Composite tube for disposable infusion set and its preparation process

Abstract

The present invention discloses a composite tube for a disposable infusion set and a preparation process thereof, belonging to the technical field of medical devices. First, the preparation process of the composite tube for a disposable infusion set comprises the following steps: mixing polyvinyl chloride resin, a light-shielding modifier, a lubricant and a plasticizer at 110 to 120°C for 1 to 2 hours, then extruding and granulating at an extrusion temperature of 135 to 140°C to obtain a modified polyvinyl chloride resin, and then co-extruding low-density polyethylene and the modified polyvinyl chloride resin to obtain a composite tube for a disposable infusion set with an inner layer of a low-density polyethylene layer and an outer layer of a modified polyvinyl chloride layer. The composite tube prepared by the present invention is a double-layer structure, with an inner layer of low-density polyethylene and an outer layer of modified polyvinyl chloride prepared by the present invention. Compared with the existing polyvinyl chloride infusion tube, the present invention aims to achieve the purpose of reducing the transmittance of light in the wavelength range of 290 to 450nm by adding a light-shielding modifier to the polyvinyl chloride resin.

Description

Technical Field

[0001] The invention belongs to the technical field of medical devices, and in particular relates to a composite tube for a disposable infusion set and a preparation process thereof. Background Art

[0002] Disposable infusion sets are a kind of medical device widely used in clinical practice, mainly composed of intravenous needle, infusion hose, liquid filter, flow rate controller, drip pot, bottle stopper puncture device and air filter of intake pipe, etc. Among them, the infusion hose is directly related to the safety and effectiveness of infusion, and the selection of its material is also of utmost importance.

[0003] Common infusion hoses in clinical practice are transparent polyvinyl chloride tubes. The good transparency of polyvinyl chloride tubes allows medical staff to clearly observe the flow of the drug solution and facilitate monitoring of the infusion process. However, when infusing certain drugs such as anti-tumor drugs cisplatin, carboplatin, oxaliplatin, antibiotics, antihypertensive drugs sodium nitroprusside, pyridine drugs nifedipine, nitrendipine, nimodipine, Chinese patent medicines such as certain vasodilators, water-soluble vitamins, etc., photochemical reactions will occur under the action of ultraviolet / visible light, causing the drug solution to decompose, discolor, oxidize, and precipitate, resulting in reduced efficacy and increased toxicity. These drugs need to be protected from light during infusion.

[0004] The traditional light-shielding method in clinical practice is to wrap the infusion hose with colored materials such as cloth. However, this will result in the inability to observe the infusion liquid (such as flow rate and bubbles) during the infusion process, which is not conducive to the safety of clinical medication. Therefore, the development of an infusion hose with low UV / visible light transmittance has positive clinical application value. Summary of the invention

[0005] The object of the present invention is to provide a composite tube for a disposable infusion set and a preparation process thereof. The present invention prepares a composite tube by improving the structure of an infusion hose, that is, using a composite structure, and finally achieves the purpose of reducing the light transmittance of the prepared composite tube by improving the raw material composition of the composite tube.

[0006] The purpose of the present invention can be achieved through the following technical solutions:

[0007] The preparation process of the composite tube for a disposable infusion set comprises the following steps:

[0008] S1, mixing polyvinyl chloride resin, light-shielding modifier, lubricant and plasticizer at 110-120° C. for 1-2 hours, and then extruding and granulating at an extrusion temperature of 135-140° C. to obtain modified polyvinyl chloride resin;

[0009] S2. Co-extrude low-density polyethylene and modified polyvinyl chloride resin to obtain a disposable composite tube for an infusion set, the inner layer of which is a low-density polyethylene layer and the outer layer of which is a modified polyvinyl chloride layer.

[0010] Furthermore, the usage ratio of the polyvinyl chloride resin, the light-shielding modifier, the lubricant and the plasticizer in S1 is 100g: 4-5g: 0.2-0.5g: 25-30g.

