Classifications

• • D—TEXTILES; PAPER
  • D06—TREATMENT OF TEXTILES OR THE LIKE; LAUNDERING; FLEXIBLE MATERIALS NOT OTHERWISE PROVIDED FOR
  • D06M—TREATMENT, NOT PROVIDED FOR ELSEWHERE IN CLASS D06, OF FIBRES, THREADS, YARNS, FABRICS, FEATHERS OR FIBROUS GOODS MADE FROM SUCH MATERIALS
  • D06M13/00—Treating fibres, threads, yarns, fabrics or fibrous goods made from such materials, with non-macromolecular organic compounds; Such treatment combined with mechanical treatment
  • D06M13/10—Treating fibres, threads, yarns, fabrics or fibrous goods made from such materials, with non-macromolecular organic compounds; Such treatment combined with mechanical treatment with compounds containing oxygen
  • D06M13/144—Alcohols; Metal alcoholates
• • D—TEXTILES; PAPER
  • D06—TREATMENT OF TEXTILES OR THE LIKE; LAUNDERING; FLEXIBLE MATERIALS NOT OTHERWISE PROVIDED FOR
  • D06M—TREATMENT, NOT PROVIDED FOR ELSEWHERE IN CLASS D06, OF FIBRES, THREADS, YARNS, FABRICS, FEATHERS OR FIBROUS GOODS MADE FROM SUCH MATERIALS
  • D06M13/00—Treating fibres, threads, yarns, fabrics or fibrous goods made from such materials, with non-macromolecular organic compounds; Such treatment combined with mechanical treatment
  • D06M13/322—Treating fibres, threads, yarns, fabrics or fibrous goods made from such materials, with non-macromolecular organic compounds; Such treatment combined with mechanical treatment with compounds containing nitrogen
  • D06M13/402—Amides imides, sulfamic acids
  • D06M13/432—Urea, thiourea or derivatives thereof, e.g. biurets; Urea-inclusion compounds; Dicyanamides; Carbodiimides; Guanidines, e.g. dicyandiamides
• • D—TEXTILES; PAPER
  • D06—TREATMENT OF TEXTILES OR THE LIKE; LAUNDERING; FLEXIBLE MATERIALS NOT OTHERWISE PROVIDED FOR
  • D06M—TREATMENT, NOT PROVIDED FOR ELSEWHERE IN CLASS D06, OF FIBRES, THREADS, YARNS, FABRICS, FEATHERS OR FIBROUS GOODS MADE FROM SUCH MATERIALS
  • D06M15/00—Treating fibres, threads, yarns, fabrics, or fibrous goods made from such materials, with macromolecular compounds; Such treatment combined with mechanical treatment
  • D06M15/19—Treating fibres, threads, yarns, fabrics, or fibrous goods made from such materials, with macromolecular compounds; Such treatment combined with mechanical treatment with synthetic macromolecular compounds
  • D06M15/37—Macromolecular compounds obtained otherwise than by reactions only involving carbon-to-carbon unsaturated bonds
  • D06M15/53—Polyethers
• • D—TEXTILES; PAPER
  • D06—TREATMENT OF TEXTILES OR THE LIKE; LAUNDERING; FLEXIBLE MATERIALS NOT OTHERWISE PROVIDED FOR
  • D06M—TREATMENT, NOT PROVIDED FOR ELSEWHERE IN CLASS D06, OF FIBRES, THREADS, YARNS, FABRICS, FEATHERS OR FIBROUS GOODS MADE FROM SUCH MATERIALS
  • D06M2101/00—Chemical constitution of the fibres, threads, yarns, fabrics or fibrous goods made from such materials, to be treated
  • D06M2101/02—Natural fibres, other than mineral fibres
  • D06M2101/04—Vegetal fibres
  • D06M2101/06—Vegetal fibres cellulosic

