A vascular coil and its coating preparation process

Abstract

The present application relates to the technical field of medical devices for treating aneurysms, and specifically discloses a vascular spring coil and a coating preparation process thereof. The coating preparation process of the vascular spring coil comprises: S1, taking a tungsten wire and cleaning the tungsten wire. S2, ion plating and etching the tungsten wire. S3, cleaning the surface of the tungsten wire with titanium ions, and depositing a titanium layer on the surface of the tungsten wire, the thickness of the titanium layer being 0.015-0.025 μm. S4, depositing a gold layer on the surface of the titanium layer, the thickness of the gold layer being 0.15-0.25 μm, to obtain a raw wire. S5, shaping the raw wire to obtain the vascular spring coil. In this process, ion plating and etching are performed on the tungsten wire to increase the surface roughness and enhance the adhesion of subsequent coatings. Titanium ion cleaning removes the residues of ion plating etching. The thinner titanium layer enhances the adhesion of the pure gold layer. The outermost gold layer makes the vascular spring coil have good biocompatibility and corrosion resistance.

Description

Technical Field

[0001] The present application relates to the technical field of medical devices for treating aneurysms, and more specifically, to a vascular spring coil and a coating preparation process thereof. Background Art

[0002] Vascular coils are medical devices used to treat aneurysms. Connected to a stainless steel guidewire, the coils can be inserted directly into the aneurysm. When a direct current is applied, the coils attract negatively charged blood components (red blood cells, white blood cells, platelets, etc.), causing electrocoagulation and forming a thrombus within the aneurysm. Simultaneously, the portion of the coil connected to the stainless steel guidewire dissolves due to electrolysis, leaving the coils in the aneurysm. The resulting thrombus can cut off the tumor's blood supply, thereby inhibiting its growth.

[0003] Currently, vascular coils are primarily made of nickel-titanium alloy, platinum, and platinum-tungsten alloy. Nickel-titanium and platinum-tungsten alloys have poor biocompatibility and are susceptible to hydrogen embrittlement in human body fluids. This occurs when hydrides are formed and distributed along grain boundaries, forming a "worm-like" pattern, reducing superelasticity and shape memory properties. Coils made of platinum have excellent biocompatibility but are relatively expensive, placing an additional financial burden on patients. Summary of the Invention

[0004] Given the poor biocompatibility of nickel-titanium alloy and platinum-tungsten alloy, they are prone to hydrogen embrittlement in human body fluids, that is, hydrides are generated and distributed along the grain boundaries, reducing superelasticity and shape memory properties. Platinum coils have good biocompatibility but are relatively expensive, increasing the financial burden on patients. This application proposes a more economical and biocompatible vascular coil to solve this problem.

[0005] In a first aspect, the present application proposes a coating preparation process for a vascular spring coil, and adopts the following technical solution.

[0006] A coating preparation process for a vascular coil, comprising:

[0007] S1, taking a tungsten wire and cleaning the tungsten wire.

[0008] S2, etching the tungsten wire by ion plating.

[0009] S3, cleaning the surface of the tungsten wire with titanium ions and depositing a titanium layer on the surface of the tungsten wire, wherein the thickness of the titanium layer is 0.015-0.025 μm.

[0010] S4, depositing a gold layer on the surface of the titanium layer, wherein the thickness of the gold layer is 0.15-0.25 μm, to obtain raw wire.

[0011] S5, shaping the raw material wire into a shape to obtain the vascular spring coil.

[0012] By employing this technical solution, ion plating etches the tungsten filament, increasing surface roughness and enhancing the adhesion of subsequent coatings. Titanium ion cleaning removes ion plating residue. The thinner titanium layer enhances the adhesion of the pure gold layer. The outermost gold layer ensures the vascular coil has excellent biocompatibility and corrosion resistance.

[0013] A preferred coating preparation process for the vascular spring coil is that step S2 includes: placing a tungsten wire into a vacuum chamber, introducing CF4 gas into the vacuum chamber, applying a negative bias voltage to ionize the CF4 gas to obtain CF4 plasma, and bombarding the surface of the tungsten wire with the CF4 plasma to increase the surface roughness of the tungsten wire.

