Lignin derivatives for reducing dishwasher film

Abstract

The present invention relates to the use of lignin derivatives for reducing and / or preventing deposits on objects during machine dishwashing. Furthermore, the present invention relates to a method for reducing and / or preventing deposits on objects and to a machine dishwasher detergent formulation comprising the lignin derivatives described herein.

Description

Technical Field

[0001] The present invention relates to the use of lignin derivatives for reducing and / or preventing deposits on objects during machine dishwashing. Furthermore, the present invention relates to a method for reducing and / or preventing deposits on objects and to a machine dishwasher detergent formulation comprising the lignin derivatives described herein. Background Art

[0002] A common problem is the formation of insoluble deposits during machine dishwashing, especially in areas with "hard" water (i.e., water with high levels of calcium and / or magnesium ions). This problem is particularly evident when high levels of carbonate and / or phosphate ions are present during the machine dishwashing process. Because carbonate is a major component of most dishwasher detergent formulations, typically in the form of sodium carbonate ("soda"), the formation of calcium carbonate deposits ("scale") is particularly evident during the machine dishwashing process. For example, calcium and magnesium ions present in the water can interact with carbonate and / or phosphate ions present in the detergent formulation and / or residual food material on the objects to be cleaned to produce white film-like and dot-like deposits on the objects. Such deposits accumulate over repeated wash cycles and are clearly visible on glassware. Therefore, "anti-filming" additives are typically included in most dishwasher detergent formulations (or added separately) to prevent and / or reduce such deposits.

[0003] Typically, anti-filming additives used in dishwasher detergents are synthetic anionic polymers, primarily polycarboxylates such as polyacrylates, polymethacrylates or polyaspartates. Commercially available examples of such polymers include Acusol 445 (Rohm & Haas), which is a homopolymer of low molecular weight partially neutralized acrylic acid. Another class of anti-filming additives are sulfonate / carboxylate copolymers.

[0004] Although effective, current anti-filming additives are primarily synthetically derived from petroleum-based chemicals. However, this makes them unattractive for use in "eco-friendly" detergent formulations that tend toward "plant-based" or "bio-based" ingredients. As a result, there is currently a high demand for bio-based environmentally friendly detergent ingredients (including dishwasher anti-filming additives) that can match the performance of petroleum-based synthetics without compromising sustainability or cost.

[0005] Various attempts have been made to increase the bio-based carbon content of anti-filming additives for dishwashers. For example, plant-derived polymeric materials (e.g., starch, protein, lignin, cellulose) have been functionalized with carboxylate-containing chemical groups, particularly polyaspartate. However, these methods only use plant-based materials as templates and still react with synthetic moieties of petroleum sources that are known to inhibit film deposition. Therefore, these methods still rely on synthetic petroleum-derived chemicals to achieve the desired anti-filming properties and therefore do not provide a sustainable "100% bio-based" solution. In addition, such modifications involving the reaction of synthetic chemicals with bio-based polymers are expected to be expensive, affecting the cost-effectiveness of additives. As an example of a method for making anti-filming materials using expensive "laboratory" chemicals, WO 2004 / 061067 proposes functionalizing substrates (e.g., CMC, cellulose ethers, cellulose polymers, lignin, PVA, polyaspartate, starch, sugars, gums, etc.) with chloroacetic acid, chlorosulfonic acid in the presence of a catalyst, wherein such functionalized substrates can be used as anti-filming agents together with surfactants.

[0006] Overall, therefore, cost-effective anti-filming solutions with up to 100% bio-based carbon content are very welcome. Summary of the invention

[0007] Based on the above, it is an object of the present invention to provide bio-based, sustainably sourced and highly effective anti-filming additives for machine dishwashing applications. Furthermore, it is desirable that the anti-filming additives can be easily and cost-effectively prepared in an industrial scale process using naturally occurring materials without the need to use expensive chemicals / reactants.

[0008] These and other objects are achieved by using the lignin derivatives as described herein to reduce and / or prevent deposits on objects during machine dishwashing.

[0009] In a first aspect, the present invention relates to the use of a lignin derivative as described herein for reducing and / or preventing deposits on objects during machine dishwashing.

[0010] In a second aspect, the present invention relates to a machine dishwasher detergent formulation comprising a lignin derivative as described herein.

[0011] In a third aspect, the present invention relates to a method of reducing or preventing deposits on an object. The method comprises the step of contacting the object with a lignin derivative as described herein during a machine washing process.

[0012] In a fourth aspect, the present invention relates to the use of a lignin derivative as described herein to reduce the viscosity of a detergent slurry during processing. DETAILED DESCRIPTION

[0013] The present invention is based, at least in part, on the surprising discovery that lignin derivatives as described herein are effective in reducing and / or preventing the formation of deposits on objects during machine dishwashing. In particular, lignin sulfonates obtained from sulfite pulping have been found to be effective in reducing and / or preventing the formation of deposits on objects during machine dishwashing. Sulfonated natural lignin and sulfonated kraft lignin have been found to be effective in reducing and / or preventing the formation of deposits on objects during machine dishwashing.

[0014] "Sulfite pulping" is known in the art of wood / plant material processing. Sulfite pulping can be advantageously used to convert almost pure cellulose fibers from lignocellulosic biomass (i.e., plant matter) into wood pulp. This "pulping" is usually achieved by extracting lignin from the lignocellulosic biomass in large pressure vessels called digesters by using various sulfites. During sulfite pulping, the lignin molecules are sulfonated and thus negatively charged and generally water-soluble. In sulfite pulping, sulfonate groups are usually introduced into the aliphatic part of the lignin, i.e. not into the aromatic part. Therefore, the lignin sulfonates obtained by sulfite pulping do not contain or do not significantly contain aromatic sulfonate groups, but only contain or essentially only contain aliphatic sulfonate groups. In addition, during sulfite pulping, carboxylate groups are introduced into the natural lignin.