Definitions

• Cellulose is the most common and important naturally occurring polymer in the world.
• cellulosic moldings such as paper, blown film, cellophane and sponge cloths
• cellulose fibers are among the important technical products that are used primarily for clothing, as insulating materials and as technical strength carriers.
• the present invention relates to cellulosic fibers having improved thermostability for applications of increased continuous use or processing temperature.
• Cellulosic fibers for industrial applications also referred to as technical viscose, rayon or lyocell
• Cellulosic fibers, filaments and multifilaments can be obtained in a variety of ways and in various forms, which are also known and familiar to the art.
• the classification can be made according to the manufacturing process - for example direct dissolving or regenerating - and / or on the nature of the product obtained, either in turn of cellulose with modified crystal structure (so-called Hydratcellulose or cellulose II) exists - for example viscose - or a polymer-analogous derivative of the cellulose represents, as for example cellulose acetates or cellulose triacetates.
• cellulosic fibers, multifilament yarns and the products containing such fibers or yarns are often exposed to high temperatures.
• thermoplastic fibers in cellulosic fibers, the registered thermal energy can only to a small extent in the form of latent heat to aggregate state change (increase the chain mobility, in consequence Reorientation, softening and melting). This is due to the comparatively high chain stiffness of cellulose and the large number of functional groups, which result in high intermolecular binding energies.
• US Pat. No. 2,278,285 discloses the stabilizing function of urea as an aging stabilizer for rayon yarns.
• urea is applied in the form of an aqueous solution by dipping and optionally a subsequent annealing above the melting temperature of urea (2-6 hours at> 135 ° C) is applied, which is to serve the homogeneous distribution of the stabilizer in the fiber.
• urea-impregnated rayon yarns can subsequently be treated with adhesion promoters such as resorcinol-formaldehyde-latex (RFL).
• adhesion promoters such as resorcinol-formaldehyde-latex (RFL).
• RRL resorcinol-formaldehyde-latex
• thermostabilizing effect is still detectable on the adhesion-impregnated yarn.
• the effects of urea pretreatment on the effectiveness of the liability mediator discussed. It is therefore an object of the present invention to provide a cellulosic fiber having improved thermostability while retaining adhesion to rubber.
• the solution to this problem is surprisingly achieved by a cellulosic fiber which is coated with a urea-containing stabilizer mixture, wherein the stabilizer mixture may additionally comprise nonionic surfactants and antioxidants.
• Urea is the main component of the claimed thermal stabilizer in a coating process together with an RFL adhesion promoter system applied, the resulting impregnated fiber also shows improved thermal stability, with consistent or slightly lower adhesion to common rubber types.
• the heat stabilization succeeds in this case, regardless of whether the stabilizer is added before the post-condensation of the RFL dispersion or only immediately before the dip impregnation.
• the addition of urea can be carried out both as a solid and in the form of an aqueous solution.
• the mass fraction of urea in the RFL impregnation solution may be 0.5-25%.
• thermostable cellulosic fiber disclosed herein exhibits higher tensile strengths (measured as maximum tensile strength), higher degrees of polymerization (viscometric one-point measurement, Cuen), and correspondingly lower thermal discoloration (unquantified) than a corresponding unstabilized thermal stress Cellulosic fiber.
• the remaining tensile strength of the coated cellulosic fiber is at least 10%, more preferably at least 50%, most preferably at least 100% higher than a corresponding uncoated fiber after identical thermal loading.
• the object of the invention is particularly characterized by a significantly increased long-term thermostability, but also shows at the same time favorable behavior during short loads at extremely high temperatures (high temperature processing).
• the high stabilizing effect is obtained in particular with those cellulosic fibers in which the nonionic surfactants in the coating agent are linear or branched polyethylene glycol alkyl ethers and / or long-chain, branched alcohols. Furthermore, it is advantageous if the antioxidants are sterically hindered phenols.
• the composition, type or presentation of the coated cellulosic fibers is not limited in itself. Optimum results are obtained by using high purity cellulose fibers with high degrees of polymerization.
