Polytetrafluoroethylene Composite Filter Material

Abstract

The present invention relates to the field of air filtration, in particular to a polytetrafluoroethylene composite filter material. The polytetrafluoroethylene composite filter material comprises a supporting layer and a polytetrafluoroethylene film layer, wherein the supporting layer is a silver-plated carbon nanomaterial-modified meltblown nonwoven fabric. The polytetrafluoroethylene composite filter material is prepared by fiberizing a resin material modified by silver-plated carbon nanomaterial on the surface of a polytetrafluoroethylene film by a melt-blowing method. The polytetrafluoroethylene composite filter material of the present invention combines filtering and sterilizing functions, has higher filtering efficiency and filtering precision, has the functions of sterilizing and killing viruses, has a good isolation effect, and greatly prolongs the service life of the filter material.

Claims

1. A polytetrafluoroethylene composite filter material, characterized by comprising a supporting layer and a polytetrafluoroethylene film layer, wherein the supporting layer is a silver-plated carbon nanomaterial-modified meltblown nonwoven fabric.

2. The polytetrafluoroethylene composite filter material according to claim 1, wherein the supporting layer has a thickness of 80 to 130 μm.

3. The polytetrafluoroethylene composite filter material according to claim 1, wherein the silver-plated carbon nanomaterial-modified meltblown nonwoven fabric is one or more of silver-plated carbon nanomaterial-modified PP meltblown nonwoven fabric, silver-plated carbon nanomaterial-modified PET meltblown nonwoven fabric and silver-plated carbon nanomaterial-modified PA meltblown nonwoven fabric.

4. The polytetrafluoroethylene composite filter material according to claim 1, wherein the silver-plated carbon nanomaterial is silver-plated graphene oxide, silver-plated single-walled carbon nanotubes or silver-plated fullerene.

5. The polytetrafluoroethylene composite filter material according to claim 1, wherein the silver-plated carbon nanomaterial is prepared by plating silver on the carbon nanomaterial substrate by pulsed laser deposition.

6. The polytetrafluoroethylene composite filter material according to claim 5, wherein the pulsed laser deposition is performed at a pulse frequency of 10 to 15 Hz, the temperature of the substrate during the deposition process is 380 to 500° C., and the time for deposition is 10 to 15 min.

7. The polytetrafluoroethylene composite filter material according to claim 1, wherein the polytetrafluoroethylene film has a thickness of 5 to 50 μm, an average pore diameter of 0.1 to and a porosity of 80% to 90%.

8. The polytetrafluoroethylene composite filter material according to claim 1, wherein the polytetrafluoroethylene composite filter material is prepared by fiberizing a resin material modified by silver-plated carbon nanomaterials on the surface of a polytetrafluoroethylene film by a melt-blowing method, and preferably, the resin material is PP resin, PET resin or PA resin.

9. The polytetrafluoroethylene composite filter material according to claim 8, wherein the resin material modified by silver-plated carbon nanomaterial is prepared by uniformly mixing the silver-plated carbon nanomaterial and the resin material at a mass ratio of (3 to 8):100.

10. The polytetrafluoroethylene composite filter material according to claim 8, wherein the polytetrafluoroethylene film is a polytetrafluoroethylene film pretreated by radiation treatment, plasma treatment or high temperature treatment.

11. The polytetrafluoroethylene composite filter material according to claim 2, wherein the silver-plated carbon nanomaterial-modified meltblown nonwoven fabric is one or more of silver-plated carbon nanomaterial-modified PP meltblown nonwoven fabric, silver-plated carbon nanomaterial-modified PET meltblown nonwoven fabric and silver-plated carbon nanomaterial-modified PA meltblown nonwoven fabric.

12. The polytetrafluoroethylene composite filter material according to claim 2, wherein the silver-plated carbon nanomaterial is silver-plated graphene oxide, silver-plated single-walled carbon nanotubes or silver-plated fullerene.

13. The polytetrafluoroethylene composite filter material according to claim 3, wherein the silver-plated carbon nanomaterial is silver-plated graphene oxide, silver-plated single-walled carbon nanotubes or silver-plated fullerene.

