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
  • C11D3/08—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
  • C11D3/39—Organic or inorganic per-compounds
  • C11D3/3947—Liquid compositions

Definitions

• the present invention relates to liquid automatic dishwashing compositions, which are free of chlorine bleach, and contain a solid water-soluble peroxygen bleach, suspended in a liquid phase;
• Liquid automatic dishwashing products are well-known; such products usually contain chlorine bleaches.
• liquid detergent compositions containing a water-soluble peroxygen bleach, such as perborate tetrahydrate, suspended in a liquid phase consisting of water and a water-miscible organic solvent a water-soluble peroxygen bleach, such as perborate tetrahydrate, suspended in a liquid phase consisting of water and a water-miscible organic solvent.
• compositions disclosed in said documents are intended to be used for the washing of textiles and in fact, they have an alkalinity below 2 grams NaOH/100 ml of composition.
• Silicates have been widely described as alkalinity-building ingredients of aqueous thixotropic liquid compositions used for automatic dishwashing purposes. Representative of this art is EP 315 024.
• EP-A-79 646, EP-A-86 614, EP-A-203 660 and EP-A-295 021 describe liquid detergent composition containing suspended builder particles where one or more "salting-out” electrolytes, or "surfactant desolubilizing” electrolytes are used, to build structured phases with the surfactant materials; such electrolytes include, among many other substances, silicates.
• liquid dishwashing compositions which are chemically and physically stable, environmentally friendly, performing at least equally as state of the art compositions and furthermore being perfectly pourable and exhibiting shear-thinning and thixothopic properties.
• composition of the invention are preferably built, with a non-phosphate builder, this latter feature completing the "environmentally friendly" character of the present composition.
• Chlorine-free liquid automatic dishwashing compositions having an alkalinity of from 20 grams to 20 grams NaOH/100 ml of composition, said composition containing from 5% to 30%, preferably from 7% to 15% by weight of silicate and comprising a solid water-soluble peroxygen compound suspended in a liquid phase containing water and at least one water-miscible organic solvent.
• the amount of the solid water-soluble peroxygen compound being such that the amount of available oxygen provided by said peroxygen compound is from 0.5 to 3%.
• the compositions preferably contain from 5% to 40% of a non-phosphate builder.
• compositions have an alkalinity of from 2 gram to 20 gram NaOH per 100 ml of composition, preferably from 3 gram to 10 grams NaOH per 100 ml of compositions.
• the alkalinity can easily be measured as it is well known, i.e., titration of a 1% solution from initial pH to pH 9.5.
• the desired alkalinity is at least partly provided by the silicate described hereinbelow, which can also be used in combination with sodium or potassium carbonate.
• a silicate is present in the present composition, at levels of from 5% to 30%, preferably 7% to 15% of the total composition; Preferred is sodium silicate, while potassium silicate can also be used.
• the silicate materials for use herein have a ratio of SiO2 to Na2O of from 1:1 to 4:1, preferably 1:1 (metasilicate) and 2:1.
• the silicate herein also provides desriable shear-thinning and thixotropic properties to the present compositions.
• compositions herein are free of chlorine-bleach. Instead, they contain a solid water-soluble peroxygen compound.
• the water-soluble solid peroxygen compound is present in the compositions herein at levels such that the amount of available oxygen provided by said peroxygen compound is from 0.5% to 3%.
• suitable water-soluble solid peroxygen compounds include the perborates, persulfates, peroxydisulfates, perphosphates and the crystalline peroxyhydrates formed by reacting hydrogen peroxide with sodium carbonate (forming percarbonate) or urea.
• Preferred peroxygen bleach compounds are perborates and percarbonates.
• Perborate tetrahydrates are especially preferred, and are present at levels of from 5% to 30% by weight of the total composition.
• a perborate tetrahydrate bleach in the form of particles having a weight-average particle diameter of from 0.5 to 20 micrometers, preferably 3 to 15 micrometers.
• the required small particles size can best be achieved by in-situ crystallization, typically of perborate monohydrate.
• In-situ crystallization encompasses processes involving dissolution and recrystallization, as in the dissolution of perborate monohydrate and subsequent formation of perborate tetrahydrate. Recrystallization may also take place by allowing perborate monohydrate to take up crystal water, whereby the monohydrate directly recrystallizes into the tetrahydrate, without dissolution step.
• In-situ crystallization also encompasses processes involving chemical reactions, as when sodium perborate is formed by reacting stoichiometric amounts of hydrogen peroxide and sodium metaborate or borax.
• the suspension system for the solid peroxygen component herein consists in a liquid phase that comprises water and a water-miscible organic solvent;
• liquid detergent compositions herein an high amount of solid water-soluble peroxygen compound, while keeping the amount of available oxygen in solution below 0.5% by weight of the liquid phase, preferably below 0.1%. Less than one fifth by weight peroxygen compound is dissolved in the liquid phase; the low level of available oxygen in solution is in fact critical for the stability of the system.
• compositions are to be kept after mixing for three days at room temperature before the AVO titration. Before measuring the products are thoroughly shaken in order to ensure correct sampling.
• samples of the compositions are centrifuged for 10 minutes at 10.000 rpm.
• the liquid is then separated from the solid and titrated for available oxygen.
• organic solvent it is not necessary that the organic solvent be fully miscible with water, provided that enough of the solvent mixes with the water of the composition to affect the solubility of the peroxygen compound in the described manner.
• Fully water-soluble solvents are preferred for use herein.
• the water-miscible organic solvent must, of course, be compatible with the peroxygen bleach compound at the pH that is used. Therefore, polyalcohols having vicinal hydroxy groups (e.g. 1,2-propanediol and glycerol) are less desirable when the peroxygen bleach compound is perborate.
• suitable water-miscible organic solvents include the lower aliphatic monoalcohols; ethers of diethylene glycol and lower monoaliphatic monoalcohols; specifically ethanol, n-propanol; iso-propanol; butanol; polyethylene glycol (e.g., PEG 150, 200, 300, 400); dipropylene glycol; hexylene glycol; methoxyethanol; ethoxyethanol; butoxyethanol; ethyldiglycolether; benzylalcohol; butoxypropanol; butoxypropoxypropanol; and mixtures thereof.
• Preferred solvents include ethanol; iso-propanol, 1-methoxy2-propanol and butyldiglycolether.
• a preferred solvent system is ethanol.
• the amount of available oxygen in solution is largely determined by the ratio water:organic solvent. It is not necessary however to use more organic solvent than is needed to keep the amount of available oxygen in solution below 0.5%, preferably below 0.1%.
• the ratio water:organic solvent is, for most systems, in the range from 0:1 to 1:3, preferably from 5:1 to 1:2.
• the present liquid compositions are formulated at a pH of from 9.5 to 12.5, preferably from 10 to 11.5.
• the alkaline pH allows to get a good bleaching action of the peroxygen compound, particularly when the peroxygen is a perborate.
• compositions may contain a series of ingredients which, while being optional, are often desirable.
• compositions contain a builder :
• the present compositions can contain from 5% to 40% of a builder which is non-phosphate material; inorganic builders useful in the present compositions include aluminosilicates (zeolites), while organic builders include polyacids such as citric acid, nitrilotriacetic acid, certain alk(en)yl-substituted succinic acid/anhydride compounds, and mixtures of tartrate monosuccinate with tartrate disuccinate.
• Polymeric carboxylate builders inclusive of polyacrylates, polyhydroxy acrylates and polyacrylates/polymaleates copolymers can also be used.
• Iminodiacetic acid derivatives such as N-glyceryl imino N,N diacetic acid, (N(-2-hydroxypropyl)imino N,N-diacetic acid are also suitable as builders.
• Preferred builders for use herein are citric acid and alk(en)yl-substituted succinic acid/anhydride compounds, wherein alk(en)yl contains from 10 to 16 carbon atoms and mixtures thereof.
• dodecenyl succinic acid/anhydride especially preferred for the present compositions are mixtures of dodecenyl succinic/anhydride and citric acid, at ratios of dodecenyl succinic acid/anhydride to citric acid of from 2:1 to 1:1.
• compositions contain a surface-active agent, at levels of from 1% to 10% by weight of the total composition;
• Said surface-active agents are preferably nonionic surfactants :
• the nonionic surfactants are conventionally produced by condensing ethylene oxide with a hydrocarbon having a reactive hydrogen atom, e.g., a hydroxyl, carboxyl, or amido group, in the presence of an acidic or basic catalyst, and include compounds having the general formula RA(CH2CH2O) n H wherein R represents the hydrophobic moiety, A represents the group carrying the reactive hydrogen atom and n represents the average number of ethylene oxide moieties. R typically contains from about 8 to 22 carbon atoms. They can also be formed by the condensation of propylene oxide with a lower molecular weight compound. n usually varies from about 2 to about 24.
• the hydrophobic moiety of the nonionic compound is preferably a primary or secondary, straight or branched, aliphatic alcohol having from about 8 to about 24, preferably from about 12 to about 20 carbon atoms.
• suitable nonionic surfactants can be found in U.S. Patent 4,111,855. Mixtures of nonionic surfactants can be desirable.
• a preferred class of nonionic ethoxylates is represented by the condensation product of a fatty alcohol having from 12 to 15 carbon atoms and from about 4 to 10 moles of ethylene oxide per mole of fatty alcohol.
