EP0137669A1

EP0137669A1 - Detergent compositions

Info

Publication number: EP0137669A1
Application number: EP84305681A
Authority: EP
Inventors: Nigel John Kermode; Charles David Bragg; Alastair John Pretty
Original assignee: Procter and Gamble Ltd; Procter and Gamble Co
Current assignee: Procter and Gamble Ltd; Procter and Gamble Co
Priority date: 1983-08-27
Filing date: 1984-08-21
Publication date: 1985-04-17
Also published as: JPS60106895A; IE842178L; EP0137669B1; JPH0635596B2; DE3472571D1; CA1230797A; IE57606B1

Abstract

Detergent compositions comprising from about 5% to about 60% organic surfactant, from about 7% to about 80% detergency builder essentially free of phosphate and a bleach system. The detergency builder has defined calcium builder capacity and defined magnesium: calcium selectivity and is preferably a mixture of an aluminosilicate and a polycarboxylate. The bleach system comprises peroxy bleaching agent, heavy metal scavenging agent and preferably a bleach activator. The compositions combine excellent bleach stability, fabric damage characteristics and detergency performance.

Description

The present invention relates to detergent compositions. In particular, it relates to built laundry detergent compositions which are essentially free of phosphate and have excellent cleaning, whiteness maintenance and stain-removal performance together with improved bleach stability and fabric-care characteristics.
The role of phosphate detergency builders as adjuncts for organic, water-soluble, synthetic detergents and their value in improving the overall performance of such detergents are well-known. In recent years, however, the use of high levels of phosphate builders, such as the tripolyphosphates, has come under scrutiny because of the suspicion that soluble phosphate species accelerate the eutrophication or ageing process of water bodies. The need exists, therefore for a built laundry detergent composition which is free of phosphate but which is comparable to a conventional tripolyphosphate-built composition in overall detergency effectiveness.
The mechanism whereby detergency builders function to improve the detergency action of water-soluble organic detergent compounds is not precisely known, but appears to depend on a combination of such factors as water-softening action, soil suspension and anti-redeposition effects, clay swelling and peptization and pH adjustment. However, present theory does not allow the prediction of which compounds will serve as effective detergency builders. Sodium aluminosilicates, commonly known as zeolites have been proposed for use as phosphate builder substitutes since they are able to soften water by removing calcium ions (see, for example, BE-A-814,874 and BE-A-813581). Zeolites are unable to duplicate the full range of builder functions demonstrated by phosphates, however, and in practice, they have been restricted to the role of a partial phosphate substitute.
One way of boosting the overall detergency of zero-phosphate formulations is through the use of bleaching auxiliaries such as the inorganic or organic peroxy bleaches and organic bleach activators. Although careful rebalancing of builder and bleach types and levels can indeed provide some improvement in performance, such formulations remain fundamentally weak in three areas, firstly bleach stability, secondly fabric damage characteristics, and thirdly, greasy and particulate soil removal especially at low wash temperatures.
Applicants have now found, however, that a zero phosphate builder system having defined building capacity and defined selectivity for magnesium versus calcium, in combination with certain heavy-metal scavenging agents results in excellent through-the-wash bleach stability and fabric damage characteristics. Moreover, applicants have further discovered that certain organic peroxy acid bleach precursors of defined chain length are operable in combination with the zero-phosphate builder system to provide at least phosphate-equivalent cleaning performance across the range of wash temperatures with particularly outstanding performance on greasy and particulate soils at low wash temperatures.
According to a first aspect of the invention, therefore, there is provided a detergent composition comprising

a) from about 5% to about 60% of organic surfactant selected from anionic, nonionic, zwitterionic, ampholytic and cationic surfactants and mixtures thereof,
b) from about 7% to about 80% of a detergency builder essentially free of phosphate having a calcium builder capacity at pH 10 and 25°C of at least 1.5 moles/kg and a magnesium:calcium selectivity factor of at least 0.2 and comprising
- (i)from 2% to 30% of polycarboxylate polymer selected from compounds having the empirical formula I
  wherein X is O or CH₂, Y is a comonomer or mixture of comonomers, R¹and R² are bleach and alkali-stable polymer-end groups, R³ is H, OH or ^C _l-4 alkyl, M is H, alkali metal, alkaline earth metal, ammonium or substituted ammonium groups, p is from O to 2, and n is at least 10, and mixtures thereof
- (ii) from 5% to 50% of a water insoluble ion-exchange material having the formula II
  wherein M is a calcium-exchange cation, z and y are at least 6; the molar ratio of z to y is in the range from about 1.0 to about 0.5; and x is from about 10 to about 264; the aluminosilicate having a calcium ion exchange capacity of at least 200 milligrams equivalent of CaC0_3/gram, a calcium ion exchange rate of at least about 2 grains of Ca²⁺/gallon/minute/gram/gallon, and a particle size diameter of from about 0.1 microns to about 10 microns, and
c) a bleach system comprising
- (i) from 5% to 35% of inorganic or organic peroxy bleaching agent,
- (ii) from 0% to 10% of organic peroxy acid bleach precursor, and
- (iii) a heavy metal scavenging agent.

In another aspect of the invention there is provided a detergent composition comprising

a) from about 5% to about 60% of organic surfactant selected from anionic, nonionic, zwitterionic, ampholytic and cationic surfacants and mixtures thereof,
b) from about 7% to about 80% of a detergency builder essentially free of phosphate having a calcium builder capacity at 25°C of at least 1.5 moles/kg and a magnesium:calcium selectivity factor of at least 0.2, and
c) a bleach system comprising
- (i) from 5% to 35% of inorganic or organic peroxy bleaching agent,
- (ii) from 0.5% to 10% of organic peroxy acid bleach precursor having the general formula IV, and
  wherein R⁴ is an alkyl group containing 6 to 12 carbon atoms wherein the longest linear alkyl chain extending from and including the carboxyl carbon contains from 5 to 10 carbon atoms and L is a leaving group, the conjugate acid of which has a pK a in the range from 6 to 13, and
- (iii) a heavy metal scavenging agent.

