GB2110259A - Peroxyacid bleaching and laundering composition - Google Patents

Abstract

An improved bleaching and laundering composition is provided comprising monoperoxyphthalic acid and/or a water-soluble salt thereof and a chelating agent capable of forming a substantially water-soluble complex with metal ion in aqueous solution. A method of bleaching and laundering soiled and/or stained materials with the aforesaid bleaching composition is also described.

Description

SPECIFICATION Peroxyacid bleaching and laundering composition This invention relates, in general, to bleaching and laundering compositions and their application to laundering operations. More specifically, this invention relates to bleaching and laundering compositions containing monoperoxyphthalic acid and/or a water-soluble salt thereof in combination with a chelating agent capable of forming a water-soluble metal complex in aqueous solution.

Bleaching compositions which release active oxygen in the laundry solution are extensively described in the prior art and commonly used in laundering operations. In general, such bleaching compositions contain peroxygen compounds, such as, perborates, percarbonates, perphosphates and the like which promote the bleaching activity by forming hydrogen peroxide in aqueous solution.A major drawback attendant to the use of such peroxygen compounds is that they are not optimally effective at the relatively low washing temperatures employed in most household washing machines in the United States, i.e., temperatures in the range of 28"C to 540C (80 to 130"F). By way of comparison, European wash temperatures are generally substantially higher extending over a range, typically, from 32 to 930C (90 to 200"F). However, even in Europe and those other countries which generally presently employ near boiling washing temperatures, there is a trend towards lower temperature laundering.

In an effort to enhance the bleaching activity of peroxygen bleaches, the prior art has employed materials called activators in combination with the peroxygen compounds. It is generally believed that the interaction of the peroxygen compounds and the activator results in the formation of a peroxyacid which is the active apecien for bleaching. Numerous compounds have been proposed in the art as activators for peroxygen bleaches among which are included carboxylic acid anhydrides such as those disclosed in U.S. Patent Nos.

3,928,775; 3,338,839; and 3,352,634; carboxylic esters such as dislcosed 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 No.3,245,913.

Pre-formed peroxyacids have also been used to effect bleaching in laundry wash solutions. U.S. Patent Nos. 3,770,8164,170,453; and 4,259,201 are illustrative of prior art disclosures relating to bleaching compositions comprising a peroxyacid compound.

It is generally recognized in the art that metal ions are capable of acting as decomposition catalysts for inorganic peroxygen compounds and organic peroxyacids. In an effort to stabilize such bleaching species in the wash solution, chelating agents have been incorporated into bleaching detergent compositions. U.S.

Patent No. 3,243,378 to Stoltz, for example, discloses a bleaching composition containing a peroxygen bleaching compound and a chelating agent to sequester metal cations. In general, the chelating agents which have been used for this purpose fall into one of two categories: (a) materials such as heterocyclic compounds and ketones, notably 8-hydroxyquinoline, which tie up metal cations in the laundry wash by precipitating them from solution; and (b) materials such as aminopolycarboxylates and aminopolyphosphonate compounds which form water-soluble metal complexes with the cations present in the wash solution. Accordingly, U.S.Patent No. 4,005,029 discloses that selected aldehydes, ketones and compounds which yield aldehydes or ketones in aqueous solution (e.g., 8-hydroxyquinoline) can be used to activate aliphatic peroxyacids, such as diperazelaic acid, diperadipic acid and aromatic peroxyacids (and water-soluble salts thereof) including monoperoxyphthalic acid and diperoxyterephthalic acid. In U.S. Patent No. 4,170,453, a mixture of 8-hydroxyquinoline, phosphoric acid and sodium pyrophosphate is disclosed as a preferred chelating system to stabilize the active oxygen generated in wash solutions containing diperoxydodecandioic acid. U.S.Patent No. 4,225,452 to Leigh discloses the combination of specified classes of chelating agents (among which are phosphonate compounds) with inorganic peroxygen compounds and an organic activator for the purpose of suppressing the decomposition of the peroxygen compound in the bleach composition. Specifically, the chelating agent is said to inhibit the unwanted side reaction of the peroxygen compound with the peroxyacid formed by the primary reaction of the peroxygen compound and the activator, the effect of the side reaction being to deplete the peroxyacid bleaching species from solution.

The Leigh patent, however, discourages the use of such chelating agents in solutions wherein the peroxyacid has a double bond between the carbon atoms in the a, a' position to the carbonyl group.

Specifically, at column 2 of the patent, beginning at line 63, the patentee excludes phthalic anhydride as an activatorforthe disclosed bleaching composition because of instability. Inasmuch as the peroxyacid formed by the reaction of phthalic anhydride and an inorganic peroxygen compound is monoperoxyphthalic acid, the Leigh patent apparently discourages the use of monoperoxyphthalic acid in the bleaching compositions of the patent.

European Patent Publication No.0,027,693, published April 29, 1981, discloses the use of magnesium monoperoxyphthalate as an effective bleaching agent. There is also disclosed the optional combination of a bleaching agent with an "aldehyde or ketone peroxyacid activator as described in U.S. Patent 4,005,029, e.g., 8-hydroxyquinoline which is a known peroxygen stabilizer". The Publication also discloses organic phosphonate compounds, along with a wide variety of other compounds, as being useful detergent builders which optionally may be included in the described washing compositions.No disclosure is made, however, concerning the beneficial effects attendant to the use of a small amount of organic phosphonate compounds to serve as chelating agents in bleaching compositions and particularly, in compositions containing magnesium monoperoxyphalate.

Thus, while the art has concerned itself with improving the stability of peroxygen and peroxyacid bleaching compounds with the use of chelating agents, it has heretofore failed to disclose or suggest the specific combination of peroxyacid compounds with chelating agents of the type which for substantially water-soluble compounds or complexes with metal cations in the aqueous wash solution in the proportions with which the presnet invention is concerned. Moreover, the beneficial effect attendant to the combination of such chelating agents with monoperoxyphthalic acid and/or a water-soluble salt thereof in particular, is unappreciated in the prior art.