• Suitable species of this class of ethoxylates include : the condensation product of C12-C15 oxo-alcohols and 7 moles of ethylene oxide per mole of alcohol; the condensation product of narrow cut C14-C15 oxo-alcohols and 7 or 9 moles of ethylene oxide per mole of fatty(oxo)alcohol; the condensation product of a narrow cut C12-C13 fatty(oxo)alcohol and 6,5 moles of ethylene oxide per mole of fatty alcohol; and the condensation products of a C10-C14 coconut fatty alcohol with a degree of ethoxylation (moles EO/mole fatty alcohol) in the range from 5 to 8.
• the fatty oxo alcohols while mainly linear can have, depending upon the processing conditions and raw material olefins, a certain degree of branching, particularly short chain such as methyl branching.
• a degree of branching in the range from 15% to 50% (weight %) is frequently found in commercial oxo alcohols.
• Preferred nonionic ethoxylated components can also be represented by a mixture of 2 separately ethoxylated nonionic surfactants having a different degree of ethoxylation.
• the nonionic ethoxylate surfactant containing from 3 to 7 moles of ethylene oxide per mole of hydrophobic moiety and a second ethoxylated species having from 8 to 14 moles of ethylene oxide per mole of hydrophobic moiety.
• a preferred nonionic ethoxylated mixture contains a lower ethoxylate which is the condensation product of a C12-C15 oxo-alcohol, with up to 50% (wt) branching, and from about 3 to 7 moles of ethylene oxide per mole of fatty oxo-alcohol, and a higher ethoxylate which is the condensation product of a C16-C19 oxo-alcohol with more than 50% (wt) branching and from about 8 to 14 moles of ethylene oxide per mole of branched oxo-alcohol.
• composition herein may, however, also contain other types of surfactant, like anionic or cationic surfactants, possibly in combination with the nonionic surfactants described above.
• Synthetic anionic surfactants can be represented by the general formula R1SO3M wherein R1 represents a hydrocarbon group selected from the group consisting of straight or branched alkyl radicals containing from about 8 to about 24 carbon atoms and alkyl phenyl radicals containing from about 19 to about 15 carbon atoms in the alkyl group.
• M is a salt forming cation which typically is selected from the group consisting of sodium, potassium, ammonium, and mixtures thereof.
• a preferred synthetic anionic surfactant is a water-soluble salt of an alkylbenzene sulfonic acid containing from 9 to 15 carbon atoms in the alkyl group.
• Another preferred synthetic anionic surfactant is a water-soluble salt of an alkyl sulfate or an alkyl polyethoxylate ether sulfate wherein the alkyl group contains from about 8 to about 24, preferably from about 10 to about 20, preferably from about 1 to about 12 ethoxy groups.
• Other suitable anionic surfactants are disclosed in U.S. Patent, 4,170,565, Flesher et al., issued October 9, 1979.
• Suitable cationic surfactants include quaternary ammonium compounds of the formula R1R2R3R4N+X ⁇ , wherein R1 is C12-C20 alkyl or hydroxyalkyl; R2 is C1-C4 alkyl or C12-C20 alkyl or hydroxyalkyl or C1-C4 hydroxyalkyl; R3 and R4 are each C1-C4 alkyl or hydroxyalkyl, or C6-C8 aryl or alkylaryl; and X ⁇ is halogen.
• R1R2R3R4N+X ⁇ wherein R1 is C12-C20 alkyl or hydroxyalkyl
• R2 is C1-C4 alkyl or C12-C20 alkyl or hydroxyalkyl or C1-C4 hydroxyalkyl
• R3 and R4 are each C1-C4 alkyl or hydroxyalkyl, or C6-C8 aryl or alkylaryl
• X ⁇ is
• Detergent enzymes can be used in the present composition. Suitable enzymes include the detergent proteases, amylases, lipases and cellulases; Enzymatic stabilizing agents for use herein include the salts of formic acid, e.g. sodium formate, but also the salts of higher carboxylic acids, such as sodium acetate, and mixtures of above species.
• the total amount of enzymatic stabilizing agent typically ranges from 0.5 to 5%.
• compositions may also contain relatively small amounts of : - Bleach stabilizers such as following organo-phosphonic acids : - ethylenediamino tetramethylenephosphonic acid, hexamethylenediamino tetramethylenephosphonic acid, diethylenetriamino pentamethylenephosphonic acid, amino-trimethylenephosphonic acid, hydroxyethylidene 1,1 diphosphonic acid and mixtures thereof.
• - Other bleach stabilizers such as ascorbic acid, dipicolinic acid, sodium stannates and 8-hydroxyquinoline.
• polyaminocarboxylates such as ethylene­diaminotetracetic acid, diethylenetriaminopentacetic acid, ethylenediamino disuccinic acid or the water-soluble alkali metals thereof.
• Silicone suds regulants - Sodium peroxide to adjust to the desired pH - opacifiers, bactericides, dyes, perfumes, etc...
• compositions illustrate the present invention :
• compositions of example I to IV are pourable, show no phase separation after storage (3 weeks), and feature a remaining percentage of initial aVO of 90%, after 3 weeks.
• compositions of example I to IV perform equally well vs. commercially available dishwashing products containing chlorine bleach.

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Cited By (16)

Citations (3)

• 1990
  • 1990-11-12 EP EP90202986A patent/EP0429124A1/fr not_active Withdrawn
  • 1990-11-15 CA CA 2030098 patent/CA2030098A1/fr not_active Abandoned
  • 1990-11-21 JP JP31758490A patent/JPH03210399A/ja active Pending

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