JPH0193473A - Production of formed ceramic article having honeycomb layer on surface - Google Patents

Abstract

PURPOSE:To produce the titled formed article having excellent strength, bacteria-removing performance and cleanability, by integrating a ceramic honeycomb plate on the surface of a ceramic substrate through a specific slurry and sintering the product. CONSTITUTION:A slurry having a concentration of 15-30wt.% and a viscosity of 5-100cps is produced by mixing 100pts.wt. of ceramic powder of the same kind as a ceramic substrate 1 and having particle diameter of <=5mum with 2-20pts.wt. of a binder (e.g. PVA) and a dispersion medium (e.g. water). The surface of the substrate 1 is coated with the slurry, topped with a ceramic honeycomb plate 2 of the same kind as the substrate 1 interposing a spacer 3, dried, heated to remove the binder and sintered.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a method for manufacturing a ceramic molded body having a honeycomb layer on its surface.

<Prior art> Various ceramic molded bodies with porous surfaces are known, and their main uses include hard tissue replacements such as artificial tooth roots and artificial bones due to their good biocompatibility and relatively high mechanical strength. Research and development of ceramic implants as a material is being actively conducted.

<Problems to be solved by the invention> Conventional porous bodies have small pore diameters and few communicating pores, and when used as an implant base material, it is difficult for bone tissue to grow within the pores. There is a problem in that it is difficult to sufficiently sterilize or clean the pores.

On the other hand, attempts have also been made to use porous bodies with relatively large pore diameters and communicating pores as implant materials.
For example, in Japanese Patent Publication No. 58-41854, granules, an aqueous binder solution, and naphthalene are mixed to form a clay-like plastic, which is molded and sintered to make a porous molded body, and this molded body is made into a dense It is described that a ceramic molded body having a porous portion inside is obtained by inserting the molded body into a high quality ceramic outer tube and heating it to sinter and integrate the body. however,
The molded body obtained by this method utilizes sintering at the contact points of the granules, and a problem was found in that the bonding strength between the granules and between the granules and the mantle was weak. In other words, there is only one contact point between the base material surface and the granules, and there are 6 to 1 contact points between the granules.
Since the number of contact points is two, the bonding between the base material surface and the granules is smaller than the bonding between granules, and sintering at the contact points as described above will only yield low strength, and furthermore, the bonding strength between the granules will not necessarily be the same. Turns out it wasn't enough.

An object of the present invention is to have a honeycomb layer on the surface and have high bonding strength between the honeycomb and the base material in order to solve the above problems.
It is an object of the present invention to provide a method for producing a ceramic molded body suitable for various structural materials, especially as an implant material.

<Means for Solving the Problems> The present invention is characterized in that a ceramic honeycomb plate of the same quality as the base material is integrated on the surface of the ceramic base material with a slurry containing ceramic powder of the same quality as the base material, and then sintered. An object of the present invention is to provide a method for manufacturing a ceramic molded body having a honeycomb layer on its surface.

The present invention will be explained in detail below.

The material of the ceramic base material used in the present invention is a dense ceramic sintered body with high strength, which is generally used as a structural material, or a molded body before sintering, such as oxides such as alumina and zirconia, It is a non-oxide material such as silicon nitride or silicon carbide, and is not particularly limited, but when used as an implant material, a material that does not cause false writing to living organisms is used. From this point of view, alumina and zirconia are preferable.

This ceramic base material can be pre-prepared and molded into the desired shape by a conventional method, or sintered, or molded into the desired shape after sintering. , or those processed after sintering are preferred.

As the ceramic honeycomb plate used in the present invention, a honeycomb-shaped molded body of ceramic having the same quality as the ceramic base material or a sintered body thereof is used, but a sintered body is preferable.This honeycomb plate can be formed by extrusion molding or injection molding. It is possible to use a material molded by a conventional method such as , or a material sintered.

The hole shape of the honeycomb plate can be polygonal, circular, etc.
The pore diameter may be selected as appropriate depending on the application, and is not particularly limited, but is preferably at least 0.3 mm.
If it is less than 0.0 mm, it is not preferable because the pores of the obtained sintered body may be filled, making it difficult to manufacture. ．． 3+- to about 20 m+s, more preferably about 0.5
- about 1511IIl, but when used as an implant material, the pore diameter is preferably in the range of about 0.8 to about 2 m+w, more preferably about 1.0 to about 1.5 m+w; A porous body is formed, which is desirable for new bone infiltration. Here, in the case of a polygon, the hole diameter means the average diameter of the inscribed circle and circumscribed circle.

