Classifications

• • C—CHEMISTRY; METALLURGY
  • C11—ANIMAL OR VEGETABLE OILS, FATS, FATTY SUBSTANCES OR WAXES; FATTY ACIDS THEREFROM; DETERGENTS; CANDLES
  • C11D—DETERGENT COMPOSITIONS; USE OF SINGLE SUBSTANCES AS DETERGENTS; SOAP OR SOAP-MAKING; RESIN SOAPS; RECOVERY OF GLYCEROL
  • C11D3/00—Other compounding ingredients of detergent compositions covered in group C11D1/00
  • C11D3/02—Inorganic compounds ; Elemental compounds
  • C11D3/04—Water-soluble compounds
  • C11D3/10—Carbonates ; Bicarbonates
• • C—CHEMISTRY; METALLURGY
  • C11—ANIMAL OR VEGETABLE OILS, FATS, FATTY SUBSTANCES OR WAXES; FATTY ACIDS THEREFROM; DETERGENTS; CANDLES
  • C11D—DETERGENT COMPOSITIONS; USE OF SINGLE SUBSTANCES AS DETERGENTS; SOAP OR SOAP-MAKING; RESIN SOAPS; RECOVERY OF GLYCEROL
  • C11D1/00—Detergent compositions based essentially on surface-active compounds; Use of these compounds as a detergent
  • C11D1/02—Anionic compounds
• • C—CHEMISTRY; METALLURGY
  • C11—ANIMAL OR VEGETABLE OILS, FATS, FATTY SUBSTANCES OR WAXES; FATTY ACIDS THEREFROM; DETERGENTS; CANDLES
  • C11D—DETERGENT COMPOSITIONS; USE OF SINGLE SUBSTANCES AS DETERGENTS; SOAP OR SOAP-MAKING; RESIN SOAPS; RECOVERY OF GLYCEROL
  • C11D11/00—Special methods for preparing compositions containing mixtures of detergents ; Methods for using cleaning compositions
  • C11D11/02—Preparation in the form of powder by spray drying
• • C—CHEMISTRY; METALLURGY
  • C11—ANIMAL OR VEGETABLE OILS, FATS, FATTY SUBSTANCES OR WAXES; FATTY ACIDS THEREFROM; DETERGENTS; CANDLES
  • C11D—DETERGENT COMPOSITIONS; USE OF SINGLE SUBSTANCES AS DETERGENTS; SOAP OR SOAP-MAKING; RESIN SOAPS; RECOVERY OF GLYCEROL
  • C11D3/00—Other compounding ingredients of detergent compositions covered in group C11D1/00
  • C11D3/02—Inorganic compounds ; Elemental compounds
  • C11D3/04—Water-soluble compounds
  • C11D3/046—Salts
• • C—CHEMISTRY; METALLURGY
  • C11—ANIMAL OR VEGETABLE OILS, FATS, FATTY SUBSTANCES OR WAXES; FATTY ACIDS THEREFROM; DETERGENTS; CANDLES
  • C11D—DETERGENT COMPOSITIONS; USE OF SINGLE SUBSTANCES AS DETERGENTS; SOAP OR SOAP-MAKING; RESIN SOAPS; RECOVERY OF GLYCEROL
  • C11D3/00—Other compounding ingredients of detergent compositions covered in group C11D1/00
  • C11D3/02—Inorganic compounds ; Elemental compounds
  • C11D3/04—Water-soluble compounds
  • C11D3/08—Silicates
• • C—CHEMISTRY; METALLURGY
  • C11—ANIMAL OR VEGETABLE OILS, FATS, FATTY SUBSTANCES OR WAXES; FATTY ACIDS THEREFROM; DETERGENTS; CANDLES
  • C11D—DETERGENT COMPOSITIONS; USE OF SINGLE SUBSTANCES AS DETERGENTS; SOAP OR SOAP-MAKING; RESIN SOAPS; RECOVERY OF GLYCEROL
  • C11D3/00—Other compounding ingredients of detergent compositions covered in group C11D1/00
  • C11D3/02—Inorganic compounds ; Elemental compounds
  • C11D3/12—Water-insoluble compounds
  • C11D3/122—Sulfur-containing, e.g. sulfates, sulfites or gypsum
• • C—CHEMISTRY; METALLURGY
  • C11—ANIMAL OR VEGETABLE OILS, FATS, FATTY SUBSTANCES OR WAXES; FATTY ACIDS THEREFROM; DETERGENTS; CANDLES
  • C11D—DETERGENT COMPOSITIONS; USE OF SINGLE SUBSTANCES AS DETERGENTS; SOAP OR SOAP-MAKING; RESIN SOAPS; RECOVERY OF GLYCEROL
  • C11D3/00—Other compounding ingredients of detergent compositions covered in group C11D1/00
  • C11D3/02—Inorganic compounds ; Elemental compounds
  • C11D3/12—Water-insoluble compounds
  • C11D3/1233—Carbonates, e.g. calcite or dolomite

Definitions

• the present invention relates to a process for preparing a particulate, free flowing detergent particle by a slurry making and spray drying technique.
• the spray-dried particle is suitable for use as a solid laundry detergent composition, or for incorporation into a solid laundry detergent composition.
• granular laundry detergent composition is prepared by spray-drying.
• the detergent components such as surfactants and builders are mixed with around 20% to 50% by weight water to form an aqueous slurry, the aqueous slurry is maintained at temperatures ranging from 60°C to 85°C and then spray-dried in a spray-drying tower.
• the level of surfactants in the detergent compositions are highly dependent on the consumer wash habits. These habits have undergone massive change with the advancement of technology and change in lifestyles. Additionally, with the penetration of the front load machines with a low liquid to cloth ratio, the requirement of surfactant level in the formulations, has come down to a large extent.
• thermally unstable surfactants typically include methyl ester sulphonate and non-ionic surfactants.
