DE10013966B4 - A method of increasing the UV absorptivity and reducing fibrillation tendency of lyocell fibers - Google Patents

Abstract

in der R₁, R₂, R₃, R₄ unabhängig voneinander jeweils bedeuten können;
– R₁ bis R₄ sind Chlor oder Fluor
– R₁ und R₃ sind Chlor oder Fluor und R₂ und R₄ bedeuten Wasserstoff ist
und die Formel der Verbindung II,

worin Y -CH₂-CH₂-SO₃Na oder -CH=CH₂ und R₁ Chlor oder Fluor sind, ist.A process for increasing the UV absorptivity and reducing the fibrillation tendency of lyocell fibers, characterized in that the fibers are treated in an alkaline wet crosslinking process with one of the compounds of the general formulas of the type I to II, wherein spun-moist, never-dried lyocell fibers be treated and where the
Formula of Compound I,

in which R ₁ , R ₂ , R ₃ , R _{4 may} each independently represent;
- R ₁ to R ₄ are chlorine or fluorine
R ₁ and R ₃ are chlorine or fluorine and R ₂ and R _{4 are} hydrogen
and the formula of compound II,

wherein Y is -CH ₂ -CH ₂ -SO ₃ Na or -CH = CH ₂ and R _{1 is} chlorine or fluorine.

Description

The The present invention relates to a method of equipping from solvent spun cellulose fibers (lyocell fibers) with the aim of their behave towards To improve ultraviolet rays and their Fibrillierneigung to reduce.

[State of the art]

On Reason for the changing Conditions in the atmosphere The protection against ultraviolet radiation plays an increasing role. This is true for one the human being, who is increasingly exposed to a high level of radiation but also for the protection of textiles fiber damage and color changes.

The Lyocell fibers are for various applications in the clothing sector. For this reason It offers itself, the new innovative fiber material in addition to to give the other benefits also UV protection.

Lyocell fibers have high strength and modulus values in the dry and also in the wet condition. Further advantages are good dyeability and the viscose fiber analogue Tragphysiologie. For the customer Textiles made of the new pulp are characterized by a pleasant Handle and a novel surface appearance out.

A Special feature of the solution-spun Cellulose fibers are their low wet scrub resistance or their high wet fibrillation. This property can be for achieving special surface effects or utilize it positively in nonwoven production, but there is one comprehensive market introduction in the way, since they are in finishing processes and also in use disturbing effect.

Fibrilliererscheinungen are characterized by a local limited cleavage of fibrils along the fiber surface at mechanical stress in the wet state. The bad wet scrub behavior Lyocell is on the comparatively poorly trained Attributed interactions between the crystalline fiber regions.

Known is that crosslinking reactions a possibility to improve wet scrub behavior Offer. Dry crosslinking processes as in the inventions WO 94/20656 and WO 95/30043 are less suitable because all crosslinks in the dry fiber for deterioration of important fiber parameters as well of the carrying physiology lead.

More interesting are products that are about the mechanism of wet crosslinking with the cellulose fiber. For networking on the swollen There are now some results from fiber, e.g. Textile Research Journal 66, 575-580 (1996); Textilveredlung 31, 96-100 and 191-194 (1996) u.v.a. In these works showed that priority Substances that form two or more bonds with cellulose can, suitable which may also be non-covalent bonds. The effect on wet scouring hangs - beside the application conditions - in strong dimensions from the structure of the respective substance. The equipment with bifunctional reactive dyes is also broader a wet crosslinking process. Here shows especially that, despite Of the same kind and number of anchor groups often a completely different one Naßscheuerverhalten can result. Thus, the substances react due to their Size, her internal mobility or the arrangement of reactive groups (place in the molecule and distance from each other) within the fiber.

In EP 0785304 A3 and US 5310424 Wet crosslinking processes for improving wet scrubbing behavior are cited. This also includes examples of dyeing with polyfunctional reactive dyes. Disadvantage with polyfunctional reactive dyes is the fact that their application is notwendi sarily connected with the color of the fiber. In addition, very few dyes are capable of achieving adequate wet scrub resistance at all, and only at high dye levels - the fabric is then deeply colored. A protection against UV rays is not given or only to a minor degree. If one leaves the linkages between the cellulose-reactive groups known from dyestuff chemistry, the problem of lacking affinity arises. An application via the exhaust process then brings only unsatisfactory results.

In EP 0538977 B1 is also by means of polyfunctional substances the wet scrubbing behavior of Lyocell fibers improved, but only through treatments of the dried fiber. This requires the fabricator additional operations. No statements are made about the change in the fiber properties; an additional or simultaneous protective function against ultraviolet radiation likewise does not occur with the products mentioned there.

In Patent WO 99/19555 discloses substances which fibrillate pushing back from lyocell fibers and simultaneously impart UV absorption properties to the fiber. adversely is that the substances mentioned there only have a dichlorotriazine anchor. Theoretically, could Although the dichlorotriazine group because of the two reactive centers probably bifunctional react and so at least partially links effect of cellulose chains. An effect like with substances that However, this is not the case for two or more anchor groups expect.

