A composition suitable for the production of a thermosetting elastomer with antimicrobial capabilities by means of vulcanization by moulding

Abstract

A composition adapted for the production of a thermosetting elastomer with antimicrobial capabilities by vulcanization by molding includes an elastomer, a catalyst and/or a vulcanization activator, and an antimicrobial additive that includes zinc pyrithione and silver phosphate glass in a 1:1 ratio by weight.

Claims

1.-15. (canceled)

16. A composition adapted for production of a thermosetting elastomer with antimicrobial capabilities by vulcanization by molding, comprising: an elastomer; a catalyst and/or a vulcanization activator; and an antimicrobial additive in a quantity varying from 0.5% to 5 by weight relative to a total weight of the composition, the antimicrobial additive comprising zinc pyrithione and silver phosphate glass in a 1:1 ratio by weight.

17. The composition according to claim 16, wherein the elastomer is selected from the group consisting of EPDM, VMQ, NBR, HNBR, NR, FKM, FFKM, BR, and IIR.

18. The composition according to claim 16, wherein the antimicrobial additive is in a quantity of 1% by weight relative to the total weight of the composition.

19. The composition according to claim 16, wherein a total quantity by weight of the zinc pyrithione and silver phosphate glass relative to a total weight of the antimicrobial additive of at least 98%.

20. The composition according to claim 16, wherein the composition comprises one or more compounds selected from the group consisting of vulcanizers, plasticizers, antioxidants, fillers, reinforcers, coloring agents, process adjuvants, accelerators, or inhibitors.

21. A process of producing a thermosetting elastomer with antimicrobial capabilities via a vulcanization process, comprising: providing a composition according to claim 16; compression molding or injection molding the composition; and post-vulcanizing the composition.

22. The process according to claim 21, wherein: the elastomer is NR; the compression molding or the injection molding is carried out in a time interval ranging from 60 to 180 seconds and at a molding temperature ranging from 140 to 200 C.; the post-vulcanizing is carried out in a time interval ranging from 1 to 3 hours and at a temperature ranging from 50 to 70 C.

23. The process according to claim 21, wherein: the elastomer is EPDM; the compression molding or the injection molding is carried out in a time interval ranging from 80 to 250 seconds and at a molding temperature ranging from 160 to 210 C.; and the post-vulcanizing is carried out in a time interval ranging from 1 to 3 hours and at a temperature ranging from 90 to 110 C.

24. The process according to claim 21, wherein: the elastomer is FKM; the compression molding or the injection molding is carried out in a time interval ranging from 80 to 300 seconds and at a molding temperature ranging from 160 to 210 C.; the post-vulcanizing is carried out in a time interval ranging from 24 to 72 hours, and at a temperature ranging from 90 to 110 C.

25. The process according to claim 21, wherein: the elastomer is NBR; the compression molding or the injection molding is carried out in a time interval ranging from 40 to 250 seconds and at a molding temperature ranging from 160 to 210 C.; the post-vulcanizing is carried out in a time interval ranging from 1 to 3 hours, and at a temperature ranging from 90 to 110 C.

26. The process according to claim 21, wherein: the elastomer is VMQ; the compression molding or the injection molding is carried out in a time interval ranging from 40 to 280 seconds and at a molding temperature ranging from 140 to 200 C.; the post-vulcanizing is carried out in a time interval ranging from 24 to 72 hours, and at a temperature ranging from 95 to 115 C.

27. The process according to claim 21, wherein: the elastomer is FFKM; the compression molding or the injection molding is carried out in a time interval ranging from 200 to 500 seconds and at a molding temperature ranging from 160 to 210 C.; the post-vulcanizing is carried out in a time interval ranging from 24 to 72 hours, and at a temperature ranging from 100 to 120 C.

28. The process according to claim 21, wherein: the elastomer is IIR; the compression molding or the injection molding is carried out in a time interval ranging from 40 to 250 seconds and at a molding temperature ranging from 160 to 210 C.; the post-vulcanizing is carried out in a time interval ranging from 1 to 3 hours, and at a temperature ranging from 90 to 110 C.

29. The process according to claim 21, wherein: the elastomer is HNBR; the compression molding or the injection molding is carried out in a time interval ranging from 40 and 250 seconds and at a molding temperature ranging from 160 to 210 C.; the post-vulcanizing is carried out in a time interval ranging from 6 to 10 hours, and at a temperature ranging from 100 to 120 C.

30. The process according to claim 21, further comprising a step of producing teatcup liners for milking, or extraction of milk from animals or humans.

31. The process according to claim 21, further comprising a step of producing packaging for food.

32. The process according to claim 31, wherein producing packaging for food comprises producing packaging for eggs or packaging for poultry meat.

33. The process according to claim 21, further comprising a step of producing: machines for manufacturing products, machines for processing food or pharmaceutical products, or drinking water treatment systems; medical devices; or domestic or industrial plumbing elements.

34. The process according to claim 33, further comprising a step of producing seal elements or gaskets.

35. The process according to claim 21, further comprising a step of producing cases, containers, or covering elements.

Description

DESCRIPTION OF THE DRAWINGS

[0044] The characteristics and advantages of the present invention will be clearer from the following description of preferred non-limiting embodiment examples thereof, in which the Figures show the experimental data of the abatement tests conducted on thermosetting elastomers according to the present invention.

