EP-4741480-A2 - NON-PHOSPHOROUS TRANSITION METAL CONTROL IN LAUNDRY APPLICATIONS

Abstract

Methods and compositions for improving laundry quality in multiple areas including detergency, bleaching and wastewater operations are provided by a laundry additive composition. The laundry additive composition and methods of using the composition control iron and other transition metals in water utilized within laundry applications.

Inventors

• LANG, Jason
• STOKES, JIMMY
• SILVERNAIL, CARTER M.
• DOTZAUER, DAVID
• LUNDBERG, STEVEN
• OTTING, KRISTA

Assignees

• Ecolab USA Inc.

Dates

Publication Date

20260513

Application Date

20180627

Claims (15)

1. A method for treating laundry comprising: contacting the laundry with a laundry additive composition comprising a gluconate chelant, at least one additional chelant comprising an aminocarboxylate or salt thereof, a carboxylate polymer and water; wherein the laundry additive composition does not contain phosphorus or a phosphorus containing compound, and wherein the laundry additive composition controls transition metal contaminants throughout the laundry process under alkaline to acid pH conditions and optionally in the presence of oxidizers.
2. The method of claim 1, wherein the laundry process comprises an initial wash process utilizing transition metal contaminated water supplied to the washer and/or transition metal contaminated soils or laundry supplied to the washer.
3. The method of any one of claims 1 to 2, wherein the laundry process comprises a steaming or direct steam injection contaminated with transition metals to heat waters utilized in the laundry process.
4. The method of any one of claims 1 to 3, wherein the dosing of the laundry additive conditioning composition is provided at a rate of: (a) about 0.5 fluid ounces to about 30 fluid ounces, (b) about 3 fluid ounces to about 30 fluid ounces per 100 pounds of linen, or (c) at a rate to control at least 0.1 ppm transition metals in the laundry process.
5. The method of any one of claims 1 to 3, wherein the dosing of the laundry additive composition is provided at a rate of about 0.5 to about 5 grams/L of solution of the water conditioning composition, wherein the composition comprises from about 0.08 to about 0.8 grams/L gluconate salt chelant.
6. The method of any one of claims 1 to 5, wherein the laundry additive composition is dosed into the washing machine, dosed into a steam receiving side of a steam injection heated process within the laundry process, and/or dosed into a water reuse or recycle storage container or output line.
7. The method of any one of claims 1 to 6, comprising an initial step of measuring iron concentration in a water source or input to the laundry process.
8. The method of any one of claims 1 to 7, wherein the contacting of the laundry additive composition is: before a bleaching and/or oxidizing step in the laundry process; and/or simultaneous with an alkaline detergent wash step in the laundry process.
9. The method of any one of claims 1 to 8, wherein the laundry additive composition reduces iron contaminant deposits in the laundry process to less than about 35 ppm, and reduces water hardness metal ion deposits to less than about 300 ppm.
10. A laundry additive composition comprising: a gluconate chelant; at least one additional chelant comprising an aminocarboxylate or salt thereof; a carboxylate polymer; and water, wherein the composition does not contain phosphorus or a phosphorus containing compound.
11. The composition of claim 10, wherein the gluconate chelant is sodium gluconate or gluconic acid.
12. The composition of any one of claims 10 to 11, wherein the aminocarboxylate comprises methyl glycine diacetic acid and/or diethylenetriaminepentaacetic acid.
13. The composition of any one of claims 10 to 12, wherein the carboxylate polymer is a polyacrylate polymer, a polyacrylic acid, a polymaleic acid, salt thereof or combination thereof.
14. The composition of any one of claims 10 to 13, wherein the gluconate salt chelants comprises from about 1 wt-% to about 30 wt-% of the composition, the at least one additional chelants comprises from about 0.1 wt-% to about 10 wt-% of the composition, the polymer comprises from about 1 wt-% to about 30 wt-% of the composition, and water comprises from about 20 wt-% to about 80 wt-% of the liquid composition.