[0011] Furthermore, the lubricant in S1 is polyethylene wax or oxidized polyethylene wax.

[0012] Furthermore, the plasticizer in S1 is dioctyl phthalate or dioctyl terephthalate.

[0013] Furthermore, the light-shielding modifier described in S1 is prepared by the following steps:

[0014] T1. Take N,N-dimethylformamide, fill it with nitrogen for protection, then add 2,4-dihydroxybenzophenone and [3-(trimethoxysilyl)propyl]succinic anhydride thereto with stirring, stir and mix for 10 to 30 minutes, then add Amberlyst-15 ion exchange resin thereto with stirring, heat to 65 to 70°C, stir and react at constant temperature for 4 to 5 hours, after the reaction is completed, filter and remove the Amberlyst-15 ion exchange resin, collect the filtrate and evaporate the solvent N,N-dimethylformamide, then wash it three times with pure water, and then dry it at room temperature for 24 hours to obtain an intermediate. In the above reaction process, 2,4-dihydroxybenzophenone and [3-(trimethoxysilyl)propyl]succinic anhydride undergo ester exchange reaction under the catalytic action of Amberlyst-15 ion exchange resin. The main reaction process is as follows:

[0015]

[0016] T2. Take anhydrous ethanol, cool it to 0-5°C, fill it with nitrogen for protection, then add the intermediate and triethylamine thereto with stirring, stir for 20-30 minutes, then add thionyl chloride thereto with stirring, stir at 0-5°C for 1-2 hours, after the stirring reaction is completed, heat it to 20-25°C, stir at constant temperature for 48 hours, after the reaction is completed, remove the solvent by rotary evaporation to obtain a crude product, wash the crude product three times with pure water, and then dry it at 30-40°C for 12 hours to obtain a light-shielding modifier. During the above reaction process, the intermediate undergoes an esterification reaction with ethanol to obtain the final prepared light-shielding modifier. The main reaction process is as follows:

[0017] .

[0018] Furthermore, the usage ratio of N,N-dimethylformamide, 2,4-dihydroxybenzophenone, [3-(trimethoxysilyl)propyl]succinic anhydride and Amberlyst-15 ion exchange resin in T1 is 1L:0.5mol:0.5-0.55mol:80-100g.

[0019] Furthermore, the usage ratio of anhydrous ethanol, intermediate, triethylamine and thionyl chloride in T2 is 300 mL: 23.8-24.0 g: 56-60 mL: 14.5-15 mL.

[0020] Furthermore, in the co-extrusion described in S2: the head temperature is set to 195-200°C, and the die temperature is set to 185-190°C.

[0021] Furthermore, the inner layer of the composite tube for the disposable infusion set described in S2 is a low-density polyethylene layer with a thickness of 120 μm, and the outer layer is a modified polyvinyl chloride layer with a thickness of 200 μm.

[0022] Furthermore, the disposable composite tube for an infusion set is prepared by the above preparation process.

[0023] Beneficial effects of the present invention:

[0024] The present invention prepares a composite tube for a disposable infusion set. The composite tube has a double-layer structure, the inner layer is low-density polyethylene, and the outer layer is modified polyvinyl chloride prepared by the present invention. Compared with the existing polyvinyl chloride infusion tube, the present invention makes two improvements: on the one hand, the composition of the polyvinyl chloride layer is improved, and on the other hand, a low-density polyethylene layer is co-extruded in the polyvinyl chloride layer. The specific improvement principle is as follows:

