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. PCT/US/80/00133 filed February 11, 1980 which in turn is a continuation-in-part of 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, e.g., temperatures of 140° F or less and particularly about 120°F or less, such as in laundry operations or in the commercial processing of textile materials, e.g., cotton grey goods, cotton/polyester blends and like 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, 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.
• the present invention is predicated on the discovery that effective bleaching of textile goods (especially cotton and blends thereof, e.g. cotton/polyester blends) can be accomplished at relatively low temperatures (e.g. below 140°F, and especially below 120°F) when the goods are exposed to an aqueous solution which contains an amount effective for bleaching of a material capable of generating positive bromine (Br + ) ions during bleaching.
• relatively low temperatures e.g. below 140°F, and especially below 120°F
• a wide variety of materials may be utilized to provide a source of positive bromine ions (Br + ) including, alkali metal hypochlorites in combination with a source of bromine (e.g. an alkali metal bromide or an organo-N-bromo compound).
• a source of bromine e.g. an alkali metal bromide or an organo-N-bromo compound.
• N-brominated hydantoins As used herein, reference to the various N-brominated hydantoins; N-chlorinated-N-brominated hydantoins; N-chlorinated hydantoins and like hydantoins is intended to include the N-halo compounds of hydantoin itself or the derivatives thereof which are monoor di-substituted at the 5 position with alkyl groups containing up to 8 carbon atoms. From an economical viewpoint the organo-N-halo-5,5dialkylhydantoins are preferred especially those of 5,5-dimethylhydantoin.
• N-brominated isocyanurates N-chlorinated-N-brominated isocyanurates; N-chlorinated isocyanurates and the like. These terms are intended to encompass both the free acid as well as alkali metal salts thereof, containing from 1 to 3 of the specified halogen.
• a method for the effective bleaching of textile goods at temperatures at or below about 140°F which consists essentially in exposing the same to an aqueous solution, at said temperatures, containing an amount effective for bleaching of a material capable of generating positive bromine ions during the bleaching of said textile goods, said material being selected from the group consisting of: a) an organo-N-bromo compound selected from the group consisting of N-brominated-5,5-d ⁇ alkylhydantoins; N-brominated isocyanurates; N-brominated melamines, N-brominated glycolurils and mixturesthereof; b) an organo-N-chloro-N-bromo compound selected from the group consisting of N-chlorinated-N-brominated-5,5-dialkylhydantoins; Nchlorinated-N-brominated isocyanurates; N-chlorinated-N-bromo
• a key feature of the present invention is the generation at low tempertures of positive bromine (Br + ) ions which results in an unexpected degree of effective bleaching at such low temperatures.
• the source of the positive bromine ion may be varied as noted above depending upon cost and availability.
• the use of mixtures of various materials e.g., an organo-N-chloro-compound together with a bromide salt or with an organo-N-bromo compound
• sole reagents such as N-chloro-N-bromo-5,5-dimethylhydantoin, an especially preferred material.
• fully brominated organo-N compounds may be used.
• source of positive bromine (Br + ) ion is intended to include not only those compounds which form the ion (e.g., organo-N-brominated compounds such as N,N-dibromo-5,5-dimethylhydantoin) under bleaching conditions, but those mixtures which under bleaching conditions will react to form compounds which generate positive bromine ions (e.g., organo-N-chloro compounds or alkali metal hypochlorites mixed with a bromide salt).
• an organo-N-bromo compound selected from the group consisting of N-brom ⁇ nated-5,5-dialkylhydantoins; N-brominated isocyanurates; N-brominated melamines and N-brominated glycolurils.
• N,N-dibromo-5,5-dialkylhydantoins e.g., 5,5-dimethyl-N,N-dibromohydantoin and N-brominated isocyanurates.
• an effective method for the bleaching of textile goods at low temperatures in the range of from 60° to 140°F 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-ehloro compound selected from the group consisting of: i) N-chlorinated-5, 5-dialkyl-hydantoins; ii) N-chlorinated isocyanurates; iii) N-chlorinated melamines; and iv) N-chlorinated glycolurils; and (b) from 75 to 25 parts of an alkali metal or alkaline earth metal bromide salt.
• the alkyl group contains up to 8 carbons.
• the organo-N-chlorinated compound component interacts with the bromide component to form positive positive bromine (Br + ) ions.
• the positive positive bromine ions act as oxidizing agents for the organic, or inorganic, stain, or other discolorations to be removed from the textile.
• the positive bromine ions are themselves chemically reduced to the bromide ions.
• Such bromide ions are thus susceptible again to oxidation to new positive bromine ions, as a result of interaction with additional molecules of the organo-Nchlorinated compound. The entire process thus repeatedly occurs until the organie-N-chloro component is itself completely consumed.
• the amount of the weight ratio of these components may be varied considerably beyond the suggested amounts so long as a sufficient amount of positive bromine ions are formed during the bleaching operation. It will readily be appreciated by those skilled in the art, that significantly less than an equivalent amount of bromide can be used.
• bleaching effectiveness of DBDMH and DCDMH are equivalent. As explained above, the equivalency is due to regeneration of Br + at the expense of C1 + .
• an improved bleaching composition which, in its preferred form, consists essentially of the combination of a 5,5-di-alkylsubstituted-N,Ndichlorohydantoin component together with sodium bromide.
• the present invention is based in part on the unexpected discovery that such combination of the organo-N-chlorinated compound and a source of positive bromine ion, (e.g., inorganic bromide - such as chlorinated hydantoin compound with sodium bromide) leads to an unexpected degree of 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 effective bleaching agents.
• sources of positive bromine ions including inorganic materials as well as fully brominated organo-Nbromo compounds are surprisingly effective for bleaching textile goods at temperatures below about 140° F and especially at 120°F or less. It has also been found according to the present invention that organo-Nbrominated-N-chlorinated compounds are almost equally effective at such low temperature but are less expensive.
• a method for the effective bleaching of textile goods at temperatures in the range of 60° to 140° which consists essentially in exposing the same to an aqueous solution, at said temperatures, containing an effective amount for bleaching of an organo-N-chloro-Nbromo compound selected from the group consisting of N-chlorinated-Nbrominated-5,5-dialkylhydantoins; N-chlorinated-N-brominated isocyanurates; N-chlorinated-N-brominated melamines and N-chlorinated-Nbrominated glycolurils, said compound being capable of generating positive bromine (Br + ) ions during the bleaching of said textile goods.
• an organo-N-chloro-Nbromo compound selected from the group consisting of N-chlorinated-Nbrominated-5,5-dialkylhydantoins; N-chlorinated-N-brominated isocyanurates; N-chlorinated-N-
• Particularly well suited compounds include the N-chloro-N-bromo-5,5dialkylhydantoins (e.g., 5,5-dimethyl-N,N-dibromohydantoin) and Nbromo-N-chloro-isocyanurates.
• N,N-dichloro-5,5-dialkylhydantoin compounds are themselves relatively ineffective as bleaching agents particularly at the lower temperatures of, for instance, 120° F (approx. 50° C) desired for today's bleaching operations, and not even very effective as a bleaching agent at higher temperature of, for instance, 160°F, and above (particularly at reasonable concentration levels).
• This is in marked contrast to the behavior of N,N-dibromo-5,5-dialkyl 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-5,5dialkyl 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 effective and economical means for achieving effective bleaching with positive bromine ions of textile materials at temperatures significantly lower than conventionally employed heretofore. It is also not to have been expected that at the desired lower temperatures the N,N-dichloro-5,5-dialkyl 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-5,5 dialkylhydantoin material.
• a primary source of positive bromine ions for use according to the present invention is a material characterized as an organo-N-bromo compound selected from the group consisting of N-brominated-5,5-d ⁇ alkylhydantoins; N-brominated isocyanurates; N-brominated melamines and N-brominated glycolurils.
