ANTIMICROBIAL FLUOROPOLYMER

Abstract

Provided is a composition having excellent antimicrobial performance. The present invention relates to a composite material, comprising: a fluoropolymer; and an antimicrobial agent; wherein the fluoropolymer and the antimicrobial agent are compounded.

Claims

1. A composite material, comprising: a fluoropolymer; and an antimicrobial agent; wherein the fluoropolymer and the antimicrobial agent are compounded.

2. The composite material according to claim 1, wherein the fluoropolymer is a fluorinated ethylene propylene copolymer.

3. The composite material according to claim 2, wherein the monomer molar ratio of tetrafluoroethylene to hexafluoropropylene is between 80:20 and 97:3.

4. The composite material according to claim 1, wherein the fluoropolymer is a copolymer of ethylene and tetrafluoroethylene.

5. The composite material according to claim 4, wherein the monomer molar ratio of ethylene to tetrafluoroethylene is between 63:37 and 15:85.

6. The composite material according to claim 1, wherein the fluoropolymer is a perfluoroalkoxy polymer.

7. The composite material according to claim 1, wherein the fluoropolymer is polyvinylidene fluoride.

8. The composite material according to claim 1, wherein the fluoropolymer is a terpolymer of ethylene, tetrafluoroethylene, and hexafluoropropylene.

9. The composite material according to claim 8, wherein the monomer molar ratio of ethylene, tetrafluoroethylene, and hexafluoropropylene is between (31.5 to 54.7):(38 to 64.7):(0.5 to 15), with the sum of the values in the molar ratio of ethylene, tetrafluoroethylene, and hexafluoropropylene being 100.

10. The composite material according to claim 8, wherein the composite material is free from an inorganic component other than the antimicrobial agent.

11. The composite material according to claim 1, wherein the fluoropolymer is polytetrafluoroethylene in the form of fine powders.

12. The composite material according to claim 1, wherein the fluoropolymer is polytetrafluoroethylene in the form of molding powders.

13. The composite material according to claim 1, wherein the antimicrobial agent comprises elemental ions selected from the group consisting of silver ions, copper ions, and zinc ions.

14. The composite material according to claim 1, wherein the antimicrobial agent comprises zeolites.

15. The composite material according to claim 1, wherein the weight ratio of the fluoropolymer to the antimicrobial agent is between 95:5 and 99.9:0.1.

16. A method for making the composite material of claim 1, the method comprising the step of: compounding the fluoropolymer and the antimicrobial agent by a co-rotating twin screw extruder.

17. A method for making the composite material of claim 1, the method comprising the step of: compounding the fluoropolymer and the antimicrobial agent by a single screw extruder.

18. A method for making the composite material of claim 1, the method comprising the step of: compounding the fluoropolymer and the antimicrobial agent by a buss kneader.

19. A method for making the composite material of claim 1, the method comprising the step of: compounding the fluoropolymer and the antimicrobial agent by an internal mixer.

20. A method for making the composite material of claim 1, the method comprising the step of: compounding the fluoropolymer and the antimicrobial agent by a two roll mill.

21. The method according to claim 16, wherein: the fluoropolymer is a fluorinated ethylene propylene copolymer; and the compounding is carried out at a temperature between 580 F. and 700 F.

22. The method according to claim 16, wherein: the fluoropolymer is a copolymer of ethylene and tetrafluoroethylene; and the compounding is carried out at a temperature between 580 F. and 650 F.

23. The method according to claim 16, wherein: the fluoropolymer is a terpolymer of ethylene, tetrafluoroethylene, and hexafluoropropylene; and the compounding is carried out at a temperature between 390 F. and 550 F.

24. The method according to claim 16, wherein the compounding is carried out at a screw speed between 15 RPM and 1,000 RPM.

25. The method according to claim 16, wherein the compounding is carried out at a screw speed between 50 RPM and 100 RPM.

26. A tube comprising the composite material according to claim 1.

27. A catheter comprising the composite material according to claim 1.

28. A thin film surface for packaging and medical surface comprising the composite material according to claim 1.

29. An injected molded article used as a medical device comprising the composite material according to claim 1.

30. A blow-molded bottle for medical or food packaging comprising the composite material according to claim 1.

Description

DETAILED DESCRIPTION OF THE INVENTION AND EMBODIMENTS

[0048] The detailed description that follows generally describes various exemplary embodiments of the present invention, and should not be considered to be exclusive of other equally effective embodiments, as would be understood by those of ordinary skill in the art. Further, numerous specific details are given in order to provide a thorough understanding of the embodiments and other examples. In some instances, however, well-known methods, procedures, and components have not been described in detail, so as to not obscure the following description. The embodiments and examples disclosed are for exemplary purposes only. Other embodiments and examples may be employed in lieu of, or in combination with, the embodiments and examples disclosed. In what follows, unless otherwise specified, the amounts of the components in a composition are all expressed in weight % relative to the total amount of the composition. Also, where a numerical range is provided, it is understood that all numerical subsets of that range, and all the individual integers contained therein, are provided as part of the invention.