14. The polytetrafluoroethylene composite filter material according to claim 2, wherein the silver-plated carbon nanomaterial is prepared by plating silver on the carbon nanomaterial substrate by pulsed laser deposition.

15. The polytetrafluoroethylene composite filter material according to claim 3, wherein the silver-plated carbon nanomaterial is prepared by plating silver on the carbon nanomaterial substrate by pulsed laser deposition.

16. The polytetrafluoroethylene composite filter material according to claim 4, wherein the silver-plated carbon nanomaterial is prepared by plating silver on the carbon nanomaterial substrate by pulsed laser deposition.

17. The polytetrafluoroethylene composite filter material according to claim 2, wherein the polytetrafluoroethylene film has a thickness of 5 to 50 μm, an average pore diameter of 0.1 to 1 μm, and a porosity of 80% to 90%.

18. The polytetrafluoroethylene composite filter material according to claim 3, wherein the polytetrafluoroethylene film has a thickness of 5 to 50 μm, an average pore diameter of 0.1 to 1 μm, and a porosity of 80% to 90%.

19. The polytetrafluoroethylene composite filter material according to claim 4, wherein the polytetrafluoroethylene film has a thickness of 5 to 50 μm, an average pore diameter of 0.1 to 1 μm, and a porosity of 80% to 90%.

20. The polytetrafluoroethylene composite filter material according to claim 5, wherein the polytetrafluoroethylene film has a thickness of 5 to 50 μm, an average pore diameter of 0.1 to 1 μm, and a porosity of 80% to 90%.

Description

EXAMPLE 1

[0027] Example 1 provides a polytetrafluoroethylene composite filter material used for air purification comprising a supporting layer and a polytetrafluoroethylene film layer, wherein the supporting layer is a PP meltblown nonwoven fabric modified silver-plated single-walled carbon nanotubes, with a thickness of 100 μm.

[0028] The polytetrafluoroethylene composite filter material was prepared by the following method:

[0029] (1) pretreatment of single-walled carbon nanotubes: 5 g of single-walled carbon nanotubes were weighed and added into a three-necked flask containing 200 mL of mixed solution of concentrated nitric acid and concentrated sulfuric acid (at mass ratio of 70:30), and the resultant was heated to reflux in an oil bath at 120° C. for 5h, then subjected to suction filtration after cooling, washing with deionized water, and drying;

[0030] (2) silver plating: the silver plating was performed at room temperature in N.sub.2 atmosphere, with high purity metallic silver as the target, pre-treated single-walled carbon nanotubes as the substrate, under the following conditions: the pulse frequency of pulsed laser was 10 Hz, the temperature of the substrate was maintained at 400° C. during the deposition process, and the time for deposition was 10 min;

[0031] (3) the silver-plated single-walled carbon nanotubes obtained in step (2) was uniformly mixed with PP resin at a mass ratio of 3:100 to obtain PP resin modified by 3% silver-plated single-walled carbon nanotubes;

[0032] (4) pretreatment of the polytetrafluoroethylene film: the polytetrafluoroethylene film was added into a plasma generator, the system of the plasma generator was vacuumized to 1.33 Pa firstly, then trace amount of argon was introduced to adjust the vacuum degree to 133.32 Pa, and the plasma generator was electrified to act for 15 min;

[0033] (5) combination: a layer of polytetrafluoroethylene film treated by low temperature plasma was laid on the receiving roller of the melt-blown nonwoven fabric making machine, and PP resin modified with 3% silver-plated single-walled carbon nanotubes was extruded in molten state from the spinneret orifice of the meltblowing machine, and was uniformly jetted on one side of the polytetrafluoroethylene film under the high-speed traction of air flow to obtain the polytetrafluoroethylene composite filter material, wherein the temperature of the hot air was 200° C., the receiving distance was 12 cm, the traverse speed was 0.5 m/min, and the extrusion volume was 40 g/min.

Example 2

[0034] Example 2 provides a polytetrafluoroethylene composite filter material used for air purification comprising a supporting layer and a polytetrafluoroethylene film layer, wherein the supporting layer is a PP meltblown nonwoven fabric modified by silver-plated graphene oxide, with a thickness of 100 μm.

