CA1205712A - Silicate-free bleaching and laundering composition - Google Patents

Abstract

Abstract of the Disclosure An improved granular bleaching detergent composition is provided comprising (a) a bleaching agent comprising a peroxygen compound in combination with an activator therefor; and (b) at least one surface active agent selected from the group consisting of anionic, cationic, nonionic, ampholytic and zwitterionic detergents; said bleaching detergent composition being substantially free of silicate compounds.

Description

B~C~(,ROUND OF T~IE INVENTION

The present in~ention relates5 :ln generalg to bleachlng detergent composltions conta,~ning as a ble~chlng a,gent a per oxygen compolmd in combina.tion with an o.r.~anic activator therefGr~ ~nd.the appllcation of such compo~sitions to launder-ing operations, More partlcularly~ the presen-t invention rel~tes to granulær bleachlng detergent composltions which pro~ide enh~nced bleaching perform~,nce concomitant with a significant ~mprovement in the stab~lity of'-~he peroxyacid bleachlng species in the wasll solu-tion~
Bleachitlg compositiorls which release active oxy~en in the wash solution are extensively described in the prior art and common~y used ln laundering operations. In general~ such bleaching compositions contaln peroxygen compounds, such as~
perborates, percarbona-tes3 perpho~pha-tes and the like which promote the bleaching ac~ivity by forming hydrogen peroxide in aqueous solutionv A ma~or drawback attendant to the use o~ such peroxygen compounds is th~* they are ilOt opt~mally effective at the relatively low washi.n~ temperatures employe~
in most household wash~ng machlnes in the Unlted States, i.e., temperatures in the range of 80 to 130Fo By way of comparl-~on, European wash temperatures are generally substanti~lly higher extending over a range3 typlcaIlD, ~rom 90 to 200F.
However, even in Europe and those other countr~es which gen erally presently employ near boilin~ washin~ temperatures, there ls a trend towards ~ower temperature :Launderin~
In an e~fort to enhance the bleaching activity o~ peroxygen blea.cheF" the ~rior art ha~ emplo,~ed mntcrlals called activators in combination with the peroxygen compoundsO It is eenerall~

~2--;i'7~

believec] that the interaction of the peroxygen compound and t~e activator results in the format:ion of a peroxyac:id which is a more active bleaching species than hydrogen peroxide at lower temperatures. Nurnerous compounds have been proposed in the art as activators Eor peroxygen bleaches among which are included carboxylic acid anhydrides such as those disclosed in U.S. Patent ~los. 3,29~,775; 3,33~,~39, and 3,532,634; carboxylic esters such as those disclosed in U.S. Patent No. 2,995,905; N-acyl compounds such as those described in U.S. Patent Nos. 3,912,648 and 3,919,102;
cyanoamines such as described in U.S. Patent No. 4,199,466; and acyl sulfoamides such as disclosed in U.S. Patent ~o. 3,245,'313.
The formation and stability oE the peroxyacid bleaching species in bleach systems containing a peroxygen compound and an organic activator has been recognized as a problem in the prior art. U.S. Patent No.
4,255,452 to Leigh, for example, specifically addresses itself to the problem of avoiding the reaction of peroxyacid with peroxygen compound to form what the patent characterizes as "useless products, viz. the corres-ponding carboxylic acid, molecular oxygen and water". The patent states that such side-reaction is "doubly deleterious since peracid and percompound . . . are destroyed simultaneously." The patentee thereafter describes certain polyphosphonic acid compounds as chelating agents which are said to inhibit the above-described peroxyacid-consuming side reaction and provide an improved bleaching effect. In contrast with the use of these chelating agents, the patentee states that other more commonly known chelating agents, such as, ethy].ene diamine tetraacetic acid (EDTA) and nitrilotriacetic acid (~TA) are substantially ineffective and do not provide improved bleaching effects. Accordingly, a disadvantage of the bleaching compositiorts of the Leigh patent is that they necessarily preclude the use of convèntional sequestrants, many of which are less expensive and more readily available than the disclosed polyphosphonic acid compounds.

The inEluence of silicates on the decompositlon of peroxyacid in the wash and/or bleaching solution has heretofore gone unrecognized in the art. U.S. Patent Nos. 3,860,391 and 4,292,575 disc:Lose that silicates are conventionally employed as additives to peroxide containing bleaching so:l.utions for the purpose oE stabilizing peroxide compounds therein.
However, the patentees note the fact that the use of silicates in such bleaching solutions may create other problems in the b.Leaching operations, such as, the formation o:E silicate precipitates which deposit on the bleached goods. Consequently, the patents are directed to processes for bleaching cellulose fiber with silicate-free bleaching so:Lutions in which peroxide stability is enhanced with compounds other than silicates.
European Patent Publication No. 0,028,~32, published ~lay 13, 1981, describes on page 7 thereof certain polyphosphonate compounds which l'have been found to be unique:Ly effective in stabilizing organic peroxyacids agai.nst the generally deleterious effect of water-insoluble silicates, especially those belonging to the zeolite and kaolin classes". ~te nature of such "deleterious effect" is not specified. A preferred embodiment of the invention is said to be a granular detergent composition comprising the defined polyphosphonate compound in combination with a water-insoluble silicate and an "organic peroxyacid bleach percursor", more commonly ~L2~5~
,...

