Formula of high-strength medical-grade halogen-free cable sheath material

Abstract

The invention relates to a formula of a high-strength medical-grade halogen-free cable sheath material. The invention aims to solve the problem that the existing medical cable sheath material has insufficient comprehensive properties in the aspects of biological safety, halogen-free flame retardance, mechanical property balance, environmental aging resistance, chemical disinfection resistance and the like. The invention provides a high-strength medical-grade halogen-free cable sheath material formula, which successfully realizes integration of excellent comprehensive performance by carefully selecting components and optimizing the proportion in order to solve the problem that the harsh medical application requirements of high strength, high flexibility, excellent flame-retardant low-smoke property, long-acting antibacterial property, wide temperature range and chemical disinfectant erosion resistance are difficult to meet at the same time, so that the high-strength medical-grade halogen-free cable sheath material has a wide application prospect. On the premise of core guarantee of biological safety and halogen-free environmental protection, mechanical property balance of the material is remarkably improved, the material has excellent long-term aging resistance and outstanding environmental tolerance, and the material is endowed with long-acting antibacterial property, so that nearly strict performance requirements of modern medical electronic equipment on cable sheath materials are comprehensively met, and the cable sheath material has wide application prospects. The key defects of the traditional PVC or conventional halogen-free flame-retardant polyolefin material in medical application are overcome.

Description

Technical Field

[0001] This article belongs to the technical field of polymer composite materials, and specifically relates to a formula of high-strength medical-grade halogen-free cable sheathing material. Background Art

[0002] As medical electronic equipment becomes increasingly intelligent and portable, medical cables serve as core connection components of key equipment such as life monitors, endoscopes, and surgical robots. The comprehensive performance of their sheath materials directly determines the safety, reliability, and service life of the equipment.

[0003] The particularity of the medical application environment places almost stringent comprehensive performance requirements on cable sheath materials. The materials need to be in contact with the human body or medical environment for a long time. First of all, they must be biosafe and prevent cytotoxicity and the precipitation of harmful substances. Secondly, they must be able to repeatedly withstand various sterilization methods such as high-temperature steam, ethylene oxide gas and chemical disinfectants without significant deterioration. At the same time, in confined spaces such as operating rooms, they must meet strict flame retardant requirements and have low smoke and halogen-free properties to avoid the release of corrosive halogen acid gases during combustion. In addition, they also need excellent resistance to repeated bending and wear, a wide temperature resistance range, and good hydrolysis resistance and long-term aging resistance to ensure long-term reliability in complex environments. Finally, the material must have sufficient strength while maintaining flexibility and the ability to inhibit the growth of microorganisms to meet hygiene requirements.

[0004] However, traditional materials currently widely used in medical cable sheaths, such as polyvinyl chloride or conventional halogen-free flame-retardant polyolefins, have significant limitations and are difficult to fully meet the above requirements.

[0005] The main problem with PVC is that it contains halogens, which produce large amounts of toxic smoke and highly corrosive hydrogen chloride gas when burned, seriously violating medical environmental protection requirements. At the same time, its plasticizers have the risk of migration and precipitation, posing potential biosafety risks.

[0006] In order to meet high flame retardancy levels, conventional halogen-free flame-retardant polyolefins usually need to be filled with a high proportion of inorganic flame retardants such as magnesium hydroxide or aluminum hydroxide. This leads to a significant increase in the rigidity of the material, a significant decrease in elongation at break, loss of flexibility and susceptibility to stress cracking. At the same time, high filling makes it difficult to balance smoke suppression and mechanical strength, exacerbating processing difficulties and the risk of surface defects in products. More importantly, such materials generally lack the inherent antibacterial properties, long-term resistance to chemical disinfectant erosion and excellent thermal aging stability required in medical scenarios. Their low-temperature brittleness is usually high, making it difficult to adapt to cold area transportation or medical scenarios involving freezing.

