US 2936288 A
Description (OCR text may contain errors)
United States Patent 7 2,936,288 LIQUID DETERGENT COMPOSITIONS William B. Coleman, Crete, Ill., assignor to Victor Chemical Works, a corporation of Illinois No Drawing. Application August 22, 1956 Serial No. 605,469
9 Claims. (Cl. 252-'137) This invention relates to liquid detergent compositions.
This application is a continuation-in-part of my copending application Serial No. 396,313 filed December 4, 1953, and now abandoned.
The improved compositions of this invention provide highly concentrated solutions of an organic wetting agent and a phosphate builder. The concentrated solution is very stable and will not separate into phases or deposit solids over long periods of standing. Stability is achieved by the use of isoamyl acid phosphate coupling agents which increase the mutual solubilities of the Wetting agent and builder in aqueous solution, thereby permitting the production of a more concentrated product. A Many attempts have been made to produce an ideal liquid detergent containing a wetting agent and a phosphate builder but only limited success has been met. Inherent disadvantages in this type of composition include incompatability of the components, relative insolubility of some of the components and instability of the composition to temperature changes. Consequently, the solutions are usually turbid or heterogeneous, making them commercially unsatisfactory.
A variety of methods have been used in an attempt to overcome these difficulties. Thus some liquid detergents are in the form of dilute solutions ready for use full strength. This type of product eliminates the solubility problem. Other detergents use a liquid hydrocarbon for a base to avoid solubility problems; others limit themselves to a specific Wetting agent or builder which has unique solubility characteristics. All of these methods of overcoming specific difiicnlties, however, have done so at the expense of either versatility, economy or quality. "Thus the ideal liquid detergent should be a concentrated solution containing an excellent wetting agent in combination with an excellent builder. Preferably there should be a wide choice among Wetting agents and builders so that a variety of specific detergents having the same general composition could be prepared for special pur- I have now found that a concentrated, stable solution of a variety of organic wetting agents and phosphate builders may beproduced by using an isoamyl acid phosphate as a coupling or solubilizing agent. This solution does not settle into layers upon standing. It may be cooled within usual temperature limits with only slight clouding and will regain its original clarity when warmed to room temperature. It may be used for all general household purposes and is particularly good for laundering wherein it has excellent cleansing and detergency qualities. The isoamyl acid phosphate coupling agents which Ihave discovered appear to be unique in their action.
Similar propyl, butyl and octyl compounds for instance do not appear to work in this invention. Either the ortho bi pyro form of the acid phosphate is suitable. These inay not be specific compounds, but when formed as shown in the following equations the products produced give produced.
2,936,288 Patented May 10, 1960 The di-isoarnyl acid pyrophosphate may be prepared as follows:
+P2O5 (i-Am)2H2P207 The simple mono-isoamyl-diacid orthophosphate and di-isoamyl acid orthophosphate are also satisfactory for The mono-di-isoamyl acid orthophosphate described above is in efiect an equimolar mixture of these two compounds.
The isoamyl alcohol used in making these compounds is preferably the commercial grade material which is commonly known as fusel oil. More refined grades are suitable but are uneconomical.
The value of these compounds lies in the fact that they appear to be uniquely able to assist the formation of a concentrated solution of an organic wetting agent and a phosphate builder.
Normally in a concentrated solution containing these two ingredients the phosphate has a tendency to salt out the wetting agent. This prevents the formation of a concentrated solution and also causes much difliculty due to phase separation, etc. In addition to the coupling effect, the amyl acid phosphates also enhance the Washing qualities of the solution since they are in themselves good Wetting agents.
The preferred class of organic wetting agents for use in this invention are the higher alkyl aryl alkali metal sulfonates; ofthese, Nacconol NRSF is especially preferred. However, other anionic synthetic detergents, such as Nacconol NR, Oronite D-40, Ninex 21, Igepon T-77, and Ultrawet K, may also be used.
In addition, nonionic organic wetting agents are also solubilized by the amyl acid phosphates. For example, among the commercially available nonionic wetting agents which have been found effective are Ninol AA62 and Alrosol.
Nacconol NR and Nacconol NRSF are synthetic anionic surface active detergents of the higher alkyl aromatic sulfonate type prepared from a starting material obtained by the Friedel-Crafts condensation of a. mono-chlorinated kerosene fraction with benzene at about 35-50 degrees C. using aluminum chloride as a "catalyst, the kerosene fraction refined from Pennsylvania crude having a high aniline point, a boiling range of ZUO' -BOO degrees C. and an average molecular weight corresponding to a saturated aliphatic hydrocarbon of about 14 carbon atoms. The alkyl aryl condensation product is separated from the cohdensatioii reaction and sulfonated with sulfuric acid moiiohyd'rate or oleiim at temperatures under 60 degrees The neutralized dried sodium sulfonate'containing about 10% or less of sulfuric acid in the form of inorganic salt is the Nacconol NRSF, the low-salt content grade, while theproduet containing about 60% of inorganic salt, mainly sodium sulfate,- is Nacconol NR.
