Coating composition for medical guide wire and preparation method thereof

Abstract

The invention relates to the technical field of A61L31 / 08, in particular to a medical guide wire coating composition and a preparation method thereof.The medical guide wire coating composition at least comprises, by mass, 15-30% of film-forming resin, 5-12% of organic solvent, 2-5% of pigment, 0.3-1% of thickener, 0.1-1% of nonionic surfactant, 0.5-2% of auxiliaries and the balance deionized water. The coating composition provided by the invention has low friction coefficient and good adhesive force to the medical guide wire, and the formed coating is smooth and is not easy to fall off, so that the subsequent use is met.

Description

Technical Field

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

[0002] With the popularization of minimally invasive interventional treatment, higher requirements are placed on the performance of the surface coating of medical guidewires. Since the coated medical guidewire is to be guided to the target lesion through imaging, it is inevitable to contact with human tissue, which requires the coating to be as smooth as possible and not to fall off during use.

[0003] The coating on the surface of existing medical guidewire products mostly uses resin as a film-forming material, and matches the corresponding additives to obtain a coating. Through a subsequent coating process, the coating is wrapped on the surface of medical guidewires made of platinum, stainless steel, tungsten, nickel-titanium alloy, and gold-plated tungsten to form a coating. However, due to the particularity of medical use, the development of coating formulas is difficult. The existing technology solves the safety problem caused by the shedding of the coating during long-term use by optimizing the formula to make the provided coating have a high adhesion to the medical guidewire. For example, a Chinese patent application (application number CN110090325A) discloses a medical guidewire hydrophilic coating formula and its preparation process, specifically introducing ascorbic acid, and under the interaction of tert-butyl hydroperoxide and ferrous chloride, realizing the formation of a hydrophilic coating with high adhesion strength on the surface of the medical guidewire by polyvinyl pyrrolidone, which mainly focuses on the optimization of the hydrophilicity of the tube, but the friction coefficient of the coating still needs to be further reduced. A Chinese patent application (authorization publication number CN110507864B) discloses a medical guide wire with excellent lubrication properties. Specifically, polyvinyl alcohol is introduced into the polyurethane system, and the coating reaches the required thickness by swelling due to water absorption. During actual use, the adhesion of the coating to the surface of the medical guide wire may be affected. Summary of the invention

[0004] In order to solve the above problems, 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 the medical guide wire. The formed coating is smooth and not easy to fall off, which meets the needs of subsequent use.

[0005] On the one hand, the present invention provides a coating composition for a medical guidewire, which comprises at least the following raw materials, by mass percentage: 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 nonionic surfactant, 0.5-2% of an additive, and the balance made up of deionized water.

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

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

[0008] Based on the problems of insufficient adhesion and high friction coefficient of existing coatings for medical guidewires, the inventors selected polytetrafluoroethylene with a smaller friction coefficient as the film-forming resin material of the coating. However, due to the non-stick properties of polytetrafluoroethylene, it cannot be effectively adhered to the surface of the medical guidewire. During the research process, the inventors found that matching polyamide-imide as a film-forming resin material can improve the adhesion performance of the subsequent coating. Based on the characteristics of the resin itself and the effect of the amount of polyamide-imide introduced on the comprehensive performance of the coating, the inventors unexpectedly found during the screening process that based on the polytetrafluoroethylene in the system of the present invention, the introduction of polyamide-imide Torlon AI-10 can effectively improve the adhesion performance of the coating, especially controlling the mass ratio of polytetrafluoroethylene to polyamide-imide within 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 the medical guidewire, and the formed coating is smooth and not easy to fall off from the surface of the medical guidewire, which greatly improves the safety of the use of the medical guidewire. The inventors analyzed that the possible reason is that the polyamide-imide Torlon AI-10 has a certain compatibility with the polytetrafluoroethylene ultrafine powder in the system. During the process of coating curing and film formation, the polyamide-imide in the coating acts on the metal interface of the medical guide wire as much as possible, so that the formed coating is firmly attached to the surface of the medical guide wire as a whole, and the coating formed by subsequent curing has a lower friction coefficient and good adhesion to the surface of the medical guide wire.

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

[0010] As a preferred technical solution, the thickener is hydrophilic fumed silica, and the mass ratio of the hydrophilic fumed silica, polytetrafluoroethylene, and polyamide-imide 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 white carbon black A200).

[0013] Based on the system of the present invention, 0.4-0.8wt% of hydrophilic fumed silica is introduced as a thickener to improve the suspension of polytetrafluoroethylene and pigment and improve the storage stability of the coating composition. The inventors found in the process of exploration that, especially when the mass ratio of hydrophilic fumed silica, polytetrafluoroethylene and polyamide-imide 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 possible reasons are: under the joint action of the dispersant in the system, 10-20nm hydrophilic fumed silica is evenly dispersed in the resin system, and the active groups on the surface of the hydrophilic fumed silica interact with the -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 3-4μm in the system, thereby improving the density of the membrane structure after curing, and improving the adhesion and smoothness of the coating on the surface of the medical guide wire. However, if the amount of hydrophobic fumed silica or hydrophilic fumed silica introduced into the system is too high, the friction coefficient of the coating will increase, which cannot meet the use requirements of medical guide wires.

