JPH0565452B2 - - Google Patents

Description

[Detailed description of the invention]

(Industrial Application Field) The present invention relates to a crystallized glass/high melting point oxide composite material suitable as an interior/exterior material for buildings, and a method for producing the same. (Prior art) Glass is a material with excellent surface gloss, but as a building material, it has problems with its strength, and various strengthening measures have been taken in the past, one of which is crystallized glass. There is a way to do it. By the way, a suitable method for producing crystallized glass is the method proposed by the present applicant in Japanese Patent Application No. 60-28415, in which fine glass powder having a wollastonite crystallization composition is press-molded and then heat-treated. There is a method of achieving crystallization by taking advantage of the fact that crystals tend to form at grain boundaries that soften and fuse during sintering. (Problems to be solved by the invention) Heat-treating the press-molded body of the above fine glass powder,
In a method (hereinafter referred to as a sintering method) in which powders are softened and fused together to make them denser and crystallize, the contact area between the powders is large and a large amount of crystals are generated. Incidentally, since the strength improvement of crystallized glass is due to precipitated crystals, the strength improvement effect is large in the sintering method in which a large amount of crystal precipitates is deposited. However, due to the physical properties of crystals, there is a limit to its strength, and the bending strength of the product is 600~
With a strength of around 700Kgf/cm ² , stronger materials are desired as building materials. In addition, in the sintering method, if the difference between the softening point and crystallization temperature of the powdered glass used is too large, it is difficult to maintain the shape during the crystallization stage after sintering, which is difficult for large products such as building materials. This trend is significant. In addition, the heat treatment is not only a two-stage heat treatment in which the sintering temperature is maintained until the sintering is finished, then the temperature is raised to the crystallization temperature, and the temperature is maintained. Complete sintering during heating 1
In the case of step-type heat treatment, if the glass powder used is a glass powder whose softening point and crystallization temperature are close to each other, sintering will actually occur at the crystallization temperature, and the viscosity will increase due to the precipitation of crystals. This prevents the powder from softening and fusing. In other words, when a single glass powder is used as a raw material, the balance between softening point and crystallization temperature remains a problem. The present invention was made in view of the above problems.
To provide a building material that has a glass-like surface gloss and superior strength compared to conventional crystallized glass,
The object of the present invention is to provide a method for producing the same building material by sintering without the problems of sintering inhibition and deformation as described above. (Means for Solving the Problems) In order to achieve the above object, the crystallized glass/high melting point oxide composite material of the present invention contains as essential components SiO ₂ : 65 to 80%, CaO: 5% by weight. ~15%, Na ₂ O + K ₂ O: 10 ~ 30%, MgO: 2 ~ 8%, and crystalline high melting point oxide particles are dispersed in a base of crystallized glass. In its production method, the essential components in weight percentage are: _SiO2 : 65-80%, CaO: 5-15%, _Na2O + _K2O : 10-30%, MgO: 2-8 % of the glass containing 90% by weight or more of particles of 200 mesh or less;
A mixed powder is obtained by mixing a powder having a particle size composition that accounts for 90% by weight or more, and the powder is molded and then heat-treated to perform sintering and crystallization. (Function) In the crystallized glass/high melting point oxide composite material of the present invention, the crystalline high melting point oxide particles dispersed and contained in the base strengthen the material like the precipitated crystals in the crystallized glass. The melting point is also higher than that of the above-mentioned precipitated crystals, and the strengthening effect is greater than that of the same crystals. In addition, during manufacturing, the glass powder used is a glass powder that contains MgO, which is a crystal growth inhibiting component, and has been made easy to sinter by specifying the ingredients. The collapse,