[0014] By adopting the above technical solution, CF4 plasma contains a large amount of ·F (fluorine radicals), and the ·F radicals can efficiently etch the tungsten wire, thereby increasing the surface roughness of the tungsten wire.

[0015] A preferred coating preparation process for the vascular spring coil is that the titanium ion cleaning and titanium layer deposition in step S3 includes: using pure titanium as a sputtering target, introducing argon gas into a vacuum chamber, applying a DC or RF electric field, causing argon plasma to bombard the titanium target, sputtering titanium atoms to clean the surface of the tungsten wire, and depositing them on the surface of the tungsten wire to form a titanium layer.

[0016] By adopting the above technical solution, after the tungsten filament is ion-plated and etched, impurities are generated on the surface of the tungsten filament. For example, if the etching medium is CF4, impurities such as tungsten fluoride may be generated on the surface of the tungsten filament after etching. By using pure titanium as a sputtering target, the titanium ions shot towards the tungsten filament can first remove these impurities and then be deposited on the surface of the tungsten filament to form a titanium layer. The titanium layer can enhance the adhesion between the tungsten filament and the gold layer.

[0017] A preferred method for preparing the coating of the vascular coil further comprises, between steps S2 and S3, oxidizing the surface of the tungsten wire to obtain a tungsten oxide layer with a thickness of 0.005-0.015 μm, and depositing a titanium layer on the surface of the tungsten oxide layer in step S3.

[0018] By adopting the above technical solution, the surface of the tungsten wire is oxidized to form tungsten oxide, thereby enhancing the bonding strength between the titanium layer and the tungsten wire substrate.

[0019] A preferred method for preparing the coating of the vascular spring coil further comprises, between steps S3 and S4, depositing a copper layer with a thickness of 0.015-0.025 μm on the titanium layer, and depositing the gold layer in step S4 on the copper layer.

[0020] By adopting the above technical solution, adding a copper layer can improve the electrical conductivity and heat transfer of the vascular spring coil, and further enhance the adhesion of the titanium layer and the gold layer.

[0021] A preferred process for preparing the coating of the vascular spring coil is that the deposited gold layer in step S4 is electroplated using an electroplating solution, specifically comprising: preparing an electroplating solution, using water as a solvent, adding potassium cyanogen gold and potassium citrate to obtain an electroplating solution; in the electroplating solution, the concentration of the potassium cyanogen gold is 2-5 g / L, and the concentration of the potassium citrate is 50-100 g / L; adjusting the pH of the electroplating solution to 4.5-5.5, heating the electroplating solution to 50-60° C., and placing the tungsten wire with the titanium layer deposited thereon into the electroplating solution to electroplate the gold layer.

[0022] By adopting the above technical solution, potassium citrate can form a stable complex with gold ions, preventing the gold ions from spontaneously reducing to elemental gold precipitation in the plating solution, thereby improving the stability of the plating solution.

[0023] A preferred method for preparing the coating of the vascular spring coil is to further add guanidine isothiocyanate to the electroplating solution, wherein the concentration of the guanidine isothiocyanate in the electroplating solution is 5-10 g / L.

[0024] By adopting the above technical solution, the isothiocyanate and amino groups of guanidine isothiocyanate are adsorbed on the surface of the gold layer, preferentially occupying high-energy active sites such as the edge of the crystal nucleus, hindering the disordered stacking of gold atoms, reducing lattice defects, and reducing the stress within the gold layer to prevent cracking or peeling, reduce the formation of coarse grains, promote the formation of a finer and more uniform grain structure, reduce the porosity of the grain boundaries, and thus improve the density of the gold layer.

[0025] In a second aspect, the present application proposes a vascular spring coil and adopts the following technical solution.

[0026] A vascular spring coil is prepared using the coating preparation process described above.

[0027] By adopting the above technical solution, the vascular spring coil uses tungsten wire as the core to reduce costs, and a titanium layer is deposited in the middle to strengthen the bonding force with the outermost gold layer. The outermost gold layer has good biocompatibility and is not easily damaged.

