Cleaning compositions for solid surfaces – auxiliary compositions – Cleaning compositions or processes of preparing – For cleaning a specific substrate or removing a specific...
Reexamination Certificate
1999-02-03
2001-01-09
Gupta, Yogendra (Department: 1751)
Cleaning compositions for solid surfaces, auxiliary compositions
Cleaning compositions or processes of preparing
For cleaning a specific substrate or removing a specific...
Reexamination Certificate
active
06172020
ABSTRACT:
FIELD OF THE INVENTION
This invention relates to an improved powdered automatic dishwashing detergent for dishwashing machines which can be in the form of a tablet. More particularly, this invention relates to a powdered dishwashing composition which contains a peroxygen bleach, at least one enzyme and a polymeric builder.
BACKGROUND OF THE INVENTION
Pre-measured amounts of detergent compositions which are compressed into water-soluble tablet form are well known and have received substantial commercial acceptance. They generally comprise a cleaning agent such as a synthetic detergent or soap and a detergency builder which is generally sodium tripolyphosphate (STP), along with suds builders, soil suspending agents and other ingredients commonly added to washing compositions. They are easy to use, avoid the problem of spillage during use, and prevent the use by the consumer of too much or too little detergent. However, manufactures of dishwashers (especially in the US) produce a wide variety dispenser cups. They vary in shape and size. We have found that certain oval shapes are preferred because they are more likely to be released from the cup into the wash water. Therefore the entire pre-measured amounts of detergent compositions will be dissolved quickly at the beginning of the main wash cycle leading to better cleaning performance. Some tablet compositions may eventually dissolve out of the cup due to the action of hot water in the machine. However, other compositions may cake in the cup and not dissolve completely. It is widely recognized that it is most desirable to have the tablet enter the main wash as soon as possible. This will allow the cleaning agents maximum time to clean dishes and silverware.
U.S. Pat. No. 3,557,003 teaches a detergent tablet containing a builder salt, an inorganic salt, surfactant and an alkali metal soap.
U.S. Pat. 3,423,322 teaches a tablet containing sodium tripolyphosphate, surfactant and potassium phosphate.
U.S. Pat. No 5,133,892 teaches a multi layer tablet which allows the incorporation of both bleach and enzyme.
The present invention teaches a powdered dishwashing composition in the form of an elliptically shaped egg shaped or elongated bar with curved ends shaped tablet which is easily dispensed from the cup of the automatic dishwasher and is readily soluble in the wash solution of an automatic dishwashing machine.
SUMMARY OF THE INVENTION
The present invention relates to an automatic dishwashing composition which can be in the form of a tablet which generally comprises a hydrated alkali metal phosphate detergent builder salt, an anhydrous alkali metal phosphate detergent builder salt, an alkali metal carbonate, a dialkali metal disilicate, a nonionic surfactant, a polymer containing sulfonic acid groups, a protease enzyme, an amylase enzyme, a hydrotrope, a peroxygen bleach, a peroxygen bleach activator and a clay.
DETAILED DESCRIPTION OF THE INVENTION
The present invention relates to a powdered automatic dishwashing composition which can be in the form of a single layer tablet which can be egg shaped or generally elliptically shaped or in the shape of an elongated bar with a pair of curved ends and the tablet comprises approximately by weight
(a) 20% to 40% of a hydrated sodium tripolyphosphate having 5 to 15 wt. % of water of hydration;
(b) 10% to 24% of a dialkali metal disilicate;
(c) 15% to 30% of an alkali metal carbonate;
(d) 5% to 15% of a peroxygen bleach;
(e) 0.1% to 6% of a low foaming nonionic surfactant;
(f) 0.5% to 5% of a polymer containing sulfonic acid groups;
(g) 0.2% to 5% of a peroxygen bleach activator;
(h) 0.5% to 3% of a protease enzyme;
(i) 0.5% to 3% of an amylase enzyme;
(j) 2% to 8% of an anhydrous sodium tripolyphosphate containing less than 1 wt. % of hydrated water;
(k) 0.1% to 1% of a hydrotrope; and
(1) 0% to 10% of a clay; wherein the clay can contain a dye which imparts a colored speckle appearance to the tablet and the tablet is not square, rectangular or round in shape and the tablet does not contain an alkali metal citrate.
