A WIPING PRODUCT

Abstract: The present invention relates primarily to a product for use in the disinfection of hard surfaces, instruments and human or animal skin. The product comprises a lofted non-woven substrate having entrapped within its structure solid particles of a chlorine release agent which, when dampened with a suitable liquid, become active. Preferably, the chlorine release agent comprises sodium dichloroisocyanurate, which becomes active when dampened with water. An indicator, such as a dye, which is acted on by the activated particles is also preferably incorporated in the substrate to give an indication of the status of the product with regard to the exhaustion of the particles therefrom. Apart from use as a wipe, the product can also be used as a sheet inclusion in processes such as a washing process for the quantitative release of the chlorine for the purpose of disinfection or bleaching.

Description: A WIPING PRODUCT The present invention relates primarily to a wiping product suitable for use in the disinfection of hard surfaces, instruments and human or animal skin. . Normally, such disinfection is accomplished by applying a disinfectant chemical or formulation to the surface, instrument or skin and acσommpanying this by spreading the disinfectant using a wiping material to ensure uniform coverage and therefore disinfection. To facilitate this, there have been developed wiping products comprising cloths, sponges, pads or other substrate materials which are either impregnated with disinfectant or retain a disinfecting agent within one or more pockets formed in the substrate material. These products are usually either pre-moistened in their packaging or require to be dampened before use. For example, United States Patent Specification No. 4,259,383 describes a tissue incorporating a disinfecting agent capable of generating hydrogen peroxide when wet. In a first example given in this specification, the disinfecting agent is sealed within a single pocket made between two layers of adsorbent non-woven paper and, in a second example, the disinfecting agent is sealed within a series of rhomboidally shaped pockets uniformly distributed over the length of the paper tissue. However, such products have a number of drawbacks and limitations in their use. In particular, the disinfectants that it is practical to use to impregnate such wipes have hitherto been limited and those used have not had a sufficient spectrum of activity, that is the ability to kill quickly and efficiently the more resistant micro-organisms such as Mycobacterium tuberculosis, Hepatitis B virus, Parvoviruε, or Polio virus. With particular reference to the surface test results given in Example 1 of the aforementioned U.S. Patent Specification, it is insufficient in many practical applications of a disinfecting wipe for the killing time for various micro-organisms to be of the order of one hour. In order to kill the afore-mentioned micro¬ organisms, it is necessary to use a "high level" or "intermediate" disinfectant, such as chlorine or a chlorine releasing compound, but using conventional methods of impregnation or coating it is not possible to treat a wiping substrate with a chlorine containing chemical and attain a stable and an effective product. Owing to their lack of stability, the application of chlorine donor disinfectants in an aqueous solution or dispersion is not feasible. The same applies to many other disinfectants with a wide spectrum of activity. However, were it not for this lack of stability, chlorine, which is an effective hard surface disinfectant as it is of wide spectrum, is fast acting and does not leave a sticky or smearing residue, would be an excellent agent for inclusion in a wiping product. The object of the present invention is primarily to provide a product suitable for use as a disinfecting wipe which overcomes the afore-mentioned disadvantage and which has a useful shelf-life. In addition, one further disadvantage of wipes or tissues such as are described in the aforementioned U.S. Patent Specification wherein an active disinfecting agent is sealed within one or more pockets formed between layers of the tissue is that the disinfecting agent tends to accumulate at the bottom of the pockets during storage and is not, therefore, uniformly distributed throughout the tissue. The disinfecting ability of the tissue can, as a result, be impaired. It is a further object of the present invention to overcome this disadvantage. According to the present invention there is provided a product comprising a non-woven substrate having entrapped within its structure solid particles which, when dampened with a suitable liquid, become active and characterised in that the non-woven substrate has been lofted to form a matrix of fibres and in that the solid particles comprise a chlorine release agent and are substantially uniformly distributed throughout and entrapped within the matrix by the fibres forming the substrate. Preferably, the chlorine release agent becomes active when dampened with water. The chlorine release agent may, for example, comprise one or more of the following chemicals: calcium hypochlorite; chlorinated tri-sodium phosphate; N,N dichlorazo-dicarbonamidine; sodium p toluene sulphon-chlora ide; p toluene sulphondichloramide; sodium benzene sulphonchloramide; suσcinchlorimide; p-εulphon-dichloramidobenzoic acid; 1,3 dichloro-5-5 diethyl hydantoin; trichloro- isoσyanuric acid; sodium dichloroisocyanurate; sodium dichloroisocyanurate dihydrate; potassium dichloroisocyanurate; or trichloromelamine. In addition, other chlorine release agents can be used which are either solid or which may be rendered as powders or granules by