k7l0wn a.s an organlc activator Thusg the art has here-tofore failed to appreclate or suggest the lmproved bleaching per-formance which can be achieved with granula.r bleaching deter~
gent compositions containing a peroxygen compound and/or a peroxyaclcl compound when such compositions are characterized by -the absence of silicate compounds o~ the type convention~
ally used in detergent compositions.

SUMMARY OF THE INVENTION

The present invention provides a granular blea.ching deter~ent compositi.on comprising: (a) a blea.ching agent com-prising a peroxygen compound in combination with an activator there~or; and (b) at least one surface ~.ct~ve agent selected from the group o~ ~n:lonic, catlonic, nonionic, ampholytic and æwitterionlc detergents; said bleaching detergent compositlon being ~ubstantially free o~ silicate compounds.
In accordance with the process of the inventlon5 bleach~
~ng o~ stained and/or soiled materials is e~ected b~ contacting such materials with an aqueous solution of the a.bove-defined blcaching detergent composition.
The pre~ent invention is predicated on the dlscovery that the undesired loss of pero.xyacid in the aqueous wash solution by the reaction of perox~acid with a peroxygen compound (or more speci~ically, hydrogen percxide formed from such peroxy-gen compound) to ~orm molecular oxygen is signi~`icantly mini-mized in bleaching systems whlch are substantially ~ree of silicate compounds Although the applicants do not wish to be bound to any particular theory of operatlon~ it is believed that the presence o~ sil.~cates in peroxygen compound/activator ~2~S71~

bleach systems ca-talyzes the aforementioned reaction of peroxy-acid with hydrogen peroxide which results in the loss of active oxy~en f'rom the wash soluti.on which would otherwise be avall-able for bleachingc It. has been recognized in the art that metal ions~ such as, for example, ions o~ :lron and copper serve to catalyze the decomposition of hydrogen peroxide and ~lso the peroxyacid react.lon with hydrogen peroxideD
Howe~er, with regard to such metal lon catalysis~ the a.ppli-cants have surpr~singly di.s^overed that conventional sequest~-rants, such a.s~ EDTA or NTA, which the prior art has deemed to be ine~fective ~or inhibiting the a.forementioned peroxyacid~
consuming reaction (see~ for example, the statement in column 4 of UoS~ Pa.tent 4,225~452) ca.n be incorporated into the composi~
tions oP the present invention to stabili~e the peroxyacid in solutionO
The term "silicate compounds" as used throughout the specification and claims is intended to encompass water-soluble as well as water-insoluble compounds containing SiO2. Sodium silicate is illustrative of a water-soluble silica.te compound which is commonly present in conventional blea.ching detergent compositions but is substantially eliminated in the composi-tion~ of the present invention~ alumino-silicate materials ~uch as clays and æeolites are illust.rative of the water- I
insoluble compounds which are -to be substantially e~i~inated in the compositions described herein. Water~soluble silicate compounds are generally considered more detrimental to peroxy-acid stabili.ty tha.n water insoluble materia.ls such as alumino-silicates~ the former being more act:lve cata.lysts in -the w~sh ~olution for the a:bove-described peroxyacid reaction with hydro-~en peroxi~e.

~2/~5~1~

~ 3 T N

The b:Leaching detergent compositions of the invention are substantially ~ree o~ silicate compounds and are compriscd o~ two essential components: (a) a bleaching agent; and (b~ a detergent sur~ace acti~re agent~ !
The bleaching agenl; use~ul in such compositlons com~
prises a peroxygen compound in combination with an organic ac~ivator therefor.
The peroxygen compounds usef'ul in the present composlt:Lons lnclude compourlds that relea~e hydrogen peroxide in aqueous media, such as~ alkali metal perborates~ e.g.~ sodium perborate and potassium perborate~ alkali metal perphosphates and alkali metal percarbonates. The alkali metal perborates are usually prererred because of thelr commercial availability and relatively low cost. Con~entional activators such as those disclosed3 ~or use in conjunction w~th the a~orement~oned peroxygen compounds, such d~sclosure being ~ncorporate~ herein by re~erence. The polyacylated amines are generally of special interest, tetra-acetyl ethylene d~amine (TAED) in particular being a highly pre~erred activator. The molar ratio o~ peroxygen compound to activator can vary w~dely depending upon the particular cholce o~ peroxygen compound and acti~rator. Howeverg molar ratio~ o~ ~rom about 0.5:1 to about 25:1 are generally suit-able ~or pro~idlng satisfactory ~leaching performance.
The blea~hing agent may optionally also contaln a peroxy-aci(3 compound in combination wlth the peroxygen compound and activator. Use~ul peroxyacld compounds include the water-soluble peroxyaclds and their water-soluble salts. The peroxyacids can be characterized by the Eollowing general formula:

~100 - C - R - Z

wherein ~ is an alkyl or a:Lkylene group containing from 1 to about 20 carbon atoms, or a phenylene group, and Z is one or more groups selected from among hydrogen, ha:Logen, alkyl, sryl and anionic groups.
The organic peroxyacids and the salts thereof can contain from about 1 to about 4, preferably 1 or 2, peroxy groups and can be aliphatic or aromatic. The preferred aliphatic peroxyacids include diperoxya~elaic acid, diperoxydodecanedioic acid and monoperoxysuccinic acid. Among the aromatic peroxyacid compounds useful herein, monoperoxyphthalic acid (MPPA), particularly the magnesium sa:Lt thereof, and diperoxyterephthalic acid are especially preferred. A detailed description oE the production of MPPA and its magnesium salt is set Eorth on pages 7-10, inclusive, of European Patent Publication 0,027,693, pu~lished April 29, 1981.
In a preferred embodiment of the invention, the bleaching compositions described herein additionally contain a sequestering agent to enhance the stability of the peroxyacid bleaching compound in solution by inhibiting its reaction with hydrogen peroxide in the presence of metal ions. The term "sequestering agent" as used herein refers to organic compounds which are ab:Le to form a comp-lex with Gu ions, such that the stability constant (pK) of the complexation is equal to or greater than 6, at 25C, in ~s~

water, at an lonic strength of 0~1 mole/liter, pK being conventlonally defined by the formula: pK = -log K where K represents the equilLbr1l~ collstant. Thus, for exampleg the pK values f'or complexatlon o~ copper ion w1-th NTA and EDTA at the stated conditions are 12~7 and 18,8, respectively, The sequesterlng agen-ts employed herein thus exclude inor~anic compounds ordinarily used in detergent formulations as builder ~alts~ Accordingly, suitable sequestertng agents include the sodl~m salt,s o~ nitrilotriacet:Lc acid ~NTA); e-thylene diamine te-traacetic acid (EDTA), dlethylene triamine pentaacetic acid (DETPA)~ diethylene triamine pentame-thylene phosphonic acid (DT.PMP); and e-thylene diamine tetrame-thylene phosphonic acid (~DITEMPA), ~DTA is especially pr~ferrecl for use ln the pre-sent compositions.

The composlLions of the present invention contain one or more surface active agents selected from the group of anionic, non:ionic, cationic, ampho:Lytic and zwitterionic detergents.
Among the anionic surEace active agents useful in the present invention are those surface active compo~mds which contain an organic hydrophobic group containing from about 8 to 26 carbon atoms and preferably Erom about lO to 18 carbon atoms in their molecu:Lar structure and at least one water-solubilizing group se:Lected from the group of sulfonate, sulfate, carboxylate, phosphonate and phosphate so as to form a water-soluble detergent.
Examples of suitable anionic detergents include soaps~ such as, the water-soluble salts (e.g., the sodium, potassium, ammonium and alkanolammonium salts) of higher fatter acids or resin salts containing from about 8 to 20 carbon atoms and preferably lO to 18 carbon atoms.
Suitable fatty acids can be obtained from oils and waxes of animal or vegetable origin, for example, tallow, grease, coconut oil and mixtures thereof. Particularly useful are the sodium and potassium salts of the fatty acid mixtures derived from coconut oil and tallow, for example, sodium coconut soap and potassium tallow soap.
The anionic class of detergents also includes the water-soluble sulfated and suLfonated detergents having an alkyl radical containing from about 8 to 26, and preferably from about 12 to 22 carbon atoms. ~The term "alkyl" includes the alkyl portion of the higher acyl radicals).
Examples of the sulfonated anionic detergents are the higher alkyl mono-nuclear aro~atic sulfonates such as the higher alkyl benzene slllfonates containing from about 10 to 16 carbon atoms in the h:Lgher alkyl group :Ln a straight or branched chain, such as, for example, the sodium, potassium and ammonium salts of higher alkyl beni~ene sulfonates, higher alkyl toluene su:Lfonates and higher alkyl phenol suLfonates.

