Opalescent porcelain and method for producing the same

Abstract

The application provides opalescent porcelain and a preparation method thereof. The raw materials of the opalescent porcelain include 65-85 parts of zirconium oxide, 5-15 parts of modified microporous zirconium oxide, 2-5 parts of yttrium oxide, 0.1-0.5 parts of aluminum oxide and 0.01-0.1 parts of colorant. The particle size of the raw materials is 0.1-0.5 microns. The modified microporous zirconium oxide is microporous zirconium oxide loaded with silicate. The microporous zirconium oxide loaded with silicate is added to the raw materials, so that the light transmittance and the refraction effect are improved, the transparent gradient of the porcelain at the edge position is improved, and the good appearance effect is achieved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of ceramic materials, in particular to a milky white porcelain and a preparation method thereof. BACKGROUND

[0002] Zirconia-based ceramic material is a kind of excellent performance denture base material, which has high strength, corrosion resistance, and is not easy to wear, etc. At the same time, zirconia denture can imitate the touch of real teeth, and provide the patient with the oral feeling like real teeth. In addition, the zirconia-based material has good biocompatibility and is not easy to cause other oral diseases.

[0003] However, zirconia-based ceramic is always a kind of ceramic material. In the process of comparing with real teeth, the light transmittance of the surface near the cutting end and the side surface of the denture cannot achieve the effect of real teeth. In order to achieve good natural tooth appearance effect, the glass-based milky white porcelain is usually used as the outer layer of the denture in the prior art. However, the glass-based milky white porcelain has poorer performance than the zirconia-based ceramic except for the appearance performance. Therefore, it has become one of the technical problems to be solved to develop a zirconia-based milky white porcelain. SUMMARY

[0004] Therefore, the present application provides a milky white porcelain and a preparation method thereof, which aims to use zirconia-based ceramic as the main material, retain strong mechanical properties, and improve the appearance effect.

[0005] The technical scheme of the present application is implemented as follows: the present application provides a milky white porcelain, the raw materials of the milky white porcelain include: 65-85 parts of zirconia, 5-15 parts of modified microporous zirconia, 2-5 parts of yttrium oxide, 0.1-0.5 parts of aluminum oxide, and 0.01-0.1 parts of colorant, wherein the raw materials are calculated by weight fraction, and the particle size of the above-mentioned raw materials is 0.1-0.5 μm, and the modified microporous zirconia is microporous zirconia loaded with silicate.

[0006] In the above-mentioned embodiment, the zirconia is a conventional zirconia powder, and the modified microporous zirconia is obtained by loading modification based on microporous zirconia. By loading silicate in the micropores, a glass base is formed after calcination through the loaded silicate, so as to improve the light transmittance of the whole ceramic. In addition, the dispersion uniformity of the small amount of glass base material is greatly improved by loading in the micropores of the microporous zirconia.

[0007] In some embodiments, the preparation method of the modified microporous zirconia includes: configuring an alkaline aqueous solution of sodium silicate, immersing microporous zirconia in the alkaline aqueous solution of sodium silicate, uniformly stirring, and then spray drying to obtain the modified microporous zirconia. In this step, the mass ratio of microporous zirconia to sodium silicate is 1:1.

[0008] In some embodiments, ultrasound is applied during stirring.

[0009] In some embodiments, the raw material of the opalescent porcelain further comprises 2-6 parts of surface-loaded modified zirconia, which is microporous zirconia loaded with nano-zinc spinel on the surface.

[0010] Since the microporous zirconia is loaded with silicate, the overall strength of the porcelain after firing decreases. In order to improve this problem, the raw material of the opalescent porcelain according to the present application further comprises microporous zirconia loaded with nano-zinc spinel. The zinc spinel has good mechanical strength and can compensate for the strength decrease caused by the introduction of silicate material. In addition, the zinc spinel has good refractive effect and blue light effect, which is beneficial to improve the appearance effect and opalescent effect of the glaze. The use of nano-zinc spinel is to uniformly load the zinc spinel on the surface of the microporous zirconia, so as to achieve uniform distribution.

