A polytetrafluoroethylene multi-lumen tube and its preparation method

Abstract

The present application relates to the field of polytetrafluoroethylene technology, and in particular to a polytetrafluoroethylene multi-lumen tube and its preparation method. The polytetrafluoroethylene multi-lumen tube comprises at least two independent lumens, each of which has a diameter of 10-80% of the total diameter of the multi-lumen tube; the raw materials for its preparation are the following components in parts by weight: 200-250 parts of polytetrafluoroethylene modified resin; 20-50 parts of filler; and 30-50 parts of solvent oil; the polytetrafluoroethylene modified resin is prepared by mixing and modifying polytetrafluoroethylene resin, glycidyl methacrylate, hexafluorobutyl methacrylate, and carbon fiber. The present application gives the polytetrafluoroethylene multi-lumen tube excellent mechanical properties through the action of the polytetrafluoroethylene modified resin, thereby broadening its application range while further reducing production costs.

Description

Technical Field

[0001] The present application relates to the technical field of polytetrafluoroethylene, and more specifically, to a polytetrafluoroethylene multi-lumen tube and a preparation method thereof. Background Art

[0002] Polytetrafluoroethylene (PTFE) is a high molecular polymer made by polymerizing tetrafluoroethylene as a monomer. It is also known as the "King of Plastics". Due to its excellent chemical resistance and safety, it is often processed into various products and widely used in medical devices or special liquid transportation fields. PTFE multi-lumen tubes are an example.

[0003] The polytetrafluoroethylene multi-lumen tube in the related art includes at least two lumens and a tube head, each of which is composed of separately manufactured (extruded) parallel tubular pipes, and is covered with an outer rubber layer that makes the outer side of the tube body arc-shaped, that is, an additional closing member.

[0004] It can be seen that although the above-mentioned polytetrafluoroethylene multi-lumen tube can meet normal usage requirements, it is limited by the need to use a step-by-step method to manufacture the component units, which has high production costs, poor bonding between the components, and cannot guarantee mechanical properties. Therefore, this application specifically provides a polytetrafluoroethylene multi-lumen tube with low production cost and excellent tensile strength and compressive strength. Summary of the Invention

[0005] In order to give the polytetrafluoroethylene multi-lumen tube better mechanical properties while reducing production costs, the present application provides a polytetrafluoroethylene multi-lumen tube and a preparation method thereof.

[0006] In a first aspect, the present application provides a polytetrafluoroethylene multi-lumen tube, which adopts the following technical solution:

[0007] A polytetrafluoroethylene multi-lumen tube, characterized in that it comprises at least two independent lumens, wherein the diameter of each lumen is 10-80% of the total diameter of the multi-lumen tube;

[0008] The raw materials for its preparation are the following components in parts by weight:

[0009] 200-250 parts of polytetrafluoroethylene modified resin;

[0010] 20-50 parts of filler;

[0011] 30-50 parts of solvent oil;

[0012] The polytetrafluoroethylene modified resin is prepared by mixing and modifying polytetrafluoroethylene resin, glycidyl methacrylate, hexafluorobutyl methacrylate and carbon fiber.

[0013] By adopting the above technical solution, the mechanical properties of the polytetrafluoroethylene multi-lumen tube made from the above raw materials and structure are significantly improved. Analysis shows that the reason may be that after the polytetrafluoroethylene resin is mixed and modified with glycidyl methacrylate, hexafluorobutyl methacrylate and carbon fiber, its surface copolymerizes to form a dense cross-linked network layer. Under the action of solvent oil, the cross-linked network layer can be fully combined and filled with the filler, thereby ensuring the density and structural strength of the polytetrafluoroethylene multi-lumen tube after molding.

[0014] Preferably, the specific modification steps of the polytetrafluoroethylene modified resin are as follows:

[0015] a. Pretreatment: First, heat the polytetrafluoroethylene resin at 320-360℃ until it is molten, then connect the electrodes, control the voltage to 100-200V, and pass the current to 0.1-0.2A, and treat for 30-60s to obtain the activated polytetrafluoroethylene resin;

[0016] b. Modification treatment: add glycidyl methacrylate, hexafluorobutyl methacrylate and carbon fiber to the activated polytetrafluoroethylene resin in sequence, and mix them at 80-120°C under closed conditions for 15-30 minutes to obtain polytetrafluoroethylene modified resin.

[0017] By adopting the above technical solution, a large number of bound free radicals will be generated inside and on the surface of the pretreated polytetrafluoroethylene resin, thereby significantly improving the copolymerization effect of the polytetrafluoroethylene resin with glycidyl methacrylate and hexafluorobutyl methacrylate, and the carbon fiber plays a skeletal support role for the cross-linked network layer formed by the copolymerization.

[0018] Preferably, the polytetrafluoroethylene modified resin is prepared by mixing and modifying polytetrafluoroethylene resin, glycidyl methacrylate, hexafluorobutyl methacrylate and carbon fiber in a weight ratio of 1:(0.12-0.18):(0.20-0.30):(0.15-0.30).

[0019] By adopting the above technical solution, the copolymerization modification effect of the polytetrafluoroethylene resin, glycidyl methacrylate, hexafluorobutyl methacrylate and carbon fiber in the above ratio is the best, and the cross-linked network copolymer structure formed is the densest, which is conducive to ensuring the structural strength and mechanical properties of the polytetrafluoroethylene multi-lumen tube after molding.

