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
  • C11D3/395—Bleaching agents
  • C11D3/3951—Bleaching agents combined with specific additives

Definitions

• the present invention relates to bleaching compositions, in particular to hypochlorite bleaching compositions, suitable for use in laundry applications such as hand and machine laundry methods.
• Bleaching compositions are well-known in the art. Amongst the different bleaching compositions available, those relying on bleaching by hypohalite bleaches such as hypochlorite are often preferred, mainly for performance reasons, especially at lower temperature.
• hypochlorite based-compositions a problem encountered with the use of hypochlorite based-compositions is the resulting yellowing of the fabrics being bleached.
• hypohalite-containing composition suitable for use in laundry applications, which provides improved fabric whiteness to fabrics treated therewith.
• pH buffering components such as silicates have been incorporated in hypochlorite compositions.
• a typical disclosure can be found in EP-A-0,653,483.
• the Applicant has thus now surprisingly found that the provision of an anionic surfactant in a hypohalite bleaching composition containing a pH buffering component provides improved fabric whiteness compared to the same without the anionic surfactant.
• compositions of the invention are chemically stable.
• chemically stable it is meant that the hypohalite bleaching compositions of the present invention should not undergo more than 15% loss of available chlorine after 5 days of storage at 50°C ⁇ 0.5°C.
• the % loss of available chlorine may be measured using the method described, for instance, in “Analyses des Eaux et Extraits de Javel” by "Lachner syndicalerance de L'eau de Javel et des building connexes", pages 9-10 (1984). Said method consists in measuring the available chlorine in the fresh compositions, i.e. just after they are made, and in the same compositions after 5 days at 50°C.
• compositions of the invention are suitable for the bleaching of different types of fabrics including natural fabrics (e.g., fabrics made of cotton, viscose, linen, silk and wool), synthetic fabrics such as those made of polymeric fibers of synthetic origin as well as those made of both natural and synthetic fibers.
• natural fabrics e.g., fabrics made of cotton, viscose, linen, silk and wool
• synthetic fabrics such as those made of polymeric fibers of synthetic origin as well as those made of both natural and synthetic fibers.
• the compositions of the present invention may be used on synthetic fibers despite a standing prejudice against the use of hypohalite bleaches, especially hypochlorite bleaches, on synthetic fibers, as evidenced by warning on labels of commercially available hypochlorite bleaches and clothes.
• the present invention is a liquid or solid bleaching composition comprising:
• the present invention also encompasses the use of an anionic surfactant, in a hypohalite bleaching composition, for providing improved fabric whiteness to the fabrics treated therewith.
• the present invention also encompasses a process of bleaching fabrics with a composition comprising:
• Hypohalite beaches may be provided by a variety of sources, including bleaches that are oxidative bleaches and subsequently lead to the formation of positive halide ions as well as bleaches that are organic based sources of halides such as chloroisocyanurates.
• Suitable hypohalite bleaches for use herein include the alkali metal and alkaline earth metal hypochlorites, hypobromites, hypoiodites, chlorinated trisodium phosphate dodecahydrates, potassium and sodium dichloroisocyanurates, potassium and sodium trichlorocyanurates, N-chloroimides, N-chloroamides, N-chloroamines and chlorohydantoins.
• the preferred hypohalite beaches among the above described are the alkali metal and/or alkaline earth metal hypochlorites selected from the group consisting of sodium, potassium, magnesium, lithium and calcium hypochlorites, and mixtures thereof, more preferably the alkali metal sodium hypochlorite.
• the preferred hypohalite bleaches among the above described are the alkali metal and/or alkaline earth metal hypochlorites selected from the group consisting of lithium hypochlorites, calcium hypochlorites, chlorinated trisodium phosphate dodecahydrates, potassium dichloroisocyanurates, sodium dichloroisocyanurates, potassium trichlorocyanurates, sodium trichlorocyanurates, and mixtures thereof, more preferably sodium dichloroisocyanurates and/or calcium hypochlorite.