• the corresponding coated fiber may be a cellulosic fiber or a corresponding multifilament yarn consisting either predominantly of cellulose or of a polymer-analogous derivative of the cellulose, e.g. Cellulose acetate or cellulose triacetate.
• the recovery process for the inventively coated cellulosic fiber or filaments is not limited.
• the cellulosic fiber or filament used in the coating may be applied by a direct dissolving method, such as a spin coating. from solutions in caustic soda, copper oxide-ammonia, phosphoric anhydrides, tertiary amine oxides such as N-methylmorpholine-N-oxide (NMMO) or ionic liquids, and subsequent precipitation in suitable coagulation media.
• a direct dissolving method such as a spin coating. from solutions in caustic soda, copper oxide-ammonia, phosphoric anhydrides, tertiary amine oxides such as N-methylmorpholine-N-oxide (NMMO) or ionic liquids, and subsequent precipitation in suitable coagulation media.
• NMMO N-methylmorpholine-N-oxide
• the cellulosic fiber is recycled by a regenerating process in which the cellulose (in the form of chemical pulp) initially chemically soluble derivatives (xanthates or carbamates) is reacted and dissolved.
• the solution is pumped through spinnerets and the spun fibers are finally coagulated and regenerated in the precipitation bath, washed and sized (functionally coated) in one or more post-treatment steps and finally either wound on endless coils or processed into fiber cut.
• High strength coated cellulosic fibers generally have a tenacity of at least 20 cN / tex, more preferably at least 35 cN / tex, most preferably greater than 45 cN / tex, prior to thermal aging or application.
• the theoretical limit of strength for cellulosic multifilament yarns is about 90 cN / tex.
• the functional cellulosic fiber of the present invention may consist of fiber cut of any length or any number of continuous filaments, such as are common in technical and consumer products.
• the yarn has a total titer in the range of 30 to 20,000 dtex and consists of 10 to 5000 correspondingly coated single filaments.
• the elongation at break of a yarn according to the invention is 5 to 30%, preferably 10 to 20%.
• the invention is further directed to a process for coating cellulosic fiber or filaments in which the cellulosic fibers or filaments are contacted with an aqueous dispersion or solution of a stabilizer mixture containing urea, and the dried cellulosic fibers or filaments are subsequently dried and further processed wherein the dispersion or solution may additionally comprise nonionic surfactants and antioxidants.
• the dispersion or solution may additionally comprise nonionic surfactants and antioxidants.
• this is done by means of passage (immersion), wetting with a Preparation roller, or spraying with the aqueous stabilizer dispersion.
• the cellulosic fibers or continuous yarns treated in this way can then be dried and, if necessary, wound up or processed into fiber short cuts.
• the coated yarn in the oven-dry state (little physisorbed water content) in the inventive embodiment contains at most 25% by mass of additive components, preferably at most 15% by mass of additive components.
• the dipping or spraying solution used for the yarn coating preferably contains at least 5% by mass, preferably at least 10% by mass, most preferably at least 15% by mass of the stabilizer mixture.
• the target pH value can already be set during the preparation with sodium hydroxide solution or just before use with solid sodium hydroxide.
• the anhydrous stabilizer mixture preferably contains 25-60% by mass of urea, preferably 25-60% by weight of polyethylene glycol alkyl ethers and optionally preferably 5-25% by mass of long-chain, preferably branched, monoalcohols and preferably less than 5% by mass of antioxidants ,
• the polyethylene glycol alkyl ethers used preferably consist of branched C 6 -C 4 -alkyl radicals and 1 to 60 ethylene oxide (EO) repeat units. The latter are preferably hydroxy (OH) -terminated.
• the preferably branched, monoalcohols used according to the invention preferably consist of C 12-C 36 -alkyl units.
• a particularly preferred dispersion of these components (hereinafter also referred to as stabilizer solution) has the following composition:
• Urea 80% by mass of water, 5-12% by mass.
• Urea 5-12 mass% of polyethylene glycol ethers, eg, dodecaethylene glycol mono (/ so- / n-) tridecyl ether, and 0-6 mass% long chain iso- or n-alcohols, for example dodecanol or hexadecanol and 0-1% antioxidants from the class of sterically hindered phenols, eg 2,6-di-tert-butyl-4-methylphenol (BHT).
• polyethylene glycol ethers eg, dodecaethylene glycol mono (/ so- / n-) tridecyl ether
• long chain iso- or n-alcohols for example dodecanol or hexadecanol and 0-1% antioxidants from the class of sterically hindered phenols, eg 2,6-di-tert-butyl-4-methylphenol (BHT).
