DE10048681B4 - Process for modifying dyeability and increasing wet modulus of cellulosic shaped bodies - Google Patents

Abstract

Method for adjusting the color affinity of cellulosic moldings, in particular fibers, to the color affinity of cotton, and to increase the wet modulus of the moldings, the moldings according to the dry-wet extrusion method of a cellulose solution of at least cellulose, an organic solvent and water and under Coagulation be prepared in an aqueous coagulation bath,
characterized,
that the shaped bodies are subjected to a treatment with the following steps:
a) bringing the moldings into contact with an aqueous solution of an aldehyde, the concentration of the aldehyde being from 1.5% to 5.0%,
b) fixing the treated shaped bodies with a catalyst, such as acidic metal salts or acidic ammonium salts,
c) condensing at elevated temperature,
d) washing out the unfixed residues of the treatment agents,
with the proviso that the shaped bodies in the period of their formation by coagulation and the implementation of the method and all process steps (a) to (d) are never dried.

Description

The The invention relates to a process for the treatment of shaped cellulose articles, in particular staple fibers and filaments produced by the dry-wet extrusion process, with aldehydes to modify the dyeability at the same time high color fastness and the increase of the wet modulus.

Under the dry-wet extrusion process is a process to be understood in which the cellulosic molded body in a solvent spinning process with a organic solvents be generated. Such cellulosic molded bodies are according to BISFA, Edition 1995, under the generic name Lyocell described.

at the production of cellulosic moldings after the lyocell process does not require any chemical transformations of cellulose to complete dissolution.

The Mixture of cellulose, organic solvent, in particular N-methyl-morpholine-N-oxide and Water leads when setting the required concentrations below defined Conditions for direct dissolution cellulose, ie a deformable cellulose solution.

One Process for the formation of a cellulose solution in aqueous NMMNO is known from DE-A 44 41 468 known. The production of cellulosic molded body this solution is described in EP-A 0574 870.

The By comparison, these fibers have been produced by this process principle too traditional produced cellulosic fibers after the viscose process better Characteristics of the fineness-related maximum tensile force in the dry and wet condition as well as the fineness-related maximum loop tension and the wet module as well as one compared to cotton and the conventional one Viscose fibers significantly different staining behavior.

Because of the characteristic of lyocell fibers compared to cotton deeper staining is in the technical manuals commercial provider, such as Lenzing, Issue 12/97; Courtaulds Fibers, Issue 3/98 pointed out that in mixed processing of Lyocell fibers with cotton vary greatly in color affinity Both fibers must be observed. This can lead to uneven tone-in-tone colorations to lead, the color difference is more pronounced in system mixtures as with intimate mixes.

process immanent Modifications of the manufacturing conditions of classical viscose processes were always on the increase the characteristic values for directed the textile-physical characteristics described above and led for the development of modal and polynosic fibers.

These Modification in the viscose fiber process leads to significant increases in production costs in the production of modal and polynosic fibers.

In Table I shows the different textile-physical characteristics represented by the different fiber types.

Table I Comparison of selected textile-physical properties of various cellulosic fibers

At the Lyocell process is the possibility the influence of textile-physical characteristics low.

The Use of formaldehyde for modifying tissue properties, like improved creasing, in cellulosic tissues Regenerate fibers that are not made by the Lyocell process are known. The wet tear strength Regenerated cellulose can be made by treatment with formaldehyde (Chwala and Anger, Handbuch der Textilhilfsmittel, Verlag Chemie, Weinheim, New York 1977). The finishing of tissues using special dialdehydes, including glyoxal, also become disclosed.

The Application of dialdehydes is also used to produce pulp produced fleeces described.

The EP 0 252 650 discloses a fibrous cellulosic material containing individualized stiffened crimped cellulosic fibers comprising a crosslinking agent selected from the group consisting of C2-C8 dialdehydes and other chemicals.

In the EP 0 251 676 For example, the same group of C2-C8 dialdehydes is used to make individualized and crimped cellulosic crosslinked (pulp) fibers.