The present invention provides a bleaching composition comprising monoperoxyphthalic acid (also referred to herein as "MPPA" for purposes of convenience) and/or a water-soluble salt thereof and a chelating agent capable of forming a substantially water-soluble compound or complex with metal ion in aqueous solution.

The bleaching detergent composition of the invention comprises the above-defined bleaching composition in combination with a surface active detergent and one or more detergent builder salts. In accordance with the process of the invention, bleaching or stained and/or soiled materials is effected by contacting such materials with an aqueous solution of the above-defined compositions.

The term "chelating agent" as used herein refers to organic compounds which, in small amounts, are capable of binding transition metal cations, (e.g., iron, nickel and cobalt) which are known to adversely affect the stability of peroxygen compounds and/or peroxyacids, in aqueous bleaching solutions. The chelating agents employed herein therefore exclude inorganic compounds ordinarily used in detergent formulations as builder salts. The chelating agents useful for the present invention are of the type capable of forming a substantially water-soluble, rather than a precipitated, metal complex in aqueous solutions with metal ions, most notably, transition metal cations such as those referred to above.Suitable chelating agents therefore include ethylene diamine tetraacetic acid (EDTA); nitrilotriacetic acid (NTA); diethylene triamine pentaacetic acid; ethylene diamine tetramethylene phosphonic acid (EDITEMPA); amino trimethylene phosphonic acid (ATMP); diethylenetriamine pentaceticacid (DETPA), all of the above-mentioned compounds being preferably employed in the form of the sodium salt. In contrast thereto, chelating agents, such as, 8-hydroxyquinoline, which form a precipated metal complex in aqueous solution are excluded from the present invention.

A preferred class of chelating agents are the organic phosphonate compounds such as those disclosed in U.S. Patent No. 4,225,452, the formulae of which are set forth in Equations I, II, and iil in columns 3 and 4 of the patent. Among this class of materials diethylene triamine pentamethylene phosphonic acid (referred to herein as "DTPMP"), and/or a water-soluble salt thereof is particularly preferred as a chelating agent for purposes of the present invention. Among the salts of DTPMP, the sodium, potassium and ammonium salts are generally preferred because of their relatively greater solubility and ease of preparation.

In general, the chelating agents, ingredient B, employed in the bleaching compositions of the invention are present in a weight ratio relative to MPPA and/or its salts, ingredient A, of from about 1 :4to about 1 :15, and more preferably, from about 1 :5 to about 1:12. In the built bleaching detergent composition of the invention, the concentration of chelating agent is generally below about 5%, by weight, preferably below about 2%, by weight, and most preferably below about 1%, by weight, of such detergent compositions. The chelating agents may be utilized alone or in combinations with one or more other chelating agents. Thus, for example, DTPMP may be advantageously employed n combination with EDTA in the compositions of the invention.

The ratio of the sum of the detergent, ingredient C, the builder, ingredient D and the optional filler salt, ingredient E, namely (C+D+E) to the sum of the MPPA and/or its salts and the chelating agent, namely (A+B) is preferably from 6:1 to 20:1, especially from 6.5:1 to 15:1.

Monoperoxyphthalic acid and/or one or more of its water-soluble salts are the primary bleaching agents in the bleaching compositions of the invention. Although MPPA provides acceptable bleaching activity, it has the disadvantage of relatively poor stability when stored in admixture with other components ordinarily present in household detergent compositions. Hence, for purposes of stability, the magnesium salt of MPPA is preferably employed in the composition of the invention, namely, magnesium monoperoxyphthalate. In a preferred bleaching composition, magnesium monoperoxyphthalate is present in combination with water and a sequestering agent, the amount of magnesium monoperoxyphthalate being about 65%, by weight.

The active oxygen content of this bleaching composition is about 5 to 6%. The alkali metal, calcium or barium alkaline earth and/or ammonium salts of MPPA may also be emoloyed in the bleaching and laundering compositions of the invention, although such salts are generally less preferred from the standpoint of stability than the aforementioned magnesium salt.

The production of MPPA is generally effected by the reaction of hydrogen peroxide and phythalic anhydride. The resultant MPPA can then be used to produce magnesium monoperoxyphthalate (MMPP) by reaction with a magnesium compound in the presence of an organic solvent. A detailed description of the production of MPPA and its magnesium salt is setforth on pages 7 to 10, inclusive, of European Patent Publication No. 0,027,693, published April 29, 1981,the aforementioned pages 7 to 10 being incorporated herein by reference.

MPPA is produced conveniently by reaction between hydrogen peroxide and phthalic anhydride which can then be employed to produce MMPP by partial neutralisation with magnesium in the presence of a non-reactive organic solvent, the solvent and the relative amounts of the reagents and the solvent preferably being so selected that the liquid phase remains as a single phase and thus the liquid components do not separate to from an emulsion. By the term 'non-reactive' we mean that solvent does not react to any marked extent with hydrogen peroxide orthe intermediate product (MPPA) or the final product (MMPP) under the prevailing reaction conditions i.e. during the period of time whilst the solvent remains in contact with a peroxy-compound. We have found that one suitable class of organic solvents comprises low molecular weight aliphatic esters.As a general guide, such esters can contain from 3 to 10 carbon atoms in total and are, preferably, acetates, especially ethyl acetate, or propionates or formates.

The hydrogen peroxide is employed in the form of an aqueous solution. We have found that the presence of an amount of water comparable with the amount of hydrogen peroxide results in formation, in reasonable yield, of product in the reaction mixture. Whilst, naturally, use of excess water leads to a particulate product having a lower active-oxygen content and thus a lower conversion of phthalic an hydride to MMPP, it has been found surprisingly that if insufficient water is present the yield of MMPP drops substantially.

