Composite catheter with double-layer composite ink and packaging method of composite catheter

Abstract

The invention relates to a composite catheter with double-layer composite ink and a packaging method of the composite catheter. Comprising a catheter body and an ink layer wrapping the catheter body. The ink layer comprises developing ink located on the inner layer and packaging ink located on the outer layer, and developing signals are arranged on the developing ink. The beneficial effects of the invention are that developing and packaging are cooperated: the inner-layer high-concentration developing particles are combined with the outer-layer nanometer enhanced packaging layer, and the developing precision and durability are both considered; the process is efficient and stable; the coating defects are reduced through the gradient curing and pressure-assisted process, and the yield is improved; clinical application has the advantages that the device is suitable for long-term implantation or high-stress intervention scenes, and instrument failure risks are reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of medical catheters, and in particular to a composite catheter with a double-layer composite ink and a packaging method thereof. Background Art

[0002] Central venous catheters (CVCs), as a common medical device, have been widely used in the diagnosis and treatment of diseases such as central venous pressure monitoring, blood volume maintenance, total parenteral nutrition, and the infusion of emergency and therapeutic drugs. Since they are typically inserted into the patient's vein via puncture, the shape and position of the intravenous catheter must be monitored at all times during use to ensure accurate insertion. Current clinical monitoring methods typically involve adding a certain amount of developer to the catheter manufacturing material. After the catheter is inserted into the human body, an external auxiliary instrument displays the catheter image in real time to determine the catheter's shape. The inserted catheter length is typically determined using scale markings on the surface of the catheter.

[0003] Looking at the existing single-layer or double-layer central venous catheters on the market, most of their scale markings are made by ink printing. Although the process is simple, the resolution is low and difficult to identify. In addition, the adhesion is limited, and there is a risk of ink falling off. At the same time, when printing ink, bumps are easily formed on the surface of the intravenous catheter, which not only greatly reduces the smoothness of the catheter itself and is not conducive to the smooth insertion of the catheter, but also makes it easier for blood cells to adhere and accumulate on the catheter, increasing the probability of thrombosis. In addition, the raw ink often contains a small amount of toxic substances. In emergency treatment, some rescue drugs and therapeutic drugs take a long time to be injected, and the catheter can be placed for up to half a month. The toxic substances in the ink will cause harm to human health, thereby seriously affecting the biocompatibility of the catheter.

[0004] The Chinese invention patent with publication number 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, wherein the inner layer is a polyurethane layer containing barium sulfate, and the outer layer is a transparent polyurethane layer. The inner layer is printed with a scale mark by laser marking. The manufacturing method comprises feeding the raw materials of the inner layer and the outer layer into different screw extruders respectively, and producing a double-layer polyurethane catheter through a double-layer co-extrusion process, and then laser marking and printing the double-layer polyurethane catheter to produce a central venous catheter. The inner and outer layers of the intravenous catheter have high bonding strength, which can effectively prevent the precipitation of barium sulfate, and has higher biocompatibility and medical safety. At the same time, the marking produced is more precise, clear, and easy to identify. No ink is required during printing, which not only reduces the harm caused by toxic substances to the human body, but also avoids the risk of unevenness on the catheter surface and ink falling off.

[0005] The double-layer ink on the tube is easy to fall off, has poor bonding ability with the substrate, and cannot effectively block the developer particles. Summary of the Invention

[0006] In order to solve the above problems existing in the prior art, the present invention provides a composite catheter with a double-layer composite ink and a packaging method thereof.

[0007] The above-mentioned problem of the present invention is solved by the following technical solutions: A composite catheter with a double-layer composite ink comprises a catheter body and an ink layer covering the outside of the catheter; the ink layer comprises a developing ink located in an inner layer and an encapsulating ink located in an outer layer, and a developing signal is provided on the developing ink.

[0008] The above technical solution is further configured as follows: the developing ink is based on epoxy resin and is mixed with barium sulfate or bismuth oxide particles.

[0009] The above technical solution is further configured as follows: the particle size of the bismuth oxide particles is 1-10 microns, and the proportion of the bismuth oxide particles in the matrix is ​​30%-50%.

[0010] The above technical solution is further configured as follows: the matrix of the packaging ink is polyurethane or modified acrylic resin, and is mixed with silicon dioxide.