15. The composition of any one of claims 10 to 14, wherein the composition is free of surfactants.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS This application claims priority under 35 U.S.C. § 119 to provisional application Serial No. 62/525,237, filed June 27, 2017, herein incorporated by reference in its entirety. FIELD OF THE INVENTION Embodiments disclosed relate to methods and compositions for improving laundry quality in multiple areas including detergency, bleaching and wastewater operations. In particular, methods and compositions for controlling transition metal contaminants in water utilized within laundry applications are provided. In an embodiment, non-phosphorous laundry additive compositions including chelants and a polymer beneficially control transition metals throughout the laundry process including but not limited to: break steps (initial alkaline detergent wash process), steaming or non-steaming, bleach and/or oxidizer steps, souring and laundry wastewater applications. BACKGROUND OF THE INVENTION In typical commercial or industrial laundry processes, textile materials such as sheets, towels, wipes, garments, tablecloths, etc. are commonly laundered at elevated temperatures with alkaline detergent materials. Such detergent materials typically contain a source of alkalinity such as an alkali metal hydroxide, alkali metal silicate, alkali metal carbonate or other such base component. When the linen is treated with an alkaline detergent composition a certain amount of carryover alkalinity may occur. Carryover alkalinity refers to the chemistry that is contained within the linen (that has not been completely removed) that is available for the next step. For example, when the detergent use solution provides an alkaline environment, it is expected that the detergent use solution will provide a certain amount of carryover alkalinity for a subsequent sour treatment step unless all of the detergent use solution is removed by rinsing. The residual components of the alkaline detergents remaining in or on the laundered item can result in fabric damage and skin irritation by the wearer of the washed fabric. This is particularly a problem with towels, sheets and garments. Sour materials contain acid components that neutralize alkaline residues on the fabric. Another challenge in laundry processes are iron and other metals. Such contaminants may be present due to stains, such as rust, or present due to water utilized within the laundry process, such as transition metals resulting from inputted water sources and/or steam to heat a laundry process. Iron can enter the water at the source or be picked up from corroding (or lines in various states of corrosion) water lines and tanks. Iron may be present in water sources in a soluble colorless form called ferrous iron. When exposed to air, ferrous iron rapidly converts to insoluble ferric iron, which can vary in color from yellow to reddish brown. If not properly removed, iron and other metals can cause permanent yellowing of fabrics and loss of fabric life due to tensile strength loss. Metal content can further result in detergent inactivation and/or inhibition, accelerated loss of oxidizing chemistries used in a laundry process, shading due to deposition of metals, as well as shading due to optical brightener modification, and still other detrimental laundry effects. To date the primary approach to removing metals from water sources utilized in laundry processes focus on water softening equipment to reduce iron impurities. In addition, the approach to remove metals from stains to date has primarily relied upon the use of high levels of caustic, which can damage delicate fabrics and, if not properly removed and brought back to neutral pH, can result in exposure of the caustic to human skin. Current laundry sour compositions to help remove residual alkali and for iron control generally include strong acids such as fluoroacetic acid, phosphoric acid, hydrofluoric acid, and hexafluorosilicic acid which are environmentally undesirable and/or hazardous. As can be seen, there is a continuing need in the art for the development of iron and other metal control treatments after alkaline washing that not only prevent yellow staining of laundered fabrics, and remove residual caustic, but also that are environmentally friendly and sustainable. Moreover, formulations for laundry applications present distinct challenges in comparison to warewash or other hard surface cleaning applications where water conditioning and metal control may also be required. Laundry presents unique challenges of a greater surface area (relative to warewashing or hard surface) and requiring chelants to treat both hardness ions and transition metals (iron, copper, manganese). Moreover, the use of surfactants and/or chelants that are common in warewashing applications do not readily provide same benefits in laundry applications. This is primarily a result of the differences between the substrates being treated, namely porous textiles in laundry present distinct challenges from hard surfaces treate