Patent Application
20080095828
The use of the terms “a,” “an,” “the,” and similar articles in the context of describing the invention are to be construed to cover both the singular and the plural, unless otherwise indicated herein or clearly contradicted by context.
Recitation of ranges of values herein are merely intended to serve as a shorthand method of referring individually to each separate value falling within the range, unless otherwise indicated herein, and each separate value is incorporated into the specification as if it were individually recited herein. All methods described herein can be performed in any suitable order unless otherwise indicated herein or otherwise clearly contradicted by context. The use of any and all examples, or exemplary language (e.g., “such as”) provided herein, is intended merely to better illuminate the invention and does not pose a limitation on the scope of the invention unless otherwise indicated.
Various embodiments of the invention describe a method for treating a surface using a cleaning substrate or article. The cleaning substrate comprises of a nonwoven web, chemical actives incorporated into the nonwoven web, and hydrophilic materials incorporated into the nonwoven web.
In accordance with an embodiment of the invention, the nonwoven web may include nonwoven fibrous sheet materials. In accordance with another embodiment of the invention, the nonwoven web includes, but is not limited to, meltblown, coform, air-laid, spun-bound, wet-laid, bonded-carded web materials, and/or hydro entangled, and spun-laced materials.
In accordance with various embodiments of the invention, the hydrophilic materials include, but are not limited to, superabsorbing polymers, silica, collagen, pectin, gelatin, starches, guar gum, gum arabic, locust bean gum, gum karaya, alginic acid, and sodium and calcium salts, and combinations thereof. The superabsorbing polymers (SAP) can be in the form of particles (e.g., granules, flakes, inter-particle aggregates, interparticle crosslinked aggregates, and the like). The SAP can also be in the form of fibers, sheets, films, foams, laminates, and the like. The hydrophilic materials may be water-swellable gelling polymers. Examples of the water-swellable gelling polymers, include but are not limited to, polysaccharides such as carboxymethyl starch, carboxymethyl cellulose, and hydroxypropyl cellulose; nonionic types such as polyvinyl alcohol, and polyvinyl ethers; cationic types such as polyvinyl pyridine, polyvinyl morpholine, N,-dimethylaminoethyl, N,-diethylaminopropyl acrylates, methacrylates, and the respective quaternary salts thereof.
In accordance with one embodiment of the invention, the hydrophilic material may be a synthetic substance. Exemplary synthetic substances include, but are not limited to, sodium carboxymethyl-cellulose, polyvinyl alcohol, polyvinyl pyrollidone, polyethylene glycols, crosslinked dextran, starch acrylonitrile graft copolymer, starch sodium polyacrylate, gluten, polymer of methyl vinyl ether and maleic acid and derivatives, polyvinyl pyrrolidone, polyethylene glycols, polypropylene glycols, metals and ammonium salts of polyacrylic acid, or copolymers thereof, or combinations thereof.
The chemical actives incorporated into the cleaning substrate, inlcude but are not limited to, antimicrobials, disinfectants, heat generating chemicals, sanitizers, surfactants and/or detergents. Exemplary chemical actives include, but are not limited to, sodium bicarbonate, citric acid, carbon, sodium hypochlorite, quaternary ammonium salts, chitosan, and any hypocholorus producing agents. The chemical active may be a naturally derived antimicrobial substance like creosote bush, rosemary, pine oil, any other essential oil or suitable plant extracts. The chemical actives may include biguanide compounds such as polyhexamethylene biguanide hydrochloride, p-chlorophenyl biguanide, 4-chlorobenzhydryl biguanide, chlorhexidine and its salts. The chemical actives may also include alcohols, peroxides, boric acid and borates, chlorinated hydrocarbons, organometallics, halogen-releasing compounds, mercury compounds, metallic salts, organic sulfur compounds, iodine compounds, silver nitrate, quaternary phosphate compounds, and phenolics.
At step 104, the surface of the cleaning substrate is exposed to a solvent. In accordance with one embodiment of the invention, the solvent is water. Water can include tap water, filtered water, bottled water, spring water, distilled water, deionized water, industrial soft water, any other suitable sources of water. The de-ionized water and/or the industrial soft water can reduce the amount of residue formation and also reduce the amount of undesirable metal ions.