• Such compounds may be fully or partially brominated and include such materials as 1,3-dibromo- and 1,3bromochloro-5,5-dimethylhydantoin; 1,3-dibromo- and l,3-bromochloro-5methyl-5-ethylhydantoin; 1,3-dibromo and l,3-bromochloro-5,5-d ⁇ so5utylhydantoin; N-monobromo-N,N-monobromo-N-monochlorocyanuric acid; N,N-dibromocyanuric acid; tribromomelamine; bromoehloromelamine and the like including the alkali metal salts thereof.
• the source of positive bromine ion may be derived in alternative ways including: a) an organo-N-bromo-N-chloro compound; or b) an organo-N-chloro compound containing no N-bromo substituent in combination with a fully brominated organo-N-bromo compound or an alkali metal or alkaline earth metal bromide salt which under bleaching conditions reacts to form a compound which generates positive bromine ions.
• organo-N-bromo-N-chloro compounds may be employed or optionally enjoy a cost savings using organo-N-bromo-N-chloro compounds; a combination of fully brominated and fully chlorinated organo-N-halo compounds or a mixture of fully chlorinated organo-N-chloro compounds with an alkali metal or alkaline earth metal salt.
• the organo-N-chloro compound may be fully or partially chlorinated and can be selected from a number of sources. Especially preferred are the N-chlorinated-5,5-dialkylhydantoins 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 dichloroisoeyanurate (NaDCC), N,N-d ⁇ chloro-5,5dimethylhydantoin (DCDMH), N-bromo-N-chloro-5,5-dimethylhydantoin (BCDMH) potassium dichloroisoeyanurate (KDCC), trichloroisocyanurate (TCC), and bromo-chloro-isocyanurate (BCCC).
• NaDCC sodium dichloroisoeyanurate
• DCDMH N,N-d ⁇ chloro-5,5dimethylhydantoin
• BCDMH N-bromo-N-chloro-5,5-dimethylhydantoin
• KDCC potassium dichloroisoeyanurate
• TCC trichloroisocyanurate
• BCCC bromo-chloro-isocyanurate
• ths invention is not limited to the use of N,Ndichloro-5,5-dimethylhydantoin.
• 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 would 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 positive bromine ions is an inorganic bromide salt, preferably sodium bromide due to its relatively low cost and availability.
• other potential sources of the positive bromine ion besides sodium bromide may also be employed, for instance, other alkali or alkaline earth metal bromide salts (e.g., KBr, MgBr2 CaBr 2 , etc).
• N,N-dibromo-5,5-dimethylhydantoin (DBDMH) in combination with N,N-dichloro-5,5-dimethyIhydantoin (DCDMH) may be employed, the DBDMH serving as a source of positive bromine ion when the composition is placed in an aqueous environment for the bleaching of textile materials.
• DBDMH N,N-dibromo-5,5-dimethylhydantoin
• DCDMH N,N-dichloro-5,5-dimethyIhydantoin
• DCDMH N,N-dimethyIhydantoin
• One may also employ other organo-N-brominated materials such as N-brominated isocyanurates, melamines or glycourils.
• an alkali metal hypohalite e.g. sodium hypochlorite
• a source of bromide e.g. an alkali metal bromide or an organo-
• the term "available halogen" as used herein, 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.
• 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.
• elemental chlorine is dissolved in water, hydrochloric acid and hypochlorous 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 Nhalogenated compounds is in the positive (equivalent to hypochlorous acid) state, and is therefore totally useful for bleaching. It is conventional in the industry to multiply the active (C1 + ) components by two and express it as available chlorine.
• the amount of material capable of generating positive bromine ions should be present in the aqueous laundry bath, in an amount sufficient to effectively bleach the textile goods.
• the amount of material used may vary significantly depending on the nature of the textile goods, water temperature, pH and the like for effective bleaching.
• the use of a sufficient amount of material to provide positive Br + ions equivalent to 75 ppm or greater of available chlorine should be effective for bleaching.
• the use of from about 150 to 300 mg of BCDMH per liter of aqueous solution provides an effective amount for bleaching at the low temperatures used according to the present invention.
• a concentration of from about 250 to about 300 mg of DBDMH is seen as effective.
• the practice and effectiveness of the present invention is illustrated by the following tests wherein unbleached cotton muslin was washed with a control detergent, AATCC Standard 124.
