Tantalum spinneret, method for producing same, and use thereof

Abstract

The application relates to the technical field of spinning, and provides a tantalum spinneret, a preparation method thereof and application thereof, wherein the tantalum spinneret comprises a tantalum spinneret body and a tantalum pentoxide oxidation film formed on the surface of the tantalum spinneret body, and the tantalum pentoxide oxidation film is prepared by anodic oxidation of an oxidation solution comprising ethylene glycol, ammonium nitrate, boric acid and water. The tantalum spinneret is prepared by adopting specific components of the oxidation solution, the tantalum pentoxide oxidation film is formed on the surface of the tantalum spinneret body, the tantalum spinneret has high-temperature resistance, corrosion resistance and conductivity, the tantalum pentoxide oxidation film on the surface of the tantalum spinneret body can prevent the tantalum from absorbing oxygen and hydrogen in a 400 DEG C environment, and does not affect the requirement of a spinning electrode potential.

Description

Technical Field

[0001] This invention relates to the field of spinning technology, and in particular to a tantalum spinneret, its preparation method, and its application. Background Technology

[0002] The tantalum spinneret spinning process involves extruding precisely metered, filtered, and deaerated spinning solution through the micropores of a tantalum spinneret to form a fine stream. This stream undergoes double diffusion and coagulation in a coagulation bath before being processed into fibers. This method is commonly used in wet spinning (such as viscose and acrylic fibers). In the tantalum spinneret spinning process, the core component, the tantalum spinneret, directly affects the quality of the spun fibers.

[0003] Tantalum spinnerets are typically made of tantalum or tantalum alloys, with thousands or tens of thousands of micropores on their surface. Currently, tantalum spinnerets are coated with an insulating film, which must be ground off to make the filament surface conductive to meet the spinning potential requirements. Furthermore, the spinning solution remaining in the micropores of the spinneret after spinning requires high-temperature steam above 400°C to clean thoroughly, causing rapid oxidation and brittleness on the spinneret surface, leading to cracking and significantly shortening its lifespan. Tantalum begins to oxidize slightly at 180°C and oxidizes rapidly at 400°C. Tantalum and hydrogen combine above 250°C to form brittle solid solutions and metal hydrides, causing the spinneret surface to become brittle and crack, further reducing its lifespan.

[0004] Therefore, in order to improve the service life of tantalum spinnerets and prepare electrode potentials that meet the requirements of spinning, it is of great significance to prepare a film layer on the surface of tantalum spinnerets. Summary of the Invention

[0005] The technical problem solved by this invention is to provide a tantalum spinneret, which has the advantages of being conductive, high temperature resistant, and corrosion resistant.

[0006] In view of this, this application provides a tantalum spinneret, including a tantalum spinneret body and a tantalum pentoxide oxide film formed on the surface of the tantalum spinneret body, wherein the tantalum pentoxide oxide film is prepared by anodizing an oxidizing solution including ethylene glycol, ammonium nitrate, boric acid and water.

[0007] In some specific embodiments, based on the total mass of the oxidizing liquid, the content of ethylene glycol is 30-88 wt%, the total content of boric acid and water is 10-60 wt%, and the content of ammonium nitrate is 0.5-35 wt%.

[0008] In some specific embodiments, the boric acid is 0.01 to 0.2 wt% of the water.

[0009] In some specific embodiments, the voltage of the anodizing is 5V~250V, the anodizing time is 0.5~3h, and / or the temperature of the oxidizing solution is 50~100℃.

[0010] In some specific embodiments, based on the total mass of the oxidizing liquid, the content of ethylene glycol is 40-80 wt%, the total mass of boric acid and water is 15-55 wt%, the content of ammonium nitrate is 5-30 wt%, and the boric acid is 0.05-0.15 wt% of the water.

[0011] In some specific embodiments, the surface resistivity of the tantalum spinneret is 0~0.2mΩ.

[0012] This application also provides a method for preparing a tantalum spinneret, comprising the following steps:

[0013] The tantalum spinneret body is anodized in an oxidizing solution to obtain the tantalum spinneret;

[0014] The oxidizing solution includes ethylene glycol, ammonium nitrate, boric acid, and water.

