阅读说明：本技术 一种采用鼓泡工艺制备牙科用二硅酸锂微晶玻璃的方法 (Method for preparing dental lithium disilicate glass ceramics by adopting bubbling process ) 是由 罗绍华 王选 王字寒 于 2021-09-28 设计创作，主要内容包括：本发明提供了一种采用鼓泡工艺制备牙科用二硅酸锂微晶玻璃的方法,包括以下步骤：(1)将原料按配比混合,过筛并经混料机混合均匀；在1350～1600℃熔制,保温时间1-5小时；(2)实施鼓泡工艺技术处理,然后继续在1350～1600℃熔制,保温时间1-5小时；得到熔制的玻璃液；(3)将熔制的玻璃液浇铸入预热好的石墨模具内,并进行退火工艺处理,得到成型玻璃块；(4)将成型玻璃块经一步法成核热处理得到含Li-(2)SiO-(3)为主晶相的微晶玻璃成核品；(5)最后再进行二次热处理得到以Li-(2)Si-(2)O-(5)为主晶相的微晶玻璃成品。本发明通过实施鼓泡工艺技术使得微晶玻璃产品的质地均匀、无气泡、透光率高,并且易于切削,接近天然牙的硬度570-600MPa,具有优良的抗弯强度及良好的生物相容性等性能。(The invention provides a method for preparing dental lithium disilicate glass ceramics by adopting a bubbling process, which comprises the following steps: (1) mixing the raw materials according to a ratio, sieving and uniformly mixing by a mixer; melting at 1350-1600 ℃ for 1-5 hours; (2) carrying out bubbling process technical treatment, and then continuously melting at 1350-1600 ℃, wherein the heat preservation time is 1-5 hours; obtaining molten glass; (3) casting the molten glass into a preheated graphite mold, andcarrying out annealing process treatment to obtain a formed glass block; (4) the formed glass block is subjected to one-step nucleation heat treatment to obtain the Li-containing glass block 2 SiO 3 A microcrystalline glass nucleator having a primary crystalline phase; (5) finally, the secondary heat treatment is carried out to obtain Li 2 Si 2 O 5 The microcrystalline glass is a finished product of the main crystal phase. The microcrystalline glass product has uniform texture, no bubbles, high light transmittance and easy cutting by implementing the bubbling technology, is close to the hardness of natural teeth of 570-600MPa, and has excellent bending strength, good biocompatibility and other properties.)

1. A method for preparing dental lithium disilicate glass ceramics by adopting a bubbling process is characterized by comprising the following steps:

(1) mixing the raw materials according to a ratio, sieving and uniformly mixing by a mixer; melting at 1350-1600 ℃ for 1-5 hours;

(2) carrying out bubbling process technical treatment, and then continuously melting at 1350-1600 ℃, wherein the heat preservation time is 1-5 hours; obtaining molten glass;

(3) casting the molten glass into a preheated graphite mold, and carrying out annealing process treatment to obtain a formed glass block;

(4) the formed glass block is subjected to one-step nucleation heat treatment to obtain the Li-containing glass block₂SiO₃A microcrystalline glass nucleator having a primary crystalline phase;

(5) finally, the secondary heat treatment is carried out to obtain Li₂Si₂O₅A microcrystalline glass finished product which is a main crystal phase;

wherein the raw materials in the step (1) are respectively in the following weight percentage: SiO 2₂ 63％～77％、Li₂O 10％～20％、K₂O 2～8％、Al₂O₃ 0％～7％、P₂O₅ 1％～10％、ZrO₂1 to 5 percent of the total weight of the raw materials, and the balance of coloring oxide, wherein the sum of the mass fractions of the raw materials is 100 percent.

2. The method according to claim 1, characterized in that the mixing process in the step (1) adopts a two-dimensional motion mixer, and the mixing time is 0.5-2 hours;

the bubbling process technology in the step (2) is characterized in that the introduced gas flow is 0.1-0.5 m³And h, rapidly stirring for 5-7 levels of stirring intensity for 30-90 s.

3. The method according to claim 1, wherein the preheating temperature of the graphite mold in the step (3) is 300-450 ℃; the annealing temperature is set to be 300-450 ℃, and the annealing furnace is cooled after heat preservation for 2-4 hours.