[0015] According to the present invention, "sulfite pulping" refers to the process of extracting natural lignin or lignin from kraft pulp or reacting it with at least one sulfite. The salt used in the pulping process is preferably sulfite (SO3 2- ) or bisulfite (HSO3 - ). By sulfite pulping, sulfonate groups are usually introduced into the aliphatic part of the lignin, ie not into the aromatic part.

[0016] As referred to herein, an "aliphatic sulfonate group" is a sulfonate group that is bonded to an aliphatic carbon atom (i.e., a carbon atom that is not part of an aromatic ring). In contrast, an "aromatic sulfonate group" as referred to herein is a sulfonate group that is bonded to a carbon atom that is part of an aromatic ring.

[0017] Depending on the pulping conditions, feed materials and post-treatment, especially sulfite pulping, lignin sulfonate polymers can have different structures and chemical functionalities, such as molecular weight, degree of sulfonation, degree of conjugation, carboxylate groups (-COOR), phenolic groups, etc. Therefore, lignin sulfonates represent a highly diverse class of materials. Figure 1 An exemplary depiction of a lignin sulfonate molecule obtained from sulfite pulping is shown.

[0018] In a first aspect, the present invention relates to the use of a lignin derivative as described herein for reducing and / or preventing deposits on objects during machine dishwashing.

[0019] The lignin derivative according to the present invention comprises both -COOR and sulfonate groups, wherein R is a cation, preferably an ammonium ion, hydrogen, an alkali metal ion or an alkaline earth metal ion, or any mixture thereof.

[0020] According to the present invention, the carbon atom of the -COOR group is already contained in the natural lignin from which the lignin derivative is derived. This means that the -COOR group is formed by oxidizing carbon atoms that are already part of the natural lignin from which the lignin derivative is derived. In other words, the -COOR group is not introduced by reacting natural lignin or lignin derivatives with other molecules containing -COOR groups. Or in other words, the -COOR group is not introduced by grafting molecules containing -COOR groups onto lignin or lignin derivatives. Molecules containing -COOR groups used to introduce -COOR groups in the art are, for example, chloroacetic acid. Therefore, if chloroacetic acid is used to form the-COOR group of lignin derivative, then-the carbon atom of the COOR group will not be included in the natural lignin that the lignin derivative is derived from, but will be included in (petroleum-based) chloroacetic acid. Obviously, this "laboratory chemistry" method of introducing-COOR group is labor-intensive, expensive, and needs to use chemicals that are usually toxic, expensive and are petroleum-based. The lignin derivative prepared in this way is not easy to carry out large-scale (industrial) processing, and can not be described as environmentally friendly, bio-based or sustainable sources. Therefore, it is not within the scope of the present invention to functionalize with molecules such as chloroacetic acid containing-COOR group.

[0021] The lignin derivatives of the present invention can generally be represented as "chemically modified" lignins containing -COOR and sulfonate groups. These groups increase the polarity of the lignin derivatives and make the lignin derivatives water-soluble.

[0022] Preferably, the bio-based carbon content of the lignin derivative is greater than 95%, more preferably greater than 98%, more preferably greater than 99%, even more preferably greater than 99.5%, and most preferably 100%.

[0023] Biobased carbon content is determined according to ASTM D6866-18 and is defined as follows:

[0024]

[0025] Preferably, the lignin derivative is part of a machine dishwasher detergent formulation as described in the second aspect.

[0026] According to the present invention, the term "water-soluble" means that the lignin sulfonate polyelectrolyte forms a solution with water and is present in water in an amount such that the resulting solution is visually clear and does not leave any noticeable precipitate when subjected to conventional filtration.

[0027] As mentioned above, a common problem associated with the machine dishwashing process is the formation of insoluble deposits over time in the machine dishwashing process. By using lignin derivatives as described herein in the machine dishwashing process, such deposits can be reduced and / or prevented. The deposits formed over time due to the machine dishwashing process are usually formed based on the calcium ions and / or magnesium ions present in the wash water and the carbonate ions and / or phosphate ions that are usually present in the machine dishwasher detergent formulation and / or the dirt of residual food materials or other sources. Such deposits are also referred to as "scale". The scale formed by carbonate ions and calcium / magnesium ions is called "carbonate scale", and the scale formed by phosphate ions and calcium / magnesium ions is called "phosphate scale". A known type of deposit occurring in the dishwashing process is scale. However, since many countries or regions including the European Union and the U.S. have banned or at least significantly restricted the use of phosphates in detergent formulations, scale is mainly formed in the form of carbonate scale nowadays.

[0028] Deposits can be of various origins and chemical compositions, and are often described in the art as "films" and "spots".

[0029] Typically, cutlery, tableware or glassware are washed in a machine dishwasher. Therefore, the object for reducing and / or preventing deposits is preferably cutlery, tableware or glassware.

[0030] Lignin (also called "native lignin") is one of the most abundant organic materials in nature, providing strength and support to trees and other plants. Lignin is sometimes referred to as the "glue" in the cellulose backbone. Chemically, lignin is a class of complex organic polymers.

[0031] Therefore, according to the present application, the term "lignin" refers to a biopolymer, a mixture of biopolymers, respectively, which is present in the supporting tissues of plants, in particular in the cell walls that provide rigidity to plants. Lignin is respectively a phenolic polymer, a mixture of phenolic polymers. The composition of lignin depends on the plant and therefore varies according to the plant from which it originates. Lignin in its natural form, i.e. the lignin present in plants, is hydrophobic and aromatic. There is no restriction on the source of lignin.

[0032] According to the present application, the term "chemically modified" lignin and / or "lignin derivative" is understood to relate to any lignin which no longer exists in its natural form, but has undergone a chemical derivatization process. Methods for preparing chemically modified lignin are generally known in the art, such as sulfite pulping.