[0020] Preferably, the solvent oil is an isoparaffin solvent oil, selected from one or more of D40, D60, D80, and D95.

[0021] By adopting the above technical solution, the solvent oils of the above components are all colorless, transparent, environmentally friendly, have excellent dispersibility for fillers, and have a certain compounding effect between the multiple components.

[0022] In a second aspect, the present application provides a polytetrafluoroethylene multi-lumen tube and a preparation method thereof, which adopts the following technical solutions:

[0023] A polytetrafluoroethylene multi-lumen tube and a preparation method thereof, comprising the following steps:

[0024] S1. Raw material mixing: Grind and sieve the polytetrafluoroethylene modified resin, then mix with the filler and auxiliary oil in corresponding parts by weight, heat and mature, and prepare a matured powder;

[0025] S2. Pressing and sintering: first add the matured powder in S1 into the mold, then press, exhaust, and maintain the pressure, and then heat and sinter to obtain the sintered material;

[0026] S3. Cooling and molding: After the sintered material is cooled to room temperature, it is taken out from the mold to obtain a polytetrafluoroethylene multi-lumen tube.

[0027] By adopting the above technical solution, the above preparation method is relatively simple, and various conditions are easy to control and achieve. The polytetrafluoroethylene multi-lumen tube is integrally formed and has stable performance and excellent mechanical properties. Compared with the polytetrafluoroethylene multi-lumen tube produced by the combined step-by-step method, it has extremely high economic benefits and is therefore suitable for industrial production and product quality control.

[0028] Preferably, the specific steps are as follows:

[0029] S1. Raw material mixing: first grind the corresponding weight of polytetrafluoroethylene modified resin, pass it through a 300μm sieve, and then mix it with the filler and auxiliary oil in corresponding parts by weight, heat it to 40-50°C, and mature it for 6-12 hours to obtain a matured powder;

[0030] S2. Pressing and sintering: Add the sintered powder into the mold, apply a pressure of 30-45 MPa, and exhaust 3-5 times. Control the pressure at 45-60 MPa and maintain the pressure for 60-90 minutes. Then raise the temperature to 350-400°C and sinter for 10-24 hours to obtain a sintered rough blank.

[0031] S3. Cooling treatment: Take out the sintered rough blank from the mold, pass liquid cooling to the surface and cavity of the sintered rough blank in sections, with a liquid flow rate of 0.15-0.25L / min. After cooling to room temperature, the polytetrafluoroethylene multi-lumen tube can be obtained.

[0032] By adopting the above technical solution, the polytetrafluoroethylene modified resin matured under the above operating conditions can be quickly formed in the subsequent pressing and sintering process, is less likely to produce microbubbles, and has a high overall structural density.

[0033] Preferably, glycidyl methacrylate is first introduced into the surface and cavity of the sintered rough blank for cooling for 5-10 minutes at a flow rate of 0.15-0.20 L / min; then cooling water is introduced at a flow rate of 0.20-0.25 L / min until it cools to room temperature, thereby obtaining a polytetrafluoroethylene multi-lumen tube.

[0034] By adopting the above technical solution and the segmented cooling method, in addition to effectively ensuring the molding quality of the polytetrafluoroethylene multi-lumen tube and making it less susceptible to being affected by changes in thermal stress, the introduced glycidyl methacrylate can also undergo a small amount of bonding and grafting with the sintered rough blank, thereby further enhancing the mechanical properties of the polytetrafluoroethylene multi-lumen tube.

[0035] Preferably, the sintered rough blank is further subjected to an electrical activation treatment before the S3 cooling treatment, and the specific steps are as follows:

[0036] After taking out the sintered rough blank from the mold, first connect electrodes at both ends of the sintered rough blank, control the voltage to 200-300V, and pass the current to 0.2-0.3A for 45-60s to obtain the activated sintered rough blank;

[0037] Then, ethyl trifluoroacetate is introduced into the surface and cavity of the activated sintered rough blank for cooling for 5-10 minutes at a flow rate of 0.15-0.20 L / min; then, cooling water is introduced at a flow rate of 0.20-0.25 L / min until it cools to room temperature, thereby obtaining a polytetrafluoroethylene multi-lumen tube.

[0038] By adopting the above technical solution, after the sintered rough blank is activated under electrical conditions, a large number of binding free radicals will be generated on the surface. In addition to further promoting the cross-linking and grafting effect between the cross-linked network copolymer itself, it can also promote the bonding of glycidyl methacrylate, thereby further enhancing the mechanical properties of the polytetrafluoroethylene multi-lumen tube.

