A composite catheter having a dual layer composite ink and a method of encapsulating the same

Abstract

The present application relates to a kind of composite catheter with double-layer composite ink and its packaging method.The composite catheter includes catheter body and ink layer coated outside the catheter;The ink layer includes developing ink located in the inner layer and packaging ink located in the outer layer, and developing signal is arranged on the developing ink.The beneficial effects of the present application are as follows: development and packaging are coordinated: high-concentration developing particles in the inner layer are combined with nano-enhanced packaging layer in the outer layer, and the developing accuracy and durability are considered;Efficient and stable process: gradient curing and pressure-assisted process reduce coating defects and improve yield;Clinical application advantage: suitable for long-term implantation or high-stress intervention scene, reduce the risk of instrument failure.

Description

Technical Field

[0001] This invention relates to the technical field of medical catheters, and more particularly to a composite catheter with a double-layer composite ink and its packaging method. Background Technology

[0002] Central venous catheters, as a common medical device, have been widely used in the diagnosis and treatment of diseases, including central venous pressure monitoring, blood volume maintenance, total parenteral nutrition, and the administration of emergency and therapeutic drugs. Since they are typically inserted into a patient's vein via puncture, the shape and position of the catheter must be monitored continuously during use to ensure accurate insertion. Currently, clinical monitoring methods usually involve adding a certain amount of contrast agent to the catheter manufacturing material. After insertion, external auxiliary instruments are used to display the catheter image in real time to determine its shape, while the insertion length is typically determined by graduations on the catheter's surface.

[0003] Looking at the existing single-layer or double-layer central venous catheters on the market, most of their markings are made by ink printing. Although the process is simple, the resolution is low, making them difficult to read. In addition, the adhesion is limited, and there is a risk of ink peeling off. At the same time, during the ink printing process, the surface of the venous catheter is prone to protrusion, which not only greatly reduces the smoothness of the catheter itself, making it difficult for the catheter to be inserted smoothly, but also makes it easier for blood cells to adhere and accumulate on the catheter, increasing the probability of thrombosis. Furthermore, the raw ink often contains small amounts of toxic substances. In emergency treatment, some emergency and therapeutic drugs are injected over a long period of time, and the catheter is left in place for up to half a month. The toxic substances in the ink can then harm human health, thus seriously affecting the biocompatibility of the catheter.

[0004] Chinese invention patent CN110812663A discloses a central venous catheter and its manufacturing method. The central venous catheter comprises a double-layer co-extruded inner layer and an outer layer. The inner layer is a polyurethane layer containing barium sulfate, and the outer layer is a transparent polyurethane layer. The inner layer is laser-marked with graduated markings. The manufacturing method involves feeding the inner and outer layer raw materials into different screw extruders and using a double-layer co-extrusion process to obtain a double-layer polyurethane catheter. Then, the double-layer polyurethane catheter is laser-marked to obtain the central venous catheter. The catheter exhibits high bonding strength between the inner and outer layers, effectively preventing the precipitation of barium sulfate, resulting in higher biocompatibility and medical safety. Furthermore, the markings are more refined, clear, and easily identifiable. The printing process eliminates the need for ink, reducing the harm caused by toxic substances to the human body and avoiding the risks of uneven catheter surfaces and ink detachment.

[0005] The double-layer ink on the conduit is prone to peeling off and has poor adhesion to the substrate, making it unable to effectively block developing particles. Summary of the Invention

[0006] To address the aforementioned problems in the prior art, this invention provides a composite conduit with a double-layer composite ink and its encapsulation method.

[0007] The above-mentioned problems of the present invention are solved by the following technical solutions:

[0008] A composite conduit with a double-layer composite ink includes a conduit body and an ink layer covering the outside of the conduit; the ink layer includes a developing ink located in the inner layer and an encapsulating ink located in the outer layer, and the developing ink is provided with a developing signal.

[0009] A further provision of the above technical solution is that the developing ink is based on epoxy resin and contains barium sulfate or bismuth oxide particles.

[0010] A further setting of the above technical solution is: the particle size of the bismuth oxide particles is 1-10 micrometers, and the proportion of them in the matrix is ​​30%-50%.

[0011] A further provision of the above technical solution is that the substrate of the encapsulating ink is polyurethane, and it is mixed with silicon dioxide.