adsorption on to a suitable carrier. Additionally, a chlorine release agent -may be used in combination with other compounds such as a detergent, for example sodium alkylbenzene sulphonate, or sodium Iauryl sulphate, or a detergent builder, for example sodium carbonate, sodium, metasilicate, or sodium sulphate. Other compounds which may be used in this way include superabsorbent polymers, fragrances, perfumes or dyes. If the product is to be used as a wipe for disinfecting surfaces, then a dye may be incorporated into the substrate so that it is bleached by the activated particles and thereby provides a visual indication of the status of the product with regard to the exhaustion of the product's disinfecting properties. Preferably, the loftable nonwoven substrate iε laminated on one or on both sides with another material through which the solid particles are unable to pass. This laminate material may, for example, comprise either a nonwoven or a textile material, or paper, or a sponge material, or a plastics film depending on the use for which the product is designed. In some cases, it may be preferable for the laminate material to be hydrophobic and impermeable or alternatively a high water absorption may be desirable. It will be appreciated that although the major purpose of this invention is to provide a product suitable for wiping and disinfecting surfaces, it is possible to utilise a product of similar physical characteristics for other purposes. For example, it could be used as a sheet inclusion in a washing process for the quantitative release of chlorine either for the purpose of disinfection or bleaching. The present invention will now be described in more detail by means of the following three examples. In all of the examples, the loftable non-woven substrate employed is a non-woven fabric comprising a carded web of fibres bonded together with a thermoplastic material, which, when heated to the softening point of the binding material, will transform into a high loft, even density structure. The loftable nature of the fabric is achieved by the use of crimped fibres which are held in a compact form by the thermoplastic bonding material, usually a low temperature adhesive polymer, and which on heating of the fabric to soften the bonding material spring apart to form an even density matrix. Different textile fibres can be used but preferred fibres are polyester or viscose or combinations of polyester with viscose or other cellulosic fibre. Such substrates are available commercially under the trade name ULTRALOFT. However, any non-woven material capable of trapping solid particles could be used as the substrate of the product. In a first example, the substrate comprises a 48 grams per square metre polyester bonded material which is laminated with a 24 grams per square metre polyester dry lay non-woven material. The combined material is firstly passed beneath a medium wave infra-red heater in order to loft the substrate layer and then subjected to a uniform scattering of particulate sodium dichloroisocyanurate dihydrate over the lofted substrate. Preferably, the particles are of a size within the range of 200 - 750 microns inclusive so that they penetrate the substrate to give an available chlorine content of 5,000 ppm when activated by absorption of the product's maximum level of water. The second example utilises a substrate comprising a 40 gram per square metre rayon fibre nonwoven material bonded by a polyester thermoplastic. This substrate is laminated with a 24 gram per square metre polyester dry-lay nonwoven material. As in the first example, the substrate is lofted by infra-red heat but the substrate is then stretched by passing it over a bowed roller in order to increase temporarily the openness of the substrate's structure. During this stretching, the substrate is subjected to a uniform scattering of a powder formulation comprising 95% sodium dichloroisocyanurate dihydrate and 5% sodium alkyl benzene εulphonate. The powder penetrates the stretched substrate and is then trapped when the stretching ceases and the substrate is relaxed. Sufficient powder penetrates the substrate in this example to give an available chlorine content of 1,000 ppm when activated by absorption of the product's maximum water level . In a third example, the substrate comprises a 108 gram per square metre 100% polyester material which is again lofted by medium wave infra-red heat. A powder composition comprising sodium dichloroisocyanurate dihydrate together with a proportion of a superabsorbent polymer, such as is commercially available under the trade mark SALSORB of Allied Colloids PLC, is then rolled into the substrate so that penetration of the lofted substrate by the powder occurs. Sufficient powder penetration can be achieved to give an available chlorine content of 100 ppm when the product has absorbed its maximum level of water. These examples serve to describe the invention more clearly. They should not be construed as qualitatively or quantitatively limiting the scope of the invention. It is, for example, readily possible to achieve available chlorine contents in excess of 5000 ppm. It will be appreciated that in all the above examples a quantitatively measurable amount of the chlorine release agent is trapped in the matrix formed by the lofted substrate. This amount can be varied over a wide range to enable the finished wiping product to function as a sanitiser at one end of the range or as a heavy duty disinfecting product at the other end of the range. The integrity of the finished product, particularly with regard to the firmness of inclusion of the applied solid particulate formulation, may be further influenced by a partial resealing