Oronite D-40 and Ultrawet K are synthetic anionic surface active detergents 'of the higher alkyl aromatic analyses which indicate that nearly a pure compound is Susanne types as are the Nacconols referred to above, exeept that instead of benzene as the aromatic hydrocarbon employed in the Friedel-Crafts alkylation condensation, the aromatic nucleus is furnished by a mixture of lower homologues of benzene such as toluene and itylene, and lesser amounts of cumene. Ultrawet K contains about of the active detergent agent in the form of the sodium sulfonate of the alkyl aryl condensation pro-duct.
Or'onite .D iO is like Nacconol NR in "being a dry product containing about 40% of the active detergent acemes A c i agent, the remainder being inorganic salt, mainly sodium I known alkali metal polyphosphate salts such as tetrasodium pyrophosphate, tetrapotassium pyrophosphate, sodium tripolyphosphate, potassium tripolyphosphate, sodium hexametaphosphate, ammonium metaphosphate, and the like. Orthophosphates such as disodium phosphate, trisodium phosphate, monopotassium phosphate, and the like are also compatible when the isoamyl acid phosphate coupling agent is used.
The preferred phosphate builder for use in this invention is Victamide. This compound, as described in U.S. Patent 2,122,122 is a substantially neutral compound consisting of a nitrogen-phosphorus complex, resulting from heating a reaction product of P and anhydrous ammonia gas or liquid'at a temperature of at least about 150 C. in the presence of excess anhydrous ammonia to produce a condensation reaction, said compound having an atomic ratio of nitrogen to phosphorus of less than 1 to 1 with the ammonium nitrogen being from 60-80% of the total nitrogen and containingsubstantially no water of constitution. For example, the product may be produced by vapor phase reaction between the ingredients under anhydrous conditions. In this reaction phosphoric anhydride and anhydrous ammonia are heated at a temperature of at least 150 C. in an excess of ammonia gas for a period suiiicient to form a product, having a total nitrogen to phosphorus mole ratio between 1 and 1.5, with the ammonium nitrogen content being from 60-80% of the total nitrogen. The product will norm-ally have a pH value-in a 1% solution of about 5.5 to 6.0, and a ratio of N to P of approximately 1.25, a P 0 content of approximately 76.1%, a total NH of about 22.4%, and nuclear or amide nitrogen calculated as'NH of about 7.0%. Such analysis is typical and is not intended to set the exact approximately one-half hour. As will be seen in'the following examples, solutions varying from 15% up to saturation are used for the various other phosphate salts. These are produced by well-known methods.
The isoamyl acid phosphate coupling agent is then added to the phosphate builder solution which usually results in a two phase mixture. The mixture is then made homogeneous by adjusting the pH with an aqueous solution of a base. Sodium hydroxide is commonly used to effect maximum solubility although ammonium-hydroxide, well-known amines, such as triethylamine, triethanolamine, and the like, may be used. Awide range of pH values may be used without adversely affecting the product. Solutions ranging from pH 5 to 10 have been used in certain cases, Generally this pH adjustment is made by adding an approximately sodium hydroxide solution until a clear detergent solution results, The total amount of caustic is generally less than i 7% of the composition, but this is not critical and despecification of the reaction product to be employed in the present invention. Various structures have been proposed for this reaction product of P 0 and NH although the structure has never been definitely ascertained.
, It appears quite certain, however, that P-O--P or PNP linkages or both are present in the final product. Since the P-OP linkage is commonly associated with polyphosphates, it is thought that Victamide as described above may properly be classified as such. For purposes of this invention the unit 'P--X-P, where X is a member of the class consisting of O and N is intended to include Victamide and the common polyphosphates. Victamide may be dissolved in water to form solutions of -60% concentration although solut-ions of approximately 30% concentration are preferred for use in this invention. 7
In addition to the three major components of, these liquid detergents certain well-known special additives may be incorporated to produce specially desired results. These additives may include foam stabilizers, whitening agents, dispersants, and the like.