• a spray-dried detergent particle prepared using a slurry route generally include a certain minimum amount of detersive surfactant because the detersive surfactant provides stability to the slurry and good slurry characteristics. Without proper slurry properties such as right phase, viscosity and pumping characteristics, the resulting particles may have one or more of the following problems such as it may be too light, too dense, too wet, of the wrong size, or sticky. Hence any reduction in the levels of surfactant will directly impact the slurry characteristics and also the resulting spray-dried particle.
• phase separation of the slurry are especially prevalent when spray-dried detergent particle has a detersive active surfactant content of lower than 7 wt.%.
• the fillers which act as balancing ingredients in such slurry includes sodium sulphate or sodium chloride which have high electrolytic strength and may further aggravate the issue of phase separation. This issue is even more pronounced when the filler is selected from the group consisting of alkali metal chloride.
• WO 2006/029676 A1 discloses a laundry detergent composition with a soluble alkali metal silicate and 0.01 wt.% to 25 wt.% alkaline earth silicate seeds.
• the alkaline earth silicate seeds are formed in-situ by reaction of sodium silicate and soluble alkaline earth metal salt in presence of anionic surfactant during the laundry detergent base powder processing.
• EP 2138565 A1 discloses a process for preparing a spray- dried laundry detergent powder which provides for increasing the capacity rate of the spray drying process.
• the process includes contacting the acid precursor of the anionic surfactant to the alkaline slurry after the mixer and before to the spray-pressure nozzle to form a mixture and spray-drying the mixture to form a spray-dried powder.
• EP 3301152 A1 (Procter & Gamble, 2018) discloses a spray-dried base detergent particle having a low pH profile and with good solubility profile and cleaning profile.
• the spray-dried base detergent particle has a low level or no sodium carbonate and/or sodium silicate and has a careful control and combination of levels of organic acid and magnesium sulphate.
• US 4139486 A (Bailey John et. al., 1979) discloses a detergent composition having superior whiteness maintenance and lower undesirable residual deposits on the fabrics which composition includes orthophosphate and pyrophosphate together as builder along with the addition of magnesium silicate.
• WO 2005/037712 A1 (Osinga Theo Jan, 2005) discloses a detergent composition having a soluble carbonate salt in combination with a soluble alkali metal silicate. It discloses a method of preparing amorphous particles of silicate-based calcium salt or silicate-based magnesium salt having the step of mixing an aqueous solution of a calcium salt or magnesium salt with a soluble alkali metal silicate salt and a soluble carbonate salt.
• a spray dried detergent particle with lower detersive surfactants levels and with good powder properties is achievable when the spray dried detergent particle is prepared from a process having a step of forming an in-situ formed silicate and/or a disilicate salt of alkaline earth metal, by reacting an alkali metal silicate with an alkaline earth metal salt and where the aqueous slurry also includes an alkali metal silicate salt, a filler and sodium carbonate salt and where the weight ratio between the sodium carbonate and filler is within specific ranges in the spray-dried detergent particle. It is also surprisingly found that the prepared spray dried detergent particle provides good powder properties over extended storage periods.
• the spray-dried particle provides desired pH in wash solution required for good stain removal performance without being harsh on the hands or the fabrics.
• the present inventors have found that reducing or lowering the levels of silicate and carbonate builders below certain levels adversely affects the storage stability of the spray dried detergent particle over extended period of time and therefore it is required to maintain optimum levels of the silicate and carbonate builders in the spray-dried detergent particle having lower detersive surfactant content while maintaining a specific weight ratio between the sodium carbonate and filler.
• the process for preparing the spray dried detergent particle according to the present invention provides an aqueous slurry which is stable and does not phase separate in presence of higher levels of specific fillers such as sodium sulphate and sodium chloride when the aqueous slurry includes an in-situ formed silicate and/or a disilicate salt of alkaline earth metal in combination with specific weight ratio ranges between the sodium carbonate and the filler.
• specific fillers such as sodium sulphate and sodium chloride
• a process for preparing a spray-dried detergent particle comprising the steps of:
• a process for preparing a spray-dried detergent particle comprising the steps as described herein below.
• Step Contacting an alkaline earth metal salt with an alkali metal silicate is a process of contacting an alkaline earth metal salt with an alkali metal silicate in an aqueous mixture.
• the aqueous mixture comprises a detersive surfactant.
• the alkaline earth metal salt is preferably a magnesium or a calcium salt or mixtures thereof.
• the alkaline earth metal salt may be preferably selected from calcium sulphate, magnesium sulphate, calcium chloride, magnesium chloride or mixtures thereof.
• the alkali earth metal is a magnesium salt selected from magnesium sulphate, magnesium chloride or mixtures thereof and still preferably the alkaline earth metal salt is magnesium sulphate.
• the process according to the present invention includes addition of an alkali metal silicate to the aqueous mixture.
• the alkali metal silicate is a soluble silicate.
• Soluble silicates are common ingredients in the laundry detergent compositions. Some commercial grades of silicates may contain a trace level of alkaline earth metal silicate, as contamination.
• the composition of trace materials in the water used for making an aqueous mixture having detersive surfactant may also contribute to the alkaline earth metal. However, the amount of amorphous material introduced through this impurity route will be low.
• the spray dried detergent particle prepared according to the process of the first aspect of the present invention preferably includes 0.1 wt.% to 5 wt.% amorphous alkaline earth metal silicate prepared in-situ.
• the alkali metal silicate salt preferably has a weight ratio of Si0 :M 0 where M is an alkali metal, within the range of 1.6 to 3.3 more preferably 1.6 to 2.4, and most preferably 2.0 to 2.85.
• the alkali metal silicate salt employed is in the form of an aqueous solution, generally having 30 wt.% to 45 wt.% solid content.
• the alkali metal silicate salt may be selected from the group consisting of sodium silicate, potassium silicate, sodium-potassium double silicate or mixtures thereof.
• the alkali metal silicate salt is water-soluble.
• the alkali metal silicate salt employed is sodium silicate having a weight ratio, Si0 2 :Na 2 0 within the range of 1.6 to 3.3 more preferably 1.6 to 2.4, and most preferably 2.0 to 2.85.
