Vacutainer

Abstract

The application relates to the field of blood sampling devices, and particularly discloses a vacuum blood collection tube, which comprises an outer tube, a PET inner tube, a sealing ring and a sealing rubber plug. The PET inner tube is accommodated in the outer tube and is arranged at intervals with the outer tube to form a cavity. The sealing ring is connected between the outer tube and the PET inner tube and seals the cavity. The sealing rubber plug is inserted into the pipe opening of the PET inner tube and seals the inner tube. The outer tube is prepared from modified PET, and the modified PET comprises the following raw materials in parts by weight: reinforced PET, 88-124 parts; toughening body, 4-10 parts; compatibilizer, 1-5 parts; and lubricant, 1-2 parts. The toughening body comprises liquid butadiene rubber and phenolic resin, and the weight ratio of the liquid butadiene rubber to the phenolic resin is (4-1):1. The application has the effect of improving the low-temperature impact resistance of the vacuum blood collection tube.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of blood sampling devices, in particular to a vacuum blood collection tube. BACKGROUND

[0002] The vacuum blood collection tube is a disposable negative pressure vacuum tube that can realize quantitative blood sampling. According to the material classification, the vacuum blood collection tube is mainly divided into glass tubes and plastic tubes, wherein the raw material of the plastic tube is mainly PET plastic. The PET vacuum blood collection tube is light in quality, pressure-resistant, and not easy to break, and gradually dominates the medical market.

[0003] In the series of PET vacuum blood collection tubes, the double-layer PET vacuum blood collection tube is usually used as a coagulation tube. The double-layer structure can play a role in blocking water and gas, prolonging the shelf life of the product.

[0004] The benzene ring and ester group of PET form a conjugated system, the flexible group is short, and it can only move as a whole with the benzene ring, so that the PET chain segment plastic reduces in toughness under low temperature conditions and is easy to be brittle. When transported in an area with the highest air temperature below minus 20 DEG C, the outer tube of the double-layer PET vacuum blood collection tube is easy to break under the action of collision and low temperature, affecting the use of the double-layer PET vacuum blood collection tube. SUMMARY

[0005] In order to improve the low-temperature impact resistance of the blood collection tube, the present application provides a vacuum blood collection tube.

[0006] The vacuum blood collection tube provided by the present application adopts the following technical scheme:

[0007] The vacuum blood collection tube comprises an outer tube;

[0008] A PET inner tube is accommodated in the outer tube and is arranged in a spaced manner with the outer tube to form a cavity;

[0009] A sealing ring connects the outer tube and the PET inner tube and seals the cavity;

[0010] A sealing rubber plug is inserted at the tube opening of the PET inner tube and seals the PET inner tube;

[0011] The outer tube is made of modified PET, and the modified PET comprises the following raw materials by weight: 88-124 parts of reinforced PET, 4-10 parts of toughening body, 1-5 parts of compatibilizer, and 1-2 parts of lubricant. The toughening body comprises liquid butadiene rubber and phenolic resin, and the weight ratio of the liquid butadiene rubber to the phenolic resin is (4-1):1.

[0012] By adopting the technical scheme, the butadiene rubber is used in cooperation with the reinforced PET, the butadiene rubber has high molecular chain backbone freedom and low energy requirement for deformation, and after being stressed in a low-temperature environment, the butadiene rubber disperses the force through deformation to avoid stress concentration. When the vacuum blood collection tube is impacted in a low-temperature environment, the butadiene rubber releases part of the force to reduce the probability of the vacuum blood collection tube being broken. The phenolic resin improves the liquid butadiene rubber to improve the bonding strength of the liquid butadiene rubber and the reinforced PET and improve the low-temperature impact resistance of the vacuum blood collection tube.

[0013] Optionally, the preparation of the toughening body includes the following steps: mixing the liquid butadiene rubber and the phenolic resin at room temperature for 0.8-1.5 hours, adding a rubber vulcanizing agent, mixing again at room temperature for 10-30 minutes, then performing vulcanization treatment for 50-60 minutes and ultrasonic treatment for 10-20 minutes to obtain a reaction product; and placing the reaction product in a constant-temperature oven at 140-150 DEG C for stabilization, then cutting and granulating to obtain the toughening body.