The compositions of the invention contain an organic surfactant, an essentially non-phosphate detergent builder and a bleach system. The detergent builder has defined calcium building capacity and defined magnesium:calcium building selectivity. The compositions can be liquid or solid, granular spray-dried compositions being preferred.
The compositions of the invention contain from about 7% to about 80%, preferably from about 10% to about 60%, more preferably from about 15% to about 50% of a detergency builder which is essentially free of phosphate, i.e. which contains less than about 2%, preferably less than about 1/2% phosphate on a compositional basis.
The detergency builder herein has a calcium building capacity at pH 10 and 25°C of at least 1.5, preferably at least 2.0, more preferably at least 3.5 moles Ca ²⁺/kg of builder and a magnesium:calcium selectivity factor of at least 0.2, preferably at least 0.25, more preferably at least 0.3. The building capacity and selectivity factor are measured as follows.
Calcium building capacity (C ) is measured using a Corning calcium ion selective electrode (from Scientific Products, Corning Medical, Corning Ltd., Halstead, Essex, England) with an Orion Double Junction Reference Electrode Model 90-02 (Orion Research Inc., Cambridge, Mass., U.S.A.) as reference. A calcium ion solution (0.05 M) is titrated into a solution (0.4%) containing the builder under test at pH 10 and 25°C. The free calcium ion concentration is determined as a function of added calcium ions using the calcium electrode precalibrated against a number of standard calcium solutions. The calcium ion solution is added until free calcium reaches 5 x 10 3M. Calcium building capacity is calculated graphically from the molar quantity of added calcium ions corresponding to the intercept at zero free calcium ion concentration of the gradient through 5 x 10^-3 M and is reported in moles Ca²⁺/kg of builder.
Magnesium:calcium selectivity factor is again determined using the calcium ion selective electrode. In this case, however, the hardness solution contains both calcium and magnesium ions (0.03 M each) and the calcium building capacity so measured (C₁), or more accurately the reduction in calcium building capacity (C_o- C₁), correlates with the selectivity of the builder for magnesium as compared with calcium. The selectivity factor herein is defined by the quotient (C₀ - C₁)/C₀.
The essentially zero-phosphate detergency builder preferably comprises a mixture of a polycarboxylate polymer and a water-insoluble, ion-exchangeable aluminosilicate. The polycarboxylate is preferably selected to have a magnesium building capacity of at least 2.0 preferably at least 3.0, more preferably at least 3.5 moles/kg as measured at both 25°C and 90°C; in other words, the builder should have substantial magnesium building capacity across the range of wash temperatures. Magnesium building capacity can be measured as for calcium building capacity above but using an Orion Divalent Cation Electrode. Alternatively, magnesium building capacity can be measured on the basis of a turbidity method as follows. A solution of magnesium ions (0.4M) is titrated into a solution of the polycarboxylate (1%) at pH 10.3 and at the specified temperature. The solution additionally contains 1.6:1 ratio sodium silicate (0.5%) as indicator. Precipitation of magnesium silicate above the building limit of the polycarboxylate is monitored using a Mettler phototitrator. Magnesium building capacity is calculated from the molar quantity of added magnesium corresponding to the point of maximum change in gradient in the turbidity vs added magnesium plot and is reported here in moles Mg²⁺/kg of polycarboxylate.
Preferred polycarboxylates fall into several categories. A first category belongs to the class of copolymeric polycarboxylates which, formally at least, are formed from an unsaturated polycarboxylic acid such as maleic acid, citraconic acid, itaconic acid and mesaconic acid as first monomer, and an unsaturated monocarboxylic acid such as acrylic acid or an alpha -C1-4 alkyl acrylic acid as second monomer. Referring to formula I, therefore, preferred polycarboxylates of this type are those in which X is CH₂, R³is H or C_1-4 alkyl, especially methyl, p is from about 0.1 to about 1.9, preferably from about 0.2 to about 1.5, n averages from about 10 to about 1500, preferably from about 50 to about 1000, more preferably from 100 to 800, especially from 120 to 400 and Y comprises monomer units of formula III
A second category belongs to the class of poly (alpha-hydroxyacrylates) in which, referring to formula I, X is CH₂, R³ is OH, p is from 0 to 0.1, preferably O and n averages from about 50 to 1500, preferably from about 100 to 1000. Y, if present, can be a polycarboxylic acid such as III above, or an ethylene oxide moiety.
A third category belongs to the class of acetal polycarboxylates in which, referring to formula I, X is O, R³is H, p is from 0 to 0.1, preferably O and n averages from 10 to 500. If present, Y again can be a polycarboxylic acid such as III above or an ethyleneoxide moiety.
A fourth category belongs to the class of homopolymeric polyacrylates in which referring to formula I, X is CH₂, R³is H or C_l-4 alkyl, p is 0 and n averages from about 10 to 1500, preferably from about 500 to 1000.
A fifth category of polycarboxylate has the formula I in which X is CH₂, R³is H or Cl-4 alkyl, especially methyl, p is from 0.01 to 0.09, preferably from 0.02 to 0.06, n averages from about 10 to about 1500, preferably from about 15 to about 300 and Y is a polycarboxylate formed from maleic acid, citraconic acid, itaconic acid or mesaconic acid, highly preferred being maleic acid-derived comonomers of formula III above.
The alkali-stable polymer end groups in formula I suitably include alkyl groups, oxyalkyl groups and alkyl carboxylic acid groups and salts and esters thereof.
In the above, n, the degree of polymerization of the polymer can be determined from the weight average polymer molecular weight by dividing the latter by the average monomer molecular weight. Thus, for a maleic-acrylic copolymer having a weight average molecular weight of 15,500 and comprising 30 mole % of maleic acid derived units, n is 182 (i.e. 15,500 / (l16 x 0.3 + 72 x 0.7).
In case of doubt, weight-average polymer molecular weights can be determined herein by gel permeation chromotography using Waters µPorasil (RTM) GPC 60 A and µBondagel (RTM) E-125, E-500 and E-1000 in series, temperature-controlled columns at 40⁰C against sodium polystyrene sulphonate polymer standards, available from Polymer Laboratories Ltd., Shropshire, UK, the polymer standards being calibrated as their sodium salts, and the eluant being 0.15M sodium dihydrogen phosphate and 0.02M tetramethyl ammonium hydroxide at pH 7.0 in 80/20 water/acetonitrile.
Mixtures of polycarboxylates are also suitable herein, especially mixtures comprising a high molecular weight component having an n value of at least 100, preferably at least 120, and a low molecular weight component having an n value of less than 100, preferably from 10 to 90, more preferably from 20 to 80. Such mixtures are optimum from the viewpoint of providing excellent bleach stability and anti-incrustation performance in the context of a zero-phosphate detergent formula.
In mixtures of this type, the weight ratio of high molecular weight component to low molecular weight component is generally at least 1:1, preferably from about 1.1:1 to about 20:1, more preferably from about 1.5:1 to about 10.1, especially from about 2:1 to about 8:1. Preferred polycarboxylates of the low molecular weight type are polycarboxylates of the fourth category (homopolyacrylates) listed above.
Of all the above, highly preferred polycarboxylates herein are those of the first category in which n averages from 100 to 800, preferably from 120 to 400 and mixtures thereof with polycarboxylates of the fourth category in which n averages from 10 to 90, preferably from 20 to 80.
According to a further aspect of the invention, therefore, there is provided a detergent composition comprising