Experiment 1

[0049] Studies were carried out to investigate the antimicrobial effects of the fluoropolymers, specifically FEPs, of the present invention. As the antibacterial agent, Agion Ak80H from Sciessent was used. Five (5) weight % of this agent was compounded with Neoflon FEP NP-120, and samples were tested for their antimicrobial performances against E. coli (ATCC #25922) and S. aureus (ATCC #6538) following the Modified ASTM-2180 standard. The sample size of the tested resins was 2 inches2 inches. The initial inoculum for the tests was at a 10.sup.6 concentration, which is consistent with what is used for medical testing. (For non-medical testing, the concentration of the initial inoculum would be 10.sup.5.)

[0050] Neoflon FEP NP-120 is a copolymer of tetrafluoroethylene and hexafluoropropylene, and is widely used in medical-device areas, such as in catheters and other tubes and hoses. It is generally characterized by high extrusion speeds and superior stress crack resistance, and has the typical properties shown in Table 1 below. The monomer ratio of tetrafluoroethylene to hexafluoropropylene in Neoflon FEP NP-120 is in the range of between 80:20 and 97:3.

[0051] Agion AK80H contains 5% by weight of silver and 13% by weight of zinc in a zeolite carrier.

TABLE-US-00001 TABLE 1 Measurement Property Method Result Melt Flow Rate, g/10 min ASTM D-2116 4.0-10.0 Melting point (DSC), C. ASTM D-2116 260-270 Tensile strength, MPa, (minimum) ASTM D-2116 20.0 Elongation, %, (minimum) ASTM D-2116 275 MIT Flex, cycles, avg. ASTM D-2176 30,000

[0052] To prepare the samples, Neoflon FEP NP-120 and Agion AK80H were compounded by a co-rotating twin screw extruder at a temperature up to 630 F. and at a screw speed up to 100 rotations per minute (RPM). For tube manufacturing, a single screw extruder may be used, and the temperature may be up to 700 F. and the screw speed up to 60 RPM. The size of a tube depends on the applications intended, and its diameter may be from 1 mm or less, to a few centimeters.

[0053] Tables 2 and 3 below show the results obtained from the antimicrobial studies, Assay (+) refers to a sample with a positive organism count (that is, contains organisms), while Assay () refers to a sample without organism. Sample 1, Sample 2, and Sample 3 in Tables 2 and 3 are samples having the same composition but represent different batches.

TABLE-US-00002 TABLE 2 Tests against E. coli Organism Count (CFU/ml) Zero 24 Hours Contact Contact Percent Sample Indentification Time Time Reduction** Assay (+) 3.9 10.sup.6 3.6 10.sup.7 No Reduction Assay () <10* <10* N/A FEP NP-120, Natural 5.0 10.sup.8 No Reduction FEP NP-120, 5% AK80H <10* 99.99999% Sample 1 FEP NP-120, 5% AK80H <10* 99.99999% Sample 2 FEP NP-120, 5% AK80H <10* 99.99999% Sample 3 Notes: *<10 = Limits of detection of assay. **Percent reduction calculated using untreated T24 hour contact time.

TABLE-US-00003 TABLE 3 Tests against S. aureus Organism Count (CFU/ml) Zero 24 Hours Contact Contact Percent Sample Indentification Time Time Reduction** Assay (+) 3.9 10.sup.6 4.6 10.sup.6 No Reduction Assay () <10* <10* N/A FEP NP-120, Natural 3.2 10.sup.7 No Reduction FEP NP-120, 5% AK80H <10* 99.9999% Sample 1 FEP NP-120, 5% AK80H <10* 99.9999% Sample 2 FEP NP-120, 5% AK80H <10* 99.9999% Sample 3 Notes: *<10 = Limits of detection of assay. **Percent reduction calcalated using untreated T24 hour contact time.

[0054] For the antimicrobial studies above, Neoflon FEP NP-130 instead of Neoflon FEP NP-120 can be used as well, with similar results expected. Neoflon FEP NP-130 is suitable, among other applications, for extrusion and compression molding that requires an elevated degree of stress crack resistance, and has the typical properties shown in Table 4 below.

TABLE-US-00004 TABLE 4 Measurement Property Method Result Melt Flow Rate, g/10 min ASTM D-2116 2.0-3.6 Melting point (DSC), C. ASTM D-2116 250-260 Tensile strength, MPa, (minimum) ASTM D-2116 17.2 Elongation, %, (minimum) ASTM D-2116 275 MIT Flex, cycles, (minimum) ASTM D-2176 95,000

Experiment 2

[0055] Tube samples were produced by extrusion molding of the respective fluoropolymers and Agion shown in Table 5, and the antimicrobial performance against S. aureus (ATCC #6538) was determined by the method shown in Table 5. The tube samples tested had a diameter of 3 mm and a length of 150 mm. The results are shown in Table 5 below.

