Cleaning compositions for solid surfaces – auxiliary compositions – Cleaning compositions or processes of preparing – For cleaning a specific substrate or removing a specific...
Reexamination Certificate
2000-06-12
2003-01-28
Gupta, Yogendra N. (Department: 1751)
Cleaning compositions for solid surfaces, auxiliary compositions
Cleaning compositions or processes of preparing
For cleaning a specific substrate or removing a specific...
C510S342000, C510S434000, C510S446000, C510S478000, C510S479000, C510S533000
Reexamination Certificate
active
06511952
ABSTRACT:
TECHNICAL FIELD
The present invention pertains to stable liquid laundry detergent formulations comprising polycarboxylate builders.
BACKGROUND ART
The use of builders to improve the overall detergency effectiveness and the whitening power of liquid laundry detergent formulations is well known. Typically, builders have been used, among other things, as sequestering agents to remove metallic ions such as calcium or magnesium (or the “hardness”) from the washing fluid, to provide solubilization of water insoluble materials, to promote soil suspension, to retard soil redeposition and to provide alkalinity. Examples of liquid laundry detergent formulations are described in U.S. Pat. Nos. 6,034,045, 5,858,951, 5,575,004, 5,308,530, 4,663,071 and 3,719,647.
Polyphosphate compounds, such as tripolyphosphates and pyrophosphates, have been widely used as builders in detergent compositions, in part because of their ability in sequestering hardness ions. While the use of such phosphate compounds has been very effective, environmental concerns have mounted regarding their possible contribution to the growth of algae in lakes and streams and the resulting eutrophication of such bodies of water. This concern has caused significant legislative pressure to lower or discontinue use of phosphates in detergent compositions to control pollution.
Detergent manufacturers have looked to polycarboxylate polymers and copolymers as potential effective, non-phosphate detergent builders. For instance, U.S. Pat. Nos. 5,308,530, 4,663,071 and 3,719,647 disclose polycarboxylate builders for use with suitable surfactants in laundry detergent formulations. In U.S. Pat. No. 3,719,647, the polycarboxylate builder comprises a copolymer of a polyether and carboxylic acid, wherein the polyether component is made up of ethylene oxide units.
Often, a polycarboxylate may be unsuited for use as a liquid laundry detergent formulation builder, even when having excellent detergency effectiveness and whitening power. This is because the polycarboxylate is not readily compatible with anionic and non-ionic surfactants, i.e., does not exhibit acceptable phase stability. If a polymer is not readily compatible with these surfactants, phase separation in the liquid laundry detergent may result, thus requiring the addition of expensive hydrotropes for stabilization.
Accordingly, there is a need to identify liquid laundry detergent formulations comprising polycarboxylate builders that do not require the use of hydrotropes to be stable in liquid laundry detergents.
DISCLOSURE OF INVENTION
It has now been surprisingly discovered that liquid laundry detergent formulations comprising polycarboxylate builders and a certain dihydric glycol carrier solvent have an extremely broad range of phase stability. The dihydric glycol carrier solvent comprises 2-methyl-1,3-propanediol, sold as MPDiol® glycol by Lyondell Chemical Company.
It has also been surprisingly discovered that certain non-hydrophobically modified, acrylic/polyether comb-branched copolymers, wherein the polyether units contain moieties derived from at least two constituents selected from the group consisting of ethylene oxide, propylene oxide, and butylene oxide, are useful as builders, even without any 2-methyl-1,3-propanediol in laundry detergent formulations.
