JP7185350B1 - RADIATION REDUCTION FILTER AND METHOD FOR MANUFACTURING RADIATION REDUCTION FILTER - Google Patents

Abstract

A radiation reduction filter that can be attached to a radiographic imaging device and a manufacturing method thereof are provided. A radiation-reducing filter comprises a composition comprising lithium oxide (Li2O), aluminum oxide (Al2O3), silicon dioxide (SiO2) and molybdenum oxide (MoO3). A raw material comprising a composition containing lithium oxide (Li2O), aluminum oxide (Al2O3), silicon dioxide (SiO2), and molybdenum oxide (MoO3) is melted at a temperature of 1600° C. to 1800° C. and refined, and the refined melt is obtained. is formed into a plate-like filter, the formed plate-like filter is subsequently heat-treated to crystallize, and the heat-treated plate-like filter is cooled. [Selection drawing] Fig. 2

Description

TECHNICAL FIELD The present invention relates to a radiation reduction filter that can be attached to a radiation imaging device and a manufacturing method of the radiation reduction filter.More specifically, the present invention significantly reduces the amount of radiation generated during imaging by the radiation imaging device and eliminates the need for related personnel. The present invention relates to a radiation-reducing filter that prevents exposure to undesired radiation while providing the same or better quality of captured images than when the filter is not attached, and a method for manufacturing the same.

In general, radiographic equipment used in hospitals is classified into fixed type imaging devices mainly used in radiography rooms and mobile type imaging devices mainly used in operating rooms.

A mobile imaging device is also called a C-arm because of its substantially C-shaped shape. ) and so on can be confirmed in real time.

Compared to the fixed type, mobile radiography equipment emits less radiation during imaging, but because it is used continuously during surgery, doctors, nurses, and patients around the radiography equipment are exposed to a large amount of radiation during surgery. had no choice but to be bombed.

On the other hand, fixed-type radiography equipment does not continuously perform imaging, but compared to the mobile type, the amount of radiation released per imaging is greater, so if repeated imaging is performed in a short period of time, a large amount of the patient will be exposed. radiation exposure.

A radiation shielding filter has been proposed as one of the measures to reduce the dose of exposure from radiation imaging equipment.

As one of conventional radiation shielding filters, there is one manufactured using a metal such as lead (Pb) or silver (Ag), which has a high radiation shielding rate. However, radiation shielding filters made of lead or silver have a problem in that image quality such as sharpness and contrast contrast is excessively degraded.

Korean Patent No. 10-1638364 (prior invention) proposes a liquid type radiation shielding filter in which the inside of a case is filled with water and powder. However, although the prior invention can also be expected to have a radiation shielding effect, it still has a problem that satisfactory image quality cannot be expected due to the limitations of silver (Ag) materials.

Korean Patent No. 10-1638364

The problem to be solved by the present invention is to reduce the amount of radiation generated during imaging from a radiation imaging device, and to prevent related persons located in the vicinity from being exposed to a large amount of radiation, and a radiation reduction filter. is to provide a manufacturing method of

Another problem to be solved by the present invention is to provide a radiation-reducing filter and a method of manufacturing a radiation-reducing filter that provides the same or better image quality than when the radiation-reducing filter is not installed. be.

As one embodiment of the present invention for solving the aforementioned problems, a composition containing lithium oxide (Li ₂ O), aluminum oxide (Al ₂ O ₃ ), silicon dioxide (SiO ₂ ) and molybdenum oxide (MoO ₃ ) A radiation reduction filter is proposed which consists of:

Other embodiments of _{the invention include lithium oxide (Li2O), aluminum oxide (Al2O3), silicon dioxide (SiO2) and molybdenum oxide (MoO3 ) , as well} as sodium oxide ( _Na2O ). , potassium oxide (K ₂ O), magnesium oxide (MgO), calcium oxide (CaO), strontium oxide (SrO), barium oxide (BaO), zinc oxide (ZnO), titanium dioxide (TiO ₂ ), zirconium oxide (ZrO ₂ ), phosphorus pentoxide (P ₂ O ₅ ), tin oxide (SnO ₂ ), iron oxide (Fe ₂ O ₃ ).

