JPH10194845A - Ceramic member and its production - Google Patents

Abstract

PROBLEM TO BE SOLVED: To produce a ceramic member having high mechanical strength, provided with porous bodies and bringing the optimum properties in the optimum parts in accordance with the use of the member. SOLUTION: This ceramic member consists of a dense ceramic body 10 and porous parts of three-dimensional network 20 formed in the prescribed parts of the dense ceramic body by sintering into one body without leaving a gap. It is produced as follows; three-dimensional network org. bodies are set at the desired positions in a metallic mold corresponding to the shape of the member to be produced and the mold is evacuated and then a ceramic slurry prepd. by uniformly mixing and dispersing ceramic powder, a thermosetting resin, a solvent and a dispersant is filled into the mold. Pressure is then applied to the inside of the mold and the slurry is hardened by heating the mold at a temp. at which the thermosetting resin polymerizes. The resultant hardened molded body is released from the mold and fired.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a ceramic member provided with a porous portion in a dense ceramic body, and a method of manufacturing the same.

[0002]

2. Description of the Related Art Conventionally, as a ceramic member having a porous portion, the strength, corrosion resistance,
Taking advantage of heat resistance, etc., there were ceramic filters and honeycombs.

[0003] In addition, dental implant materials, artificial bones,
Attempts have been made to make the contact surface with the bone porous in order to make the bond with the bone stronger in artificial joints and the like.

[0004] New bone is induced in the porous portion of the ceramic, whereby the connection with natural bone is strengthened, and loosening (loosening) which has conventionally occurred after implant implantation is eliminated. It is an effective means. For this reason, various techniques have been introduced to make porous ceramic biomaterials such as alumina, hydroxyapatite and zirconia used as implant materials. However, in general, the strength of the material itself is reduced by making it porous, so it is proposed to make the deep part dense for high load parts and make only the contact part with bone porous. It has become
In the case of artificial joints, a composite of a dense body and a porous body has been used, for example, by making the side fixed to the bone porous, and making the sliding portion dense.

[0005] As a method of obtaining a dense / porous composite ceramic, a method of separately producing a dense body and a porous body and bonding them using glass or the like, or a method using an organic material such as plastic powder or plastic fiber as a raw material. At the time of adjustment, it is dispersed in a ceramic raw material, and the raw material and the raw material of the ceramic simple substance are simultaneously press-formed, and the organic portion is oxidatively decomposed and disappeared by firing to obtain pores, and the porous portion and the dense portion are formed. There is a method of integrally sintering.

There is also a method in which a three-dimensional network-like organic substance is set in a mold by casting, and after firing, the organic portion is made to be porous by oxidizing and disappearing by drying and firing, and simultaneously sintered together with the dense portion. is there.

As another method, there has been proposed a method in which a dense ceramic body is first prepared, a slurry of the same quality mixed with an organic substance is applied thereto, and dried and sintered to obtain a dense and porous body.

[0008]

2. Description of the Related Art In a method in which a dense portion and a porous portion are separately manufactured and integrated with an adhesive such as glass, the strength is weakened because an intermediate layer is included between the dense portion and the porous portion. And there are drawbacks such as an increase in the number of work steps.

Further, the method of integrally molding the dense portion and the porous portion by pressing or the like can be applied to a simple-shaped product, but it is difficult to apply to a complicated-shaped product, and there is a limit to a shape which can be naturally applied.

Next, when a three-dimensional network organic material is set in a mold and a dense / porous composite ceramic is to be produced by casting, the three-dimensional network organic material is made porous. It is necessary to process the organic material by cutting or hot pressing etc. according to the shape of the part, and it takes a lot of effort to set the processed three-dimensional organic material inside the mold, and furthermore, Setting may be extremely difficult depending on the shape.

[0011] In addition, regarding the method of obtaining a dense and porous body by drying and sintering a homogeneous slurry in which an organic substance is mixed into a dense ceramic body, it is difficult to control the thickness of the porous body by this method. In addition, this method has a problem that distortion is easily generated at the boundary surface, and peeling and cracking at the boundary surface are observed by firing.

