Bleaching and dyeing; fluid treatment and chemical modification – Chemical modification of textiles or fibers or products thereof
Reexamination Certificate
2001-08-08
2004-09-28
Boyer, Charles (Department: 1751)
Bleaching and dyeing; fluid treatment and chemical modification
Chemical modification of textiles or fibers or products thereof
C008S137000, C510S320000, C510S321000, C510S392000, C510S393000
Reexamination Certificate
active
06797010
ABSTRACT:
FIELD OF INVENTION
The present invention relates to compositions and methods for reducing or preventing the backstaining of dye on textile materials, especially indigo on denim and specially the backstaining of pocket parts of denim during the stonewashing of denim fabric.
BACKGROUND OF THE INVENTION
By stonewashing of denim the usually blue-dyed denim is given a faded or worn appearance with the characteristic white and blue contrast. Stonewashing the denim material is typically carried out in the presence of purmice stone or cellulase or a combination thereof and results in the removal of dye to give areas of lighter color. The use of cellulase instead of purmice stone has the advantages that it is more environmental friendly, more economical and prevents that the denim is damage because of the rough treatment with the purmice stones. However, the use of cellulase is not without disadvantages.
The dye removed from the denim material after the treatment with cellulase or by a conventional washing process may cause “backstaining” or “redeposition” onto the denim material, e.g. re-coloration of the blue threads and blue coloration of the white threads, resulting in a less contrast between the blue and white threads. In order to remove the dye the denim manufactures are using huge amount of surfactants to make parts white again at a soaping process with heavy washing condition. The heavy washing condition causes color change or color-fading problems for finished denim products. Also additional water has to be used in the subsequent soaping process.
The problem of redeposition or backstaining of dye during stonewashing has also been addressed by adding anti-redeposition chemicals, such as surfactants or other agents into the cellulase wash. Also the use of different cellulases with less specific activity on denim has been tried. WO-A-9407983 describes the use of a cellulase to inhibit the backstaining of denim. WO-A-9429426 and WO-A-9325655 describes backstain inhibition by treatment with a redoposition cellulase composition and added protease as an improvement over the use of redeposition cellulase alone.
Although, these methods aim to solve the problem with the backstaining or redeposition of dye onto the denim material, they may still be improved. In particular, the backstaining or redeposition of dye onto the pocket parts of the denim material poses a problem.
SUMMARY OF THE INVENTION
We have developed a process for treating fabric, especially indigo-dyed denim, with a composition comprising a lipolytic enzyme.
This treatment reduces the risk of back-staining (redeposition of dye onto textile) even when less water is used. The enzymatic treatment of released dyestuff will decrease process time as well as the amount of energy and water needed to achieve a satisfactory quality of the textile, and the color of the wastewater is reduced.
The method of the invention can result in a decreased number of washes, thereby increasing the productivity and decreasing the consumption of water and chemicals, including surfactants.
Accordingly, the present invention provides a method for reducing the backstaining of fabric or textile, comprising contacting the fabric or textile with a composition comprising an effective amount of a lipolytic enzyme (EC 3.1.1).
In another aspect, the present invention relates to a stonewashing composition comprising a lipolytic enzyme and a cellulase.
In a third aspect, the invention relates to the use of the composition for reducing backstaining of fabric or textile.
DETAILED DISCLOSURE OF THE INVENTION
Denim that is stonewashed with the addition of an effective amount of added lipolytic enzyme during cellulase treatment shows a reduction in the level of backstaining, especially the backstaining of pocket parts.
The method of the present invention comprises contacting the denim to be enzymatically stonewashed with a composition comprising the lipolytic enzyme in a amount sufficient to reduce backstaining and thus, to decrease the blue-coloring of e.g. the pocket parts.
The amount of added lipolytic enzyme depends upon others on the purity and amount of cellulase used in the stonewashing process, the contact time, the amount of dye removed during stonewashing, the activity of the cellulase, the pH and temperature of the stonewashing process, the formulation of the product and the like.
The composition to be added may further comprise various adjuvants as known to the skilled person, e.g. surfactants. Other materials can also be used with the composition as desired, including stones, fillers, solvents, buffers, pH control agents, enzyme activators, builders, enzyme stabilizers, other anti-deposition agent and the like. The composition may be formulated at a solid product, granular product or as a liquid product.
The lipolytic enzyme may be added to the composition containing the cellulase for use in stonewashing process or added directly to the stonewashing bath or to a subsequent rinse treatment. The lipolytic enzyme may also be added to a composition for washing purposes thereby reducing or inhibiting the backstaining of removed dye during the washing process.
Fabrics
The process of the present invention applies to fabrics in general. In the context of this invention fabrics include fabrics or textiles prepared from man-made fibers, e.g. polyester, nylon, etc., as well as cellulosic fabrics or textiles.
The term “cellulosic fabric/textile” indicates any type of fabric, in particular woven fabric, prepared from a cellulose-containing material, containing cellulose or cellulose derivatives, e.g. from wood pulp, and cotton. The main part of the cellulose or cellulose derivatives present on the fabric is normally size with which the yarns, normally warp yarns, have been coated prior to weaving. In the present context, the term “fabric” is also intended to include garments and other types of processed fabrics. Examples of cellulosic fabric is cotton, viscose (rayon); lyocell; all blends of viscose, cotton or lyocell with other fibers such as polyester; viscose/cotton blends, lyocell/cotton blends, viscose/wool blends, lyocell/wool blends, cotton/wool blends; flax (linen), ramie and other fabrics based on cellulose fibers, including all blends of cellulosic fibers with other fibers such as wool, polyamide, acrylic and polyester fibers, e.g. viscose/cotton/polyester blends, wool/cotton/polyester blends, flax/cotton blends etc. The fabric may also include man-made fibers alone such as polyester fibers.
The process of the invention is preferably applied to cellulose-containing fabrics, such as cotton, viscose, rayon, ramie, linen or mixtures thereof, or mixtures of any of these fibers with synthetic fibers. In particular, the fabric may be denim. The fabric may be dyed with vat dyes such as indigo, direct dyes such as Direct Red 185, sulfur dyes such as Sulfur Green 6, or reactive dyes fixed to a binder on the fabric surface. In a preferred embodiment of the present process, the fabric is indigo-dyed denim, including clothing items manufactured therefrom.
In a most preferred embodiment, the fabric subjected to the process of the invention is made of hydrophobic fibres such as polyamide fibres, e.g. nylon, acrylic fibres, vinylon and polyester fibres. As mention above the fabric may be made of mixtures of different fibres. Especially contemplated is polyester or polyester/cotton mixtures, which are the material used for pocket parts of garments, in particular dyed cotton garments or denim jeans.
Enzyme
The enzymatic process of the invention may be accomplished using any carboxylic ester hydrolases, in particular lipolytic enzyme and/or any biopolyester hydrolytic enzyme. Such enzymes are well known and defined in the literature, cf. e.g. Borgström B and Brockman H L, (Eds.);
Lipases
; Elsevier Science Publishers B. V., 1984, and Kolattukudy P E;
The Biochemistry of Plants
, Academic Press Inc., 1980, 4 624-631.
In the context of this invention lipolytic enzymes are classified in E.C. 3.1.1 and include true lipases, esterases, phospholipases, and lyso-phospholipases
Daimon Kosaku
Uyama Naoto
Boyer Charles
Hamlin Derrick G.
Lambiris Elias J.
Novozymes A/S
LandOfFree
Redeposition or backstain inhibition during stonewashing... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Redeposition or backstain inhibition during stonewashing..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Redeposition or backstain inhibition during stonewashing... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3209821