A coating composition for a medical guide wire and a preparation method thereof

Abstract

The present invention relates to the technical field of A61L31 / 08, and specifically relates to a coating composition for a medical guide wire and a preparation method thereof. By mass percentage, it at least includes the following raw materials: 15-30% of a film-forming resin, 5-12% of an organic solvent, 2-5% of a pigment, 0.3-1% of a thickener, 0.1-1% of a non-ionic surfactant, 0.5-2% of an auxiliary agent, and deionized water to make up the balance. By optimizing the product formula design, the provided coating composition has a low friction coefficient and good adhesion to the medical guide wire, and the formed coating is smooth and not easy to fall off, meeting subsequent use requirements.

Description

Technical Field

[0001] The present invention relates to the technical field of A61L31 / 08, and particularly to a coating composition for a medical guide wire and a preparation method thereof. Background Art

[0002] With the popularization and application of minimally invasive interventional therapy, higher requirements are put forward for the performance of the surface coating of medical guide wires. Since the medical guide wire with a coating needs to be guided to the target lesion position through imaging and inevitably comes into contact with human tissues, it is required that the coating be as smooth as possible and not fall off during use.

[0003] The coatings on the surfaces of existing medical guide wire products mostly use resin as the film-forming material, and corresponding additives are used to obtain the coating. The coating is formed by wrapping the coating on the surfaces of medical guide wires made of platinum, stainless steel, tungsten, nitinol alloy, and gold-plated tungsten through subsequent coating processes. However, due to the particularity of medical use, the development of coating formulations is difficult. The prior art solves the safety problem caused by the peeling off of the coating during long-term use by optimizing the formulation to provide a coating with high adhesion to the medical guide wire. For example, Chinese Patent Application (Application No. CN110090325A) discloses a hydrophilic coating formulation for a medical guide wire and its preparation process. Specifically, ascorbic acid is introduced, and under the interaction of tert-butyl hydroperoxide and ferrous chloride, polyvinylpyrrolidone forms a hydrophilic coating with high adhesion fastness on the surface of the medical guide wire, mainly focusing on the hydrophilicity optimization of the coating, but the friction coefficient of the coating still needs to be further reduced. Chinese Patent Application (Authorized Publication No. CN110507864B) discloses a medical guide wire with excellent lubrication performance. Specifically, polyvinyl alcohol is introduced into the polyurethane system, and the coating reaches the required thickness through water absorption and swelling. During actual use, it may affect the bonding force between the coating and the surface of the medical guide wire. Summary of the Invention

[0004] To solve the above problems, the present invention provides a coating composition for a medical guide wire. By optimizing the product formulation design, the provided coating composition has a low friction coefficient and good adhesion to the medical guide wire, and the formed coating is smooth and not easy to fall off, meeting the subsequent use requirements.

[0005] On the one hand, the present invention provides a coating composition for a medical guide wire, which at least includes the following raw materials by mass percentage: film-forming resin 15 - 30%, organic solvent 5 - 12%, pigment 2 - 5%, thickener 0.3 - 1%, non-ionic surfactant 0.1 - 1%, additive 0.5 - 2%, and deionized water to make up the balance.

[0006] As a preferred technical solution, the film-forming resin is selected from at least one of polytetrafluoroethylene, polyamideimide, polyurethane, and polyvinylpyrrolidone. Preferably, the film-forming resin is a combination of polytetrafluoroethylene and polyamideimide; the mass ratio of polytetrafluoroethylene to polyamideimide is (4.5 - 6):(4 - 5.5).

[0007] As a preferred technical solution, the type of polyamideimide is at least one of Torlon AI-10, Torlon AI-10LM, Torlon 4000T, and Torlon 4000TF. Preferably, the type of polyamideimide is Torlon AI-10.

