US2421703A

US2421703A - Detergent paste

Info

Publication number: US2421703A
Application number: US605186A
Authority: US
Inventors: Kamlet Jonas
Original assignee: Boyle Midway Inc
Current assignee: Boyle Midway Inc
Priority date: 1945-07-14
Filing date: 1945-07-14
Publication date: 1947-06-03
Anticipated expiration: 1964-06-03

Description

Patented June 3, 194 7 DETERGENT ras're Jonas Kamlet, New York, N. Y., assignoi' a none-g .Midway Inc., New York, N. Y., a corporation of Delaware No Drawing. Application July 14, 1045, a Serial No, 605,186

7 Claims. (Cl. 252-110) This invention relates to a detergent paste containing trisodium phosphate, and more particularly to a detergent paste suitable for household, toilet, laundry and industrial use which contains finely divided, uniformly distributed, solid trisodium phosphate in non-abrasive form. It has for one object to provide a composition in paste form possessing as nearly as possible the characteristics of an ideal all-purpose detergent. It has for a further object to provide a process for the manufacture of an inexpensive detergent paste composition possessing various desirable properties. Other objects and advantages will be apparent from the following description.

An ideal all-purpose detergent should possess the following characteristics:

- (a) A limited high pH value in dilute solution coupled with absence of causticity;

() Good buffering properties;

(0) Good emulsifying activity;

(d) Marked surface-tension-lowering activity;

(e) Lack of abrasive properties;

(I) Ability to form copious suds;

(9') Absence of insoluble-soap or scum formation on solution in hard water; and

(h) Absence of irritating dust due to the presence of fines.

Trisodium phosphate (NaaPOl) has long been used as a detergent and as an ingredient of detergent mixtures (e. g., as a builder for laundry soap, as a component of soap powders, etc.). It

possesses the first three characteristics enumerated above to a satisfactory extent.

(a) Trisodium phosphate gives solutions of higher pH value than any other common noncaustic alkali (i. e., with the exception of such excessively caustic alkalls as sodium hydroxide).

I A 0.033% solution of trisodium phosphate has a pH of 10.80 (sodium hydroxide-pH 11.85; sodium carbonate-pH 10.65); a 0.66% solution of trisodium phosphate has a pH of 11.45 (sodium hydroxidepH 12.90; 11.20).

(b) Trisodium phosphate possesses excellent buffering properties. Thus, it retains its detergency in the presence of acid soils which would destroy the cleansing ability of other alkalls.

(c) Trisodium phosphate has remarkable propcities as an emulsifying agent for saponiflable oils and greases, approaching in emulsifying power the properties of a colloidal dispersing and emulsifying agent. Nocompletely satisfactory explanation of thisproperty has yet been put forth. It is probable, however, that this emulsifying activity is due to the ability of trisodium sodium carbonate-pH phosphate to form sodium soaps by double displacement reactions with greases (which areheavy metal salts of fatty acids) and by saponification of fats and oils. These sodium soaps, formed at the interface of the soil particle, and the aqueous solution are powerful emulsifying agents, particularly in the nascent 'or formative stage,

However, crystalline trisodium phosphate does not possess other characteristics of an ideal allpurpose detergent: It does not possess any marked surface tension-lowering activity; the solid compound, either anhydrous or as the hydrate, forms harsh and abrasive crystals; it is totally devoid of sudsing properties; it forms a scum of insoluble calciumand magnesium phosphates in hard water and it usually contains a considerable amount of flnes" which cause an irritating and sternutatory dust when the dry powder is shaken.

By this invention I provide detergents based on trisodium phdsphate possessing in addition to (a) Trisodium phosphate,

(1)) A surface-active compound capable of sequestering or forming soluble compounds with alkali-earth metal ions, in amount from 0.5% to 5.0% of the total weight of the composition,

(0) An emulsifying agent chosen from the group of compounds consisting of the salts of aliphatic acids containing from 7 to 22 carbon atoms with the alkali metals and the primary, secondary and tertiary hydroxyalkylamines in amount-from 1.0% to 5.0% of the total weight of the composition, and

(d) Water, in amount between two and three times the weight of the trisodium phosphate, taken as anhydrous NasPOr,

are. cooled (or permitted to'cool), a stable and uniform detergent paste is obtained. I have further discovered that under these conditions, although insuflieient' water'is present to dissolve all the trisodium phosphate at room temperature,

the latter is present in a form completely devoid of harmful abrasiveproperties. These new products possess to a marked degree all of the desir able characteristics of an ideal all-purpose detergent.

