CN116059849A - Polytetrafluoroethylene compound and porous membrane thereof, preparation method and application - Google Patents
Polytetrafluoroethylene compound and porous membrane thereof, preparation method and application Download PDFInfo
- Publication number
- CN116059849A CN116059849A CN202111281846.3A CN202111281846A CN116059849A CN 116059849 A CN116059849 A CN 116059849A CN 202111281846 A CN202111281846 A CN 202111281846A CN 116059849 A CN116059849 A CN 116059849A
- Authority
- CN
- China
- Prior art keywords
- component
- polytetrafluoroethylene
- groups
- porous membrane
- polytetrafluoroethylene composite
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
- -1 Polytetrafluoroethylene Polymers 0.000 title claims abstract description 105
- 229920001343 polytetrafluoroethylene Polymers 0.000 title claims abstract description 105
- 239000004810 polytetrafluoroethylene Substances 0.000 title claims abstract description 105
- 239000012528 membrane Substances 0.000 title claims abstract description 48
- 150000001875 compounds Chemical class 0.000 title claims abstract description 9
- 238000002360 preparation method Methods 0.000 title claims abstract description 9
- 239000002131 composite material Substances 0.000 claims abstract description 58
- 238000001125 extrusion Methods 0.000 claims abstract description 26
- 239000011347 resin Substances 0.000 claims abstract description 26
- 229920005989 resin Polymers 0.000 claims abstract description 26
- 230000035699 permeability Effects 0.000 claims abstract description 13
- 239000000463 material Substances 0.000 claims abstract description 9
- 238000002156 mixing Methods 0.000 claims description 25
- 238000001816 cooling Methods 0.000 claims description 24
- 238000000034 method Methods 0.000 claims description 20
- 238000009998 heat setting Methods 0.000 claims description 19
- 239000003350 kerosene Substances 0.000 claims description 15
- 238000003490 calendering Methods 0.000 claims description 14
- 230000006835 compression Effects 0.000 claims description 10
- 238000007906 compression Methods 0.000 claims description 10
- 238000001914 filtration Methods 0.000 claims description 9
- 230000002457 bidirectional effect Effects 0.000 claims description 5
- 230000008569 process Effects 0.000 claims description 5
- 230000036541 health Effects 0.000 claims description 4
- 238000003756 stirring Methods 0.000 claims description 3
- 238000005096 rolling process Methods 0.000 claims description 2
- 238000004519 manufacturing process Methods 0.000 claims 5
- 239000006185 dispersion Substances 0.000 claims 1
- 238000006116 polymerization reaction Methods 0.000 claims 1
- 230000000903 blocking effect Effects 0.000 abstract description 2
- 239000002994 raw material Substances 0.000 description 8
- 230000004888 barrier function Effects 0.000 description 6
- 239000000835 fiber Substances 0.000 description 6
- 230000000052 comparative effect Effects 0.000 description 5
- 239000000203 mixture Substances 0.000 description 5
- 239000000843 powder Substances 0.000 description 5
- 230000001360 synchronised effect Effects 0.000 description 5
- CNPVJWYWYZMPDS-UHFFFAOYSA-N 2-methyldecane Chemical compound CCCCCCCCC(C)C CNPVJWYWYZMPDS-UHFFFAOYSA-N 0.000 description 4
- 150000003839 salts Chemical class 0.000 description 4
- 238000001878 scanning electron micrograph Methods 0.000 description 3
- FAPWRFPIFSIZLT-UHFFFAOYSA-M Sodium chloride Chemical group [Na+].[Cl-] FAPWRFPIFSIZLT-UHFFFAOYSA-M 0.000 description 2
- 230000007774 longterm Effects 0.000 description 2
- 239000011148 porous material Substances 0.000 description 2
- 238000003860 storage Methods 0.000 description 2
- 238000009423 ventilation Methods 0.000 description 2
- 206010070834 Sensitisation Diseases 0.000 description 1
- 230000006978 adaptation Effects 0.000 description 1
- 230000032683 aging Effects 0.000 description 1
- 230000010485 coping Effects 0.000 description 1
- 230000007123 defense Effects 0.000 description 1
- 238000012674 dispersion polymerization Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 230000005611 electricity Effects 0.000 description 1
- 238000000635 electron micrograph Methods 0.000 description 1
- 230000007613 environmental effect Effects 0.000 description 1
- 238000002474 experimental method Methods 0.000 description 1
- 210000001724 microfibril Anatomy 0.000 description 1
- 239000012982 microporous membrane Substances 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 231100000957 no side effect Toxicity 0.000 description 1
- 231100000956 nontoxicity Toxicity 0.000 description 1
- 239000013618 particulate matter Substances 0.000 description 1
- 238000003825 pressing Methods 0.000 description 1
- 230000001681 protective effect Effects 0.000 description 1
- 230000005180 public health Effects 0.000 description 1
- 230000008313 sensitization Effects 0.000 description 1
- 239000011780 sodium chloride Substances 0.000 description 1
- 230000003068 static effect Effects 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
- 239000004753 textile Substances 0.000 description 1
- 238000009827 uniform distribution Methods 0.000 description 1
- 238000005406 washing Methods 0.000 description 1
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 1
Images
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D71/00—Semi-permeable membranes for separation processes or apparatus characterised by the material; Manufacturing processes specially adapted therefor
- B01D71/06—Organic material
- B01D71/30—Polyalkenyl halides
- B01D71/32—Polyalkenyl halides containing fluorine atoms
- B01D71/36—Polytetrafluoroethene
