United States Patent 3,325,404 COMPOSITION FOR SIMULTANEOUSLY LAUN- DERING AND SOFTENING FABRICS Sidney Cohen, Jersey City, N.J., and Reginald L. Wakenlan, Philadelphia, Pa., assignors, by mesne assignments, to Millmaster Onyx Corporation, New York, N.Y., a corporation of New York No Drawing. Filed Sept. 19, 1963, Ser. No. 310,136 3 Claims. (Cl. 2528.75)
The object of this invention is to provide a composition for simultaneously laundering and softening fabrics. It is a further object of this invention to provide composition whereby cationic softeners can be applied to fabrics at the same time that the goods are being laundered with anionic detergents. It is still another object of this invention to provide a method whereby the housewife can launder goods while, at the same time, applying thereto a cationic softener. It is a still further object of this invention to provide a process by which textile fabrics or fibers may be finished with cationic softeners while simultaneously applying anionic wetting agents or other anionic surfactants to the fabric or fibers.
It is well known to the art to apply to laundered goods a quaternary ammonium salt as a cationic softener of the type RG'QR wherein R and R represent alkyl radicals having 14 to 20 carbon atoms, R is a methyl radical, R' is a methyl, ethyl or an ethoxylated radical (CH CH O),,H where n is an integer of at least one, and X is a chlorine, bromine, sulfate, methosulfate and ethosulfate anion, by dissolving such a softener in the final rinse water. Similar materials have also been used by textile mills as softeners applied in the final rinse. In the preceding formula, R and R represent an alkyl radical or mixture of alkyl radicals having from 14 to 20 carbon atoms usually derived from tallow. Quaternary ammonium compounds of this type are sold in substantial volume and are used in the application set forth above, more particularly in the last rinse in household laundering operations. They impart to the treated goods a pleasant, soft hand and have found much favor with housewives.
The preferred alkyl radical, R, in these compounds is usually a mixture containing about 60 to 80% of stearyl and about 20 to 40% of cetyl radicals and is ordinarily derived from tallow, preferably by hydrogenation or by by hydrogenation of its derivatives used as intermediates in the production of the quaternary ammonium compounds. Softeners of this type being high molecular weight compounds of cationic nature are precipitated by anionic surfactants such as ordinary soaps, alkyl aryl sulfonates, fatty alcohol sulfates, and the like. They cannot, therefore, be used as such in a detergent solution because they are precipitated thereby and deposit an insoluble precipitate on the laundered goods which, rather than having a softening effect, actually leaves them as harsh to the feel, or even more so, than as if the softener had not been applied.
We have now found the surprising fact that when cationic softeners of the foregoing type are combined with a stabilizer, which is a selected quaternary ammonium compound containing only one alkyl radical having from 8 to 20 carbon atoms in the alkyl chain, hereinafter referred to as monoalkyl quaternary ammonium salts, they can be dissolved in aqueous solutions of anionic detergents to yield stable dispersions showing little or no tendency to precipitate. Furthermore, when goods are laundered with such solutions, they are not only 3,325,404 Patented June 13, 1967 effectively washed by the anionic detergent, but they are also softened by the cationic softener of the type hereinabove delineated. The monoalkyl quaternary ammonium compound of itself may possess litte or no softening power. The optimum characteristics of good softening and good compatibility with anionic detergents are exhibited by ratios of dialkylto monoalkyl quaternary ammonium compounds lying within the range of about 1:1 to about 8:1 by weight.
The monoalkyl quaternary ammonium salts which may be used as a stabilizer in conjunction with the dialkyl quaternary ammonium softener compounds previously described conform, in general, to the following structure:
wherein R is selected from the group consisting of an alkyl or alkaralkyl radical containing from 8 to 22 carbon atoms, an alkyl benzyl phenoxy ethyl radical in which the alkyl radical contains from 8 to 9 carbon atoms and in which the phenyl radical may be .substituted by a methyl group; R and R" are selected from the group consisting of methyl, ethyl, propyl, and isopropyl radicals and radicals which, in combination with the nitrogen atom of the above formula, form a monocylic, heterocyclic ring system including pyridine, pyrrolidine, and morpholine; R' is selected from the group consisting of methyl, ethyl, propyl, and i'sopropyl radicals and a benzyl group or substituted benzyl group including monochlorobenzyl, dichlorobenzyl, methyl benzyl, dimethyl benzyl, ethylbenzyl, diethyl benzyl, isopropyl benzyl, tertiary butyl benzyl, or another benzyl radical containing from 1 to 4 carbon atoms as a single or as multiple side chains, or R' is the same radical as R" when R and R" are members of an unsaturated heterocyclic ring in which the group, R", is doubly bonded to nitrogen, including pyridine; and X is selected from the group consisting of chloride, bromide, sulfate, methosulfate and ethosulfate ions. Typical examples of these stabilizer monoalkyl quaternary ammonium compounds are alkyl trimethyl ammonium chlorides, alkyl benzyl trimethyl ammonium chlorides, lalkyl dimethyl benzyl ammonium chlorides, alkyl dimethyl substituted-benzyl ammonium chlorides wherein the substituted-benzyl radical is methyl benzyl, dimethyl benzyl, ethyl benzyl, and the like, alkyl methyl pyrrolidinium chlorides, alkyl ethyl morpholinium chlorides, alkyl benzyl morpholinium chlorides, and the like, as well as corresponding metho and etho sulfates, in all of which the alkyl group has from 8 to 20 carbon atoms. Other monoalkyl quaternary ammonium salts which may also be employed include alkyl phenoxy ethyl dimethyl benzyl (and methyl benzyl) ammonium chlorides in which the alkyl radical is isooctyl or isononyl.