• the alkali metal and/or alkaline earth metal hypochlorites selected from the group consisting of lithium hypochlorites, calcium hypochlorites, chlorinated trisodium phosphate dodecahydrates, potassium dichloroisocyanurates, sodium dichloroisocyanurates, potassium trichlorocyanurates, sodium trichlorocyanurates, and mixtures thereof, more preferably sodium dichloroisocyanurates and/or calcium hypochlorite.
• the liquid compositions according to the present invention comprise said hypohalite bleach such that the content of active halide in the composition is of from 0.1% to 20% by weight, more preferably from 2% to 8% by weight, most preferably from 3% to 6% by weight of the composition.
• the solid compositions according to the present invention comprise said hypohalite bleach such that the content of active halide in the composition is of from 20% to 95% by weight, more preferably from 25% to 60% by weight of the composition.
• a pH buffering component is another essential component for the compositions of the invention.
• the pH buffering component ensures that the pH of the composition is buffered to a pH value ranging from 7.5 to 13, preferably from 8 to 12, more preferably from 8.5 to 11.5 after the composition has been diluted into 1 to 500 times its weight of water.
• Suitable pH buffering components for use herein are selected from the group consisting of alkali metal salts of carbonates, polycarbonates, sesquicarbonates, silicates, polysilicates, borates, metaborates, phosphates, stannates, alluminates and mixtures thereof, and preferably are selected from the group consisting of sodium carbonate, sodium silicate, sodium borate, and mixtures thereof.
• the raw materials involved in the preparation of hypohalite bleaches usually contain by-products, e.g calcium carbonate resulting in an amount of up to 0.4% by weight of by-product within the hypohalite composition. However, at such amount, the by-product will not have the buffering action defined above.
• Liquid bleaching compositions herein will contain an amount of pH buffering component of from 0.5% to 9% by weight, preferably from 0.5% to 5% by weight, and more preferably in an amount of from 0.6% to 3% by weight of the composition.
• Solid bleaching compositions herein will preferably contain an amount of pH buffering component of from 3% to 30% by weight, more preferably from 5% to 25% by weight, and most preferably in an amount of from 10% to 20% by weight of the composition.
• anionic surfactant Another essential component of the invention is an anionic surfactant.
• Anionic surfactants have been extensively described in the art, and suitable anionic surfactants for use herein are alkylbenzenesulphonates, alkylsulphates, alkylethoxysulphates or alkylethoxycarboxylates with an alkyl chain from 4 to 24 carbon atoms, preferably 8 to 18, most preferably 8 to 16.
• the counterion for the anionic functionality is typically chosen from alkali metals, most preferred is sodium.
• the anionic surfactant is typically used at levels of from 0.1% to 10% by weight of the total composition, preferably 0.1% to 5%, most preferably 0.3% to 3%.
• An effective amount of anionic surfactant will inprove the whiteness to fabrics which are treated with the bleaching composition comprising the anionic surfactant.
• the whitening effect i.e. the yellowing-prevention effect of the present invention can be evaluated by comparing the composition according to the present invention to the same composition without anionic surfactant, by either visual or instumental grading.
• the difference in yellowing between items treated with different compositions can be determined by a team of expert panelists.
• the assessment can be determined with the help of Colorimeters such as Ganz Griesser® instruments (e.g., Datacolor® Spectraflash® SF 500, Machbet White-eye® 500) or a ZEISS ELREPHO® or others which are available for instance from Hunterlab® or Gardner®.
• anionic surfactants are suitable for use herein.
• some anionic surfactants for use herein may be poorly soluble in the hypochlorite matrixes herein, when they are liquid.
• Such surfactants typically alkylbenzenesulphonates, may thus require the use of a co-surfactant and/or a hydrotrope.
• Such suitable co-surfactants include alkyl sulphates or alkylethoxysulphates having from 4 to 12 carbon atoms in the alkyl chain, or alkylethoxycarboxylates having from 6 to 24 carbon atoms in the alkyl chain, such as Akyposoft® 100NV from Chemy or Sandosan LNCS from Sandoz.
• alkyl sulphates or alkylethoxysulphates having from 4 to 12 carbon atoms in the alkyl chain or alkylethoxycarboxylates having from 6 to 24 carbon atoms in the alkyl chain, such as Akyposoft® 100NV from Chemy or Sandosan LNCS from Sandoz.
• Preferred are C8 alkyl sulphate and C12-14 alkylethoxycarboxylates with 10 ethoxylations in the molecule.
• Suitable hydrotropes are, for example, sodium cumenesulphonate and xylenesulphonate.
• Such co-surfactants and/or hydrotropes herein should be used in amounts required to solubilize the anionic surfactant in need thereof.
• the liquid compositions of the present inventions are prepared in a process wherein the anionic surfactant and the co-surfactant and/or hydrotrope are first-mixed to form a premix, before the premix is then mixed with the remainder of the composition which has been separately prepared.
• compositions according to the present invention are either in liquid or solid form.
• Solid forms include forms such as powders, tablets and granules.
• the compositions of the invention are in liquid aqueous form. More preferably, they comprise water in an amount of from 60% to 98% by weight, more preferably of from 80% to 97% and most preferably of from 85% to 97% by weight of the total aqueous liquid bleaching composition.
• the pH of the liquid compositions according to the present invention is typically from 12 to 14 measured at 25°C.
• Solid compositions or liquid compositions of the invention have a pH of from 7.5 to 13, preferably from 8 to 12, more preferably from 8.5 to 11.5, when diluted into 1 to 500 times its weight of water. It is in this alkaline range that the optimum stability and performance of the hypohalite as well as fabric whiteness and/or safety are obtained.
• the pH range is suitably provided by the pH buffering component and the hypohalite bleach mentioned hereinbefore, which are alkalis. However, in addition to these components, a strong source of alkalinity may also optionally be used.
• Suitable sources of alkalinity are the caustic alkalis such as sodium hydroxide, potassium hydroxide and/or lithium hydroxide, and/or the alkali metal oxides such as sodium and/or potassium oxide.
• a preferred strong source of alkalinity is a caustic alkali, more preferably sodium hydroxide and/or potassium hydroxide. Typical levels of such caustic alkalis, when present, are of from 0.1% to 1.5% by weight, preferably from 0.5% to 1.5% by weight of the composition.
• composition according to the invention may also comprise further optional components such as perfumes, bleach-stable surfactants, organic or inorganic alkalis, pigments, dyes, optical brighteners, solvents, chelating agents, radical scavengers and mixtures thereof.
• perfumes bleach-stable surfactants, organic or inorganic alkalis, pigments, dyes, optical brighteners, solvents, chelating agents, radical scavengers and mixtures thereof.
• the compositions of the invention are used in diluted form in laundry applications.
• the expression "used in diluted form” herein includes dilution by the user, which occurs for instance in hand laundry applications, as well as dilution by other means, such as in a washing machine.
• the composition is diluted into 5 to 500 times its weight of water for hand laundry application and 10 to 500 times its weight of water in a washing machine.
• compositions for providing improved whiteness to the fabrics treated therewith.
• the compositions preferably, but not compulsorily, comprise a pH buffering component.
• composition weight %) 1 2 3 4 5 6 7 8
• Sodium hypochlorite 5.0 5.0 5.0 2.5 2.5 2.5 2.5 5.0 5.0
• Sodium hydroxide 0.9 0.7 0.7 0.9 0.7 0.5 -
• Sodium carbonate 1.2 1.2 1.2 1.2 1.2 - 1.5
• Sodium silicate - 0.5 - - 0.5 - - - Sodium metaborate - - 1.0 - - 1.0 - C8 alkylsulphate 1 1 1 - - 0.5 - - Akyposoft 100NV - - - 1 0.5 - 0.5 1.5

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• Engineering & Computer Science (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Oil, Petroleum & Natural Gas (AREA)
• Wood Science & Technology (AREA)
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• Detergent Compositions (AREA)

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Citations (5)

• 1997
  • 1997-03-27 EP EP97870041A patent/EP0867501A1/de not_active Withdrawn
• 1998
  • 1998-03-18 JP JP54132998A patent/JP2001517261A/ja active Pending
  • 1998-03-25 MA MA25010A patent/MA24507A1/fr unknown
  • 1998-03-25 PE PE1998000219A patent/PE76599A1/es not_active Application Discontinuation
  • 1998-03-26 AR ARP980101390A patent/AR011700A1/es unknown
  • 1998-03-26 ZA ZA982575A patent/ZA982575B/xx unknown
  • 1998-03-27 CO CO98017306A patent/CO5300462A1/es not_active Application Discontinuation

Patent Citations (5)

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