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D67/00—Processes specially adapted for manufacturing semi-permeable membranes for separation processes or apparatus
- B01D67/0002—Organic membrane manufacture
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D69/00—Semi-permeable membranes for separation processes or apparatus characterised by their form, structure or properties; Manufacturing processes specially adapted therefor
- B01D69/12—Composite membranes; Ultra-thin membranes
Landscapes
- Chemical & Material Sciences (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Engineering & Computer Science (AREA)
- Manufacturing & Machinery (AREA)
- Manufacture Of Porous Articles, And Recovery And Treatment Of Waste Products (AREA)
Abstract
The invention relates to the field of polytetrafluoroethylene filter materials, and discloses a polytetrafluoroethylene compound, a porous membrane, a preparation method and application thereof, wherein the polytetrafluoroethylene compound comprises a component A, a component B and a component C; the component A and the component B are polytetrafluoroethylene resins, and the average relative standard density of the component A is larger than that of the component B; and the component C is an extrusion aid. The polytetrafluoroethylene porous membrane provided by the invention has the composite characteristic, and has high blocking efficiency and good air permeability.
Description
Technical Field
The invention relates to the field of polytetrafluoroethylene filter materials, in particular to a polytetrafluoroethylene compound, a porous membrane, a preparation method and application thereof.
Background
The polytetrafluoroethylene porous membrane has the advantages of high tensile strength, large specific surface area, high porosity, good air permeability, high inertia, no toxicity, no side effects such as sensitization and the like, and is widely used in the fields of national defense, aerospace, petrochemical industry, clothing, medical treatment and health and the like. In the field of medical and health, the polytetrafluoroethylene porous membrane has the advantages of high filtering efficiency, water resistance, moisture permeability, repeated use after washing, aging resistance and the like, is widely applied to aspects of medical masks, reusable protective clothing, surgical gowns and the like, and is particularly suitable for being used as strategic materials needing long-term storage. When facing large-scale epidemic situation, the disadvantage of traditional disposable medical protection product is highlighted, for example the shelf life of disposable surgical mask is not enough for two years, the filter performance of the mask can be greatly reduced by the attenuation of static electricity, and the mask is not suitable for strategic reserve, and the productivity is difficult to meet the demand when facing sudden large-scale demand, and meanwhile, the disposable medical textile after a large amount of use can only be burnt to treat, so that serious environmental problems are brought. The disposable medical protection product and the reusable medical protection product coexist for a long time, and the reusable medical protection product has more advantages when coping with the crisis of large-scale public health, and the polytetrafluoroethylene porous membrane is the material capable of meeting the requirement of long-term storage and repeated use.
At present, a biaxial stretching method is a main method for preparing a polytetrafluoroethylene porous membrane, and the microporous membrane prepared by the method has the advantages of small pore diameter, uniform distribution, high porosity and the like. In the last 70 th century, the us Gore company had first adopted a biaxially oriented method to prepare polytetrafluoroethylene porous membranes and has been used until now. The process flow comprises PTFE resin and extrusion aid, mixing, preforming, pushing, calendaring, biaxial stretching, heat setting treatment, longitudinal and transverse stretching, and heat setting treatment to obtain the final film product. Through biaxial stretching, polytetrafluoroethylene forms microporous structure with microfibrils connected to nodes, pore size of 0.1-10 microns, porosity over 80%, wide use temperature range (-200-260 deg.c), small friction coefficient, stable chemical performance, low surface energy, etc. The polytetrafluoroethylene porous membrane relies on pure physical interception to achieve efficient filtration, so that the air permeability of the polytetrafluoroethylene porous membrane is lost while the interception efficiency is improved, and the polytetrafluoroethylene porous membrane cannot simultaneously have the characteristics of high barrier efficiency and good air permeability under the condition of high barrier efficiency.
At present, the polytetrafluoroethylene porous membrane with good barrier efficiency and air permeability is provided, and the technical problem to be solved at present.
Disclosure of Invention
Aiming at the technical problems, the invention provides a polytetrafluoroethylene compound, a porous membrane, and a preparation method and application thereof. The polytetrafluoroethylene porous membrane provided by the invention has the composite characteristic, and has high blocking efficiency and good air permeability.
One of the objects of the present invention is to provide a polytetrafluoroethylene composite comprising a component A, a component B and a component C; the component A and the component B are polytetrafluoroethylene resins, and the average relative standard density of the component A is larger than that of the component B; and the component C is an extrusion aid.
