1. The Field of the Invention
The present invention relates to sodium hypochlorite and other hypohalite or hypohalous acid compositions (e.g., aqueous solutions) that include a cationic polymer, as well as methods of making and using such compositions.
2. Description of Related Art
Consumers recognize sodium hypochlorite as a highly effective cleaning, bleaching and sanitizing agent that can be widely used in cleaning and sanitizing various hard and soft surfaces, in laundry care, etc. Often, sodium hypochlorite solutions in a relatively concentrated form are delivered to the consumer, who then dilutes them. A wide variety of automated washing machines which can control the addition of sodium hypochlorite to laundry washwater are also available. When used in washing machines, the sodium hypochlorite solution will typically come in contact with the detergent being used in the laundering process. Complex interactions between sodium hypochlorite and components of the detergent, such as surfactants, builders, enzymes, fragrances, dyes, fabric brighteners, fabric softener components, and anti-redeposition polymers and fabric care polymers can occur, and are thought to result in some cases in a reduction in the stain removal and bleaching performance of sodium hypochlorite, or reduction in the aesthetics or detergency performance of the detergent formulation used. Such complex interactions are commonly observed when the stain removal and whitening performance of sodium hypochlorite solutions is measured in the presence of different detergent formulations, whereby some detergent formulations are more compatible with the sodium hypochlorite solution than others. For example, fabric brighteners are often less effective or ineffective when contacted with the bleaching agent of the bleach solution.
In the case of manual washing of laundry, where sodium hypochlorite is employed, the relative volume of water to fabrics may be reduced, and hence the levels of suspended soils, both particulate and oily, may be significantly higher than in an automatic washing machine.
Sodium hypochlorite solutions designed to be diluted in such laundering processes may contain a variety of adjuvants to enhance the stability of the hypochlorite or enhance the aesthetics of use of the product (e.g., lower odor). Fragrances, hydrotropic materials (e.g., such as sodium xylene sulfonates), buffers, certain electrolytes (e.g., alkali metal halides, etc.) may be added to hypohalite solutions for such purposes.
However, variation in the overall consumer-perceivable fabric whitening and stain removal still exists when hypohalite solutions are used in combination with commercial detergent formulations. Thus, there continues to be a need for liquid compositions including hypohalite species, which compositions would exhibit improved or more consistent cleaning, bleaching, and whitening performance when used with various modern detergent formulations, or when used under conditions of high loads of suspended soils.