Polishing Parts of Medical Devices and Manufacturing Method Thereof

Abstract

The present invention discloses a polished component of a medical device and a method for manufacturing the same. The polished component of the medical device has a mass loss rate in the polishing process of 20% to 60%, and has good mechanical properties, surface properties, and biological safety. Further, the present invention discloses a method for manufacturing the above-mentioned polished component of the medical device, which has the advantages of high polishing accuracy, simple and convenient operation, and low cost.

Description

Technical Field

[0001] The present invention relates to the field of chemical polishing, and specifically, to a polishing component of a medical device and a polishing method thereof.

Background Art

[0002] Currently, the polishing methods commonly used in the field of medical devices include electrochemical polishing method, grinding and polishing method, and chemical polishing method. For example, Patent CN102356184B discloses a method and solution for electrochemically polishing a stent made of high-strength medical alloy. This method requires attaching one or more conductive adapters to each stent, and also requires a current conductive member for connecting the cathode and anode. However, not only does it have high requirements for equipment, but in the embodiment, it is necessary to repeat the entire polishing process 4 times. After polishing, it is also disclosed that the washed stent is infiltrated into the passivation solution to passivate the new polished surface formed by polishing, thereby preventing the new polished surface from being rapidly oxidized in the air. This patent has a complex disclosed process and cumbersome operation. Patent Application US5746691A discloses a grinding and polishing method that achieves the purpose of polishing by bringing a fluid abrasive into contact with each surface of the stent. However, on the one hand, the abrasive is likely to remain, and the surface of the polished part is scratched, making the polished part not smooth enough. US Patent Application Publication No. 4704126 discloses a method for purely chemically polishing a medical implant made of titanium or a titanium alloy. In this method, a polishing solution composed of lactic acid or glycerin, hydrofluoric acid, and nitric acid is moved relative to the implant to achieve the purpose of polishing a medical implant made of titanium or a titanium alloy. However, in this polishing method, the gloss of the polished surface is insufficient, the polishing time is short, it is difficult to control the quality and dimensional accuracy, and both the size stability and reproducibility of the polished product are low. Even for finished products polished under the same conditions, there are large errors in size and quality, so it is not suitable for large-scale industrial production. Furthermore, this polishing method is suitable for titanium or titanium alloys, but not necessarily suitable for polishing other metals or metal alloys.

[0003] Furthermore, most of the currently disclosed prior arts only discuss methods for removing the oxide layer on the surface of polished parts of medical devices and ensuring the smoothness of the surface of the polished parts, and do not discuss improving the mechanical properties of medical devices through the polishing process, thereby improving the product yield and reducing safety risks.

Summary of the Invention

Problems to be Solved by the Invention

[0004] In order to solve the above-mentioned deficiencies in the prior art, the present invention provides a polished part of a medical device and a method for manufacturing the same. The polished part of this medical device has a smooth surface, no burrs, rounded edges and corners, excellent mechanical properties, high safety when implanted into the human body, less damage to the human body, and high polishing accuracy.

Means for Solving the Problems

[0005] In one aspect, the present invention provides a polished part of a medical device with excellent mechanical properties by breaking through the limitations caused by internal defects of the material. The mass loss rate of the polished part of the medical device during the polishing process is 20 - 60%, and further, the mass loss rate of the polished part of the medical device during the polishing process is 20 - 55%, 20 - 45%, 20 - 50%, 15 - 50%, 25 - 55%, 25 - 50%, 25 - 60%, 30 - 60%, 40 - 60%, 35 - 60%, 42 - 60%, or 40.1 - 60%.

[0006] The "polished part" referred to in the present invention refers to the finished medical device after polishing.

[0007] As used in the present invention, the "mass loss rate of the polished part of a medical device in the polishing process" refers to the ratio of the reduction in the mass of the polished part of the medical device before and after polishing to the mass of the polished part of the medical device before polishing, that is, the mass loss rate of the polished part of the medical device in the polishing process = (the mass of the polished part of the medical device before polishing - the mass of the polished part of the medical device after polishing) / the mass of the polished part of the medical device before polishing. Also, the meaning of the mass loss rate as used in the present invention is synonymous with the polishing removal rate, and the "polishing removal amount" refers to the mass loss amount of the polished part of the medical device before and after polishing, that is, the polishing removal amount of the polished part of the medical device in the polishing process = the mass of the polished part of the medical device before polishing - the mass of the polished part of the medical device after polishing.

[0008] In the above-mentioned polished part according to the present invention, the one-sided removal depth after polishing of the inner wall, outer wall and side wall of the polished part is 1.5 μm or more. Further, the one-sided removal depth after polishing of the inner wall, outer wall and side wall of the polished part is 2.5 μm, 3 μm, 3.5 μm, 4 μm, 4.5 μm, 5 μm, 5.5 μm, 6 μm, 6.5 μm, 7 μm, 7.5 μm, 8 μm, 8.5 μm, 9 μm, 9.5 μm, or 10 μm or more. Even further, the one-sided removal depth after polishing of the inner wall, outer wall and side wall of the polished part is controlled to be 10 - 30 μm, and further more than 30 μm.

[0009] The present invention can completely control the total polishing removal amount of the polished part and the polishing removal amount of each surface (inner wall, outer wall, side wall) of the polished part according to the internal structure of each polished part, ensuring that structural defects and cracks in the material can be completely removed by polishing. Thereby, the mechanical properties of the polished part of the medical device are significantly improved, and thus a series of safety problems caused by the mechanical properties of the finally manufactured medical device falling below the standard due to internal defects of the polished part are avoided.

[0010] The one-sided removal depth in the present invention refers to half of the reduction value of the total width or total thickness in the axial direction or longitudinal direction of the medical device. For example, when the medical device is a stent, the one-sided removal depth refers to half of the reduction value of the width or thickness of the stent rod.

[0011] Based on the short plate principle of the bucket, the present invention further controls the polishing uniformity of each part of the polished parts of medical devices, and keeps parameters such as the thickness of each part of the polished parts of medical devices in a consistent state as much as possible. Thereby, due to excessive polishing of some parts, the mechanical properties of specific parts of the polished parts of medical devices are significantly reduced and defects occur. As a result, the overall quality of the polished parts of medical devices is reduced, and problems such as the quality falling below the standard during use are prevented. Therefore, the present invention sufficiently controls the polishing removal amount of each part of the polished parts of medical devices during the polishing process, and ensures that the polishing uniformity of the polished parts reaches 85% or more. Preferably, the polishing uniformity of the polished parts is controlled to 90%, 95%, or even 98% or more, whereby there are no weaknesses throughout the polished parts of the medical device, and the overall mechanical properties are improved.