In a preferred embodiment of the present invention,the average relative standard density of the component A and the component B is 2.1-2.2g/cm respectively 3 Between them.
In a preferred embodiment of the invention, the component A has an average relative standard density of 2.161 to 2.2g/cm 3 。
In a preferred embodiment of the invention, the component B has an average relative standard density of from 2.13 to 2.160g/cm 3 。
In a preferred embodiment of the invention, the thermal instability coefficients of the component a and of the component B are each not more than 50.
According to the invention, the ratio is chosen within a wide range, in a preferred embodiment of the invention, the content of component A is 5-90% by weight, the content of component B is 5-90% by weight and the content of component C is 5-50% by weight, relative to the total weight of the polytetrafluoroethylene composite. More preferably, the component A is contained in an amount of 10 to 50% by weight, the component B is contained in an amount of 30 to 70% by weight, and the component C is contained in an amount of 5 to 30% by weight, relative to the total weight of the polytetrafluoroethylene composite.
According to the invention, the component A is present in an amount of 5 to 90% by weight, preferably 10 to 50% by weight, for example 10% by weight, 20% by weight, 30% by weight, 40% by weight, 50% by weight, and any value between 10% by weight and 50% by weight and any interval between any two values, relative to the total weight of the polytetrafluoroethylene composite.
According to the invention, the component B content is 5-90 wt.%, preferably 30-70 wt.%, for example 30 wt.%, 40 wt.%, 50 wt.%, 60 wt.%, 70 wt.%, and any value between 30 wt.% and 70 wt.%, and any interval between any two values, relative to the total weight of the polytetrafluoroethylene composite.
According to the invention, the component C is present in an amount of 5 to 50% by weight, preferably 5 to 30% by weight, for example 5% by weight, 10% by weight, 15% by weight, 20% by weight, 25% by weight, 30% by weight, and any value between 5% by weight and 30% by weight and any interval between any two values, relative to the total weight of the polytetrafluoroethylene composite.
In a preferred embodiment of the present invention, the component a and the component B are each independently selected from polytetrafluoroethylene resins obtained by dispersion polymerization.
The component C may be selected from a plurality of choices, and in a preferred embodiment of the present invention, the component C is selected from at least two of aviation kerosene, white oil, naphtha, isoparaffin and kerosene; preferably, the component C is selected from at least two of aviation kerosene, white oil and isoparaffin. More preferably, the component C is selected from aviation kerosene and isoparaffin, the content of the aviation kerosene is 10-50 wt% and the content of the isoparaffin is 50-90 wt%, based on the total weight of the component C as 100%.
The second object of the invention is to provide a preparation method of the polytetrafluoroethylene composite porous membrane, which comprises the steps of mixing the component A, the component B and the component C.
In a preferred embodiment of the invention, the mixing is carried out under pressure, preferably at a pressure of 0.2-10MPa; and/or, the mixing time is 10-150h.
In a preferred embodiment of the invention, the mixing is non-stirring, preferably rotation of the container to mix the contents of the container, preferably at a speed of 10-200rpm.
In a preferred embodiment of the invention, the mixing is followed by a rest, preferably for a time of 10-20 hours; and/or the standing temperature is 40-80 ℃.
It is still another object of the present invention to provide a polytetrafluoroethylene composite porous membrane prepared from the polytetrafluoroethylene composite described above.
In a preferred embodiment of the present invention, the filtration efficiency of the salt medium of the polytetrafluoroethylene composite porous membrane is not less than 95%; and/or at a pressure of 7kPa, a test area of 20cm 2 The air permeability under the condition is 2-10L/min, preferably 2-5L/min。
The fourth object of the present invention is to provide a method for preparing the polytetrafluoroethylene composite porous membrane, comprising the steps of forming a membrane from the polytetrafluoroethylene composite; preferably, the polytetrafluoroethylene compound is subjected to preforming, pushing extrusion, calendaring, biaxial stretching, heat setting and cooling.
In a more preferred embodiment of the present invention, the process comprises mixing the raw materials of the polytetrafluoroethylene composite described above under pressure, then standing, preforming, extrusion by pressing, calendaring, synchronous or asynchronous biaxial stretching, heat setting, and then cooling.
In a preferred embodiment of the present invention, the conditions of mixing under pressure include: the pressure is 0.2-10MPa, preferably 0.2-3MPa; and/or for a time of from 10 to 150 hours, preferably from 30 to 150 hours. According to the invention, the mixing mode can be selected in various ways, preferably, the mixing is performed by adopting a non-stirring mixing mode, more preferably, the container drives the materials to rotate for mixing, and still more preferably, a low-speed roller is adopted as the mixing means. For the rotational speed, the selection range is wide, preferably 10-200rpm.
According to the present invention, the conditions for standing are widely selected, and in a preferred embodiment of the present invention, the conditions for standing include: for a time of 10-20 hours and/or at a temperature of 40-80 ℃.
According to the invention, the conditions for preforming are selected within a wide range, and in a preferred embodiment of the invention, the preforming is performed at a preforming pressure of 5-50MPa and a dwell time of 10s-10min.