As still another embodiment of the present invention, there is proposed a radiation imaging apparatus equipped with the radiation reduction filter of the above embodiment.

In yet another embodiment of _the present invention, a raw material is provided comprising a composition comprising lithium oxide ( _Li2O ), aluminum oxide ( _Al2O3 ), silicon dioxide ( _SiO2 ) and molybdenum oxide ( _MoO3 ). Preparing; melting and refining after melting the raw material at a temperature of 1600° C. to 1800° C.; forming a plate filter through at least one process of casting, compressing, rolling and floating the refined melt. and sintering the shaped filter by subsequent heat treatment to crystallize it.

The manufacturing method of the radiation reducing filter according to the embodiment may further include annealing the molded filter by gradually heating the molded filter after the molding.

As still another embodiment of the present invention, the crystallization step includes a primary heating step of gradually heating the filter to reach 650° C. within a range of minimum 10 minutes to maximum 60 minutes; a secondary heating step of gradually heating to 800° C. within a maximum range of 100 minutes, a tertiary heating step of gradually heating to 980° C. within a range of minimum 10 minutes to maximum 80 minutes; A method for manufacturing a radiation reducing filter is proposed, further comprising a temperature maintenance step to keep the sub-heated filter at 980° C. within 60 minutes.
In addition to lithium oxide (Li ₂ O), aluminum oxide (Al ₂ O ₃ ), silicon dioxide (SiO ₂ ), and molybdenum oxide (MoO ₃ ), the method for manufacturing the radiation reduction filter of the still other embodiment includes oxide Sodium ( _Na2O ), potassium oxide ( _K2O ), magnesium oxide (MgO), calcium oxide (CaO), strontium oxide (SrO), barium oxide (BaO), zinc oxide (ZnO), titanium dioxide ( _TiO2 ), zirconium _oxide ( _ZrO2 ), phosphorus pentoxide ( _{P2O5 )} , tin oxide ( _SnO2 ), iron oxide ( _Fe2O3 ).

According to the embodiments of the present invention, it is possible to significantly reduce the amount of radiation emitted from a radiographic imaging device during imaging, and to prevent persons involved in the vicinity of the device from being exposed to a large amount of radiation.

According to embodiments of the present invention, the quality of captured images is guaranteed to be equal to or better than when the radiation reduction filter is not attached.

4 is a photograph showing the imaging result of a radiographic imaging device to which the radiation reduction filter of Example 1 is applied. 4 is a photograph showing the imaging result of a radiographic imaging device to which the radiation reduction filter of Example 1 is applied. 4 is a photograph showing the imaging result of a radiographic imaging device to which the radiation reduction filter of Example 1 is applied. 4 is a photograph showing the imaging result of a radiographic imaging device to which the radiation reduction filter of Example 1 is applied. 6 is a flow chart showing a method for manufacturing the radiation reducing filter of Example 2 in chronological order. 10 is a flow chart chronologically showing a manufacturing method of the radiation reduction filter of Example 3. FIG.

As used herein, the term "embodiment" can refer to an illustration, instance, illustration, or the like. However, the subject matter of the present invention is not limited by the embodiments described herein, and any change, conversion, equivalent or alternative to the embodiments included in the technical spirit of the present invention It should be understood that any such substance is included in the present invention.

The terms "include," "comprise," "have," or similar terms may be used herein. When those terms are used in the claims, they should be translated and interpreted as "comprising," an open type transition meaning not excluding additional elements.

Unless defined otherwise, all terms, including technical or scientific terms, used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. have.

In the present invention, "radiographic imaging equipment" is a general term for equipment that diagnoses a subject using radiation, and includes an X-ray imaging machine, a C-arm, a CT imaging machine, and a PETCT imaging machine used in hospitals. , and non-destructive inspection equipment used in industrial sites. In addition, it is not necessarily limited to them, and any device that diagnoses a subject using radiation corresponds to the "radiographic imaging device" of the present invention regardless of its name.