[0028] In summary, the vascular spring coil and its coating preparation process of the present application have the following beneficial effects: the vascular spring coil includes tungsten wire material, pure titanium layer and pure gold layer from the inside to the outside, which reduces material costs and achieves performance at the level of high-priced platinum materials, providing a complete coating solution for new materials of vascular spring coils. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 This is a picture of the raw material wire of the vascular spring coil prepared in Example 1. DETAILED DESCRIPTION

[0030] The technical solutions in the embodiments are described clearly and completely below. Obviously, the embodiments described are only part of the embodiments of this application, not all of them. Based on the following embodiments, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application. Example 1

[0031] A coating preparation process for a vascular spring coil comprises the following steps.

[0032] S1, select high-strength, low-density medical-grade tungsten wire, place the tungsten wire in an ultrasonic cleaning machine, and perform ultrasonic degreasing and pure water cleaning in sequence to make the surface of the tungsten wire clean.

[0033] S2, ion plating etching of tungsten wire: Place the cleaned tungsten wire into the vacuum chamber of a fully automatic reactive ion beam etcher, introduce CF4 gas into the vacuum chamber with a flow rate of 30 sccm and a gas pressure of 1 Pa. After stabilization, apply a negative bias voltage with a power of 150 W to ionize the CF4 gas to obtain CF4 plasma, which lasts for 10 minutes. The CF4 plasma bombards the surface of the tungsten wire to increase the surface roughness of the tungsten wire, thereby enhancing the adhesion of subsequent coatings.

[0034] S3: Titanium ions clean the tungsten filament surface and deposit a titanium layer on the tungsten filament surface. This step specifically uses a radio frequency vacuum plasma cleaner with high-purity titanium powder as the sputtering target. Argon gas is introduced into the vacuum chamber at a flow rate of 20 seem and a pressure of 0.3 Pa. After stabilization, an radio frequency electric field is applied at a power of 150 W for 5 minutes. This causes the argon plasma to bombard the titanium target, sputtering titanium atoms that clean the tungsten filament surface. These atoms are then deposited on the tungsten filament surface to form a titanium layer as a transition layer. The thickness of the titanium layer is 0.02 μm, as measured by X-ray.

[0035] S4, depositing a gold layer on the surface of the titanium layer, reference Figure 1 , obtaining the raw wire: using electroplating equipment, preparing an electroplating solution, using water as a solvent, adding potassium cyanogen gold and potassium citrate to obtain an electroplating solution; in the electroplating solution, the concentration of potassium cyanogen gold is 3.5g / L, and the concentration of potassium citrate is 75g / L; using hydrochloric acid / sodium hydroxide to adjust the pH of the electroplating solution to 5, heating the electroplating solution to 55°C, placing a tungsten wire deposited with a titanium layer into the electroplating solution, electroplating a gold layer outside the titanium layer, the thickness of the gold layer is 0.2μm, and the thickness is measured by X-ray.

[0036] S5, shaping the raw material wire into a shape to obtain a vascular spring coil. Example 2

[0037] Compared with the first embodiment, the parameters of steps S3 and S4 are adjusted in this embodiment, as follows.

[0038] A coating preparation process for a vascular spring coil comprises the following steps.

[0039] S1, select high-strength, low-density medical-grade tungsten wire, place the tungsten wire in an ultrasonic cleaning machine, and perform ultrasonic degreasing and pure water cleaning in sequence to make the surface of the tungsten wire clean.

[0040] S2, ion plating etching of tungsten wire: Place the cleaned tungsten wire into the vacuum chamber of a fully automatic reactive ion beam etcher, introduce CF4 gas into the vacuum chamber with a flow rate of 30 sccm and a gas pressure of 1 Pa. After stabilization, apply a negative bias voltage with a power of 150 W to ionize the CF4 gas to obtain CF4 plasma, which lasts for 10 minutes. The CF4 plasma bombards the surface of the tungsten wire to increase the surface roughness of the tungsten wire, thereby enhancing the adhesion of subsequent coatings.