The nonionic surfactants that can be used in the present powdered automatic dishwasher detergent compositions at a concentration of 0.1% to 6.0%, more preferably 0.5% to 5% by weight are well known. A wide variety of these surfactants can be used. The nonionic synthetic organic detergents are generally described as ethoxylated propoxylated fatty alcohols which are low-foaming surfactants and may be possibly capped, characterized by the presence of an organic hydrophobic group and an organic hydrophilic group and are typically produced by the condensation of an organic aliphatic or alkyl aromatic hydrophobic compound with ethylene oxide and/or propyleneoxide (hydrophilic in nature). Practically any hydrophobic compound having a carboxy, hydroxy, amide or amino group with a free hydrogen attached to the oxygen or the nitrogen can be condensed with ethylene oxide or propylene oxide or with the polyhydration product thereof, polyethylene glycol, to form a nonionic detergent. The length of the hydrophilic or polyoxyethylene chain can be readily adjusted to achieve the desired balance between the hydrophobic and hydrophilic groups. Typical suitable nonionic surfactants are those disclosed in U.S. Pat. Nos. 4,316,812 and 3,630,929.
Preferably, the nonionic detergents that are used are the low-foaming polyalkoxylated lipophiles wherein the desired hydrophile-lipophile balance is obtained from addition of hydrophilic poly-lower alkoxy group to a lipophilic moiety. A preferred class of the nonionic detergent employed is the poly-lower alkyoxylated higher alkanol wherein the alkanol is of 9 to 18 carbon atoms and wherein the number of moles of lower alkylene oxide (of 2 or 3 carbon atoms) is from 3 to 15. Of such materials, it is preferred to employ those wherein the higher alkanol is a high fatty alcohol of 9 to 11 or 12 to 15 carbon atoms and which contain from 5 to 15 or 6 to 16 lower alkoxy groups per mole. Preferably, the lower alkoxy is ethoxy but in some instances, it may be desirably mixed with propoxy, the latter, if present, usually being major (more than 505) portion. Exemplary of such compounds are those wherein the alkanol is of 12 to 15 carbon atom and which contain about 7 ethylene oxide groups per mold.
Useful nonionics are represented by the low foam Plurafac series from BASF Chemical Company which are the reaction product of a higher linear alcohol and a mixture of ethylene and a propylene oxides, containing a mixed chain of ethylene oxide and propylene oxide, terminated by a hydroxyl group. Examples include Product A (a C
12
-C
15
fatty alcohol condensed with 6 moles ethylene oxide and 3 moles propylene oxide). Product B (a C
12
-C
15
fatty alcohol condensed with 7 mole propylene oxide and 4 mole ethylene oxide), and Product C (a C
12
-C
15
fatty alcohol condensed with 5 moles propylene oxide and 10 moles ethylene oxide). Another group of liquid nonionics are available from Shell Chemical Company, Inc. under the Dobanol trademark: Dobanol 91-5 is a low foam ethoxylated C
2
-C
11
fatty alcohol with an average of 5 moles ethylene oxide and Dobanol 25-7 is an ethoxylated C
12
-C
15
fatty alcohol with an average of 7 moles ethylene oxide. Another liquid nonionic surfactant that can be used is sold under the tradename Lutensol SC 9713.
Poly-Tergent nonionic surfactants from Olin Organic Chemicals such as Poly-Tergent SLF-18, a biodegradable, low-foaming surfactant is specially preferred for the powdered automatic dishwasher detergent compositions of this instant invention. Poly-Tergent SLF-18, a water dispersible, having a low cloud point has lower surface tension and lower foaming is very suitable for automatic dishwasher detergent. Synperonic nonionic surfactant from ICI such as Synperonic LF/D25, LF/RA30 are especially preferred nonionic surfactants that can be used in the powdered automatic dishwasher detergent compositions of the instant invention. Poly-Tergent nonionic surfactants from Olin Organic Chemicals such as Poly-Tergent SLF-18, a biodegradable, low-foaming
Binstock Gary
Cummings Bruce
Kenkare Divaker
Kinscherf Kevin
Phillips Steve
Colgate-Palmolive Company
Gupta Yogendra
Nanfeldt Richard E.
Webb Gregory E.
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