[0033] A preferred example of a lignin derivative is a lignin sulfonate. Lignin sulfonates are obtained when lignin, lignin-containing cellulosic biomass (also including "kraft pulp", i.e. cellulosic biomass that has been subjected to a kraft pulping treatment) are subjected to sulfite cooking, respectively. Thus, lignin sulfonates are organic salt products recovered from wood cooking (e.g. acidic or alkaline sulfite pulping with sulfite). Thus, preferred lignin sulfonates can be described as anionic polyelectrolyte polymers.

[0034] The term "lignin sulfonate" as used in the context of this application refers to any lignin derivative formed during the sulfite pulping of lignin-containing materials such as wood in the presence of, for example, sulfur dioxide and sulfite ions, respectively, bisulfite ions. For example, during the acidic sulfite pulping of lignin-based materials, electrophilic carbon cations are generated in lignin as a result of the acid-catalyzed cleavage of ether bonds. Therefore, lignin can react with sulfite ions, respectively, bisulfite ions via these carbocations to form lignin sulfonates.

[0035] Another example of chemically modified lignin is "kraft" lignin. Kraft lignin is precipitated from kraft alkaline pulping liquor, in particular from the kraft pulping process, during which lignin is decomposed from its natural form present in the wood pulp and represents a molecular part of the original biopolymer. Therefore, kraft lignin can be described as precipitated, unsulfonated alkaline lignin. Kraft lignin is structurally and chemically different from lignin sulfonates, for example, kraft lignin is insoluble in water. Therefore, if kraft lignin is used in the present invention, the kraft lignin is further sulfonated. Therefore, in one embodiment of the present invention, the lignin derivative is a sulfonated lignin obtained from kraft lignin. In one embodiment, such a sulfonated kraft lignin can be obtained when kraft lignin is treated with alkali metal sulfites and alkyl aldehydes at high temperature and pressure.

[0036] The lignin derivatives useful in all aspects of the present invention are now described in further detail:

[0037] Lignin derivatives contain sulfonate groups and -COOR groups. Wherein, "R" is a cation, preferably an ammonium ion, hydrogen, an alkali metal ion, an alkaline earth metal ion or any mixture thereof. The fact that "R" can be any mixture of ammonium ions, hydrogen, alkali metal ions, alkaline earth metal ions is due to the fact that lignin derivatives contain a large number of -COOR groups that can exist in different forms. For example, some -COOR groups can exist in the form of -COOH groups, while others exist in the form of salts, such as in the form of -COONa groups. Typically, the -COOR group can be described as a carboxylic acid group or a salt thereof. However, as known to those skilled in the art, when the lignin derivative actually contacts an object during machine dishwashing, the lignin derivative is present in an aqueous solution, and therefore, -COOR may be in a deprotonated form (i.e., -COOH). - ) exists. When the present invention refers to a -COOR group, such a form is also included.

[0038] As referred to herein, a sulfonate group is a group having the chemical formula -SO3R', wherein R' is selected from the group consisting of an alkali metal ion or an alkaline earth metal ion. However, when the lignin derivative actually contacts an object during machine dishwashing, the sulfonate group may be in its free form (i.e., SO3 - ) are present. Such and similar cases are also included when referring to a sulfonate group.

[0039] The lignin derivatives according to the invention can be obtained in different ways.

[0040] According to a preferred embodiment, the lignin derivative is obtained by treating natural lignin during sulfite pulping to introduce -COOR and sulfonate groups.

[0041] Preferably, the lignin derivative contains no -COOR groups and / or sulfonate groups other than groups from the sulfite pulping process. Furthermore, preferably, the lignin derivative contains no sulfonate groups and -COOR groups other than groups from the sulfite pulping process.

[0042] In a further preferred embodiment, this step of treating the native lignin in the sulfite pulping process is followed by one or more post-pulping functionalization steps for reducing the molecular weight and / or increasing the amount of -COOR groups.

[0043] As referred to herein, a "lignin sulfonate obtained from sulfite pulping" is a lignin sulfonate having a chemical structure that is the result of sulfite pulping of natural lignin from cellulose. Or in other words, a "lignin sulfonate obtained from sulfite pulping" is a lignin sulfonate obtained directly from the sulfite pulping process without applying any post-pulping functionalization steps. Therefore, a lignin sulfonate obtained as a by-product of cellulose production by sulfite pulping is a "lignin sulfonate obtained from sulfite pulping" within the meaning of the present invention.

[0044] As referred to herein, a "post-pulping functionalization step" is a chemical or physical treatment step applied after sulfite pulping that changes the molecular structure of the lignin sulfonates obtained from sulfite pulping. However, any step applied after sulfite pulping that merely increases the purity of the lignin sulfonates obtained from sulfite pulping without changing their chemical structure, such as washing steps, etc., is not a "post-pulping functionalization step" within the meaning of this application.

[0045] Preferably, the one or more post-pulping functionalization steps for reducing the molecular weight and / or increasing the amount of -COOR groups are an oxidation step or a heat treatment step.

[0046] Preferably, the lignin derivative is obtained by treating lignin sulfonates obtained from sulfite pulping in a post-pulping oxidation step. This means that lignin sulfonates are first prepared by treating natural lignin in sulfite pulping and then the lignin sulfonates obtained from sulfite pulping are oxidized in a post-pulping oxidation step. It should be understood that in this case, apart from washing and other purification steps that do not change the molecular structure in any significant way, no other post-pulping functionalization steps are applied.

[0047] In a preferred embodiment, the lignin derivative is lignin sulfonate obtained from sulfite pulping. This means that the lignin derivative is prepared by treating natural lignin during sulfite pulping to form lignin sulfonate.