DETAILED DISCLOSURE OF THE INVENTION

[0045] It has surprisingly been found that the composition according to the present invention allows the production by means of vulcanization by moulding (compression or injection) of a thermosetting elastomer having antimicrobial capabilities.

[0046] The antimicrobial capabilities of the thermosetting elastomer obtained from said composition derive from the presence of an antimicrobial additive in a quantity that varies from 0.5% to 5%, preferably approximately 1% by weight relative to the total weight of said composition. Said antimicrobial additive in turn comprises zinc pyrithione and silver phosphate glass in a 1:1 ratio by weight, preferably in a total quantity by weight relative to the total weight of said antimicrobial additive of at least 98%.

[0047] The zinc pyrithione (Cas. No. 13463-41-7) is a zinc coordination compound in which the Zn.sup.2+ ions are coordinated by the oxygen and sulphur atoms of the pyrithione ligand. It has an antimycotic and antibacterial activity.

[0048] The silver phosphate glass (Cas. No. 308069-39-8) is a compound that allows controlled release of silver ions.

[0049] The antimicrobial properties of silver against bacteria and fungi have been known since ancient times. Interest in these properties has re-emerged with the increase in recorded cases of bacterial resistance.

[0050] Specifically, it has surprisingly been found that the antimicrobial activity of said antimicrobial additive remains even after treating said composition by means of vulcanization by compression moulding or injection moulding in order to obtain the relative thermosetting elastomer.

[0051] The latter, specifically, is obtained through a vulcanization process comprising: [0052] a compression moulding step or an injection moulding step of the composition according to one of the claims 1-2 and [0053] a post-vulcanization step.

[0054] It should be noted that the antimicrobial effectiveness of the various thermosetting elastomers obtained from said composition as previously described has a high speed of action, long duration and ability to remain even after cleaning processes. This is due to the fact that the antimicrobial additive included in the initial composition is incorporated in the polymer matrix.

[0055] Furthermore, since said thermosetting elastomers can be obtained both by compression moulding and injection moulding, they benefit from the versatility in terms of processability, uniformity and production volume offered by the two processes.

[0056] In a particular embodiment, said composition comprises one or more compounds selected from the group formed of vulcanizers, plasticizers, antioxidants, fillers, reinforcers, colouring agents, process adjuvants, accelerators and inhibitors.

[0057] Examples of vulcanizing agents (namely compounds that carry out the chemical cross-linking reaction consisting in the formation of stable chemical bonds between the polymer chains) are benzyltriphenylphosphonium salt with 4,4-[2,2,2-trifluoro-1-(trifluoromethyl) ethylidene]bis [phenol](1:1), 4,4-(hexafluoroisopropylidene) diphenol, benzyltriphenylphosphonium chloride, 2,5-dimethyl-2,5-di(tert-butylperoxy)hexane, propylidene trimethyl trimethacrylate, sulphur, 4-4 dithiodimorpholine, bis(ter-butyldioxyisopropyl)benzene, zinc diethyldithiocarbamate (ZDEC), tetramethylthiuram disulphide (TMTD), zinc pyrithione.

[0058] Examples of plasticizing agents are mineral oil, paraffin oil, refined oil, waxes like carnauba wax or dipolyethylene wax or refined rice bran wax, long-chain fatty acids and derivatives thereof.

[0059] Examples of antioxidant agents are 2,2-methylene-bis-(4-methyl-6-tert-butyl-phenol), 1,2-dihydro-2,2,4-trimethylquinoline, 6,6-di-ter-butyl-2,2-methylenedi-p-cresol and styrenated phenol.

[0060] Examples of filler agents are barium sulphate, calcium metasilicate (wollastonite) and calcium carbonate.

[0061] Examples of reinforcing agents (namely agents with anti-wear effect regarding mechanical factors such as abrasion, tearing, cutting) are carbon black, kaolin and calcined kaolin, silica and fused silica, precipitated silica, silicon dioxide, barium sulphate, calcium carbonate and talc.

[0062] Examples of colouring agents are chromium oxide (iii), titanium dioxides (anatase or rutile), iron oxides (red and yellow) and phthalocyanine blue.

[0063] Examples of process adjuvant agents are poly(tetrafluoroethylene), magnesium oxide, zinc oxide, ammonium chloride, carnauba wax and polyethylene.

[0064] Examples of accelerating agents are tetraethylthiuram monosulphide or TMTM, 2,2-dithiobis(benzothiazole) or MTBS, tetramethylthiuram disulphide or TMTD, n-cyclohexyl-2-benzothiazolesulfenamide and n-ter-butylbenzothiazole-2-sulfenamide, zinc dibutyldithiocarbamate or ZDBC.

[0065] Examples of inhibitor agents are benzoic acid and salicylic acid and derivatives of the phthalimides (such as, for example, cyclohexylthiophthalimide).

[0066] In a particular embodiment: [0067] said elastomer included in said composition is selected from the group consisting of NR; [0068] said compression moulding step or said injection moulding step is carried out in a time interval ranging from 60 to 180 seconds and at a moulding temperature ranging from 140 to 200 C., more preferably approximately 170 C.; [0069] said post-vulcanization step is carried out in a time interval ranging from 1 to 3 hours, more preferably approximately 2 hours, and at a temperature ranging from 50 to 70 C., more preferably approximately 60 C.