• this very successfully used formulation which has a solids content of about 41% by mass commercially available, should be diluted with sodium hydroxide to 25 to 75 vol .-% before use, so that solids contents of 10 to 30 mass% can be achieved ,
• the native pH of the additive - if not already done by dilution with sodium hydroxide solution - moderately alkaline by stirring solid sodium hydroxide.
• the yarn may be used by itself, or as a fiber short or after processing into a cord or subsequent processing into a woven or knitted fabric as a reinforcing material for synthetic and natural elastomers, or for other synthetic or renewable raw materials based materials, for example thermoplastic and thermosetting plastics , serve.
• elastomeric, thermoplastic, and duromeric materials include natural rubber, other poly (isoprene) s, poly (butadiene) s, polyisobutylenes, butyl rubber, poly (butadiene-co-styrene) s, poly (butadiene-co-acrylonitrile) s, poly (ethylene) co-propylene) s, poly (ethylene-co-propylene-co-diene) s, also known as EPDM, poly (isobutylene-co-isoprene) s, poly (chloroprene) s, polyacrylates, polyamide, polyesters, polylactic acid, polycarbonates , Polyglucans, polyurethanes, polysulfides, silicones, polyvinyl chloride, poly (ether-esters), thermoplastic polyesters, crosslinked unsaturated polyesters, epoxy resins, or mixtures thereof.
• the invention is likewise directed to adhesion promoters, preferably based on
• Resorcinol-formaldehyde latex isocanate or resorcinol-formaldehyde-silica, for the Bonding of fiber-containing reinforcements to rubber, which is characterized in that the bonding agent additionally contains urea.
• present urea is preferably between 0.5 and 25%, more preferably between 2.5 and 15%,
• Resorcinol-formaldehyde precondensates are known as adhesion promoter component for rubberized fabrics. For the preparation of the dips is doing the
• Precondensate processed together with the latex dispersions and other ingredients to form so-called resorcinol-formaldehyde-latex (RFL) dips.
• RTL resorcinol-formaldehyde-latex
• thermostabilizing effect of the urea In order to exploit the thermostabilizing effect of the urea, it is added during or shortly after the production of the dipping agent.
• the fibrous reinforcements contain fibers or filaments, which consist predominantly of viscose, lyocell or a polymer-analogous derivative of
• Cellulose e.g. Cellulose acetate or cellulose triacetate.
• the liability remains at least at a good level.
• a simple fiber coating equipment consists of a braked spool, a passively driven impeller through a flat, unheated, non-circulated immersion tray (5-10 cm immersion distance, approx. 100 mL immersion solution), a simple scraper, a dryer unit from a passively driven heating grid duo ( 100 ° C surface temperature, approx. 3 m heating distance), a drive roller (5 - 10 m / min) and an automatic winding.
• concentration of the dipping solution can be considered approximately constant.
• a pilot-scale fiber-coating equipment consists of a braked unwinding system, a jet-jet impregnation unit with metering pump, heated and stirred 5-liter storage vessel, staggered scraper teeth with collecting trough and return, a multi-stage roller dryer with active drive (50-60 m / min) and automatic rewinding , Following coating trials, about 30-50 m of coated yarn are rewound onto test tubes for textile tests and aging tests.
• the selected conditions of the aging tests are based on two basic application scenarios. These are on the one hand increased processing temperatures, on the other hand increased elevated service temperatures: 4.1. Short-term exposure at elevated processing temperatures
• the resistance of the cellulosic materials to short term high temperature (> 200 ° C) loads is of great benefit for injection molding of rayon-thermoplastic composites, i. of yarn short cut in a polymer melt.
• the test temperature approximated the processing temperatures of the higher melting materials (240 ° C).
• the maximum life in a hot extruder or an injection molding machine was estimated to be 20 minutes.
• LTTS long-term thermal stability
• temperatures reached in runflat tires and the desired long-term stability of radiator hoses were used as an order of magnitude.
• conditions were chosen in which a slower and steady decrease (“plateau") had set in preliminary experiments after an initially strong decrease in the average degree of polymerization (DP) and the mechanical properties, the first approximation being a
• plateau a slower and steady decrease
• the conditions of the standard long-term aging were set at 7 days (168 hours) at 150 ° C.
• the aging tests additionally became common aging conditions in the automotive supply industry (1000 h at 120-150 ° C) extended. 5. Verification of thermal aging according to the selected scenarios