[0011] In some embodiments, the preparation method of the surface-loaded modified zirconia comprises the following steps: preparing an ethanol suspension of nano-zinc spinel, immersing microporous zirconia in the ethanol suspension of nano-zinc spinel, uniformly stirring, and then spray drying. The dried product is heated to 1100°C at a heating rate of 8-10°C / min, and then heat treated for 30-60 min. After the heat treatment is completed, the temperature is lowered to room temperature to obtain the surface-loaded modified zirconia. In this step, the mass ratio of microporous zirconia to nano-zinc spinel is 1:2.

[0012] In the above embodiments, the nano-zinc spinel is uniformly coated on the surface of the microporous zirconia by suspension impregnation. After spray drying, uniformly coated microparticles can be formed, and the stability of the coating can be improved after drying and firing.

[0013] In the above embodiments, the nano-zinc spinel is nano-zinc spinel obtained by ball milling of zinc spinel, and the particle size of the nano-zinc spinel is 50-100 nm.

[0014] In the above embodiments, the colorant is at least one of iron oxide, chromium oxide or cobalt oxide.

[0015] The present application also provides a preparation method of the opalescent porcelain, comprising the following steps:

[0016] The raw material of the opalescent porcelain and the binder are mixed in a mass ratio of 1:0.5, and then ball-milled and stirred. Then, the ball-milled slurry is spray dried to prepare granular material with a particle size of 0.1-0.2 mm. The granular material is pressed in a mold to obtain a blank, and the blank is calcined to obtain the opalescent porcelain.

[0017] In some embodiments, the ball-milling and stirring time is 30-60 min.

[0018] In some embodiments, the pressing pressure is 200-240 MPa, and the pressing time is 5-10 min.

[0019] In some embodiments, the calcination temperature of the blank is 900-1100℃, and the calcination time is 3-5 h.

[0020] In some embodiments, the binder is an acrylic emulsion.

[0021] The opalescent porcelain and the preparation method thereof have the following beneficial effects compared with the prior art:

[0022] The opalescent porcelain based on zirconia provided by the application has higher structural strength compared with the conventional opalescent porcelain based on glass, and the special formula and preparation process make the corresponding opalescent porcelain not only have good opalescent effect, but also be brighter and whiter. DETAILED DESCRIPTION

[0023] The technical solutions in the embodiments of the application will be clearly and completely described below with reference to the embodiments of the application. Obviously, the described embodiments are only part of the embodiments of the application, rather than all the embodiments of the application. Based on the embodiments of the application, all other embodiments obtained by those skilled in the art without creative work fall within the protection scope of the application.

[0024] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which the embodiments of the application belong. If the definitions stated in this section are contrary to or otherwise inconsistent with the definitions stated in the patents, patent applications, published patent applications, and other publications that are incorporated herein by reference, the definitions stated in this section are preferred.

[0025] The following examples and comparative examples are used to further illustrate the technical solutions of the application.

[0026] The preparation method of the examples and comparative examples is as follows:

[0027] Example 1

[0028] Preparation of modified microporous zirconia:

[0029] 100 g of sodium silicate was weighed into 1 L of water, and after stirring, 100 g of microporous zirconia with a particle size of 0.1 μm was added, and the pH value was adjusted to 10 by adding sodium hydroxide. After uniform stirring under ultrasonic wave, spray drying was performed to obtain modified microporous zirconia.

[0030] Preparation of opalescent porcelain:

[0031] Take 65 g of zirconium oxide, 15 g of modified microporous zirconia, 2 g of yttrium oxide, 0.1 g of aluminum oxide, 0.01 g of cobalt oxide, the particle size of the above raw materials is 0.1-0.5 μm, mix the above raw materials with 41 g of acrylic emulsion and perform ball milling stirring, after 30 min of ball milling treatment, perform spray drying, prepare granules with a particle size of 0.1 mm, press the obtained granules in a denture mold, the pressing pressure is 200 MPa, after 5 min of pressing treatment, obtain a blank, heat the blank to 1000℃ at 10℃ / min, and keep the temperature for 4 h to obtain opalescent porcelain.