[0011] The above technical solution is further configured as follows: the particle size of the silicon dioxide is 50-100 nanometers, and the proportion of the silicon dioxide in the matrix is ​​5%-10%.

[0012] The thickness of the developing ink is 5-10 microns, and the thickness of the encapsulating ink is 20-50 microns.

[0013] The present invention also provides a packaging method for a composite catheter, which is used to form the composite catheter with a double-layer ink, comprising the following steps: S1. Surface pretreatment of the catheter body: cleaning and decontamination, wiping the outer surface of the catheter body in an axial unidirectional manner; S2. Primary ink coating: After the prepared developer ink is stirred and defoamed, it is applied to the surface of the catheter body by a pad printing machine and pre-cured; S3, secondary ink coating: applying the prepared developing ink to the surface of the catheter body coated in step S2 by a pad printing machine and performing final curing; S4. Performance verification: Test the packaging effect.

[0014] 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.

[0015] The above technical solution is further configured as follows: in step S3, the edge of the encapsulated ink layer extends beyond the boundary of the developed ink layer by at least 2 mm.

[0016] The above technical solution is further configured as follows: in step S2, pre-curing is hot air circulation curing; in step S3, final curing is gradient temperature rising curing assisted by pressure.

[0017] Compared with the prior art, the present invention has the following beneficial effects: 1. Synergy between development and encapsulation: The inner layer of high-concentration development particles is combined with the outer nano-enhanced encapsulation layer to balance development accuracy and durability; 2. Efficient and stable process: Gradient curing and pressure-assisted process reduce coating defects and improve yield; 3. Clinical application advantages: Suitable for long-term implantation or high-stress intervention scenarios, reducing the risk of device failure. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 This is the process control table in Example 2. DETAILED DESCRIPTION

[0019] In order to further illustrate the technical means and effects adopted by the present invention to achieve the predetermined purpose of the invention, the specific implementation methods, structures, features and effects of the present invention are described in detail below in conjunction with the accompanying drawings and preferred embodiments.

[0020] The following embodiments disclose a composite catheter having a double-layer composite ink and a packaging method thereof.

[0021] Example 1: A composite catheter with a double-layer composite ink includes a catheter body and an ink layer covering the outside of the catheter; the ink layer includes a developing ink located in an inner layer and an encapsulating ink located in an outer layer, and a developing signal is provided on the developing ink.

[0022] The above is the basic solution of this embodiment.

[0023] In this embodiment, a developing ink with a developing signal is coated on the outside of the catheter, and the developing ink is encapsulated by the encapsulating ink, that is, the developing signal is encapsulated in the encapsulating ink, thereby realizing physical encapsulation and chemical bonding of the developing ink, solving the problem of easy shedding of the developing ink, and meeting the dual needs of in vitro marking and in vivo X-ray development.

[0024] In this embodiment, the developer ink is based on epoxy resin and is mixed with barium sulfate or bismuth oxide particles.

[0025] Barium sulfate or bismuth oxide particles are mixed into the matrix so that under X-ray irradiation, the impact of the catheter in the human body can be displayed in real time, ensuring smooth diagnostic placement.

[0026] Preferably, in this embodiment, the particle size of the bismuth oxide particles is 1-10 microns, and the proportion of the bismuth oxide particles in the matrix is ​​30%-50%.

[0027] In this embodiment, the matrix of the packaging ink is polyurethane or modified acrylic resin, and is mixed with silicon dioxide.

[0028] Preferably, in this embodiment, the silica is usually treated with a silane coupling agent before being added, such as KH550. The hydroxyl groups (-OH-) on its surface react with the coupling agent to form a chemical bond SiO2-OH + KH550 → SiO2-O-Si-(CH2)3-NH2. The modified silica surface has an amino group (-NH2), which can covalently bond with the isocyanate group (-NCO) in the 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 (<10 kJ / mol) of external effects (such as friction or body fluid flushing), thereby achieving permanent anchoring.

[0029] In this embodiment, the encapsulated ink forms a three-dimensional cross-linked network, physically blocks the developer particles, and enhances interlayer bonding through chemical bonding.

[0030] Preferably, the silica has a particle size of 50-100 nanometers and accounts for 5%-10% of the matrix.