• the thermal stability of the cellulosic materials according to the invention was investigated by means of rayon yarn.
• additive-coated yarn samples and untreated reference yarns are aged under identical conditions, ideally in the same experiment and in duplicate.
• the aging capsules are preferably made of glass and temperature-stable plastics.
• the yarn is generally very sensitive to the choice of aging method, which is why strict attention must be paid to reproducible performance.
• the decisive factor for the level of residual tensile strength and residual polymerization after stress is the exact preparation of the yarn sample.
• the ratio of capsule volume to amount of sample has an influence, but more important is the extent to which the yarn is accessible to oxygen and volatile decomposition products (differences between 2 meter yarn sample on a steel hanger and 250 meter yarn samples on cardboard cores).
• Pieces of two meters length of the coated yarn and the untreated output yarn are wound on separate steel wire hanger (10 turns of 20 cm) and predried at 105 ° C in a drying oven for 3 hours. Each stirrup is taken out of the oven one at a time and placed in a heated test tube filled with ambient air, which is sealed airtight with a glass stopper and PTFE tape. Another drying oven, which was previously adjusted so that the temperature inside an empty test tube is 240 ° C, is preheated for one hour. The aging samples in test tubes are placed horizontally on a slide in the center of the oven. After 5 minutes, the target temperature of 240 ° C in the test tube is reached, after 20 more minutes, the test tubes are removed and opened. The yarn samples are carefully stripped from the yarn straps and prepared for tensile testing (Eplexor 500 N) and DP determination.
• Eplexor 500 N tensile testing
• Pieces of two meters length of the coated yarn and the untreated output yarn are wound on separate steel wire hanger (10 turns of 20 cm) and predried at 105 ° C in a drying oven for 3 hours.
• Each stirrup is taken out of the oven one at a time and placed in a heated and air-filled test tube which is closed with a thermally stable rubber septum. With the aid of two cannulas, a vigorous stream of nitrogen is passed through the test tube for 20 minutes (> 3 bubbles / s).
• One another drying oven which was previously adjusted so that the temperature inside an empty test tube is 240 ° C, is preheated for one hour.
• the aging samples in test tubes are placed horizontally on a slide-in plate in the middle of the oven where, after 5 minutes, the setpoint temperature of 240 ° C in the test tube is reached. The samples are loaded for a further 20 minutes at 240 ° C and then removed from the oven. After cooling for 5 minutes, the encapsulated test tubes are opened and the aging samples are removed. The yarn samples are carefully stripped from the yarn straps and prepared for tensile testing (Eplexor 500 N) and DP determination.
• Eplexor 500 N tensile testing
• Pieces of two meters length of the coated yarn and the untreated output yarn are wound on separate steel wire hanger (10 turns of 20 cm) and predried at 105 ° C in a drying oven for 3 hours. Each stirrup is taken out of the oven one at a time and placed in a heated test tube filled with ambient air, which is sealed airtight with a glass stopper and PTFE tape. Another drying oven, which was previously adjusted so that the temperature inside an empty test tube is 150 ° C, is preheated for one hour. The aging samples in test tubes are placed horizontally on a slide in the center of the oven. After 7 days (168 hours), the test tubes are removed and opened. The yarn samples are carefully stripped from the yarn straps and prepared for tensile testing (Eplexor 500 N) and DP determination.
• Eplexor 500 N tensile testing
• 250 meters of the coated yarn and the untreated starting yarn are wound on cardboard tubes (diameter 4 cm) and pre-dried at 105 ° C in a drying oven for at least 3 hours.
• Each yarn package is sold individually taken out of the oven, into a heated and filled with ambient air wide-mouth vessel, which is sealed with a PTFE screw cap with polysulfone seal.
• Another drying oven which was previously adjusted so that the temperature inside an empty wide-mouth vessel is 150 ° C, is preheated for one hour.
• the wide-mouthed containers filled with aging samples are placed upright on a slide-in tray. After 7 days (168 hours), the glass jars are removed and opened.
• the wound yarn samples are prepared for the tensile test (Statimat 4U) and DP determination.
• 250 meters of the coated yarn and the untreated starting yarn are wound on cardboard tubes (diameter 4 cm) and pre-dried at 105 ° C in a drying oven for at least 3 hours.