• the machine used was a Terg-O-Tometer (60 cpm) with distilled water and a washing time of 10 minutes, followed by a 5 minutes rinse cycle and two cold water hand rinses.
• To measure the bleaching effectiveness 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 120oF (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 1 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 hydantoin, 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.
• the combination with NaBr greatly increases the bleaching effect of DCDMH, however, the bleaching effectiveness of all materials is depressed under these alkaline conditions.
• a bleach composition formed from a mixture of sodium hypochlorite and sodium bromide is effective at lower concentrations than used hereto for for NaOCl at high temperatures.
• a hunter Model D-40 was used to measure fabric reflectance. The difference between fabric reflectance before and after bleaching, i.e., reflectance increase, was measured. A green filter was used to exclude fluorescence. Two measurements at right angles were made on the specimens before and during washing. Hard water was used in the washing tests. It was prepared by adding enough CaCl 2 .2H 2 O and MgC1 2 .6H 2 O to give 150 ppm hardness as CaCO 3 with a Ca/Mg ratio of 3:1.
• the specimens were washed for ten minutes at 100 r.p.m.
• the swatches were squeezed by hand, and rinsed twice for two minutes in the Terg-O-Tometer with the hard water; squeezed dry by hand, and dried at 120°F in a forced air oven.
• BCDMH bleaching effectiveness of BCDMH was compared with sodium hypochlorite and sodium dichloroisoeyanurate (NaDCC) at pH 11.
• BCDMH and NaDCC were compared at concentrations of 150, 300 and 600 mg per liter.
• concentrations of sodium hypochlorite (5.25% NaOCl) used were 1665, 3330 and 6660 mg per liter, or concentrations of available chlorine equivalent to those contributed by 150, 300 and 600 mg/1 of NaDCC.
• BCDMH is a remarkably more effective bleach than either NaDCC or sodium hypochlorite at a temperature of 60°F over a concentration range of 150 to 600 mg/liter. The increased effectiveness is observable throughout the temperature range of 60°F to 160°F.
• BCDMH provides a unique bleach which is highly efficient at both high and low temperatures, offering therefore a significant potential means of conserving energy.
• MBDMH hydrolyzes at higher temperatures, while the MCDMH hydrolyzes to a lesser degree.
• the It values also show that at 160°F the bleaching properties of MBDMH are equivalent to those of dibromodimethylhydantoin (at equivalent bromine concentration) further supporting the conclusion that MBDMH is hydrolyzed to the same extent at 160° F.
• the dotted lines in Figure 4 show the R values for BCDMH which contains both chlorine and bromine. The combined halogens lower the activation temperature, compared with the MBDMH and MCDMH above. At 100 and 150 ppm of available chlorine equivalent the bleaching properties of DBDMH and BCDMH are equivalent.
• BCDMH is six times more effective than sodium hypochlorite and sodium dichloroisoeyanurate at 60°F, and at 160°F, BCDMH is more than four times as effective as these two bleaching agents under the high pH conditions used in industrial and institutional laundries. Under milder conditions at pH 7, BCDMH is twice as effective as sodium dichloroisoeyanurate.
• the outstanding bleaching power of BCDMH at both high and low temperatures is due to its low temperature of activation, the greater bleaching properties of bromine, and a complete and controlled release of the active chlorine and bromine.
• the invention is not limited to the use of approximately 50:50 weight mixtures of the organo-N-chloro or alkali metal hypochlorite and bromide components in the composition. Considering, for example, the N,N-dichloro dimethylhydantoin and sodium bromide combination, weight ratios in the range of at least 25:75 up to 75:25, preferably 40:60 up to 60:40 may be employed.
• organo-N-chloro compounds and bromide salts 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. Again where cost considerations permit, the use of solely an organo-N-brominated compound is very effective at low temperatures.

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• 1980
  • 1980-02-11 WO PCT/US1980/000133 patent/WO1981002313A1/en not_active Ceased
  • 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
  • 1980-11-21 WO PCT/US1980/001563 patent/WO1981002314A1/en not_active Ceased

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