US2947701A - Spray dried detergent composition - Google Patents

Description

l l l l l i l r l United States Patent 2,947,701 SPRAY DRIED DETERGENT COMPOSITION Edgar E. Ruff, 'Bergerifield, N.'J., assignor to Lever Brothers Company, New York, N.Y., a corporation of Maine No Drawing. Filed May 9, 1955, Ser. No. 507,133

8 Claims. (Cl. 252-109) The present invention relates to a detergent composition, and more particularly to a spray dried detergent composition containing soap.

In the production of spray dried detergent compositions containing nonionics as the active components, the nonionic surfactants frequently tend to separate out in the crutcher or in the relay storage tank used to insure continuous feed to the spray drying tower. Such separation causes the spray dried compositions to be nonuniform. Furthermore, the heterogeneity of the separated slurry as it passes through the tower nozzles results in the formation of many dense masses containing insufficient nonionic surfactant to provide the necessary particle expansion, thereby resulting in a product having an undesirablyhigh specific gravity.

These difficulties as well as others discussed below have been overcome by the inclusion of a small amount of soapin the low sudsing spray dried nonionic detergent composition of the present invention.

"The composition of the present invention comprises fgom' about to about by weight of the nonionic surfactants Pluronic L-64 plus Oronite Dispersant NIW. Preferably, the composition contains about 10% of Pluronic L-64 and about 1% of Oronite Dispersant NIW. Pluronic' L-64 is a compound having the empirical formula HO(C H O),,(C H O) (C H O) H prepared by condensing ethylene oxide with a hydrophobic base formedby the condensation of propylene oxide with propylene glycol where b is 26-30. The molecular weight of the base unit (C l-I 0) is about 1501 to 1800 and a plus 0 is an integer such that the molecule contains from 40% to 50% ethylene oxide. Oronite Dispersant NIVV is a polypropylene alkyl phenol averaging tetradecyl in the alkyl radical condensed with ethylene oxide to an average of 9 ethylene oxide groups.

,The composition also contains from about 0.2% to about 2.0% by weight of a soap which is a salt of one or more of the saturated or unsaturated fatty acids having an acyl group of from about 8 to about 22 carbon atoms with analkali metal, such as sodium, and may include, for example, the alkali metal salts of myristic acid, palmitie acid, tallow fatty acids and coconut oil fatty acids.

'The composition also contains an amount up to about 10% water, preferably about 4%, as Well as a builder, such as, pentasodium tripolyphosphate, and watersoluble supplemental builders, such as, sodium carbonate, or other alkaline inorganic salts, sodium silicate, and sodium sulfate. From about to about 50% by weight of pentasodium tripolyphosphate may be employed although about39% thereof is preferred. The sodium carbonate oifflotheralkaline inorganic salt content, to supply an alkali reserve in washing operations of the composition may vary from about 10% to about 20% .by weight, about 17% being preferred.

-Sodium silicate is used for its well known property of lesseningthe extent of corrosion of the metals commonly exposed to asolution of the detergent composition in washing appliances. It is preferred to limit this compo:

Patented Aug. 2, 1960 nent to an amount effective for the aforementioned purpose, but which is at the same time not so high that excessively cloudy washing solutions are obtained. Pickup carbon dioxide from the atmosphere during trade storage of products containing silicates tends to cause formation of free silica, which is insoluble in water and forms cloudy solutions. From about 5% to about 15 by weight of sodium silicate may be employed, about 11% being preferred. It is also preferred to use the more alkaline soluble silicates, such as, for example, those having SiO to Na O ratios of 2.4 to 1 or 2.0 to 1.

The neutral salt filler, sodium sulfate, makes up essentially the balance of the composition, although the detergent composition may contain minor proportions of a dye and salts of carboxymethyl cellulose or carboxymethyl hydroxyethyl cellulose. About 0.5% of sodium carboxymethyl hydroxyethyl cellulose is generally added to the composition. Generally about 0.05% of a fluorescent dye, such as the disodium salt of 4,4-bis(4-phenylylamino)-2,2'-stilbene disulfonic acid, may be addedto the composition.

The spray dried detergent composition is prepared by mixing the components thereof in an aqueous slurry in a crutcher for about 30 minutes. The aqueous slurry has a low water content, i.e., from about 12% to about 20% and a relatively high temperature of about 185 F. The actual water used is selected at as low a level as may be possible consistant with obtaining a pumpable viscous crutcher mix using any particular combination of desired inorganic builders and fillers. The slurry is then pumped to a relay storage tank from which it is continuously fed into a spray drying tower having an air inlet temperature of about 490 F. In the tower the composition is spray dried to a free flowing powder having a moisture content below about 10%, and preferably about 4%, and a specific gravity of not more than about 0.4 g./cc., and preferably about 0.3 g./cc.