~J

Other sultable anionic detergents are the olefi.n sul.fonates including long~ chai.n al~ene sulfonates, long cha:Ln hydroxyalkane sul.f`orlates or m.lxtu:res o~` alkene sul~
fonates and hydroxya.lkane sulfona-tes rrhe olefin sulfonate detergents may be prepared :in a conventi.onal manner by the reaction of S03 wlth long chain olef:Lns containing from about ~ to 25, and preferably from about 12 to ~1 ca.rbon atoms, such olefins having the formula RCH=CHRl wherein X
is a higher alk~l group o~ ~rom abou-t 6 tv 23 car~ons and Rl is an alkyl ~roup containing from a:~out 1 to 17 carbon atoms, or hydrogen to form a mix-ture of sultones ænd alkene sulfonic acids which is then treated to convert the sultones to sulfonates. Other e.xamples of sulfate o~; sulfona-te deter-~ents are para.rfin sulfonates containing from about 10 to 20 carbon atoms, and preferably from abou-t 15 to 20 carbon atoms. The primary paraffin sulfonates are made by reacting long chain alpha olefins and bisul~ites. Par-~ffin sul~onates having the sulfonate ~roup distributed along the paraffin chain are shown in U.S. Mos~ 23503g380;

2,507,088; 3,260j741; 33372,188 and German Patent No.
7~5,o96. Other useful sulfate and sulfonate detergents include sodium and potassium sulfates o~ higher alcohols containing from about 8 to 18 car~on atoms, such as, for example, sodium lauryl sulfate and sodium tallow alcohol sulfate, sodlum and ~otæsslum salts of alpha-sulfofatt~
acid esters containing about 10 to 20 carbon ator.ls in the acyl ~roup, for example, methyl alpha-sulfomyristate and methyl alpha~
sul-fotallowate, ammonlum sulfates of mono- or di~ ~lycerldes of 7:~

higher (ClO ~ ~L8) fatty ac:ids, for example, stearic monoglyceride mono-sulfate; sodi~lm and alkylol a~inonium salts of alkyl polyethenoxy ether slllFates produced by condensing L to 5 mo:Les of ethy:Lene oxide with 1 moLe oE h:igher (C~ - CL~) alcohol; sod:ium higher alkyl (C10 - C18) glyceryl ether sulEoDates; and sodium or potassium alkyl phenol poly-ethelloxy ether sulfates with about 1 to 6 oxyethylene groups per mo:Lecule and in which the alkyl radicals contain about 3 to L2 atoms.
The most highly preferred water-soluble anionic detergent com-:L0 pounds are the ammonium and substituted ar~.onium (such as mono, di and tri- ;
ethanolamine), alkali meta:l (such as sodium and po-tassium) and alkaline earth metal (such as, calcium and magnesium) salts of the higher alkyl benzene sulfonates7 olefin sulfonates and higher alkyl sulfates. Among the above-listed anionics, the most preEerred are the sodium linear alkyl benzene sulfonates (LABS).
The nonionic synthetic organic detergents are characterized by the presence of an organic hydrophobic group and an organic hydrophilic group and are typically produced by the condensation of an organic alphatic or alkyl aromatic hydrophobic compound with ethylene oxide (hydrophilic in nature). Practically any hydrophobic compound having a carboxy, hydroxy, amido or amino group with a free hydrogen attached to the nitrogen can be condensed with ethylene oxide or with the polyhydration product thereof, polyethylene glycol, to form a nonionic detergent. The length of the hydrophilic or polyoxyethylene chain can be readily adjusted to achieve the desired balance between the hydrophobic and hydrophilic groups.
The nonionic detergents include the po]yethylene oxide condensate of 1 mole of alkyl phenol containing from about 6 to 12 carbon atoms in a straight or branched chain configuration with about 5 to 30 moles of ethylene oxide. Examples of the aEorementioned condensates include nonyl phenol condensed with ~ moLes o~ ethy:lene oxide; dodecyl phenol condensed wlth :L5 moLes of ethylene oxide; and dinonyl phenol condensed ~:Lth 15 moles i7~

of ethylene o~ide. Condensation produc~s of the corresponding alkyl thiophenols with 5 to 30 moles of ethylene oxide are also suitable.
0f the above-described types oE nonionic surfactants, those of the ethoxyLated a'Lcohol type are preferred. Particularly preferred nonionic surfactants include the condensation product of coconut fatty alcohol with about 6 moles of ethylene oxide per mole of coconut fatty alcohol, the condensation product of tallow fatty alcohol with about 11 moles of ethylene oxide per mole of tallow fatty alcohol, the condensation product of a secondary fatty alcohol containing about 11-15 carbon atoms with about 9 moles of ethylene oxide per mole of fatty alcohol and condens-ation products of more or less branched primary alcohols, whose branching is predominantly 2-methyl, with from about 4 to 12 moles of ethylene oxide.
Zwitterionic detergents such as the betaines and sulfobetaines having the following Eormula are also useful:

R3 / ¦ 0 wherein R is an alkyl group containing Erom about 8 to 18 carbon atoms, R2 and R3 are each an alkylene or hydroxyalkylene group containing about 1 to 4 carbon atoms, R~ ls an alkylene or hydroxyalkylene group containing 1 to 4 carbon atoms, and X is C or S:0. The alkyl group can contain one or more intermediate linkages such as amido, ether, or polyether linkages or nonfunctional substituents such as hydroxyl or halogen which do not substantially affect the hydrophobic character of the group. When X is G, the detergent is called a betaine; and when X is S:0, the detergent is called a sulfobetaine or sultaine.
Cationic surface active agents ma-,y also be employed. They comprlse surface active detergent compo~mds which contain an organic p~

hydrophobic group ~hich forms part of a cation when the compound is dissolved in water, and an anionic group. Typical cationic surface active agents are amine and quaternary ammonium compotmds.
Examples oE suit:abLe synthetic cation:ic detergents include:
normal pr:imary amines of the formtlla P~IH2 wherein R is an alkyl group containing from about :l2 to 15 atoms; dlamines having the formula ~NHC2H4N~I2 wherein ~ is an alkyl group containing from about 12 to 22 carbon atoms, such as N-2-aminoethyl-stearyl amine cmd N-2-aminoetllyl myristyl amine; amide-linked amines such as those having the formula RlCO~IC2H~NH2 wherein Rl is an alkyl group containing about ~ to 20 carbon atoms, such as N-2-amino ethylstearyl amide and N-amino ethylmyristyl ami&e;
quaternary ammonium compounds wherein typically one of the groups linked to the nitrogen atom is an alkyl group containing about 8 to 22 carbon atoms and three of the groups linked to the nitrogen atom are alkyl groups which contain l to 3 carbon atoms, including a:lkyl groups bearing inert substi-tuents, suc'n as phenyl groups, and there is present an anion such as halo-gen, acetate, methosulfate, etc. The alkyl group may contain intermediate linkages such as amide which do not substantially affect the hydrophobic character of the group, for e~a~p]e, stearyl amido propyl quaternary ammnoium chloride. Typical quaternary ammonium detergents are ethyl-dimethyl-steary:L-ammonium chloride, benzyl-dimethyl-stearyl am~.onium chloride, trimethyl-stearyl ammonium chloride, trimethyl-cetyl ammonium bromide, dimethyl-ethyl-lauryl an~onium chloride, dimethyl-propyl-myristyl ammonium chloride, and the corresponding methosulfates and acetates.
Ampholytic detergents are also suitable for the invention.
pholytic detergents are well kno~rn in the ar-t and many operable detergents of this class are disclosed 'Dy A. M. Schwartz, J. W. Perry and J. Birch in "Surface Active Agents and Detergents", Interscience Publishers, New York, 1958, vol. 2. Examples of suitable amphoteric detergents include:
alkyl betaiminodipropionates, RN(C2H4COOM)2; alkyl beta-amino propionates, !/,~ ' RN(H)C2~14COOM; and long chain imidazole derivatives having the general formula:

M Cll ll 1 2 R C / I\ C~2 2 2 01~ C~12COOM

wherein in each of the above formulae R is an acyclic hydrophobic group containing from about 8 to 18 carbon atoms and M is a cation to neutralize the charge of the anion. SpeciEic operable amphoteric detergents include the disodium salt oE undecylcycloimidinium-ethoxyethionic acid-2-ethionic acid, dodecyl beta alanine, and the inner salt of 2-trimethylamino lauric acid.
The bleaching detergent compositions of the invention optionally contain a detergent builder of the type commonly used in detergent formulations. Useful builders include any of the conventional inorganic water-soluble builder salts, such as, for example, water, soluble salts of phosphates, pyrophosphates, orthophosphates, polyphosphates, carbonates and the like. Organic builders include water-soluble phosphonates, polyphosphonates, polyhydroxysulfonates, polyacetates, carboxylates, polycarboxylates~ succinates and the like.
Specific examples of inorganic phosphate builders include sodium and potassium tripolyphosphates, pyrophosphates and hexametaphosphates.
The organic polyphosphonates specifically inc:Lude, for example, the sodium and potassium salts of ethane l-hydroxy-l, l~disphosphonic acid and the sodium and potassium salts of ethane-l, 1, 2-triphosphonic acid. Examples of these and other phosphorous builder compounds are disclosed :Ln U.S.
Patent Nos. 3,213,030; 3,~22,021; 3a~l22,137 ancl 3,~00,176. Pentasodium tr-lpo:lypllosphate and tetrasodlum pyrophosphate are especially preferred -- LS