or compacting of the lofted substrate. This may be achieved by pressure or by a combination of heat and pressure, for example by a suitable arrangement of nip rol lers . In use, if the product is to be used as a wipe for disinfecting surfaces then it is advantageous if a visual indicator is incorporated into the wipe to show the status of the disinfecting capability of the wipe at any given time. Such a visual indicator can be incorporated into the product by dyeing all or portions of the substrate with a dye which is bleached at a known rate by the chlorine released once the wipe is used. Preferably, the indicator dye gradually fades or disappears from the substrate at a similar rate to the rate at which the proportion of unreleased chlorine within the wipe decreases during use. If the substrate material employed in the product incorporates cellulosic fibres, suitable dyes have been found amongst those capable of dyeing cellulosic fibres, for example amongst the so-called "reactive dyes". Such dyes are marketed by ICI pic under its trade mark PROCION, Ciba Geigy pic under its trade mark CIBACRON, and Sandoz pic under its trade mark DRIMARENE. Of these, the dyes which have been found to be particularly useful are PROCION yellow MX-8G, PROCION red MX-5b, PROCION red HE-3B, and PROCION navy MX- D. It has also been found possible to combine dyes, which are bleached by the chlorine released by the product, with other dyes, which are totally resistant to chlorine bleaching, to produce colour changes or colour disappearances which can also be used to signal the effective chlorine level available in the product. These other chlorine resistant dyes can be other forms of reactive dye or other types of cellulose dyes. In practice, the substrate used in the product of the invention is dyed with one or more stripes of the dye ot dyes before being lofted and impregnated with the chlorine releasing particles. The dyeing process can, therefore, form a stage in the production process of the product, as described in the above examples, and the use of cold acting reactive dyes is advantageous in this regard.

Claims: CLAIMS 1. A product comprising a nonwoven substrate having entrapped within its structure solid particles which, when dampened with a suitable liquid, become active and characterised in that the nonwoven substrate has been lofted to form a matrix of fibres and in that the solid particles comprise a chlorine release agent and are substantially uniformly distributed throughout and en "-*pped within the matrix by the fibres forming the substrate. 2. A product as claimed in Claim 1, characterised in that chlorine release agent becomes active when dampened with water. 3. A product as claimed in Claim 1 or Claim 2, characterised in that the chlorine release agent comprises one or more of the following chemicals: calcium hypochlorite; chlorinated tri-sodium phosphate; N,N dichlorazo-diσarbona idine; sodium p toluene sulphondichloramide; p toluene sulphon- dichlora ide; sodium benzene sulphonchloramide; succinchlorimide; p-sulphondichloramidobenzoic acid; 1,3 dichloro-5-5 diethyl hydantoin; trichloro- isocyanuric acid; sodium dichloroisocyanurate; sodium dichloroisocyanurate dihydrate; potassium dichloroisocyanurate; trichloromelamine. 4. A product as claimed in any one of Claims 1 to 3, characterised in that the solid particles comprise a chlorine release agent in combination with a detergent or a detergent builder. 5. A product as claimed in any one of Claims 1 to 3, characterised in that the solid particles comprise a chlorine release agent in combination with one or more of the following chemicals: sodium alkylbenzene sulphonate; sodium lauryl sulphate; sodium carbonate; sodium etasi1icate; sodium sulphate. 6. A product as claimed in any one of Claims 1 to 5, characterised in that the particles are of a size within the range of 200 to 750 microns inclusive. 7. A product as claimed in any one of Claims 1 to 6, characterised in that the substrate is laminated on one or on both sides with another material through which the solid particles are unable to pass. 8. A product as claimed in any one of Claims 1 to 7, characterised in that an indicator is incorporated with the substrate, which indicator is affected by the activated particles to provide an indication of the status of the product with regard to the exhaustion of the particles therefrom. 9. A product as claimed in Claim 8, characterised in that the indicator is a dye which is bleached out by the chlorine when released from the particles to provide a visual indication of the status of the product. 10. A product as claimed in Claim 9, characterised in that the indicator is combined with a second dye which is resistant to chlorine bleaching so that there is a colour change in or a colour disappearance from the substrate when chlorine is released from the particles to provide the visual indication of the status of the product. 11. A product as claimed in any one of Claims 1 to 10, characterised in that the substrate has been at least partially sealed after entrapment of the solid particles therein either by the application of pressure thereto or by a combination of the application of heat and pressure thereto. 12. A product as claimed in any one of Claims 1 to 11, characterised in that the substrate comprises a web of fibres bonded together with a thermoplastic material, the fibres comprising either polyester fibres or cellulosic fibres or a combination of polyester and cellulosic fibres.

Inventors: FELLOWS ADRIAN NEVILLE, FELLOWS, ADRIAN, NEVILLE
Applicants: FIBRE TREATMENTS HOLDING LTD, FIBRE TREATMENTS (HOLDINGS) LIMITED
Application year: 1988
Main classification: A01N25
IPC codes: A01N25