[0070] In a particular embodiment: [0071] said elastomer included in said composition is selected from the group consisting of EPDM; [0072] said compression moulding step or said injection moulding step is carried out in a time interval ranging from 80 to 250 seconds and at a moulding temperature ranging from 160 to 210 C., more preferably approximately 190 C.; [0073] said post-vulcanization step is carried out in a time interval ranging from 1 to 3 hours, more preferably approximately 2 hours, and at a temperature ranging from 90 to 110 C., more preferably approximately 100 C.

[0074] In a particular embodiment: [0075] said elastomer included in said composition is selected from the group consisting of FKM; [0076] said compression moulding step or said injection moulding step is carried out in a time interval ranging from 80 to 300 seconds and at a moulding temperature ranging from 160 to 210 C., more preferably approximately 190 C.; [0077] said post-vulcanization step is carried out in a time interval ranging from 24 to 72 hours, more preferably approximately 48 hours, and at a temperature ranging from 90 to 110 C., more preferably approximately 100 C.

[0078] In a particular embodiment: [0079] said elastomer included in said composition is selected from the group consisting of NBR: [0080] said compression moulding step or said injection moulding step is carried out in a time interval ranging from 40 to 250 seconds and at a moulding temperature ranging from 160 to 210 C., more preferably approximately 190 C.; [0081] said post-vulcanization step is carried out in a time interval ranging from 1 to 3 hours, more preferably approximately 2 hours, and at a temperature ranging from 90 to 110 C., more preferably approximately 100 C.

[0082] In a particular embodiment: [0083] said elastomer included in said composition is selected from the group consisting of VMQ; [0084] said compression moulding step or said injection moulding step is carried out in a time interval ranging from 40 to 280 seconds and at a moulding temperature ranging from 140 to 200 C., more preferably approximately 170 C.; [0085] said post-vulcanization step is carried out in a time interval ranging from 24 to 72 hours, more preferably approximately 48 hours, and at a temperature ranging from 95 to 115 C., more preferably approximately 105 C.

[0086] In a particular embodiment: [0087] said elastomer included in said composition is selected from the group consisting of FFKM; [0088] said compression moulding step or said injection moulding step is carried out in a time interval ranging from 200 to 500 seconds and at a moulding temperature ranging from 160 to 210 C., more preferably approximately 180 C.; [0089] said post-vulcanization step is carried out in a time interval ranging from 24 to 72 hours, more preferably approximately 48 hours, and at a temperature ranging from 100 to 120 C., more preferably approximately 110 C.

[0090] In a particular embodiment: [0091] said elastomer included in said composition is selected from the group consisting of IIR; [0092] said compression moulding step or said injection moulding step is carried out in a time interval ranging from 40 to 250 seconds and at a moulding temperature ranging from 160 to 210 C., more preferably approximately 190 C.; [0093] said post-vulcanization step is carried out in a time interval ranging from 1 to 3 hours, more preferably approximately 2 hours, and at a temperature ranging from 90 to 110 C., more preferably approximately 100 C.

[0094] In a particular embodiment: [0095] said elastomer included in said composition is selected from the group consisting of HNBR; [0096] said compression moulding step or said injection moulding step is carried out in a time interval ranging from 40 to 250 seconds and at a moulding temperature ranging from 160 to 210 C., more preferably approximately 190 C.; [0097] said post-vulcanization step is carried out in a time interval ranging from 6 to 10 hours, more preferably approximately 8 hours, and at a temperature ranging from 100 to 120 C., more preferably approximately 110 C.

[0098] As previously mentioned, said thermosetting elastomer can be used for producing teatcup liners for milking and/or extraction of milk from animals and/or humans. Said use would limit the risk of infection when the same milking equipment is used on several potentially infected animals.

[0099] Said thermosetting elastomer can also be used in the field of food packaging, more preferably for packaging eggs or for packaging poultry meat. Said use would limit the risk of infection and/or food-borne illnesses from infected food.

[0100] Said thermosetting elastomer can also be used in the field of non-food packaging or in the field of protection of objects for human use, for example for the production of cases, containers, covering elements and the like such as, for example, mobile phone covers or cases for electronic devices. Said thermosetting elastomer can also be used in other applications. For example, it can be applied in elements of machines for production plants or processing of food and/or pharmaceutical products, machines for drinking water treatment systems, or in plumbing systems for domestic or industrial use or in the sector of medical devices, in particular sealing elements or gaskets.

[0101] In the embodiments described above, a person skilled in the art can modify and/or replace the elements described with equivalent elements in order to meet specific needs, without departing from the scope of the attached claims.

[0102] The following examples are provided for purely illustrative purposes.

