US2739129A - Cleaning composition - Google Patents

Description

CLEANING comroslrron Willy Manchot, Hubbelratll, near Dusseldorf, Germany,

assignor to Henkel & 'Cie, G. m..b. H., Dusseldorf, Germany No Drawing. Application July 3, 1951,

Serial No. 235,100

Claims priority, application Germany October 1, 1948 1 Claim. (Cl. 252-89 The invention relates to cleaning compositions, and more particularly. to scouring, cleansing, and polishing powders, of which the mechanically cleansing waterunsoluble components are of-such a fineness .that they will pass completely through a sieve having a mesh size of .3 mm. In general, such compositions comprise a major part of water-insoluble mineral particles and a minor part of water-soluble particles.

Powders of said type are frequently used for the cleansing and polishing of metals as well as for the cleaning of dirty hands. For this purpose, the mineral particles must be of a small grain size, as otherwise skin injuries, or scratches on shiny metal surfaces would occur. cleaning compositions, a grain size under 0.3 mm. of the alkaline reaction, various phosphates, and soaps or synthetic capillary activematerials. These combinations of various substances have been heretofore, as usual in the manufacture of washing agents, frequently brought into powder form by spraying a mixture of the starting materials in form of a warm aqueous pasty mass having a high content of solids. This method is less a drying of the paste but rather a crystallizing out, on cooling, of the inorganic components dissolved by heating. Especially neutral salts, as, e. g. sodium sulfate or sodium chloride, which result from the preparation of fatty alcohol sulfonates, alkylaryl sulfonates, parai'lin sulfonates or other synthetic capillary active agents, form large and relatively sharply-edged crystals, and often coarsen the finely granulated cleaning compositions in an undesired manner.

It was also found that such powders are especially suitable as water-soluble ingredients of scouring, cleansing, and polishing compositions which are prepared by spray-drying of solutions, in which the starting materials are dissolved as completely as possible. The liquid droplets, finely distributed in the warm air current, dry to a fine powder without allowing the formation of large crystals. The more diluted the solution, and the finer the distribution by the spray nozzles is, the softer and the more finely granulated is the obtained powder. Of course,

"in the interest of the economy of the process, I will normally'not use excessively diluted starting solutions; howmechanically acting insoluble scouring agents has been considered necessary in order to prevent skin injuries on constant use.

I hav'e'found that not only the Water-insoluble, but also the water-soluble particles, as e. g. sharply edged soda or sodium sulfate crystals of a corresponding grain size, may cause scratches and that the efficiency ofscouring, cleansing and polishing agents having a major proportion of such finely granulated water-insoluble particles is considerably greater if the'water-soluble components are present in a smaller grain .size than the water-insoluble particles.

The selection of the water-insoluble components of a particle size under 0.3 depends on the intended use of the powder. Quartz dust has been found suitable for cleansing purposes, but it may also be incorporated in polishing powders if a particularly finely granulated prodnet is used or if the proportion of the water-soluble components is increased. Other suitable mineral agents are,

e. g. kaolin, powdered pumice, marble dust, and the like. Suitable water soluble agents are especially salts having alkaline reaction, such as sodium carbonate, sodium bicarbonate, dior tri-sodium phosphate, but also sodium pyrophosphate, sodium metaphosphate, sodium tripolyphosphate or sodium hexarnetaphosphate may be used. The action of these salts is assisted by an addition of capillary active substances, such as soap, alkylaryl sulfonates, olefinic or parafiinic sulfonates, and others.

The cleaning composition can be prepared in various ways; for instance, the alkali salts which are to be incorporated can be brought to the desired fineness by prolonged grinding, sieving and/ or sifting. Especially if vibrating mills are used, a particularly finely ground product is obtained. The water-soluble ingredients may be ground also in the presence of moderate amounts of water-insoluble mineral ingredients; this procedure is especially recommended when very hard mineral ingredients such as quartz dust, areemployed. In this case the mineral powder assists in a very efiicient way the grinding operation, so as to produce a finely granulated powder in a shorter time.

As mentioned above, scouring and polishing compositions contain often as water-soluble ingredients combinations of materials which may consist of salts having an ever, with a suitable operation of the spraying apparatus, even substantially saturated'starting solutions, which contain no more undissolved solids, yield a powder which is completely satisfactory for the requirements of the method according to the invention. If a small amount of fine mineral powder is blown into the tower, an intimate mixture of the two ingredients is obtained which can be mixedreadily with the main amount of the mineral ingredient and which produces already after a short miX- ingperiod a very homogeneous powder.

The present invention is by no means limited to polishing and scouring compositions of which the water-soluble component has an a kaline reaction; also substances of neutral or acid reaction can be successfully used. Examples of acid components are amidosuli'onic acid, urea nitrate, oxalic acid as well as organic, especially aromatic aminosulfonic acids; also other solid substances of acid reaction of similar or other groups, as e. g. sodium bisulfate, can be used together with finely powdered mineral components, particularly for the removal of acid-soluble stains.

Like the alkaline compositions, also the neutral or acid polishing and scouring compositions may contain, in addition to the anion active ingredients, also cation active or electro-neutral wetting or foaming agents. Beside the acid resistant anion active wetting agents, certain cation active substances are particularly suitable as admixtures to acid polishing and scouring compositions, since they display in addition to the disinfecting action desired in a hand cleaning composition, also an inhibitive action in the metal treatment. it is, of course, also possible to incorporate other disinfecting substances into acid, neutral or alkaline cleaning compositions.