[0025] First, the outer layer of the composite tube of the present invention is the modified polyvinyl chloride layer prepared by the present invention. The present invention aims to reduce the transmittance of light in the wavelength range of 290 to 450 nm by adding a light-shielding modifier to the polyvinyl chloride resin, and meets the relevant provisions of GB 18458.3-2005 "Special Infusion Set Part 3: Disposable Light-shielding Infusion Set", that is, the light transmittance of the pipeline components in the wavelength range of 290 to 450 nm is ≤15%. Specifically, the working principle of the light-shielding modifier prepared by the present invention is as follows: The light-shielding modifier prepared by the present invention is a benzophenone compound. The present invention aims to improve the shortcomings of 2,4-dihydroxybenzophenone, such as small molecular weight, easy migration and poor stability, by modifying the existing 2,4-dihydroxybenzophenone. Specifically, the present invention utilizes [3-(trimethoxysilyl)propyl]succinic anhydride to carry out an ester exchange reaction with 2,4-dihydroxybenzophenone, and introduces silicon oxide. The alkane chain molecular structure improves the molecular weight of the light-shielding modifier and increases the molecular structure. The improvement of the molecular weight and the molecular structure helps to reduce the mobility of the light-shielding modifier. At the same time, the introduction of the siloxane chain molecular structure improves the compatibility of the light-shielding modifier with the polyvinyl chloride resin substrate. At the same time, the siloxane chain molecular structure has low surface activity, which can improve the antifouling and antibacterial properties of the finally prepared composite pipe. Then, the present invention uses ethanol to end-cap the intermediate, aiming to improve the stability of the finally prepared light-shielding modifier and reduce problems such as self-esterification. The benzophenone structure consumes radiation through the keto-enol arc edge isomerism phenomenon, reduces self-esterification, that is, reduces enol consumption, and helps to ensure the stability and long-term effect of the light-shielding performance.

[0026] At the same time, the lubricant, plasticizer and self-made light-shielding modifier added to the modified polyvinyl chloride prepared by the present invention all have relatively large molecular weights. Compared with commonly used small molecule additives, the additives of the present invention have better compatibility and migration resistance in the modified polyvinyl chloride layer.

[0027] Finally, there are plasticizers and other additives in the traditional polyvinyl chloride infusion hose. In order to reduce the migration of additives into the liquid medicine in the infusion tube, the present invention achieves physical barrier by co-extruding a low-density polyethylene layer in the modified polyvinyl chloride layer; at the same time, polyvinyl chloride is incompatible with insulin, nitroglycerin and tumor drugs (such as paclitaxel), and the active ingredients of such drugs are easily absorbed by the PVC tube, resulting in reduced or even lost efficacy. Therefore, the present invention achieves bidirectional barrier by co-extruding a low-density polyethylene layer with excellent inertness in the modified polyvinyl chloride layer; and low-density polyethylene has excellent softness, extensibility, transparency and chemical stability. At the same time, low-density polyethylene has good compatibility with polyvinyl chloride, and low-density polyethylene has better adhesion than similar materials such as high-density polyethylene. The present invention finally achieves the purpose of improving the compatibility between the two layers in the composite tube by improving process parameters such as the die temperature in the hole co-extrusion process. DETAILED DESCRIPTION

[0028] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0029] Example 1

[0030] Preparation of light-shielding modifier:

[0031] T1. Add 1L of solvent N,N-dimethylformamide (AR; purchased from Sinopharm Chemical Reagent Co., Ltd.) to reactor A, fill with nitrogen to replace the air in reactor A, so that reactor A is in a nitrogen atmosphere, then add 0.5 mol of 2,4-dihydroxybenzophenone (99%; purchased from Shanghai MacLean Biochemical Technology Co., Ltd.) and 0.5 mol of [3-(trimethoxysilyl)propyl]succinic anhydride (95%; purchased from Sinopharm Chemical Reagent Co., Ltd.) to reactor A with stirring, stir and mix for 10 minutes, then add 80g of Amberlyst-15 ion exchange resin (purchased from Shanghai Yuanye Biotechnology Co., Ltd.) to reactor A with stirring, heat reactor A to 65°C, stir and react at constant temperature for 4 hours, after the reaction is completed, filter and remove Amberlyst-15 ion exchange resin, collect the filtrate and evaporate to remove solvent N,N-dimethylformamide, then wash three times with pure water, and then dry at room temperature for 24 hours to obtain an intermediate.

