US20060085926A1

US20060085926A1 - Process for dyeing a mixture of two or more different fibre types

Info

Publication number: US20060085926A1
Application number: US11/218,364
Authority: US
Inventors: Jorg Schlangen; Marina Crnoja-Cosic; Christian Baumgartinger
Original assignee: Lenzing AG
Current assignee: Lenzing AG
Priority date: 2003-03-13
Filing date: 2005-09-02
Publication date: 2006-04-27
Also published as: ATA4002003A; EP1601831A1; CN100346029C; TR200503591T1; TW200427896A; WO2004081279A1; CN1759217A; AT413825B

Abstract

The invention relates to a process for dyeing a mixture of two or more different fibre types with one or more dyes. The process according to the invention is characterized in that the mixture contains a portion of cationized cellulosic fibres. Furthermore, the invention relates to fibre blends obtainable by the process according to the invention.

Description

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a continuation of International Patent Application No. PCT/AT2004/000084 filed Mar. 11, 2004, designating the United States and published in the German language on Sep. 23, 2004 under International Patent Publication No. WO 2004/081279, which is based on Austrian Patent Application No. A 400/2003 filed Mar. 13, 2003, to each of which priority is claimed, and each of which is incorporated by reference in its entirety herein.

FEDERALLY FUNDED GRANT SUPPORT

Not applicable.

1. INTRODUCTION

The present invention relates to a process for dyeing a mixture of two or more different fibre types as well as fibre blends.

2. BACKGROUND OF THE INVENTION

Conventionally mixtures of fibres of different origins are used to produce textiles such as woven fabrics or knitted fabrics. Furthermore, it is known that by using differently dyed fibres or yarns it is possible to achieve colour effects in the textiles. However, it is laborious that the starting products for the production of the textile, i.e. the fibres or yarns, respectively, often have to be dyed with different dyes separately from each other so as to achieve the desired effect in the fabric. In particular when manufacturing a so-called denim fabric, the warp yarn must be warp-dyed in the exhaust process during the indigo dyeing process, i.e. it is not feasible to dye finished cloths. Such problems arise especially when using cellulosic fibres such as viscose fibres, Lyocell fibres but also cotton fibres. The object of the present invention is to provide a process for dyeing a mixture of two or more different fibre types with one or more dyes, by means of which process the disadvantages discussed above can be overcome.

3. SUMMARY OF THE INVENTION

The object of the present invention is to provide a process for dyeing a mixture of two or more different fibre types with one or more dyes, by means of which process those disadvantages can be overcome.

4. DETAILED DESCRIPTION OF THE INVENTION

It has been shown that, by using cationized cellulosic fibres, various problems associated with the production of textile products showing colour effects can be solved or new possibilities can be opened up, in particular:

- the attainment of differences in colour intensity (Differential Dyeing) between two fibre types (a cationized cellulosic fibre and another, especially cellulosic, fibre) with only one dye being used
- the attainment of mixed colours when dyeing with several dyes, whereby the different fibre types are each coloured differently or optionally not at all, respectively, with the dyes being used
- an acceleration of the dyeing process when dyeing mixtures of cationized cellulosic fibres and synthetic fibres such as polyester fibres or polyamide fibres.