Example 1

[0103] In order to test its antimicrobial capability, a thermosetting elastomer was produced according to the present invention from the following composition (the reference compound is known as PRPFKM105FDA):

TABLE-US-00001 COMPONENT CAS No. % Function POLY (VINYLIDENE FLUORIDE- 9011-17-0 50-60 Polymer CO-HEXAFLUOROPROPYLENE) BARIUM SULPHATE 7727-43-7 30-35 Filler CARBON BLACK 1333-86-4 4-7 Reinforcing filler CALCIUM DIHYDROXIDE 1305-62-0 2-5 Activator MAGNESIUM OXIDE 1309-48-4 1-4 Activator BENZYLTRIPHENYL- 75768-65-9 0-3 Vulcanizer PHOSPHONIUM SALT WITH 4,4-[2,2,2-TRIFLUORO-1- (TRIFLUOROMETHYL) ETHYLIDENE]BIS[PHENOL] (1:1) 4,4- 1478-61-1 0-3 Vulcanizer (HEXAFLUOROISOPROPYLIDENE) DIPHENOL POLY (TETRAFLUOROETHYLENE) 9002-84-0 0-3 Process adjuvant CARNAUBA WAX 8015-86-9 0-3 Process adjuvant POLYETHYLENE 9002-88-4 0-3 Process adjuvant ANTIMICROBIAL ADDITIVE 1 Anti- ACCORDING TO CLAIM 1 microbial additive

[0104] The load abatement test was carried out using a cell culture plate with 24 wells (016 mm, volume 1 ML). For improved handling, a rectangular section was sampled from which a disc was subsequently obtained having dimensions suitable for introduction into the above plate. Using sterile tweezers, each disc was deposited on the bottom of a well and covered with 1 mL of each bacterial suspension.

[0105] Bacterial species such as Staphylococcus aureusATCC 6538, Streptococcus agalactiaeATCC 13813, Escherichia coliATCC 25922 and Salmonella enteritidisATCC 13076 were tested at two different concentrations: 10.sup.3 UFC/mL and 10.sup.4 UFC/mL.

[0106] The time-points analysed to obtain an indication of the abatement dynamics of the bacterial load were: [0107] T0: thermosetting elastomer-bacteria contact; [0108] T1: 5 minutes post-contact (PT); [0109] T2: 30 minutes PT; [0110] T3: 1 hour PT; [0111] T5: 6 hours PT; [0112] T6: 24 hours PT.

[0113] At each time-point a portion of microbial suspension (50 L) was appropriately diluted in sterile physiological solution (NaCl 0.9%) and seeded (50 L) in the plate with solid medium. After incubation at 37 C. for 24 hours, the colonies were counted to obtain the starting load at each time-point.

[0114] The experimental data obtained, reported in FIGS. 1a, 1b, 1c and 1d, show an antimicrobial activity that can be summarised as follows: [0115] Str. agalactiae: activity evident at 30 minutes and total abatement at 6 h:

TABLE-US-00002 % Reduction % Reduction Concentration Concentration TIME 1 10.sup.3 1 10.sup.4 0 0% 0% 5 min 9% 12% 30 min 74% 81% 1 hour 91% 99% 6 hours 100% 100% 24 hours 100% 100% [0116] S. aureus: activity evident at 30 minutes and total abatement at 6 h;

TABLE-US-00003 % Reduction % Reduction Concentration Concentration TIME 1 10.sup.3 1 10.sup.4 0 0% 0% 5 min 9% 2% 30 min 50% 25% 1 hour 90% 53% 6 hours 100% 100% 24 hours 100% 100% [0117] E. coli: activity evident at 30 minutes and total abatement at 6 hours;

TABLE-US-00004 % Reduction % Reduction Concentration Concentration TIME 1 10.sup.3 1 10.sup.4 0 0% 0% 5 min 14% 16% 30 min 66% 67% 1 hour 98% 98% 6 hours 100% 100% 24 hours 100% 100% [0118] S. enteritidis: activity evident at 1 h and total abatement at 24 h.

TABLE-US-00005 % Reduction % Reduction Concentration Concentration TIME 1 10.sup.3 1 10.sup.4 0 0% 0% 5 min 8% 10% 30 min 16% 20% 1 hour 37% 67% 6 hours 89% 94% 24 hours 100% 100%

Example 2

[0119] A thermosetting elastomer was produced as previously described starting from the following composition (the reference compound is known as PRPEPDM105FDA):

TABLE-US-00006 COMPONENT CAS No. % Function EPDM 25038-36-2 44-54 Polymer CARBON BLACK 1333-86-4 20-30 Reinforcing filler MINERAL OIL 8042-47-5 7-12 Plasticizer CALCIUM CARBONATE 471-34-1 7-12 Filler ZINC OXIDE 1314-13-2 0.5-2.5 Activator 2,5-DIMETHYL-2,5-DI(TERT- 78-63-7 1.5-3.5 Vulcanizer BUTYLPEROXY)HEXANE PROPYLIDENE TRIMETHYL 3290-92-4 0.5-2 Vulcanizer TRIMETHACRYLATE SULPHUR 7704-34-9 0.1-1.5 Vulcanizer ANTIMICROBIAL ADDITIVE 1 Antimicrobial ACCORDING TO CLAIM 1 additive

[0120] Applying the same analysis conditions as in Example 1, five bacterial species were tested (Staphylococcus aureusATCC 6538, Streptococcus agalactiaeATCC 13813, Escherichia coliATCC 25922, Listeria monocytogenes ATCC 13932, Legionella pneumophila ATCC 33152) at two different concentrations: 10.sup.3 UFC/mL and 10.sup.4 UFC/mL.

