Non-woven fabric containing a biocide and method of manufacture thereof

Abstract: A non-woven fabric is provided wherein the binder includes at least one phenolic biocide, a water soluble film forming polymer, and at least one surfactant. A method of impregnating a fabric to prevent rot is also provided, which comprises contacting a non-woven fabric with a biocidal preparation containing at least one phenolic biocide, a water soluble film forming polymer, and at least one surfactant.

Description: The present invention relates to a biocidal preparation, in particular to a non-woven fabric. The invention has been developed for use as an impregnation agent. Biocides are chemical compositions that are widely used in industry for disinfection and to prevent microbiological contamination and deterioration of commercial products, materials and systems. Of the biocides presently available, phenolic biocides are widely used. In general, phenolic biocides are colorless and have minimal toxicological effects to humans i.e. cause little or no irritation to the skin. Although most phenolics have a characteristic odor, some of them, such as phenylphenols and dichlorophenes have little odor and others, such as triclosan have none. These properties are desirable as they enable such biocides to be used as an ingredient in orally administered pharmaceutical preparations; as an approved biocide for use in food establishments and plants; and in packaging material. Phenolic biocides also have other desirable properties including a wide biocidal spectrum against microorganisms such as bacteria and fungi; residual bacteriostatic properties; and unlike other biocides are not readily deactivated by organic matter, such as blood, serum and milk. These biocides therefore have a wide application as disinfectants and antimold products in general household, industrial, and other areas requiring disinfection, as they can be used in the destruction of the microorganisms present or the prevention of their further proliferation to numbers that would be significantly destructive to the substrate or system being protected. An example of a phenolic biocide is dichlorophene which, in addition to its antibacterial properties, is particularly effective against fungi, such as yeast mold and mildew. This property enables such derivatives to be used mainly as a preservative against mildew and rot in a variety of products including paper and textiles. Another example of a phenolic biocide used is trichloro hydroxy diphenyl ether (Triclosan) which is an effective ingredient in deodorant and in skin cleansing preparations. Hitherto, phenols have been used in industrial cleaners in an aqueous solution at very high pH (above pH 11). The use of cleaners with such high pH is undesirable in households. In order to overcome this problem, phenols have been used in alcoholic solution but such use leaves visable surface residues and is disadvantageous for household use. To obtain aqueous detergent solutions of phenolic biocides they have first to be converted into their water soluble alkali salts, usually with sodium hydroxide, resulting in alkaline solutions of a pH of at least 11.0. The high alkalinity of these solutions excludes them from application in households and on surfaces susceptible to deterioration by alkalis. Their use has therefore been restricted to industrial cleaners for stainless steel equipment and hard floor surfaces in food processing and glass bottle washing plants and other industrial plants and areas where the higher alkalinity is acceptable. When dissolved in an alcoholic-aqueous mixture with the addition of a small amount of a suitable surfactant to form a disinfectant cleaning preparation, such a solution will on drying leave streaks and partly greyish areas on treated surfaces due to the remaining insoluble residues of the biocide. Triclosan which finds its main application in antiseptic skin and hand cleansing preparations has been either used in suspension, or solubilized with nonionic surfactants with resultant loss in activity. In mildew and rot proofing of paper and textiles phenylphenol and especially dichlorophene are widely used as their sodium salt solution for the impregnation of these materials against fungal infection and prevention of mold formulations. The high alkalinity of these solutions causes weakening of the strength of fibers and loss of the biocides either by leaching out in moist climates or by lack of binding to the surfaces treated. This has been prevented in the past by neutralization of the alkali salt and/or bonding the biocides by means of a metal salt such as zirconium acetate. These processes necessitate a further manufacturing procedure, use of additional equipment and additional cost for the neutralising agent. These additional measures are required as bonding the biocidal agent onto the material to be protected was not always effective, especially when prolonged periods of protection were required. It is therefore an object of the invention to ameliorate at least some of the above disadvantages. WO-A-86/05391 discloses compositions including phenolic biocides with film formers and modes of delivery of the compositions by means of a container with a pad. WO-A-93/21899 discloses disinfecting compositions which may cntain phenolic biocides , surfactants, film formers, and which may be absorbed on non-woven fabrics. The invention provides a non-woven fabric treated with a biocidal composition for rot proofing, comprising at least one biocide, which is a halogenated phenolic biocide or o-phenyl phenol, a water soluble film forming polymer being a polyvinylpyrrolidone polymer or co-polymer, and at least one surfactant, wherein a complex is formed between the biocide and the water soluble film forming polymer, wherein said complex dries to form a clear film. The film forming polymer may be polyvinylpyrrolidone or its copolymer with vinylacetate, or polyvinyl-maleic copolymer. The phenolic biocides may be selected from the group consisting of pentachlorophenol (PCP); p-chloro-m-xylenol (PCMX), hexachlorophene; o-phenylphenol, dichlorophene; chlorophene; bromophene; triclosan or a combination thereof. The invention also provides a method of impregnating a fabric to prevent rot, comprising contacting a non-woven fabric with a biocidal composition containing at least one biocide, which is a halogenated phenolic biocide or o-phenyl phenol, a water soluble, film forming polymer, which is a polyvinylpyrrolidone polymer or copolymer; and at least one surfactant, wherein a complex is formed between the biocide and the water soluble film forming polymer, wherein said complex dries to form a clear film. The amount of polymer used may be within the range of from 0.01 to 99.9 parts of polymer per 1 part of phenolic biocide. The amount of uptake of the biocide is preferably between 0.05% to 1% based on the weight of the fabric. The film forming polymers preferably used in the present invention are polymers in which the biocide is soluble, and are usually selected based on their intended application. Polyvinylpyrrolidone (PVP) and its copolymers with vinylacetate aminoacrylates and trimethylammonium chloride are a preferred choice for disinfecting surface cleaners with residual biocidal activity and polyvinyl-maleic copolymers for impregnation of paper and textile materials. For impregnation, the amount of polymer used is preferably in the range of from 0.01 parts of the polymer to 99.9 parts of polymer for each 1 part of phenolic biocide. More preferably the polymer is in the range of from 0.01 to 50 parts and most preferably from 0.01 to 1 part for each part of phenolic biocide. Preferably, the phenolic biocides are selected from the group consisting of pentachlorophenol (PCP); p-chloro-m-xylenol (PCMX); hexachlorophene; o-phenylphenol; dichlorophene; chlorophene; bromophene; Triclosan or a combination of these biocides. . The concentration of the biocides used for the impregnation of paper and textiles is often dependent on the method of preparation. Preferably, the amount of uptake is between 0.05 to 1.0% based on the weight of the material. More preferably the range is between 0.1 to 0.5% by weight of the material. Including a small amount of a surfactant in an impregnation solution ensures uniform wetting of the treated material. Suitable anionic surfactants include sodium salts of dodecylbenzenesulphonate and laurylether sulphate; phosphate esters of nonylphenolethoxylates; nonylphenoxyphosphoric acid esters or a combination of these surfactants. A preferred surfactant is the sodium salt of dodecylbenzenesulphonate which can be used on its own or in combination with another anionic surfactant. An effective amount of surfactant will depend on the intended application of the final product. For impregnation of paper and textile materials the content of the surfactant will be much lower as their purpose is only in wetting the surfaces of the paper and textile fibers and assuring better penetration. Suitable alcohols, include any water soluble lower alkyl alcohols such as methanol and ethanol, but higher alkyl alcohols, such as iso- and n-propanol, may be used on their own or in combination with lower alcohols preferably in an amount not exceeding 30% weight by volume in disinfectant cleaner and impregnation liquid. It is advantageous where a higher degree of disinfection is desired, to include one or more aromatic alcohols, such as benzyl-, phenoxy-and dichlorobenzylalcohol generally in an amount of not more than 2.0% by weight. Example of Impregnation Fluid Formulations prepared for this purpose will depend on the type of material to be impregnated, the degree of rot proofing required and the type and conditions of application. The recommended phenolic biocide for that purpose is dichlorophene with a deposit of 0.1-0.7% by weight of the material for textiles and 0.05-0.5% by weight of the material for paper. Film forming polymers to be used would be a polyvinyl maleic polymer, such as Gantrez AN (GAF Inc.). The alcohol could be isopropyl and the concentration of the anionic surfactants would be sufficient to obtain satisfactory wetting of the surfaces to be treated. Due to possible excessive foaming in some formulations, a de-foaming agent(s) is sometimes added. A typical formulation for the impregnation of a non-woven cloth would be: Dichlorophene 12.0 kg Gantrez AN 119 0.3 g Empicol SQ770 2.75 g Ven Gell B 0.5 kg Water to make 30.0 kg The components are mixed into a uniform slurry. The amount is incorporated into 200 kg of a standard binder--resulting in an active content of dichlorophene of about 5.0% by weight. At an average pick-up of the binder of 7 g/sq meter, the deposit of the biocide will be approximately 0.3% by weight.