The EP 0 691 426 describes the use of glutaraldehyde to reduce the fibrillation of lyocell fibers in the "never dried" state, where the "never dried" state refers to spun-moist, never-dried lyocell fibers.

Also is the aftertreatment of fabrics from cellulosic shaped bodies, which are not made by the lyocell process, with finishing agents known. The finishing takes place on the fabric. At the refining will be a permanent improvement of the functional properties of textile fabrics reached. In particular, the Krumpfstabilität and wrinkle recovery of textile fabrics be by the incorporation / modification of cellulose with different High-grade finishing and products improved.

• 1. Dimethylol- bzw. Dimethoxymethyl-Verbindungen von Harnstoff, Melaminen, Carbamaten und zyklischen Harnstoffen mit 5 oder 6 Ringatomen sowie Carbon-Säureamiden, Alkansäureamiden und Alkandioldiurethanen.
• 2. Methylolierte zyklische Harnstoffe mit 5 oder 6 Ringatomen sowie Epichlorhydrin und Sulfonium-Betaine.
• 3. Aldehyde

Common and well-known finishing agents are:

• 1. dimethylol or dimethoxymethyl compounds of urea, melamines, carbamates and cyclic ureas with 5 or 6 ring atoms and carboxylic acid amides, alkanoic acid amides and alkanediol diurethanes.
• 2. Methylolated cyclic ureas with 5 or 6 ring atoms as well as epichlorohydrin and sulfonium betaines.
• 3. aldehydes

Surprisingly, it was found by the inventors that in the treatment of the spin-wet lyocell fiber with dimethylol or dimethoxymethyl compounds of urea, melamines, carbamates, cyclic ureas having 5 or 6 ring atoms, carboxylic acid amides, alkanoic acid amides, alkanediol diurethanes or methylolated cyclic ureas with 5 or 6 ring atoms, epichlorohydrin and sulfonium Be an increase in the wet modulus value of the fiber is achieved.

The Strength and elongation values deteriorate very clearly, so that despite the improvement of the wet module the resulting fibers for a textile processing are partially unsuitable.

Especially the embrittlement fiber, characterized by the reduction of the fineness-related Loop maximum tensile strength, increases so much that one textile processing of the fiber and the performance characteristics of the fiber fabric made therefrom are problematic.

task The present invention is an inexpensive method of treatment of lyocell fibers available with which the color affinity of the lyocell fibers at the same time High color fastness is modified to match the color affinity of cotton to approach and further requirements for tone-on-tone coloration in mixtures of lyocell fibers to create cotton. Another task is, at the same time to improve the wet modulus of the lyocell fibers with the aforementioned objects.

The Tasks are according to the technical features according to the independent claim solved. Preferred embodiments are in the dependent claims shown.

It was surprising found that one Treatment of the fiber-wet fiber with aldehydes in an advantageous Way next to the increase wet module values a lower impact compared to other finishing agents the strength and elongation values shows. The embrittlement of Fiber is also significantly lower than other high-grade finishing agents. There are values of the fineness-related maximum loop tension reached that over those of classical viscose fiber lie. A processing of these fibers in the textile industry is possible without problems.

to solution the tasks of the invention is the way that the spinnfeuchte, never dried (never dried) lyocell moldings treated with aldehydes. Here, the spun in the dry-wet extrusion process moldings after its production, but before its initial drying, a treatment with a solution, containing at least one aldehyde and at least one catalyst, subjected, and subsequently at elevated Temperature condenses. In a less preferred embodiment The treatment can also be carried out by means of two solutions, the a solution at least one aldehyde and the other solution at least one catalyst contains. Crucial according to the invention is alone, that the Concentrations of the respective active ingredients in the undried moldings are sufficiently high.

The Application of the solution takes place expediently in a dipping bath. However, there are also other application methods like spraying possible, it only has to be ensured that the shaped body to be treated is adequate from the solution, or the solutions imbued becomes.

The Concentrations of the aldehydes and the catalysts in the application solution are subject no significant restrictions. Particularly suitable were concentrations of aldehydes in the range of 1.5-5.0%, preferably 2.0-3.0%, more preferably 3%. As particularly suitable Concentrations of the catalysts were found to be 2.5-5.0%, preferably 3.0-4.0%, more preferably 3.0%.

