NZ203817A - Pourable gel dishwasher detergent composition - Google Patents

Description

New Zealand Paient Spedficaiion for Paient Number £03817 2 03 81 7 Priority Date(s): /vl. M .

Complete Specification Filed: .T.Ci .*$3. Class: <LUQ I./%$+.....

Publication Dale: .. B.I. APR. 1986.

P.O. Journal, No: .

NO DRAWS ;■ V >> >* -7 APR 1983 NEW ZEALAND PATENTS ACT. 1953 No.: Date: COMPLETE SPECIFICATION POURABLE GEL DISHWASHER COMPOSITIONS (X/ We, AMERICAN HOME PRODUCTS CORPORATION, a Corporation organised and existing under the laws of the State of Delaware, United States of America, of 685 Third Avenue, New York, New York 10017, United States of America, hereby declare the invention for which K/ we pray that a patent may be granted toMtK/us, and the method by which it is to be performed, to be particularly described in and by the following statement: - * \j O O I ( -1c\- POUIIABLE GEL DISHWASHER COMPOSITIONS This specification relates to new and novel dishwashing detergent compositions. More particularly, the instant invention concerns a po.urable dishwashing detergent gel composition comprising: on aqueous xanthan gum 5 thickcner, a detcrgency builder, nn alkalinity builder or an alkalinity builder mixture, a mixture of anionic and non-ionic surfactants, a chelating agent and water in the form of a gel having a Brookfield viscosity from substantially 3,000 to substantially 7,000 cps and a yield point from substantially 250 to substantially 825. The dishwashing detergent can attain additional '0 agents such as dye, perfume, preservatives, corrosion inhibitors, etc.

In recent years, there has been a strong growth in dishwasher machine ownership. This has resulted in a plettiera of dishwasher detergents on the market. These detergents to date have been powders, such as Cascade by Proctor & Gamble, Eleetrosol by Economies Laboratory, and Dishwasher All by '■5 Lever Brothers. These dishwasher detergents are specially formulated for use in automatic dishwashers and are more fully described in several of the popular magazines, such as Consumers Research Magazine, August, 1977, pp. 14-17 and Consumers Reports, June, 1980, pp. 371-373. The drawbacks of the conventional dishwasher detergents are well described in U.S. patents 4,260,528 to Fox et al 20 and 4,226,736 to Bush et al. The first of said patents describes much related art. The ideal product, according to this patent, despite its high viscosity, must flow easily so it may be dispensed from a tube or plastic squeeze bottle. The product of the patent uses standard, low-foaming surfactants, builders and alkalinity agents to formulate a liquid automatic dishwasher detergent of high viscosity. 25 Thickening action is provided by the addition of certain types of thickeners, among which are natural and biopolymeric gums and chemical derivatives thereof. Stability and flow are controlled by the addition of critical amounts of urea and polyhydric alcohol with appropriate adjustment of the pH. The urea should be added at a level of about 0.5% to about 8%, and preferably from about 30 2.0 to 5.0% in order to provide adequate stability without objectionable odor. The products of this patent also have from about 0.3 to about 10% of a polyhydric alcohol selected from thegroup consisting of glycerol, ethylene glycol, propylene glycol and mixtures thereof. The products still further have a Brookfield viscosity from about 13,000 cps to about 150,000 cps. u.s. Potent No. 4,226,736 discloses a low-foaming machine dishwasher detergent composition comprising an aqueous thickener, non-ionic surfactant and water in the form of a gel having a minimum yield point of at least 1170 so that it will not leak out of a sealed or closcd cup, prior to its automatic opening for 5 dispensing the detergent for a second or subsequent wash cycle. This patent discloses multitudeness thickening agents including xanthan gum, although such material is not disclosed in any of the specific examples. The products have a minimum yield point of at leust about 1170 and a Brookfield viscosity of about 472,000 cps.

We have found certain pourable gel dishwashing detergents having a relatively low viscosity and a relatively low yield point whereby the gel formulation can be conveniently filled into bottles at the point of manufacture, easily and conveniently poured into dispensing cups of a dishwasher machine by the user. The gel formulation sets up sufficiently in the dishwasher cups so that little or no leakage occurs from a sealed or closed cup, prior to its automatic opening for dispensing the detergent for a second or subsequent wash cycle, as seen by a satisfactory cleansing of the dishes and silverware in the automatic dishwasher, even though the gel formulation is placed into the sealed cup only.

