MIXED PEROXYACID BLEACHES HAVING IMPROVED BLEACHING POWER

Abstract: A dry laundry bleach composition comprising a mixture of peroxyacids provides enhanced bleaching of «real world» soils. The compositions of this invention comprise at least two beaches selected from different classes of peroxyacids. A preferred composition com­ prises perlauric acid, a hydrophobic bleach and diper­ oxydodecanedioic acid, a hydrotropic bleach.

Description: TECHNICAL FIELD This invention relates broadly to bleaching compositions. More particularly, this invention relates to bleaching compositions which derive their bleaching activity from a compound having an active oxygen content. Still more particularly, this invention relates to peroxyacid bleaching compositions. BACKGROUND ART Many compounds which have oxidative bleaching activity are well known in the art. Among these are the dipero..yacids, monoperoxyacids, perborates, hydrogen peroxide, sodium peroxide, organic peroxides, dichromates and certain chlorine-containing compounds such as sodium hypochlorite, sodium chlorite and chlorine dioxide. Such compounds are not always satisfactory for any given bleaching application, however. Some are frequently caracter- ized by insufficient or excessive bleaching action under certain conditions and they are frequently characterized by sufficient bleaching action for certain types of soils or stains. Peroxygen bleaching agents in general and peroxy-acid compounds in particular have long been recocfnized as effective bleaching agents for use ;iten the adverse color and fabric damage effects of harsh active halogen bleaching agents cannot be tolerated. See, for example, Canadian Pat. No. 635,620, issued January 30, 1962, to McCune. U.S. Pat. No. 3,414,593, issued December 3, 1968, to Robson, discloses alpha-sulfo peroxy fatty acid compounds as detergents and bleaching agents. Utilization of peroxyacid materials in commercial bleaching products, however, posed several problems. Liquid bleaching compositions containing peroxyacid materials as the active bleaching agent have the tendency to diminish in bleaching effectiveness over prolonged storage periods. Likewise, granular bleaching products containing peroxyacid compounds also tended to lose bleaching activity during storage, as well as pose a safety problem due to their exothermic decomposition properties. Dry peroxyacid compositions having improved exotherm control are discloses in U.S. Pat. No. 4,100,095, issued July 11, 1978, to J. P Hutchins Peroxyacid bleach compositions having increased solubility are also disclosed in U.S. Pat. No. 4,126,573, November 21, 1978, to Johnston. Johnston discovered that the solubility ef solid peroxyacids can be maintained by coating the peroxyacid particles with a surfactant compound and thereby maintain bleach effectiveness and fabric safety over an extended shelf life. Two early patents of interest are-: U.S Pat. Nos. 1,687,803 and 1,687,804, October 16, 1928, both to Stoddard et al., which relate to mixtures of bleaches for bleaching foodstuffs, soaps, wares and the like, particularly flour, cottonseed, seed meals, egg yolks oils and fats. These patents disclose that "peroxide or per acids of fatty acids, notably peroxids of higher or so-called soap forming fatty acids' act as "activators" for liquid or semi-liquid organic peroxides such as benzoyl peroxides. U.S. Pat. 1,687,804 discloses that inorganic and organic peroxide which has a high proportion of available oxygen but an ordinarily low efficacy as a bleach may be activated by the addition of 1-20% of an organic peroxide which is a more active bleach. The preferred activating organic peroxyacids are the fatty acids. In accordance with the present invention, it has been discovered that hydrophilic peroxyacid bleachers are effective bleaches for hydrophilic soils, but ineffective for bleaching hydrophobic soils, and vice versa, hydrophobic peroxyacid bleaches are more effective on hydrophobic soils. Yet other peroxyacid bleaches, hydrotropic, are somewhere in between the hydrophilic and hydrophobic bleaches in effectiveness on a particular type of soil. Bleaching ineffectiveness on a particular type of sail equates with poorer overall bleaching. This problem has not been recognized and addressed in modern peroxyacid bleach art. In typical laundry loads, fabr'ics contain both hydrophilic and hydrophobic stains. It is an object of the present invention to