US 3870647 A
An improved biodegradable, concentrated liquid cleansing agent containing propylene glycol, a small amount of monoethanolamine, fatty acids, and ethoxylates with small amounts of other adjuvants such as optical brightners and a bacteriostat.
Description (OCR text may contain errors)
United States Patent 1 Travers LIQUID CLEANING AGENT  Inventor: Hal Travers, Snyder, NY.
 Assignee: Seneca Chemicals, Inc., Buffalo,
 Filed: June 5, 1972  Appl. No.: 259,548
 U.S. Cl 252/118, 252/107, 252/117, 252/122, 252/546, 252/548, 252/DIG. 14  Int. Cl.. ..Cl1d 9/02, C1 1d 9/30  Field of Search 252/117, 118, 122, 153, 252/548, 546, 106, 107, D16. 14
 References Cited UNITED STATES PATENTS 2,196,763 4/1940 Figg 252/107 2,826,596 3/1958 Maher 2,914,482 l1/1959 Kopp 252/548 5] Mar. 11, 1975 3,360,471 Kwiatkowski.........; 252/114 3,360,476 12/1967 Krusius 252/107 3,558,495 1/1971 Mace 252/90 3,591,510 7/1971 Zenk 252/153 X 3,625,909 12/1971 Berg et a1. 252/153 3,663,445 5/1972 Augustin et a1... 252/117 3,700,601 10/1972 Bloching.... 252/105 3,723,328 3/1973 Pelizza 252/1 ll T903,0l0 IO/i972 Katstra 252/546 Primary Examiner-P. E. Willis, Jr. Attorney, Agent, or Firm-Christel & Conrad  ABSTRACT An improved biodegradable, concentrated liquid cleansing agent containing propylene glycol, a small amount of monoethanolamine, fatty acids,'and ethoxylaws with small amounts of other adjuvants such as optical brightners and a bacteriostat.
7 Claims, N0 Drawings LIQUID CLEANING AGENT BACKGROUND OF THE INVENTION This invention relates to liquid cleansing agents and, more particularly, to concentrated liquid detergent compositions.
The continued usage of non-biodegradable synthetic detergents, which are indiscriminately discharged into our streams and waters, is creating increasing concern on the part of the general public and the public health authorities. Accordingly, various regulatory agencies have passed pollution abatement codes to minimize pollution of our environment, such laws including bans against the sale of detergents containing phosphates and other contaminating chemicals.
In an effort to comply with such laws and to reduce contamination of our waters, much development has been directed towards the formulation of biodegradable detergents. While many of these recently devel oped detergents are somewhat biodegradable and do not contain harmful chemical pollutants, they possess other disadvantages. For example, many of these detergents have a relatively high pH value, are extremely toxic and contain human eye and skin irritants. Often, these known detergents contain excessive insoluble additives, such as fillers, fabric softeners, and the like, which contribute to pollution and sometimes leave a powdery residue on the laundered fabrics. Moreover, many of these bi-DdegradabIe" detergents exhibit poor detergency and often produce laundered fabrics that are irritable to the skin, relatively stiff, and uncomfortable to wear.
SUMMARY OF THE INVENTION It is therefore, an object of the present invention to provide an improved biodegradable, non-polluting cleansing agent obviating the above disadvantages and which is relatively mild, exhibiting substantially no toxicity and only negligible human skin and eye irritation, thus being well within the limits permissable under Federal Food and Drug Administration standards.
It is another object of this invention to provide an improved concentrated liquid cleansing agent having optimum detergency in both hot and cold water of varying degrees of hardness.
It is still another object of the present invention to provide a concentrated liquid cleansing agent having a relatively low pH value while maintaining the laundered fabrics soft without residual irritants embedded therein.
It is a further object of this invention to provide a concentrated liquid cleansing agent which has only negligible amounts of additives, is completely rinseable, effectively removes particulates and oils, and can be produced at reasonable costs.
The foregoing and other objects, advantages and characterizing features of the present invention will become apparent from the ensuing detailed description thereof.
DESCRIPTION OF THE PREFERRED EMBODIMENT The composition of the present invention contains at least one hydrophilic solvent, at least one fatty acid, a small amount of alkanolamine and an ethoxylated alcohol. The hydrophilic solvents utilized in the composition of the present invention are glycols or mixtures thereof where the glycol has from about 2 to 6, preferably about 2 to 3 carbon atoms. The fatty acids used in the present invention include saturated and unsaturated fatty acids of from 8 to 22 carbon atoms, of both natural and synthetic origin, and preferably include mixtures of naturally occurring fatty acids, especially tall oil. The alkanolamines are mono or di-tri-hydroxy amines of from about 2 to 7 carbon atoms per chain, preferably 2 to 5 carbon atoms per chain, most preferably ethanolamines and are used to control pH. Finally the ethoxylated alcohols are the reaction products of alcohols of from 12 to l5 carbon atoms and an average of from 3 to 9 moles of ethylene oxide per mole of alcohol. Additionally other components such as optical brighteners and bacteriostats may be present. The four main components are usually present in amounts which provide a biodegradable solution exhibiting substantially no animal toxicity or skin and eye irritation under FDA standards and which possesses optimum detergency. The cleansing agents of the present invention are especially useful as a laundry detergent, as will hereinafter be described in detail. However, it should be appreciated that its use is in no manner restricted thereto, but the composition finds utility as a cleanser in various applications, such as in the cleansing of the human body, the removal of oils and greases, the cleaning of hard surfaces and the like.