[0041] S3: Titanium ions clean the tungsten filament surface and deposit a titanium layer on the tungsten filament surface. This step specifically uses a radio frequency vacuum plasma cleaner, using high-purity titanium powder as the sputtering target. Argon gas is introduced into the vacuum chamber at a flow rate of 20 seem and a pressure of 0.3 Pa. After stabilization, an radio frequency electric field is applied at a power of 150 W for 3 minutes. This allows the argon plasma to bombard the titanium target, sputtering titanium atoms that clean the tungsten filament surface. These atoms are then deposited on the tungsten filament surface to form a titanium layer as a transition layer. The thickness of the titanium layer is 0.015 μm, as measured by X-ray.

[0042] S4, depositing a gold layer on the surface of the titanium layer to obtain a raw wire: preparing an electroplating solution, using water as a solvent, adding potassium cyanogen gold and potassium citrate to obtain an electroplating solution; using electroplating equipment, in the electroplating solution, the concentration of potassium cyanogen gold is 2g / L, and the concentration of potassium citrate is 50g / L; using hydrochloric acid / sodium hydroxide to adjust the pH of the electroplating solution to 5.5, heating the electroplating solution to 50°C, placing the tungsten wire deposited with the titanium layer into the electroplating solution, and electroplating a gold layer outside the titanium layer. The thickness of the gold layer is 0.15μm, and the thickness is measured by X-ray.

[0043] S5, shaping the raw material wire into a shape to obtain a vascular spring coil. Example 3

[0044] Compared with the first embodiment, the parameters of steps S3 and S4 are adjusted in this embodiment, as follows.

[0045] A coating preparation process for a vascular spring coil comprises the following steps.

[0046] S1, select high-strength, low-density medical-grade tungsten wire, place the tungsten wire in an ultrasonic cleaning machine, and perform ultrasonic degreasing and pure water cleaning in sequence to make the surface of the tungsten wire clean.

[0047] S2, ion plating etching of tungsten wire: Place the cleaned tungsten wire into the vacuum chamber of a fully automatic reactive ion beam etcher, introduce CF4 gas into the vacuum chamber with a flow rate of 30 sccm and a gas pressure of 1 Pa. After stabilization, apply a negative bias voltage with a power of 150 W to ionize the CF4 gas to obtain CF4 plasma, which lasts for 10 minutes. The CF4 plasma bombards the surface of the tungsten wire to increase the surface roughness of the tungsten wire, thereby enhancing the adhesion of subsequent coatings.

[0048] S3: Titanium ions clean the tungsten filament surface and deposit a titanium layer on the tungsten filament surface. This step specifically uses a radio frequency vacuum plasma cleaner, using high-purity titanium powder as the sputtering target. Argon gas is introduced into the vacuum chamber at a flow rate of 20 seem and a pressure of 0.3 Pa. After stabilization, an radio frequency electric field is applied at a power of 150 W for 7 minutes. This allows the argon plasma to bombard the titanium target, sputtering titanium atoms that clean the tungsten filament surface. Titanium atoms are then deposited on the tungsten filament surface to form a titanium layer as a transition layer. The thickness of the titanium layer is 0.025 μm, as measured by X-ray.

[0049] S4, depositing a gold layer on the surface of the titanium layer to obtain a raw wire: using electroplating equipment, preparing an electroplating solution, using water as a solvent, adding potassium cyanogen gold and potassium citrate to obtain an electroplating solution; in the electroplating solution, the concentration of potassium cyanogen gold is 5g / L, and the concentration of potassium citrate is 100g / L; using hydrochloric acid / sodium hydroxide to adjust the pH of the electroplating solution to 4.5, heating the electroplating solution to 60°C, placing the tungsten wire deposited with the titanium layer into the electroplating solution, electroplating a gold layer outside the titanium layer, the thickness of the gold layer is 0.25μm, and the thickness is measured by X-ray.

