Classifications

• • D—TEXTILES; PAPER
  • D01—NATURAL OR MAN-MADE THREADS OR FIBRES; SPINNING
  • D01F—CHEMICAL FEATURES IN THE MANUFACTURE OF ARTIFICIAL FILAMENTS, THREADS, FIBRES, BRISTLES OR RIBBONS; APPARATUS SPECIALLY ADAPTED FOR THE MANUFACTURE OF CARBON FILAMENTS
  • D01F11/00—Chemical after-treatment of artificial filaments or the like during manufacture
  • D01F11/02—Chemical after-treatment of artificial filaments or the like during manufacture of cellulose, cellulose derivatives, or proteins
• • D—TEXTILES; PAPER
  • D01—NATURAL OR MAN-MADE THREADS OR FIBRES; SPINNING
  • D01F—CHEMICAL FEATURES IN THE MANUFACTURE OF ARTIFICIAL FILAMENTS, THREADS, FIBRES, BRISTLES OR RIBBONS; APPARATUS SPECIALLY ADAPTED FOR THE MANUFACTURE OF CARBON FILAMENTS
  • D01F2/00—Monocomponent artificial filaments or the like of cellulose or cellulose derivatives; Manufacture thereof
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
  • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
  • Y10T428/00—Stock material or miscellaneous articles
  • Y10T428/29—Coated or structually defined flake, particle, cell, strand, strand portion, rod, filament, macroscopic fiber or mass thereof
  • Y10T428/2913—Rod, strand, filament or fiber
  • Y10T428/2933—Coated or with bond, impregnation or core
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
  • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
  • Y10T428/00—Stock material or miscellaneous articles
  • Y10T428/29—Coated or structually defined flake, particle, cell, strand, strand portion, rod, filament, macroscopic fiber or mass thereof
  • Y10T428/2913—Rod, strand, filament or fiber
  • Y10T428/2933—Coated or with bond, impregnation or core
  • Y10T428/2964—Artificial fiber or filament
  • Y10T428/2965—Cellulosic

Definitions

• the invention relates to cellulosic fibers or yarns with a reduced tendency to form fibrils and to a method for producing such fibers or yarns, the fibers preferably being produced by the NMMO thread-forming process.
• ORIGINAL DOCUMENTS essentially in that a suspension is first prepared from cellulose, for example cotton linters, cellulose and the like, Hasser and NMMO, and this is converted into a solution by heating and removing part of the water.
• This solution is then filtered and extruded through a nozzle, preferably with the interposition of an air gap, into a mostly aqueous precipitation bath, the shaped bodies such as threads, yarns, films and the like being coagulated. arise.
• These moldings are then washed to remove any tertiary amine oxide still present.
• the shaped body can then be dried and further processed in the usual manner, e.g. be wound up, etc.
• the NMMO process is distinguished from the classic process for the production of cellulosic molded articles primarily by the fact that it is essentially a matter of physical processes, so that, at least in theory, no chemical reactions take place and no chemical by-products arise which are disposed of as waste products or would have to be converted back into the starting products by chemical methods.
• the NMMO process is therefore fundamentally one of the very environmentally friendly processes.
• the actual starting product is a renewable raw material, and the cellulosic end product is highly biodegradable.
• the cellulosic fibers in particular those which are produced by the NMMO process, tend to fibrillate, particularly when wet, especially when mechanical forces act on the fibers. This is the case with dyeing, among other things, it also occurs when the fibers are washed if they are to be freed of solvent that is still present after leaving the precipitation bath.
• the fibrils once present, are of course more or less unpleasantly noticeable in all further processing operations, even when dry. Dust forms to a greater extent, fine fibrils split off and curled up in a ring shape. Whole fibrils can also tear off.
• fibril formation can be useful for achieving special surface effects, but fibril formation is undesirable for most applications.
• the object of the invention is therefore to provide cellulosic fibers and yarns, in particular those which have been obtained by the NMMO process and which have a reduced tendency to form fibrils, but which at the same time have very good dyeability, that is to say dyeability which essentially corresponds to the dyeability of untreated fibers or is only insignificantly reduced, and whose mechanical textile data, in particular the elongation compared to untreated fibers, are not or only insignificantly deteriorated. It is also an object of the invention to provide a corresponding method by means of which such fibers are accessible, which works economically, leads to reproducible results, which works continuously, which allows a high spinning speed and which does not require subsequent cleaning or cleaning Neutralization levels required.