[0031] Preferably, in this embodiment, the thickness of the developing ink is 5-10 microns, and the thickness of the encapsulating ink is 20-50 microns.

[0032] In this embodiment, in order to ensure the encapsulation effect, the encapsulation ink completely covers the developing layer.

[0033] The encapsulation principle of this embodiment is that after the encapsulation ink is cured, it forms a three-dimensional network with a pore size of less than 1μm. The developer particles are physically locked in (similar to the "molecular sieve" effect) because their size is much larger than the pores (1-10μm vs. 0.1-1μm).

[0034] The chemical bonding principle in this embodiment is: epoxy resin and polyurethane form an interfacial interpenetrating network (IPN) through an ester exchange reaction; Nano-silica fills the network pores and improves the mechanical strength (modulus increased by 30%-50%).

[0035] Example 2: The purpose of this example is to form the composite catheter with double-layer ink in Example 1, including the following steps:

[0036] S1. Surface pretreatment of the catheter body: cleaning and decontamination, wiping the outer surface of the catheter body in an axial unidirectional manner; S2. Primary ink coating: After the prepared developer ink is stirred and defoamed, it is applied to the surface of the catheter body by a pad printing machine and pre-cured; S3, secondary ink coating: applying the prepared developing ink to the surface of the catheter body coated in step S2 by a pad printing machine and performing final curing; S4. Performance verification: Test the packaging effect.

[0037] The above is the basic solution of this embodiment.

[0038] In this embodiment, a dust-free cloth dipped in anhydrous ethanol or isopropyl alcohol or other chemical detergent can be used to wipe the surface of the catheter to remove grease and dust. To ensure the decontamination effect, a new dust-free cloth can be used to wipe repeatedly.

[0039] At the same time, in order to avoid secondary contamination, the dirt on the dust-free cloth is smeared onto the wiped part during the wiping process. In this embodiment, the wiping direction is unidirectional along the axial direction of the catheter.

[0040] Specifically, in step S1 , the outer surface of the catheter body is plasma treated, and the cleaning effect is verified.

[0041] Specifically, in this embodiment, the gas used for plasma treatment is preferably a mixture of argon and oxygen with a volume ratio of 4:1 to enhance surface oxidation and the introduction of polar groups.

[0042] During the plasma treatment, the power is preferably 200W, the treatment time is 60 seconds, and the chamber pressure is preferably set to 50Pa. Figure 1 shown.

[0043] After the plasma treatment, the treatment effect needs to be verified until the surface energy of the treated catheter surface is not less than 55mN / m in the dyne pen test and the contact angle is not greater than 30°.

[0044] The purpose of step S2 is to form a uniform developer layer and ensure the dispersion and physical locking of developer particles, wherein the developer particles have a size of 1-10 μm.

[0045] To ensure uniform coating, in this embodiment, a silicone rubber with a hardness of Shore A 25° is selected to adapt to contact with the PEEK curved surface.

[0046] The printing pressure range is 0.3-0.5Mpa and the speed is 15cm / s to avoid particle extrusion and agglomeration, which will cause uneven pad printing.

[0047] The developer (such as barium sulfate / tungsten powder) in the ink accounts for 30%-40%. After thorough stirring, pass through a 200-mesh sieve to defoam.

[0048] In step S2, pre-curing is hot air circulation curing; During the pre-curing process, the set temperature and pre-curing time are 60℃±2℃ with hot air circulation curing for 10 minutes to ensure that the solvent evaporates and the humidity is controlled to <30% RH.

[0049] After pre-curing, the curing effect needs to be tested. The test requires the film thickness to be measured to be 20±5μm by white light interferometer and the particle distribution uniformity of the developed ink layer to be observed by microscope.

[0050] In this embodiment, the purpose of coating the encapsulation ink is to construct a dense encapsulation layer to achieve a "molecular sieve" effect and enhance chemical bonding.

[0051] To ensure the encapsulation effect, specifically, in step S3, the edge of the encapsulating ink layer exceeds the boundary of the developing ink layer by at least 2 mm.

[0052] With such an arrangement, the encapsulating ink layer can completely encapsulate the developing ink layer, thus preventing the developing ink from peeling off and causing failure.

