US2308992A - Method for producing washing, cleansing, bleaching, and rinsing agents containing percompounds - Google Patents

Description

Jan. 19, 1943. A. MERTENS 2,308,992

METHOD FOR PRODUCING WASHING, CLEANSING, BLEACHING, AND

RINSING AGENTS CONTAINING PERCOMPOUNDS Filed Sept. 29, 1958 INVENTOR 4ND254 5 M52 TENS ATTORNEYS Patented Jan. 19, 1943 METHOD FOR PRODUCING WASHING. CLEANSING, BLEACHING, AND

RINSING AGENTS CONTAINING PEBCOMPOUNDS Andreas Mertens, Dusseldorf-Benrath, Germany,

assignor, by mesne assignments,

to The Procter at Gamble Company, Cincinnati, Ohio, a corporation of Ohio Application September 29, 1938, Serial No. 232,359 In Germany October 2, 1937 3 Claims. (Cl. 252-97) This invention relates to washing. cleansin bleaching and rinsing agents containing percompounds and to a process for producing the same.

At the present time agents of this nature containing percompounds are generally produced through a mechanical mixing operation of the various constituents. Since the individual constituents of such compositions possess different specific gravities, the various substances tend to separate from each other and to result in a deterioration of some of the compounds. which effect may prove quite undesirable at the time the detergents or cleansing agents are used for their intended purposes. Efforts have been made to overcome this difilculty and to produce a uniform product, success having been reached by atomizing solutions, suspensions or fusions of the various constituents of the detergents, in suitable spray drying equipment. Atomizing proc esses as used by prior art, however, are not suitable for the production of uniform products from compositions containing percompounds. Upon atomization of solutions, suspensions or fusions which, besides the other constituents of the detergent, contain percompounds, the percompounds are decomposed because of the effect of the elevated temperatures required during the atomizing treatment and the presence of water, thereby causing the loss of their effective bleaching ingredient, namely, the active oxygen. Efforts have been made to produce compositions of the nature above referred to by atomizing and drying together all of the constituents with the exception of the percompounds, and then mixing the powdered percompound to form the final composition. This method, however, did not re suit in uniform products, due to the different specific gravities of the ingredients and the disadvantages connected therewith.

An object of the present invention is to produce granular washing, cleansing, bleaching and rinsing agents containing percompounds wherein the individual particles are homogeneous in composition and contain the percompound in a form which does not permit separation and loss of active oxygen due to such separation. Another object is to produce such agents in the form of a uniform powder of homogeneous structure and grain size. Another object is to produce powdered agents as described above in which each individual powder grain is a unit whose percentage of composition of the various ingredients approximates that of the entire composition.

Although the instant invention is applicable to washing, cleansing, bleaching and rinsing may be agents in general which contain percompounds, it is particularly applicable to compositions containing soaps or soap substitutes and alkaline salts. No novelty is claimed for the specific combinations of the ingredients of the compositions. The invention lies, rather, in the physical form of such compositions and in the process and apparatus for producing the same. The compositions may contain soap, soap substitutes, foaming agents, percompounds and other substances. As percompounds there may be used, for aample, those which liberate oxygen from aqueous solutions of the same, such as perborates, as sodium perborate; percarbonates; perphosphates; perpyrophosphates; addition compounds of hydrogen peroxide of various solid substances and similar compounds. If necessary to suit specific conditions, stabilizers may be employed in addition to the percompounds.

Instead of soap, other substances possessing decided washing, and cleansing action may be used. Outstanding examples comprise the sodium salts of sulfuric acid esters of higher fatty alcohols, mixtures of such salts, soluble salts of methyl taurines acylated by means of higher fatty acid radicals, and like soap substitutes. The aforesaid substances possessing decided deterging properties are designated hereinafter as saponaceous materials.

