Cleaning compositions for solid surfaces – auxiliary compositions – Cleaning compositions or processes of preparing – For cleaning a specific substrate or removing a specific...
Reexamination Certificate
2001-04-10
2003-05-20
Douyon, Lorna M. (Department: 1751)
Cleaning compositions for solid surfaces, auxiliary compositions
Cleaning compositions or processes of preparing
For cleaning a specific substrate or removing a specific...
C510S356000, C510S421000, C510S446000, C510S470000, C510S506000, C510S535000
Reexamination Certificate
active
06566317
ABSTRACT:
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
Not applicable.
BACKGROUND OF THE INVENTION
The present invention generally relates to a process for inhibiting gel formation of laundry detergent tablets containing anionic and/or nonionic surfactants, and particularly ethoxylated nonionic surfactants upon their introduction into water. More particularly, highly concentrated anionic and nonionic surfactants, and especially ethoxylated nonionic surfactants, when dispersed in water, tend to form highly viscous gels. Gel formation is immediate, particularly when linear alcohol ethoxylates having a high ethylene oxide content are hydrated.
This gel formation can significantly inhibit the complete hydration and dispersion of an anionic and/or nonionic surfactant, and particularly an ethoxylated nonionic surfactant, in solution. Since detergents used for various types of cleaning processes, such as the laundering of clothes, require rapid dispersion of the surfactant in water in order to realize optimal cleaning effect, it is imperative that an effective solution to this gelling phenomenon be found.
Reducing the gelling tendency of anionic and nonionic surfactants, especially nonionic ethoxylates such as LAE and NPE present in detergent compositions, is important for various cleaning product applications. In heavy duty laundry powders and liquids, surfactant gelling slows down the dissolution rate of the detergent composition, resulting in poor cleaning performance and residues.
This problem is particularly acute with respect to laundry detergents in tablet form. Two types of laundry detergent tablet formulations are becoming popular with consumers, namely, detergent tablets in solid form and those which contain a concentrated liquid inside a soluble outer shell/covering made, for example, from a cellulosic material. The popularity of these types of laundry detergent tablet formulations is already growing quickly in Europe, and similar products are currently being introduced in the US and throughout the world. However, due to the high concentration of anionic and/or nonionic surfactants present in these tablet formulations, surfactant gelling caused by hydration of these surfactants upon exposure to water inhibits1) in the case of solid tablets, the direct contact of the water with the disintegration agents contained in the solid tablet formulations used to facilitate the swelling and break up of the tablet for rapid dissolution, 2) in the case of liquid tablets, the rapid and complete dispersion of the product formulation in the wash liquor. In either case, the tablet dissolution can be incomplete resulting in poor product performance and unwanted residues in the wash tub and on the consumer's laundry.
In the case of solid tablets, these surfactants, especially nonionic ethoxylates, when hydrated will gel and encapsulate the disintegration agents. These disintegration agents (e.g. swelling cellulosic polymers), however, require contact with water in order to expand/swell. Therefore it is important to reduce or eliminate the gelling affect of these anionic and/or nonionic surfactants.
As was alluded to above, liquid laundry “Tablets” or pouches are the newest laundry detergent products recently launched in Europe. These laundry detergent pouches are based on highly active surfactant systems, typically nonionic based, with minimal water content. Reducing the gelling tendency of these products upon hydration is critical to optimal cleaning.
Finally, with respect to processing aids for aqueous based liquid surfactant products, surfactant gelling which occurs during the processing of liquid products will significantly slow down the process time, thus adding to its costs.