[0012] Note that the polishing uniformity of the polished parts in the present invention refers to the relatively uniform dimensions of the polished parts after polishing. That is, the polishing uniformity refers to the ratio of the width / thickness R of the same part of the polished part after polishing i to the average value of the width / thickness of the same part of the polished part after polishing, that is, R i / R 平均 For example, when the uniformity of the dimensions of each part of the polished parts of medical devices after polishing during the polishing process is 85% or more, it means R i / R 平均 ≧85%.

[0013] Note that in the present invention, the "same part" refers to a part belonging to the same category. For example, in a vascular stent, the components of the stent include connecting rods, support rods, etc. Connecting rods at different positions are regarded as being at the same position, and support rods at different positions are also regarded as the same part, but connecting rods and support rods at different positions are not regarded as the same part.

[0014] In addition to considering methods for improving the mechanical properties of polished parts of medical devices, the present invention also takes into account the biological safety of the polished parts and prevents a series of safety problems such as blood clots caused by the rough surface of the polished parts of medical devices as much as possible. Therefore, the present invention also provides polished parts of medical devices with very high smoothness and roundness that ensure that the device does not cause further damage to the human body during implantation into the body and sufficiently improve the safety of the device.

[0015] In the polished parts of the medical device according to the present invention, after being magnified 100 times with an optical electron microscope, the surface is smooth and shiny. Furthermore, in the polished parts, even when magnified 200 times or 250 times with an optical electron microscope, the surface is still smooth and shiny.

[0016] In the polished parts according to the present invention, after the polished parts are magnified 500 times with an SEM electron microscope, there are minute scratches on the surface of the polished parts of the device, and the ratio of the area occupied by the scratches to the total surface area of the polished parts is 20% or less. Furthermore, when the polished parts according to the present invention are magnified 500 times with an SEM electron microscope, the area of the scratches on the surface of the polished parts is only 15% or 10% or less, and further 6% or less of the total surface area of the polished parts.

[0017] In the polished parts according to the present invention, the scratch depth h of the polished parts is 2.5 μm or less, and furthermore, the scratch depth of the polished parts may be less than 1 μm, and furthermore, the scratch depth of the polished parts may be less than 0.5 μm or less than 0.3 μm.

[0018] In the polished parts according to the present invention, the surface roughness Sa of the polished parts of the medical device is 50 nm or less, and furthermore, the surface roughness Sa of the polished parts of the medical device is 30 nm or less, and furthermore, the surface roughness Sa of the polished parts of the medical device is 20 nm or less.

[0019] In the above polishing part according to the present invention, a thin protective film is attached to the surface of the polished part. As a result, the surface of the polished part is relatively stable, not easily oxidized by air or the like, and the surface appearance and characteristic stability during transportation and storage of the polished part of the device are ensured.

[0020] In the above polishing part according to the present invention, the protective film attached to the surface of the polishing part may be an inorganic protective film or an organic protective film. That is, in some embodiments, the protective film attached to the surface of the polishing part is an inorganic material, while in other embodiments, the protective film attached to the surface of the polishing part is an organic material. However, whether the protective film is inorganic or organic, this protective film is safe for the living body and does not have an adverse effect on the human body after being implanted into the human body.

[0021] In the above polishing part according to the present invention, each edge and corner of the polishing part is round and smooth. Furthermore, all the edges and corners of the polished part of the medical device are arc-shaped, rounded, without spikes or protrusions, and are very smooth.

[0022] In the above polishing part according to the present invention, the mass of the polishing part is 0.5 kg or less, further, the mass of the polishing part is 0.25 kg or less, and further the mass of the polishing part is 0.10 kg or less.

[0023] In the above technical solution according to the present invention, the mass-to-volume ratio of the polished part of the medical device is 0.001 - 10 g / cm 3 The mass-to-volume ratio of the polished part of the medical device is 0.001 - 5 g / cm 3 The mass-to-volume ratio of the polished part of the medical device is 0.001 - 0.4 g / cm 3 Furthermore, the mass-to-volume ratio of the polished part of the medical device is 0.002 - 0.3 g / cm 3 Furthermore, the mass-to-volume ratio of the polished part of the medical device is 0.005 - 0.25 g / cm 3 It is.

[0024] In the above polishing component according to the present invention, the polishing component is one of an intervention device or an implant device.

[0025] In the above polishing component according to the present invention, the polishing component may be a device with a simple structure such as a patch, or a device with a very complex structure such as a stent.

[0026] The medical device according to the present invention includes an intervention material / device or a transplantable material / device used in vivo.

[0027] In the above polishing component according to the present invention, the polishing component of the medical device is either a degradable metal or a metal alloy. The medical device includes any one of a vascular stent, a heart valve, a non-vascular endovascular stent, an occluder, an orthopedic implant, a dental implant, a respiratory implant, a gynecological implant, a male medical implant, a suture or a bolt. The orthopedic implant includes a bone nail, a bone plate, etc.

[0028] The polishing component according to the present invention is an iron-based or iron-based alloy, and further, the polishing component according to the present invention is a product having a small and complex structure.

[0029] In the above polishing component according to the present invention, the polishing component is a degradable medical device, and includes a degradable metal or alloy material, for example, a degradable material mainly composed of iron, magnesium, zinc, etc., but not limited thereto. This degradable material includes degradable materials of pure iron, pure magnesium, pure zinc, and alloys doped with other elements such as nitrogen, hydrogen, oxygen, sulfur, phosphorus, and other non-metallic or metal elements, but is not limited thereto.

[0030] In the above technical solution according to the present invention, the iron-containing medical device is pure iron or an iron-based alloy with a carbon content of 2.11 wt% or less.

[0031] In another aspect, the present invention provides a method for improving the mechanical properties of a medical device by a polishing process. On the one hand, this method can completely remove deep cracks and other defect structures in the polished parts, thereby improving the mechanical properties of the polished parts such as stents and preventing problems such as breakage during expansion. Also, this method further improves the uniformity and stability of the mechanical properties of the polished parts by controlling the polishing uniformity of each part of the polished parts. If the polishing removal rate of some parts of the polished parts is too high and the polishing removal amount of other parts is too small, the parts with too much removal amount will break, and the mechanical properties of the entire polished parts will deteriorate. As a result, quality problems such as breakage of the medical device during use will occur, causing a series of safety risks. That is, through this polishing process, problems such as a decrease in mechanical properties caused by internal structure defects of the product and non-uniform structures of each part can be completely avoided, thereby sufficiently improving the yield of the product and ensuring that the biological safety of the product meets the standards. On the other hand, this process ensures that the surface of the polished parts of the medical device is smooth and the edges and corners are rounded, reducing the associated safety risks after the device is implanted into the human body. Furthermore, this polishing process has simple steps, does not require complex equipment or complex operation processes, and can directly manufacture polished parts with high mechanical properties, high uniformity, high smoothness, rounded and smooth edges and corners by a one-step polishing method. Also, the surface stability of the polished parts can be improved by directly forming a thin protective film on the surface of the polished parts.