This is prevented by the mixed crystalline high melting point oxide powder. In addition, by mixing the crystalline high melting point oxide powder, when the glass powder is sintered (softened and fused), the air existing between the powders can be moved along the surface of the unsoftened crystalline high melting point oxide particles. Since it is discharged to the outside of the molded body, the molded body and the composite material after the crystallization heat treatment can be easily densified. Note that fine powder is used for both the glass powder and the oxide powder, and as a result, sintering starts and progresses at a low temperature slightly above the softening point of the powdered glass, and as the temperature rises, the oxide becomes Component migration also takes place, and a good shrinkage and densification state of the molded article is obtained. (Example) First, the reasons for limiting the components of the glass used as powder will be described. SiO ₂ : 65-80% SiO ₂ is a skeleton component of the glass structure, and if it is less than 65%, it is difficult to adjust the crystallization rate, while if it exceeds 80%, the viscosity becomes too high and densification becomes poor. CaO: 5 to 15% CaO is a component that lowers the melting point and softening point and facilitates vitrification, but if it exceeds 15%, the crystallization rate increases and the sintered body becomes insufficiently densified. On the other hand 5
If it is less than %, crystallization becomes difficult. Na ₂ O + K ₂ O: 10-30% Both Na ₂ O and K ₂ O are components that lower the melting point and softening point and facilitate vitrification, and the total of both is 10%.
If it is less than 30%, the softening point will be high and crystallization will be rapid, resulting in insufficient shrinkage and densification of the sintered body, and if it exceeds 30%, crystallization will be insufficient. MgO: 2-8% MgO is a component that suppresses crystal growth,
If it is less than 2%, the suppression effect is not sufficient, and if it is less than 8%
If the addition exceeds 100%, crystals containing MgO will easily precipitate. By appropriately selecting the above components within the above specific range, it is possible to obtain a glass that is difficult to crystallize, a glass that has a large difference between the softening point and the crystallization temperature, or a glass that has a slow crystallization rate near the softening shrinkage start temperature. . It is desirable that the sum of the above components is 90% or more, and components other than the above components, such as glass colorants, should be added by 10%.
It is also possible to contain within %. Next, regarding crystalline high-melting point oxides, the same oxides must have a temperature at least 500 below the softening point of the above-mentioned glass.
℃ has a high melting point and good wettability with the above-mentioned glass. For example, Al ₂ O ₃ -based and SiO ₂ -based oxides are suitable. Specific examples include alumina, kaolin, feldspar, There are silica stones etc. The raw glass and oxide mentioned above are both mixed as a powder with a particle size composition of 90% by weight or more of fine powder of 200 mesh or less. This is because sintering starts and progresses at a low temperature slightly above the point, and sufficient integral densification is achieved by the movement of components between the glass and the oxide as the temperature rises. In addition, the finer the oxide powder, the better the surface gloss of the product after polishing, and if more than 10% by weight of coarse particles exceeding 200 meshes are included, the gloss will be extremely poor, which is also the case as mentioned above. This is one of the reasons for particle size limitations. The powders whose particle sizes have been adjusted in this way are mixed, and the mixing ratio is preferably 5 to 40% by weight of oxide powder and the balance glass powder. In other words, if the oxide powder is less than 5% by weight, it will not be able to prevent the molded product from deforming during heat treatment;
Exceeding this will impede the integral densification of the particles constituting the molded body. Note that if it exceeds 30% by weight, the surface gloss will be significantly reduced, so from the viewpoint of gloss, it is desirable that the content be 30% by weight or less. It is also possible to mix colored oxide powder uniformly or non-uniformly into the above mixed powder for the purpose of imparting a color pattern. For example, suitable amounts of addition are 1% by weight or less for Cr ₂ O ₃ , CuO, and MnO _{2 ,} 3% by weight or less for CoO, and 10% by weight or less for FeO, Fe ₂ O ₃ , and NiO. The thus blended mixed powder can be molded by ordinary pressure molding. For this pressure molding, a mold is used to press the mixture at room temperature, and a mold or roll is used to press the mixed powder heated to near the softening point of the glass powder (usually slightly lower than the softening point). There is high-temperature molding, and in the room-temperature molding, a binder, such as a polyvinyl alcohol (PVA) solution, is added to maintain the shape of the molded product during handling. On the other hand, in high-temperature molding, glass powder acts as a binder, and a molded product with high strength can be obtained without the addition of a binder. The thus obtained molded body may be heat-treated by raising the temperature to the crystallization temperature of the glass powder and maintaining the same temperature to perform sintering and crystallization, or by sintering at an appropriate temperature below the crystallization temperature. , heat treatment for crystallization is also possible. Next, specific examples of the present invention will be shown. The powder raw materials used in the examples, their compositions, and particle sizes are listed in Table 1 below.