[0014] By adopting the technical scheme, the liquid butadiene rubber and the phenolic resin are fully crosslinked to improve the compactness of the outer tube, the bonding strength of the liquid butadiene rubber and the reinforced PET is increased, the toughening effect of the toughening body is fully exerted, and the low-temperature impact resistance of the vacuum blood collection tube is improved.

[0015] Optionally, the reinforced PET includes PET granules, polyethylene naphthalate and a sheet layer barrier agent, and the weight ratio of the PET granules, the polyethylene naphthalate and the sheet layer barrier agent is (20-80):(7-10):1.

[0016] By adopting the technical scheme, the PET granules and the polyethylene naphthalate form an interlaced network structure to improve the impact resistance of the blood collection tube; the polyethylene naphthalate improves the low-temperature strength of the modified PET, and the sheet layer barrier agent blocks the straight-line movement trajectory of air and water molecules to improve the ability of the modified PET to block water molecules and gas.

[0017] Optionally, the sheet layer barrier agent includes sericite and reinforcing micro powder, and the weight ratio of the sericite and the reinforcing micro powder is (25-75):2.

[0018] By adopting the technical scheme, the reinforcing micro powder and the sericite are used in cooperation to improve the strength of the reinforced PET; the sericite is used in cooperation with the PET granules and the polyethylene naphthalate to improve the polymerization of the PET granules and the polyethylene naphthalate to form low-temperature-resistant modified PET, thereby improving the low-temperature impact resistance of the vacuum blood collection tube.

[0019] Optionally, the reinforcing micro powder is one or more of martensite micro powder, graphene micro powder or spherical silicon micro powder.

[0020] By adopting the above technical scheme, the micro powder is used in cooperation with the phenolic resin, the combination firmness of the toughening body to the reinforced PET is improved, and thus the uniformity and overall low-temperature impact resistance of the blood collection tube are improved. The reinforcing micro powder can be martensite micro powder, graphene micro powder, spherical silicon micro powder, white corundum micro powder, active silicon micro powder, etc., and preferably the reinforcing micro powder is one or more of martensite micro powder, graphene micro powder or spherical silicon micro powder.

[0021] Optionally, the preparation of the sheet layer barrier agent comprises the following steps: swelling of the sericite, adding the reinforcing micro powder, heating to 145-150 DEG C and stirring for 1.5-2.5 h, centrifugal drying, and then adding the mixture into an autoclave with water as the solvent, vacuum reaction, discharging after cooling to room temperature, to obtain the sheet layer barrier agent.

[0022] By adopting the above technical scheme, the micro powder enters the sheet layer of the swollen sericite, and when the sheet layer barrier agent and the PET granules and polyethylene naphthalate are mixed and reacted, the chain segments of the PET granules and polyethylene naphthalate are inserted into the sheet layer of the sericite, thereby improving the combination strength of the reinforcing micro powder, the PET granules and the polyethylene naphthalate, and further improving the combination strength of the toughening body and the reinforced PET.

[0023] Optionally, the compatilizer is ethylene-vinyl alcohol copolymer grafted maleic anhydride.

[0024] By adopting the above technical scheme, the ethylene-vinyl alcohol part of the ethylene-vinyl alcohol copolymer grafted maleic anhydride is used in cooperation with the sheet layer barrier agent, the barrier property of the blood collection tube is improved, the maleic anhydride part improves the compatibility of the polymer in the modified PET, and thus the strength and toughness of the vacuum blood collection tube are provided.

[0025] Optionally, the lubricant is ethylene bis-stearamide.

[0026] By adopting the above technical scheme, the ethylene bis-stearamide powder is smooth and lubricious, the melt flow rate of the reinforced PET is improved, the compatibility of the reinforced PET and the toughening body blend is improved, and the demolding effect of the reinforced PET is excellent, which is convenient for the processing and molding of the vacuum blood collection tube.

[0027] Optionally, the sealing ring is detachably connected with the PET inner tube, and the sealing ring is detachably connected with the outer tube.