According to the present invention, the condition of the pushing extrusion is selected in a wide range, and in a preferred embodiment of the present invention, the compression ratio of the pushing extrusion is 10 to 200, preferably 10 to 30.
According to the invention, the conditions of the calendering are chosen within a wide range, in a preferred embodiment of the invention the pressure of the calendering is between 0.1 and 10MPa, preferably between 0.5 and 5MPa.
According to the invention, the condition selection range of stretching is wider, and in a preferred embodiment of the invention, the stretching is performed in a bidirectional manner by adopting a mode that longitudinal stretching and transverse stretching are synchronously performed; preferably, the stretching temperature is 20-300 ℃, preferably 150-250 ℃.
According to the invention, the condition selection range is wide, and in a preferred embodiment of the invention, the bidirectional stretching is performed in a mode that longitudinal stretching and transverse stretching are performed asynchronously; preferably, the stretching temperature is 20-300 ℃, preferably 150-250 ℃.
According to the invention, the conditions for heat setting are selected in a wide range, and in a preferred embodiment of the invention, the heat setting temperature is 300-380 ℃ and the heat setting time is 20-300 seconds.
According to the invention, the conditions of the cooling are selected in a wide range, and in a preferred embodiment of the invention, the cooling is carried out at a rate of 5-100 ℃/min.
In a more preferred embodiment of the present invention, the preparation method of the porous polytetrafluoroethylene membrane comprises the steps of mixing, preforming, pushing and extruding, calendaring, synchronous/asynchronous biaxial stretching, heat setting and cooling the raw materials of the polytetrafluoroethylene composite under pressure; preparing a polytetrafluoroethylene porous membrane; mixing under the pressure condition of 0.2-10MPa, standing for 10-20h at 40-80 ℃, and mixing the components in the polytetrafluoroethylene composite to perform under the pressure condition of 5-50MPa for 10s-10min; the pushing extrusion is carried out with a compression ratio of 10-200; the rolling is carried out under the pressure of 0.1-10MPa; the synchronous bidirectional stretching is performed by synchronous longitudinal stretching and transverse stretching, and the stretching temperature is 20-300 ℃; the asynchronous biaxial stretching is sequentially performed by longitudinal stretching and transverse stretching, and the stretching temperature is 20-300 ℃; the heat setting is carried out at the temperature of 300-380 ℃ for 20-300 seconds; the cooling is at a cooling rate of 5-100 ℃ per minute until room temperature is reached.
The fifth purpose of the invention is to provide an application of the polytetrafluoroethylene composite porous membrane in industrial filtration and medical and health protection materials.
Compared with the prior art, the invention has the advantages that:
(1) The polytetrafluoroethylene resin with a plurality of optimized two relative standard densities is mixed for use, so that the product has the composite characteristic and has the advantages of high barrier efficiency and good air permeability. The inventor of the present invention considers that the present invention combines the difference of tensile properties of different raw materials under the same conditions and the difference of microstructure, and in the same stretching process, polytetrafluoroethylene with two components shows the difference of tensile properties to form different fiber structures, and the obtained porous membrane has a composite structure.
(2) The invention adopts the specific composite extrusion aid and two polytetrafluoroethylene raw materials with different densities to prepare, the composite extrusion aid promotes the compatibility of two polytetrafluoroethylene resins with different densities, and the composite material with the advantages is promoted to be obtained, and the economy and the functionality are taken into consideration;
(3) The invention adopts a specific method to mix the preparation raw materials under the pressure condition, so that the composite material with the advantages is obtained, and the possibility is that the mixing under the pressure condition improves and accelerates the mixing property of the extrusion aid and the polytetrafluoroethylene resin, so that the prepared material has the composite characteristic.
(4) The composite material obtained by the method has the advantages of high salt medium filtering efficiency up to 97%, ventilation rate of about 3L/min, high barrier efficiency and good ventilation.
Drawings
FIG. 1 is a scanning electron micrograph of a polytetrafluoroethylene porous membrane obtained in example 8;
FIG. 2 is a scanning electron micrograph of the polytetrafluoroethylene porous membrane obtained in example 6;
FIG. 3 is a scanning electron micrograph of the polytetrafluoroethylene porous membrane obtained in comparative example 1. By comparing fig. 1, 2 and 3, it can be seen that fig. 1 and 2 contain two fibers of larger diameter difference, while fig. 3 only contains fibers of one diameter. It was confirmed that during the same stretching process, the polytetrafluoroethylene of the two components exhibited differentiated stretching properties, forming different fiber structures, and the resulting porous film had a composite structure.
Detailed Description
The present invention is described in detail below with reference to the specific drawings and examples, and it is necessary to point out that the following examples are given for further illustration of the present invention only and are not to be construed as limiting the scope of the present invention, since numerous insubstantial modifications and adaptations of the invention to those skilled in the art will still fall within the scope of the present invention.
(1) Experimental basic equipment: the stretching equipment is a bruker biaxial stretching machine in Germany.
