MXPA00005294A - Improved biocide and biocidal cloth - Google Patents

Abstract

The invention provides a biocidal concentrate including zinc pyridinethione;and a second biocide selected to be biocidally effective in a pH range complementary to zinc pyridinethione. The second biocide may be an aromatic halogenated phenol such as triclosan, dichlorophen and trichlorcarban. The invention also provides biocidal cleaning devices and plastic materials and methods of manufacture thereof.

Description

BIOCIDA IMPROVED AND FABRIC WITH BIOCIDE TECHNICAL FIELD The invention relates to a biocidal cleaning composition and to the incorporation thereof into a fabric, sponge, paper, wound dressing, biocidal plastic or other substrate.

ANTECEDENTS OF THE TECHNIQUE In domestic and hospital environments, one of the most common methods for cleaning large surfaces is to rub a cloth over said surface. Normally, the fabric will be moistened with water and can additionally have a detergent or disinfectant added. Fabrics that do not contain a disinfectant are inefficient to control the growth of microorganisms. In fact, the fabric itself can provide favorable conditions for the proliferation of said microorganisms and the action of rubbing said infected fabric on a surface can have a counterproductive effect on the desired result of making a more hygienic surface. The common cleaning fabrics that remain wet for a period of time also stand out for the smell they develop, which are the result of microbial action.

Dipping a cloth in disinfectant provides short-term relief and requires reapplication of the disinfectant to the fabric. Although this method uses only small amounts of disinfectant, the amount must be greater than what is required to achieve an adequate bactericidal action. An extremely effective disinfectant is also required to prevent bacterial proliferation in the cleaning cloth itself, especially against the wide variety of bacteria that occurs in domestic and hospital situations. This somewhat unsophisticated method is also costly since every time the fabric is rinsed or washed, the disinfectant is removed and a new aliquot should be applied. The incorporation of an antimicrobial agent into a non-woven fabric has been practiced as a colloidal suspension within an amorphous polymeric binding agent. The antimicrobial is not bound and is available to migrate to the surface of the binding agent. Such systems require an internal reservoir that has a large amount of antimicrobial agent - typically 12 to 30 grams per square yard, and they are more expensive and less durable than what is desired. Cellulose sponges containing zinc pyridinothione are known as an active antibacterial agent. These sponges have the disadvantage that a single wash in a washing machine is enough to remove a large amount of zinc pyridinothione. Therefore, the sponge continues to be an effective weapon against bacteria only for a limited portion of its working life, and can lead to users having little confidence in its potency. The reason why zinc pyridinothione is easily removed under normal washing conditions is that it is mainly hydrolyzed at around pH 11. Zinc pyridinothione is an effective biocide, but it has the defect that its optimum scale of effectiveness is within from the scale of a pH of 4.5 to 9.5. Many detergents and household cleaning agents have pH on this scale (for example, washing powders produce solutions at a pH of around 11 and household bleach has a pH of around 13), and, because in use They present in greater amounts than zinc pyridinothione, they are able to make it ineffective. The use of high concentrations of zinc pyridinothione to compensate for its high loss under domestic cleaning conditions is undesirable since it has some toxicity in humans and is slightly irritable to the skin, and also to the eyes. In addition, zinc pyridinothione has been shown to irremediably leach from the sponge over time. The problem persists of providing a cleaning device, such as a cloth, sponge or the like, that remains effective against a wide variety of bacteria for a significant period of time, and that is non-toxic at the same time. In a surprising way, the inventor has found that one or more selected biocides, for example triclosan, dichlorophen (sometimes known as "dichlorophen" or DCP) or other chlorinated phenolic biocides, phenolic biocides, or trichlorocarbons, in combination with an organometallic biocide, for example a metallic pyridinothione, present a synergy that allows the combination to be effective against a wide variety of bacteria under a large scale of pH conditions. Furthermore, it has also been found that the addition of an acrylate binding agent, with or without other immobilization agents such as PVP, provides the biocidal mixture suitable for incorporation into a substrate, for example a woven or non-woven fabric. It should be noted that said biocide and bonding method is not limited to textiles used for cleaning, but can also be applied to other materials, such as sponges, paper, wound dressings, plastics or even concrete.