[0028] By adopting the above technical scheme, the assembly and disassembly of the vacuum blood collection tube are facilitated; the outer tube and the PET inner tube are connected through the sealing ring, the air in the cavity is easily extracted to form a vacuum cavity, the sealing ring plays a buffering role between the outer tube and the PET inner tube, the impact force is not easily transmitted to the PET inner tube when the outer tube is impacted, and the probability of breakage of the PET inner tube is reduced.

[0029] Optionally, the sealing plug is inserted and matched with the outer tube.

[0030] By adopting the above technical solution, the sealing plug is connected to both the inner and outer tubes of the PET tube, which improves the fixing firmness of the sealing plug and thus enhances the safety of vacuum blood collection tubes.

[0031] In summary, this application includes at least one of the following beneficial technical effects:

[0032] 1. Phenolic resin improves the viscosity of liquid butadiene rubber and enhances its adhesion to reinforced PET, facilitating the toughening agent's function. The combined use of polyethylene naphthalate, sheet barrier agent, and PET granules improves the low-temperature toughness and gas barrier performance of vacuum blood collection tubes. The martensitic micropowder in the sheet barrier agent, combined with the phenolic resin component of the toughening agent, increases the bonding strength between the toughening agent and reinforced PET, facilitating the buffering effect of liquid butadiene rubber and improving the low-temperature impact resistance of the blood collection tubes.

[0033] 2. The sheet structure of the sheet barrier agent blocks the linear movement of air and water molecules, thereby improving the ability of the blood collection tube to block water molecules and gases;

[0034] 3. Sericite, as an intermediate linker, improves the bonding strength between martensitic powder, PET granules, and polyethylene naphthalate. The martensitic powder attracts phenolic resin, which in turn binds liquid cis-butadiene rubber, thereby increasing the bonding strength between reinforced PET and toughening agent. The toughening agent and reinforced PET are mixed evenly and bonded firmly, facilitating the toughening agent's function and thus improving the low-temperature impact resistance of blood collection tubes. Attached Figure Description

[0035] Figure 1 This is a schematic diagram of the overall structure of an embodiment of this application;

[0036] Figure 2 This is a cross-sectional view of an embodiment of this application;

[0037] Figure 3 This is an exploded view of an embodiment of this application.

[0038] Explanation of reference numerals in the attached figures:

[0039] 1. Outer tube; 11. Cavity; 12. Spiral groove; 13. Positioning ring; 2. PET inner tube; 21. Ring bar; 22. Sealing ring; 3. Sealing ring; 31. Threaded bar; 32. Ring groove; 4. Sealing plug; 41. Edge body; 411. Outer tube groove; 412. Inner tube groove; 42. Plug body. Detailed Implementation

[0040] The following examples, comparative examples, and accompanying manual are described below. Figures 1-3 This application will be described in further detail.

[0041] The following examples were carried out under conventional conditions or under conditions recommended by the manufacturer, and the raw materials used in the following examples were commercially available unless otherwise specified.

[0042] PET granules are white PET masterbatch, effective component > 99%;

[0043] Sericite moisture content is 0.1%, particle size is 800 mesh, whiteness is 40%;

[0044] Martensite powder is a mechanically prepared martensitic stainless steel alloy powder, particle size is 15-53 μm, Fe content is ≥18%;

[0045] Liquid butadiene rubber is a transparent liquid, Mooney viscosity is ≤48, molecular weight is 50,000, ash content is ≤0.5%;

[0046] Phenolic resin is in powder form, density is 1.7 g / cm3.

[0047] Examples

[0048] Example 1

[0049] S1, a sufficient amount of polyethylene terephthalate, PET granules, ethylene-vinyl copolymer grafted maleic anhydride was dried in a 80℃ air drying oven for 12h for standby;

