US2806001A - Polyethyleneglycols as laundering aids - Google Patents

Description

United States Patent() assiguors to the United States of America the Secretary of Agriculture Willie Fong,

ley, Califi, as represented by No rawing. Application December 5, 1952, Serial No. 324,422

2 Claims. (Cl. 252-461) (Granted under Title 35, U. S. Code (1952), see. 266) A non-exclusive, irrevocable, royalty-free license in the invention herein described, for all governmental purposes, throughout the world, with the power to grant sublicenses for such purposes, is hereby granted to the Government of the United States of America.

This invention relates to washing procedures particularly to the washing of textile materials such as fabrics and fibers with aqueous media. In particular the invention concerns the use of polyethyleneglycol in the aqueous washing medium whereby to minimize the re-deposition of soil during the washing procedure.

It is well known in the art that a successful Washing operation involves two separate factors, i. e., (a) the removal of dirt from the textile material and (b) keeping the soil suspended in the medium so that it will not be re-deposited on the textile. In general aqueous Washing media containing soap fulfill both of these criteria as soap not only is a good soil remover but also keeps the removed soil in suspension so that little re-deposition takes place. However, the present trend is toward the use of anionic synthetic detergents such as the alkyl benzene sulphonates since these agents can be used in hard water areas as their detersive power is not decreased by the presence of calcium and magnesium ions. However, these anionic detergents have the disadvantage that their suspending power is poor. Whereas they are very effective from the standpoint of removing soil they are not so efiective in preventing re-deposition and so cotton fabrics washed with such agents will be grayer than when using soap. In order to overcome this disadvantage, various soil suspending agents are commonly added to the anionic detergents. One of the most commonly used agents is sodium carboxymethyl cellulose.

It has now been found that polyethyleneglycol has useful soil-suspending properties and when added to aqueous washing media the degree of soil re-deposition is greatly reduced. As Well known in the art, polyethyleneglycol is not a single, individual compound but may be obtained in almost any degree of polymerization. The degree of polymerization is most easily expressed in terms of average molecular weight. Although this invention comprises in its broad aspect the use of polyethyleneglycol having any degree of polymerization and which is soluble in water at least to the extent of about .001% to about 0.1%, it is to be understood that not all the polymers possess the same degree of effectiveness. Thus polyethyleneglycols having an average molecular weight from about 1,000 to about 10,000 exhibit maximum soil-suspending activity. For this reason it is preferred to use a polyethyleneglycol of such molecular weight range as a soil-suspending agent in washing operations.

In applying this invention in practice the polyethyeneglycol may be dispersed into the aqueous washing medium in a concentration from about 0.001% to about 0.1%, the higher proportions giving the greater degree of protection against soil redeposition. It is obvious that the proportion of polyethyleneglycol can be higher than the above ice ' range but in' general increasing the concentration above 0.1% gives little if any added protection. If desired, the polyethyleneglycol can be incorporated with the detergent so as to form a composition which on dissolving in water furnishes the desired washing medium. To this end, the detergent is mixed with about 2 to 10% of the aforesaid soil-suspending agent.

In carrying out washing operations in accordance with this invention, the fabric or other textile material is agitated in the usual'manner preferably at elevated temperatures as commonly used in laundries with the aqueous media containing the polyethyleneglycol and the detergent. As the detergent one may use any of the materials commonly used for washing purposes.

The detergent may be, for example, of the anionic'or non-ionic types. In the first category are included ordinary soaps, that is, sodium or potassium salts of the higher fatty acids, or usually, mixtures of higher fatty acids as are present in naturally occurring oils and fats. Also included in the anionic category are the detergents of the sulphonate or sulphate type. As well known in the art, a multitude of such materials are available, including the alkyl (C8Cl8) sulphates, the alkyl (Cs-C13) sulphonates, the alkyl (Cs-C18) aromatic sulphonates, the monoor di-alkyl (Cs-C13) esters of sulphosuccinic acid, sulphonated or sulphated amides of the higher fatty acids such as N-sulphoethyl stearamide, and so fourth. These compounds are generally employed in the form of their salts, i. e., their sodium, potassium, ammonium or amine salts. Some of the particular detergents which may be used are: sodium octyl sulphate, sodium nonyl sulphate, sodium decyl sulphate, sodium undecyl sulphate, sodium dodecyl sulphate, sodium tridecyl sulphate, sodium tetradecyl sulphate, sodium pentadecyl sulphate, sodium hexadecyl sulphate, sodium heptadecyl sulphate, sodium octadecyl sulphate, sodium oleyl sulphate, sodium octyl sulphonate, sodium nonyl sulphonate, sodium decyl sulphonate, sodium undecyl sulphonate, sodium dodecyl sulphonate, sodium tridecyl sulphonate, sodium tetradecyl sulphonate, sodium pentadecyl sulphonate, sodium hexadecyl sulphonate, sodium octadecyl sulphonate, sodium oleyl sulphonate, sodium salt of dioctyl sulpho succinate, sodium octyl benzene sulphonate, sodium nonyl benzene sulphonate, sodium decyl benzene sulphonate, sodium undecyl benzene sulphonate, sodium dodecyl benzene sulphonate, sodium tridecyl benzene sulphonate, sodium tetradecyl benzene sulphonate, sodium pentadecyl benzene sulphonate, sodium hexadecyl benzene sulphonate, sodium heptadecyl benzene sulphonate, sodium octadecyl benzene sulphonate, sodium tri (isopropyl) benzene sulphonate, sodium tri (isobutyl) benzene sulphonate, sodium tri (isopropyl) naphthalene sulphonate, sodium tn' (isobutyl) naphthalene sulphonate, and so forth. The commercially available detergents are generally not pure compounds but are mixtures of homologous compounds and are quite satisfactory. Thus for example, the sodium alkyl benzene sulphonate wherein the alkyl group contains 12 to 18 carbon atoms is a Well known detergent. Others are: a mixture of sodium alkyl sulphates consisting mostly of sodium lauryl sulphate; a mixture of sodium alkyl phenol sulphonates wherein the alkyl group contains 12 to 18 carbon atoms; and a mixture of sodium alkyl sulphonates wherein the alkyl group contains 10 to 18 carbon atoms. As non-anionic detergents one may employ polyalkylene glycol esters, ethers and thioethers of the following types:

wherein the Rs represent long chain alkyl radicals of 8 to 12 carbon atoms and n is an integer from about 4 to 12. Other non-anionic detergents are the long-chain fatty acid esters of anhydrosorbitol, or the polyethylene glycol addition products of such esters. It is evident that the particular detergent used is not critical except that one should be chosen which is generally useful in emulsitying and detergent applications.

The concentration of the detergent is not critical within a wide range and depending on the soil removal etficiency of the particular agent, the range of concentration may be from about 0.05% to about 0.5%. If desired, the soil removal efilciency of the detergent maybe increased by addition to the aqueous medium of any of the usual types of builders such as sodium hexametaphosphate, tetrasodium pyrophosphate, sodium tripolyphosphate, trisodium phosphate, borax, sodium carbonate, sodium silicate, sodium metasilicate, and so forth.

The following examples illustrate the invention in greater detail. The known soil-suspending agent, sodium carboxymethyl cellulose, was employed in some of the experiments for comparative purposes. In all the experiments, carbon black was added to the washing media to test the soil-suspending power of the various materials under test. Obviously in practice of the invention, no carbon black or other soil would be added to the washing medium.

' Example I A series of experiments were carried out in which clean swatches of cloth were agitated in an aqueous media containing a synthetic detergent, various soil-suspending agents at various'concentration levels, and carbon black. The treated swatches were then subjected to reflectance measurements to measure the amount of soil (carbon black) which had been deposited on the fabric thus to compare the effectiveness of the soil-suspending agents. The reflectance values are an index of the cleanness of the cloth; the higher the proportion of light reflected the cleaner the. cloth. The experiments were carried out as follows:

A standard washing medium was prepared containing: water; sodium alkyl (C12C18) benzene sulphonate, 0.12%; sodium tripolyphosphate, 0.08%; sodium carbonate, 0.04%; and carbon black, 0.1%. The pH of this solution was about 10.3. To samples of the standard medium were added various soil-suspending agents as hereinafter indicated. Each solution so prepared was tested as follows:

Two hundred cc. of the test solution was placed in a pint jar together with a swatch of a standard bleached muslin (cotton) cloth and 20%" stainless-steel balls.

The jar was then sealed and placed in a Launderometer and agitated by rotation at 140 F. for 20 minutes. The test swatch was then removed, rinsed 4 times with distilled water and agitated with 200 cc. of distilled water in the Launderometer for 10 minutes at 140 F. This washing in distilled water was done to remove loosely adherent carbon black so that the results would relate solely to adsorbed soil. The treated swatch was then dried in air, ironed, and the reflectance measured.

The materials and proportions used and the results obtained are tabulated below:

Reflectance (percent) of washed samples using various soil-suspending agents at various concentration levels Concentration of soil-suspending agent, Polyethylene Polyethylene- Polyethylene- Sodium percent glycol, glycol, glycol, carboxy- Average mol. average 1110]. average mol. methyl Wt. 6,000- wt. 1,300- wt. 380-420 cellulose The reflectance of the original cloth sample was Having thus described our invention We claim:

1. A process for removing soil from a textile material and minimizing the re-deposition of removed soil which comprises washing the material with a solution comprising water, about 0.05% to about 0.5% of a sodium alkyl benzene sulphonate wherein the alkyl group contains 12 to 18 carbon atoms, and a soil suspending agent consisting of about 0.001% to about 0.1% concentration in said solution of a polyethyleneglycol having an average molecular weight of 6,000 to 7,500.

2. A washing solution which is effective to remove soil from textile materials and to minimize re-deposition of removed soil which comprises water, about 0.05 to about 0.5% of sodium alkyl benzene sulphonate wherein the alkyl group contains 12 to 18 carbon atoms, and a soil suspending agent consisting of about 0.001% to about 0.1% concentration in said solution of a polyethyleneglycol having an average molecular weight of 6,000 to 7,500.

References Cited in the file of this patent UNITED STATES PATENTS bide and Carbon Chem. Corp., N. Y. (1946), page 9.

Synthetic Organic Chemicals, Carbide and Carbon Chem. Corp., N. Y., 12th ed. (1945), pages l923.

Claims (1)

1. A PROCESS FOR REMOVING SOIL FROM A TEXTILE MATERIAL AND MINIMIZING THE RE-DEPOSITION OF REMOVED SOIL WHICH COMPRISES WASHING THE MATERIAL WITH A SOLUTION COMPRISING WATER, ABOUT 0.05% TO ABOUT 0.5% OF A SODIUM ALKYL BENZENE SULPHONATE WHEREIN THE ALKYL GROUP CONTAINS 12 TO 18 CARBON ATOMS, AND A SOIL SUSPENDING AGENT CONSISTING OF ABOUT 0.001% TO ABOUT 0.1% CONCENTRATION IN SAID SOLUTION OF A POLYETHYLENEGLYCOL HAVING AN AVERAGE MOLECULAR WEIGHT OF 6,000 TO 7,500.