Field of the Invention The present invention relates to a detergent composition comprising a high ratio of

SKS-6, in comparison to other builders and alkaline materials, to provide a low dosage in terms of weight per usage.

Background of the Invention Conventional detergents for clothing have been produced by adding fillers, which do not substantially contribute to the detergent performance to them.

However, since a large amount of these detergents must be used for attaining sufficient detergency in washing with them, not only their transportation cost increased but also a considerably large space was required for their custody and display. Further, in general homes, a place to put the same was troublesome and their weighing was difficult. Thus, in recent year, a high-bulk density detergent capable of undergoing washing in a small amount thereof for use has been put on the market.

In general, when such a high-bulk density detergent is used for washing with 30 liters of water, the dose thereof is from 25 to 30g. However, it has heretofore been considered difficult to further reduce the dose thereof still with maintaining the same detergent power, namely with maintaining the suitable pH, the suitable calcium- sequestering capacity and the suitable surfactant amount as the high bulk density detergent on the market.

Under the situation, the present inventors have noted a crystalline stratiform sodium silicate having plural functions of alkalines source and detergent builder. They have incorporated high level of said silicate into a detergent composition at the reduction of other alkaline sources and detergent builders. By replacement of other builders and other alkaline materials with said crystalline stratiform sodium silicate, they have attained reduction of the dose of a detergent composition to be less than 25g per 30 liter, preferably from 14g to 21g per 30 liters of washing water, while maintaining the excellent detergent power. A detergent composition containing a crystalline stratiform sodium silicate has been disclosed, for example, in JP-A 2- 178398 (assigned to Lion Corp.)(the term "JP-A" as used herein means an "unexamined published Japanese patent application") and WO9218594 (assigned to Procter & Gamble Co.), which, however, do not have an object of small dose of the detergent composition to be from 14g to 21g per 30 liters of washing water, unlike the present invention.

Detailed Description of the Invention The present invention relates to a detergent composition comprising:

(i) from 10 % to 40 %, preferably from 20 % to 35 %, of a crystalline stratiform sodium silicate,

(ii) from 25 % to 65 %, preferably from 30 % to 50 %, of a detergent surfactant, (iii) from 0 % to 20 % , preferably from 0 % to 18 %, of a bleaching component, and (iv) less than 50 %, preferably less than 30 %, of other builders and other alkaline materials, wherein the ratio R of crystalline stratiform sodium silicate to the sum of other builders and other alkaline materials is not less than 0.34, preferably not less than 0.5, and more preferably not less than 1. The above-mentioned crystalline stratiform sodium silicate, preferably has a composition represented by the following formula.

NaMSi _x θ2χ+i yH2θ wherein M represents sodium or hydrogen; x is from 1.9 to 4; and y is from 0 to 20. Such crystalline stratiform sodium silicate is described in JP-A 60-227895 and 2- 178398. It is available, for example, as SKS-6 (made by Hoechst AG) having a chemical formula of Na2Si2θ5.

Another preferred layered silicate is disclosed in EP Publication 550,048, July 7, 1993 (Kao), which discloses a synthesized crystalline material having a chain structure and having a composition represented by the following formula in anhydrous form: _x M2θ ySiθ2 z O, wherein M represents Na and/or K; M' represents Ca and/or Mg; y/x is 0.5 to 2.0; and z/x is 0.005 to 1.0, said chain structure appearing as a main scattering peak in Raman spectra at least 970+20 cm ^-1 in the range of 900 to 1200 cm ^-1 .

The detergent surfactant of the present invention is selected from anionic surfactant, nonionic surfactant, cationic surfactant, amphoteric surfactant and mixture thereof. The anionic surfactant can include secondary Cio - Ci8 alcohol sulfates, Cio - Ci8 alkylbenzene sulfonates, alkyl sulfates, and alkylethoxy sulfates, a-sulfofatty acid ester salts, fatty acid salts (soap) and olefinsulfonates. The nonionic surfactant can include Cio - Ci6 alcohol ethoxylates comprising an alcohol having ethylene oxide added thereto, nonylphenol ethoxylate, adducts comprising an alcohol having propylene oxide and ethylene oxide added thereto, fatty acid alkanolamides, sucrose fatty acid esters, alkylamine oxides and polyhydroxy-fatty acid amides. The detergent

surfactant of the present invention also can be selected from description of WO9218594 which is incorporated herein by reference.

