JPS60161368A - Manufacture of high strength calcium phosphate sintered body - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing a high-strength calcium phosphate sintered body by ordinary sintering.

Calcium phosphate has an affinity for living organisms, and its sintered body has been proposed to be used as a biomaterial that can replace bones and teeth. In addition, it is useful as a highly expandable ceramic material in addition to being used as an IC package substrate by utilizing its highly dense properties.

Conventionally, the method for manufacturing this calcium phosphate sintered body is as follows:
There are the normal sintering method, which involves sintering under normal pressure after pressing, and the hot pressing method. Calcium phosphate powder is sintered under normal pressure (
When sintered (ordinary sintering), it has a compressive strength of about 90011z/aa (Ceramics 10 (711975, p. 474)) and has a low density, and also tends to spall during the cooling process after firing, which means it is weak in spalling resistance. There is.

On the other hand, the hot press method has a compressive strength of 1000 to 2000.
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Although the strength is considerably high, the manufacturing method is complicated, the equipment cost is high, and mass production is difficult.

In order to eliminate the drawbacks of the above-mentioned prior art, the applicant of the present application has developed a powder mainly composed of calcium phosphate with a calcium/phosphorus atomic ratio of L4 to L75, which weighs 0.5 to 15% by weight based on the fired calcium phosphate sintered body. % of alkali metal, zinc and/or alkaline earth metal oxide-phosphoric acid frit and sintering it is disclosed in JP-A-55-14.
It was disclosed in Japanese Patent No. 0756. As a result of intensive research, the inventors found that among the methods disclosed in the above publication, powders mainly composed of calcium phosphate have a specific surface area of zO~aOi/S.
It has been found that it is desirable to use a frit whose specific surface area is greater than or equal to the specific surface area of the powder and less than three times the specific surface area of the powder.

The present invention was made based on the above knowledge, and the gist thereof is as described in the claims. The reason why the specific surface area of the raw material used in the present invention is limited as described above will be explained below.

The specific surface area of powder mainly composed of calcium phosphate is 2
．． If it is less than (la'/f, a dense and high-strength sintered body cannot be obtained, and at) I! If it exceeds 1'/f, it becomes an ultrafine powder and is difficult to handle, so it is limited to zO to aO//f.

If the specific surface area of the frit is smaller than that of the powder mainly composed of calcium phosphate, the frit will not be dispersed uniformly and the strength of the sintered body will decrease, while on the other hand, if the specific surface area exceeds three times the specific surface area of the powder, The above-mentioned limitations were made because the sintered body was agglomerated into fine powder, formed into a water reservoir, and conversely had many pores inside the sintered body, resulting in a decrease in strength.

Examples are shown below.

Example H3PO4r BaCO so as to have the composition shown in Table 1
5+ CaCO3 and Al2O3 were weighed and mixed, the mixture was placed in an alumina pot and melted in the atmosphere at the temperature shown in Table 1, the melt was poured onto a carbon plate, and left to cool to form frit A.
And frit B was obtained. The characteristic values of frits A and B are also listed in Table 1.

Table 1 The above frits were ground in an alumina ball mill at different times to prepare three types of frits A and B, each having a specific surface area α of 6.2.5 and 45 m/f.

Frits with different specific surface areas and specific surface areas L4vf/f
of hydroxyapatite, tricalcium phosphate with a specific surface area of 2.4 t#/f and mixtures thereof (mixing ratio X)
and 100 parts by weight of total inorganic powder as a binder, 3 parts by weight of camphor dissolved in ether was added, and after drying the mixture was heated at a pressure of 800 Kf/
cn! The material is molded into a size of 12 m wide x 40 m long x 4 m thick, and fired at a heating rate of 300°C/hr and a holding time of 1 hour at each stage of temperature from 1000 to 1500°C to produce a sintered body. did. Among the sintered bodies fired at each of the above temperatures, the bending strength was measured and the one with the highest strength is shown in Table 2 as an optimum example.

Claims (1)

[Claims] A powder mainly composed of calcium phosphate with a calcium/phosphorus atomic ratio of 14 to L75. is added with Q5 to 15% by weight of alkali metal, zinc and/or alkaline earth metal based on the fired calcium phosphate sintered body. In the method of adding and firing an oxide-phosphoric acid frit, the powder has a specific surface area of 2.0-aOvt/f, and the ratio of the specific surface area of the frit to that of the powder is Il. A method for producing a high-strength calcium phosphate sintered body, characterized by: