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

• This application is a continuation-in- part of co-pending application Serial No. 911,190, filed May 30, 1978.
• This invention relates to an improved bleaching agent composition for use in low temperature aqueous systems, such as in laundry operations or in the commercial processing of textile materials, e.g., cotton grey goods.
• halogen-releasing agents for bleaching as well as disinfecting purposes in the processing or laundering of textile materials
• Various inorganic halogen-based bleaching agents are known including not only elemental chlorine gas, but also sodium hypochlorite, sodium hypobromite, etc.
• halogen-releasing organic agents have been disclosed as bleaching agents. These include, for instance, halogenated glycourils described in U.S. Patent 3,071,591 and a number of other N-halogenated derivatives of amines, amides, imides and various N-heterocyclic compounds, such as those mentioned in U.S. Patent 3,412,021.
• N-halogenated organic compounds include of course organo-N-chlorinated compounds such as the
• N,N-dihalo-substituted hydantoin compounds N,N-dihalo-substituted hydantoin compounds. It is with respect to this class of organo N-chlorinated materials in combination with a potential source of bromonium (Br + ) ion, e.g., an inorganic bromide, that the present invention is particularly concerned.
• a potential source of bromonium (Br + ) ion e.g., an inorganic bromide
• an effective method for the bleaching of textile goods at low temperatures in the range of from 60° to 140oF by exposing the textile goods to an aqueous solution at said temperatures, which solution consists essentially of a mixture by weight of:
• an organo-N-chloro compound selected from the group consisting of: i) N-chlorinated-5,5-cialkyl- hydantoins; ii) N-chlorinated isccyanurates; iii) N-chlorinated rcelamines; and iv) N-chlorinated giycolurils; and (b) from 75 to 25 parts of an alkali metal, alkaline earth metal or ammonium bromide salt.
• the bromide salt serves as a potential source of bromonium ions for the mixture under bleaching conditions (i.e., in aqueous solution also containing the organo-N-chloro compound).
• the alkyl group contains up to 8 carbons.
• an improved bleaching composition which, in its preferred form, consists essentially of the combination of a 5 ,5-di-substituted-N,N-dichloro hydantoin component together with sodium bromide.
• the present invention is based on the unexpected discovery that such combination of the organo-N-chlorinated compound and source of bromonium ion, (e.g., inorganic bromide - such as chlorinated hydantoin compound with sodium bromide) leads to an unexpected potentiation of the bleaching activity than would otherwise be expected from use of the organo-N-chlorinated compound alone.
• N-halogenated organic compounds are thought to be due to the release of positive halogen ions which are themselves powerful oxidizing agents and act as the effective bleaching agent. It is also generally considered that positive bromine ions are more powerful and effective bleaching agents than positive chlorine ions.
• N-bromo- substituted organic compounds are characteristically more expensive than N-chloro- substituted organic compounds. Thus, the use of such brominated compounds has not been and is not as attractive as using the corresponding chlorinated compound from a cost consideration point of view, provided that adequate bleaching effectiveness could be realized from the chlorinated material.
• N,N-dichloro hydantoin compounds are themselves relatively ineffective as bleaching agents particularly at the lower temperatures of, for instance, 120oF. (approx. 50oC.) desired for today's bleaching operations, and not even very effective as a bleaching agent at higher temperatures of, for instance, 160oF. and above (particularly at reasonable concentration levels).
• This is in marked contrast to the behavior of N,N-dibromo-substituted hydantoins which are nearly as effective at 160°F. as they are at 120°F., on a weight-for-weight basis.
• the activity of the N,N-dichloro substituted hydantoins declines even more severely, with a lower temperature, than is experienced with the presently used sodium dichloroisocyanurate.
• the present method and compositions used therein provide for a safe, clean and economical means for achieving effective bleaching with positive bromonium ions of textile materials at temperatures significantly lower than conventionally employed heretofor.
• N,N-dichloro-substituted hydantoins would function as effective bleaching agents, even in combination with the sodium bromide component because the lower temperatures appear to be below the required level for oxidizing effectiveness of the dichloro hydantoin material.
• the organo-N-chlorinated compound component interacts with the bromide component to form positive bromonium (Br + ) ions.
• Such positive bromonium ions then act as oxidizing agents for the organic, or inorganic, stain, or other discolorations to be removed from the textile.
• the positive bromonium ions are themselves chemically reduced back to the bromide ions.
• Such re-formed bromide ions are thus susceptible again to oxidation to new bromonium ions, as a result of interaction with additional molecules of the organo-N-chlorinated compound. The entire process thus repeatedly occurs until the organic-N-chloro component is itself completely consumed.
• the organo-N-chloro compound may be selected from a number of sources. Especially preferred are the N-chlorinated -5 ,5-alkylhydantoins and the N-chlorinated isocyanurates. One may also use N-chlorinated melamines or glycolurils as described in the aforementioned U.S. Patents Nos. 3,071,591 and 3,412,021.
• organo-N-chlorinated compounds are sodium dichloroisocyanurate (NaDCC), N,N-dichloro-5,5-dimethylhydantoin (DCDMH) and N-bromo-N-chloro-5,5-dimethylhydantoin (BCDMH) .
• this invention is not limited to the use of N,N-dichloro-5,5-dimethyl hydantoin.
• other alkyl groups may be present in place of the methyl groups, as desired, up to, for instance, lower alkyl groups of 8 carbon atoms.
• the N,N-dichloro hydantoin parent compound may also be used. No significant advantage is, however, seen from using alkyl groups larger than the methyl group because the resulting increased molecular weight v/ould simply require the addition of more organic material to the system for an equivalent bleaching activity.