[0035] The polytetrafluoroethylene composite filter material was prepared by the following method:

[0036] (1) pretreatment of graphene oxide: 2 g of graphene oxide were weighed and added into a three-necked flask containing 200 mL of a mixed solution of concentrated nitric acid and concentrated sulfuric acid (at a mass ratio of 70:30), and the resultant was heated to reflux it in an oil bath at 120° C. for 5h, then subjected to suction filtration after cooling, washing with deionized water, and drying;

[0037] (2) silver plating: the silver plating was performed at room temperature in N.sub.2 atmosphere, with high-purity metallic silver as target, pre-treated graphene oxide as substrate, under the following conditions: the pulse frequency of pulsed laser was 10 Hz, the temperature of substrate was maintained at 400° C. during the deposition process, and the time for deposition was 10 min;

[0038] (3) the silver-plated graphene oxide obtained in step (2) was uniformly mixed with PP resin at a mass ratio of 3:100 to obtain PP resin modified by 3% silver-plated graphene oxide;

[0039] (4) pretreatment of polytetrafluoroethylene film: the polytetrafluoroethylene film was added into a plasma generator, the system of the plasma generator was vacuumized to 1.33 Pa first, then trace amount of argon was introduced to adjust the vacuum degree to 133.32 Pa, and the plasma generator was electrified to act for 15 min;

[0040] (5) combination: a layer of polytetrafluoroethylene film after plasma treatment was laid on the receiving roller of the melt-blown nonwoven fabric making machine, and PP resin modified with 3% of silver-plated graphene oxide was extruded in molten state from the spinneret orifice of the meltblowing machine, and was uniformly jetted on one side of the polytetrafluoroethylene film under the high-speed traction of air flow to obtain the polytetrafluoroethylene composite filter material, wherein the temperature of the hot air was 200° C., the receiving distance was 12 cm, and the traverse speed was 0.5 m/min, and the extrusion volume was 40 g/min.

Example 3

[0041] Example 3 provides a polytetrafluoroethylene composite filter material used for air purification comprising a supporting layer and a polytetrafluoroethylene film layer, wherein the supporting layer is a PP meltblown nonwoven fabric modified by silver-plated fullerene, with a thickness of 100 μm.

[0042] The polytetrafluoroethylene composite filter material was prepared by the following method:

[0043] (1) pretreatment of fullerene: 5 g of fullerene were weighed and added into a three-necked flask containing 200 mL of a mixed solution of concentrated nitric acid and concentrated sulfuric acid (at a mass ratio: 70:30), and the resultant was heated to reflux in an oil bath at 120° C. for 5h, then subjected to suction filtration after cooling, washing with deionized water, and drying;

[0044] (2) silver plating: the silver plating was performed at room temperature in N.sub.2 atmosphere, with high-purity metallic silver as target, pre-treated fullerene as substrate, under the following conditions: the pulse frequency of pulsed laser was 10 Hz, the temperature of the substrate was maintained at 400° C. during the deposition process, and the time for deposition was 10 min;

[0045] (3) the silver-plated fullerene obtained in step (2) was uniformly mixed with PP resin at a mass ratio of 3:100 to obtain PP resin modified by 3% silver-plated fullerene;

[0046] (4) pretreatment of polytetrafluoroethylene film: the polytetrafluoroethylene film was placed in propylene monomers, and then irradiated with γ-ray for 15 min;

[0047] (5) combination: a layer of polytetrafluoroethylene film after radiation treatment was laid on the receiving roller of the melt-blown nonwoven fabric making machine, and PP resin modified with 3% of silver-plated fullerene was extruded in molten state from the spinneret orifice of the meltblowing machine, and was uniformly jetted on one side of the polytetrafluoroethylene film under the high-speed traction of air flow to obtain the polytetrafluoroethylene composite filter material, wherein the temperature of hot air was 200° C., the receiving distance was 12 cm, and the traverse speed was 0.5 m/min, and the extrusion volume was 40 g/min.

