US2326772A - Dry cleaning composition - Google Patents

Description

Patented Aug. 17, 1943 DRY CLEANING coMrosrrIou Lawrence H. Flett, Hamburg, N. Y., assig'nor "to Allied Chemical & Dye Corporation, a corpora-\ tion of New York No Drawing. Application November 25, 1938,

Serial No. 242,150

9- Claims.

This invention relatesto improvements in the dry-cleaning of fibrous, textile and related materials. It relates particularly to improved compositions for use in dry-cleaning and to processes of dry-cleaning in which said improved compositions are employed.

It is well known that certain types of textile fabrics and materials such as leather cannot be cleaned by means of. ordinary soap and water since they are prone to shrink, harden, wrinkle and/or fade when they are wetted with water. For the cleaning of such materials a dry-cleaning process must be used. In such dry-cleaning processes volatile organic solvents such as naphtha, trichlorethylene, Stoddards solvent, etc. are used; such" solvents are effective in removing from the fabrics or materials practically all grease stains as well as dust and dirt which commonly adhere to the greasy spots. ther known that if a small amount of water is sufficiently well dispersed in the dry-cleaning fluid, water soluble stains, such as those caused by sugary liquids, candy, soft drinks, etc., are removed simultaneously without adversely affecting the material so treated.

There are available on the market a number of soaps or other alkaline preparations for use in the dry-cleaning process. These soaps are used in spite of several very objectionable features. To be effective such preparations must be used in large quantities. Soaps and free fatty acids which accompany them are left in the goods where they become rancid and so cause an objectionable odor. The alkaline reaction affects the colors of dyed fabrics. The soaps serve mostly to hold water in the dry-cleaning solvent and do not effect a greatly increased degree of cleaning.

According to the present invention a dry-cleaning bath is used which contains as essential components a dry-cleaning solvent or mixture of dry-cleaning solvents and at least one salt of a primary alkyl sulfuric acid derivative having at least 4 carbon atoms in an alkyl group. In the preferred form of the invention, the dry-cleaning bath also contains a small amount of water dispersed in the dry-cleaning solvent.

The said primary alkyl sulfuric acid derivatives are salts of compounds of the general formula: RCH2S, where R represents an alkyl radical which contains at least 3 carbon atoms and which alkyl radical may contain an intermediate oxygen atom or an ester or acid-amide radical, or it represents an alkylated phenyl radical wherein the alkyl group contains at least 12 It is furacid, ;cetyl sulfonic acid, beta-sulfo ethyl oleate;

p-lauryl benzyl sulfonic acid, beta-sulfo ethyl ester of ricinoleic acid, beta-sulfo ethyl ester of meth'oxy oleic acid, 9- or IO-chloroctadecyl-sulfuric acid; lauroxy-ethyl sulfonic acid;f9,l0-dichloroctadecyl sulfuric acid, and lauric acid amide of amino ethyl sulfuric acid.

Sulfuric acid compounds or derivatives of the above described general class are found to give excellent results in improving dry-cleaning compositions, but it has been found that certain of these compounds give even better results than the class as a whole. Such preferred compounds are primary aliphatic monosulfates which contain an alkyl residue of at least 8 carbon atoms, and preferably at least 12 carbon atoms.

This inventionv contemplates the use of salts of compounds of the above general formula in which the acidic hydrogen is replaced by an inorganic or organic salt-forming radical. Among the more easily obtained salts are the ammonium, alkali metal and alkaline earth metal salts. Salts in which the acidic groups are neutralized by organicbases. (such as.mono-, dior tri-ethanolamine, pyridine, ethylene-diamine,. amylamine, triethylene-tetra-mine, etc.) may also be v used, however. If the salt-forming basic radical-.is polybasic, it may be neutralized wholly withthe sulfuric acid compound of the abovegen'eral formula or in part with such a compound and in part. with other acidic materials, -which advantageously mayhave detergent properties. ,Examples of .such other acid materials arei di-isopropyl naphthalene sulfonic acid, n-propyl sulfuric acid, hydrochloric acid, naphthalene sulfonic acid, sulfuric acid, etc.

The presence as dry-cleaning assistants of the hereinbeiore defined organic sulfuric acid derivatives in a dry-cleaning fluid has been foundto be particularly effective in enabling the dry-' cleaning fluid in which water is normally practically immiscible to hold in finely dispersed form a limited amount of water.