• This object is achieved by a process for the production of cellulosic fibers or yarns with a reduced tendency to form fibrils by treating fibers or yarns washed but not yet dried after the thread-forming process with a crosslinking agent, characterized in that the fibers or yarns treated with amino, polyalkylene oxide, epoxy or carboxyl functional modified reactive polysiloxanes with self-crosslinking thereof.
• the reactive siloxanes are preferably used in combination in crosslinking agents known per se, but especially with low or free formaldehyde.
• the reactive polysiloxanes are preferably side chain-modified. Fibers or yarns which have been obtained in accordance with the NMMO process are preferably treated.
• the self-crosslinking, reactive polysiloxanes as an aqueous dispersion or as a solution in a concentration of 0.1 to 5%, calculated as reactive polysiloxane.
• Solutions of the siloxanes can be in the form of aqueous, alcoholic or aqueous / alcoholic solutions; however, the solutions can also be made using other solvents such as toluene, acetone and the like. have been produced.
• Aqueous micro-emulsions are particularly suitable as aqueous dispersions.
• Microemulsions are particularly fine-particle emulsions in which the particle sizes of the distributed liquid particles are predominantly in the nanometer range, e.g. at 40 nm.
• the emulsions can contain customary ionic or nonionic emulsifiers.
• the treatment according to the invention preferably takes place at a temperature of 180 to 250 ° C., treatment times of 0.5 seconds to 5 minutes, in particular 10 seconds to 20 seconds, being preferred. Treatment on a hot contact plate is particularly advantageous.
• the process according to the invention can advantageously be carried out continuously.
• the fiber After impregnation, spraying or application of the siloxane, the fiber is expediently passed between two rollers in order to squeeze off excess solution or dispersion.
• the fiber is then fed to a zone where the temperature is elevated.
• This route preferably has a temperature of 180 to 250 ° C.
• This treatment at the elevated temperature simultaneously involves drying the fibers.
• this temperature zone there is crosslinking of the applied siloxane, which essentially consists of self-crosslinking, i.e. crosslinking of the polysiloxane with the OH groups of the cellulose does not take place or only to a minor extent.
• a conventional convection dryer operated with hot air can be used for treatment at higher temperatures.
• the fibers or the yarn can be passed over a contact heating plate which is set to a temperature of, for example, 250 ° C.
• the treatment time is usually even shorter than is the case with a conventional convection dryer. Times of around 0.5 to 1 to 2 seconds are sufficient to effect self-crosslinking and to dry the fiber.
• the method according to the invention can be carried out, for example, as follows:
• a slurry consisting of approx. 13% cellulose 80% Viskokraft ELV and 20% Viskokraft VHV, commercially available cellulose products eg from International Pulp Sales Comp., New York, USA
• 87% aqueous NMMO solution with one Water content of approx. 20 ° is continuously fed to an extruder which contains a device for removing water.
• Partial water separation produces a spinning solution with the following composition: cellulose 14%, water 11%, NMMO 74.86%.
• the spinning solution additionally contains 0.14% propyl gallic acid as a stabilizer.
• This spinning solution which has a temperature of 120 ° C., is pressed into an air gap by means of a spinning pump through a spinneret with 50 holes - the single hole diameter is 130 ⁇ .
• the air gap has a length of 18 cm.
• a stretching of 15.9 takes place in the air gap; the filaments are then coagulated in an aqueous precipitation bath.
• the threads are withdrawn from the precipitation bath and passed into a washing section in which the NMMO still remaining in the thread is washed out. After leaving the washing section, part of the water is wiped off; in addition, the fiber is blown with an air jet at room temperature so that the fiber still has a residual water content of about 300%.
• An aqueous dispersion of the active siloxane is applied via a rotating godet. After passing through a squeeze roller, the fiber is passed through a convection dryer that has a temperature of 250 ° C. The fiber stays in the dryer for 10 seconds.
• the fiber After leaving the dryer, the fiber is adjusted to a moisture content of 11% using a nozzle. A conventional finishing agent is applied at the same time.
• the values compiled in Table 1 show that self-crosslinking on the wet yarn, that is to say which has not yet been dried and therefore still has the primary swelling, has excellent elongation, ie the elongation is not reduced.
• the dyeability is excellent.
• the tearing times in particular are very high and at least doubled compared to the tearing times on the untreated thread, for which a very low concentration of the crosslinking agent in the bath is sufficient.