[0121] The experimental data obtained, reported in FIGS. 2a, 2b, 2c, 2d and 2e, show an antimicrobial activity that can be summarised as follows: [0122] Str. agalactiae: activity evident at 30 minutes and total abatement at 6 h;

TABLE-US-00007 % Reduction % Reduction Concentration Concentration TIME 1 10.sup.3 1 10.sup.4 0 0% 0% 5 min 6% 6% 30 min 38% 31% 1 hour 77% 58% 6 hours 100% 100% 24 hours 100% 100% [0123] S. aureus: activity evident at 6 h and total abatement not reached at 24 h;

TABLE-US-00008 % Reduction % Reduction Concentration Concentration TIME 1 10.sup.3 1 10.sup.4 0 0% 0% 5 min 1.5% 0.2% 30 min 5% 2.2 1 hour 11% 5% 6 hours 51% 32% 24 hours 99% 99% [0124] E. coli: [0125] 10.sup.3 UFC/mL: activity evident after 30 minutes and total abatement at 24 h; [0126] 10.sup.4 UFC/mL: activity evident after 30 minutes and total abatement at 6 h.

TABLE-US-00009 % Reduction % Reduction Concentration Concentration TIME 1 10.sup.3 1 10.sup.4 0 0% 0% 5 min 6% 9% 30 min 27% 42% 1 hour 57% 78% 6 hours 97% 100% 24 hours 100% 100% [0127] Legionella pneumophila: activity evident at 6 h and total abatement at 24 h;

TABLE-US-00010 % Reduction % Reduction Concentration Concentration TIME 1 10.sup.3 1 10.sup.4 0 0% 0% 5 min 1% 0% 30 min 5% 0% 1 hour 9% 0% 6 hours 88% 92% 24 hours 100% 100% [0128] Listeria monocytogenes: total abatement reached at 24 h with 10.sup.4 UFC/mL;

TABLE-US-00011 % Reduction % Reduction Concentration Concentration TIME 1 10.sup.3 1 10.sup.4 0 0% 0% 5 min 4% 1% 30 min 23% 7% 1 hour 44% 14% 6 hours 80% 61% 24 hours 99% 100%

Example 3

[0129] A thermosetting elastomer was produced as previously described starting from the following composition (the reference compound is know PRPNBR105FDA):

TABLE-US-00012 COMPONENT CAS No. % Function NBR 9003-18-3 40-50 Polymer CARBON BLACK 1333-86-4 19-29 Reinforcing filler MINERAL OIL 103-23-1 5.5-8.5 Plasticizer CALCIUM CARBONATE 471-34-1 11.5-16.5 Filler ZINC OXIDE 1314-13-2 1-2 Activator 4-4 DITHIODIMORPHOLINE 103-34-4 0.1-3 Vulcanizer TETRAMETHYLTHIURAM 137-26-8 0.1-3 Accelerant DISULPHIDE 2,2-METHYLENE-BIS- 119-47-1 0.1-2 Antioxidant (4-METHYL-6-TERT- BUTYL-PHENOL) SULPHUR 7704-34-9 0.1-2 Vulcanizer N-CYCLOHEXYL-2- 95-33-0 0.1-3 Accelerant BENZOTHIAZOLESULFENAMIDE ANTIMICROBIAL ADDITIVE 1 Anti- ACCORDING TO CLAIM 1 microbial additive

[0130] Applying the same analysis conditions as in Example 1, four bacterial species were tested (Staphylococcus aureusATCC 6538, Streptococcus agalactiaeATCC 13813, Escherichia coliATCC 25922 and Salmonella enteritidisATCC 13076) at two different concentrations: 10.sup.3 UFC/mL and 10.sup.4 UFC/mL.

[0131] The experimental data obtained, reported in FIGS. 3a-3d, show an antimicrobial activity that can be summarised as follows: [0132] Str. agalactiae activity evident after 5 minutes and total abatement at 1 h;

TABLE-US-00013 % Reduction % Reduction Concentration Concentration TIME 1 10.sup.3 1 10.sup.4 0 0% 0% 5 min 35% 55% 30 min 80% 90% 1 hour 100% 100% 6 hours 100% 100% 24 hours 100% 100% [0133] S. aureus: [0134] 10.sup.3 UFC/mL: activity evident after 1 h and total abatement at 24 h; [0135] 10.sup.4 UFC/mL: activity evident after 6 h and total abatement at 24 h.

TABLE-US-00014 % Reduction % Reduction Concentration Concentration TIME 1 10.sup.3 1 10.sup.4 0 0% 0% 5 min 3% 1% 30 min 19% 6% 1 hour 37% 12% 6 hours 65% 74% 24 hours 100% 100% [0136] E. coli: [0137] 10.sup.3 UFC/mL: activity evident after 30 minutes and total abatement at 6 h; [0138] 10.sup.4 UFC/mL: activity evident after 1 h and total abatement at 6 h.

TABLE-US-00015 % Reduction % Reduction Concentration Concentration TIME 1 10.sup.3 1 10.sup.4 0 0% 0% 5 min 8% 0.6% 30 min 32% 13% 1 hour 59% 33% 6 hours 100% 100% 24 hours 100% 100% [0139] S. enteritidis: [0140] 10.sup.3 UFC/mL: activity evident after 1 h and total abatement at 24 h; [0141] 10.sup.4 UFC/mL: activity evident after 6 h and total abatement at 24 h.