Aldehydes suitable according to the invention include:
Nalonaldehyde (1,3 propanedial)
Succinaldehyde (1,4 butanedial)
Glutaraldehyde (1,5 pentandial)
Adipaldehyde (1.6 hexanedial)
Pimelinaldehyde (1,7 heptanedial)

Catalysts suitable according to the invention include, for example, preferably acidic metal salts such as:
Aluminum sulfate, magnesium chloride, zinc nitrate and acidic ammonium salts such as ammonium sulfate, ammonium nitrate, particularly suitable is MgCl ₂ .

The Exposure time or soaking time the treatment solution, or the treatment solutions are subject to restriction only, that the Agents have sufficient time in sufficient concentration in the moldings to be treated penetrate. Suitable drinking times are 2-5 min, especially 4 min.

Conveniently, the impregnation takes place at slightly elevated Temperature to the distribution of active ingredients in the molding accelerate and / or even out. Suitable temperatures are in the range of 20 ° C up to 30 ° C, especially 25 ° C.

By the combined effect of at least one aldehyde with the at least a catalyst finds a first fixation of the active ingredients in the moldings instead of.

To the application of said treatment solution or treatment solutions is the soaked moldings subjected to a condensation reaction. The condensation reaction takes place at elevated Temperatures, with the proviso that the temperatures are sufficiently high to the chemical reaction of the active agents with the spun molding to effect. The same applies to the condensation time.

When suitable temperatures for the condensation reaction showed temperatures in the range of 90 ° C to 150 ° C, preferably 90 ° C to 130 ° C, especially preferably 100 ° C. Suitable times for the condensation reaction is 5 to 20 minutes, preferably 8 to 15 min, more preferably 10 min.

To Conclusion of the Condensation reaction, the shaped bodies are washed to unreacted active agents to remove, and the molding can be dried for further processing.

Between the step of applying the active agents and the step of the condensation reaction can expediently excess water be removed, e.g. by squeezing.

The The present invention will now be described by way of example as well as Comparative examples further described.

The characteristic textile-physical properties were determined according to the following instructions:
Fineness-related maximum tensile strength / maximum tensile force elongation: DIN ISO 5079; Textiles and fibers; Determination of the maximum tensile strength and maximum tensile strength of staple fibers (clamping length = 10 mm)
Fineness-related maximum loop tensile force: DIN 53843 (part 2); Testing of textiles; Loop tension test on fibers
Wet modulus: BISFA, internationally agreed methods for testing viscose, modal, cupro, lyocell, acetate and triacetate, staple fibers and tows (1995 edition), which at 5% elongation determined result was multiplied by 20.

In The following examples illustrate the influence of the treatment with the mentioned Demonstrates active agents.

Treatment with aldehydes:

Example 1:

The application is carried out on a certain amount of spun-moist, never-dried lyocell fiber (10 g atro) at a liquor ratio of 1:20. The fiber is treated with a solution consisting of 5% aldehyde (100% glutaraldehyde) and 3% MgCl ₂ (100% MgCl ₂ ) at 25 ° C for 4 minutes. The fiber is then squeezed, condensed at 150 ° C for 4 min, washed, washed and dried. The wet modulus value is 254 cN / tex (initial value 228 cN / tex).

Example 2:

The application is carried out as in Example 1. The fiber is treated with a solution consisting of 3% aldehyde (glutaraldehyde 100%) and 3% MgCl ₂ (100% MgCl ₂ ), 4 min at 25 ° C. The fiber is then squeezed, condensed at 100 ° C for 10 min, washed, washed and dried. The wet modulus value is 218 cN / tex (initial value 178 cN / tex).

Example 3:

The application is carried out as in Example 1. The fiber is treated with a solution consisting of 2.5% aldehyde (100% glutaraldehyde) and 3% MgCl ₂ (100% MgCl ₂ ) for 4 min at 25 ° C. The fiber is then squeezed, condensed at 100 ° C for 10 min, washed, washed and dried. The wet modulus value is 190 cN / tex (initial value 178 cN / tex).