The non-hydrophobically modified, acrylic/polyether comb-branched polymers of the present invention exhibit surprisingly good anti-redeposition and stability properties when used in liquid laundry detergent formulations. Furthermore, it has also been surprisingly discovered that the non-hydrophobically modified, acrylic/polyether comb-branched copolymers of the present invention exhibit surprisingly good anti-redeposition and anti-encrustation properties when used in a solid laundry detergent formulation.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Minimally, liquid laundry detergent formulations made in accordance with the present invention comprise a surfactant (surface active agent), a polycarboxylate builder, water, and 2-methyl-1,3-propanediol solvent. Additionally, the liquid laundry detergent formulations of the present invention may also comprise ion exchangers, alkalis, anti-corrosion materials, anti-redeposition materials, optical brighteners, fragrances, dyes, fillers, chelating agents, enzymes, fabric whiteners and brighteners, sudsing control agents, bleaching agents, bleach precursors, buffering agents, soil removing agents, soil release agents, fabric softening agents, and opacifiers. Examples of liquid laundry detergent formulations and the manner in which they are made are described in U.S. Pat. Nos. 6,034,045, 5,858,951, 5,575,004, 5,308,530, 4,663,071 and 3,719,647, which are incorporated herein by reference.
The 2-methyl-1,3-propanediol is present in the liquid laundry detergent formulation in an amount effective to increase the phase stability of the liquid laundry detergent formulation relative to liquid laundry detergent formulations not containing the effective amount of the 2-methyl-1,3-propanediol. Preferably, the liquid laundry detergent formulations of the present invention comprise between about 0.1 to about 60 weight percent of a surfactant, about 0.1 to about 70 weight percent of a polycarboxylate builder, about 0.1 to 50 weight percent 2-methyl-1,3-propanediol and about 50 to about 99 weight percent water. More preferably, the liquid laundry detergent formulations of the present invention comprise between about 0.5 to about 30 weight percent of a surfactant, about 0.1 to about 40 weight percent of a polycarboxylate builder, about 0.1 to 40 weight percent 2-methyl-1,3-propanediol, and about 50 to about 99 weight percent water. Most preferably, the liquid laundry detergent formulations of the present invention comprise between about 5 to about 20 weight percent of a surfactant, about 0.1 to about 30 weight percent of a polycarboxylate builder, about 0.1 to 20 weight percent 2-methyl-1,3-propanediol, and about 50 to about 99 weight percent water. In each formulation, the sum of all weight percentages totals 100%, including, of course, the weight percentages of the aforementioned additional ingredients.
The 2-methyl-1,3-propanediol functions as carrier solvent or as a surfactant compatabilizer. 2-Methyl-1,3-propanediol is available commercially as MPDiol® glycol from Lyondell Chemical Company. In addition to the 2-methyl-1,3-propanediol, other carrier solvents may be used. Suitable examples of other carrier solvents include methanol, ethanol, propanol, isopropanol, 1,3-propanediol, ethylene glycol, glycerine, and 1,2-propanediol (propylene glycol).
The chemical nature of the surfactants, as well as the various optional components used in detergent compositions, are well known to those skilled in the art. Typical disclosures of these materials may be found in U.S. Pat. No. 4,663,071, which is incorporated herein by reference. It should be understood that the surfactant portion of the liquid laundry detergent formulation may comprise one surfactant or a blend of surfactants. The surfactants may include nonionic surfactants, anionic surfactants, cationic surfactants, and amphoteric surfactants.
Any suitable polycarboxylate builder can be used. The polycarboxylate builder component can comprise one polycarboxylate builder, a mixture of polycarboxylate builders, or a mixture of one or more polycarboxylate builders with one or more non-polycarboxylate builders. Suitable polycarboxylate and non-polycarboxylate builders are well known in the art and can be found in various literature sources, such as U.S. Pat. Nos. 4,663,071, 5,308,530, 3,719,647, and 5,574,004, which are incorporated herein by reference.
A preferred polycarboxylate builder comprises a non-hydrophobically modified, acrylic/polyether comb-branched copolymer wherein the polyether portion comprises moieties derived from at least two constituents selected from the group consisting of ethylene oxide, propylene oxide and butylene oxide. By non-hydrophobically modified, it is meant that the polyether chain does not bear any hydrophobic end
ARCO Chemical Technology L.P.
Brooks & Kushman P.C.
Gupta Yogendra N.
Mruk Brian P.
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