[0015] In some specific embodiments, based on the total mass of the oxidizing liquid, the content of ethylene glycol is 30-88 wt%, the total content of boric acid and water is 10-60 wt%, the content of ammonium nitrate is 0.5-35 wt%, and the boric acid is 0.01-0.2 wt% of the water.

[0016] In some specific embodiments, the voltage of the anodizing is 5V~250V, the anodizing time is 0.5~3h, and the temperature of the oxidizing solution is 50~100℃.

[0017] This application provides the application of the tantalum spinneret described in the above-described scheme or the tantalum spinneret prepared by the preparation method described in the above-described scheme in the spinning process.

[0018] This application provides a tantalum spinneret, comprising a tantalum spinneret body and a tantalum pentoxide oxide film formed on the surface of the tantalum spinneret body. The tantalum pentoxide oxide film is prepared by anodic oxidation of an oxidation solution comprising ethylene glycol, ammonium nitrate, boric acid, and water. Boric acid can increase the growth rate of the tantalum pentoxide oxide film and adjust the stability and pH value of the oxidation solution, thereby improving the performance of the tantalum pentoxide oxide film. Ammonium nitrate serves as a nitrogen source to generate a nitrogen-doped tantalum pentoxide oxide film, which improves the conductivity and surface hardness of the film. Furthermore, the generated tantalum pentoxide oxide film blocks the reaction between the tantalum spinneret body and oxygen and hydrogen, thus extending the service life of the tantalum spinneret. Therefore, the tantalum spinneret provided by this application has the advantages of high temperature resistance and corrosion resistance, and the tantalum pentoxide oxide film on its surface is conductive, meeting the electrode potential requirements for spinning. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the tantalum spinneret of the present invention. Detailed Implementation

[0020] To further understand the present invention, preferred embodiments of the present invention are described below in conjunction with examples. However, it should be understood that these descriptions are only for further illustrating the features and advantages of the present invention, and not for limiting the scope of the claims of the present invention.

[0021] In view of the high temperature resistance and the requirement of meeting the spinning electrode potential of existing tantalum spinnerets, this application provides a tantalum spinneret that forms a tantalum pentoxide oxide film on the surface of the tantalum spinneret body by using a specific oxidation liquid composition, so that the tantalum spinneret has high temperature resistance, corrosion resistance and conductivity; specifically, the present invention discloses a tantalum spinneret including a tantalum spinneret body and a tantalum pentoxide oxide film formed on the surface of the tantalum spinneret body, wherein the tantalum pentoxide oxide film is prepared by anodic oxidation of an oxidation liquid including ethylene glycol, ammonium nitrate, boric acid and water.

[0022] In this disclosure, the tantalum spinneret includes a tantalum spinneret body and a tantalum pentoxide oxide film formed on the surface of the tantalum spinneret body, such as... Figure 1 As shown, Figure 1 The figure shows a schematic diagram of the structure of the tantalum spinneret disclosed herein. As shown, a tantalum pentoxide oxide film is formed on the surface of the filament exit surface of the tantalum spinneret body and on the surface of the micropores of the spinneret.

[0023] In this disclosure, the tantalum spinneret body is a tantalum spinneret body well known to those skilled in the art, and this application does not impose any special limitations on it.

[0024] In this disclosure, the tantalum pentoxide oxide film on the surface of the tantalum spinneret body is obtained by anodizing the tantalum spinneret body in an oxidizing solution, wherein the oxidizing solution includes ethylene glycol, ammonium nitrate, boric acid, and water. In some specific embodiments, based on the total mass of the oxidizing solution, the content of ethylene glycol is 30-88 wt%, the total content of boric acid and water is 10-60 wt%, and the content of ammonium nitrate is 0.5-35 wt%. In the above-mentioned oxidizing solution, ethylene glycol and water are used as solvents. Boric acid can increase the growth rate of the tantalum pentoxide oxide film and is used to adjust the stability and pH value of the oxidizing solution, so as to indirectly affect the performance of the film by influencing the growth kinetics and dissolution balance of the tantalum pentoxide oxide film. Other acids will reduce the growth rate of the tantalum pentoxide oxide film.