Claims: A non-woven fabric treated with a biocidal composition for rot proofing, comprising at least one biocide, which is a halogenated phenolic biocide or o-phenyl phenol, a water soluble film forming polymer being a polyvinylpyrrolidone polymer or co-polymer, and at least one surfactant, wherein a complex is formed between the biocide and the water soluble film forming polymer, wherein said complex dries to form a clear film. A non-woven fabric according to claim 1 wherein the film forming polymer is polyvinylpyrrolidone or its copolymer with vinylacetate, or polyvinyl-maleic copolymer. A non-woven fabric according to claim 1 or 2 wherein the phenolic biocide is selected from the group consisting of pentachlorophenol (PCP); p-chloro-m-xylenol (PCMX); hexachlorophene; o-phenylphenol; dichlorophene; chlorophene; bromophene; triclosan or a combination thereof. A method of impregnating a fabric to prevent rot comprising contacting a non-woven fabric with a biocidal composition containing at least one biocide, which is a halogenated phenolic biocide or o-phenyl phenol, a water soluble, film forming polymer, which is a polyvinylpyrrolidone polymer or copolymer; and at least one surfactant, wherein a complex is formed between the biocide and the water soluble film forming polymer, wherein said complex dries to form a clear film. A method according to claim 4 wherein the amount of polymer used is within the range of from 0.01 to 99.9 parts of polymer per 1 part of biocide. A method according to claim 4 or 5 wherein the amount of uptake of the biocide is between 0.05% to 1% based on the weight of the fabric.

Inventors: KRITZLER STEVEN, KRITZLER, STEVEN
Applicants: NOVAPHARM RES AUSTRALIA, NOVAPHARM RESEARCH (AUSTRALIA) PTY. LIMITED
Application year: 1996
Main classification: A61L2
IPC codes: D06M13, C11D11, D06M16, C11D3, A01N31, D06M15, A01N25