[0032] T2, add 300mL of solvent anhydrous ethanol (AR; purchased from Sinopharm Chemical Reagent Co., Ltd.) to reactor B, cool reactor B to 5°C, then fill with nitrogen to replace the air in reactor B, so that reactor B is in a nitrogen atmosphere, then add 23.8g of the above-prepared intermediate and 56mL of triethylamine (CP; purchased from Sinopharm Chemical Reagent Co., Ltd.) to reactor B with stirring, stir for 20min, then add 14.5mL of thionyl chloride (AR; purchased from Sinopharm Chemical Reagent Co., Ltd.) to reactor B with stirring, control the system in reactor B to be placed at a constant temperature of 5°C, and then stir and react at a constant temperature for 1h. After the stirring reaction is completed, heat it to 20°C, stir and react at a constant temperature for 48h. After the reaction is completed, remove the solvent by rotary evaporation to obtain a crude product, wash the crude product three times with pure water, and then dry it at 30°C for 12h to obtain a light-shielding modifier.

[0033] Example 2

[0034] Preparation of light-shielding modifier:

[0035] T1. Add 1 L of solvent N,N-dimethylformamide (AR; purchased from Sinopharm Chemical Reagent Co., Ltd.) to reactor A, fill with nitrogen to replace the air in reactor A, so that reactor A is in a nitrogen atmosphere, then add 0.5 mol of 2,4-dihydroxybenzophenone (99%; purchased from Shanghai MacLean Biochemical Technology Co., Ltd.) and 0.55 mol of [3-(trimethoxysilyl)propyl]succinic anhydride (95%; purchased from Sinopharm Chemical Reagent Co., Ltd.) to reactor A with stirring, stir and mix for 30 minutes, then add 100 g of Amberlyst-15 ion exchange resin (purchased from Shanghai Yuanye Biotechnology Co., Ltd.) to reactor A with stirring, heat reactor A to 68° C., stir and react at constant temperature for 5 hours, after the reaction is completed, filter and remove Amberlyst-15 ion exchange resin, collect the filtrate and evaporate to remove solvent N,N-dimethylformamide, then wash three times with pure water, and then dry at room temperature for 24 hours to obtain an intermediate.

[0036] T2, add 300mL of solvent anhydrous ethanol (AR; purchased from Sinopharm Chemical Reagent Co., Ltd.) to reactor B, cool reactor B to 0°C, then fill with nitrogen to replace the air in reactor B, so that reactor B is in a nitrogen atmosphere, then add 24.0g of the above-prepared intermediate and 58mL of triethylamine (CP; purchased from Sinopharm Chemical Reagent Co., Ltd.) to reactor B with stirring, stir for 30min, then add 15mL of thionyl chloride (AR; purchased from Sinopharm Chemical Reagent Co., Ltd.) to reactor B with stirring, control the system in reactor B to be placed at a constant temperature of 0°C, and then stir and react at a constant temperature for 2h. After the stirring reaction is completed, heat it to 25°C, stir and react at a constant temperature for 48h. After the reaction is completed, remove the solvent by rotary evaporation to obtain a crude product, wash the crude product three times with pure water, and then dry it at 40°C for 12h to obtain a light-shielding modifier.

[0037] Example 3

[0038] Preparation of light-shielding modifier:

[0039] T1. Add 1L of solvent N,N-dimethylformamide (AR; purchased from Sinopharm Chemical Reagent Co., Ltd.) to reactor A, fill with nitrogen to replace the air in reactor A, so that reactor A is in a nitrogen atmosphere, then add 0.5 mol of 2,4-dihydroxybenzophenone (99%; purchased from Shanghai MacLean Biochemical Technology Co., Ltd.) and 0.55 mol of [3-(trimethoxysilyl)propyl]succinic anhydride (95%; purchased from Sinopharm Chemical Reagent Co., Ltd.) to reactor A with stirring, stir and mix for 30 minutes, then add 100 g of Amberlyst-15 ion exchange resin (purchased from Shanghai Yuanye Biotechnology Co., Ltd.) to reactor A with stirring, heat reactor A to 70° C., stir and react at constant temperature for 5 hours, after the reaction is completed, filter and remove Amberlyst-15 ion exchange resin, collect the filtrate and evaporate to remove solvent N,N-dimethylformamide, then wash three times with pure water, and then dry at room temperature for 24 hours to obtain an intermediate.