[0008] Based on the problems of insufficient adhesion and relatively high friction coefficient existing in the existing coatings for medical guidewires, the inventor selected polytetrafluoroethylene with a relatively small friction coefficient as the film-forming resin material for the coating. However, due to the non-stick property of polytetrafluoroethylene, effective adhesion cannot be achieved on the surface of the medical guidewire. During the exploration process, the inventor found that matching polyamideimide as the film-forming resin material together can improve the adhesion performance of the subsequent coating. Based on the characteristics of the resin itself and the influence of the introduction amount of polyamideimide on the comprehensive performance of the coating, the inventor unexpectedly found during the screening process that, based on the polytetrafluoroethylene in the system of the present invention, introducing polyamideimide Torlon AI-10 can effectively improve the adhesion performance of the coating. Especially when the mass ratio of polytetrafluoroethylene to polyamideimide is controlled within the range of (4.5 - 6):(4 - 5.5), without affecting other properties of polytetrafluoroethylene, the provided coating has excellent adhesion on the surface of the medical guidewire, and the formed coating is smooth and not easy to fall off from the surface of the medical guidewire, greatly improving the use safety of the medical guidewire. The inventor analyzed the reason and it may be that: polyamideimide Torlon AI-10 has a certain compatibility with the ultrafine powder of polytetrafluoroethylene in the system. During the process of coating curing and film formation, the polyamideimide in the coating acts on the metal interface of the medical guidewire as much as possible, making the formed coating firmly adhere to the surface of the medical guidewire as a whole, so that the subsequent cured coating has a low friction coefficient while having good adhesion on the surface of the medical guidewire.

[0009] As a preferred technical solution, the addition amount of the thickener is 0.4 - 0.8 wt%, and the thickener is selected from one of fumed silica, polyvinyl alcohol, cellulose thickeners, and polyurethane thickeners.

[0010] As a preferred technical solution, the thickener is hydrophilic fumed silica, and the mass ratio of hydrophilic fumed silica, polytetrafluoroethylene, and polyamideimide is (0.4 - 0.8):(8 - 9):(7 - 10).

[0011] Preferably, the polytetrafluoroethylene is polytetrafluoroethylene ultrafine powder, and the average particle size of the polytetrafluoroethylene ultrafine powder is 2.5 - 10 μm, preferably 3 - 4 μm. Preferably, the polytetrafluoroethylene ultrafine powder is selected from at least one of TF 9202Z (3M), Algoflon L101 - 1 (Solvay, USA), MP1200 (DuPont, USA), and MP1100 (DuPont, USA).

[0012] Preferably, the particle size of the hydrophilic fumed silica is 5 - 20 nm, preferably 10 - 20 nm, and the hydrophilic fumed silica is preferably fumed silica with a particle size of 12 nm (Degussa A200).

[0013] Based on the system of the present invention, by introducing 0.4 - 0.8 wt% of hydrophilic fumed silica as a thickener, the suspension of polytetrafluoroethylene and pigments is improved, and the storage stability of the coating composition is enhanced. The inventors found during the exploration that especially when the mass ratio of hydrophilic fumed silica, polytetrafluoroethylene, and polyamideimide in the system is (0.4 - 0.8):(8 - 9):(7 - 10), the adhesion performance and surface smoothness of the cured coating are improved. The inventors analyzed that the reason may be: under the combined action of the dispersant in the system, the hydrophilic fumed silica with a particle size of 10 - 20 nm is uniformly dispersed in the resin system, and the active groups on the surface of the hydrophilic fumed silica interact with -NH in the polymer structure and are fixed in the polymer network structure during the curing process, matching the polytetrafluoroethylene with a particle size of 3 - 4 μm in the system, improving the denseness of the cured film structure, and enhancing the adhesion and smoothness of the coating on the surface of the medical guide wire. However, introducing hydrophobic fumed silica or introducing too much hydrophilic fumed silica in the system will cause an increase in the friction coefficient of the formed coating, unable to meet the usage requirements of medical guide wires.