[0025] In this disclosure, ammonium nitrate serves as a nitrogen source, which generates a nitrogen-doped tantalum pentoxide oxide film in an oxidizing solution, significantly improving the film's conductivity and surface hardness. Other nitrates, such as lithium nitrate, form a lithium tantalate-containing tantalum pentoxide oxide film on the surface of the tantalum spinneret, which has insulating properties, making the spinning process inconsistent with the electrode potential requirements.

[0026] In this disclosure, the content of ethylene glycol is 30-88 wt%. In some specific embodiments, the content of ethylene glycol is 40-80 wt%. In some specific embodiments, the content of ethylene glycol is 45-72 wt%. In some specific embodiments, the content of ethylene glycol is 50-70 wt%. In some specific embodiments, the content of ethylene glycol is 54-63 wt%. In some specific embodiments, the content of ethylene glycol is 58-60 wt%.

[0027] In this disclosure, the total content of boric acid and water is 10-60 wt%, wherein boric acid is 0.01-0.2 wt% of water. In some specific embodiments, the total content of boric acid and water is 15-55 wt%, wherein boric acid is 0.05-0.15 wt% of water. In some specific embodiments, the total content of boric acid and water is 20-52 wt%. In some specific embodiments, the total content of boric acid and water is 24-46 wt%. In some specific embodiments, the total content of boric acid and water is 28-40 wt%. In some specific embodiments, the boric acid and water... The total water content is 30-38 wt%, and in some specific embodiments, the total content of the boric acid and the water is 32-36 wt%; in the boric acid and the water, the boric acid is 0.02 wt%, 0.03 wt%, 0.04 wt%, 0.05 wt%, 0.06 wt%, 0.07 wt%, 0.08 wt%, 0.09 wt%, 0.10 wt%, 0.11 wt%, 0.12 wt%, 0.13 wt%, 0.14 wt%, 0.15 wt%, 0.16 wt%, 0.17 wt%, 0.18 wt%, or 0.19 wt% of the water.

[0028] In this disclosure, the content of ammonium nitrate is 0.5-35 wt%. In some specific embodiments, the content of ammonium nitrate is 5-30 wt%. In some specific embodiments, the content of ammonium nitrate is 8-28 wt%. In some specific embodiments, the content of ammonium nitrate is 10-26 wt%. In some specific embodiments, the content of ammonium nitrate is 13-22 wt%. In some specific embodiments, the content of ammonium nitrate is 16-19 wt%.

[0029] In this disclosure, the temperature of the oxidizing liquid is 50~100℃. In some specific embodiments, the temperature of the oxidizing liquid is 60~90℃. In some specific embodiments, the temperature of the oxidizing liquid is 65~85℃. In some specific embodiments, the temperature of the oxidizing liquid is 70~80℃.

[0030] In this disclosure, the anodizing process is a well-known technique to those skilled in the art, and this application does not impose any particular limitations on its specific implementation. The anodizing voltage is 5~250V, and the anodizing time is 0.5~3h. In some specific embodiments, the anodizing voltage is 10~200V, and the anodizing time is 0.8~2.2h. In some specific embodiments, the anodizing voltage is 15~160V, and the anodizing time is 1.0~2.0h. In some specific embodiments, the anodizing voltage is 20~150V, and the anodizing time is 1.2~1.6h. In some specific embodiments, the anodizing voltage is 32~140V, and the anodizing time is 1.3~1.5h. In some specific embodiments, the anodizing voltage is 45~120V. In some specific embodiments, the anodizing voltage is 50~110V. In some specific embodiments, the anodizing voltage is 60~100V. In some specific embodiments, the anodizing voltage is 65~90V. In some specific embodiments, the anodizing voltage is 70~85V.

[0031] In this disclosure, the surface resistance of the tantalum spinneret is 0~0.2mΩ, and in some specific embodiments, the surface resistance of the tantalum spinneret is 0.1~0.2mΩ; the tantalum pentoxide oxide film formed on the surface of the tantalum spinneret body is conductive, thereby enabling the prepared filament to meet the requirements of the electrode potential.

[0032] This disclosure also provides a method for preparing a tantalum spinneret, comprising the following steps:

[0033] The tantalum spinneret body is anodized in an oxidizing solution to obtain the tantalum spinneret;

[0034] The oxidizing solution includes ethylene glycol, ammonium nitrate, boric acid, and water.