Analysis of solid MMPP demonstrated that MMPP as formed under the process conditions described herein is hydrated, and thus the reaction mixture preferably contains sufficient water for all the MMPP that is formed to be hydrated and precipitated out of solution. In general, we prefer to use hydrogen peroxide and water in amounts equivalent to a 40 to 60% w/w aqueous hydrogen peroxide, or in the form of a solution having a concentration in that range already, although some MMPP can be produced where the concentration is somewhat outside the preferred range, but desirably still within the range 30 to 75 % w/w hydrogen peroxide.The amount of the aqueous hydrogen peroxide of water and aqueous hydrogen peroxide in total that is employed in practice is often from 50 to 1009 per litre of orgainic solvent and where it is desired to minimise the use of solvent, the total amount is preferably within 10 % of the maximum permissible whilst retaining a single phase liquid system, and desirably the amounts of phthalic anhydride and magnesium compound to be used are determined in accordance therewith, also taking into account the following preferred features.

The stoichiometric mole ratio of hydrogen peroxide to phthalic anhydride is 1:1. It is desirable to employ at least the stoichiometric ratio and preferably only a slight excess, i.e. in the range 1.01:1 to 1.2:1, and particularly 1.05:1 to 1.12:1. Naturally, it is possible to employ mole ratios outside these ranges but still in the range 1:2 to 2:1, particularly where for example the reaction mixtures are to be recycled. It will be recognised that when the solid phthalic anhydride is introduced, part dissolves and part can remain in solid form, thereby creating a slurry, and therefore, it is desirable to maintain stirring to promote good solid/liquid contact. A convenient amount of anhydride to add is often from 0.6 to 1.5 moles per 10009 reaction mixture, which in the case of phthalic anhydride is about 96g to about 1259 per 10009 final reaction mixture.

The final magnesium compound is preferably present in an amount theoretically sufficient to neutralise the carboxylic acid in all the monoperoxyphthalic acid produced by reaction between the phthalic anhydride and hydrogen peroxide. In order to achieve this, it is desirable to employ a mole ratio of magnesium compound as Mg to phthalic anhydride (PA) of at least 1:2 and conveniently less than 1:1. In more preferred embodiments the Mg:PA mole ratio is in the range 1:2 to 1.2:2, and in many of the preferred embodiments is approximately half the hydrogen peroxide:PA mole ratio. Where the anhydride contains or generates x carboxylate groups per molecule then the ranges are multiplied by xfor example, 1x:2 to 1.2x2. It is highly desirable to employ as the magnesium compound, one that does not introduce anions of strong acids.

Compounds that fulfil that desideratum include magnesium oxide, magnesium hydroxide, magnesium carbonate and basic magnesium carbonates.

The order of introduction of the reagents into the solution can be varied. Thus, the aqueous hydrogen peroxide can be introduced into a slurry of magnesium compound and phthalic anhydride in the organic solvent or the introduction of the solid reagents can be first. Alternatively all three could be introduced together. However, it is important in any order of introduction to control the temperature during the period that the phthalic anhydride and hydrogen peroxide are brought into contact, herein termed the initial reaction period. By so doing, the proportion of monoperoxyphthalic acid reacting with further phthalic anhydride to form diphthaloyl peroxide can be minimised, and, where the temperature is in the region of 10 "C to 12"C or lower during the initial reaction period, that proportion is substantially nil.It will be recognised that the maximum temperature appertaining throughout the initial reaction period that can be tolerated depends upon the proportion of diphthaloyl peroxide that can be tolerated, the higher the temperature the higher the proportion. For example, if the temperature is maintained at 20 "C during the initial reaction period, the proportion of diphthaloyl peroxide can be in the region of about 5 %. In consequence, the reaction temperature during the initial reaction period is in practice in the range of 0 to 30 "C and preferably from 5 to 15 "C.After the reactants have been brought into contact or within 15 minutes thereof, the temperature of the slurry can be allowed to rise, since the risk of diphthaloyl peroxide forming is much lower than during the initial reaction period, suitably to a temperature in the range of 15 to 30 OC. During this latter period, MMPP is forming as a particulate solid. For a batch process, the secondary reaction period typically lasts from 0.5 hours to 5 hours, and often from 1 to 2 hours.

After the MMPP has been formed as a particulate precipitate, it can then be separated employing standard solid/liquid separators such as drum and plate filters, or centrifuges. It is then, preferably, washed with a non-aqueous solvent for phthalic anhydride, which can be, conveniently, a small amount of fresh solvent employed as the reaction solvent. The separated solid can then be dried, but preferably, where it is known that in the dried state it would not be sufficiently insensitive to impact or to thermal shock, it is desensitised whilst it is still in the damp state by intimate contact with a suitable amount of one or more of the desensitising compounds described herein.

Where separated liquor still contains hydrogen peroxide and/or phthalic anhydride and/or MPPA, it can be re-employed, suitably by making-up the concentrations of the reactants to within the ranges of mole ratios described hereinbefore and particularly to achieve steady-state levels under the reaction conditions described.Thus the process in some embodiments, is cyclical comprising the steps of (i) dissolution of aqueous hydrogen peroxide, in a slected organic solvent and introduction of phthalic anhydride and magnesium compound therein, in amounts as described herein; (ii) separating particulate MMPP from the liquid phase; (iii) determining the contents of phthalic anhydride MPPA, water, hydrogen peroxide and magnesium compound in the liquid phase; (iv) recycling the liquid phase to step (i) for make-up of the reagents, preferably achieve steady state to levels, the process applying mutatis mutandis to the production of the other magnesium salts in classes 1 to 3. By so recycling, it has been found that the average particle size of the product can be increased, the proportion of fine particles in the product tending to diminish.