Embodiment 1 of the present invention relates to a radiation reduction filter that can be attached to a radiation section of a radiation imaging device.

The radiation reduction filter of Example 1 is composed of lithium oxide (Li ₂ O), aluminum oxide (Al ₂ O ₃ ), silicon dioxide (SiO ₂ ) and molybdenum oxide (MoO ₃ ).

In addition, the radiation reduction filter of Example 1 contains, based on the total weight, 55 to 75% by weight of silicon dioxide (SiO ₂ ), 14 to 28% by weight of aluminum oxide (Al ₂ O ₃ ), and lithium oxide (Li ₂ O). It may be composed of 2-8.5% by weight and 0.005-0.6% by weight of molybdenum oxide (MoO ₃ ).

Silicon dioxide makes the radiation-reducing filter vitreous and accounts for the largest weight ratio in the composition components constituting the radiation-reducing filter of Example 1. If the weight ratio of silicon dioxide is less than 55% by weight, the weight ratios of aluminum oxide, lithium oxide, and molybdenum oxide are relatively high, which may reduce the sharpness of captured images. Moreover, when the weight ratio of silicon dioxide exceeds 75% by weight, the weight ratios of aluminum oxide, lithium oxide, and molybdenum oxide become relatively low, and the strength or radiation reduction performance of the filter may deteriorate.

Aluminum oxide shields radiation in the low energy range and induces curing of the composition. If the weight ratio of aluminum oxide exceeds 28% by weight, the contrast of the captured image increases, making it difficult to identify the object in the captured image. If the weight ratio of aluminum oxide is less than 14% by weight, the ability to reduce radiation in the low-energy region may decrease.

Lithium oxide improves the water-proofing and thermal resistance of radiation-reducing filters. Lithium oxide also serves to strengthen the surface of the radiation reduction filter. The composition of lithium oxide provides sufficient durability even when the radiation reducing filter is formed into a thin plate.

Molybdenum oxide determines the light transmittance of the radiation reduction filter by weight ratio. Molybdenum oxide contributes to the formation of crystallization nuclei in the manufacturing process of the filter, and its content contributes to the degree of coloration of the filter. A large amount of molybdenum oxide reduces the viscosity of the filter. Molybdenum oxide should be contained in a relatively small amount, and if the weight ratio exceeds 0.6% by weight, the sharpness of the captured image may be deteriorated.

_The radiation reduction filter of Example 1 contains sodium oxide (Na 2 O) in addition to lithium oxide (Li ₂ O), aluminum oxide (Al ₂ O ₃ ), silicon dioxide (SiO ₂ ) and molybdenum oxide (MoO ₃ ). , potassium oxide (K ₂ O), magnesium oxide (MgO), calcium oxide (CaO), strontium oxide (SrO), barium oxide (BaO), zinc oxide (ZnO), titanium dioxide (TiO ₂ ), zirconium oxide (ZrO ₂ ), phosphorus pentoxide ( _{P2O5 )} , tin oxide ( _SnO2 ), and _iron oxide ( _Fe2O3 ).

Here, the radiation reduction filter comprises 3.55% by weight of lithium oxide (Li ₂ O), 21.2% by weight of aluminum oxide (Al ₂ O ₃ ), silicon dioxide (SiO _{2 )} , based on the total weight of the composition. ) 66.6 wt%, molybdenum oxide ( _MoO3 ) 0.009 wt%, sodium _oxide (Na2O) 0.5 wt%, potassium oxide ( _K2O ) 0.08 wt%, magnesium oxide (MgO) 0.26 wt%, 0.38 wt% calcium oxide (CaO), 0.04 wt% strontium oxide (SrO), 0.89 wt% barium oxide (BaO), 1.5 wt% zinc oxide (ZnO), Titanium dioxide ( _TiO2 ) 2.28% by weight, zirconium _oxide ( _ZrO2 ) 1.88% by weight, phosphorus pentoxide ( _P2O5 ) 0.025% by weight, tin oxide ( _SnO2 ) 0.13% by weight , iron oxide (Fe ₂ O ₃ ) 0.015% by weight.