BRIEF SUMMARY OF THE INVENTION
The present invention is directed to a process for inhibiting tablet-form laundry detergents from gelling upon hydration involving the steps of: (a) providing a detergent formulation containing a surfactant selected from the group consisting of an anionic surfactant, a nonionic surfactant, and mixtures thereof; (b) providing an anti-gelling agent selected from the group consisting of an alkyl polyglycoside corresponding to formula I:
R
1
O(Z)
a
(I)
wherein R
1
is a monovalent organic radical having from about 6 to about 30 carbon atoms; Z is a glucose residue; a is a number having a value from about 1 to about 6; a polymeric surfactant comprising at least one product of the reaction between:
(i) at least one linking agent of formula II:
R
2
(Y)
3
(II)
wherein each Y group is a halogen atom or one Y group is a halogen atom and two Y groups with two adjacent carbon atoms in the R
2
group and an oxygen atom form an epoxy group, and R
2
is an alkanetriyl group containing from 3 to 10 carbon atoms; and
(ii) at least one compound of formula (III)
R
3
(EO)
n
(PO)
m
(BO)
p
X (III)
wherein R
3
is a substituted or unsubstituted saturated or unsaturated, aliphatic oxy or thio group having from 1 to about 36 carbon atoms or a secondary amino group having from 2 to about 36 carbon atoms; n, m, and p are independently numbers of from 0 to about 50; X is hydrogen, or a mercapto group or an amino group in place of a terminal —OH group, provided that when X is mercapto or amino, the sum of n, m, and p must be at least 1; and wherein the mole ratio of component (I) to component (ii) is from about 0.2/1 to about 5/1; an alkyl sulfate; and mixtures thereof; (c) combining the detergent formulation and the anti-galling agent to form a finished formulation and; (d) processing the finished formulation into a tablet-form laundry detergent product.
The present invention is also directed to a process for inhibiting an ethoxylated nonionic surfactant present in a cleaning composition from gelling upon hydration, the process involving:
(a) providing an ethoxylated nonionic surfactant;
(b) providing an anti-gelling agent selected from the group consisting of an alkyl polyglycoside corresponding to formula I:
R
1
O(Z)
a
(I)
wherein R
1
is a monovalent organic radical having from about 6 to about 30 carbon atoms; Z is a glucose residue; a is a number having a value from about 1 to about 6; a polymeric surfactant comprising at least one product of the reaction between:
(i) at least one linking agent of formula II:
R
2
(Y)
3
(II)
wherein each Y group is a halogen atom or one Y group is a halogen atom and two Y groups with two adjacent carbon atoms in the R
2
group and an oxygen atom form an epoxy group, and R
2
is an alkanetriyl group containing from 3 to 10 carbon atoms; and
(ii) at least one compound of formula (III)
R
3
(EO)
n
(PO)
m
(BO)
p
X (III)
wherein R
3
is a substituted or unsubstituted saturated or unsaturated, aliphatic oxy or thio group having from 1 to about 36 carbon atoms or a secondary amino group having from 2 to about 36 carbon atoms; n, m, and p are independently numbers of from 0 to about 50; X is hydrogen, or a mercapto group or an amino group in place of a terminal —OH group, provided that when X is mercapto or amino, the sum of n, m, and p must be at least 1; and wherein the mole ratio of component (i) to component (ii) is from about 0.2/1 to about 5/1; an alkyl sulfate; and mixtures thereof; and
(c) mixing the ethoxylated nonionic surfactant with the anti-gelling agent.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING
Not applicable.
DETAILED DESCRIPTION OF THE INVENTION
Other than in the operating examples, or where otherwise indicated, all numbers expressing quantities of ingredients or reaction conditions are to be understood as being modified in all instances by the term “about”.
The term “tablet-form” is meant to encompass concentrated laundry detergents in the form of solid tablets, concentrated liquid detergent formulations present inside a water-soluble outer covering, i.e., a pouch, and the like.
The present invention is directed to the surprising discovery that the gelling tendencies of concentrated anionic and/or nonionic surfactants, and particularly ethoxylated nonionic surfacta
Allen Charles B.
Gross Stephen F.
Morris Timothy C.
Valesky Robert J.
Cognis Corporation
Douyon Lorna M.
Drach John E.
Trzaska Steven J.
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