The general procedure followed in producing these liquid detergents is to first form clear, water solutions of the phosphate builder. In the case of the preferred Victamide this may be accomplished by allowing the solution to stand overnight at room temperature or the process may be hastened by heating at 60-90" C. .for
. Percent Tetrasodium pyrophosphate 7.3 Mono-di-isoamyl acid orthophosphate 13.1
. Nacconol NRSF 10.9 NaOH v 0.7 Water 68.0
. COMPOSITION 3 Tetrapotas'sium pyrophosphate 35.7 Mono-di-isoarnyl acid orthophosphate 12.8 Nacconol NRSF 10.7 NaOH 1.0 Water 39.8
COMPOSITION 4' Sodium tripolyphosphate 10.6 Mono-di-isoamyl acid orthophosphate 16.9 Nacconol NRSF 10.6 NaOH 0,4 Water 61.5
pends on the desired pH.
My clear, homogeneous, concentrated aqueousliquid detergent compositions may contain 35. to 75 parts by weight water, 5 to 30 parts by weight of'a water-soluble inorganic phosphate builder, 5 to 20 parts by weight wetting agent from the group consisting of nonsoap synthetic anionic organic wetting agents and synthetic alkylolamide non-ionic organic wetting agents, and 2-20 parts weight of a coupling agent from the group consisting of isoamyl acid orthophosphate and isoamyl acid pyrophosphate, said composition having a pH of from 5 to 10. i
The following compositions illustrate the wide range of different phosphate builders and wetting agents which can be'used with the isoamyl acid phosphate coupling agents.
' COMPOSITION 1 I Percent Victamide" 2O Mono-di-isoamyl acid orthophosphate 4.5 Nacconol NRSF 10.0 NaOH 0.7 Water -Q 64.8
The pH of this composition was 5.1. It was possible to raise this clear through the range up to a pH of 9.5
by increasing the NaOH to 5.4% and reducing the amount of water accordingly.
COMPOSITION 2 bba'eiz's's c oml osi'rron's Grams 30% potassium tripolyphosphate soln 100 Di-isoamylacid pyrophosphate 20 Nacconol NRSF 20% NaOH solution to a pH of 6 gave a clear solution. COMPOSITION 6 COMPOSITION 7 15% sodium hex ametap hosphate soln u. 100 Monodi-isoamyl acid orthophosphate 6 Nacconol NRSF 20% NaOH solution to make a clear soln.
. ,COMPOSITION s 30% Victamide solution 100 Mono-di-isoamyl acid orthophosphate 6 Ultrawct K 6 (No NaOH was needed.)
. COMPOSITION 9 =40% -Vi ctamide solution t -1 100 Mono-di-isoamyl acid orthophosphate Oronite 13-407 22% NaOH soln to make a clear soln 65 COMPOSITION 10 Percent Trisodium phosphate.12H O 12.0 Mono-di-isoamyl acid orthophosphate 7.5 fNacconol NRSF 10.0 Water 70.5
100.0 4 COMPOSITION 11 Victamide Q0 Mono-di-isoamyl acid orthophosphate 7.5 Ninex 2l i 10.0 Water and caustic 62.5
100.0 COMPOSITION 12 Victamide" 20 Mono-di-isoamyl acid orthophosphate 7.5 Ninol AA62 10.0 Water and caustic 62.5
100.0 COMPOSITION 13 "Victamide" 20 Mono-di-isoamyl acid orthophosphate 7.5 "AlrosoP 10.0 Water and caustic 62.5
In the following washing tests four examples of liquid detergents representative of the present invention are compared with two well-known commercial liquid detergents. The samples tested had the following compositions.
6 Sample No.2 Tetrapotassium pyrophosphate 20.7 Mono-di-isoamyl acid orthophosphate 4. 1 Nacconol NRSF 6.2 Water 69.0
100.0 Sample No. 3
Tetrasodium pyrophosphate 7.0 Mono-di-isoamyl acid orthophosphate 12.5 Nacconol NRSF 10.4 Water and caustic 70.1
' 100.0 Sample No. 4 Sodium tn'polyphosphate 11.0 Mono di-isoamyl acid orthophosphate 4.4 Nacconol NRSF 11.0 Water and caustic 73.6
Sample No. 5
A commercial liquid detergent comprising approximately 60% triethanolamine salt of lauryl acid sulfate 20% alcohol 20% water Sample No. 6
were used in an amount equivalent to 0.3% concen- Sample No. 1
Percent Victamide 21.6 Mono-di-isoamyl acid orthophosphate 4.3 Nacconol NRSF 14.4 Water and caustic 59.7
tration calculated on the basis of the dry active ingredient.
Detergency is measured by the percent reflectance value which is a measure of light reflected in a reflectometer as compared to for an unsoiled white cloth. Each reflectance value is the average of four washes.
TABLE I [Detergency tests at F.]
Water Hardness Active Total Sample No. Cone Cone p.p.m. 300 p.p.m.
' Per- Percent cent pH ReflectpH Reflectance ance TABLE 11 [Detergency tests at 150 F.]