The bleaching component which can optionally be used in the detergent composition of the present invention. The bleaching component can be a source of " OOH group, such as sodium perborate monohydrate, sodium perborate tetrahydrate and sodium percarbonate. Sodium percarbonate (2Na2CO3*3H2O2) is preferred since it has a dual function of both a source of HOOH and a source of sodium carbonate.

Another useful bleaching component is a bleaching precursor, for example, nonanoyloxybenzene sulfonate represented by a formula; O

II

R - C - O - (C6H4) -SO3 " Q ⁺ wherein R represents a linear or branched alkyl chain having approximately from 5 to 12 carbon atoms, preferably approximately from 6 to 8 carbon atoms, and preferably at least one alkyl group is bonded to the second or third carbon atom counting from carbonyl group; and Q represents sodium or potassium. The bleaching precursor is used in combination with a source of "OOH group such as sodium perborate monohydrate, sodium perborate tetrahydrate and sodium percarbonate to form a peracid in the wash solution. Another bleaching component is a peracid per se, such as a formula:

CH3(CH2)w-NH-CO-(CH2)zCO3H wherein z is from 2 to 4 and w is from 4 to 10. (The compound of the latter formula where z is 4 and w is 8 is hereinafter referred to as NAPAA.) The bleaching component can contain, as a bleaching component stabilizer, a chelating agent of polyaminocarboxylic acids polyaminocarboxylates such as ethylenediaminetetraacetic acid, diethylenetriaminepentaacetic acid and ethylenediaminedisuccinic acid and their salts with water-soluble alkali metals.

The other builders and other alkaline materials which can be used in the detergent composition of the present invention in addition to crystalline stratiform sodium silicate, are for example, a phosphate and non-phosphate calcium ion sequestering builder, a dispersing agent, and an alkaline builder. The phosphate calcium ion sequestering builder can include sodium tripoly phosphate and sodium pyrophosphate as well as organic phosphonates and aminoalkylene poly (alkylene phosphonates). Organic phosphonates and amino alkylene poly (alkylene phosphonates) include alkali metal ethane 1-hydroxy diphosphonates, nitrilo trimethylene phosphonates, ethylene diamine tetra methylene phosphonates and diethylene triamine penta methylene phosphonates, although these materials are less preferred where the minimisation of

phosphorus compounds in the compositions is desired. The non-phosphate calcium ion sequestering builder can include alkali metal aluminosilicates, monomeric polycarboxylates, homo or copolymeric polycarboxylic acids or their salts in which the polycarboxylic acid comprises at least two carboxylic radicals separated from each other by not more than two carbon atoms, carbonates, silicates, citric acid and mixtures of any of the foregoing. Whilst a range of aluminosilicate ion exchange materials can be used, preferred sodium aluminosilicate zeolites have the unit cell formula

Nar [ ( A102 ) r ( Siθ2 ) s ] t H ₂ O wherein r and s are at least 6; the molar ratio of r to s is from 1.0 to 0.5 and t is at least 5, preferably from 7.5 to 276, more preferably from 10 to 264. The aluminosilicate materials are in hydrated form and are preferably crystalline, containing from 10% to 28%, more preferably from 18% to 22% water in bound form. The above aluminosilicate ion exchange materials are further characterised by a particle size diameter of from 0.1 to 10 micrometers, preferably from 0.2 to 4 micrometers. 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 or by means of a laser granulometer. The aluminosilicate ion exchange materials are further characterised by their calcium ion exchange capacity, which is at least 200mg equivalent of CaCO3 water hardness/g of aluminosilicate, calculated on an anhydrous basis, and which generally is in the range of from 300mg eq./g to 352mg eq./g. The aluminosilicate ion exchange materials herein are still further characterised by their calcium ion exchange rate which is at least 130mg equivalent of CaCθ3/liter/minute/(g liter) [2 grains Ca ⁺⁺ /gallon/minute/(gram/gallon)] of aluminosilicate (anhydrous basis), and which generally lies within the range of from 130mg equivalent of CaCO3/liter/minute/(gram/liter) [2 grains/gallon/minute (gram/gallon)] to 390mg equivalent of

