US2471645A - Detergent composition - Google Patents

Description

. Patented May 3 1, 1949 v UNITED sTA Es PATENT OFFICE 2,471,645 DETERGENT COMPOSITION Delaware No Drawing. Application August so, 1946, Serial No. 694,148

4 Claims. (01.252-137) Our invention relates to a detergent, and more particularly to a liquid detergent which is particularly adapted for the ready removal of grease, pencil and crayon marks, grime spotting on hands, the cleaning of the usual soiled areas found upon household walls and woodwork, and the washing of automobile and other vehicle bodies.

Products of this type are well known but they present the problem of producing a corrosive effect on the users hands, which is naturally undesirable for women using the product for household cleaning. Also, they generally attack paint on painted surfaces, not only to the extent of dulling the paint but also removing the paint,

' and effecting a "yellowing of white and other light colored paints.

Our invention is designed to overcome such problems; and it has as its objects, among others,

the provision of an improved liquid detergent or cleaning solution particularly adapted for household and vehicle body cleaning and which will not destroy washable paint coatings or dull the finish thereof; not cause yellowing of painted surfaces; not irritate the skin of persons applying it, which is important where large areas are to be cleaned and the users hands are, therefore, in contact with the solution over relatively long periods of time; will clean efiicaciously without streaking; is in such concentration in solution as to enable the solution to be employed directly on surfaces which may be quite soiled,

such as painted walls and vehicle bodies but which is still efiective when diluted with water in the cleaning of objects not requiring a stronger detergent action; and which is economical, and easy to manufacture. Other objects of our invention will become apparent from a perusal of the following description.

We have found that for the type of solution to which our invention relates, the pH (measure of hydrogen ion concentration) is extremely im- I portant. It should not be much below nine (9) As the pH increases much above ten (10), there is a definite paint attack, paint yellowing and a deleterious effect upon hands. Generally, we desire a pH range of between nine and two tenths (9.2) and ten (10), and preferably a pHof approximately nine and six tenths ($2.6)

We have found that an alkali metal hexametaphosphate, such as sodium or potassium hexametaphosphate, is particularly adapted as a cleaning agent which will enable obtaining the desired pH in the aqueous solution of our detergent, as it will provide initially a pH sufllciently low so that the solution can be readily increased to the desired point by addition of our preferred softening agent for fats and grease, namely, triethanolamine, as will be explained more fully hereinafter.

Other types of phosphates, such astrisodium phosphate and tetra sodium pyrophosphate, which have been employed in thepast give a pH which is too high in concentrations adapted for cleaning solutions of the type to which our invention relates, thus making them unsuitable. We, therefore, employ as a principal cleaning agent base in our solution, an alkali metal hexametaphosphate, such as sodium hexametaphosphate, in quantities ranging from about five tenths percent (0.5%) to two percent (2%) by weight of the solution. In quantities much below five tenths percent (0.5%) by weight of the alkali metal hexametaphosphate, the desired amount of cleaning is not obtained whereas if the concentration is much above two percent (2%) by weight of the solution, the surfaces cleaned are left in streaky condition, and definite paint attack is apt to occur. At such preferred concentration range of the alkali metal hexametaphosphate, the pH of the solution will be in the order of about six and five tenths (6.5). To bring our solution to the desired pH range of between nine .and two tenths (9.2) and ten (10) we have found that a compound consisting principally of triethanolamine should be used. This product is desirable as it also provides a cooperative cleaning effect with the alkali metal hexametaphosphate, and in addition acts as a grease and fat softening agent. Such product is also known as tri-2-hydroxy ethylamine. Although the chemically pure product may be used, it is cheaper to employ the commercial product which consists essentially of triethanolamine. Such commercial product contains more than eighty percent triethanolamine, not more than about two and five tenths percent (2.5%) monoethanolamine, and not more than fifteen percent (15%) diethanolamine. -Other amines which are capable of bringing our solution to the desired pH range and some of which also have a desirable cleaning effect and fat softening effect, such as methylamine, morpholine, isopropylamine and monoethanolamine are not suitable because of their distinct characteristic of yellowing paint.

The quantity of the triethanolamine, either the commercial or the substantially pure product, which we employ to produce the desired pH eflfect, ranges from about five tenths percent (0.5%) to two percent (2%) by weight of the solution. Thus, our preferred cleaning solution having a pH range of between nine and two tenths (9.2) and ten (10), contains amounts of the alkali metal hexametaphosphate and the triethanolamine ranging from about five tenths percent (0.5%) to two percent (2%) byweight of each. The mixture of these two substances produces a very definite buffering effect, so that the desired pH range is maintained even when the solution comes into contact with grimy or greasy surfaces. Also, such mixture of substances has been found efllcacious in quickly loosening dirt and grime so that they may be removed readily and efficiently with a minimum of effort.