In further detail, our invention relates to a dishwasher gel formulation 20 which is stable, with a high pH and retains its viscosity. The gel is completely soluble in hot water and completely rinses out from a dishwasher cup without gritty deposits or powder detergent residues. It is pseudoplastic in nature so that it may pour freely and completely from a bottle, yet set up and resist draining from the machine dishwasher cup. It creates minimal foam even with 25 proteinaceous soils, reduces the deposition of hard water scale that causes spots and haze, removes tough dried-on soils and is safe for fine china and silver. It is not corrosive to the machine and the contents. Thus, the dishwasher gel detergent composition of the present invention comprises: (a) from substantially 0.5 to substantially 1.5% of an aqueous xanthan gum thickener; (b) from substantially 8 to substantially 15% of a detergency builder; • \ (c) from substantially 3 to substantially 7% of an alkalinity builder or an alkalinity builder mixture; (d) from substantially 2 to substantially 5.5% of a mixture of anionic and low foaming, non-ionic surfactants; (e) from substantially 2 to substantially 9% of a chelating agent or a chelating agent mixture; and (f) water, said composition having a pH of 11-13 and being in the form of a gel characterized as having a Brookfield viscosity from substantially 3,000 to substantially 7,000 cps and a yield point from substantially 250 to substantially 825.

More preferably, the dishwasher detergent gel composition of the present invention comprises: (a) from substantially 0.8 to substantially 1.2% of an aqueous xanthan gum thickener; (b) from substantially 9 to substantially 14% of a detergency builder; (c) from substantially 2 to substantially 4% of a first alkalinity builder and substantially 1 to substantially 3% of a second alkalinity builder; (d) from substantially 0.3 to substantially 1.2% of an anionic surfactant and from substantially 1.7 to substantially 4.3% of a non-ionic surfactant; (e) from substantially 3 to substantially 5% of a first chelating agent and substantially 1 to substantially 4% of a second chelating agent; and (f) water.

Test methods: (A) Viscosity: All viscosities of products were measured on a Brookfield Model RVT Synchro-Lectric Viscometer using appropriate speeds and spindles as suggested by the manufacturer. With very gelatinuous materials, with which there is a tendency for the spindle to "bore" a hole in the sample and thus give erroneous readings, a Brookfield Model LVT Viscometer was supported on a Brookfield Helipath Stand (Model C)and the corresponding spindles were used. The Helipath stand slowly lowers tiie viscometer spindle deeper into the sample so the spindle continuously encounters fresh sample. All viscosities are read at 25°C. just prior to testing the sample for cup retention. "i? Z UJ5 « (B) Yield Value: Our values are determined in a manner as in U.S. Patent 4,266,736. The viscosities are determined, as described Above, at 0.3 and 0.6 rpm spindle speeds. At these speeds very little shear is placed on the sample. The vulucs are then applied in the formula: Yield Value _ (apparent Viscosity at 0.3 rpm) - (apparent Viscosity at 0.6 rpm) 100 where the viscosities are given in centipoises.

(C) Evaluation: Performance testing on the compositions is done in the following manner, which is a variation of that prescribed by the American '0 Society for Testing and Materials in the "Method for Measurement of Depositions on Glassware During Mechanical Dishwashing" (D 3556-76T).

Ten dinner plates were uniformly soiled. Two of each plates had (a) a mixture of margarine and powdered milk, (b) spinach, (c) eggs, (d) cereal and (e) mustard. Seven grams of each of the above soils was placed uniformly in the '5 center area of each of two dinner plates. One gram of the above standard soils was placed on one each knife, fork and spoon. Two grains of milk was placed into each of eight glasses. The soiled items, along with four unsoiled glasses, were placed in a Kitchen Aid Energy Saver IV Superba dishwosher by Hobart. The water supply was adjusted to 140° F. and 150 ppm hardness. When using the 20 gel compositions of the present invention, fifty-two grams of detergent, which is approximately three tablespoons, was placed into the second cup; no detergent was placed in the first cup. With the control, forty-one grams of detergent was placed in each cup.

After washing, each soiled dish and each eating utensil was evaluated 25 by a panel of ten. Each panelist counted the number of particles of soil remaining up to a maximum of ten. Articles with more than ten particles of soil were rated 10+. Any particle of 10 mm. or larger in any direction was rated 10+.

