method for producing a ceramic extrudate according to any one of the first to tenth aspects. Thereafter, the ceramic extruded body is fired to produce a ceramic fired body.

According to the twelfth aspect, a ceramic fired body with few surface depressions and protrusions and few defects in appearance can be obtained.
(13) The present invention is the thirteenth aspect (ceramic fired body) obtained by the method for producing a ceramic fired body according to the twelfth aspect.

  Since the ceramic fired body of the thirteenth aspect is obtained by the manufacturing method described above, the surface of the fired body has small irregularities. Therefore, when the fired body is used as a support for a ceramic filter, there is an effect that defects are hardly generated in the separation membrane on the surface of the support.

Hereinafter, each configuration of the present invention will be described.
-As an apparatus used for the said extrusion molding, a screw type extruder, a plunger type extruder, etc. are mentioned, for example.
-As a ceramic which is a material of a ceramic extrusion molding, an alumina, a cordierite, etc. are mentioned, for example. When this alumina or cordierite is used, it can be fired at 1000 to 1600 ° C. Moreover, the glass type inorganic binder containing a silica and an additive can be added as a sintering auxiliary agent.

-As the water-insoluble organic solution, an oil for lubricating oil different from water can be used. Further, for example, fatty acids, fatty acid esters, higher alcohols and the like can be used, and a solution having a kinematic viscosity of about 30 to 100 mm ² / s can be used.

As fatty acids, butyric acid, oleic acid, linoleic acid, linolenic acid, caprylic acid, isostearic acid, fatty acid esters as methyl laurate, myristic acid methyl ester, octyl palmitate, isopropyl myristate, butyl stearate, Examples of the higher alcohol include oleyl alcohol, ralyl alcohol, isostearyl alcohol, hexyl decanol, octyl decanol, and decyl tetradecanol.
-There is no particular limitation on the coating amount of the water-insoluble organic solution, and it is sufficient that the roller surface (the surface in contact with the ceramic extrusion intermediate) is wetted with the water-insoluble organic solution (clay). Does not stick to the roller).

  The water-insoluble organic solution applied to the roller is preferably the same material as the water-insoluble organic solution added to the clay, but may be different.

3 is an explanatory view showing a method for producing a ceramic extruded body of Example 1. FIG. It is explanatory drawing which shows the structure of the rotary dryer used for manufacture of the ceramic extrusion molding of Example 1. FIG. FIG. 3 is a perspective view showing a part (ceramic layer) of the ceramic filter of Example 1 in a broken state. It is a perspective view which shows the structure of the various through-holes of a ceramic extrusion molding.

  Hereinafter, examples of the ceramic extruded body and the manufacturing method thereof according to the present invention will be described with reference to the drawings.

a) First, the manufacturing method of the ceramic extrusion molding of a present Example is demonstrated.
As a raw material (clay material) of a ceramic extruded body, 100 parts by weight of alumina, 25 parts by weight of borosilicate glass frit, 10 parts by weight of methyl cellulose, 20 parts by weight of water, and a mixed liquid (kinematic viscosity; 5 parts by weight of 60 mm ² / s, boiling point: 280 ° C. (at 760 mmHg) was prepared.

The fatty acid ester compound is specifically a neopentyl type polyol fatty acid ester.
Next, this mixed solution was mixed and kneaded with a mixer to obtain clay for a ceramic extruded body.

Next, a mold having an outer diameter of φ13 mm and an inner diameter of φ9 mm was attached to a known screw-type extruder, and extrusion was performed using the clay for the ceramic extruded body.
Next, as shown in FIG. 1A, the molded body obtained by the extrusion molding was cut so as to have a total length of 550 mm, and a cylindrical ceramic extruded intermediate 1 was obtained.

Further, as shown in FIG. 1 (b), a mixed liquid (kinematic viscosity: 60 mm ² / s, boiling point: 280 ° C. (at 760 mmHg)), the main component of which is a fatty acid ester compound, is soaked into a cloth (cloth). Using a waste cloth, the mixed solution was applied evenly on the surfaces of rollers 5a and 5b (collectively referred to as 5) of the rotary dryer 3.

  The fatty acid ester compound is the same as that added as a clay material. Further, the mixed liquid is a lubricating solution in which clay is less likely to adhere to the roller 5 than water, and various hydraulic oils (synthetic lubricating oils) marketed as neopentyl polyol fatty acid esters can be used. . For example, NOF Corporation Unistar (registered trademark) can be used.