The novel cleansing, securing, and polishing compositions of the invention are of advantage not only in dry but also in wet cleaning. in dry cleaning, which is particularly recommended for the cleansing of aluminum, or copper, the fine abrasive particles are embedded in the finer water-soluble components, in such a way that the cleaning composition applied to the base assumes already after a few strokes a surface of smooth appearance and displays a conspicuous polishing effect after the removal of superficial stains from the metal surface. This effect becomes especially apparent on relatively soft, transparent plastics, such as, for instance, Plexiglas. A cleaning composition containing 17 per cent of water-soluble components, having a particle size equal to the size of the quartz powder, leaves theron a great number of microscopic fine scratches, which render the material dull. However, when the water-soluble component is finegranulated and soft, as it is obtained particularly by atomizing aqueous solutions, much less scratches are observed on microscopic inspection. This effect could not be expected from a hard quartz dust containing composition prepared in accordance with the invention, as for such purposes soft substances, such as powdered soapstone, were preferred heretofore. Also, for milder abrasives, such as iron oxide red, chrome green, clay minerals, and the like, an admixture of water-soluble substances of a smaller particle size is recommended because this makes them still more suitable for the cleaning of soft materials, for instance noble metals.

In wet cleaning, the mechanical cleaning action of the abrasive agents shall be assisted by the chemical action of the components dissolved in water; therefore, a high solution rate of the soluble admixtures is desired. Powders of a particle size of a .3 mm. have a relatively high rate of solution in water, and an increase of the cleaning action by a further decrease of the particle size could not be expected; nevertheless, I have observed a considerably increased cleaning action of such cleaning compositions. The explanation for this effect may be found in the particular conditions of diffusion and solution obtaining in wet cleaning. Whereas the dissolution of a water-soluble substance of .3 mm. particle size, when thrown into water takes place quickly in most cases, assisted by diffusion and agitation of the water, this is not the case in a cleaning composition wetted only with little water. Because of the large proportion of insoluble components, the turbulence of the water and the ditfusion of the dissolved substances is considerably reduced, and the dissolution is slowed down. The great advantage of the cleaning compositions according to the invention is due to the fact that the very fine water-soluble components are dissolved very quickly and yield a relatively concentrated cleaning liquid, which is capable of assisting very efficiently the mechanical cleaning action of the insoluble components. This results in a dissolution of the stains at the first strokes.

The following examples, which, it is to be understood, are not to be considered as limiting the invention in any manner, are given to illustrate the preparation of some cleaning compositions according to the invention.

Unless noted otherwise, all parts are given by weight.

Example .I

83 parts of quartz dust of such a fineness that 80 per cent pass through a sieve having meshes of .09 mm., are mixed with 17 parts of a finely powdered mixture of soda, bicarbonate of soda, and Glaubers salt, which, by grinding and sifting, have been brought to such a fineness that 99.5 per cent pass through a sieve having meshes of .09 mm. Subsequently, one part of fatty alcohol sulfonate of the same particle size is added. A cleaning composition is obtained which has a very soft feel and does not attack the skin of the hands even on prolonged use.

Example 2 25 parts of alkyl sulfonate or alkyl aryl sulfonate in the form of a 20-30 per cent paste containing neutral salts are mixed with 35 parts of calcined soda. To this paste, hot water is added in such an amount that a complete dissolution of the substances is obtained. The solution contains'about 40 to 45 per cent of solids.

The composition of this mixture may be changed. For instance, the soda may be replaced, wholly or in part, by orthophosphatcs or by anhydric phosphates, such as ym-phosphates, metaphosphates, or polyphcsphates. Salts of polycarboxyamines may be added. The hot solution is sprayed by means of a nozzle, which produces fine droplets, in a countercurrent of hot air. A very fine powder is obtained of approximately the following composition: 20% of capillary active substance, 35% of NazCOs, 23 of water; the balance is N212SO4 and/ or NaCl.

It is not possible to determine the particle size of this powder by sieving, as the individual particles of the powder readily agglomcrate to larger structures by shaking on the sieve because of the high content of capillary active substances.

However, when this powder is mixed with a fine waterinsoluble mineral powder, e. g. in the form of quartz sand or pumice flour, the agglomerated particles are separated from each other and distributed between the insoluble mineral powder. in this way, the cleaning composition in accordance with the invention is obtained, which may contain 5 to 25 per cent of the water-soluble powder recited hereinabove.

What I claim is:

In an abrasive, capillary active detergent cleaning composition; a powdered, water-insoluble inorganic abrasive selected from the group consisting of quartz, kaolin, pumice and marble dust, and a water soluble salt selected from the group consisting of sodium sulfate, sodium carbonate, sodium bicarbonate, (ii-sodium phosphate, sodium pyrophosphate, sodium metaphosphate, sodium tripolyphosphate and sodium hexametaphosphate, said water insoluble abrasive having a particle size passing completely through a sieve having meshes of .3 mm., said water soluble salts having a particle size smaller than that of said water-insoluble abrasive, and being present in an amount ranging from about 5% to about 33% by weight of said water-soluble abrasive.

References (Jited in the file of this patent UNITED STATES PATENTS 2,020,228 Ashton Nov. 5, 1935 2,191,199 Hall Feb. 20, 1940 2,257,545 Curtis Sept. 30, 1941 2,296,690 Soderberg Sept. 22, 1942 2,489,848 Bacon et al Nov. 29, 1949 2,555,285 Black May 29, 1951 OTHER REFERENCES Modern Polishes and Specialties, 1947; Chemical Pub- Co. Inc., N. Y.; pages 260284.