The presence of soap in the detergent composition prevents the components thereof from Separating out in the crutcher or in the relay storage tank having slow moving agitators by apparently exerting an emulsifying action thereon. Hence the spray dried detergent composition is uniform and free flowing. Moreover, the presence of soap in the detergent composition enables the specific gravity of the composition to be controlled, since it was found that an increase in the soap content produced a decrease in the specific gravity of the spray dried product. A microscopic examination of the particles of the spray dried product showed that as the soap content of the detergent composition was increased the particles of the spray dried product became more puffed and hence were lighter and had a lower specific gravity.

Data showing these properties of the detergent composition due to the presence of soap therein is given below in Examples 1-5 of Table I wherein the amounts of the components of the composition are given as percentages gravity. In examples 2-5, howe ver, wherein soap was added to the composition the aqueous slurry was homo geneous and the spray dried product was uniform and had a low specific gravity which could be readily controlled,

The nonionic surfactants, Pluro'nic L 64 andOroiiite- 1 Dispersant NIW, and detergent compositions containing TABLE I Example No 1 2 3 4 5 Pluronio L-64 9. 72 0. 72 9. 72 9. 72 9. 72 Oronite Dispersant N1W 1. 39 1. 39 1. 39 1.39 1. 39 Pentasodium Tripolyphosphate. 38. 89 38. 89 38. 89 88. 89 38. 89 Sodium Caronate 16. 67 16. 67 16. 67 16. 67 16. 67 Sodium Silicate 11.11 11.11 11.11 11. 11 11.11 Sodium Carboxymcthyl Hydroxyethyl Cellulose 0.55 0.55 0.55 0. 55 0. 55 Anhyd ous Sodium Tallow Soap 0.27 0.55 1.11 2. 22 Sodium Sulfate 21. 62 21. 35 21.07 20. 51 19. 42 Fluorescent Dye 0.05 0.05 0.05 0. 05 0.05

Total 100 100 100 100 100 Operating Data:

Water Content of Slurry 20 20 207 20%. Slurry Temperature- 185 F 185 F 185 F 185 F 185 F. Tower Air Inlet Temperature 490 F 490 F 490 F 490 F 490 F. Mixing Time in Crutcher 30 min 30 min 30 min 30 min 30 min. Characteristics of Slurry Hetero- Homoge Homoge Homoge Homogegeneous. neous neous neous neous. Final Product:

Specific Gravity (g./cc.) 0. 46 0.375 0.3 0.317 0. 20. Percent Moisture 3. 8.," 1. R 1. 6 2 1.6. Characteristics of Final Product Free flow Free flow- Free flow- Free flow- Free flow lug, non tug, uni- 111g, unlmg, uniing, uniform. form. form. form. form.

The disodlum salt of 4,4-b1s (tphenylamlno-fi-(bis(2-hydroxyethyl)) amino-s-trlazine-2-ylamino)-2,2 stllbene disulfonic id them are sufficiently soluble in water at lower tempera- 25 118 F.--Much clearer than at 130 F.; only slightly.

tures such as 120 F. to about 140 F., to produce substantially clear solutions. at typical usage concentration. They are, however, less soluble in both hard and soft water at higher temperatures used in washing, such as about 140 F. to 190 F., so that these nonionics separate from such heated solutions as suspended minute droplets forming turbid solutions. This is clearly illustrated by the following Examples 6-8 wherein the percentages are by weight.

Example 6 One liter of distilled water was added to 3.0 grams of the following spray dried detergent composition and the resulting solution heated and observations made of the turbidity thereof.

The observations of the turbidity of this solution as it was heated and subsequently cooled were as follows:

120 F.-Faintly hazy; some undissolved particles.

130 F.140 F.-Slightly'n1ore hazy than at 120 F.

160 F.-Slightly turbid; printing could be read through 100 mm. of the solution.

170 F.--Turbid; printing could be read through 100 mm. of the solution.

174 F.-More turbid; printing could not be read through 100 mm. of the solution, but objects could be discerned.

180 F.-Very turbid; objects could not be seen through 100 mm. of the solution.

190 F.-Slightly more turbid than at 180 F.

180 F. down to 150 F.-Turbid; printing could not be read through 100 mm. of the solution, but objects could be discerned.

140 F. down to 130 F.--S1ightly' clearer than at 150 F., but still turbid; printing could not be read through 100 mm. of the solution, but objects could be discerned.

