Bleaching and dyeing; fluid treatment and chemical modification – Organic additive for dye composition – dye composition... – Oxygen-containing hetero ring
Reexamination Certificate
1999-12-21
2001-03-13
Einsmann, Margaret (Department: 1751)
Bleaching and dyeing; fluid treatment and chemical modification
Organic additive for dye composition, dye composition...
Oxygen-containing hetero ring
C008S582000, C008S611000, C008S673000, C008S680000, C008S685000, C008S920000, C008S924000, C008S529000
Reexamination Certificate
active
06200355
ABSTRACT:
FIELD OF THE INVENTION
The present invention relates generally to dyeing of fiber-containing textile articles. In preferred forms, the present invention relates more specifically to dyeing of textile articles which contain melamine fibers.
BACKGROUND AND SUMMARY OF THE INVENTION
Fibers made from melamine resin are dyeable under conventional disperse dyeing conditions without significantly degrading the fiber properties. In this regard, the melamine fiber content of the melamine fiber-containing articles is not significantly reduced when they are dyed in pH ranges from 4 to 10, unless very high temperatures or prolonged dyeing times are employed.
However, under conventional disperse dyeing conditions it is very difficult to achieve deep shades on articles containing melamine fibers, even with the inclusion of producer-colored companion fibers such as pigmented meta- or para-aramids. Disperse-dyed blend fabrics also show inferior wash and/or light fastness. While deep shades can be achieved using acid dyes at a pH below 4.0, under such conditions, there can be loss of an unacceptable amount of melamine fibers due to acid hydrolysis, particularly at elevated temperatures. Deep shades can also be achieved using acid dyes for the melamine fibers and basic dyes for the aramid fibers. These fabrics formed of a blend of melamine and aramid fibers also show poor crock and wash fastness in deep shades.
Recently, it has been proposed to dye condensation products obtainable by condensation of a mixture comprised of unsubstituted melamine, substituted melamine and hydroxyphenyl compounds with formaldehyde or formaldehyde donor compounds in the form of fibers, yarns threads, wovens, knits or nonwovens, in an aqueous liquor with one or more dyes of the class of azo, anthraquinone, coumarin, methine, azamethine, quinophthalone or nitro dyes. (See U.S. Pat. No. 5,624,466 to Schindler et al, the entire content of which being expressly incorporated hereinto by reference.) Also, it has been proposed to dye articles composed of a blend of melamine and cellulose fibers by the use of dyes which preferentially dye the cellulose fibers and not the melamine fibers so that when such a fiber blend is incorporated into a fabric, a chambray appearance results. (See U.S. Pat. No. 5,830,574 to Gadoury, the entire content of which is expressly incorporated hereinto by reference.)
According to the present invention, articles formed of melamine fibers can be dyed to deep shades with minimal (if any) loss of the melamine fibers due to hydrolysis. More specifically, according to the present invention, melamine fiber-containing articles are dyed to deep shades using a dye bath containing an acid dye in combination with an acid donor. During the dyeing process, the dye bath is slowly lowered to provide maximum exhaustion of the dyes at the higher temperatures employed, while limiting the amount of time the melamine fibers are exposed to the lower pH and higher temperature conditions.
These aspects, and others, will become more clear from the following more detailed description of the preferred exemplary embodiments thereof which follow.
DETAILED DESCRIPTION OF THE INVENTION
The term “melamine” as used herein and in the accompanying claims is meant to refer to the resulting condensation reaction product of a mixture comprised of (i) from 90 to 90.99 mol % of from 30 to 99 mol % melamine and from 1 to 70 mol % of a substituted melamine (e.g., most preferably melamine substituted with hydroxyalkyl groups), and from 0.1 to 10 mol % of a phenol, with formaldehyde or formaldehyde donor compounds in a molar ratio of melamines to formaldehyde within the range from 1:1.15 to 1:4.5. See in this regard, U.S. Pat. Nos. 4,996,289, 5,084,488 and 5,322,915, the entire content of each being expressly incorporated hereinto by reference. The preferred melamine fibers that are employed in the practice of the present invention are BASOFIL® melamine fibers commercially available from BASF Corporation, Enka, N.C.