After exposing the cleaning substrate to the solvent, at step 106, the cleaning substrate absorbs the solvent. The hydrophilic materials incorporated in the nonwoven web are used to absorb and contain the solvent. This allows controlled dissolution and/or controlled reaction of the chemical actives with the solvent in the nonwoven web. A combination point may be in the process step that allows the final nonwoven web structure to be formed, it may be prior to use or it could include the actual point of use so that the functional efficacy is at its peak during the desired usage of the cleaning substrate.
At step 108, a spatial interaction between the chemical actives and the hydrophilic materials is created. The creation of the spatial interaction between the chemical actives and the hydrophilic materials can occur in a variety of ways. In one embodiment of the invention, the chemical actives and the hydrophilic particles can be held in parallel layers to create sufficient proximity for spatial interaction. This is further illustrated in conjunction with
In accordance with another embodiment of the invention the chemical actives and the hydrophilic particles can be held in a random blended proximity to create a spatial interaction which means having the hydrophilic particles in sufficient proximity so that compete with the chemical actives when they are exposed to a solvent. The chemical actives incorporated into the nonwoven web, require the spatial interactionbetween the hydrophilic particles and chemical actives so that the release rate of the actives may be controlled.
The chemical actives may serve a variety of purposes, for example, when a surface soil is being treated, the surface soil is exposed to a concentration of chemical active that may dissolve, loosen and/or physically abrade the soil thereby helping its release from the surface to which it connects. The chemical actives can also be used for disinfecting a surface from microorganisms. This requires the surface to be exposed to a certain concentration level of the chemical actives, which is easier to accomplish with a cleaning substrate that controls the release of active chemicals. The disinfecting mechanism depends on a contact time between the chemical actives and the targeted microorganisms. The controlled release of actives also enables the cleaning substrate be an effective disinfecting cleaning tool for longer periods of time because of the controlled release of active chemicals.
In accordance with an embodiment of the invention, the spatial interaction of the chemical actives and the hydrophilic particles allows the chemical actives to have a gradual release profile. A gradual release profile or controlled release means that there is a substantially slow and steady release of actives over time. Generally, when the solvent contacts a standard cleaning substrate with actives, a spike in the concentration is observed at the targeted area, and then the remaining chemical active is diluted and moved from the target due to salvation and mechanical surface fluid dynamics of the target. However, when the chemical actives are incorporated along with the hydrophilic materials in the nonwoven web, the solvent is taken up and held so that the chemical actives can be released at a substantially stable concentration profile, relative to the target.
This gradual release profile provides an advantage over a standard cleaning substrate impregnated with actives because many of the actives are released at the initial exposure to the solvent which creates an excess of actives at the beginning of use and a sharp decrease in actives over time. Since many of the actives are released at the beginning of use for a standard cleaning substrate there are fewer actives available to be released later in use which results less cycles where the cleaning substrate can effectively release actives for cleaning surfaces.
In accordance with another embodiment of the invention, the reaction between the chemical actives and the solvent generates heat that can be controlled over a period of time. The incorporation of the hydrophilic materials in the nonwoven web leads to exothermic attenuation as the hydrophilic materials compete with the actives for solvent. The nonwoven web solid particles blended with solid particles in a random walk type low shear solid blending system, which is not enough to degrade the particles. Further, the particle size of one or more chemical actives and hydrophilic materials may be varied to refine exothermic attenuation. The exothermic attenuation characteristics may vary depending on the ratio of the chemical actives to the hydrophilic materials. This is described in detail in conjunction with
As illustrated in
As illustrated in
As illustrated in
The gradual release profile of the chemical actives was tested using a foam mileage test as described below.
The test procedure included placing a Plexiglas template with two 6″×6″ glass tiles stacked on top of each other. The Gardner Abrasion Tester counter was set to 50 reps. The cover of the counter was closed and the reset button was pressed. The scrubby side was placed down on a glass tile and the syringe was filled with 34 cc for initial wetting. It was dosed on evenly over the nonwoven web to ensure the wetting of the edges. The amount of foam coverage was evaluated visually so that it encompassed the glass tile and was done at the end of 50 reps. The nonwoven web was removed when the Gardner stopped and the hi-loft was placed side down. The water and foam were removed from the Gardner surface. The template and the glass tile were removed of all the surfactant. The two steps of placing and setting of the Gardner count were repeated. During the second and consecutive cycles the amount of blue lotion remaining on the scrubby side was noted. This indicates the presence of the lotion in the absorbent layer. The evaluation was done till the foam failed to appear. The foam failure cycle is not used for determining the square feet covered by the nonwoven web. The calculations are made as follows:
No. of cycles×Sq ft. Example 10 cycles×16.86 square feet=168.6 square feet covered.