[0050] S2, 1kg of sericite was put into 5kg of anhydrous ethanol for swelling, 0.08kg of martensite powder was added, the oil bath pot was stirred at 150℃ for 2h, the stirring speed was 1000rmp, after centrifugal drying, the mixture was added into an autoclave with water as solvent, the autoclave was pumped into nitrogen after vacuumizing, the temperature was raised to 200℃, the pressure was 1.2Mpa, and it was kept for 2h; the pressure was reduced to standard atmospheric pressure, the temperature was raised to 250℃ and reacted for 1h; after the gas was discharged, vacuumizing was carried out, the temperature was raised to 280℃ and reacted for 0.5h; nitrogen was filled, the reaction kettle was lowered to room temperature and discharged, and a lamellar barrier agent was obtained; S3, 80kg of PET granules, 7kg of polyethylene terephthalate and 1kg of the lamellar barrier agent prepared in S2 were weighed and mixed uniformly, then melt-extruded in a twin-screw extruder, the temperature of each section was 270℃ for the first section, 270℃ for the second section, 270℃ for the third section, 275℃ for the fourth section, 265℃ for the fifth section and 260℃ for the sixth section; the screw rotation speed was 70r / min, and an extrudate was obtained; the extrudate was cooled in air, cut into granules by a granulator and dried in a 75℃ oven, and a reinforced PET with a particle size of 3-5cm was obtained;

[0051] S4, 8 kg of liquid butadiene rubber and 2 kg of phenolic resin are mixed at room temperature for 1 h, and then left to stand for 24 h; after adding a rubber vulcanizing agent, the mixture is mixed at room temperature for 20 min, and then vulcanized for 60 min at a temperature of 160 °C and a pressure of 10 MPa; the vulcanizate is left to stand in a thermostat oven after being treated with ultrasonic waves for 15 min, and the temperature of the oven is 150 °C; the vulcanizate is cut into pieces and granulated after being left to stand, and a toughening body with a particle size of 3 cm is obtained;

[0052] S5, 88 kg of the reinforcing PET prepared in S3, 10 kg of the toughening body prepared in S4, 5 kg of ethylene-vinyl alcohol copolymer grafted with maleic anhydride, and 1 kg of ethylene bis-stearamide are mixed uniformly to form an outer tube material;

[0053] S6, the outer tube material prepared in Example 2 is placed in an injection molding machine, and an injection molding machine is used to form a plurality of transparent outer tubes with a capacity of 4 ml and a wall thickness of 4 mm, wherein the pressure is 146 MPa, the temperature is 270 °C, the preheating time is 60 s, and the clamping force is 2280 kN;

[0054] S7, the outer tube and the conventional PET inner tube are assembled in a conventional manner, and a vacuum blood collection tube is obtained.

[0055] Examples 2-17

[0056] The difference from Example 1 is that the addition amount of each material is different, as shown in Table 1.

[0057] Example 18

[0058] Referring to Figure 1 and Figure 2 , a vacuum blood collection tube includes an outer tube 1, a PET inner tube 2 for containing a blood sample, a sealing ring 3 for connecting the outer tube 1 and the PET inner tube 2, and a sealing plug 4 for sealing the PET inner tube 2. The PET inner tube 2 is accommodated in the outer tube 1 and is arranged to be spaced apart from the outer tube 1 to form a cavity 11, and the sealing ring 3 seals the cavity 11. The sealing plug 4 is inserted at the tube opening of the PET inner tube 2. The double-layer structure improves the impact strength and barrier performance of the vacuum blood collection tube.

[0059] Referring to Figure 2 and Figure 3 , the PET inner tube 2 is a tube body with one open end. The outer peripheral wall of the open end of the PET inner tube 2 is fixedly connected with a ring strip 21, and the axis of the ring strip 21 is collinear with the axis of the PET inner tube 2. The outer peripheral wall of the PET inner tube 2 is fixedly connected with an elastic sealing ring 22, and the sealing ring 22 is located on the side of the ring strip 21 away from the bottom wall of the PET inner tube 2. The end wall of the sealing ring 22 away from the bottom wall of the PET inner tube 2 is flush with the end wall of the PET inner tube 2.

[0060] Referring to Figure 2 and Figure 3The sealing ring 3 is coaxially arranged with the PET inner tube 2, the sealing ring 3 is made of elastic material, a threaded strip 31 is fixedly connected to the outer peripheral wall of the sealing ring 3, and a ring groove 32 is formed in the inner wall of the sealing ring 3, and the ring strip 21 is in clamping connection with the ring groove 32.