a) from about 5% to about 60% of organic surfactant selected from anionic, nonionic, zwitterionic, ampholytic and cationic surfacants and mixtures thereof,
b) from about 7% to about 80% of a detergency builder essentially free of phosphate having a calcium builder capacity at 25°C of at least 1.5 moles/kg and a magnesium:calcium selectivity factor of at least 0.2, wherein the builder comprises from 2% to 30% of a mixture of
- (i) a copolymeric polycarboxylate having the general formula I:
  wherein X is CH₂, Y is a maleic-acid derived unit, R¹ and R² are bleach and alkali stable polymer-end groups, R³ is H, M is H, alkali metal, alkaline earth metal, ammonium or substituted ammonium, p is from about 0.1 to about 1.9 and n averages from 120 to 400, and
- (ii) a homopolymeric polyacrylate having the general I in which X, R^l, R², R and M are each as defined in (i) above, p is 0 and n averages from 10 to 90, preferably from 20 to 80, the weight ratio of copolymeric polycarboxylate to homopolymeric polyacrylate being at least 1:1, and
c) a bleach system comprising
- (i) from 5% to 35% of inorganic or organic peroxy bleaching agent,
- (ii) from 0% to 10% of organic peroxy acid bleach precursor, and
- (iii) a heavy metal scavenging agent.

