US3432251A

US3432251A - Process of removing dyestuff from foam backing

Info

Publication number: US3432251A
Application number: US466427A
Authority: US
Inventors: Sallie A Fisher
Original assignee: Techniservice Corp
Current assignee: Techniservice Corp
Priority date: 1965-06-23
Filing date: 1965-06-23
Publication date: 1969-03-11
Anticipated expiration: 1986-03-11

Description

United States Patent 3,432,251 PROCESS OF REMOVING DYESTUFF FROM FOAM BACKING Sallie A. Fisher, Berwyn, Pa., assignor of three-fourths to Robinette Research Laboratories, Inc., Berwyn, and

one-fourth to Techniservice Corporation, Lester, Pa.,

both corporations of Pennsylvania No Drawing. Filed June 23, 1965, Ser. No. 466,427 US. Cl. 8-102 11 Claims Int. Cl. D061 3/00 ABSTRACT OF THE DISCLOSURE The treatment of dyed solid foam-backed textile material, such as carpeting, particularly selective removal of dyestulf from the foam backing thereof without significantly affecting the dyeing of the textile component, such as carpet yarn.

When solid foam-backed textile material, such as carpeting, is dyed in a bath the foam backing is likely to sorb dyestuff from the bath, and normal rinsing procedure is ineffective to remove the sorbed dyestuff from the backing. On some floor surfaces the retained dyestuff may transfer from the backing to the floor surface to produce an objectionable staining. This is a particular problem with disperse-dyed, polyurethane foam-backed, nylon carpets on vinyl tile floors.

A primary object of the present invention is prevention of the aforementioned carpet staining of vinyl floor tile or other flooring material.

Another object is selective desorption of dyestuif from the backing component of dyed solid foam-backed textile material without disturbance of the dyestulf on the textile component thereof.

A further object is provision of solvents and procedures for accomplishing the foregoing objects.

Other objects of this invention, together with means and methods for attaining the various objects, will be apparent from the following description and examples.

In general, the objects of the present invention are accomplished by treating dyed solid foam-backed textile material with an appropriate solvent for the dyestuif and then removing the solvent in liquid form therefrom with the dyestuff from the backing component of the textile material dissolved therein, without significantly affecting the dyestuif on the textile component thereof.

Suitable solvents are organic compounds containing carbonyl groups, such as organic acids and esters thereof, aldehydes, and ketones, preferably liquid at and somewhat above ordinary room temperature. Examples of closely related operable compounds from these various classes include acetic acid, ethyl acetate, and acetone. Acetaldehyde has too low a boiling temperature to be useful, but salicylaldehyde is suitable. Another Suitable acid is 2- ethylhexoic acid. However, the ketones are preferred, such as, in addition to acetone, the following: diacetone alcohol, methyl isoamylketone, and methyl isobutylketone.

The solvent may be applied by immersing the textile material therein or by spraying the solvent thereon, in which event the operating temperature may be fixed at or above (usually not below) room temperature. A modified form of hot application may be accomplished by volatilizing the solvent, condensing it onto the textile material, which is kept at room temperature or otherwise relatively cool, and draining off the condensed solvent with dyestuff removed from the foam backing dissolved therein.

2 Example 1 A section of nylon carpet backed with polyurethane foam and disperse-dyed to a deep shade of blue was cut up into small squares. These squares were dipped into a variety of anhydrous organic solvents for a suflicient length of time to wet out both the foam and the face fibers. The solvent-Wet squares of carpet were then squeezed between white paper towels, and the success of the extraction was evaluated in terms of the removal of color from the foam back and the absence of evidence of color removal from the face fibers as shown by the absence of color on the paper squeezed in contact with the face of the test sample.

Typical results from the variety of solvents employed in Example 1 are tabulated in Table I. Solvents rated as very good in extraction are those wherein the foam color Was changed from a deep blue to white in a single extraction. Good solvents are those in which the removal left the foam light or faintly blue, a fair extraction showed some lightening of the foam color, a poor rating is indicated by only traces of color on the paper during the extraction process, and a very poor rating indicated no evidence of extraction.

TABLE I Solvent: Dye removal from backing Acetic acid Very good. Acetone do. Ethyl acetate do. Methyl isobutylketone do. Salicylaldehyde Good. Diacetone alcohol do. Methyl isoamylketone do. 2-ethylhexoic acid do. 1,3 butyl glycol Fair. Diethylene glycol Poor. Ethylene glycol do. Hexyl alcohol do. Isopropyl alcohol Very poor.