[0032] Example 2

[0033] Preparation of modified microporous zirconia:

[0034] Take 100 g of sodium silicate and add it to 1 L of water, stir, then add sodium hydroxide to adjust the pH value to 10, add 100 g of microporous zirconia with a particle size of 0.1 μm, stir uniformly under ultrasonic wave, then spray dry to obtain modified microporous zirconia.

[0035] Preparation of opalescent porcelain:

[0036] Take 75 g of zirconium oxide, 10 g of modified microporous zirconia, 3 g of yttrium oxide, 0.3 g of aluminum oxide, and 0.1 g of cobalt oxide, the particle size of the above raw materials is 0.1-0.5 μm, mix the above raw materials with 44 g of acrylic emulsion and perform ball milling stirring, after 50 min of ball milling treatment, perform spray drying, prepare granules with a particle size of 0.2 mm, press the obtained granules in a denture mold, the pressing pressure is 220 MPa, after 8 min of pressing treatment, obtain a blank, heat the blank to 800℃ at 10℃ / min, and keep the temperature for 5 h to obtain opalescent porcelain.

[0037] Example 3

[0038] Preparation of modified microporous zirconia:

[0039] Take 100 g of sodium silicate and add it to 1 L of water, stir, then add sodium hydroxide to adjust the pH value to 10, add 100 g of microporous zirconia with a particle size of 0.1 μm, stir uniformly under ultrasonic wave, then spray dry to obtain modified microporous zirconia.

[0040] Preparation of opalescent porcelain:

[0041] Take 85g zirconium oxide, 5g modified microporous zirconium oxide, 5g yttrium oxide, 0.5g aluminum oxide, 0.04g cobalt oxide, the particle size of the above raw materials is 0.1-0.5μm, mix the above raw materials with 48g acrylic emulsion and then perform ball milling stirring, after 60min of ball milling treatment, perform spray drying to prepare granules with a particle size of 0.1mm, press the obtained granules in a denture mold, the pressing pressure is 240MPa, after 10min of pressing treatment, obtain a blank, heat the blank to 1100℃ at a rate of 10℃ / min, and keep the temperature for 3h of heat treatment to obtain opalescent porcelain.

[0042] Example 4

[0043] Preparation of modified microporous zirconium oxide:

[0044] Take 100g sodium silicate and add it to 1L water, after stirring, add sodium hydroxide to adjust the pH value to 10, add 100g microporous zirconium oxide with a particle size of 0.1μm, stir uniformly under ultrasonic wave, and then perform spray drying to obtain modified microporous zirconium oxide.

[0045] Preparation of surface modified zirconium oxide:

[0046] Take 20g nanometer zinc spinel with a particle size of 50-100nm and add it to 500ml ethanol, stir until mixed uniformly to obtain nanometer zinc spinel ethanol suspension, take 10g microporous zirconium oxide and immerse it in the nanometer zinc spinel ethanol suspension, stir uniformly, and then perform spray drying, heat the collected and dried product to 1100℃ at a rate of 8℃ / min, keep the temperature for 30min of heat treatment, and then cool to 30℃ to obtain surface modified zirconium oxide.

[0047] Preparation of opalescent porcelain:

[0048] Take 65g zirconium oxide, 15g modified microporous zirconium oxide, 2g surface modified zirconium oxide, 2g yttrium oxide, 0.1g aluminum oxide, and 0.01g cobalt oxide, the particle size of the above raw materials is 0.1-0.5μm, mix the above raw materials with 42g acrylic emulsion and then perform ball milling stirring, after 30min of ball milling treatment, perform spray drying to prepare granules with a particle size of 0.1mm, press the obtained granules in a denture mold, the pressing pressure is 200MPa, after 5min of pressing treatment, obtain a blank, heat the blank to 1000℃ at a rate of 10℃ / min, and keep the temperature for 4h of heat treatment to obtain opalescent porcelain.