The aluminosilicate ion-exchange materials herein are preferably those having the unit cell formula
wherein M is a calcium-exchange cation, z and y are at least 6; the molar ratio of z to y is from about 1.0 to about 0.5 and x is at least 5, preferably from about 7.5 to about 276, more preferably from about 10 to about 264. The aluminosilicate materials are in hydrated from and are preferably crystalline containing from about 10% to about 28%, more preferably from about 18% to about 22% water.
The aluminosilicate ion exchange materials are further characterized by a particle size diameter of from about 0.1 micron to about 10 microns, preferably from about 0.2 micron to about 4 microns. The term "particle size diameter" herein represents the average particle size diameter of a given ion exchange material as determined by conventional analytical techniques such as, for example, microscopic determination utilizing a scanning electron microscope. The aluminosilicate ion exchange materials herein are usually further characterised by their calcium ion exchange capacity, which is at least about 200 mg. equivalent of CaC0₃ water hardness/g of aluminosilicate, calculated on an anhydrous basis, and which generally is in the range of from about 300 mg eq./g to about 352 mg eq./g. The aluminosilicate ion exchange materials herein are still further characterized by their calcium ion exchange rate which is at least about 2 grains Ca /gallon/minute/gram/gallon of aluminosilicate (anhydrous basis), and generally lies within the range of from about 2 grains/gallon/minute/gram/gallon to about 6 grains/gallon/minute/gram/gallon, based on calcium ion hardness. Optimum aluminosilicates for builder purposes exhibit a calcium ion exchange rate of at least about 4 grains/gallon/minute/gram/gallon.
Aluminosilicate ion exchange materials useful in the practice of this invention are commercially available and can be naturally occurring aluminosilicates or synthetically derived. A method for producing aluminosilicate ion exchange materials is discussed in U.S.-A-3,985,669. Preferred synthetic crystalline aluminosilicate ion exchange materials useful herein are available under the designations Zeolite A, Zeolite B, Zeolite X, Zeolite HS and mixtures thereof. In an especially preferred embodiment, the crystalline aluminosilicate ion exchange material is Zeolite A and has the formula
wherein x is from about 20 to about 30, especially about 27. Zeolite X of formula Na₈₆ [(AlO₂)₈₆(SiO₂)₁₀₆] .^{276 H} ₂ ⁰ is also suitable, as well as Zeolite HS of formula ^Na₆ [(AlO₂)₆(Sio₂)₆] 7.5 H₂ ⁰).
The polycarboxylate and aluminosilicate components constitute from about 2% to about 30% and from about 5% to about 50% by weight of composition respectively, more preferably from about 3% to about 10% and from about 10% to about 25% respectively. As a percentage of the builder, polycarboxylate and aluminosilicate constitute from about 5% to about 60% and from 20% to 95% respectively, preferably from about 10% to about 40% and from 25% to 75% respectively. Importantly, the selection of polycarboxylate and the relative amounts of polycarboxylate and aluminosilicate should be such as to meet the critical magnesium:calcium selectivity factor. Usually, the weight ratio of polycarboxylate:aluminosilicate is from about 2:1 to 1:20, preferably from about 1:1 to 1:5. Preferred mixtures herein are such, however, that at a l:l ratio, the builder displays a magnesium:calcium selectivity factor of at least about 0.3, preferably at least about 0.35, more preferably at least about 0.4.
The polycarboxylate and aluminosilicate components of the present compositions can be replaced at least in part by other non-phosphate builder materials provided that the total builder system meets the constraints of calcium builder capacity and magnesium:calcium selectivity factor specified earlier.
Specific examples of non-phosphorus, inorganic builders are sodium and potassium carbonate, bicarbonate, sesquicarbonate, tetraborate decahydrate, and silicate having a molar ratio of Si0₂ to alkali metal oxide of from about 0.5 to about 4.0, preferably from about 1.0 to about 3.2, more preferably from about l.6 to about 2.4. "Seeded carbonate" builders as disclosed in Be-A-798,856 are also suitable. Water-soluble, non-phosphorus organic builders useful herein include the various alkali metal, ammonium and substituted ammonium carboxylates, monomeric polycarboxylates, polyhydroxysulfonates and nitrilotriacetates. Examples of monomeric polycarboxylate builders are the sodium, potassium, lithium, ammonium and substituted ammonium salts of oxydisuccinic acid, mellitic acid, benzene polycarboxylic acids, and citric acid.
Other useful builders herein are sodium and potassium carboxymethyloxymalonate, carboxymethyloxysuccinate, nitrilotriacetate, cis-cyclohexanehexacarboxylate, cis-cyclopentanetetracarboxylate, and phloroglucinol trisulfonate. Such additional non-phosphorus inorganic builders can be included in levels of from about 0.5% to about 8%, preferably from about 1% to about 4% by weight of composition.
The detergent compositions herein contain from about 5% to about 60% by weight of an organic surfactant selected from anionic, nonionic, zwitterionic, ampholytic and cationic surfactants, and mixtures thereof. The surfactant preferably represents from about 8% to about 30%, more preferably from about 10% to about 20% by weight in the case of solid compositions and from about 10% to about 50%, more preferably from about 15% to about 40% in the case of liquid compositions. Surfactants useful herein are listed in US-A-4,222,905 and US-A-4,239,659.
The anionic surfactant can be any one or more of the materials used conventionally in laundry detergents. Suitable synthetic anionic surfactants are water-soluble salts of alkyl benzene sulphonates, alkyl sulphates, alkyl polyethoxy ether sulphates, paraffin sulphonates, alpha-olefin sulphonates, alpha-sulpho-carboxylates and their esters, alkyl glyceryl ether sulphonates, fatty acid monoglyceride sulphates and sulphonates, alkyl phenol polyethoxy ether sulphates, 2-acyloxy alkane-l-sulphonate, and beta-alkyloxy alkane sulphonate.
A particularly suitable class of anionic surfactants includes water-soluble salts, particularly the alkali metal, ammonium and alkanolammonium salts or organic sulphuric reaction products having in their molecular structure an alkyl or alkaryl group containing from about 8 to about 22, especially from about 10 to about 20 carbon atoms and a sulphonic acid or sulphuric acid ester group. (Included in the term "alkyl" is the alkyl portion of acyl groups). Examples of this group of synthetic detergents which form part of the detergent compositions of the present invention are the sodium and potassium alkyl sulphates, especially those obtained by sulphating the higher alcohols (C8-18) carbon atoms produced by reducing the glycerides of tallow or coconut oil and sodium and potassium alkyl benzene sulphonates, in which the alkyl group contains from about 9 to about 15, especially about 11 to about 13, carbon atoms, in straight chain or branched chain configuration, e.g. those of the type described in U.S-A- 2,220,099 and U.S-A- 2,477,383 and those prepared from alkylbenzenes obtained by alkylation with straight chain chloroparaffins (using aluminium trichloride catalysis) or straight chain olefins (using hydrogen fluoride catalysis). Especially valuable are linear straight chain alkyl benzene sulphonates in which the average of the alkyl group is about _11.8 carbon atoms, abbreviated as C_ll.₈ LAS, and C12-C15 methyl branched alkyl sulphates.
Other anionic detergent compounds herein include the sodium C_10-18 alkyl glyceryl ether sulphonates, especially those ethers of higher alcohols derived from tallow and coconut oil; sodium coconut oil fatty acid monoglyceride sulphonates and sulphates; and sodium or potassium salts of alkyl phenol ethylene oxide ether sulphate containing about 1 to about 10 units of ethylene oxide per molecule and wherein the alkyl groups contain about 8 to about 12 carbon atoms.
Other useful anionic detergent compounds herein include the water-soluble salts or esters of alpha-sulphonated fatty acids containing from about 6 to 20 carbon atoms in the fatty acid group and from about 1 to 10 carbon atoms in the ester group; water-soluble salts of 2-acyloxy-alkane-l-sulphonic acids containing from about 2 to 9 carbon atoms in the acyl group and from about 9 to about 23 carbon atoms in the alkane moiety; alkyl ether sulphates containing from about 10 to 18, especially about 12 to 16, carbon atoms in the alkyl group and from about 1 to 12, especially 1 to 6, more especially 1 to 4 moles of ethylene oxide; water-soluble salts of olefin sulphonates containing from about 12 to 24, preferably aout 14 to 16, carbon atoms, especially those made by reaction with sulphur trioxide followed by neutralization under conditions such that any sultones present are hydrolysed to the corresponding hydroxy alkane sulphonates; water-soluble salts of paraffin sulphonates containing from about 8 to 24, especially 14 to 18 carbon atoms, and beta-alkyloxy alkane sulphonates containing from about 1 to 3 carbon atoms in the alkyl group and from about 8 to 20 carbon atoms in the alkane moiety.
The alkane chains of the foregoing non-soap anionic surfactants can be derived from natural sources such as coconut oil or tallow, or can be made synthetically as for example using the Ziegler or Oxo processes. Water solubility can be achieved by using alkali metal, ammonium or alkanolammonium cations; sodium is preferred. Suitable fatty acid soaps can be selected from the ordinary alkali metal (sodium, potassium), ammonium, and alkylolammonium salts of higher fatty acids containing from about 8 to about 24, preferably from about 10 to about 22 and especially from about 16 to about 22 carbon atoms in the alkyl chain. Suitable fatty acids can be obtained from natural sources such as, for instance, from soybean oil, castor oil, tallow, whale and fish oils, grease, lard and mixtures thereof). The fatty acids also can be synthetically prepared (e.g., by the oxidation of petroleum, or by hydrogenation of carbon monoxide by the Fischer-Tropsch process). Resin acids are suitable such as rosin and those resin acids in tall oil. Napthenic acids are also suitable. Sodium and potassium soaps can be made by direct saponification of the fats and oils or by the neutralization of the free fatty acids which are prepared in a separate manufacturing process. Particularly useful are the sodium and potassium salts of the mixtures of fatty acids derived from tallow and hydrogenated fish oil.
Mixtures of anionic surfactants are particularly suitable herein, especially mixtures of sulfonate and sulfate surfactants in a weight ratio of from about 5:1 to about 1:5, preferably from about 5:1 to about 1:1, more preferably from about 5:1 to about 1.5:1. Especially preferred is a mixture of an alkyl benzene sulfonate having from 9 to 15, especially 11 to 13 carbon atoms in the alkyl radical, the cation being an alkali metal, preferably sodium; and either an alkyl sulfate having from 10 to 20, preferably 12 to 18 carbon atoms in the alkyl radical or an ethoxy sulfate having from 10 to 20, preferably 10 to 16 carbon atoms in the alkyl radical and an average degree of ethoxylation of 1 to 6, having an alkali metal cation, preferably sodium.
The nonionic surfactants useful in the present invention are condensates of ethylene oxide with a hydrophobic moiety to provide a surfactant having an average hydrophilic-lipophilic balance (HLB) in the range from about 8 to 17, preferably from about 9.5 to 13.5, more preferably from about 10 to about 12.5. The hydrophobic moiety may be aliphatic or aromatic in nature and the length of the polyoxyethylene group which is condensed with any particular hydrophobic group can be readily adjusted to yield a water-soluble compound having the desired degree of balance between hydrophilic and hydrophobic elements.
Examples of suitable nonionic surfactants include:

1. The polyethylene oxide condensates of alkyl phenol, e.g. the condensation products of alkyl phenols having an alkyl group containing from 6 to 12 carbon atoms in either a straight chain or branched chain configuration, with ethylene oxide, the said ethylene oxide being present in amounts equal to 3 to 30, preferably 5 to 14 moles of ethylene oxide per mole of alkyl phenol. The alkyl substituent in such compounds may be derived, for example, from polymerised propylene, di-isobutylene, octene and nonene. Other examples include dodecylphenol condensed with 9 moles of ethylene oxide per mole of phenol; dinonylphenol condensed with 11 moles of ethylene oxide per mole of phenol; nonylphenol and di-isooctylphenol condensed with l3 moles of ethylene oxide.
2. The condensation product of primary or secondary aliphatic alcohols having from 8 to 24 carbon atoms, in either straight chain or branched chain configuration, with from 2 to about 40 moles, preferably 2 to about 9 moles of ethylene oxide per mole of alcohol. Preferably, the aliphatic alcohol comprises between 9 and 18 carbon atoms and is ethoxylated with between 2 and 9, desirably between 3 and 8 moles of ethylene oxide per mole of aliphatic alcohol. The preferred surfactants are prepared from primary alcohols which are either linear (such as those derived from natural fats or, prepared by the Ziegler process from ethylene, e.g. myristyl, cetyl, stearyl alcohols), or partly branched such as the Lutensols, Dobanols and Neodols which have about 25% 2-methyl branching (Lutensol being a Trade Name of BASF, Dobanol and Neodol being Trade Names of Shell), or Synperonics, which are understood to have about 50% 2-methyl branching (Synperonic is a Trade Name of I.C.I.) or the primary alcohols having more than 50% branched chain structure sold under the Trade Name Lial by Liquichimica. Specific examples of nonionic surfactants falling within the scope of the invention include Dobanol 45-4, Dobanol 45-7, Dobanol 45-9, Dobanol 91-2.5, Dobanol 91-3, Dobanol 91-4, Dobanol 91-6, Dobanol 91-8, Dobanol 23-6.5, Synperonic 6, Synperonic 14, the condensation products of coconut alcohol with an average of between 5 and 12 moles of ethylene oxide per mole of alcohol, the coconut alkyl portion having from 10 to 14 carbon atoms, and the condensation products of tallow alcohol with an average of between 7 and 12 moles of ethylene oxide per mole of alcohol, the tallow portion comprising essentially between 16 and 22 carbon atoms. Secondary linear alkyl ethoxylates are also suitable in the present compositions, especially those ethoxylates of the Tergitol series having from about 9 to 15 carbon atoms in the alkyl group and up to about 11, especially from about 3 to 9, ethoxy residues per molecule.

The compounds formed by condensing ethylene oxide with a hydrophobic base formed by the condensation of propylene oxide with propylene glycol. The molecular weight of the hydrophobic portion generally falls in the range of about 1500 to 1800. Such synthetic nonionic detergents are available on the market under the Trade Name of "Pluronic" supplied by Wyandotte Chemicals Corporation.
Especially preferred nonionic surfactants for use herein are the C₉-C₁₅ primary alcohol ethoxylates containing 3-8 moles of ethylene oxide per mole of alcohol, particularly the C₁₂-C₁₅ primary alcohols containing 6-8 moles of ethylene oxide per mole of alcohol.
Cationic surfactants suitable for use herein include quaternary ammonium surfactants and surfactants of a semi-polar nature, for example amine oxides.
Suitable surfactants of the amine oxide class have the general formula V
wherein R⁵ is a linear or branched alkyl or alkenyl group having 8 to 20 carbon atoms, each R⁶ is independently selected from C_1-4 alkyl and -(C_nH_2nO)_mH where i is an integer from 1 to 6, j is 0 or 1, n is 2 or 3 and m is from 1 to 7, the sum total of C_nH_2nO groups in a molecule being no more than 7.
In a preferred embodiment R has from 10 to 14 carbon atoms and each R⁶ is independently selected from methyl and -(C_nH_2nO)_mH wherein m is from 1 to 3 and the sum total of C_nH_2nO groups in a molecule is no more than 5, preferably no more than 3. In a highly preferred embodiment, j is O and each _R ⁶ is methyl, and R⁵ is C12-C14 alkyl.
Another suitable class of amine oxide species is represented by bis-amine oxides having the following substituents.

j : 1
R⁵: tallow C₁₆-C₁₈ alkyl; palmityl; oleyl; stearyl
^R ₆: hydroxyethyl
i : 2 or 3