4. The method of claim 1, wherein the one-step nucleation heat treatment in step (4) is performed at 500-700 ℃ for 1-4 hours; and (5) calcining the secondary heat treatment at 750-870 ℃ for 2-10 minutes.

5. The method of claim 1, wherein the colored oxide comprises: CeO (CeO)₂And TiO₂。

6. The production device of the dental lithium disilicate glass ceramics adopted in the preparation method according to claim 1 comprises a base (1), and is characterized in that the device comprises a raw material mixing module (3) and a bubbling and ventilating module (6), wherein the bubbling and ventilating module (6) comprises a calcining box (61), an overturning stirring system (64), a rotating stirring system (65) and a bubbling and ventilating system (69), a heat insulation layer (66) is arranged on the inner wall of the calcining box (61), the rotating stirring system (65) and an electric heating tube (682) are arranged in the calcining box (61), air outlets (63) are communicated with four sides of the upper part of the calcining box (61), and the bubbling and ventilating system (69) is communicated with the rotating stirring system (65) through a ventilating hose (692).

7. The production device according to claim 6, wherein an end lifting platform (2) is installed on the upper portion of the base (1), a raw material mixing module (3) is connected to the upper portion of the lifting platform (2) in a sliding mode through an electric sliding rail (31), a mixing barrel (4) is connected to the upper portion of the raw material mixing module (3) in a rotating mode, a material inlet and outlet (42) is formed in the upper portion of the mixing barrel (4), and a sealing door (41) is installed on the upper portion of the material inlet and outlet (42).

8. The production device according to claim 6, characterized in that a control console (5) is provided at the other end of the upper portion of the base (1), a turnover stirring system (64) is fixedly connected to the upper portion of the base (1) through a bracket (70), the turnover stirring system (64) is driven by a YZR180L-4 type motor, the turnover stirring system (64) is connected with a turnover rotating shaft (641), the turnover stirring system (64) is in a turnover range of-45 degrees to 45 degrees, a turnover transmission rotating shaft (643) is provided at the other end opposite to the turnover rotating shaft (641), the turnover transmission rotating shaft (643) is installed at one side of a turnover support column (642), and an MSP430F 149 single chip microcomputer controller is provided inside the control console (5).

9. The production device according to claim 6, wherein the rotary stirring system (65) is driven by a YZR180L-4 type variable-frequency multi-speed motor, a first rotary stirring rod (652) is fixedly connected to the upper portion of the rotary stirring system (65) through a rotary rotating shaft (651), a second rotary stirring rod (653) is installed on the upper portion of the first rotary stirring rod (652), an air nozzle (654) is connected to the upper portion of the second rotary stirring rod (653), the air nozzle (654) is communicated with the bubbling ventilation system (69) through a ventilation hose (692) arranged on the side face, a temperature sensor (67) is arranged on the upper portion of the rotary rotating shaft (651), and the temperature sensor (67) is a heat-resistant thermocouple type temperature sensor.

10. The production device according to claim 6, wherein an air inlet (691) is arranged at the upper part of the bubbling and ventilating system (69), an air pump (693) is arranged on the side surface of the air inlet (691), an electric heating pipe (682) is arranged at the bottom side in the calcining box (61), the electric heating pipe (682) is connected with a temperature control device (68) through a data control line (681), the model of the temperature control device (68) is SUNDI-320/420W/430W, a mixing inlet (62) is arranged at the upper part of the calcining box (61), an inlet cover (621) is arranged at the upper part of the mixing inlet (62), the electric heating pipe (682) is controlled by the temperature control device (68), the temperature control device (68) is electrically connected with the console (5), and a discharge port (71) is arranged at one side of the calcining box (61).

Technical Field

The invention relates to the field of denture materials, in particular to a method for preparing dental lithium disilicate glass ceramics by adopting a bubbling process and related matched equipment thereof.

Background

With the increasing awareness of people on oral health care, the requirements on oral repair materials and aesthetic effects are higher and higher. The zirconia ceramics are widely applied to the field of oral restoration due to high strength, toughness and good biocompatibility. However, zirconia has a hardness and elastic modulus much greater than enamel, causing frictional wear with natural teeth during chewing movement.