pro- vide mixtures of peroxyacids which have enhanced bleaching for "real world soils" laundering situations involving both hydrophilic and hydrophobic soils. Other objects of the present invention will be apparent in the light of the following disclosure. SU±4ARY OF THE INVENTION The present invention is directed to a laundry bleach comprising a mixture of peroxyacid bleaches selected from the group consisting of: a + b, a + c, b + c, a + (b + c), b -t- (a + c), c + (a + b) wherein "a" is a hydrophilic bleach, "b is a hydrotropic bleach, and "c" is a hydrophobic bleach, and wherein said peroxyacid bleaches in said mixture are in a ratio of a/b, a/c, b/c, a/(b+c), b/ta+c), or c/(a;b) of from 1:20 to 20:1 on a parts per million (ppm) available oxygen basis. The "hydrophilic" peroxyacid bleach of the present invention is a bleach whose parent carboxylic acid or salt thereof has no measurable critical micelle concentration (CMC) below 0.5 moles per liter and a high pressure liquid chromatographic retention time of less than 5 minutes under the conditions as described herein The "hydrotropic" bleach is one whose parent carboxylic acid has no measurable CMC below 0.5M and has a high pressure liquid chromatographic retention time of greater than 5-minutes, and the "hydrophobic" bleach is-one whose parent carboxylic acid has a measurable CMC of less than 0,5M, In accordance with the present invention, the CMC is measured in aqueous solu-tion at 200-500C. flTAItED DESCRIPTION OF THE IMENTION The two essential components of the present invention are at least two peroxyacid compounds selected from different classes of peroxyacids. These will be described in turn below. The peroxyacid bleach composition of the instant invention comprises a mixture of at least two peroxyacid compounds. The preferred peroxyacid compounds are "normally solid", i,e., dry or solid at room temperature. The peroxyacid compounds of the present invention, in general, are the inorganic peroxyacids, water-soluble salts thereof which yield a species containing a -0-0 moiety in aqueous solution, and adducts of the organic peroxyacids and urea. These materials have the general formulae: EMI5.1 and EMI5.2 wherein R1 and R2 are alkylene groups containing from 1 to about 20 carbon atoms or phenylene groups, and X and Y are hydrogen, halogen, alkyl, aryl or any group which provides an anionic moiety in aqueous solution. Such X and Y groups can include, for example, EMI5.3 or EMI5.4 wherein M is H or a water-soluble, - salt-forming cation It is preferred that the acids used in the present invention be dried to a moisture level lower than 1.0%, and preferably lower than 0.58. Herein, peroxyacids are classified as either (1) hydrophilic, (2) hydrophobic, or (3) hydrotropic. These classifications are based on their different levels of effectiveness on real world soils. Real world soils contain hydrophilic and/or hydrophobic components. A hydrophilic bleach- is most effective on a hydrophilic bleachable soil, such as tea (tannic acid based), fruit juices, and the like On the other hand, hydrophobic bleaches are most effective on hydrophobic bleachable soils, such as body soils (fatty acid/triglyceride based). Hydrotropic bleaches find utility on both types of soils, but are less'effective on hydro- philic soils than hydrophilic bleaches and less effective on hydrophobic soils than hydrophobic bleaches. Combinations of peroxyacids of the different classes result in better overall bleaching than is achieved with a single peroxyacid. The "hydrophilic bleach'1 is defined as a peroxyacid whose parent carboxylic acid (or the salts thereof): (1) has no measurable critical micelle concentration (Ci;C) below 0.5 moles per liter (b5/1) and (2) has a chromato- - graphic retention time of less than 5.0 minutes under the following high pressure liquid chromatographic (HPLC) conditions: Elution with 50:50 methanol/water solvent at the rate of 1.5 ml/min, through a DuPont Zorbax ODS -- column using a Waters R-401 Refractive Index Detector The "hydrophobic bleach" is defined as a peroxyacid whose parent carboxylic acid (or salts thereof) has a CMC of less than 0.5M. The hydrotropic bleach" is defined as a peroxyacid whose parent carboxylic acid (or salts thereof) has no measurable CMC below 0.5M and has a chromatographic retention time of greater than 5.0 minutes- under the HPLC- conditions described above. In accordance-with the present invention, the CMC is measured in aqueous. solution at 200-500C. Examples of the three classes of peroxyacid bleaches are as follows: Class a - Hydrophilic peroxyacid bleaches can include: 1. Alkyl alpha, omega - diperoxyacids HO3C-(CH2)n-CO3H n = 2-7, preferably 2-5; e.g., diperoxyadipic acid wherein n = 4. 