When a steady state is obtained step (iii) need not be carried out every cycle, but the previously calculated amounts used.

It will be recognised that the ratios of reagents introduced in subsequent cycles can appear two be outside the ranges of ratios specified earlier herein. Assuming thea the volume of filtrate/washings on recycle is adjusted where necessary to approximately the same level the amount of phthalic an hydride introduced in subsequent cycles is, in many cases, approximately half that introduced in the first cycle, the amount of hydrogen peroxide introduced is approximately 60 % of that introduced in the first cycle and the amount of magnesium oxide introduced likewise is substantially the same in first and subsequent cycles.In practice, this means that in the subsequent cycles the mole ratio of Mg:PA introduced is preferably in the range of 5:4 to 4:5, the hydrogen peroxide:PA mole ratio is preferably in the range of 1.1:1 to 1.3:1, and the amount of PA introduced is often in the range 0.35 to 0.75 moles per 10009 reaction mixture.

The MPPA bleaching agent (or a salt thereof) may optionally be combined in the present bleaching compositions with a conventional peroxygen bleach compound and an activator therefor. Examples of suitable peroxygen compounds include alkali metal perborates, percarbonates, perphosphates and the like, sodium perborate being particularly preferred because of its commercial availability. Conventional activators such as those disclosed, for example, at column 4 of the U.S. patent 4,259,200 are suitable for use in conjunction with such poroxygen compound. The polyacylated amines are generally of special interest, tetra acetyl ethylene diamine (TAED) in particular being a preferred activator. Other suitable activators include anhydride compounds, such as, benzoic, maleic, succinic and phthalic; and acyl compounds such as N-acetyl and N-benzoyl-imidazoles.The useof MPPA in combination with a peroxygen compound activated with phthalic anhydride is a particularly preferred bleaching composition. In general, the molar ratios of peroxygen compound to activator can vary widely depending upon the particular choice of peroxygen compound and activator. However, molar ratios of from about 0.5:1 to about 25:1 are generally suitable for providing satisfactory bleaching performance.

In accordance with another embodiment of the invention, the bleaching agent employed in the bleaching composition described here is devoid of a peroxygen compound and is solely comprised of MPPA and/or its water-soluble salts. In general, such bleaching compositions are most effective at the relatively low washing temperatures employed in typical household washing machines in the United States.

The amount of bleaching composition added to the wash solution is generally selected to provide an amount of peroxy-acid compound within the range corresponding to about 3 to 100 parts of active oxygen per million parts of the wash solution.

MPPA and/or its water-soluble salt in combination with a chelating agent may be formulated as a separate bleach product, or alternatively may be employed in a built detergent composition. Accordingly, the bleaching composition of the invention may include conventional additives used in the fabric washing art, such as, binders, fillers, builders salts, proteolytic enzymes, optical brightners, perfumes, dyes, corrosion inhibitors, anti-redeposition agents, foam stabilizers and the like, all of which may be added in varying quantities depending on the desired properties of the bleaching composition and their compatability with such composition.Additionally, the bleaching compositions of the invention may be incorporated into laundering detergent compositions containing one or more surface active agents selected from the group consisting of anionic, cationic, nonionic, ampholytic and zwitterionic detergents.

When the instant bleaching compositions are incorporated into a conventional laundering composition and are thus provided as fully formulated bleaching detergent composition, the latter compositions will comprise the following: from about 5 to 50%, by weight, of the instant bleaching composition; from about 5 to 50%, by weight, of a detergent surface active agent, preferably from about 5 to 30%, by weight; and from about 5 to 80%, by weight, of a detergent builder salt which can also function as a buffer to provide the requisite pH range when the laundering composition is added to water.

According to a preferred form of the present invention a bleaching detergent composition comprises as ingredient A), a bleaching agent comprising monoperoxyphthalic acid or water soluble salt thereof or a mixture thereof, the said bleaching agent preferably being devoid of an inorganic peroxygen compound; as ingredient B), a chelating agent capable of forming a substantially water-insoluble metal complex in aqueous solution, preferably DTPMP; as ingredient C), one or more detergent surface active agents selected from the group consisting of anionic, cationic, nonionic, ampholytic and zwitterionic detergents; as ingredient D), one or more detergent builder salts; as optional ingredient E), one or more filler salts; the balance being water and minor amounts of adjuvants; the weight ratio of ingredient A to ingredient B preferably being less than 15:1, more preferably no more than 12:1 e.g. in the range of 10:1 to 4:1, and the weight ratio of the sum of ingredients C, D and E to the sum of ingredients A and B being at least 6:1, preferably at least 6.5:1 e.g. in the range 6:1 to 20:1 and especially in the range 6:1 to 15:1. The aqueous wash solutions will have a pH range of from about 7 to 12, preferably from about 8 to 10, and most preferably from about 8.5 to 9. A preferred amount of the builder salt is from about 8.5 to 9. A preferred amount of the builder salt is from about 20% to about 65%, by weight of the composition. The balance of the composition will predominantly comprise water, filler salts, such as, sodium sulfate, and optionally, minor additives, such as, optical brightners, perfumes, dyes, anti-redeposition agents and the like.

Ampng the anionic agents useful in the present invention are those surface active or detergent compounds which contain an organic hydrophobic group containing generally from about 8 to 26 carbon atoms and preferably 10 to 18 carbon atoms in their molecular structure and at least one water-solubilizing group selected from the groups 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 fatty acids or resin salts containing from about 8 to 20 carbon atoms and preferably 10 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. Examples of the sulfonated anionic detergents are the higher alkyl mononuclear aromatic sulfonates such as the higher alkyl benzene sulfonates containing from about 10 to 16 carbon atoms in the higher alkyl group in a straight or branched chain, such as, for example, the sodium, potassium and ammonium salts of higher alkyl benzene sulfonates, higher alkyl toluene sulfonates and higher alkyl phenol sulfonates.