Example 4

[0048] Example 4 provides a polytetrafluoroethylene composite filter material used for air purification comprising a supporting layer and a polytetrafluoroethylene film layer, wherein the supporting layer is a PP meltblown nonwoven fabric modified by silver-plated graphene oxide, with a thickness of 85 μm.

[0049] The polytetrafluoroethylene composite filter material was prepared by the following method:

[0050] Steps (1) to (2) were the same as those in Example 2.

[0051] (3) the silver-plated graphene oxide obtained in the step (2) was uniformly mixed with PP resin at a mass ratio of 5:100 to obtain PP resin modified by 5% silver-plated graphene oxide;

[0052] (4) pretreatment of the polytetrafluoroethylene film: the polytetrafluoroethylene film was added into a plasma generator, the system of the plasma generator was vacuumized to 1.33 Pa firstly, then trace amount of argon was introduced to adjust the vacuum degree to 133.32 Pa, and the plasma generator was electrified to act for 15 min;

[0053] (5) combination: a layer of polytetrafluoroethylene film after plasma treatment was laid on the receiving roller of the melt-blown nonwoven fabric making machine, and PET resin modified with 5% of silver-plated graphene oxide was extruded in molten state from the spinneret orifice of the meltblowing machine, and was uniformly jetted on one side of the polytetrafluoroethylene film under the high-speed traction of air flow to obtain the polytetrafluoroethylene composite filter material, wherein the temperature of the hot air was 200° C., the receiving distance was 12 cm, and the traverse speed was 0.5 m/min, and the extrusion volume was 30 g/min.

Example 5

[0054] Example 5 provides a polytetrafluoroethylene composite filter material used for air purification comprising a supporting layer and a polytetrafluoroethylene film layer, wherein the supporting layer is a PA meltblown nonwoven fabric modified by silver-plated single-walled carbon nanotubes, with a thickness of 120 μm.

[0055] The polytetrafluoroethylene composite filter material was prepared by the following method:

[0056] Steps (1) to (2) were the same as those in Example 2.

[0057] (3) the silver-plated graphene oxide obtained in step (2) was uniformly mixed with PA resin at a mass ratio of 8:100 to obtain PA resin modified by 8% silver-plated graphene oxide;

[0058] (4) pretreatment of polytetrafluoroethylene film: the polytetrafluoroethylene film was placed in propylene monomers, and then irradiated with γ-ray for 15 min;

[0059] (5) combination: a layer of polytetrafluoroethylene film after radiation treatment was laid on the receiving roller of the melt-blown nonwoven fabric making machine, and PA resin modified with 8% silver-plated single-walled carbon nanotubes was extruded in molten state from the spinneret orifice of the meltblowing machine, and was uniformly jetted on one side of the polytetrafluoroethylene film under the high-speed traction of air flow to obtain the polytetrafluoroethylene composite filter material, wherein the temperature of the hot air was 200° C., the receiving distance was 12 cm, and the traverse speed was 0.5 m/min, and the extrusion volume was 52 g/min.

Comparative Example 1

[0060] Comparative Example 1 provides a polytetrafluoroethylene composite filter material used for air purification comprising a supporting layer, a silver-plated graphene layer and a polytetrafluoroethylene film layer, wherein the supporting layer is PP meltblown nonwoven fabric with a thickness of 100 μm, and the silver-plated graphene layer has a thickness of 5 μm.

[0061] The polytetrafluoroethylene composite filter material was prepared by the following method:

[0062] (1) preparation of PP meltblown nonwoven fabric: PP resin was extruded in molten state from a spinneret orifice of a meltblowing machine, and was uniformly jetted on a receiving roller under the high-speed traction of air flow to obtain PP meltblown nonwoven fabric, wherein the temperature of the hot air was 200° C., the receiving distance was 12 cm, the traverse speed was 0.5 m/min, and the extrusion amount was 40 g/min;

[0063] (2) preparation of silver-plated graphene oxide film: silver was plated on graphene oxide by the same steps as the steps (1) to (2) in Example 2, and then the obtained silver-plated graphene oxide was dissolved in absolute ethanol solution, and then subjected to suction filtration so as to obtain the silver-plated graphene oxide film;

[0064] (3) pretreatment of polytetrafluoroethylene film: the polytetrafluoroethylene film was added into a plasma generator, the system of the plasma generator was vacuumized to 1.33 Pa first, then trace amount of argon was introduced to adjust the vacuum degree to 133.32 Pa, and the plasma generator was electrified to act for 15 min;

[0065] (4) PP meltblown nonwoven fabric, graphene film and polytetrafluoroethylene film were laminated and combined to obtain polytetrafluoroethylene composite filter material.