120 F.Much clearer than at 130 F.; printing could be read through 100 mm. of the solution.

turbid. 113 F.--Clear.

To substantiate that it wasthe nonionic detergents inthe composition. of Example 6 which were separating from solution. and producing the turbidity, the following 5 tests and observations were made, Pluronic L-64 beingvv tested in Example 7 and Oronite Dispersant NIW'in Ex-'- I ample 8.

Example 7 One liter of distilled water was added to 0.26 gram of Pluronic L-64 (the amount of Pluronic L-64 in 3 grams of the composition in Example 6) and the mix-- ture heated and subsequently cooled. Observations were made as to the turbidity of the resulting solution.

160 F. down to 130 F.--Progressively clearer as the solution cooled; only a faint haze at 130 F. F.--Clearer than at F.; barely noticeable haze. 105 F .-Clear.

Example 8 One liter of distilled water was added to 0.04 gram of Oronite Dispersant NIW (the amount of Oronite Dispersant NIW present in 3 grams of the composition in Example 6) and the mixture heated and subsequently cooled. Observations were made as to the turbidity of the resulting solution.

130 F.--Clear.

F.- F.Faint haze.

160 F.-190 F.--Slightly more haze than. at 150 F.

solution cooled; at 120 F. the solution was almost perfectly clear; only a barely noticeable haze was evident 85 F.Same as when at 120 F.

The turbidity observed in the above example is a separation which is similar to the separation existing in plant slurries in the absence of extraordinary violent agitation except that in plant operations when soap is' F. down to 120 F.--Progressively clearer as the I not used there is not only separation of minuteparticles but layers of separate ingredients can be observed resulting in objectionable nonuniformity of the slurry and the spray dried product.

Solubilization by surface-active agents, such as soap, is a well known. phenomenon known to occur at concentrations of the solubilizing agent at or above a critical level known as the critical concentration for the formation of micelles or more commonlyjas the critical micelle concentration." Above this level, agglomerates of more or less definitely'oriented molecules are known to exist in solutions of surface-active agents. Such agglomerates are called micelles, and they have a solubilizing effect on many substances not solublefin water alone or in solutions of surfactants at concentrations below the critical level. Contrariwise, however, a small proportion of a soap in the composition of Example 6, namely about 0.5% to about 2.0% by weight of the total detergent composition and being well below the critical micelle concentration at washing concentrations of the detergent, had a solubilizing effect on the nonionics in either hard or soft water. This is demonstrated by the following Examples 9-12.

Example 9 0.015 gram (0.5% by weight of the total composition) of sodium tallow soap were mixed with 3.0 grams of the composition in Example 6 contained in one liter of distilled water and the mixture heated. Observations were made as to the turbidity of the solution.

120 F..-l60 F.Clear. 180 F.-190 F.Very slightly hazy; printing could be read easily through the solution.

Example 10 One liter of water having a hardness of 180 parts per million was added to a mixture of 3 grams of the composition of Example 6 containing 0.015 gram of sodium tallow soap (0.5% by weight of the total composition) and the mixtures heated. Observations were made as to the turbidity of the resulting solution.

120 F.Very slight haze; some undissolved particles.

140 F.Slightly clearer than at 120 F.

150 F.170 F.Same as at 140 F.

180 F.Just slightly more haze than at 170 F.

190 F.-Same as when at 180 F.; printing could easily be read through 100 mm. of the solution.

Example 11 Example 12 0.015 gram of sodium palmitate (0.5% by weight of the total composition) was added to 3 grams of the composition in Example 6 contained in one liter of distilled water and the solution heated to 177 F. Observations of the solution during heating showed that the turbidity of the solution was considerably less than the values shown for the corresponding temperature recording in Example 6. This amount, 0.015 gram per liter, of sodium palmitate is also lower than that corresponding to the accepted critical micelle concentration of approximately 0.11 gram per liter.

The data in Examples 9-12 thus readily show that the addition of about 0.5% by weight of the total composition ofa soap to the detergent composition contain ing the nonionics shown in Example 6 substantially prevents the separation of the nonionic surfactants from solutions of the composition at washing temperatures in either hard or soft water.