[0061] The sealing ring 3 is sleeved on the open end of the PET inner tube 2, and the ring groove 32 is in clamping connection with the ring strip 21, at this time, the sealing ring 22 is extruded to fill the gap between the sealing ring 3 and the open end of the PET inner tube 2.

[0062] Referring to Figure 2 and Figure 3 , the outer tube 1 and the PET inner tube 2 are on the same side of the opening, the tube opening end of the outer tube 1 is fixedly connected with a positioning ring 13, and the outer peripheral wall of the positioning ring 13 is fixedly connected with the inner wall of the outer tube 1. A spiral groove 12 matched with the threaded strip 31 is formed in the inner wall of the tube opening end of the outer tube 1, the spiral groove 12 is located on the side of the positioning ring 13 away from the tube bottom of the outer tube 1, and when the threaded strip 31 is matched with the spiral groove 12, the sealing ring 3 is compressed to fill the gap between the inner wall of the opening end of the outer tube 1 and the outer peripheral wall of the opening end of the PET inner tube 2.

[0063] The PET inner tube 2 is inserted into the outer tube 1 until the threaded strip 31 of the sealing ring 3 abuts against the groove wall of the spiral groove 12, the sealing ring 3 and the PET inner tube 2 are rotated until the sealing ring 3 abuts against the positioning ring 13, at this time, the cavity 11 is formed between the sealing ring 3, the PET inner tube 2 and the outer tube 1, and the air in the cavity 11 is extracted to form a vacuum cavity. The cooperation of the threaded strip 31 and the spiral groove 12 blocks the air, plays a role in sealing the cavity 11, and facilitates the assembly and disassembly of the vacuum blood collection tube.

[0064] Referring to Figure 2 and Figure 3 , the sealing rubber plug 4 comprises a rim body 41 and a plug body 42, the outer diameter of the rim body 41 is greater than the outer diameter of the outer tube 1, an outer tube groove 411 is formed in the lower end wall of the rim body 41 and is in plug-in connection with the end wall of the opening end of the outer tube 1, and an inner tube groove 412 is formed in the lower end wall of the rim body 41 and is in plug-in connection with the end wall of the opening end of the PET inner tube 2. The upper end wall of the plug body 42 is integrally formed with the lower end wall of the rim body 41, the outer diameter of the plug body 42 is slightly greater than the inner diameter of the PET inner tube 2, and the plug body 42 is in plug-in connection with the PET inner tube 2.

[0065] The plug body 42 is inserted into the PET inner tube 2, at this time, the plug body 42 is extruded to fill the gap between the outer peripheral wall of the plug body 42 and the inner wall of the PET inner tube 2, so as to seal the PET inner tube 2. The sealing rubber plug 4 is continuously pressed until the end wall of the outer tube 1 abuts against the groove wall of the outer tube groove 411 and the end wall of the PET inner tube 2 abuts against the groove wall of the inner tube groove 412, at this time, the sealing ring 22 is extruded to fill the gap between the PET inner tube 2 and the groove wall of the inner tube groove 412, so that the sealing rubber plug 4 is not easy to be separated from the PET inner tube 2.

[0066] The implementation principle of the embodiment is as follows:

[0067] The sealing ring 3 is sleeved on the outer tube 2, and the ring groove 32 is matched with the ring strip 21. The inner tube 2 is inserted into the outer tube 1, and the inner tube 2 and the sealing ring 3 are rotated until the sealing ring 3 abuts against the positioning ring 13. The air in the cavity 11 is extracted to form a vacuum cavity. The sealing plug 4 is installed at the open end of the outer tube 1, so that the sealing plug 4 seals the inner tube 2. The air in the inner tube 2 is extracted to form a vacuum blood collection tube.

[0068] Comparative example

[0069] Comparative example 1

[0070] 100 kg of PET granules, 5 kg of ethylene-vinyl alcohol copolymer grafted maleic anhydride and 1 kg of ethylene bis-stearamide are uniformly mixed and then put into an injection molding machine. The pressure is 146 MPa, the temperature is 270°C, the preheating time is 60 s, the clamping force is 2280 kN, and the injection molding forms a plurality of outer tubes with a capacity of 4 ml and a wall thickness of 4 mm.