A specific example of this preferred class of bis-amine oxides is N-hydrogenated C16-C18 tallow alkyl-N,N',N'tri-(2-hydroxyethyl) -propylene-1,3-diamine oxide.
Suitable quaternary ammonium surfactants for use in the present composition can be defined by the general formula VI:
wherein R⁷ is a linear or branched alkyl, alkenyl or alkaryl group having 8 to 16 carbon atoms and each R⁸ is independently selected from C_1-4 alkyl, C_1-4 alkaryl and -(C_nH_2nO)_m wherein i is an integer from 1 to 6, j is 0 or 1, n is 2 or 3 and m is from 1 to 7, the sum total of C_nH_2nO groups in a molecule being no more than 7, and wherein Z represents counteranion in number to give electrical neutrality.
In a preferred embodiment, R⁷ has from 10 to 14 carbon atoms and each R⁸ is independently selected from methyl and (CnH_2nO)_mH wherein m is from 1 to 3 and the sum total of C_nH_2nO groups in a molecule is no more than 5, preferably no more than 3. In a highly preferred embodiment j is 0, R⁸ is selected from methyl, hydroxyethyl and hydroxypropyl and R⁷ is C₁₂-C₁₄ alkyl. Particularly preferred surfactants of this class include C₁₂ alkyl trimethylammonium salts, C₁₄ alkyltrimethylammonium salts, coconutalkyltrimethylammonium salts, coconutalkyldimethyl-hydroxyethylammonium salts, coconutalkyldimethylhydroxy-propylammonium salts, and C₁₂ alkyldihydroxyethylmethyl ammonium salts.
Another group of useful cationic compounds are the diammonium salts of formula VI in which j is 1, R⁷ is C₁₂-C₁₄ alkyl, each R⁸is methyl, hydroxyethyl or hydroxypropyl and i is 2 or 3. In a particularly preferred surfactant of this type, R ,is coconut alkyl, R⁸is methyl and i is 3.
The detergent compositions of the invention also include a bleach system comprising an inorganic or organic peroxy bleaching agent, a heavy metal scavenging agent and in preferred compositions, an organic peroxy acid bleach precursor.
Suitable inorganic peroxygen bleaches include sodium perborate mono- and tetrahydrate, sodium percarbonate, sodium persilicate and urea-hydrogen peroxide addition products and the clathrate 4Na2So4:2H202:lNaCl. Suitable organic bleaches include peroxylauric acid, peroxyoctanoic acid, peroxynonanoic acid, peroxydecanoic acid, diperoxydodecanedioic acid, diperoxyazelaic acid, mono- and diperoxyphthalic acid and mono-and diperoxyisophthalic acid. The bleaching agent is present in the compositions of the invention at a level of from about 5% to about 35% preferably from about 10% to about 25% by weight.
The heavy metal scavenging agent is preferably a water-soluble chelating agent. Preferred are aminopolyacids having four or more acidic protons per molecule. Suitable chelating agents include aminocarboxylate chelating agents such as ethylenediaminetetraacetic acid (EDTA), hydroxyethylethylenediaminetriacetic acid (HEEDTA), dihydroxyethylethylenediaminediacetic acid (DHEEDDA), diethylenetriaminepentaacetic acid (DETPA), 1,2-diaminocyclohexane-N,N,N',N'-tetraacetic acid (DCTA) and water-soluble salts thereof, and aminopolyphosphonate chelating agents such as ethylenediaminetetra(methylenephosphonic acid) (EDTMP), diethylenetriaminepenta(methylenephosphonic acid) (DETPMP), nitrilotri(methylenephosphonic acid) (NTMP), hexamethylenediaminetetramethylenephosphonic acid (HMTPM) and water-soluble salts thereof. The above water-soluble sequestrants are generally at a level of from about 0.05% to about 4% preferably from about 0.1% to about 1.0% by weight. In any event the total content of phosphorus in the present compositions is preferably no more than about 1%, more preferably no more than about 0.1% by weight of total composition.
The heavy metal scavenging agent herein can also be represented by water-soluble smectite-type clays selected from saponites, hectorites and sodium and calcium montmorillorites (sodium and calcium here designating the principal inorganic cation of the clay).
While any of the above smectite-type clays can be incorporated in the compositions of the invention, particularly preferred smectite-type clays have ion-exchange capacities of at least 50 meq/100g clay, more preferably at least 70 meq/100g (measured, for instance, as described in "The Chemistry and Physics of Clays", p.p. 264-265, Interscience (1979)). Especially preferred materials are as follows:-

Sodium Montmorillonite
- Brock
- Volclay BC
- Gelwhite GP
- Thixo-Jel
- Ben-A-Gel
- Imvite
Sodium Hectorite
- Veegum F
- Laponite SP
Sodium Saponite
- Barasym NAS 100
Calcium Montmorillonite
- Soft Clark
- Gelwhite L
Lithium Hectorite
- Barasym LIH 200