Other suitable anionic detergents are the olefin sulfonates including long chain alkene sulfonates, long chain hydroxyalkane sulfonates or mixtures of alkene sulfonates and hydroxyalkane sulfonates. The olefin sulfonate detergents may be prepared in a conventional manner by the reaction of S03 with long chain olefins containing from about 8 to 25, and preferably from about 12 to 21 carbon atoms, such olefins having the formular RCH=CHR1 wherein R is a higher alkyl group of 6 to 23 carbons and R1 is an alkyl group containing from about 1 to 17 carbon atoms or hydrogen to form a mixture of sultones and alkene sulfonic acids which is then treated to convert the sultones to sulfonates. Other examples of sulfate or sulfonate detergents are paraffin sulfonates containing from about 10 to 20 carbon atoms, and preferably from about 15 to 20 carbon atoms.The primary paraffin sulfonates are made by reacting long chain alpha olefins and bisulfites. Paraffin sulfonates having the sulfonate group distributed along the paraffin chain are shown in U.S. Patents Nos. 2,503,280; 2,507,088; 3,260,741; 3,372,188 and German Patent No.735,096. Other useful sulfate and sulfonate detergents include sodium and potassium sulfates of higher alcohols containing from about 8 to 18 carbon atoms, such as for example, sodium aluryl sulfate and sodium tallow alcohol sulfate, sodium and potassium salts of alpha-sulfofatty acid esters containing about 10 to 20 carbon atoms in the acyl group, for example, methyl alpha-sulfomyristate and methyl alpha-sulfotallowate, ammonium sulfates of mono- or di- glycerines of higher (C10 - C18) fatty acids, for example atearic monoglyceride monosulfate; sodium and alkylol ammonium salts of alkyl polyethenoxy ether sulfates produced by condensing 1 to 5 moles of ethylene oxide with 1 mole of higher (C8 -C18) alcohol; sodium higher alkyl (ClO - C18) glyceryl ether sulfonates; and sodium or potassium alkyl phenol polyethenoxy ether sulfates with about 1 to 6 oxyethylene groups per molecule and in which the alkyl radicals contain about 8 to 12 atoms.

The most highly preferred water-soluble anionic detergent compounds are the ammonium and substituted ammonium (such as mono, di and triethanolamine), alkali metal (such as, sodium and potassium) and alkaline earth metal (such as, calcium and magnesium) salts of the higher alkyl benzene sulfonates, olefin sulfonates and high alkyl sulfates. Among the above-listed anionics, the most preferred 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 aliphatic 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 polyethylene 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, for example, nonyl phenol condensed with 9 moles of ethylene oxide; dodecyl phenol condensed with 15 moles of ethylene oxide; and dinonyl phenol condensed with 15 moles of the ethylene oxide. Condensation products of the corresponding alkyl thiophenolswith 5 to 30 moles of ethylene oxide are also suitable.

Of the above-described types of nonionic surfactants, those of the ethoxylated alcohol type are preferred.

Particularly preferred non ionic 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 condensation products of primary alcohols which are branched to some degree and 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 formula are also useful:

wherein R is an alkyl group containing from about 8 to 18 carbon atoms, R2 and R3 are each an alkylene or hydroxyalkylene group containing about 1 to 4 carbon atoms, R4 is an alkylene or hydroxyalkylene group containing 1 to 4 carbon atoms, and Xis C or S:O. The alkyl group can contain one or more intermediate linkages such as amido, ether, or polyether linkages or non-functional substituents such as hydroxyl or halogen which do not substantially affect the hydrophobic character of the group. When X is C, the detergent is called a betaine; and when Xis S:O, the detergent is called a sulfobetaine or sultaine.

Cationic surface active agents may also be employed. They comprise surface active detergent compounds which contain an organic hydrophobic group which 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 compounds.

Examples of suitable synthetic cationic detergents include: normal primary amines of the formula RNH2 wherein R is an alkyl group containing from about 12 to 15 atoms; diamines having the formula RNHC2H4NH2wherein R is an alkyl group containing from about 12to 22 carbon atoms, such as N-2-aminoethyl-stearyl amine and N-2-aminoethyl myristyl amine; amide-linked amines, such as those having the formula R1CONHC2H4NH2 wherein R1 is an alkyl group containing about 8 to 20 carbon atoms, such as N-2-amino ethylstearyl amide and N-amino ethylmyristyl amide; 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 1 to 3 carbon atoms, including alkyl groups bearing inert substituents, such as phenyl groups, and there is present an anion such as halogen, 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 example, stearyl amido propyl quaternary ammonium chloride.Typical quaternary ammonium detergents are ethyl dimethyl-stearyl-ammonium chloride, benzyl-dimethyl-stearyl ammonium chloride, trimethyl-stearyl ammonium chloride, trimethyl-cetyl ammonium bromide, dimethyl-ethyl-lauryl ammonium chloride, dimethyl-propyl-myristyl ammonium chloride, and the corresponding methosulfates and acetates.

Ampholytic detergents are also suitable for the invention. Ampholytic detergents are well known in the art and many operable detergents of this class are disclosed by 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)C2H4COOM; and long chain imidazole derivatives having the general formula:

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.Specific operable amphoteric detergents include the disodium salt of undecylcycloimidinium- ethoxyethionic acid-2-ethionic acid, dodecyl beta alanine, and the inner salt of 2-trimethylamino lauric acid.