[0071] Comparative example 2

[0072] The difference from example 2 is that polyethylene naphthalate is not added.

[0073] Comparative example 3

[0074] The difference from example 2 is that the sheet barrier agent is not added.

[0075] Comparative example 4

[0076] The difference from example 2 is that sericite is not added.

[0077] Comparative example 5

[0078] The difference from example 2 is that the martensite micro-powder is not added.

[0079] Comparative example 6

[0080] The difference from example 2 is that the toughening body is not added.

[0081] Comparative example 7

[0082] The difference from example 2 is that the liquid butadiene rubber is not added.

[0083] Comparative example 8

[0084] The difference from example 2 is that the phenolic resin is not added.

[0085] Comparative example 9

[0086] The difference from Example 2 is that no compatibilizer ethylene-vinyl alcohol copolymer grafted maleic anhydride is added.

[0087] Comparative Example 10

[0088] The difference from Example 2 is that S2 and S3 are combined, 80 kg of PET granules, 7 kg of polyethylene naphthalate, 1 kg of sericite and 0.08 kg of martensite powder are weighed, uniformly mixed and then melt-extruded in a KS-20 type double screw extruder, the temperature of each section being 270°C for the first section, 270°C for the second section, 270°C for the third section, 275°C for the fourth section, 265°C for the fifth section and 260°C for the sixth section; the screw rotation speed is 70 r / min, to obtain an extrudate; the extrudate is cooled in air, cut into granules by a granulator and dried in a 75°C oven to obtain reinforced PET with a particle size of 3-5 cm.

[0089] Comparative Example 11

[0090] The difference from Example 2 is that S3 and S4 are combined, 80 kg of PET granules, 7 kg of polyethylene naphthalate, 1 kg of the sheet barrier agent prepared in S2, 8 kg of liquid butadiene rubber and 2 kg of phenolic resin are mixed uniformly and then melt-extruded in a KS-20 type double screw extruder, the temperature of each section being 270°C for the first section, 270°C for the second section, 270°C for the third section, 275°C for the fourth section, 265°C for the fifth section and 260°C for the sixth section; the screw rotation speed is 70 r / min, to obtain an extrudate; the extrudate is cooled in air, cut into granules by a granulator and dried in a 75°C oven to obtain reinforced PET with a particle size of 3-5 cm.

[0091] Table 1 Raw materials of outer tubes in examples and comparative examples (kg)

[0092]

[0093]

[0094] Performance test

[0095] Test method

[0096] 1. The method in GB-T 1043-1993 "Hard Plastics Simple Beam Impact Test Method" is used, the outer tube material prepared in Examples and Comparative Examples S1-S5 is processed into a sample of type 2 and a sample of notch type C according to the processing parameters in S6, and the low temperature impact strength (kJ / m2) is determined, wherein the sample is placed in a zero 20°C environment for 24 h before testing, and the test results are shown in Table 2.

[0097] 2. The outer tube prepared from the examples and comparative examples S1-S5 was processed into the container described in 4.2 according to the processing parameters in S6 by using the method in GBT 28765-Test methods of permeability to organic gases of plastic films, sheeting and containers. The gas permeability of the container [cc / (bottle.d.atm)] was determined. The test results are shown in Table 2.

[0098] Table 2: Test results of each example and comparative example

[0099]

[0100]

[0101] It can be seen from the combination of Example 1, Example 2 and Example 3 and Table 2 that by adjusting the proportion of the reinforcing PET, the toughening body, the ethylene-vinyl alcohol copolymer grafted maleic anhydride and the ethylene bis-stearamide, the low-temperature impact strength of the sample is improved and the gas permeability of the sample is reduced.

[0102] It can be seen from the combination of Example 2 and Comparative Example 1 and Table 2 that compared with the sample processed by using the conventional PET granules, the PET granules are modified by the present application and the impact strength of the sample in the low-temperature environment is significantly improved after adding the toughening body in the system.

[0103] It can be seen from the combination of Example 2, Example 4 and Example 5 and Table 2 that with the increase of the weight ratio of the reinforcing PET to the toughening body, the low-temperature impact strength of the sample first increases and then decreases, and the gas permeability of the sample decreases.