[0032] The present invention sufficiently improves the mechanical properties and surface properties of the polished parts of a medical device by controlling the composition of the composition in the polishing process and the polishing process parameters. Specifically, the present invention a) performing a pre-treatment for polishing on the substrate of the device; b) placing the pre-treated substrate of the device in a polishing solution containing an acidic polishing composition and polishing; c) cleaning the polished substrate of the device to obtain the polished parts of the device. The present invention provides a polishing method for manufacturing the polished parts of the above-mentioned medical device, which includes the above steps.

[0033] The polishing method of the polished parts of the medical device according to the present invention is not limited to its specific implementation method, and may be a pure chemical polishing method, a chemical mechanical polishing method, or an electrochemical polishing method. However, most preferably, as the polishing method of the polished parts of the medical device according to the present invention, pure chemical polishing is most preferred.

[0034] In the above polishing method according to the present invention, in step b), the pH value of the polishing liquid is 1 or less, and further, the pH of the polishing composition used in the present invention is 0.8 or less, and also 0.5 or less, and further, the pH of the polishing composition used in the present invention is 0.2 or less.

[0035] In the above polishing method according to the present invention, in step b), the viscosity of the polishing liquid is 1 to 4 mPa·s, and further, the viscosity of the polishing liquid in step b) is 1.2 to 4 mPa·s, and further still 1.6 to 3.8 mPa·s.

[0036] In the above polishing method according to the present invention, in step b), the polishing temperature is 20 to 35 °C.

[0037] In the above polishing method according to the present invention, in step b), the polishing time is 1 to 20 minutes, and further, the polishing time in step b) is 1 to 10 minutes, 1 to 10 minutes, 5 to 10 minutes, 5 to 20 minutes, 2 to 15 minutes, 2 to 10 minutes, 10 to 20 minutes, or 12 to 18 minutes.

[0038] In the above polishing method according to the present invention, in step b), the flow rate of the polishing liquid during the polishing process is 0.1 to 1.5 m / s, and further, the flow rate of the polishing liquid during the polishing process in step b) is 0.1 to 1.0 m / s, and further, the flow rate of the polishing liquid during the polishing process in step b) is 0.1 to 0.8 m / s.

[0039] In the above polishing method according to the present invention, in step b), during the polishing process, the flow pattern of the polishing liquid includes a swirling flow or a linear flow.

[0040] In the above polishing method according to the present invention, the polishing composition contains an acid, an oxidizing agent, a thickening agent, and a surface protecting agent. When the mass fraction of the entire polishing composition is 100%, each component is as follows. JPEG2025524215000002.jpg23142

[0041] In the present invention, by using specific types of inorganic acids and strong oxidizing agents and adjusting their contents, the rates of oxidation and corrosion of the surface of the pre-polished parts can be sufficiently controlled. Also, by increasing the removal amount of the device surface and completely removing the cracks inside the pre-polished parts generated in the previous step, the mechanical properties of the polished parts can be improved, meeting the requirements for the mechanical properties of various devices. On the other hand, the polishing efficiency of the polished parts can be sufficiently improved, and the polishing cost can be reduced.

[0042] The acid in the polishing composition according to the present invention is at least one selected from sulfuric acid, phosphoric acid, nitric acid, perchloric acid, or hydrofluoric acid, and the inorganic strong oxidizing agent is at least one selected from persulfate, perchloric acid and its salts, perbromic acid and its salts, periodic acid and its salts, permanganic acid and its salts, peroxysulfate, iodic acid and its salts, chlorous acid and its salts, hypochlorous acid and its salts, hypoiodous acid and its salts, bromic acid and its salts, percarbonate, bromic acid and its salts, chloric acid and its salts, hydrogen peroxide, potassium nitrate, or sodium nitrate.

[0043] In the above technical solution according to the present invention, the viscosity of the polishing liquid is 1.1 to 4 mPa·s. Further, the viscosity of the polishing liquid is 1.5 to 4 mPa·s, 1.2 to 4 mPa·s, 1.4 to 4 mPa·s, 1.6 to 4 mPa·s, 1.2 to 3.5 mPa·s, 1.4 to 3.5 mPa·s, 1.6 to 3.5 mPa·s, 1 to 3.5 mPa·s, 1.8 to 3.5 mPa·s, 2.0 to 3.5 mPa·s, 1.2 to 3.4 mPa·s, 1.2 to 3.4 mPa·s, 1.2 to 3.2 mPa·s, 1.2 to 3.6 mPa·s, 1.2 to 3.0 mPa·s, 1.4 to 3.3 mPa·s. Further, the viscosity of the polishing liquid is 1.4 to 3.0 mPa·s, 1.4 to 3.2 mPa·s, 1.6 to 3.0 mPa·s, 1.6 to 2.9 mPa·s. In some embodiments of the present invention, the viscosity of the polishing liquid is 1.9 mPa·s, 1.7 mPa·s, 2.1 mPa·s, 2.3 mPa·s, 2.5 mPa·s, 2.7 mPa·s, 2.9 mPa·s, 3.0 mPa·s, 3.1 mPa·s, or 3.3 mPa·s. In some other embodiments, the viscosity of the polishing liquid is 3.5 mPa·s, 3.7 mPa·s, or 3.9 mPa·s.

[0044] In the above technical solution of the present invention, a thickening agent is used to further adjust the viscosity of the polishing liquid, and the mass percentage of the thickening agent is 1.5% to 7%. Further, the mass percentage of the thickening agent is 2% to 7%, 2.5% to 7%, 3% to 7%, 3.5% to 7%, 4.5% to 7%, 4% to 7%, 3.5% to 6.5%, 2.5% to 6.5%, 2.5% to 7%, 2% to 6.5%. Further, the mass percentage of the thickening agent is 2% to 6%, 2.5% to 6%, 3% to 6%, 4% to 6%, 3.5% to 6%, 1.5% to 6%.

[0045] In the above technical solution according to the present invention, the thickener in the polishing composition is at least one selected from alcohol, silicic acid, silicate, alginic acid, alginate, polyvinylpyrrolidone, modified organic matter of polyvinylpyrrolidone, ethyl cellulose, methyl cellulose, hydroxyethyl cellulose, hydroxypropyl methyl cellulose, carboxymethyl celluloses, polyacrylic acid, sodium polymethacrylate, sodium polycarboxylate salt, sodium carboxylate salt copolymer, carboxylic acid sulfonic acid copolymer, guar gum, sodium starch phosphate, sodium polyacrylate, polyoxyethylenes, carbomer, xanthan acid, gum arabic, carrageenan, agar, gelatin, gum arabic and their derivatives. For example, in some embodiments of the present invention, the thickener of the polishing composition is silicic acid, and in some other examples, the thickener is hydroxypropyl methyl cellulose, and in still some other embodiments, the thickener is a composition of an arabic gum derivative and alcohol.

[0046] In the above technical solution of the present invention, the thickener in the polishing composition is composed of at least one of component A and at least one of component B.