Also, there are no particular limitations on the wall thickness of the honeycomb frame.
It can be determined by considering the hole diameter and strength, but it is usually 0.1 to about 5.
11+m s Approximately 0.1~ for use in implant parts
A range of about 0.5+gm is preferred.

Furthermore, in the present invention, a spacer may be interposed between the ceramic base material and the honeycomb layer as necessary, and the spacer is made of the same material as the ceramic base material.

In the present invention, the above ceramic base material, spacer,
All of the honeycomb plates can be manufactured as pre-sintered compacts or as a combination of sintered compacts, but in consideration of shrinkage during sintering, it is preferable that all of the honeycomb plates are sintered compacts. .

The ceramic raw material powder is a ceramic powder of the same quality as the ceramic substrate and has a particle size of 5 μm or less, preferably 1 μm or less. The smaller the particle size, the better the sinterability and the better the stability of the slurry.

The binder and dispersion medium are not particularly limited as long as they are selected to form a solution upon dissolution, and any known binder and dispersion medium can be used. Examples include polyvinyl alcohol, polyethylene oxide, hydroxycellulose, etc. when the dispersion medium is water, and polyvinyl alcohol, polyvinyl alcohol, etc. when the dispersion medium is non-aqueous.
Examples include polymethyl methacrylate and cellulose acetate butyrate. The slurry can be prepared by a well-known method, and it is important that the ceramic powder is well dispersed in the binder solution.

The concentration of binder and ceramic powder are important factors governing the viscosity of the slurry.

The viscosity of the slurry may be such as to be able to bond and integrate the honeycomb plate and the base material, and can be appropriately determined usually within the range of 5 to 100 centivoids.

The ceramic powder concentration is preferably in the range of 15 to 30% by weight of the slurry, and the binder concentration is 10% by weight of the ceramic powder.
It is preferably in the range of 2 to 20 with respect to 0 (weight), but is not particularly limited, and can be determined as appropriate in consideration of the ceramic powder concentration and the viscosity of the slurry. Furthermore, when preparing the ceramic powder slurry, it is of course possible to add commonly used additives such as sintering aids, plasticizers, and dispersants.

Next, a method for forming a honeycomb layer according to the present invention will be explained.

First, a slurry of ceramic raw material powder is injected or applied onto the surface of a ceramic base material, and a honeycomb plate is immediately placed on the surface of the base material to integrate the slurry. In addition, as another aspect, when providing a spacer between the base material and the honeycomb board, the slurry is applied to the base material surface, and then after the spacer is placed, the slurry is further injected or applied onto the spacer, and then the honeycomb board These are integrated by placing them on the base material surface.

When molding on the surface of a flat base material or around a cylinder, a prism, etc., the operation is easy if an appropriate mold is used. It is easier to form it in a recess formed on the base.

Thereafter, a slurry of the ceramic raw material powder is injected so that the particles are immersed in the slurry, and then dried. By drying, the ceramic raw material powder is concentrated and aggregated at each contact point between the honeycomb plate and the substrate.

Next, if necessary, the mold is removed, and then the binder is removed by heating in a conventional manner, followed by sintering to obtain a ceramic molded body having a honeycomb layer on the surface. The amount of slurry injected from the ceramic raw material powder does not necessarily have to be enough to reach immersion, but may be an amount that sufficiently wets the honeycomb plate.

According to the method of the present invention, the ceramic raw material powder is sintered at the contact point between the ceramic base material surface and the honeycomb plate, so that the base surface of the obtained sintered body and the honeycomb plate are bonded together. are integrated and develop high strength.

FIG. 1, which shows an example of the use of the ceramic molded body obtained by the method of the present invention, schematically shows an example in which the ceramic molded body is used as an implant material for a joint. That is, it is an implant material in which the ceramic base 1, the ceramic honeycomb plate 2, and the spacer 3 are firmly joined, and the bone 4 is fitted and integrated with the implant material. Reference numeral 5 indicates a sliding surface where bone tissue intrudes into the holes of the honeycomb plate and grows to firmly connect the implant to the bone. Ceramic molded bodies can be manufactured and used in desired shapes depending on the body part.