[0012] A further setting of the above technical solution is: the particle size of the silicon dioxide is 50-100 nanometers, and its proportion in the matrix is ​​5%-10%.

[0013] The thickness of the developing ink is 5-10 micrometers, and the thickness of the encapsulating ink is 20-50 micrometers.

[0014] The present invention also provides a method for encapsulating a composite conduit, for molding the above-mentioned composite conduit with a double-layer composite ink, comprising the following steps:

[0015] S1. Surface pretreatment of the catheter body: cleaning and decontamination, axial unidirectional wiping of the outer surface of the catheter body;

[0016] S2, One-time ink coating: After stirring and defoaming the prepared developing ink, it is coated onto the surface of the conduit body through a pad printing machine and pre-cured;

[0017] S3, Secondary Ink Coating: The prepared packaging ink is applied to the surface of the conduit body after step S2 coating using a pad printing machine and then cured.

[0018] S4. Performance Verification: Test the packaging effect.

[0019] The above technical solution is further configured as follows: in step S1, the outer surface of the catheter body is subjected to plasma treatment, and the cleaning effect is verified.

[0020] A further setting of the above technical solution is: in step S3, the edge of the encapsulating ink layer extends at least 2 mm beyond the boundary of the developing ink layer.

[0021] The above technical solution is further configured as follows: in step S2, the pre-curing is hot air circulation curing; in step S3, the final curing is gradient temperature curing supplemented with pressure.

[0022] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0023] 1. Synergistic development and packaging: The combination of high-concentration developing particles in the inner layer and nano-reinforced packaging layer in the outer layer balances developing accuracy and durability;

[0024] 2. Highly efficient and stable process: Gradient curing and pressure-assisted processes reduce coating defects and improve yield;

[0025] 3. Clinical application advantages: Suitable for long-term implantation or high-stress intervention scenarios, reducing the risk of device failure. Attached Figure Description

[0026] Figure 1 This is the process control table in Example 2. Detailed Implementation

[0027] To further illustrate the technical means and effects of the present invention in achieving its intended purpose, the following detailed description of the specific implementation methods, structures, features, and effects of the present invention, in conjunction with the accompanying drawings and preferred embodiments, is provided below.

[0028] The following embodiments disclose a composite conduit with a double-layer composite ink and its encapsulation method.

[0029] Example 1: A composite conduit with a double-layer composite ink, comprising a conduit body and an ink layer covering the outside of the conduit; the ink layer comprises a developing ink located in the inner layer and an encapsulating ink located in the outer layer, wherein the developing ink is provided with a developing signal.

[0030] The above is the basic scheme of this embodiment.

[0031] In this embodiment, a developing ink with a developing signal is wrapped around the outside of the catheter. The developing ink is then encapsulated with an encapsulating ink, that is, the developing signal is encapsulated within the encapsulating ink. This achieves physical encapsulation and chemical bonding of the developing ink, solving the problem of the developing ink easily falling off, and simultaneously meeting the dual requirements of in vitro marking and in vivo X-ray imaging.

[0032] In this embodiment, the developing ink is based on epoxy resin and contains barium sulfate or bismuth oxide particles.

[0033] Barium sulfate or bismuth oxide particles are mixed into the matrix to enable real-time visualization of the catheter's effects within the body under X-ray irradiation, ensuring the smooth placement of diagnostic materials.

[0034] Preferably, in this embodiment, the bismuth oxide particles have a particle size of 1-10 micrometers and account for 30%-50% of the matrix.

[0035] In this embodiment, the base of the encapsulating ink is polyurethane, and it is mixed with silicon dioxide.

[0036] Preferably, in this embodiment, the silica is usually treated with a silane coupling agent, such as KH550, before being added. The hydroxyl groups (-OH-) on its surface react with the coupling agent to form a chemical bond OH + KH550 → SiO2-O-Si-(CH2)3-NH2. The modified silica surface has amino groups (-NH2), which can covalently bond with the isocyanate groups (-NCO) in polyurethane (PU) -NCO+-NH2→-NH-CO-NH- (urea bond). The bond energy is as high as 300-400 kJ / mol, which is much higher than the destructive energy of external forces (such as friction or body fluid flushing) (<10 kJ / mol), thus achieving permanent anchoring.