Each soiled and unsoiled glass and each article of silver was examined for spotting and filming; each piece of silver was examined for cleaning and 30 spotting. The spotting evaluation was by a panel of ten according to the following criteria: no spots, 1; spots at random, 2; about 1/4 of surface covered, 3; about 1/2 of surface covered, 4; and virtually complete coverage, 5.

| ( The filming cvaluution was by a panel of ten according to the following criteria: none, 1; barely perceptible, 2; slight, 3; moderate, 4; and heavy, 5. The tests were completed five times with the position of the various 5 soiled articles altered each time. The values for each material was averaged together to provide an overall rating.

The following examples will serve to further illustrate the present invention. All percentages herein are by weight. In Examples 1-4, liquid gel dishwasher detergent formulations were made up with the following 10 compositions: DISHWASHER GEL FORMULATIONS Ingredient Function Example 1 2 3 4 Xanthan gum Thickener 1.0 1.0 1.1 1.1 Tetrapotnssium pyrophosphate Detergent Builder 13.0 13.0 .0 .0 NaEDTA (38%) Chelating Agent .0 .0 13.0 13.0 Na metasilicate pentahydrate Alkalinity Builder 3.0 3.0 3.0 3.0 Na2C03 Alkalinity Builder 2.0 2.0 2.0 2.0 Gluconic Acid (50%) Chelating Agent 3.0 3.0 7.0 6.0 Gafac RE-610 Anionic Surfactant 1.0 1.0 1.0 0.5 Tetronic 150-R1 Non-ionic Surfactant 2.0 2.0 2.0 - Triton CF-87 Non-ionic Surfactant - - 1.0 - zD6817 Ingredient Function Example Triton CF-32 Non-ionic Surfactant - — — 4.0 Sodium sulfite Preservative - 0.2 0.2 0.1 Dye - 0.055 0.0275 0.0275 Perfume - 0.1 0.08 0.08 Water 65.0 65.6 59.6 60.2 Viscosity cps 5000 5600 5000 5400 pH 12.5 12 11.3 11.7 Yield Value 270 271.5 815 535 Examples and the formulations of Examples 2-4 were tested as to their cleaning capacity, filming and spotting. Formulation 1 is the same as formulation 2 without the preservative, dye and perfume. The results were shown hereinbelow according to the following table using commercially available Cascade, containing 8.7% phosphorus as phosphates, as a control: EXAMPLE 5 TABLE Product Cleaning Spotting Filming of Example Dishes Tableware Glasses Glasses 2 0.49 0.44 2.7 1.7 3 0.17 0.17 2.9 1.6 4 0.07 0.17 2.4 2.6 Control 0.2 0.17 1.7 2.1 The products of the present invention average less than about 2.4% 25 phosphorus in the the form of phosphates, or less than about 1.3 grams for a 3 tablespoon level use (52 grams). Cascade, containing 8.796 phosphorus, on the other hand, provides 7.14 grams, when 41 grams is used in each cup. As can be seen from the above, although the products of the present invention are W6B17 comparable in cleaning, spotting and filming to Cascade, the phosphate level is only about one-fifth that of the phosphate level in Cascade.

The particular dye and perfume used herein is not critical, provided said dye and/or perfume is stable at the pH of the dishwasher gel composition and 5 does not react with any of the other ingredients in the dishwasher composition. It may be desirable to use sodium sulfite as a preservative for some of the ingredients herein. This is also, however, not critical to the functioning of the present invention, but merely is to increase the shelf life thereof.

Xanthan gum is available under the tradename Xanthan Gum K9C57 10 from Kelco, a division of Merck ic Co. The Gafae RE-610 anionic surfactant is an organic phosphate ester free acid complex available from GAF Corporation. The Tetronic 150-R1 non-ionic surfactant is a polyoxyethylene-polyoxypropylene ethylenediamine condensate available from BASF Wyandotte Corporation. Triton CF-32 is a non-ionic, low-foam surfactant, an amine polyglycol 15 condensate available from Rohm & Haas Co. Triton CF-87 is an alkyl aryl ether-modified terminated 90% non-ionic surfactant available from Rohm & Haas Co. Illustratory specific dyes useful herein are: Acid Blue 239, available under the name Erionyl Brilliant Blue 7GS from Ciba-Geigy; Acid Yellow 40S, available under the name Polar Yellow 5GL from Ciba-Geigy, while an illustratory 20 perfume is Alpine 101-911, available from Alpine Aromatics Intl.