[0039] In summary, this application has the following beneficial effects:

[0040] 1. The mechanical properties of the polytetrafluoroethylene multi-lumen tube of the above-mentioned raw materials and structure in this application are significantly improved. Analysis shows that the reason for this may be that after the polytetrafluoroethylene resin is modified, its surface copolymerizes to form a dense cross-linked network layer. Under the action of solvent oil, this cross-linked network layer can fully combine and fill with the filler, thereby ensuring the density and structural strength of the polytetrafluoroethylene multi-lumen tube after molding;

[0041] 2. The pretreated polytetrafluoroethylene resin in the present application generates a large number of bound free radicals, thereby significantly improving the copolymerization modification effect of the polytetrafluoroethylene resin, and the carbon fiber plays a skeletal support role for the cross-linked network layer formed by the copolymerization; 3. The preparation method in the present application is relatively simple and easy to control the conditions. The obtained polytetrafluoroethylene multi-lumen tube is integrally formed and has stable performance. Compared with the polytetrafluoroethylene multi-lumen tube produced by the combined step-by-step method, it has significant economic benefits and is therefore suitable for industrial production and product quality control;

[0042] 4. After the sintered rough blank in this application is subjected to electrical treatment, a large number of bound free radicals will be generated on the surface, and the mechanical properties of the polytetrafluoroethylene multi-lumen tube will be further enhanced by promoting cross-linking and grafting; and the segmented cooling method is not likely to affect the molding quality of the polytetrafluoroethylene multi-lumen tube. DETAILED DESCRIPTION

[0043] The present application is further described in detail below with reference to the embodiments.

[0044] The raw materials used in the examples of this application are commercially available except for the following special instructions:

[0045] Polytetrafluoroethylene resin, CAS 9002-84-0;

[0046] Glycidyl methacrylate, CAS 106-91-2;

[0047] Hexafluorobutyl methacrylate, CAS 36405-47-7;

[0048] Glycidyl methacrylate, CAS 106-91-2.

[0049] Preparation Example

[0050] Preparation Example 1

[0051] A polytetrafluoroethylene modified resin, the preparation steps of which are as follows:

[0052] a. Pretreatment: First, heat the polytetrafluoroethylene resin at 360°C until it is molten, then connect the electrodes, control the voltage to 100V, and pass the current to 0.1A for 60s to obtain the activated polytetrafluoroethylene resin;

[0053] b. Modification treatment: add glycidyl methacrylate, hexafluorobutyl methacrylate and carbon fiber to the activated polytetrafluoroethylene resin in sequence, and mix them at 80°C under closed conditions for 30 minutes to obtain polytetrafluoroethylene modified resin;

[0054] In b, polytetrafluoroethylene resin, glycidyl methacrylate, hexafluorobutyl methacrylate and carbon fiber are mixed in a weight ratio of 1:0.1:0.1:0.1.

[0055] Preparation Example 2

[0056] A polytetrafluoroethylene modified resin, which differs from Preparation Example 1 in that its preparation steps are as follows:

[0057] a. Pretreatment: First, heat the polytetrafluoroethylene resin at 360°C until it is molten, then connect the electrodes, control the voltage to 180V, and pass the current to 0.15A for 45 seconds to obtain the activated polytetrafluoroethylene resin;

[0058] b. Modification treatment: add glycidyl methacrylate, hexafluorobutyl methacrylate and carbon fiber to the activated polytetrafluoroethylene resin in sequence, and mix them at 100°C under closed conditions for 20 minutes to obtain polytetrafluoroethylene modified resin.

[0059] Preparation Example 3

[0060] A polytetrafluoroethylene modified resin, which differs from Preparation Example 1 in that its preparation steps are as follows:

[0061] a. Pretreatment: First, heat the polytetrafluoroethylene resin at 360°C until it is molten, then connect the electrodes, control the voltage to 200V, and pass the current to 0.2A for 60s to obtain the activated polytetrafluoroethylene resin;

[0062] b. Modification treatment: add glycidyl methacrylate, hexafluorobutyl methacrylate and carbon fiber to the activated polytetrafluoroethylene resin in sequence, and mix them at 120°C under closed conditions for 15 minutes to obtain polytetrafluoroethylene modified resin.

[0063] Preparation Example 4

[0064] A polytetrafluoroethylene modified resin, which differs from Preparation Example 1 in that its preparation steps are as follows:

[0065] a. Pretreatment: First, heat the polytetrafluoroethylene resin at 360°C until it is molten, then connect the electrodes, control the voltage to 300V, and pass the current to 0.3A for 60s to obtain the activated polytetrafluoroethylene resin;

[0066] b. Modification treatment: add glycidyl methacrylate, hexafluorobutyl methacrylate and carbon fiber to the activated polytetrafluoroethylene resin in sequence, and mix them at 150°C under closed conditions for 30 minutes to obtain polytetrafluoroethylene modified resin.

[0067] Preparation Example 5

[0068] A polytetrafluoroethylene modified resin is different from Preparation Example 1 in that the polytetrafluoroethylene resin, glycidyl methacrylate, hexafluorobutyl methacrylate and carbon fiber in Preparation Example (b) are mixed in a weight ratio of 1:0.12:0.20:0.15.

[0069] Preparation Example 6

[0070] A polytetrafluoroethylene modified resin is different from Preparation Example 1 in that the polytetrafluoroethylene resin, glycidyl methacrylate, hexafluorobutyl methacrylate and carbon fiber in Preparation Example (b) are mixed in a weight ratio of 1:0.15:0.25:0.20.

[0071] Preparation Example 7

[0072] A polytetrafluoroethylene modified resin is different from Preparation Example 1 in that the polytetrafluoroethylene resin, glycidyl methacrylate, hexafluorobutyl methacrylate and carbon fiber in Preparation Example (b) are mixed in a weight ratio of 1:0.18:0.30:0.30.

[0073] Preparation Example 8

[0074] A polytetrafluoroethylene modified resin is different from Preparation Example 5 in that the polytetrafluoroethylene resin, glycidyl methacrylate, hexafluorobutyl methacrylate and carbon fiber in Preparation Example (b) are mixed in a weight ratio of 1:0.2:0.4:0.4.

