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EP-4370638-B1 - CATIONIC NONIONIC BLENDS FOR CLEANING OILY SOILS

EP4370638B1EP 4370638 B1EP4370638 B1EP 4370638B1EP-4370638-B1

Inventors

  • GHOSH, KAUSTAV
  • NEVILLE, Olivia
  • HUNKER, Lauren Michelle
  • CHEN, EMILY

Dates

Publication Date
20260513
Application Date
20220902

Claims (11)

  1. A method of washing textiles comprising the steps of: a. contacting textiles with a laundry detergent composition, comprising - a cationic amine surfactant having one of the following general structures RR'R"N + HX - or RR'R"N + R‴X - , wherein R is an unsubstituted or substituted alkyl chain, R', R", and R‴ may be either unsubstituted or substituted long alkyl chains having at least C8 chain length or smaller C1-C7alkyl or aryl groups or hydrogen and X is an anion; - at least one nonionic surfactant; and - water and/or a carrier suitable for a solid composition; wherein a pH of the laundry detergent in a use composition is between 6 to 9; b. contacting the textiles with an alkalinity source comprising a source of alkalinity or an alkaline detergent composition; and c. washing the textiles in an institutional or a household washing machine to remove soils; wherein the steps of contacting the textiles comprises a two-step cleaning wash process comprising first contacting the textiles with the laundry detergent composition at a pH between 6 to 9 during a wash cycle, and thereafter contacting the textiles with the alkalinity source or the alkaline detergent composition to increase the pH above the pKa of the cationic amine surfactant.
  2. The method of claim 1, wherein the cationic amine surfactant is cocoalkylbis(hydroxyethyl)methyl, ethoxylated, ammonium chloride.
  3. The method of claim 1 or claim 2, wherein the cationic amine surfactant comprises between 0.5 wt-% to 20 wt-% of the composition, the nonionic surfactants comprise between 20 wt-% to 90 wt-% of the composition, and the water or carrier comprises between 0.1 wt-% to 50 wt-% of the composition.
  4. The method of any one of claims 1 to 3, wherein the nonionic surfactants are a fatty alcohol alkoxylate, alcohol alkoxylate, EO/PO block copolymers, ethoxylated castor oil, alkyl polyglucosides, or combinations thereof.
  5. The method of any one of claims 1 to 4, wherein the cationic amine surfactant comprises from 1% to 15% on an actives basis of the total surfactant concentration of the composition.
  6. The method of any one of claims 1 to 5, further comprising diluting the laundry detergent composition at a point of use with water to form an aqueous use solution of the composition.
  7. The method of claim 6, wherein the aqueous use solution of the laundry detergent composition has a pH between 7 and 9.
  8. The method of claim 1, wherein the step of contacting the textiles with the alkalinity source or the alkaline detergent composition increases the pH above 9.
  9. The method of any one of claims 1 to 8, wherein a second application of the laundry detergent composition at a pH between 6 to 9 during a wash cycle follows the contacting step with the alkalinity source or the alkaline detergent composition.
  10. The method of any one of claims 1 to 9, wherein the textile comprises at least one of polyester, cotton or polycotton blends, and/or wherein the textile is one or more of a mop, napery, food service coat, industrial garment, or towels.
  11. The method of any one of claims 1 to 10, wherein the wash cycle provides ≤ 500 ppm alkalinity for a low alkalinity laundry program, and optionally wherein the wash cycle further comprises a bleaching step, antichlor step, souring step, a rinsing phase and/or a draining phase.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS This application claims priority under 35 U.S.C. § 119 to provisional application Serial No. 63/260,880, filed September 3, 2021. FIELD OF THE INVENTION This disclosure relates methods of using a laundry detergent composition in a two-part wash process with an alkali step, wherein the laundry detergent compositions functions as a neutral detergent containing a cationic amine surfactant in combination with nonionic surfactants to beneficially remove difficult to treat soils, including for example food and industrial oils on various textile substrates including polyester, cotton and polycotton blends. BACKGROUND OF THE INVENTION In laundry processes, particularly commercial laundry processes with high amounts of soil, textiles are commonly laundered at elevated temperatures with highly 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 similar alkaline component. Such processes can cause residual or carryover alkalinity that require acidic souring steps to remove or mitigate the carryover alkalinity. Sour materials contain acid components that neutralize alkaline residues on the fabric. US 5863887A discloses a method of washing textiles with a laundry sheet providing antistatic and fabric softening properties. Despite numerous advances in laundry detergent compositions and methods of using them, there remain ongoing needs in the laundering field for enhanced removal of difficult to treat soils, namely food and beverage oils (e.g. oily soil and/or oily stains) from various types of textiles. Textiles contain a variety of different fibers, including natural, manmade, and/or synthetic fibers. Natural fibers are generally derived from plants or animals. For example, protein-based natural fibers include wool and silk, while cellulosic fibers include cotton and linen. Manmade fibers such as rayon and acetate are generally manufactured from regenerated cellulose. Synthetic fibers include, for example, nylon, olefin, polyester, acrylic, and corterra. Cotton in particular is one of the most popular fibers used in textiles. Cotton can be combined or blended with other fibers to create blends that dry easily, demonstrate excellent elasticity, and feel soft. Cotton-containing textiles also demonstrate high absorbency, which is a desirable property for use but also means cotton stains easily. Additionally, cotton has poor resilience and poor abrasion resistance. The poor resiliency and abrasion resistance combined with harsher cleaning products typically required to remove soil from cotton-containing textiles result in a short lifespan and high replacement rate. Synthetic fibers are generally hydrophobic and oleophilic. As such the oleophilic characteristics of the fiber permit oil and grime to be readily embedded in the fiber, and the hydrophobic properties of the fiber prevent water from entering the fiber to remove the contaminants from the fiber. These challenges are often exacerbated in the presence of stubborn soils such as oily soils found on textiles from food, beverage and industrial applications, such as mops including bar mops, napery, food service coats, industrial garments, shop towels, and the like. As a result, costs in various food, beverage and industrial applications using textiles often include textile replacement costs as a result of stains, namely oily stains, that simply cannot be fully removed from the fabric. Thus, despite various existing laundry detergent compositions there remains a long-standing need to improve stain removal and thereby reduce replacement rate of fabrics, allowing the textiles to remain in use for a longer time. Accordingly, there is a need to provide cleaning methods which provide effective soil removal, including for example food, beverage and industrial soils that are conventionally difficult to remove and result in high replacement costs for textiles. A further object of the disclosure is to provide cleaning methods and compositions that are effective at removing soils at low temperature and low alkali conditions. Other objects, aspects and advantages of this invention will be apparent to one skilled in the art in view of the following disclosure, the drawings, and the appended claims. SUMMARY OF THE INVENTION An advantage of the compositions and methods disclosed herein is that they are effective at removing difficult to treat soils, including food and industrial oils, from various textiles, including at low temperature and low alkali conditions. It is an advantage that the compositions and methods contribute to stubborn soil removal, even oily soils, through the combined use of cationic and nonionic surfactants in a neutral detergent that is combined with or followed by an alkali detergent. The laundry detergent compositions employed in the method of the invention comprise: a cationic amine surfactan