The laundry detergent composition 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 builders salts, such as, for example, water-soluble salts of phosphates, pyrophosphates, orthophosphates, polyphosphates, silicates, carbonates, and the like. Organic builders include water-soluble phosphonates, polyphosphonates, polyhydroxysu lfonates, 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 include, for example, the sodium and potassium salts of ethane 1-hydroxy-1, 1-diphosphonic acid and the sodium and potassium salts of etha ne-l, 1, 2-tri phosphonic acid. Examples of these and other phosphorous builder compounds are disclosed in U.S. Patent Nos. 3,213,030; 3,422,021; 3,422,137 and 3,400,176. Pentasodium tripolyphosphate and tetrasodium pyrophosphate are especially preferred water-soluble inorganic builders. Specific examples of non-phosphorous inorganic builders include water-soluble inorganic carbonate, bicarbonate and silicate salts.The alkali metal, for example, sodium and potassium, carbonates, bicarbonates and silicates are particularly useful herein.

Water-soluble organic builders are also useful. For example, the alkali metal, ammonium and substituted ammonium polyacetates, carboxylates, polycarboxylates and polyhydroxysulfonates are useful builders for the compositions and processes of the invention. Specific examples of polyacetate and polycarboxylate builders include sodium, potassium, lithium, ammonium and substituted ammonium salts of ethylene diaminetetracetic acid, nitrilotriacetic acid, benzene polycarboxylic (i.e. penta- and tetra-) acids, carboxymethoxysuccinic acid and citric acid.

Water-insoluble builders may also be used, particularly, the complex silicates and more particularly, the complex sodium alumino silicates such as, zeolites, e.g., zeolite 4A, a type of zeolite molecule wherein the univalent cation is sodium and the pore size is about 4 Angstroms. The preparation of such type zeolite is described in U.S. Patent 3,114,603. The zeolites may be amorphous or crystalline and have water of hydration as known in the art.

An inert, water-soluble filler salt is desirably included in the laundering 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, anti-redeposition agents, such as, carboxymethyl-cellulose, optical brightners, such as anionic, cationic, or nonionic brightners; foam stabilizers, such as, alkanolamides, proteolytic enzymes and the like are all well known in the fabric washing art for use in detergent compositions.

The bleaching composition of the invention are prepared by admixing the ingredients as hereinafter illustrated. When preparing laundering compositions containing the bleaching composition in combination with a surface active detergent compound and/or builder salts, MPPA and/or a salt thereof and the chelating agent of choice can be mixed either directly with the detergent compound, builder and the like, or the MPPA and/or its salt can be coated with a 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 or its salt and the like.

EXAMPLE 1 A preferred low temperature bleach product has the following composition: Component Weight percent Sodium linear C10 - C13 alkyl 5 benzene sulfonate Ethoxylated C11 - C18 alcohol 3 (11 moles of EO per mole alcohol) Soap (sodium salt of C12- C22 5 carboxylic acids) Sodium silicate (1 Na2O: 2 sio2) 3 Pentasodium tripolyphosphate (TPP) 40 Sodium Salt of diethylene triamine 0.5 pentamethylene phosphonic acid (DTPMP) Enzyme (a) 0.4 Optical brightners 0.2 Mg salt of MPPA (b) 7.0 Perfume 0.18 Sodium sulfate 22 Water q.s.

Notes (a) A proteolytic enzyme purchased as Alcalase 2M (2 anson unit/gram) or as Maxatase P.

(b) A bleaching composition containing as as active ingredient about 65 wt.% magnesium monoperoxyphthalate, and having an active oxygen content of 5.1% It will be observed that the ratios of ingredients are A/B, 9:1 and (C + D + E)/(A + B), 15:1.

The foregoing product is produced by spray drying an aqueous slurry containing 60%, by weight of a mixture containing all of the above components except the enzyme, perfume and Mg salt of MPPA bleaching composition. The resultant spray dried product has a particle size in the range of 8 mesh to 150 mesh, (U.S.

Sieve Series) and a moisture content of about 14%. 92.5 part by weight of said spray dried product are mixed with 7 parts by weight of the Mg salt of MPPA of similar mesh size, 0.3 parts by weight of enzyme and 0.18 part by weight of perfume in a rotary drum to yield a particulate product of the foregoing composition having a moisture of approximately 13%, by weight.

The above described product is used to wash soiled fabrics in a washing machine, and good laundering and bleaching performace is obtained.

EXAMPLE 2 Test procedure Bleaching test were carried out on standard stained test swatches (described below) using the various bleaching and laundering compositions described in table 1 ofthis Example in a Tergotometervessel manufactured by the U.S. Testing Company. The Tergotometer was maintained at a constant temperature of 49"C (120"F) and operated at 100 rpm.

Each of the test compositions described in Table 1 below was added to one liter of tap water at 49"C (1 20"F) having a water hardness of about 100 ppm, as calcium carbonate. The test compositions were agitated for about one minute and then a mixed fabric load consisting of two swatches each (3" x 4") of the stained fabrics described below was added to each wash receptacle. After a 15 minute wash at 49"C at (1 20"F), the test fabrics were rinsed in 38"C (1 00"F) tap water and then dried.The percent stain removal was measured by taking a reflectance reading for each stained test swatch priorto and after the washing using a Gardner Color Difference Meter, and the percent stain removal (%S.R.) was calculated as follows: (Rd after washing) - (Rd before washing) % S.R. = x 100 (Rd before staining) - (Rd before washing) wherein "Rd before washing" represents the Rd value after staining.

The value of percent stain removal calculated for all five cloths were averaged from each test laundering composition. A difference greater than 2% in the average of the five stained cloths tested is considered significant.

At the end of each wash, the active oxygen content of the wash solution was determined by acidification with dilute sulfuric acid followed by treatment of the wash solution with potassium iodide and a minor amount of ammonium molybdate, and thereafter titration with standardized sodium thiosulfate using starch as the indicator.