[0035] In the method for preparing a tantalum spinneret, the tantalum spinneret body is a tantalum spinneret well-known to those skilled in the art, specifically as follows: Figure 1 As shown. The oxidizing solution includes ethylene glycol, ammonium nitrate, boric acid, and water. The oxidizing solution has already been described in detail above and will not be repeated here.

[0036] In this disclosure, the anodizing process is a technique well-known to those skilled in the art, and this application does not impose any particular limitations on it. The anodizing process has been described in detail above and will not be repeated here.

[0037] The tantalum spinneret body is anodized using the above-mentioned oxidizing solution, resulting in a tantalum pentoxide oxide film on the surface of the tantalum spinneret body. The film is fine, uniform, and conductive, meeting the requirements of the spinning electrode potential. It can be used in large quantities in actual production, solving the problem of oxidation cracking of tantalum spinnerets at high temperatures above 400℃, and greatly improving the corrosion resistance of the spinneret.

[0038] Furthermore, this disclosure also provides the application of the tantalum spinneret described in the above-described scheme or the tantalum spinneret prepared by the preparation method described in the above-described scheme in the spinning process.

[0039] In this disclosure, the spinning process is a spinning process well known to those skilled in the art, and there are no particular limitations thereto; since the tantalum pentoxide oxide film on the surface of the tantalum spinneret is conductive, the spinning meets the requirements of the electrode potential.

[0040] To further understand the present invention, the tantalum spinneret provided by the present invention will be described in detail below with reference to the embodiments. The scope of protection of the present invention is not limited by the following embodiments.

[0041] Example

[0042] The tantalum spinneret was placed in an oxidizing solution for anodizing. The oxidizing solution, based on its total mass, included 60 wt% ethylene glycol, 10 wt% ammonium nitrate, and a total of 30 wt% boric acid and water, with boric acid comprising 0.05 wt% of water. The relevant parameters for anodizing are shown in Table 1.

[0043] Table 1. Data on relevant parameters for anodic oxidation in the embodiments.

[0044]

[0045] As shown in Table 1, the resistance of the tantalum pentoxide oxide film increases with increasing voltage, which can be considered as conductivity by those skilled in the art.

[0046] The tantalum spinneret prepared in Example 2 was placed in a muffle furnace and heated at 450°C for different times to test its hardness. The results are shown in Table 2.

[0047] Table 2. Hardness (HV) data for tantalum spinneret body and tantalum spinnerets with tantalum pentoxide oxide film on surface.

[0048]

[0049] As shown in Table 2, the hardness of the tantalum spinneret body increases with the extension of heating time, and the surface turns blue, indicating that the tantalum spinneret body absorbs hydrogen and oxygen severely. However, the hardness of the tantalum spinneret with a tantalum pentoxide oxide film on the surface remains stable and the color does not change, indicating that the film layer on the surface of the tantalum spinneret effectively blocks the absorption of hydrogen and oxygen, thus improving the high temperature resistance of the tantalum spinneret.

[0050] The tantalum spinneret and tantalum spinneret body (tantalum spinneret without oxide film) prepared in Example 1 were subjected to corrosion tests, and the results are shown in Tables 3 and 4:

[0051] Table 3 Corrosion data of tantalum spinnerets at 200℃ / 8h in 98% concentrated sulfuric acid.

[0052]

[0053] As shown in Table 3, the tantalum spinneret prepared in Example 1 lost 0.0031 g of total mass after being boiled in 98% concentrated sulfuric acid at 200°C for 8 hours (4 hours each time). The tantalum wire head body, used as a comparison, also lost 0.0034 g of total mass after being boiled in 98% concentrated sulfuric acid at 200°C for 8 hours (4 hours each time). Overall, the tantalum spinnerets prepared in Example 1 maintained excellent sulfuric acid corrosion resistance. In some cases, the sulfuric acid corrosion resistance of the tantalum spinnerets prepared in Example 1 was even slightly better than that of spinnerets without a film on the wire exit surface. However, the sulfuric acid concentration and operating temperature in the actual working conditions are much lower than the experimental temperatures mentioned above. Therefore, the tantalum spinnerets prepared in this application have excellent acid resistance and can well meet the needs of actual production.