The trisodium phosphate, present to the extent of from,22.5% to 32.8% of the total weight of the composition (taken as anhydrous NBJPO i) may be ,used in the formof the anhydrous salt, the monohydrate and/or the dodecahydrate in the formulation of this product.

The surface-active compound capable of sequesterin or forming soluble compounds with alkali-earth metal ions may advantageously but not necessarily be chosen from thewell-known industrial wetting, penetrating, emulsifying and dispersing agents possessing this property. Typical examples of such agents suitable for the formulation of the detergent products of the present invention are:

Aerosol OT (sodium di-octyl sulfosuccinate) Aerosol MA (soduim di-hexyl sulfosuccinate) Aerosol AY (sodium di-amyl sulfosuccinate) Aerosol OS (sodium isopropyl naphthalene sulfonate) Naccanol NR (sodium kerylbenzene sulfonate) Sodium lauryl sulfate Sodium salts of sulfonated petroleum hydrocarbons Gardinol LS (sodium These may be added to the composition as dry powders, pastes or aqueous solutions, and are present to the extent of from 0.5% to 5.0% (dry basis) of the total weight of the composition.

The emulsifying agent is chosen from the group of compounds consisting of the salts of aliphatic acids containing from 7 to 22 carbon with the alkali metals and the primary, secondary and tertiary hydroxyalkylamines. The aliphatic acids falling within this classification include, for example monobasic acids, such as oenanthic, caprylic, capric, lauric, myristic, palmitic, oleic, stearic, linoleic, arachidic and behenic, and also dibasic acids, such as pimelic, suberic, azelaic, sebacic and brassilic; or they may be mixtures of'fatty acids, such as coconut oil fatty acids, palm oil fatty acids, tallow fatty acids, etc.

The emulsifying agents are prepared by comsalt of oleyl sulfuric acid) bining the above identified acids with an alkali metal hydroxide, such as sodium hydroxide or potassium hydroxide, or with a primary, secondary or tertiary hydroxyalklamine. The following are examples of such typical hydroxyalkylamines'z Primaryethanolamine, propanolamine, Z-amino, 2-methylpropandiol- 1,3, hydroxyethylethylene diamine secondary diethanolamine, dipropanolamine, N-methylethanolamine, N-butylethanolamine; tertiarytriethanolamine, triisopropzmolamine, N,N-di.methylethanolamine, N-methyl, N-ethylethanolamine.

This salt formation may be eifected by combin ing the acids and the bases in stoichiometric amounts in aqueous solution. In the case Of the organic bases, melting these together with eq molar equivalents of the acids suffices to form the corresponding salt by addition. The salt formation may be efiected extraneously, and the resultant compound added to the composition as an emulsifying agent. Alternatively, the base and theacid may be combined in the course of formulation and the resultant salt formed in situ Where it acts as an emulsifying agent.

The concentration of the emulsifying agent, anhydrous basis, is from 1.0% to 5.0% of the total weight of the composition. This suflices to yield .a stable and uniform emulsion.

The water is present to the extent of from 60.0% to. 73.9% of the total Weight of the' composition and from two to three times the weight of the trisodium phosphate, taken as anhydrous NaaPoi. Within the above delineated limits of concentration for each component, a detergent paste of the. desired characteristics is obtained.

The emulsion is formulated by dissolving the trisodium phosphate in the water heated .to between 75 C. and 100 C. If the monohydrate, octahydrate', or the dodecahydrate of trisodium phosphate is employed, the water content of the crystalline material must be reckoned'as part of the water content of the final product. Triso-' dium phosphate dodecahydrate will dissolve in its water of crystallization when heated above 75 C., and the resultant solution 'may be diluted with hot water to obtain the desired Na3PO4:HaO

. ratio.

To this hot solution are now added with vigorous agitation the surface-active agent and the emulsifying agent, ,each or both of these being in solid, paste or liquid form. Stirring is continued while the emulsioncools, or is cooled by extraneous means. "When the emulsion commences to thicken (e. g., around 50 to 0.), it is poured into containers and permitted to gel to a homogeneous paste.

An alternative method is to dissolve the tri-. sodium phosphate, the surface active agent and the basic component of the emulsifying agentin the water, heated to between 75 C. and. 100 C. To this well stirred, hot solution the acidic component of the emulsifying agent is now added. The emulsifying agent is formed in situ and immediately dispersed in the solution. The emulsion is cooled to the thickenin point, as above, and poured into containers where it is permitted to gel.