Example 4:

The application is carried out as in Example 1. The fiber is treated with a solution consisting of 2% aldehyde (glutaraldehyde 100%) and 3% MgCl ₂ (100% MgCl ₂ ) for 4 min at 25 ° C. The fiber is then squeezed, condensed at 100 ° C for 10 min, washed, washed and dried. The wet modulus value is 194 cN / tex (starting value 178 cN / tex).

Example 5:

The application is carried out as in Example 1. The fiber is treated with a solution consisting of 1.5% aldehyde (100% glutaraldehyde) and 3% MgCl ₂ (100% MgCl ₂ ) at 25 ° C for 4 min. The fiber is then squeezed, condensed at 100 ° C for 10 min, washed, washed and dried. The wet modulus value is 206 cN / tex (initial value 178 cN / tex).

Treatment with urea derivatives (Comparative Examples)

Example 6 (comparison):

The application is carried out as in Example 1. The fiber was treated with a solution consisting of 8% urea derivative (Fixapret ^® ECO 100%) and 3% MgCl ₂ (100% MgCl ₂ ), 4 min at 25 ° C pressed off the fiber, condensed at 160 ° C for 4 min, washed, washed and dried. The wet modulus value is 256 cN / tex (initial value 228 cN / tex).

Example 7 (comparison):

The application is carried out as in Example 1. The fiber was treated with a solution consisting of 8% urea derivative (Arcofix ^® NDL 100%) and 3% MgCl ₂ (100% MgCl ₂ ), 4 min at 25 ° C. The fiber is then squeezed, condensed at 150 ° C for 4 min, washed, washed and dried. The wet modulus value is 238 cN / tex (initial value 228 cN / tex).

Example 8 (comparison):

The application is carried out as in Example 1. The fiber was treated with a solution consisting of 8% urea derivative and 3% MgCl ₂ (100% MgCl ₂ ), 4 min at 25 ° C. The fiber is then squeezed, condensed at 150 ° C for 4 min, washed, washed and dried. The wet modulus value is 278 cN / tex (initial value 228 cN / tex).

The Compilation of all tested Values can be found in the following tables.

Table II: glutaraldehyde

Table III: Urea derivatives (comparison)

In order to was the approach given, possible changes the dyer Properties of aldehyde-treated lyocell fibers.

It In each case two direct and two reactive dyes were selected, the for one comparative staining of glutaraldehyde-treated lyocell fiber and cotton were.

The Results are surprising.

It shows that with Glutaraldehyde treated lyocell fibers much brighter than normal Color lyocell fibers. The color depths are in the range of cotton.

The Results are from the detailed descriptions below the dyeing tests refer to.

The staining of the fibers was carried out according to the following recipes: 1. Preparation: a. pre-cleaning: 1 g / l Utravon EL (available from Ciba Spezialitätenchemie Pfersee GmbH) 1g / l soda calcine, treat at 60 ° C for 20 min b. Do the washing up: Soft water, cold 2. Coloring: liquor ratio 1:10 (soft water) 2.1. Direct dyeings: 10g / l Glauber's salt calc dyes: a. 1% Optisalorange GL (based on the fiber weight)

b. 1% Optisal Red 7B (based on fiber weight) (dyes available at Clariant (Germany) GmbH, Lörrach)

The Glauber's salt is added to the 50 ° C dyebath. After 5 minutes, the well-dissolved dye is added. It is then heated at 1.5 ° C / min to a temperature of 120 ° C. The dyeing time at 120 ° C is 30 min. After cooling to 80 ° C, the fibers can be removed. 2.2. reactive dyeing a. Dye: 1% Cibacron Red HW (available from Ciba Specialty Chemicals) 60 g / l Glauber's salt kalz 20 g / l Soda kalz.

at 30 ° C is the dyebath the well solved Dye added. After 10 min within 5 min of the Addition of Glauber's salt in 2 portions. Thereafter, it is heated to 1.6 ° C / min Heated to 80 ° C. After a residence time of 5 minutes, 20 g / l of soda are added to the dyebath and another 45 minutes at 80 ° C colored.

b. Dye: 1% Cibacron blue C-R 40 g / l Glauber's salt calc 12.5 g / l soda calc.