(2) Instrument for measuring experimental data: the relative standard density in the experiments was performed in accordance with GB/T1033.1. Electron micrograph is obtained from Hitachi S4800-SEM, COXEM EM-30AX + Shooting.
In the following examples, some sources of the raw materials of the present invention are described in examples, and other raw materials are commercially available, unless otherwise specified.
Example 1
1kg of polytetrafluoroethylene resin (DuPont 605xt, average relative standard density 2.165), 1kg of polytetrafluoroethylene resin (DuPont 605xt, average relative standard density 2.16), 0.1kg of aviation kerosene (3#), 0.1kg of isoparaffin (Exxon Mobil Isopar G), and the mixture were mixed under 0.5MPa for 30 hours (a sealed pot was rotated at 50rpm for 30 hours so that the resin powder was thoroughly mixed with the extrusion aid), and allowed to stand at 40℃for 10 hours to obtain a polytetrafluoroethylene composite.
Example 2
1kg of polytetrafluoroethylene resin (Shanghai Sanaifu FR203A-2, average relative standard density 2.18), 2kg of polytetrafluoroethylene resin (Japanese Dajin F106, average relative standard density 2.158), 0.4kg of aviation kerosene (5#), 0.1kg of isoparaffin (Exxon Mobil Isopar M), and the mixture were mixed under 0.2MPa for 120 hours (a sealed pot was rotated at 50rpm for 120 hours so that the resin powder was thoroughly mixed with the extrusion aid), and allowed to stand at 80℃for 20 hours to obtain a polytetrafluoroethylene composite.
Example 3
3kg of polytetrafluoroethylene resin (the eastern mountain DF205, average relative standard density of 2.165), 1kg of polytetrafluoroethylene resin (the morning light CGF216Y, average relative standard density of 2.15), 0.8kg of white oil (3#), 1.2kg of aviation kerosene (3#), were mixed under 2MPa for 100 hours (a sealed pot was rotated at 50rpm for 100 hours so that the resin powder was sufficiently mixed with the extrusion aid), and left standing at 60℃for 15 hours to obtain a polytetrafluoroethylene composite.
Example 4
1kg of polytetrafluoroethylene resin (Sichuan morning light CGF216G, average relative standard density 2.162), 4kg of polytetrafluoroethylene resin (DuPont 605xt, average relative standard density 2.16), 0.1kg of aviation kerosene (3#), 0.1kg of isoparaffin (Ekksen Mobil Isopar G), and the mixture were mixed at 0.5MPa for 150 hours (a sealed pot was rotated at 50rpm for 150 hours so that the resin powder was thoroughly mixed with the extrusion aid), and allowed to stand at 80℃for 10 hours to obtain a polytetrafluoroethylene composite.
Example 5
1kg of polytetrafluoroethylene resin (Sichuan morning light CGF216G, average relative standard density 2.162), 1kg of polytetrafluoroethylene resin (Sichuan morning light CGF216Y, average relative standard density 2.15), 0.1kg of naphtha, 0.4kg of isoparaffin (Ekksen Mobil Isopar G) were mixed at 0.5MPa for 50 hours (a sealed pot was rotated at 50rpm for 50 hours so that the resin powder was sufficiently mixed with the extrusion aid), and left to stand at 40℃for 20 hours to obtain a polytetrafluoroethylene composite.
Example 6
The polytetrafluoroethylene composite in example 4 was subjected to preforming (pressure: 10MPa, dwell time: 1 min), push extrusion (compression ratio: 20), calendaring (pressure: 5 MPa), simultaneous biaxial stretching (stretching temperature: 150 ℃) and heat setting (temperature: 300 ℃ for 60 seconds), and cooling (cooling rate: 30 ℃ per minute) to prepare a polytetrafluoroethylene porous membrane.
Example 7
The polytetrafluoroethylene composite in example 5 was subjected to preforming (pressure 5MPa, dwell time 30 s), push extrusion (compression ratio 25), calendaring (pressure 3 MPa), asynchronous biaxial stretching (longitudinal stretching temperature 200 degrees, transverse stretching temperature 70 degrees c), heat setting (temperature 340 degrees c for 30 seconds), and cooling (cooling rate 30 degrees c per minute) to prepare a polytetrafluoroethylene porous membrane.
Example 8
The polytetrafluoroethylene composite in example 1 was subjected to preforming (pressure: 30MPa, dwell time: 3 min), push extrusion (compression ratio: 50), calendaring (pressure: 10 MPa), simultaneous biaxial stretching (stretching temperature: 250 ℃) and heat setting (temperature: 380 ℃ for 20 seconds), and cooling (cooling rate: 50 ℃ per minute) to prepare a polytetrafluoroethylene porous membrane.
Example 9
The polytetrafluoroethylene composite in example 2 was subjected to preforming (pressure: 50MPa, dwell time: 10 s), push extrusion (compression ratio: 10), calendaring (pressure: 0.5 MPa), asynchronous biaxial stretching (longitudinal stretching temperature: 250 ℃ C., transverse stretching temperature: 150 ℃ C.), heat setting (temperature: 300 ℃ C., duration: 300 seconds), and cooling (cooling rate: 15 ℃ C./minute) to prepare a polytetrafluoroethylene porous membrane.