BRIEF DESCRIPTION OF THE INVENTION It should be understood that the use of the term "biocide" in the description is used in the sense that it eliminates one or more organisms, and therefore comprises the term "with biocide" and "biostatic" as it is commonly referred to as reducing or maintaining the number of microorganisms in a colony. According to a first aspect, the invention consists of a biocidal composition comprising a first biocide which is a metal pyridinothione; and a second biocide selected because it is biocidally effective on a pH scale complementary to the metal pyridinothione, said second biocide selected from the group consisting of halogenated phenols, phenols, halogenated phenol derivatives, phenol derivatives and trichlorcarban. Examples of derivatives include diphenyl ether derivatives, bridged methylene derivatives and the like. The most preferred compounds are triclosan, dichlorophen and trichlorcarban. Examples of phenolic biocides that may be used include, but are not limited to, ortho-phenylphenol, methyl parahydroxybenzoate, propyl parahydroxybenzoate, ortho-cresol, meta-cresol and para-cresol. Preferably the metal pyridinothione is zinc, sodium or magnesium, and most preferably it is zinc pyridinothione. According to a second aspect, the invention consists of a biocidal cleaning device comprising a biocidal composition according to the first aspect and a substrate. A third aspect of the invention is a method for making a biocide cleaning device comprising the steps of combining a biocidal composition according to the first aspect with a binding agent and contacting the resulting formulation with a substrate. Preferably, the method further includes the step of agglutinating the composition to the substrate.

According to a fourth aspect, the invention consists of a biocidal plastic material comprising a biocidal composition according to the first aspect. According to a fifth aspect, the invention consists in a method for manufacturing a biocidal plastic material according to the fourth aspect comprising the steps of dissolving a biocidal composition according to the first aspect in a plasticizer, then incorporating the plasticizer into a polymer and forming the polymer into a desired shape. Preferably, in a biocide cleaning device the metal pyridinothione is present in amounts up to 2.5% of the weight of the device. Very preferably it is presented in amounts of 0.05 to 1.0% of the weight of the device. Still very preferably it is presented in amounts of 0.1 to 1.0% of the weight of the device. Preferably, in the biocidal cleaning device the second biocide is present in amounts up to 6% of the weight of the device. Very preferably it is presented in amounts of 0.05 to 2.0% of the weight of the device. Still very preferably it is presented in amounts of 0.1 to 2.0% of the weight of the device. Conveniently the biocidal composition is prepared as a concentrate which is diluted before impregnation in a substrate. In the concentrate, the metal pyridinothione is present in amounts of up to 40% w / w, and most preferably from 20 to 30% w / w.

Preferably the second biocide is presented in the biocide concentrate in amounts up to 60% w / w, and most preferably from 20 to 40% w / w. The biocide composition or concentrate may also include, in any combination, a mineral oil, (PVP) polyvinyl pyrrolidone, an alcohol solvent, an anionic surfactant, a nonionic surfactant and water. The substrate for use in the biocidal cleaning device is preferably a cloth. Preferably, the weight of the fabric is around 30 to 200 g / m2, and most preferably from about 30 to 120 g / m2 and the fabric comprises about: 70-100% rayon and 0-30% polyester. Preferably, the fabric also includes 0-30% polypropylene. The substrate can also be a sponge or a synthetic equivalent, paper or woven textile. In the case of a sponge, the weight can be up to 250 g / m2 or more. When the biocidal mixture is bound to a substrate, preferably the binding means comprises a heat activated entanglement reaction. The heat activated entanglement reaction can be carried out by a drum heated by steam or by infrared means. The entanglement reaction can also be activated by UV or visible light, electron beam or the like, or chemical initiation.The binding agent used to attach a biocidal mixture to a substrate can be a polymer or acrylate latex formulation, in particular acrylate copolymers. In making a biocide plastics material, the plasticizer is optionally a hydrocarbon, preferably selected from the group comprising polybutene, low density polyethylene, low density polypropylene and paraffin wax. The plasticizer may also be, for example, an ester preferably selected from the group comprising dibutyl phthalate, dioctyl phthalate, or epoxidized vegetable oil or mixtures thereof. Unless the context clearly requires otherwise, throughout the description and claims, the words "comprises", "comprising", and the like should be considered in an included sense, as opposed to an exclusive or exhaustive sense: that is, in the sense of "including, but not limiting." DETAILED DESCRIPTION OF THE INVENTION Next, the preferred embodiments of the invention will be described only by way of example. In the described embodiments, zinc pyridinothione is used as the first biocide and triclosan as the second. However, it should be understood that the invention is not limited to this embodiment.