  Here, the rotary dryer 3 will be described. As shown in FIG. 2, the rotary dryer 3 used in this embodiment includes a plurality of (here, two) rollers 5 arranged horizontally and in parallel, This is a well-known drying device including a burner 7 that blows hot air onto the ceramic extrusion intermediate 1 placed on the roller 5.

Among these, the roller 5 is, for example, a metal cylinder such as iron, and can be rotated at the same rotational speed in the same direction (arrow A direction) by a driving device such as a motor or a chain (or belt) (not shown). It is configured to be able to.
Next, returning to FIG. 1 (c), the ceramic extruded intermediate 1 was placed on the roller 5 coated with the mixed solution in the same long direction.

Next, as shown in FIG.1 (d), the ceramic extrusion intermediate body 1 is rotated in the arrow B direction by rotating the roller 5 in the arrow A direction.
And in this state, the hot air was sprayed from the burner 7 to the ceramic extrusion intermediate body 1, and it dried. Specifically, drying was performed for 1 hour under a warm air stream of 50 ° C. within a temperature range of 35 to 80 ° C., for example.

  Next, after rotary drying, using a warm air dryer (not shown) set at 80 ° C. higher than the temperature at the time of rotary drying (for example, 50 ° C.), it is dried for 24 hours (post-drying) to completely remove moisture. Removal was performed to obtain a dried product (not shown).

Next, as shown in FIG.1 (e), after cooling this dry body, the cut trace part of both ends was excised and finished to 500 mm in total length. As a result, a ceramic extruded body 9 was obtained.
And when the surface of this ceramic extrusion molding 9 was investigated using the magnifier, the surface was smooth without a big protrusion and a hollow.

Next, as shown in FIG.1 (f), the ceramic extrusion molding 9 was baked at 1200 degreeC for 2 hours under atmospheric airflow. Thereby, a ceramic fired body (sintered body) 11 was obtained.
Then, when the surface of the ceramic fired body 11 was examined using a magnifying glass, the surface was smooth with no large protrusions and dents, and was a porous body having an average pore diameter of 1.80 μm with a good appearance. .

  Moreover, this ceramic fired body 11 was evaluated by the maximum height roughness Rz by a straight needle type surface roughness meter. Specifically, the roughness measurement is performed by cutting the (cylindrical) ceramic fired body 11 into a length of 10 mm in the axial direction, and further dividing into four in the cross-sectional direction (that is, four when viewed from the axial direction). Individual pieces were cut out (divided into four so as to have the same shape), and in accordance with JISB0601 2013, the surface of the individual pieces (the surface other than the cut surface) was cut under the condition of a cutoff wavelength of 0.08 mm. As a result, the maximum height roughness Rz of the concavo-convex portion that could be slightly confirmed on the surface was 3 μm.

  Note that the surface shape of the ceramic extruded body 9 and the surface shape of the ceramic fired body 11 are substantially the same, and therefore the maximum height roughness Rz of the uneven portion of the ceramic extruded body 9 is also 3 μm.

b) Next, a method for manufacturing a ceramic filter using the ceramic fired body 11 will be described.
As partly broken and shown in FIG. 3, the ceramic filter 13 is obtained by forming a separation membrane 15 as a thin ceramic layer on the surface of a ceramic fired body 11 as a support.

The procedure for manufacturing the ceramic filter 13 is as follows.
First, an alumina slurry comprising 100 parts by weight of alumina, 2 parts by weight of a dispersant, 10 parts by weight of a water-soluble binder, and 200 parts by weight of water is prepared.

Next, using this alumina slurry, a slurry film was formed (formed) on the surface of the ceramic fired body 11 by dip coating.
Next, the formed ceramic fired body 11 was dried with hot air at 60 ° C. to dry the slurry film.

  Next, the fired ceramic body 11 provided with the dried film was fired at 1200 ° C. for 1 hour under an air current. As a result, a ceramic filter 13 provided with a separation membrane 15 (which is an alumina membrane) having a thickness of 50 μm was obtained.

And when this ceramic filter 13 was evaluated for the maximum pore diameter of the separation membrane 15 by the bubble point method, it was 0.28 μm.
c) Next, the effect of the present embodiment will be described.