[0037] In this embodiment, the encapsulating ink forms a three-dimensional cross-linked network, physically blocking the developing particles, and enhancing the interlayer bonding through chemical bonding.

[0038] Preferably, the silica has a particle size of 50-100 nanometers and accounts for 5%-10% of the matrix.

[0039] Preferably, in this embodiment, the thickness of the developing ink is 5-10 micrometers, and the thickness of the encapsulating ink is 20-50 micrometers.

[0040] In this embodiment, to ensure the encapsulation effect, the encapsulation ink completely covers the developing layer.

[0041] The encapsulation principle of this embodiment is: after the encapsulation ink is cured, it forms a three-dimensional network with a pore size of <1μm. The developing particles are physically locked because their size is much larger than the pores (1-10μm vs. 0.1-1μm) (similar to the "molecular sieve" effect).

[0042] The chemical bonding principle in this embodiment is as follows: epoxy resin and polyurethane form an interpenetrating network (IPN) through an ester exchange reaction.

[0043] Nano-silica fills the network pores, improving mechanical strength (modulus increases by 30%-50%).

[0044] Example 2: The purpose of this example is to mold the composite conduit with double-layer composite ink as in Example 1, including the following steps:

[0045] S1. Surface pretreatment of the catheter body: cleaning and decontamination, axial unidirectional wiping of the outer surface of the catheter body;

[0046] S2, One-time ink coating: After stirring and defoaming the prepared developing ink, it is coated onto the surface of the conduit body through a pad printing machine and pre-cured;

[0047] S3, Secondary Ink Coating: The prepared packaging ink is applied to the surface of the conduit body after step S2 coating using a pad printing machine and then cured.

[0048] S4. Performance Verification: Test the packaging effect.

[0049] The above is the basic scheme of this embodiment.

[0050] In this embodiment, a lint-free cloth can be used to wipe the surface of the conduit with chemical detergents such as anhydrous ethanol or isopropanol to remove grease and dust. To ensure the cleaning effect, a new lint-free cloth can be used to wipe the surface repeatedly.

[0051] Meanwhile, to avoid secondary contamination, the dirt on the lint-free cloth is applied to the wiped area during the wiping process. In this embodiment, the wiping direction is unidirectional along the axial direction of the conduit.

[0052] Specifically, in step S1, the outer surface of the catheter body is subjected to plasma treatment, and the cleaning effect is verified.

[0053] Specifically, in this embodiment, the gas used for plasma treatment is preferably a mixture of argon and oxygen in a volume ratio of 4:1, in order to enhance surface oxidation and the introduction of polar groups.

[0054] During plasma treatment, the preferred power is 200W, the treatment time is 60 seconds, and the preferred chamber pressure is 50Pa. (See details...) Figure 1 As shown.

[0055] After plasma treatment, the treatment effect needs to be verified until the surface energy of the treated conduit is not less than 55mN / m and the contact angle is not greater than 30° in the dyne pen test.

[0056] The purpose of step S2 is to form a uniform developing layer to ensure the dispersion and physical locking of developing particles, wherein the size of developing particles is 1-10 μm.

[0057] To ensure uniform coating, in this embodiment, a silicone hardness of Shore A 25° is selected to adapt to the curved surface contact of PEEK.

[0058] The printing pressure range is 0.3-0.5 MPa, and the speed is 15 cm / s, to avoid particle compression and agglomeration, which would cause uneven pad printing.

[0059] The proportion of developer (such as barium sulfate / tungsten powder) in the ink is 30%-40%, and it is defoamed after being thoroughly stirred and passed through a 200-mesh sieve.

[0060] In step S2, pre-curing is performed by hot air circulation curing;

[0061] During the pre-curing process, the temperature and pre-curing time are set at 60℃±2℃ with hot air circulation for 10 minutes to ensure solvent evaporation and humidity control <30% RH.

[0062] After pre-curing, the curing effect needs to be tested. The test requires measuring the film thickness at 20±5μm using a white light interferometer and observing the uniformity of particle distribution in the developing ink layer using a microscope.

[0063] In this embodiment, the purpose of coating the encapsulating ink is to construct a dense encapsulation layer in order to achieve the "molecular sieve" effect and enhance chemical bonding.

[0064] To ensure the encapsulation effect, specifically in step S3, the edge of the encapsulation ink layer extends at least 2 mm beyond the boundary of the developing ink layer.