[0075] Performance testing

[0076] The polytetrafluoroethylene six-lumen tubes (inner lumen diameter 2 mm / outer diameter 8 mm / six lumens evenly distributed in a honeycomb pattern / center distance between adjacent lumens is 3 mm) prepared in the examples and comparative examples were selected as test objects, and their tensile strength and compressive strength were tested respectively.

[0077] For specific testing steps and standards, please refer to GB / T 1447-2005 "Test Method for Tensile Properties of Fiber Reinforced Plastics", GB / T 1039-1992 "General Rules for Test Methods for Mechanical Properties of Plastics" and QB / T 4877-2015 "Polytetrafluoroethylene Tube".

[0078] Example

[0079] Examples 1-6

[0080] A polytetrafluoroethylene multi-lumen tube, the corresponding weights of the components of the raw materials for its preparation are shown in Table 1, and is prepared by the following steps:

[0081] S1. Raw material mixing: First, grind the corresponding weight of the polytetrafluoroethylene modified resin obtained in Preparation Example 1, pass it through a 300 μm sieve, and then mix it with the filler and auxiliary oil in corresponding parts by weight, heat it to 40° C., and mature it for 12 hours to obtain a matured powder;

[0082] The filler is 1mm glass fiber; the auxiliary oil is isoparaffin solvent oil D40;

[0083] S2. Pressing and sintering: Add the sintered powder into the mold, apply a pressure of 30 MPa, and exhaust 5 times. After controlling the pressure at 45 MPa and maintaining the pressure for 90 minutes, heat it to 350°C and sinter for 24 hours to obtain a sintered rough blank.

[0084] S3. Cooling treatment: Take out the sintered rough blank from the mold, first pass cooling water to the surface and cavity of the sintered rough blank for 5 minutes at a flow rate of 0.15L / min; then pass cooling water at a flow rate of 0.20L / min for secondary cooling until it cools to room temperature, and the polytetrafluoroethylene multi-lumen tube can be obtained.

[0085] Table 1 Weight of each component in Examples 1-6 (kg)

[0086]

[0087] Comparative Example 1

[0088] A polytetrafluoroethylene multi-lumen tube is different from Example 1 in that the polytetrafluoroethylene resin in its preparation raw material has not been modified.

[0089] Three groups of polytetrafluoroethylene multi-lumen tubes prepared in Examples 1-6 and Comparative Example 1 were each selected and their compressive strength (MPa) and tensile strength (MPa) were tested according to the above measurement steps and measurement standards. The average values ​​of the test results were recorded in the table below.

[0090] Table: Performance test results of Examples 1-6 and Comparative Example 1

[0091]

[0092]

[0093] As can be seen from the above table, the polytetrafluoroethylene multi-lumen tubes prepared in Examples 1-6 all have excellent mechanical properties, with a compressive strength of up to 29.3-32.2 MPa, which is 45.0-59.4% higher than that of Comparative Example 1; and a tensile strength of up to 49.3-53.9 MPa, which is 59.0-73.9% higher than that of Comparative Example 1.

[0094] It can be seen that the mechanical properties of the polytetrafluoroethylene multi-lumen tube made from the above raw materials and structures are significantly improved, compared with the use of unmodified polytetrafluoroethylene resin, that is, comparative example 1, its mechanical properties are significantly improved; and it is well known in the art that the more lumens a multi-lumen tube has, the worse its mechanical properties generally are.

[0095] Analysis shows that the reason may be that after the polytetrafluoroethylene resin is modified by mixing glycidyl methacrylate, hexafluorobutyl methacrylate and carbon fiber, its surface copolymerizes to form a dense cross-linked network layer. Under the action of solvent oil, the cross-linked network layer can be fully combined and filled with the filler, thereby ensuring the density and structural strength of the polytetrafluoroethylene multi-lumen tube after molding.

[0096] Examples 7-9

[0097] A polytetrafluoroethylene multi-lumen tube is different from Example 1 in that the usage of the polytetrafluoroethylene modified resin used in its preparation raw materials is different, and the specific corresponding relationship is shown in the following table.

[0098] Table: Comparison of usage of polytetrafluoroethylene modified resin in Examples 7-9

[0099] Group Polytetrafluoroethylene modified resin Example 7 Prepared from Preparation Example 2 Example 8 Prepared from Preparation Example 3 Example 9 Prepared from Preparation Example 4

[0100] Three groups of polytetrafluoroethylene multi-lumen tubes prepared in Examples 7-9 were selected and their compressive strength (MPa) and tensile strength (MPa) were tested according to the above measurement steps and measurement standards. The average values ​​of the test results were recorded in the table below.

[0101] Table: Performance test results of Examples 1, 7-9

[0102]

[0103]

[0104] As can be seen from the above table, the polytetrafluoroethylene multi-lumen tubes prepared in Examples 1 and 7-9 all have excellent mechanical properties, with a compressive strength of up to 29.1-29.3 MPa and a tensile strength of up to 49.0-49.3 MPa; and relatively stable and uniform performance;

[0105] It can be seen that the polytetrafluoroethylene modified resin prepared under the above parameter conditions can significantly improve the mechanical properties of the polytetrafluoroethylene multi-lumen tube. As can be seen from Examples 1, 7-8, when the parameter conditions are controlled within a certain range, its performance remains basically unchanged, which is beneficial to product quality control.