Although preferred ingredients are disclosed and claimed, the obvious equivalents are included within said claims. Part of the tetrapotassium pyrophosphate can be replaced by other pyrophosphates, such as sodium tripyrophosphate; ethylenediamine tetraacetic acid and gluconic acid can be replaced in part or totally by a water soluble salt thereof or such salt may be formed in situ in the manufacture of the formulation. Other suitable chelating agents are nitrilotriacetic acid or citric acid and the water soluble salts of either, such as the sodium or potassium salt. The NaCO^ alkalinity builder can be substituted by equivalent alkalinity builders such as ^2^3 or NaOH, etc. Although sodium metasilicates are preferred, other water soluble silicates such as alkali metal, eg., sodium or potassium, silicates, with varying M^O/SiO^ ratios (alkali metal salt oxide to silicon dioxide) are suitable.

Claims (11)

WHAT WE CLAIM IS: -a - 203817

1. A pourablc dishwasher detergent gel composition, comprising: (a) from substantially 0.5 to substantially 1.5% of an aqueous xanthan gum thickener; (b) from substantially 8 to substantially 15% of a detergency. builder; (c) from substantially 3 to substantially 7% of an alkalinity builder or an alkelir.ity builder mixture; (d) from substantially 2 to substantially 5.5% of a mixture of anionic and low foaming, non-ionic surfactants; (e) from substantially 2 to substantially 9% of a chelating agent or a chelating agent mixture; and (f) water, said composition having a pH of 11-13 and being in the form of a gel characterized as having a Brookfield viscosity from substantially 3,000 to substantially 7,000 cps and a yield point from substantially 250 to substantially 825.

2. The dishwasher detergent gel composition of claim 1, comprising: (a) from substantially 0.8 to substantially 1.2% of an aqueous xanthan gum thickener; (b) from substantially 9 to substantially 14% of a detergency builder; (c) from substantially 2 to substantially 4% of a first alkalinity builder and substantially 1 to substantially 3% of a second alkalinity builder; (d) from substantially 0.3 to substantially 1.2% of an anionic surfactant and from substantially 1.7 to substantially 4.3% of a non-ionic surfactant; (e) from substantially 3 to substantially 5% of a first chelating agent and substantially 1 to substantially 4% of a second chelating agent; and (f) water.

3. The composition of claim 1 or claim 2 additionally containing a dye and perfume.

4. The composition of any one of claims 1 to 3 additionally containing a preservative. -9-

5. The composition of claim 3, comprising: (a) about 1% xanthan gum; (b) about 13% tctrapotassium pyrophosphate; (c) about 3% sodium metusilicate and about 2% sodium carbonate; 5 (d) about 1% anionic surfactant and about 2% non-ionic surfactant; (e) about 3.8% ethylenediamine tetraacetic acid and about 1.5% gluconic acid; and (0 the balance comprising water, dye and perfume. 10

6. The composition of claim 3, comprising: (a) about 1.1% xanthan gum; (b) about 10% tetrapotassium pyrophosphate; (c) about 3% sodium metasilicate and about 2% sodium carbonate; (d) about 1% anionic surfactant and about 2% non-ionic 15 surfactant; (e) about 5% ethylenediamine tetraacetic acid and about 3.5% gluconic acid; and (f) the balance comprising water, dye and perfume.

7. The composition of claim 3, comprising: (a) about 1.1% xanthan gum; (b) about 10% tetrapotassium pyrophosphate; (c) about 3% sodium metasilicate and about 2% sodium carbonate; (d) about 0.5% anionic surfactant and about 4% non-ionic surfactant;- 25 (e) about 5% ethylenediamine tetraacetic acid and about 3% gluconic acid; and (0 the balance comprising water, dye and perfume.

8. A method for cleaning food-soiled dishware and cutlery in an automatic dishwasher machine while reducing the loss of a detergent composition due to 30 leakage from the dispenser cup prior to its utilization during the washing step of the machine, which comprises adding to the dishwasher dispenser cup prior to the operation of the dishwasher, the detergent composition claimed in any one of claims 1 to 7. -10- £- \J*J O f;

9. The method of claim 8, wherein said composition comprises that claimed in claim 5.;

10. The method of claim 8, wherein said composition comprises that clained in claim 6.;

11. The method of claim 8, wherein said composition comprises that claiired in claim 7.;oated this * °« Of "13 A. J. PARK & SON P£(V JJ. . AGENTS FOK THE APPLICANTS -7APRI98J1" 5#-