[0104] The reinforcing PET includes the PET granules, the polyethylene naphthalate and the sheet layer barrier agent. It can be seen from the combination of Example 2 and Comparative Example 2 and Table 2 that the low-temperature impact strength of the sample is improved and the gas permeability of the sample is reduced after adding the polyethylene naphthalate. The polyethylene naphthalate forms an entanglement network structure with the molten PET granules after melting, thereby improving the impact resistance of the sample. The polyethylene naphthalate modifies the reinforcing PET and provides the gas barrier performance of the sample.

[0105] It can be seen from the combination of Example 2, Example 6 and Example 7 and Table 2 that with the increase of the proportion of the polyethylene naphthalate, the low-temperature impact strength of the sample first increases and then decreases, and the gas permeability of the sample first increases and then decreases. The naphthalene ring of the polyethylene naphthalate is more rigid than the benzene ring in the PET, thereby improving the impact resistance of the sample after adding the polyethylene naphthalate. However, with the increase of the amount of the polyethylene naphthalate, the sample is not easy to deform to disperse the impact force when receiving the impact in the low-temperature environment, thereby reducing the low-temperature impact resistance.

[0106] It can be seen from Example 2, Example 8 and Example 9 in combination with Table 2 that with the increase of the amount of polyethylene naphthalate, the low-temperature impact strength of the sample first increases and then decreases, and the gas permeability of the sample first increases and then decreases.

[0107] It can be seen from Example 2 and Comparative Example 3 in combination with Table 2 that the addition of the sheet layer barrier agent effectively reduces the gas permeability of the sample and improves the impact strength of the sample. The sheet layer barrier agent includes sericite and martensite micro powder. The martensite micro powder improves the strength of the modified PET, the sericite improves the connection strength of the martensite and the PET granules after melting, and at the same time improves the connection strength of the reinforced PET and the toughening body, thereby improving the compactness and impact resistance of the sample.

[0108] It can be seen from Example 2, Example 10 and Example 11 in combination with Table 2 that with the increase of the amount of the sheet layer barrier agent, the low-temperature impact strength of the sample first increases and then decreases, and the gas permeability of the sample first increases and then decreases.

[0109] It can be seen from Example 2 and Comparative Example 4 in combination with Table 2 that the addition of the sericite in the sheet layer barrier agent effectively reduces the gas permeability of the sample and improves the low-temperature impact strength of the sample. The sheet structure of the sericite blocks the straight-line motion trajectory of the gas, thereby reducing the gas permeability of the sample.

[0110] It can be seen from Example 2 and Comparative Example 5 in combination with Table 2 that the addition of the martensite micro powder in the sheet layer barrier agent improves the low-temperature impact strength of the sample.

[0111] It can be seen from Example 2, Example 12 and Example 13 in combination with Table 2 that with the increase of the weight ratio of the sheet layer barrier agent to the martensite micro powder, the low-temperature impact strength of the sample first increases and then decreases, and the gas permeability of the sample decreases.

[0112] It can be seen from Example 2 and Comparative Example 6 in combination with Table 2 that the addition of the toughening body effectively improves the low-temperature impact strength of the sample. The toughening body includes liquid butadiene rubber and phenolic resin. The phenolic resin modifies the liquid butadiene rubber, improves the viscosity of the liquid butadiene rubber, and the phenolic resin captures the martensite micro powder, thereby improving the bonding strength of the liquid butadiene rubber to the PET and polyethylene naphthalate on the sheet layer barrier agent, facilitating the toughening body to provide elastic buffer for the PET, and thereby improving the impact strength of the sample.

[0113] It can be seen from Example 2, Example 14 and Example 15 in combination with Table 2 that with the increase of the amount of the toughening body, the low-temperature impact strength of the sample first increases and then decreases, and the gas permeability of the sample first increases and then decreases.

[0114] It can be seen from the combination of Example 2 and Comparative Example 7 and Table 2 that the addition of liquid butadiene rubber in the toughening body effectively improves the low-temperature impact strength of the sample.