2. Alkyl monoperoxydioic acids HO2C-(CH2)2-CO3H n = 2-7, preferably 2-5,- e.g., monoperoxyadipic acid wherein n = 4. 3. Alkyl monoperoxyacids. CH3-(CH2)nCO3H n = 0-5, preferably 0-3; e.g., peroxybutyric acid wherein n = 2 . s. Alpha-substituted monoperoxyacids EMI6.1 n = 0-5, preferably 0-3; X = CH2CO2H, -CH CO H, -SO3Na+, or -N+R+R1R2R3 and wherein L 3 1 2 3 any R = H or C1-C4; e.g., peroxypentanoic acid, 2-propyl monoperoxy succinic acid, diperoxysuccinic acid, alpha-sulfo peroxypentanoic acid and alpha-tetramethylammonium peroxypentanoic acid, respectively, wherein n = 2 5. Aromatic monoperoxyacids EMI7.1 X: substitution in 2-6 position n = 0-6, preferably 0-3; X = Hydrogen, Halogen, -(CH2) CO H or Aromatic; m = 0-7 and n+m = 0-7; e.g,, peroxybenzoic acid wherein n = 0 and X = Hydrogen. 6. Aromatic diperoxyacids EMI7.2 X and - (CH2)mCO3H; substitution in 2-6 position X = Hydrogen, Halogen or Aromatic n+m = 0-7, preferably 0-4; e.g., diperoxyphthalic acid wherein n = m = 0 and X = hydrogen. Class b - Hydrotropic peroxyacid-bleaches can include: 1. Alkyl alpha, omega - diperoxyacids HO3C-(CH2)n-CO3H n = 8-14, preferably 9-12; e.g., diperoxydodecanedioic acid wherein n = 10. 2. Alkyl monoperoxydioic acids HO2C-(CH2)n-CO3H n = 8-14, preferably 9-12; e.g., monoperoxydodecanedioic acid. 3. Aromatic diperoxyacids EMI8.1 X and (CH2)mCO3H: substitution in 2-6 position X = Hydrogen, Halogen or Aromatic n+m = 8-14, preferably 9-12; e.g., 1,2-(5-peroxypentanoic acid) benzene wherein m = n = 5 and X = Hydrogen. 4. Aromatic monope-roxydicic acids EMI8.2 X and -(CH2)mCO3H: substitution in 2-6 position X = Hydrogen, Halogen or Aromatic n+m = 8-14, preferably 10-14; e.g., 1- (5-pentanoic acid) -2- (5-peroxypentanoic acid)benzene wherein m = n = 5 and X = Hydrogen. Class c - Hydrophobic peroxyacid bleaches can include 1. Alkyl monoperoxyacids CH3(CH2)nCO3II n = 6-16, preferably 8-12; e.g., peroxylauric acid wherein n = 10. For example, C8-C16 monoperoxyacids belong to the hydrophobic class- since the CMC of each parent acid is less than 0.5M. (Table I-A) 2. Alpha-substituted alkyl monoperoxyacids CH3 (CH2)n-CH-CO3H x n = 6-16, preferably 8-16; X = -CH2CO24H -CH2CO3H, -SO3Na , or -N R1R2R3 and R = Hydrogen or C1-C-6; e.g., 2-lauryl monoperoxysuccinic acid wherein n= 11; 2-lauryl diperoxysuccinic acid wherein n = 11; alpha-sulfo hexadecanoic acid wherein n = 13; and alpha-tetramethylanunonium hexa decanoic acid wherein n = 13 and the R's = CH3. 3. Aromatic peroxyacids EMI9.1 substitution in 3-5 position m = 8-16, preferably 10-16; n = 0-16; e.g., 4-lauryl peroxybenzoic acid. TABLE I-A Typical Critical Micelle ConcentrationslFor The Sodium Salts of Carboxylic Acids Critical Micele Concentration (Molar) Sodium octanoate 3.5 x 10-1 Sodium decanoate 9.6 x 10-2 Sodium dodecanoate 2.3 x 10-2 Sodium tetradecanoate 6.9 x lO Sodium hexadecanoate3 2.1 x 10- Source: Critical Micelle Concentrations of Aqueous Surfactant Systems, NSRDS-NBS 36, 1971. 2250C, aqueous solution. 3500C, aqueous solution. In accordance with the present invention, among the hydrophobic-peroxyacid bleaches, it has been found that those which have a long hydrocarbon chain with the percarboxylate group at one end (e.g,, perlauric acid) tend to be more effective (on an equal available -oxygen basis) in the bleaching of hydrophobic stains from fabrics than those which are not constructed in this way7- e.g., peroxybenzoic acid and diperoxydodecanedioic acid. The.loncJ chain peroxyacids with the percarboxylate groups at one end have a structure similar to surface active agents (surfactants) It is believed that in a washing solution, their hydrophobic "tail" tends to be attached to tile hydrophobic stains on the fabrics1 thereby causing a localized increase in bleach concentracion around the. stain and thus resulting in increased efficieny in bleaching for a given concentration of active oxygen in the bleaching solution, Optional Cortponents Surfactants Because of the relatively poor dispersibility of some peroxyacid bleaches, the surface active peroxyacid bleaches, it is highly desirable that surfactants be present in the bleaching solutions