[0049] Example 5

[0050] Preparation of modified microporous zirconium oxide:

[0051] Take 100 g of sodium silicate into 1 L of water, after stirring, add sodium hydroxide to adjust the pH value to 10, add 100 g of microporous zirconia with a particle size of 0.1 μm, stir uniformly under ultrasonic wave, and then spray dry to obtain the modified microporous zirconia loaded on the surface.

[0052] Preparation of surface modified zirconia loaded on the surface:

[0053] Take 20 g of nano-zinc spinel with a particle size of 50-100 nm into 500 ml of ethanol, stir until mixed uniformly to obtain a nano-zinc spinel ethanol suspension, take 10 g of microporous zirconia, immerse it in the nano-zinc spinel ethanol suspension, stir uniformly, and then spray dry, heat the collected dry product to 1100℃ at a heating rate of 10℃ / min, keep the temperature for 60 min, and then cool to 30℃ to obtain the surface modified zirconia loaded on the surface.

[0054] Preparation of opalescent porcelain:

[0055] Take 65 g of zirconia, 15 g of modified microporous zirconia loaded on the surface, 6 g of surface modified zirconia, 2 g of yttrium oxide, 0.1 g of aluminum oxide, and 0.01 g of cobalt oxide, all of which have a particle size of 0.1-0.5 μm, mix the above raw materials with 42 g of acrylic emulsion, and then perform ball milling stirring, spray dry after 30 min of ball milling treatment, and prepare granular material with a particle size of 0.1 mm, press the obtained granular material in a denture mold, the pressing pressure is 200 MPa, and the pressing treatment is 5 min, then heat the blank to 1000℃ at a heating rate of 10℃ / min, and keep the temperature for 4 h of calcination treatment to obtain opalescent porcelain.

[0056] Comparative Example 1

[0057] Preparation of zirconia-based ceramic:

[0058] Take 80 g of zirconia, 6 g of surface modified zirconia loaded on the surface, 2 g of yttrium oxide, 0.1 g of aluminum oxide, and 0.01 g of cobalt oxide, all of which have a particle size of 0.1-0.5 μm, mix the above raw materials with 42 g of acrylic emulsion, and then perform ball milling stirring, spray dry after 30 min of ball milling treatment, and prepare granular material with a particle size of 0.1 mm, press the obtained granular material in a denture mold, the pressing pressure is 200 MPa, and the pressing treatment is 5 min, then heat the blank to 1000℃ at a heating rate of 10℃ / min, and keep the temperature for 4 h of calcination treatment to obtain opalescent porcelain.

[0059] Comparative Example 2

[0060] Preparation of zirconia-based ceramic:

[0061] The 65 g of zirconium oxide, 7.5 g of microporous zirconium oxide, 7.5 g of sodium silicate, 6 g of surface loaded modified zirconium oxide, 2 g of yttrium oxide, 0.1 g of aluminum oxide, and 0.01 g of cobalt oxide are mixed with 42 g of acrylic emulsion, and then ball-milled and stirred. After 30 minutes of ball-milling, the mixture is spray-dried to prepare granules having a particle size of 0.1 mm. The granules are pressed in a denture mold at a pressure of 200 MPa for 5 minutes to obtain a blank. The blank is heated to 1000°C at a rate of 10°C / min, and then heat-treated for 4 hours to obtain a zirconium oxide-based ceramic.

[0062] Comparative Example 3

[0063] Preparation of modified microporous zirconium oxide:

[0064] The 100 g of sodium silicate is added to 1 L of water, and then stirred. Sodium hydroxide is added to adjust the pH to 10. 100 g of microporous zirconium oxide having a particle size of 0.1 μm is added, and then stirred under ultrasonic waves. The mixture is spray-dried to obtain modified microporous zirconium oxide.

[0065] Preparation of opalescent porcelain:

[0066] The 65 g of zirconium oxide, 15 g of modified microporous zirconium oxide, 0.7 g of microporous zirconium oxide, 1.3 g of nano-zinc spinel having a particle size of 50-100 nm, 2 g of yttrium oxide, 0.1 g of aluminum oxide, and 0.01 g of cobalt oxide are mixed with 42 g of acrylic emulsion, and then ball-milled and stirred. After 30 minutes of ball-milling, the mixture is spray-dried to prepare granules having a particle size of 0.1 mm. The granules are pressed in a denture mold at a pressure of 200 MPa for 5 minutes to obtain a blank. The blank is heated to 1000°C at a rate of 10°C / min, and then heat-treated for 4 hours to obtain opalescent porcelain.