[0014] As a preferred technical solution, the non - ionic surfactant is at least one of fatty acid monoethanolamide polyoxyethylene ether, fatty alcohol polyoxyethylene ether, nonylphenol polyoxyethylene ether, octylphenol polyoxyethylene ether, and isomeric decanol polyoxyethylene ether; preferably, the non - ionic surfactant is a combination of fatty acid monoethanolamide polyoxyethylene ether, fatty alcohol polyoxyethylene ether, nonylphenol polyoxyethylene ether, and octylphenol polyoxyethylene ether; the mass ratio of fatty acid monoethanolamide polyoxyethylene ether, fatty alcohol polyoxyethylene ether, nonylphenol polyoxyethylene ether, and octylphenol polyoxyethylene ether is (0.1 - 0.3):(0.1 - 0.2):(0.05 - 0.15):(0.05 - 0.08). The fatty acid monoethanolamide polyoxyethylene ether (PC98723) is from Wengjiang Reagent, and the fatty alcohol polyoxyethylene ether is C16 - C18 fatty alcohol polyoxyethylene ether (cetearyl alcohol polyether - 10).

[0015] As a preferred technical solution, the organic solvent is a combination of furfuryl alcohol and N-methylpyrrolidone; the mass ratio of furfuryl alcohol to N-methylpyrrolidone is (4.8 - 5.2):(4.0 - 4.5).

[0016] Based on the system of the present invention, a nonionic surfactant combination of fatty acid monoethanolamide polyoxyethylene ether, fatty alcohol polyoxyethylene ether, nonylphenol polyoxyethylene ether, and octylphenol polyoxyethylene ether with a mass ratio of (0.1 - 0.3):(0.1 - 0.2):(0.05 - 0.15):(0.05 - 0.08) is introduced to ensure the stability of the coating composition system; in addition, under the condition that the organic solvent exists in the system, the compatibility between polytetrafluoroethylene and polyamideimide in the system is effectively balanced, realizing that the coating composition cures into a self-stratifying coating with a gradient distribution, and at the same time achieving high adhesion and low friction coefficient. The inventor analyzed the reason as follows: at this mass ratio, the fatty acid monoethanolamide polyoxyethylene ether in the coating composition system has good solubility, and together with fatty alcohol polyoxyethylene ether, nonylphenol polyoxyethylene ether, and octylphenol polyoxyethylene ether, it realizes good compatibility between polyamideimide and polytetrafluoroethylene, forming a uniform and stable composition system. During the subsequent film-forming process, as the water evaporates, the separation tendency between polyamideimide and polytetrafluoroethylene increases, forming a self-stratifying coating with a gradient distribution. At this time, the polyamideimide in the coating firmly adheres to the surface of the medical guide wire, and at the same time, a polytetrafluoroethylene layer with a low friction coefficient is distributed on the surface layer of the coating.

[0017] As a preferred technical solution, the additives include a dispersant, a wetting and defoaming agent, and a pH regulator, and the mass ratio of the dispersant, the wetting and defoaming agent, and the pH regulator is (0.1 - 0.3):(0.2 - 0.4):(0.3 - 1).

[0018] As a preferred technical solution, the dispersant is DS-171.

[0019] As a preferred technical solution, the wetting and defoaming agent is polyether-modified tetramethyl decynediol( FS620).

[0020] As a preferred technical solution, the pH regulator is triethylamine and N,N-dimethylethanolamine, and the mass ratio of triethylamine to N,N-dimethylethanolamine is (0.3 - 0.6):(0.1 - 0.3).

[0021] On the other hand, the present invention provides a preparation method of a coating composition for a medical guide wire. According to the formula amount, a film-forming resin, an organic solvent, a pigment, a thickener, a nonionic surfactant, additives, and deionized water are mixed to obtain it.

[0022] Beneficial effects

[0023] 1. The present invention provides a coating composition for medical guide wires. By optimizing the product formula design, the provided coating composition has a low friction coefficient and good adhesion to medical guide wires. The formed coating is smooth and not easy to fall off, meeting the subsequent use requirements.

[0024] 2. Based on the polytetrafluoroethylene in the system of the present invention, introducing polyamide-imide Torlon AI-10 effectively improves the adhesion performance of the coating. Especially when controlling the mass ratio of polytetrafluoroethylene to polyamide-imide to be in the range of (4.5 - 6):(4 - 5.5), on the basis of not affecting other properties of polytetrafluoroethylene, the provided coating has excellent adhesion on the surface of medical guide wires. The formed coating is smooth and not easy to fall off from the surface of medical guide wires, greatly improving the use safety of medical guide wires.

