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
  • C11D17/00—Detergent materials or soaps characterised by their shape or physical properties
  • C11D17/06—Powder; Flakes; Free-flowing mixtures; Sheets
  • C11D17/065—High-density particulate detergent compositions
• • 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
  • C11D3/16—Organic compounds
  • C11D3/20—Organic compounds containing oxygen
  • C11D3/2075—Carboxylic acids-salts thereof
  • C11D3/2086—Hydroxy carboxylic acids-salts thereof

Definitions

• the present invention relates to detergent powders intended for use in drum-type fabric washing machines.
• the invention is of especial applicability to detergent powders containing no, or reduced levels of, phosphate builders and to powders of high bulk density, which have a tendency to dispense poorly.
• the invention also relates to a process for preparing these detergent powders.
• US-A-4,414,130 discloses detergent compositions comprising an effervescent material which promotes dissolution and dispersion of the detergent particles.
• the detergent particles may comprise sodium carbonate or bicarbonate and that the balance of the composition may include citric acid.
• the present invention provides a granular detergent composition having a bulk density of from 650 to 1100 kg/m3 and comprising anionic and/or nonionic surfactants, from 5 to 30% by weight of sodium carbonate and/or -bicarbonate and/or sesquicarbonate, other builder material, and from 1 to 15% by weight of particulate citric acid, whereby more than 80% by weight of the citric acid has a particle size which is in the range of from 350 to 1500 ⁇ m.
• the invention also provides a process for preparing this composition, wherein the citric acid is added as a separate granular component to a granular detergent base composition.
• the first aspect of the invention is a granular detergent composition having a bulk density of from 650 to 1100 kg/m3, preferably from 700 to 1100 kg/m3.
• the composition comprises a base composition to which particulate citric acid, and optionally a foam depressing agent, has been added.
• the base composition may be prepared by spray-drying and dry-mixing/agglomeration. For obtaining high bulk densities, it is preferably prepared by dry-mixing/agglomeration.
• the base composition contains one or more anionic and/or nonionic surfactants, and builder material.
• the base composition preferably also comprises sodium carbonate and/or sodium bicarbonate and/or sodium sesquicarbonate.
• the granular composition of the invention may further contain any of the materials conventionally included in detergent compositions. These are described in more detail below.
• the surfactant component is the surfactant component
• the total amount of surfactant present in the composition of the invention will generally range from 5 to 40 % by weight, more preferably from 10 to 30% by weight, and especially from 12 to 20% by weight. These figures are typical for fully formulated detergent compositions, and as a spray-dried or dry-mixed/agglomerated base forms only part of such a composition the surfactant content of that base, as a percentage, may of course be higher.
• the invention is of especial applicability to compositions containing anionic and nonionic surfactants.
• the amount of anionic surfactant present is desirably at least 3% by weight, and may suitably be in the range of from 3 to 30% by weight, these figures again being based on the fully formulated composition.
• Anionic surfactants are well known to those skilled in the art. Examples of suitable anionic surfactants include alkylbenzene sulphonates,particularly sodium linear alkylbenzene sulphonates having an alkyl chain length of C8-C15; primary and secondary alkyl sulphates, particularly sodium C12-C15 primary alkyl sulphates; sodium salts of fatty acids (i.e. soaps); olefin sulphonates; alkane sulphonates; dialkyl sulphosuccinates; and fatty acid ester sulphonates.
• Suitable nonionic surfactants include, in particular, the reaction products of compounds having a hydrophobic group and a reactive hydrogen atom, for example, aliphatic alcohols, acids amides or alkyl phenols with alkylene oxides, especially ethylene oxide either alone or with propylene oxide.
• Specific nonionic surfactants are alkyl (C6-C22) phenols-ethylene oxide condensates, generally with 5 to 25 units of ethylene oxide (i.e.: 5-25 EO) per molecule, and the condensation products of aliphatic ( C8-C18) primary or secondary linear or branched alcohols with ethylene oxide, generally 3-40 EO.
• alkyl polyglycosides and glucose ethers and esters may be effectively used as nonionic surfactants.
• the sodium carbonate and/or bicarbonate and/or - sesquicarbonate may be added to the base composition but is preferably present in it.
• the amount of this material present in the composition of the invention is in the range of from 5 to 30% by weight based on a fully formulated detergent composition. In zeolite built detergent powder according to the invention this amount is preferably in the range of from 5 to 15% by weight, whereas in detergent powder including a calcite/sodium carbonate builder system this amount is preferably in the range of from 15 to 30% by weight.
• the citric acid is a separate granular component and needs to be added to the base composition.
• the amount of particulate citric acid needed to obtain the desired good dispensing characteristics and storage stability is in the range of from 1 to 15% by weight, preferably from 2 to 12% by weight, more preferably from 3 to 10% by weight, based on a fully formulated composition.
• more than 80% by weight of the particulate citric acid has a particle size of from 350 to 1500 ⁇ m, preferably from 350 to 1000 ⁇ m, a particle size range of 350-750 ⁇ m being most preferred.
• the composition according to the invention includes at least one further builder material capable of reducing the level of free calcium ions in the wash liquor and preferably providing the composition with other beneficial properties such as the generation of an alkaline pH and the suspension of soil removed from the fabric.
• the total level of the detergency builder may be from 10% to 70% by weight, preferably from 25% to 50% by weight of the detergent composition.
• Preferred builders are ion exchange builders such as the crystalline (zeolite) or amorphous alkali metal alumino-silicates.
• organic and inorganic polymers may be present, for example, polycarboxylate polymers such as polyacrylates, acrylic-maleic copolymers such as SOKALAN types of polymers may be present.
• polycarboxylate polymers such as polyacrylates
• acrylic-maleic copolymers such as SOKALAN types of polymers
• Other preferred builder systems are precipitant builders such as those containing calcite and sodium carbonate as described in EP-A-267,042.
• the detergent composition according to the invention is preferably essentially free of phosphates-containing builders such as orthophosphates and alkali metal tripolyphosphates.
• the incorporation of citric acid and sodium (bi)carbonate and/or sodium sesquicarbonate preferably results in a reduction in the residue of at least 10 percentage points, most preferably at least 20 percentage points.
• an improvement of this magnitude can only be observed if the control powder exhibits poor dispensing properties.
• the present invention is therefore especially applicable to powders which, without citric acid and sodium (bi)carbonate and/or -sesquicarbonate, give dispenser residues of at least 20% by weight. That is especially likely to be the case if the powder is a zero-phosphate composition built with amorphous or crystalline (zeolite) sodium alumino-silicate; and/or if it has a bulk density of at least 650, preferably of at least 700 kg/m3.
• the granular detergent composition of the invention preferably also contains one or more foam depressing agents.
• Silicone oil based compositions containing high or low viscosity silicone oil, particularly high viscosity silicone oil, may be effectively used as antifoaming agents.
• bleaches are the oxygen bleaches, for example in the form of an inorganic persalt, preferably with a precursor, or as a peroxy acid compound. From an environmental point of view, the most preferred bleach compound is percarbonate. Effective amounts of these bleach compounds present in the detergent composition of the invention range from 5 to 20% by weight, preferably from 10 to 20% by weight.
• the powder of the invention may contain sodium silicate.
• High levels of silicate can in themselves have a beneficial effect on dispensing, as well as on powder structure and prevention of machine corrosion, but are undesirable in powders containing alumino-silicate because the two components react together to form insoluble siliceous species.
• the present invention enables the dispensing behaviour of zeolite-built powders to be improved without a corresponding increase in the level of insoluble material. Accordingly, the invention is of especial applicability to powders containing less than 10% by weight, more especially less than 5% by weight, of sodium silicate.
• fluorescers include fluorescers, antiredeposition agents, inorganic salts such as sodium sulphate, enzymes, bleach activators, and bleach stabilizers. These may be included in the spray-dried base powder or postdosed according to their known suitability for undergoing spray-drying processes and their compatibility with other slurry ingredients.
• a phosphate-free detergent base powder was prepared, by slurry-making, spray-drying and subsequently densifying in a Lödige "Recycler/ploughshare", as described in EP-A-367,339, to form the following nominal composition: Parts LAS 8.3 Nonionic EO 6.7 Soap 1.8 Zeolite 4A 28.0 Sokalan CP5 4.5 Carbonate 8.5 Minor ingredients + moisture 14.8
• the bulk density of the detergent powder obtained was 850 kg/m3.
• citric acid of which more than 80% by weight has a particle size in the range of 350-1000 ⁇ m was added at four different levels.
• the dispensing properties of the thus obtained compositions were tested in a Philips (trade mark) AWB 126 washing machine using 100 g powder, and 5 litres of water at 20°C flowing in over a period of 1 minute.
• Other samples were stored during 6 weeks in wax-laminated cartons at 28 °C and 70% RH, and thereafter tested in the Philips washing machine.
• Table 1 shows the resulting dispenser residues. TABLE 1 1 2 3 4 Parts citric acid added 0 1 2 3 Dispenser Residue (%) 80 50 0 0 Dispenser Residue after After storage for 6 weeks 80 65 10 0
• the bulk density of the detergent powder obtained was 850 kg/m3.
• citric acid of which more than 80% by weight has a particle size in the range of 350-1000 ⁇ m was added at four different levels.
• Samples of the thus obtained compositions were tested in a Philips (trade mark) AWB 126 washing machine, as described above. Other samples were stored during 6 weeks in wax-laminated cartons at 28°C and 70% RH, and thereafter tested in the Philips washing machine.
• Table 2 shows the resulting dispenser residues. TABLE 2 5 6 7 8 9 Parts citric acid added 0 2 4 6 8 Dispenser Residue (%) 80 70 40 0 0 Dispenser Residue after Storage for 6 weeks (%) 80 70 40 10 0
• particulate citric acid of which more than 80% by weight has a larger partical size than according to the present invention is not very effective at improving dispensing, neither immediately after preparation of the detergent powder nor after storage for 4 weeks.

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• Chemical & Material Sciences (AREA)
• Life Sciences & Earth Sciences (AREA)
• Engineering & Computer Science (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Oil, Petroleum & Natural Gas (AREA)
• Wood Science & Technology (AREA)
• Organic Chemistry (AREA)
• Health & Medical Sciences (AREA)
• Emergency Medicine (AREA)
• Inorganic Chemistry (AREA)
• Detergent Compositions (AREA)

Applications Claiming Priority (2)

Publications (4)

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ID=10702133

Family Applications (1)

Country Status (9)

Cited By (30)

Family Cites Families (8)

• 1991
  • 1991-09-27 GB GB919120657A patent/GB9120657D0/en active Pending
• 1992
  • 1992-09-11 EP EP92202764A patent/EP0534525B2/de not_active Expired - Lifetime
  • 1992-09-11 ES ES92202764T patent/ES2097860T3/es not_active Expired - Lifetime
  • 1992-09-11 DE DE69216191T patent/DE69216191T3/de not_active Expired - Fee Related
  • 1992-09-21 CA CA002078718A patent/CA2078718C/en not_active Expired - Lifetime
  • 1992-09-21 JP JP4251218A patent/JPH05202398A/ja active Pending
  • 1992-09-25 AU AU25355/92A patent/AU651732B2/en not_active Ceased
  • 1992-09-25 BR BR929203769A patent/BR9203769A/pt not_active IP Right Cessation
  • 1992-09-25 ZA ZA927383A patent/ZA927383B/xx unknown

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