[0106] Analysis shows that the reason may be that after the above-mentioned pretreatment, a large number of bound free radicals will be generated inside and on the surface of the polytetrafluoroethylene resin, which significantly improves the copolymerization effect of polytetrafluoroethylene resin with glycidyl methacrylate and hexafluorobutyl methacrylate. The carbon fiber plays a skeletal support role for the cross-linked network layer formed by the copolymerization, and the copolymerization and support role can be carried out stably.

[0107] Examples 10-13

[0108] A polytetrafluoroethylene multi-lumen tube is different from Example 1 in that the usage of the polytetrafluoroethylene modified resin used in its preparation raw materials is different, and the specific corresponding relationship is shown in the following table.

[0109] Table: Comparison of usage of polytetrafluoroethylene modified resin in Examples 10-13

[0110] Group Polytetrafluoroethylene modified resin Example 10 Prepared from Preparation Example 5 Example 11 Prepared from Preparation Example 6 Example 12 Prepared from Preparation Example 7 Example 13 Prepared from Preparation Example 8

[0111] Three groups of polytetrafluoroethylene multi-lumen tubes prepared in Examples 10-13 were selected and their compressive strength (MPa) and tensile strength (MPa) were tested according to the above measurement steps and measurement standards. The average values ​​of the test results were recorded in the following table.

[0112] Table: Performance test results of Examples 1, 10-13

[0113]

[0114]

[0115] As can be seen from the above table, the polytetrafluoroethylene multi-lumen tubes prepared in Examples 1 and 10-13 all have excellent mechanical properties, with a compressive strength of up to 29.3-30.4 MPa and a tensile strength of up to 49.3-51.2 MPa;

[0116] It can be seen that the copolymerization modification effect of the polytetrafluoroethylene resin, glycidyl methacrylate, hexafluorobutyl methacrylate and carbon fiber in the above ratio is the best, and the cross-linked network copolymer structure formed is the densest, which is conducive to ensuring the structural strength and mechanical properties of the polytetrafluoroethylene multi-lumen tube after molding;

[0117] In addition, it can be seen from the above table that Examples 10-12 are preferred examples. When the polytetrafluoroethylene modified resin is prepared by mixing and modifying polytetrafluoroethylene resin, glycidyl methacrylate, hexafluorobutyl methacrylate and carbon fiber in a weight ratio of 1:(0.12-0.18):(0.20-0.30):(0.15-0.30), the improvement in the final performance is most significant.

[0118] Example 14

[0119] A polytetrafluoroethylene multi-lumen tube is different from Example 1 in that the solvent oil in its preparation raw material is isoparaffin solvent oil D60.

[0120] Example 15

[0121] A polytetrafluoroethylene multi-lumen tube is different from Example 1 in that the solvent oil in its preparation raw materials is composed of isoparaffin solvent oil D40 and D60 in a weight ratio of 1:0.2.

[0122] Three groups of polytetrafluoroethylene multi-lumen tubes prepared in Examples 14-15 were selected and their compressive strength (MPa) and tensile strength (MPa) were tested according to the above measurement steps and measurement standards. The average values ​​of the test results were recorded in the table below.

[0123] Table: Performance test results of Examples 14-15

[0124]

[0125] As can be seen from the above table, the polytetrafluoroethylene multi-lumen tubes prepared in Examples 1 and 14-15 all have excellent mechanical properties, with a compressive strength of up to 29.2-29.5 MPa and a tensile strength of up to 49.3-49.6 MPa;

[0126] It can be seen that the solvent oils of the above components are colorless, transparent and environmentally friendly, and have a better promoting effect on the dispersibility of the filler. In addition, it can be seen from Example 15 that the solvent oils of different components have a certain compounding effect.

[0127] Example 16

[0128] A polytetrafluoroethylene multi-lumen tube, which differs from Example 1 in that it is prepared by the following steps:

[0129] S1. Raw material mixing: First, grind the corresponding weight of the polytetrafluoroethylene modified resin obtained in Preparation Example 1, pass it through a 300 μm sieve, and then mix it with the filler and auxiliary oil in corresponding parts by weight, heat it to 45° C., and mature it for 9 hours to obtain a matured powder;

[0130] S2. Pressing and sintering: Add the sintered powder into the mold, apply a pressure of 40 MPa, and exhaust 4 times. After controlling the pressure at 50 MPa and maintaining the pressure for 80 minutes, heat it to 380°C and sinter for 10-24 hours to obtain a sintered rough blank.

[0131] S3. Cooling treatment: Take out the sintered rough blank from the mold, first pass cooling water to the surface and cavity of the sintered rough blank for 8 minutes at a flow rate of 0.18 L / min; then pass cooling water at a flow rate of 0.22 L / min for secondary cooling until it cools to room temperature, and the polytetrafluoroethylene multi-lumen tube can be obtained.

[0132] Example 17

[0133] A polytetrafluoroethylene multi-lumen tube, which differs from Example 1 in that it is prepared by the following steps:

[0134] S1. Raw material mixing: First, grind the corresponding weight of the polytetrafluoroethylene modified resin obtained in Preparation Example 1, pass it through a 300 μm sieve, and then mix it with the filler and auxiliary oil in corresponding parts by weight, heat it to 50° C., and mature it for 6 hours to obtain a matured powder;

[0135] S2. Pressing and sintering: Add the sintered powder into the mold, apply a pressure of 45 MPa, and exhaust 3 times. After controlling the pressure at 60 MPa and maintaining the pressure for 60 minutes, heat it to 400°C and sinter for 10 hours to obtain a sintered rough blank.