TABLE-US-00016 % Reduction % Reduction Concentration Concentration TIME 1 10.sup.3 1 10.sup.4 0 0% 0% 5 min 9% 8% 30 min 12% 10% 1 hour 27% 19% 6 hours 96% 99% 24 hours 100% 100%

Example 4

[0142] A thermosetting elastomer was produced as previously described starting from the following composition (the reference compound is known as PRPHNBR105FDA):

TABLE-US-00017 COMPONENT CAS No. % Function HNBR 88254-10-8 36-42 Polymer CARBON BLACK 1333-86-4 5-10 Reinforcing filler CALCINED KAOLIN 92704-41-1 22-27 Reinforcing filler PRECIPITATED SILICA 112926-00-8 5-10 Reinforcing filler MAGNESIUM OXIDE 1309-48-04 0-2 Process adjuvant ZINC OXIDE 1314-13-2 0-2 Activator STEARIC ACID 57-11-4 0-1 Activator 6,6-DI-TER-BUTYL-2,2- 119-47-1 0-1 Antioxidant METHYLENEDI-P-CRESOL BIS (TER- 25155-25-3 1-4 Vulcanizer BUTYLDIOXYISOPROPYL) BENZENE ANTIMICROBIAL ADDITIVE 1 Antimicrobial ACCORDING TO CLAIM 1 additive

[0143] Applying the same analysis conditions as in Example 1, three bacterial species were tested (S. aureusATCC 6538, Streptococcus agalactiaeATCC 13813, Escherichia coliATCC 25922) at two different concentrations: 10.sup.3 UFC/mL and 10.sup.4 UFC/mL. The experimental data obtained, reported in FIGS. 4a-4c, show an antimicrobial activity that can be summarised as follows: [0144] S. aureus: total abatement at 24 h;

TABLE-US-00018 % Reduction % Reduction Concentration Concentration TIME 1 10.sup.3 1 10.sup.4 0 0% 0% 5 min 0% 3% 30 min 2% 15% 1 hour 3% 30% 6 hours 53% 60% 24 hours 100% 100% [0145] Str. agalactiae: [0146] 10.sup.3 UFC/mL: total abatement at 24 h; [0147] 10.sup.4 UFC/mL: total abatement at 24 h.

TABLE-US-00019 % Reduction % Reduction Concentration Concentration TIME 1 10.sup.3 1 10.sup.4 0 0% 0% 5 min 2% 5% 30 min 11% 26% 1 hour 22% 52% 6 hours 83% 96% 24 hours 100% 100% [0148] E. coli: [0149] 10.sup.3 UFC/mL: total abatement at 24 h; [0150] 10.sup.4 UFC/mL: total abatement at 24 h.

TABLE-US-00020 % Reduction % Reduction Concentration Concentration TIME 1 10.sup.3 1 10.sup.4 0 0% 0% 5 min 5% 1% 30 min 27% 10% 1 hour 95% 19% 6 hours 82% 67% 24 hours 100% 100%

Example 5

[0151] A thermosetting elastomer was produced as previously described from the following composition (the reference compound is known as PRPNR105FDA):

TABLE-US-00021 COMPONENT CAS No. % Function NR 9006-04-6 27-37 Polymer BR 9003-17-2 12-17 Polymer CARBON BLACK 1333-86-4 3-6 Reinforcing filler MINERAL OIL 8042-47-5 6-9 Plasticizer SILICA 7631-86-9 23-33 Reinforcing filler [3-(2,3-EPOXYPROPOXY)- 2530-83-8 0.1-5 Activator PROPYL]-TRIMETHOXY SILANE ZINC CARBONATE 51839-25-9 0.1-3 Activator N-TER-BUTYLBENZOTHIAZOLE- 95-31-8 0.1-3 Accelerator 2-SULFENAMIDE STYRENATED PHENOL 61788-44-1 0.1-3 Antioxidant SULPHUR 7704-34-9 0.1-3 Vulcanizer N-CYCLOHEXYL-2- 95-33-0 0.1-3 Accelerator BENZOTHIAZOLESULFENAMIDE ANTIMICROBIAL ADDITIVE 1 Anti- ACCORDING TO CLAIM 1 microbial additive

[0152] Applying the same analysis conditions as in Example 1, two bacterial species were tested (Staphylococcus aureusATCC 6538 and Streptococcus agalactiaeATCC 13813) at two different concentrations: 10.sup.3 UFC/mL and 10.sup.4 UFC/mL. The experimental data obtained, reported in FIGS. 5a and 5b, show an antimicrobial activity that can be summarised as follows: [0153] Str. agalactiae: [0154] 10.sup.3 UFC/mL: activity evident at 30 minutes and total abatement at 6 h; [0155] 10.sup.4 UFC/mL: activity evident at 30 minutes and total abatement at 24 h;

TABLE-US-00022 % Reduction % Reduction Concentration Concentration TIME 1 10.sup.3 1 10.sup.4 0 0% 0% 5 min 7% 6% 30 min 31% 33% 1 hour 73% 78% 6 hours 100% 98% 24 hours 100% 100% [0156] S. aureus: [0157] 10.sup.3 UFC/mL: activity evident after 6 h, total abatement not reached at 24 h; [0158] 10.sup.4 UFC/mL: activity evident after 1 h and total abatement at 24 h.