• the amount of alkali metal silicate present in the aqueous mixture is in stoichiometric excess of the amount required for reacting with alkaline earth metal salt.
• the amount of alkali metal silicate present in the aqueous mixture is such that the spray dried detergent particle formed preferably comprises from 8 wt.% to 17 wt.% alkali metal silicate salt.
• the amount of alkali metal silicate added to the aqueous mixture is from 14 wt.% to 40 wt.% of the aqueous mixture.
• the weight ratio between the alkali metal silicate to the alkaline earth metal salt added to the aqueous mixture is in the range from 270:1 to 5:1, preferably 24:1 to 12:1.
• the amount of alkali metal silicate present in the aqueous mixture is in stoichiometric excess of the amount required for reacting with alkaline earth metal salt.
• the amount of alkali metal silicate present in the aqueous mixture is such that the spray dried detergent particle formed preferably comprises from 8 wt.% to 17 wt.% alkali metal silicate salt.
• the excess amount of alkali metal silicate (after the formation of the in-situ alkaline earth metal silicate) may be added into the slurry at any stage before spray-drying, more preferably after the addition of filler.
• Aqueous mixture comprises a detersive surfactant.
• the aqueous mixture includes a detersive surfactant.
• the detersive surfactant is preferably an anionic surfactant.
• the detersive anionic surfactant is either pre-neutralized and added into the aqueous mixture or a liquid acid form of the anionic surfactant is added to the aqueous mixture and neutralized in-situ.
• the acid form of the anionic surfactant may be partly neutralized and thereafter added into the aqueous mixture such that the remaining un-neutralized part of the liquid acid form of the anionic surfactant is neutralized in-situ in the aqueous mixture.
• Pre-neutralized surfactant is commercially available in solid form or in the form of paste.
• the detersive surfactant is added to the aqueous mixture before addition of the alkaline earth metal salt.
• the detersive surfactant is added to the aqueous mixture after addition of the alkaline earth metal salt or along with the alkaline earth metal salt.
• the partly neutralized anionic surfactant is preferably prepared by a neutralization process which involves the step of mixing a liquid acid form of the anionic surfactant and a neutralizing agent to form a partially neutralized solution; preferably the neutralizing agent is an alkali metal hydroxide, more preferably sodium hydroxide, wherein the amount of alkali metal hydroxide neutralizing agent is sufficient to react with a portion of liquid acid anionic surfactant precursor to form in-situ anionic surfactant salt.
• the neutralizing agent is an alkali metal hydroxide, more preferably sodium hydroxide, wherein the amount of alkali metal hydroxide neutralizing agent is sufficient to react with a portion of liquid acid anionic surfactant precursor to form in-situ anionic surfactant salt.
• the neutralized anionic surfactant formed by neutralizing the acid form with the alkali metal hydroxide neutralizing agent contributes from 28 parts to 98 parts of the total anionic surfactant by weight present in the spray-dried particle.
• alkali metal silicate to the partly neutralized anionic surfactant in the aqueous mixture, the remaining unreacted acid form of the anionic surfactant precursor reacts with the alkali metal silicate salt to form fully neutralized salt form of the anionic surfactant.
• a fully neutralized anionic surfactant is added to the aqueous mixture.
• liquid acid anionic surfactant precursor is reacted with an alkali metal hydroxide to form fully neutralized anionic surfactant salt before addition to the aqueous mixture. More preferably the liquid acid precursor of the anionic surfactant is partly or fully neutralized in-situ.
• the detersive surfactant is present when the alkaline earth metal salt is contacted with the alkali metal silicate salt.
• the most preferred order of addition is to contact the pre-neutralized detersive surfactant or the acid detersive surfactant precursor with water followed by contacting with the alkali metal silicate salt and then adding the alkaline earth metal salt.
• the part or full neutralization may be carried out in the same vessel by contacting the acid form of the anionic surfactant with an aqueous solution of neutralizing agent (alkali metal hydroxide, preferably sodium hydroxide) to form the neutralized anionic surfactant salt.
• neutralizing agent alkali metal hydroxide, preferably sodium hydroxide
• the order of addition may be reversed wherein the step involves adding alkaline earth metal salt to the aqueous mixture followed by the alkali metal silicate salt.
• Suitable detersive surfactants include anionic detersive surfactants, non-ionic detersive surfactant, cationic detersive surfactants, zwitterionic detersive surfactants and amphoteric detersive surfactants.
• Suitable detersive surfactants may be linear or branched, substituted or un-substituted, and may be derived from sources well known to the person skilled in the art.
• the detersive surfactant is an anionic surfactant.
• Suitable anionic detersive surfactants include sulphonate and sulphate surfactants.
• Suitable sulphonate surfactants include methyl ester sulphonates, alpha olefin sulphonates, alkyl benzene sulphonates, especially alkyl benzene sulphonates, preferably Cm to Cm alkyl benzene sulphonate.
• a preferred detersive anionic surfactant is linear alkyl benzene sulphonate, where the alkyl chain has 5 to 20 carbon atoms, more preferably the linear alkylbenzene sulphonate surfactant has a Cm to Cm alkyl group.
• Suitable alkyl benzene sulphonate is obtainable, preferably obtained, by sulphonating commercially available linear alkyl benzene (LAB); suitable LAB includes low 2-phenyl LAB, other suitable LAB include high 2-phenyl LAB, such as those supplied by Sasol under the tradename Hyblene®.
• Suitable sulphate surfactants include alkyl sulphate, preferably C 8 to Cm alkyl sulphate, or predominantly Cm to Cm alkyl sulphate.
• One or more anionic surfactant may be present in the spray-dried detergent particle.