It has been found that by using the sulfuric acid derivatives herelnbefore defined a substantially greater amount of water in relation to the amount of dry-cleaning assistant present can be held in a well dispersed form in the dry-cleaning solution than was heretofore possible. With the dry-cleaning agents herein-defined, the mathe absence of water with excellent results.

However, better results are usually obtained by adding a small amount of water as such to the dry-cleaning bath. Due to the presence of the sulfuric acid compounds the water becomes incorporated and dispersed in such an extremely finely divided state in the dry-cleaning composition that water-sensitive materials can be drycleaned in such water-containing dry-cleaning compositions, without fear of water spotting. The exact amount of water needed in any given case varies somewhat according to the type of soil which is to be removed and this generally varies with the particular material to be treated. For example, about 0.25%- of water hasbeen found to give good results in many cases. In general there must not be so much water present that it is in poorly dispersed form and so causes water-spotting of the material being dry cleaned. As is well known, the amount of moisture which the material will tolerate without suffering water-damage (wrinkling, shrinking, etc.) depends upon the particular material and its state of dryness as well as on the degree of dispersion of the moisture in the dry-cleaning solvents. The amount of water which a drycleaning solvent can hold in a very finely-dispersed or non-wetting state with respect to the material to be cleaned depends altogether upon the dry-cleaning assistant which is added to the solution, and it has been found that the members of the class of dry-cleaning assistants hereinbefore defined are very substantially better for the purpose than those heretofore employed in the art. Practical comparative tests show that the. dry-cleaning compositions of this invention are substantially better that the drycleaning compositions used according to the prior art.

An important feature of the compositions of this invention is that they have no tendency to become rancid; hence they do not leave or cause objectionable odors of rancid matter in materials cleaned with them. The presence of such odors from matter which is left in the drycleaned material and becomes rancid subsequently is a difficulty which is commonly experienced with dry-cleaning compositions of the prior art. The dry-cleaning compositions of this invention are free from this difficulty. The primary sulfuric acid derivatives hereinbefore defined are more stable than the corresponding secondary or tertiary sulfuric acid derivatives and are, therefore, less prone to release insoluble organic matter which is apt to be retained in the fiber of the dry-cleaned material and to ive rise to rancid odors.

This improved stability of the sulfuric acid derivatives hereinbefore defined may be attributed to the presence therein of the primary grouping CH2SO3 or =CH2OSO3, whereas the secondary or tertiary groups =CHSO3, =CHOSO3, ECSO3 r ECOSO: are less stable. The bonds shown in these formulas represent linkage to other carbon atoms.

Much of the difliculty caused by rancidity which is found in many of the compositions of the prior art is also probably due to the use of oleic acid and its salts which are not necessary for the dry-cleaning compositions of the present invention.

It has been found further that substantial economies in dry cleaning are shown by the use of the hereinbefore defined sulfuric acid compounds in the dry-cleaning compositions of this assistants per 1000 2,326,772 terial to be cleaned may be solvent washed ininvention. This is due to the fact that much less of the dry-cleaning assistants hereinbefore defined is necessary to produce an excellent cleaning effect than has previously been used of the currently-known dry cleaning assistants. Thus, it has been found, when the primary alkyl sulfates defined above are used, that less than one-third of the usual amount of dry-cleaning assistant need be added to the dry-cleaning solvent to prepare adequate dry-cleaning compositions. An outstanding characteristic of the new dry cleaning compositions of this application is their ability to attain excellent cleaning action with very low concentrations of compound, particularly when water is added to the bath in small amounts, The weight ratio of the sulfuric acid derivative salt to organic substantially water-immiscible dry-cleaning solvent or solvent mixture need not be greater than 1.0:100 and is preferably less than 3:100. In fact, dry-cleaning compositions co taining between about 1 and about 3 parts of the dry-cleaning parts of solvent by weight have been found to give highly satisfactory cleansing.

Although the dry-cleaning compositions of the present invention have increased cleaning action yet they have no harmful and undesirable effects on color and finish of the materials cleaned in them. Further, the sulfuric acid compounds which are incorporated in these compositions as dry-cleaning assistants are for the most part not lime sensitive, and therefore they do not form insoluble calcium salts nor cause undesirable dewhich are used in the dry-cleaning compositions' of the present invention may be used with excellent results in practically any dry cleaning solvet. The presence of the hereinbefore defined sulfuric acid derivatives in the dry-cleaning compositions of the present invention also has the very desirable effect of greatly decreasing the internal electrical resistance of inflammable solvents,-or solvent mixtures; thereby substantially decreasing the danger of fire from spark discharges or static electricity.