Cationized cellulose fibres are known per se. Fibres which incorporate the cationic groups are particularly preferred for use in the process according to the invention. Such fibres are manufactured in that a cationizing agent which is stable in the respective manufacturing process is added to the spinning dope for producing the fibre or to a precursor of said spinning dope.
Furthermore it is known that cationized cellulose fibres exhibit particular colouring properties which differ from those of non-cationized cellulose fibres.
Cationized viscose fibres, i.e. fibres which were produced by the viscose process and which carry cationic groups, are particularly preferred for use in the process according to the invention.
The manufacture of cationized cellulosic fibres is known per se and is described, for instance, in JP-A 61-258801, JP-A 52-26561, JP-A 2-274738, EP-A 0 683 251, EP-A 0 690 166 or WO 96126220.
In a prefesred embodiment of the process according to the invention, the mixture contains a portion of non-cationized cellulosic fibres. The non-cationized cellulosic fibres may be selected from the group consisting of standard viscose fibres, modal fibres, Lyocell fibres, cotton fibres and linen fibres.
Due to the varying colouring properties of cationized cellulose fibres and non-cationized cellulose fibres, interesting colour effects can be achieved in a simple manner, f.i. , when colouring with only one dye.
The process according to the invention can be realized effectively in that the mixture is dyed with a direct dye and/or a reactive dye.
Cationized cellulose fibres, in particular cationized viscose fibres, are coloured more intensely by direct dyes and reactive dyes than non-cationized cellulose fibres.
Surprisingly, the achievable mixed-colour effect thereby depends particularly strongly on the salt concentration used for dyeing (less strongly on the pH value and the temperature of dyeing). The concentration of the dye in the batch also plays a role, with the difference in colour depth between the fibres decreasing, the greater the dye concentration.
When dyeing with direct dyes, the mixed-colour effect is particularly pronounced at low salt concentrations of 3 to 5 dl. At higher salt concentrations of up to 25 dl, on the other hand, almost equal colour depths of the cationized and the non-cationized cellulose fibres are achieved.
When dyeing with reactive dyes, the mixed-colour effect is particularly pronounced at salt concentrations of up to 20 g/l. At higher salt concentrations of up to 80 g/l, almost equal colour depths of the cationized and the non-cationized cellulose fibres are achieved.
Furthermore, it can be shown that the mixed-colour effect is more strongly pronounced if modal fibres or cotton fibres are used as non-cationized cellulosic fibres than if standard viscose fibres or Lyocell fibres are used.
Interesting effects are also achieved if a mixture of cationized cellulose fibres and noncationized cellulose fibres is dyed with two different reactive dyes. In doing so, dyeing can be carried out first with one of the reactive dyes under conditions in which only the cationized cellulose fibre is coloured. Subsequently, the second reactive dye is added, and dyeing is carried out under conditions in which both the cationized cellulose fibre and the non-cationized cellulose fibre are coloured.
Another aspect of the process according to the invention is characterized in that the mixture is dyed with a wool dye and at least one other dye, in particular a direct dye and/or a reactive dye. Also in this embodiment, the use of a fibre blend containing cationized cellulose fibres and non-cationized cellulose fibres is particularly suitable.
Under wool dyes, a person skilled in the art will understand dyes by means of which it is feasible to dye wool or polyarnide. Among those are acid dyes, metallized dyes and acid reactive dyes. It is particularly preferred to use a metallized dye as a wool dye.
While the non-cationized cellulose fibres in a mixture of cationized cellulose fibres and noncationized cellulose fibres virtually fail to be coloured by the wool dye, the cationized cellulose fibres are coloured by the wool dye.
The non-cationized cellulose fibres are coloured by the second dye that is used (preferably a direct dye or a reactive dye) at appropriate dyeing conditions. Said second dye optionally also colours the cationized cellulose fibre at least partially.
Thus, on the one hand, a mixed colouring between cationized and non-cationized cellulose fibres is created. On the other hand, a mixed colour is optionally also created in the cationized cellulose fibres itself as a result of dyeing with the wool dye and the competing dyeing process involving the second dye.
If a dye that is used is a metallized dye, the use of Lyocell fibres as the non-cationized cellulosic fibres in the mixture has proven favourable, since those fibres are stained the least by the metallized dye.
Another preferred embodiment of the process according to the invention is characterized in that the fibre blend contains a portion of non-cellulosic fibres. In this respect, in particular polyester fibres (PES) or polyamide fibres (PA) appear to be interesting for different applications. Thereby, in particular mixtures of two components (cationized cellulose fibre/synthetic fibre) or three components (cationized cellulose fibre 1 non-cationized cellulose fibre/synthetic fibre) are advantageous.
It can be shown, for example, that the duration of the dyeing process can be drastically reduced if a mixture of cationized cellulose fibres and polyester fibres is dyed with reactive dyes under the conditions of reactive dyeing.

In doing so, the achievable effects are dependent on different parameters depending on the components and types of dyes that are used. In the following table, the influence of the dyeing temperature and the pH value on various embodiments of the process according to the invention is demonstrated.