The 60 ° C warm dyebath the well-dissolved dye and after 10 min 40 g / l Glauber's salt in 2 portions was added within 5 min. After a further 35 min at 60 ° C, the addition of 12.5 g / l of soda. At constant temperature is colored for another 45 min. 3. Post-treatment a. direct dyeing 1. rinse bath: Cold for 10 minutes 2nd rinse bath: Cold for 10 minutes 3. rinsing bath: Cold for 10 minutes with the addition of 0.1 g / l magnesium chloride b. reactive dyeing 1. rinse bath: 10 min at 50 ° C 2nd rinse bath: 10 min at 50 ° C Neutralize with 1 ml of 60% acetic acid 3. rinsing bath: 15 min at 95 ° C 4. rinsing bath: 10 min at 50 ° C 5. rinsing bath: Cold for 10 minutes.

The Dry all dyed Fibers occurred in the air.

The Measurement of dyeability of the fibers was determined using a spectrophotometer SF 600 (manufacturer Datacolor / Switzerland) carried out.

to Assessment of staining The K / S value is based on Kubelka and Munk at the wavelength of greatest absorption. A high K / S value means a high color depth.

In Table IV reproduces the values given to those before Carding parallelized fibers have been obtained. Compared Glutaraldehyde-treated Lyocell fiber is K / S values from the same conditions, dyed cotton and untreated Lyocell fibers shown. The dyeability of glutaraldehyde Treated lyocell fiber is good. Particularly positive is the similar staining compared to cotton. This results in favorable conditions for a mixed processing with cotton.

On the other hand show the untreated lyocell fibers in all dyeings significantly higher K / S values on. This means that in case of mixed processing to tone-in-tone staining problems between the darker coloring untreated lyocell fibers and lighter-colored cotton.

Table IV: Spectral values (K / S)

One Another advantage is the high color fastness of glutaraldehyde treated lyocell fiber.

In Table V shows the results of a laundry tested according to DIN EN ISO 105 - C01 40 ° C shown.

Table V: Wash fastness in grades

Claims (11)

Method for adjusting the color affinity of cellulosic moldings, in particular fibers, to the color affinity of cotton, and to increase the wet modulus of the moldings, wherein the moldings by the dry-wet extrusion method of a cellulose solution of at least cellulose, an organic solvent and water and under Coagulation be prepared in an aqueous coagulation bath, characterized in that the shaped bodies are subjected to a treatment with the following steps: a) contacting the moldings with an aqueous solution of an aldehyde, wherein the concentration of the aldehyde of 1.5% to B) fixing the treated shaped bodies with a catalyst, such as acid metal salts or acidic ammonium salts, c) condensing at elevated temperature, d) washing out the unfixed residues of the treatment agents, with the further proviso that the shaped bodies in the period of their formation by Ko agulation and the implementation of the method and all process steps (a) to (d) are never dried. Method according to claim 1, characterized in that that glutaraldehyde is used as aldehyde. Method according to claim 1 or 2, characterized that the concentration of aldehydes is 2 to 3%. Method according to one of claims 1 to 3, characterized in that an acidic metal salt is used as the catalyst. Method according to one of the preceding claims, characterized characterized in that the concentration of acid metal salts is 2.5% to 5.0%. Method according to one of the preceding claims, characterized in that MgCl _{2 is} used as the metal salt. Method according to one of the preceding claims, characterized in that the bringing into contact the shaped body with the aqueous solution of Aldehydes at a temperature of 20 to 30 ° C, over a period of 2 to 5 minutes, carried out becomes. Method according to one of the preceding claims, characterized characterized in that the condensation temperature is 90 ° C to 150 ° C. Method according to one of the preceding claims, characterized characterized in that the condensation time is 5 to 20 minutes. Lyocell fiber with a cotton-matched color affinity and a increased wet modulus, treated with a method according to any one of claims 1 to 9th Textile fabric, made from a intimate or system mixture of cotton with Lyocell fibers, wherein the lyocell fibers with a method according to a the claims 1 to 9 have been produced.