In many moderndry-cleaning plants it is the practice to remove undissolved dirt from the drycleaning solution by filtration. The presence of the sulfuric acid compounds of this application aid in decreasing the clogging effects of the dirt on the filter media and retards the development of back pressures in the filters. In this way the period during which the dry-cleaning solution can be recirculated before plugging the filter is substantially increased with resulting economy in operation. I

The invention i illustrated by the following examples in which the parts are by weight.

Example 1.A cleaning bath was obtained by mixing 3.0 parts of technical sodium cetyl sulfate with 1115 parts of V, M. P. naphtha, which had a specific gravity of 0.746, and a boiling range of 215 F. to 320 F, and of which per cent of the distillate distilled between 215 F. and 279 F. A piece of flannel soiled with a mixture of tallow and carbon blackwas agitated mechanically in this dry cleaning composition for about half an hour. The flannel was withdrawn and allowed to dry. Good cleaning action was obtained.

In the following Table I, in which Examples 2 to 23 are summarized, the same procedure was followed; 1. e., the dry cleaning compositions were first prepared by mixing the ingredients and then used to clean soiled flannel.

TABLE I SUMMARY OF Exaurms Cleaning compositions E Sulfuric acid deriv. salts Dry cleaning solvents Vax. er No. used Amt. Kind Amt. Kind amt.

Part: Part: i! i! wt. wt. 2 3.0 Sodium cetylsul- 1,115 V. M. P. naphtha. 2.5

{agate (techni- 3 1.5 Sodium isobutyl 1,115 -.--d

sulfate. 4 1.5 Sodiumlaurylsul- 1,l15 do fonate. 5 1.5 ...-.do 1,115 -.-do.- 2.5 6 1.5 Sodiumsaltofthe 1,115 -do oleic acid ester of fl-hydroxyethyl sulfonic acid. 7 1.5 ..-.-do. -do 2.5 8 1.5 do Trichlorethylene" 9 1.5 do o 2.5 10 1.5 .----do Tetrachlorethylene. 11 1.5 ....-do..... -do 2.5 12 1.5 Gardinol (com- V. M. P. naphtha.

P ili' aury an a esaltfree). 13 1.5 io 1,115 do 2.5 14 1.5 Sodium n-amyl- 1,115 do sulfate. 15 1.5 -do 1,115 -.d') 2.6 16 3.0 Sofdium cotylsul- 2,190 Trichlorethylcno oimtc. 17 3.0 .do 2,190 -d0 2.5 18 1.5 Sodiumlaurylsul- 2,100 do fouute. 19 1.5 .do 2,190 d0 2.5 20 3.0 Sodium cctyl sul- 2,390 Tetrachlorethylfouate. one. 21 3.0 -do 2,390 do 2.5 22 1.5 Sodiumlaurylsul- 2,390 do fonate. Z3 1.5 do 2,390 --do 2.5

In each of the above examples good cleansing r action was obtained. It was noted that the drycleaning compositions which contained water in addition to a dry-cleaning assistant .which was a sulfuric acid derivative represented by the foregoing general formula gave decidedly better cleansing action than the same compositions without water.

An improved finish and/or feel of the drycleaned materials can often be obtained by incorporating a small amount of paraflln hydrocarbon or similar agent such as paraflin wax or paraflin oil into the cleaning composition. Thus the presence of about 0.1 to about 1.0 per cent of paraflin oil has been found effective for this purpose.

As has been noted above, the hereinbefore defined sulfuric acid derivatives are effective as dry-cleaning assistants in dry-cleaning compositions made as illustrated in the foregoing examples from naphtha, trichlorethylene and tetrachlorethylene which were used as representative dry cleaning solvents. Similarly, other volatile organic liquids of the dry cleaning type, such as carbon tetrachloride, Stoddards solvent, benzene, gasoline, and even less common substances which are useful as dry-cleaning solvents, may be used.

The defined sulfuric acid compounds which are added as dry-cleaning assistants to form the drycleaning compositions of this invention may be prepared in any convenient manner. The customary sulfonation procedure or any other method of preparation is satisfactory.

The compounds of this invention have been found to give excellent results in the dry-cleaning of all kinds of materials and fabrics such as wool, silk, cotton, leather and rayon. The compositions are effective in the removal of all types of soil, dirt or stains. They may be used in practically any machinery or device used in commercial dry cleaning and in any type of purifying or recovery process which is applied to the drycleaning fluid.