DE 197 20 683 A1 describes the use of triazine-containing compounds as UV absorbers, in particular for photochemical stabilization and for improving the sun protection factor of polyamide- or cellulose-containing textile materials, wherein the finished fabrics are treated with the compounds. The compounds thus reach fibers which have already been dried at least once in the course of their previous processing.

EP 850 934 A1 also describes the use of triazine-containing compounds to improve the sun protection factor and additionally the whiteness of textile materials, for example cotton, wool, polyamide, polyester, polyacrylic, silk or mixtures thereof. These materials show no fibrillation tendency.

EP 950 750 A1 describes the use of triazine-containing compounds to reduce fibrillation tendency in tissues made from lyocell cellulosic fibers.

OBJECT OF THE INVENTION

aim The invention relates to a process, textiles made from solution-spun cellulose fibers a permanent protective function against ultraviolet radiation too while reducing their fibrillation tendency, without that change the other properties or the inherent color of the fiber.

These The object was inventively achieved in that the fibers over a Wet crosslinking process with compounds, the two or more cellulose-reactive anchor groups and a UV-absorbing Part contain, be treated.

• – Stilbenderivate, die neben dem UV-Schutz auch noch eine Aufhellung des Textils durch Fluoresenz bewirken (z.B. Verbindung I)
  
  Verbindung I
• – Verbindungen nach II oder deren Derivate
  
  Verbindung II

For the combination of UV sorption and reduction of fibrillation tendency, the following structures were determined according to the invention:

• Stilbene derivatives which, in addition to the UV protection, also bring about a lightening of the textile by fluorescence (eg compound I)
  
  Compound I
• - Compounds according to II or their derivatives
  
  Compound II

• 1. eine nucleophile Substitution oder
• 2. einen Eliminierungs-Additionsmechanismus

mit den alkalisch aktivierten Hydroxylgruppen der Cellulose umsetzen können. Beispiele für die Gruppe 1 sind Strukturen, die Monochlortriazin-, Dichlortriazin-, Fluortriazin-, Difluortriazin-, Dichlorpyrimidin-, Trichlorpyrimidin-, Dichlorfluorpyrimidin- oder Dichlorchinoxalin-Strukturen, enthalten. Für die Gruppe 2 stehen Verbindungen mit Vinylsulfon- oder deren Vorläufer Sulfatoethylsulfonyl-Gruppen.These substances contain at least two anchor groups. Since the crosslinking of cellulose fibers in the dry state leads to significant deterioration of other important parameters, especially the anchor groups are of interest, with which one can cause a cellulose cross-linking in the swollen state. These are anchor groups that overlap

• 1. a nucleophilic substitution or
• 2. an elimination addition mechanism

can react with the alkali-activated hydroxyl groups of cellulose. Examples of group 1 are structures containing monochlorotriazine, dichlorotriazine, fluorotriazine, difluorotriazine, dichloropyrimidine, trichloropyrimidine, dichlorofluoropyrimidine or dichloroquinoxaline structures. For group 2 are compounds with vinyl sulfone or their precursor sulfatoethylsulfonyl groups.

links with these or similar Structures react with cellulose in the alkaline state implement. Before geous are padding method, because while the affinity of the substances does not play the crucial role.

to Improvement of solubility can the bridge member with solubility enhancing Groups, e.g. sulfonic acid groups, be substituted.

There Naßvernetzungsprozesse only stabilize the swollen fiber state, change the fiber properties little. Reactions with the compounds mentioned can be used as wet crosslinking on the swollen fiber at low temperature and under alkaline Conditions, as they are typical in textile finishing make.

• – über die ausgewählten Substanzen erhält man am Textil für den Menschen einen ausreichenden Schutz gegen die Ultraviolette Strahlung der Sonne
• – die ausgewählten Substanzen bewirken einen gewissen Schutz der Cellulosefaser gegen Ultraviolette Strahlung
• – die ausgewählten Substanzen verleihen der Faser einen höheren Weißgrad
• – bei künstlicher UV-Strahlung, wie sie beispielsweise in Diskotheken auftritt, fluoreszieren die ausgerüsteten Textilien
• – die Faser ist durch die Applikation der Substanz gegen Beanspruchungen, wie sie in der Textilveredlung und im Gebrauch auftreten, geschützt
• – die Faserparameter bleiben nach der Vernetzung weitgehend erhalten
• – die Vernetzersubstanzen können auf die spinnfeuchte, noch niemals getrocknete, Faser aufgebracht werden.

If the wet scrubbing behavior is improved with the substances which are the subject of the invention, the advantages already indicated result:

• - on the selected substances obtained on the textile for humans a sufficient protection against the ultraviolet radiation of the sun
• - The selected substances cause some protection of the cellulose fiber against ultraviolet radiation
• - The selected substances give the fiber a higher degree of whiteness
• In the case of artificial UV radiation, as occurs, for example, in discotheques, the finished textiles fluoresce
• - The fiber is protected by the application of the substance to stresses, as they occur in textile finishing and in use
• - The fiber parameters are largely retained after crosslinking
• - The crosslinking agents can be applied to the wet, never-dried, fiber.

