Bleaching and dyeing; fluid treatment and chemical modification – Pattern effect dyeing – process – compositions – or products – Cross dyeing
Reexamination Certificate
2000-07-11
2002-12-31
Einsmann, Margaret (Department: 1751)
Bleaching and dyeing; fluid treatment and chemical modification
Pattern effect dyeing, process, compositions, or products
Cross dyeing
C008S478000, C008S597000, C008S598000, C008S599000, C008S602000, C008S604000, C008S196000, C008S115660
Reexamination Certificate
active
06500215
ABSTRACT:
FIELD OF THE INVENTION
In general, the present invention is directed to a process for dyeing textile fibers, yarns and fabrics, especially cotton, cellulosic, wool, nylon and polyester products. More particularly, the present invention is directed to a process for increasing the absorptivity of textile materials in order to increase their receptiveness to dyes.
BACKGROUND OF THE INVENTION
In the past, various and sundry methods and processes have been developed in order to improve the dyeability of cotton and other fibers. Further, many attempts have also been made to develop a process for dyeing fibers where the amount of dye used in the process is minimized. Decreasing the amount of dye used to dye fibers can lead to significant cost savings especially in view of the ever increasing prices of dyes and the problem of handling and disposing of spent dyebaths.
For instance, many attempts in the past to reduce the amount of dye used in a dying process for cotton fabrics or otherwise to improve the process have involved placing various chemical agents into the dye bath. Such chemical agents have included wetting agents and salts that primarily assist or facilitate exhaustion of the dyes to the fabrics. These agents also assist in leveling or uniformly applying the dye to the fabric.
Another problem that those skilled in the art have attempted to solve is the ability to dye “dead cotton”. Dead cotton refers to immature cotton fibers contained within cotton fabrics. Dead cotton does not readily accept dyes. Consequently, cotton containing dead cotton has sold for substantial discounts over higher quality cotton and can not be employed to manufacture fine garments.
In view of the above, various needs currently exist for methods that will improve cotton, cellulosics, wool, nylon and polyester dyeing processes. In particular, a need exists for a process for dyeing fabrics in which less amounts of dye are used during the process or deeper shades are required that are achieved by increasing dye absorption above the normal level. A need also exists for a process for dyeing cotton fabrics that contain dead cotton so that the dead cotton becomes dyed to the same extent as the other cotton fibers.
SUMMARY OF THE INVENTION
The present invention recognizes and addresses the foregoing disadvantages, and drawbacks of prior art constructions.
Accordingly, it is an object of the present invention to provide an improved process for dyeing cellulosic materials, such as cotton, wool, nylon and polyester fibers.
Another object of the present invention is to provide a process for treating materials so that they will have a greater affinity for dyes.
Still another object of the present invention is to provide a process for chemically treating cotton fibers to make the cotton fibers appear more cationic so that the fibers will be more receptive to anionic dyes.
These and other objects of the present invention are achieved by providing a process for making textile fibers more receptive to dyes. The process includes the steps of contacting the fibers with selected amine oxides. It is believed that the amine oxide reacts with cellulosic fibers, making the fibers appear as if they are more cationic. Once contacted with an amine oxide, the cellulosic fibers are heated to a specific temperature for optimum yield and at least partially dried. The said fibers are then dyed with an anionic dye. It has been discovered that by treating the said fibers with an amine oxide makes the fiber absorb anionic dyes quicker, and dye to a deeper shade versus the untreated fiber.
Materials that can be treated in accordance with the present invention include cotton, and other cellulosic materials. Wool, nylon and polyester also respond positively albeit by what we think is an alternative mechanism such as the amine oxide functions like a carrier plasticising and swelling the fibers. The materials treated can be fibers, yarns, or fabrics. The amine oxides used in the process of the present invention can vary. For most applications, the amine oxides can be represented by the following formula:
wherein
R
1
, R
2
and R
3
are C
1
to C
8
linear or branched alkane radicals or hydroxyalkyl groups.
R
1
and R
2
can be linked to form five and six membered heterocyclic rings.
R
1
, R
2
and R
3
can be the same or different.
Examples of amine oxides includes: N-methylmorpholine oxide, N-(2-hydroxyethyl)morpholine oxide, N,N-dimethylethanolamine oxide, N-ethylmorpholine oxide, N,N-dimethyloctylamine oxide, and mixtures thereof. In one embodiment of the present invention, the amine oxide can be a trialkylamine oxide, such as trimethylamine oxide. Most amine oxides besides making cellulosic fibers more cationic have a tendency to dissolve the fibers causing the fibers to bond together, creating a stiffer product. It has been discovered, however, that trimethylamine oxide does not cause the cellulosic fibers to dissolve resulting in an even softer hand than the untreated fiber.
In order to apply the amine oxide to the textile material, the material can be dipped into an aqueous solution or dispersion containing the amine oxide. For instance, the aqueous solution can contain an amine oxide in an amount from about 20% to about 50% by weight. The aqueous mixture can be applied to the textile material so that the add on causes the weight of the material to increase up to 120%, and particularly from about 50% to about 120%.
In an alternative embodiment of the present invention, an amine oxide composition can also be printed onto the textile material. For instance, the amine oxide can be combined with a thickener for forming a printing paste. The printing paste is applied to a fabric containing textile fibers according to a particular design. Once the fabric is dyed, the design will then appear on the fabric as a more deeply dyed area.
Once the amine oxide is applied to the textile material, the textile material is then heated, such as to a temperature of from about 140° F. to about 300° F., and particularly from about 200° F. to about 250° F. After being heated, if desired, the textile materials can then be rinsed.
In order to dye the textile materials after treatment with the amine oxide, the materials can be dipped into a dye bath containing an anionic dye. In general, any suitable anionic dye may be used. In one embodiment, the dye bath can contain a salting agent, such a metal salt, that facilitates exhaustion of the dye to the textile material. Such salting agents have been used in the past. However, it has been discovered by the present inventors that less salting agent is required to achieve the required shade if the textile materials have been previously contacted with an amine oxide. For instance, a salting agent can be present in the bath at a concentration of less than about 120 grams/liter, and particularly from about 5 grams/liter to about 120 grams/liter.
Other objects, features and aspects of the present invention are discussed in greater detail below.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
The present invention is generally directed to a process for treating textile fibers namely cotton, cellulosics, wool, nylon and polyester fibers, in order to make them more receptive to dyes. More particularly, it is believed in the case of cotton and cellulosics, the process of the present invention increases the cationic charge of the cellulosic materials making them have a greater affinity for anionic dyes. In this manner, less dye and salt is required when dyeing the materials. The process of the present invention generally includes the step of contacting the cellulosic materials with an amine oxide. The amine oxide we believe chemically reacts with the cellulosic material causing the cellulosic material to have an increased cationic charge.
In the past, amine oxides have been used in order to dissolve cellulose from wood and other sources and then form cotton-like fibers from the dope after extrusion into water, which is a solvent for the amine oxide but not for the cellulose.
As opposed to the above prior art, in one embodim
Bella Otto
Hosie Lynn
Login Robert B.
Wicker, Jr. Calvin McIntosh
Dority & Manning
Einsmann Margaret
Sybron Chemicals Inc.
LandOfFree
Utility of selected amine oxides in textile technology does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Utility of selected amine oxides in textile technology, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Utility of selected amine oxides in textile technology will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2983348