The addition of various other products such as other organic sulfuric acid derivatives, soaps, fatty acids, etc. does not substantially affect the excellent properties of the dry-cleaning compositions of the present invention.

In the specification and claims the term sulfuric group includes both the sulfate group, -OSO3H, and the sulfonic group, -SO:H. The term primary alkyl sulfuric acid derivative" means an organic compound which contains a sulfuric group attached to a primary carbon atom of an alkyl group, and includes compounds which contain an aromatic nucleus as a part thereof in addition to said alkyl group.

I claim: I

1. A dry cleaning composition comprising an emulsion of water in a volatile organic dry cleaning solvent, the water being in the internal phase, and a salt of an aliphatic organic compound containing an alkyl group of at least 4 carbon atoms and a sulfuric group attached to a primary alkyl carbon atom, as a dry cleaning assistant and as an emulsifying agent for the water, said salt being selected from the group consisting of ammonium, alkali metal, alkaline earth metal, and organic ammonium salts.

2. A dry cleaning composition comprising an emulsion of water in a. volatile organic dry cleaning solvent, the water being in the internal phase, and a salt of an aliphatic organic compound containing an alkyl group of at least 12 carbon atoms and a "sulfuric group attached to a primary alkyl carbon atom, as a dry cleaning assistant and as an emulsifying agent for the water, said salt being selected from the group consisting of ammonium, alkali metal, alkaline earth metal,

and organic ammonium salts.

3. A dry cleaning composition comprising an emulsion of water in a volatile organic dry cleaning solvent, the water being in the internal phase. and a salt of a primary alkyl sulfate having at least 8 carbon atoms in the alkyl group, as a dry cleaning assistant and as an emulsifyin agent for the water, said salt being selected from the group consisting of ammonium, alkali metal, alkaline earth metal, and organic ammonium salts.

4. A dry cleaning composition comprising an emulsion of water in a volatile organic dry cleaning solvent, the water being in the internal phase, and a salt of a sulfonated aliphatic organic compound containing an alkyl group of at least 4 carbon atoms and a sulfonic group attached to a primary alkyl carbon atom, as a dry cleaning assistant and as an emulsifying agent for the water, said salt being selected from the group consisting of ammonium, alkali metal, alkaline earth metal, and organic ammonium salts.

5. A dry cleaning composition compr sing an emulsion of water in a volatile organic dry cleaning solvent, th'water being in the internal phase, and a salt of a primary aliphatic monosulfate containing an alkyl group of at least 12 carbon atoms, as a dry cleaning assistant and as an emulsifying agent for the water, said salt being selected from the group consisting of ammonium, alkali metal, alkaline earth metal, and organic ammonium salts. I

6. A dry cleaning composition comprising an emulsion of water in a volatile organic dry cleaning solvent, the water being in the internal phase, and a salt of an alkyl sulfate having at least 8 carbon atoms in the alkyl group and a sulfonic group attached to a prima y carbon atom. as a dry cleaning assistant and as an emulsifying alkaline earth metal, and organic ammonium 'salts.

7. A dry cleaning composition comprising an.

emulsion of water in' a volatile organic dry cleaning solvent, the water being in the internal phase, and sodium iauryl sulfate as a dry cleanin assistant and as an emulsifying agent for the water.

8. A dry cleaning composition comprising an emulsion of water in a volatile organic dry cleaning solvent, the water being in the internal phase, and sodium cetyl sulfate as a dry cleaning assistant and as an emulsifying agent for the water.

9. A dry cleaning composition comprising an emulsion of water in a volatile organic dry cleaning solvent, the water being in the internal phase,

and sodium'lauryl sulfonate as a dry cleaning assistant and as an emulsifying agent for the agent for the water, said salt being selected from 20 water,

the group consisting of ammonium, alkali metal,

LAWRENCE H. FLET'I'.

CERTIFICATE or cpnmscrxou. Patent No. 2,526,772. v August 17, 1915,

mwmcr n. FLET'I'.

It is hereby certi-fied that error appea ra in the printed specification of the above numbered patent requiring correction as followe: Page 2, first column, 1ine58, for "that" read --then--;' and second column, line 147-148,

for 'eo1vet' read --so1vent--;'pegeh, first mnfline 16, cllim, for

"sulfate" read---sulfonate--; and that the said Letters Patent should-be read with this correction therein that the same may conform to the record of the one in the Potent Office. 4

si ed and sealed this 5th a of October, A. n. 1915.

I Henry Van Aradale, (Seal) Acting Commissioner of Patent.