in which the peroxyacids are used. Surfactants should generally be present in the bleaching solution at a level of at least 150 ppm. It is the usual practice to bleach fabrics in a laundering solution which contains a laundry detergent. Such detergents contain surfactants and are generally used at solution concentrations which provide more than 200 ppm surfactant to the solution. Thus, if the bleach compositions herein are to be used with a laundry detergent there is no need to incorporate a surfactant into the bleach composition. If surfactants are incorporated into the bleach compositions herein they will generally be present at levels of from 0.5% to fizz 60%,,preferably from 20% to - 308 of-the compositiop. Examples of suitable surfactants are given below. Water-soluble salts of the higher fatty acids, i.e., "soaps," are useful as the anionic surfactant herein. This class of surfadtants includes ordinary alkali metal soaps such as the sodium, potassium, ammonium and alkanolammonium salts of higher fatty acids containing from 8 to 24 carbon atoms and preferably from 10 to 20 carbon atoms. Soaps can be made by direct saponfcaton of fats and oils or by the neutralization of free fatty acids. Particularly useful are the sodium and potassium salts of the mixtures of fatty acids derived from coconut oil and tallow, i.e., sodium or potassium tallow and coconut soaps. Another class of anionic surfactants includes water-soluble salts, particularly the alkali metal, ammonium and alkanolammonium salts, of organic sulfuric reaction products having in their molecular structure an alkyl group containing from 8 to 22 carbon atoms and a sul fonic acid or sulfuric acid ester group. (Included in the term "alkyl" is the alkyl portion of acyl groups.) Examples of this group of synthetic surfactants which can be used in the present bleaching compositions are the sodium and potas sium alkyl sulfates, especially those ob-tained by sulfating the higher alcohols (C8-C18 carbon atoms) produced by reduc ilig the glycerides of tallow or coconut oil; and sodium and potassium alkyl benzene sulfonates, in which the alkyl group contains from s -, 9 to - 15 carbon atoms in straight chain or branched chain configuration, e.g., those of the type described in U.S. Pat. Nos. 2,220,099, Guenther et al, issued November 5, 1940,- and 2,477,383, Lexis, issued July 26, 1949. Other anionic surfactant compounds useful herein include the sodium alkyl glyceryl ether sulfonates, especially those ethers of higher alcohols derived -from tallow and- coconut oil, sodium coconut oil fatty acid monoglyceride sulfonates and sulfates; and sodium or potassium salts of alkyl phenol ethylene oxide ether sulfates containing 1 to 10 units of ethylene oxide per molecule and wherein the alkyl groups contain 8 to 12 carbon atoms¯. Other useful anionic surfactants herein include the water-soluble salts of esters of a-sulfonated fatty acids containing from 6 to 20 carbon atoms in the ester group; water-soluble salts of 2-acyloxy-al}ane-1- sulfuric acids containing from 2 to --9 carbon - atoms in the acyl group and from 9 to 23 carbon atoms in the alone moiety; alkyl ether sulfates containing from 10 to 20 carbon atoms in the alkyl group and from 1 to 30 moles of ethylene oxide; water soluble salts of olefin sulfonates containing from 12 to 24 carbon atoms, and p-alSiyl alkane sulfonates containing from 1 to 3 carbon atoms in the alkyl group and from 8 to 20 carbon atoms in the alkane moiety. Preferred water-soluble anionic organic surfactants herein include linear alkyl benzene sulfonates containing from 11 to 14 carbon atoms in the alkyl group; the tallow range alkyl sulfates; the coconut range alkyl glyceryl sulfonates; and alkyl ether sulfates wherein the alkyl moiety contains from 14 to 18 carbon atoms and wherein the average degree of ethoxylation varies between 1 and 6. Specific preferred anionic surfactants for use herein include: sodium linear C10-Cl2 alkyl benzene sulfonate; triethanolamine C10-C12 alkyl benzene sulfonate; sodium tallow alkyl sulfate; sodium coconut alkyl glyceryl ether sulfonate; and the sodium salt of a sulfated condensation product of tallow alcohol with from 3 tQ 10 moles of ethylene oxide. It is to be recognized that any of the foregoing anionic surfactants can be used separately herein or as mixtures. Nonionic surfactants include the water-soluble ethoxylates of C10-C20 aliphatic alcohols and C6-C12 alkyl phenols. Many nonionic surfactants are especially suitable for use as suds controlling agents in combination with anionic surfactants of the type disclosed herein Semi-pplar surfactants useful herein include water-soluble amine oxides containing one alkyl moiety of from 10 to 28 carbon atoms and 2. moetes selected from the group consisting of alkyl groups and hydroxylakyl groups containing from 1 to 3 carbon atoms; water-soluble phosphine oxides containing one alkyl moiety of 10 to . 