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
  • D01F6/00—Monocomponent artificial filaments or the like of synthetic polymers; Manufacture thereof
  • D01F6/58—Monocomponent artificial filaments or the like of synthetic polymers; Manufacture thereof from homopolycondensation products
  • D01F6/62—Monocomponent artificial filaments or the like of synthetic polymers; Manufacture thereof from homopolycondensation products from polyesters
• • 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
  • D01F1/00—General methods for the manufacture of artificial filaments or the like
  • D01F1/02—Addition of substances to the spinning solution or to the melt
  • D01F1/10—Other agents for modifying properties
• • 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

Definitions

• the present invention relates to polyester fibers having high abrasion and bending resistance, in particular monofilaments, which can be used for example in screens or in conveyor belts.
• polyester fibers in particular monofilaments for technical applications, are in most cases subjected to high mechanical and / or thermal stresses during use.
• the material must have good dimensional stability and constancy of force-elongation properties over as long as possible usage periods.
• Molding compositions with high chemical and physical resistance and their use for fiber production are known. Widely used Materials are polyester. It is also known to combine these polymers with other materials, for example, to set the abrasion resistance targeted.
• polyester-based manmade fibers have proven successful in such environments, when used in humid-hot environments, polyesters are prone to mechanical abrasion in addition to hydrolytic degradation.
• abrasion can have a variety of causes.
• the sheet forming screen is pulled in paper machines for dewatering suction boxes with the result of increased Siebverschl constituentes.
• screen wear occurs due to differences in speed between the paper web and the screen surface or between the screen surface and the surface of the drying drums.
• Tissue wear also occurs in other technical fabrics due to abrasion; e.g. in conveyor belts by grinding over fixed surfaces, in filter fabrics by mechanical cleaning and in screen printing fabrics by passing a squeegee over the screen surface.
• polyester raw material containing finely dispersed silica gels is known.
• the individual particles have diameters of up to 60 nm and aggregates, if present, are not larger than 5 ⁇ m.
• the filler is said to result in polyester fibers having improved mechanical properties, improved color and improved handleability. Notes on applications for these polyester fibers are not apparent from the document.
• Monofilaments are described, which can be used, inter alia, in paper machines.
• the description mainly refers to polyamide monofilaments;
• polyester raw materials are also mentioned.
• the described monofilaments are characterized by the presence of nanoscale inorganic materials. These cause an increased abrasion resistance.
• platelets are also described.
• the described non-spherical particles are nanotons, ie layered particles. These can be treated with swelling agents, such as phosphonium or ammonium compounds, so that the laminations completely or partially dissolve, thereby forming particles that are less than 10 nm thick in one dimension.
• platelet-shaped particles this document thus mentions either the use of layered particles whose layer structure has not or only partially dissolved, with aggregates having thicknesses below 100 nm or whose layer structure has completely dissolved, with particles having thicknesses below 10 nm are present.
• exfoliated montmorillonites are mentioned in this document.
• nanoclays in polyester spinning masses has shown that in the As a rule, difficulties during spinning occur. Either the spinning masses can not be processed at all or special measures must be taken to be able to produce a thread at all. If, on the other hand, nanoparticles of too small thickness are used, it has been found that fibers are formed which do not have satisfactory textile-technological properties. It is believed that the high level of interfaces created by these very small particles in the polymer interfere with stretching so that the polymer chains are poorly ordered after the stretching process. This has a negative effect on the mechanical properties, such as the strength of the thread.
• nanoscale fillers can lead to fibers with improved mechanical properties.
• filler additions in addition to the desired improvement of some properties, simultaneously cause the deterioration of other properties.
• selected polyester raw materials comprising certain nanoscale fillers have a significantly improved abrasion resistance compared to unmodified polyester raw materials without their dynamic load capacity, expressed by the bending resistance, being appreciably reduced or even increased by the filler insert. This property profile was found on selected polyester raw materials.
