Bacteriostatic cellulosic textile reacted with derivatives of dihydroxy hexachloro diphenyl methane

Patented July 10, 1951

2,559,986

UNITED STATES PATENT OFFICE

2.559,986

BACTERIOSTATIC CELLULOSIC TEXTILE REACTED WITH DERIVATIVES OF DIHYDROXY HEXACHLORO DIPHENYL METHANE

David M. Musser, Clemson, S. C., assignor to Pacific Mills, Boston, Mass., a corporation of Massachusetts

No Drawing. Application August 31,1946, Serial No. 694,422

Claims.

The present invention relates to a new composition of matter, particularly useful as a textile finish, to processes for preparing this composition, and to textile material, finished with the same, characterized by the desirable property of inhibiting the growth of bacteria.

Pathogenic germs are frequently present in or on the surface of textile fabrics, either as a result of contact of the fabric with the human body, as in the case of sheets, pillow cases, towels and the like, or simply as a result of exposure of the textile to an atmosphere in which such bacteria are present. These germs cling tenaciously to the textile fibres and may, under favorable moisture and temperature conditions, spread and grow colonies, which then present a serious danger of contamination. Means have long been sought for rendering a textile material permanently antagonistic or resistant to such bacteria so as to prevent their growth into colonies on the textile material and to lessen the danger of contamination from contact with the textile material. It has been proposed to overcome this contamination hazard by applying to textile fabric a coating of a germicidal compound such as a mercurial, a phenolic, or the like. Such compounds are adequately bacteriostatic in this relationship, but the art heretofore has not succeeded in rendering textile materials permanently bacteriostatic by treatment with them. Textiles coated with such materials commonly lose substantially all of their bacteriostatic property upon a single laundering and it is therefore necessary that the coating treatment be repeated each time the textile article is laundered. Such coating processes. _3grequire considerable mechanical equipment and therefore, are not a practicable procedure in most hotels, hospitals and private homes in which bed linens and towels are used.

It is an object of the present invention to provide an improved bacteriostatic compound, and process for making the same, suitable for use in association with cellulosic materials such as textile fabrics, threads, yarns and fibers. A further object of the invention is to provide cellulosic textile materials having improved bacteriostatic properties and capable of retaining these properties more or less indefinitely.

I have found that the desirable property of inhibiting the growth of bacteria may be imparted to cellulosic material by treatment of the material, involving chemical reaction, in which there is attached to the cellulose molecule a hydrocarbon chain containing bactericidal and hydrophilic groups. The combination of such groups (Cl. 8—116)

IS employed in the present invention increases the affinity of the cellulose for water but without, however, causing it to reach a degree of solubility undesirable in textile materials. The cellulosic materials of the present invention provide a bacteriostatic environment which restricts the growth of bacteria thereon under all conditions of moisture and temperature.

The novel bacteriostatic and hydrophylic compounds of the present invention comprise derivatives of 2,2'-dihydroxy 3,5,6,3',5',6'-hexachlorodiphenylmethane having the general formula

<img file="US2559986A_D0001.tif" />

wherein R represents one of the group of radicals comprising —CHz-CHOH—CHr-O—CU₂C1

HaC—O—CH₂C1 —CHj-i—O-CHaCl

- H and their higher homologues.

These bacteriostatic and hydrophilic compounds may be formed by reacting one of the hydroxyl groups of the chlorinated hydroxy diphenylmethane having the formula

<img file="US2559986A_D0002.tif" />

with chlorinated glycerin, paraformaldehyde and hydrochloric acid, or with epichlorohydrin or the like, to form thereon a hydroxylated hydrocarbon chain. In the finished cellulosic product this hydrocarbon chain is attached to the cellulose . molecule.

The following examples, given by way of illustration and not of limitation of the invention, show practical methods for the preparation of bacteriostatic and hydrophylic compounds suitable for use in finishing textile material, and the preparation of cellulosic materials having improved bacteriostatic properties.

Example 1

2,2'-dihydroxy 3,5,6,3',5',6'-hexachlorodiphenylmethane is dissolved in ethyl alcohol and metallic sodium is added slowly to this solution in molar

2,550,986 equivalents (1 mol of Na to 1 mol of diphenylmethane) to form a sodium phenolate. The solution is heated to the boiling point and a-monochlorglycerine is added slowly in molar proportions, i. e., 1 mol of glycerine to 1 mole of diphenylmethane, with the formation of a sodium chloride precipitate. The alcoholic solution is recovered by filtration, and the alcohol evaporated or distilled off, leaving a residue having a melting point of 97° C. This residue is dissolved in benzene and then paraformaldehyde is added to the solution in molar proportions (1 to 2 mols of paraformaldehyde to 1 mol of the compound). Gaseous hydrochloric acid is passed through the benzene solution until the paraformaldehyde is completely dissolved. The solution is then neutralized with .pyridine, using litmus paper as an indicator. ¹

The compound contained in the resulting solution may be applied to textile fabrics in any one of the three following ways, to form a cellulose derivative which is bacteriostatic.

(A) Cotton fabric is pretreated with a 5% to 10% solution of sodium acetate, and squeezed to about 100% pick-up. The treated fabric is then impregnated with a 1% to 2% solution of the compound in benzene. The cloth is passed through squeeze rolls (about 80% to 100% pickup) and then heated to about 130-150° C.

(B) The pyridine neutralized benzene solution of the bacteriostatic compound is evaporated on a water bath and the resulting solid residue dispersed in warm water by stirring. The textile fabric to be treated is pretreated with sodium acetate as in (A) above, and then impregnated with the water dispersion. Thereafter the fabric is heated to 130-150° C.

(C) The pyridine neutralized benzene solution of the bacteriostatic compound is evaporated and the resulting solid residue dispersed in a warm water solution of 5% to 10% sodium acetate. The textile fabric is impregnated directly, without pretreatment, with the water dispersion, and the excess removed by squeezing to a pickup of about 100% and the fabric thereafter heated at 130-150° C. as before.

Example 2

Cotton fabric is impregnated with caustic soda of mercerizing strength and then exposed to gaseous epichlorohydrin at 15 mm. pressure and a temperature of 50° C. for two hours, washed in water, soured in dilute acetic acid, washed again, and dried with a solvent (alcohol or the like). The fabric is then refluxed for several hours in an alcohol solution (or a carbon tetrachloride solution) of mono potassium salt of 2,2'-dihydroxy 3,5,6,3',5',6'-hexachlorodiphenylmethane.

The fabrics resulting from the treatment of the foregoing examples exhibit very pronounced bacteriostatic properties and retain these properties, even after several commercial launderings.

The present invention is applicable generally to materials of a cellulosic nature, either native or regenerated, on which there are free hydroxyl groups. Cellulosic textile materials, such as cotton and other natural products, may be treated in the form of fibers, threads, yarns, or in the piece, as a woven, braided, netted or knitted fabric. The treatment of this invention involves a chemical reaction upon the cellulose molecule with the production of a new substance. The bacteriostatic qualities of this substance are not impaired by washing, dyeing or other treatments encountered in the finishing or use of the material.

The foregoing disclosure of preferred embodiments of my invention is made by way of illustration and not of limitation. It will be appreciated that changes may be made therein by those skilled in the art without departure from my invention, as expressed in the following claims.