28 carbon atoms and 2 moieties selected from the group conisting of alkyl groups and hydroxyalkyl yroups containing from 1 to 3 carbon atoms, and water-soluble sulfoxides co t L ing ohè alkyl moiety of from 10 to 28 carbon atoms and a moiety selected from the group consisting of alkyl and hydroxyalkyl moieties of from 1 to 3 carbon atoms. Ampholytic surfactants include derivatives of aliphatic amines or aliphatic derivatives of heterocyclic secondary and tertiary amines in which the aliphatic moiety can be straight chain or branched and wherein one of the aliphatic substituents contains from 8 to 18 carbon atoms and at lea-st one,aliphatic substituent contains an anionic water-solubilizing group Zwitterionic surfactants include derivatives of aliphatic quaternary ammonium, phosphonium and sulfonium compounds in which the aliphatic moieties can be straight or branched chain, and wherein one of the -aliphatic substituents contains from '8 to 18 carbon atoms and one contains an anionic water-solubilizing group Detergency Builders The instant granular compositions can also com- prise those detergency builders commonly taught for use in laundry compositions. Useful-builders herein include any of the conventional inorganic and organic water-soluble builder salts, as well as various water-insoluble and-socalled "seeded" builders. Inorganic detergency builders useful herein include, for example, water-soluble salts of phosphates, pyrophosphates, orthophosphates, polyphosphates, carbonates, bicarbonates, borates and silicates. Specific examples of inorganic phosphate builders include sodium and potassium tripolyphosphates, phosphates, and hexametaphosphates. Sodium tripolyphospilate is an especially preferred, watersoluble inorganic builder herein. Nonphosphorus-containing sequestrants can also he selected for use herein as detergency builders. Specific examples of nonphosphorus, inorganic builder ingredients include water-soluble inorganic carbonate, bicarbonate, borate and silicate salts. The alkali metal, e,g., sodium and potassium, carbonates, bicarbonates, borates (Borax) and silicates are particularly useful herein. Water-soluble, organic builders are also useful herein. For example, the alkali metal, ammonium and substituted ammonium polyacetates, carboxylates, polycarboxylates, succinates, and polyhydroxysulfonates are useful builders in the present compositions and processes. Specific examples of the polyacetate and polycarboxylate builder salts include sodiun, potassium, lithium, ammonium and substituted ammonium salts of ethylene divine tetraacetic acid, nitrilotriacetic acid, oxydisuccinic acid, mellitic acid, benzene polycarboxylic acids, and citric acid. Highly preferred nonphsophorous builder materials (both organic and inorganic) herein include sodium carbonate. sodium bicarbonate, sodium'silicate, sodium ciersste, sodium oxydisuccinate, sodium mellitate, sodium nitrilotriacetate, and sodium ethylenediaminetetraacetate, and mixtures thereof. Another type of detergency builder material useful in the present compositions comprises a water-solublc material capahle of forming a water-insoluble reaction product with. water hardness cations in combination with a crystallization seed which is capable of providing growth sites for said reaction product. Specific examples of materials capable of forming the water-insoluble reaction product include the watersoluble salts of carbonates, bicarbonates, sesquicarbonates, silicates, aluminates and oxalates. The alkali metal, especially sodium, salts of thc foregoing materials are preferred for convenience and ecomony. Another type of builder useful herein includes various substantially water-inso-luble materials which are capable bf reducing the -hardness content of laundering liquors, e.g., by ion-exchange processes. Examples of such builder materials include- the phosphorylated cloths disclosed in U S. Pat. No.,3,424,545, Bauman, issued January 28,'1969. The complex aliminosilicates, i.e., zeolite-type' materials, are useful detergency builders herein in that these materials soften water, ie., remove hardness ions. Both the naturally occurring and synthetic "zeolites," especially zeolite A and hydrated zeolite A materials, are useful forsthis purpose. A description of zeolite materials and a method of preparation appear in U.S. Pat. No. 2,882,243, Milton, issued April 14, 1959, Also useful are aminophosphonate stabilizers, which are commercially available compounds sold under the names Dequest 2000, Dequest 2041 and Dequest 2060, by The Monsanto Company, St. Louis, Missouri. These compounds have the following structures: EMI16.1 Dquest 2000 Dequest 2041 EMI16.2 Dequest 2060 In preferred compositi,ons of the present invention the aminophosphonate compounds-can be used in their acid form, represented by the above formulas, or one or more of the acidic hydrogens can be replaced by an alkali metal ion, e.g., sodium or potassium.. Additional stabilizers can also be. used, primarily to protect the peroxyacids against decomposition which is catalyzed by heavy metals such as iron and copper. Such additional stabilizing agents are preferably present at levels of from 0.005% to 1.0% of the composition. These additional stabilizers can be any of the wellknown chelating agents, but certain ones are preferred. U.S, Pat. No. 3,442,937, Sennewald et al., issued May 6, 1969, discloses a chelating system comprising quinoline or a salt thereof, an alkali metal polyphosphate, and optionally, a synergistic amount of urea. U.S. Pat. o, 2,838,459, Sprout, Jr., issued July 10, 1959, discloses a variety of polyphosphates as stabilizing agents for peroxide baths. These materials are useful herein. U.S. Pat. No. 3,192,255, Cann, issued June 29, 1965, discloses the use o quinaldic. acid to stabilize percarboxylic acids. This material, as well as picolinic acid and dipicolinic acid, would also be useful in the compositions of the present invention. A preferred auxilliary chelating system for the present invention is a mixture of 8-hydroxyquinoline or dipicolinic acid and an acid polyphosphate, preferably acid sodium pyrophosphate. The later may be a mixture of phosphoric acid and sodium pyrophosphate wherein the ratio of theformer to the latter is from 0.2:1 to 2:1 and the ratio of the mixture of 8-hydroxyquinoline or dipicolinic acid is from 1:1 to 5:1. The foregoing patents relating to stabilizers are incorporated herein by reference. Coatings The dry granular compositions can be coated with coating materials in order to protect them against moisture andother environmental factors astich may tend to cause deterioration of the compositions when stored for long periods of time. Such coating-materials may be in general, acids, esters, ethers, surfactants and hydrocarbons and include-such a wide variety of materials as fatty acids, derivatives of fatty alcohols such as esters and ethers, poly function carboxylic acids and amides, alkyl benzene sulfonates, alkyl sulfates and hydrocarbon oils and waxes. These materials aid in preventing moisture from reaching the peroxyacid compound. Secondly, the coating may be used to segregate the peroxyacid -compound from other agents which may be present in the composition and which could adversely affect the peroxyacid's stability. TJne amount of the coating material used is generally from : 2.58 to 20% based on the weight of the peroxy- acid compound. Solubility Improvers Agents; which improve the solubility of the peroxyacid product such as sodium sulfate, starch, celluaos derivatives, surfactants, etc., are also advantageously used herein. (See U.S. Pat. No. 4,126,573, Johnson, issued November 21, 1978) These agents can be called solubilizers and are generally used in an amount of from 10% to 200% based on the weight of the peroxyacid. Exotherm Control Agents When subjected to excessive heat, organic peroxyacids can undergo a self-accelerating decomposition which can generate sufficient heat to ignite the peroxyacid For this rcason, it is desirable to include an exotherm control agent in pero*,acid bleaching compositions. Suitable materials include urea, hydrates of potassium aluminium sulfate and aluminum sulfate. A preferred exotherm agent is boric acid (See U.S. Pat. No. 4,100,095, Hutchins, issued July ,--1978). The exotherm agent is preferably used in the composition at a level of from 50% to 4008 of the