Fabric (woven – knitted – or nonwoven textile or cloth – etc.) – Coated or impregnated woven – knit – or nonwoven fabric which... – Coating or impregnation absorbs chemical material other than...
Reexamination Certificate
2001-10-09
2004-12-21
Del Cotto, Gregory R. (Department: 1751)
Fabric (woven, knitted, or nonwoven textile or cloth, etc.)
Coated or impregnated woven, knit, or nonwoven fabric which...
Coating or impregnation absorbs chemical material other than...
C510S295000, C510S500000, C442S164000
Reexamination Certificate
active
06833336
ABSTRACT:
FIELD OF THE INVENTION
The present invention relates to a laundry additive article that provides effective dye absorbing and dye transfer inhibiting benefit. More specifically, the invention uses a substantially insoluble cross-linked polymeric amine fixed to an insoluble substrate to selectively remove extraneous dyes from a wash solution before redeposition onto other articles and/or garments can occur. The dye absorber is also dye-selective to prevent interference with detergents or other additives.
BACKGROUND OF THE INVENTION
One problem that has persistently troubled the fabric care industry has been the problem of dyes bleeding from colored articles and/or garments in the washing machine and then redepositing on lighter-colored articles and/or garments in the same wash load. Several attempts have been made to try to remedy this problem of “fugitive dyes,” but to date none has been completely successful. Typically laundry is hand sorted into like-colored groups before washing. While this method often provides satisfactory results, it is time-consuming, inconvenient, and prone to oversights. A single oversight when sorting laundry can ruin a whole wash load of lighter colored articles and/or garments.
Several methods have been developed to address this problem of unwanted dye transfer, though none have solved the problem satisfactorily. Methods designed to increase the affinity of fabrics for dyes have not been able to resolve the problem of the fabric releasing the dyes in the washing solution. Another approach has been to bleach the dyes that are released into the washing solution before they have a chance to transfer to other articles and/or garments (U.S. Pat. Nos. 5,451,337, 5,474,576). The use of bleaching agents has the undesirable effect of bleaching not only the fugitive dyes, but also bleaching the dyes still attached to the articles and/or garments, resulting in fading or color change of the dyed articles and/or garments. The oxidizing agents can also interfere with laundry detergent components, making the detergents less effective.
Polymers have been used as dye transfer inhibitors (U.S. Pat. Nos. 5,698,476, 5,534,182, 5,478,489, 4,065,257) and as dye absorbers (U.S. Pat. Nos. 5,698,476, 3,816,321, 3,694,364, EP Pat. Appl. 0 341 205), again with unsatisfactory results. Polymers chosen as dye transfer inhibitors thus far have been cationic, to facilitate interaction with dyes which are known to those skilled in the art to be anionic. Cationic polymers have been used as laundry additives in both soluble and insoluble forms. The cationic polymers do bind with the anionic dyes, but they are non-selective and bind to other anionic compounds in the wash solution, such as anionic surfactants which are present at much higher concentrations than fugitive dyes, decreasing the efficiency of the dye inhibitor and the detergent's cleaning power. They also tend to bind the optical brighteners, another anionic component of laundry detergents. Binding the optical brighteners makes the laundered clothes appear less bright and clean and the consumer perceives the detergent as being less effective. Furthermore, and perhaps most significant, the soluble cationic polymers tend to bind to articles of clothing in the wash solution, then act as dye absorbers, absorbing and then permanently fixing the fugitive dyes to the articles and/or garments.
Recently, the above methods have been combined to try to circumvent problems inherent in the individual methods, again with only limited success. One method discloses the combination of a dye transfer inhibiting water-soluble cationic polymer, which absorbs fugitive dyes, and an oxidizing agent (U.S. Pat. No. 5,478,489). The problem still remaining is that some cationic polymer is attracted to articles and/or garments, adsorbs to the articles and/or garments and then absorbs and fixes unwanted fugitive dyes to those articles and/or garments. Other recent inventions have used cationic polymers bound to substrates to take up fugitive dyes. By incorporating the cationic polymers into a substrate, the binding of these polymers to the articles and/or garments and subsequent transfer of dye to the garment is intended to be eliminated. However, the cationic polymers are never completely insoluble, so the problem persists.
U.S. Pat. No. 5,698,476 discloses a system which uses a cationic polymer dye absorber bound to a substrate in combination with a soluble dye transfer inhibitor. The expectation was that since both the cationic dye absorber and the dye transfer inhibitor capture some portion of the fugitive dye the adsorption of fugitive dyes onto other articles and/or garments would be eliminated. Unfortunately, this method, too, has been found unsatisfactory. Using this dual method the dyes are scavenged from the laundering solution, but again, the cationic polymers cannot be made completely insoluble; they are, in fact, up to 20% soluble. The result is that there is always some soluble cationic material that then adsorbs to articles and/or garments, absorbing and fixing fugitive dyes to those articles and/or garments.
Accordingly, the need remains for an laundry aid which can bind fugitive dyes and effectively keep the bound dyes from redepositing onto other articles and/or garments; provide a signal for the consumer to know that the fugitive dyes have been bound; and not interfere with detergents, surfactants, or optical brighteners, change the color of dyed fabrics, or increase the release of dyes from fabrics.
SUMMARY OF THE INVENTION
The present invention solves the aforementioned problems by providing a laundry additive article that effectively and selectively absorbs extraneous dyes in a wash solution and prevents redeposition onto other articles and/or garments. The invention incorporates an insoluble dye-selective absorber, and optionally, a dye transfer inhibitor. The article is simply added to a washing machine with the articles and/or garments and allowed to circulate freely during the wash. It selectively removes extraneous dyes in solution without interfering with the cleaning and brightening power of the detergent. The article can also safely be placed in a clothes dryer with the articles and/or garments.
The dye absorber is a substantially insoluble cross-linked polymeric amine, selected from existing polymers, polymeric amines formed by copolymerization, polymeric amines formed by cross-linking soluble polyamines, or polymeric amines formed by reacting poly amines with cross-linking agents. It can be grafted onto the substrate by any suitable grafting technique, including but not limited to chemical, thermal, and ultraviolet grafting techniques. When dyes are bound by the dye absorber, a color change may signal to the consumer that extraneous dyes have been scavenged from the wash solution and redeposition onto articles and/or garments has been prevented.
It is therefore an object of the invention to provide a laundry additive article that effectively and selectively absorbs extraneous dyes in a wash solution and prevents redeposition of those dyes on other articles and/or garments in the same wash solution. It is a further object to achieve absorption of extraneous dyes in a wash solution without interfering with the detergent's cleaning and brightening power.
DETAILED DESCRIPTION OF THE INVENTION
The laundry additive article of the present invention comprises a substantially insoluble polyamine dye absorber fixably adhered to an insoluble substrate. Optionally, the article may additionally contain a dye transfer inhibitor, a visual signal designed to indicate that the article has removed extraneous dyes from the wash solution, as well as a variety of other adjuncts.
By substantially insoluble it is meant that the dye absorber has a solubility in water that is less than or equal to about 20 percent by weight. By extraneous dyes or fugitive dyes it is meant the dyes that bleed from fabrics in an aqueous wash solution. When referring to fabric, it is meant to encompass any clothes, towels, linens, and any other articles
Aouad Yousef Georges
Panandiker Rajan Keshav
Randall Sherri Lynn
Wertz William Conrad
Corstanje Brahm J.
Del Cotto Gregory R.
Dressman Marianne
Glazer Julia A.
The Procter & Gamble & Company
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