Articles comprising antioxidizing agents and bacteriostatic agents, and production processes thereof

Abstract

An article may include a material having a surface containing at least one zinc oxide and/or salt, and at least one antioxidant. A method of using a mixture including at least one zinc oxide and/or salt, and at least one antioxidant, as bacteriostatic agent may include: applying the mixture to a surface of an article.

Claims

1. An article, comprising: a material having a surface containing at least one zinc oxide and/or salt, and at least one antioxidant selected from the group consisting of a selenium oxide and/or salt, a flavonoid, and a β-glucan, wherein the material is selected from macromolecular, metallic, or mineral material, and wherein the article is selected from the group consisting of a textile, a worktop or surface, and an equipment.

2. The article of claim 1, wherein the at least one zinc oxide and/or salt is selected from: zinc oxide, zinc hydroxide, zinc acetate, zinc-PCA (pyrrolidine carboxylic acid zinc salt), zinc chloride, zinc carbonate, zinc sulfate, zinc phosphate and zinc-EDTA (ethylenediaminetetraacetic acid), zinc gluconate, or mixtures thereof.

3. The article of claim 1, wherein an amount of the at least one zinc oxide and/or salt ranges from 0.00001% to 10.0%, and wherein the percentages are percentages by weight with respect to a total weight of the material.

4. The article of claim 1, wherein an amount of the at least one antioxidant ranges from 0.00001% to 10.0%, and wherein the percentages are percentages by weight with respect to a total weight of the material.

5. The article of claim 1, wherein the at least one antioxidant is selected from the group consisting of selenium oxide, selenium phloroglucinol, selenium chloride, and selenium gluconate.

6. The article of claim 1, wherein the at least one antioxidant is a flavonoid and the flavonoid is anthocyan.

7. The article of claim 1, wherein the at least one antioxidant is a μ-glucan.

8. The article of claim 1, wherein the material comprises: an inorganic adhesion promoter selected from hydroxyapatite, brushite, tricalciumphosphate, amorphous silica, zeolites, clays, montmorillonite, or mixtures thereof.

9. The article of claim 1, wherein the material comprises: an organic adhesion promoter selected from shellac, fish-glue, chitins, proteins, lipid proteic derivatives, or albumin.

10. A method of using a mixture comprising at least one zinc oxide and/or salt, and at least one antioxidant selected from the group consisting of a selenium oxide and/or salt, a flavonoid, and a μ-glucan, as a bacteriostatic agent, the method comprising: applying the mixture to a surface of a material, wherein the material is selected from macromolecular, metallic, or mineral material, wherein the material is configured to be part of an article selected from the group consisting of a textile, a worktop or surface, and an equipment.

11. A process for producing the article of claim 1, wherein the material comprises macromolecular material, the process comprising: subjecting the macromolecular material to thermal or chemical treatment to soften the macromolecular material; dispersing the at least one zinc oxide and/or salt, and the at least one antioxidant, onto the softened macromolecular material; and using the so-treated macromolecular material to produce the article.

12. A process for producing the article of claim 1, the process comprising: dispersing the at least one zinc oxide and/or salt and the at least one antioxidant, in a resin; and treating the material with the resin containing the at least one zinc oxide and/or salt, and the at least one antioxidant to obtain a coating film.

13. The article of claim 1, wherein the material comprises an inorganic adhesion promoter.

14. The article of claim 1, wherein the material comprises an organic adhesion promoter.

15. The article of claim 1, wherein the material comprises hydroxyapatite.

16. The method of claim 10, wherein the article is already formed prior to applying the mixture to the surface of the article.

Description

BRIEF DESCRIPTION OF THE FIGURES

(1) The present invention is described hereunder for illustrative but non-limiting purposes according to its preferred embodiments, with particular reference to the enclosed figures, wherein:

(2) FIGS. 1A and 1B respectively show the SEM (scanning electron microscope) image and the image of EDX elemental analysis carried out on a synthetic fabric treated according to the present invention.