When present, the above clays are generally added at a level of from about 1% to about 20%, more preferably from about 2% to about 10% by weight of composition. Such clays also provide a fabric softening benefit to the compositions.
Another suitable heavy metal scavenging agent is water-insoluble, preferably colloidal magnesium silicate or a water-soluble magnesium salt forming magnesium silicate in the aqueous slurry crutcher mix prior to spray-drying. The magnesium silicate or salt is generally added at a level in the range from about 0.015% to about 0.2%, preferably from about 0.03% to about 0.15%, more preferably from about 0.05% to about 0.12% by weight (magnesium basis). Suitable magnesium salts include magnesium sulfate, magnesium sulfate hepatydrate, magnesium chloride and magnesium chloride hexahydrate.
The compositions of the invention preferably also contain an organic peroxy acid bleach precursor at a level of from about 0.5% to about 10%, preferably from about 1% to about 6% by weight. Suitable bleach precursors are disclosed in UK-A-2040983, and include for example, the peracetic acid bleach precursors such as tetraacetylethylenediamine, tetraacetylmethylenediamine, tetraacetylhexylenediamine, sodium p-acetoxybenzene sulphonate, tetraacetylglycouril, pentaacetylglucose, octaacetyllactose, and methyl o-acetoxy benzoate. Highly preferred bleach precursors, however, have the general formula IV
wherein R₄ is an alkyl group containing from 6 to 12 carbon atoms wherein the longest linear alkyl chain extending from and including the carboxyl carbon contains from 5 to 10 carbon atoms and L is a leaving group, the conjugate acid of which has a pK a in the range from 6 to 13.
The alkyl group, R₄, can be either linear or branched and, in preferred embodiments, it contains from 7 to 9 carbon atoms. Preferred leaving groups L have a pK a in the range from about 7 to about 11, more preferably from about 8 to about 10. Examples of leaving groups are those having the formula
and
wherein Z is H, R⁹or halogen, R⁹ is an alkyl group having from 1 to 4 carbon atoms, x is 0 or an integer of from 1 to 4 and Y is selected from S0₃M, OS0₃M, C0₂M, N⁺(R⁹)₃Q^- and N⁺(R⁹)₂-O^- wherein M is H, alkali metal, alkaline earth metal, ammonium or substituted ammonium, and Q is halide or methosulfate.
The preferred leaving group L has the formula (a) in which _Z is H, x is 0 and Y is sulfonate, carboxylate or dimethylamine oxide radical. Highly preferred materials are sodium 3,5,5,-trimethylhexanoyloxybenzene sulfonate, sodium 3,5,5-trimethylhexanoyloxybenzoate, sodium 2-ethylhexanoyl oxybenzenesulfonate, sodium nonanoyl oxybenzene sulfonate and sodium octanoyl oxybenzenesulfonate, the acyloxy group in each instance preferably being p-substituted.
The bleach activator herein will normally be added in the form of particles comprising finely-divided bleach activator and a binder The binder is generally selected from nonionic surfactants such as the ethoxylated tallow alcohols, polyethylene glycols, anionic surfactants, film forming polymers, fatty acids and mixtures thereof. Highly preferred are nonionic surfactant binders, the bleach activator being admixed with the binder and extruded in the form of elongated particles through a radial extruder as described in European Patent Application No. 62523.
The compositions of the invention can be supplemented by all manner of detergent and laundering components, inclusive of suds suppressors, enzymes, fluorescers, photoactivators, bleach catalysts, soil suspending agents, anti-caking agents, pigments, perfumes, fabric conditioning agents etc.
Suds suppressors are represented by materials of the silicone, wax, vegetable and hydrocarbon oil and phosphate ester varieties. Suitable silicone suds controlling agents include polydimethylsiloxanes having a molecular weight in the range from about 200 to about 200,000 and a kinematic viscosity in the range from about 20 to about 2,000,000 mm ²/s, preferably from about 3000 to about 30,000 mm²/s, and mixtures of siloxanes and hydrophobic silanated (preferably trimethylsilanated) silica having a particle size in the range from about 10 millimicrons to about 20 millimicrons and a specific surface area above about 50 m²/g. Suitable waxes include microcrystalline waxes having a melting point in the range from about 65⁰C to about 100^oC, a molecular weight in the range from about 400-1000, and a penetration value of at least 6, measured at 77°F by ASTM-D1321, and also paraffin waxes, synthetic waxes and natural waxes. Suitable phosphate esters include mono- and/or di-^C ₁₆-^C ₂₂ alkyl or alkenyl phosphate esters, and the corresponding mono- and/or di alkyl or alkenyl ether phosphates containing up to 6 ethoxy groups per molecule.
Enzymes suitable for use herein include those discussed in US-A-3,519,570 and US-A-3,533,139 to McCarty and McCarty et al issued July 7, 1970 and January 5, 1971, respectively. Suitable fluorescers include Blankophor MBBH (Bayer AG) and Tinopal CBS and EMS (Ciba Geigy). Photoactivators are discussed in EP-A-57088, highly preferred materials being zinc phthalocyanine tri- and tetra-sulfonates. Suitable fabric conditioning agents include di-C12-C24 alkyl or alkenyl amines and ammonium and quaternary ammonium salts. Suitable bleach catalysts are discussed in European Patent Application No. 72166 and European Patent Application No. 84302774.9.
Antiredeposition and soil suspension agents suitable herein include cellulose derivatives such as methylcellulose, carboxymethylcellulose and hydroxyethylcellulose.
Liquid detergent compositions of the invention can additionally be supplemented by pH regulators such as potassium hydroxide, potassium carbonate, potassium bicarbonate, sodium hydroxide, sodium carbonate, sodium bicarbonate, and mono-, di-and triethanolamine; solvents such as ethyl alcohol, isopropanol, propylene glycol, propane-1, 2-diol, hexyleneglycol; and hydrotopes such as urea.
Granular detergent compositions of the invention are preferably prepared by spray-drying an aqueous slurry comprising the anionic surfactant and detergency builder. The aqueous slurry is mixed at a temperature in the range from about 70-90°C and the water-content of the slurry adjusted to a range of about 25% Spray drying is undertaken with a drying gas inlet temperature of from about 250-350°C, preferably about 275-330°C, providing a final moisture content in the range of from about 8% to 14% by weight.
In the Examples which follow, the abbreviations used have the following designations:-

Examples I to VIII

Granular detergent compositions are prepared as follows. A base powder composition is first prepared by mixing all components except Dobanol 45E7, bleach, bleach activator, enzyme and suds suppressor in a crutcher as an aqueous slurry at a temperature of about 80°C and containing about 35% water. The slurry is then spray dried at a gas inlet temperature of about 300°C to form base powder granules. The bleach activator, where present, is then admixed with TAE₈₀ as binder and extruded in the form of elongate particles through a radial extruder as described in European Patent Application Number 62523. The bleach activator noodles, bleach, enzyme and suds suppressor are then dry-mixed with the base powder composition and finally Dobanol 45E7 is sprayed into the final mixture.

EXAMPLES

EXAMPLES (Contd)

The above compositions are zero phosphate detergent compositions displaying excellent bleach stability, fabric care and detergency performance across the range of wash temperatures with particularly outstanding performance in the case of Examples I to IV on greasy and particulate soils at low wash temperatures.

Examples IX to XII

The following granular detergent compositions are prepared as described in Examples I to VIII above.
The above compositions are zero phosphate detergent compositions displaying excellent bleach stability, fabric care and detergency performance across the range of wash temperatures with outstanding whiteness maintenance performance and low wash temperature detergency performance on greasy and particulate soils.