The respective stains and test swatches were as follows: Stain Test cloth 1. Grape - 65 Dacron - 35 cotton 2. Blueberry - Cotton 3. Sulfa dye - EMPA 115 (cotton) 4. Red wine - EMPA 114 (cotton) 5. Coffee/tea - Cotton Stained test cloths 1 and 2 are prepared by passing rolls of unsoiled fabric through a padding and drying apparatus (manufactured by Benz of Zurich, Switzerland) containing either grape of blueberry solutions at 31"C (90"F). After drying at 121"C (250"F) the fabric is cut into 3" x 4" swatches. Eighty of these swatches, impregnated with the same stain, are rinsed in 17 gallons of 29"C (85"F) water in an automatic home washer.

They are then dried by a passage through a Beseler Print Dryer at a machine temperature setting of 6 and a speed of 10.

Stained fabrics 3 and 4 are purchased from Testfabrics Incorporated of Middlesex, New Jersey, and cut into 3" x 4" swatches.

Stained fabric 5 is prepared by agitating and soaking unsoiled cotton strips (18" x 36") in a washing machine filled with a solution of coffee/tea (8:1 weight ratio) at 66"C (150"F). The machine is allowed to rinse-spin dry to remove the coffee/tea solution. The stained fabric is then machine washed twice with hot pyrophosphate-surfactant solution by two complete water wash cycles at 60"C (1 40"F). The strips are then dried by two passes through an Ironrite machine set at 10 and then cut into 3" x 4" swatches.

A granular detergent composition (designated herein as "HDD") was prepared by conventional spray-drying and had the following approximate composition: Composition Weight percent Sodium tridecylbenzenesulfonate 15 Ethoxylated C12 - C15 1 primary alcohol (7 moles EO/mole alcohol) Sodium tripolyphosphate 33 Sodium carbonate 5 Sodium silicate 7 Sodium carboxymethylcellulose 0.5 Optical brighteners 0.2 Perfume 0.2 Water 11 Sodium sulfate balance Detergent compositions A-E containing HDD were formulated as set forth in Table 1.

TABLE 1 Component Composition A B C D E Detergent, HDD 4.50g 4.50g 4.50g 4.50g 4.509 Mg sale of MPPA(1) ---- 0.49 0.49 0.49 0.49 DTPMP(2) ---- ---- 0.09 EDTA(3) ---- ---- -- 0.09 NTA4 -- -- ---- ---- 0.18 (1) A bleaching composition containing about 65 wt.% monoperoxyphthalate acid (as magnesium salt) and having an active oxygen content of 5.1% (2) Sodium diethylene triamine pentamethylene phosphate obtained from P.A. Hunt Chemical Corp., Lincoln, Rhode Island, U.S.A.

(3) Ethylene diamine tetraacetic acid, disodium salt.

(4) Nitrilotriacetic acid, trisodium salt.

Compositions A through E were tested in accordance with the prodecure described above and the results of the bleaching tests are tabulated in Table 2 which sets forth the initial and final values of the active oxygen (A.O.) in the wash solution (expressed as "initial grams" and "residual grams", respectively) and the stain removal achieved for each of the 5 stains.

It will be observed from Table 1 that the ratios of ingredients are A/B, 5.6:1 and (C+D+E)/(A+B), 6.9:1.

TABLE 2 Comparative bleaching performance Composition A B C D E Initial grams ---- 25.0 25.0 25.0. 25.0 (A.O. x 103) Residual grams ---- 15.9 18.6 18.5 15.6 (A.O. x 103) Grams consumed ---- 9.1 6.4 6.5 9.4 (A.O. x 103) Stain removal: % % % % Grape 47 69 72 74 72 Blueberry 44 65 68 66 67 Sulfodye(EMPA115) 3 3 3 3 4 Red wine (EMPA 114) 38 49 51 44 45 Coffee/tea 17 43 39 38 41 Avg. (%) 30 46 47 45 46 The results of Table 2 indicate that composition C consumes less active oxygen that any of the other examples, being slightly better than 2D, and provides about an equivalent level of stain removal relative to composition E containing NTA or composition B which contains no chelating agent, though Example 2C provides better stain removal than 2E or 2B and 2D provides worse stain removal than 2E or 2B.

EXAMPLE 3 Bleaching tests are carried out using a detergent formulation "A" having the following composition: Component Weight percent Sodium linear alkyl benzene 5 sulfonate (LAS) Soap (sodium salt of high 5 M.W. Fatty acid) Ethoxylated alcohol (11 moles 3 EO per mole alcohol) Sodium silicate 3 Sodium tripolyphosphate (TPP) 40 Optical brightners 0.2 Sodium sulfate 23.5 Enzyme 0.3 Perfume 0.2 Mg salt of MPPA (1) 9 Water balance The tests are carried out in an Ahiba washing machine under the following test conditions: Ahiba wash cycle = heating-up period + washing period; Initial bath temperature = 30"C Cycle Heating-up period Washing period 40"C 5 mins. 15 mins.

60"C 15 mins. 15 mins.

95"C 30 mins. 15 mins.

(1) A bleaching composition described in footnote (b) in the table of Example 1.

Detergent concentration : 10 grams/liter; Tap water hardness : 350 ppm; six 10 x 10 cm. wine-stained swatches per bucket, in 600 ml. detergent solution; Reflectance readings are taken before and after the wash with a Gardner reflectometer XL-20, all the results being expressed as A Rd.

Detergent compositions B through F were formulated by adding the sequestering agents described below to Composition A.

Composition Added sequestering agent B 0.5 wt.% diethylene triamine pentamethylene phosphonic acid (1) C 0.1 wt.% diethylene triamine pentaacetic acid Mg. salt D 1 wt.% nitrilo triacetic acid (NTA) E 1 wt.% EDTA F 0.5 wt.% ethylene diamine tetramethylene phosphonic acid (2) The results of the bleaching tests are set forth below in Tables 1, the values of A Rd being provided as an average value for the particular composition and temperature indicated.

(1) Sold as Dequest 2060 by Monsanto Company, Inc., St. Louis, Missouri, U.S.A.

(2) Sold as Dequest 2041 by Monsanto Company, Inc.