TABLE 1


Behaviour during
competing dyeings of
cationized cellulose
and non-cationized	Cationized	Non-Cationized	Cationized	Non-Cationized
cellulose	cellulose	cellulose	cellulose	cellulose

Dyeing temperature	T = 80-90° C.	T = 80-90° C.	T = 110-130° C.	T = 110-130° C.
Wool dyes	is dyed	is no dyed	is dyed	is not dyed
(metallized dyes)	completely		completely
Direct dyes	is dyed	is dyed from slightly	is dyed	is dyed from slightly
	completely	to completely	completely	to not at all
		depending on the		depending on the
		salt concentration		salt concentration
Reactive dyes	is dyed	is dyed from moderately	is dyed	is dyed from slightly
	completely	to completely	completely	to not at all
		depending on the		depending on the
		salt concentration		salt concentration
Behaviour during	cationized	polyamide	cationized	polyamide
competing dyeings of	cellulose		cellulose
cationized cellulose
and polyamide
pH value	4 to 6	4 to 6	9 to 11	9 to 11
Wool dyes	is dyed from	is dyed	is dyed	is dyed from
(metallized dyes)	slightly to	completely	completely	slightly to
	not at all			not at all

The table shows in particular that, in case of mixtures of cationized and non-cationized cellulose fibres, there are differences in the colouring behaviour above and below a dyeing temperature of 100° C.
The fibre blend may be dyed in the form of a yarn or a part of a yarn, respectively, or in the form of a textile or a part of a textile, respectively.
It is particularly preferred that the fibre blend is dyed in the form of a fabric so as to achieve a denim effect.
At present, the indigo effect desireable for jeans fabrics is achieved by an indigo dyeing process. Should one wish to dye indigo continuously on cellulosic fibres, an elaborate multistage process is necessary. A warp-dyeing process must be carried out, i.e. it is not feasible to dye finished cloths.
It has been shown that in particular mixed fabrics made of cationized cellulose fibres, polyester fibres and cotton fibres may be dyed such that the specific indigo effect can be achieved without multi-stage indigo dyeing and on an already finished cloth.
Furthermore, it is possible to achieve specific and selective melange effects. Also the wearability of pieces of clothing made of blended fabrics dyed in such a manner is better, as a softer and more pleasant feel can be achieved. In addition, another result is a better washing resistance in comparison with that of standard indigo products.
It can be shown that the mixed colourings achievable by the process according to the invention are excellently reproducible.
Furthermore, the invention relates to a fibre blend obtainable in accordance with the process according to the invention.
Furthermore, the invention relates in particular to a fibre blend containing a portion of cationized cellulosic fibres and a portion of non-cationized cellulosic fibres, which fibre blend is characterized in that the portion of cationized cellulosic fibres and the portion of non-cationized cellulosic fibres are coloured with the same direct dye and/or a reactive dye and that there is a difference in the colouring intensity between the portion of cationized cellulosic fibres and the portion of non-cationized fibres.
As described above, it is possible to control the varying degree of colouring in particular by selecting the salt concentration for the dyeing process.
Said embodiment of the fibre blend according to the invention is preferably characterized in that the difference in the colouring intensity between the cationized cellulosic fibres and the non-cationized fibres amounts to 5 to 50 CIELAB units according to the measuring method as indicated below.
Another preferred embodiment of the present invention relates to a fibre blend containing a portion of cationized cellulosic fibres and a portion of non-cationized cellulosic fibres, which fibre blend is characterized in that the portion of cationized cellulosic fibres is coloured with a wool dye and optionally at least partially with another dye, in particular a direct dye and/or a reactive dye, whereas the portion of non-cationized fibres is coloured only by said other dye. As already described before, interesting colour effects can be achieved in a simple manner with such fibre blends.
Fibres from the group consisting of standard viscose fibres, modal fibres, Lyocell fibres, cotton fibres and linen fibres can be included as non-cationized cellulosic fibres.
In the fibre blends according to the invention, the cationized cellulosic fibres preferably incorporate the cationic groups.
Furthermore, it is preferred that the cationized cellulosic fibres are cationized viscose fibres. The fibre blends according to the invention preferably contain a portion of non-cellulosic fibres such as polyester fibres or polyamide fibres.
A particularly preferred embodiment of the fibre blend according to the invention is provided in the form of a denim fabric.
In the following, preferred embodiments of the present invention are explained in greater detail by way of exemplary embodiments.
All the cationized viscose fibres mentioned in the following examples were produced in accordance with processes described in WO 96126220.