[0040] T2, add 300mL of solvent anhydrous ethanol (AR; purchased from Sinopharm Chemical Reagent Co., Ltd.) to reactor B, cool reactor B to 0°C, then fill with nitrogen to replace the air in reactor B, so that reactor B is in a nitrogen atmosphere, then add 24.0g of the above-prepared intermediate and 60mL of triethylamine (CP; purchased from Sinopharm Chemical Reagent Co., Ltd.) to reactor B with stirring, stir for 30min, then add 15mL of thionyl chloride (AR; purchased from Sinopharm Chemical Reagent Co., Ltd.) to reactor B with stirring, control the system in reactor B to be placed at a constant temperature of 0°C, and then stir and react at a constant temperature for 2h. After the stirring reaction is completed, heat it to 25°C, stir and react at a constant temperature for 48h. After the reaction is completed, remove the solvent by rotary evaporation to obtain a crude product, wash the crude product three times with pure water, and then dry it at 40°C for 12h to obtain a light-shielding modifier.

[0041] Comparative Example 1

[0042] Comparative Example 1 is the control group of Example 2, except that step T2 in Example 2 is removed, that is, the intermediate prepared according to step T1 in Example 2 is used as the light-shielding modifier in Comparative Example 1.

[0043] Example 4

[0044] The preparation process of the composite tube for a disposable infusion set comprises the following steps:

[0045] S1. Mix polyvinyl chloride resin (SH-200M medical grade; purchased from Ningbo Jinchi Plastic Co., Ltd.), the light-shielding modifier prepared in Example 1, polyethylene wax (Mn3000-4000; purchased from Sinopharm Chemical Reagent Co., Ltd.) and dioctyl phthalate (95%; purchased from Shanghai MacLean Biochemical Technology Co., Ltd.) at 110°C for 1 hour, and then extrude and granulate at an extrusion temperature of 135°C to obtain a modified polyvinyl chloride resin, wherein the amount ratio of polyvinyl chloride resin, light-shielding modifier, lubricant and plasticizer is 100g:4g:0.2g:25g.

[0046] S2. Co-extrude low-density polyethylene (melt index 70 g / 10 min; 600 mesh; purchased from Shanghai MacLean Biochemical Technology Co., Ltd.) and the modified polyvinyl chloride resin prepared above, wherein the head temperature is set to 195°C and the die temperature is set to 185°C. After extrusion, a disposable composite tube for an infusion set is obtained, wherein, by controlling the amount of low-density polyethylene and modified polyvinyl chloride resin, it is ensured that the inner layer of the disposable composite tube for an infusion set finally prepared is a low-density polyethylene layer with a thickness of 120 μm, and the outer layer is a modified polyvinyl chloride layer with a thickness of 200 μm.

[0047] Example 5

[0048] The preparation process of the composite tube for a disposable infusion set comprises the following steps:

[0049] S1. Mix polyvinyl chloride resin (SH-200M medical grade; purchased from Ningbo Jinchi Plastic Co., Ltd.), the light-shielding modifier prepared in Example 2, oxidized polyethylene wax (purchased from Shanghai Maclean Biochemical Technology Co., Ltd.) and dioctyl terephthalate (98%; purchased from Shanghai Maclean Biochemical Technology Co., Ltd.) at 120°C for 2 hours, and then extrude and granulate at an extrusion temperature of 140°C to obtain modified polyvinyl chloride resin, wherein the amount ratio of polyvinyl chloride resin, light-shielding modifier, lubricant and plasticizer is 100g:5g:0.4g:28g.