Examples XIII to XV

Claims

1. A detergent composition characterized by:

a) from about 5% to about 60% of organic surfactant selected from anionic, nonionic, zwitterionic, ampholytic and cationic surfactants and mixtures thereof,

b) from about 7% to about 80% of a detergency builder essentially free of phosphate having a calcium builder capacity at pH 10 and 25°C of at least 1.5 moles/kg and a magnesium:calcium selectivity factor of at least 0.2 and comprising

(i) from 2% to 30% of polycarboxylate polymer selected from compounds having the empirical formula I

wherein X is O or CH , Y is a comonomer or comonomer mixture, R and R² are bleach and alkali-stable polymer-end groups, R³ is H, OH or C_1-4 alkyl, M is H, alkali metal, alkaline earth metal, ammonium or substituted ammonium, p is from O to 2, and n is at least 10, and mixtures thereof (ii) from 5% to 50% of a water insoluble ion-exchange material having the formula II

wherein M is a calcium-exchange cation, z and y are at least 6; the molar ratio of z to y is in the range from about 1.0 to about 0.5; and x is from about 10 to about 264; the aluminosilicate having a calcium ion exchange capacity of at least 200 milligrams equivalent of CaC0_3/gram, a calcium ion exchange rate of at least about 2 grains of Ca²⁺/gallon/minute/gram/gallon, and a particule size diameter of from about 0.1 microns to about 10 microns, and

c) a bleach system comprising

(i) from 5% to 35% of inorganic or organic peroxy bleaching agent,

(ii) from 0% to 10% of organic peroxy acid bleach precursor, and

(iii) a heavy metal scavenging agent.

2. A composition according to claim 1 characterized in that in formula I, Y comprises monomer units having formula III

3. A composition according to claim 1 or 2 characterized in that in formula I, X is CH₂, R³ is H or c_1-4 alkyl, p is from 0.1 to 1.9 and n averages from 10 to 1500, preferably from 100 to 800, more preferably from 120 to 400.

4. A composition according to claim 1 or 2 characterized in that in formula I, X is CH₂, R³is OH, p is from 0 to 0.1, preferably 0, and n averages from 50 to 1500.

5. A composition according to claim 1 or 2 characterized in that in formula I, X is O, R³ is H, p is from 0 to 0.1, preferably 0 and n averages from 10 to 500.

6. A composition according to claim 1 or 2 characterized in that in formula I, X is CH₂, R³is H or C_l-4 alkyl, p is 0, and n averages from 10 to 1500.

7. A composition according to claim 1 or 2 characterized in that in formula I, X is CH₂, R³is H or C_l-4 alkyl, p is from 0.01 to 0.09, and n averages from 10 to 1500, preferably from 15 to 300.

8. A composition according to any of claims 1 to 7 characterized by from 3% to 10% of polycarboxylate and from 10% to 25% of water-insoluble aluminosilicate.

9. A composition according to any of claims 1 to 8 characterized in that the polycarboxylate polymer is a mixture comprising a high molecular weight component having an n value averaging at least 100, preferably at least 120, and a low molecular weight component having an n value averaging less than 100, preferably from 10 to 90, more preferably from 20 to 80, the weight ratio of high molecular weight component to low molecular weight component being at least 1:1, preferably from 1.1:1 to 10:1.

10. A composition according to Claim 1 characterized in that the polycarboxylate polymer comprises a mixture of

(i)a copolymeric polycarboxylate having the general formula I:

wherein X is CH₂, Y is a maleic-acid derived unit, _R ¹ and R² are bleach and alkali stable polymer-end groups, R³ is H, M is H, alkali metal, alkaline earth metal, ammonium or substituted ammonium, p is from about 0.1 to about 1.9 and n averages from l20 to 400, and

(ii) a homopolymeric polyacrylate having the general I in which X, R^l, R², R³ and M are each as defined in (i) above, p is 0 and n averages from 10 to 90, preferably from 20 to 80, the weight ratio of copolymeric polycarboxylate to homopolymeric polyacrylate being at least 1:1.

11. A composition according to any of claims 1 to 10 characterized in that the heavy metal scavenging agent is a chelating agent selected from water-soluble aminopolycarboxylates and aminopolyphosphonates having at least four acidic protons per molecule or a water-insoluble smectite-type clay selected from saponites, hectorites and sodium and calcium montmorillonites.

12. A composition according to any of claims 1 to 11 characterized in that the organic peroxy acid bleach precursor has the general formula IV.

wherein R⁴ is an alkyl group containing from 6 to 12 carbon atoms wherein the longest linear alkyl chain extending from and including the carboxyl carbon contains from 5 to 10 carbon atoms and L is a leaving group, the conjugate acid of which has a pK a in the range from 6 to 13.

l3. A composition according to any of claims 1 to 12 characterized by a phosphorus content of no more than 1%, preferably no more than 0.1% by weight.

14. A detergent composition characterized by:

a) from about 5% to about 60% on organic surfactant selected from anionic, nonionic, zwitterionic, ampholytic and cationic surfactants and mixtures thereof,

b) from about 7% to about 80% of a detergency builder essentially free of phosphate having a calcium builder capacity at pH 10 and 25°C of at least 1.5 moles/kg and a magnesium:calcium selectivity factor of at least 0.2, and

c) a bleach system comprising

(i) from 5% to 35% of inorganic or organic peroxy bleaching agent,

(ii) from 0.5% to 10% of organic peroxy acid bleach precursor having the general formula IV

wherein R⁴ is an alkyl group containing from 6 to 12 carbon atoms wherein the longest linear alkyl chain extending from and including the carboxyl carbon contains from 5 to 10 carbon atoms and L is a leaving group, the conjugate acid of which has a pK in the range from 6 to 13, and

(iii) a heavy metal scavenging agent.

15. A detergent composition characterized by

(a) from about 5% to about 60% of organic surfactant selected from anionic, nonionic, zwitterionic, ampholytic and cationic surfacants and mixtures thereof,

b) from about 7% to about 80% of a detergency builder essentially free of phosphate having a calcium builder capacity at 25°C of at least 1.5 moles/kg and a magnesium:calcium selectivity factor of at least 0.2, wherein the builder comprises from 2% to 30% of a mixture of

(i) a copolymeric polycarboxylate having the general formula I:

wherein X is CH₂, Y is a maleic-acid derived unit, R and _R ² are bleach and alkali stable polymer-end groups, R³ is H, M is H, alkali metal, alkaline earth metal, ammonium or substituted ammonium, p is from about 0.1 to about 1.9 and n averages from 120 to 400, and

(ii) a homopolymeric polyacrylate having the general I in which X, R¹, R², R³ and M are each as defined in (i) above, p is 0 and n averages from 10 to 90, preferably from 20 to 80, the weight ratio of copolymeric polycarboxylate to homopolymeric polyacrylate at least 1:1, and

c) a bleach system comprising

(i) from 5% to 35% of inorganic or organic peroxy bleaching agent,

(ii) from 0% to 10% of organic peroxy acid bleach precursor, and

(iii) a heavy metal scavenging agent.