Example 10
The polytetrafluoroethylene composite in example 3 was subjected to preforming (pressure of 15MPa, dwell time of 30 s), push extrusion (compression ratio of 15), calendaring (pressure of 2 MPa), asynchronous biaxial stretching (longitudinal stretching temperature of 300 degrees, transverse stretching temperature of 200 degrees), heat setting (temperature of 320 degrees for 100 seconds), and cooling (cooling rate of 40 degrees c per minute) to prepare a polytetrafluoroethylene porous membrane.
Comparative example 1
2kg of polytetrafluoroethylene resin (DuPont 605xt, average relative standard density of 2.16) and 0.2kg of aviation kerosene were mixed under normal pressure for 50 hours, and allowed to stand at 60 ℃ for 15 hours, to obtain polytetrafluoroethylene composite. The polytetrafluoroethylene porous membrane is prepared through the working procedures of preforming (the pressure is 10MPa, the dwell time is 1 min), pushing extrusion (the compression ratio is 20), calendaring (the pressure is 5 MPa), synchronous biaxial stretching (the stretching temperature is 150 ℃), heat setting (the temperature is 300 ℃ for 60 seconds), and cooling (the cooling rate is 30 ℃ per minute).
Comparative example 2
2kg of polytetrafluoroethylene resin (DF 205, average relative standard density 2.165) and 0.6kg of isoparaffin (Exxon mobil Isopar G) were mixed under normal pressure for 80 hours, and the mixture was allowed to stand at 80℃for 10 hours to obtain a polytetrafluoroethylene composite. The polytetrafluoroethylene porous membrane was prepared by the steps of preforming (pressure 10MPa, dwell time 1 min), push extrusion (compression ratio 20), calendaring (pressure 5 MPa), asynchronous biaxial stretching (longitudinal stretching temperature 300 ℃ C., transverse stretching temperature 150 ℃ C.), heat setting (temperature 300 ℃ C., duration 60 seconds), and cooling (cooling rate 30 ℃ C./min).
Comparative example 3
A polytetrafluoroethylene composite was prepared in the same manner as in example 1 except that the mixture was mixed at normal pressure for 30 hours and left to stand at 40℃for 10 hours to obtain a polytetrafluoroethylene composite. A polytetrafluoroethylene porous membrane was prepared as in example 8.
Test case
The porous membranes prepared in examples 6-10 and comparative examples 1-2 were subjected to a salt medium filtration efficiency test by using the national standard GB/T32610-2016 appendix A method, wherein the test medium is NaCl particulate matter and the test flow is 85L/min; the air permeability of the prepared porous membrane is tested by adopting the national standard GB/T5453-1997 method, the test pressure is 7kPa, and the test area is 20cm 2 . The above test results are shown in Table 1.
TABLE 1
As can be seen from table 1, the filtration efficiency of the salt medium of the polytetrafluoroethylene composite porous membrane in the embodiment of the invention is not less than 95%; at a pressure of 7kPa and a test area of 20cm 2 The air permeability under the condition is more than 2.2L/min. Therefore, the porous membrane obtained by adopting the raw materials with two densities has obvious fibers with different thicknesses in microcosmic view, different fiber structures are formed, and the obtained porous membrane has a composite structure and can achieve both air permeability and barrier effect.
Claims (15)
1. A polytetrafluoroethylene composite comprising a component A, a component B and a component C;
the component A and the component B are polytetrafluoroethylene resins, and the average relative standard density of the component A is larger than that of the component B; and the component C is an extrusion aid.
2. The polytetrafluoroethylene composite according to claim 1, wherein:
the average relative standard density of the component A and the component B is 2.1-2.2g/cm respectively 3 Between them; preferably, the method comprises the steps of,
the average relative standard density of the component A is 2.161-2.2g/cm 3 The method comprises the steps of carrying out a first treatment on the surface of the And/or the number of the groups of groups,
the average relative standard density of the component B is 2.13-2.160g/cm 3 The method comprises the steps of carrying out a first treatment on the surface of the And/or the number of the groups of groups,
the thermal instability coefficients of the component A and the component B are not more than 50 respectively.
3. Polytetrafluoroethylene composite according to claim 1 or 2, characterized in that:
the content of the component A is 5-90 wt%, the content of the component B is 5-90 wt% and the content of the component C is 5-50 wt% relative to the total weight of the polytetrafluoroethylene compound;
preferably, the component A is contained in an amount of 10 to 50% by weight, the component B is contained in an amount of 30 to 70% by weight, and the component C is contained in an amount of 5 to 30% by weight, relative to the total weight of the polytetrafluoroethylene composite.