It has generally been supposed that surface-active cationic materials are universally precipitated by surfaceactive anionic materials. This is, indeed, the case when dialkyl dimethyl ammonium chloride, dialkyl dimethyl ammonium metho sulfate, and dialkyl ethoxylated hydroxy ethyl methyl ammonium chloride solutions are added, alone, to conventional anionic detergent solutions such as aqueous solutions of soap, alkyl benzene sulfonates, aliphatic hydrocarbon sulfonates, sulfonated oils, sulfonated esters such as sulfonated butyl oleate or sulfonated castor oil, alkyl sulfates, dialkyl esters of alpha sulfo succinic acid, and the like, which are described in Schwartz, Surface Active Agents, 1949, New York, Interscience Publishers, Inc., pages 25141. We have found that such precipitation is inhibited. or completely prevented when the dialkyl quaternary is combined with the monoalkyl quaternary ammonium compounds above enumerated in the proportions hereinabove set forth.
Conventional concentrates of dialkyl quaternary ammonium salts usually supplied to formulators for dilution with water to 3 to 6% active aqueous solutions which are sold in this dilute form to the housewife usually contain about 75% of dialkyl dimethyl quaternary ammonium compound. The balance is water, together with a suitable Water-soluble organic solvent such as isopropanol. We prefer to prepare approximately 75 active concentrates of a blend of dialkyl and monoalkyl quaternary which can be readily cut to a 3 to 6% active solution, if desired, that can be used by the housewife, laundry, or textile mill by direct addition to the washing solution containing anionic detergent.
In current practice, it is customary for the housewife to add a measured amount of cationic softener of the dialkyl dimethyl ammonium salt type to the final rinse water used in a home washing machine so that the amount of softener applied to the fabric by exhaustion from the final rinse will usually be within the range of 200 to 1000 parts per million of dry clothes, preferably about 750 parts per million. The process of this invention represents a major advance in household laundering procedures because laundering and softening can both be performed at the same time. Thus, the housewife preferably adds the softener comprising both dialkyl and monoalkyl quaternary salts directly to the soap or other detergent solution and launders and rinses in the conventional manner. Similarly, in mill operations, softening can be carried out in the final scouring operation without interposition of an additional softening step before final drying of the goods.
It should be understood that the concentrated softeners employed in our invention may, if desired, contain a water-miscible organic solvent such as ethanol or isoproanol. P The compatibility of blends of dialkyl quaternaries and monoalkyl quaternaries with various anionic surfactants is illustrated in Table I, using a 0.225% active content of cationic.
figures generally resulted in incompatibility. In all the cases given above, however, the minimum compatible anionic/cationic ratios are well below the ratios which would be required for use in home laundering or in textile finishing. Thus, in home laundering, where the use of a 14% active powdered anionic detergent is in the range of 8 ounces per 10 pounds of goods, and the softener is used at a concentration of approximately 0.07% on the weight of goods, the anionic/cationic ratio required in the washing solution would be approximately 10.0, which is well above the minimum anionic/cationic ratios required for the selected compatible anionic/cationic mixtures stated above.
In the practice of this invention, we prefer to use an anionic/ cationic ratio, based on the weights of active ingredient of each agent, of 1.5 to 20.0. Generally, the higher values of this range of the ratio are utilized in home laundering applications, while the lower values of this range are utilized in textile finishing operations.
The method of simultaneously laundering and softening fabrics according to this invention is illustrated by the following example.