The combination of zinc pyridinothione and triclosan or dichlorophen provides important advantages over the use of any disinfectant alone. Zinc pyridinothione is effective at pH scales of 4.5 to 9.5. Since many detergents are strongly basic in nature, they can make zinc pyridinothione ineffective at very high pH. Triclosan, dichlorophen, triclocarban, chlorinated phenolic biocides and phenolic biocides in general, on the other hand, become more effective at higher pH scales, in particular at a pH of 9.5 and above. Under conditions of neutral or near neutral pH, that is, in the absence of large quantities of detergent, both the zinc pyridinothione and the complementary biocide work well. However, zinc pyridinothione, although effective against gram-positive microorganisms, has shown intrinsically limited effectiveness against gram-negative bacteria. Triclosan and dichlorophen, for example, on the other hand while having good gram negative activity are particularly effective against gram positive bacteria. In particular, the combination of zinc pyridinothione and the complementary biocide as described above, shows a marked synergistic effect to eliminate Pseudomonas aeruginosa. The amount of zinc pyridinothione used in the mixture to achieve a given bactericidal result is lower than if it is used alone, with the additional advantage that less of this relatively toxic compound is used.

In this way, the combination of the two active ingredients is effective against a wide variety of microorganisms at neutral pH, and retains a good part of their effectiveness at higher pH, in the presence of detergents. The compositions of the present invention can also be used against mold. Toxicologically, DCP is safer than zinc pyridinothione. The toxicological data are shown in Table 1. It is possible to formulate a biocidal mixture having a high biocidal activity on a wide pH scale, against a broad spectrum of microorganisms, still exhibiting a low level of toxicity in humans.

TABLE 1 PVP (polyvinyl pyrrolidone) can optionally be added as a complexing material. PVP modifies the solubility and dispersibility of the biocide in water, as described in PCT / AU96 / 00224. The ability of PVP to modify solubility and dispersibility has been found to be extremely useful when mixtures of mixed biocide of the present invention are incorporated onto a substrate, eg, a fabric. It has been postulated that the PVP and the second biocidal compound (non-zinc pyridinothione) form a complex that provides excellent agglutination between the fabric and the active ingredients, retaining the biocidal dispersion and providing a longer effective life for the biocidal fabric. A postulated complex is shown in scheme 1. It will be evident that dichlorophen should not be complexed with an individual polymer chain of the PVP, but can be intertwined to one or more chains. Scheme 1 shows the structure of the complex formed between dichlorophen and PVP.