• a preferred sulphate detersive surfactant is alkyl alkoxylated sulphate, preferably alkyl ethoxylated sulphate, preferably a C 8 to Cm alkyl alkoxylated sulphate, preferably a C 8 to Cm alkyl ethoxylated sulphate, preferably the alkyl alkoxylated sulphate has an average degree of alkoxylation of from 0.5 to 20, preferably from 0.5 to 10, preferably the alkyl alkoxylated sulphate is a C 8 to Cm alkyl ethoxylated sulphate having an average degree of ethoxylation of from 0.5 to 10, preferably from 0.5 to 5, more preferably from 0.5 to 3 and most preferably from 0.5 to 1.5.
• alkyl sulphate, alkyl alkoxylated sulphate and alkyl benzene sulphonate may be linear or branched, substituted or un-substituted and may be derived from petrochemical material or biomaterial.
• suitable anionic detersive surfactants include, Soaps, alkyl ether carboxylates.
• Suitable anionic detersive surfactants may be in salt form, suitable counter-ions include sodium, calcium, magnesium, amino alcohols, and any combinations thereof. A preferred counterion is sodium.
• the detersive surfactant is anionic surfactant selected from alkyl benzene sulphonate, primary alkyl sulphate, secondary alkyl sulphate, alkyl ether sulphate or mixtures thereof, still preferably selected from linear alkyl benzene sulphonate, alkyl ether sulphate or mixtures thereof, still preferably selected from LAS, SLES or mixtures thereof.
• Suitable non-ionic detersive surfactants are selected from the group consisting of: C 8 to Ci 8 alkyl ethoxylates, such as, NEODOL® non-ionic surfactants from Shell; Ce to C12 alkyl phenol alkoxylates wherein preferably the alkoxylate units are ethyleneoxy units, propyleneoxy units or a mixture thereof; C to Ci 8 alcohol and C 6 to C alkyl phenol condensates with ethylene oxide/propylene oxide block polymers such as Pluronic® from BASF; alkyl polysaccharides, preferably alkyl polyglycosides; methyl ester ethoxylates; polyhydroxy fatty acid amides; ether capped poly(oxyalkylated) alcohol surfactants and mixtures thereof.
• C 8 to Ci 8 alkyl ethoxylates such as, NEODOL® non-ionic surfactants from Shell
• Ce to C12 alkyl phenol alkoxylates wherein preferably the alk
• Suitable non-ionic detersive surfactants are alkyl polyglucoside and/or an alkyl alkoxylated alcohol.
• Suitable non-ionic detersive surfactants include alkyl alkoxylated alcohols, preferably C 8 to Ci 8 alkyl alkoxylated alcohol, preferably a C 8 to Ci 8 alkyl ethoxylated alcohol, preferably the alkyl alkoxylated alcohol has an average degree of alkoxylation of from 1 to 50, preferably from 1 to 30, or from 1 to 20, or from 1 to 10, preferably the alkyl alkoxylated alcohol is a C 8 to Ci 8 alkyl ethoxylated alcohol having an average degree of ethoxylation of from 1 to 10, preferably from 1 to 7, more preferably from 1 to 5 and most preferably from 3 to 7.
• the alkyl alkoxylated alcohol can be linear or branched and substituted or un-substituted.
• Suitable nonionic detersive surfactants include secondary alcohol-
• Zwitterionic surfactant Suitable zwitterionic detersive surfactants include amine oxides and/or betaines.
• One or more detersive surfactant may be present in the spray-dried particle according to the present invention.
• the surfactants are preferably those which are thermally stable during processing conditions of a tower with inlet air temperature ranging from 250°C to 500°C and those which are chemically stable at the pH conditions of the spray-drying slurry.
• Non-limiting examples of the anionic surfactant includes the ones mentioned above.
• the aqueous slurry includes LAS.
• the detersive surfactant present in the aqueous slurry is a combination of LAS and alkyl ether sulphate, still preferably a combination of LAS and SLES (1EO to 3EO).
• the aqueous slurry may also preferably include a combination of anionic surfactant and non-ionic surfactant as the cosurfactant.
• Step (ip: Forming in-situ silicate salt or disilicate salt of alkaline earth metal The alkali metal silicate reacts with the alkaline earth metal salt to form in-situ silicate or disilicate salt of alkaline earth metal or mixtures thereof.
• the alkaline earth metal salt present in the reaction is magnesium sulphate or magnesium chloride, more preferably magnesium sulphate.
• the magnesium sulphate reacts with alkali metal silicate to form in-situ magnesium silicate or magnesium disilicate or mixtures thereof.
• the alkali metal silicate is sodium silicate.
• the reaction of the alkali metal silicate with the alkaline earth metal salt is carried out by heating the aqueous mixture in a mixer at a temperature of 20°C to 80°C, more preferably from 70°C to 80°C.
• the reaction is carried out for a duration of
• the reaction may also produce hydroxide of alkaline earth metal and some amount of the alkaline earth metal salt may remain unreacted.
• the aqueous may include an amount of unreacted magnesium sulphate.
• the aqueous mixture includes the in-situ formed silicate salt or disilicate salt of alkaline earth metal or mixtures thereof, alkali metal silicate salt, detersive surfactant and water.
• the resulting aqueous mixture obtainable from the process of the first aspect includes:
• silicate salt or disilicate salt of the alkaline earth metal is 50% amorphous, more preferably 60% amorphous, still preferably 80%, further preferably 90% amorphous. In a highly preferred embodiment, all of the in-situ formed silicate salt and/or disilicate salt of alkaline earth metal salt is amorphous.
• the next step involves adding sodium carbonate to form an aqueous slurry.
• a sodium carbonate is added to the aqueous mixture obtained in step (ii) and addition of fillers selected from the group consisting of alkali metal sulphate, alkali metal chloride, alkaline earth metal carbonate or mixtures thereof to form an aqueous slurry.
• fillers selected from the group consisting of alkali metal sulphate, alkali metal chloride, alkaline earth metal carbonate or mixtures thereof to form an aqueous slurry.
• laundry ingredients may be added to the aqueous slurry.