[0048] In an embodiment, in case the lignin derivative of the invention is obtained by a sulfite pulping step, no (further) post-pulping functionalization step is applied. This also means that the lignin derivative does not contain sulfonate groups or -COOR groups other than groups from the sulfite pulping process. In particular, this means that the lignin derivative does not contain aromatic sulfonate groups. This embodiment is particularly advantageous because in this case, lignin sulfonates obtained as a by-product of cellulose production by sulfite pulping can be used, making the lignin derivative highly cost-effective and environmentally friendly. Sulfite pulping is advantageously used for industrial-scale processing of cellulose-based biomass because sulfite pulping is part of an integrated process that not only produces lignin sulfonates, but also produces cellulose pulp that can be further processed to produce valuable products / chemical platforms.

[0049] It has been found that in preferred embodiments, the structure (particularly molecular weight and amount of -COOR groups) of the lignin sulfonates obtained from sulfite pulping can be further fine-tuned by varying the sulfite pulping conditions. In embodiments, a sulfite pretreatment step may be applied.

[0050] In a preferred embodiment, cellulosic biomass, in particular lignocellulosic biomass, is used as substrate in the process which does not require mechanical (pre)treatment and wherein sulfite (pre)treatment ("cooking") is used as the only (pre)treatment.

[0051] Sulfite pulping can be generally divided into four categories: acid, acid bisulfite, alkaline and alkaline sulfite pulping.

[0052] In a preferred embodiment of the invention, the cellulosic biomass is cooked with sulfites, preferably sodium sulfite, calcium sulfite, ammonium sulfite or magnesium sulfite, under acidic, neutral or alkaline conditions. This sulfite cooking dissolves most of the natural lignin present in the cellulosic biomass as sulfonated lignin (lignin sulfonate; water-soluble lignin), as well as dissolving part of the hemicellulose.

[0053] Sulfite pretreatment is preferably carried out according to one of the following embodiments. In and throughout this disclosure, "sulfite pretreatment" is also referred to as "cooking":

[0054] Acidic cooking (preferably SO2 with hydroxide, more preferably with Ca(OH)2, NaOH, NH4OH or Mg(OH)2),

[0055] Bisulfite cooking (preferably SO2 with hydroxide, more preferably with NaOH, NH4OH or

[0056] Mg(OH)2),

[0057] Weak alkaline cooking (preferably Na2SO3, more preferably with Na2CO3) and

[0058] Alkaline cooking (preferably Na2SO3 and hydroxide, more preferably NaOH).

[0059] With regard to sulfite cooking, the corresponding disclosure of WO 2010 / 078930, filed on December 16, 2009, entitled “Lignocellulosic Biomass Conversion” is incorporated into the present disclosure by reference.

[0060] According to another preferred embodiment, the lignin derivative is prepared by sulfonating kraft lignin, ie lignin which has been chemically modified in a kraft pulping process. In a preferred embodiment, sulfite cooking as described above is used to further modify the kraft lignin.

[0061] According to another preferred embodiment, the lignin derivative obtained from sulfite pulping / cooking as described herein and above, or the lignin derivative obtained from sulfonated kraft lignin as described herein and above, is subjected to a further chemical treatment step, wherein the further step is selected from at least one oxidation step and / or a thermal treatment step, preferably at least one oxidation step.

[0062] This oxidation step increases the number of -COOR groups and / or reduces the molecular weight beyond the levels already achieved by the sulfite pulping / cooking step. As shown in the following experimental scheme, increasing the -COOR content and / or reducing the molecular weight (MW) generally improves anti-filming properties.

[0063] In a preferred embodiment, the oxidation step is selected from at least one of the following: oxidation with air (oxygen) and / or periodate, peroxide, ozone, etc. (optionally at high temperature), TEMPO oxidation (optionally in the presence of an oxidation catalyst) and other methods and reagents known to those skilled in the art for oxidizing cellulosic biomass.

[0064] Preferably, the lignin derivative comprises -COOR groups in an amount of greater than 4 wt.-%, more preferably greater than 8 wt.-%, even more preferably greater than 12 wt.-%, even more preferably greater than 14 wt.-%, based on dry matter. The amount of -COOR groups is determined by potentiometric titration as described in Methods in Lignin Chemistry, Stephen Y. Lin and Carlton W. Dence, Springer-Verlag Berlin Heidelberg, 1992, pp. 458-464.

[0065] Preferably, the lignin derivative does not contain aromatic sulfonate groups and / or has not been treated with chlorosulfonic acid. It is also preferred that the -COOR groups do not originate from a reaction with chloroacetic acid.

[0066] It is further preferred that the lignin derivative has not been treated with chloroacetic acid at all. It is further preferred that the lignin derivative does not contain -COOR groups other than groups in which carbon atoms are already contained in the natural lignin from which the lignin derivative is derived. This means that the -COOR groups are not formed by functionalizing lignin or a lignin derivative (such as lignin sulfonate or kraft lignin) with a molecule containing a -COOR group (such as chloroacetic acid).

[0067] The molecular weight (weight average molecular weight, MW) of the lignin derivative is preferably less than 45000Da, or 2000Da to 45000Da, or less than 42000Da, or less than 31000Da, or less than 10000Da, or 2000Da to 42000Da, or 2000Da to 31000Da, or 2000Da to 10000Da, or 3500Da to 45000Da, or 3500Da to 42000Da, or 3500Da to 31000Da, or 3500Da to 10000Da. The molecular weight is determined by size exclusion chromatography as described in G. Fredheim et al., "Molecular weight determination of lignosulfonates by size-exclusion chromatography and multi-angle laser light scattering", J Chromatogr A., ​​942, 2002, 191-199.

[0068] As shown in the examples, it has been found that low molecular weights lead to particularly effective film reduction properties.

[0069] Thus, generally, a combination of low molecular weight and relatively large numbers of -COOR groups is preferred.