Suitable alkaline salts for the compositions of the present invention include waterglass, sodium metasiiicate, borax, soda, phosphates such as the alkali metal orthophosphates, meta-phosphates and pyrophosphates, alkali metal salts of those organic amino-carboxylic acids which for every basic nitrogen atom possess more than one carboxyl group, and other substances. The aforesaid suitable alkaline salts may be classified as water-soluble cleansing salts.

In accordance with the process of the present invention, the new washing, cleansing, bleaching and rinsing agents are obtained by an atomizing-drying treatment in a single operation. The constituents other than the percompounds are prepared in the form of solutions, suspensions or fusions, are atomized in a suit able tower, preferably in the presence of a gaseous current, in the form of a hollow cone. The percompounds are simultaneously sprayed in a powdered form into the interior of the hollow cone formed by the atomized particles into contact with such particles. A heated gas current employed to simultaneously dry the atomized liquid. Upon the passage of the finely atomized solution into the heated gaseous medium,

the greatest part of the water evaporates. Immediately before complete dryness is attained, or while the atomized particles are still in a semimoist state, the solid particles of the percompounds come in contact therewith and bring about deposition of the moist particles upon the powdered particles. The atomized particles surround the powdered particles like an insulating layer, and as a result the percompound is protected to a very large extent against the deteriorating effect of the hot aqueous vaporization of the gas current. In this manner a powdered composition is obtained composed of homogeneous grains, each grain containingthe individual constituents of the composition. In contrast to prior practice the particles of the pereompounds are not separate from the remaining constituents but are agglomerated or agglutinated with them. The new compositions are composed of particles of uniform specific gravity which do not separate or readily deteriorate.

The conditions under which the process is carried out, such for instance as the temperature of the gas current, the duration of the treatment, the circulation of gas, the pressure with which the solution is atomized and the pressure under which the powdered percompounds are sprayed are chosen in accordance with known technic.

Depending upon the desired condition of the final product, the gas current for the drying operation may be conducted into contact with the atomized particles either concurrently or in a countercurrent operation. The gas current may be either hot or cold. It so desired, other solid compounds in powdered state may be introduced with the percompound through the spray nozzle, examples of other suitable compounds being stabilization agents, disinfectants, fillers and similar substances.

'The process of the present invention may be satisfactorily carried out in the apparatus illustrated, diagrammatically in part, in the accompanying drawing.

With reference to Fig. 1 there is shown in vertical section a tower l having a conical bottom I! leading to a rotary discharging device I3, an inlet conduit M for the introduction of a gaseous 3 medium as air, nitrogen, carbon dig ide, this conduit bein connected aroun an into the ....a...- m g a t n;eausesctheaatornimdliililifi.. L9-

At a

spread in the form of a hollow cone l8. point below the atomizing nozzle i1 within the hollow cone l8 there is an upwardly turned spray nozzle I9 adapted to project particles of powder outwardly in contact with the atomized liquid.

With reference to Fig. 2, there is illustrated th atomizing nozzle H for the most part in elevation. This nozzle comprises a base portion containing an inserted element 2! having a series of spirally arranged grooves 22 communicating with the hole 26, which is connected with the orifice 28. Furthermore, the nozzle H comprises a portion 23 which is screwed on the base portion 20. On its upper end, the portion 23 is connected with an exchangeable part 25 containing the orifice 2B. Depending upon the nature of the desired product, the cross-section of the orifice 28 may be varied by exchanging the part 25. At the dischargin end of the orifice 28, the portion 25 forms a funnel-shaped hole, of which the cone 24 of the portion 23 is a continuation.

With reference to Fig. 3 the spray nozzle [9 is illustrated in vertical section. This nozzle has a cylindrical base portion 29 flaring outwardly at its discharging end to form a cone shaped element. Within the cone of the base portion there is a second conical element 30, shown in elevation, which causes the powdered materials to pass through the nozzle and to be projected in a substantially lateral direction toward the interior of the atomized liquid in the cone Hi.