CaCθ3/liter/minute (gram/liter) [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 260mg equivalent of CaC03/liter/minute/(gram/liter) [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 materials, but are preferably synthetically derived. A method for producing aluminosilicate ion exchange materials is discussed in US Patent No. 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

Na 12 [(A102) 12 (Siθ2)l2]. *H2 O wherein x is from 20 to 30, especially 27. Zeolite X of formula Na86[(AlO2)86(SiO2)l06]-276H2O is also suitable, as well as Zeolite HS of formula Na6[(AlO2)6(SiO2)6] 7.5H2O.

Suitable water-soluble monomeric or oligomeric carboxylate builders can be selected from a wide range of compounds but such compounds preferably have a first carboxyl logarithmic acidity/constant (pKi) of less than 9, preferably of between 2 and 8.5, more preferably of between 4 and 7.5. The logarithmic acidity constant is defined by reference to the equilibrium

H+ + A «** H+A

where A is the fully ionized carboxylate anion of the builder salt.

The quilibrium constant is therefore

(H+ A) Kl =

(H+) (A)

and pKi = logioK. For the purposes of this specification, acidity constants are defined at 25°C and at zero ionic strength. Literature values are taken where possible (see Stability Constants of Metal-Ion Complexes, Special Publication No.25, The Chemical Society, London): where doubt arises they are determined by potentiometric titration using a glass electrode. Preferred carboxylates can also be defined in terms of their calcium ion stability constant (pKCa++) defined, analogously to pKi, by the equations ρKCa++ = logioKCa- ^H "

(Ca ⁴ -*- A) where KCa" ^1-1 "

(Ca+÷) (A)

Preferably, the polycarboxylate has a pKCa" ^1-1 " in the range from about 2 to about 7, especially from about 3 to about 6. Once again, literature values of stability constant are taken where possible. The stability constant is defined at 25°C and at zero ionic strength using a glass electrode method of measurement as described in Complexation in Analytical Chemistry by Anders Ringbom (1963). The carboxylate or polycarboxylate builder can be monomeric or oligomeric in type although monomeric polycarboxylates are generally preferred for reasons of cost and performance. Monomeric and oligomeric builders can be selected from acyclic, alicyclic, heterocyclic and aromatic carboxylates having the general formulae

or

(c) (C6H4)

wherein Ri represents H,Ci-30 alkyl or alkenyl optionally substituted by hydroxy, carboxy, sulfo or phosphono groups or attached to a polyethylenoxy moiety containing up to 20 ethyleneoxy groups; R2 represents H,Ci-4 alkyl, alkenyl or hydroxy alkyl, or alkaryl, sulfo, or phosphono groups;

X represents a single bond; O; S; SO; Sθ2; or NRι;

Y represents H; carboxy; hydroxy; carboxymethyloxy; or

Cl-30 alkyl or alkenyl optionally substituted by hydroxy or carboxy groups;

Z represents H; or carboxy; m is an integer from 1 to 10; n is an integer from 3 to 6;