[0070] According to a preferred embodiment, the lignin derivative has a molecular weight of less than 100000 Da and comprises -COOR groups in an amount greater than 4 wt.-% (based on dry matter).

[0071] According to another preferred embodiment, the lignin derivative has a molecular weight of less than 100 000 Da and comprises -COOR groups in an amount greater than 8 wt.-% (based on dry matter).

[0072] According to another preferred embodiment, the lignin derivative has a molecular weight of less than 100 000 Da and comprises -COOR groups in an amount greater than 12 wt.-% (based on dry matter).

[0073] According to another preferred embodiment, the lignin derivative has a molecular weight of less than 100 000 Da and comprises -COOR groups in an amount greater than 14 wt.-% (based on dry matter).

[0074] According to another preferred embodiment, the lignin derivative has a molecular weight of less than 50000 Da and comprises -COOR groups in an amount greater than 4 wt.-% (based on dry matter).

[0075] According to another preferred embodiment, the lignin derivative has a molecular weight of less than 50000 Da and comprises -COOR groups in an amount greater than 8 wt.-% (based on dry matter).

[0076] According to another preferred embodiment, the lignin derivative has a molecular weight of less than 50000 Da and comprises -COOR groups in an amount greater than 12 wt.-% (based on dry matter).

[0077] According to another preferred embodiment, the lignin derivative has a molecular weight of less than 50000 Da and comprises -COOR groups in an amount greater than 14 wt.-% (based on dry matter).

[0078] According to another preferred embodiment, the lignin derivative has a molecular weight of less than 25000 Da and comprises -COOR groups in an amount greater than 4 wt.-% (based on dry matter).

[0079] According to another preferred embodiment, the lignin derivative has a molecular weight of less than 25000 Da and comprises -COOR groups in an amount greater than 8 wt.-% (based on dry matter).

[0080] According to another preferred embodiment, the lignin derivative has a molecular weight of less than 25000 Da and comprises -COOR groups in an amount greater than 12 wt.-% (based on dry matter).

[0081] According to another preferred embodiment, the lignin derivative has a molecular weight of less than 25000 Da and comprises -COOR groups in an amount greater than 14 wt.-% (based on dry matter).

[0082] According to another preferred embodiment, the lignin derivative has a molecular weight of less than 20000 Da and comprises -COOR groups in an amount greater than 4 wt.-% (based on dry matter).

[0083] According to another preferred embodiment, the lignin derivative has a molecular weight of less than 20000 Da and comprises -COOR groups in an amount greater than 8 wt.-% (based on dry matter).

[0084] According to another preferred embodiment, the lignin derivative has a molecular weight of less than 20000 Da and comprises -COOR groups in an amount greater than 12 wt.-% (based on dry matter).

[0085] According to another preferred embodiment, the lignin derivative has a molecular weight of less than 20000 Da and comprises -COOR groups in an amount greater than 14 wt.-% (based on dry matter).

[0086] According to another preferred embodiment, the lignin derivative has a molecular weight of less than 15000 Da and comprises -COOR groups in an amount greater than 4 wt.-% (based on dry matter).

[0087] According to another preferred embodiment, the lignin derivative has a molecular weight of less than 15000 Da and comprises -COOR groups in an amount greater than 8 wt.-% (based on dry matter).

[0088] According to another preferred embodiment, the lignin derivative has a molecular weight of less than 15000 Da and comprises -COOR groups in an amount greater than 12 wt.-% (based on dry matter).

[0089] According to another preferred embodiment, the lignin derivative has a molecular weight of less than 15000 Da and comprises -COOR groups in an amount greater than 14 wt.-% (based on dry matter).

[0090] According to another preferred embodiment, the lignin derivative has a molecular weight of less than 10000 Da and comprises -COOR groups in an amount greater than 4 wt.-% (based on dry matter).

[0091] According to another preferred embodiment, the lignin derivative has a molecular weight of less than 10000 Da and comprises -COOR groups in an amount greater than 8 wt.-% (based on dry matter).

[0092] According to another preferred embodiment, the lignin derivative has a molecular weight of less than 10000 Da and comprises -COOR groups in an amount greater than 12 wt.-% (based on dry matter).

[0093] According to another preferred embodiment, the lignin derivative has a molecular weight of less than 10000 Da and comprises -COOR groups in an amount greater than 14 wt.-% (based on dry matter).

[0094] Preferably, lignin derivative has 3500Da or larger molecular weight, wherein each molecular weight greater than 3500Da disclosed above can represent the molecular weight upper limit.This means that the molecular weight range disclosed herein is 3500Da to the molecular weight greater than 3500Da as described above.For example, 10000Da, 15000Da or 20000Da (etc.) can constitute the upper limit of this scope.

[0095] Preferably, the lignin derivative is used in an amount of greater than 0.02 g, preferably greater than 0.5 g, more preferably greater than 1.0 g, such as 0.02-20.0 g, 0.5-5.0 g or 1.0-3.0 g per washing cycle. These amounts have been shown to result in effective film reduction performance while allowing the use of relatively low amounts of lignin derivatives. Increasing the amount of the lignin derivative above these ranges does not reduce the film reduction performance, but does not significantly improve the film reduction performance. Therefore, increasing the amount of the lignin derivative above the range only represents a waste of material without resulting in any significant beneficial effect.

[0096] In a second aspect, the present invention relates to a machine dishwasher detergent formulation comprising a lignin derivative as described herein.

[0097] The machine dishwasher detergent formulation may be in any suitable form. For example, the machine dishwasher detergent formulation may be in the form of a tablet, powder, granules, paste, liquid or gel.

[0098] Because the lignin derivatives described herein are particularly effective in reducing and / or preventing deposits during machine dishwashing, no additional film-reducing components are required. Thus, machine dishwasher detergent formulations may be free or substantially free of other anti-filming additives, such as synthetic anionic polymers, such as polycarboxylates, polyacrylates, polymethacrylates, polyaspartates.