  In this example, the ceramic extruded intermediate 1 formed by extrusion molding is placed on a plurality of rollers 5, the ceramic extruded intermediate 1 is rotated by rotating the rollers 5, and during the rotation, The ceramic extrusion intermediate 1 is dried by blowing warm air, and when the drying is performed, a roller 5 having a surface coated with a liquid mixture mainly composed of the above-described fatty acid ester compound that is a water-insoluble organic solution is used. Use.

  That is, since the surface of the roller 5 is covered with a wet mixed liquid (different from the water used for clay), even if the roller 5 and the ceramic extruded intermediate 1 are in contact with each other, the ceramic extruded intermediate 1 A part of the surface clay is difficult to peel off and hardly adhere to the roller 5.

  Therefore, it can suppress that a dent arises in the surface of the ceramic extrusion intermediate body 1 by peeling of clay, and the deposit | attachment on the roller 5 forms a dent in the other location of the molded object surface, or an deposit | attachment is the surface. Since it is possible to suppress sticking to a protrusion, it is possible to reduce the occurrence of defects in appearance. As a result, the ceramic extruded body 9 (and hence the ceramic fired body 11) can be manufactured with a high yield.

  In this embodiment, since the unevenness of the surface of the ceramic extruded body 9 is small, when the ceramic extruded body 9 (specifically, the ceramic fired body 11) is used as the support of the ceramic filter 13, the surface of the support There is an effect that defects are hardly generated in the separation film 15 to be formed.

That is, in this embodiment, since the surface of the ceramic extruded body 9 (and hence the ceramic fired body 11) is smooth, there is an effect that it is difficult to cause film defects during film formation.
In addition, in this embodiment, the temperature of the hot air at the time of rotary drying is equal to or lower than the boiling point of the liquid mixture applied to the roller 5, so that the liquid mixture is difficult to volatilize at the time of hot air drying, and a sufficient wetting effect Is obtained. That is, even during drying, the surface of the roller 5 is sufficiently covered with the liquid mixture, so that the surface clay of the ceramic extruded intermediate 1 is less likely to adhere to the roller 5.

In the present example, the maximum height roughness Rz of the uneven portion on the surface of the ceramic extruded body 9 (and hence the ceramic fired body 11) is 30 μm or less, so the unevenness on the surface is small.
Therefore, when the ceramic filter 13 is manufactured, there is an advantage that film defects (such as film holes) are hardly generated when the separation film 15 is formed on the surface of the ceramic fired body 11.

  In this example, the clay is 5 to 20 parts by weight of the organic binder, 10 to 40 parts by weight of the aqueous solvent, and 0.5 to 20 parts by weight of the fatty acid ester compound (solution) with respect to 100 parts by weight of the ceramic powder. Since it is the range of a part, extrusion molding can be performed suitably.

  In this embodiment, since the fatty acid ester compound contained in the clay and the fatty acid ester compound applied to the roller 5 are the same type of solution, the work process can be simplified and unexpectedly caused by using different solutions. Reaction can be prevented.

In this example, the temperature of the warm air during rotary drying is 35 ° C. to 80 ° C., so the drying rate is high, and the mixed solution is difficult to volatilize, so that a sufficient wetting effect is obtained.
In this embodiment, since the ceramic extruded product 9 dried by rotary drying is further post-dried at a temperature higher than the temperature at the time of rotary drying, the moisture in the ceramic extruded product 9 can be sufficiently removed. . Therefore, when firing thereafter, defects such as cracks are unlikely to occur, which is preferable.

  ・ In this example, there is no risk of unevenness due to wear or peeling of the coat layer or parallel displacement due to wear as in the case of using a roller with a coat layer formed of Teflon (registered trademark). There is an advantage that it is possible to manufacture a ceramic extruded body 9 with less unevenness and excellent dimensional accuracy.

  Next, the second embodiment will be described, but the description of the same contents as the first embodiment will be omitted or simplified. In addition, the number of each member is demonstrated using the number similar to Example 1. FIG.

a) First, a method for producing the ceramic extruded body 9 will be described.
Using the same clay as in Example 1, a mold having an outer diameter of φ13 and an inner diameter of φ9 was attached to a screw type extruder and extrusion molding was performed.