• the slurry Preferably along with sodium carbonate the slurry includes potassium carbonate. It is further preferred that when present along with potassium carbonate, sodium carbonate makes up at least 75 wt.%, more preferably at least 85 wt.% and even more preferably at least 90 wt.% of the total weight of the carbonate salt.
• inorganic builders include crystalline and amorphous aluminosilicates for example, zeolites as disclosed in GB 1 473201 (Henkel), amorphous aluminosilicates as disclosed in GB 1 473202 (Henkel) and mixed crystalline/amorphous aluminosilicates as disclosed in GB 1 470 250 (Procter & Gamble); sodium alkaline silicates and layered silicates as disclosed in EP 164 514 B (Hoechst).
• Inorganic phosphate builders for example sodium orthophosphate, pyrophosphate and tripolyphosphate are preferably present at relatively low levels, for example less than 5 wt.%, still preferably less than 3 wt.%, further preferably less than 1 wt.%.
• the spray-dried detergent particle prepared from the process according to the first aspect of the present invention is substantially free of inorganic phosphate builders, i.e; the slurry includes 0 wt.% inorganic phosphate builder and the resulting spray-dried detergent particle includes 0 wt.% inorganic phosphate builder.
• substantially free it is meant that the spray dried particle prepared according to the process of the first aspect does not include any deliberately added inorganic phosphate builder.
• Zeolite builders used in most commercial particulate detergent compositions is zeolite A.
• aluminium zeolite P zeolite MAP
• zeolite MAP is an alkali metal aluminosilicate of the P type having a silicon to aluminium ratio not exceeding 1.33, preferably not exceeding 1.15, and more preferably not exceeding 1.07.
• Zeolite builders are preferably present at relatively low levels, for example less than 5 wt.%, still preferably less than 3 wt.%, further preferably less than 1 wt.% in the aqueous slurry.
• the spray- dried detergent particle prepared from the process according to the first aspect of the present invention is substantially free of zeolite builders, that is the aqueous slurry and the spray dried detergent particle according to the present invention includes 0 wt.% zeolite builder.
• substantially free it is meant that the spray dried particle prepared according to the process of the first aspect does not include any deliberately added inorganic zeolite builder.
• the aqueous slurry may include an organic builder.
• organic builder include polycarboxylate polymers such as polyacrylates, acrylic/maleic copolymers, and acrylic phosphinates; monomeric polycarboxylates such as citrates, gluconates, oxydisuccinates, glycerol mono-, di-and trisuccinates, carboxymethyloxysuccinates, carboxymethyloxymalonates, dipicolinates, hydroxyethyliminodiacetates, alkyl- and alkenylmalonates and succinates; and sulphonated fatty acid salts.
• polycarboxylate polymers such as polyacrylates, acrylic/maleic copolymers, and acrylic phosphinates
• monomeric polycarboxylates such as citrates, gluconates, oxydisuccinates, glycerol mono-, di-and trisuccinates, carboxymethyloxysuccinates, carboxymethyloxymalonates, dipi
• the organic builder is selected from monomeric polycarboxylates such as citrates, gluconates, oxydisuccinates, glycerol mono-, di-and trisuccinates, carboxymethyloxysuccinates, carboxymethyloxymalonates, dipicolinates, hydroxyethyliminodiacetates, alkyl- and alkenylmalonates and succinates, more preferably alkali metal citrate, most preferably it is sodium citrate.
• Organic builders may be used in minor amounts as supplement to carbonate builder.
• Preferred supplementary organic builders are citrates, suitably used in amounts of from 0.1 wt.% to 30 wt.% more preferably of alkaline metal compounds, preferably from 10 wt.% to 25 wt.%; and acrylic polymers, more especially acrylic/maleic copolymers, suitably used in amounts of from 0.5 wt.% to 15 wt.%, preferably from 1 wt.% to 10 wt.%.
• Powder flow properties may be improved by the incorporation of a small amount of a powder structurant, for example, a fatty acid (or fatty acid soap), a sugar, an acrylate or acrylate/maleate polymer.
• a powder structurant for example, a fatty acid (or fatty acid soap), a sugar, an acrylate or acrylate/maleate polymer.
• a powder structurant is fatty acid soap, suitably present in an amount of from 1 wt.% to 5 wt.%.
• aqueous slurry includes but are not limited to, any one or more of the following: soap, sequestrants, calcium chloride, other inorganic salts, Fluorescers, foam controllers, foam boosters, dyes, antiredeposition agents, colourants, shading dyes and combinations thereof.
• a filler selected from the group consisting of alkali metal sulphate, alkali metal chloride, alkaline earth metal carbonate is added to the aqueous slurry before spray-drying.
• the filler may be added either before the addition of the sodium carbonate or after the addition of the sodium carbonate salt to the aqueous mixture to form the aqueous slurry. It is preferred that the filler is added at the end of the batch i.e. after sodium carbonate addition.
• the alkali metal sulphate filler is sodium sulphate, preferably the alkali metal chloride filler is sodium chloride, preferably the alkaline earth metal carbonate filler is selected from the group consisting of calcium carbonate (calcite), magnesium carbonate, calcium magnesium carbonate (dolomite) or mixtures thereof.
• the filler acts as a balancing ingredient and is preferably sodium sulphate or sodium chloride.
• the filler is selected from the group consisting of alkali metal chloride, alkaline earth metal carbonate or mixtures thereof, still preferably the filler is selected from sodium chloride, calcium carbonate (calcite), magnesium carbonate, calcium magnesium carbonate (dolomite) or mixtures thereof.
• the aqueous slurry according to the first aspect comprises:
• silicate salt and/or disilicate salt of alkaline earth metal (v) silicate salt and/or disilicate salt of alkaline earth metal; (v) a filler selected from the group consisting of alkali metal sulphate, alkali metal chloride, alkali metal carbonate or mixtures thereof.