The above components constitute the basic composition of the liquid cleansing agent of this invention with water preferably being added to such preparation. However, it should be understood that the concentrated liquid composition can be formulated without water. When water is used, the amount present in the composition will vary depending upon the concentration desired and hence water will comprise the balance of the composition. In general, water can be present in a range from about 1% to and usually from about 40% to 60% by volume of the composition. The composition further contemplates the inclusion therein of relatively small amounts of various compatible adjuvants which do not adversely affect the composition.
Although most of the glycols and derivatives thereof as noted above can be employed, propylene glycol is especially desirable as the solvent medium because of its excellent properties as a wetting agent and because of its low oral and skin toxicity. Thus, propylene glycol does not produce any harmful effects upon ingestion or absorption of the cleansing agent through the skin.
Monoethanolamine, commonly referred to as MEA, is the preferred alkanolamine for neutralization and saponification and is used in moderate amounts in the composition of the cleansing agent of the present invention. The alkanolamine serves as one of the detergent active materials of the composition and is generally present thereof in an amount from about 1% to 6.5% by volume, preferably about 1.8% by volume based on the concentrate in order to provide a relatively low composition pH while exhibiting excellent detergency. Maintaining a low alkalinity virtually eliminates residual irritants that otherwise will be embedded in the laundered fabrics causing discomfort and possible skin disorders; in this light, the pH should be above 7 but below about l0, preferably below 9, in the concentrated cleansing agent of the present invention.
The preferred mixture of fatty acids is tall oil, a byproduct from the manufacture of chemical pulp, which is employed as another of the detergent active materi- 'als for saponification because of its fatty acid content and its low viscosity and high solubility characteristics. The ethoxylates, preferably non-ionic, which are employed in the present composition consist of linear primary alcohols with even and odd numbered carbon atoms in the C and C detergent range and their derivatives, such as ethoxylates being identified by the formula: RO (CH CH 0),, H, where n equals the number of moles of ethylene oxide per mole of alcohol and R is the alcoholic carbon residue defined above. Preferably, the cleansing agent composition of this invention includes a mixture of three different ethoxylated derivatives, namely those in which n equals 3. 7 and 9, respectively. These ethoxylates are excellent wetting agents and are particularly important in the controlled foaming cleansing agent of this invention. Also, they serve to soften the water and facilitate the removal of dirt and soil from the fabric being laundered. They are especially significant in the removal of oils and greases and are present in combined amounts of from 0.5% to 60% by volume, and preferably in an amount of from about 30% to 40 by volume, based on the concentrate.
Other additives that are used in the cleansing agent of this invention include suitable conventional optical brighteners for removing the yellowish cast in certain fabrics and a conventional bacteriostat for inhibiting the growth of bacteria in the composition.
A suitable concentrated cleansing agent preparation, for use with or without water, may have the following active ingredients and ranges, expressed in percentages by volume:
lngredient Range 7c MEA 1.2 4.9 Tall oil 5.6 33.0 Propylene Glycol 1.2 75.0 Ethoxylates .5 60.0 Optical hrightener 0 10.0 Bacteriostat 0 .3
The following example illustrates the preferred cleansing agent composition of this invention as a laundry detergent, it being understood that such example is illustrative only and is not used in a restricting sense.
Table 11 lngredient 7( by Volume MEA Tall oil Propylene Glycol Ethoxylate 9:l* Ethoxylate 7:l* Ethoxylate 3:1 Optical brighteners Bateriostat Ratio of moles of ethylene oxide to moles of alcohol heat generated by this reaction raises the temperature of the product up to about 130-140F. When the reaction is completed, as evidenced by the stabilization thereof and a gradual temperature decrease. the remaining propylene glycol and the other ingredients are added to the solution in the desired proportions and blended together. The propylene glycol maintains this composition in solution throughout the blending process and thereafter for storage as a homogeneous solution.
As earlier noted, water can be added to the above preparation in amounts ranging from 1% to by volume of the totalcomposition, the preferred range being from about 40% to 60% by volume. Of course, the proportion of water added depends upon the concentration desired. The preferred range forms an effective concentrated liquid detergent requiring only two ounces thereof in a laundry appliance receptacle having approximately a l0-gallon water capacity to efficiently clean natural and synthetic fabrics. It has been found that a ratio by volume of the present concentrate to water can be as high as l to 900 to produce satisfactory results. Moreover, complete rinseability of the laundered fabrics is realized whereby particulates and other foreign matter are not re-deposited on the fabrics.