Comparative Example 2

[0066] Comparative Example 2 provides a polytetrafluoroethylene composite filter material used for air purification comprising a supporting layer and a polytetrafluoroethylene film layer, wherein the supporting layer is a PP meltblown nonwoven fabric modified by silver-plated graphene oxidem with a thickness of 100 μm.

[0067] The polytetrafluoroethylene composite filter material was prepared by the following method:

[0068] Steps (1) to (4) were the same as those in Example 2.

[0069] (5) combination: PP resin modified by 3% silver-plated graphene oxide was extruded in molten state from the spinneret orifice of the meltblowing machine, and was uniformly jetted on the receiving roller under the high-speed traction of air flow to obtain PP meltblown nonwoven fabric, wherein the temperature of the hot air was 200° C., the receiving distance was 12 cm, the traverse speed was 0.5 m/min, and the extrusion amount was 40 g/min. PUR adhesive was uniformly coated on one side of the obtained silver-plated graphene oxide-modified PP meltblown nonwoven fabric with a coating amount of 1.6 g/m.sup.2, the adhesive coating surface of the silver-plated graphene oxide-modified PP meltblown nonwoven fabric was overlapped with the low-temperature plasma treated polytetrafluoroethylene film, subjected to pressurizing and heating treatment, carried out at a temperature of 55° C. under a pressure of 2.1 MPa, to make them adhere to each other, and finally subjected to curing treatment at 58° C. for 10h to obtain the polytetrafluoroethylene composite filter material of the present Comparative Example.

Experimental Example

[0070] The air permeability, filtering efficiency and antibacterial rate of the polytetrafluoroethylene composite filter materials prepared in the above Examples and Comparative Examples were measured, and the results were shown in Table 1. Among them, the air permeability measurement was carried out according to GBT 1038-2000 “Plastics-Film and sheeting-Determination of gas transmission”, measurement of the filtering efficiency was carried out according to GB 2626-2019 “Respiratory Protection-Non-powered air-purifying particle respirator”, and the antibacterial rate was carried out according to GBT 20944.3-2008 “Textiles-Evaluation for antibacterial activity”.

TABLE-US-00001 TABLE 1 Example Example Example Example Example Comparative Comparative Item 1 2 3 4 5 Example 1 Example 2 Air   94%   93%   96%   95%   92%   93%   87% permeability Filtering 98.6% 98.7% 99.2% 98.1% 98.4% 96.5% 95.2% efficiency Antibacterial 99.5% 99.9% 99.7% 99.9% 99.8% 98.3% 99.1% rate

[0071] Although the present invention has been described in detail by general description, specific embodiments and experiments in the above, it is obvious to a person skilled in the art that some modifications or improvements can be made on the basis of the present invention. Therefore, all these modifications or improvements made without departing from the spirit of the present invention belong to the scope of the present invention.

INDUSTRIAL APPLICABILITY

[0072] The present invention provides a polytetrafluoroethylene composite filter material. The polytetrafluoroethylene composite filter material comprises a supporting layer and a polytetrafluoroethylene film layer, wherein the supporting layer is a silver-plated carbon nanomaterial-modified meltblown nonwoven fabric. The polytetrafluoroethylene composite filter material is prepared by fiberizing a resin material modified by silver-plated carbon nanomaterial on the surface of a polytetrafluoroethylene film by a melt-blowing method. The polytetrafluoroethylene composite filter material of the present invention combines filtering and sterilizing functions, has higher filtering efficiency and filtering precision, has the functions of sterilizing and killing viruses, has a good isolation effect, greatly prolongs the service life of the filter material, and has better economic value and application prospect.