4. Polytetrafluoroethylene composite according to claim 1 or 2, characterized in that:
the component A and the component B are respectively and independently selected from polytetrafluoroethylene resin obtained by polymerization in a dispersion method; and/or the number of the groups of groups,
the component C is at least two selected from aviation kerosene, white oil, naphtha, isoparaffin and kerosene;
preferably, the component C is selected from at least two of aviation kerosene, white oil and isoparaffin;
more preferably, the component C is selected from aviation kerosene and isoparaffins; most preferably, the aviation kerosene is present in an amount of 10 to 50% by weight and the isoparaffin is present in an amount of 50 to 90% by weight, based on 100% by weight of the total weight of component C.
5. A method of preparing the polytetrafluoroethylene composite as set forth in any one of claims 1-4 comprising mixing the components of component a, component B, and component C.
6. The process according to claim 5, wherein the mixing is carried out under pressure, preferably,
the pressure of the mixing is 0.2-10MPa; and/or, the mixing time is 10-150h;
further preferably, the mixing mode is non-stirring mixing, preferably rotating the container to drive the materials in the container to mix, preferably at a rotating speed of 10-200rpm.
7. The preparation method according to claim 5, characterized in that the mixing comprises a standing, preferably,
standing for 10-20h; and/or the standing temperature is 40-80 ℃.
8. A polytetrafluoroethylene composite porous membrane made from a polytetrafluoroethylene composite comprising the polytetrafluoroethylene composite of any one of claims 1-4.
9. The polytetrafluoroethylene composite porous membrane according to claim 8, wherein:
the filtration efficiency of the saliency medium of the polytetrafluoroethylene composite porous membrane is not less than 95%; and/or the number of the groups of groups,
the polytetrafluoroethylene composite porous membrane has a test area of 20cm under the pressure of 7kPa 2 The air permeability under the condition is 2-10L/min, preferably 2-5L/min.
10. The method for producing a polytetrafluoroethylene composite porous membrane according to claim 8 or 9, comprising forming a membrane from the polytetrafluoroethylene composite; preferably, the polytetrafluoroethylene compound is subjected to preforming, pushing extrusion, calendaring, biaxial stretching, heat setting and cooling.
11. The method of manufacturing according to claim 10, wherein:
the preforming pressure is 5-50MPa, and the pressure maintaining time is 10s-10min; and/or the number of the groups of groups,
the compression ratio of the pushing extrusion is 10-200; and/or the number of the groups of groups,
the pressure of the rolling is 0.1-10MPa.
12. The method of manufacturing according to claim 10, wherein:
the bidirectional stretching is performed by adopting a mode that longitudinal stretching and transverse stretching are performed synchronously; preferably, the stretching temperature is 20-300 ℃.
13. The method of manufacturing according to claim 10, wherein:
the bidirectional stretching is performed in a mode that longitudinal stretching and transverse stretching are performed asynchronously; preferably, the stretching temperature is 20-300 ℃.
14. The method of manufacturing according to claim 10, wherein:
the heat setting temperature is 300-380 ℃, and the heat setting time is 20-300 seconds; and/or the number of the groups of groups,
the cooling rate of the cooling is 5-100 ℃/min.
15. Use of the polytetrafluoroethylene composite porous membrane of claim 8 or 9 in industrial filtration, medical and health protection materials.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202111281846.3A CN116059849B (en) | 2021-11-01 | 2021-11-01 | Polytetrafluoroethylene compound and porous membrane thereof, preparation method and application |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202111281846.3A CN116059849B (en) | 2021-11-01 | 2021-11-01 | Polytetrafluoroethylene compound and porous membrane thereof, preparation method and application |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN116059849A true CN116059849A (en) | 2023-05-05 |
| CN116059849B CN116059849B (en) | 2024-10-15 |
Family
ID=86182455
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202111281846.3A Active CN116059849B (en) | 2021-11-01 | 2021-11-01 | Polytetrafluoroethylene compound and porous membrane thereof, preparation method and application |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN116059849B (en) |
Citations (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5064593A (en) * | 1989-12-07 | 1991-11-12 | Daikin Industries Ltd. | Process for producing multilayer polytetrafluoroethylene porous membrane |
| CN1107383A (en) * | 1994-02-26 | 1995-08-30 | 宫香山 | Porous membrane preparation with polytetrafluorethylene |
| JP2003190749A (en) * | 2001-12-26 | 2003-07-08 | Nitto Denko Corp | Production method for porous polytetrafluoroethylene film composite |