[Table] Using the above raw materials and the raw material composition and molding conditions shown in Table 2 below, molded bodies No. ~ in the same table were obtained. However, the dimensions of the molded objects are 350 x 350 x 20 ~
It is 25 (mm).

[Table] The above molded body was heated at 850℃ x 4Hr (temperature rise 30
℃/Hr), a sintered body that did not lose its shape (the base glass was crystallized) was obtained. The bending strength of each sintered body is shown in Table 3.

[Table] By using the glass powder and alumina powder having the compositions shown in Table 1 and the raw material composition and molding conditions shown in Table 4 below, molded bodies No. ~ in the same table (350
x 350
When heat treatment was performed (temperature increase: 30°C/hr), sintered bodies that did not lose their shape were obtained. Bending strength is the 5th
As shown in the table.

[Table] However, the average particle size of glass powder is 9.7μm (about 1600 mesh), and the average particle size of alumina is 1.2μm (about 14000 mesh).
(equivalent to mesh).

[Table] However, is colored blue because it contains CoO. Furthermore, when we investigated the crystals in the sintered body, we found that
Both were Al ₂ O ₃ crystals and Na _{2 O.Al 2} O 3.2SiO ₂ crystals. Considering that SiO ₂ crystals and Na ₂ O・3CaO・6SiO ₂ crystals precipitate in the heat treatment of the above glass powder alone, Na ₂ O・Al ₂ O ₃・2SiO ₂ crystals will react with the glass and alumina. It can be assumed that it was generated by Furthermore, if alumina with an iron content of 0.03% or less is used,
It is added that it increases the whiteness of the product. (Effects of the Invention) According to the crystallized glass/high melting point oxide composite material of the present invention, crystalline high melting point oxide particles are dispersed and contained in the crystallized glass matrix of a specific component that is easy to sinter. Since the strengthening effect of crystalline high melting point oxide particles is greater than that of precipitated crystals in crystallized glass, high strength can be achieved in conjunction with the densification effect of crystalline high melting point oxide particles. Further, according to the manufacturing method of the present invention, a glass powder with a specific component that is easy to sinter is used, and a glass powder with a specific particle size configuration and a crystalline high melting point oxide powder are used.
Sintering of the glass powder starts at a relatively low temperature, and the air between the glass powders is easily discharged along the surface of the unsoftened crystalline high melting point oxide particles, making it easy to densify and create a crystalline high melting point oxide. Due to the shape-preventing effect of the melting point oxide particles, it is possible to easily produce a high-strength composite material that is dense and has good shape accuracy.

Claims (1)

[Claims] 1 Contains SiO ₂ : 65 to 80%, CaO: 5 to 15%, Na ₂ O + K ₂ O: 10 to 30%, and MgO: 2 to 8% as essential components in weight percentage. 1. A composite material of crystalline glass-ceramic and high-melting-point oxide, characterized in that crystalline high-melting-point oxide particles are contained in a matrix of crystallized glass. 2 200 meshes of glass containing as essential components SiO ₂ : 65-80%, CaO: 5-15%, Na ₂ O + K ₂ O: 10-30%, MgO: 2-8%. Powder with a particle size composition of 90% by weight or more of the following particles, and particles of 200 mesh or less of high melting point oxide in the crystal chamber.
A crystallized glass with a high melting point characterized by mixing the powder with a particle size composition that accounts for 90% by weight or more to obtain a mixed powder, molding the powder, and performing post-heat treatment to perform sintering and crystallization. Method for manufacturing oxide composites. 3 The mixed powder is a crystalline high melting point oxide powder 5
3. The method for producing a crystallized glass/high melting point oxide composite material according to claim 2, wherein the glass powder is comprised of 40% by weight and the remainder is the glass powder described above.