[0012]

Means for Solving the Problems In order to solve the above-mentioned problems of the prior art, the present inventors have made intensive studies and as a result, a manufacturing method using a thermosetting resin and a mold as described below has been described.
It has been found that a ceramic member can be obtained in which a three-dimensional mesh-like porous portion which is sintered integrally with the dense body without any gap is formed at a specific portion of the dense ceramic body.

That is, the present invention provides a novel ceramic member which solves the problems of the prior art, and further provides a novel manufacturing method for obtaining such a ceramic member. And a ceramic member having a porous portion integrally sintered with the dense body without any gap at a predetermined portion, and a three-dimensional mesh at a desired position in a mold corresponding to the shape of the member to be manufactured. After setting the fuselage, ceramic powder, a thermosetting resin, a solvent and a dispersant are uniformly mixed and dispersed, and a ceramic slurry is charged into a depressurized mold, and then the inside of the mold is pressurized. Is heated at a temperature at which the thermosetting resin can be polymerized, the slurry is cured, and the cured molded body is removed from the mold and fired, followed by firing. It is intended.

The ceramic member of the present invention has a novel construction in itself, in which a porous portion is formed at a predetermined portion of the dense ceramic body and integrally sintered with the dense body without any gap. It is not limited to a member produced by the method. The following method can be used to obtain a ceramic member in which a porous portion that is integrally formed with a part of the dense ceramic body and is sintered without gaps is formed.

First, a ceramic slurry is obtained by uniformly mixing and dispersing a ceramic powder, a thermosetting resin, a solvent and a dispersant. Next, a three-dimensional mesh-like organic material is set at a desired position in a mold corresponding to the shape of a member to be manufactured, and the depressurized mold is filled with the slurry, and the inside of the mold is pressurized. Thereby, the slurry is filled to every corner in the pores of the three-dimensional network organic material. Subsequently, the slurry is cured by heating the mold at a temperature at which the thermosetting resin can be polymerized, and the cured molded body is removed from the mold.
Then, the formed body is dried, degreased, and fired to obtain a ceramic member having the porous portion.

As the above ceramics, alumina, zirconia, apatite, nitride ceramics, carbonized ceramics and the like can be appropriately used. Examples of the thermosetting resin include all resins that can be cured by heating: for example, compounds having an unsaturated bond such as unsaturated polyesters, acrylates, and methacrylates.

As a method of adjusting the properties of the porous body formed on the ceramic member, for example, the volume occupancy of the three-dimensional mesh-like organic body is set to a predetermined value, or the density or the like changes in a gradient manner. Can be used.

In addition, as a three-dimensional mesh for obtaining a porous body, a woven sheet, a granular shaped article, or the like may be used.

As the type of the mold, it is preferable to use a material that is light and has good heat conductivity, such as duralumin. Further, a resin mold may be used instead of a metal mold from the viewpoint of workability and economy.

The lower the viscosity of the slurry, the better the filling properties.
Further, it is preferable because generation of entrapment pores can be prevented and degassing efficiency at the time of removing air is good. Particularly, 20 poise or less is preferable.

The material of the three-dimensional network-like organic material is as follows:
Various organic substances such as urethane, polypropylene, polyester, and Teflon which have shape retention properties even in a solvent can be used.

[0022]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below with reference to the drawings.

Example of Spiral Filter A slurry of (20 poise) in which high-purity alumina ceramic (average particle size: 0.6 μm), a thermosetting resin (unsaturated polyester), a solvent, and a dispersing agent are uniformly mixed is mixed with (alumina). (Filling rate 60 vol%).

On the other hand, a spirally shaped mold (duralumin) is prepared, and a three-dimensional mesh-like organic material spirally molded therein, specifically, a sponge-like resin made of polypropylene (volume occupancy of 70%). %) Was set. Both ends of the sponge-like resin are fixed inside the mold and can be set at any position. The inside of the mold is evacuated and the slurry is filled and pressurized. In this manner, the slurry can be filled into the sponge-like gaps set in the corners of the mold. After filling, the mold is heated and molded at a temperature at which the thermosetting resin in the slurry can be cured. The mold is split, and the molded body is dried, degreased and fired to obtain a product. In this way, a ceramic filter having continuous porosity at the center of the spiral dense body can be obtained.