• the aqueous slurry obtainable according to the process of the first aspect comprises:
• filler selected alkali metal sulphate, alkali metal chloride, alkaline earth meta carbonate or mixtures thereof, still preferably the filler is selected from sodium sulphate, magnesium carbonate, sodium chloride, calcium carbonate(calcite), calcium magnesium carbonate (dolomite), or mixtures thereof;
• (viii) optionally, from 0.0 wt.% to1.2 wt.% un reacted alkaline earth metal salt.
• (ix) optionally, from 0 wt.% to 3 wt.% polymer
• (x) optionally organic builder, preferably 0 wt.% to 10 wt.% citrate salt;
• optical brighteners which is preferably selected from fluorescers, colourants, shading dye, pigments;
• the detersive surfactant present in the aqueous slurry is an anionic surfactant. It may also be a mixture of anionic surfactant and nonionic surfactant where the mixture has a higher content of anionic surfactant.
• the polymer is selected from a cleaning polymer, soil releasing polymer, care polymer, antiredeposition polymer or mixtures thereof.
• the aqueous slurry includes from 0.1 wt.% to 5 wt.% detersive surfactant, still preferably from 0.7 wt.% to 5 wt.% detersive surfactant, still preferably from 0.1 to 4.5 wt.%, still more preferably from 0.7 to 4.5 wt.%, further more preferably from 0.7 wt.% to 3.5 wt.% detersive surfactant.
• the detersive surfactant is an anionic detersive surfactant, still more preferably the anionic detersive surfactant is selected from a linear alkyl benzene sulphonate surfactant, primary alkyl sulphate, secondary alkyl sulphate, alkyl ether sulphate surfactant or mixtures thereof.
• the aqueous slurry is spray dried to form a spray-dried particle.
• the spray-drying is carried out using any of the conventional spray drying system known in the art.
• the aqueous slurry is transferred through a pipe system to a pump system consisting of one or more pump and then further to a spray nozzle through which the slurry is released under pressure into a drying tower.
• a typical spray-drying process involves the step of transferring the aqueous slurry through a pipe system leading to a first pump and then through a second pump and from a second pump to a plurality of spray nozzles.
• the first pump is typically a low- pressure pump, such as a pump that can generate a pressure of from 1x10 5 Nnr 2 to 1x10 6 Nnr 2 , which ensures proper flooding of the second pump.
• the second pump is a high-pressure pump, such as a pump that is capable of generating a pressure ranging from 2x10 6 Nnr 2 to 2x10 7 Nnr 2 .
• the aqueous detergent slurry may be transferred through bolt catchers, magnetic filters, lump breakers, disintegrators such as the Ritz Mill, during the transfer of the aqueous slurry through the pipe system downstream the pump system/mixer in which the aqueous slurry is formed.
• the disintegrator is preferably positioned between the pumps.
• the flow rate of the aqueous slurry along the pipes is typically in the range from 800 Kg/hour to more than 50,000 Kg/hour.
• the spray drying system may include a deaeration system.
• the deaeration system is preferably a vacuum assisted de-aerator, which is preferably fed by a transfer pump.
• the deaeration system remove air bubbles formed during the slurry preparation, thus increasing the bulk density of the spray-dried detergent particle.
• De- aeration of the slurry may also be carried out by other mechanical means or chemical de-aeration means using antifoams or de-foamers.
• air injection system may be provided along the pipe system.
• the air injection system may be provided before or after the pump system.
• the air injection includes air flow and pressure controls, static mixer, pulsation dampener and compressor set which can aerate the slurry to get a lower bulk density for the spray dried particle.
• the gas injected into the slurry may be nitrogen, carbon dioxide, or simply atmospheric air introduced under a pressure higher than the pressure of the aqueous slurry maintained in the pipe system.
• a typical spray drying system can optionally include both the de-aeration system and air injection system to optimize the desired bulk density of the spray dried particle.
• Typical spray drying tower for detergent applications are counter-current spray drying tower.
• the inlet hot air/hot steam temperature introduced into the spray drying tower is the range from 250°C to 500°C depending on the evaporation capacity and sizing of the tower.
• the tower exhaust air temperature can range from, 60°C to 200°C, more preferably 80°C to 200°C, still more preferably 80°C to 100°C depending on the loading of the tower.
• the aqueous detergent slurry introduced into the spray nozzle of the spray drying tower is preferably at a temperature ranging from 60°C to 95°C.
• the spray drying tower may be a co-current spray drying tower but are less common.
• the spray- dried detergent particle-exiting the tower is maintained at a temperature less than 150°C, still preferably less than 100°C.
• the spray-drying is preferably conducted where the spray drying zone is under a negative pressure of at least 50 Nnr 2 , still preferably the negative pressure is from 50 Nnr 2 to 600 Nnr 2 .
• the vacuum conditions are achieved by controlling the speed and/or dampener setting of the inlet and the outlet air fans.
• the spray-dried particle collected at the bottom of the tower may be subjected to cooling and conditioning by using an air lift or any similar process.
• the spray-dried detergent is subject to particle size classification to remove oversize material (> 2 mm typically) to provide a spray dried detergent particle which is free flowing.
• the fine material ⁇ 100 microns typically is elutriated with the exhaust air in the spray drying tower and captured and recycled back into the system via the dry cyclone, wet cyclone or bag filter system.
• Spray-dried particle formed from the process of the first aspect of the present invention preferably has a pH of 11.5 or less, preferably a pH ranging from 10.5 to 11.5 when measured using a 10% solution with distilled water at 25°C.
• the spray-dried particle is generally referred to as the base powder.
• This base powder may be used as a fully formulated laundry detergent composition.
• the spray-dried detergent particle includes:
• a filler selected from the group consisting of alkali metal sulphate, alkali metal chloride, alkaline earth metal carbonate or mixtures thereof, preferably from 55 wt.% to 85 wt.% filler selected from the group consisting of sodium sulphate, sodium chloride, calcium carbonate (calcite), magnesium carbonate, calcium magnesium carbonate (dolomite) or mixtures thereof;
• organic builder preferably 0 wt.% to 10 wt.% citrate salt;
• organic builder optionally from 0 wt.% to 1.5 wt.% hydroxide salt of alkaline earth metal;
• (x) optionally, from 0 wt.% to 1.5 wt.% unreacted alkaline earth metal salt wherein the weight ratio of the sodium carbonate to the filler in the spray dried detergent particle ranges from 1 :3 to 1 :18.