Water Hardness Active Total Sample No. Cone, Cone 150 p.p.m 300 p.p.m.
Pcr- Percent cent pH ReflectpH Reflectance ance As can be seen from the above results, Samples 1 and 2 amas are noticeably superior to Samples 5 and 6 at water hardnesses of both 150 and '300 p.p.m. Samples 3 and 4 are in all cases better than the commercial detergents although not to the "extent ofsamples -1 and" 2.
Compositions similar to Samples 1 and after aging have been found to retain -this excellent degree of aletergency for at least six months as shown by tests similar tothose shown above.
Thus although Samples 5 "and 6 contain a higher concentration of a single active ingredient than doSamples 1 through 4, the detergency-tests show that Samples 1 to 4 produce better washing results. This ispossible since the isoamyl acid phosphate coupling agent provides a means of combining a wetting agent and a phosphate builder in a concentrated liquid solution wherein the advantage of the well-known synergistic detergency effect of the combination ispreserved. In other words, the unique property of the isoamyl phosphate'enables' mefto produce a detergent composition of superior quality having all of the qualities and advantages d'e'siredin "a "concentrated liquid form. 8
All percentages and relative amounts given herein are by'weight.
Having described my invention as related to the embodiments described herein, it is my intention that the invention be not limited by any of the details of description, unless otherwise specified, but rather be construed broadly within its spirit and scope asset out in the accompanying claims.
I claim: i
1. A clear, homogeneous, concentrated aqueous liquid detergent composition comprising 35 to 75 parts by weight water, 5 to 30 parts by weight of a water-soluble inorganic phosphate builder, 5 to 20 parts by weight wetting agent from the group consisting of nonsoap synthetic anionic organic wetting agents and synthetic valkylolarnide nonionic organic wetting agents, and a solubilizing amount of a coupling agent from the group consisting of isoamyl acid orthophosphate and isoamyl acid pyrophosphate, said composition having a pH of from 5 to 10.
2. The composition of claim 1 wherein the synthetic anionic wetting agent is a higher alkyl aryl alkali metal sulfonate. I
3. The composition of claim 1 wherein the water-soluble inorganic phosphate builder is a polyphosphate.
4. The composition of claim 1 wherein the water-soluble inorganic phosphate builder is a substantially neutral compound consisting of a nitrogen-phosphorus complex resulting from heating a reaction product of P and anhydrous ammonia at a temperature of at least about 150 degrees C. in the presence of excess anhydrous ammonia to produce a condensation reaction, said compound having an atomic ratio of nitrogen to phosphorus of less than 1 to 1 with the ammonium nitrogen being from -80% of the tofalnitrog'en and containing substantially no water of constitution.
'5. The composition of laim 1 herein the toppling agent consists essentially of mono-di-isoarnyl a'cid'forthoe phosphate. p a q M 1 I J 6. A clear, homogeneous, concentrated aqueous liquid detergent composition comprising 35 to parts bywei'ght water, 5 to 30 parts by weight of a water-soluble inorganic .phosphate builder, 5 to 20 parts :by weight wetting agent from the .group consisting er nonsoap synthetic anionic organic wetting agents and. synthetic alkylolamide nonionic organic wetting agents, and :2-20parts by weight of a coupling agent from the group consisting of isoamyl acid orthophosphate and 'isoa'mylac'id pyrophosphate, said 'composition-having a pH of :from'5 to :10.
7. The composition of claim 6 wherei the-synthetic anionic wetting agent is a higher alkyl and alkali mam sulfonate.
8. The composition of claim 6 wherein the water-soluble inorganic phosphate builder is a substantially neutral ,compound consisting of a nitrogen-phosphorus compleqr resulting from heating a reaction product of P 0 anhydrous ammonia at a temperature of at least about degrees C. in the presence of excess anhydrous ammonia to produce a condensation reaction, said compound having an atomic ratio of nitrogen to phosphorus of less than 1 /2 to 1 with the ammonium tnitrogen being from 60-80% of the total nitrogen and containing substantially no water of constitutipn. v, r
9. The composition of claim 6 wherein the synthetic ane ionic wetting agent is a higher alkyl aryl alkali metal sulfonate and the water-soluble inorganic phosphate builder is 'a substantially neutral compound consisting of a nitrogen-phosphorus complex resulting from heating "areacjtion product of P 0 and anhydrous ammonia at "a tempera, ture of 'at least about '150 "degrees 'C. in "the presence of excess anhydrous ammonia to produce "a condensation reaction, said compound having an atomic ratio of nitrogen to phosphorus of less than 1 /2 to 1 with the ammonium nitrogen being from 60-80% "of the'total nitrogen and containing substantially no water of constitution.
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