Another alternative method is to dissolve the trisodium phosphate and the surface active agent in the hot water, disperse the fatty acid in the r hot solution (takingadvantage of the excellent fat-emulsifying properties of the trisodium phosphate) and add the basic component of the emulsifying agent thereto. Here again, the formation of the emulsifying agent occurs in situ, and the emulsion is treated as above.

. Ordinarily when a concentrated hot aqueous solution of trisodium phosphate is cooled, or permitted to cool, the trisodium phosphate will precipitate as hydrated crystals. For some purposes these crystals are satisfactory, but for.

an ideal all-purpose detergent they have the disadvantage of being harshly abrasive, a property that obviously unfits them for many purposes for which a detergent is used. By following the process comprised in my invention and observing the limitations as to quantities and conditions disclosed, I have discovered that trisodium phosphate can be incorporated in relatively high concentration into a detergent paste in such a way as to keep available its above-described desirable properties but to eliminate entirely its usual harsh abrasive properties. While I do not wish to be limited to any particular theory or mechanism in explaining this result, it appears that the condition of cooling the concentrated aqueous solution of trisodium phosphate in the presence of a surface-active agent and an emulsifying agent as above described result in the precipitation of the trisodium phosphate in an extremely finely divided and thoroughly disversed o m- The salt so preclpitatedsppearsbeamrphwsbutmay emicrocrystalline, and

its particles are probably individually surrounded by an adsorbed film *of the colloids present. Whatever the explanatiomrobtain a detergent paste containing a relatively high. concentration of trlsodium phosphatflaisurface-active material, an emulsifying agent and insuflicient wa- Y lies to dissolve the trisodium phosphate at room temperature, in which the trisodium phosphate retains it desirable detergent and chemical properties but is devoid of undesirable abrasive properties.

The addition-of an emulsifying a ent chosen from the group delineated above aids in obtaining a uniform emulsion when hot which on cooling gels to a uniform paste containing solid, dispersed trlsodium phosphate in the desired form; it furthermore enhances and accentuates the emulsifying action of the trisodium phosphate on greases,

, fats and oily soils.

The detergent pastes ofthe present invention, containing from 22.5% to 32.8% of trisodium phosphate on an anhydrous basis (NasPOO have an actual or equivalent content of from 52.1% to 76.0% of the dodecahydrate' (Na3PO4.12H2O) Since the dodecahydrate is by far the most comduce the surface tensionsufliciently to efiect excellent wetting of the-material being cleansed by the detergent solution. It also lowers the interfacial tension between the particles of soil and the detergent solution and thus facilitates the cleaning process. Not all surface-active agents.

eliminate. In Frost's product,- crystallization is not in any way interfered with; in fact Frost states that larger and better formed crystals of trisodium phosphate will develop in his product than in the ordinary commercial salt. The prodnot of my invention, on the other hand, is a non-crystalline paste, and (as pointed out above) the trisodium' phosphate is uniformly distributed in the paste in amorphous form' or, if crystalline, in such a microcrystalline .state as to be have, for practical detergent purposes as noncrystalline and be free of harsh abrasive properties.

The products of the present invention will form copious suds in water, cold as well as warm.

This property is primarily due to the content of surface active agents in the formulation, since both detergency and foaming are phenomena closely related to the lowering of surface tension. The sudsing of the product is also enhanced materially by the presence of the emulsi-- fying agent. Salts of oleic acid, coconut oil fatty acids, hydrogenated coconut oil fatty acids, palm oil fatty acids, castor oil fatty acids, olive oil fatty acids, y istic acid and linoleic acid are among the best producers of foam or suds.

The presence of the calcium-ionseq1uestering surface active agent also inhibits scum formation due to precipitation of insoluble calcium and magnesium phosphates. This serves to prevent undesirable contamination of fabrics, hair, glassware, etc., during washing and subsequent rinsing operations, to prevent the formation of a ring of dirt around wash basins, bath tubs, etc., and to prevent the spotting of clothes, or uneven applicationof dyes in dyeing operations. It also serves to prevent the precipitation of scale in steam boilers through and in which solutions of the detergent compositions of the present invention may be circulated or stored.