The lithium disilicate glass ceramic is a glass ceramic which takes lithium disilicate as a main crystal phase and contains a small amount of other crystal phases such as lithium metasilicate, lithium phosphate, quartz and the like, and has high mechanical strength and good semi-permeability. Has the advantages of high strength, beautiful appearance, good biocompatibility, higher wear resistance, color and luster similar to natural teeth and the like, and becomes an ideal material for manufacturing the dental prosthesis.

CN106365456A provides a lithium disilicate glass ceramics, a preparation method thereof and application thereof in dental materials, wherein substances such as silicon dioxide, lithium oxide, phosphorus pentoxide and the like are used as raw materials, firstly, basic glass is obtained through step-by-step calcination, pouring forming and annealing, then, nucleation heat treatment and two-step crystallization heat treatment are carried out, the finally obtained lithium disilicate glass ceramics has the three-point bending strength of 318-365MPa and the microhardness of 644-742HV, but the bending strength of 300MPa of the material can not be used as a triple bridge, but is more used for veneering ceramics. With the development of the dental industry, lithium disilicate can replace zirconia ceramic due to excellent light transmittance and is used as a triple bridge. Therefore, the invention aims to improve the quality of the lithium disilicate glass ceramics, make the texture of the glass more uniform and obtain higher bending strength.

CN106927681A proposesA lithium-sodium-potassium co-doped dental glass ceramics and its preparation and application are disclosed, which is prepared from silicon dioxide, lithium oxide and sodium oxide through ball grinding, preburning, calcining, smelting and quenching to obtain glass frit, pulverizing, remelting, annealing, crystallizing, and heat treating again to obtain the final product, and features high anti-bending mechanical performance (392 plus 406 MPa), high HV1 Vickers hardness (665 plus 681), low softening point and expansion coefficient (11.1-12 plus 10)^-6However, the softening point of the material is reduced, and simultaneously, the crystal structure of the microcrystalline glass is loosened, and the expansion coefficient is lower only by the compact crystal structure.

The bubbling process is a necessary process for preparing float glass, but no corresponding matched equipment is provided for preparing the dental microcrystalline glass. At present, a method for bubbling in the preparation of dental glass in a laboratory is to take out a fused microcrystalline glass raw material from a common high-temperature furnace, insert a quartz glass tube for manual stirring and bubbling, and then put the fused microcrystalline glass raw material into the high-temperature furnace again for continuous fusion, wherein the method can lead the fused raw material to be subjected to irregular temperature rise and temperature reduction and is unfavorable for the crystallization process; and the air quantity and the foam density cannot be controlled by manual bubble blowing, and products with uniform quality cannot be obtained.

Therefore, the optimization of the existing preparation process and equipment of the microcrystalline glass is carried out, so that the denture material with more uniform texture, more uniform crystallization degree, more compact crystal structure, higher three-point bending resistance mechanical property and lower thermal expansion coefficient is obtained, and the method has extremely important significance and can greatly improve the yield of the material in the actual production.

Disclosure of Invention

Aiming at the problems in the prior art, the invention provides a method for preparing the dental lithium disilicate glass ceramics by adopting a bubbling process. The microcrystalline glass product has uniform texture, no bubbles, high light transmittance and easy cutting by implementing the bubbling technology, is close to the hardness of natural teeth of 570-600MPa, and has excellent bending strength, good biocompatibility and other properties.

The technical scheme of the invention is as follows:

a method for preparing dental lithium disilicate glass ceramics by adopting a bubbling process comprises the following steps:

(1) mixing the raw materials according to a ratio, sieving and uniformly mixing by a mixer; melting at 1350-1600 ℃ for 1-5 hours;

(2) carrying out bubbling process technical treatment, and then continuously melting at 1350-1600 ℃, wherein the heat preservation time is 1-5 hours; obtaining molten glass;

(3) casting the molten glass into a preheated graphite mold, and carrying out annealing process treatment to obtain a formed glass block;

(4) the formed glass block is subjected to one-step nucleation heat treatment to obtain the Li-containing glass block₂SiO₃A microcrystalline glass nucleator having a primary crystalline phase;

(5) finally, the secondary heat treatment is carried out to obtain Li₂Si₂O₅A microcrystalline glass finished product which is a main crystal phase;

wherein the raw materials in the step (1) are respectively in the following weight percentage: SiO 2₂ 63％～77％、Li₂O10％～20％、K₂O 2～8％、Al₂O₃ 0％～7％、P₂O₅ 1％～10％、ZrO₂1 to 5 percent of the total weight of the raw materials, and the balance of coloring oxide, wherein the sum of the mass fractions of the raw materials is 100 percent.