[0025] 3. Based on the system of the present invention, by introducing 0.4 - 0.8 wt% of hydrophilic fumed silica as a thickener, the suspension of polytetrafluoroethylene and pigments is improved, and the storage stability of the coating composition is enhanced.

[0026] 4. When the present invention controls the mass ratio of hydrophilic fumed silica, polytetrafluoroethylene, and polyamide-imide in the system to be (0.4 - 0.8):(8 - 9):(7 - 10), the adhesion performance and surface smoothness of the cured coating are improved.

[0027] 5. Based on the system of the present invention, introducing a non-ionic surfactant combination of fatty acid monoethanolamide polyoxyethylene ether, fatty alcohol polyoxyethylene ether, nonylphenol polyoxyethylene ether, and octylphenol polyoxyethylene ether with a mass ratio of (0.1 - 0.3):(0.1 - 0.2):(0.05 - 0.15):(0.05 - 0.08) ensures the stability of the coating composition system. In addition, under the condition of the presence of organic solvents in the system, the compatibility between polytetrafluoroethylene and polyamide-imide in the system is effectively balanced, realizing a self-stratifying coating with a gradient distribution when the coating composition is cured, and simultaneously achieving high adhesion and low friction coefficient. Brief description of the drawings

[0028] Figure 1 It is a diagram of the actual coating product formed by applying the coating composition for medical guide wires provided in Example 1 of the present invention on the surface of a medical guide wire. Detailed description of the invention

[0029] Example 1

[0030] Example 1 of the present invention provides a coating composition for a medical guide wire, which comprises the following raw materials by mass percentage: film-forming resin 18%, organic solvent 9.3%, pigment 3%, thickener 0.6%, non-ionic surfactant 0.5%, auxiliary agent 1.2%, and deionized water to make up the balance.

[0031] The film-forming resin is a combination of polytetrafluoroethylene and polyamide-imide; the mass ratio of polytetrafluoroethylene to polyamide-imide is 8.5:9.5.

[0032] The model of the polyamide-imide is Torlon AI-10LM.

[0033] The thickener is hydrophilic fumed silica, and the hydrophilic fumed silica is fumed silica with a particle size of 12 nm (Degussa white carbon black A200).

[0034] The polytetrafluoroethylene is polytetrafluoroethylene ultrafine powder, and the average particle size of the polytetrafluoroethylene ultrafine powder is 4 μm, and the model is TF 9202Z (3M).

[0035] The non-ionic surfactant is a combination of fatty acid monoethanolamide polyoxyethylene ether, fatty alcohol polyoxyethylene ether, nonylphenol polyoxyethylene ether, and octylphenol polyoxyethylene ether; the mass ratio of fatty acid monoethanolamide polyoxyethylene ether, fatty alcohol polyoxyethylene ether, nonylphenol polyoxyethylene ether, and octylphenol polyoxyethylene ether is 0.2:0.15:0.1:0.05. The fatty acid monoethanolamide polyoxyethylene ether (PC98723) is from Wengjiang Reagent, and the fatty alcohol polyoxyethylene ether is C16-C18 fatty alcohol polyoxyethylene ether (cetearyl alcohol polyether-10).

[0036] The organic solvent is a combination of furfuryl alcohol and N-methylpyrrolidone; the mass ratio of furfuryl alcohol to N-methylpyrrolidone is 5:4.3.

[0037] The auxiliary agent includes a dispersant, a wetting and defoaming agent, and a pH regulator, and the mass ratio of the dispersant, the wetting and defoaming agent, and the pH regulator is 0.2:0.3:0.7.

[0038] The dispersant is DS-171.

[0039] The wetting and defoaming agent is polyether-modified tetramethyl decynediol ( FS620).

[0040] The pH regulator is triethylamine and N,N-dimethylethanolamine, and the mass ratio of triethylamine to N,N-dimethylethanolamine is 0.5:0.2.