[0014] As a preferred technical solution, the nonionic 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 nonionic 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 derived from Wengjiang reagent, and the fatty alcohol polyoxyethylene ether is C16-C18 fatty alcohol polyoxyethylene ether (cetostearyl 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 combination of fatty acid monoethanolamide polyoxyethylene ether, fatty alcohol polyoxyethylene ether, nonylphenol polyoxyethylene ether and octylphenol polyoxyethylene ether nonionic surfactants in 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 of the presence of an organic solvent in the system, the compatibility between polytetrafluoroethylene and polyamide-imide in the system is effectively balanced, so that the coating composition can be cured into a self-stratified coating with a gradient distribution, while achieving high adhesion and a low friction coefficient. The inventors analyzed that the reason may be: at this mass ratio, the fatty acid monoethanolamide polyoxyethylene ether in the coating composition system has good solubility, and works together with fatty alcohol polyoxyethylene ether, nonylphenol polyoxyethylene ether, and octylphenol polyoxyethylene ether to achieve good compatibility between polyamideimide and polytetrafluoroethylene, forming a uniform and stable composition system. In the subsequent film formation process, as the water evaporates, the separation trend between polyamideimide and polytetrafluoroethylene increases, and the coating has a gradient distribution of self-stratified coating. At this time, the polyamideimide in the coating is firmly attached to the surface of the medical guide wire, and a polytetrafluoroethylene layer with a low friction coefficient is distributed on the surface of the coating.

[0017] As a preferred technical solution, 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 (0.1-0.3): (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 defoamer is polyether-modified tetramethyldecynediol ( 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] Another aspect of the present invention provides a method for preparing a coating composition for a medical guidewire, which is obtained by mixing a film-forming resin, an organic solvent, a pigment, a thickener, a nonionic surfactant, an additive, and deionized water according to a formula.

[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 the medical guide wire. The formed coating is smooth and not easy to fall off, which meets the requirements of subsequent use.

[0024] 2. Based on the polytetrafluoroethylene in the system of the present invention, the polyamide-imide Torlon AI-10 is introduced to effectively improve the adhesion performance of the coating, especially controlling the mass ratio of polytetrafluoroethylene to polyamide-imide within 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 the medical guide wire, and the formed coating is smooth and not easy to fall off from the surface of the medical guide wire, which greatly improves the safety of the use of the medical guide wire.

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

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

[0027] 5. Based on the system of the present invention, a combination of fatty acid monoethanolamide polyoxyethylene ether, fatty alcohol polyoxyethylene ether, nonylphenol polyoxyethylene ether, and octylphenol polyoxyethylene ether nonionic surfactants in 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 of the presence of an organic solvent in the system, the compatibility between polytetrafluoroethylene and polyamide-imide in the system is effectively balanced, so that the coating composition can be cured into a gradient distributed self-stratified coating, while achieving high adhesion and low friction coefficient. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 This is a picture of an actual coating product formed by applying the coating composition for medical guidewire provided in Example 1 of the present invention to the surface of a medical guidewire. DETAILED DESCRIPTION

[0029] Example 1

[0030] Embodiment 1 of the present invention provides a coating composition for a medical guidewire, which comprises the following raw materials, by mass percentage: 18% film-forming resin, 9.3% organic solvent, 3% pigment, 0.6% thickener, 0.5% non-ionic surfactant, 1.2% auxiliary agent, 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 the polytetrafluoroethylene to the 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, the average particle size of the polytetrafluoroethylene ultrafine powder is 4 μm, and the model is TF 9202Z (3M).

[0035] The nonionic 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 derived from Wengjiang reagent, and the fatty alcohol polyoxyethylene ether is C16-C18 fatty alcohol polyoxyethylene ether (cetostearyl 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 defoamer 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 guidewire, which is obtained by mixing a film-forming resin, an organic solvent, a pigment, a thickener, a non-ionic surfactant, an additive, and deionized water according to the formula amount.

[0043] Example 2

[0044] Embodiment 2 of the present invention provides a coating composition for a medical guidewire, which comprises the following raw materials, by mass percentage: 18% film-forming resin, 9.2% organic solvent, 3% pigment, 0.5% thickener, 0.5% non-ionic surfactant, 1.2% auxiliary agent, and deionized water to make up the balance.

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

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

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

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

[0049] The nonionic 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 derived from Wengjiang reagent, and the fatty alcohol polyoxyethylene ether is C16-C18 fatty alcohol polyoxyethylene ether (cetostearyl 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 guidewire, which is obtained by mixing a film-forming resin, an organic solvent, a pigment, a thickener, a non-ionic surfactant, an additive, and deionized water according to the formula amount.