[0050] S5, shaping the raw material wire into a shape to obtain a vascular spring coil. Example 4

[0051] This embodiment provides a coating preparation process for a vascular coil. Compared to Example 1, the only difference is that, between steps S2 and S3, a further step is included: oxidizing the surface of the tungsten filament to enhance the bonding strength between the titanium layer and the tungsten filament substrate. Tungsten surface oxidation conditions: using a muffle furnace, pure oxygen input, a pressure of 0.1 MPa, a set temperature of 500°C, and a hold time of 10 minutes. A tungsten oxide layer with a thickness of 0.005 μm is formed on the surface of the tungsten filament, as measured by X-ray. Step S3 then deposits a titanium layer on the surface of the tungsten oxide layer. Example 5

[0052] This embodiment provides a coating preparation process for a vascular coil. Compared to Example 1, the only difference is that, between steps S2 and S3, a further step is included: oxidizing the surface of the tungsten filament to enhance the bonding strength between the titanium layer and the tungsten filament substrate. Tungsten surface oxidation conditions: using a muffle furnace, pure oxygen input, a pressure of 0.1 MPa, a set temperature of 500°C, and a hold time of 30 minutes. A tungsten oxide layer with a thickness of 0.015 μm is formed on the surface of the tungsten filament, as measured by X-ray. Step S3 then deposits a titanium layer on the surface of the tungsten oxide layer. Example 6

[0053] This embodiment provides a coating preparation process for a vascular spring coil. Compared with the first embodiment, the only difference is that the following steps are added between steps S3 and S4: using electroplating equipment, preparing an electroplating solution, using water as a solvent, adding copper pyrophosphate and potassium pyrophosphate to obtain an electroplating solution, using a copper plate as an anode, and a tungsten wire covered with a titanium layer as a cathode. In the electroplating solution, the concentration of copper pyrophosphate is 60g / L, and the concentration of potassium pyrophosphate is 300g / L; adjusting the pH of the electroplating solution to 8 with ammonia water, heating the electroplating solution to 40°C, and depositing a copper layer with a thickness of 0.015μm on the titanium layer to improve the electrical conductivity and thermal conductivity of the spring coil. The thickness is measured by X-ray. Potassium pyrophosphate is used to complex copper ions, so that the copper ions basically do not react with ammonia water to form a precipitate. The gold layer of step S4 is deposited on this copper layer. Example 7

[0054] This embodiment provides a coating preparation process for a vascular spring coil. Compared to the first embodiment, the only difference is that between steps S3 and S4, the following steps are added: using electroplating equipment, preparing an electroplating solution, using water as a solvent, adding copper pyrophosphate and potassium pyrophosphate to obtain an electroplating solution, using a copper plate as an anode, and a tungsten wire covered with a titanium layer as a cathode. In the electroplating solution, the concentration of copper pyrophosphate is 60g / L, and the concentration of potassium pyrophosphate is 300g / L; adjusting the pH of the electroplating solution to 9 with ammonia water, heating the electroplating solution to 50°C, and depositing a copper layer with a thickness of 0.025μm on the titanium layer to improve the electrical conductivity and thermal conductivity of the spring coil. The thickness is measured by X-ray. Potassium pyrophosphate is used to complex copper ions, so that the copper ions basically do not react with ammonia water to form a precipitate. The gold layer of step S4 is deposited on this copper layer. Example 8

[0055] This embodiment provides a coating preparation process for a vascular spring coil. Compared with the first embodiment, the only difference is that guanidine isothiocyanate is also added to the electroplating solution in step S4. In the electroplating solution, the concentration of guanidine isothiocyanate is 5 g / L. Embodiment 9

[0056] This embodiment provides a coating preparation process for a vascular spring coil. Compared with the first embodiment, the only difference is that guanidine isothiocyanate is also added to the electroplating solution in step S4. In the electroplating solution, the concentration of guanidine isothiocyanate is 10 g / L.

[0057] Comparative Example 1

[0058] This comparative example provides a coating preparation process for a vascular spring coil. Compared with Example 1, the only difference is that the titanium coating step of the original step S3 is eliminated, as follows.

[0059] A coating preparation process for a vascular spring coil comprises the following steps.

[0060] S1, select high-strength, low-density medical-grade tungsten wire, place the tungsten wire in an ultrasonic cleaning machine, and perform ultrasonic degreasing and pure water cleaning in sequence to make the surface of the tungsten wire clean.