amount of peroxyacid. Miscellaneous Various other optional ingredients such as dyes, optical brighteners, perfumes, soil suspending agents and the like may also be used in the compositions herein at the levels conventionally present in detergent and bleaching compositions. In the following examples, which are illustrative only and are not to be construed as limiting the invention, the Hunter1vhiteness values set froth are a measure of the bleaching activity of the bleaching agents tested. The larger Hunter Whiteness value represents greater cleaning and whitening. EXAMPLE 1 I. Preparation of the hydrophobic bleach composition. The hydrophobic peroxyacid, peroxylauric acid, was prepared by the oxidation of the parent carboxylic acid, lauric acid, with hydrogen peroxide in the presence of water and sulfuric acid. The CMC of sodium laurate equals 2 x 10-2 molar. Reaction donditions were typical of those cited in the literature (e.g., Parker et al., J. Am. Chew. Such, 77,*4337 (1955). The resulting -/?/30 peroxylauric acid-water mixture was blended with finely ground urea (3 parts urea to 1 part peroxy lauric acid) and dried to form the peroaci adduct. Tile adduct was analyzed and determined to contain 1.7% AvO. 2. Preparation of the hydrotropic bleach composition. The hydrotropic peroxyacid, diperoxydodecanedioic acid, was prepared by the oxidation of dodecanedioic acid with hydrogen peroxide in- the'presence of sulfuric acid. Reaction conditions were typical of those cited in the literature -(e,g,, McCune Can. 635, 620). Neither the mono- or disodium salts of dodecanedioic acid has a measurable CMC below 0.SM and the parent acid has a retention time of 23.3 minutes under the chromatographic conditionspreviously cited. The diperoxyacid-water mixture resulting from the syn thesis contained 34 peroxyacid. This mixture was blended with finely ground urea (3 parts urea to I part peroxyacid) and dried. The resulting chemical was par tially adducted and was analyzed to contain 2.7% AvO. 3. Preparation of Bleaching Solution. A six liter, 1000F washing solution was used. Bleach product was weighed out according to the values in Table I to obtain the required AvO in the wash. Each bleach composition was added to the-wash in combination with 1.5 g/l Tide detergent. The solution pH was adjusted to 8.5 with 102 solutions of either sodium hydroxide or sulfuric aci'd. 4. Preparation of Bleachable Stains. A representative hydrophilic stain was prepared when cotton swatches were stained with tea. Hunter Whiteness of the swatches was measured on a Hunter Color Meter. A -xepresentative hydrophobic stain was obtained by selecting normally soiled dingy T-shirts. 3" x 3g1 swatches were prepared; from the bottom halves of- the T-shirts. Hunter Whiteness readings are recorded and the swatches were uniformly distributed between the - three treatments shown in Table I. 5. Bleach Test. After execution of µ3 for each of the three bleach compositions in Table I, 6 tea stains and/ or 5-6 dingy T-shirt swatches were added and washed for 14 minutes. After rinsing, fabrics were dried and then final Hunter Whiteness values recorded. The average increase in Hunter Whiteness over all the fabrics is reported in Table I. The results show that the mixture is superior to per lauric acid on hydrophilic stains and is superior to either individual component on hydrophobic stains. When the composite of results on both stains is,con sidered, the mixture has an overall advantage over the individual components. -TABL-E I Hunter Whiteness (avg.) -Hydrophilic Hydrophobic Bleach Gms/l ppm AvO Tea Stains Dingy T-Shirts PLA1 0,70 12 29 6.7 DPDA/ 0.22 6 40 0.35 6 40 - 9.0 3 DPDA 0.44 12 43 6.0 3-Peroxylauric acid adduct; 2Diperoxydodecanedioic acid adduct; Peroxylauric. acid adduct; and 3Diperoxydodecanedioic acid abduct. EX2JtPLE 2 1. Preparation of Hydrotropic Bleach Composition. The-hydrotropic-'peroxyacid, diperopytridecanedioic acid, was prepared by oxidation- of tridecanedioic acid with hydrogen peroxide in the presence of sulfuric acid and water. Typical reaction conditions involve diluting 408g of concentrated sulfuric acid with water to 42Og and with chilling, adding 80g of 50t hydrogen peroxide. 