7~

water-soluble inorganic builders.
Specific exai~ples of non-phosphorous inorganic builders include water-soluble inorganic carbonate and bicarbonate salts. The alkali metal, ~or example, sodium ancl potass-ium, carbonates and bicarbonates are particularLy useful herein.
Water-soluble organic builders are also useEuL. For example, the alkali metal, ammonium and substituted ammonium polyacetates, car-boxylates, polycarboxylates and polyhydroxysulfonates are useful builders for the compositions and processes of the invention. Specific examples of polyacetate and polycarboxylate builders inc]ude, sodium potassium li-thium, ammonium and substituted ammonium salts of ethylene diamine-tetracetic acid, nitrilotriacetic acid, benzene polycarboxylic (i.e. penta- and tetra- ) acids, carboxymethoxysuccinic acid and citric acid.
~le use of inert, water-soluble fil:Ler salts is desirable in the compositions of the invention. A preferred filler salt is an alkali metal sulfate, such as, potassium or sodium sulfate, the latter being especially preferred.
Various adjuvants may be included in the bleaching detergent compositions of the invention. For example, colorants, e.g., pigments and dyes, antiredeposition agents, such as, carboxymethylcellulose, optical brightene~s, such as, anionic, cationic and nonionic brighteners; foam stabilizers, such as, alkanolamides, proteolytic enzymes and the like are all well-known in the fabric washing art for use in detergent compositions.
A preferred compositior. in accordance with the invention typica:L:Ly comprises (a) from about 2 to 50%, by weigh-t, of a bleaching agent compris-ing a peroxygen compound in combination with an activator therefor; (b) from about 5 to 50%, by weigh-t, of a detergent surface active agent; (c) from about 1 to about 60% by weight, of a detergent builder salt; and (d) from about 0.1 to about 10%, by weight, of a sequestering agent. The balance of the compositLon will predominantly comprise water, fi:L:ler sa:Lts, 7:~

such as, sodium sulfate, and minor additives selected from among the various adjuvants described above.
The granular bleaching detergent compositioTIs oE the invention are prepared by admixing the bleaching agent and optional sequestering agent with the spray~dried detergent composition, the latter being formu-lated so as to avoid the use oE silicate compounds, such as, for example, sodium silicate, clays and/or zeolites. The presence of very minor amounts of silicate compounds in the final compositions, i.e., below about 0.1%, preferably below about 0.01%, and most preferably no greater than about 0.005%, by weight, such as may occur with the use of silicate-containing pigments or dyes is contemplated by the present invention.
The spray drying of a silicate-free detergent formulation may result in a relatively dusty granular product due to the absence of silicate as a binder for the spray dried beads. However, alternative organic binder materials may be employed, such as, for example, starch, carboxymethyl-cellulose and materials comparable thereto. The strength of the spray dried beads may also be enhanced by maximizing the solids content of the silicate-free slurry in the crutcher and/or by maintaining the inlet tempera-ture of the hot air stream in the spray tower as low as possible.`

The bleaching agent can be mixed either directly with the spray dried powder or the bleaching agent and optional sequestering agent can be separately or collectively coated with coating material to prevent premature activation of the bleaching agent. The coating process is conducted in accordance with procedures well known in the art. Suitable coating materials include compounds such as magnesium sulfate, polyvinyl alcohol, lauric acid and its salts and the like.
The bleaching detergent compositions of the invention are added to the wash solution in an amount sufficient to provide from about 3 to about 100 parts of active oxygen per milLion parts of solution, a concen-tration of from about 5 to about 40 ppm being generally preferred.

The term "granular" as used herein with regard to the above-described bleaching detergent compositions refers to particulate composl-tions producecl by spray-drying methods of manufacture as well as by methocls oE clry-b:Lendlng or agglomeration of the ind:ividual components.

! 1. 8 -EX~IPL~ l A preferred silicate-free bleaching detergent composition is comprised of the follo~ing:

C~mponent Welght Percent Sodium linear ClO - C.L3 6 alkyl benzene sulEonate Ethoxylated Cll - C18 primary alcohol (11 moles EO per mole alcohol) Soap (sodium salt of C12 ~ C22 4 carboxylic acid) Pentasodium tripolyphosphate (TPP) 32.0 TAED 2.3 Carboxymethyl cellulose 0.5 Sodiurn perborate tetrahydrate 13.2 Optical brighteners, pigment 0.4 and perfume Proteol.ytic en~ymes 0.5 Sodium sulfate and water balance The foregoing product is produced by spray drying an aqueous slurry containing 60%, by weight, oE a mixture contalning all of the above comporlents except the enzyme, perfume and sodium perborate. The resultant 5~-t;~

granular spray clried product has a particle size in the range of 14 mesh to 270 mesh, (U.S. Sieve Series). The spray dried product is then mixed in a rotary drum with the appropriate amounts oE sodium perborate of similar mesh siæe, enzyme and perfume to yield a particulate product of the fore-going composition having a moisture of approximately l8%, by weight.
The above-descr:ibed product is used to wash soi:Led fabrics by hand-washing as well as in a washing machine, and good laundering and b:leaching performance is obtained for both methods of laundering.
Other satisfactory products can be obtained by varying the con-centrations of the following principal components in the above described composition as follows:

Componentl~eight Percent Alkyl benzene sulfonate ~-12 Ethoxylated alcohol 1-6 Soap 1-10 Enzymes 0.1-l EDTA 0.1-2 TAED l-10 Sodium perborate 5-20 ~leaching tests are carried out as described bèlow comparing the bleaching performance of silicate-free bleaching detergent compositions in accordance with the invention and silicate-containing compositions, the latter compositions being comparable to the former in near:Ly all respects except for the presence of silicates. Specifically, the silicate-free compositions are characterized by the presence of sodium metaborate; the sLlicate-containing compositions contain sodium silicate. The compositions are ~ormulated by post-aclding to a spray-dried granular detergent compos-ition, granules of sodium perborate tetrahydrate and tetraacetyl ethylene diamine ~TAED) to form the bleaching detergent compositions shown in Table 1 below. The numbers indicated in the Table represenl, the percentage of each component, by weight, in the composition.