The difference from Example 1 is the compound applied to the surface of the roller 5.
And it cut | disconnected so that it might become full length 550mm, the ceramic extrusion intermediate body 1 was produced, and it dried with the rotary dryer 3. FIG.

Here, prior to rotary drying, a compound containing oleyl alcohol as a main component (kinematic viscosity: 66 mm ² / s, boiling point: 250 ° C. (20 hPa)) was impregnated into the waste and applied uniformly to the surface of the roller 5.

Next, the ceramic extruded intermediate body 1 rotated by the roller 5 was dried for 1 hour by warm air flow at 50 ° C.
After the rotary drying, it was kept for 24 hours with a warm air dryer set at 80 ° C. to completely remove moisture.

Next, after the dried body from which moisture had been removed was cooled, cut trace portions at both ends were excised and finished to a total length of 500 mm to obtain a ceramic extruded body 9.
Next, the ceramic extruded body 9 was fired at 1200 ° C. for 2 hours under an air stream to obtain a ceramic fired body 11.

The surface of the ceramic fired body 11 is a porous body having an average pore diameter of 1.80 μm that is smooth and free from large protrusions and depressions and has a good appearance.
Moreover, this ceramic fired body 11 was evaluated by the maximum height roughness Rz by a straight needle type surface roughness meter. Specifically, the roughness measurement is performed by cutting the (cylindrical) ceramic fired body 11 into a length of 10 mm in the axial direction, and further dividing into four in the cross-sectional direction (that is, four when viewed from the axial direction). Individual pieces were cut out (divided into four so as to have the same shape), and in accordance with JISB0601 2013, the surface of the individual pieces (the surface other than the cut surface) was cut under the condition of a cutoff wavelength of 0.08 mm. As a result, the maximum height roughness Rz of the concavo-convex portion that could be slightly confirmed on the surface was 3 μm.

b) Next, a method for manufacturing the ceramic filter 13 will be described.
First, an alumina slurry comprising 100 parts by weight of alumina, 2 parts by weight of a dispersant, 10 parts by weight of a water-soluble binder, and 200 parts by weight of water was prepared, and a film was formed on the surface of the ceramic fired body 11 by dip coating.

Next, after 60 ° C. hot air drying, firing was performed at 1200 ° C. for 1 hour under an air stream to obtain a ceramic filter 13 with an alumina membrane (separation membrane 15) having a thickness of 50 μm.
When the maximum pore diameter of the separation membrane 15 was evaluated for the ceramic filter 13 by a bubble point method, it was 0.30 μm.

  Also in the second embodiment, the same effects as in the first embodiment are obtained.

  Next, the third embodiment will be described. The description of the same contents as those of the first embodiment will be omitted or simplified. In addition, the number of each member is demonstrated using the number similar to Example 1. FIG.

a) First, a method for producing the ceramic extruded body 9 will be described.
Using the same clay as in Example 1, a mold having an outer diameter of φ13 and an inner diameter of φ9 was attached to a screw type extruder and extrusion molding was performed.

The difference from Example 1 is the compound applied to the surface of the roller 5.
And it cut | disconnected so that it might become full length 550mm, the ceramic extrusion intermediate body 1 was produced, and it dried with the rotary dryer 3. FIG.

Here, prior to spin drying, a compound containing oleic acid as a main component (kinematic viscosity: 50 mm ² / s, boiling point: 360 ° C. (under atmospheric pressure)) is soaked in the waste and applied to the surface of the roller 5 without unevenness. did.

Next, the ceramic extruded intermediate body 1 rotated by the roller 5 was dried for 1 hour by warm air flow at 50 ° C.
After the rotary drying, it was kept for 24 hours with a warm air dryer set at 80 ° C. to completely remove moisture.

Next, after the dried body from which moisture had been removed was cooled, cut trace portions at both ends were excised and finished to a total length of 500 mm to obtain a ceramic extruded body 9.
Next, the ceramic extruded body 9 was fired at 1200 ° C. for 2 hours under an air stream to obtain a ceramic fired body 11.