The textile articles may be formed of only melamine fibers or may be formed of a blend of melamine fibers with at least one other synthetic or natural fiber. Most preferably, the textile articles include blends of melamine fibers with aramid fibers, such as aramid fibers which are the polycondensation reaction produces of iso-terephthalic acid with a meta- or para-phenylenediamine. Such m-aramid and p-aramid fibers are known and commercially available from DuPont as NOMEXO® or KEVLAR® aramid fibers. Blends of melamine fibers and aramid fibers are especially well suited for use in the formation of garments employed in high-temperature environments. Blends of about 30%/70% to about 50%/50%, and most preferably about 40%/60%, melamine fiber to aramid fiber are especially well suited for being dyed in accordance with the present invention.
As noted previously, the present invention is most preferably employed for the purpose of dyeing textile articles. As used herein and in the accompanying claims, the term “textile article” is meant to refer to articles formed of fibers. The textile articles employed in the practice of this invention may thus be dyed in the form of fibers, yarns, slivers, tops and tows, as well as in the form of woven, non-woven or knit fabrics formed of the same. The term “fiber” includes fibers of extreme or indefinite length (filaments) and fibers of short length (staple). The term “yarn” refers to a continuous strand or bundle of fibers. The term “sliver” means a continuous strand of loosely assembled untwisted fibers. The term “top” means a sliver which has been combed to straighten the fibers and remove short fiber. The term “tow” means a large strand of continuous fiber filaments without definite twist collected in a loose, rope-like form held together by crimp.
The textile articles are treated in a dye bath which necessarily contains a dyestuff and an acid donor. As used herein and in the accompanying claims, the term “dyestuff” means any substance which adds color to fibers by absorption into the fiber. Most preferably the dyestuffs employed in the practice of the present invention are non-complexed acid or 1:2 metal complexed acid dyes prepared with chrome, iron, cobalt, copper, aluminum, or any transition metal. Direct dyestuffs typically employed to dye textile articles may also be employed, however.
Specific exemplary acid dyes include the following dyes commercially available by their respective Color Index (C.I.) dyes: Acid Yellow 40; Acid Yellow 79; Acid Yellow 159; Acid Yellow 184; Acid Yellow 204; Acid Yellow 241; Acid Orange 116; Acid Orange 142; Acid Orange 162; Acid Green 104; Acid Green 108; Acid Blue 113; Acid Blue 185; Acid Blue 193; Acid Red 50; Acid Red 52; Acid Red 138; Acid Red 299; Acid Red 362; Acid Violet 90; Acid Black 131:1; Acid Black 132:1; Acid Black 194; Acid Black 52; and Acid Black 172. In addition, the following acid dyes may be used which are available commercially without C.I. numbers: Lanaset Blue 2R; Lanaset Navy R; Lanaset Red G; Lanaset Red 2GA; Lanaset Violet B; Lanaset Brown B; Burconyl Brick Red AF-3B; Burconyl Rubine AF-GR; Burconyl Orange AF-3R; Burconyl Green AF-B; Burconyl Brilliant Blue AF-R; Burconyl Royal Blue AF-R; Burconyl Brilliant Yellow AF-4G; Erionyl Red A-3G; Erionyl Blue RL 200; and Nylanthrene Brilliant Blue 2RFF.
The acid donor that is employed in the practice of the present invention include those compounds which hydrolyze to alcohol or acid under the conditions of processing.
Preferred acid donor compounds that may be employed in the practice of the present invention include ethyl lactate and diethyl tartrate, &ggr;-butyrolactones, ethylene glycol monoformates, ethylene glycol diformates. These acid donor compounds may be used alone or in combinations of two or more the same. Exemplary acid donors which are commercially available include Sandacid® VS (from Clariant Corporation, Charlotte, N.C.), Phycone® (from American Emulsion, Dalton, Ga), Burco® Acid Donor (from Burlington Chemical, Burlington, N.C.), Buffer ADB (from Clariant Corporation, Cha
BASF Corporation
Einsmann Margaret
Nixon & Vanderhye P.C.
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