[0041] The pigment is titanium cobalt green (Ranbar Green I-GN).

[0042] On the other hand, Example 1 of the present invention provides a method for preparing a coating composition for a medical guide wire. According to the formula amount, a film-forming resin, an organic solvent, a pigment, a thickener, a non-ionic surfactant, an auxiliary agent, and deionized water are mixed to obtain the composition.

[0043] Example 2

[0044] On the one hand, Example 2 of the present invention provides a coating composition for a medical guide wire. By mass percentage, it includes the following raw materials: 18% of a film-forming resin, 9.2% of an organic solvent, 3% of a pigment, 0.5% of a thickener, 0.5% of a non-ionic surfactant, 1.2% of an auxiliary agent, and the balance is made up with deionized water.

[0045] The film-forming resin is a combination of polytetrafluoroethylene and polyamide-imide; the mass ratio of polytetrafluoroethylene to polyamide-imide is 1:1.

[0046] The polyamide-imide has the model Torlon AI-10LM.

[0047] The thickener is hydrophilic fumed silica, and the hydrophilic fumed silica has a particle size of 12 nm (Degussa silica A200).

[0048] The polytetrafluoroethylene is polytetrafluoroethylene ultrafine powder, and the average particle size of the polytetrafluoroethylene ultrafine powder is 3 μm, MP1200 (DuPont, USA).

[0049] The non-ionic surfactant is a combination of fatty acid monoethanolamide polyoxyethylene ether, fatty alcohol polyoxyethylene ether, nonylphenol polyoxyethylene ether, and octylphenol polyoxyethylene ether; the mass ratio of fatty acid monoethanolamide polyoxyethylene ether, fatty alcohol polyoxyethylene ether, nonylphenol polyoxyethylene ether, and octylphenol polyoxyethylene ether is 0.2:0.15:0.1:0.05. The fatty acid monoethanolamide polyoxyethylene ether (PC98723) is from Wengjiang Reagent, and the fatty alcohol polyoxyethylene ether is C16-C18 fatty alcohol polyoxyethylene ether (cetearyl alcohol polyether-10).

[0050] The organic solvent is a combination of furfuryl alcohol and N-methylpyrrolidone; the mass ratio of furfuryl alcohol to N-methylpyrrolidone is 5:4.3.

[0051] The auxiliary agent includes a dispersant, a wetting and defoaming agent, and a pH regulator, and the mass ratio of the dispersant, the wetting and defoaming agent, and the pH regulator is 0.2:0.3:0.7.

[0052] The dispersant is DS-171.

[0053] The wetting defoamer is polyether-modified tetramethyl decynediol ( FS620).

[0054] The pH regulator is triethylamine and N,N-dimethylethanolamine, and the mass ratio of triethylamine to N,N-dimethylethanolamine is 0.5:0.2.

[0055] The pigment is titanium cobalt green (Ranbar Green I-GN).

[0056] On the other hand, Example 2 of the present invention provides a method for preparing a coating composition for a medical guide wire. According to the formula amount, a film-forming resin, an organic solvent, a pigment, a thickener, a nonionic surfactant, an auxiliary agent, and deionized water are mixed to obtain the composition.

[0057] Comparative Example 1

[0058] Comparative Example 1 of the present invention provides a coating composition for a medical guide wire and a method for preparing the same. The specific method is the same as that of Example 1, except that the mass ratio of polytetrafluoroethylene to polyamide-imide is 2:1.

[0059] Comparative Example 2

[0060] Comparative Example 2 of the present invention provides a coating composition for a medical guide wire and a method for preparing the same. The specific method is the same as that of Example 1, except that, by mass percentage, the coating composition comprises the following raw materials: 18% of a film-forming resin, 9.3% of an organic solvent, 3% of a pigment, 1.2% of a thickener, 0.5% of a nonionic surfactant, 1.2% of an auxiliary agent, and the balance is made up with deionized water.

[0061] Comparative Example 3

[0062] Comparative Example 3 of the present invention provides a coating composition for a medical guide wire and a method for preparing the same. The specific implementation method is the same as that of Example 1, except that the thickener is hydrophobic fumed silica, with the model of Degussa R974 (average particle size 16 nm).