5. WORKING EXAMPLES

Preferred embodiments of the invention are explained in more detail by way of the following examples.

Example 1

A fabric consisting of a mixture of standard viscose fibres and cationized viscose fibres was dyed at a dyeing temperature of 80° C. with a dye bath containing 2% dye (Sirius Rubin K-2BL -direct dye, manufacturer Messrs. DyStar), based on 20 g of fabric (600 ml batch), and a nonionic wetting agent at various salt concentrations (Na₂SO₄).
The brightness of the coloured standard viscose fibres and the cationized viscose fibres, respectively, was measured according to the following measuring method:
The CIELAB whiteness of the fibres was determined according to the following method:
The colour coordinates of the fibres according to R_x, R_y, R_zwere determined according to DIN 6174 and DIN 5033 with illuminant D65 and at an observation angle of 10°. From those colour coordinates, the CIE whiteness and the colour cast in the redlgreen axis are computed according to DIN 55981 (=colour drift according to GartnerIGriesser) as follows:
CIE whiteness: W=Y+800″(x_o−x)+1700 (y_o−y)
Colour cast (=tint): T=900*(x_o−x)−650″(y_o−y)
(Note: T negative=red tinge, T positive=green tinge)
Y . . . standard colour value for the green sensitivity (=R_y.reflectance value green)
x_oy_o, . . . standard colour value parts of the achroniatic point (at D65/10° the following is valid:
x_o=0.3138; y_o=0.3310)
x,y . . . standard colour value parts of the samples, to be computed according to:
x=X/(X+Y+Z)
y=U/(X+Y+Z)
2=1−x−y
The standard colour values X, Y, Z, appearing in those formulas, are in turn computed from the reflectance values (=filter values) R_x, R_y, R_z, at illuminant D65 and at an observation angle of 10° according to the formulas:
X=0.94811*R_x
Y=R_y
Z=1.07304* R_z
In the following table, the respective difference in the CIELAB brightness evaluated for the two dyed fibre types is indicated - depending on the salt concentration that is used:

TABLE 2

Difference in brightness

Salt concentration (g/l) (CIELAB units)

2 10

5 7

10 6

20 4.5

Example 2

Fabrics consisting of

- cationized viscose fibres;
- weakly fibrillating Lyocell fibres (type “Lyocell LF”, manufacturer Lenzing AG); and
- modal fibres (manufacturer Lenzing AG).

were each dyed with two types of dye, namely with a direct dye (Sirius dyes, manufacturer Messrs. DyStar) and a metallized dye (Isolan dyes, manufacturer Messrs. DyStar), with the dye bath containing both dyes. The following standard parameters were maintained:



	Liquor ratio:	10 g fabric with 600 ml batch
	Nonionic wetting agent
	Salt content:	10 g/l
	pH value:	7
	Dyeing temperature:	80° C.
	Duration of dyeing:	45 min

Dyeings were carried out with batches containing the following dyes:

2.0% Sirius yellow K-GRL; 0.15% Isolan dark blue 2s-GL 01
2.0% Sirius yellow K-GRL; 0.4% Isolan dark blue 2s-GL 01
2.0% Sirius yellow K-GRL; 0.8% Isolan dark blue 2s-GL 01
2.0% Sirius yellow K-GRL; 0.4% Isolan bordeaux R 220%
2.0% Sirius yellow K-GRL; 0.8% Isolan bordeaux R 220%
2.0% Sirius yellow K-GRL; 0.8% Sirius turquoise GL 01
2.0% Sirius yellow K-GRL; 0.8% Isolan grey S-GL
1.0% Sirius blue K-GRL; 1.5% Isolan yellow K-GLN 250%
1.0% Sirius blue K-GRL; 0.5% Isolan yellow K-GLN 250%
1.0% Sirius blue K-GRL; 1.0% Isolan scarlet K-GLS 150%
1.0% Sirius blue K-GRL; 0.5% Isolan scarlet K-GLS 150%
1.0% Sirius blue K-GRL; 1.5% Isolan grey S-GS
1.5% Sirus scarlet K-CF; 1.0% Isolan yellow K-GLN 250%
1.5% Sirus scarlet K-CF; 0.5% Isolan yellow K-GLN 250%
1.5% Sirus scarlet K-CF; 0.8% Isolan olive SG
1.5% Sirus scarlet K-CF; 0.2% Isolan olive SG
1.5% Sirus scarlet K-CF; 0.15% Isolan dark blue 2s-GL 01
1.5% Sirus scarlet K-CF; 1.5% Isolan grey S-GL

In all cases, the non-cationized cellulose fibres (Lyocell or modal, respectively) were coloured virtually exclusively with the direct dye; in addition, the cationized viscose fibres were coloured with the metallized dye, whereby - depending on the colour and concentration of the dyes that were used - mixed colourings controllable in wide areas emerged in the cationic fibres.
Those mixed colourings (and the difference in colour between the cationized viscose fibre and the other cellulose fibre) produce interesting effects in fabrics which contain a mixture of those two fibres and are dyed with the above-mentioned dyes.
Similar effects were observed inl analogous tests involving fabrics made of cationized viscose fibres and cotton fibres.

Example 3

Striped socks (alternately 1 cm of cationized viscose fibres and 1 cm of Lyocell fibres) were manufactured and dyed with the following dye mixtures:
3a) 2.0% Sirius yellow K-GRL; 0.15% Isolan dark blue 2s-GL 01
3b) 2.0% Sirius yellow K-GRL; 0.4% Isolan bordeaux R 220%
The dyed striped socks exhibited striped areas with markedly different colourings. In example 3a), the sections of the Lyocell fibres were each dyed yellow; the sections of the cationized viscose fibres each exhibited a green mixed colour (from the yellow direct dye and the blue wool dye).
In example 3a), the sections of the Lyocell fibres were also each dyed yellow; the sections of the cationized viscose fibres each exhibited an orangelreddish mixed colom (from the yellow direct dye and the red wool dye).
Furthermore,

- knitted stockings made of a yarn containing cationized viscose fibres and Lyocell fibres (Nm 5011);
- twill fabrics 311 made of a twisted yarn (Nm 5012)—a mixture of cationized viscose fibres and Lyocell fibres—in the woof and modal fibres in the warp; and
- herringbone fabrics made of a twisted yarn (Nm 5012)—a mixture of cationized viscose fibres and Lyocell fibres—in the woof and modal fibres in the warp. were dyed with the dye mixtures described above, whereby also interesting colour effects resulted.

In all cases, the mixed colourings that were achieved were excellently reproducible, i.e. a repetition of the test yielded virtually identical dyeing results.

Example 4

A knitted fabric made of a twisted yarn—containing cationized viscose fibres and cotton fibres at a ratio of 50150—and a PES filament was dyed in a bath first under the dyeing conditions for PES fibres (i.e. at 130° C.) with a dye complex consisting of a metallized dye and a disperse dye and subsequently at 90° C. with a direct dye at a salt concentration of 7 g/l of salt. The procedure of dyeing can be illustrated as follows:

- start: temperature 50° C., dye bath: metallized dye+disperse dye; 20 g/l Na-acetate, dispersing agent: Setamol NS
- heating to 130° C.
- dyeing within 30-45 min
- cooling to 50° C.
- adding dye bath with direct dye, 7 g/l of salt
- heating to 90° C.
- dyeing within 30 min
- cooling

The following dye combinations were chosen:
4a) 2.0% Sirius yellow K-GRL (direct dye); 0.4 Isolan bordeaux R 220% (metallized dye)
4b) 2.0% Sirius yellow K-GRL (direct dye); 0.8% Supranol turquoise GGL (metal complex; manufacturer: Messrs. DyStar)
A black disperse dye (Dianix Schwarz CC, manufacturer Messrs. DyStar) was selected as the disperse dye for the PES fibres.
As a result, fabrics with interesting mixed colourings were obtained, wherein the PES filament was dyed black with the disperse dye; the cationized viscose fibre was mixed-dyed with the metallized dye and the direct dye; the cotton fibres were coloured only with the direct dye.