Wherein a two-dimensional motion mixer is adopted in the mixing process in the step (1), and the mixing time is 0.5-2 hours;

the bubbling process technology in the step (2) is characterized in that the introduced gas flow is 0.1-0.5 m³And h, rapidly stirring for 5-7 levels of stirring intensity for 30-90 s.

Wherein the stirring speed converted from 5-7 grade stirring strength is 30-80 r/min.

Preheating the graphite mould in the step (3) at the temperature of 300-450 ℃; the annealing temperature is set to be 300-450 ℃, and the annealing furnace is cooled after heat preservation for 2-4 hours.

The one-step nucleation heat treatment in the step (4) is heat preservation for 1-4 hours at 500-700 ℃; and (5) calcining the secondary heat treatment at 750-870 ℃ for 2-10 minutes.

The coloring oxide includes: CeO (CeO)₂And TiO₂。

The invention also provides a device for producing the dental lithium disilicate glass ceramics, which comprises a base (1) and is characterized by comprising a raw material mixing module (3) and a bubbling ventilation module (6), wherein the bubbling ventilation module (6) consists of a calcining box (61), an overturning stirring system (64), a rotary stirring system (65) and a bubbling ventilation system (69), a heat insulation layer (66) is arranged on the inner wall of the calcining box (61), the rotary stirring system (65) and an electric heating tube (682) are arranged in the calcining box (61), air outlets (63) are communicated with four sides of the upper part of the calcining box (61), and the bubbling ventilation system (69) is communicated with the rotary stirring system (65) through a ventilation hose (692).

Preferably, one end elevating platform (2) is installed on base (1) upper portion, there are raw materials mixing module (3) elevating platform (2) upper portion through electronic slide rail (31) sliding connection, raw materials mixing module (3) upper portion is rotated and is connected with blending barrel (4), blending barrel (4) upper portion is equipped with into discharge gate (42), sealed door (41) are installed on into discharge gate (42) upper portion.

Preferably, the other end of the upper portion of the base (1) is provided with a control console (5), the upper portion of the base (1) is fixedly connected with a turnover stirring system (64) through a bracket (70), the turnover stirring system (64) is driven by a YZR180L-4 type motor, the turnover stirring system (64) is connected with a turnover rotating shaft (641), the turnover stirring system (64) is in a turnover range of-45 degrees to 45 degrees, the other end opposite to the turnover rotating shaft (641) is provided with a turnover transmission rotating shaft (643), the turnover transmission rotating shaft (643) is installed on one side of a turnover support column (642), and an MSP430F 149 single chip microcomputer controller is arranged in the control console (5).

Preferably, the rotating stirring system (65) is driven by a YZR180L-4 type variable-frequency multi-speed motor, a first rotating stirring rod (652) is fixedly connected to the upper portion of the rotating stirring system (65) through a rotating shaft (651), a second rotating stirring rod (653) is installed on the upper portion of the first rotating stirring rod (652), an air jet port (654) is connected to the upper portion of the second rotating stirring rod (653), the air jet port (654) is communicated with the bubbling ventilation system (69) through a ventilation hose (692) arranged on the side face, a temperature sensor (67) is arranged on the upper portion of the rotating shaft (651), and the temperature sensor (67) is a heat-resistant thermocouple type temperature sensor.

Preferably, bubbling air-breather system (69) upper portion is equipped with air inlet (691), it is provided with air pump (693) to lead to air inlet (691) side, the inside bottom side of calcining case (61) is equipped with electrothermal tube (682), electrothermal tube (682) is connected with temperature control device (68) through data control line (681), temperature control device (68) model is SUNDI-320/420W/430W, calcining case (61) upper portion is provided with compounding import (62), import lid (621) is installed on compounding import (62) upper portion, electrothermal tube (682) passes through temperature control device (68) control, temperature control device (68) and control cabinet (5) electric connection, calcining case (61) one side is equipped with discharge gate (71).

More preferably, the raw materials are SiO in a mass ratio₂:Li₂O＝2:1～10:1；SiO₂:Li₂O＝2:1～6:1；K₂O:Al₂O₃＝1:1～1.5:1；

More preferably, the pigmented oxide formulation is: by mass fraction CeO₂ 0～0.05％、TiO₂ 0～0.01％；CeO₂：TiO₂＝4:1～8:1。

More preferably, the melting temperature in the step (1) is 1550 ℃ and the temperature is kept for 4 hours.

