Bleaching and dyeing; fluid treatment and chemical modification – Bleaching – Wave energy
Reexamination Certificate
1997-06-06
2001-07-10
Diamond, Alan (Department: 1753)
Bleaching and dyeing; fluid treatment and chemical modification
Bleaching
Wave energy
C008S111000, C008S128100, C008S128300, C008S127500, C008S115520, C435S263000
Reexamination Certificate
active
06258129
ABSTRACT:
FIELD OF THE INVENTION
The present invention relates to a method of providing wool or animal hair with improved properties, e.g. reduced felting, increased whiteness, reduced pilling tendency, improved softness and improved dyeing characteristics, by enzymatic treatment. More specifically, the method comprises subjecting the wool or animal hair material to a plasma treatment and a treatment with a proteolytic enzyme, i.e. a protease.
BACKGROUND OF THE INVENTION
For many years, the wool industry has tried to develop methods to reduce felting of wool which do not result in release of damaging substances to the environment. Recent developments have pointed towards low-temperature plasma treatment or the Delhey process as possible solutions to this problem.
Thus, it is known to treat wool fibre material with electrical gas discharges (socalled plasma), i.e. in a dry process. Plasma treatment provides a changed surface finish of the wool fibre which reduces the tendency to felt, improves the printability and accelerates the dyeability of the wool. The use of plasma treatment in textile finishing, especially in wool finishing, is highly advantageous, since the process potentially is an environmentally acceptable alternative to the conventional chlorination finishing processes, cf. Byrne, K. M. et al.:
Corona discharge treatment of wool—commercial implications
in DWI Report, (1992), vol. 109, p. 589-599, (Aachener Textiltagung 1991).
In textile finishing, the applicable plasma treatment is a low-temperature or unbalanced plasma treatment (“cold plasma” treatment), in particular the corona discharge treatment and glow discharge treatment, cf. Thomas, H. et al.:
Environmentally friendly finishing processes for wool by pretreatment with electrical discharges in gas
(
plasma
)
in ITB
vol. 2, 1993. The corona discharge treatment is carried out under atmospheric conditions and is a weak-current discharge providing an oxidation, and thereby a polarization, of the fibre surface. The glow discharge treatment is carried out under reduced pressure, i.e. producing electrons of higher energy than is possible in the corona discharge treatment, and may modify the fibre surface more intensively.
Accordingly, the plasma treatment provides to the wool or animal hair material reduced felting tendency and improved dying characteristics without the use of damaging chemicals and without wastewater (dry process). Also, the treatment provides improved shrink-proof properties to the treated material which, however, at present cannot meet the demands of the end-users. Furthermore, the treatment may reduce the soft handle of the wool or animal hair material.
Published Japanese Patent Application Tokkai Hei 4-327274 discloses a method for a shrink-proofing treatment of e.g. wool fibers by subjecting the fibers to a low-temperature plasma treatment followed by treatment with a shrink-proofing resin, e.g. block-urethane resin, polyamide epochlorohydrin resin, glyoxalic resin, ethylene-urea resin or acrylate resin, and then a weight reducing treatment with a proteolytic enzyme for obtaining a softening effect.
The Delhey process is described in DE-A-43 32 692 and in J. Delhey: PhD Thesis, RWTH Aachen (1994). In this process the wool is treated in an aqueous solution of hydrogen peroxide in the presence of soluble wolframate, optionally followed by treatment in a solution or dispersion of synthetic polymers, for improving the anti-felting properties of the wool, However, neither does this treatment meet the demands of the end-users.
It is the object of the present invention to provide a method for treating wool or animal hair material to obtain wool or animal hair material with reduced felting tendency, improved softness, increased whiteness, reduced pilling tendency and/or improved dyeing characteristics, in an easy and a purely biological way without the use of environmentally damaging chemicals or resins.
SUMMARY OF THE INVENTION
Surprisingly, it has been found that certain properties of plasma-treated or Delhey-treated wool or animal hair may be improved by subjecting the plasma-treated or Delhey-treated wool or animal hair to a treatment with a proteolytic enzyme in an amount effective for providing the desired effect. Depending on the special characteristics of the actual wool subjected to the treatment according to the present invention, the improved properties can be reduction of felting tendency, higher whiteness, reduction of pilling tendency, improvement of softness, or improvement of dyeing characteristics.
Thus, according to the present invention it is possible to obtain good and satisfactory shrink-proofing properties without the use of a shrink-proofing polymer resin by treating the wool or animal hair material with a proteolytic enzyme either prior to or after a plasma treatment, preferably a low-temperature plasma treatment, or prior to or after a Delhey-treatment. Further to the improved shrink-proofing or anti-felting properties, the enzyme treatment can also improve the dyeing characteristics of the wool or animal hair material, provide a convenient bleaching (improved whiteness) and a reduced tendency of pilling, and provide the regain of the soft handle of the treated material.
Accordingly, the present invention relates to a method for producing wool or animal hair material with improved properties comprising the steps of
a. pretreating wool, wool fibres or animal hair material in a process selected from the group consisting of plasma treatment processes and the Delhey process, and
b. subjecting the pretreated wool or animal hair material to a treatment with a proteolytic enzyme (a protease) in an amount effective for improving the properties.
It is contemplated that the treatment with a proteolytic enzyme can take place prior to the plasma treatment or after the plasma treatment, either in a separate step or e.g. in combination with the scouring or the dyeing of the wool or animal hair material. Further, a surfactant or a softener can be present in the enzyme treatment step, or a separate step wherein the wool or animal hair material is subjected to a softening treatment can be applied.
By using the method of the present invention, it is possible to eliminate the use of environmentally damaging chemicals, since the present method is only using environmetally-friendly biological substances, and obtain improved properties of the treated wool or animal hair material which are highly desired by the end-user.
In another aspect, the present invention further relates to wool or animal hair material which has been treated according to the method of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
In the present context, the terms “shrink-proof” and “anti-felting” are intended to mean a highly reduced tendency to shrinkage or felting after soaking, washing or rinsing the material in question as compared to the tendency of shrinking or felting of material which has not been subjected to a shrink-proof or anti-felting treatment. More specifically, the present invention provides a method for producing wool or animal hair material having improved shrink-proof or anti-felting properties.
Preferably, the shrink-proof improvement of plasma and enzyme treated wool or animal hair material corresponds to an area shrinkage which is less than 10%, more preferably less that 8%, more preferably less that 7%, more preferably less that 5%, even more preferably less than 3%, especially less that 2%, after 2 cycles of ISO 5A; or to an area shrinkage of less than 15%, more preferably less than 10%, more preferably less that 8%, even more preferably less than 6%, especially less that 5%, after 5 cycles of ISO 5A; measured according to the IWS Test Method 31.
Preferably, the shrink-proof improvement of wool or animal hair material treated in the Delhey process followed by an enzymatic treatment corresponds to an area shrinkage which is less than 25%, more preferably less that 20%, more preferably less that 15%, more preferably less that 12%, more preferably less that 10%, more preferably less than 8%, e
Dybdal Lone
Heine Elisabeth
Hocker Hartwig
Diamond Alan
Garbell Esq. Jason I.
Lambins, Esq. Eliao J.
Novozymes A/S
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