Cleaning compositions for solid surfaces – auxiliary compositions – Cleaning compositions or processes of preparing – For cleaning a specific substrate or removing a specific...
Reexamination Certificate
2001-08-03
2004-05-25
Mruk, Brian P. (Department: 1751)
Cleaning compositions for solid surfaces, auxiliary compositions
Cleaning compositions or processes of preparing
For cleaning a specific substrate or removing a specific...
C510S226000, C510S237000, C510S392000, C510S413000, C510S421000, C510S426000, C510S433000, C510S475000, C510S514000, C134S025200, C134S025300, C134S039000, C134S040000, C134S042000
Reexamination Certificate
active
06740627
ABSTRACT:
TECHNICAL FIELD
The present invention relates to liquid or gel dishwashing detergent compositions suitable for use in manual dishwashing operations. These compositions contain amphoteric and anionic surfactants, organic diamines, and solvents selected from the group consisting of diols and polymeric glycols and mixtures thereof as well as other detergent adjuvants. These components, in the combinations disclosed herein, serve to impart preferred food soil cleaning, handling and sudsing characteristics to such dishwashing detergent products.
BACKGROUND OF THE INVENTION
Light-duty liquid (LDL) or gel detergent compositions useful for manual dishwashing are well known in the art. Such products are generally formulated to provide a number of widely diverse performance and aesthetics properties and characteristics. First and foremost, liquid or gel dishwashing products must be formulated with types and amounts of surfactants and other cleaning adjuvants that will provide acceptable solubilization and removal of food soils, especially greasy soils, from dishware being cleaned with, or in aqueous solutions formed from such products. Thus, there is a continuing effort by formulators of liquid dishwashing compositions to incorporate additional components into LDL detergents to provide consumers with improved cleaning benefits.
Second, liquid dishwashing products must be formulated to be physically stable and free of adverse heterogeneity. “Physical stability” in this sense refers to the tendency of a liquid composition to remain as a homogeneous solution rather than having one or more components precipitate (if the discontinuous phase is a solid) or separate (if the discontinuous phase is a liquid) out of the liquid. Thus, a useful detergent composition is one that is free of inhomogeneties and is stable under a variety of different service conditions and storage temperatures—previous formulators have found cold temperature stability particularly difficult to obtain. Physical stability not only enhances the appearance and hence the consumer perception of the product, but is also essential to providing effective cleaning performance.
Third, liquid dishwashing products should be formulated to have a viscosity that makes the use of the product convenient and practicable. Thus, a liquid dishwashing composition should not be so thick that it cannot be easily poured out of its container and at the same time not so thin that it is difficult to concentrate onto the surface of a sponge or kitchen article. Liquid dishwashing compositions should also have a favorable “dilution profile”, meaning that as the liquid dishwashing product is further diluted with water, the composition decreases in viscosity. This is in contrast to how many typical liquid dishwashing compositions behave, in which compositions upon first aqueous dilution become more viscous, thus making them not only more difficult to use but also impairing their dissolution. “Dissolution” is another important attribute of liquid dishwashing products. By dissolution is meant the rate at which the liquid dishwashing product mixes with water. Generally it is preferable that a detergent product mix quickly with water so that its detersive benefits are immediately available to the consumer, thus minimizing the amount of time he or she must devote to cleaning tasks.
Fourth, special care has to be taken in formulating liquid dishwashing products which include enzymes so that the enzymes are not degraded or decomposed by their interaction with other detergent ingredients. Enzymes are important components of dishwashing compositions because they offer improved cleaning benefits on proteintased soils and have also been shown to provide consumers with a mildness or skin feel/appearance advantage over other similar detergent compositions which do not contain enzymes. However, it can be difficult to incorporate enzymes into liquid dishwashing compositions because they are unstable in the presence of many standard LDL ingredients, such as citric acid. Also because enzymes are active in the presence of water and because most liquid dishwashing compositions are aqueous, care must be taken that the enzymes are not activated during storage and thus depleted by the time the LDL composition is ready for use.
Given the foregoing, there is a continuing need to formulate manual dishwashing liquids that provide excellent cleaning benefits, have stable formulations over a broad temperature range, and yet have a viscosity and consistency so that they are useful and convenient for a manual dishwashing operation. Accordingly, it is a benefit of the present invention to provide light-duty liquid dishwashing compositions which not only provide improved cleaning benefits, but are also of a convenient consistency and viscosity, are colorless and odorless, stable and serviceable under a broad range of service temperatures and have improved enzyme stability over existing liquid dishwashing composition formulations.
SUMMARY OF THE INVENTION
It has now been determined that the use of a solvent selected from the group consisting of certain diols, certain polymeric glycols and mixtures thereof, as outlined in detail below, in combination with amphoteric surfactants, anionic surfactants and organic diamines in a specific ratio provides superior cleaning, grease cutting, physical stability, dissolution and theological behavior over typical liquid dishwashing compositions. In particular it has been found that the addition of diols can improve the physical and enzymatic stability of a liquid dishwashing composition. The diols prepared according to the present invention and described in greater detail below have been shown to improve the physical stability of liquid dishwashing compositions even at high pHs (above 10.0) and low temperatures where typically it is likely that certain components will separate out from the composition solution and form inhomogeneities. These diols have also been shown to improve enzymatic stability even in compositions with high water levels.
Moreover, these diols, like other solvents, provide stabilizing benefits to dishwashing compositions, but unlike other solvents (e.g. ethanol), do not thin the dishwashing compositions in which they are included. This allows a formulator to stabilize dishwashing compositions over a greater range of viscosities, because the diols provide formula stability benefits without the corresponding cost of decreasing formula viscosity.
Additionally it has been found that the addition of certain polymeric glycols, particularly in combination with sodium chloride or other alkali metal inorganic salts, can improve the dilution profile and low temperature stability of a LDL detergent composition.
The detergent compositions according to the first aspect of the present invention comprise: (a) a low molecular weight organic diamine having a pK1 and a pK2, wherein the pK1 and the pK2 of said diamine are both in the range of from about 8.0 to about 11.5; (b) an anionic surfactant; (c) an amphoteric surfactant; and (d) a solvent selected from the group consisting of diols, polymeric glycols and mixtures thereof; wherein said diol is selected from the group consisting of:
wherein n=0-3, R
7
=H, methyl or ethyl; and R
8
=H, methyl, ethyl, propyl, isopropyl, butyl and isoubutyl; and wherein the polymeric glycol is selected from the group consisting of:
(PO)
x
(EO)
y
H
wherein PO represents a propylene oxide group and EO represents an ethylene oxide group and x+y is from about 17 to 68, and x/(x+y) is from about 0.25 to 1.0;
The pH (as measured as 10% aqueous solution) is from about 5.0 to about 12.5 and the mole ratio of said anionic surfactant to said amphoteric surfactant to said diamine is from about 100:40:1 to about 9:0.5:1.
In accordance with a second aspect of the present invention, a detergent composition suitable for use in hand dishwashing, said composition comprising: (a) from about 0.1% to about 5%, by weight of a diamine having a molecular weight less than or equal to 400 g/mol; (b) from
Clarke Joanna Margaret
Embleton Garry Kenneth
Hutton Howard David
Kacher Mark Leslie
Sadler John David
Echler Sr. Richard S.
Mruk Brian P.
The Procter & Gamble & Company
Waugh Kevin L.
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