[0061] S2, ion plating etching of tungsten wire: Place the cleaned tungsten wire into the vacuum chamber of a fully automatic reactive ion beam etcher, introduce CF4 gas into the vacuum chamber with a flow rate of 30 sccm and a gas pressure of 1 Pa. After stabilization, apply a negative bias voltage with a power of 150 W to ionize the CF4 gas to obtain CF4 plasma, which lasts for 10 minutes. The CF4 plasma bombards the surface of the tungsten wire to increase the surface roughness of the tungsten wire, thereby enhancing the adhesion of subsequent coatings.

[0062] S3, depositing a gold layer on the surface of the tungsten wire to obtain a raw wire: using electroplating equipment, preparing an electroplating solution, using water as a solvent, adding potassium cyanogen gold and potassium citrate to obtain an electroplating solution; in the electroplating solution, the concentration of potassium cyanogen gold is 3.5g / L, and the concentration of potassium citrate is 75g / L; using hydrochloric acid / sodium hydroxide to adjust the pH of the electroplating solution to 5, heating the electroplating solution to 55°C, placing the tungsten wire in the electroplating solution, and electroplating a gold layer on the outside of the tungsten wire. The thickness of the gold layer is 0.2μm, and the thickness is measured by X-ray.

[0063] S4, shaping the raw material wire into a shape to obtain a vascular spring coil.

[0064] Test Example 1

[0065] The following tests were performed on the vascular coils of Examples 1 to 9 and Comparative Example 1.

[0066] (1) 100-grid adhesion test verifies the adhesion of the coating: Use a blade to draw a 1×1mm grid on the untested sample, apply 3M tape and tear it off to evaluate the peeling area.

[0067] (2) Verify the thermal stability of the coating by high-temperature quenching at 200°C: Place the sample in a muffle furnace at 200°C for 30 minutes, then transfer it to 25°C water for 10 seconds, remove it and blow it dry. Repeat this process three times, and check whether the coating has blistering, peeling or discoloration. The adhesion of the sample coating after high-temperature quenching at 200°C is tested by a 100-grid test.

[0068] (3) Immerse the sample in 90℃ hot water and start ultrasonic testing to verify the thermal shock resistance of the coating: Place the sample in an ultrasonic cleaning machine, set the frequency to 40kHz, heat the water to 90℃, and keep it for 60 minutes; observe whether the coating after the hot water ultrasonic test is bubbling, peeling or discoloring; and test the bonding strength of the sample coating after the hot water ultrasonic test.

[0069] The results of the above three tests are shown in Table 1.

[0070] Table 1 Performance test results of vascular coils of various embodiments and comparative examples

[0071]

[0072] In Table 1: the first 100 grid tests are the 100 grid tests of item (1) performed on samples that have not undergone other tests; the last 100 grid tests represent the 100 grid tests performed after the corresponding items have been tested.

[0073] As can be seen from Table 1, the vascular coils of each embodiment have good adhesion. When no other test items are performed, the 100-grid test reaches 5B. After the 200°C high-temperature quenching test or the 90°C hot water ultrasonic test, the 100-grid test also reaches at least 4B. The results in Table 1 show that the vascular coils prepared in each embodiment have good heat resistance and can withstand the initial high temperature of power supply during application. They can still maintain good adhesion, without blistering or peeling, and have a stable crystalline structure. The results in Table 1 show that the vascular coils prepared in each embodiment can withstand general vibration and high temperature in the human body, and the coating can still maintain good adhesion, without blistering or peeling, and have a stable crystalline structure.

[0074] Compared with Examples 1 to 3, Examples 4 and 5 oxidize the outer surface of tungsten to obtain a thinner tungsten oxide layer. The products have better results in 90°C hot water ultrasonic testing, indicating that the tungsten oxide layer helps to improve the bonding strength between the titanium layer and the tungsten filament substrate.

[0075] Compared with Examples 1 to 3, Examples 6 and 7 added a copper layer between the titanium layer and the gold layer. The products had better results in the high-temperature quenching test at 200°C, indicating that the addition of the copper layer further improved the bonding strength between the titanium layer and the gold layer.