[0050] S2. Co-extrude low-density polyethylene (melt index 70 g / 10 min; 600 mesh; purchased from Shanghai MacLean Biochemical Technology Co., Ltd.) and the modified polyvinyl chloride resin prepared above, wherein the head temperature is set to 200°C and the die temperature is set to 190°C. After extrusion, a disposable composite tube for an infusion set is obtained, wherein, by controlling the amount of low-density polyethylene and modified polyvinyl chloride resin, it is ensured that the inner layer of the disposable composite tube for an infusion set finally prepared is a low-density polyethylene layer with a thickness of 120 μm, and the outer layer is a modified polyvinyl chloride layer with a thickness of 200 μm.

[0051] Example 6

[0052] The preparation process of the composite tube for a disposable infusion set comprises the following steps:

[0053] S1. Mix polyvinyl chloride resin (SH-200M medical grade; purchased from Ningbo Jinchi Plastic Co., Ltd.), the light-shielding modifier prepared in Example 3, oxidized polyethylene wax (purchased from Shanghai Maclean Biochemical Technology Co., Ltd.) and dioctyl phthalate (95%; purchased from Shanghai Maclean Biochemical Technology Co., Ltd.) at 120°C for 2 hours, and then extrude and granulate at an extrusion temperature of 140°C to obtain modified polyvinyl chloride resin, wherein the amount ratio of polyvinyl chloride resin, light-shielding modifier, lubricant and plasticizer is 100g:5g:0.5g:30g.

[0054] S2. Co-extrude low-density polyethylene (melt index 70 g / 10 min; 600 mesh; purchased from Shanghai MacLean Biochemical Technology Co., Ltd.) and the modified polyvinyl chloride resin prepared above, wherein the head temperature is set to 200°C and the die temperature is set to 190°C. After extrusion, a disposable composite tube for an infusion set is obtained, wherein, by controlling the amount of low-density polyethylene and modified polyvinyl chloride resin, it is ensured that the inner layer of the disposable composite tube for an infusion set finally prepared is a low-density polyethylene layer with a thickness of 120 μm, and the outer layer is a modified polyvinyl chloride layer with a thickness of 200 μm.

[0055] Comparative Example 2

[0056] Comparative Example 2 is the control group of Example 5, in which the light-shielding modifier prepared in Example 2 in Example 5 is replaced by the light-shielding modifier prepared in Comparative Example 1, and the remaining raw materials, raw material amounts and preparation process steps remain unchanged, and finally a composite tube for a disposable infusion set is obtained.

[0057] Comparative Example 3

[0058] Comparative Example 3 is the control group of Example 5, in which the light-shielding modifier prepared in Example 2 in Example 5 is replaced with 2,4-dihydroxybenzophenone, and the remaining raw materials, raw material amounts and preparation process steps remain unchanged, and finally a composite tube for a disposable infusion set is obtained.

[0059] Comparative Example 4

[0060] Comparative Example 4 is the control group of Example 5, in which the light-shielding modifier prepared in Example 2 in Example 5 is removed, and the remaining raw materials, raw material amounts and preparation process steps remain unchanged, and finally a composite tube for a disposable infusion set is obtained.

[0061] The transmittance performance test was performed on the composite tubes for disposable infusion sets prepared in Examples 4 to 6 and Comparative Examples 2 to 4. The transmittance performance test process is as follows:

[0062] Light transmittance: The light transmittance was measured with reference to Appendix A of GB 18458.3-2005 "Specialized infusion sets Part 3: Disposable light-proof infusion sets". A spectrophotometer (V730 UV-visible spectrophotometer) was purchased from JASCO. The light transmittance (%) within the wavelength range of 290 nm to 450 nm was measured, and the maximum light transmittance was recorded, as shown in Table 1 below.

