Cleaning compositions for solid surfaces – auxiliary compositions – Cleaning compositions or processes of preparing – Specific organic component
Reexamination Certificate
1999-01-05
2001-01-30
Gupta, Yogendra (Department: 1751)
Cleaning compositions for solid surfaces, auxiliary compositions
Cleaning compositions or processes of preparing
Specific organic component
C510S434000, C510S477000, C524S779000, C524S780000, C524S788000, C524S791000, C528S275000, C528S297000, C528S298000, C528S302000, C528S306000
Reexamination Certificate
active
06180589
ABSTRACT:
FIELD OF THE INVENTION
This invention relates to novel polyether hydroxycarboxylate copolymers which are effective sequestering agents. The polyether hydroxycarboxylate copolymer when used in a cleaning composition enhances or “builds” the cleaning efficiency of a surfactant by inactivating hardness ions. The copolymers also assist in cleaning by dispersing and suspending soils to prevent the redeposition of soils onto cleaned articles.
BACKGROUND OF THE INVENTION
The role of sequestering agents in softening water by complexing the “hardness” cations in water supplies is well-known. Sequestering agents are recognized aids in detergent processes because they form a soluble complex with calcium and magnesium ions which can react with soaps and other anionic surfactants and otherwise adversely affect detergency.
Polyphosphates such as tripolyphosphates and pyrophosphates are widely used as ingredients in detergent compositions in part because of their property of sequestering hardness ions. Such phosphorus-containing compounds as well as nitrogen-containing compounds, e.g., nitrilotriacetates, are highly effective. However, the effect of the phosphorus content and the nitrogen content of these sequestering agents upon eutrophication of lakes and streams has been questioned and the use of phosphates in detergent compositions has been subject to government scrutiny, regulation or prohibition.
These circumstances have developed a need for highly effective and efficient phosphorus-free and nitrogen-free sequestering agents and detergency builders.
U.S. Pat. No. 3,692,685, describes detergent compositions containing an ether polycarboxylate having the structure:
In the above structure of U.S. Pat. No. 3,692,685, R is H or —CH
2
COONa.
U.S. Pat. No. 4,228,300, describes ether polycarboxylate sequestering agents and detergency builders having the structure:
In the above structure of U.S. Pat. No. 4,228,300, M is alkali metal or ammonium, R
1
and R
2
are hydrogen, methyl or ethyl and R
3
is hydrogen, methyl, ethyl or COOM.
U.S. Pat. No. 3,769,223, describes 1-oxacyclopropane-2,3-dicarboxylic acid (i.e., epoxysuccinic acid) and its soluble salts as detergent builders.
U.S. Pat. No. 3,776,850, describes polymers to be used as detergent builders which have the structure:
In the above structure of U.S. Pat. No. 3,776,850, R is hydrogen or other specified radicals and n is from 2 to about 40, preferably from 2 to about 6. The polymers are prepared by polymerization of the diethyl ester of 1-oxacyclopropane-2,3-dicarboxylic acid (i.e., epoxysuccinic acid) in the presence of a boron trifluoride catalyst followed by saponification. Detergent compositions are exemplified in which n is said to have an average value of approximately 3 or 4. In fact, the disclosed synthesis method yields mixtures of materials which contain very low levels of the n=3 and n=4 components.
U.S. Pat. No. 4,654,159 describes the use of polyepoxy succinic acid as a sequestering agent in detergent compositions.
SUMMARY OF THE INVENTION
The invention provides a novel polyether hydroxycarboxylate copolymer comprising
wherein M
+
is a cation wherein M is independently selected from the group consisting of hydrogen, ammonia, alkali metals, alkaline earth metals, zinc, copper, organic amines, amino acids, and amino saccharides; R
1
is the residue of an ethylenically unsaturated comonomer having at least one functional group which is selected from the group consisting of carboxylic acid, sulfonic acid and phosphonic acid; R
2
and R
3
are independently selected from the group consisting of hydrogen, and a substituted or unsubstituted alkyl group having 1 to 4 carbon atoms; n is from about 2 to about 100; x
1
and x
2
are independently 0 or 1; a is from 0 to 99 mole percent; and b is from 100 to 1 mole percent, provided that (a+b) is 100 mole percent.
