Cleaning compositions for solid surfaces – auxiliary compositions – Cleaning compositions or processes of preparing – For cleaning a specific substrate or removing a specific...
Reexamination Certificate
2002-06-13
2003-12-16
Hardee, John (Department: 1751)
Cleaning compositions for solid surfaces, auxiliary compositions
Cleaning compositions or processes of preparing
For cleaning a specific substrate or removing a specific...
C510S439000, C510S446000, C510S507000, C510S515000
Reexamination Certificate
active
06664222
ABSTRACT:
BACKGROUND OF INVENTION
1. 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 suitable for use in the wash cycle of an automatic washing machine.
2. Background of the Invention
Detergent compositions manufactured in the form of compacted detergent powder are known in the art. U.S. 5,225,100, for example, describes a tablet of compacted powder comprising an anionic detergent compound which will adequately disperse in the wash water.
U.S. Pat. Nos. 6,258,767; 6,294,516 and 6,291,421 assigned to Colgate-Palmolive Company describe unit dose granular and encapsulated liquid fabric softening compositions suitable for use as an additive to the wash cycle of a washing machine, or during hand washing of laundry.
Another possible option for providing a unit dose softener apart from the wash cycle 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. Moreover, in common with the general use of rinse cycle softeners, it is necessary to clean the rinse dispenser on a regular basis to avoid residue from accumulating within the dispenser or even, at times, prevent bacterial growth from occurring.
Still further, a unit dose composition for the rinse cycle 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 with any commercially available product and hence there remains a need in the art for a unit dose softener capable of activation in the rinse cycle.
Laundry detergent compositions which further include a fabric softener to provide softening or conditioning of fabrics in the wash cycle of the laundering operation are well-known in the art and described in the patent literature. See, for example, U.S. Pat. No. 4,605,506 to Wixon; U.S. Pat. No 4,818,421 to Boris et al. and U.S. Pat. No. 4,569,773 to Ramachandran et al., all assigned to Colgate-Palmolive Co., and U.S. Pat. No. 4,851,138 assigned to Akzo. U.S. Pat. No. 5,972,870 to Anderson describes a multi-layered laundry tablet for washing which may include a detergent in the outer layer and a fabric softener, or water softener or fragrance in the inner layer. But, these type of multi-benefit products suffer from a common drawback, namely, there is an inherent compromise which the user necessarily makes between the cleaning and softening benefits provided by such products as compared to using a separate detergent composition solely for cleaning in the wash cycle and a separate softening composition solely for softening in the rinse cycle. In essence, the user of such detergent softener compositions does not have the ability to independently adjust the amount of detergent and softener added to the wash cycle of a machine in response to the cleaning and softening requirements of the particular wash load.
Some attempts have been made in the art to develop wash cycle active fabric softeners, typically in powder form. But, these type products are characterized by the same inconvenience inherent with the use of powered detergents, namely, problems of handling, caking in the container or wash cycle dispenser, and the need for a dosing device to deliver the desired amount of active softener material to the wash water.
It has now been found that softening of laundry can be effected in the wash cycle with a flexibility which is independent of the detergent dosage, and with great convenience by the consumer by the use of a compacted granular unit dose wash cycle softener which avoids the common problems associated with the pouring and handling of granular or liquid detergent compositions, and which provides enhanced dispersibility of the compacted granular composition in the wash water.
SUMMARY OF INVENTION
There is provided herein a unit dose wash cycle fabric softening composition for softening or conditioning fabrics which is readily dispersible during hand wash or in the wash cycle of an automatic washing machine, and which substantially avoids the deposition of residue on the washed fabrics, said unit dose comprising a compacted granular fabric softener composition comprising a softening clay component in an amount sufficient to form a unit dose capable of providing effective softening or conditioning of fabrics in the wash cycle, and wherein said compacted fabric softener composition is formed from granules of softener, which granules are formed from a powder of said clay component wherein at least 90% of the particles of said powder are below about 200 microns in size.
In a preferred embodiment the unit dose fabric softening composition is characterized by being in the form of a tablet and having no discrete outer layer surrounding the fabric softener comprised of an alkaline material such that the pH of the wash water is increased upon dissolution of said outer layer in said wash water.
The particles of powder of the softening clay component used to form the aforementioned granules of softener are preferably at least 90% and more preferably at least 95% below about 200 microns in size or alternatively about 150 microns in size and most preferably, at least 90% and even more preferably at least 95% below about 53 microns in size. Avoiding the deposition of residue on the washed fabrics in accordance with the invention is predicated on the use of particle sizes of the softening clay component as described herein.
In accordance with the process aspect of the invention there is provided a process for softening or conditioning laundry which comprises contacting the laundry with an effective amount of the unit dose laundry composition defined above.
DETAILED DESCRIPTION
The clays that are useful components of the invented products 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
Cao Hoai-Chau
Epp Jeffrey T.
Farooq Amjad
Gourgue Alain
Jacques Alain
Colgate-Palmolive Co.
Hardee John
Lieberman Bernard
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