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

Definitions

• the invention relates to synthetic fibers made of polyesters, prefers polyester monofilaments, which are made by adding a Combination of mono- and polycarbodiimides against the thermal and especially hydrolytic degradation have been stabilized and appropriate procedures for their Manufacturing.
• Polyester molecules are split such that for example, in the case of a polyethylene terephthalate Splitting of the ester bond to form one Carboxyl end group and a vinyl ester takes place, the Vinyl ester then with elimination of acetaldehyde reacted further.
• thermal decomposition will especially by the level of the reaction temperature, the Dwell time and possibly by the nature of the Polycondensation catalyst influenced.
• the hydrolysis resistance is one Polyester strongly by the number of carboxyl end groups per Weight unit pending. It is known to be an improvement to achieve hydrolysis resistance by the fact that this Carboxyl end groups closed by chemical reactions will. As such a "closure" of the carboxyl end groups are already multiple reactions with aliphatic, aromatic, but also cycloaliphatic mono-, bis- or Polycarbodiimides have been described.
• JP-AS 1-15604 / 89 can be removed, it is for the desired thermal and hydrolytic resistance of threads made therefrom of particular importance that in the finished threads or Monofilaments still contain free carbodiimide because otherwise, for example, among the very aggressive Conditions in a paper machine such materials would soon be unusable.
• the JP-AS is still closed see that the use of polycarbodiimides not corresponds to the state of the art already achieved.
• the subject of the invention are therefore Polyester fibers and filaments, in which the closure of the Carboxyl end groups predominantly by reaction with mono- and / or Biscarbodiimiden takes place, the fibers and filaments according to the invention, however, only 30 to 200 ppm of these Contain carbodiimides in free form and the content of free mono-carbodiimides is not 33 ppm.
• polyester content of free mono- and / or biscarbodiimides should in principle be as low as possible, it has now been found that fibers and filaments which do not contain more than 200 ppm of these substances in free form are very suitable for applications in Equipment that is completely closed or that is equipped with systems for cleaning exhaust air and waste water is suitable.
• An example of such an application of the fibers and filaments according to the invention is their use for the production of paper machine screens.
• polyester fibers and filaments still contain at least 0.02% of at least one polycarbodiimide, this polycarbodiimide in free form or with at least some reactive carbodiimide groups.
• the desired polyester fibers and filaments with significantly improved resistance to thermal and / or hydrolytic attack should contain less than 3 meq / kg carboxyl end groups in the polyester. Fibers and filaments in which the number of carboxyl end groups has been reduced to less than 2, preferably even less than 1.5 meq / kg polyester are preferred.
• the content of free mono- and / or bis-carbodiimides should preferably be 30 to 150 ppm, in particular 30 to 100 ppm, based on the weight of the polyester. This applies on the condition that the content of monocarbodiimide is not 33 ppm. It must be ensured that the fibers and filaments still contain polycarbodiimides or their reaction products with groups which are still reactive. Concentrations of 0.05 to 0.6, in particular 0.1 to 0.5% by weight of polycarbodiimide in the polyester fibers and filaments are preferred.
• the molecular weight of suitable carbodiimides is between 2000 and 15000, preferably between 5000 and about 10000.
• polyesters that have a high, medium molecular weight, corresponding to an intrinsic viscosity (intrinsic viscosity) of at least 0.64 [dl / g].
• intrinsic viscosity intrinsic viscosity
• the process according to the invention for producing the claimed stabilized polyester fibers and filaments consists in the addition of mono- and / or biscarbodiimide in an amount of 0.5% by weight or less, based on polyester, and additionally in an amount of at least 0.05% by weight of a polycarbodiimide .
• the amounts of mono- and / or biscarbodiimides and of polycarbodiimides are selected so that the resulting polyester is 30 to 200 ppm, preferably 30 to 150 ppm, in particular 30 to 100 Contains ppm of mono- and / or biscarbodiimides and at least 0.02% by weight of polycarbodiimides and the content of free monocarbodiimide is not 33 ppm.