(3) Further characteristics and advantages of the present invention will appear evident from the following detailed description.

(4) According to a preferred aspect of the present invention, said at least one zinc oxide and/or salt is selected from: zinc oxide, zinc hydroxide, zinc acetate, zinc-PCA (pyrrolidine carboxylic acid zinc salt), zinc chloride, zinc carbonate, zinc sulfate, zinc phosphate and zinc-EDTA, zinc gluconate, or mixtures thereof.

(5) According to another preferred aspect, the quantity of said at least one zinc oxide and/or salt ranges from 0.00001% to 10.0%, preferably from 0.0001% to 7.0%, wherein said percentages are weight percentages with respect to the total weight of the material.

(6) According to a further preferred aspect, the quantity of said at least one antioxidizing agent ranges from 0.00001% to 10.0%, preferably from 0.0001% to 7.0%, wherein said percentages are weight percentages with respect to the total weight of the material.

(7) According to a preferred aspect of the invention, the at least one antioxidizing agent is selected from selenium oxides and/or salts, preferably selenium oxide, selenium phloroglucinol, selenium chloride, selenium gluconate.

(8) According to another preferred aspect, the at least one antioxidizing agent is selected from flavonoids (or bioflavonoids), preferably from anthocyans (or anthocyanins).

(9) According to a further preferred aspect, the at least one antioxidizing agent is selected from citric acid salts, preferably sodium citrate, calcium citrate, potassium citrate and magnesium citrate.

(10) According to another preferred aspect, the at least one antioxidizing agent is a β-glucan.

(11) As indicated above, the article according to the present invention comprises a material that can be macromolecular, metallic or mineral.

(12) As far as macromolecular materials are concerned, these can be natural, artificial or synthetic.

(13) The macromolecular material is preferably synthetic and may be selected from: thermoplastic polymers, elastomeric polymers, thermoplastic elastomeric polymers, thermosetting (crosslinked) polymers. Alternatively, the macromolecular material is of natural origin, such as, for example, cellulose, wood, paper, cardboard, hemp, vegetable fibers.

(14) If the material is metallic or mineral, the zinc oxide and/or salt and the antioxidizing agent are preferably applied to the surface of the article already formed. Metallic materials that can be used are, for example, aluminium, steel, stainless steel, and the like. Mineral materials that can be used are marble, granite, stone, terracotta, ceramic, glass.

(15) According to another preferred aspect of the present invention, the material also comprises an adhesion promoter. In particular, the Applicant has found that various kinds of inorganic or organic fillers are particularly effective as adhesion promoters as they allow a better adhesion and permanence of the bacteriostatic and antioxidizing agents on the article of interest.

(16) The adhesion promoter is preferably inorganic and is selected from: hydroxyapatite, brushite, calcium phosphate, tricalciumphosphate, amorphous silica, zeolites, clays, montmorillonite or mixtures thereof. The adhesion promoter is preferably hydroxyapatite. The adhesion promoter is preferably organic and is selected from: shellac, fish-glue, chitins, proteins, lipid protein derivatives, albumin.

(17) According to a preferred aspect, the adhesion promoter is used when the combination of bacteriostatic agent and antioxidizing agent is applied on the surface of the article already formed, preferably in spray applications.

(18) Said adhesion promoter is preferably applied in a quantity ranging from 0.2% to 10%, preferably from 0.5% to 5%, wherein said percentages are expressed by weight with respect to the total weight of the material.

(19) According to a preferred aspect of the invention, the article is a textile material composed of natural or synthetic fibers, for example, cotton, linen, wool, silk, rayon, polyesters, polyamides, nylon or the like.

(20) According to another preferred aspect, the article is a worktop or surface used for example in healthcare-hospital environments, in food processing or in industrial processing in general.

(21) A second aspect of the present invention relates to the use of a mixture comprising at least one zinc oxide and/or salt and at least one antioxidant as bacteriostatic agent.