Sodium oxide increases the shock resistance of the radiation reduction filter and evenly distributes the components as the silicon dioxide and aluminum oxide solidify.

Strontium oxide plays a role in reducing radiation. Barium oxide is used as a substitute for lead oxide in the production of filters. Zinc oxide strengthens the surface of the filter by preventing the formation of macrostructures on the surface of the crystallized filter.

Phosphorus pentoxide, potassium oxide, magnesium oxide, calcium oxide, zirconium oxide, and iron oxide increase the strength and durability of radiation-reducing filters.

Titanium dioxide, zirconium oxide, tin oxide are allowed to influence the microcrystalline structure during the crystallization process of the filter.

The radiation-reducing filter manufactured with the composition exemplified above exhibits a light transmittance of 70% or more at a thickness of 3 mm to 5 mm, and the absorption rate of ultraviolet (UV) is increased, so that the radiation can be sufficiently reduced. At the same time, it can ensure high-quality shooting images.

Radiation Shielding Rate Test Table 1 shows the measurement environment and shielding results of the radiation shielding rate test of the radiation reducing filter according to Example 1.

In Table 1, the shielding rate was calculated by Equation 1.

In Equation 1, _I1 is the ionization current (A) measured before placing the specimen and _I2 is the ionization current (A) measured after placing the specimen.

As can be seen in Table 1, the radiation reduction filter according to Example 1 exhibited an excellent shielding rate of 71.1%.

Imaging Result Test Table 2 shows test conditions for confirming the imaging results of the radiation imaging equipment equipped with the radiation reduction filter according to Example 1.

Under the test conditions shown in Table 2, the radiation reduction filters of Example 1 were positioned at the beam emitting portion of the C-arm, and the number of radiation reduction filters was changed for measurement.

1A to 1D are photographs showing the imaging results of the radiation imaging equipment to which the radiation reduction filter of Example 1 is applied. Specifically, FIGS. 1A and 1B are the results obtained by attaching one (1 ea) 5 mm radioactivity reduction filter to the beam emitting part, respectively, and FIGS. ) is attached to the beam emitting part and photographed.

In FIGS. 1A to 1D, the four horizontal lines L1 to L4 indicate that the blood vessels and skeleton are sufficiently displayed in the image captured with the radiation reduction filter of Example 1 attached. It is a test indicator that allows you to check whether

1A and 1B, four marker lines L1 and L2 can be seen clearly when one (1 ea) 5 mm radioactivity reduction filter is attached. In addition, as can be seen in the image results of FIGS. 1C and 1D, even when two (2ea) 5mm radiation reduction filters are attached to further increase the radiation shielding rate by one level, there are still four It can be confirmed that the marker lines L3 and L4 of are clearly visible.

Example 2 relates to a method of manufacturing the radiation reducing filter of Example 1. FIG. 2 is a flow chart showing the method of manufacturing the filter of Example 2 in time series.

Referring to FIG. 2, the method of manufacturing the filter of Example 2 comprises preparing raw materials (S110), melting and refining the raw materials (S120), and forming the refined melt into a plate filter. (S130), and crystallizing the molded filter (S150). After the molding step (S130), a step of removing stress (S140) or a cutting step (not shown) for improving transparency. ) can be further included.

In the raw material preparation step (S110), raw materials are composed of a composition containing lithium oxide (Li ₂ O), aluminum oxide (Al ₂ O ₃ ), silicon dioxide (SiO ₂ ) and molybdenum oxide (MoO ₃ ). At this time, silicon dioxide (SiO ₂ ) 55-75 wt%, aluminum oxide (Al ₂ O ₃ ) 14-28 wt%, lithium oxide (Li ₂ O) 2-8.5 wt%, based on the total weight of the raw materials. %, and molybdenum oxide (MoO ₃ ) 0.005 to 0.6% by weight.

Next, the raw material melting and scouring step (S120) is performed.

The melting and refining step (S120) heats the prepared raw materials at a temperature of 1600° C. to 1800° C. to melt them, and then removes impurities by removing gas inclusions (or bubbles) from the melt. This is the stage of refining.