[0063] Comparative Example 4

[0064] Comparative Example 4 of the present invention provides a coating composition for medical guidewires and a preparation method thereof. The specific implementation is the same as that of Example 1, except that the non-ionic surfactant is a combination of nonylphenol polyoxyethylene ether, octylphenol polyoxyethylene ether, and isodecyl alcohol polyoxyethylene ether; the mass ratio of nonylphenol polyoxyethylene ether, octylphenol polyoxyethylene ether, and isodecyl alcohol polyoxyethylene ether is 0.2:0.1:0.1; the organic solvent is a combination of N,N-dimethylacetamide, N-methylpyrrolidone, and propylene glycol; the mass ratio of N,N-dimethylacetamide, N-methylpyrrolidone, and propylene glycol is 3:4.8:1.5.

[0065] Performance test method

[0066] 1. Spray the coating compositions prepared in the examples and comparative examples onto the surface of a stainless steel plate substrate with a spray gun, and cure at 380 °C for 3 min to obtain a coating with a thickness of 6.5 μm. Observe the appearance of the coating, and refer to GB / T9286—1998 (cross-cut method) to test the adhesion of the coating. The results are shown in Table 1.

[0067] 2. Use the self-assembly device (from Jiangmen Taile Medical Technology Co., Ltd.) to dip-coat and cure the coating compositions prepared in the examples and comparative examples on a nitinol medical guidewire with a diameter of 0.3 mm. After curing at 380 °C for 3 min, a coating with a thickness of 6.5 μm is obtained (20 samples in parallel for each group, and the sample specification is 0.3*400 mm). Test the friction force of the medical guidewire on a friction tester and calculate the friction coefficient. The average value of the friction coefficient results is recorded in Table 1, where the test conditions are set according to ASTM D3359 standard: the clamping force is 4 N, the number of friction times is 25 times, the length of the test sample is 20 cm, the pulling speed is 10 cm / s, and the test temperature is 26 ± 2 °C.

[0068] 3. Perform in vitro cytotoxicity test and hemolysis test on the coated steel wire obtained by applying the coating composition for medical guidewires provided in Example 1 of the present invention to the surface of a medical guidewire (detected by Vico Testing Group Co., Ltd., report number WT220620). The results are shown in Table 2.

[0069] Table 1.

[0070]

[0071]

[0072] Table 2.

[0073]

Claims

1. A coating composition for a medical guide wire, characterized in that, By mass percentage, it at least includes the following raw materials: Film-forming resin 15-30%, organic solvent 5-12%, pigment 2-5%, thickener 0.4-0.8%, non-ionic surfactant 0.1-1%, auxiliary agent 0.5-2%, deionized water makes up the balance; the film-forming resin is a combination of polytetrafluoroethylene and polyamideimide; the mass ratio of polytetrafluoroethylene to polyamideimide is (4.5-6):(4-5.5); the thickener is hydrophilic fumed silica, and the mass ratio of the hydrophilic fumed silica, polytetrafluoroethylene, and polyamideimide is (0.4-0.8):(8-9):(7-10), and the particle size of the hydrophilic fumed silica is 5-20 nm; the polytetrafluoroethylene is polytetrafluoroethylene ultrafine powder, and the average particle size of the polytetrafluoroethylene ultrafine powder is 2.5-10 μm; the non-ionic surfactant is a combination of fatty acid monoethanolamide polyoxyethylene ether, fatty alcohol polyoxyethylene ether, nonylphenol polyoxyethylene ether, and octylphenol polyoxyethylene ether with a mass ratio of (0.1-0.3):(0.1-0.2):(0.05-0.15):(0.05-0.08); the organic solvent is a combination of furfuryl alcohol and N-methylpyrrolidone.

2. A preparation method of the coating composition for a medical guide wire according to claim 1, characterized in that, According to the formula amount, mix the film-forming resin, organic solvent, pigment, thickener, non-ionic surfactant, auxiliary agent, and deionized water to obtain it.

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