[0047] Component A is at least one selected from alcohol, ethyl cellulose, methyl cellulose, hydroxyethyl cellulose, hydroxypropyl methyl cellulose, carboxymethyl celluloses, polyvinylpyrrolidone, polyacrylic acid, polymethacrylate, sodium polycarboxylate salt, sodium carboxylate salt copolymer, carboxylic acid sulfonic acid copolymer, and their derivatives.

[0048] Component B is at least one selected from silicic acid, silicate, alginic acid, alginate, modified organic matter of polyvinylpyrrolidone, guar gum, sodium starch phosphate, sodium polyacrylate, polyoxyethylenes, carbomer, xanthan acid, gum arabic, carrageenan, agar, gelatin, gum arabic, and their derivatives or a mixture of these.

[0049] In some embodiments of the present invention, the thickening agent is ethyl cellulose and guar gum, and in another embodiment, the thickening agent is sodium silicate and sodium polymethacrylate.

[0050] In the above technical solution according to the present invention, the mass ratio of component A to component B of the thickening agent in the polishing composition is 0.5:1 to 15:1. Further, the mass ratio of component A to component B of the thickening agent is 0.5:1 to 10:1. Further, the mass ratio of component A to component B of the thickening agent is 1.5:1 to 10:1.

[0051] In the above technical solution according to the present invention, the molecular weight Mn of the alcohol in the thickening agent is 800 g / mol or less. Further, the molecular weight in the thickening agent is 720 g / mol or less. Further, the alcohol and its derivatives in the present invention refer to alcohols that are liquid at room temperature. These may be linear or branched, such as butylene glycol, the position of the hydroxy is not fixed, four methyls, methylenes, and / or methines may be arranged in a straight chain, and the carbon chain may contain a quaternary carbon atom. Further, the positions of the two hydroxy groups can also be freely changed on the four carbon atoms, and the same applies to others.

[0052] In the above technical solution according to the present invention, the alcohol and its derivatives are at least one of a monoalcohol monomer and a polyol monomer having 6 or less carbon atoms, and a polymer formed of a monoalcohol or a polyol having 6 or less carbon atoms.

[0053] Note that in the present invention, "less than or equal to" means that it may be less than or equal to. In the present invention, "monoalcohols and polyols having 6 or less carbon atoms" means monoalcohols or polyols having less than 6 or equal to 6 carbon atoms.

[0054] In the above technical solution according to the present invention, the alcohol and its derivatives are at least one of ethylene glycol, propylene glycol, glycerol, butylene glycol, polyethylene glycol, butanol, cyclohexanol, polypropylene glycol, and polybutylene glycol.

[0055] In the above polishing method according to the present invention, the polishing composition further contains a complexing agent, and the content of the complexing agent is characterized by being 0.5 to 2%.

[0056] In the above technical solution according to the present invention, the complexing agent is at least one selected from hydroxycarboxylic acids, aminocarboxylic acids, hydroxyaminocarboxylic acids, hydroxyphosphonic acids, dicarboxylic acids, and their salts.

[0057] In the above technical solution according to the present invention, the complexing agent is at least one selected from oxalic acid, aminotrimethylenephosphonic acid, hydroxyethylidene diphosphonic acid, ethylenediaminetetramethylenephosphonic acid, aminotrimethylenephosphonic acid, diethylenetriamine pentacarboxylic acid, ethylenediaminetetramethylenephosphonic acid, ethylenediaminetetraacetic acid, diethylenetriamine pentamethylenephosphonic acid, aminotrimethylenephosphonic acid, hydroxyethylenediphosphonic acid, 2-hydroxyphosphonoacetic acid, dihexenetriamine pentamethylenephosphonic acid, 2-phosphono-1,2,4-butanetricarboxylic acid, heptose acid, 2-phosphonobutane-1,2,4-tricarboxylic acid, itaconic acid, succinic acid, tartaric acid, maleic acid, glycolic acid, malonic acid, oxalic acid, malic acid, gluconic acid, alanine, glycine, lactic acid, diethylenetriamine pentaacetic acid, triethylenediamine, propylenediaminetetraacetic acid, hydroxyethylethylenediamine, hydroxyethylethylenediamine triacetic acid, pyrophosphoric acid, 2-aminoethylphosphonic acid, 1-hydroxyethylidene-1,1-diphosphonic acid, aminotrimethylenephosphonic acid, ethylenediaminetetramethylenephosphonic acid, diethylenetriamine pentamethylenephosphonic acid, ethane-1,1-diphosphonic acid, ethane-1,1,2-triphosphonic acid, methanehydroxyphosphonic acid, 1-phosphonobutane-2,3,4-tricarboxylic acid and its salts, dihydroxyglycine, EDTA disodium, succinic acid, polyvinyl alcohol, triethanolamine and its salts.

[0058] In the above polishing method according to the present invention, the polishing composition further contains a surfactant, and the content of the surfactant is 0.05 to 1%.

[0059] In the above technical solution according to the present invention, the surfactant is at least one selected from higher fatty acid salts, alkyl sulfonates, alkyl ether carboxylate surfactants, silicone surfactants, alkane sulfates, alkane sulfonates, substituted amine salts, betaines, polyethylene oxides, polyvinyl alcohols, polyvinyl acetates, polyacrylic acids, polyvinyl pyrrolidones, lecithins, amino acid derivatives, alkylphenol polyoxyethylene ethers, sodium fatty alcohol polyoxyethylene ether sulfates, isooctanol polyoxyethylene ethers, alkyl glucosides, polyoxyethylene ethers, polyethyleneimines, alkyltrimethyl quaternary ammonium salts, alkyl dimethyl benzyl ammonium chloride salts or pyridinium salts.

[0060] In the above technical solution according to the present invention, the surfactant is at least one selected from sodium dodecyl sulfate, sodium dodecyl sulfonate, OP-10, sodium linear alkylbenzene sulfonate (LAS), sodium fatty alcohol polyoxyethylene ether sulfate (AES), ammonium fatty alcohol polyoxyethylene ether sulfate (AESA), sodium lauryl sulfate (SDS), lauroyl glutamate, nonylphenol polyoxyethylene ether (TX-10), glyceryl monostearate, lignosulfonate, heavy alkylbenzene sulfonate, alkyl sulfonate, dispersant NNO, dispersant MF, alkyl polyether (PO-EO copolymer), fatty alcohol polyoxyethylene ether (AEO-3), betaine, alkyltrimethyl quaternary ammonium salt, lecithin, amino acid derivative, alkylphenol polyoxyethylene ether, sodium fatty alcohol polyoxyethylene ether sulfate, isooctanol polyoxyethylene ether, alkyl glucoside, polyoxyethylene ether, alkyl dimethyl benzyl ammonium chloride salt, or pyridinium salt.

[0061] In the above polishing method according to the present invention, the polishing composition further contains a surface protective agent, and the content of the surface protective agent is 0.05 to 1%.