TABLE-US-00005 TABLE 5 Organism Organism Agion Count of Count of Fluoropolymer Agion Content Control Sample Bacteria (Neoflon) Type (wt %) Article (CFU/ml) (CFU/ml) Reduction* ASTM PFA AK80H 0.5 Tubing 1.37 10.sup.6 1.00 10 99.999% E2149-13a AP201 1.0 1.37 10.sup.6 1.00 10 99.999% 3.0 1.37 10.sup.6 1.00 10 99.999% FEP AK80H 0.5 Tubing 1.37 10.sup.6 1.00 10 99.999% E2149-13a NP120 1.0 1.37 10.sup.6 1.00 10 99.999% 3.0 1.37 10.sup.6 1.00 10 99.999% ETFE AK80H 0.5 Tubing 1.37 10.sup.6 1.00 10 99.999% E2149-13a EP521 1.0 1.37 10.sup.6 1.00 10 99.999% 3.0 1.37 10.sup.6 1.00 10 99.999% EFEP AK80H 0.5 Tubing 1.37 10.sup.6 1.00 10 99.999% E2149-13a RP5000 1.0 1.37 10.sup.6 1.00 10 99.999% 3.0 1.37 10.sup.6 1.00 10 99.999% Notes: *Bacteria Reduction = (1-Organism Count of Sample/Organism Count of Control) 100% The samples containing EFEP had a less colored appearance than samples free from Agion.

[0056] In the present invention, the temperature of compounding a fluoropolymer and an antimicrobial agent may be adjusted as appropriate. For example, a composite material containing FEP may be heated at a temperature between 580 F. and 700 F., a composite material containing ETFE may be heated at a temperature between 580 F. and 650 F., and a composite material containing EFEP may be heated at a temperature between 390 F. and 550 F.

[0057] The screw speed for compounding may also be adjusted as appropriate in the present invention, depending on such factors as screw designs, temperature settings, and screw extruder sizes. For example, the screw speed may be between 15 RPM and 1,000 RPM, or it may be between 50 RPM and 100 RPM.

[0058] In addition to compounding by a co-rotating twin screw extruder or a single screw extruder, the compounding can also be conducted by use of a buss kneader, an internal mixer, a two roll mill, or other apparatuses known in the field.

[0059] In an operation of compounding, various materials are mixed, melted and pumpedgenerally in an extruder or other equipmentand made into forms of pellets. Twin screw extruders, either of a co-rotating design or a counter-rotating design, are the most popular equipment for compounding. The two screws in a twin screw extruder rotate either in the same direction (co-rotating) or in opposite directions (counter-rotating). They can be intermeshing, or non-intermeshing. Single-screw extruders are also used for compounding with improved mixing design. Other types of equipment, such as buss kneaders and mixers, are also found useful in compounding materials, while buss kneaders are applied more in heat- and shear-sensitive areas, such as PVC compounding. An internal mixer and a two roll mill can be used to make such FEP compounds as well. However, they are not continuous technique and are widely used in rubber compounding instead.

[0060] Now that exemplary embodiments of the present invention have been shown and described in detail, various modifications and improvements thereon will become readily apparent to those skilled in the art.

[0061] It will be understood that one or more of the elements or exemplary embodiments described can be rearranged, separated, or combined without deviating from the scope of the present invention. For ease of description, various elements are, at times, presented separately. This is merely for convenience and is in no way meant to be a limitation.

[0062] Further, it will be understood that one or more of the steps described can be rearranged, separated, or combined without deviating from the scope of the present invention. For ease of description, steps are, at times, presented sequentially. This is merely for convenience and is in no way meant to be a limitation.

[0063] While the various elements, steps, and exemplary embodiments of the present invention have been outlined above, it is evident that many alternatives, modifications, and variations will be apparent to those skilled in the art. The various elements, steps, and exemplary embodiments of the present invention, as described above, are intended to be illustrative, not limiting. Various changes can be made without departing from the spirit and scope of the present disclosure. Accordingly, the spirit and scope of the present disclosure is to be construed broadly and not limited by the foregoing specification.

[0064] No element, act, or instruction used in the description of the present invention should be construed as critical or essential unless explicitly described as such. Also, as used herein, the article a is intended to include one or more items. Where only one item is intended, the term one, single, or similar language is used.

[0065] The present invention has industrial applicability in that it provides, among other things, fluoropolymers having antimicrobial capabilities and methods for making them.