50g of tridecanedioic acid powder is added to the chilled solution with continuous agitation; ; Temperature of the reaction is raised slowly two 25-30 C and held for 2 hours. - Reaction mix was chilled and quenched with 500g of cold 1120. Crystals of diperoxydodecanedioic acid were collected and washed with water to remove sulfuric- acid. The re resulting product was a mixture of peroxyacid and water, which analyzed to contain 4.6% AvO. The mono- and disodium salts of tridecanedioic acid have no appar ent CìlC below 0.5M, and the parent acid has a reten tion time of 97 minutes under the previously cited chromatographic conditions. 2. Preparation of Hydrophilic Bleach Composition. The hydrophilic bleach, diperoxyadipic acid, was prepared by oxidation of adipic acid- with hydrogen peroxide in the presence of sulfuric acid Reaction conditions were typical of those cited in the literature (e.g., Parker et al., J. Am. Chew. Soc., 79, 1929 (1957), The mono- and disodium salts of adipic acid have no apparent CM below 0.5M, and the parent acid has a retention time of 2.4 minutes under the previously cited chromatographic conditions. - The aiperoxyacid was further processed to make a granule. 25g of dip-roxy - adipic acid was mixed with 34g of boric acid, 140g of anhydrous sodium sulfate and 21g of a surfactant paste. The paste contained approximately 288 C13 LAS, 22% sodium sulfate, and the remainder water. The paste contained typical peroxyacid stabilizers (O.lg dipicolinic acid, 0.05g sodium pyrophosphate and 0.05g phosphoric acid). After mixiny the product was dried. Analysis showed that the granules contained 2.2t AvO. 3. Preparation of Bleach Solution and Bleachable Stains. Bleach solution and bleachable stains were prepared the same as in Example 1. The bleach compositions used are listed in Table II. The results show an increase in bleaching efficacy on both the hydrophile and hydro phobic stains for the mixture over the individual cor.R- ponents. The mixture has an overall advantage over the individual components when both stains are considered. TABLE II Hunter Whiteness (avg.) Hydrophilic Hydrophobic Bleach Gms/l ppm AvO Tea Stains Dingy T-Shirts DATA 0.33 15 41 7.0 DPTDA/ 0.15 7 44.5 8.3 0.37 8 DPAA3 0.69 15 41 6.5 1Diperoxytridecaned loic acid. Diperoxytridecanedloic acid/ DiperoseyadipLc acid granule Diperoxyaclipic acid granule 'EXAMPLE 3 - The preparation and properties of the hydrophilic bleach, diperoxyadipic acid, are described in Example 2, paragraph 2. The preparation and description of the hydrophobic peroxyacid, peroxylauric acid, are described in Example l, paragraph 1. The preparation of the bleach solution and bleachable stains are as described in Example 1. The three bleach compositions are listed in Table III. The results show an increase in hydrophilic stain removal for the mixture over the individual components, and an increase in hydrophobic stain removal for the mixture over DPAA. When the composite'of results¯on both stains is considered'the mixture has an overall advantage over the individual components. TABLE III Hunter Whiteness (avg.) Hydrophilic Hydrophobic Bleach Gms/l ppm AvO Tea Stains Dingy T-Shirts PLA1 .81 14 35 4.6 PLA/ 2 0*23 4 DPhR 10 37.5 10 DPAA3 0.65 14 34 5 3.0 1peroxylauric acid adduct; 2Pexoxylauric acid adduc,t/- Diperoxyadipic acid granule; and Diperoxyadipic acid granule.

Claims: CLAIMS 1. A laundry hleach composition chaxacter-ised in hat it comprises a mixture'of peroxyacid bleaches selected from: a + b, a + C, b + a + (b + c), b + (a + .c), c + (a + b), wherein "a" is a hydrophilic bleach which is most effective on hydrophilic soils, wherein "b" is a hydrotropic bleach which is effective on both hydrophilic and hydrophobic soils, and wherein "c" is a hydrophobic bleach which is most effective on hydrophobic soils, and wherein said peroxyacid bleaches in said mixture have a ratio of from 1:20 to 20:1 on a parts per million (ppm) available oxygen basis. 2. A composition according to Claim 1 wherein said ratio is from 10:1 to 1:10. 3. A composition according to either one of Claims 1 and 2 wherein said ratio is from 3:1 to 1:3. 4. A composition according to any one of Claims 1-3 wherein said mixture is perlauric acid and diperoxydodecanedisic acid. 5. A composition according to any one of Claims 1-3 wherein said mixture is perlauric aci7d and dipe-roxyadipic acid, 6. A composition according to any one of Claims 1-3 wherein said mixture is diperoxyadipic acid and diperoxytridecanedioic acid.

Inventors: BOSSU, FRANK PAUL, KACHER, MARK LESLIE
Applicants: THE PROCTER & GAMBLE COMPANY
Application year: 1982
Main classification: C11D3
IPC codes: C11D3, C11D7