[0062] In the above technical solution according to the present invention, the surface protective agent is at least one selected from tannic acid, phytic acid, stearic acid, palmitic acid, and their salts. That is, the surface protective agent may be at least one of tannic acid, phytic acid, stearic acid, palmitic acid, tannate, phytate, stearate, and palmitate, or may be a mixture of at least one of tannic acid, phytic acid, stearic acid, and palmitic acid and at least one of tannate, phytate, stearate, and palmitate. The salts include, but are not limited to, sodium salts, potassium salts, ammonium salts, calcium salts, or magnesium salts.

[0063] Note that when a specific component in the polishing composition of the present invention is at least one selected from a, b, c, d, and their derivatives, or when a specific component in the polishing composition of the present invention is at least one selected from a, b, c, d, and their salts, it means that the specific component in the polishing composition is at least one selected from a, a derivative, b, b's derivative, c, c's derivative, d, d's derivative, or the specific component in the polishing composition is at least one selected from a, a's salts, b, b's salts, c, c's salts, and d, d's salts. For example, "the complexing agent is at least one selected from hydroxycarboxylic acids, aminocarboxylic acids, hydroxyaminocarboxylic acids, hydroxyphosphonic acids, dicarboxylic acids, and their salts" means that the complexing agent is at least one selected from hydroxycarboxylic acids, aminocarboxylic acids, hydroxyaminocarboxylic acids, hydroxyphosphonic acids, dicarboxylic acids, hydroxycarboxylate salts, aminocarboxylate salts, hydroxyaminocarboxylate salts, hydroxyphosphonate salts, and dicarboxylate salts.

[0064] All of the specific salts described in the present invention refer to sodium salts, potassium salts, ammonium salts, calcium salts, and magnesium salts formed by the corresponding acids and the corresponding metal ions. For example, alginates include sodium alginate, potassium alginate, ammonium alginate, calcium alginate, and magnesium alginate. Silicates include aluminum silicate, iron silicate, calcium silicate, magnesium silicate, potassium silicate, sodium silicate, etc., and the same applies to others.

[0065] In the present invention, " / " means "or". For example, "intervention material / device" means "intervention material or intervention device".

Advantages of the Invention

[0066] The beneficial effects of the present invention are as follows. 1) In the present invention, by controlling the removal amount and uniformity during the polishing process, cracks and the like deep inside the pre-polished parts can be surely and completely removed. Thereby, when certain properties do not meet the standards due to internal cracks during use, problems such as the discard of the polished parts can be avoided. On the other hand, by making the thickness of each part of the polished part constant, good mechanical properties can be ensured, and it can be avoided that some parts are too thin while other parts are too thick, resulting in non-uniform mechanical properties of each part of the polished part and safety accidents.

[0067] 2) The polished parts of this medical device have a smooth surface, no burrs, not only are the edges and corners rounded, but also have excellent mechanical properties. Furthermore, since the surface of this polished part is smooth, there are no burrs, and the edges and corners are rounded and smooth, the safety during implantation into the human body is high and the damage to the human body is small.

[0068] 3) The present invention directly forms in one step without dividing the polishing process into multiple steps, and the operation is simple. Also, during the polishing of parts, a thin protective film can be formed on the surface of the polished parts after polishing, thereby preventing the oxidation reaction of the surface of the polished parts during transportation and storage, and enhancing the surface characteristics and appearance stability.

[0069] 4) In the present invention, the polishing process is simple, easy to industrialize, the polishing conditions are mild, the time is appropriate and controllable, the reproducibility is good, and it is useful for the precision control of the stents after polishing. When multiple identical stents are polished under the same conditions, the quality / weight RSD of the polished multiple stents is within 2%, and further within 0.8%.

[0070] The values of the interval ranges according to the present invention are not limited to the specified interval ranges, and may be the values of a new interval composed of any two values within the said interval, or any one specific value within the said interval. For example, in the present invention, "the content of the surfactant is 0.05 - 0.1%" means that the value of the content of the surfactant is not limited to the value range of 0.05 - 1%, and may be a new interval composed of any two values among countless values between 0.05 - 1%, such as 0.05 - 0.5, 0.1 - 0.8, etc. Also, when there are multiple combinations of numerical values, each parameter can take any value within its value range, and the values of multiple parameters can be arbitrarily combined. When the pH value of the polishing liquid is 1 or less and the viscosity of the polishing liquid is 1 - 4 mPa·s, the pH value of the polishing liquid can be any value within the range of 1 or less, and the viscosity of the polishing liquid can be any value within the range of 1 - 4 mPa·s. These two parameters can also be arbitrarily combined, for example, the pH value is 0.1 and the viscosity of the polishing liquid is 3.5 mPas, etc.

[0071] It should be understood that the terms used in this specification are for the purpose of describing particular exemplary embodiments only and are not intended to be limiting. As used in this specification, the singular forms "a", "one", and "the" are to be construed to include the plural forms as well, unless the context clearly dictates otherwise. The terms "comprising", "including", "containing", and "having" are inclusive and thus specify the presence of the stated features, steps, operations, elements, and / or components, but do not preclude the presence or addition of one or more other features, steps, operations, elements, components, and / or combinations thereof. Method steps, processes, and operations described herein are not to be construed as necessarily being executed in the particular order described or illustrated, unless the execution order is explicitly indicated. It should also be understood that additional or alternative steps may be used.

Brief Description of the Drawings

[0072] Various other advantages and benefits will become apparent to those of ordinary skill in the art upon reading the following detailed description of the preferred embodiments. The drawings are for the purpose of illustrating the preferred embodiments only and are not to be construed as limiting the invention. Also, throughout the figures, the same reference numerals are used for the same parts.

Figure 1

Figure 2

Figure 3

Modes for Carrying Out the Invention

[0073] Hereinafter, exemplary embodiments of the present invention will be described in more detail with reference to the drawings. Although exemplary embodiments of the present invention are shown in the drawings, it should be understood that the present invention can be embodied in various forms and should not be limited to the embodiments described herein. Rather, these embodiments are provided to provide a complete understanding of the present invention and to fully convey the scope of the present invention to those skilled in the art.

[0074] Test Method 1. Roughness In the present invention, the surface roughness of the polished parts was detected using a Q-SIX cardiovascular stent detector manufactured by SENSOFAR, magnified 400 times under an interference lens, and detected under the condition of a scanning height of 50 μm.

[0075] 2. Viscosity The polishing liquid was poured into a Zahn cup CUP1#, the outflow time t was recorded, and the viscosity of the solution was calculated according to the formula kinematic viscosity = 1.1(t - 29)*ρ (ρ is the density of the solution).

[0076] 3. Measurement of Stent Width and Thickness The stent was placed under an optical microscope and observed with an optical microscope at a magnification of 100 - 200 times to measure its size.