• the present invention the object of the invention to provide filled polyester fibers, which in addition to excellent abrasion resistance compared with the unfilled polyester fibers have comparable or even improved dynamic loads.
• Another object of the present invention was to provide transparent fibers having high abrasion resistance and excellent dynamic loadability.
• the invention relates to fibers containing aliphatic-aromatic polyester and non-layered, platelet-shaped particles selected from the group of inorganic oxides, hydroxides, carbonates, bicarbonates, nitrides and carbides whose thickness is 20 nm to less than or equal to 100 nm and whose aspect ratio is not more than 20: 1.
• thickness is understood to be the smallest extent of the particle along one of the main axes of inertia.
• the aspect ratio is understood as meaning the quotient of the greatest extent of the particle along one of the principal axes of inertia to the smallest extent of the particle along one of the principal axes of inertia; i.e. the aspect ratio is the quotient of the largest length of the particle (along one of the principal axes of inertia) to the thickness.
• polyester fibers having a content of free carboxyl groups of less than or equal to 3 meq / kg.
• These preferably contain a means for occluding free carboxyl groups, for example a carbodiimide and / or an epoxide compound.
• Such equipped polyester fibers are stabilized against hydrolytic degradation and are particularly suitable for use in humid-hot environments, especially in paper machines or as a filter.
• the fiber-forming polyesters can be of any nature, as long as they are have aliphatic and aromatic groups and are deformable in the melt. Within the scope of this description, aliphatic groups are also to be understood as meaning cycloaliphatic groups.
• thermoplastic polyesters are known per se. Examples of these are polybutylene terephthalate, polycyclohexanedimethyl terephthalate, polyethylene naphthalate or, in particular, polyethylene terephthalate. Building blocks of thread-forming polyesters are preferably diols and dicarboxylic acids, or appropriately constructed oxycarboxylic acids.
• the main acid constituent of the polyesters is terephthalic acid or cyclohexanedicarboxylic acid, but other aromatic and / or aliphatic or cycloaliphatic dicarboxylic acids may also be suitable, preferably para- or trans-aromatic compounds, e.g.
• Aliphatic dicarboxylic acids e.g. Adipic acid or sebacic acid, are preferably used in combination with aromatic dicarboxylic acids.
• Typical suitable dihydric alcohols are aliphatic and / or cycloaliphatic diols, for example ethylene glycol, propanediol, 1,4-butanediol, 1,4-cyclohexanedimethanol or mixtures thereof. Preference is given to aliphatic diols having from two to four carbon atoms, in particular ethylene glycol; furthermore preferred are cycloaliphatic diols, such as 1,4-cyclohexanedimethanol.
• polyesters which have repeating structural units which are derived from an aromatic dicarboxylic acid and an aliphatic and / or cycloaliphatic diol.
• thermoplastic polyesters are in particular selected from the group consisting of polyethylene terephthalate, polyethylene naphthalate, polybutylene naphthalate, polypropylene terephthalate, Polybutylene terephthalate, polycyclohexanedimethanol terephthalate or a copolycondensate containing polybutylene glycol, terephthalic acid and naphthalenedicarboxylic acid units.
• the polyesters used according to the invention usually have solution viscosities (IV values) of at least 0.60 dl / g, preferably from 0.60 to 1.05 dl / g, particularly preferably from 0.62 to 0.93 dl / g ( measured at 25 ° C in dichloroacetic acid (DCE)).
• IV values solution viscosities
• the nanoscale fillers used according to the invention impart excellent abrasion resistance to the polyester fibers without adversely affecting the dynamic properties, expressed by the bending resistance.
• the fillers used according to the invention are special non-layered, platelet-shaped particles. These are selected from the group of inorganic oxides, hydroxides, carbonates, bicarbonates, nitrides and carbides.
• the particles are not spherical but platelike. Their thickness is less than or equal to 100 nm, preferably less than or equal to 80 nm and in particular 20-60 nm.