• This mixture of polyester and carbodiimides can be spun in a known manner to form threads and monofilaments or staple fibers and processed further.
• polyesters to be used are less than 20, preferably even less than 10 meq carboxyl end groups should have per kg. In these values is already the Increase due to melting has also been taken into account.
• Polyesters and carbodiimides are not at high temperatures to store for any length of time. It was already mentioned above noted that when melting polyesters additional Carboxyl end groups arise. Even the ones used Carbodiimides can at high temperatures Decompose polyester melts. It is therefore desirable that Contact or reaction time of the carbodiimide additives with the to limit molten polyesters as much as possible. When in use of melt extruders, it is possible to spend this time in the molten state to less than 5, preferably less less than 3 minutes. A limitation of Melting time in the extruder is only given by the fact that for a perfect reaction between carbodiimide and polyester carboxyl end groups sufficient mixing of the Reactants must take place. This can be done by appropriate Design of the extruder or, for example, by use by static mixers.
• polyesters i.e. aliphatic / aromatic polyesters such as e.g. Polyethylene terephthalate or polybutylene terephthalate, but also completely aromatic and for example Halogenated polyesters can be used in the same way.
• Building blocks of thread-forming polyesters are preferred Diols and dicarboxylic acids, or correspondingly constructed Oxycarboxylic acids.
• the main acid component of the polyester is Terephthalic acid, of course others are also suitable preferably para- or trans-permanent connections such as e.g. 2,6-naphthalenedicarboxylic acid but also p-hydroxybenzoic acid call.
• Typical suitable dihydric alcohols would be for example ethylene glycol, propanediol, 1,4-butanediol also hydroquinone, etc.
• Preferred aliphatic diols have two up to four carbon atoms.
• Ethylene glycol is particularly preferred.
• Longer-chain diols can, however, be used in proportions of up to approx. 20 mol%, preferably less than 10 mol% for modification of the properties are used.
• Polyester fibers and filaments the predominant or consist entirely of polyethylene terephthalate and especially those that have a molecular weight an intrinsic viscosity (intrinsic viscosity) of at least 0.64, preferably at least 0.70 [dl / g].
• the Intrinsic viscosities are in dichloroacetic acid at 25 ° C certainly.
• the stabilization of the filaments according to the invention or fibers by adding a combination of one Mono- and / or biscarbodiimide on one side and one polymeric carbodiimide achieved on the other hand.
• the use of monocarbodiimides is preferred since they are especially by a high reaction rate the reaction with the carboxyl end groups of the polyester award.
• polyesters after the polycondensation remaining carboxyl groups should according to the invention Process mainly by reaction with a mono- or
• Biscarbodiimide be closed. A lower proportion the carboxyl end groups is among these according to the invention Conditions also with carbodiimide groups in addition used polycarbodiimide react.
• the polyester fibers and filaments of the invention therefore contain instead of the carboxyl end groups in essentially their reaction products with those used Carbodiimides.
• Mono- or bis-carbodiimides which only if at all, to a very small extent in free form in the Fibers and filaments may occur are the known, Aryl, alkyl and cycloalkyl carbodiimides.
• Both Diarylcarbodiimides, which are preferably used, the aryl nuclei may be unsubstituted. Preferably however, are substituted in the 2- or 2,6-position and thus sterically hindered aromatic carbodiimides used.
• DE-AS 1 494 009 Variety of monocarbodiimides with steric disabilities the carbodiimide group listed.
• N, N '- (di-o-tolyl) carbodiimide and the N, N '- (2,6,2', 6'-tetraisopropyl) diphenyl carbodiimide are particularly suitable for example, of the monocarbodiimides, the N, N '- (di-o-tolyl) carbodiimide and the N, N '- (2,6,2', 6'-tetraisopropyl) diphenyl carbodiimide.
• Biscarbodiimide, which according to the Invention are suitable, for example, in DE-OS 20 20 330.