[0099] Preferably, the lignin derivative is contained in the machine dishwasher detergent formulation in an amount of 0.5-60.0 wt. %, preferably 1.0-20 wt. %, more preferably 2.0-15 wt. %, based on the total weight of the dishwasher detergent formulation.

[0100] In a third aspect, the present invention relates to a method of reducing and / or preventing deposits on an object, said method comprising the step of contacting said object with a lignin derivative as described herein during a machine washing process.

[0101] Preferably, the step of contacting the object with a lignin derivative as defined herein during machine washing is a step of contacting the object with an aqueous solution comprising (i) calcium ions and / or magnesium ions, (ii) carbonate ions and / or phosphate ions and / or food deposits (fat etc.), and (iii) a lignin derivative as defined herein. Under these conditions, if the lignin derivative (and other film reducing agents) are not present, deposits in the form of carbonate and / or phosphate scale will form during machine dishwashing.

[0102] More preferably, the step of contacting said object with a lignin derivative as defined herein during a machine washing process is a step of contacting said object with an aqueous solution comprising (i) calcium ions and / or magnesium ions, (ii) carbonate ions and (iii) a lignin derivative as defined herein.

[0103] As already stated in the first aspect, the lignin derivative is preferably used in an amount of 0.02-20.0 g, preferably 0.5-5.0 g, more preferably 1.0-3.0 g per washing cycle.

[0104] Preferably, the object is not in contact with any other anti-filming additives such as synthetic anionic polymers, polycarboxylates, polyacrylates, polymethacrylates and polyaspartates.

[0105] Preferably, the object is cutlery, tableware or glassware.

[0106] As mentioned above, the deposits are preferably carbonate scale and / or phosphate scale, more preferably carbonate scale.

[0107] In a fourth aspect, the present invention relates to the use of a lignin derivative as described herein to reduce the viscosity of a detergent slurry during processing.

[0108] Lignin sulfonates generally reduce the viscosity of mineral slurries and pastes. This allows for more efficient processing of powders, granules and tablets. In one embodiment of the invention, the lignin derivatives as described herein are used to reduce detergent slurry viscosity during processing. This provides for more efficient manufacturing because less water needs to be removed during the drying process, it provides improved spray-dried detergent powders, and it provides denser detergent tablets, etc.

[0109] The present invention is now further described by items 1-34:

[0110] Item 1. Use of lignin derivatives for reducing and / or preventing deposits on objects during machine dishwashing

[0111] The method comprises a method for preparing a lignin derivative, wherein the lignin derivative comprises a -COOR group and a sulfonate group, wherein R is a cation, preferably an ammonium ion, a hydrogen, an alkali metal ion or an alkaline earth metal ion, or any mixture thereof,

[0112] The carbon atom of the -COOR group is already contained in the natural lignin from which the lignin derivative is derived. Item 2. The use according to Item 1, wherein the lignin derivative is any one of Items 24-27

[0113] A part of a detergent formulation for use in a machine dishwasher as defined.

[0114] Item 3. The use according to any one of the preceding items, wherein the lignin derivative is water-soluble. Item 4. The use according to any one of the preceding items, wherein the bio-based carbon content of the lignin derivative is

[0115] The amount is greater than 95%, preferably greater than 98%, more preferably greater than 99%, even more preferably greater than 99.5%,

[0116] Even more preferably 100%, wherein the "biobased" carbon content is determined according to ASTM D6866-18,

[0117] And defined as follows:

[0118] [Number of bio-based carbon atoms] / [Number of total carbon atoms]*100%.

[0119] Item 5. The use according to any one of the preceding items, wherein the lignin derivative is produced by sulfite

[0120] Obtained by treating natural lignin in a sulfite pulping step, wherein the sulfite pulping step is optionally followed by one or more post-pulping functionalization steps for reducing the molecular weight and / or increasing the amount of -COOR groups.

[0121] Item 6. The use according to Item 5, wherein the molecular weight is reduced and / or the amount of COOR groups is increased.

[0122] The one or more steps are at least one oxidation step.

[0123] Item 7. The use according to Item 5 or Item 6, wherein the lignin derivative is obtained by

[0124] Obtained by treating lignin sulfonates obtained from sulfite pulping in an oxidation step.

[0125] Item 8. The use according to any one of Items 1 to 7, wherein the lignin derivative is derived from natural wood

[0126] Sulfonated lignin obtained by sulfite pulping of high-quality lignin or sulfite treatment of kraft lignin.

[0127] Item 9. The use according to any one of Items 1 to 8, wherein the lignin derivative has not been aromatically

[0128] Sulfonation step.

[0129] Item 10. The use according to any one of Items 5-9, wherein the lignin derivative does not contain

[0130] Sulfonate groups other than groups from the sulfite pulping process.

[0131] Item 11. The use according to any one of Items 5 to 10, wherein the lignin derivative does not contain

[0132] -COOR groups other than those resulting from the sulfite pulping process.

[0133] Item 12. The use according to any one of Items 5 to 11, wherein the lignin derivative does not contain

[0134] Sulfonate groups and -COOR groups other than those from the sulfite pulping process.

[0135] Item 13. The use according to any one of the preceding items, wherein the lignin derivative does not contain aromatic sulfones

[0136] Acid salt group.

[0137] Item 14. The use according to any one of the preceding items, wherein the lignin derivative is not treated with chlorosulfonic acid.

[0138] Over.

[0139] Item 15. The use according to any one of the preceding items, wherein the sulfonate group is not derived from chlorosulfonic acid

[0140] reaction.

[0141] Item 16. Use according to any one of the preceding items, wherein the -COOR group does not originate from a reaction with ethyl chloride

[0142] Acid reaction.