(22) A third aspect of the present invention relates to a process for the production of an article comprising a macromolecular material as defined above, comprising the following steps: subjecting the macromolecular material to thermal or chemical treatment to soften the macromolecular material; dispersing at least one zinc oxide and/or salt and at least one antioxidizing agent on the softened macromolecular material; using the so treated macromolecular material for producing the article.

(23) In this case, the macromolecular material is in the form of granules or pellets, and is preferably selected from thermoplastic polymers such as, for example, polyethylene (PE), polypropylene (PP), polystyrene, polyurethane, polyester, polyamide, polycarbonate, polyvinylchloride (PVC), polyethyleneterephthalate (PET), styrene copolymers (for example acrylonitrile-butadiene-styrene copolymers, ABS) and the like. The softening process of the macromolecular material can be carried out by means of thermal treatment, preferably at a temperature ranging from 30° C. to 260° C., more preferably from 40° C. to 240° C. The duration of said treatment may range from 20 minutes to 80 minutes, preferably from 30 minutes to 50 minutes.

(24) Alternatively, the softening of the macromolecular material can be effected by means of chemical treatment, for example by using an organic solvent (such as acetone, ethyl alcohol, isopropyl alcohol, THF, dichloromethane or mixtures thereof), which is added to the macromolecular material at a temperature generally ranging from 15° C. to 50° C., preferably from 20° C. to 40° C., and is left in contact with the material until a surface softening of the same is obtained.

(25) A fourth aspect of the present invention relates to a process for producing an article comprising a material according to the present invention, comprising the following steps: dispersing at least one zinc oxide and/or salt and at least one antioxidizing agent in a resin; treating the article with said resin containing said at least one zinc oxide and/or salt and at least one antioxidizing agent to obtain a coating film.

(26) The treatment step of the article may be carried out for example by means of spraying, coating, film forming or dipping.

(27) According to a preferred aspect, said at least one zinc oxide and/or salt and at least one antioxidizing agent can be dispersed in the molten resin or dissolved in a solvent. In the latter case, for example, the resin can be dissolved, according to its physico-chemical characteristics, in:

(28) an aqueous solution containing a base, for example sodium hydroxide, potassium hydroxide or ammonia;

(29) an organic solvent, preferably hydrosoluble and possibly in a mixture with water, for example an alcohol, such as isopropyl alcohol.

(30) The resin, having a film forming function, can be selected, for example, from: polyvinylpyrrolidone (PVP), polyethyleneglycol (PEG), polyvinylacetate, polyvinyl alcohol and cellulose acetate, collagen of animal origin, pectin, polyvinyl alcohol, cellulose acetate, or mixtures thereof. Natural resins, for example rosin copal, amber, putty, sandarac, turpentine or mixtures thereof, can also be used.

(31) The article according to the present invention can be of different types and can be used in various fields wherein a reduction or elimination of bacterial proliferation is required and wherein oxidative processes must be controlled to avoid contaminations or infections. By way of example, the following can be indicated: fabrics, non-woven fabrics, worktops or equipment, used in particular in the food or healthcare field.

(32) The present invention is further illustrated by means of some working examples as described hereunder.

EXAMPLE 1

(33) The counting of microorganisms was carried out on a growth plate, after the incubation period (as regards the type of microorganisms, they are microorganisms usually present in the environment). The obtained result, considered as a control, was 597 cfu (colony forming units). Then, the bacteriostatic effect was evaluated of:

(34) a solution of selenium phloroglucinol (20 ppm of selenium, i.e. corresponding to 0.002% by weight);

(35) three solutions of zinc PCA, with a concentration of zinc of 10 ppm, 20 ppm and 30 ppm respectively (i.e. respectively corresponding to 0.001%, 0.002% and 0.003% by weight).

(36) The results obtained are indicated in Table 1.