[0136] S3. Cooling treatment: Take out the sintered rough blank from the mold, first pass cooling water to the surface and cavity of the sintered rough blank for primary cooling for 10 minutes at a flow rate of 0.20 L / min; then pass cooling water at a flow rate of 0.25 L / min for secondary cooling until it cools to room temperature, and the polytetrafluoroethylene multi-lumen tube can be obtained.

[0137] Example 18

[0138] A polytetrafluoroethylene multi-lumen tube, which differs from Example 1 in that it is prepared by the following steps:

[0139] S1. Raw material mixing: First, grind the corresponding weight of the polytetrafluoroethylene modified resin obtained in Preparation Example 1, pass it through a 300 μm sieve, and then mix it with the filler and auxiliary oil in corresponding parts by weight, heat it to 60° C., and mature it for 4 hours to obtain a matured powder;

[0140] S2. Pressing and sintering: Add the sintered powder into the mold, apply a pressure of 20 MPa, and exhaust 8 times. After maintaining the pressure at 30 MPa for 120 minutes, heat it to 320°C and sinter for 28 hours to obtain a sintered rough blank.

[0141] S3. Cooling treatment: Take out the sintered rough blank from the mold, first pass cooling water into the surface and cavity of the sintered rough blank for 15 minutes at a flow rate of 0.10 L / min; then pass cooling water at a flow rate of 0.15 L / min for secondary cooling until it cools to room temperature, and the polytetrafluoroethylene multi-lumen tube can be obtained.

[0142] Three groups of polytetrafluoroethylene multi-lumen tubes prepared in Examples 16-18 were selected and their compressive strength (MPa) and tensile strength (MPa) were tested according to the above measurement steps and measurement standards. The average values ​​of the test results were recorded in the table below.

[0143] Table: Performance test results of Examples 1, 16-18

[0144]

[0145] As can be seen from the above table, the polytetrafluoroethylene multi-lumen tubes prepared in Examples 1 and 16-18 all have excellent mechanical properties, with a compressive strength of up to 28.5-29.4 MPa and a tensile strength of up to 48.8-49.6 MPa;

[0146] It can be seen that the obtained polytetrafluoroethylene multi-lumen tubes are integrally formed and have excellent mechanical properties. Compared with the polytetrafluoroethylene multi-lumen tubes produced by the combined step-by-step method, they have extremely high economic benefits and are therefore suitable for industrial production and product quality control.

[0147] In addition, it can be seen from the above table that Examples 1 and 16-17 are preferred examples. The performance of the polytetrafluoroethylene multi-lumen tube produced within a specific operating condition range is stable, and the matured polytetrafluoroethylene modified resin can be quickly formed in the subsequent pressing and sintering process, is less likely to produce microbubbles, and has a high overall structural density.

[0148] Example 19

[0149] A polytetrafluoroethylene multi-lumen tube, which differs from Example 1 in that the segmented cooling step of S3 is different, as follows:

[0150] After the sintered rough blank is taken out from the mold, glycidyl methacrylate is first introduced into the surface and cavity of the sintered rough blank for cooling for 5 minutes at a flow rate of 0.20 L / min; then cooling water is introduced at a flow rate of 0.25 L / min until it cools to room temperature, and a polytetrafluoroethylene multi-lumen tube can be obtained.

[0151] Example 20

[0152] A polytetrafluoroethylene multi-lumen tube, which differs from Example 1 in that the segmented cooling step of S3 is different, as follows:

[0153] After the sintered rough blank is taken out from the mold, glycidyl methacrylate is first introduced into the surface and cavity of the sintered rough blank for cooling for 8 minutes at a flow rate of 0.18 L / min; then cooling water is introduced at a flow rate of 0.25 L / min until it cools to room temperature, and a polytetrafluoroethylene multi-lumen tube can be obtained.

[0154] Example 21

[0155] A polytetrafluoroethylene multi-lumen tube, which differs from Example 1 in that the segmented cooling step of S3 is different, as follows:

[0156] After the sintered rough blank is taken out from the mold, glycidyl methacrylate is introduced into the surface and cavity of the sintered rough blank for cooling for 10 minutes at a flow rate of 0.15 L / min; then cooling water is introduced at a flow rate of 0.25 L / min until it cools to room temperature, and a polytetrafluoroethylene multi-lumen tube is obtained.

[0157] Example 22

[0158] A polytetrafluoroethylene multi-lumen tube, which differs from Example 1 in that the segmented cooling step of S3 is different, as follows:

[0159] After the sintered rough blank is taken out from the mold, glycidyl methacrylate is first introduced into the surface and cavity of the sintered rough blank for cooling for 20 minutes at a flow rate of 0.05 L / min; then cooling water is introduced at a flow rate of 0.20 L / min until it cools to room temperature, and a polytetrafluoroethylene multi-lumen tube can be obtained.

[0160] Three groups of polytetrafluoroethylene multi-lumen tubes prepared in Examples 19-22 were selected and their compressive strength (MPa) and tensile strength (MPa) were tested according to the above measurement steps and measurement standards. The average values ​​of the test results were recorded in the table below.