We also incorporate in the cleaning solution, a wetting agent which by lowering of the surface tension of the water eifects quick wetting of relatively large surfaces, and also has the property of enhancing penetration of the solution below layers of grime or' grease to cause them to. be lifted and thus aid in their removal. Any suitable wetting'agent may be employed, such as sulfonated alcohols, sulfonated castor oil and sulfonated soy bean oil; the quantity of wetting agent ,being suflicient to produce the desired wetting effect but below that at which the solution may cause streaking as too much wetting agent will produce such effect. Also, too much wetting agent will result in excessive foaming which is undesirable in the bottling line.

We have found a wetting agent consisting of the class of alkyl aryl sulfonates having mo-' lecular weights of between three hundred (300) and fourhundred (400) to be most satisfactory in our solution containing the alkali metal hexametaphosphate and the triethanolamine in the proportions stated, because such type of wetting agent produces the desired Wetting effect without disturbing the desired pH of our solution. As the molecular weight of the preferred wetting agents rises much above four hundred (400) they will not go into solution, and as such weight falls much below three hundred (300), the surface tension effect thereof changes to such extent as to impair their wetting properties. Preferably the molecular weight of our preferred wetting agent should be about three hundred and sixty (360). A desirable wetting agent of the preferredqtype is Oronite" wetting agent manufactured by the Standard Oil Company of California.

The quantity of wetting agent for best results should be in the ratio of approximately one (1) part of the wetting agent by weight to about ten (10) parts by weight of the alkali metal hexametaphosphate. Materially lesser amounts of the wetting agent will not impart the desired covering effect to the solution, while as previously stated, materially greater amounts result in excessive foaming causing great difliculty when the solution is bottled in the bottling line, particularly the type of line having an automatic type filler. In addition, excessive-amounts of wetting agent result in streaking of the surfaces being cleaned.

In order to obtain a solution as close to water white as possible, the wetting agent should be low in iron content. This enables employment of true and delicate colors which may be obtained by the use of any standard alkaline-fast water-soluble dye in the solution, should tinting thereof be desired.

Our preferred formula which we have developed for commercial purposes consists essentially of water in which are dissolved about one percent (1.0%) by weight of sodium hexametaphosphate, about one percent (1.0%) by weight of triethanolamine, and about one tenth percent (0.1%) by weight of our preferred wetting agent, 5 namely, an alkyl aryl sulfonate having a molecular weight of about three hundred and sixty (360). The resultant pH of the solution is approximately nine and six tenths (9.6). In this ,connection, a one percent .0%) concentration by weight of only the sodium hexametaphosphate in water produces a pH under seven (7), and approximately six and one-half (6.5); while a one percent (1.0%) concentration by weight of only the triethanolamine in water produces a pH of approximately eleven (11). The mixture of the two solutions produces the desired pH of about nine and six tenths 09.6) Other types of phosphates, such as trisodium phosphate and tetra sodium pyrophosphate which have been used in the past, produce an initial pH of approximately ten (10) to eleven (11) when dissolved alone in water in a one percent (1.0%) by weight concentration, which is too high for our purposes.

In our preferred commercial formula, the quantitles of the alkali metal hexametaphosphate and the triethanolamine may vary plus or minus five hundredths percent (0.05%) by weight; so that such solution may contain ninety-five hundredths percent (0.95%) to one and five hundredths percent (1.05%) by weight of the alkali metal hexametaphosphate, and ninety-five hundredths percent (0.95%) to one and five hundredths percent (1.05%) by weight of the triethanolamine, together with the described amount of wetting agent.

The solution of our invention is odorless, and has a natural light colored appearance approaching water white. It can be readily tinted, if desired, to pleasing colors by means of any suitable alkaline fast dye; and the desired color can be duplicated at all times. The solution can be used directly without dilution for the cleaning of all types of washable painted woodwork or walls, 45 automobile body finishes, and such types of finish as are found on stoves, refrigerators, bath room fixtures, glass,'mirrors, upholstery, metal utensils, linoleum and hardwood floors.

The properties of the solution are such that for 5 cleaning it requires onl a wetting of the surface with the solution, after which a light rubbing with a cloth dampened with the solution will quickly remove grease, grime and other common soils. Our solution will not destroy, attack nor yellow paint and may be freely used'by a woman or child with no deleterious action upon the skin of the hands. In many cases where the soil is not extensive, the solution maybe diluted with water, and still emcaciously perform its cleaning action.

. Any suitable method may be employed for preparing the solution but for best results, and

to avoid foaming particularly in the bottling line,

we preferably first prepare separate aqueous solutions of the alkali metal hexametaphosphate, the

ficient water to effect their-solution which is enhanced by agitation. In the case 'of the wetting agent and the triethanolamine, heat may be applied to aid in dissolvin these substances, but the solution of the alkali metal hexametaphosphate should be in cold or room temperature water because reconversion of the hexametaphosphate to the phosphate (P04) might occur with consequent loss of some effective hexametaphosphate. While warm water could be used, it is notnecestriethanolamine, and the wetting agent in sufsary and is undesirable because of the possible reconversion of the hexametaphosphate.