The surface of the ceramic fired body 11 is a porous body having an average pore diameter of 1.81 μm that is smooth and free from large protrusions and depressions and has a good appearance.
Moreover, this ceramic fired body 11 was evaluated by the maximum height roughness Rz by a straight needle type surface roughness meter. Specifically, the roughness measurement is performed by cutting the (cylindrical) ceramic fired body 11 into a length of 10 mm in the axial direction, and further dividing into four in the cross-sectional direction (that is, four when viewed from the axial direction) Individual pieces were cut out (divided into four so as to have the same shape), and in accordance with JISB0601 2013, the surface of the individual pieces (the surface other than the cut surface) was cut under the condition of a cutoff wavelength of 0.08 mm. As a result, the maximum height roughness Rz of the concavo-convex portion that could be slightly confirmed on the surface was 3 μm.

b) Next, a method for manufacturing the ceramic filter 13 will be described.
First, an alumina slurry comprising 100 parts by weight of alumina, 2 parts by weight of a dispersant, 10 parts by weight of a water-soluble binder, and 200 parts by weight of water was prepared, and a film was formed on the surface of the ceramic fired body 11 by dip coating.

Next, after 60 ° C. hot air drying, firing was performed at 1200 ° C. for 1 hour under an air stream to obtain a ceramic filter 13 with an alumina membrane (separation membrane 15) having a thickness of 50 μm.
When the maximum pore diameter of the separation membrane 15 was evaluated for the ceramic filter 13 by a bubble point method, it was 0.30 μm.

Also in the third embodiment, the same effects as in the first embodiment are obtained.
[Comparative example]
Next, although a comparative example is demonstrated, about the content similar to the said Example 1, the description is abbreviate | omitted or simplified. In addition, the number of each member is demonstrated using the number similar to Example 1. FIG.

a) First, a method for producing the ceramic extruded body 9 will be described.
Using the same clay as in Example 1, a mold having an outer diameter of φ13 and an inner diameter of φ9 was attached to a screw type extruder and extrusion molding was performed.

And it cut | disconnected so that it might become full length 550mm, the ceramic extrusion intermediate body 1 was produced, and it dried with the rotary dryer 3. FIG.
In this comparative example, unlike the above examples, the water-insoluble organic solvent is not applied to the surface of the roller 5, and the ceramic extruded intermediate 1 is dried for 1 hour in a hot air stream at 50 ° C. went.

  As a result, the clay of the ceramic extrusion intermediate 1 sticks to the surface of the roller 5 to form a dent, and the protrusions formed on the surface of the roller 5 (by the adhesion of the clay) are separated from the ceramic extrusion intermediate 1. It was transcribed at the location of and a dent was formed. Further, it was confirmed that the deposits on the surface of the roller 5 adhered to the ceramic extrusion intermediate 1 to form protrusions.

And after rotary drying, it kept with the warm air dryer set to 80 degreeC for 24 hours, and removed the water | moisture content completely.
Next, after the dried body from which moisture had been removed was cooled, cut trace portions at both ends were excised and finished to a total length of 500 mm to obtain a ceramic extruded body 9.

Next, the ceramic extruded body 9 was fired at 1200 ° C. for 2 hours under an air stream to obtain a ceramic fired body 11.
The surface of the ceramic fired body 11 was confirmed to have a dent of a size that can be confirmed with the naked eye. When the roughness was measured under the same measurement conditions as in the example, the maximum height roughness Rz of the dent was 43 μm. there were.

b) Next, a method for manufacturing the ceramic filter 13 will be described.
First, an alumina slurry comprising 100 parts by weight of alumina, 2 parts by weight of a dispersant, 10 parts by weight of a water-soluble binder, and 200 parts by weight of water was prepared, and a film was formed on the surface of the ceramic fired body 11 by dip coating.

Next, after 60 ° C. hot air drying, firing was performed at 1200 ° C. for 1 hour under an air stream to obtain a ceramic filter 13 with an alumina membrane (separation membrane 15) having a thickness of 50 μm.
When the maximum pore diameter of the separation membrane 15 was evaluated for the ceramic filter 13 by the bubble point method, it was 2.15 μm, and a value similar to the average pore diameter of the ceramic fired body 11 was obtained.

From this, it is surmised that the separation membrane 15 has a defect caused by a depression or protrusion of the ceramic fired body 11.
The characteristics of Examples 1 to 3 and Comparative Example described above are summarized in Table 1 below.

  As apparent from Table 1, in Examples 1 to 3, which are the scope of the present invention, the maximum height roughness Rz of the ceramic fired body 11 is 3 to 5 μm, and the surface is very smooth. Further, the maximum pore diameter of the alumina membrane (separation membrane) 15 is as small as 0.28 to 0.30 μm, which is preferable since no defects are observed.