SCHEME 1 Preferably, to disinfect and clean, polyvinylpyrrolidones are used with a degree of polymerization (K value) of 15, 30, 60 and 90, most preferably 90 or vinylacetate copolymers comprising 20 to 80% polyvinylpyrrolidone (most preferably comprising at least 50% vinylacetate and possibly possessing cationic character). For impregnation, the amount of PVP polymer used is preferably in the range of 0.01 to 99.9 parts of the polymer for each part of biocide. Most preferably the polymer is on the scale of 0. 01 to 50 parts and most preferably 0.01 to 10 parts for each part of phenolic biocide. Triclosan, DCP, trichlorocarban or other complementary biocides can be substituted at any time by PVP / DCP, PVP / triclosan, PVP / trichlorocarban of PVP / complementary biocidal combination. The addition of a binding agent such as an acrylate increases the binding of the biocide in a woven or nonwoven fabric. The addition of polyvinylpyrrolidone has also been shown to increase the binding of biocidal agents to the fabric, either alone or in combination with the acrylate binding agent. Importantly, it has been shown that the addition of polyvinylpyrrolidone limits the biocide, so as the surface wears, fresh biocide is exposed to the fresh surface. The biocidal mixture in any of its forms can be mixed in binding agents such as crystalline networks or acrylic or acrylic copolymer solutions, crystalline networks of PVA or crystalline networks or solutions of PVA copolymer, or any other latex, solution or polymer mixture of any of the polymers described above. The biocidal mixture, with or without PVP or binding agents can be used for the treatment of any type of substrate, including woven or non-woven textiles, fabrics, sponges, abrasives and the like, paper or any other material. The treatments can be applied from solutions, suspensions or emulsions at room temperature or other operating temperatures. The inclusion of a mineral oil and an acrylate binding agent in any of the above formulations may increase the proper character of the biocidal mixture for fabric impregnation. The most suitable fabrics for impregnation with the biocide mixture are those that are rayon / polyester fabrics that contain 70 to 100 percent rayon, although most known fabrics work properly. In particular, fabrics with a weight of around 30 and 200 g / m2 and especially 30 and 120 g / m2 have proven to be the most suitable. Plasticizers are commonly added to synthetic polymers to modify their hardness and / or flexibility. Some common plasticizers are hydrocarbon polymers, such as polybutene, low density polyethylene, low density polypropylene and paraffin wax. Other commonly used plasticizers are esters, such as dibutyl phthalate, dioctyl phthalate and similar esters, such as epoxidized vegetable oils or mixtures thereof and similar ester. The biocidal combination can be dissolved in a plasticizer or plasticizers and then integrated into a polymer that is molded by extrusion, injection molding or some other process. The resulting article will resist the growth of microorganisms on the surface of the article by virtue of the incorporated biocides. If the plasticizer is selected to be incompatible with the binding agent material, it is slowly removed by leaching, carrying effective amounts of the biocidal composition with it to the surface. One use of particular interest is on materials used is evaporative cooling systems. Such systems typically carry a wide range of bacterial varieties, including legionella. The use of a bactericide agglutinated in such systems will provide a low but long-lasting level of activity against bacteria. Such systems typically use a number of plastic plates, and if they are impregnated with a biocide mixture and a binding agent that was incompatible with the plastic, to slowly leach out to the surface, it will provide a constantly self-renewing biocidal active surface.

EXAMPLES EXAMPLE 1 Formulation of biocide concentrate The following formulation was prepared: Raw material% p / p Zinc pyridinothione 17.19 Dichlorofen 34.39 Mineral oil 22.92 PVP 8.44 Ethanol 3.44 Sodium lauryl ether sulfate 0.70 Dioctyl Sulfoccinate 1.50 Water c.b.p. 100% EXAMPLE 2 Alternative biocide concentrate Raw material% p / p Zinc pyridinothione 24.60 Dichlorofen 24.60 Mineral oil 16.40 PVP 7.20 Ethanol 2.40 Sodium lauryl ether sulfate 0.70 Dioctyl Sulfoccinate 1.50 Water c.b.p. 100% EXAMPLE 3 Formulation of the binding agent Crude material% p / p Self-entangling binder emulsion of 46.0 acrylic polymer (approx 56% solids) Foam anti-foaming emulsion 0.15 (Foam Master, Henkel) Emulsion to control the viscosity of acrylic copolymer 3.60 (Latekol DG, BASF) Dioctyl sulfosuccinate sodium 1.0 Ammonium hydroxide (30%) 1.0 Ammonium nitrate 1.0 Dispersion of dye for standard color cbp Water 47.25 The acrylic polymer binding emulsions are of a kind of soft entanglement formulated with good resistance and rewet properties for use in non-woven applications.

EXAMPLE 4 Application to fabric In this process, textile fiber bales are fed into a machine for making bound, carded or hydroentangled nonwoven fabric. These fibers can be of a single type or of various combinations, for example, most of the bonded non-woven fabrics used for rubbing fabrics are made of rayon fibers or a combination of rayon and polyester fibers.

In the joining process, carding, the fibers are entangled together by one or more units in series, while the entanglement takes place using water jets at high pressure in hydroentanglement. In both cases, at the end of the entanglement stage, the material is in the form of a continuous tape and is a little wet due to the waste water that has been used in the course of each procedure. Then, the wet web is printed using a suitable dilution of the concentrate of example 1 or 2 and the binding agent of example 3, which is applied in isolated areas of the tape. The wet printed tape passes through a heated zone to dry the printed fabric and interlock the polymeric bonding agent. These heated zones are usually composed of steam-heated drums over which the cloth passes and is dried by contact, or by infrared lamps that heat by radiation, or combinations thereof. This dry printed tape is rolled up for future cutting and cutting into strips.