p, q are integers from 0 to 6, p+q being from 1 to 6; and wherein, X, Y, and Z each have the same or different representations when repeated in a given molecular formula, and wherein at least one Y or Z in a molecule contain a carboxyl group. Suitable carboxylates containing one carboxy group include the water soluble salts of lactic acid, glycolic acid and ether derivatives thereof as disclosed in Belgian Patent Nos. 831,368, 821,369 and 821,370. Polycarboxylates containing two carboxy groups include the water-soluble salts of succinic acid, malonic acid, (ethylenedioxy) diacetic acid, maleic acid, diglycolic acid, tartaric acid, tartronic acid and fumaric acid , as well as the ether carboxylates described in German Offenlegenschrift 2,446,686, and 2,446,687 and U.S. Patent No. 3,935,257 and the sulfinyl carboxylates described in Belgian Patent No. 840,623. Polycarboxylates containing three carboxy groups include, in particular, water-soluble citrates, aconitrates and citraconates as well as succinate derivatives such as the carboxymethyloxysuccinates described in British Patent No. 1,379,241, lactoxysuccinates described in British Patent No. 1,389,732, and aminosuccinates described in Netherlands Application 7205873, and the oxypolycarboxylate materials such as 2-oxa-l,l,3-propane tricarboxylates described in British Patent No. 1,387,447. Polycarboxylates containing four carboxy groups include oxydisuccinates disclosed in British Patent No. 1,261,829, 1,1,2,2-ethane tetracarboxylates, 1,1, 3, 3 -propane tetracarboxylates and 1,1,2,3-propane tetracarboxylates. Polycarboxylates containing sulfo substituents include the sulfosuccinate derivatives disclosed in British Patent Nos. 1,398,421 and 1,398,422 and in U.S. Patent No. 3,936,448, and the sulfonated pyrolysed citrates described in British Patent No. 1,439,000. Alicyclic and heterocyclic polycarboxylates include cyclopentane-cis, cis, cis-tetracarboxylates, cyclopentadienide pentacarboxylates, 2,3,4,5-tetrahydrofuran - cis, cis, cis-tetracarboxylates, 2,5-tetrahydrofuran - cis - dicarboxylates, 2,2,5,5-tetrahydrofuran - tetracarboxylates, 1,2,3,4,5,6-hexane - hexacarboxylates and carboxymethyl derivatives of polyhydric alcohols such as sorbitol, mannitol and xylitol. Aromatic polycarboxylates include mellitic acid, pyromellitic acid and the phthalic acid derivatives disclosed in British Patent No. 1,425,343. Of the above, the preferred polycarboxylates are hydroxycarboxylates containing up to three carboxy groups per molecule, more particularly citrates. The parent acids of the monomeric or oligomeric polycarboxylate chelating agents or mixtures thereof with their salts, e.g. citric acid or citrate/citric acid mixtures are also contemplated as components of builder systems of detergent compositions in accordance with the present invention. Other suitable water soluble organic salts are the homo- or co-polymeric polycarboxylic acids or their salts in which the polycarboxylic acid comprises at least two carboxyl radicals separated from each other

by not more than two carbon atoms. Polymers of the latter type are disclosed in GB- A-1,596,756. Examples of such salts are polyacrylates of MWt 2000-5000 and their copolymers with aleic anhydride, such copolymers having a molecular weight of from 20,000 to 70,000, especially about 40,000. These materials are normally used at levels of from 0.5% to 10% by weight more preferably from 0.75% to 8%, most preferably from 1% to 6% by weight of the composition.

The dispersing agent can include acrylic acid-maleic acid copolymers, polyaspartic acid, polyacrylates and the like. The alkaline builder can include alkaline metal silicates, alkaline metal carbonates and bicarbonate, and the like. However, to minimize t e amount of ingredients contained in the product, such other builders and other alkali materials should be contained at less than about 50 %, preferably less than 30 % of the composition. Furthermore, the ratio R of crystalline stratiform sodium silicate to the sum of other builders and other alkaline materials should not be less than 0.34, preferably not less than 0.5, and more preferably not less than 1. The dose of the detergent composition of the present invention should be less than 25g, preferably from 14g to 21g, and more preferably from 15g to 20g, per 30 liters of washing water. The detergent composition of the present invention can optionally contain, in addition to the crystalline stratiform sodium silicate, surfactant, optional bleaching component and other builders and other alkaline materials, other additives such as a brightening agent, a color migration inhibitor, a suds reducing agent, enzymes such as protease, alkalase, cellulase and the like, fabric softening agents such as clays and quaternary ammonium compounds and others.