(37) TABLE-US-00001 TABLE 1 Reduction % Treatment cfu/plate observed control 597 — Selenium 20 ppm 506 15.9 Zinc 10 ppm 571 5.1 Zinc 20 ppm 550 6.0 Zinc 30 ppm 491 17.1

(38) In order to evaluate the synergic effect between zinc and antioxidizing agent, the tests indicated above were repeated, using three solutions separately, respectively containing: selenium 20 ppm+zinc 10 ppm; selenium 20 ppm+zinc 20 ppm; selenium 20 ppm+zinc 30 ppm. The results are reported in Table 2.

(39) TABLE-US-00002 TABLE 2 Treatment cfu/plate Reduction % observed Selenium 20 ppm + 468 22.2 Zinc 10 ppm Selenium 20 ppm + 433 27.2 Zinc 20 ppm Selenium 20 ppm + 381 36.4 Zinc 30 ppm

(40) As can be noted, the combination of zinc and selenium allows to achieve a significant improvement in terms of reduction in cfu with respect to the use of the two separate components.

EXAMPLE 2

(41) A formulation was prepared which is particularly suitable for the treatment of fabrics. 200 grams of distilled water were added to 1 g of finely ground granulate composed of zinc acetate (0.2 grams), zinc PCA (0.6 grams) and selenium phloroglucinol (0.2 grams), and the mixture was subjected to stirring until the complete dissolution of the agents was obtained. 2 grams of hydroxyapatite were subsequently added. Hydroxyapatite exerts the function of adhesion promoter, as it is believed that selenium and zinc bind to hydroxyapatite which, in turn, adheres to the textile fibers.

(42) FIGS. 1A and 1B respectively show the SEM (scanning electron microscope) image of the fabric obtained and the EDX elemental analysis image in which the presence of zinc on the surface of the fabric can be observed.

(43) The fabrics thus obtained were subjected to 20 and 40 washing cycles with standard detergent, to evaluate the bacteriostatic effect after mechanical stress.

(44) The bacterial count was measured as an exponential value; the logarithmic value is obtained from this value, which corresponds to an abatement percentage value.

(45) The starting bacterial suspensions were diluted so as to obtain a known bacterial concentration, expressed in colony forming units (cfu/ml). The samples under examination were inoculated with reference microbial strains and placed in an incubator at a temperature of 37±1° C. for 24 hours. At the end of the incubation period, the treated samples and the remaining non-treated samples were adequately washed and the residual microbial charge was then determined in the washing solution.

(46) As can be observed from the data indicated in Table 3, the effectiveness in terms of bacteriostatic effect with respect to the two relevant bacteria in any case remains higher than 99%.

(47) TABLE-US-00003 TABLE 3 20 washings 40 washings Reduct. Reduct. MICROBIAL STRAINS Reduct. % log Reduct. % log Escherichia Coli 99.67 2.47 99.44 2.25 Staphilococcus Aureus 99.89 2.95 99.43 2.25

EXAMPLE 3

(48) 10 g of rosin were dissolved in 100 g of isopropyl alcohol at a temperature of 25° C. for 12 hours, until the complete dissolution of the resin was obtained. 1 kg of woody material (chipboard) was then introduced into a mixer, an aliquot of the resin dissolved in isopropyl alcohol was then added, and the whole mixture was subjected to stirring for 20 minutes. At the end of the stirring process, a quantity equal to 40 g of finely ground granulate composed of zinc acetate (10 g), zinc PCA (20 g) and selenium phloroglucinol (10 g) was added to the mass of woody chipboard. Finally, the chipboard obtained was subjected to drying treatment in hot air at 40° C. for a total of 20 minutes.

EXAMPLE 4

(49) 18 grams of zinc PCA and 10 grams of zinc gluconate were suitably mixed with 10 grams of selenium gluconate and mixed in an alcohol solution (isopropyl alcohol) of polyethyleneglycol (PEG).

(50) The solution with antioxidizing and antibacterial properties was thus added to a quantity of PP polymer (polypropylene) equal to 1 kg. The polypropylene was moulded and the substantial absence of bacterial proliferation was verified on the surface of the article according to the method described above.