Various modifications and changes may be made in' 1. A spray dried detergent composition comprising from about 5% to about 15% of (1) a compound hav prepared by condensing ethylene oxide with a hydrophobic base formed by the condensation of propylene oxide with propylene glycol where b is an integer selected from the group consisting of 26 to 30 and a plus c is an integer such that the molecule contains from 40% to 50% ethylene oxide, and (2) a polypropylene alkyl phenol averaging tetradecyl in the alkyl radical condensed with ethylene oxide to an average of 9 ethylene oxide groups; from about 20% to about 50% of pentasodium tripolyphosphate; from about 10% to about 20% of sodium carbonate; from about 5% to about 15% of sodium silicate; from about 0.2% to about 2.0% by weight of a water-soluble alkali metal salt of a fatty acid having an acyl group of from about 8 to about 22 carbon atoms; an amount up to about 10% water; and the balance essentially sodium sulfate, the above amounts being expressed as percentages by weight on a dry basis with the exception of water.

2. A spray dried detergent composition as set forth in claim 1 containing about 0.5% sodium carboxymethyl hydroxyethyl cellulose and about 0.05% of a fluorescen dye.

3. A spray dried detergent composition comprising about 10% of a compound having the empirical formula prepared by condensing ethylene oxide with a hydrophobic base formed by the condensation of propylene oxide with propylene glycol where b is an integer selected from the group consisting of 26 to 30 and a plus c is an integer such that the molecule contains from 40% to 50% ethylene oxide; about 1% of a polypropylene alkyl phenol averaging tetradecyl in the alkyl radical condensed with ethylene oxide to an average of 9 ethylene oxide groups; from about 20% to about 50% by weight of pentasodium tripolyphosphate; from about 10% to about 20% by weight of sodium carbonate; from about 5% to about 15% by weight of sodium silicate; from about 0.2% to about 2.0% of a water-soluble alkali metal salt of a fatty acid having an acyl group of from about 8 to about 22 carbon atoms; an amount up to about 10% water; and the balance essentially sodium sulfate, the above amounts being expressed as percentages by weight on a dry basis with the exception of water.

4. A spray dried detergent composition comprising about 10% of a compound having the empirical formula prepared by condensing ethylene oxide with a hydrophobic base formed by the condensation of propylene oxide with propylene glycol where b is an integer selected from the group consisting of 26 to 30 and a plus 0 is an integer such that the molecule contains from 40% to 50% ethylene oxide; about 1% of a polypropylene alkyl phenol averaging tetradecyl in the alkyl radical condensed with ethylene oxide to an average of 9 ethylene oxide groups; about 39% of pentasodium tripolyphosphate; about 17% of sodium carbonate; about 11% of sodium silicate; from about 0.2% to about 2.0% of a watersoluble alkali metal salt of a fatty acid having an acyl 7. group of from about 8' to about 22 carbon atoms; about 4%- of water; and the balance essentiallysodium sulfate, theabove amounts being expressed as percentages by weight on a dry basis with the exception of water.

5. A spray dried detergent composition as set forth 5 in claim 4 wherein the Water-soluble alkali metal salt of a fatty acid is sodium tallow soap.

6. A spray dried detergent composition as set forth in claim 4 wherein the water-soluble alkali metal salt of a fatty acid is sodiumpalmitate.

7. A spray dried detergent composition as set forth in claim 4 wherein the Water-soluble alkali metal salt of a fatty acid is sodium myristatc.

8. A spray dried detergent composition as set forth" in-claim 4 containing about 0.5% sodium carboxymethyl hydroxyethyl-cellulose and about- 0.05% of a fluorescent dye.

ReferencesCited in the file of this patent V UNITED STATES PATENTS 2,667,458: Adams et al. Jan. 26, 1954 OTHER REFERENCES Ricciardi Nov. 13, 1956 UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No, 2,947,701 I V August 2, 1960,

Edgar E. Ruff It is hereby certified that error appears in the printed specification of the above numbered patent requiring correction and that the said Letters Patent should readas corrected below.

Column 2, lines '19 and 20, for "4,4 bis(4phenyly1amino) 2,2stilbene disulfonic acid" read 4-,4 -bis((4-phenylamino- 6(bis(2hydr0xyethyl))amino-striazine2-*ylamino))2,2stilbene disulfonic acid columns 3 ajfid 4, TABLE I first column thereof, line 5, for "Caronate" read Carbonate same TABLE 1, column 2 thereof last item, for "Free flowing, nonform, read Free flowing, nonuniform. same TABLE I column 5 thereof, last item, for "Free ffowi'n'g, uniform." read Free flowing, uniform.

Signed and sealed this 31st day of January 1961.

(SEAL) Attest:

KARL H. AXLINE ROBERT C. WATSON Attesting Officer Commissioner of Patents

Claims (1)

1. A SPRAY DRIED DETERGENT COMPOSITION COMPRISING FROM ABOUT 5% TO ABOT 15% OF (1) A COMPOUND HAVING THE EMPIRICAL FORMULA