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US-12624314-B2 - Biobased dispersants for laundry cleaning applications

US12624314B2US 12624314 B2US12624314 B2US 12624314B2US-12624314-B2

Abstract

The present invention relates to the use of lignin derivatives, having a specific combination of degree of sulfonation and degree of oxidation, as an additive in a laundry detergent composition. Further, the present invention relates to a laundry detergent composition comprising the lignin derivative and to a laundry cleaning method.

Inventors

  • Ross Johannes Ellis

Assignees

  • BORREGAARD AS

Dates

Publication Date
20260512
Application Date
20220314
Priority Date
20210316

Claims (20)

  1. 1 . An additive for a laundry detergent composition, the additive comprising a sulfonated lignin derivative characterized in that the sulfonated lignin derivative has an amount of organic sulfur which is associated with sulfonate groups attached to lignin of at least 4.5% w/w, as measured in dry solid relative to overall dry solids weight of the sulfonated lignin derivative, and a carboxylate content of at least 6% w/w, as measured in the dry solid, relative to the overall dry solids weight of the sulfonated lignin derivative.
  2. 2 . The additive of claim 1 , wherein the sulfonated lignin derivative has been obtained by treating native lignin in a sulfite pulping process or wherein the sulfonated lignin derivative has been obtained by treating native lignin in a Kraft pulping process followed by one or more post-pulping sulfonation steps.
  3. 3 . The additive of claim 2 , wherein the sulfonated lignin derivative has been obtained by treating native lignin in a Kraft pulping process followed by one or more post-pulping sulfonation steps and no post-pulping steps apart from the one or more post-pulping sulfonation steps have been applied.
  4. 4 . The additive according to claim 1 , wherein the sulfonated lignin derivative is lignosulfonate or wherein the sulfonated lignin derivative is sulfonated Kraft lignin.
  5. 5 . The additive according to claim 1 , wherein the sulfonated lignin derivative has not been subjected to any functionalization step other than sulfite pulping, Kraft pulping, or one or more post-pulping sulfonation steps.
  6. 6 . The additive according to claim 1 , wherein the sulfonated lignin derivative does not contain functional groups other than those obtained from sulfite pulping, Kraft pulping or one or more post-pulping sulfonation steps.
  7. 7 . The additive according to claim 1 , wherein the sulfonated lignin derivative is lignosulfonate as obtained from sulfite pulping.
  8. 8 . The additive according to claim 1 , wherein the sulfonated lignin derivative is sulfonated Kraft lignin.
  9. 9 . The additive according to claim 1 , wherein the sulfonated lignin derivative is lignosulfonate that is used in combination with carboxymethyl cellulose (CMC).
  10. 10 . The additive according to claim 1 , wherein an average molecular weight of the sulfonated lignin derivative is less than 100,000 Da.
  11. 11 . The additive according to claim 1 , wherein the sulfonated lignin derivative does not comprise non-native hydrophobic substituents.
  12. 12 . A laundry detergent composition comprising the lignin derivative additive as defined in claim 1 .
  13. 13 . The laundry detergent composition according to claim 12 , wherein the sulfonated lignin derivative is comprised in the laundry detergent composition in an amount of 0.01-10% w/w based on total weight of the laundry detergent composition.
  14. 14 . A method for cleaning laundry, comprising the step of contacting laundry with the additive as defined in claim 1 .
  15. 15 . The method according to claim 14 comprising preventing redeposition of soil onto fabric during the cleaning.
  16. 16 . A detergent slurry composition comprising the additive of claim 1 , wherein the sulfonated lignin derivative is present in an amount of 0.001-15% w/w based on total weight of the detergent slurry composition and the detergent slurry composition has a reduced viscosity as compared to an otherwise equivalent detergent slurry composition without the additive.
  17. 17 . The additive of claim 1 , wherein the amount of organic sulfur is in a range from 4.5% w/w to 14% w/w as measured in the dry solid, relative to the overall dry solids weight of the sulfonated lignin derivative.
  18. 18 . The additive of claim 1 , wherein the amount of organic sulfur is in a range from 6% w/w to 10% w/w as measured in the dry solid, relative to the overall dry solids weight of the sulfonated lignin derivative.
  19. 19 . The additive of claim 1 , wherein the carboxylate content is in a range from 6% w/w to 30% w/w as measured in the dry solid, relative to the overall dry solids weight of the sulfonated lignin derivative.
  20. 20 . The additive of claim 1 , wherein the carboxylate content is in a range from 6% w/w to 20% w/w as measured in the dry solid, relative to the overall dry solids weight of the sulfonated lignin derivative.