The proportions of the constituents forming the preferred cleansing agent composition may be varied within the limits specified, as dictated by the specific usage of the composition. By way of example, where it is intended to remove excessive oils, the percentage of those ethoxylates having a larger number of moles of ethylene oxide per mole of alcohol can be increased with consequent reduction in propylene glycol. for example. Where higher alkalinity presents no problems, such as in the cleaning of hard surfaces for example, the MEA content may be increased with a commensurate decrease in propylene glycol.
EXAMPLE 1 The composition shown in Table 11 was used by several families to evaluate its cleaning powers. The liquid was used in amounts of 2 oz. per wash load and proved to be an excellent laundry detergent.
Tests conducted to determine the alkalinity of the preferred laundry detergent composition revealed that the undiluted concentrate (approximately 40% by volume of water) had a pH value of 7.75 as determined by glass electrode. The same concentrate, when tested as a 1% solution by volume in distilled water, had a pH value of 8.25. Comparative studies showed that a leading phosphate detergent, tested under the same conditions, has a pH of 9.8 and 10.9, respectively. The low pH value of the composition of this invention virtually eliminates residual alkaline material in the laundered fabric, which if present not only causes skin irritation, but also tends to structurally weaken fabrics, particularly those formed of natural fibers.
The preferred cleansing agent composition of this invention is substantially non-toxic and extremely mild to human skin. Tests were conducted on sample compositions made in accordance with the preferred formulation set forth above to determine the extent of eye and skin irritation to rabbits subjected to such compositions as well as to determine toxicity.
Following the procedures outlined in No. 191.10 of the Federal Hazardous Substances Act (FHSA), the
undiluted preparation of this invention was administered by stomach intubationto three groups of five rats at dosages of 2.5, 5.0 and 7.5 ml/kg of body wt. and none of the rats died during the test. Thus the lethal dosage of this cleansing agent composition was found to be greater than 7.5 ml/kg and considered nontoxic" by Fl-lSA standards.
Again, following the procedures outlined in No. 191.10 of FHSA, the undiluted preparation was applied to the covered skin of four rabbits at dosages of 2.5 and 5.0 mg/kg., respectively. The skins of two male albino rabbits at each dosage level was abraded and the other two left intact and none of the test animals died during the test.
Accordingly the LD was found to be greater than 5.0 ml/kg and the composition is considered nontoxic as defined by FHSA standards.
in skin irritation studies, the undiluted composition, when applied to the abraded and intact skin of albino rabbits, clipped free of hair, was found to be noncorrosive. Furthermore, using the empirical scoring system outlined in No. 191.11 of the Federal Hazardous Substance Act, the composition was considered to be a non-irritant to the skin.
Following the process set forth in No. 191.12 of FHSA, the subject composition was administered to one eye of each of six male albino rabbits. After periods of 24. 48 and 72 hours, the eyes of the animals were examined and evaluated in accordance with the guidelines in the pamphlet Illustrated Guide for Grading Eye Irritation by Hazardous Substances," U.S. Department of Health, Education and Welfare. The composition was found to be non-irritant to the eye as defined by No. 191.12 of FHSA.
From the foregoing, it is apparent that the objects of the present invention have been fully accomplished. As a result of this invention a new and improved biodegradable, non-polluting cleansing agent composition has been provided, such composition being relatively mild, exhibits excellent detergency in hot and cold water and in hard and soft water, is substantially nontoxic and non irritating, is relatively low in cost and can be readily prepared.
What is claimed is:
1. A biodegradable liquid laundry detergent composition consisting essentially of:
a. from about 1.2 to volume percent of a hydrophillic solvent consisting essentially of propylene glycol,
b. from 5.6 to 33 volume percent of tall oil acids,
c. from 1.0 to 6.5 volume percent of an alkanolamine of from about 2 to 7 carbon atoms sufficient to provide a pH in the range above 7 and below about 10 in the resulting liquid laundry detergent composition, and
d. from 0.5 to 60 volume percent of at least one ethoxylate of an alcohol of from 12 to 15 carbon atoms produced by the reaction 'of from 3 to 9 moles of ethylene oxide per mole of alcohol. said amounts based on the non-aqueous components of said composition.
2. The composition of claim 1 wherein water is present in an amount of from 1 to by volume based on the total composition.
3. The composition of claim 2 wherein said water is present in an amount of from 40 to 60 volume percent.
4. The composition of claim 1 wherein said alkanolamine is present in an amount of about 1.8% by volume.
5. The composition of claim 1 wherein said alkanolamine is an ethanolamine.
6. The composition of claim 1 wherein said ethoxylate is a mixture of ethoxylates having 3 moles of ethylene per mole of alcohol, 7 moles of ethylene per mole of alcohol, and 9 moles of ethylene per mole of alcohol. respectively.
7. The composition of claim 6 wherein said ethoxylates are present in an amount of from 30 to 40 volume percent.