More preferably, the melting temperature in the step (2) is 1400 ℃, and the temperature is kept for 2 hours;

more preferably, the preheating temperature of the graphite mould in the step (3) is 400 ℃; the annealing temperature was set at 400 ℃ and held for 3 hours.

More preferably, the temperature of the one-step nucleation heat treatment in the step (5) is 640-680 ℃, and the heat preservation time is 2-4 hours; the temperature rise rate of the one-step nucleation heat treatment is 5 ℃/min or 10 ℃/min;

more preferably, the calcination temperature in the step (6) is 800-850 ℃, and the calcination time is 2-6 minutes; the temperature rise rate of the secondary heat treatment is 30-50 ℃/min, and the preferred calcining temperature rise rate is 50 ℃/min.

The microcrystalline glass productWith lithium disilicate Li₂Si₂O₅As the main crystalline phase.

The microcrystalline glass product contains 0 to 5 vol.% of zirconium lithium curbstone (Zr)₂KLi₃(Si₁₂O₃₀) Has toughening effect on lithium disilicate, can improve the fracture toughness of the lithium disilicate, can ensure that the microcrystalline glass is more transparent in the aspect of appearance characteristics, and can be better used as a veneer.

The beneficial technical effects of the invention are as follows:

1. compared with CN106365456A and CN106927681A, the invention adds zirconia component in the raw materials, can be used as nucleating agent to synergistically promote glass crystallization together with phosphorus pentoxide, and simultaneously the mechanism of phase change toughening can effectively control crystallization rate and crystal size, so that the lithium disilicate glass ceramic is more uniform and transparent, and the strength is obviously improved.

The invention also uses the colorant different from the above patent in the raw materials, so that the finally crystallized lithium disilicate glass ceramic has the color closer to natural teeth, and the simulation effect is enhanced. And the crystallized lithium disilicate glass ceramic can show different color tones by adjusting the component combination of the new colorant, thereby meeting the requirement of customization of private characteristics.

2. According to the invention, when the microcrystalline glass is prepared, a bubbling process is added, a short-time dynamic process is added in a static raw material melting process, and the problem of uneven color caused by precipitation is prevented by adopting the three-dimensional full stirring of glass liquid.

3. According to the invention, the bubbling ventilation system is matched with the rotary stirring system for use, so that large bubbles formed by bubbling are fully contacted with the glass liquid, and the small bubbles mixed in the glass liquid are fully absorbed by the bubbling bubbles in the rising process to form larger bubbles to discharge the glass liquid, thereby achieving the purpose of fully clarifying the glass liquid and improving the glass quality.

4. The invention controls the crystal size and the number of the crystals within a certain range through a special heat treatment method, thereby obtaining the Li-based material of the invention₂Si₂O₅Micro crystal phase of main crystal phaseThe microcrystalline glass has the properties of high light transmittance, easy cutting, hardness close to that of natural teeth, excellent bending strength, good biocompatibility and the like based on the principle of bidirectional regulation and control of components and structures, and can be used for dental all-ceramic repair materials.

Drawings

Fig. 1 is a schematic structural view of the present invention.

Fig. 2 is a front view of the present invention.

Fig. 3 is a schematic diagram of the mixing material pouring structure of the present invention.

Figure 4 is a schematic diagram of the structure of the bubble-vent module of the present invention.

Fig. 5 is a partial cross-sectional view of the present invention.

Fig. 6 is an enlarged view of a portion of fig. 5 according to the present invention.

FIG. 7 is a schematic view of the rotary stirring system of the present invention.

Fig. 8 is an XRD pattern of the glass ceramics obtained in example 1 after the secondary heat treatment.

Fig. 9 is an SEM image of the crystallized glass obtained after the secondary heat treatment in example 1.

