Sulfur dye protection systems and compositions and methods employing same

Abstract

The present invention relates to sulfur dye protection systems and compositions and methods employing same, as well as processes for making sulfur dyes, especially bleach stable sulfur dyes, processes for dying textiles with sulfur dyes and textiles dyed by such processes. More particularly, the present invention relates to modifying existing dyes and / or making newly formed sulfur dyes. Even more particularly, the present invention relates to materials that can chemically or physically interact with sulfur dyes to protect the sulfur dyes from oxidation by oxidizing agents, such as bleaching agents.

Description

CROSS REFERENCE TO RELATED APPLICATIONS [0001] This application claims priority under 37 U.S.C. § 119(e) to U. S. Provisional Application Ser. No. 60 / 198,701, filed Apr. 20, 2000 (Attorney Docket No.8053P) and U.S. Provisional Application Ser. No. 60 / 198,728, filed Apr. 20, 2000 (Attorney Docket No. 8054P).FIELD OF THE INVENTION [0002] The present invention relates to sulfur dye protection systems and compositions and methods employing same, as well as processes for making sulfur dyes, especially bleach stable sulfur dyes, processes for dyeing textiles with sulfur dyes and textiles dyed by such processes. More particularly, the present invention relates to modifying existing dyes and / or making newly formed sulfur dyes. Even more particularly, the present invention relates to materials that can interact (i.e., chemically or physically) with sulfur dyes to protect the sulfur dyes from oxidation by oxidizing agents, such as bleaching agents. BACKGROUND OF THE INVENTION [0003] Dyeing of...

AI Technical Summary

Benefits of technology

[0008] The present invention fulfills the needs identified above by providing sulfur dye protection systems that protect sulfur dyes, especially sulfur dyes on textiles and / or other fibrous materials, from oxidation by oxidizing agents, such as bleaching agents, compositions comprising such systems, and methods for using such systems; processes for making sulfur dyes, especially bleach stable sulfur dyes, processes for using such sulfur dyes to dye textiles and textiles dyed by such sulfur dyes. More particularly, the present invention provides a process for modifying existing dyes and / or making newly formed sulfur dyes such that the sulfur dyes exhibit increased bleach stability as compared to unmodified sulfur dyes and / or sulfur dyes that are not initially formed with the increased bleach stability properties “built-into” the sulfur dye at the time of forming the sulfur dye.

[0014] In even yet another aspect of the present invention, a process for making sulfur dyes, especially bleach stable sulfur dyes, comprises the step of: modifying a sulfur dye in need of modification such that the modified sulfur dye exhibits increased bleach stability as compared to the unmodified sulfur dye is provided.

[0017] b. reacting the sulfur dye with a stabilizing agent such that the sulfur dye exhibits increased bleach stability as compared to the sulfur dye in the absence of such a stabilizing agent is provided.

Problems solved by technology

However, in the recent years, the cost advantages of sulfur dyes has diminished such that there is no longer a large competitive edge for using sulfur dyes as compared to other classes of dyes.

As a result of this diminishing of the cost advantages of sulfur dyes, the disadvantages of sulfur dyes has become more of a factor in the selection of dyes for such uses.

One of the most noticeable disadvantages associated with sulfur dyes, especially black and brown sulfur dyes, is the susceptibility of sulfur dyes to become over-oxidized by bleaching agents, such as chlorine bleaches, oxygen bleaching agents, activated oxygen bleaches and UV radiation, such as from the sun, and the like.

As a result of the over-oxidizing of the sulfur dye, the sulfur dyed textile and / or other fibrous material begins to exhibit dye damage leading to color change.

Another problem associated with conventional sulfur dyes and textiles dyed by the conventional sulfur dyes is the problem of aging or tendering.

Aging of the textiles results in large part from the fiber damage caused by sulfuric acid produced during storage and transportation of the conventional sulfur dyed textiles.

Yet another problem associated with conventional sulfur dyes and textiles dyes by the conventional sulfur dyes is the problem of the poor wash fastness.

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