The The following examples contain principal possibilities of application of crosslinkers with several vinylsulfone groups.

[Examples]

The The following examples contain principal possibilities of application of crosslinkers with several vinylsulfone groups.

Example 1 Treatment with the compound I

Laundry:

The Fibers were first in a staining device for 30 min at 80 ° C with a solution of 1 g / l of trisodium phosphate and 1 g / l of nonionic surfactant in deionized water at a liquor ratio of 1:30, then thoroughly with warm and cold flowing Rinsed off water and finally 10 min at 60 ° C with pure deionized water at the same liquor ratio in Dyeing device rinsed. The The fibers were dried for 60 minutes at 80 ° C. in a vacuum drying oven. The Fibers were until further treatment in desiccators on silica gel stored.

Treatment:

• – der Lösung des Vernetzers
• – einer 2%igen Natronlauge

im Becherglas. Nach Kontrolle des pH-Wertes wurden 1,00 g Lyocell-Faser (Trockenmasse) in die Flotte getaucht und 30 s mit dem Glasstab gerührt. Dann wurde die Faser herausgenommen und am Laborfoulard 3 mal bei 3 bar abgedrückt. Die Flottenaufnahme der Faser betrug nach dem Abquetschen 90%. Danach lagerte die Faser luftdicht in einer Plastetüte eingeschlossen.First, Compound I was dissolved in water at a concentration of 10 g / l. The production of the padding liquor took place only immediately before the treatment from the corresponding quantities

• - the solution of the crosslinker
• - A 2% sodium hydroxide solution

in the beaker. After checking the pH, 1.00 g of lyocell fiber (dry matter) were immersed in the liquor and stirred for 30 s with the glass rod. Then the fiber was taken out and pressed 3 times at 3 bar at the laboratory pad. The liquor pickup of the fiber after squeezing was 90%. Thereafter, the fiber was airtight enclosed in a plastic bag.

After treatment:

• – 15 min bei 50°C in 50 ml deionisiertem Wasser
• – 15 min bei 30°C in 50 ml leicht verdünnter Schwefelsäure zum Neutralisieren (der pH-Wert der Flotte betrug nach der Behandlung pH 6...8)
• – 15 min bei 60°C in 50 ml deionisiertem Wasser
• – 15 min bei 30°C in 50 ml deionisiertem Wasser

After the specified storage time, the aftertreatment was carried out, also in the dyeing machine, at a liquor ratio of 1:50 in different fleets:

• - 15 min at 50 ° C in 50 ml deionized water
• - 15 min at 30 ° C in 50 ml of slightly diluted sulfuric acid to neutralize (the pH of the liquor was after treatment pH 6 ... 8)
• - 15 min at 60 ° C in 50 ml deionized water
• - 15 min at 30 ° C in 50 ml deionized water

To the respective individual post-treatment procedures became the fibers taken from the cups, over expressed in the cups and the next Post-treatment step supplied. In conclusion, were the fibers for 60 min at 105 ° C. dried.

The Lyocell fibers had a wet scrub number of 138 largely unchanged Tear resistance, elongation at break and loop strength. The absorption for ultraviolet radiation was clearly improved. The whiteness increased to CIE from 75 to 90.

Example 2 Treatment with the compound II

Laundry:

The fibers was carried out as in Example 1.

Treatment:

The washed fibers were analogous to the procedure in Example 1 treated with the compound II.

The After-treatment was carried out as in Example 1.

At the so equipped Lyocell fibers were a wet scrub number from 212 to watch. Tensile strengths, elongation at break and loop strength of the fiber were largely retained. Of the Whiteness is increasing from 75 to 85.

Claims (4)

A process for increasing the UV absorptivity and reducing the fibrillation tendency of lyocell fibers, characterized in that the fibers are treated in an alkaline wet crosslinking process with one of the compounds of the general formulas of the type I to II, wherein spun-moist, never-dried lyocell fibers be treated and wherein the formula of the compound I,

in which R ₁ , R ₂ , R ₃ , R _{4 may} each independently represent; R ₁ to R ₄ are chlorine or fluorine - R ₁ and R ₃ are chlorine or fluorine and R ₂ and R _{4 are} hydrogen and the formula of the compound II,

wherein Y is -CH ₂ -CH ₂ -SO ₃ Na or -CH = CH ₂ and R _{1 is} chlorine or fluorine. Method according to claim 1, characterized in that that the Compounds I to II contain one or more sulfonic acid groups. Method according to claims 1 to 2, characterized that the Compounds from an aqueous, alkaline adjusted fleet with a pH between 10 - 13 the fiber will be applied. Method according to Claims 1 to 3, characterized that 0.5 % to 15% of the compound in terms of fiber weight on the fiber be applied.