US2084483A - Naphtha soluble soap - Google Patents

Description

Patented June 22, 1937 UNITED STATES I 2,084,483 NAPHTHA sonunm soar- Theodore a. Domain,

Irvingto to Standard Oil Development Company, a

poration of Delaware n, N. J., assignor cor- No Drawing. Application October 29, 1932, Serial 6 Claims.

This invention relates to improvements in the art of soap compositions and more particularly to improved soap compositions which are readily soluble in hydrocarbon solvents and which are particularly adaptable for use as a dry cleaners soap in the cleaning of textile fabrics, clothing, and the like.

It has been found that an improved soap composition may be prepared by mixing oil-soluble ,0 sulfonates with fatty acid soaps in suitable proportions. The sulfonates may be derived from petroleum oils by treating the same with strong or fuming sulfuric acid, separating the resulting so-called oilsoluble sulfonic acids from the ,5 treated oil and converting the sulfonic acids into the corresponding ammonium or alkali metal salts. Especially suitable sulfonates are the socalled emulsifiable sulfonates, which form solutions in hydrocarbon oils that emulsify readily when added to water. Such sulfonates are characterized by substantial freedom from inorganic salts. They may be prepared from acid treated petroleum oil, in which fuming acid treated oil, after separation of sludge, is neutralized with an alkali such as caustic soda or sodium carbonate and then washed with aqueous alcohol. The aqueous alcohol extracts sulfonate soaps and inorganic salts from the oil. This aqueous alcohol solution may be evaporated to dryness and an improved sulfonate obtained by extraction from the residue with strong alcohol. The aqueous alcohol solution may also be treated with a dehydrating agent, such as anhydrous sodium carbonate or sodium carbonate monohydrate, in suflicient quantity to substantially dehydrate the alcohol. The alcohol is then settled, filtered if necessary, and evaporated to dryness, leaving as a residue the purified emulsiflable oil soluble sulfonates.

The fatty acid soaps suitable for use with these sulfonates include the soaps derived from the saturated and unsaturated fatty acids of preferably about 12 to 20 carbon atoms and the acids of corresponding molecular weight obtained by limited oxidation of paraflin wax. It has been found that the presence of a certain amount of water aids the ease ofpreparation of the soap composition and also the ease of its solution in dry cleaners naphtha or other hydrocarbon and similar solvents.

It has also been found desirable to add a heavy oil, such as a viscous lubricating oil, to the soap composition. This 011 aids in the solution of the soap in the lighter hydrocarbons customarily used and also is of advantage in maintaining the "life of clothing and other fabrics which are cleaned with a naphtha solution of this soap compositio It is well known that in ordinary dry cleaning, fabrics become harsh to the touch and lose many desirable characteristics after being dry cleaned three or four times. The use of aviscous hydrocarbon oil fraction in the soap composition serves to prevent this degradation of the goods-cleaned. This oil is preferably a highly refined petroleum white oil, that is, a viscous fraction of a petroleum oil which has been treated with an excess of strong or fuming sulfuric acid to remove all asphaltic, resinous and unstable constituents. The following example illustrates a preferred method for preparing my improved soap composition but it is understood that my invention is not to be limited tothe particular process described, nor'to the particular composition stated: Ten pounds of an oil-solublesodium sulfonate derived from a fuming sulfuric acid treated lubricating fraction of a petroleum oil are mixed with fifty pounds of a viscous petroleum white oil until complete solution occurs. Sufiicient commercial oleic acid, bleached elain oil or red oil is then added with stirring to be the equivalent of twenty pounds of potassium oleate in the finished composition. Twenty pounds of water, containing in solution the equivalent amount of potassium hydroxide necessary for neutralization of the oleic acid, are then added slowly to the oil with vigorous stirring or crutching. This operation may be conducted satisfactorily at roomtemperature, although a slight rise in temperature due to the heat of neutralization of the oleic acid is not objectionable. The mixture is crutched until there is secured as the product a stiff transparent I clear jell or paste which is the improved naphthasoluble soap. This soap works into dry cleaners naphtha. or Varsol easily and forms clear and stable solutions therein. It improves the ease and effectiveness of the cleaning operation when used in such volatile solvents for dry cleaning clothing and the like. Varsol is a volatile petroleum distillate having a gravity of at least A. P. I., Saybolt color of 22, low sulfur of about .05%, non-corrosive, and showing no color reaction of contacting with sodium plumbite and sulfur. This distillate, on redistilling, should be at. least volatile at 350 F. andvolatile at 392 F. with a final end point of not over 410 F.

While the soap may be used in any desired proportion in dry cleaning compositions, a very small amount will usually be found satisfactory; for example, about 1 to 5 or 10 pounds of the improved naphtha-soluble soap per 100 gallons of VarsoP' or other suitable solvent.

My improved naphtha-solublev soap may be prepared by various other methods than that described above. For example, the sulfonic acids and fattyacids may be neutralized together; a part or all of the sulfonic acids may be used as fat splitting agents for obtaining fatty acids and the mixture may be neutralized directly, or after solution in a heavy hydrocarbon oil, with a suitable alkali.

While the relative proportions of the constituents used in my improved naphtha-soluble soap may vary widely, it has been found that an especially desirable composition is obtained if the.

concentrations of the'constituents are held within certain approximate limits. If the soap composition is prepared with less than about 7% of sulfonates, it is obtained as a resilient composition of the type known as a singing jell. This composition disolves in volatile hydrocarbon solvents such as Varsol with somewhat more difficulty than do the preferred compositions containing about 10% to 25% or more oi.- sulfcnates.

The amount of fatty acid soap will be about 10 to 30% by weight of thetotal composition. The

amount of water is preferably about equal to that of the fatty acid soap. If too little water-is used a hard and tough composition results which is very difficult to work while if too much water is used the stability of the finished composition is impaired. In general the amount of water in the preferred composition will be about 10 to 30% and will also be within about 5% 'of the amount of fatty acid soap used. The heavy hydrocarbon oil may be used. in substantially any proportion, althoughfrom about 30 to 70% I is considered the preferred range for its concentration.

This invention is not to be limited to any speciflc examples which are presented herein solely for illustration, nor to any theories regarding the composition of my products, but only by the following claimsin which I- wish to claim all novelty insofar as the prior art permits.

I claim:

1. Improved naphtha soluble soap composi tion comprising about 20% by weight of potassium oleate, 20% of water, 10% of oil-soluble in the finished composition, and then adding slowly with stirring 20 parts of water containing the equivalent amount of potassium hydroxide necessary for neutralization of the oleic acid.

3. Improved dry-cleaning composition comprising a dry-cleaner's petro eum naphtha con-,- taining in solution a soap composition containingabout 10 to 30% of potassiumoleate, a substantially equalamount of water and any oil soluble alkali metal sulfonate derived from a fuming sulfuric acid treated lubricating fraction v of a petroleum oil in an amount not less than 7%, and a major proportion of a heavy hydrocarbon oil.

grslmproved naphtha-soluble dry-cleaning soap composition comprising about 10 to 30% of potassium oleate, a substantially equal amount of water, and an oil soluble alkali metal sulfonate obtained from petroleum oils in an. amount not less than 7%, and-a major proportion of a heavy hydrocarbon ofl.

5. Improved naphtha-soluble dry-cleaning soap composition comprising about 10 to 30% of an alkali metal soap of a fatty acid of about 12 to 20 7% and a major proportion of a heavy hydro- THEODORE R. Dom-AN. 54

carbonoil.