• the dimethyl-substituted hydantoin is also the presently preferred material from a standpoint of cost and availability.
• a preferred source of the potential source of bromonium ions is an inorganic bromide salt, preferably sodium bromide due to its relatively low cost and availability.
• other potential sources of the bromonium icn besides sodium bromide may also be employed, for instance, other alkali or alkaline earth metal or ammonium bromide salts (e.g., KBr, MgBr2 Ca3r2, etc).
• it is not a cation associated with the bromide ion that is of significance to the invention; rather, the bromide ion may be derived from any desired non-interfering source.
• N,N-dibromo-5,5-dimethylhydentoin (DBDMH) in combination with N,N-dichloro-5,5- dimethyl-hydantoin (DCDMH) may be employed, the DBDMH serving as a source of bromonium ion when the composition is placed in an aqueous environment for the bleaching of textile materials.
• DBDMH N,N-dibromo-5,5-dimethylhydentoin
• DCDMH N,N-dichloro-5,5- dimethyl-hydantoin
• the data generally shows that equivalent bleaching is obtained with DCDMH and NaBr with substantially lesser amounts of DCDMH if potentiated with NaBr. Since the present invention preferably utilizes the relatively inexpensive sodium bromide salt as a substantial amount of the bleaching composition provided herein (even above 50% by weight), cost advantages can be readily realized. Moreover, since the relative amount of organic material is also reduced, effluent polluting problems can also be minimized.
• available halogen is a term established for comparing a potential bleaching or disinfecting power of halogen atoms with that of the elemental halogen on a weight basis. Elemental halogen is defined as containing 100% "available” halogen. When elemental chlorine is dissolved in water, hydrochloric acid and hypcchlorous acid are generated. The hypochlorous acid is the active bleaching component. Therefore, one half of the original weight of the elemental chlorine is useless. The chlorine contained in the N-halogenated compounds is in the positive
• compositions of the present invention would appear to leave substantially intact the optical brighteners, typically in a detergent composition, for their desired effect on the appearance of the finished laundry, and it is also not seen that there is a deteriorative effective on the fabric itself.
• the machine used was a Terg-O-Tometer (60cpm) with distilled water and a washing time of 10 minutes, followed by a 5 minute rinse cycle and two cold water hand rinses.
• the light reflectance of the fabric was measured before and after each wash with a Photovolt reflectometer equipped with a blue filter. The results are recorded as an increase in the light reflectance of the dry samples.
• the test procedure was as follows. The standard detergent (2.5 grams/liter of water) was used with varying concentrations (per liter) of the bleaching agents, as listed hereinbelow.
• the washing cycle was conducted, as indicated above, at a water temperature of 120°F. (48.9°C.), at a pH of 7 (adjusted by the use of dilute sulfuric acid and sodium carbonate).
• the results of the reflectance readings, measured as described above, are tabulated below.
• Control represents the results when the standard detergent alone was used.
• DCDMH concentrations used in the admixture with NaBr
• DBDMH concentrations e.g., the three DCDMH concentrations thus used, 66 mg, 99 mg, 132 mg, respectively provide the same number of halogen atoms as do 96, 144 and 192 mg of DBDMH.
• these data for a pH of 7 are graphically portrayed in the attached Figure wherein the solid curves connect data points measured at 120°F. and the dashed curves connect data points at 160 °F. in the above tests. The data is plotted on the basis of the concentration of the organic bleaching agent present.
• DCDMH the triangular points
• DCDMH the triangular points
• it is even more effective than the dibromo dimethyl hydntoin, on a weight-for-weight basis.
• a concentration of approximately 115 mg per liter of DCDMH, in combination with sodium bromide is sufficient, whereas for the same increase in reflectance reading a concentration approximately 145 mg of DBDMH is necessary, i.e., 26 weight percent more.
• the bleaching effectiveness of the DCDMH is some 80% of that of the DBDMH, when the former is used in combination with sodium bromide. In absence of sodium bromide, at 120 ° F. and a pH of 7, the DCDMH is only about 30% as effective as DBDMH, on the same basis.
• organo-N-chlorinated compounds herein rather than sodium hypochlorite (NaHOCl) a known bleaching agent, avoids harsh and detrimental treatment of the textile material.
• NaHOCl sodium hypochlorite
• a bleach composition formed from a mixture of sodium hypochlorite and sodium bromide when placed in water reacts to evolve elemental bromine which not only is harsh on fabrics, but is highly corrosive to people and equipment which may come in contact therewith.
• the invention is not limited to the use of approximately 50:50 weight mixtures of the organo-N-chloro and bromide components in the composition.
• weight ratios in the range of at least 25:75 up to 75:25,, preferably 40:60 up to 60:40 may be employed. Similar proportions may also be used, calculated on a basis of available chlorine on the one hand and bromide ion on the other hand when other organo-N-chloro compounds and bromide salts are employed.

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• Chemical Kinetics & Catalysis (AREA)
• Oil, Petroleum & Natural Gas (AREA)
• Wood Science & Technology (AREA)
• Organic Chemistry (AREA)
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• 1980
  • 1980-02-11 WO PCT/US1980/000133 patent/WO1981002313A1/en unknown
  • 1980-02-11 EP EP19800900844 patent/EP0045740A1/de not_active Withdrawn
  • 1980-03-13 AR AR280301A patent/AR221639A1/es active
  • 1980-11-21 EP EP19810900362 patent/EP0046767B1/de not_active Expired
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