[0007] Therefore, the medical device industry urgently needs to develop an innovative, high-performance, integrated cable sheath material that must simultaneously achieve the following breakthroughs while ensuring its halogen-free, environmentally friendly nature and biosafety:

[0008] The synergistic unity of high strength and high flexibility;

[0009] Synergistic improvement of flame retardancy, low smoke properties and wear resistance;

[0010] Ability to adapt to extreme temperature environments;

[0011] As well as long-lasting antibacterial properties and excellent chemical resistance. Summary of the Invention

[0012] In view of the insufficient comprehensive performance of existing medical cable sheath materials in terms of biosafety, halogen-free flame retardancy, mechanical property balance, environmental aging resistance and chemical disinfection resistance, especially the difficulty in simultaneously meeting the stringent medical application requirements of high strength, high flexibility, excellent flame retardancy and low smoke, long-term antibacterial properties, wide temperature range and resistance to chemical disinfectants, this article provides a formula for a high-strength medical-grade halogen-free cable sheath material.

[0013] A formula for a high-strength medical-grade halogen-free cable sheath material, comprising the following components in parts by weight:

[0014] 55-65 parts of polyolefin elastomer;

[0015] 20-30 parts of magnesium hydroxide;

[0016] 5-10 parts of nano kaolin;

[0017] 1-2 parts of high wear-resistant pigment carbon black;

[0018] PE wax 1-3 parts;

[0019] 1 part of silver ion carrier antibacterial agent;

[0020] 1-3 parts talcum powder;

[0021] 5-8 parts of amino silane coupling agent;

[0022] 1-2 parts of anti-UV agent;

[0023] 2-3 parts of stearic acid;

[0024] 2-5 parts of plasticizer;

[0025] Antioxidant 1010 1-4 parts.

[0026] The performance of the sheath material prepared by the above formula meets the following key index requirements:

[0027] Flame retardant and low smoke halogen-free: The flame retardant grade reaches UL94 V-0, the flame spread carbonization distance ≤40mm; the smoke density during combustion ≤100, the light transmittance ≥60%; the total amount of halogen acid gas released ≤0.5%, and the pH value of the combustion product>4.3.

[0028] Aging and temperature resistance: After aging for 168 hours at 80℃, the change rate of tensile strength is ≤±20%, and the change rate of elongation at break is ≤±20%; low temperature resistance can reach -20℃; long-term use temperature range is -40℃ to 125℃.

[0029] Biological safety: Passed ISO 10993-5 cytotoxicity test; GC-MS detection showed no phthalates and polycyclic aromatic hydrocarbons were released.

[0030] Environmental tolerance: Performance retention rate ≥80% after hydrolysis at 70℃ for 14 days; can withstand immersion in 75% alcohol and 3% hydrogen peroxide for 24 hours without swelling or cracking.

[0031] In addition, key components in the formulation have specific requirements:

[0032] Nano-kaolin particles have a particle size of 100-500nm and are used to synergistically improve mechanical strength and smoke suppression performance;

[0033] High wear-resistant pigment carbon black DBP absorption value ≥110ml / 100g, nitrogen adsorption specific surface area ≥100m 2 / g.

[0034] Beneficial effects:

[0035] In summary, this formula has successfully achieved excellent comprehensive performance integration through the selection of components and optimization of ratios. Under the premise of core guarantee of biosafety and halogen-free environmental protection, it has significantly improved the balance of mechanical properties of the material, has excellent long-term aging resistance and outstanding environmental tolerance, and has given the material long-lasting antibacterial properties, thus fully meeting the almost stringent performance requirements of modern medical electronic equipment for cable sheath materials, and solving the key defects of traditional PVC or conventional halogen-free flame-retardant polyolefin materials in medical applications. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 This is a schematic diagram showing a comparison of raw material formulas for a high-strength medical-grade halogen-free cable sheathing material.

[0037] Figure 2 This is a schematic diagram of the preparation process parameters of a high-strength medical-grade halogen-free cable sheathing material.

[0038] Figure 3 This is a schematic diagram comparing the mechanical and aging properties of a high-strength medical-grade halogen-free cable sheath material.

[0039] Figure 4 This is a schematic diagram of the flame retardant and environmental performance of the formula of a high-strength medical-grade halogen-free cable sheath material.

[0040] Figure 5This is a schematic diagram of the biological safety and environmental tolerance of the formula of a high-strength medical-grade halogen-free cable sheathing material. DETAILED DESCRIPTION

[0041] In order to deepen the understanding of the present invention, the present invention will be further described in detail below with reference to the embodiments and drawings. The embodiments are only used to explain the present invention and do not constitute a limitation on the scope of protection of the present invention.