• Each bobbin is taken out of the oven one at a time, placed in a heated and filled with ambient air wide-mouth vessel (1, 25 liters), which is sealed with a PTFE screw cap with polysulfone seal.
• Another drying oven which was previously adjusted so that the desired aging temperature prevails inside an empty wide-mouth vessel, is preheated for one hour.
• the wide-mouthed containers filled with aging samples are placed upright on a slide-in tray. After 41 days and 16 hours (1000 hours), the glass jars are removed and opened.
• the wound yarn samples are prepared for the tensile test (Statimat 4U) and DP determination.
• Tab. 1 Overview of the aging methods used. All experiments were stored in closed vessels in convection ovens; RG: test tube 20 mL, WHG:
• breaking strength By measuring the residual tensile force ("breaking strength"), combined aging effects on the mechanical structure of the fibers are detected, including the thermal change of the supramolecular structure and fiber morphology as well as the thermohydrolytic degradation of the individual cellulose chains.
• Eplexor 500N Laboratory rapid tests with 50 mm clamping length
• the tensile strength of thermally stressed fibers is tested in a rapid test.
• the measurement is either performed on pre-twisted Z100 samples, or the protective swirl is applied manually immediately prior to measurement.
• Useful is the use of 10 cm long, kink-free pieces (1/2 turn on the steel bracket).
• the tensile test is carried out on a GABO Eplexor 500N dynamic testing machine with a clamping length of 50 mm and a breaking rate of 100% (50 mm / min) .Your yarn sample is subjected to 5 individual measurements and the mean value of the remaining maximum tensile force ("breaking strength") is calculated.
• Statimat 4L tensile tests in standard climate with a clamping length of 500 mm
• the tensile strength of the thermally stressed fibers in a standardized tensile test on a "Textechno Statimat 4U The measurement is either performed on pre-twisted Z100 samples, or the protective swirl is applied immediately prior to measurement by the tensile tester, It is convenient to measure directly from the coil after overdrawing mm and tear rate 100% (500 mm / min) an average of the remaining maximum tensile force ("breaking strength") was obtained.
• reference fibers mentioned in the examples were dip-treated (distilled water instead of stabilizer dispersion), predried for at least 3 hours at 105 ° C., encapsulated, subjected to the appropriate aging program and tested on the identical tensile tester.
• Z100-twisted rayon multifilament yarn (f1350) of fineness 2440 dtex is impregnated at room temperature of a stabilizer solution and then dried.
• Dipping medium is a 20 mass% stabilizer solution in the sense of this invention or a 20 mass% solution of the main components urea and polyethylene glycol alkyl ether.
• Subsequent aging tests are carried out according to Methods A and B (air and nitrogen) (20 min at 240 ° C). The highest tensile forces and degrees of polymerization measured after thermal stress are shown graphically in FIG. 1. After aging in air, the stabilized fibers show a 25-30%, under nitrogen 17-21% higher relative residual strengths than the unstabilized fiber.
• Z100-twisted rayon multifilament yarn (f1350) having a fineness of 2440 dtex is impregnated at room temperature with a stabilizer solution and then dried.
• Dipping medium is a 20 mass% stabilizer solution according to the invention or a 20 mass% solution of the main components urea and polyethylene glycol alkyl ether.
• Subsequent aging tests are carried out according to method C (air, 7 days at 150 ° C). The maximum tensile forces and degrees of polymerization measured after thermal stress are shown graphically in FIG. 2. While the strength of an untreated fiber breaks down after aging to about 45% of the initial value, with additivated fibers still 64-67% residual strength is measured. This corresponds to 41-47% higher relative residual strengths.
• Z100-twisted rayon multifilament yarn (f1350) having a fineness of 2440 dtex is impregnated at room temperature with a stabilizer solution according to the invention and then dried.
• a stabilizer concentration in the dipping solution of 2% by mass a stabilizer uptake of about 7% by mass based on the titer of the untreated yarn, at a concentration of 15% by mass.
• the yarn absorbs about 17% by mass of stabilizer.
• Subsequent aging tests are carried out according to Methods A and B (20 min at 240 ° C, air or nitrogen). The maximum tensile forces and degrees of polymerization measured after thermal stress are shown graphically in FIG. 3.
• Z100-twisted rayon multifilament yarn (f1350) having a fineness of 2440 dtex is impregnated at room temperature with a stabilizer solution according to the invention and then dried.