In the drawings, the corresponding relationship between the component names and the reference numbers is as follows:

1. a base; 2. a lifting platform; 3. a raw material mixing module; 4. a mixing barrel; 5. a console; 6. a bubbling ventilation module; 31. an electric slide rail; 41. a closing door; 42. feeding and discharging ports; 61. calcining the box; 62. a mixing inlet; 63. an air outlet; 64. turning over the stirring system; 65. a rotary stirring system; 66. a thermal insulation layer; 621. an inlet cover; 67. a temperature sensor; 68. a temperature control device; 69. a bubble vent system; 70. a support; 71. a discharge port; 641. turning over the rotating shaft; 642. turning over the support; 643. turning over the transmission rotating shaft; 651. rotating the rotating shaft; 652. a first rotating stirring rod; 653. a second rotating stirring rod; 654. an air jet; 681. a data control line; 682. an electric heating tube; 691. an air inlet; 692. an air hose; 693. an air pump.

Detailed Description

The present invention will be described in detail with reference to the accompanying drawings and examples. It is to be understood that the described embodiments are merely exemplary of the invention, and not restrictive of the full scope of the invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

As shown in fig. 1 to 7, the present invention provides a dental glass bubbling device and equipment required by a glass preparation method, the device comprises a base 1, the device comprises a raw material mixing module 3 and a bubbling ventilation module 6, the bubbling ventilation module 6 comprises a calcining box 61, an overturning stirring system 64, a rotating stirring system 65 and a bubbling ventilation system 69, a heat insulation layer 66 is installed on the inner wall of the calcining box 61, the rotating stirring system 65 and an electric heating tube 682 are installed inside the calcining box 61, air outlets 63 are communicated on four sides of the upper portion of the calcining box 61, and the bubbling ventilation system 69 is communicated with the rotating stirring system 65 through a ventilation hose 692.

Specifically, the raw materials are fully mixed through the raw material mixing module 3, then the mixed materials enter the calcining box 61 through the mixed material inlet 62, the electric heating tube 682 is controlled to start heating in the calcining box 61 through the temperature control device 68, the temperature is controlled to be 1350-1600 ℃, and the melting is carried out, and the heat preservation time is 1-5 hours; then stirring the glass liquid by a turnover stirring system 64, a rotary stirring system 65 and a bubbling ventilation system 69 in the bubbling ventilation module 6 to prevent the glass liquid from forming layering, wherein the flow rate of the introduced gas is 0.1-0.5 m³The 65-speed stirring of the rotary stirring system is 5-7-grade stirring intensity, the turnover angle of the turnover stirring system is-45 degrees, the turnover rate is 3-5 degrees/s, and the stirring time is 30-90 s; the stirring speed is set by the control console 5, and the setting of the turnover angle range and the turnover speed is also controlled by the control console 5, so that the raw materials do not overflow the air outlet 63, and the raw materials can be set to be fixed and not to be turned over; then, the temperature control device 68 is used for controlling the electric heating tube 682 to heat and controlling the temperature to 1350-1600 ℃ for melting, and the heat preservation time is 1-5 hours.

In the above process, the bubbling ventilation system 69 is used in cooperation with the rotary stirring system 65, so that the bubbling gas is in sufficient contact with the molten glass, and the bubbles and impurities in the molten glass are removed.

As shown in fig. 1 to 4, in the above embodiment, specifically, one end elevating platform 2 is installed on the upper portion of the base 1, the upper portion of the elevating platform 2 is connected with the raw material mixing module 3 through the electric sliding rail 31 in a sliding manner, the upper portion of the raw material mixing module 3 is connected with the mixing barrel 4 in a rotating manner, the upper portion of the mixing barrel 4 is provided with the material inlet and outlet 42, and the upper portion of the material inlet and outlet 42 is provided with the sealing door 41.

The raw material mixing module 3 is a two-dimensional motion mixer, and can fully mix raw materials.

As shown in fig. 2 to 5, in the above embodiment, specifically, a control console 5 is disposed at the other end of the upper portion of the base 1, the upper portion of the base 1 is fixedly connected with an overturning stirring system 64 through a bracket 70, the overturning stirring system 64 is driven by a YZR180L-4 type motor, the overturning stirring system 64 is connected with an overturning rotating shaft 641, the overturning stirring system 64 is in an overturning range of-45 ° to 45 °, an overturning transmission rotating shaft 643 is disposed at the other end opposite to the overturning rotating shaft 641, the overturning transmission rotating shaft 643 is mounted at one side of an overturning strut 642, and an MSP430F 149 single chip microcomputer controller is disposed inside the control console 5.