[0143] Item 17. The use according to any one of the preceding items, wherein the lignin derivative is not treated with chloroacetic acid

[0144] Over.

[0145] Item 18. The use according to any one of the preceding items, wherein the lignin derivative does not contain any carbon

[0146] The atoms already contain -COOR groups other than those in the natural lignin from which the lignin derivative is derived.

[0147] Item 19. The use according to any of the preceding items, wherein the -COOR group is not formed by functionalizing lignin or a lignin derivative (such as lignin sulfonate or kraft lignin) with a molecule containing a -COOR group (such as chloroacetic acid).

[0148] Item 20. The use according to any one of the preceding items, wherein the lignin derivative is obtained by

[0149] The lignin is prepared by sulfonation of chemically modified lignin obtained from a salt pulping process, preferably by sulfite treatment.

[0150] Item 21. The use according to any one of the preceding items, wherein the lignin derivative is based on the lignin

[0151] The dry matter of the oxadiazine derivative comprises -COOR groups in an amount of greater than 4 wt.-%, more preferably greater than 8 wt.-%, even more preferably greater than 12 wt.-%, even more preferably greater than 14 wt.-%.

[0152] Item 22. The use according to any one of the preceding items, wherein the molecular weight of the lignin derivative is less than

[0153] 45000Da, or 2000Da to 45000Da, or less than 42000Da, or less than 31000Da, or less than 10000Da, or 2000Da to 42000Da, or 2000Da to 31000Da, or 2000Da to 31000Da.

[0154] Da to 10000Da, or 3500Da to 45000Da, or 3500Da to 42000Da, or 3500Da to 45000Da

[0155] Da to 31000Da, or 3500Da to 10000Da.

[0156] Item 23. The use according to any one of the preceding items, wherein the lignin derivative is present in an amount of 0.02 to 20.0 g,

[0157] Preferably, it is used in an amount of 0.5 to 5.0 g, more preferably 1.0 to 3.0 g.

[0158] Item 24. A detergent formulation for a machine dishwasher comprising a detergent as defined in any one of Items 1 to 23

[0159] Lignin derivatives.

[0160] Item 25. A machine dishwasher detergent formulation according to Item 24, wherein the machine dishwasher

[0161] Detergent formulations may be in the form of tablets, powders, granules, pastes, liquids or gels.

[0162] Item 26. A machine dishwasher detergent formulation according to Item 24 or Item 25, wherein the machine

[0163] The dishwasher detergent formulations do not contain other anti-filming additives such as synthetic anionic polymers, polycarboxylates, polyacrylates, polymethacrylates and polyaspartates.

[0164] Item 27. A machine dishwasher detergent formulation according to any one of Items 24-26, wherein the wood

[0165] The cellulose derivative is contained in the machine dishwasher detergent formulation in an amount of 0.5-60.0 wt. %, preferably 1.0-20 wt. %, more preferably 2.0-15 wt. %, based on the total weight of the dishwasher detergent formulation.

[0166] Item 28. A method for reducing and / or preventing deposits on an object, the method comprising:

[0167] A step of contacting an object with a lignin derivative as defined in any one of items 1 to 23 during a machine dishwashing process.

[0168] Item 29. The method according to Item 28, wherein the object is washed in a machine with the mixture as described in Items 1-23.

[0169] The step of contacting the object with a lignin derivative as defined in any one of items 1 to 23 is a step of contacting the object with an aqueous solution, wherein the aqueous solution contains (i) calcium ions and / or magnesium ions, (ii) carbonate ions and / or phosphate ions and / or food sediments such as fat, and (iii) a lignin derivative as defined in any one of items 1 to 23.

[0170] Item 30. The method according to Item 29, wherein the object is washed in a machine with the mixture as described in Items 1-23.

[0171] The step of contacting the object with a lignin derivative as defined in any one of the items is a step of contacting the object with an aqueous solution, the aqueous solution comprising (i) calcium ions and / or magnesium ions, (ii) carbonate ions and (iii) the lignin derivative as defined in item

[0172] A lignin derivative as defined in any one of items 1 to 23.

[0173] Item 31. A method according to any one of Items 28-30, wherein the lignin derivative is washed

[0174] The amount of 0.02 to 20.0 g, preferably 0.5 to 5.0 g, more preferably 1.0 to 3.0 g, is used in a washing cycle. Item 32. The method according to any one of Items 28 to 31, wherein the object is not combined with any other anti-component

[0175] Membrane additives such as synthetic anionic polymers, polycarboxylates, polyacrylates, polymethacrylates and polyaspartates are contacted.

[0176] Item 33. A method according to any one of Items 28-32, wherein the object is tableware, tableware or glassware

[0177] Glassware.

[0178] Item 34. A method according to any one of Items 28-33, wherein the deposit is a film or a dot, preferably a carbonate

[0179] Salt scale and / or phosphate scale, preferably carbonate scale.

[0180] Example

[0181] Example 1: Scale reduction performance of bio-based lignin sulfonates obtained from sulfite pulping

[0182] Prepare a basic detergent composition. Different bio-based water-soluble lignin sulfonates (according to the examples of the present invention) or, in the comparative example, polyacrylates (2000 Da polyacrylic acid; commercially available from Acros Organics, CAS: 9003-01-4), which are widely used as anti-filming agents in dishwasher detergent compositions, were added to the basic detergent composition. The basic detergent formulation used in all examples consisted of the usual builders and pH control ingredients used in automatic dishwasher detergent formulations. For the purposes of this example, the hardness of the wash water (i.e., the calcium and magnesium content) was set to be significantly higher than that encountered in any consumer dishwashing application in order to evaluate performance, and was selected to provide very harsh conditions that resulted in significant filming in only 2 cycles.

[0183] Experimental conditions:

[0184] Basic detergent

[0185] The composition of the basic detergent is as follows: 10g Na2CO3; 5g sodium citrate; 4g sodium silicate; 1g bleach.