Example 1 A five-pound load of soiled terry towels was placed in a Westinghouse Commercial Laundromat. Four ounces of Tide, a commercially available household detergent containing both alkyl aryl sulfonate and sodium alkyl sulfate sold by the Procter & Gamble Company, was added to the charge and the machine was turned to the Hot position to start the addition of water. Softener solution was then added through the external opening provided for addition of liquids, at a level of 750 parts active softener per million of towelling. The goods were then laundered in the conventional manner, a single cycle consisting of a wash, three rinses, and a spin. Four complete cycles were performed in each test, detergent and softener both being applied in the same wash bath except in the case of controls. After the final rinse, the towels were tumble dried and evaluated for cleanliness, yellowing, softness, and absorbency.
TABLE I Ratio of Anionic to Cationic Anionic 1 Cationic by Compatibllity Weight of 100% Active Material 2T2MMS 2 1. 38 Preolpltate. 2T2MMS:T2MCl(3:1) 1. 38 Compatible. 2'I2MCl 4 1. 38 Preclpitate. 212MClz'12MCl (3:1) 1. 38 Compatible. 2T2MMSzCPC (3:1) 1.3a 1 )o 2T2MC1 g. 2?] gleclp'liiiih ornp e. 2T2MMS'T2MC1 (3 1) 0. 40 Precipitate.
0. 40 Compatible. 0. 4.0 Precipitate. do 0. 40 Compatible. 2T2MMS Di-2-ethyl hexyl snliosuccinatm. 1. 10 Preeipitate. 2T2MMS:T2MC1 (3:1) o 1.10 Compatible. 2T2MC1 Sodium salt of coconut fatty 1. 3 Preeipitate.
acids. 2T2MMSzT2MCl (3.1)..- --do 1.3 Compatible.
1 Anionic in the form of its sodium salt. 2 2T2MMS is dialkyl dimethyl mixture, primarily C -C present in hydrogenated tallow ammonium methosuliate where the alkyl group is the 3 T2MCl is alkyl dimethyl benzyl ammonium chloride, where the alkyl radical is as defined under note 2. 4 ZTZMCl is dialkyl dimethyl ammonium chloride, where the alkyl group is under note 2.
B CPC is eetyl pyridinium chloride.
as defined For comparative purposes, comparable four-cycle launderings of terry towels were carried out without softener, and another four-cycle laundering was carried out using a softener in the last rinse, only, of each cycle.
In all cases, cleanliness was excellent. The relative soft- 75 ness of the washed goods was evaluated by a panel of methyl benzyl ammonium chloride, tested as described in Example 1, with the following results:
Softener Ratio of Dialkyl to Softness Rating Monoalkyl Quaternary TABLE II Softener Location softness Discoloration Wicking,
Added Rating 1 in.
4. 8 None 2. 0 1.0 Noticeable yellowing 0.0 5. 8 None 1. 3 1. O Noticeable ye1lowing 0. 0 3. 0 None 1. 3
1 1 shows greatest softness.
A softness rating of 3 or less indicates good softening. Hence, it is apparent that addition of the 3:1 blend of dialkyl quaternary ammonium salt and monoalkyl quaternary ammonium salt during the soaping operation gave substantially improved softening over the control wash run without softener, whereas addition of the dialkyl quaternary ammonium salt, only, during the soaping seriously impaired softness as compared with the control. Furthermore, the addition of the 3:1 blend during washing resulted in washed goods having no discoloration and exhibiting good absorbency, a measure of the utility of the towel in drying operations, as compared with use of the same blend in the last rinse. In the later case, although softness was somewhat better, the goods were discolored by the cationic and the wicking was impaired.
Example 2 Another series of tests was run in the same manner as in Example 1 using 3:1 blends of dialkyl dimethyl ammonium metho sulfate and cetyl pyridinium chloride, the same dialkyl quaternary and alkyl dimethyl benzyl ammonium chloride, and dialkyl dimethyl ammonium chlo ride and alkyl dimethyl benzyl ammonium chloride. Table III shows the results of evaluation.
It is thus apparent that within the range of 85:15 to 60:40 of dialkyl quaternary to monoalkyl quaternary,
there is marked softening of the goods when the softener is applied during the washing cycle.
It will be apparent that, while We have shown the marked utility of this invention in household laundering 0 operations, similar advantages accrue to the textile mill degree of water absorbency. The desirably soft handle imparted to textile fabrics by cationic softeners, which are cationic surfactants of various structures containing one or more long alkyl groups of 16 to 22 carbon atoms, cannot be duplicated by the use of anionic or nonionic types of softening agents. Indeed, the term cationic hand has become a descriptive term in the textile finishing industry to describe the unique, soft, handle produced by cationic softeners.
It is apparent from this series of tests that all three combinations of dialkyl quaternaries and monoalkyl quaternaries gave markedly improved softening over the blank, Whereas the color of the laundered fabric and the wicking was better, in each case, than when the dialkyl quaternary alone or the dialkyl quaternary in combination with the monoalkyl quaternary was used in the final rinse.
