US3032506A - Detergent compositions having improved foam-stability - Google Patents

Description

United States PatentO Delaware No Drawing. Filed Jan. 8, 1957, Ser. No. 632,967 3 Claims. (Cl. 252-161) The present invention relates to the manufacture of detergent compositions. The invention likewise relates to detergent compositions exhibiting improved foam-stability. Other objects and advantages of the invention will appear hereinafter.

In accordance with the present invention an improvement in the foam-stability characteristics of alkyl aryl sulfonate detergents has been discovered in compositions containing the said sulfonates in combination with hydrolyzed polyacrylonitrile.

The sulfonate component of the present invention is an alkaline salt such as an amine salt, potassium, ammonium or sodium salt of the sulfonate of an alkylated aromatic hydrocarbon which may be prepared by condensing an aliphatic hydrocarbon having from 5 to 18 carbon atoms with an aromatic hydrocarbon selected from the class consisting of benzene, toluene and xylene, and thereafter sulfonating the product and neutralizing it with an alkaline material. The preferred aromatic hydrocarbon which is alkylated of this group is usually benzene, but the compounds obtained from toluene and xylene have also been found to have desirable properties as detergent compositions. The alkyl group may have from 5 to 18 carbon atoms, preferably about 9 to 18 carbon atoms average length, or more preferably 10 to 12 carbon atoms average chain length, such as may be obtained from olefin polymers or from kerosene. A typical composition of this type is produced by alkylating the aromatic hydrocarbon with an olefin hydrocarbon averaging 5 to 18 carbon atoms in the molecule, and thereafter sulfonating and neutralizing the product.

It has been found that detergent agents based solely upon the alkaline salts of alkyl aryl sulfonates have only moderately effective foam-stability, particularly in the presence of greases, soiled clothing or dishes. It is ob viously desirable to maintain a stable foam in detergents since the efiiciency of the detergents is often judged by the foam characteristics thereof.

The second component of the present composition is hydrolyzed polyacrylonitrile, such as is obtained by the acid or alkali catalyzed hydrolysis of polyacrylonitrile, as described in US. Patents 2,625,529 and 2,727,835. The polyacrylonitrile may be of either a high or low molecular weight and the hydrolyzed product may have a wide range of viscosities as employed in the present invention.

Examples will now be given illustrating preferred embodiments of the invention, but it will be understood that the present invention is not to be limited by the details thereof. Parts are by weight unless otherwise indicated.

A mixture was prepared from 99% by weight of the sodium salt of dodecyl benzenesulfonic acid, together with 1% by weight of hydrolyzed polyacrylonitrile (viscosity 0.17 poises at 1% concentration). This mixture was dissolved in water to give a series of solutions of various concentrations. The foam-stability of each of "ice these samples was determined by the method set forth below and the following results obtained.

Concentration: Percent foam-stability at 180 min.

surface-active components is dissolved in distilled water.

The solution is then transferred to a 500 ml. volumetric flask and diluted to approximately 150-200 ml. with dis-' Two hundred and fifty ml. of hard water tilled water. of 600 ppm hardness is then added to the solution, which is then brought to the mark with distilled water'to provide a final test solution of 300 p.p.m. hardness.

In carrying out the foam-stability test, 50 ml. of the above-described test solution is first used to rinse the Walls of the 1000 ml. graduate used as the test vessel. A foam pipette is then filled with the above test solution to the 200 ml. mark. The pipette is immediately clamped in position with the outlet centered cm. above the 50 ml. mark on the graduate, after which the stopcock is opened. The 200 ml. of solution is run from the pipette into the 1000 ml. graduated cylinder, and the volume of the liquid level is noted, together with the time. After obtaining the value for the liquid volume, the graduate is set to one side and covered with a petri dish cover, thus preventing particles of foreign matter from dropping into the foam. The total volume in the cylinder (foam plus liquid) is read and the initial foam volume is then calculated as:

Total volume-liquid volume=foam volume Total volume readings are then taken at 120, and minutes after initial foam formation and the foam volumes calculated. The calculation of the foam-stability is carried out in accordance with the following formula:

Foam volume at 180 minutes Initial foam volume The compositions of the present invention are of particular utility in detergent compositions in which a stable foam is desirable such as in household dishwashing compositions and in other household and commercial detergents when foam-stability is required. For general washing purposes the composition is employed in concentrations varying from 0.075% to 10% by weight of hydrolyzed polyacrylonitrile stabilizer relative to the sulfonate component. The composition may be produced as a dry mixture of the two components but it is also contemplated that other detergents, dyes, builders, fillers, etc. may be mixed with or employed together with the above composition.

When used as a detergent the herein-disclosed compositions may be employed either in the 100% active form of the sulfonate with the stabilizer, or they may be combined with alkali metal builder salts such as alkali metal phosphates, sulfates, carbonates, silicates, or with carbohydrate materials such as starch, carboxymethylcellulose, etc. or mixtures of these materials. When employed with X 100: foam stability buildefsalts-the combination of the activecomponents are utilized in amount varying from 10% to 50% or more by weight of active material in the built composition. Suitable alkali metal salts utilizable in these compositions are the disodium orthophosphate, trisodium orthophosphate, tetrasodium pyrophosphate, sodium metaphosphate, sodium tripolyphosphate, sodium carbonate, sodium bicarbonate, sodium sesquicarbonate, sodium silicate, sodium sulfate, etc.

The compositions of the present invention may also be marketed and,utilized as solutions such as aqueous or ethanol solutions; slurries or pastes of suitable'concentration which maybe used directly or may be diluted at' the time of appl'ication. For example, a paste concen tratefor use in a dishwashing composition may be provided from the following components given asWveight percent:

Percent Sbdium sulfonate of dodecyl benzene; (technical gifade containing 20%sodium"sulfate")' 76 Hydrolyzed polyacrylonitril'e 9 Water 1 5 The-present invention -isnot'to be considered to be Iimited -byr any of the examples described herein which areigiven by 'w'ay 'of illustration only; but isto belimited solely bythe scope of the appended claims.

What isclaimed is: I 1. A, foam-stable detergent composition consisting es' sentially of thecombination" cha -mixture of from 90% i to"'99.925 b'yweight of a'compoundof the' groupcon sisting of the sodium alkyl benzene, alkyl toluene, and alkyl xylene sulfonates, wherein the alkyl group has from 5 to 18 carbon atoms, and from 0.075% to 10% of hydrolyzed polyacrylonitrile.

2. A foam-stable detergent composition consisting essentially of the combination of a mixture consisting of from to 99.925% of a sodium alkyl benzene sulfonate, wherein the alkyl group has from 5 to 18 carbon atoms and from 0.075% to l0% of hydrolyzed polyacrylonitrile.

3. A foam-stable detergent composition consisting essentially of i the combinationoff'a mixtureconsisting of from 90% to' 99.9 2 -5% ofisodium dodecyl b'enzene sulfonatea'nd from 0.075% to10%ofhydrolyzed poly-- acrylonitrile.

References Cited-in the fileof this patent UNITEDsTAT' Es PATENTS OTHER REF ERENCES Surface 'A'ctive Agents," by 'Schwartz'and Perry, 1949',

Intersien'ce"Publishers, Incl, N.YiC.,.New York, pages 235, 379, 380.

Claims (1)

1. A FOAM-STABLE DETERGENT COMPOSITION CONTAINING ESSENTIALLY OF THE COMBINATION OF A MIXTURE OF FROM 90% TO 99.925% BY WEIGHT OF A COMPOUND OF THE GROUP CONSISTING OF THE SODIUM ALKYL BENZENE, ALKYL TOLUENE, AND ALKYL XYLENE SULFONATES, WHEREIN THE ALKYL GROUP HAS FROM 5 TO 18 CARBON ATOMS, AND FROM 0.075% TO 10% OF HYDROLYZED POLYACRYLONITRILE.