• the weight ratio of the sodium carbonate to filler in the spray dried detergent particle ranges from 1 :3 to 1 :18. More preferably the weight ratio of the sodium carbonate to filler in the spray-dried detergent particle ranges from 1 :3.5 to 1 :18, still more preferably from 1 :3.9 to 1 :18, still further preferably from 1 :4 to 1 :17.1 , still more preferably from 1 :4 to 1 :15.
• the amount of the in-situ formed silicate salt and/or disilicate salt of alkaline earth metal is from 0.1 wt.% to 1.6 wt.% still preferably 0.1 wt.% to 1.55 wt.%.
• the amount is filler is from 58 wt.% to 83 wt.%.
• the spray dried detergent particle may preferably include from 0 wt.% to 4 wt.% polymer selected from antiredeposition polymer, soil release polymer, structuring polymer, or mixtures thereof.
• the polymer is a polymeric carboxylate, preferably polyacrylate or a copolymer of acrylic acid and maleic acid.
• other polymers may also be suitable such as polyamines (including the ethoxylated variants thereof), polyethylene glycol and polyesters.
• Polymeric soil suspending aids and polymeric soil release agents are particularly suitable.
• the spray-dried detergent particle has a bulk density of less than 550g/L.
• the spray-dried detergent particle has a weight average particle size of from 300 micrometres to 600 micrometres.
• the spray-dried detergent particle comprises from 1 wt.% to 6 wt.% anionic surfactants, which is preferably a Cio to C o linear alkyl benzene sulphonate and which is substantially neutralized with little or no acid residues.
• anionic surfactants which is preferably a Cio to C o linear alkyl benzene sulphonate and which is substantially neutralized with little or no acid residues.
• the spray-dried particle is typically post dosed with ingredients that are incompatible with the spray-drying process conditions to form a fully formulated laundry detergent composition. These components may be incompatible for many reasons including heat sensitivity, pH sensitivity or degradation in aqueous systems. It is also preferred that the anionic surfactant is a combination of alkyl benzene sulphonate and either or both alkyl sulphate surfactant and alkyl ethoxylated sulphate.
• the spray-dried particle is typically post dosed with ingredients that are incompatible with the spray-drying process conditions to form a fully formulated laundry detergent composition.
• a fully formulated laundry detergent composition includes from 30 wt.% to 95 wt.% of the spray-dried particle according to the first aspect.
• the other laundry ingredients are post dosed by dry mixing the spray-dried particle with other laundry ingredients. These laundry ingredients and generally those that are not thermally stable.
• Non-limiting example of the other post dosed laundry ingredients includes enzymes, shading dye, fragrance, antifoams, cleaning polymers, care polymers, foam boosters, visual cues, chelating agents and mixtures thereof. These components may be incompatible for many reasons including heat sensitivity, pH sensitivity or degradation in aqueous systems.
• Detergent compositions of low to moderate bulk density may be prepared by spray- drying the aqueous slurry to form a spray-dried particle and optionally postdosing (drymixing) further ingredients.
• “compact" detergent compositions may be prepared by further mixing the spray dried particle prepared according to the present invention in a high-speed mixer/granulator, or other non-tower processes.
• the spray dried detergent particle may also be used for preparing a tablet composition by compacting powders, especially "concentrated" powders using the known tableting process.
• the spray dried detergent particle may be used for preparing an unit dose product where the spray-dried detergent particle is enclosed in a pouch, preferably a water-soluble pouch, more preferably a water-soluble pouch comprising a film forming polymer selected from polyvinyl alcohol, polyvinylpyrrolidone and other known film forming polymer.
• the base powder/spray-dried particle is preferably formulated into a finished detergent composition by dry mixing heat sensitive ingredients into the base powder. In addition to heat sensitive ingredients some amount of alkalinity may be added back into the base powder by addition of alkaline ingredients, additionally other acidic or neutral may also be added to formulate the finished detergent composition.
• the spray-dried detergent particle may be used as a fully formulated laundry detergent composition or may be additionally combined with other optional ingredients to form a fully formulated laundry detergent composition.
• the optional post-dosed benefit ingredients includes but is not limited to enzymes, anti-redeposition polymers, perfumes, additional surfactant selected from amphoteric surfactant, zwitterionic surfactant, cationic surfactant and non-ionic surfactant, optical brighteners, antifoaming agent, foam boosters, fabric softeners such as smectite clays, amine softeners and cationic softeners; bleach and bleach activators; dyes or pigments, fillers, fluorescers, salts, soil release polymers, dye transfer inhibitors.
• These optional ingredients are well known to be used in a laundry detergent composition and added preferably by post-dosing.
• Non-limiting examples of the post-dosed polymers include cleaning polymers, antiredeposition polymers, soil release polymers structuring polymers. Some examples include PET-PEOT polymer (Repel-o-Tex® SF2 ex.Solvay), copolymer of acrylic acid and maleic acid (Sokalan CP5 ex. BASF). Fluorescers:
• Suitable fluorescent brighteners include dis-styryl biphenyl compounds example Tinopal® CBS-X, di-amino stilbene di-sulfonic acid compounds, e.g. Tinopal® DMS pure Xtra and Blankophor® HRH, and Pyrazoline compounds, e.g. Blankophor® SN, and coumarin compounds, e.g. Tinopal® SWN.
• Preferred brighteners are: sodium 2 (4- styry)-3-sulfophenyl)-2H-napthol(1 ,2-d]triazole, disodium 4,4’bis ⁇ [4-anilino-6-(N methyl- N-2 hydroxyethyl)amino 1 ,3,5- triazin-2-yl)]amino]stilbene-2-2' disulfonate, disodium 4,4’bis([(4-anilino-6-morpholino-l,3,5-triazin-2-yl)]amino ⁇ stilbene-2-2'disulfonate, and disodium 4,4’- bis(2-sulfostyryl)biphenyl.