[0063] Table 1 Performance test results

[0064] project Example 4 Example 5 Example 6 Comparative Example 2 Comparative Example 3 Comparative Example 4 Transmittance / % 9.1 8.5 8.7 9.8 12.3 25.4

[0065] It can be seen from Table 1 that the composite tubes for disposable infusion sets prepared in Examples 4 to 6 of the present invention have excellent shielding properties for light within the wavelength range of 290 nm to 450 nm.

[0066] It should be noted that, in this article, terms such as "include", "comprises" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, article or equipment that includes a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or equipment.

[0067] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A process for preparing a composite tube for a disposable infusion set, characterized in that: The following steps are involved: S1, mixing polyvinyl chloride resin, light-shielding modifier, lubricant and plasticizer at 110-120° C. for 1-2 hours, and then extruding and granulating at an extrusion temperature of 135-140° C. to obtain modified polyvinyl chloride resin; S2, co-extruding a low-density polyethylene and a modified polyvinyl chloride resin to obtain a disposable composite tube for an infusion set, wherein the inner layer is a low-density polyethylene layer and the outer layer is a modified polyvinyl chloride layer; The light-shielding modifier described in S1 is prepared by the following steps: T1. Take N,N-dimethylformamide, fill it with nitrogen for protection, then add 2,4-dihydroxybenzophenone and [3-(trimethoxysilyl)propyl]succinic anhydride thereto with stirring, stir and mix for 10 to 30 minutes, then add Amberlyst-15 ion exchange resin thereto with stirring, heat to 65 to 70° C., stir and react at constant temperature for 4 to 5 hours, after the reaction is completed, filter and remove the Amberlyst-15 ion exchange resin, collect the filtrate and evaporate the solvent N,N-dimethylformamide, then wash with pure water three times, and then dry at room temperature for 24 hours to obtain an intermediate; T2, take anhydrous ethanol, cool it to 0-5°C, fill it with nitrogen protection, then add the intermediate and triethylamine thereto with stirring, stir for 20-30 minutes, then add thionyl chloride thereto with stirring, stir at 0-5°C for 1-2 hours, after the stirring reaction is completed, heat it to 20-25°C, stir at constant temperature for 48 hours, after the reaction is completed, remove the solvent by rotary evaporation to obtain a crude product, wash the crude product three times with pure water, and then dry it at 30-40°C for 12 hours to obtain a light-shielding modifier; The amount ratio of N,N-dimethylformamide, 2,4-dihydroxybenzophenone, [3-(trimethoxysilyl)propyl]succinic anhydride and Amberlyst-15 ion exchange resin in T1 is 1L:0.5mol:0.5-0.55mol:80-100g; The usage ratio of anhydrous ethanol, intermediate, triethylamine and thionyl chloride in T2 is 300mL:23.8-24.0g:56-60mL:14.5-15mL.

2. The process for preparing the composite tube for a disposable infusion set according to claim 1, characterized in that: The usage ratio of the polyvinyl chloride resin, the light-shielding modifier, the lubricant and the plasticizer in S1 is 100g: 4-5g: 0.2-0.5g: 25-30g.

3. The process for preparing the composite tube for a disposable infusion set according to claim 1, characterized in that: The lubricant in S1 is polyethylene wax or oxidized polyethylene wax.

4. The process for preparing the composite tube for a disposable infusion set according to claim 1, characterized in that: The plasticizer in S1 is dioctyl phthalate or dioctyl terephthalate.

5. The process for preparing the composite tube for a disposable infusion set according to claim 1, characterized in that: In the coextrusion described in S2: the head temperature is set at 195-200°C, and the die temperature is set at 185-190°C.

6. The process for preparing the composite tube for a disposable infusion set according to claim 1, characterized in that: The inner layer of the composite tube for the disposable infusion set described in S2 is a low-density polyethylene layer with a thickness of 120 μm, and the outer layer is a modified polyvinyl chloride layer with a thickness of 200 μm.

7. A composite tube for a disposable infusion set, characterized in that: The invention is prepared by the preparation process described in any one of claims 1 to 6.

Images