[0067] The opalescent porcelain and the zirconium oxide-based ceramic obtained in the above examples and comparative examples are subjected to opalescent effect judgment. The judgment is performed by placing the porcelain and the real tooth under the same light source, and then visually judging.

[0068] The opalescent porcelain and the zirconium oxide-based ceramic obtained in the above examples and comparative examples are subjected to bending strength and fracture strength tests, and the data are shown in the following table.

[0069]

[0070] From the above data, it can be seen that the opalescent porcelain according to the present application can achieve good appearance effect, and the mechanical property of the opalescent porcelain is not substantially reduced compared with the conventional zirconia-based porcelain, and is even better. As can be seen from Comparative Example 2 and Comparative Example 3, even in the case of the same raw materials, the opalescent porcelain obtained by using the modified microporous zirconia according to the present application has stronger mechanical property compared with the zirconia-based porcelain obtained by mixing conventional raw materials, which is probably because the distribution of the loaded component is more uniform after loading, so that the structural strength of the zirconia-based porcelain is maintained.

[0071] The above description is merely preferred embodiments of the present application, but not intended to limit the present application. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall fall within the protection scope of the present application.

Claims

1. A type of opalescent porcelain, characterized in that, The raw materials for the opalescent ceramic, calculated by weight, include: 65-85 parts of zirconium oxide, 5-15 parts of supported modified microporous zirconium oxide, 2-5 parts of yttrium oxide, 0.1-0.5 parts of alumina, and 0.01-0.1 parts of pigment. The particle size of all the above raw materials is 0.1-0.5 μm. The supported modified microporous zirconium oxide is microporous zirconium oxide supported on silicates. The preparation method of the supported modified microporous zirconium oxide includes: preparing an alkaline aqueous solution of sodium silicate, immersing the microporous zirconium oxide in the alkaline aqueous solution of sodium silicate, stirring evenly, and then spray drying to obtain the supported modified microporous zirconium oxide. In this step, the mass ratio of microporous zirconium oxide to sodium silicate is 1:

1. During the process, ultrasound is applied. The raw material of the opalescent ceramic also includes 2-6 parts of surface-loaded modified zirconia. The surface-loaded modified zirconia is microporous zirconia with nano-zinc spinel loaded on its surface. The preparation method of the surface-loaded modified zirconia includes: preparing an ethanol suspension of nano-zinc spinel, immersing the microporous zirconia in the ethanol suspension of nano-zinc spinel, stirring evenly and then spray drying, heating the dried product to 1100℃ at a heating rate of 8-10℃ / min, holding it at that temperature for 30-60min, and cooling it to room temperature after the holding time is completed to obtain surface-loaded modified zirconia. In this step, the mass ratio of microporous zirconia to nano-zinc spinel is 1:

2.

2. The method for preparing opalescent porcelain according to claim 1, characterized in that, The process includes the following steps: mixing the raw materials of opalescent porcelain with the binder at a mass ratio of 1:0.5 and then ball milling and stirring; then spray drying the ball-milled slurry to prepare granules with a particle size of 0.1-0.2 mm; pressing the granules in a mold to obtain a blank; and then firing the blank to obtain opalescent porcelain.

3. The method for preparing opalescent porcelain as described in claim 2, characterized in that, The ball milling time is 30-60 minutes.

4. The method for preparing opalescent porcelain as described in claim 2, characterized in that, The pressing pressure is 200-240 MPa, and the pressing time is 5-10 min.

5. The method for preparing opalescent porcelain as described in claim 2, characterized in that, The billet is calcined at a stable temperature of 900-1100℃ for 3-5 hours.

6. The method for preparing opalescent porcelain as described in claim 2, characterized in that, The adhesive is an acrylic emulsion.

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