The detergent composition of the present invention may be prepared by the following method. The detergent surfactants, the builders, the alkaline materials, and so on are mixed to be a detergent slurry, then the detergent slurry are dried to be a base granule. If necessary a part of the crystalline stratiform sodium silicate can be added into the detergent slurry. However, since the crystalline stratiform sodium silicate is water-soluble, it is most preferred to add all of the crystalline stratiform sodium silicate as a dry material with the dried base granule. Moisture-or heat-sensitive materials such as the bleaching component, the perfume, the enzyme, the crystalline stratiform sodium silicate, the color migration inhibitor and reducing subs agent are added to the base granule and they are mixed to obtain the detergent composition. Optionally, portions of the detergent surfactant and other builders and alkaline materials can be added as dry particles to the base granule particularly when formulating a high density, compact detergent product. Also optionally, the dried base granule can be disintegrated into smaller particles and agglomerated or re-combined to form a dense, compact base granule. Examples of

such methods of making dense, compact detergent products are described in Japanese patent publication (Kokai) No. 169900/1987, 161898/1987, 86700/1990, 81500/1992 and WO9206170 which is assigned to Procter & Gamble Co., Japanese patent publication (Kokai) No. 72999/1985 which is assigned to Kao Corp., and USP 4,919,847 which is assigned to Colgate-Palmolive Company.

In accordance with the present invention of providing a detergent composition comprising from 10 % to 40 % of a crystalline stratiform sodium silicate, from 25 % to 65 % of a detergent surfactant, from 0 % to 20 % of a bleaching component, and less than 50 % of other builders and other alkaline materials, wherein the ratio R of crystalline stratiform sodium silicate to the sum of other builders and other alkaline materials is not less than 0.34; the dose of the detergent composition in washing with it can be reduced to be less than 25g, preferably from 14g to 21g per 30 liters of washing water while maintaining the excellent detergent power, namely while maintaining the suitable pH, the suitable calcium-sequestering capacity and the suitable surfactant amount.

Next, the present invention will be explained in more detail by way of the following examples.

Examples of the Invention (1) Test Fabric

(a) Artificial dirt manufactured by Lion Corporation

Dirtv Component wt%

Organic dirt:

Oleic acid 28.3

Triolein 15.6

Cholesterol oleate 12.2

Liquid paraffin 2.5

Squalene 2.5

Cholesterol 1.6

Sum of oily dirts 62.7

Gelatin 7.0

Inorganic dirt 29.8

Carbon black (designated by Japan 0.5

Oil Chemists' Society)

(b) EMPA 101 (artificial dirt manufactured by EMPA Corporation)

Dirty Component: olive oil and carbon black.

(2) Washing Method

Washed in the following condition using Terg-O-Tometer (120 rpm). Water temperature 20°C

Washing time lO min. Rinse 5 min.

Water City water

(3) Calculation of detergent power

The reflecting power before and after washing, were measured by a color- difference signal (made by Nihon-Denshoku Corporation). The detergent power

(D%) was calculated in accordance with the following equation. D (%) = (L2-L / L1 X 100

Li : the reflecting power of test fabrics before washing. L2: the reflecting power of test fabrics after washing.

(4) Preparation of Detergent Samples to be Tested

Sodium C12 linear alkylbenzene sulfonate (flake), sodium C14-15 alkylsulfate (flake) and powdered acrylic acid/maleic acid copolymer are mixed well by mixer, and the mixture is fed to COMPACTOR (BCS25 made by Shinto

Industry) having a roller rate of 8-12 rpm, and a screw feeder rate of 12-20 rpm. The compacted mixture is grained by Hammer mill operating at between 1000-3000 rpm, and a screen opening size of 2 mm x 2 mm and then the grained mixture is sifted by a sieves (0.85 mm mesh). C12-14 polyoxyethylene alkyl ether, water, zeolite and brightening agent are mixed with the sifted mixture (powder). After the mixture is sifted by a sieves (0.85 mm mesh), enzyme, bleaching component, SKS-6 (made by Hoechst AG) and the remaining components are added thereto to obtain test samples and comparison samples mentioned in Table 1 and 2 below.