As shown in fig. 1 to fig. 6, in the above embodiment, specifically, the rotating stirring system 65 is driven by a YZR180L-4 type variable frequency multi-speed motor, a first rotating stirring rod 652 is fixedly connected to an upper portion of the rotating stirring system 65 through a rotating shaft 651, a second rotating stirring rod 653 is installed on the upper portion of the first rotating stirring rod 652, an air vent 654 is connected to an upper portion of the second rotating stirring rod 653, the air vent 654 is communicated with the bubbling ventilation system 69 through a ventilation hose 692 arranged on a side surface, a temperature sensor 67 is arranged on an upper portion of the rotating shaft 651, and the temperature sensor 67 is a heat-resistant thermocouple type temperature sensor.

Wherein, the exterior of the first rotating stirring rod 652, the second rotating stirring rod 653 and the air jet 654 is provided with a high temperature resistant material layer; the high-temperature resistant material layer is isolated from the insulating layer 66 and the electric heating tube 682, an air outlet grid with the same shape as the air outlet 63 is arranged at the position of the air outlet 63, and a discharge channel is arranged at the position of the discharge port 71. The raw materials are melted in the high-temperature resistant layer and are not in contact with the heat-insulating layer 66 and the electric heating tube 682; the high-temperature resistant material is selected from quartz, corundum, ceramic and the like.

Specifically, the turnover stirring system 64 and the rotary stirring system 65 realize the three-dimensional stirring of the calcining box 61, so that the effect of full stirring is achieved, and the problem that the pigment in the raw materials is settled in the melting process to form serious uneven color is solved.

As shown in fig. 2 to 7, in the above embodiment, specifically, an air inlet 691 is provided at an upper portion of the bubbling ventilation system 69, an air pump 693 is provided at a side surface of the air inlet 691, an electric heating tube 682 is provided at a bottom side inside the calcining box 61, the electric heating tube 682 is connected to a temperature control device 68 through a data control line 681, the temperature control device 68 is of a sun di-320/420W/430W type, a mixing inlet 62 is provided at an upper portion of the calcining box 61, an inlet cover 621 is installed at an upper portion of the mixing inlet 62, the electric heating tube 682 is controlled by the temperature control device 68, the temperature control device 68 is electrically connected to the console 5, and a discharge port 71 is provided at one side of the calcining box 61.

Further, during the stirring process, the bubbling and ventilating system 69 is used for introducing gas into the calcining box 61 through the gas spraying port 654, so as to fully ensure the gas to be contacted with the molten glass, and the temperature control device 68 is used for controlling the electric heating tube 682.

Examples 1 to 7: the lithium disilicate glass ceramics prepared by the equipment has the following specific preparation process:

(1) mixing the raw materials according to a ratio, sieving and uniformly mixing by a raw material mixing module 3, wherein the mixing time is 0.5-2 hours; then pouring the mixture into a high-temperature resistant material layer of a calcining box 61, melting at 1350-1600 ℃, and keeping the temperature for 1-5 hours;

(2) carrying out bubbling process technical treatment, starting the turnover stirring system 64, the rotary stirring system 65 and the bubbling ventilation system 69, and carrying out stirring and bubbling process treatment; the overturning speed of the overturning and stirring system 64 is 5 degrees/s, the overturning angle range is set to be proper to prevent the raw materials from overflowing the air outlet 63, and the angle is selected to be-10 to 10 degrees;

after bubbling is finished, continuously melting the mixture in the high-temperature resistant material layer of the calcining box 61 at 1350-1600 ℃ for 1-5 hours; obtaining molten glass;

(3) pouring molten glass into a preheated graphite mold from a discharge port 71, and carrying out annealing process treatment to obtain a formed glass block; the preheating temperature of the graphite mold is 300-450 ℃; the annealing temperature is set to be 300-450 ℃, and the annealing furnace is cooled along with the annealing furnace after heat preservation for 2-4 hours;

(4) the formed glass block is subjected to one-step nucleation heat treatment to obtain the Li-containing glass block₂SiO₃A microcrystalline glass nucleator having a primary crystalline phase; the temperature rise rate of the one-step nucleation heat treatment is 5 ℃/min, and the temperature is kept at 500-700 ℃ for 1-4 hours;

(5) finally, the secondary heat treatment is carried out to obtain Li₂Si₂O₅A microcrystalline glass finished product which is a main crystal phase; the temperature rise rate of the secondary heat treatment is 50 ℃/min, and the secondary heat treatment is carried out for 2-10 minutes at the temperature of 750-870 ℃.