Next, a melt forming step (S130) is performed.

The forming step (S130) is a process of forming the melt into a plate filter using at least one of forging, compressing, rolling and floating. be. The forming step (S130) is not necessarily limited to those processes, and may be performed by various methods such as the Fourcault method, the Pittsburgh method, and the Fusion Down Draw method. .

Next, a stress relief step (S140) is performed.

The stress removing step (S140) is a step of removing the internal residual stress introduced in the previous process while gradually heating the molded filter to a preset temperature, and is understood as an annealing process. may be

The annealing process softens the shaped filter sufficiently to relieve stresses inherent in the filter while absorbing heat uniformly throughout the process as it is gradually heated to 450-600°C.

On the other hand, in the present specification and claims, "relief of stress" means not only complete elimination of stress, but also relaxation of stress below a preset standard or almost complete elimination of stress. may be interpreted. Also, the stress relief step (S140) may be omitted if stringent requirements for strength reliability are not presented.

Next, a crystallization step (S150) is performed.

The crystallization step (S150) may be performed by a subsequent heat treatment of the annealed filter.

For example, the crystallization step (S150) is a step of putting the filter into a ceramics furnace or a ceramics chamber and performing a subsequent heat treatment process to sufficiently strengthen the molded filter.

Thereafter, at least one of an etching step (not shown) and a cooling step (not shown) may be further included to improve the translucency of the filter or planarize the surface of the filter. The cooling step is a step of sufficiently cooling the filter at room temperature or a preset temperature after the subsequent heat treatment of step S150 is completed.

The filter manufactured by the above process has characteristics such that tensile stress is generated by cooling and reheating during the molding process, the internal strength is strengthened, and the filter is resistant to external impact.

Example 3 is a method for making the radiation reduction filter of Example 1.

FIG. 3 is a flow chart showing a method for manufacturing the radiation reduction filter of Example 3;

Referring to FIG. 3, the method of Example 3 includes the steps of preparing raw materials (S210), refining the raw materials after melting (S220), forming into a plate filter (S230), and removing stress (S230). S240), crystallizing the filter by successive heating (S250-S270), and homogenizing the crystalline structure of the filter by maintaining a constant temperature (S280).

The raw material preparation stage (S210), the melting and refining stage (S220), the filter forming stage (S230), and the stress relief stage (S240) in Example 3 are the raw material preparation stage (S110), the melting and refining stage (S240) in Example 2. S120), the filter forming step (S130), and the stress removing step (S140) are the same, and redundant descriptions thereof will be omitted.

The first heating step (S250) is to gradually heat the stress-relieved filter to a temperature of about 650° C. within a range of minimum 10 minutes to maximum 60 minutes in a ceramic chamber. Preferably, it is gradually heated to 650° C. within about 30 minutes.

The second heating step (S260) is a step of gradually heating the firstly heated 650° C. filter further to 800° C. within the range of minimum 10 minutes to maximum 100 minutes. Preferably, the primary heated 650° C. filter is gradually heated to 800° C. within about 20 minutes. A filter made of ceramic glass is manufactured while crystallization nuclei are formed in the filter by the primary and secondary heating.

The tertiary heating step (S270) is a step of gradually heating the secondarily heated 800° C. filter further to 980° C. within the range of minimum 10 minutes to maximum 80 minutes. Preferably, the secondary heated 800° C. filter is gradually heated to 918° C. at a rate of 5° C./min for about 25 minutes. After the crystallization nuclei are formed by the primary and secondary heating, the formed crystallization nuclei are sufficiently grown by the tertiary heating.

The temperature maintenance step (S280) is a step of maintaining the maximum temperature of the tertiary heating within 60 minutes. Preferably, the maximum temperature of the tertiary heating, ie, 918° C., is maintained for about 10 minutes. By maintaining a constant temperature for a preset period of time, the crystal microstructure is homogenized.

Thereafter, at least one of an etching step (not shown) and a cooling step (not shown) may be further included to improve the translucency of the filter or planarize the surface of the filter. The cooling step is a step of sufficiently cooling the filter to room temperature or a preset temperature after the temperature maintenance in step S280 is completed.