Example 3 In order to determine the effective range of ratios of dialkyl quaternary to monoalkyl quaternary when added to the detergent wash, dialkyl dimethyl ammonium metho sulfate was combined in varying amounts with alkyl di- However, treatment of textile materials with efiicient cationic softeners leads to a decrease in the water absorbency of the goods, making them unattractive for end uses such as towels and diapers. In addition, goods intended for these end uses are usually treated with an anionic wetting agent to confer high absorbency upon them, and the simultaneous application of cationic softeners with the anionic wetting agent has heretofore been impossible to carry out because of the incompatibility of the cationic softeners with the anionic wetting agent.
As examples of the novel process by which textile materials may now be finished to provide a soft hand and a high absorbency, the following illustrations are given:
7 Example 4 Unfinished terry cloth (Test Fabrics, Inc.; Style #420) was thoroughly wet out in water and mangled under sufficient pressure to leave the goods with an 85% pickup of water. The moist terry cloth was then treated in a three roll padder with a solution containing the following ingredients, all percentages being given by weight:
Percent 3:1 mixture of 2T2MMS and T2MCl (75% active)- 1.5 Sulfated butyl oleate (60% active) 3.0
Water to 100%.
Example 5 46 pounds of 2T2MMS, 9.5 pounds of T2MCl and 19 pounds of isopropyl alcohol were mixed in a kettle at 50 C. until a uniform blend was obtained. To this mixture were then added 18. pounds of a 50% solution in isopropyl alcohol of sodium di-(2 ethylhexyl)-sulfosuccinate and 25 pounds of the condensation product of nonyl phenol with 9.5 moles of ethylene oxide. The ingredients were mixed for a short time until a uniform blend was obtained.
A 2% by weight aqueous solution of the above blend was prepared and used to impregnate cotton terry cloth by the same procedure as described in Example 4. The resulting goods had a very soft handle and a wicking test of 1.4 inches.
We claim:
1. A composition for treating fabrics consisting essentially of a surface-active anionic agent and a compatible softening agent, said softening agent consisting essentially of (1) a softener having the structure:
R C R wherein R and R are alkyls having 14 to 20 carbon atoms, R" is methyl, R' is a member of the group consisting of methyl and ethyl, and X is a member of the group consisting of chlorine, bromine, sulfate, methosulfate and ethosulfate, and (2) a stabilizer having the structure:
wherein R is a member of the group consisting of alkyl and alkaralkyl containing 8 to 22 carbon atoms, alkyl benzyl phenoxy ethyl wherein the alkyl has 8 to 9 carbon atoms, and the benzyl is selected from the group consisting of unsubstituted and methyl substituted benzyls, R and R" are members of the group consisting of methyl, ethyl, propyl, isopropyl, and individual valences of the hydrocarbon residues of heterocyclic systems selected from the group consisting of pyridine, pyrrolidine and morpholine, R is a member of the group consisting of methyl, ethyl, propyl, isopropyl and benzyl, said benzyl being selected from the group consisting of unsubstituted and substituted benzyls wherein the substituted benzyl is substituted in at least one position by a member of the group consisting of chlorine, methyl, ethyl, isopropyl, tertiary butyl and a second benzyl, said second benzyl being substituted in at least one position by a lower alkyl of 1 to 4 carbon atoms, and X is a member of the group consisting of chloride, bromide, sulfate, methosulfate and ethosulfate, the ratio of softener to stabilizer being between about 1:1 and 8:1 by weight, and the ratio of softening agent to anionic agent being between about 121.5 and 1:20.
2. A process for simultaneously laundering and softening fabrics which comprises treating fabrics with an aqueous composition as defined in claim 1.
3. A composition for simultaneously laundering and softening fabrics consisting essentially of an anionic surface-active agent and a softener composition in the amount by weight of about 1.5 to 1, about 20.0 to 1, respectively, said softener composition consisting essentially of softener agent dialkyl dimethyl ammonium methosulfate wherein the alkyl group has 14 to 20 carbon atoms derived from hydrogenated tallow and as stabilizer alkyl dimethyl benzyl ammonium chloride wherein the alkyl group has 14 to 20 carbon atoms derived from hydrogenated tallow, the amount of said softener and stabilizer ranging in the ratio by weight from about 85:15 to about 60:40.
References Cited UNITED STATES PATENTS 2,746,928 5/1956 Darragh et a1. 252106 3,044,962 7/1962! Brunt et al. 2528.8 X 3,117,113 1/1964 Tudor 252875 3,122,502 2/1964 Waldman et al. 252-8.8 3,154,489 10/1964 Du Brow et al. 2528.8 X 3,178,366 4/1965 Du Brow et al 2528.8 3,256,180 6/1966 Weiss 2528.8
' LEON D. ROSDOL, Primary Examiner.