Finally, it may be noted that the detergent compositions of the present invention are totally devoid of irritating or sternutatory dusts or flnes" since they are produced in the form of gels or pastes.

possess surface-tension-loweringproperties?"'Cer ;;t--is--obviousthat coloring agents, perfumtain non-ionic dispersing agents owe their activity to their ability to decrease the mutual attraction between suspendedor dispersed particles, thereby lowering the viscosity of the dispersions and eflecting a stabilization. However, calcium-ionsequestering surface-active agents are anionic in nature and possess marked surface-tension-lowering properties. .This group of anionic surface active agents includes the sulfonated oils (such as Turkey red oil), the sulfonated higher alkanols and higher alkyl sulfates, the sulfonated naphthenates, the sulfonated petroleum fractions, the 60 aromatic sulfonates (such as the sulfonated alhylnaphthalenes, the sulfonated alkyl benzenes and the Twitchell reagents), the esters of sulfosuccinic acids, the sulfonated amides, etc.

I am aware that it has been proposed by Frost (U. S. Patent 1,885,905, patented November 1,

1032) to co-crystallize trisodium phosphate with less than 1%, and preferably about 0.3% of a fatty acid soap. The resultant crystals are stated to have a satin-like sheen or luster and to be less susceptible to caking or lumping under varying humidity conditions. Frost's product, however, is

not'o'nly entirely difiere'nt in chemical compoposition and physical form from the products of this invention, but the properties of the trisodium ing agents, deodorizing agents, and other ancillary substances may be incorporated in the products of the present invention without changing the basic nature thereof.

The detergent pastes described in the present application may be used for washing dishes, glassware, china, greasy and charred cooking ,utensils, silverware, linoleumv and composition floors,

.sinks, toilet bowls, refrigerators, tables, tile, marble, terrazzo, painted and unpainted walls, furniture, for all laundering purposes, for badly grimed overalls, as a detergent paste for me:

V chanics' hands, for softening hard water in industrial plants, laundry and bath, for mopping, scrubbing, metal cleaning, for drapes, rugs,

blankets, woolens, etc., etc., or wherever an allpurpose detergent is applicable.

The following examples are given to define to illustrate the present invention, but in no way to limit it as to reagents, proportions 0r conditions described therein. Obvious modifications will occur to any person skilled in the art. All proportions given are parts by weight.

Example 1 300.0 arts of anhydrous trisodium phosphate,

20.0 parts of Naccanol NR (sodium kerylbenzene rfi i hitecrritaisinms product": aiintai properties that this invention aims to and does and . '1 sulfonate, manufactured by the National Aniline Division, Allied Chemical 8: Dye Corporation) and 2.0 parts of potassium hydroxide are dissolved in- 662.0 parts of water heated-to between 75 C. and

100 C. To the resultant solution there are added, with vigorous stirring, 11.0 parts of oleic acid and 5.0 parts of pine oil. Agitation is continued while the emulsion is cooled. When the temperature has fallen to between 50 C. and 60 0., the emulsion is poured into its ultimate containers (e. g., bottles, jars, tins, etc.) where it is permitted to set to. a paste. The gelling process .may be accelerated by cooling or chilling the filled container.

Example II 521.6 parts of trisodium phosphate dodecahydrate are heated at 75 C. to 85 C. until it has dissolved in its water of crystallization. 200.0 parts of a 25% aqueous solution of Aerosol OT (sodium di-octyl sulfosuccinate), 50.0 parts of the monoethanolamine salt of coconut oil fatty acids, 0.4 part of the sodium salt of fiuorescein (uranine WSS) and 228.0 parts of boiling water are added with vigorous agitation. The resultant emulsion is stirred until it has cooled to within the 50 C.-to-60 C. range, and is then poured into its ultimate containers and permitted to gel.

The emulsifying agent is preparedby melting together coconut oil fatty acids with 30.0% of their weight of monoethanolamine.

Example III 305.0 parts of anhydrous trisodium phosphate and 25.0 parts of sodium isopropyl naphthalene sulfonate are dissolved in 635.0 parts of water heated .to between 75 C. and 100 C., and 12.5 parts of palm oil fatty acids are dispersed in the resultant solution. To the well agitated reaction mixtures are now added 7.5 parts of triethanolamine and 15.0 parts of limonene. The emulsion thus obtained is cooled to incipient gelling and poured into its ultimate containers.

Example IV 695.4 parts of trisodium phosphate dodecahydrate are dissolved in 204.6 parts of boiling water, and 50.0 parts of sodium iauryl sulfate and 50.0 parts of sodium myristate are added to the resultant solution with vigorous stirring. When a uniform emulsion is obtained, it is cooled to between 55 C. and 60 C., and poured into its ultimate containers where it is permitted to gel.