According to another aspect the invention also provides a cleaning composition comprising from about 0.5 to about 98 weight percent, based on the weight of the cleaning composition, of the polyether hydroxycarboxylate copolymer.
In a cleaning composition, the polyether hydroxycarboxylate copolymer enhances or “builds” the cleaning efficiency of a surfactant by inactivating hardness ions such as calcium and magnesium, and other metal ions such as iron. The polyether hydroxycarboxylate copolymers soften water by sequestration. In addition, the polyether hydroxycarboxylate copolymers assist in cleaning by dispersing and suspending soils to prevent the redeposition of soils onto cleaned articles.
DESCRIPTION OF THE INVENTION
The polyether hydroxycarboxylate copolymers have the structure
wherein M
+
is a cation wherein M is independently selected from the group consisting of hydrogen, ammonia, alkali metals, alkaline earth metals, zinc, copper, organic amines, amino acids, and amino saccharides. Preferably the cation is independently hydrogen or sodium.
In the above structure for the polyether hydroxycarboxylate copolymer, R
2
and R
3
are independently selected from the group consisting of hydrogen, an alkyl group having 1 to 4 carbon atoms, a substituted alkyl group having 1 to 4 carbon atoms, and combinations thereof. When R
2
and R
3
are hydrogen, the monomer used to prepare the repeating unit (a) is maleic acid. However, methylmaleic acid (citraconic acid) and other substituted cisbutenedioic acids can be substituted for maleic acid.
In the above structure for the polyether hydroxycarboxylate copolymer, R
1
is the residue of an ethylenically unsaturated comonomer having at least one functional group which is selected from the group consisting of carboxylic acid, sulfonic acid and phosphonic acid. Suitable ethylenically unsaturated comonomers having a carboxylic acid functional group are acrylic acid, methacrylic acid, itaconic acid, ethacrylic acid, alpha-chloro-acrylic acid, alpha cyano acrylic acid, crotonic acid, alpha phenyl acrylic acid, beta acryloxy propionic acid, sorbic acid, angelic acid, cinnamic acid, glutaconic acid, 2-acrylamido glycolic acid, and tricarboxyethylene. A preferred ethylenically unsaturated comonomer having carboxylic acid functional groups is itaconic acid.
Suitable ethylenically unsaturated comonomers having a sulfonic acid or phosphonic acid functional group are vinyl sulfonic acid, sodium methallyl sulfonate, 2-acrylamido 2 methyl propane sulfonic acid, allyloxybenzene sulfonic acid, and vinyl phosphonic acid. Preferred ethylenically unsaturated comonomers having a sulfonic acid or phosphonic acid functional group are vinyl sulfonic acid and vinyl phosphonic acid.
Thus, the polyether hydroxycarboxylate copolymer is prepared from (a) and (b) repeating units. The (a) repeat units are derived from either maleic acid, methylmaleic acid, or other substituted cisbutenedioic acids. The (b) repeat units are derived from an ethylenically unsaturated comonomer having at least one functional group which is selected from the group consisting of carboxylic acid, sulfonic acid and phosphonic acid.
In the above structure for the polyether hydroxycarboxylate copolymer, n is from about 2 to about 100. Preferably n is from about 2 to about 20, more preferably from 2 to 10. The letters x
1
and x
2
are independently 0 or 1. The letter a is from 0 to 99 mole percent, preferably 20 to 99 mole percent. The letter b is from 1 to 100 mole percent, preferably 1 to 80 mole percent, provided that (a+b) is 100 mole percent.
A preferred process for preparing the polyether hydroxycarboxylate copolymers involves mixing the monomer(s) responsible for repeating unit (a) and comonomer(s) responsible for repeating unit (b) together with water to form a mixture. The monomer(s) and comonomer(s) in the mixture are neutralized or partially neutralized using a base. A preferred base is sodium hydroxide. Preferably, at least 60% of the total acid groups are neutralized.
The next step involves epoxidation of the ethylenically unsaturated double bonds present in the monomer(s) and comonomer(s) to form a mixture of epoxides. Methods for epoxid
Carrier Allen M.
Rodrigues Klein A.
Gupta Yogendra
Mruk Brian P.
National Starch and Chemical Investment Holding Corporation
Roland, Esq. Thomas F.
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