[0042] 1. Raw material formula

[0043] The formula of the high-strength medical-grade halogen-free cable sheath material of the present invention comprises the following components by mass (kg):

[0044] Polyolefin elastomer: used as a base material to provide chemical corrosion resistance and low precipitation properties. The weight of Example 1 is 55 kg, Example 2 is 60 kg, and Example 3 is 65 kg.

[0045] Magnesium hydroxide: used as a halogen-free flame retardant to ensure high-temperature stability, 30 kg for Example 1, 25 kg for Example 2, and 20 kg for Example 3;

[0046] Nano-kaolin: synergistically enhances mechanical strength and smoke suppression performance. Example 1 is 5 kg, Example 2 is 7 kg, and Example 3 is 10 kg.

[0047] High wear-resistant pigment carbon black: improves the wear resistance and crack growth resistance of the rubber compound. The amount used in Example 1 is 1 kg, in Example 2 is 1.5 kg, and in Example 3 is 2 kg.

[0048] PE wax: used as an internal lubricant to reduce melt viscosity. The amount of PE wax in Example 1 is 1 kg, in Example 2 is 2 kg, and in Example 3 is 3 kg.

[0049] Silver ion carrier antibacterial agent: fixed dosage 1kg, used to inhibit microbial growth;

[0050] Talc: plays a reinforcing role and maintains chemical stability. The amount of talc in Example 1 is 1 kg, in Example 2 is 2 kg, and in Example 3 is 3 kg.

[0051] Silane coupling agent: improves the dispersion of filler, 5 kg for Example 1, 6 kg for Example 2, and 8 kg for Example 3;

[0052] Anti-UV agent: to prevent ultraviolet aging, 1 kg for Example 1, 1.5 kg for Example 2, and 2 kg for Example 3;

[0053] Stearic acid: softens the plasticized material, promotes carbon black diffusion and alkaline accelerator activity, 2 kg for Example 1, 2.5 kg for Example 2, and 3 kg for Example 3;

[0054] Plasticizer: provides softening and lubricating functions. The amount of plasticizer in Example 1 is 2 kg, in Example 2 is 3 kg, and in Example 3 is 5 kg.

[0055] Antioxidant 1010: delays oxidative aging of materials. The dosage of Example 1 is 1 kg, Example 2 is 2 kg, and Example 3 is 4 kg.

[0056] 2. Preparation process

[0057] The preparation process is carried out in the following steps:

[0058] Pretreatment: The nano-kaolin, talc and magnesium hydroxide were dried at 110° C. for 4 hours, and the nano-kaolin was spray-coated with 50% KH-550 ethanol solution and stirred at 80° C. for 30 minutes.

[0059] Mixing, 120℃, rotor speed 60rpm:

[0060] Stage 1: Add polyolefin elastomer, PE wax and stearic acid and mix for 2 minutes;

[0061] Second stage: Add plasticizer, antioxidant 1010 and anti-UV agent and mix for 3 minutes;

[0062] The third stage: add pretreated nano-kaolin and high wear-resistant pigment carbon black and mix for 5 minutes;

[0063] Stage 4: Add magnesium hydroxide and silver ion antibacterial agent and mix for 8 minutes.

[0064] Extrusion granulation: transfer the mixed rubber material to a twin-screw extruder, set the four zone temperatures to 140°C, 160°C, 170°C, and 165°C, the screw speed to 300 rpm, and pelletize to obtain sheath material particles.

[0065] 3. Performance Verification

[0066] Performance before aging:

[0067] Example 1 has a tensile strength of 12.3 MPa and an elongation at break of 280%.

[0068] Example 2 has a tensile strength of 14.1 MPa and an elongation at break of 265%.

[0069] Example 3 has a tensile strength of 11.8 MPa and an elongation at break of 240%.

[0070] Aging resistance, 80℃×168h:

[0071] Example 1: tensile strength change rate +12%, elongation at break change rate -10%;

[0072] Example 2: change rate of tensile strength +8%, change rate of elongation at break -7%;

[0073] In Example 3, the change rate of tensile strength is -15%, and the change rate of elongation at break is -18%.

[0074] Flame retardant and environmentally friendly:

[0075] All examples have passed UL94 V-0 certification, with a carbonization distance of ≤40 mm. The measured values ​​are: 32 mm for Example 1, 28 mm for Example 2, and 35 mm for Example 3.