, ~

Table 1 Component omLlo___:Lon A B C D E F

Sodi~lm :linear CLo - CL3 8~ 8~ 8% 8~ 8% 8 alkyl benzene sulfonate Eth xy at Cll C18 primary alcohol (11 moles EO per mole alcoho:L) Soap (sodium salt of 3 3 3 3 3 3 C12 - C22 carboxylic acid) Sodium silicate (lNa20:2SiO~) - - - 4 4 4 -Sodium metaborate 5 5 5 - - -Pentasodium tripolyphosphate35 35 35 35 35 35 (TPP) Optical brightener (stilbene)0.2 0.2 0.2 0.2 0.2 0.2 Sodium perborate tetrahydrate6 6 6 6 6 6 EDTA

EDITEMPA( ) Sodium sulfate 2:L 20 20 21 20 20 Water - - - - - - balance - - - ~ - -__ ( )Sold as Dequest 2041 by Monsanto Company, St. Lou:Ls, Missouri '7~

rESr PKOCEDURE
BLeaching tesLs are carried out in an Al~iba apparatus at maximum temperatures of 60C and 90C, respectively, as hereinafter described.
600 Ml of tap water having a water hardness of about 320 ppm, as calcium carbonate, are introduced into each oE six buckets oE the Ahiba. Six cotton swatches (S cm x 12 cm) soi:Led with immedial black are introduced into each bucket, the initial reflectance oE each swatch being measured with a Gardner XL 20 reflectometer.
Six grams oE each of compositions A through F described in Table 1 are introduced separately into the six buckets oE the Ahiba, a different composition being introduced into each bucket. The bleaching detergent compositions are thoroughly mixed in each bucket with a blender-type apparatus and the wash cycle thereafter initiated. The bath temperature, initially at 30C, is allowed to rise about 1 Centigrade per minute until the maximum test temperature (60 or ~0C~ is reached, such maximum tempera-ture being then maintained for about 15 minutes. The buckets are then re-moved and each swatch washed twice with cold water and dried.
The final reflectance of the swatches are measured and the difference (~Rd~ between the Einal and initial reflectance values is determined. An average value of ~Rd for the six swatches in each bucket is then calculated. The results of the bleaching tests are set forth below in Table 2, the values of ~Rd being provided as an average value for the particular composition and test indicated.

------~

. r~
a ~ , ~ ~ __ ~.__ h ~ ~I~ OD
1 ~D

_____ ~_~

~6 ~ ~ ~~ .
~ a~
1 ___ , a ~ ~ '~ ~

E~ ~ ~ ~ .
___ ~ 2b, --7~

As indicated ln Tahle 2, the silicate-free compositions (A, B and C) provided an improved bleaching performance relative to the silicate-containing compositions at both -~est temperatures. The silicate-containing composition F WlliCh contained 1% EDITE~A provided an improved bleaching eEEect re:lative to composition D which contained no sequestrant, but only at the higher test temperature oE 90C. However, at both test temperatures, the silicate-free composition A containing no sequestrant provided the best bleaching effect oE all compositions tested.
EXA~lPLE 3 The active oxygen concentration in solution is determined as a function of time for wash solutions oontaining each of compositions A
through F described in Table 1. The test procedure is as follows:
One liter of tap water is in-troduced into a two liter beaker and then heated to a constant temperature oE 60C in a water bath. Ten grams of the particular composition being tested are added to the beaker (time = O) with thorough mixing to form a uniform wash solution. Af-ter given periods of time (5, 15, 30, 45 and 60 minutes), a 50 ml aliquot is withdrawn from the wash solution and the total active oxygen concentration is determined by the procedure set forth below.

Determination of Total Active 2 ~oncentration The aforementioned 50 ml aliquot is poured into a 300 ml erlenmeyer flask fitted with a ground stopper and containing 15 ml of a sulfuric/mo:Lyb-date mixture, the latter ~.ixture having been prepared in large-scale amounts by dissolving 0.18 grams of ammonium molybdate in 750 ml of deionized water and then adding thereto 320 ml of H2S04 (about 36N) with stirring.
The solution in the erlenmeyer is thoroughly mixed and 5 ml of a 10% Kl solution in deionized water is then added thereto. The erlenmeyer is sealed with a stopper, agitated and then allowed to stand in a dark place for seven minutes. The solution in the flask is then titrated with a solut:lon of O.lN sodLum thlosulEate :Ln deionlzed water. The volume oE

t;hiosulfate required, in ml, is equal to the total active oxygen concentra-tion, in ~lllimole/lit in the wash solution. The tests results for the six composit-ions tested are shown in Table 3 below.