On the other hand, the raw materials used in the production method of Example 3 are lithium oxide (Li ₂ O), aluminum oxide (Al ₂ O ₃ ), silicon dioxide (SiO ₂ ), molybdenum oxide (MoO ₃ ), sodium oxide (Na ₂ O), potassium oxide ( _K2O ), magnesium oxide (MgO), calcium oxide (CaO), strontium oxide (SrO), barium oxide (BaO), zinc oxide (ZnO), titanium dioxide ( _TiO2 ), zirconium oxide ( _ZrO2 ), phosphorus pentoxide ( _{P2O5 ) ,} tin oxide ( _SnO2 ), iron oxide ( _Fe2O3 ).

At this time, in Example 3, the composition ratio of the raw materials was 3.55% by weight of lithium oxide (Li ₂ O), 21.2% by weight of aluminum oxide (Al ₂ O ₃ ), and 21.2% by weight of silicon dioxide, based on the total weight. ( _SiO2 ) 66.6 wt%, molybdenum oxide ( _MoO3 ) 0.009 wt%, sodium oxide ( _Na2O ) 0.5 wt%, potassium oxide ( _K2O ) 0.08 wt%, magnesium oxide (MgO) 0.26 wt%, calcium oxide (CaO) 0.38 wt%, strontium oxide (SrO) 0.04 wt%, barium oxide (BaO) 0.89 wt%, zinc oxide (ZnO) 1.5 2.28 wt.% titanium dioxide ( _TiO2 ) _, 1.88 wt.% zirconium oxide ( _ZrO2 ), 0.025 wt.% phosphorus pentoxide ( _P2O5 ), 0.025 wt.% tin oxide ( _SnO2 ). 13% by weight and 0.015% by weight _of iron oxide ( _Fe2O3 ).

Also, in the method of Example 3, the raw material may further include tantalum oxide (Ta ₂ O ₅ ) to facilitate crystallization or homogenization of the filter. Alternatively, tantalum oxide (Ta ₂ O ₅ ) may be included in place of at least one of titanium dioxide (TiO ₂ ), zirconium oxide (ZrO ₂ ), and tin oxide (SnO ₂ ) among the raw materials.

Although the invention has been described above with reference to certain embodiments of the invention, it will be appreciated by those skilled in the art that the spirit and scope of the invention as set forth in the following claims will not deviate from the spirit and scope of the invention. It will be understood that various modifications and alterations may be made to the invention without departing from the scope of the invention.

Claims (10)

