Cleaning compositions for solid surfaces – auxiliary compositions – Auxiliary compositions for cleaning – or processes of preparing – Textile softening or antistatic composition
Reexamination Certificate
2002-01-22
2003-12-16
Hardee, John (Department: 1751)
Cleaning compositions for solid surfaces, auxiliary compositions
Auxiliary compositions for cleaning, or processes of preparing
Textile softening or antistatic composition
C510S298000, C510S446000, C510S507000
Reexamination Certificate
active
06664226
ABSTRACT:
FIELD OF THE INVENTION
This invention relates to wash cycle unit dose laundry compositions for softening or conditioning fabrics. More particularly, this invention relates to unit dose fabric softening compositions which are compacted granular compositions spherical in shape and suitable for use in the wash cycle of an automatic washing machine.
BACKGROUND OF THE INVENTION
Detergent compositions manufactured in the form of tablets of compacted detergent powder are known in the art. U.S. Pat. No. 5,225,100, for example, describes a tablet of compacted powder comprising an anionic detergent compound which will adequately disperse in the wash water.
Although detergent compositions shaped as tablets have received much attention in the patent literature, the use of such tablets to provide a unit dose fabric softener which will soften or condition fabrics without impairing detergency is not known.
One possible option for providing a unit dose softener is to introduce the softening ingredients directly into the rinse cycle. But, for this type of product to be effective several practical requirements must be met. To begin with, the size and shape of the unit dose container must be readily compatible with the geometry of a wide variety of rinse cycle dispensers designed for home washing machines in order to insure its easy introduction into the dispenser.
Further, the unit dose composition must be formulated to readily dispense its contents upon contact with water in a period of time corresponding to the residence time of the unit dose in the dispenser, namely, the period of time during which water enters and flows through the rinse cycle dispenser. The aforementioned practical requirements have to date not been successfully met and therefore there remains a need in the art for a commercially acceptable unit dose softener capable of activation in the rinse cycle.
Wash cycle softeners are known in the art which condition fabrics during the period of the wash cycle. Tablet unit doses for detergent compositions are also known. Such tablets are typically flat compacted unit compositions which conceptually offer numerous advantages to the consumer such as: ease of dosing; cleaner wash cycle dispensers resulting from not being dosed with loose powder; less bulk to carry and dispense; ease of handling relative to liquids; and environmental benefits attendant to reduced packaging requirements.
But, despite these advantages, there is a major drawback which occurs in front loading washing machines which represent at least 90% of the European market, and are gaining in consumer acceptance in North America. In front loading machines, a flat compacted object when introduced into the wash cycle often becomes trapped within a few minutes in the rubber seal surrounding the window of the washing machine. Once trapped in the seal, the tablet tends to remain trapped until the wash cycle is over and is consequently not dispersed in the wash water. To overcome this problem, different approaches have been taken.
Some tablet manufacturers provide a net or sachet designed to contain the tablet unit dose, and thereby avoid the problem of direct contact between the tablet and the seal. Another proposed solution involves providing a rapidly dispersible tablet in the wash water by incorporating an effervescent matrix and/or a disintegration agent into the tablet. But, these proposed options are generally uneconomical and often result in an unduly fragile tablet unable to readily withstand normal handling by the consumer without fracturing. Thus, there is a need for an economical unit dose tablet capable of providing conditioning of fabrics, and which retains its physical integrity during normal handling prior to being introduced into the washing machine.
SUMMARY OF THE INVENTION
The present invention provides a non-foaming unit dose laundry composition for softening or conditioning fabrics which is suitable as an additive to the wash cycle of an automatic washing machine, said unit dose composition comprising a compacted granular composition comprising a fabric softener or a fabric conditioner, said compacted granular composition being characterized by having a spherical shape and having no discrete outer layer surrounding said fabric softener or conditioner, which outer layer is comprised of an alkaline material such that the pH of the wash water is increased upon the dissolution of said outer layer in said wash water, said unit dose laundry composition being free of (i) a soap surfactant; and (ii) a quaternary ammonium compound fabric softener; and containing less than about 5%, by weight, of sodium bicarbonate, and less than about 2%, by weight, of an organic acid.
In a preferred embodiment of the invention the fabric softener or conditioner is comprised of a fabric softening clay and an organic fatty softening material. Especially preferred fabric softeners comprise a clay mineral softener, such as bentonite, in combination with a pentaerythritol compound as further described herein. Useful combinations of such softener may very from about 83%, to about 90%, by weight, of clay, and from about 10% to about 17%, by weight, of fatty softening material such as a pentaerythritol compound (often abbreviated herein as “PEC”).
In a further preferred embodiment of the invention the fabric softener or conditioner is free of a soap surfactant. The unit dose composition is also most preferably free of sodium bicarbonate but may contain up to an amount below about 5%, by weight, thereof. It also preferably contains less than about 2%, by weight, of organic acid and most preferably less than about 1%, by weight.
In accordance with the process aspect of the invention there is provided a process for softening or conditioning laundry which comprises contacted the laundry with an effective amount of the unit dose laundry composition defined above.
DETAILED DESCRIPTION OF THE INVENTION
The clays that are useful components of the invented products are those which cooperate with the organic fatty softener materials to provide enhanced softening of laundry. Such clays include the montmorillonite-containing clays which have swelling properties (in water) and which are of smectite structure, so that they deposit on fibrous materials, especially cotton and cotton/synthetic blends, such as cotton/polyester, to give such fibers and fabrics made from them a surface lubricity or softness. The best of the smectite clays for use in the present invention is bentonite and the best of the bentonites are those which have a substantial swelling capability in water, such as the sodium and potassium bentonites. Such swelling bentonites are also known as western or Wyoming bentonites, which are essentially sodium bentonite. Other bentonites, such as calcium bentonite, are normally non-swelling and usually are, in themselves, unacceptable as fabric softening agents. However, it has been found that such non-swelling bentonites exhibit even better fabric softening in combination with PEC's than do the swelling bentonites, provided that there is present in the softening composition, a source of alkali metal or other solubilizing ion, such as sodium (which may come from sodium hydroxide, added to the composition, or from sodium salts, such as builders and fillers, which may be functional components of the composition). Among the preferred bentonites are those of sodium and potassium, which are normally swelling, and calcium and magnesium, which are normally non-swelling. Of these it is preferred to utilize calcium (with a source of sodium being present) and sodium bentonites. The bentonites employed may be produced in the United States of America, such as Wyoming bentonite, but also may be obtained from Europe, including Italy and Spain, as calcium bentonite, which may be converted to sodium bentonite by treatment with sodium carbonate, or may be employed as calcium bentonite. Also, other montmorillonite-containing smectite clays of properties like those of the bentonites described may be substituted in whole or in part for the bentonites describ
Cao Hoai-Chau
Jacques Alain
Rousselet Juliette
Colgate-Palmolive Co
Hardee John
Lieberman Bernard
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