Description

FIELD OF THE INVENTION The present invention relates to the use of lignin derivatives, having a specific combination of degree of sulfonation and degree of oxidation, as an additive in a laundry detergent composition. Further, the present invention relates to a laundry detergent composition comprising the lignin derivative and to a laundry cleaning method. BACKGROUND OF THE INVENTION Laundry, in particular clothes, can become soiled with a variety of different soils, ranging from highly hydrophilic soils (e.g. clay) to highly hydrophobic soils (e.g. oil and grease). Laundry detergent compositions that are capable of removing a wide range of different soils, including hydrophilic and hydrophobic ones, are therefore generally sought after. To achieve that purpose, laundry detergent compositions comprising a complex mixture of ingredients such as surfactants, chelating agents, enzymes, and builders have been developed. Such laundry detergent compositions often further comprise dispersants for dispersing soils and preventing redeposition thereof onto the laundry. Among others, ethoxylated polyalkylene imines and polycarboxylates have been used as dispersants. Such compounds, however, are generally petroleum-derived and prepared via laboratory chemical synthesis processes, which renders them quite costly and ecologically unfriendly. Therefore, there is a generally high demand for bio-based and eco-friendly yet effective dispersants for use in laundry detergent compositions. Lignin derivatives have been used as a component of laundry detergent compositions. Lignin (also referred to as “native lignin”) is one of the most abundant organic materials in nature and provides strength and support to trees and other plants. Lignin is a biopolymer, more precisely a mixture of biopolymers, that is/are present in the support tissues of plants, particularly in the cell walls providing rigidity to the plants. Lignin is a phenolic polymer, more precisely a mixture of phenolic polymers. The specific structure and composition of lignin depends on the plant and therefore varies depending on the plant from which it is derived. Lignin in its native form, i.e. as present in the plant, comprises an aromatic backbone structure and is generally hydrophobic and water-insoluble. Lignin is sometimes also referred to as the “glue” in the cellulosic skeleton. WO 03/062254, for example, reports the use of lignin phenols and lignin phenol derivatives derived from Kraft lignin or from lignosulfonate via catalytic reduction as described in U.S. Pat. Nos. 6,207,808, 6,100,385, and 5,230,814 for use in household cleaning and laundry detergent compositions. However, the preparation of these lignin phenols and lignin phenol derivatives requires the use of rather harsh chemical synthesis, which increases their cost and their environmental impact. Further, WO 2010/033743 reports the use of a modified lignin polymer in cleaning compositions. The lignin polymer comprises a randomly substituted lignin backbone wherein two or more of the hydroxyl groups on the randomly substituted lignin backbone have been substituted with R substituent groups, wherein each R substituent group is independently an R substituent type selected from the group consisting of nitrogen containing substituents R1 with a substitution weight percentage ranging from 0% to 75%, anionic substituents R2 with a substitution weight percentage ranging from 0% to 90%, alkoxy substituents R3 with a substitution weight percentage ranging from 0% to 90%, and combinations of any thereof, provided that the randomly substituted lignin backbone comprises at least two different R substituent types. However, again, the preparation of these lignin derivatives requires the use of dedicated laboratory chemistry, which increases their cost and their environmental impact. Thus, overall, bio-based, eco-friendly, and low-price yet effective dispersants for use as an additive in laundry detergent compositions are highly sought-after. SUMMARY OF THE PRESENT INVENTION Based on the above, it is an object of the present invention to provide bio-based, sustainably sourced, easy to produce, and highly effective dispersants for use as an additive in laundry detergent compositions. Further, it is desired that the dispersants can be prepared easily and cost-effectively in industrial-scale processes using naturally occurring materials, without the need for expensive chemicals/reactants. It is particularly desired to use compounds that are produced as by-products in industrial processes and therefore are available in large quantities. These objects are achieved by the sulfonated lignin derivative of the present invention. The present invention is based on the surprising finding that lignin derivatives having a specific combination of degree of sulfonation and oxidation (as measured as the content of carboxylate groups in the lignin) are effective anti-redeposition aids for laundry cleaning purposes. However, not ever