The ingredients thus separately dissolved are then transferred to a large blending tank where additional water is added to make the desired final concentration. Preferably, to further minimize foaming, the hexametaphosphate solution is first introduced into such tank; anda partial dilution is effected before the Wetting agent and then the triethanolamine solutions are added to the tank. In such tank, the combined solutions are thoroughly agitated by any suitable means until a completely mixed solution is obtained. If any water soluble dye or perfume material is to be incorporated in the solution, they may be added before the final mixing operation.

With respect to our preferred formula, our preferred method of preparation is as follows. -To a mixing tank filled with approximately six hundred (600) to one thousand (1,000) gallons of cold or room temperature water, We add one thousand and fifty (1,050) pounds of sodium hexametaphosphate, and agitate to a complete solution. Such solution is then transferred to a blending tank where it is diluted with water to at least about six thousand (6,000) gallons before any further additions.

The wetting agent solution is prepared by adding one hundred and five (105) pounds thereof to approximately four hundred (400) to eight hundred (800) gallons of water at approximately one hundred and thirty degrees Fahrenheit (130 F.). The liquid is then agitated by any suitable means until the wetting agent is completely in solution, after which it is transferred to the blending tank containing the solution of the sodium hexametaphosphate. Although we have found that the specified temperature of the Wetting agent solution is a very efficient operating temperature, it is not critical, as long as the water is warm enough to dissolve completely and readily the wetting agent.

For dissolving the triethanolamine, we add one thousand and fifty (1,050) pounds thereof to approximately four hundred (400) to eight hundred (800) gallons of water, and effect the solution under agitation b an suitable means. While this operation may be carried out with cold or room temperature water, mixing of the liquid with consequent solution of the amine is facilitated if the water is heated, because of the relatively viscous nature of the triethanolamine. Any temperature above one hundred degrees Fahrenhgit (100 F.) up to boiling temperature is suit-1 a e.

The resultant solution of the triethanolamine is then added to the blending tank containing the solution of the wetting agent and the sodium hexametaphosphate. The resultant liquid is then diluted with water to about twelve thousand five hundred (12,500) gallons, and thoroughly agitated by any suitable means to a completely mixed solution. 1

We claim:

1. An aqueous household cleaning solution consisting essentially of water and the following three active ingredients in the following proportions by weight: an alkali metal hexametaphosphateabout five tenths percent (0.5%) to two percent (2.0%); triethanol amine-about five tenths percent (0.5%) to two percent (2.0%); wetting agent selected from the group consisting of alkyl aryl sulfonates, sulfonated alcohols, sulfonated castor oil and sulfonated soybean oil-- 6 about one tenth 5) the amount of the alkali metal hexametaphosphate; said solution having a pH of'between about nine and two tenths (9.2) and ten (10).

2. An aqueous household cleaning solution consisting essentially of water and the following three active ingredients in the following proportions by weight: an alkali metal hexametaphosphate-about five tenths percent (0.5%) to two percent (2.0%); triethanol amine-about five tenths percent (0.5%) to two percent (2.0%); an alkyl aryl sulfonate wetting agent having a molecular weight of between about three hundred (300) and four hundred (400)about one tenth the amount of the alkali metal hexametaphosphate; said solution having a pH of between about nine and two tenths (9.2) and ten (10).

3. An aqueous household cleaning solution consisting essentially of water, about ninety-five hundredths percent (0.95%) to one and five hundredths percent. (1.05%) by weight of an alethanol amine, and about one tenth percent (0.1%) by weight of a wetting agent selected from the group consisting of alkyl aryl sulfonates, sulfonated alcohols, sulfonated castor oil and sulfonated soybeanv oil, said solution having a pH of about nine and six tenths (9.6).

4. An aqueous household cleaning solution consisting essentially of water, about ninety-five hundredths percent (0.95%) to one and five hundredths percent (1.05%) by weight of an alkali metal hexametaphosphate, about ninety-five hundredths percent (0.95%) to one and five hundredths percent (1.05%) by weight of triethanol amine, and about one tenth percent (0.1%) by weight of an alkyl aryl sulfonate wetting agent having a molecular weight of between about three hundred (300) and four hundred (400), said solution having a pH of about nine and six tenths (9.6).

MARK M. MORRIS. ANNETTE K. KLEEMAN.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS OTHER REFERENCES "Oil and Soap," vol. 12, Feb. 1935, reprint of an article by B. H. Gilmore, "A New Principle and Agent in Detergent Operations. The Utility of Sodium Hexametaphosphate as an Adjuvant to Soap."