[0076] Compared with Examples 1 to 3, Examples 8 and 9 added guanidine isothiocyanate to the plating solution of the gold electroplating layer. The products showed better tolerance in both the 90°C hot water ultrasonic test and the 200°C high-temperature quenching test, indicating that the addition of guanidine isothiocyanate helps to form a more delicate and dense gold layer, improve the structural firmness of the gold layer and the bonding strength of the gold layer to the titanium layer.

[0077] Compared with Examples 1 to 3, Comparative Example 1 eliminates the titanium layer. The performance of its product in the first 100 grid tests, 90°C hot water ultrasonic test, and 200°C high-temperature quenching test is not as good as that of Examples 1 to 3, indicating that the titanium layer, as a transition layer, helps to improve the bonding strength between the tungsten substrate and the gold layer.

[0078] The vascular coil of this application uses a tungsten wire as the core layer, followed by a titanium layer, and finally an electroplated gold layer. Compared to pure platinum solutions, this significantly reduces costs. The titanium layer helps improve the adhesion of the gold layer to the tungsten wire, enhancing the product's durability, heat resistance, and shock resistance. The gold layer has excellent biocompatibility and can maintain stable physical and chemical properties in human body fluids. The gold layer does not deteriorate, and its structure is not easily damaged. All of this makes this product have excellent application prospects.

[0079] Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art can still modify the technical solutions described in the aforementioned embodiments, or make equivalent substitutions for some of the technical features therein. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present application should be included in the scope of protection of the present application.

Claims

1. A coating preparation process for a vascular coil, characterized in that: include: S1, taking a tungsten wire and cleaning the tungsten wire; S2, ion plating etching of the tungsten wire; S3, cleaning the surface of the tungsten wire with titanium ions and depositing a titanium layer on the surface of the tungsten wire, wherein the thickness of the titanium layer is 0.015-0.025 μm; S4, depositing a gold layer on the surface of the titanium layer, wherein the thickness of the gold layer is 0.15-0.25 μm, to obtain a raw wire; S5, shaping the raw material wire into a shape to obtain the vascular spring coil; The deposited gold layer in step S4 is electroplated using an electroplating solution, specifically comprising: preparing an electroplating solution, using water as a solvent, adding potassium cyanogen gold and potassium citrate to obtain an electroplating solution; in the electroplating solution, the concentration of the potassium cyanogen gold is 2-5 g / L, and the concentration of the potassium citrate is 50-100 g / L; adjusting the pH of the electroplating solution to 4.5-5.5, heating the electroplating solution to 50-60° C., and placing the tungsten wire on which the titanium layer is deposited into the electroplating solution to electroplate the gold layer; Guanidine isothiocyanate is further added to the electroplating solution, and the concentration of the guanidine isothiocyanate in the electroplating solution is 5-10 g / L.

2. The coating preparation process for a vascular coil according to claim 1, characterized in that: Step S2 includes: placing a tungsten filament into a vacuum chamber, introducing CF4 gas into the vacuum chamber, applying a negative bias voltage to ionize the CF4 gas to obtain CF4 plasma, and bombarding the surface of the tungsten filament with the CF4 plasma to increase the surface roughness of the tungsten filament.

3. The coating preparation process for a vascular coil according to claim 1, characterized in that: The titanium ion cleaning and titanium layer deposition in step S3 include: using pure titanium as a sputtering target, introducing argon gas into a vacuum chamber, applying a DC or RF electric field, causing argon plasma to bombard the titanium target, sputtering titanium atoms to clean the surface of the tungsten wire, and depositing them on the surface of the tungsten wire to form a titanium layer.

4. The coating preparation process for a vascular coil according to claim 1, characterized in that: Between step S2 and step S3, the process further includes: oxidizing the surface of the tungsten filament to obtain a tungsten oxide layer with a thickness of 0.005-0.015 μm; and step S3 depositing a titanium layer on the surface of the tungsten oxide layer.

5. The coating preparation process for a vascular coil according to claim 1, characterized in that: The method further includes, between steps S3 and S4: depositing a copper layer with a thickness of 0.015-0.025 μm on the titanium layer; and depositing the gold layer on the copper layer in step S4.

6. A vascular coil, characterized in that: The coating is prepared by the coating preparation process described in any one of claims 1 to 5.

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