Example 2 Sections of polyurethane foam-backed nylon carpet which had been disperse-dyed a brilliant blue, a vivid purple, and a dark red were soaked in separate portions of acetone and diacetone alcohol at ambient temperatures. These samples were then removed from the solution, squeezed as dry as possible by passing through pressure rollers, washed with water and dried. In no case was there a difference in face color between the extracted samples and pieces of the same carpet before extraction. The success of the extraction in terms of color of the foam side was good, in the case of the blue and purple rugs, with both solvents. Extraction of the red carpet was rated as somewhat less successful (Table II) in terms of the residual foam color. Sections of extracted carpet were placed with their foam side against white vinyl tile, along with unextracted portions of carpet. The samples were weighted down to insure good contact between the foam and the tile and held in a constant temperature oven at C. for three days. No transfer of dye from the extracted foam to the tile was noted. In the same length of time the unextracted blue carpet had stained the tile deeply, the purple produced a stain of moderate intensity and the red a light stain. Therefore, it is concluded that while the extraction of the red dye with the two solvents had not greatly reduced the observed color, the dye that migrates to the tile had been removed in the process so Example 3 Sections of the same three polyurethane-backed nylon carpets used in Example 2 were hung in a device of such design that when a solvent was boiled in it its vapors condensed on the carpet sample and the liquid formed therefrom dripped back into the still pot. Separate experiments were conducted using, on the one hand, acetone and, on the other hand, diacetone alcohol as the solvent. Extraction of the three rug colors with hot acetone took place very rapidly with no loss of color of the face yarn. Extraction with higher boiling diacetone alcohol was somewhat slower and in the case of the red carpet visibly complete (Table H). The extracted samples were again squeezed to remove excess solvent and were washed with water and dried. They were tested on white vinyl tile as described in Example 2. Again no transfer of dye from the extracted samples to the tile was noted.

Example 4 Polyurethane-backed polyester carpets that had been disperse-dyed a medium blue, a deep red and a medium brown were tested for extractability with acetone and diacetone alcohol at ambient temperatures using exactly the same procedure as that described in Example 2. Again the extraction of color from the foam dyed with the red dye was less complete than that of the other two colors. The results are summarized in Table III under the heading Cold. When these extracted carpets were placed on a white vinyl tile, foam side down, and weighted down and held in an oven at 70 C. for three days in comparison with unextracted carpet under the same conditions, the extracted carpets again did not stain the white tile. Staining from all three unextracted samples was very dark.

TABLE III Extraction Solvent Rug color Cold Hot Acetone... Blue Good.-.-- Good.

Do.. Red Fair Do. Do Brown Good....- Do. Dlacetone alcohol Blue ..do Do. Do Red Poor Fair. Do Brown Good..... Good.

1 Slight loss of face yarn dye.

Example 5 Samples of the same three polyurethane-backed polyester carpets used in Example 4 were extracted following the procedure in Example 3 utilizing the vapors of acetone and diacetone alcohol. The results are summarized in Table III under the heading Hot. As indicated, the extraction of all three colors by acetone was good. Extraction with diacetone alcohol, however, resulted in some loss in face color before the color was completely removed from the foam side. This was particularly noticeable in the blue and the brown rugs. When these hotextracted samples were tested on white vinyl tile as previously described no staining of the tile was noted.

I claim:

1. Process of removing water-insoluble textile dyestuff selectively from the solid foam backing of dyed solid polyurethane foam-backed textile material while leaving the textile material dyed with the dyestuff, comprising applying to the dyed material, as solvent for the dyestufi, a carbonyl-containing liquid from the class consisting of acetic acid, acetone, ethyl acetate, methyl isobutylketone, salicylaldehyde, diacetone alcohol, methyl isoamylketone, and Z-ethylhexoic acid, and subsequently removing the solvent in liquid form therefrom with dystulf from the foam backing dissolved therein.

2. The process of claim 1 wherein the solvent is condensed from vapor form onto the textile material and then drained therefrom.

3. The process of claim 1 wherein the textile material is immersed in the solvent, which there after is removed therefrom by squeezing.

4. The process of claim 1 wherein the textile material has a nylon textile component.

5. The process of claim 1 wherein the textile material has a polyester textile component.

6. Process comprising treating carpeting composed of dyed solid foam backed textile material with a liquid from the group consisting of acetic acid, acetone, ethyl acetate, and methyl isobutylketone as solvent for the dyestuff, which is water-insoluble, dissolving the dyestuif selectively from the solid foam backing while leaving the textile material dyed with the dyestulf, and removing therefrom the resulting solution of the treating solvent and dyestuif dissolved therein.

7. The process of claim 6 wherein the foam backing comprises polyurethane.

8. The process of claim 6 wherein the textile material is nylon.

9. The process of claim 6 wherein the dyestulr' is a disperse dyestuif.

10. Process of removing water-insoluble disperse dyestuff selectively from the foam component of dyed solid polyurethane foam-backed nylon textile material useful as a floor covering while leaving the textile component dyed with the dyestuif, and thereby rendering the same non-staining to floor tile as when in place on a vinyl tile floor, comprising treating the textile material with diacetone alochol to dissolve the dyestuff from the foam component and removing the solvent in liquid form therefrom with dyestuff dissolved therein.

11. Process of removing water-insoluble disperse dyestulf selectively from the foam component of dyed solid polyurethane foam-backed polyester textile material useful as a floor covering while leaving the textile component thereof dyed with the dyestuff, and thereby rendering the same non-staining to floor tile as when in place on a vinyl tile floor, comprising treating the textile material with acetone to dissolve the dyestulf from the foam component and removing the solvent in liquid form therefrom with dyestulf dissolved therein.

References Cited UNITED STATES PATENTS 2/ 1925 Kocher 8-102 10/ 1950 Koberlein 8-102 OTHER REFERENCES MAYOR WEINBLATT, Primary Examiner.

US. Cl. X.R.