In the apparatus shown in Fig. 1 it is almost essential that the distance between the two nozzles be so arranged that the powdered percompounds are projected into the upper part or near the apex of the cone of the atomized particles. The nozzles, however, need not be of necessity arranged in the upper part of the atomizing tower. They alternatively may be in the center or near the lower end of the atomizing tower, depending upon the operation of the process, that is, how the atomizing is to be effected within the tower, from top to bottom or from bottom to top.

A specific example of a process and a typical product is given in the following:

An aqueous solution containing approximately 43 parts of soap, 17 parts of soda and 3 parts of waterglass, all parts by weight, are atomized in the tower I0 through nozzle i1 into a coneshaped spray I 8. Simultaneously, sodium perbcrate in powdered form is blown through the nozzle l9 into the interior of the cone I8 into contact with the atomized particles therein. The sodium perborate is introduced in measured quantities, which produces final products having 10% sodium perborate. The individual particles of sodium perborate come in contact with the semi-moist particles, thereby forming larger particles containing each of the constituents of the whole composition. The perborate particles are generally completely enclosed by the deposit of the atomized compounds. The particles formed by the contact of the two operations move in countercurrent direction to a stream of hot air emerging from the apertures I5 and passing out through outlet Hi. When the falling particles pass apertures l5 they are substantially completely dry. When they have fallen to the bottom of the tower, they may be removed in con vcntional manner.

The temperature in the upper half of the atomizing tower under which the atomization is effected may be satisfactorily at about C. In the lower part of the atomizing tower the temperature is progressively lower, resulting in a temperature of about 35 C. at the bottom. It desired, cold air may be introduced within the tower for more rapidly or more effectively cooling the atomized materials.

The cleansing composition obtained by the foregoing process comprises a uniform powder of homogeneous structure and grain size, the particles of which also possess a uniform specific gravity. Since the perborate particles are in close contact and agglomerated or agglutinated with the remaining constituents of the detergent, deterioration of the individual constituents of the powder does not occur. Another advantage in the compositions as herein produced lies in their complete freedom from dust.

In the above composition the soap may be replaced by sulfonated fatty alcohols, alkali metal salts of fatty acids obtained by oxidation of paraflins, alkali metal salts of methyl taurines, acylated by means of higher fatty acid radicals or other soap substitutes.

It should be understood that the present inven- 'tionisnotlimitedtothespeciiiccompoimdacomof washing, cleansing, bleaching and rinsin agents of uniform constitution and comprising a saponaeeous material and an oxygen-liberating percompound bleaching agent in undecomposed form which comprises atomizing an aqueous mixture of the constituents of the composition other than the peroompound into a drying tower, in the form of a hollow cone. spraying the percompound in powdered form near the interior apex of said cone into contact with the atomized particles while the same are in a moist condition, and quickly drying the resulting composite particles by means or a stream of an inert gas flowing in a direction countercurrent to the flow of the atomized particles to form a dry granular mass, the temperature of the gas being insuflicient to cause decomposition of the percompound.

2. A process for producing a detergent and bleaching composition comprising an oxygenliberating percompound, a saponaceous material and a water-soluble alkaline detergent salt which comprises atomizing an aqueous mixture of the constituents of the composition other than the peroompound into a drying tower in the form or a vertical hollow cone, spraying the percompound in the form of a powder into the interior of said cone in contact with the moist atomized particles and passing a heated current of an inert gas medium in contact with the resulting composite particles formed to quickly dry said particles thereby producing a dry granular mass.

3. The method of forming spray dried particles or washing. cleans M L L K and rinsing agents of uniiorm constitution and comprising a saponaceous material and an oxygen liberating percompound bleaching agent in undecomposed form, which comprises atomizing an aqueous mixture of the constituents of the composition other than the percompound into a drying tower in the form of a hollow cone. spraying the percompound in powdered form near the interior apex oi said cone into contact with the atomized particles while the same are in a moist condition and passing a heated current of an inert gas medium in contact with the resulting composite particles formed to quickly d y said particles, thereby producing a dry granular mass, the temperature of the gas being insuflicient to cause decomposition oi the percompound.

ANDREAS MER'IENS.

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