• a stabilizer concentration in the dipping solution of 2% by mass stabilizer uptake of about 7% by mass based on the titer of the untreated yarn is achieved, at a concentration of 20% by mass, the yarn absorbs about 19% by mass of stabilizer .
• Subsequent aging tests are carried out according to method C (7 days at 150 ° C). The maximum tensile forces and degrees of polymerization measured after thermal stress are shown graphically in FIG. 4.
• Z100-twisted rayon multifilament yarn (f1350) having a fineness of 2440 dtex is impregnated at room temperature with a stabilizer solution according to the invention and then dried.
• the aqueous immersion solutions have a constant stabilizer content of 10%, but vary from pH 9 to 12.
• Subsequent aging tests are carried out according to Methods A and B (20 min at 240 ° C, air or nitrogen).
• the maximum tensile forces and degrees of polymerization measured after thermal stress are shown graphically in FIG.
• the residual strength and residual polymerization after thermal stress depend not only on the concentration but also on the pH of the stabilizer dispersion.
• the best properties after aging show yarns which have been impregnated with dip solutions at pH 1 1. While the strengths after impregnation at pH 12 are still comparable to the values at pH 1 1, the more sensitive degree of polymerization is already off the plateau.
• the effectiveness of the formulation as a processing stabilizer can thus be further optimized by adjusting the pH.
• Z100-twisted rayon multifilament yarn (f1350) having a fineness of 2440 dtex is impregnated at room temperature with a stabilizer solution according to the invention and then dried.
• the aqueous immersion solutions have a constant stabilizer content of 10% but vary from pH 9 to 12.
• Subsequent aging tests are carried out according to the method C performed (7 days at 150 ° C).
• the highest tensile forces and degrees of polymerization measured after thermal stress are shown graphically in FIG.
• the residual strength and residual polymerization after thermal stress depend not only on the concentration but also on the pH of the stabilizer dispersion. While the strengths in the short-term test remain stable up to pH 12 after impregnation, the optimum in the long-term test is between pH 10 and 11. By adjusting the pH, the effectiveness of the stabilizer can therefore also be optimized for applications with elevated continuous service temperatures.
• the strength of the unstabilized fiber is drastically reduced, its average degree of polymerization is below the limit of quantification.
• a fiber with 10 mass% stabilizer achieves a three times higher residual strength compared to the unstabilized fiber thermal load under air.
• An increase of the stabilizer content to 15% by mass results in this experiment also a disproportionate increase in the residual strength as well as the degree of polymerization in the long-term aging test.
• the stabilizer according to the invention therefore has in optimal composition and concentration the potential to equip cellulosic products for applications with increased continuous service temperatures of 150 ° C and more.
• a 10% by mass urea solution is added so that the total concentration of urea in the batch is about 7% by weight.
• the mixture is post-condensed in the presence of urea overnight.
• the total amount of adhesion promoter and stabilizer applied is about 6-7% by mass.
• the total amount of adhesion promoter and stabilizer applied is about 7-8% by mass.
• Subsequent aging tests are carried out according to Method D (168 hours in a wide-mouth bottle at 150 ° C).
• the adhesion values before thermal stress and the maximum tensile forces before and after thermal stress are shown graphically in FIG. 11.
• the adhesion value determined in peel tests remains at a good level despite stabilizer addition and is still about 85% of the peel force of the unstabilized adhesion-impregnated sample.
• the initial strength of the stabilized, unaged fiber is slightly lower than that of an unstabilized sample. However, 96% of this strength remains after 168 hours of aging at 150 ° C.

Landscapes

• Engineering & Computer Science (AREA)
• Textile Engineering (AREA)
• Chemical & Material Sciences (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Treatments For Attaching Organic Compounds To Fibrous Goods (AREA)

Priority Applications (1)

Applications Claiming Priority (2)

Publications (2)

Family

ID=48794043

Family Applications (1)

Country Status (2)

Cited By (1)

Citations (1)

Family Cites Families (4)

• 2013
  • 2013-03-27 EP EP13737548.1A patent/EP2831334B1/fr active Active
  • 2013-03-27 WO PCT/EP2013/056629 patent/WO2013144261A2/fr not_active Ceased

Patent Citations (1)

Also Published As

Similar Documents

Legal Events