[0077] 4. Depth of Scratch The stent was sealed and polished with a polishing machine until the cross-section of the stent was exposed. Finally, the polished cross-section was placed under a metallurgical microscope to measure the depth of the scratch.

[0078] 5. Radial Strength Radial Strength: From the perspective of the performance test of the lumen stent, the radial strength of the lumen stent was used to uniformly apply radial pressure to the stent through a compression module to compress the stent to cause uniform deformation. The radial strength of the stent is defined as the radial pressure applied when the stent is deformed by 10% in the radial direction (outer diameter).

[0079] 6. Overexpansion Plasticity A balloon catheter with a corresponding length and appropriate outer diameter was selected for the stent. It was pressurized from 6 to 8 atm for expansion and the pressure was maintained for 30 seconds. Then, the entire stent was observed with a three-dimensional measurement microscope at 200 times magnification to record whether there were cracks / rod fractures. If there were no cracks / rod fractures, the operation of pressurizing at 2 atm and holding for 30 seconds was repeated until cracks / rod fractures were found or the expanded outer diameter of the stent reached the passing standard, and observations were made and recorded.

[0080] 7. Appearance Using a three-dimensional measurement microscope, the gloss and roughness of the outer wall and inner wall of the entire stent were thoroughly inspected at an appropriate magnification (for example, 50 - 200 times).

[0081] <Example 1> The 30018 stent was cut, and the cut stent was washed with ultrasonic waves for 2 minutes. Then it was placed in a polishing liquid with a viscosity of 4.0 mPa·s prepared by mixing 100 ml of sulfuric acid, 3 g of EDTA, 10 ml of glycerol, 5 g of sodium nitrate, 5 g of sodium silicate, 0.1 ml of phytic acid, 0.05 g of sodium lauryl sulfate, and 50 ml of water. The flow rate of the polishing liquid was controlled at 1.0 m / s and polished at 20°C for 3 minutes. The stent was taken out, washed, and dried. When the dried stent was observed under an optical microscope at 200 times magnification, the surface was smooth and shiny. When observed under SEM at 500 times magnification, for the stent, the edges and corners were round, the area ratio of scratches on the surface was 2%, the maximum depth of the scratches was 1 μm, the removal depth on one side of the stent rod was 15 μm, the polishing uniformity of the stent was 90%, the mass loss rate of the stent was 45%. When measured with a sensofar3D optical profiler, the surface roughness Sa of the stent was 15 nm, the radial strength of the stent was 120 kPa, and no cracks or fractures were observed even when the balloon was used to expand it to a diameter of 4.6 mm. As a result of continuously and repeatedly polishing 5 stents, the RSD of the quality of the polished stents was less than 1%.

[0082] <Example 2> The stent was cut, and the cut stent was washed with ultrasonic waves for 2 min. It was then placed in a polishing liquid with a viscosity of 2.0 mPa·s, which was prepared by mixing 100 ml of hydrochloric acid, 5 g of tartaric acid, 10 ml of ethylene glycol, 10 ml of perchloric acid, 5 g of sodium alginate, 0.1 g of sodium phytate, 0.05 g of OP-10, and 50 ml of water. The flow rate of the polishing liquid was controlled to 0.8 m / s, and polishing was carried out at 25 °C for 3 min. The stent was taken out, washed, and dried. When the dried stent was observed under an optical microscope with a magnification of 200 times, the surface was smooth and shiny. When observed under SEM with a magnification of 500 times, for the stent, the edges and corners were round, the proportion of the area of scratches on the surface was 2%, the maximum depth of the scratches was 0.5 μm, the removal depth on one side of the stent rod was 15 μm, the polishing uniformity of the stent was 95%, the mass loss rate of the stent was 42%. When measured with a sensofar 3D optical profiler, the surface roughness Sa of the stent was 10 nm, the radial strength of the stent was 115 kPa, and no cracks or fractures were observed even when the balloon was used to expand it to a diameter of 4.6 mm. As a result of continuously and repeatedly polishing five stents, the RSD of the quality of the polished stents was less than 1.5%. As a result of continuously and repeatedly polishing five stents, the RSD of the quality of the polished stents was less than 1.5%.

[0083] <Example 3> The stent was cut, and the cut stent was washed with ultrasonic waves for 5 min. It was then placed in a polishing liquid with a viscosity of 3.0 mPa·s, which was a mixture of 100 ml of phosphoric acid, 5 g of disodium EDTA, 10 ml of butanediol, 10 ml of nitric acid, 5 g of sodium silicate, 0.1 ml of tannic acid, 0.05 g of polyethylene glycol, and 50 ml of water. The flow rate of the polishing liquid was controlled to 0.5 m / s, and polishing was carried out at 30 °C for 3 min. The stent was taken out, washed, and dried. When the dried stent was observed under an optical microscope with a magnification of 200 times, the surface was smooth and shiny. When observed under SEM with a magnification of 500 times, for the stent, the edges and corners were round, the proportion of the area of scratches on the surface was 2%, the maximum depth of the scratches was 1.5 μm, the removal depth on one side of the stent rod was 15 μm, the polishing uniformity of the stent was 92%, the mass loss rate of the stent was 45%. When measured with a sensofar 3D optical profiler, the surface roughness Sa of the stent was 20 nm, the radial strength of the stent was 125 kPa, and no cracks or fractures were observed even when the balloon was used to expand it to a diameter of 4.6 mm. As a result of continuously and repeatedly polishing five stents, the RSD of the quality of the polished stents was less than 2%.

[0084] <Example 4> The stent was cut, and the cut stent was washed with ultrasonic waves for 2 min. Then, it was placed in a polishing liquid with a viscosity of 1.5 mPa·s, which was prepared by mixing 100 ml of hydrochloric acid, 3 g of succinic acid, 10 ml of propylene glycol, 10 ml of hydrogen peroxide, 5 g of sodium silicate, 0.1 g of stearic acid, 0.05 g of sodium dodecyl sulfonate, and 50 ml of water. The flow rate of the polishing liquid was controlled to 0.5 m / s, and polishing was performed at 30 °C for 3 min. The stent was taken out, washed, and dried. When the dried stent was observed under an optical microscope with a magnification of 200 times, the surface was smooth and shiny. When observed under SEM with a magnification of 500 times, for the stent, the edges and corners were round, the area ratio of the scratches on the surface was 2%, the maximum depth of the scratches was 2 μm, the removal depth on one side of the stent rod was 15 μm, the polishing uniformity of the stent was 92%, the mass loss rate of the stent was 44%. When measured with a sensofar 3D optical profiler, the surface roughness Sa of the stent was 20 nm, the radial strength of the stent was 120 kPa. Even when the balloon was used to expand it to a diameter of 4.6 mm, no cracks or fractures were observed. Even when the stent was stored for 4 weeks, no obvious changes were observed. As a result of continuously and repeatedly polishing 5 stents, the RSD of the quality of the polished stents was less than 2.5%.