• a suitable fluorescent brightener is S C.l. Fluorescent Brightener 260, which may be used in its beta or alpha crystalline forms, or a mixture of these forms.
• the composition of the present invention preferably includes an enzyme. It may preferably include one or more enzymes. Preferred examples of the enzymes include those which provide cleaning performance and/or fabric care benefits.
• suitable enzymes include, but are not limited to, hemicellulases, peroxidases, proteases, cellulases, xylanases, lipases, xyloglucanase, phospholipases, esterases, cutinases, pectinases, mannanases, pectate lyases, keratinases, reductases, oxidases, phenoloxidases, lipoxygenases, ligninases, pullulanases, tannases, pentosanases, malanases, G-glucanases, arabinosidases, hyaluronidase, chondroitinase, laccase, and amylases, or mixtures thereof.
• a typical combination is an enzyme cocktail that may comprise, for example, a protease and lipase in conjunction with one or more of amylase, mannanase and cellulase.
• the enzymes When present in a detergent composition, the enzymes may be present at levels from about 0.00001% to about 2%, from about 0.0001% to about 1% or from 0.001% to about 0.5% enzyme protein by weight of the detergent composition.
• Packaging and dosing may comprise, for example, a protease and lipase in conjunction with one or more of amylase, mannanase and cellulase.
• the spray dried detergent particle or a laundry composition having the spray dried detergent particle prepared according to the invention may be packaged as unit doses in polymeric film soluble in the wash water.
• the spray-dried detergent particle or a composition including the particle of the invention may be supplied in multidose plastics packs with a top or bottom closure.
• a dosing measure may be supplied with the pack either as a part of the cap or as an integrated system.
• the packaging material suitable for packaging may include but not limited to multilayer polyethylene film, laminate, paper based, and other materials known to a person skilled in the art.
• the packaging material is selected from material which are biodegradable or recyclable.
• a method of laundering fabric using a spray dried detergent particle or a laundry composition comprising a spray dried detergent particle according to the present invention which involves the step of diluting the dose of detergent composition with water to obtain a wash liquor and washing fabrics with the wash liquor so formed.
• the dose of detergent composition is typically put into a dispenser and from there it is flushed into the machine by the water flowing into the machine, thereby forming the wash liquor. From 5 up to about 65 litres of water may be used to form the wash liquor depending on the machine configuration.
• the dose of detergent composition may be adjusted accordingly to give appropriate wash liquor concentrations.
• the dilution step preferably provides a wash liquor which comprises inter alia from about 3 to about 20 g/wash of detersive surfactants (as are further defined above). Examples
• Example 1 Preparing an aqueous slurry and a spray dried detergent particle according to the present invention
• An aqueous slurry to make a spray-dried laundry detergent particle according to the present invention was prepared by first mixing water, neutralizing agent (NaOH, 45% aqueous solution) and linear alkyl benzene sulphonic acid in a crutcher and agitated to neutralize the linear alkyl benzene sulphonic acid to its salt form.
• neutralizing agent NaOH, 45% aqueous solution
• linear alkyl benzene sulphonic acid in a crutcher and agitated to neutralize the linear alkyl benzene sulphonic acid to its salt form.
• magnesium sulphate alkaline earth metal salt
• sodium silicate 45% aqueous solution, alkali metal silicate
• the sodium silicate has a Na 0 to Si0 2 ratio of 1 :2.4 and the aqueous mixture was continuously agitated, and the mixture was heated to a temperature of around 78°C to 80°C upon addition of sodium silicate and the temperature was maintained till the end of the batch preparation.
• the sodium silicate and magnesium sulphate react to form in-situ magnesium silicate and/or in-situ magnesium disilicate.
• Further sodium carbonate, sodium sulphate as filler was added in this order to form an aqueous slurry.
• the composition of the ingredients added to the form a batch of 3000 gm aqueous slurry is provided in Table 1.
• Example 2 Evaluation of the stability of the aqueous slurry prepared according to present invention The stability of the aqueous slurry (Ex 1) prepared according to the present invention and described above in Example 1 was subjected to a slurry stability test.
• Slurry Stability test The slurry stability was evaluated at a temperature of 80°C. At this temperature the slurry was kept unagitated and undisturbed.
• a sample of 250 mL of the slurry was drained from the crutcher and poured into glass container and the glass container was covered by closing the lid. The covering of the glass container will ensure that the evaporation losses are prevented.
• the glass container was kept in an oven which was maintained at 80°C for 2 hours. At the end of 2 hours the slurry was observed for any visible phase separation.
• a stable slurry upon visual evaluation will show uniform phase throughout the glass container at the end of 2 hours storage in the oven.
• slurry which are susceptible to undergo phase separation will separate and this separation can be visually seen either on the top or bottom of the glass container.
• the height of separated top phase was measured, and the measured height was noted.
• the slurry separation % was calculated according to the formula provided below. A slurry separation% of greater than 5 is not desirable as such slurry leads to fluctuations and operational difficulties and also a greater variability in the active levels in the resulting spray-dried particle.
• % Slurry separation (Height of separated top phase of slurry/ total height of slurry) *100
• the presence of sodium carbonate, sodium silicate improves the slurry stability while the higher the moisture the lower is the slurry stability.
• the slurry according to the invention is stable even when the silicate and carbonate levels are lower than the control and the moisture content is increased.
• the slurry includes alkaline earth metal silicate along with specific ratio ranges between the carbonate and filler.
• Higher slurry stability also indicates that the slurry prepared according to the process of the present invention was easily processable and provided a spray dried particle with good powder properties.

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• 2022
  • 2022-05-17 WO PCT/EP2022/063266 patent/WO2022243283A1/en active Application Filing
  • 2022-05-17 CN CN202280030794.9A patent/CN117255847A/zh active Pending
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