FIG. 1 is a perspective view of an alumina helical filter 1 manufactured in this manner, and FIG.
FIG. 3 is a cross-sectional view taken along line A. As shown in these figures, the outside of the filter is a dense body 10 and a helical porous portion 20 is formed inside, and the dense body and the porous body are integrated. Since they are molded and integrally sintered, there is no interface between them at all due to gaps or the like.
Since the filter 1 is helical, the filter effect by the centrifugal force is high, and since the dense body 10 and the porous portion 20 are integrally sintered without an interface, the mechanical strength of the member is also high (there is an interface gap). Cracks are likely to occur therefrom, and the mechanical strength is reduced). As a result of observing the interface between the porous body 20 and the dense body 10 of the filter 1 with a metallographic microscope (× 100), no gaps or cracks were observed. Further, if the filter 1 having such a shape is used, space saving can be realized, which is very practical.

As described above, when the present method is used, a porous portion having an arbitrary three-dimensional network property (porosity control, stepless slope of the porosity) is formed at an arbitrary position on a molded article of an arbitrary shape. The arranged ceramic members can be easily manufactured.

Embodiment of Artificial Root A mold (duralumin) molded in the form of an artificial tooth root is prepared, and a high-purity alumina ceramic as shown in FIGS. Artificial root R
Was prepared.

As shown in the perspective sectional view of FIG. 4, the artificial tooth root R has a porous body 20 on the outer side of the intermediate portion R1 and a dense body 10 on the inner side. The intermediate portion R1 of the artificial tooth root R was cut horizontally and the interface between the porous body 20 and the dense body 10 was observed with a metallographic microscope (× 100).
No gaps or cracks were observed.

The volume porosity of the porous portion 20 is as follows.
10-70% is preferred. If the volume porosity is less than 10%, the bonding strength between the bone and the porous portion 20 may be insufficient, while if it exceeds 70%, the strength of this portion may be insufficient. It is more preferable that the volume porosity is in the range of 20 to 50%. The average pore size of the porous portion 20 is 50 μm to
It is preferable that the average pore diameter is less than 50 μm or more than 300 μm.

[0030]

As described above, a ceramic member formed by forming a three-dimensional mesh-like porous portion integrally sintered with the dense body without any gap at a predetermined portion of the dense ceramic body of the present invention as described above. , Since it has a large mechanical strength and a porous body of the most appropriate part according to the purpose of the member,
This is an excellent effect that the use of the porous ceramic member can be expanded more than before. According to the manufacturing method of the present invention capable of obtaining such a member, an excellent effect that a useful ceramic member as described above can be obtained accurately, in large quantities and at low cost using a mold. Is played.

[Brief description of the drawings]

FIG. 1 is a perspective view of a spiral filter according to an embodiment of the present invention.

FIG. 2 is a sectional view taken along line AA of FIG.

FIG. 3 is a side view of the artificial tooth root according to the embodiment of the present invention.

FIG. 4 is a perspective sectional view showing an intermediate portion of the artificial tooth root of FIG. 3;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Filter 2 Pipe 10 Dense body 20 Porous part 30 Hollow

Claims (2)

[Claims] 1. A ceramic member having a three-dimensional mesh-like porous portion formed integrally with a predetermined portion of a dense ceramic body and sintered with the dense body without gaps. 2. A ceramic in which a three-dimensional mesh-like organic substance is set at a desired position in a mold corresponding to the shape of a member to be produced, and ceramic powder, a thermosetting resin, a solvent and a dispersant are uniformly mixed and dispersed. After filling the rally into the depressurized mold, the inside of the mold is pressurized, and then the slurry is cured by heating the mold at a temperature at which the thermosetting resin can be polymerized, and the cured molded body is cured. A method for manufacturing a ceramic member, comprising taking out from a mold and firing.