[0085] <Example 5> The stent was cut, and the stent was washed ultrasonically with 12.5% hydrochloric acid for 2 min. It was then placed in a solution with a viscosity of 1.0 mPas consisting of 100 ml of hydrofluoric acid, 3 g of diethylenetriamine pentamethylenephosphonic acid, 10 ml of cyclohexanol, 10 ml of potassium permanganate, 5 g of sodium alginate, 0.1 g of palmitic acid, and 50 ml of pure water. The solution was placed in a low-temperature magnetic tank, the temperature was set at 30°C, and the flow rate of the polishing liquid was set at 0.80 m / s. The stent was placed in the low-temperature magnetic tank and polished for 3 min. The stent was taken out, washed, and dried. When the dried stent was observed under an optical microscope with a magnification of 200 times, the surface was smooth and shiny. When observed under SEM with a magnification of 500 times, for the stent, the edges and corners were round, the proportion of the area of scratches on the surface was 2%, the maximum depth of the scratches was 0.5 μm, the removal depth on one side of the stent rod was 15 μm, the polishing uniformity of the stent was 92%, the mass loss rate of the stent was 46%. When measured with a sensofar 3D optical profiler, the surface roughness Sa of the stent was 20 nm, the radial strength of the stent was 115 kPa, and no cracks or fractures were observed even when the balloon was used to expand it to a diameter of 4.6 mm. As a result of continuously and repeatedly polishing five stents, the RSD of the quality of the polished stents was less than 3%.

[0086] <Example 6> The stent was cut, and the stent was ultrasonically cleaned with 12.5% hydrochloric acid for 2 min. Then it was placed in a solution with a viscosity of 2.5 mPas consisting of 100 ml of perchloric acid, 5 g of sodium gluconate, 10 ml of butanol, 5 g of potassium nitrate, 5 g of sodium alginate, 0.1 g of sodium stearate, 0.05 g of betaine, 0.05 g of sodium lauryl sulfate, and 50 ml of pure water. The solution was placed in a low-temperature magnetic tank, the temperature was set at 25°C, the flow rate of the polishing liquid was set at 0.6 - 0.0 m / s, the stent was placed in the low-temperature magnetic tank and polished for 3 min. Then the stent was taken out, washed, and dried. When the dried stent was observed under an optical microscope with a magnification of 200 times, the surface was smooth and shiny. When observed under SEM with a magnification of 500 times, for the stent, the edges and corners were round, the proportion of the area of scratches on the surface was 2%, the maximum depth of the scratches was 0.3 μm, the removal depth on one side of the stent rod was 15 μm, the polishing uniformity of the stent was 95%, the mass loss rate of the stent was 43%. When measured with a sensofar 3D optical profiler, the surface roughness Sa of the stent was 12 nm, the radial strength of the stent was 118 kPa, and no cracks or fractures were observed even when the balloon was used to expand it to a diameter of 4.6 mm. As a result of continuously and repeatedly polishing five stents, the RSD of the quality of the polished stents was less than 3%.

[0087] <Example 7> The stent was cut, and the cut stent was washed with ultrasonic waves for 2 min. Then it was placed in a polishing liquid with a viscosity of 2.5 mPa·s, which was prepared by mixing 100 ml of sulfuric acid, 5 g of disodium EDTA, 10 ml of ethylene glycol, 5 g of sodium nitrate, 0.1 ml of phytic acid, and 50 ml of water. The flow rate of the polishing liquid was controlled at 0.5 m / s, and polishing was carried out at 25°C for 3 min. The stent was taken out, washed, and dried. When the dried stent was observed under an optical microscope with a magnification of 200 times, the surface was smooth and shiny. When observed under SEM with a magnification of 500 times, for the stent, the edges and corners were round, the proportion of the area of scratches on the surface was 2.5%, the maximum depth of the scratches was 2 μm, the removal depth on one side of the stent rod was 15 μm, the polishing uniformity of the stent was 85%, the mass loss rate of the stent was 44%. When measured with a sensofar 3D optical profiler, the surface roughness Sa of the stent was 18 nm, the radial strength of the stent was 115 kPa. As a result of expanding it to a diameter of 4.5 mm using a balloon, breakage occurred. As a result of continuously and repeatedly polishing 5 stents, the RSD of the quality of the polished stents was less than 3%.

[0088] <Example 8> The stent was cut, and the cut stent was washed with ultrasonic waves for 2 min. Then, it was placed in a polishing liquid with a viscosity of 3.5 mPa·s, which was prepared by mixing 100 ml of hydrochloric acid, 3 g of succinic acid, 10 ml of glycerol, 10 ml of nitric acid, 5 g of sodium alginate, and 50 ml of water. The flow rate of the polishing liquid was controlled at 0.6 m / s, and polishing was carried out at 30 °C for 3 min. The stent was taken out, washed, and dried. When the dried stent was observed under an optical microscope with a magnification of 200 times, the surface was smooth and shiny. When observed under SEM with a magnification of 500 times, for the stent, the edges and corners were round, the proportion of the area of scratches on the surface was 2%, the maximum depth of the scratches was 1.2 μm, the removal depth on one side of the stent rod was 1.5 μm, the polishing uniformity of the stent was 88%, the mass loss rate of the stent was 48%. When measured with a sensofar 3D optical profiler, the surface roughness Sa of the stent was 25 nm, the radial strength of the stent was 120 kPa. Even when the balloon was used to expand it to a diameter of 4.6 mm, no cracks or fractures were observed. After the stent was stored for 7 days, yellow spots were observed on the surface. As a result of continuously and repeatedly polishing 5 stents, the RSD of the quality of the polished stents was less than 2%.

[0089] <Example 9> The stent was cut, and the cut stent was washed with ultrasonic waves for 2 min. Then it was placed in a polishing liquid with a viscosity of 3.5 mPa·s, which was a mixture of 100 ml of phosphoric acid, 5 g of malic acid, 10 ml of butanediol, 10 ml of perchloric acid, and 50 ml of water. The flow rate of the polishing liquid was controlled at 0.8 m / s, and polishing was carried out at 35°C for 3 min. The stent was taken out, washed, and dried. When the dried stent was observed under an optical microscope with a magnification of 200 times, the surface was smooth and shiny. When observed under SEM with a magnification of 500 times, for the stent, the edges and corners were round, the proportion of the area of scratches on the surface was 3%, the maximum depth of the scratches was 2.5 μm, the removal depth on one side of the stent rod was 15 μm, the polishing uniformity of the stent was 82%, the mass loss rate of the stent was 48%. When measured with a sensofar 3D optical profiler, the surface roughness Sa of the stent was 30 nm, the radial strength of the stent was 128 kPa. When the balloon was used to expand it to a diameter of 4.0 mm, the stent broke. As a result of continuously and repeatedly polishing five stents, the RSD of the quality of the polished stents was less than 1.5%.