• Another characteristic property of the fillers is their aspect ratio, ie the ratio of the largest dimension of the particle along one of the main axes of inertia to the smallest extent of the particle along one the main axis of inertia. The aspect ratio is not more than 20: 1.
• Layered fillers such as sheet silicates (so-called nanotones), ie, such as montmorillonites, are not desired in the context of this invention, since their use on the one hand disturbs the processing of the fibers and on the other hand, no significant property improvement could be observed.
• the nanoscale and non-spherical oxides used according to the invention are typically oxides of metals of group IIa of the Periodic Table, preferably oxides of magnesium, calcium or strontium, or oxides of metals of group IIIb of the Periodic Table, preferably oxides of aluminum, Gallium or indium, or oxides of metals of group IVa of the periodic table, preferably oxides of titanium, zirconium or hafnium, or oxides of metals of group IIIa of the periodic table, preferably oxides of scandium or yttrium, or oxides of metals or Semimetals of Group IVb of the Periodic Table, preferably oxides of silicon, germanium or tin.
• oxides it is also possible to use the corresponding hydroxides or it is also possible to use mixed crystals of different metal oxides, for example Al 2 O 3 .2SiO 2 (mullite).
• the nanoscale and non-spherical carbonates used according to the invention are carbonates of metals of group IIa of the periodic table, preferably carbonates of magnesium, calcium or strontium.
• the nanoscale and non-spherical carbides used according to the invention are typically carbides of metals of group IIIb of the periodic system, preferably carbides of aluminum, gallium or indium, or carbides of metals or semimetals of group IVb of the periodic table, preferably carbides of the periodic table Silicon, germanium or tin.
• the nanoscale and non-spherical nitrides used in the invention are nitrides of metals Group IIIb of the Periodic Table, preferably to nitrides of aluminum, gallium or indium, or to nitrides of metals or metalloids of Group IVb of the Periodic Table, preferably to nitrides of silicon, germanium or tin.
• polyester raw materials required and filled to produce the fibers according to the invention can be produced in different ways.
• polyester and filler and optionally further additives can be melted with the polyester in a mixing unit, for example in an extruder, mix and the composition is then fed directly to the spinneret or the composition is granulated and spun in a separate step. If appropriate, the resulting granules can also be spun as a masterbatch together with additional polyester. It is also possible to add the nanoscale fillers before or during the polycondensation of the polyester.
• Suitable nanoscale non-spherical fillers are commercially available.
• the product DP 6096 (calcium carbonate in ethylene glycol) from Nano Technologies, Inc. Ashland, MA, U.S.A. may be used.
• the content of nanoscale non-spherical filler of the fiber according to the invention can vary within wide limits, however, is typically not more than 5% by weight, based on the mass of the fiber.
• the content of nanoscale spherical filler in the range of 0.1 to 2.5 wt.%, In particular from 0.5 to 2.0 wt.%.
• the type and amount of components a) and b) are preferably chosen so that transparent products are obtained.
• the polyesters used according to the invention are distinguished by transparency. Surprisingly, it has been shown that the nanoscale non-spherical fillers do not adversely affect the transparency.
• the abrasion resistance of the fibers according to the invention can be further increased by the addition of polycarbonate.
• the amount of polycarbonate is up to 5 wt.%, Preferably 0.1 to 5.0 wt.%, Particularly preferably 0.5 to 2.0 wt.%, Based on the total mass of the polymers.
• fibers are to be understood as meaning any fibers.
• filaments or staple fibers which consist of several individual fibers, but in particular monofilaments.
• polyester fibers according to the invention can be prepared by processes known per se.
• the polyester fibers according to the invention are drawn one or more times in the preparation.
• a polyester produced by solid phase condensation is used in the production of the polyester fibers.
• polyester fibers according to the invention can be present in any desired form, for example as multifilaments, as staple fibers or in particular as monofilaments.
• the titer of the polyester fibers according to the invention can likewise vary within wide limits. Examples are 100 to 45,000 dtex, in particular 400 to 7,000 dtex.