A radiation reduction filter to be attached to a radiation section of a radiation imaging device,
The radiation reduction filter is
Based on the total weight of the radiation reduction filter,
Lithium oxide (Li ₂ O) 2-8.5% by weight, aluminum oxide (Al ₂ O ₃ ) 14-28% by weight, silicon dioxide (SiO ₂ ) 55-75% by weight, molybdenum oxide (MoO ₃ ) 0.005 consisting of a composition comprising ~0.6% by weight,
A radiation-reducing filter that does not contain a metal element that is not in the form of an oxide . The radiation reduction filter is
Sodium oxide ( _Na2O ), potassium oxide ( _K2O ), magnesium oxide (MgO), calcium oxide (CaO), strontium oxide (SrO), barium oxide (BaO), zinc oxide (ZnO), titanium dioxide (TiO ₂ ), zirconium oxide ( _ZrO2 ), phosphorus _pentoxide ( _P2O5 ), tin oxide ( _SnO2 ), iron oxide ( _Fe2O3 ) _. reduction filter. The radiation reduction filter is
Based on the total weight of the filter,
Lithium oxide ( _Li2O ) 3.55% by weight, aluminum oxide ( _Al2O3 ) 21.2% by weight, silicon dioxide ( _SiO2 ) 66.6% by weight, molybdenum oxide ( _{MoO3 )} 0.009% by weight , sodium oxide (Na ₂ O) 0.5% by weight, potassium oxide (K ₂ O) 0.08% by weight, magnesium oxide (MgO) 0.26% by weight, calcium oxide (CaO) 0.38% by weight, oxide Strontium (SrO) 0.04% by weight, barium oxide (BaO) 0.89% by weight, zinc oxide (ZnO) 1.5% by weight, titanium dioxide (TiO ₂ ) 2.28% by weight, zirconium oxide (ZrO ₂ ) 1.88% by _weight , 0.025% by weight phosphorus pentoxide ( _P2O5 ), 0.13% _by weight tin oxide ( _SnO2 ), 0.015% by weight iron oxide ( _Fe2O3 ) 3. The radiation reduction filter of claim 2 , comprising: The radiation reduction filter according to claim 1, wherein the radiation reduction filter is formed with a thickness of 3 mm to 5 mm. A radiation imaging device equipped with the radiation reduction filter according to any one of claims 1 to 4 . preparing _a raw material comprising a composition comprising lithium oxide ( _Li2O ), aluminum oxide ( _Al2O3 ), silicon dioxide ( _SiO2 ), and molybdenum oxide ( _MoO3 );
melting and refining the raw material after melting at a temperature of 1600° C. to 1800° C.;
shaping the refined melt into a plate-like filter;
Crystallizing the molded plate-like filter by subsequent heat treatment; and Cooling the plate-like filter subjected to the subsequent heat treatment.
including
The raw material is
Based on the total weight of raw materials,
Lithium oxide (Li ₂ O) 2-8.5% by weight, aluminum oxide (Al ₂ O ₃ ) 14-28% by weight, silicon dioxide (SiO ₂ ) 55-75% by weight, molybdenum oxide (MoO ₃ ) 0.005 A method for producing a radiation-reducing filter comprising ˜0.6% by weight and containing no metal elements that are not in the form of oxides . 7. The method of manufacturing a radiation reduction filter according to claim 6 , further comprising the step of gradually heating the molded plate-shaped filter to a preset temperature to relieve stress (annealing) after the molding step. . The step of crystallizing comprises:
A first heating stage in which the plate-shaped filter is gradually heated to 650° C. within a range of minimum 10 minutes to maximum 60 minutes, and a step of gradually heating to 800° C. within a minimum range of 10 minutes to maximum 100 minutes. a secondary heating step of heating, a tertiary heating step of gradually heating to 980° C. within a minimum of 10 minutes to a maximum of 80 minutes, and a filter heated to 980° C. within 60 minutes. 7. The method of manufacturing a radiation reduction filter according to claim 6 , further comprising a temperature maintaining step of keeping the temperature at . The raw material is
Sodium oxide ( _Na2O ), potassium oxide ( _K2O ), magnesium oxide (MgO), calcium oxide (CaO), strontium oxide (SrO), barium oxide (BaO), zinc oxide (ZnO), titanium dioxide (TiO ₂ ), zirconium oxide ( _ZrO2 ), phosphorus _pentoxide ( _P2O5 ) _, tin oxide ( _SnO2 ), iron oxide ( _Fe2O3 ). A method for manufacturing a reduction filter. The raw material is
Based on the total weight of raw materials,
Lithium oxide ( _Li2O ) 3.55% by weight, aluminum oxide ( _Al2O3 ) 21.2% by weight, silicon dioxide ( _SiO2 ) 66.6% by weight, molybdenum oxide ( _{MoO3 )} 0.009% by weight , sodium oxide (Na ₂ O) 0.5% by weight, potassium oxide (K ₂ O) 0.08% by weight, magnesium oxide (MgO) 0.26% by weight, calcium oxide (CaO) 0.38% by weight, oxide Strontium (SrO) 0.04% by weight, barium oxide (BaO) 0.89% by weight, zinc oxide (ZnO) 1.5% by weight, titanium dioxide (TiO ₂ ) 2.28% by weight, zirconium oxide (ZrO ₂ ) 1.88% by _weight , 0.025% by weight phosphorus pentoxide ( _P2O5 ), 0.13% _by weight tin oxide ( _SnO2 ), 0.015% by weight iron oxide ( _Fe2O3 ) The method for manufacturing a radiation reduction filter according to claim 9 , comprising:

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