The raw material quality and the bubbling process are shown in table 1, and the preparation method is shown in table 2. Wherein the raw materials are purchased from chemical reagents of national drug group, Inc.

TABLE 1

The colorants used in the examples not listed in table 1 were: CeO (CeO)₂ 0.045％、TiO₂ 0.005％。

TABLE 2

Comparative example 1: the procedure was as in example 1 except that the bubbling process was not conducted.

Comparative example 2: the procedure was as in example 1, except that a commercially available bubbling machine (HYGD type glass tank furnace bottom dry bubbler) was used for the bubbling process.

Comparative example 3: after obtaining base glass by stepwise calcination, cast molding and annealing according to the method provided in CN106365456A example 1, the base glass is processed by the bubbling device of the present invention, and then the preparation is continued according to the steps of this example 1, and the obtained lithium disilicate glass ceramics are obtained.

Comparative example 4: the same preparation method as in comparative example 3 was used, except that a commercially available bubbling machine (a HYGD type glass tank furnace bottom dry bubbler) was used for the bubbling process step.

Wherein XRD and SEM images of example 1 are respectively shown in figures 8 and 9, and the XRD images show that the material of the invention is Li₂Si₂O₅The glass ceramics are the main crystal phase, and the crystal phase is relatively pure without impurities. From SEM image, the long rod-like needle-like crystal grains formed by the material of the invention are cross-linked and interlocked and are uniformly distributed in the microcrystalline glass.

The properties of the crystallized glasses prepared in the above examples and comparative examples are shown in tables 3 to 5.

TABLE 3

TABLE 4

	Vickers hardness (HV5)	Coefficient of linear expansion (10)-6K-1)	Density (g/cm)3)
				Example 1	659±10	7.8	2.5247
Example 2	657±10	8.0	2.4802
				Example 3	673±10	7.9	2.5138
Example 4	663±10	7.6	2.4728
				Example 5	664±10	7.9	2.4861
Example 6	658±10	8.0	2.4853
				Comparative example 1	742697±10	8.3	2.4017
Comparative example 2	697±10	8.1	2.4352
				Comparative example 3	672±10	8.0	2.4669
Comparative example 4	704±10	8.2	2.4215

TABLE 5

From the above data, Li is contained in the formulation of different components of the present invention₂Si₂O₅The appearance characterization of the microcrystalline glass with the main crystal phase shows different transparencies, the microcrystalline glass with different components has different crystallization evenness, and the Li-containing glass obtained by two-step heat treatment₂Si₂O₅The microcrystalline glass in the main crystal phase presents higher or lower degrees of transparency, which is beneficial for preparing the denture meeting the requirements of different colors and different transmittances. Generally, the higher the heat preservation temperature and the longer the heat preservation time of the one-step heat treatment, the higher the crystallization degree of a sample and the larger the Vickers hardness; the higher the heat preservation temperature of the two-step heat treatment is, the longer the heat preservation time is, the larger the growth of the sample crystal is, and the Vickers hardness and the three-point bending strength are increased. Furthermore, the strength is alsoThe crystallization uniformity of the sample is closely related, and the bending strength of the sample is seriously reduced due to the nonuniform crystallization of the sample.

The dental glass prepared by the bubbling process technology has the high-quality performances of uniform texture, no bubbles and no cracks, and the yield of the product is greatly improved. The Li-based material of the present invention is obtained by controlling the crystal size and number within a certain range by a two-step heat treatment process₂Si₂O₅Microcrystalline glass which is a main crystal phase. The microcrystalline glass has the advantages of high light transmittance, easiness in cutting, hardness close to that of natural teeth, excellent bending strength, good biocompatibility and the like based on the principle of bidirectional regulation and control of components and structures, and can be used for dental all-ceramic repair materials.

While the embodiments of the present invention have been disclosed above, it is not limited to the applications listed in the description and embodiments, but is fully applicable to various fields suitable for the present invention, and it will be apparent to those skilled in the art that various changes, modifications, substitutions and alterations can be made in the embodiments without departing from the principle and spirit of the present invention, and therefore the present invention is not limited to the specific details without departing from the general concept defined in the claims and the scope of equivalents thereof.