[0054] Table 4 Corrosion test results of 40% sodium hydroxide solution at 80°C for 1 hour

[0055]

[0056] As shown in Table 4, the tantalum spinneret prepared in Example 1 lost 0.0050 g of total mass after being boiled in 40% sodium hydroxide solution at 80°C for 1 hour (0.5 hours each time). In contrast, the tantalum spinneret body lost 0.0305 g of total mass after being boiled in 40% sodium hydroxide solution at 80°C for 1 hour (0.5 hours each time). Based on these data, the tantalum spinneret prepared in Example 1 is nearly 6 times more resistant to alkali corrosion than the tantalum spinneret body (the tantalum spinneret without a film).

[0057] Comparative Example

[0058] The tantalum spinneret was placed in an oxidizing solution for anodizing; the total mass of the oxidizing solution included 60 wt% ethylene glycol, 10 wt% lithium nitrate, and 30 wt% phosphoric acid and water, with phosphoric acid comprising 0.05 wt% of water; the relevant parameters for anodizing are shown in Table 5.

[0059] Table 5. Data on relevant parameters for anodic oxidation in the embodiments.

[0060]

[0061] As shown in Table 5, the resistance of the oxide film increases with increasing voltage, and the resistance of the tantalum pentoxide oxide film prepared in the comparative example is significantly higher than that in the example.

[0062] In actual production, 660 spinnerets were shipped in March 2025, and by December 11, none of them showed signs of oxidation or discoloration, nor any cracking. However, of the 300 tantalum spinneret bodies shipped in August 2023, customers reported that 25 of them cracked due to oxidation and hydrogenation of the filament exit surface, which made them brittle.

[0063] The above description of the embodiments is only for the purpose of helping to understand the method and core ideas of the present invention. It should be noted that those skilled in the art can make several improvements and modifications to the present invention without departing from the principles of the present invention, and these improvements and modifications also fall within the protection scope of the claims of the present invention.

[0064] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A tantalum spinneret, comprising a tantalum spinneret body and a tantalum pentoxide oxide film formed on the surface of the tantalum spinneret body, the tantalum pentoxide oxide film being prepared by anodizing an oxidizing solution comprising ethylene glycol, ammonium nitrate, boric acid and water.

2. The tantalum spinneret according to claim 1, characterized in that, Based on the total mass of the oxidizing liquid, the content of ethylene glycol is 30-88 wt%, the total content of boric acid and water is 10-60 wt%, and the content of ammonium nitrate is 0.5-35 wt%.

3. The tantalum spinneret according to claim 1 or 2, characterized in that, The boric acid is 0.01~0.2 wt% of the water.

4. The tantalum spinneret according to claim 3, characterized in that, The voltage for anodizing is 5V~250V, the anodizing time is 0.5~3h, and / or the temperature of the oxidizing solution is 50~100℃.

5. The tantalum spinneret according to claim 1 or 2, characterized in that, Based on the total mass of the oxidizing liquid, the content of ethylene glycol is 40-80 wt%, the total mass of boric acid and water is 15-55 wt%, the content of ammonium nitrate is 5-30 wt%, and the boric acid is 0.05-0.15 wt% of the water.

6. The tantalum spinneret according to claim 1, characterized in that, The surface resistivity of the tantalum spinneret is 0~0.2mΩ.

7. A method for preparing a tantalum spinneret, comprising the following steps: The tantalum spinneret body is anodized in an oxidizing solution to obtain the tantalum spinneret; The oxidizing solution includes ethylene glycol, ammonium nitrate, boric acid, and water.

8. The preparation method according to claim 7, characterized in that, Based on the total mass of the oxidizing liquid, the content of ethylene glycol is 30-88 wt%, the total content of boric acid and water is 10-60 wt%, the content of ammonium nitrate is 0.5-35 wt%, and the boric acid is 0.01-0.2 wt% of the water.

9. The preparation method according to claim 7, characterized in that, The voltage for anodizing is 5V~250V, the anodizing time is 0.5~3h, and the temperature of the oxidation solution is 50~100℃.

10. The application of the tantalum spinneret according to any one of claims 1 to 6 or the tantalum spinneret prepared by the preparation method according to any one of claims 7 to 9 in the spinning process.

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