TABLE-US-00023 % Reduction % Reduction Concentration Concentration TIME 1 10.sup.3 1 10.sup.4 0 0% 0% 5 min 0.2% 3% 30 min 7% 21% 1 hour 14% 36% 6 hours 58% 64% 24 hours 98% 100%

Example 6

[0159] A thermosetting elastomer was produced as previously described from the following composition (the reference compound is known as PRPVMQ105FDA):

TABLE-US-00024 COMPONENT CAS No. % Function SILICON RUBBER 63394-02-5 98.8-99.7 Polymer 2,5-DIMETHYL-2,5-DI (TER- 78-63-7 0.3-1.2 Catalyst BUTYLPEROXY) HEXANE ANTIMICROBIAL ADDITIVE 1 Antimicrobial ACCORDING TO CLAIM 1 additive

[0160] Applying the same analysis conditions as in Example 1, two bacterial species were tested (Staphylococcus aureusATCC 6538 and Streptococcus agalactiaeATCC 13813) at two different concentrations: 10.sup.3 UFC/mL and 10.sup.4 UFC/mL. The experimental data obtained, reported in FIGS. 6a and 6b, show an antimicrobial activity that can be summarised as follows: [0161] Str. agalactiae: total abatement at 6 h;

TABLE-US-00025 % Reduction % Reduction Concentration Concentration TIME 1 10.sup.3 1 10.sup.4 0 0% 0% 5 min 1% 2% 30 min 5% 8% 1 hour 7% 12% 6 hours 100% 100% 24 hours 100% 100% [0162] S. aureus: activity evident at 6 h and total abatement at 24 h.

TABLE-US-00026 % Reduction % Reduction Concentration Concentration TIME 1 10.sup.3 1 10.sup.4 0 0% 0% 5 min 3% 2% 30 min 10% 6% 1 hour 20% 10% 6 hours 49% 35% 24 hours 100% 100%

Example 7

[0163] A thermosetting elastomer was produced as previously described from the following composition (the reference compound is known as PRPVMQ105FDA-V1):

TABLE-US-00027 COMPONENT CAS No. % Function SILICONE RUBBER 63394-02-5 95-99 Polymer ZINC OXIDE 1314-13-2 1-5 Process adjuvant MAGNESIUM OXIDE 1309-48-4 1-5 Process adjuvant 2, 5-DIMETHYL-2, 5-DI (TER- 78-63-7 0.3-1.2 Catalyst BUTYLPEROXY) HEXANE ANTIMICROBIAL ADDITIVE 1 Antimicrobial ACCORDING TO CLAIM 1 additive

[0164] Applying the same analysis conditions as in Example 1, three bacterial species were tested (Staphylococcus aureusATCC 6538, Streptococcus agalactiaeATCC 13813 and Escherichia coliATCC 25922) at two different concentrations: 10.sup.3 UFC/mL and 10.sup.4 UFC/mL. The experimental data obtained, reported in FIGS. 7a, 7b and 7c, show an antimicrobial activity that can be summarised as follows: [0165] S. aureus: activity evident and total abatement at 24 h.

TABLE-US-00028 % Reduction % Reduction Concentration Concentration TIME 1 10.sup.3 1 10.sup.4 0 0% 0% 5 min 1% 7% 30 min 6% 44% 1 hour 12% 87% 6 hours 64% 99% 24 hours 97% 100% [0166] Str. agalactiae: total abatement at 6 and 24 h;

TABLE-US-00029 % Reduction % Reduction Concentration Concentration TIME 1 10.sup.3 1 10.sup.4 0 0% 0% 5 min 3% 2% 30 min 15% 10% 1 hour 29% 20% 6 hours 100% 99% 24 hours 100% 100% [0167] E. coli: abatement evident at 24 h;

TABLE-US-00030 % Reduction % Reduction Concentration Concentration TIME 1 10.sup.3 1 10.sup.4 0 0% 0% 5 min 3% 5% 30 min 20% 29% 1 hour 41% 58% 6 hours 66% 76% 24 hours 96% 98%

Example 8

[0168] A thermosetting elastomer was produced as previously described from the following composition (the reference compound is known as PRPVMQ105FDA-V3):

TABLE-US-00031 COMPONENT CAS No. % Function SILICONE RUBBER 63394-02-5 93-96 Polymer ZINC OXIDE 1314-13-2 1-5 Process adjuvant MAGNESIUM OXIDE 1309-48-4 1-5 Process adjuvant AMMONIUM CHLORIDE 12125-02-09 1-5 Process adjuvant 2,5-DIMETHYL-2,5-DI (TER- 78-63-7 0.3-1.2 Catalyst BUTYLPEROXY) HEXANE ANTIMICROBIAL ADDITIVE 1 Antimicrobial ACCORDING TO CLAIM 1 additive

[0169] Applying the same analysis conditions as in Example 1, S. enterica was tested at two different concentrations: 10.sup.3 UFC/mL and 10.sup.4 UFC/mL. Effects on the cyanobacteria Limnothrix sp. and Phormidium were also tested. The tests on the antibacterial effect on the cyanobacteria were conducted by evaluation, in terms of growth inhibition, on solid medium. The test was carried out by growing the two cyanobacteria on a solid support, to simulate a condition of undesired growth of cyanobacteria on surfaces of receptacles or pipes with stagnant water. The solid surface was prepared with a standard culture medium used for the growth of cyanobacteria (BG11) with the addition of 1%, by volume, of agar to solidify. After appropriate sterilization, the cyanobacteria were inoculated in a Petri dish a few days prior to the beginning of the test. The dishes were then placed in a culture chamber set to 201 C., with light intensity of 90-120 mol m-2 s-1, following a photoperiod of 16:8 hours of light:darkness. After addition of the elastomer, the dishes were tested.