[0065] With this configuration, the encapsulating ink layer can completely encapsulate the developing ink layer, preventing the developing ink from peeling off and causing failure.

[0066] To ensure the uniformity of the encapsulation ink, in this embodiment, a silicone hardness of Shore A 15° is selected, and double-layer printing is performed. After the first layer is encapsulated, it is pre-cured at 80°C for 5 minutes before the second layer is printed.

[0067] Specifically, in step S3, the final curing is a gradient temperature curing process supplemented by pressure.

[0068] In this embodiment, the preferred requirement for gradient temperature rise is to first trigger the epoxy-polyurethane IPN reaction at 80℃ for 20 min, and then raise the temperature to 120℃ for 10 min to promote the dispersion of nano-SiO2.

[0069] During the curing process, the oven environment is set to a pressure environment with a pressure of 0.1 MPa to reduce air bubbles at the interface.

[0070] After encapsulation, the encapsulation effect is verified: the physical encapsulation effect is verified by observing the pore size under a microscope. The preferred pore size is <1μm, which meets the requirement of locking the developing particles.

[0071] The effectiveness of chemical bonding strength was verified by detecting the characteristic peaks of ester bonds and Si-O-Si using an infrared spectrometer.

[0072] If the developing particles fall off during the testing process, it means that the pre-curing temperature is insufficient and the solvent residue causes the porosity of the encapsulation ink to increase. In this case, infrared drying after pre-curing at 60℃ can be added to remove trace amounts of solvent.

[0073] If the encapsulation ink opens, indicating insufficient polyurethane IPN reaction leading to internal stress concentration, interfacial compatibility can be improved by adding 1%-2% silane coupling agent (KH-550).

[0074] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make some modifications or alterations to the above-disclosed technical content to create equivalent embodiments without departing from the scope of the present invention. Any simple modifications, equivalent changes and alterations made to the above embodiments based on the technical essence of the present invention without departing from the scope of the present invention shall still fall within the scope of the present invention.

Claims

1. A composite catheter with double-layer composite ink, comprising a catheter body and an ink layer coated on the catheter; characterized in that: the ink layer comprises a developing ink in an inner layer and an encapsulating ink in an outer layer, and the developing ink is provided with a developing signal; the encapsulating ink has a polyurethane base and is mixed with silica; the silica is treated with a silane coupling agent; the developing ink has an epoxy resin base and is mixed with barium sulfate or bismuth oxide particles; the epoxy resin and the polyurethane form an interpenetrating network (IPN) at the interface through an ester exchange reaction. 2.The composite catheter with double-layer composite ink according to claim 1, characterized in that: the bismuth oxide particles have a particle size of 1-10 microns and a proportion of 30%-50% in the base. 3.The composite catheter with double-layer composite ink according to claim 1, characterized in that: the silica has a particle size of 50-100 nanometers and a proportion of 5%-10% in the base. 4.The composite catheter with double-layer composite ink according to claim 1, characterized in that: the developing ink has a thickness of 5-10 microns, and the encapsulating ink has a thickness of 20-50 microns. 5.An encapsulating method for a composite catheter, used for forming the composite catheter with double-layer composite ink according to claim 1, characterized in that: the method comprises the following steps, S1, surface pretreatment of the catheter body: cleaning and decontamination, and unidirectional wiping of the outer surface of the catheter body; S2, primary ink coating: after stirring and defoaming of the prepared developing ink, the ink is coated on the surface of the catheter body by a pad printer and is pre-cured; S3, secondary ink coating: after the prepared encapsulating ink is coated on the surface of the catheter body coated in step S2 by a pad printer, the ink is post-cured; S4, performance verification: detection of the encapsulating effect.

6. The method of packaging a composite conduit of claim 5, wherein: In step S1, the outer surface of the catheter body is treated with plasma, and the cleaning effect is verified.

7. The method of packaging a composite conduit of claim 5, wherein: In step S3, the edge of the encapsulating ink layer exceeds the boundary of the developing ink layer by at least 2 mm.

8. The method of packaging a composite conduit of claim 5, wherein: In step S2, the pre-curing is hot air circulation curing; and in step S3, the post-curing is gradient temperature curing supplemented with pressure action.

Images