168.6 square feet/109 square feet=No. of shower tubs cleaned.
The following non-limiting examples are provided to further illustrate different configurations of the nonwoven web:
The results of the foam mileage test for Example 1, Example 6 and Example 8 are set forth in Table 1, Table 2 and Table 3, respectively.
In the above-mentioned examples the scrubby layer is blue in color. However, the invention should not be construed to be limited to only the blue color of the scrub layer. It will apparent to a person skilled in the art that the scrub layer can be of any color.
It was observed that Example 6 produced the best results with the foam delivery cycle lasting up to 34 cycles. The foam mileage test for Examples 3 and 7 resulted in foam delivery cycle lasting up to 6 cycles and 18 cycles, respectively. In accordance with various embodiments of the invention, there is a controlled long lasting foam delivery to the surface being treated. Foam appearance is an indication of the release rate of the chemical actives. In accordance with various embodiments of invention, the chemical actives have a gradual release profile, which allows the nonwoven web to release foam during a greater number of cleaning cycles. Thus the graphical representations in
In accordance with various embodiments of the invention, the hydrophilic materials and the chemical actives are bonded by methods including, but not limited to, Thermal Bonding, Through-Air-Bonding (TAB), Needling, Chemical Bonding, Point Bonding, Ultrasonic Bonding and combinations thereof. Point bonding is the main method of binding in the case of disposables like diapers, sanitary products and medical products. The method generally involves heating for a few milliseconds. Bonded areas are completely compressed and dense, and un-bonded areas are open, breathable and porous. The products obtained can be of a very wide parameters ranging from thin, inelastic, strong, stiff, bulky, weak, flexible and extensible. Ultrasonic Bonding generally provides a high amount of softness and breathability to the nonwoven web. The hi-loft layers can also be bonded by Through-Air-Bonding. Through-Air-Bonding involves the application of hot air to the surface of the nonwoven web and results in the formation of products, which are soft, breathable, extensible and absorbent. In a preferred embodiment, during the foam mileage test, different layers of the nonwoven web are bonded with ultrasonic bonding.
Table 4 provides details of different compositions of the nonwoven web.
In one embodiment of the invention,the cleaning substrate is used for treating the surfaces of refrigerators, microwaves, counter tops, toilet seats, laminate floors, hardwood floors, tiles, and ceramics etc.
Another embodiment of the invention provides a cleaning substrate, which can be used as a floor cleaner.
Still another embodiment of the invention provides a cleaning substrate that can be used in superabsorbent towels and dispenser rolls.
Yet another embodiment of the invention provides a cleaning substrate that can be used to form a functional and protective layer in litter boxes, animal cages and animal pee pads.
Yet another embodiment of the invention provides a cleaning substrate that can be used in personal care or medical applications to clean and/or sanitize skin, hair, nails, hands, etc.
Reference throughout this specification to “one embodiment”, “an embodiment”, or “a specific embodiment” means that a particular feature, structure or characteristic described in connection with the embodiment is included in at least one embodiment of the present invention and not necessarily in all embodiments. Thus, respective appearances of the phrases “in one embodiment”, “in an embodiment” or “in a specific embodiment” in various places throughout this specification are not necessarily referring to the same embodiment. Furthermore, the particular features, structures or characteristics of any specific embodiment of the present invention may be combined in any suitable manner with one or more other embodiments. It is to be understood that other variations and modifications of the embodiments of the present invention described and illustrated herein are possible in light of the teachings herein and are to be considered as part of the spirit and scope of the present invention.
While the invention is described herein in connection with certain preferred embodiments, there is no intent to limit the present invention to those embodiments. On the contrary, it is recognized that various changes and modifications to the described embodiments will be apparent to those skilled in the art upon reading the foregoing description, and that such changes and modifications may be made without departing from the spirit and scope of the present invention. Skilled artisans may employ such variations as appropriate, and the invention may be practiced otherwise than as specifically described herein. Accordingly, the intent is to cover all alternatives, modifications, and equivalents included within the spirit and scope of the invention. Moreover, any combination of the above-described elements in all possible variations thereof is encompassed by the invention unless otherwise indicated herein or otherwise clearly contradicted by context.