[0161] Table: Performance test results of Examples 1, 19-22

[0162]

[0163] As can be seen from the above table, the polytetrafluoroethylene multi-lumen tubes prepared in Examples 19-22 all have excellent mechanical properties, with a compressive strength of up to 29.8-30.4 MPa and a tensile strength of up to 51.0-51.8 MPa; all of which are improved to varying degrees compared to Example 1; it can be seen that the above-mentioned segmented cooling method not only effectively ensures the molding quality of the polytetrafluoroethylene multi-lumen tube and makes it less likely to be affected by changes in thermal stress, but the introduced glycidyl methacrylate can also undergo a small amount of bonding and grafting with the sintered rough blank, thereby further enhancing the mechanical properties of the polytetrafluoroethylene multi-lumen tube. For details, see Examples 1 and 19-22 in the above table.

[0164] In addition, it can be seen from the above table that Examples 19-21 are preferred examples. The performance of the polytetrafluoroethylene multi-lumen tube obtained by segmented cooling within a specific operating condition range is better. If the conditions are exceeded, the actual performance will be reduced, see Example 22.

[0165] Example 23

[0166] A polytetrafluoroethylene multi-lumen tube is different from Example 20 in that the sintered rough blank is further subjected to an electrical activation treatment before the S3 cooling treatment. The specific steps are as follows:

[0167] After taking the sintered rough blank out of the mold, electrodes are connected at both ends of the sintered rough blank, with a controlled voltage of 200V and a current of 0.2A for 60s to obtain an activated sintered rough blank.

[0168] Then, ethyl trifluoroacetate was introduced into the surface and cavity of the activated sintered rough blank for cooling for 5 minutes at a flow rate of 0.20 L / min; then, cooling water was introduced at a flow rate of 0.25 L / min until it cooled to room temperature, thereby obtaining a polytetrafluoroethylene multi-lumen tube.

[0169] Example 24

[0170] A polytetrafluoroethylene multi-lumen tube is different from Example 20 in that the sintered rough blank is further subjected to an electrical activation treatment before the S3 cooling treatment. The specific steps are as follows:

[0171] After taking the sintered rough blank out of the mold, electrodes are connected at both ends of the sintered rough blank, with a controlled voltage of 250V and a current of 0.25A for 50 seconds to obtain an activated sintered rough blank.

[0172] Then, ethyl trifluoroacetate was introduced into the surface and cavity of the activated sintered rough blank for cooling for 8 minutes at a flow rate of 0.18 L / min; then, cooling water was introduced at a flow rate of 0.20 L / min until it cooled to room temperature, thereby obtaining a polytetrafluoroethylene multi-lumen tube.

[0173] Example 25

[0174] A polytetrafluoroethylene multi-lumen tube is different from Example 20 in that the sintered rough blank is further subjected to an electrical activation treatment before the S3 cooling treatment. The specific steps are as follows:

[0175] After taking the sintered rough blank out of the mold, electrodes are connected at both ends of the sintered rough blank, with a controlled voltage of 300V and a current of 0.3A for 45 seconds to obtain an activated sintered rough blank.

[0176] Then, ethyl trifluoroacetate was introduced into the surface and cavity of the activated sintered rough blank for cooling for 10 minutes at a flow rate of 0.15 L / min; then, cooling water was introduced at a flow rate of 0.20 L / min until it cooled to room temperature, thereby obtaining a polytetrafluoroethylene multi-lumen tube.

[0177] Example 26

[0178] A polytetrafluoroethylene multi-lumen tube is different from Example 20 in that the sintered rough blank is further subjected to an electrical activation treatment before the S3 cooling treatment. The specific steps are as follows:

[0179] After taking the sintered rough blank out of the mold, first connect electrodes at both ends of the sintered rough blank, control the voltage to 400V, and pass the current to 0.5A for 15s to obtain the activated sintered rough blank;

[0180] Then, ethyl trifluoroacetate was introduced into the surface and cavity of the activated sintered rough blank for cooling for 20 minutes at a flow rate of 0.1 L / min; and cooling water was introduced at a flow rate of 0.2 L / min until it cooled to room temperature, thereby obtaining a polytetrafluoroethylene multi-lumen tube.

[0181] Three groups of polytetrafluoroethylene multi-lumen tubes prepared in Examples 23-26 were selected and their compressive strength (MPa) and tensile strength (MPa) were tested according to the above measurement steps and measurement standards. The average values ​​of the test results were recorded in the table below.

[0182] Table: Performance test results of Examples 20, 23-26

[0183]

[0184] As can be seen from the above table, the polytetrafluoroethylene multi-lumen tubes prepared in Examples 23-26 all have excellent mechanical properties, with a compressive strength of up to 30.8-31.2 MPa and a tensile strength of up to 52.9-53.8 MPa; all of which are improved to varying degrees compared to Example 20; it can be seen that after the above-mentioned sintered rough blank is activated under electrical conditions, a large number of bound free radicals will be generated on the surface, which not only further promotes the cross-linking and grafting effect between the cross-linked network copolymer itself, but also promotes the binding of glycidyl methacrylate, thereby further enhancing the mechanical properties of the polytetrafluoroethylene multi-lumen tube. For details, see Examples 23-26 in the above table.

