Classifications

• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
  • C08G63/00—Macromolecular compounds obtained by reactions forming a carboxylic ester link in the main chain of the macromolecule
  • C08G63/68—Polyesters containing atoms other than carbon, hydrogen and oxygen
  • C08G63/695—Polyesters containing atoms other than carbon, hydrogen and oxygen containing silicon
  • C08G63/6954—Polyesters containing atoms other than carbon, hydrogen and oxygen containing silicon derived from polxycarboxylic acids and polyhydroxy compounds
  • C08G63/6956—Dicarboxylic acids and dihydroxy compounds
• • 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
  • D01F6/00—Monocomponent artificial filaments or the like of synthetic polymers; Manufacture thereof
  • D01F6/78—Monocomponent artificial filaments or the like of synthetic polymers; Manufacture thereof from copolycondensation products
  • D01F6/84—Monocomponent artificial filaments or the like of synthetic polymers; Manufacture thereof from copolycondensation products from copolyesters
• • 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
• • 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
  • Y10T428/2967—Synthetic resin or polymer
• • 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
  • Y10T428/2967—Synthetic resin or polymer
  • Y10T428/2969—Polyamide, polyimide or polyester

Definitions

• the invention relates to a process for the preparation of dirt-repellent and abrasion-resistant monofilaments with a diameter of 0.1 to 1.0 mm, from a linear polyethylene terephthalate / polydialkylsiloxane for the production of screen fabrics, and monofilaments for their use.
• Solid-repellent properties for paper machine screens are understood to mean wet soiling, which also requires resistance to hydrolysis.
• the dirt repellency is intended to extend the cleaning cycles of a sieve, the cleaning work being carried out under a high-pressure water jet and, if necessary, with a brush.
• Dirt-repellent monofilaments are processed into technical fabrics, which are used in the wet section, in the press and dryer sections of a paper machine. Such screens are exposed to moisture and temperatures well above 100 ° C, as well as to increased mechanical stress when cleaning. Pure polyester monofilaments have disadvantages because of their dirtiness, susceptibility to hydrolysis or their relative brittleness. By adding additives in the form of stabilizers, an improvement in the resistance to hydrolysis was achieved. The increase in
• “Abrasion-resistant” monofilaments are understood to mean those monofilaments in which no weight loss measurable in practice and no or only slight fibrillation are found in the fibrillation test.
• copolyesters which are modified with siloxanes are eminently suitable for the abovementioned field of application, since their surface characteristics can be easily modified thanks to better sliding properties and a lower coefficient of friction, which significantly reduces the brittleness and the Dirt repellency is significantly improved.
• the fabric can easily be post-treated.
• Polyester / polydimethylsiloxanes which are either in granular form or are modified by addition immediately before extrusion, have proven to be particularly suitable.
• Polyoxisilanes of the type which are modified polyesters and which are provided as starting material for the use according to the invention are known from US Pat. No. 5,123,392.
• the known chemically modified polymers are used for the production of hydrophilic staple fibers, but should also be able to be used for fabrics made from filament yarns.
• the hydrophilic properties enable moisture to be absorbed quickly and are therefore used primarily in a mixture with cotton and wool.
• yarns with the stated hydrophilic properties are unsuitable in the present form for paper machine screens or fishing lines.
• EP-A-0 269 023 also discloses silicone-modified polyesters which are suitable for producing fibers.
• silicone units are formed in a polyester matrix. These silicone units migrate into air during extrusion and into the outer casing of the filament during stretching. The surface obtained acts like a hydrophobic film.
• the cross-sectional chemical composition is not homogeneous.
• the object of the invention is to provide a dirt-repellent and abrasion-resistant monofilament which is homogeneous in cross-section and which meets the high demands of a technical fabric with regard to its chemical, dirt-repellent, mechanical and abrasion-resistant properties and is used particularly in the paper industry.
• the object is achieved according to the invention in that 0.15-5.0% by weight of polydialkylsiloxane by co-condensation, i.e. during the polycondensation; be built into the chain of the polymer.
• the tenacity of the monofilaments is higher than 36 cN / tex, with an elongation of ⁇ 44%, based on the unstretched filament, the key feature being surprisingly good dirt repellency and low fibrillation.
• the dirt repellency was determined as the soiling index with ⁇ 10 after 5 soiling / washout cycles, compared to> 14 ' for a polyester filament without polydimethylsiloxane.
• polyester which consists of at least 85% by weight of polyethylene terephthalate and a polydialkylsiloxane, the polyethylene
• ERSA ⁇ ZBLA ⁇ (RULE 26 terephthalate / polydialkylsiloxane in the finished monofilament contains 0.05 to 2% by weight, preferably 0.1 to 1.0% by weight of silicon, based on the polymer, and the homogeneous mixture is extruded into a monofilament. As . It should be emphasized that the monofilament produced has a homogeneous composition over the entire cross section.
• a polyethylene terephthalate which has an intrinsic viscosity of> 0.60 dl / g is suitable.
• copolymers used are preferably difunctional polydiorganosiloxanes of the general formula:
• R1, R2 represent the same or different radicals having 2 to 20 carbon atoms.
• PDMS Polydimethylsiloxanes
• the silicon content in the monofilament is 0.05 to 2.0% by weight, in particular 0.1 to 2% by weight, preferably 0.1 to 1.0% by weight.
• the polymer is prepared in a known manner by transesterification of dimethyl terephthalate and ethylene glycol and addition of 3.9% by weight of polydimethylsiloxane (PDMS) and manganese acetate in a stirred autoclave at 160 to 230 ° C, the resulting methanol distilling off quantitatively.
• the subsequent polycondensation is carried out in the temperature range from 245 to 285 ° C using an antimony catalyst for 200 min, in a first step under progressive vacuum (1000 -> 50 bar) for 40 min and in a second step in a high vacuum ( ⁇ 1mbar) is condensed.
• the polyethylene terephthalate / polydimethylsiloxane (PET / PDMS) is melted at a temperature of 290 ° C.
• the extrusion takes place via a spinneret with 13 capillaries and a capillary diameter of 1.8 mm with a polymer throughput of 486 g / min.
• the extruded monofilaments are cooled in a water bath at 70 ° C. After cooling, the monofilaments are spin-prepared and stretched to a residual elongation of approximately ⁇ 44%, relaxed and wound up at a speed of 100 m / min.
• the resulting thread has a soiling coefficient after five treatments of less than 10 ( ⁇ 10), has a tensile strength (Ft) of 36.1 cN / tex with an elongation (Dt) of 38.8% at a stretch of 500%, based on the unstretched monofilament.
• Ft tensile strength
• Dt elongation
• PET / PDMS polydimethylsiloxane
• AI - [DL *] / L * 0 x 100
• ERS ⁇ ZBLA ⁇ T (RULE 26) struck against a standardized solid for 10 minutes.
• Example grade 1 > a punch J: requenz [lj / min] 2000 2500 3000 3200
• Example 1 shows the result of the monofilament according to the invention, with no fibrillation at all at 2000 beats per minute, while fibrillation of less than half compared to the prior art occurs at 3200 beats.
• Example 2 shows the result of a "dirt repellent" polyester made with fluoropolymers and the examples
• PET / PDMS monofilaments produced according to the invention are also less stiff than known monofilaments.
• Fig. 1 is a force / strain diagram
• the values of the soiling indices shown in FIG. 2 show the influence of the successive cycles “soiling / washing out”. Average values of two samples after soiling and after washing are shown.
• Curve 1 shows the monofilament thread according to the invention.
• Curve 2 shows a comparison thread made of polyester according to the prior art, that is to say without the polydimethylsiloxane component. After (five) 5 soiling / washing cycles, the inventive monofilament indexes below 10 are achieved.
• Figure 3 shows the result of a fibrillation test in the form of photographic images.
• Figure 3a shows a polyester with a fluoropolymer; 3b the monofilament according to the invention. It can be seen from this that the monofilament according to the invention shows significantly low fibrillation.
• a sample of prior art polyethylene terephthalate shows
• the monofilament according to the invention brings an improvement in the soiling test by at least a factor of 1.5 compared to the prior art.
• the dirt repellency of the threads modified with siloxanes shows a significant improvement compared to the standard and roughly corresponds to the fluorine-containing special threads, which are questionable due to environmental pollution.
• the abrasion resistance of the threads is clearly increased compared to the prior art.
• the monofilaments according to the invention are preferably suitable for use in paper machine fabrics.