[0170] The experimental data obtained, reported in FIGS. 8a, 8b and 8c, show an antimicrobial activity that can be summarised as follows: [0171] S. enterica: 10.sup.4 UFC/Ml: total abatement at 24 h.

TABLE-US-00032 % Reduction % Reduction Concentration Concentration TIME 1 10.sup.3 1 10.sup.4 0 0% 0% 5 min 0% 0% 30 min 0% 0% 1 hour 0% 0% 6 hours 30% 85% 24 hours 58% 100% [0172] Limnothrix sp. (filament diameter <1.5 m): total abatement at 30 days;

TABLE-US-00033 % Concentration TIME Reduction 0 0% 10 days 40% 20 days 80% 30 days 100% 40 days 100% [0173] Phormidium sp (filament diameter <5-6 m): total abatement at 30 days

TABLE-US-00034 % Concentration TIME Reduction 0 0% 10 days 36% 20 days 70% 30 days 100% 40 days 100%

Example 9

[0174] A thermosetting elastomer was produced as previously described from the following composition (the reference compound is known as PRPBUT105FA):

TABLE-US-00035 COMPONENT CAS No. % Function BUTYL RUBBER 9010-85-9 54-57 Polymer CARBON BLACK 1333-86-4 26-29 Reinforcing filler CALCIUM CARBONATE 1317-65-3 9.5-11 Filler ZINC OXIDE 1314-13-2 0.6-2 Activator STEARIC ACID 57-11-4 0.1-1 Activator ZDEC 14324-55-1 0.25-1 Vulcanizer TMTD 137-26-8 0.4-1.8 Vulcanizer SULPHUR 7704-34-9 0.1-2 Vulcanizer ANTIMICROBIAL ADDITIVE 1 Antimicrobial ACCORDING TO CLAIM 1 additive

[0175] Applying the same analysis conditions as in Example 1, three bacterial species were tested (Staphylococcus aureusATCC 6538, Salmonella and Escherichia coliATCC 25922) at two different concentrations: 10.sup.3 UFC/mL and 10.sup.4 UFC/mL. The experimental data obtained, reported in FIGS. 9a, 9b and 9c, show an antimicrobial activity that can be summarised as follows: [0176] S. aureus: almost total abatement at 24 h.

TABLE-US-00036 % Reduction % Reduction Concentration Concentration TIME 1 10.sup.3 1 10.sup.4 0 0% 0% 5 min 2% 3% 30 min 10% 18% 1 hour 19% 33% 6 hours 52% 64% 24 hours 97% 96% [0177] Salmonella: almost total abatement at 24 h;

TABLE-US-00037 % Reduction % Reduction Concentration Concentration TIME 1 10.sup.3 1 10.sup.4 0 0% 0% 5 min 1% 2% 30 min 7% 13% 1 hour 13% 25% 6 hours 69% 56% 24 hours 93% 97% [0178] E. coli: abatement at 24 h;

TABLE-US-00038 % Reduction % Reduction Concentration Concentration TIME 1 10.sup.3 1 10.sup.4 0 0% 0% 5 min 2% 0% 30 min 8% 1% 1 hour 16% 2% 6 hours 63% 55% 24 hours 100% 100%

Example 10

[0179] A thermosetting elastomer was produced as previously described from the following composition (the reference compound is known as PRPFFKM102FDAP):

TABLE-US-00039 COMPONENT CAS No. % Function PERFLUOROELASTOMER FFKM 24625-79-6 70-90 Polymer CARBON BLACK 1333-86-4 10-20 Reinforcing filler MAGNESIUM OXIDE 1309-48-4 1-4 Activator ZINC OXIDE 1314-13-2 1-4 Activator 1,3,5-TRIALLYL-1,3,5-TRIAZINE- 1025-15-6 1-4 Vulcanizer 2,4,6 (1H, 3H, 5H, )-TRIONE 2,5-DIMETHYL-2,5-DI (TERT- 78-63-7 0.1-2.5 Vulcanizer BUTYLPEROXY) HEXANE ANTIMICROBIAL ADDITIVE 1 Antimicrobial ACCORDING TO CLAIM 1 additive

[0180] Applying the same analysis conditions as in Example 1, two bacterial species were tested (Staphylococcus aureusATCC 6538 and Escherichia coliATCC 25922) at two different concentrations: 10.sup.3 UFC/mL and 10.sup.4 UFC/mL. The experimental data obtained, reported in FIGS. 10a and 10b, show an antimicrobial activity that can be summarised as follows: [0181] S. aureus: total abatement at 24 h.

TABLE-US-00040 % Reduction % Reduction Concentration Concentration TIME 1 10.sup.3 1 10.sup.4 0 0% 0% 5 min 2% 8% 30 min 10% 46% 1 hour 19% 92% 6 hours 35% 97% 24 hours 70% 100% [0182] E. coli: almost total abatement at 24 h;

TABLE-US-00041 % Reduction % Reduction Concentration Concentration TIME 1 10.sup.3 1 10.sup.4 0 0% 0% 5 min 1% 3% 30 min 8% 16% 1 hour 16% 33% 6 hours 55% 77% 24 hours 96% 99%