EXAMPLE 5 Simulated fabric life cycle The treated fabric is placed in an automatic domestic laundry washing machine set in a warm wash (35 ° C). Five wash cycles are applied which constitute the simulated fabric life. At the end of the five wash cycles, the fabric undergoes the following tests to validate that the biocidal performance remains effective at the end of the working life of the fabric.

EXAMPLE 6 Standard sensory tests The standard sensory tests (tests to check if it stays fresh) are applied to the fabric to examine the fabric's resistance to odors produced by bacterial attack on food residues trapped in clothing in the normal course of kitchen use. The biocidal fabrics produced according to the invention gave good results when they were subjected to the following tests: AS 2609.1, AS 2542.1.1, As 2542.1.2 and AS 2542.2.3 EXAMPLE 7 Standard quantitative microbiological test A biocidal fabric according to the invention was subjected to a standard quantitative test for microorganisms, "Assessment of Antibacterial Finishes on Textile Materials ": AATCC Test Method 100- 1993. This test is designed specifically to evaluate the biocidal properties of cloth treatments.These treatments are designed to eliminate microorganisms inside the fabric, rather than on surfaces that are put on in contact with the fabric.

EXAMPLE 8 Table II shows the effect of Pseudomonas aeruginosa on cloth impregnated with zinc pyridinothione (0.85%), a second cloth impregnated with dichlorophen (0.85%) and a third cloth impregnated with a combination of dichlorophen (0.5%) and zinc pyridinothione ( 0.5%). The weights are given in relation to the weight of the dry cloth. A positive sign indicates an increase in the bacterial population and a negative sign shows a decrease.

TABLE II Although the invention has been described herein with reference to zinc pyridinothione, those skilled in the art will appreciate that the use of other metal pyridinothiones also form part of the same inventive concept.

Claims (50)

NOVELTY OF THE INVENTION CLAIMS

1. - A biocidal concentrate comprising: a first biocide which is a metal pyridinothione; and a second biocide selected to be biocidally effective on a pH scale complementary to said metal pyridinothione, said second biocide is selected from the group consisting of: halogenated phenols, phenols, halogenated phenol derivatives, phenol derivatives and trichlorocarban.

2. A biocidal concentrate according to claim 1, further characterized in that said metallo-pyridinothione is zinc pyridinothione.

3. A biocidal concentrate according to claim 1, further characterized in that said metallo-pyridinothione is sodium pyridinothione.

4. A biocidal concentrate according to claim 1, further characterized in that said metallo-pyridinothione is magnesium pyridinothione.

5. A biocidal concentrate according to any of claims 1 to 4, further characterized in that the second biocide is dichlorophen.

6. - A biocidal concentrate according to any of claims 1 to 4, further characterized in that the second biocide is triclosan.

7. A biocidal concentrate according to any of the preceding claims, further characterized in that said metal pyridinothione comprises 5-25% w / w of the mixture.

8. A biocidal concentrate according to any of the preceding claims, further characterized in that said metal pyridinothione comprises 11-16% w / w of the mixture.

9. A biocidal concentrate according to any of the preceding claims, further characterized in that said second biocide comprises 32-37% of the mixture.

10. A biocidal concentrate according to any of the preceding claims, further characterized in that said second biocide comprises 25-45% w / w of the mixture.

11. A biocidal concentrate according to any of the preceding claims, further characterized in that it includes a mineral oil.

12. A biocidal concentrate according to any of the preceding claims, further characterized in that it includes polyvinylpyrrolidone.

13. - A biocidal concentrate according to any of the preceding claims, further characterized in that it includes an alcohol solvent.

14. A biocidal concentrate according to any of the preceding claims, further characterized in that it includes water.

15. A biocidal cleaning device comprising: a biocidal concentrate according to any of claims 1 to 14; and a substrate.

16. A biocidal cleaning device according to claim 15, further characterized in that the metal pyridinothione is present in an amount of up to 2.5% of the weight of the device.

17. A biocidal cleaning device according to claim 15 or 16, further characterized in that the metal pyridinothione is present in an amount of 0.05-1.0% of the weight of the device.