[0076] Smoke density ≤ 100, measured values: 85 for Example 1, 78 for Example 2, and 92 for Example 3;

[0077] Light transmittance ≥ 60%, measured values: 68% for Example 1, 75% for Example 2, and 63% for Example 3;

[0078] Halogen acid gas release ≤ 0.5%, measured values: 0.32% for Example 1, 0.28% for Example 2, and 0.41% for Example 3;

[0079] The pH value of the combustion product is ≥4.3, and the measured values ​​are: 5.1 for Example 1, 5.4 for Example 2, and 4.8 for Example 3.

[0080] Biosafety:

[0081] All examples passed the ISO 10993-5 cytotoxicity test, with cell viability rates of 82% for Example 1, 89% for Example 2, and 76% for Example 3, all ≥70%;

[0082] GC-MS analysis did not detect the precipitation of phthalates and polycyclic aromatic hydrocarbons.

[0083] Environmental tolerance:

[0084] The performance retention rate after hydrolysis at 70°C for 14 days is ≥80%, and the measured values ​​are: 85% for Example 1, 92% for Example 2, and 83% for Example 3;

[0085] There was no swelling or cracking after immersion in 75% alcohol or 3% hydrogen peroxide for 24 hours;

[0086] The long-term operating temperature range covers -40°C to 125°C, and all examples have been verified to be qualified.

[0087] 4. Technical Effect Description

[0088] 1. Mechanical properties: tensile strength before aging ≥10MPa, elongation at break ≥125%, and the change rate of strength and elongation after aging ≤±20%;

[0089] 2. Extreme temperature adaptability: long-term use temperature -40℃~125℃, low temperature resistance -20℃;

[0090] 3. Safety and environmental protection: UL94 V-0 flame retardant grade, smoke density SDR ≤ 100, halogen acid gas release ≤ 0.5%, pH ≥ 4.3;

[0091] 4. Biocompatibility: Cell survival rate ≥ 70%, no harmful substances precipitated;

[0092] 5. Environmental stability: hydrolysis resistance (70℃ / 14 days), alcohol / hydrogen peroxide erosion resistance.

[0093] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A formula of high-strength medical-grade halogen-free cable sheath material, characterized in that: The total weight of the components includes the following: 55-65 parts of polyolefin elastomer; 20-30 parts of magnesium hydroxide; 5-10 parts of nano kaolin; 1-2 parts of high wear-resistant pigment carbon black; PE wax 1-3 parts; 1 part of silver ion carrier antibacterial agent; 1-3 parts talcum powder; 5-8 parts of amino silane coupling agent; 1-2 parts of anti-UV agent; 2-3 parts of stearic acid; 2-5 parts of plasticizer; Antioxidant 1010 1-4 parts.

2. The formula of a high-strength medical-grade halogen-free cable sheath material according to claim 1, characterized in that: The performance of the sheath material meets the following requirements: Flame retardant grade UL94 V-0, flame spread carbonization distance ≤40mm; When burning, the smoke density is ≤100, and the light transmittance is ≥60%; The total amount of halogen acid gas released is ≤0.5%, and the pH value of the combustion product is >4.

3.

3. The formula of a high-strength medical-grade halogen-free cable sheath material according to claim 1, characterized in that: The aging performance of the sheath material meets the following requirements: After aging at 80℃ for 168 hours, the change rate of tensile strength is ≤±20%, and the change rate of elongation at break is ≤±20%; Low temperature resistance up to -20℃; The long-term operating temperature range is -40℃ to 125℃.

4. The formula of a high-strength medical-grade halogen-free cable sheath material according to claim 1, characterized in that: The biological safety of the sheath material meets the following requirements: Passed ISO 10993-5 cytotoxicity test; GC-MS detection showed no precipitation of phthalates and polycyclic aromatic hydrocarbons.

5. The formula of a high-strength medical-grade halogen-free cable sheath material according to claim 1, characterized in that: The environmental tolerance of the sheath material meets the following requirements: Performance retention rate after 14 days of hydrolysis at 70℃≥80%; It can withstand immersion in 75% alcohol and 3% hydrogen peroxide for 24 hours without swelling or cracking.

6. The formula of a high-strength medical-grade halogen-free cable sheath material according to claim 1, characterized in that: The nano-kaolin particle size is 100-500nm, which is used to synergistically improve mechanical strength and smoke suppression performance; The high wear-resistant pigment carbon black DBP absorption value is ≥110ml / 100g, and the nitrogen adsorption specific surface area is ≥100m 2 / g。

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