[0115] It can be seen from the combination of Example 2, Example 16 and Example 17 and Table 2 that as the proportion of liquid butadiene rubber in the toughening body increases, the low-temperature impact strength of the sample first increases and then decreases, and the gas permeability of the sample first increases and then decreases.

[0116] It can be seen from the combination of Example 2 and Comparative Example 8 and Table 2 that the addition of phenolic resin in the toughening body effectively improves the low-temperature impact strength of the sample.

[0117] It can be seen from the combination of Example 2 and Comparative Example 9 and Table 2 that the addition of ethylene-vinyl alcohol copolymer grafted maleic anhydride improves the low-temperature impact strength of the sample and reduces the gas permeability of the sample.

[0118] It can be seen from the combination of Example 2 and Comparative Example 10 and Table 2 that compared with directly mixing sericite and martensite micropowder with PET granules, intercalating sericite before martensite micropowder and then blending with PET granules effectively improves the low-temperature impact strength of the sample and reduces the gas permeability of the sample.

[0119] It can be seen from the combination of Example 2 and Comparative Example 11 and Table 2 that compared with directly mixing liquid butadiene rubber and phenolic resin with PET granules, first participating in the vulcanization reaction of butadiene rubber and then mixing the vulcanization product with modified PET granules effectively improves the low-temperature impact strength of the sample.

[0120] The specific embodiments are merely an explanation of the present application, which is not a limitation of the present application. Those skilled in the art can make modifications to the embodiments without creative contribution after reading the present specification, as long as the modifications are within the scope of the claims of the present application.

Claims

1. A vacuum blood collection tube, characterized in that, include: Outer tube (1); The PET inner tube (2) is housed inside the outer tube (1) and is spaced apart from the outer tube (1) to form a cavity (11). A sealing ring (3) connects the outer tube (1) and the PET inner tube (2) and seals the cavity (11). A sealing plug (4) is inserted into the opening of the PET inner tube (2) and seals the PET inner tube (2). The outer tube (1) is made of modified PET, which includes the following raw materials in parts by weight: reinforced PET, 88-124 parts; toughening agent, 4-10 parts; compatibilizer, 1-5 parts; lubricant, 1-2 parts; the toughening agent includes liquid butadiene rubber and phenolic resin, and the weight ratio of liquid butadiene rubber to phenolic resin is (1-4):1; The reinforced PET comprises PET pellets, polyethylene naphthalate, and a sheet barrier agent, wherein the weight ratio of the PET pellets, polyethylene naphthalate, and sheet barrier agent is (20-80):(7-10):1; The sheet barrier agent comprises sericite and reinforcing micro powder, wherein the weight ratio of sericite to reinforcing micro powder is (25-75):2; The enhanced micro powder is one or more of martensitic micro powder, graphene micro powder, or spherical silicon micro powder. The compatibilizer is an ethylene-vinyl alcohol copolymer grafted with maleic anhydride. The lubricant is ethylene bis-stearamide.

2. The vacuum blood collection tube according to claim 1, characterized in that, The preparation of the toughened body includes the following steps: Liquid butadiene rubber and phenolic resin are mixed at room temperature for 0.8-1.5 hours, a rubber vulcanizing agent is added, and the mixture is mixed again at room temperature for 10-30 minutes. Then, the mixture is vulcanized for 50-60 minutes and ultrasonically treated for 10-20 minutes to obtain the reactant. The reactant is placed in a constant temperature oven at 140-150℃ for static stabilization, and then cut into blocks and granulated to obtain the toughened body.

3. The vacuum blood collection tube according to claim 1, characterized in that, The preparation of the sheet barrier agent includes the following steps: sericite swelling, addition of reinforcing micro powder, heating to 145-150℃ and stirring for 1.5-2.5h, centrifugation and drying, adding the mixture to an autoclave with water as a solvent, vacuum reaction, cooling to room temperature and discharging to obtain the sheet barrier agent.

4. The vacuum blood collection tube according to any one of claims 1-3, characterized in that, The sealing ring (3) is detachably connected to the PET inner tube (2), and the sealing ring (3) is detachably connected to the outer tube (1).

5. The vacuum blood collection tube according to claim 4, characterized in that, The sealing plug (4) is inserted into the outer tube (1).

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