| CN1775847A (en) * | 2005-12-05 | 2006-05-24 | 浙江理工大学 | Method for preparing PTFE film material for air degerming |
| CN103987449A (en) * | 2011-12-05 | 2014-08-13 | 住友电工超效能高分子股份有限公司 | Porous polytetrafluoroethylene resin film, porous polytetrafluoroethylene resin film composite, and separation membrane element |
| CN108912359A (en) * | 2018-06-12 | 2018-11-30 | 苏州优可发新材料科技有限公司 | A kind of high bubble pressure microporous teflon membran and preparation method thereof |
| KR20190060586A (en) * | 2017-11-24 | 2019-06-03 | 주식회사 엘지화학 | Preparation method of porous fluorine resin sheet |
| CN110054855A (en) * | 2019-02-18 | 2019-07-26 | 浙江格尔泰斯环保特材科技股份有限公司 | A kind of polytetrafluoroethylene (PTFE) bubble point film and preparation method thereof |
| CN112044278A (en) * | 2020-09-14 | 2020-12-08 | 浙江格尔泰斯环保特材科技股份有限公司 | Preparation method of PTFE microporous membrane with multilayer structure |
| CN113043632A (en) * | 2021-03-09 | 2021-06-29 | 山东森荣新材料股份有限公司 | Preparation method of polytetrafluoroethylene high-strength microporous membrane |
-
2021
- 2021-11-01 CN CN202111281846.3A patent/CN116059849B/en active Active
Patent Citations (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5064593A (en) * | 1989-12-07 | 1991-11-12 | Daikin Industries Ltd. | Process for producing multilayer polytetrafluoroethylene porous membrane |
| CN1107383A (en) * | 1994-02-26 | 1995-08-30 | 宫香山 | Porous membrane preparation with polytetrafluorethylene |
| JP2003190749A (en) * | 2001-12-26 | 2003-07-08 | Nitto Denko Corp | Production method for porous polytetrafluoroethylene film composite |
| CN1775847A (en) * | 2005-12-05 | 2006-05-24 | 浙江理工大学 | Method for preparing PTFE film material for air degerming |
| CN103987449A (en) * | 2011-12-05 | 2014-08-13 | 住友电工超效能高分子股份有限公司 | Porous polytetrafluoroethylene resin film, porous polytetrafluoroethylene resin film composite, and separation membrane element |
| KR20190060586A (en) * | 2017-11-24 | 2019-06-03 | 주식회사 엘지화학 | Preparation method of porous fluorine resin sheet |
| CN108912359A (en) * | 2018-06-12 | 2018-11-30 | 苏州优可发新材料科技有限公司 | A kind of high bubble pressure microporous teflon membran and preparation method thereof |
| CN110054855A (en) * | 2019-02-18 | 2019-07-26 | 浙江格尔泰斯环保特材科技股份有限公司 | A kind of polytetrafluoroethylene (PTFE) bubble point film and preparation method thereof |
| CN112044278A (en) * | 2020-09-14 | 2020-12-08 | 浙江格尔泰斯环保特材科技股份有限公司 | Preparation method of PTFE microporous membrane with multilayer structure |
| CN113043632A (en) * | 2021-03-09 | 2021-06-29 | 山东森荣新材料股份有限公司 | Preparation method of polytetrafluoroethylene high-strength microporous membrane |
Also Published As
| Publication number | Publication date |
|---|---|
| CN116059849B (en) | 2024-10-15 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| EP0850265B1 (en) | Strong, air permeable membranes of polytetrafluoroethylene | |
| AU2005233004C1 (en) | Porous water filtration membrane of vinylidene fluoride resin hollow fiber and process for production thereof | |
| CA1271907A (en) | Hollow fiber membrane made by melt-spinning polyolefin/filler composition | |
| KR101162403B1 (en) | Gas separation membrane | |
| CN111151149B (en) | Preparation method of polytetrafluoroethylene microporous membrane | |
| JPH10512620A (en) | Co-continuous blend of fluoropolymer and thermoplastic polymer and method of manufacture | |
| JPH0240254B2 (en) | ||
| AU2012274402B2 (en) | Porous polymer film and production method for porous polymer film | |
| JPS5964640A (en) | Microporous sheet material | |
| WO2002089955A1 (en) | Preparation of microporous films from immiscible blends via melt processing and stretching | |
| EP0574588A1 (en) | Biaxially oriented high-molecular polyethylene film and production thereof, and surface-modified, biaxially oriented high-molecular polyethylene film and production thereof | |
| CN101879416A (en) | Method for preparing cellulose composite sodium filter membrane | |
| US5358780A (en) | Breathable water-resistant fabrics | |
| JPH0317859B2 (en) | ||
| CN116059849B (en) | Polytetrafluoroethylene compound and porous membrane thereof, preparation method and application | |
| US20240123411A1 (en) | Preparation method for high-moisture-permeability fluorine-containing super-oleophobic microporous membrane | |
| AU697548B2 (en) | Gas permeable fabric | |
| CN104607061A (en) | A method of preparing a poly(ethene-co-tetrafluoroethene) film | |
| EP0077691B1 (en) | Supported reverse osmosis membranes | |
| CA1311591C (en) | Formation of halogenated polymeric microporous membranes having improved strength properties | |
| JPH09169867A (en) | Microporous film and its production | |
| JP3009495B2 (en) | Polyolefin microporous membrane and method for producing the same | |
| CN117946483A (en) | Antistatic polytetrafluoroethylene compound, antistatic porous membrane, and preparation methods and applications thereof | |
| CN114917766A (en) | Preparation method of PTFE composite membrane | |
| JP3914302B2 (en) | Method for producing porous film made of polytetrafluoroethylene |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant |