Medical conductive silicone tube and preparation method thereof

Abstract

The invention relates to the technical field of medical polymer materials, and provides a medical conductive silicone tube and a preparation method thereof.The preparation method comprises the following steps that insulating medical silicone is made into a tubular structure, and one end of the tubular structure is sealed; conducting liquid silica gel is injected from the open end of the tubular structure, so that the conducting liquid silica gel is attached to the whole inner wall of the tubular structure; pouring out the redundant conductive liquid silica gel in the tubular structure, enabling the remaining conductive liquid silica gel to form a film layer on the inner wall of the tubular structure, and carrying out standing and leveling; and heating and curing the tubular structure with the film layer on the inner wall so as to form a conductive liquid silica gel layer on the inner wall of the tubular structure. The preparation method of the medical conductive silicone tube is simple in process and low in cost, complex co-extrusion equipment or film composite equipment is not needed, the medical conductive silicone tube can be produced by using simple pouring, leveling and heating curing processes, and the equipment investment and the operation cost are greatly reduced.

Description

Technical Field

[0001] This invention relates to the field of medical polymer materials technology, and in particular provides a medical conductive silicone tube and its preparation method. Background Technology

[0002] In the field of medical polymer materials, silicone tubing is widely used due to its excellent biocompatibility, flexibility, and sterilization resistance. In some applications, such as catheters in electrophysiological surgery, connecting tubing between certain bioelectrical signal monitoring sensors, or precision drug delivery systems that require the prevention of static electricity buildup, silicone tubing is required not only to be insulating but also to have a certain degree of conductivity in its walls to transmit electrical signals or dissipate charges.

[0003] Currently, there are two main methods for manufacturing conductive medical silicone tubing: one is co-extrusion, which involves simultaneously extruding an insulating outer layer and a conductive inner layer; the other is laminating a conductive film layer inside the finished tubing. Co-extrusion requires significant equipment investment and involves complex processes, and for slender tubes, controlling the bonding and thickness uniformity of the two layers is challenging. The composite conductive film method carries risks of discontinuous interfaces, weak adhesion, and easy detachment, and the process is equally complex and costly.

[0004] Therefore, there is a need for a manufacturing method that is simple, low-cost, and capable of producing medical conductive liquid silicone tubing with a uniform, continuous conductive layer that is firmly bonded to the base tube. Summary of the Invention

[0005] The purpose of this invention is to provide a medical conductive silicone tube and its preparation method, aiming to solve the problem that the existing preparation methods for medical conductive liquid silicone tubes are complex and difficult.

[0006] To achieve the above objectives, the technical solution adopted by the present invention is as follows: In a first aspect, this application provides a method for preparing a medical conductive silicone tube, the method comprising the following steps: Insulating medical silicone is made into a tubular structure, and one end of the tubular structure is sealed. The conductive liquid silicone is poured in from the open end of the tubular structure, so that the conductive liquid silicone adheres to the entire inner wall of the tubular structure; The excess conductive liquid silicone is poured out of the tubular structure, so that the remaining conductive liquid silicone forms a film on the inner wall of the tubular structure, and is then allowed to stand and level. The tubular structure with the membrane layer on its inner wall is heated and cured to form a conductive liquid silicone layer on the inner wall of the tubular structure.

[0007] The beneficial effects of the present invention are as follows: The preparation method of the medical conductive silicone tube of the present invention is simple and low in cost. It does not require complex co-extrusion equipment or film composite equipment. It can be produced by simple pouring, leveling and heat curing process, which greatly reduces equipment investment and operating costs. Since both the conductive liquid silicone and the tubular structure are made of silicone, they can form a strong chemical bond during the heat curing process, which is not easy to peel off or fall off, and the product has high reliability.

[0008] In some embodiments, prior to the step of injecting conductive liquid silicone from the open end of the tubular structure, causing the conductive liquid silicone to adhere to the entire inner wall of the tubular structure. The conductive liquid silicone is stirred evenly using a mixer, and then vacuumed to remove air bubbles.

[0009] In some embodiments, in the step of curing the tubular structure having the film layer on its inner wall to form a conductive liquid silicone layer on the inner wall of the tubular structure... The curing conditions are a temperature of 100℃~130℃ and a curing time of 5min~15min.

[0010] In some embodiments, the conductive liquid silicone comprises the following raw materials in parts by weight: 40 to 80 parts of methyl vinyl silicone rubber raw material 30-60 parts of fluorosilicone 30 to 150 parts of conductive filler 5 to 180 parts of weather-resistant silica 1 to 5 parts of structure control agent Vulcanizing agent: 0.5 to 3 parts.

[0011] In some embodiments, the conductive filler includes at least one of conductive carbon black, conductive carbon fiber, graphite, graphene, nickel-coated graphene, carbon nanotubes, and metal powder.

[0012] In some embodiments, the conductive filler is prepared by compounding nickel-coated graphene and metal powder in a ratio of (1:2) to (2:1).

[0013] In some embodiments, the metal powder includes at least one of copper powder, nickel-plated copper powder, silver powder, glass silver, aluminum powder, copper silver, gold powder, graphene-plated nickel, and silver-plated copper powder.

[0014] In some embodiments, the conductive liquid silicone further includes a heat-resistant additive, wherein the heat-resistant additive is present in parts by weight of 2 to 10 parts.

[0015] In some embodiments, the heat-resistant additive includes iron oxide or cerium carbonate.

[0016] In some embodiments, the specific surface area of ​​the fumed silica is 100~400 m² / g.

[0017] Secondly, this application also provides a medical conductive silicone tube, which is prepared by the above-described method for preparing a medical conductive silicone tube.

[0018] Understandably, the beneficial effects of the second aspect can be referenced from the beneficial effects of the first aspect, and will not be elaborated here. Attached Figure Description

[0019] To more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0020] Figure 1 A flowchart illustrating the preparation method of a medical conductive silicone tube provided in an embodiment of the present invention. Detailed Implementation

[0021] Embodiments of the present invention are described in detail below, examples of which are illustrated in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the present invention, and should not be construed as limiting the present invention.

[0022] In the description of this invention, it should be understood that the terms "length", "width", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0023] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified.

[0024] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0025] Firstly, please refer to Figure 1 This application provides a method for preparing a medical conductive silicone tube, comprising the following steps: S001. Insulating medical silicone is made into a tubular structure, and one end of the tubular structure is sealed.

[0026] S002. Inject conductive liquid silicone into the tubular structure through the open end, so that the conductive liquid silicone adheres to the entire inner wall of the tubular structure.

[0027] S003. Pour out the excess conductive liquid silicone from the tubular structure, so that the remaining conductive liquid silicone forms a film on the inner wall of the tubular structure, and allow it to stand and level.

[0028] Understandably, in this step, the surface tension of the liquid and gravity are used to make the conductive liquid silicone flow automatically and level, forming a uniform inner liner film. This step is the key to ensuring the uniformity of the conductive layer.

[0029] S004. Heating and curing the tubular structure with a film layer on the inner wall to form a conductive liquid silicone layer on the inner wall of the tubular structure.

[0030] The preparation method of the medical conductive silicone tube of the present invention is simple and low in cost. It does not require complex co-extrusion equipment or film composite equipment. It can be produced by simple pouring, leveling and heat curing process, which greatly reduces equipment investment and operating costs. Since both the conductive liquid silicone and the tubular structure are made of silicone, they can form a strong chemical bond during the heat curing process, which is not easy to peel off or fall off, and the product has high reliability.

[0031] In some embodiments, prior to the step of injecting conductive liquid silicone through the open end of the tubular structure, causing the conductive liquid silicone to adhere to the entire inner wall of the tubular structure. The conductive liquid silicone is stirred evenly using a mixer, and then vacuumed to remove air bubbles.

[0032] Understandably, the mixer speed can be 60-120 rpm, and the mixing time can be 5-10 minutes.

[0033] In some embodiments, in the step of curing the tubular structure with a film layer on its inner wall to form a conductive liquid silicone layer on the inner wall of the tubular structure... The curing conditions are a temperature of 100℃~130℃ and a curing time of 5min~15min.

[0034] In some embodiments, the conductive liquid silicone comprises the following raw materials in parts by weight: 40 to 80 parts of methyl vinyl silicone rubber raw material 30-60 parts of fluorosilicone 30 to 150 parts of conductive filler 5 to 180 parts of weather-resistant silica 1 to 5 parts of structure control agent Vulcanizing agent: 0.5 to 3 parts.

[0035] Understandably, the resistance of conductive liquid silicone is precisely controllable, allowing for relatively low external and surface resistance, resulting in better product consistency. It boasts excellent overall performance, maintaining a moderate hardness of 30-80A while achieving low resistance. The wires exhibit good overall flexibility, are resistant to bending, and withstand high and low temperatures (-60°C to 200°C), resulting in a long lifespan. It offers high safety performance; the specific low resistance range ensures rapid discharge of static charge, preventing static buildup, while avoiding the risk of accidental short circuits due to the resistance not being too low. It is particularly suitable for applications with strict requirements for anti-static and electromagnetic shielding, such as semiconductor production lines, medical equipment, aerospace, and military electronics. It can also be used in special devices requiring flexible power conduction.

[0036] In some embodiments, the conductive filler includes at least one of conductive carbon black, conductive carbon fiber, graphite, graphene, nickel-coated graphene, carbon nanotubes, and metal powder.

[0037] Here, conductive carbon black is an extremely fine black powder produced by the incomplete combustion or thermal decomposition of hydrocarbons (oil or natural gas) at high temperatures. Its main component is carbon, with small amounts of hydrogen, oxygen, and other elements. Carbon black particles are nanoscale (typically 10-500 nanometers), but these primary particles aggregate into complex three-dimensional aggregate structures in the form of chains or grapes through van der Waals forces. This structure easily interconnects with each other in the matrix, forming a conductive network. When the amount of carbon black added reaches a critical value (percolation threshold), it contacts each other in the insulating matrix, forming a continuous conductive path, thus achieving conductivity.

[0038] Conductive carbon fiber is a fibrous material with a carbon content exceeding 90%, made from organic fibers such as polyacrylonitrile (PAN), pitch, or viscose through high-temperature carbonization and graphitization. It has a one-dimensional linear structure, typically with a diameter of 5-10 micrometers and lengths ranging from tens of micrometers to continuous filaments. It possesses high axial conductivity. Within the matrix, carbon fibers act like tiny wires, forming a conductive network through mutual contact. A higher aspect ratio facilitates network formation, requiring a lower addition amount.

[0039] Graphite is an allotrope of carbon with a layered structure. It is composed of stacked layers of carbon atom planes arranged in a honeycomb lattice (graphene sheets). The layers are held together by relatively weak van der Waals forces, allowing them to slide easily. Graphite sheets themselves are good conductors, forming conductive pathways in the matrix through the contacts between the sheets. The conductivity is anisotropic, with better conductivity along the planar direction of the sheets.

[0040] Graphene is a two-dimensional material with a honeycomb lattice formed by a single layer of carbon atoms hybridized in sp². It can be considered as the basic unit that makes up graphite. Due to its two-dimensional properties and extremely high specific surface area, a very small amount of graphene can form a very dense conductive network in the matrix, with an extremely low percolation threshold. It has extremely high intrinsic electrical conductivity, a huge theoretical specific surface area, and an extremely low percolation threshold (typically 0.5-3%), while also possessing excellent thermal conductivity and mechanical strength.

[0041] Nickel-coated graphene is a core-shell structured composite conductive material, with graphene as the core and a layer of metallic nickel chemically plated or coated on its surface. The surface of the graphene sheets is covered by a continuous and uniform layer of nickel metal. The nickel layer separates the graphene sheets, effectively preventing aggregation and making them easier to disperse. Nickel is a good conductor, which can establish more metallic conductive bridges between adjacent graphene sheets, reducing contact resistance. Nickel's ferromagnetism, combined with its conductivity, makes it excellent in electromagnetic shielding applications, especially adept at absorbing electromagnetic waves.

[0042] Carbon nanotubes are seamless, hollow, one-dimensional tubular nanomaterials formed by rolling up single or multiple layers of graphene sheets. They are classified into single-walled carbon nanotubes (SWCNTs) and multi-walled carbon nanotubes (MWCNTs). Their diameters are in the nanometer range (1-100 nanometers), and their lengths can reach the micrometer or even millimeter range, thus exhibiting extremely high aspect ratios. Due to their extremely high aspect ratio, carbon nanotubes easily overlap in a matrix, forming a highly efficient conductive network (similar to a "bird's nest" structure) with an extremely low percolation threshold. Depending on their chirality, single-walled carbon nanotubes can be metallic or semiconducting.

[0043] In some embodiments, the conductive filler is prepared by compounding nickel-coated graphene and metal powder in a ratio of (1:2) to (2:1).

[0044] Understandably, conductive fillers are prepared by compounding nickel-coated graphene and metal powder in a ratio of (1:2) to (2:1) to achieve the best balance between the amount and dispersibility of conductive fillers, thereby realizing a stable and controllable conductive network.

[0045] Optionally, the weight ratio of nickel-coated graphene to metal powder can be 1:2, 1:1.5, 1:1, 1.5:1, 2:1, etc.

[0046] In some embodiments, the metal powder includes at least one of copper powder, nickel-plated copper powder, silver powder, glass silver, aluminum powder, copper silver, gold powder, graphene-plated nickel, and silver-plated copper powder.

[0047] In some embodiments, the conductive liquid silicone also includes a heat-resistant additive, wherein the heat-resistant additive is present in parts by weight of 2 to 10 parts.

[0048] Understandably, heat-resistant additives can further enhance the thermal stability of conductive liquid silicone.

[0049] In some embodiments, the heat-resistant additive includes iron oxide or cerium carbonate.

[0050] In some embodiments, the specific surface area of ​​the fumed silica is 100~400 m² / g.

[0051] In some embodiments, the structuring control agent may be hydroxyl silicone oil, diphenylsilanediol, methoxy-terminated polydimethylsiloxane, hexamethyldisilazane, etc.

[0052] Understandably, structure control agents are a class of functional additives used to suppress problems such as hardening, increased viscosity, and decreased mechanical properties of silicone rubber during storage caused by the interaction of hydroxyl groups on the surface of fillers (such as silica).

[0053] In some embodiments, the vulcanizing agent may be tetramethylthiuram disulfide, N-cyclohexyl-2-benzothiazole sulfenamide, N-tert-butyl-2-benzothiazole sulfenamide, diphenylguanidine, dicumyl peroxide, bis-tert-butylperoxyisopropylbenzene, dicumyl peroxide, benzoyl peroxide, 2,5-dimethyl-2,5-dihexane, 2,4-dichlorobenzoyl peroxide, etc.

[0054] Understandably, vulcanizing agents are substances that can form chemical bridges (crosslinks) between rubber molecular chains, transforming the rubber from a plastic linear structure into a three-dimensional network structure, thereby obtaining the desired mechanical properties and elasticity.

[0055] In some embodiments, the method for preparing the conductive liquid silicone of this application includes the following steps: The raw materials for conductive liquid silicone are mixed evenly to form conductive liquid silicone compound.

[0056] Understandably, the surface resistivity of conductive liquid silicone rubber compound is 0.1Ω to 5Ω; the Shore A hardness is 30A to 80A; the outer skin thickness can be 0.15mm to 50mm; and the outer surface resistivity is 2Ω to 10Ω. This resistance range can effectively discharge static electricity while avoiding the risk of short circuits.

[0057] In some embodiments, in the step of uniformly mixing the raw materials of conductive liquid silicone to prepare conductive liquid silicone compound, Place the conductive liquid silicone raw material in a mixer, with a stirring rate of 40 rpm to 60 rpm, a mixing temperature of 120℃ to 160℃, and a mixing time of 30 min to 60 min. Example 1

[0058] In this embodiment, the raw materials for the conductive liquid silicone are proportioned by weight as follows: 50 parts of methyl vinyl silicone rubber raw rubber 50 parts of fluorosilicone 20 parts acetylene black 40 parts of graphene coated with nickel 8 parts of meteorological white carbon black 3 parts hydroxy silicone oil 5 parts of iron oxide 2,4-Dichlorobenzoyl peroxide 2.5 parts; The above raw materials were placed in an internal mixer at a stirring speed of 40 rpm and a mixing temperature of 120°C for 30 minutes to prepare a conductive liquid silicone rubber compound. The conductive liquid silicone rubber compound was then cooled to 40°C and rolled on a two-roll mill for 15 minutes. The mixture was then degassed in a vacuum chamber at -0.1 MPa for 5 minutes, and then poured into a tubular structure. The tubular structure was inverted to pour out most of the conductive liquid silicone rubber, and then allowed to stand vertically for 5 minutes for self-leveling. The tubular structure was then placed horizontally in an oven at 120°C and baked for 8 minutes. After cooling, the surface resistivity of the conductive layer on the inner wall of the tubular structure was measured to be 75 Ω, and the hardness was 50 Shore A. A peel test showed that the conductive layer adhered firmly to the tube wall without detachment. Example 2

[0059] In this embodiment, the raw materials for the conductive liquid silicone are proportioned by weight as follows: 80 parts of methyl vinyl silicone rubber raw rubber 50 parts of fluorosilicone 15 parts of conductive carbon fiber 35 parts nickel powder 10 parts of weather-resistant precipitated silica 3 parts hydroxy silicone oil 3 parts cerium carbonate 2,4-Dichlorobenzoyl peroxide, 2 parts; The above raw materials were placed in an internal mixer at a stirring speed of 60 rpm and a mixing temperature of 150°C for 50 minutes to prepare a conductive liquid silicone rubber compound. The conductive liquid silicone rubber compound was then cooled to 40°C and rolled on a two-roll mill for 30 minutes. The mixture was then degassed in a vacuum chamber at -0.1 MPa for 5 minutes, and then poured into a tubular structure. The tubular structure was inverted to pour out most of the conductive liquid silicone rubber, and then allowed to stand vertically for 8 minutes for self-leveling. The tubular structure was then placed horizontally in an oven at 125°C and baked for 12 minutes. After cooling, the surface resistivity of the conductive layer on the inner wall of the tubular structure was measured to be 60 Ω, and the hardness was 65 Shore A. A peel test showed that the conductive layer adhered firmly to the tube wall without detachment.

[0060] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for preparing a medical conductive silicone tube, characterized by: The preparation method comprises the following steps: an insulating medical silica gel is made into a tubular structure, and one end of the tubular structure is closed; an electrically conductive liquid silica gel is poured into the open end of the tubular structure so that the electrically conductive liquid silica gel adheres to the entire inner wall of the tubular structure; the electrically conductive liquid silica gel in the tubular structure is poured out, and the remaining electrically conductive liquid silica gel forms a film layer on the inner wall of the tubular structure, and the tubular structure is left to flow flat; the tubular structure with the film layer on the inner wall is heated and solidified to form an electrically conductive liquid silica gel layer on the inner wall of the tubular structure.

2. The preparation method of the medical electrically conductive silica gel tube according to claim 1, wherein before the step of pouring the electrically conductive liquid silica gel into the open end of the tubular structure so that the electrically conductive liquid silica gel adheres to the entire inner wall of the tubular structure, the electrically conductive liquid silica gel is stirred evenly by a stirrer, and air bubbles are removed by a vacuum machine.

3. The preparation method of the medical electrically conductive silica gel tube according to claim 1, wherein in the step of solidifying the tubular structure with the film layer on the inner wall to form an electrically conductive liquid silica gel layer on the inner wall of the tubular structure, the solidification condition is that the temperature is 100-130 DEG C, and the solidification time is 5-15 min.

4. The preparation method of the medical electrically conductive silica gel tube according to claim 1, wherein the electrically conductive liquid silica gel comprises the following raw materials in parts by weight: methyl vinyl silicone rubber raw rubber 40-80 parts fluorosilicone 30-60 parts electrically conductive filler 30-150 parts meteorological white carbon black 5-180 parts structure control agent 1-5 parts vulcanizing agent 0.5-3 parts. The electrically conductive filler comprises at least one of electrically conductive carbon black, electrically conductive carbon fiber, graphite, graphene, nickel-coated graphene, carbon nanotube and metal powder. The electrically conductive filler is compounded by nickel-coated graphene and metal powder in a ratio of (1:2) to (2:1). The metal powder comprises at least one of copper powder, nickel-coated copper powder, silver powder, glass silver, aluminum powder, copper silver, gold powder, nickel-coated graphene and silver-coated copper powder. The electrically conductive liquid silica gel further comprises a heat-resistant additive, and the weight fraction of the heat-resistant additive is 2-10 parts. The heat-resistant additive comprises iron oxide or cerium carbonate. The specific surface area of the meteorological white carbon black is 100-400 m² / g. The medical electrically conductive silica gel tube is prepared by the preparation method of any one of claims 1-10. ​ ​ ​ ​ 5. The method for preparing the medical conductive silicone tube according to claim 1, characterized in that: ​ 6. The method for preparing the medical conductive silicone tube according to claim 2, characterized in that: ​ 7. The method for preparing a medical conductive silicone tube according to claim 2 or 3, characterized in that: ​ 8. The method for preparing the medical conductive silicone tube according to claim 1, characterized in that: ​ 9. The method for preparing the medical conductive silicone tube according to claim 5, characterized in that: ​ 10. The method of claim 1, wherein: ​ 11. A medical conductive silicone tube, characterized by: ​

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