[0185] In addition, it can be seen from the above table that Examples 23-25 ​​are preferred examples. The performance of the polytetrafluoroethylene multi-lumen tube obtained by electro-activation treatment is better within a specific operating condition range. Beyond this condition, the actual performance will be reduced. See Example 26. The reason may be that the voltage is too high and the actual treatment is too long, resulting in catalysis of part of the structure of the sintered rough blank.

[0186] This specific embodiment is merely an explanation of the present application and is not a limitation of the present application. After reading this specification, those skilled in the art may make non-creative modifications to the present embodiment as needed, but as long as they are within the scope of the claims of the present application, they are protected by the patent law.

Claims

1. A polytetrafluoroethylene multi-lumen tube, characterized in that: The multi-lumen tube comprises at least two independent lumens, wherein the diameter of each lumen is 10-80% of the total diameter of the multi-lumen tube; The raw materials for its preparation are the following components in parts by weight: 200-250 parts of polytetrafluoroethylene modified resin; 20-50 parts of filler; 30-50 parts of solvent oil; The polytetrafluoroethylene modified resin is prepared by mixing and modifying polytetrafluoroethylene resin, glycidyl methacrylate, hexafluorobutyl methacrylate and carbon fiber; The specific modification steps of the polytetrafluoroethylene modified resin are as follows: a. Pretreatment: First, heat the polytetrafluoroethylene resin at 320-360℃ until it is molten, then connect the electrodes, control the voltage to 100-200V, and pass the current to 0.1-0.2A, and treat for 30-60s to obtain the activated polytetrafluoroethylene resin; b. Modification treatment: add glycidyl methacrylate, hexafluorobutyl methacrylate and carbon fiber to the activated polytetrafluoroethylene resin in sequence, and mix them at 80-120°C under closed conditions for 15-30 minutes to obtain polytetrafluoroethylene modified resin.

2. The polytetrafluoroethylene multi-lumen tube according to claim 1, characterized in that: The polytetrafluoroethylene modified resin is prepared by mixing and modifying polytetrafluoroethylene resin, glycidyl methacrylate, hexafluorobutyl methacrylate and carbon fiber in a weight ratio of 1:(0.12-0.18):(0.20-0.30):(0.15-0.30).

3. The polytetrafluoroethylene multi-lumen tube according to claim 1, characterized in that: The solvent oil is an isoparaffin solvent oil, which is selected from one or more of D40, D60, D80 and D95.

4. The method for preparing a polytetrafluoroethylene multi-lumen tube according to any one of claims 1 to 3, characterized in that: The following steps are involved: S1. Raw material mixing: Grind and sieve the polytetrafluoroethylene modified resin, then mix with the filler and auxiliary oil in corresponding parts by weight, heat and mature, and prepare a matured powder; S2. Pressing and sintering: first add the matured powder in S1 into the mold, then press, exhaust, and maintain the pressure, and then heat and sinter to obtain the sintered material; S3. Cooling and molding: After the sintered material is cooled to room temperature, it is taken out from the mold to obtain a polytetrafluoroethylene multi-lumen tube.

5. The method for preparing a polytetrafluoroethylene multi-lumen tube according to claim 4, characterized in that: The specific steps are as follows: S1. Raw material mixing: first grind the corresponding weight of polytetrafluoroethylene modified resin, pass it through a 300μm sieve, and then mix it with the filler and auxiliary oil in corresponding parts by weight, heat it to 40-50°C, and mature it for 6-12 hours to obtain a matured powder; S2. Pressing and sintering: Add the sintered powder into the mold, apply a pressure of 30-45 MPa, and exhaust 3-5 times. Control the pressure at 45-60 MPa and maintain the pressure for 60-90 minutes. Then raise the temperature to 350-400°C and sinter for 10-24 hours to obtain a sintered rough blank. S3. Cooling treatment: Take out the sintered rough blank from the mold, pass liquid cooling to the surface and cavity of the sintered rough blank in sections, with a liquid flow rate of 0.15-0.25L / min. After cooling to room temperature, the polytetrafluoroethylene multi-lumen tube can be obtained.

6. The method for preparing a polytetrafluoroethylene multi-lumen tube according to claim 5, characterized in that: The specific steps of S3 are as follows: First, glycidyl methacrylate is introduced into the surface and cavity of the sintered rough blank for cooling for 5-10 minutes at a flow rate of 0.15-0.20 L / min; then cooling water is introduced at a flow rate of 0.20-0.25 L / min until it cools to room temperature, thereby obtaining a polytetrafluoroethylene multi-lumen tube.

7. The method for preparing a polytetrafluoroethylene multi-lumen tube according to claim 6, characterized in that: Before the sintered rough blank is subjected to the S3 cooling treatment, it is also subjected to the electric activation treatment. The specific steps are as follows: After taking out the sintered rough blank from the mold, first connect electrodes at both ends of the sintered rough blank, control the voltage to 200-300V, and pass the current to 0.2-0.3A for 45-60s to obtain the activated sintered rough blank; Then, glycidyl methacrylate is introduced into the surface and cavity of the activated sintered rough blank for cooling for 5-10 minutes at a flow rate of 0.15-0.20 L / min; Then, cooling water is introduced at a flow rate of 0.20-0.25 L / min until the tube is cooled to room temperature, thereby obtaining a polytetrafluoroethylene multi-lumen tube.

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