[0053] To ensure uniform packaging ink, in this embodiment, a silica gel with a hardness of Shore A 15° is selected and double-layer printing is performed. After the first layer is packaged, it is pre-cured at 80°C for 5 minutes before printing the second layer.

[0054] Specifically, in step S3, the final curing is performed by gradient temperature rise curing assisted by pressure.

[0055] In this embodiment, the requirement for the gradient temperature increase is preferably to first trigger the epoxy-polyurethane IPN reaction at 80°C for 20 minutes, and then increase the temperature to 120°C for 10 minutes to promote the dispersion of nano-SiO2.

[0056] During the curing process, the oven environment was set to a pressure environment with a pressure of 0.1 MPa to reduce bubbles on the interface.

[0057] After the encapsulation is completed, the encapsulation effect is verified: the physical encapsulation effect is verified by observing the pore size under a microscope. The preferred pore size is <1 μm, which meets the requirements for developing particle locking.

[0058] The effect of chemical bonding strength was verified by detecting the characteristic peaks of ester bonds and Si-O-Si using an infrared spectrometer.

[0059] During the inspection process, if the developer particles fall off, that is, the pre-curing temperature is insufficient, and the solvent residue causes the porosity of the encapsulated ink to increase. The infrared drying after pre-curing at 60°C can be increased to remove trace solvents.

[0060] If the packaging ink is open, that is, the polyurethane IPN reaction is insufficient, resulting in internal stress concentration, the interface compatibility can be improved by adding 1%-2% silane coupling agent (KH-550).

[0061] The above description is merely a preferred embodiment of the present invention and does not constitute any form of limitation to the present invention. Although the present invention has been disclosed as above in terms of a preferred embodiment, it is not intended to limit the present invention. Any person skilled in the art can, without departing from the scope of the technical solution of the present invention, make some changes or modifications to equivalent embodiments using the technical contents disclosed above. However, any brief modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention are still within the scope of the technical solution of the present invention.

Claims

1. A composite catheter with a double-layer composite ink, comprising a catheter body and an ink layer covering the outside of the catheter; characterized in that: The ink layer includes a developing ink located in an inner layer and a packaging ink located in an outer layer, and a developing signal is provided on the developing ink.

2. The composite catheter with double-layer composite ink according to claim 1, characterized in that: The developer ink is based on epoxy resin and is mixed with barium sulfate or bismuth oxide particles.

3. The composite catheter with double-layer composite ink according to claim 2, characterized in that: The particle size of the bismuth oxide particles is 1-10 microns, and the proportion of the bismuth oxide particles in the matrix is ​​30%-50%.

4. The composite catheter with double-layer composite ink according to claim 1, characterized in that: The matrix of the packaging ink is polyurethane or modified acrylic resin, and is mixed with silicon dioxide.

5. The composite catheter with double-layer composite ink according to claim 4, characterized in that: The silicon dioxide has a particle size of 50-100 nanometers and accounts for 5%-10% of the matrix.

6. The composite catheter with double-layer composite ink according to claim 1, characterized in that: The thickness of the developing ink is 5-10 microns, and the thickness of the encapsulating ink is 20-50 microns.

7. A method for packaging a composite catheter, for forming the composite catheter with a double-layer ink according to claim 1, characterized in that: The following steps are included: S1. Surface pretreatment of the catheter body: cleaning and decontamination, wiping the outer surface of the catheter body in an axial unidirectional manner; S2. Primary ink coating: After the prepared developer ink is stirred and defoamed, it is applied to the surface of the catheter body by a pad printing machine and pre-cured; S3, secondary ink coating: applying the prepared developing ink to the surface of the catheter body coated in step S2 by a pad printing machine and performing final curing; S4. Performance verification: Test the packaging effect.

8. The method for packaging a composite catheter according to claim 7, wherein: In step S1 , the outer surface of the catheter body is plasma treated, and the cleaning effect is verified.

9. The method for packaging a composite catheter according to claim 7, wherein: In step S3 , the edge of the encapsulated ink layer extends beyond the boundary of the developed ink layer by at least 2 mm.

10. The method for packaging a composite catheter according to claim 7, wherein: In step S2, pre-curing is hot air circulation curing; in step S3, final curing is gradient temperature curing assisted by pressure.

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