  On the other hand, in the comparative example outside the scope of the present invention, the maximum height roughness Rz of the ceramic fired body 11 is 43 μm, which is not preferable because the surface is rough. Further, the maximum pore diameter of the alumina membrane (separation membrane) 15 is as large as 2.15 μm, which is not preferable because of defects.

As mentioned above, although the Example of this invention was described, this invention is not limited to the said Example, A various aspect can be taken.
For example, in Examples 1 to 3, as the ceramic extruded body, as shown in FIG. 4 (a), an example in which one through hole 21 is opened in the axial direction is given. As shown in FIG. 4B, a honeycomb type in which a large number of through-holes 23 surrounded by a thin wall are formed, or as shown in FIG. The present invention can be applied to a monolith type in which a plurality of through holes 25 are mentioned.

  In addition, as warm air (heated wind), the wind (for example, air) warmed from the surrounding environment temperature (for example, room temperature), for example, the wind warmed by various heating apparatuses other than a burner is mentioned.

DESCRIPTION OF SYMBOLS 1 ... Ceramic extrusion intermediate body 3 ... Rotary dryer 5, 5a, 5b ... Roller 7 ... Burner 9 ... Ceramic extrusion molding 11 ... Ceramic sintered body 13 ... Ceramic filter 15 ... Separation membrane 21, 23, 25 ... Through-hole

Claims (13)

In a method for producing a ceramic extruded body, using a clay mainly composed of ceramic powder, producing a ceramic extruded intermediate by extrusion, and then drying the ceramic extruded intermediate to produce a ceramic extruded molded body.
The ceramic extruded intermediate is placed on a plurality of rollers, the ceramic extruded intermediate is rotated by rotating the roller, and hot air is blown to the ceramic extruded intermediate to be dried,
And in the case of the said drying, the said roller which apply | coated the water-insoluble organic type solution on the surface is used, The manufacturing method of the ceramic extrusion-molding body characterized by the above-mentioned.   2. The method for producing a ceramic extruded body according to claim 1, wherein the temperature of the hot air is equal to or lower than a boiling point of a water-insoluble organic solution applied to the roller.   3. The method for producing a ceramic extruded body according to claim 1, wherein the maximum height roughness Rz of the uneven portion seen on the surface of the ceramic extruded body is 30 μm or less.   The clay according to any one of claims 1 to 3, wherein the clay includes at least four kinds of the ceramic powder, an organic binder, an aqueous solvent, and a water-insoluble organic solution solvent. A method for producing a ceramic extruded body.   The clay contains 5 to 20 parts by weight of an organic binder, 10 to 40 parts by weight of an aqueous solvent, and 0.5 to 20 parts by weight of a water-insoluble organic solution with respect to 100 parts by weight of the ceramic powder. The manufacturing method of the ceramic extrusion molding of Claim 4 characterized by the above-mentioned.   6. The ceramic extruded body according to claim 4 or 5, wherein the water-insoluble organic solution contained in the clay and the water-insoluble organic solution applied to the roller are the same type of solution. Method.   The method for producing a ceramic extruded body according to any one of claims 1 to 6, wherein the temperature of the warm air is 35 ° C to 80 ° C.   The method for producing a ceramic extruded body according to any one of claims 1 to 7, wherein the ceramic extruded body is a long shaped body having an axial dimension longer than a radial dimension. .   The ceramic extrudate has at least one or more through holes formed in a longitudinal direction, and the shape thereof is a tube shape, a honeycomb shape, or a monolith shape. A method for producing a ceramic extruded body.   The ceramic extrusion-molded body according to any one of claims 1 to 9, wherein the ceramic extrusion-molded body dried by the warm air is further post-dried at a temperature higher than the temperature at the time of drying. Method.   A ceramic extruded product obtained by the method for producing a ceramic extruded product according to any one of claims 1 to 10.   The ceramic extruded body is manufactured by the method for manufacturing a ceramic extruded body according to any one of claims 1 to 10, and then the ceramic extruded body is fired to produce a ceramic fired body. A method for producing a ceramic fired body.   A ceramic fired body obtained by the method for producing a ceramic fired body according to claim 12.

Images