., l 1--`
~,~
~ --- -- ~
~ ~ ~- ~ ~ oo u~ ~
~ ~ ~ ~ ~ o o o ~ o ~ - - ~
~ ~ ~ ~ `J oo ~ ~
~3 '~ ~ C9 ~ . . . . .
U~ ,~ GC`l ~ O O O

~ ~ __ ~ ~ ., H E~ r~ ~ ~1 t~C`l O
~ :~ ~e '-) '~- _ ~'1 O ~O
~ C~ ~ ~~ ~ ~ ~ C~i ~d ~ ;~
E~ ~~ ~
~ _~_ _. _.
~r~ ~
~ a)~ ~ o ~ oo ~
'~ ~ ~ ~ C`i ~
~a _._ __ _____ ___ _ _ _ ~ _ As shown in Table 3, the silicate-free compositions A, B and C
are s~lbstantially more stable and are characterized by a far slower loss of act:ive oxygen from solution than the corresponding silicate-containing compositions D, E and F, respectively. Among the silicate-containing compositions, the one containing 1~ EDITEMPA (F) provided the maximum stability, however, such composition was less stable than all of t'ne silicate-free compositions, including composition ~ which contained no sequestrant. Among the silicate-free compositions, the presence of a sequestrant in compositions B and C resulted in improved oxygen stability relative to composition A.

Claims (21)

WHAT IS CLAIMED IS:

1. A granular bleaching detergent composition comprising:
(a) a bleaching agent comprising a peroxygen compound in combination with an activator therefor; and (b) at least one surface active agent selected from the group consisting of anionic, cationic, non-ionic, ampholytic and zwitterionic detergents;
said bleaching detergent composition being sub-stantially free of silicate compounds.

2. A composition in accordance with claim 1 also containing a sequestering agent,

3. A composition in accordance with claim 2 wherein said sequestering agent comprises ethylene diamine tetra-acetic acid.

4. A composition in accordance with claim 1 wherein said bleaching agent comprises an alkali metal perborate in combination with tetraacetyl ethylene diamine.

5. A composition in accordance with claim 1 wherein said bleaching agent also contains a peroxyacid compound.

6. A composition in accordance with claim 1 also containing a detergent builder salt.

7. A composition in accordance with claim 1 wherein said surface active agent is an anionic detergent.

8. A composition in accordance with claim 7 wherein said anionic detergent is a linear alkyl benzene sulfonate.

9. A bleaching detergent composition comprising:
(a) from about 2 to about 50%, by weight, of a bleaching agent comprising a peroxygen compound in combination with an activator therefor;

(b) from about 5 to about 50%, by weight, of a detergent surface active agent selected from the group consist-ing of anionic, cationic, nonionic, ampholytic and zwitterionic detergents;
(c) from about, 1 to about 60%, by weight, of a detergent builder salt;
(d) from about 0.1 to about 10% by weight, of a sequest-ering agent; and (e) the balance comprising water and optionally filler salts.

10. A composition in accordance with clam 9 wherein said bleach-ing agent comprises an alkali metal perborate in combination with tetraacetyl ethylene diamine.

11. A composition in accordance with claim 9 also containing a sequestering agent,

12. A composition in accordance with claim 9 wherein said bleach-ing agent also contains a peroxyacid compound,

13. A process for bleaching which comprises contacting the stained and/or soiled material to be bleaching with all aqueous solution of a granular bleaching detergent composi-tion comprising:
(a) a bleaching agent comprising a peroxygen compound in combination with an activator therefor; and, (b) at least one surface active agent selected from the group consisting of anionic, cationic, nonionic, ampholytic and zwitterionic detergents; said bleach ing detergent composition being substantially free of silicate compounds.

14. The process of claim 13 wherein the bleaching agent comprises an alkali metal perborate in combination with tetraacetyl ethylene diamine.

15. The process of claim 13 wherein the bleaching agent also contains a peroxyacid compound.

16. The process of claim 13 wherein said surface active agent is an anionic detergent.

17. The process of claim 16 wherein said anionic detergent is a linear alkyl benzene sulfonate.

18. The process of claim 13 wherein said composition also contains a sequestering agent.

19. The process of claim 18 wherein said sequestering agent comprises ethylene diamine tetraacetic acid.

20. The process of claim 13 wherein aid composition also contains a detergent builder salt.

21. The process of claim 20 wherein said builder salt comprises pentasodium tripolyphosphate.