TABLE 1

Comparison Sample No. 1 Test Sample No. 1

Dose 30g / 30 liter 20g / 30 liter weight % ppm in water weight % ppm in water at dosage at dosage

Surfactant

Sodium C12 linear 18 180 27 180 alkylbenzene sulfonate

Sodium C 14- 15 6 60 9 60 alkylsulfate

C12-14 polyoxyethylene 1.5 15 2.3 15 alkyl ether

Builder and Alkaline Material

SKS-6 (supplied by 0 0 24 160 Hoechst AG)

Acrylic acid Maleic acid 2 20 3 20 copolymer

Zeolite 19 190 6 40

Sodium Carbonate 17 170 3 20

Sodium Silicate 20 200 0 0

Bleaching Component

Nonanoyloxy benzene 6 60 9 60 sulfonate

Sodium Percarbonate 6 60 9 60 (supplied by Tokai Denka Kogyo KK)

Enzyme

Protease 2 20 3 20

Others

Brightening Agent 0.1 1 0.15 1

Sodium Sulfate 0.2 2 0.3 2

Polyethylene glycol 0.3 3 0.5 3 (molecular weight 4000)

Miscellaneous 1.9 19 3.75 25

TOTAL 100 1000 100 666

TABLE 2

Comparison Sample No. 2 Test Sample No. 2

Dose 25g / 30 liter 20g / 30 liter weight % ppm in water weight % ppm in water at dosage at dosage

Surfactant

Sodium C12 linear 22 183 27 180 alkylbenzene sulfonate

Sodium C14-15 7 58 9 60 alkylsulfate

C12-14 polyoxyethylene 1.8 15 2.3 15 alkyl ether

Builder and Alkaline Material

SKS-6 (supplied by 0 0 24 160 Hoechst AG)

Acrylic acid/Maleic acid 2.5 21 3 20 copolymer

Zeolite 22 183 16 107

Sodium Carbonate 15 125 6 40

Sodium Silicate 24 200 5 33

Enzyme

Protease 2.4 20 3 20

Others

Brightening Agent 0.12 1 0.15 1

Sodium Sulfate 0.24 2 0.3 2

Polyethylene glycol 0.4 3 0.5 3 (molecular weight 4000)

Miscellaneous 2.54 21 3.75 25

TOTAL 100 833 100 666

Example 1

Test sample No.l in Table 1 [containing 38.3% of total detergent surfactant, 24% of crystalline stratiform sodium silicate, 18.8% of other builders and other alkaline

materials (include the contribution of sodium carbonate from the sodium percarbonate material) and 18% of bleaching component] and Comparison Sample No. l in Table 1 [containing 25.5% of total detergent surfactant, no crystalline stratiform sodium silicate, 62.5% of other builders and other alkaline materials (include the contribution of sodium carbonate from the sodium percarbonate material) and 12% of bleaching component] contribute almost the same levels of components in water at the indicated dosage except for builder and alkaline material. These two samples were tested in accordance with the above mentioned Evaluation Method of Detergent Power. The test results are shown in Table 3.

TABLE 3

Dosage Detergent Power (%) per 30 liter Test Fabric (a) Test Fabric (b)

Comparison Sample No. 30 g 46 57 1

Test Sample No. 1 20 g 46 59

Example 2

Test sample No.2 in Table 2 (containing 38.3% of total detergent surfactant, 24% of crystalline stratiform sodium silicate, 30% of other builders and other alkaline materials and no bleaching component) and Comparison Sample No.2 in Table 2 (containing 30.8% of total detergent surfactant, no crystalline stratiform sodium silicate and 63.5% of other builders and other alkaline materials) contribute almost the same levels of components in water at the indicated dosage except for builder and alkaline material. These two samples were tested in accordance with the above mentioned Evaluation Method of Detergent Power. The test results are shown in Table 4.

TABLE 4

Dosage Detergent Power (%) per 30 liter Test Fabric (a) Test Fabric (b)

Comparison Sample No. 25 g 45 57 2

Test Sample No. 2 20 g 47 59

Formulation Example

Another examples of the present invention are shown in Table 5.

TABLE 5

Sodium Sulfate 2.0 - 1.0

Target Dose 15 g/30 liter 20 g/30 liter 15 g/30 liter