Carpet fibers can be severely and permanently stained or soiled when certain household substances such as coffee, chocolate, mud and fruit drinks are inadvertently spilled on them. These items contain artificial and natural colorants. Many of these colorants are acid dyes which cause the most severe stains, as these acid dyes often attach themselves to available dye sites on the carpet fiber. As a result, some carpets must be prematurely replaced because of unsightly soiling or staining.
Many carpet manufacturers have attempted to prevent unwanted staining of fibers by treating the carpet fibers with a stain resisting coating material. Examples of such stain resisting coatings include condensation productions made from aromatic sulfonic acids, and formaldehyde. Although these coatings have imparted some stain resistance, many of the coatings do not completely eliminate it. In addition, often foot traffic on carpet wears off the coating, leaving the exposed carpet fibers with little or no protection against staining.
Various fluorochemicals have also been applied to carpet fibers in order to reduce their water and oil wettability. The fluorochemical reduces the tendency of soils to adhere to the fibers, thereby making the removal of soils from the carpet fibers easier than if the fluorochemicals were omitted, but offers little protection to the carpet fibers from spills containing acid dye colorants unless the colorants are immediately removed from the fibers. Foot traffic on carpet will often wear off the fluorochemicals as well.
A number of cleaning solutions have been proposed in the past for removing stains and soils from fibers. For instance, volatile solvent dry-cleaning fluids have been proposed, but such fluids are less than satisfactory in removing water-soluble stains or soils. In addition, aqueous compositions containing synthetic detergents have been proposed for removing stains and soils from fibers, but such compositions have not been found to be particularly effective.
One of the problems with these cleaning solutions is that while they may, at times, loosen and/or disperse the soil, they often fail to prevent redeposition of the dispersed soil onto the cleaned carpet fibers. Suspension of the soil in the cleaning liquor allows the soil to be picked up by a cleaning implement such as a cloth or sponge. The soil which is not removed is redeposited on the fibers. For example, it has been found that if residual coffee stains, which are dispersible or soluble in water, remain after cleaning, the stains can be concentrated at the surface of the cleaned carpet as it dries, resulting in an appearance of inadequate cleaning. An additional problem with cleaning solutions is the carpet fibers can become tacky due to film left behind by residual cleaning components. The film attracts and retains soils, which results in a cleaned carpet that will soil more easily after a cleaning than prior thereto. Finally, rinsing current cleaning solutions with large amounts of water causes the fibers in the carpet and, many times, the pad under the carpet, to become saturated with water, which can result in degradation of the pad and/or carpet. The moisture trapped in the padding promotes microbial growth which can present health and/or odor problems.
In order to avoid leaving a tacky residue, formulations based on volatile solvent systems have been proposed. Although these systems clean well without leaving residues, they contain substantial amounts of volatile organic compounds ("VOCs" ) which are regulated because of their potential adverse effects on air quality within the home as well as in the environment. Accordingly, it is an object of the present invention to provide a cleaning composition which effectively removes stains and soil from a soft surface using substantially less VOCs.
It is an additional object of the present invention to provide a method of cleaning a soft surface which requires a minimal amount of rinsing.
It is a further object of the present invention to provide efficacious cleaning composition which removes stains and soil without removing the permanent color from the carpeting.
These objects and others will become apparent to one of ordinary skill in the art from the following description of the present invention.