This implant material has high strength and is easy and reliable to sterilize or clean before use.

<Effects of the Invention> According to the present invention, it is possible to obtain a ceramic molded body having a honeycomb layer on the surface and in which the base material and the honeycomb layer are firmly bonded, and this molded body can be used for various purposes as a structural material. It is particularly useful as an implant material.

<Examples> The present invention will be described in more detail with reference to Examples, but the present invention is not limited to these Examples in any way. In addition, in the examples, parts mean parts by weight.

Example 1 100 parts of fine alumina powder (AKP-20 manufactured by Sumitomo Chemical ■, average particle size 0.5 μ-), fine magnesia powder (Kiriwamag 030 manufactured by Kyowa Chemical ■) as a sintering aid,
Average particle size: 0.35 μm) 0.2 parts, 8 parts of polyvinyl butyral (Nislex@B BLS manufactured by Tanemizu Chemical Industry ■) as a binder, 3.6 parts of dibutyl phthalate as a plasticizer, 1 part of glycerin triolate as a dispersant ．．
7 parts, 230 parts of trichlorethylene and 70 parts of ethanol as a dispersion medium, and a mixture thereof was mixed in a ball mill for 96 hours to prepare an alumina slurry.

On the other hand, a formwork with an inner dimension of 7 x 13 m, a depth of 8 s+m, and a thickness of 1 s+m was prepared using paraffin wax. In this, as a base material, 7 x 13+*al x thickness 211+1
A dense alumina sintered body was laid down, and the alumina slurry described above was applied on top of this. Furthermore, add 1 as a spacer on top of this.
Two alumina dense sintered plates of 5×7 ms+×1 mm thickness were placed on both ends of the substrate. Apply the above alumina slurry on this spacer, and then add a 7 x 13 mm x 1 mm thick alumina honeycomb plate (opening 1.6 m + w x
1.6 mm, frame thickness 0.4 mm). Thereafter, the alumina slurry was injected into the mold until the honeycomb plate was completely immersed. Thereafter, it was dried overnight at room temperature, demolded, heated at 250"C for 3 hours to remove the binder, and then heated at 1600"C for 1 hour to sinter.

In the obtained sintered body, an alumina layer was formed in a cross-linked manner between the honeycomb plate, the spacer, and the alumina base material, and the bonding was strong.

Example 2 100 parts of fine alumina powder (AKP-20° manufactured by Sumitomo Chemical, average particle size 0.5 μM), fine magnesia powder (
Kyowa Mag 030 manufactured by Kyowa Chemical Industry ■, average particle size 0.
An alumina slurry was prepared by dispersing a mixture of 0.05 part of 35 μ+m), 2 parts of polyvinyl alcohol (Poval@217 manufactured by Kuraray ■), and 567 parts of an aqueous hydrochloric acid solution having a pH of 2 for 30 minutes in a water tank. The other conditions were the same as in Example 1 to produce a sintered body. In the obtained sintered body, the honeycomb and spacers were firmly bonded to the alumina substrate.

Example 3 40× with a recess of 3×7mm×2.5mm deep
After applying alumina slurry to the concave portion of an alumina dense sintered body plate of 4011111×thickness 10++ m in the same manner as in Example 1, spacer placement, alumina slurry application, honeycomb plate placement, and immersion in the alumina slurry were performed, followed by drying and sintering. I did it.

The obtained sintered body had honeycomb plates and spacers firmly bonded to the alumina base material, and an alumina molded body having a honeycomb layer on the surface was obtained.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram showing an example of a state in which an implant material and bone are bonded when a ceramic molded body obtained according to the present invention is used as an implant. 1-- Ceramic base material, 2-- Ceramic honeycomb layer, 3-- Spacer, 4--
-One bone, 5...-Sliding surface

Claims (1)

[Claims] A method for manufacturing a ceramic molded body having a honeycomb layer on the surface thereof, which comprises integrating a ceramic honeycomb plate of the same quality on the surface of a ceramic base material with a slurry containing a ceramic powder of the same quality, and then sintering it.