• polyester raw material can be used. This typically has levels of free carboxyl groups of 15 to 50 meq / kg of polyester. Preference is given to using polyester raw materials produced by solid phase condensation; in these, the content of free carboxyl groups is typically 5 to 20 meq / kg, preferably less than 8 meq / kg of polyester.
• polyester raw material which already contains the nanoscale, non-layered, platelet-shaped filler.
• the filler is added during the polycondensation and / or at least one of the monomers.
• the hot polymer filament is cooled, e.g. in a cooling bath, preferably in a water bath, and then wound up or peeled off.
• the removal speed is greater than the injection rate of the polymer melt.
• the polyester fiber thus produced is then preferably a Post-drawing, more preferably in several stages, in particular a two- or three-stage post-drawing, with a total draw ratio of 1: 3 to 1: 8, preferably 1: 4 to 1: 6 subjected.
• the take-off speed is usually 10 - 80 m per minute.
• polyester fibers according to the invention may contain, in addition to nanoscale, non-layered, platelet-shaped filler, further auxiliaries.
• processing aids antioxidants, plasticizers, lubricants, pigments, matting agents, viscosity modifiers or crystallization accelerators.
• processing aids are siloxanes, waxes or longer-chain carboxylic acids or their salts, aliphatic, aromatic esters or ethers.
• antioxidants are phosphorus compounds, such as phosphoric acid esters or sterically hindered phenols.
• pigments or matting agents examples include organic dye pigments or titanium dioxide.
• viscosity modifiers are polybasic carboxylic acids and their esters or polyhydric alcohols.
• the fibers of the invention can be used in all industrial fields. They are preferably used in applications in which increased wear due to mechanical stress is to be expected. Examples include the use in screens or in conveyor belts. These uses are also the subject of the present invention.
• polyester fibers according to the invention are preferably used for the production of fabrics, in particular fabrics, which are used in fabrics.
• polyester fibers in the form of monofilaments according to the invention relates to their use as conveyor belts or as components of conveyor belts.
• Another object of the present invention is the use of non-layered, platelet-shaped particles selected from the group of inorganic oxides, hydroxides, carbonates, bicarbonates, nitrides and carbides whose thickness is less than 100 nm and whose aspect ratio is not more than 20: 1 is for the production of fibers, in particular monofilaments, with high abrasion resistance.
• PET polyethylene terephthalate
• optionally hydrolysis stabilizer were mixed in the extruder, melted and spun through a 20 hole spinneret with a hole diameter of 1.0 mm at a flow rate of 488 g / min and a take-off speed of 31 m / min to monofilaments , stretched three times with degrees of stretching 1: 4,95; 1: 1.13; and 1: 0.79; and heat-set in the hot air duct at 255 ° C under heat shrinkage.
• the total draw was 1: 4.52.
• Monofilaments with a diameter of 0.25 mm were obtained.
• the PET used was a type with an IV value of 0.72 dl / g, to which 0.04% by weight of nanoscale Al 2 O 3 of 50 nm had been added.
• Example V1 Monofilaments were prepared as described in the procedure of Example 1. Different PET raw materials but no nanoscale fillers were used. In Example V1, a type having an IV value of 0.72 dl / g was used and in Example V2 a type having an IV value of 0.9 dl / g.

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• Engineering & Computer Science (AREA)
• Chemical & Material Sciences (AREA)
• Chemical Kinetics & Catalysis (AREA)
• General Chemical & Material Sciences (AREA)
• Textile Engineering (AREA)
• Manufacturing & Machinery (AREA)
• Artificial Filaments (AREA)

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• 2005
  • 2005-07-16 DE DE102005033350A patent/DE102005033350A1/de not_active Ceased
• 2006
  • 2006-06-23 EP EP06012933A patent/EP1743963A1/fr not_active Withdrawn
  • 2006-07-10 US US11/483,988 patent/US20070014989A1/en not_active Abandoned
  • 2006-07-14 JP JP2006193469A patent/JP2007023474A/ja not_active Withdrawn

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