[0090] <Comparative Example 1> The 30018 stent was cut, and the cut stent was washed with ultrasonic waves for 2 min. Then it was put into a polishing solution mixed with 140 ml of glacial acetic acid and 60 ml of perchloric acid, and polished with a DC power supply at a constant current of 0.1 A for 20 s. The stent was taken out, washed, and dried. When the dried stent was observed under an optical microscope with a magnification of 200 times, the surface was smooth and shiny. However, part of the stent was yellowed, the sizes at both ends were small, and the size in the central part was large. When observed under an SEM with a magnification of 500 times, for the stent, the edges and corners were round, the proportion of the area of scratches on the surface was 5%, the maximum depth of the scratches was 6 μm, the one-sided removal depth of the inner wall of the stent rod was 5 μm, the polishing uniformity of the stent was 50%, the mass loss rate of the stent was 50%. When measured with a sensofar3D optical profiler, the surface roughness Sa of the stent was 200 nm, the radial strength of the stent was 95 kPa. When the balloon was used to expand it to a diameter of 3.5 mm, the stent broke. As a result of continuously and repeatedly polishing 5 stents, the RSD of the quality of the polished stents was less than 3%.

[0091] <Comparative Example 2> The 30018 stent was cut, and the cut stent was washed with ultrasonic waves for 2 min. A polishing solution mixed with 60 ml of phosphoric acid, 30 ml of sulfuric acid, and 10 ml of nitric acid was heated until boiling, the stent was put into the polishing solution and polished for 10 s, then washed and dried. When the dried stent was observed under an optical microscope with a magnification of 200 times, the surface was rough, uneven, and yellowish. When observed with an SEM with a magnification of 500 times, for the stent, the edges and corners were round, the proportion of the area of scratches on the surface was 8%, the maximum depth of the scratches was 0.5 μm, the one-sided removal depth of the inner wall of the stent rod was 16 μm, the polishing uniformity of the stent was 90%, the mass loss rate of the stent was 65%. When measured with a sensofar3D optical profiler, the surface roughness Sa of the stent was 250 nm, the radial strength of the stent was 70 kPa. When the balloon was used to expand it to a diameter of 4.0 mm, the stent broke. As a result of continuously and repeatedly polishing 5 stents, the RSD of the quality of the polished stents exceeded 10%.

[0092] As can be seen from the comparative examples, in Comparative Example 1, for the stent that underwent electrochemical polishing, there were variations in the sizes of each part, the surface was yellowish, rough, the proportion of the area of scratches on the surface was high, the depth of the scratches was large, and both the radial support force and the expansion ability of the stent were low. In Comparative Example 2, for the stent that underwent high-temperature chemical polishing, the surface was yellowish and rough, and the proportion of the area of scratches on the surface of the polished parts was also high. Also, in this method, the polishing time was as short as 5 s, the polishing accuracy of the product was low, and after multiple polishings, the RSD of the sizes and qualities of multiple polished products became large, and the stability of polishing deteriorated.

[0093] The above description is only a preferred embodiment of the present invention and does not limit the present invention. The above description is only a preferred example of the present invention and does not limit the present invention. In the embodiments of the present invention, the stent has been described as an example. However, the form of the present application is not only applicable to the polishing of stents, but also means that it can be applied to the polishing of some other medical devices and even some other non-medical devices with small mass precision parts. Although the present invention has been described in detail with reference to the above embodiments, for those skilled in the art, the technical solutions described in the above embodiments can be modified, or some of the technical features can be equivalently replaced. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. 1. An abrasive part of a medical device, comprising: An abrasive part of a medical device, characterized in that the mass loss rate of the abrasive part of the medical device during the abrasion process is 20 to 60%.

2. The abrasive part of a medical device according to claim 1, characterized in that the abrasive uniformity in the abrasive process reaches 85% or more.

3. 2. The abrasive part of a medical device according to claim 1, wherein the removal depth on one side of the inner wall, outer wall and side wall after abrasion is 1.5 μm or more.

4. 10. The abrasive part of a medical device according to claim 1, characterized in that the surface is smooth and shiny after 100x magnification under an optical electron microscope.

5. The abrasive part of a medical device described in claim 1, characterized in that, after magnification of 500 times with an SEM electron microscope, there are microscopic scratches on the surface of the abrasive part of the device, and the depth h of the scratches on the surface of the abrasive part is 2.5 μm or less.

6. 2. The abrasive part of a medical device according to claim 1, characterized in that the surface roughness Sa is 50 nm or less.

7. 10. The abrasive part of claim 1, wherein the edges and corners are rounded and smooth, and the edges and corners are arcuate.

8. The abrasive part of the medical device according to claim 1, characterized in that it has a protective film on its surface.

9. The mass-to-volume ratio of the abrasive component of the medical device is 0.001 to 10 g / cm ３ , the mass-to-volume ratio of the abrasive component of the medical device is 0.001 to 5 g / cm ３ , the mass-to-volume ratio of the abrasive component of the medical device is 0.001 to 0.4 g / cm ３ 2. The abrasive part of claim 1, wherein:

10. 10. The abrasive part of a medical device according to claim 1, wherein the abrasive part of the medical device is an interventional or implantable device, the abrasive part of the medical device is any one of a degradable metal or metal alloy, and the medical device includes any one of a vascular stent, a heart valve, a non-intravascular stent, an occluder, an orthopedic implant, a dental implant, a respiratory implant, a gynecological implant, a male medical implant, a suture, or a bolt.

11. 10. A polishing method for producing an abrasive component of the medical device of claim 1, comprising: a) subjecting a substrate of the device to a polishing preparation; b) polishing the pretreated device substrate in a polishing solution comprising an acidic polishing composition; c) washing and drying the substrate of the polished device to obtain a polished part of the device.

12. 12. The polishing method according to claim 11, wherein the pH value of the polishing liquid in step b) is 1 or less, and the viscosity of the polishing liquid in step b) is 1 to 4 mPa·s.

13. the polishing temperature in step b) is 20-35°C, the polishing time in step b) is 1-20 minutes, and the polishing liquid during the polishing process in step b) flows at a speed of 0.1-1.5 m / s; 12. The polishing method according to claim 11, wherein the pre-polishing treatment is ultrasonic treatment in an acidic solution for 2 to 10 minutes.

14. The polishing method according to claim 11, characterized in that the polishing composition contains an acid, an oxidizing agent, and a thickening agent, and when the mass fraction of the entire polishing composition is 100%, each component is as follows.

15. The polishing composition further comprises a complexing agent, the content of the complexing agent being 0.5 to 2%; The polishing composition further comprises a surfactant, and the content of the surfactant is 0.05 to 1%; The polishing composition further comprises a surface protective agent, and the content of the surface protective agent is 0.02 to 1%; 15. The polishing method according to claim 14, wherein the thickening agent comprises a main thickening agent and an auxiliary thickening agent, and the mass ratio of the main thickening agent to the auxiliary thickening agent is 0.5:1 to 15:1.

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