Example V 240.0 parts of trisodium phosphate anhydrous, 8.0 parts of Naccanol FSNO (a purified grade of sodium kerylbenzene sulfonate) and 6.3 parts of diethanolamine are dissolved in 720.0 parts of bilizing alkali-earth metal compounds under detergent conditions and chosen fromthe group of compounds consisting'of sulfonated and sulfated non-soap detergents, an emulsifying agent chosen from the group of compounds consisting of the salts of aliphatic acids containing from '1 to 22 carbon atoms with the alkali metals and the primary, secondary and tertiary hydroxyalkylamines in an amount suflicient to maintain the ingredients of the mixture in dispersed state, and water in. an amount insufficient to dissolve all th trisodium phosphate in the mixture at room temperature but sufiicient to impart to the mixture a pasty consistency.

2. A detergent paste containing from about 22% to about 33% trisodium phosphate calculated as the anhydrous salt, from about 0.5% to about 5.0% of a surface-active compound capable of solubilizing alkali-earth-metal compounds under detergent conditions and chosen from the group of compounds consisting of sulfonated and sulfated non-soap detergents, from about 1.0% to about 5.0% of an emulsifying agent chosen from the group of compounds consisting of the salts of aliphatic acids containing from 7 to 22 carbon atoms with the alkali metals and the primary, secondary and tertiary hydroxyalkylamines, and from about 60% to about of water, the amount of water being between two and three times the amount of the trisodium phosphate.

3. A detergent paste as defined in claim 2,'in which the emulsifyin agent is potassium oleate.

4. A detergent paste as defined in claim 2, in which the emulsifying agent is a hydroxyalkylamine salt of an aliphatic acid containing from 7 to 22 carbon atoms.

5. A detergent paste as defined in claim 2, in which the surface-active compound is sodium kerylbenzene sulfonate.

6. A process for the manufacture of a detergent paste, which comprises mixing trisodium phosphate, a surface-active material capable of solubilizing alkali-earth metal compounds under detergent conditions and chosen from the group of compounds consisting of sulfonated and sulfated non-soap detergents, an emulsifying agent chosen from the group of compounds consisting of the salts of aliphatic acids containing from 7 to 22 carbon atoms with the alkali metals and the primary, secondary and tertiary hydroxyalkylamines in an amount suflicient to maintain the ingredients of the mixture in dispersed state, and water in an amount insufliceint to dissolve all the trisodium phosphate in the mixture at room temperature but sufficient to impart to the 22% to about 33% trisodium phosphate calcu-.

lated as the anhydrous salt, from about 0.5% to about 5.0% of a surface-active compound capable of solubilizing alkali-earth metal compounds under detergent conditions and chosen from the group of compounds consisting of sulfonated and sulfated non-soap detergents, from about 1.0% to about 5.0% of an emulsifying agent chosen from the group of compounds consisting of the salts of aliphatic acids containing from 7 to 22 carbon atoms with thealkali metals and the primary, secondary and tertiary hydroxyalkylamines and from about 60% to about 75% of ,water, the amount of water being between two and three times the amount of trisodium phosphate, heating the mixture to a temperature be- 9 tween 75 and 100 0., violently agitating the Number mixture while heated to effect unii'orm dispersion 1,999,631 of the ingredients, and cooling the resultant 2,097,737 2,294,975

emulsion to a temperature below 75 C.

Nanie Date" Kise et al Nov. '24, 1942 Number Name Date Friesenhahn Apr. 30. 1935 Pickett Nov. 2,1937 Colgate Aug. 25, 1942 Tucker Feb. 16, 1943 Toone Mar, 16, 1943 FQREIGN PATENTS Country Date Great Britain Apr. 23, 1941 Australia. Apr. 11, 1939 Certificate of Correction Patent No. 2,421,703. V JONAS KAMLET It is hereby certified that errors appear in the printed specification of the above numbered patent requiring correction as follows: Column 9, line 12, for the patent number 2,302,212 read 2,303,212; column 10, line 10, before 535,809 insert 443,487 Great Britain Feb. 24, 1986; and that the said Letters Patent should be read With these corrections therein that the same may conform to the record of the case in the Patent Ofiice.

Signed and sealed this 29th day of July, A. D. 1947.

[SEAL] LESLIE FRAZER,

First Assistant Uommz'ssz'oner of Patents.

4 June 3,1947.