[0057] Comparative Example 1

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

[0059] Comparative Example 2

[0060] Comparative Example 2 of the present invention provides a coating composition for a medical guidewire and a preparation method thereof, and its specific method is the same as Example 1, except that, by mass percentage, the coating composition includes the following raw materials: 18% film-forming resin, 9.3% organic solvent, 3% pigment, 1.2% thickener, 0.5% non-ionic surfactant, 1.2% additive, and deionized water to make up the balance.

[0061] Comparative Example 3

[0062] Comparative Example 3 of the present invention provides a coating composition for a medical guidewire and a preparation method thereof, and its specific implementation manner is the same as that of Example 1, except that the thickener is a hydrophobic fumed silica, model number is Degussa R974 (average particle size 16 nm).

[0063] Comparative Example 4

[0064] Comparative Example 4 of the present invention provides a coating composition for a medical guidewire and a preparation method thereof. The specific implementation manner is the same as that of Example 1, except that the nonionic surfactant is a combination of nonylphenol polyoxyethylene ether, octylphenol polyoxyethylene ether, and isomeric decanol polyoxyethylene ether; the mass ratio of nonylphenol polyoxyethylene ether, octylphenol polyoxyethylene ether, and isomeric decanol 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 Testing Methods

[0066] 1. The coating composition prepared in the embodiment and the comparative example was sprayed onto the surface of the stainless steel plate substrate with a spray gun, and cured at 380° C. for 3 min to obtain a coating with a thickness of 6.5 μm. The appearance of the coating was observed, and the adhesion of the coating was tested with reference to GB / T9286-1998 (cross-hatch method). The results are shown in Table 1.

[0067] 2. The coating composition prepared in the embodiment and the comparative example was used for dipping and curing of a nickel-titanium alloy medical guide wire with a diameter of 0.3 mm using a self-assembly device (sourced from Jiangmen Taile Medical Technology Co., Ltd.), and a coating with a thickness of 6.5 μm was obtained after curing at 380°C for 3 min (20 samples in parallel in each group, and the sample specification was 0.3*400 mm). The friction force of the medical guide wire was tested on a friction tester and the friction coefficient was calculated. The average value of the friction coefficient results is recorded in Table 1, where the test conditions were set according to the ASTM D3359 standard: a holding force of 4 N, a friction number of 25 times, a test sample length of 20 cm, a pulling speed of 10 cm / s, and a test temperature of 26±2°C.

[0068] 3. The coating composition for medical guide wire provided in Example 1 of the present invention was applied to the surface of the medical guide wire to obtain a coated steel wire, and an in vitro cytotoxicity test and a hemolysis test were performed (tested by Weco 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: Calculated by mass percentage, at least the following raw materials are included: Film-forming resin 15-30%, organic solvent 5-12%, pigment 2-5%, thickener 0.3-1%, non-ionic surfactant 0.1-1%, auxiliary agent 0.5-2%, and deionized water to make up the balance.

2. The coating composition for medical guide wire according to claim 1, characterized in that: The film-forming resin is selected from at least one of polytetrafluoroethylene, polyamide-imide, polyurethane and polyvinyl pyrrolidone.

3. The coating composition for medical guide wire according to claim 2, characterized in that: The film-forming resin is a combination of polytetrafluoroethylene and polyamide-imide; the mass ratio of the polytetrafluoroethylene to the polyamide-imide is (4.5-6): (4-5.5).

4. The coating composition for medical guide wire according to claim 3, characterized in that: The added amount of the thickener is 0.4-0.8wt%, and the thickener is selected from one of fumed silica, polyvinyl alcohol, cellulose thickener, and polyurethane thickener.

5. The coating composition for medical guide wire according to claim 4, characterized in that: The thickener is hydrophilic fumed silica, and the mass ratio of the hydrophilic fumed silica, polytetrafluoroethylene and polyamide-imide is (0.4-0.8):(8-9):(7-10).

6. The coating composition for medical guide wire according to claim 5, characterized in that: The polytetrafluoroethylene is polytetrafluoroethylene ultrafine powder, and the average particle size of the polytetrafluoroethylene ultrafine powder is 2.5-10 μm.

7. The coating composition for medical guide wire according to claim 5, characterized in that: The particle size of the hydrophilic fumed silica is 5-20 nm.

8. The coating composition for medical guide wire according to claim 5, characterized in that: The nonionic 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.

9. The coating composition for medical guide wire according to claim 8, characterized in that: The organic solvent is a combination of furfuryl alcohol and N-methylpyrrolidone.

10. A method for preparing the coating composition for medical guidewire according to any one of claims 1 to 9, characterized in that: The film-forming resin, organic solvent, pigment, thickener, non-ionic surfactant, additive and deionized water are mixed according to the formula.

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