• concentrations of 2% crosslinker in the crosslinking bath the tear time is increased from 0.9 minutes to more than 15 minutes, ie by more than an order of magnitude.
• the number L which was measured in the following manner, is used to assess the dyeability.
• the fiber was dyed according to the following recipe:
• the well-dissolved dye is added to the 60 ° C dyebath and the fabric is dyed for 15 minutes at a constant temperature. Then 5 g / 1 Glauber's salt (dissolved with boiling water) are added in 3 portions within 5 minutes and dyed for a further 15 minutes at a constant temperature. The total dyeing time is 35 minutes.
• the tissue stainability was measured using the Minolta Chroma-Meter Cr-300, Cr-310 and CR-331.
• the value L is a measure of the brightness of the colored product. The lower this value, the better the dyeability.
• Table 2 shows the values which were obtained on the same yarn as in Table 1, with the difference that the treated yarns had already been dried before the treatment, ie no longer had any primary swelling. The tearing times are practically unchanged compared to the untreated yarn at the lower concentrations. An improvement can only be ascertained at elevated concentrations, but this cannot in any way match the improvement that is obtained with yarns that have not yet dried.
• the invention further relates to cellulosic fibers and / or yarns with a reduced tendency to form fibrils, characterized in that the fibers or yarns have a coating applied to the fibers which still have the primary swelling and which consists of essentially self-crosslinked, at least bifunctional reactive siloxanes .
• the amount of the coating is preferably 0.1 to 1% by weight, based on the cellulosic fibers or yarns.
• the fibers are further characterized in that they have no or only an insignificant reduction in elongation and dyeability compared to the untreated fibers or yarns. They are also characterized in that they have at least twice the tearing time compared to the untreated fibers.
• the fibers or yarns have preferably been produced by the NMMO thread-forming process.
• the breaking time is a measure of the tendency of the fibers or yarns to fibrillate (see Tables I and II).
• a bundle (1) of 50 filaments which is fixed at one end with a thread clamp (2), is guided through a thread guide (3).
• the bundle (1) is adjusted with a Y-piece (4) in relation to an ejector (10).
• a thread guide (5) adjoins the ejector (10), with which the bundle (1) is deflected, which has a weight 6 of at its second end 20 grams is loaded.
• the distance between the first thread guide (3) and the Y-piece (4) and between the Y-piece (4) and the ejector inlet is approx. 3 cm in each case.
• the distance between the ejector outlet and the second thread guide (5) is approximately 11 cm.
• the ejector (10) has a length of 22 mm.
• the ejector (10) has an inlet gap (11) with a square cross section for the bundle (1).
• the width b e and the height h e of the entry gap (11) are 1 mm.
• the thread channel (12) extending through the entire ejector (10) in the two side walls (13, 13 ') has opposite liquid supply channels (14, 14'). Water flows through these liquid supply channels (14, 14 ') at a temperature of approximately 25 ° C. at an angle ⁇ of 15 ° relative to the axis of the bundle (1).
• the water flows into the thread channel (12) at a total volume flow of 45 l / h and exits the ejector (10) at the outlet gap (15).
• the width b z of the liquid supply channels (14, 14 ') is 0.6 mm and their height h z 1 mm.
• the length l z of the feed channels (14, 14 ') is 6 mm.
• the width b of the thread channel (12) from the confluence of the liquid supply channels (14, 14 ') to the outlet gap (15) is 1.2 mm.
• the height h is 1 mm.
• the supply with water takes place through bores (16, 16 ') with a diameter of 4 mm from the underside of the ejector (10).
• the ejector (10) is closed from above with a cover, not shown, lying flat.
• the filament bundle (1) according to FIG. 1 is placed in the device parts and loaded with the weight.
• the water supply in the ejector (10) represents the start of the time measurement.
• the time measurement is ended at the point in time when the weight falls, ie when the bundle breaks. 10 individual measurements were carried out for each example, and the data given mean values from these 10 measurements represent the tearing time. The higher this value, the lower the fibrillation.
• Functionally reactive in the context of the invention means that when the fibers are treated with the coating composition, at which an elevated temperature is preferably used, the applied composition crosslinks with itself, as in the case of self-condensation and that there is practically no crosslinking with the cellulose , ie with the hydroxyl groups of cellulose takes place.
• crosslinking with the cellulose is to be avoided in this treatment, the self-crosslinking can in principle be carried out in the absence of catalysts.