[0186] Anti-filming agent

[0187] In an example according to the invention, a range of lignin sulfonate polymers were tested. The lignin sulfonates were produced from various hardwood sources (elm, cherry) and softwood sources (douglas fir, norway spruce) under various sulfite pulping conditions, with various post-pulping treatments, and had a range of MW and -COOH contents.

[0188] In the comparative example, 2000 Da polyacrylic acid (Acros Organics) was used as the anti-filming agent.

[0189] Amount of lignin sulfonate used per wash cycle

[0190] 4g

[0191] Water hardness

[0192] The total hardness used was 1400 ppm expressed as CaCO3 with a Ca:Mg ratio of 4:1 added as a chloride salt.

[0193] Dirt

[0194] 40g margarine + 10g milk powder (apply on the dishwasher door).

[0195] dishwasher

[0196] Miele Glass Washer G7883.

[0197] tableware

[0198] Six 250 mL laboratory glass beakers are distributed across the top of the dishwasher.

[0199] Cycle times 2

[0201] process

[0202] After washing under the above conditions, the beakers were checked for filming. Based on the amount of film on the beakers, a comparative score (low, medium and high performance) was given for the performance of the anti-filming additive. Figure 2 The extent to which film on the beaker is reduced when using base detergents with different lignin sulfonate and polyacrylate anti-filming additives is compared to the film formed by the base detergent without the anti-filming additive.

[0203] Table 1 and Figure 3 The anti-filming properties of various lignin sulfonate polymers with respect to -COOH content and molecular weight (MW) are shown.

[0204] Table 1

[0205]

[0206] It can be clearly seen that the lignin sulfonates found to have the best anti-filming properties are characterized by a high -COOR content and a relatively low molecular weight.

Claims

1. Use of a lignin derivative for reducing and / or preventing deposits on objects during machine dishwashing, wherein the lignin derivative comprises a -COOR group and a sulfonate group, wherein R is a cation, wherein the carbon atom of the -COOR group is already contained in the natural lignin from which the lignin derivative is derived, The lignin derivative has a molecular weight of less than 50,000 Da and comprises -COOR groups in an amount of greater than 4 wt.-%, based on dry matter, wherein the sediment is formed from an aqueous solution comprising (i) calcium ions and / or magnesium ions, and (ii) carbonate ions and / or phosphate ions.

2. The use according to claim 1, wherein the lignin derivative is obtained by treating natural lignin in a sulfite pulping step.

3. Use according to claim 1 or 2, wherein the lignin derivative is obtained by treating lignin sulfonates obtained from sulfite pulping in a post-pulping oxidation step.

4. The use according to claim 1 or 2, wherein the lignin derivative is sulfonated lignin obtained by sulfite pulping of natural lignin or sulfite treatment of kraft lignin.

5. The use according to claim 2, wherein the lignin derivative does not contain sulfonate groups and -COOR groups other than those from a sulfite pulping process.

6. The use according to claim 1 or 2, wherein the lignin derivative does not contain aromatic sulfonate groups.

7. Use according to claim 1 or 2, wherein the sulfonate group does not originate from a reaction with chlorosulfonic acid and / or wherein the -COOR group does not originate from a reaction with chloroacetic acid.

8. The use according to claim 1 or 2, wherein the lignin derivative contains no -COOR groups other than -COOR groups whose carbon atoms are already contained in the natural lignin from which the lignin derivative is derived.

9. The use according to claim 1 or 2, wherein the -COOR groups are not formed by functionalizing lignin or lignin derivatives with molecules containing -COOR groups.

10. The use according to claim 1 or 2, wherein the lignin derivative is prepared by sulfonating chemically modified lignin obtained from a kraft pulping process.

11. The use according to claim 1 or 2, wherein the carbonate ions and / or phosphate ions originate from residual food materials.

12. A machine dishwasher detergent formulation comprising a lignin derivative as defined in any one of claims 1 to 10.

13. A machine dishwasher detergent formulation according to claim 12, wherein the machine dishwasher detergent formulation is free of further anti-filming additives.

14. A machine dishwasher detergent formulation according to claim 12 or 13, wherein the lignin derivative is contained in the machine dishwasher detergent formulation in an amount of 0.5 to 60.0 wt.-%, based on the total weight of the machine dishwasher detergent formulation.

15. A machine dishwasher detergent formulation according to claim 14, wherein the lignin derivative is contained in the machine dishwasher detergent formulation in an amount of 1.0 to 20 wt. %, based on the total weight of the machine dishwasher detergent formulation.

16. A machine dishwasher detergent formulation according to claim 14, wherein the lignin derivative is contained in the machine dishwasher detergent formulation in an amount of 2.0-15 wt. %, based on the total weight of the machine dishwasher detergent formulation.

17. A method for reducing and / or preventing carbonate scale and / or phosphate scale on an object, said method comprising the step of contacting said object with a lignin derivative as defined in any one of claims 1 to 10 during a machine washing process.

18. The method according to claim 17, wherein the step of contacting the object with a lignin derivative as defined in any one of claims 1 to 10 during machine washing is a step of contacting the object with an aqueous solution comprising (i) calcium ions and / or magnesium ions, (ii) carbonate ions and / or phosphate ions, and (iii) a lignin derivative as defined in any one of claims 1 to 10.

19. The method according to claim 18, wherein the step of contacting the object with a lignin derivative as defined in any one of claims 1 to 10 during machine washing is a step of contacting the object with an aqueous solution comprising (i) calcium ions and / or magnesium ions, (ii) carbonate ions, and (iii) a lignin derivative as defined in any one of claims 1 to 10.

20. The method of claim 18, wherein the carbonate ions and / or phosphate ions originate from residual food material.

21. The method of claim 20, wherein the residual food material is fat.

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