TABLE 2 A Rd Values (average) Temp. B C D E F A 10"C 36 34.5 34.5 33 33 32 60"C 41 39 39 38.5 38.5 38 95"C 47 45 44 43 43 43 As indicated in Table 2, all the compositions containing sequestering agents provided improved bleaching performance relative to composition A which contained no sequestrant. Composition B containing Dequest 2060 provided the most improvement in bleaching of all the compositions tested.

It will be observed from Table 2 that the ratios of ingredients are A/B, 11.7:1 and (C+D+E)/(A+B), 12.5:1.

Claims (28)

1. A bleaching and laundering composition comprising monoperoxyphthalic acid and/or a water-soluble thereof and a chelating agent capable of forming a substantially water-solubie metal complex in aqueous solution.

2. A composition in accordance with Claim 1 which contains magnesium monoperoxyphthalate.

3. A composition in accordance with Claim 1 wherein the chelating agent is diethylene triamine pentamethylene phosphonic acid and/or a water-soluble salt thereof.

4. A composition in accordance with Claim 1 wherein the chelating agent is ethylene diamine tetraacetic acid and/or a water-soluble salt thereof.

5. A composition in accordance with Claim 1 wherein the weight ratio of chelating agent to monoperoxyphthalic acid and/or its salt is from about 1:5 to about 1:50..

6. A composition in accordance with Claim 5, wherein said weight ratio is from about 1:7 to about 1:20.

7. A composition in accordance with Claim 1, which additionally contains one or more surface active agents selected from the group consisting of anionic, cationic, nonionic, ampholytic and zwitterionic detergents.

8. A composition in accordance with Claim 1 wherein the concentration of the chelating agent is below about 2%, by weight.

9. A bleaching detergent composition comprising: (a) from about 5 to 50%, by weight, of a bleaching agent comprising monoperoxyphthalic acid and/or a water-soluble salt thereof, said bleaching agent being devoid of an inorganic peroxygen compound: (b) a chelating agent capable of forming a substantially water-soluble metal complex in aqueous solution: (c) from about 5 to 50, by weight, of one or more detergent surface active agents selected from the group consisting of anionic, cationic, non ionic, ampholytic and zwitterionic detergents: (d) from about 5 to 80%, by weight, of a detergent builder salt: and (e) the balance comprising water and optionally a filler salt.

10. A bleaching detergent composition comprising: as ingredient A, a bleaching agent comprising monoperoxyphthalic acid or a water-soluble salt thereof or a mixture thereof: as ingredient B), a chelating agent capable of forming a substantially water-soluble metal complex in aqueous solution: as ingredient C), one or more detergent surface active agents selected from the group consisting of anionic, cationic, nonionic, ampholytic and zwitterionic detergents, as ingredient D), one or more detergent builder salts: as optional ingredient E), one or more filler salts: the balance being water and minor amounts of adjuvants: the weight ratio of ingredient A two ingredient B being less than 15:1 and the weight ratio of the sum of ingredients C, D and E to the sum of ingredients A and B being at least 5.5:1.

11. A bleaching detergent composition as claimed in Claim 10 in which A/B is no more than 12:1.

12. A bleaching detergent composition as claimed in Claim 11 in which A/B is in the range 10:1 to 4:1.

13. A bleaching detergent composition as claimed in Claim 10, 11 or 12 in which (C+D+E)/(A+B) is at least 6.

14. A bleaching detergent composition as claimed in Claim 13 in which (C+D+ E)/(A+ B) is at least 10.

15. A bleaching detergent composition as claimed in Claim 14 in which (C+D+E)/(A+E) is in the range 10:1 to 20:1.

16. A bleaching detergent composition as claimed in any one of Claims 10 to 15 which is devoid of an organic peroxygen compound.

17. A bleaching detergent composition as claimed in any one of claims 10 to 16 in which the said bleaching agent comprises magnesium monoperoxyphthalate.

18. A composition as claimed in any one of Claims 10 to 17 in which the chelating agent comprises diethylene triamine pentamethylene phosphonic acid or a water-soluble salt thereof, or a mixture thereof.

19. A composition as claimed in any one of claims 10 to 18 in which the chelating agent comprises ethylene diamine tetraacetic acid or a water-soluble salt thereof, or a mixture thereof.

20. A composition as claimed in any one of Claims 10 to 19 in which the weight ratio of chelating agent to monoperoxyphthalic acid and/or its salt is from about 1:5 to about 1:50.

21. A bleaching detergent composition as claimed in any one of Claims 10 to 20 in which the concentration of the chelating agent is below about 5% by weight.

22. A bleaching detergent composition as claimed in Claim 21 in which the concentration of the chelating agent is below about 2%, by weight.

23. A process for bleaching which comprises containing the stained and/or soiled material to be bleached with an aqueous solution of a composition as claimed in ay one of Claims 10 to 22.

24. A process for manufacturing a composition as claimed in any one of Claims 10 to 22 which comprises: (a) forming an aqueous slurry containing said detergent surface active agent(s) and said detergent builder salt; (b) Spray-drying said aqueous slurry to form granular particles thereof: and (c) adding to the granular particles formed in step (b) a composition comprising monoperoxyphthalic acid and/or a water-soluble salt thereof and a chelating agent capable of forming a substantially water-soluble metal complex in aqueous solution to form the bleaching detergent composition.

25. A composition according to Claim 1 substantially as described with reference to any one of Examples 1, 2 and 3.

26. A process for bleaching stained and/or soiled material according to Claim 23 substantially as described with reference to any one of Examples 1, 2 and 3.

27. A process for manufacturing a composition according to Claim 24, substantially as described with reference to any one of Examples 1, 2 and 3.

28. An article or material whenever bleached and/or laundered by a process according to Claim 23 or 27 using a composition according to any one of Claims 1 to 22 and 25.