Landscapes

• Chemical & Material Sciences (AREA)
• Chemical Kinetics & Catalysis (AREA)
• General Chemical & Material Sciences (AREA)
• Engineering & Computer Science (AREA)
• Textile Engineering (AREA)
• Health & Medical Sciences (AREA)
• Medicinal Chemistry (AREA)
• Polymers & Plastics (AREA)
• Organic Chemistry (AREA)
• Artificial Filaments (AREA)
• Paper (AREA)

Applications Claiming Priority (3)

Publications (1)

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Family Applications (1)

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• 1994
  • 1994-06-28 AU AU69358/94A patent/AU680511B2/en not_active Ceased
  • 1994-06-28 US US08/392,926 patent/US5759685A/en not_active Expired - Fee Related
  • 1994-06-28 EP EP94917779A patent/EP0658222A1/de not_active Withdrawn
  • 1994-06-28 JP JP7503383A patent/JPH08501355A/ja active Pending
  • 1994-06-28 BR BR9405439-8A patent/BR9405439A/pt not_active Application Discontinuation
  • 1994-06-28 WO PCT/IB1994/000183 patent/WO1995001471A1/de not_active Application Discontinuation
  • 1994-06-28 CA CA002143424A patent/CA2143424A1/en not_active Abandoned
• 1995
  • 1995-03-01 FI FI950954A patent/FI950954A0/fi unknown

Non-Patent Citations (1)

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