• post-crosslinking takes place during storage. Sometimes this is even desirable and can e.g. promoted by pH adjustment and / or catalysts.
• this postcrosslinking differs from a direct crosslinking in which the various OH groups of the cellulose molecules are crosslinked to one another in that the network formed by self-crosslinking is only connected to cellulose at individual points. This creates a wide-meshed, elastic network, so to speak, which is anchored to the cellulose in only a few places.
• the self-crosslinking is preferably carried out at pH values from 4 to 12.
• Reactive polysiloxanes which can be used under the conditions of self-crosslinking are described, for example, in Textilveredlung 20 (1985) No. 1, pages 8 to 12.
• the amino, polyalkylene oxide and epoxide functionally modified reactive siloxanes are exemplified in this Review by formulas that the Figures 7, 9, 10 correspond.
• Carboxyl-functional modified polysiloxanes accordingly have the carboxyl group as side chain modification.
• the polysiloxanes which are functionally modified on the side chain are preferably used.
• the polysiloxanes can be simply modified in the side chain, ie they only have functional groups of a certain type, but it is also possible to use double-modified siloxanes, ie polysiloxanes which have different functional groups.
• the end groups of the modified polysiloxanes are preferably hydroxyl, alkoxy and saturated alkyl groups, especially the methyl group.
• Polysiloxanes with the vinyl group as the end group are less suitable in the context of the invention.
• the functionally modified polysiloxanes which are used according to the invention are all commercially available products.
• amino-functional silicones are shown as they can be used according to the invention.
• Further usable functional silicones can be found in the brochure.
• Suitable microemulsions are also offered there, e.g. the silicone microemulsion CT96E on page 14 of the brochure.
• the functional reactive polysiloxanes used according to the invention are preferably used with further customary crosslinking agents, in particular in combination with crosslinking agents which are low in formaldehyde or free of formaldehyde.
• crosslinkers which can be used are described in the following literature references, to which reference is expressly made here: 1. Stephen B. Sello
• the silicones in the article specified there serve for crosslinking in the case of cellulose fibers which no longer have a primary swelling, i.e. have already been dried, e.g. to give the fibers a water-repellent finish.
• the treatment under self-crosslinking conditions is carried out according to the invention on the fibers, threads and yarns between the washing section which adjoins the spinning bath and the dryer. This means that the treatment takes place on the fibers that have not yet dried.
• fibers include filaments, i.e. Understand endless fibers.
• the process according to the invention gives fibers, filaments and yarns which essentially still have their original elongation and have excellent dyeability and also have an unexpectedly high reduction in the tendency to form fibrils.
• the fibers can be processed further in the usual way, ie wound up into yarns of a wide variety of deniers. Fabrics, knitted fabrics and other textile fabrics can be produced, which are advantageous compared to other products due to their low tendency to fibrillate.
• fibers, filaments and yarns can be made from all conventional cellulosic raw materials, such as cotton linters, cellulose and the like. produce.

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• Chemical & Material Sciences (AREA)
• Chemical Kinetics & Catalysis (AREA)
• General Chemical & Material Sciences (AREA)
• Engineering & Computer Science (AREA)
• Textile Engineering (AREA)
• Treatments For Attaching Organic Compounds To Fibrous Goods (AREA)
• Artificial Filaments (AREA)
• Yarns And Mechanical Finishing Of Yarns Or Ropes (AREA)

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• 1995
  • 1995-12-22 DE DE59508458T patent/DE59508458D1/de not_active Expired - Fee Related
  • 1995-12-22 JP JP8520206A patent/JPH10511439A/ja active Pending
  • 1995-12-22 AU AU44339/96A patent/AU4433996A/en not_active Abandoned
  • 1995-12-22 CA CA002207856A patent/CA2207856A1/fr not_active Abandoned
  • 1995-12-22 EP EP95943196A patent/EP0799333B1/fr not_active Expired - Lifetime
  • 1995-12-22 WO PCT/EP1995/005109 patent/WO1996020302A1/fr active IP Right Grant
  • 1995-12-22 US US08/860,220 patent/US6048479A/en not_active Expired - Fee Related
  • 1995-12-22 AT AT95943196T patent/ATE193737T1/de not_active IP Right Cessation
• 1996
  • 1996-03-26 TW TW085103581A patent/TW293043B/zh active
• 1999
  • 1999-04-16 US US09/292,826 patent/US6180234B1/en not_active Expired - Fee Related

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