18. A biocidal cleaning device according to any of claims 15-17, further characterized in that the metal pyridinothione is present in an amount of 0.1-1.0% of the weight of the device.

19. A biocidal cleaning device according to any of claims 15-18, further characterized in that the second biocide is presented in an amount up to 6% of the weight of the device.

20. - A biocidal device according to any of claims 15-19, further characterized in that the second biocide is presented in an amount of 0.05-2.0% of the weight of the device.

21. A biocidal cleaning device according to any of claims 15-20, further characterized in that the second biocide is present in an amount of 0.1-2.0% of the weight of the device.

22. A biocidal cleaning device according to any of claims 15-21, further characterized in that the substrate is fabric.

23. A biocidal cleaning device according to claim 22, further characterized in that the weight of the fabric is 30-200 g / m2.

24. A biocidal cleaning device according to any of claims 22 or 23, further characterized in that the weight of the fabric is 30-120 g / m2.

25. A biocide cleaning device according to any of claims 22-24, further characterized in that the fabric comprises: 70-100% rayon; and 0-30% polyester.

26. A biocidal cleaning device according to claim 25, further characterized in that it comprises 0-30% polypropylene.D.

27. - A biocidal cleaning device according to any of claims 15-21, further characterized in that the substrate is sponge or a synthetic equivalent.

28. A biocidal cleaning device according to claims 15-21, further characterized in that the substrate is paper.

29. A biocidal cleaning device according to claims 15-21, further characterized in that the substrate is woven fabric.

30. A method for preparing a biocide cleaning device comprising the steps of: combining a biocidal concentrate according to any of claims 1 to 14 with a binding agent; contacting the resulting formulation with a substrate; and joining the formulation to the substrate with bonding means.

31.- A method according to claim 30, further characterized in that said joining means are in the form of a heat treatment.

32. A method for producing a biocidal cleaning device according to claim 31, further characterized in that the heat treatment is carried out by a drum heated with steam.

33.- A method for preparing a biocide cleaning device according to claim 31, further characterized in that the heat treatment is applied by infrared means.

34. - A method according to claim 30, further characterized in that said joining means are in the form of ultraviolet light or visible light.

35. A method for preparing a biocide cleaning device according to any of claims 30-34, further characterized in that the binding agent is a polymer latex formulation.

36. A method for preparing a biocidal cleaning device according to any of claims 30-34, further characterized in that the binding agent is acrylate.

37.- A method for making a biocide cleaning device according to any of claims 30-36, further characterized in that the substrate is selected from the group consisting of cloth, sponge or a synthetic equivalent, paper and woven textiles.

38.- A method for preparing a biocide cleaning device according to any of claims 30-37, further characterized in that the absorbent material is fabric.

39.- Biocidal plastic material that incorporates a biocidal concentrate according to any of claims 1-14.

40. A method for making a biocidal plastic material comprising the steps of: a) dissolving a biocidal mixture according to any of claims 1-14 in a plasticizer; b) incorporating the plasticizer-biocidal mixture formed previously into a polymer; and c) forming the plastic in the desired figure. 2

41. - A method for making a biocide plastic material according to claim 40, further characterized in that the plasticizer is a hydrocarbon.

42. A method for making a biocidal plastic material according to claim 41, further characterized in that the plasticizer is selected from the group comprising polybutene, low density polyethylene, low density polypropylene and paraffin wax.

43.- A method for making a biocidal plastic material according to claim 40, further characterized in that the plasticizer is an ester.

44. A method for making a biocidal plastic material according to claim 43, further characterized in that the plasticizer is selected from the group comprising dibutyl phthalate and dioctyl phthalate.

45. A method for making a biocidal plastic material according to claim 43, further characterized in that the plasticizer is an epoxidized vegetable oil or a mixture thereof.

46.- A biocide concentrate substantially as described herein with reference to any of the examples.

47.- A biocide cleaning device substantially as described herein with reference to any of the examples.

48. - A method for making a biocide cleaning device substantially as described herein with reference to any of the examples. 49.- A biocidal plastic material substantially as described herein with reference to any of the examples. 50.- A method for making a biocidal plastic material substantially as described herein with reference to any of the examples.