Example 5

In order to achieve a denim effect, a fabric consisting of a mixture of cationized viscose fibres and PES fibres (60140) in the warp and cotton fibres in the woof was dyed, such as described in example 4, first under the dyeing conditions for PES fibres with a dye mixture from a disperse dye and a metallized dye.
The samples dyed in this way correspond to the results of a standard-indigo-denim production, if equal tints were used for the disperse dye and the metallized dyes. By using different tints melange optics are generated, the obtainment of which by an indigo-standard technology would be very laborious and expensive. Subsequently, a few more samples were dyed with direct dyes in the same bath, immediately upon the PES dyeing. Thereby, it is possible to dye also the cotton component in the same dyeing process.
The monobath, approximately one-hour long competing dyeing process described above can be regarded as an interesting alternative to the laborious and technically demanding indigo dyeing process. Moreover, the dyeing processes according to the invention for producing a denim effect offer an outstandingly good flexibility, since no previous warp dyeing is necessary and hence a quick and efficient adjustment to the market becomes possible.

Claims

1-20. (canceled)

21. A dyeing process comprising dyeing a mixture of two or more different fiber types with one or more dyes, wherein the fiber mixture comprises a portion of cationized cellulosic fibers.

22. A dyeing process according to claim 21, wherein the cationized cellulosic fibers comprise cationic groups.

23. A dyeing process according to claim 21, wherein the cationized cellulosic fibers are cationized viscose fibers.

24. A dyeing process according to claim 21, wherein the mixture contains a portion of non-cationized cellulosic fibers.

25. A dyeing process according to claim 21, comprising dyeing the mixture with a dye selected from the group consisting of a direct dye and a reactive dye.

26. A dyeing process according to claim 25, wherein dyeing with the direct dye involves working at a salt concentration of 2 to 25 g/l.

27. A dyeing process according to claim 25, wherein dyeing with the reactive dye involves working at a salt concentration of up to 80 g/l.

28. A dyeing process according to claim 21, wherein the mixture is dyed with a wool dye and at least one other dye selected from the group consisting of a direct dye and a reactive dye.

29. A dyeing process according to claim 28, wherein the wool dye is a metallized dye.

30. A dyeing process according to claim 21, wherein the mixture contains a portion of non-cellulosic fibers.

31. A process according to claim 21, wherein the fibre blend is dyed in the form of a yarn or a part of a yarn.

32. A process according to claim 21, wherein the fibre blend is dyed in the form of a textile or a part of a textile.

33. A process according to claim 32, wherein the fibre blend is dyed in the form of fabric so as to achieve a denim effect.

34. A fibre blend produced by a process according to claim 21.

35. A fibre blend comprising a portion of cationized cellulosic fibers and a portion of non-cationized cellulosic fibers, wherein (i) the portion of cationized cellulosic fibers and the portion of non-cationized fibers are coloured with the same dye and, (ii) there is a difference in the coloring intensity between the portion of cationized cellulosic fibers and the portion of non-cationized fibers.

36. A fibre blend according to claim 35, wherein the difference in the coloring intensity amounts to 5 to 50 CIELAB units.

37. A fibre blend comprising a portion of cationized cellulosic fibers and a portion of non-cationized cellulosic fibers, wherein the portion of cationized cellulosic fibers is colored with a wool dye, and the portion of non-cationized fibers is colored by another dye.

38. A fibre blend according to claim 35, wherein the cationized cellulosic fibers incorporate the cationic groups.

39. A fiber blend according to claim 35, wherein the cationized cellulosic fibers are cationized viscose fibers.

40. A fiber blend according to claim 35, wherein the mixture contains a portion of non-cellulosic fibers.

41. A fiber blend according to claim 35, which is in the form of a denim fabric.