• compounds are polycarbodiimides suitable in which the carbodiimide units on or doubly substituted aryl nuclei linked together are, as aryl nuclei phenylene, naphthylene, diphenylene and the divalent radical derived from diphenylmethane in Come into consideration and the substituents according to type and The place of substitution is the substituent in the aryl nucleus correspond to substituted mono-diarylcarbodiimides.
• a particularly preferred polycarbodiimide is the commercially available aromatic polycarbodiimide, which is substituted with isopropyl groups in the o-position to the carbodiimide groups, ie in the 2,6- or 2,4,6-position on the benzene nucleus.
• the polycarbodiimides contained free or bound in the polyester filaments according to the invention preferably have an average molecular weight of from 2000 to 15,000, but in particular from 5,000 to 10,000. As already stated above, these polycarbodiimides react with the carboxyl end groups at a significantly lower rate. If such a reaction occurs, preferably only one group of the carbodiimide will initially react.
• the other groups present in the polymeric carbodiimide lead to the desired depot effect and are the cause of the substantially improved stability of the fibers and filaments obtained.
• the polymeric carbodiimides present in them have not yet been completely reacted, but instead have free carbodiimide groups for trapping further carboxyl end groups.
• polyester fibers and filaments produced according to the invention usual additives such as Titanium dioxide as Matting agents or additives for example for Improve the dyeability or to reduce electrostatic charges included.
• additives such as Titanium dioxide as Matting agents or additives for example for Improve the dyeability or to reduce electrostatic charges included.
• additions or comonomers are of course also suitable the flammability of the fibers and filaments produced can reduce in a known manner.
• Colored pigments, soot or soluble Dyes are incorporated into the polyester melt or already included.
• Polymers e.g. Polyolefins, polyesters, polyamides or polytetrafluoroethylene it is possible, if necessary to achieve completely new textile-technical effects. Also the Addition of cross-linking substances and similar additives can bring advantages for selected areas of application.
• polyester fibers and filaments As already stated above for the production of the polyester fibers and filaments according to the invention Mixing and melting required. Preferably can this melting in the melt extruder directly before actual spinning process take place.
• the addition of the Carbodiimide can be added to the polyester chips, Impregnate the polyester material before the extruder suitable solutions of the carbodiimides, but also by Breading or the like.
• Another type of Additive is especially for the metering of the polymer Carbodiimide, the production of master batches in Polyester (masterbatches). With these concentrates it can Polyester material to be treated directly in front of the extruder or, when using for example one Twin screw extruder, also mixed in the extruder will. If the polyester material to be spun is not is in chip form, but for example continuously as Corresponding melt must be delivered Metering devices for the carbodiimide optionally in melted form, can be provided.
• the amount of the Amount of mono and / or to be added in individual cases Biscarbodiimides according to the carboxyl end group content of the starting polyester taking into account the probable at the Melting process still occurring additional Carboxyl end groups.
• a preferred form of addition for the Polycarbodiimide represents the addition of base batches, which have a higher percentage, e.g. 15% Polycarbodiimide in a conventional polymer Contain polyester granulate.
• the dwell time of the Carbodiimides in the melt preferably less than 5 min, in particular be less than 3 minutes.
• Quantities of mono- or biscarbodiimide largely quantitative, i.e. they are then no longer in free form in the squeezed threads detectable. It also responds to a percentage, albeit a significantly lower one some of the carbodiimide groups used Polycarbodiimides, which primarily function as a depot take over.
• the temperature in the first stage stretching was 80 ° C and in the second stage 90 ° C, the Running speed of the spinning threads after leaving the Quench bath was 32 m / min. Subsequently, one Heat setting in a fixing channel at one temperature of 275 ° C. All spun monofilaments had a final diameter of 0.4 mm.
• Example 1 was also used here for comparison purposes repeated. However, this time an amount of 0.876% by weight of the polycarbodiimide described above in the form of a 15% masterbatch. This attempt was made carried out once again the information in the previous literature check after which even with a noticeable excess of polycarbodiimide, probably due to the low Responsiveness, one over the prior art reduced thermal and hydrolytic resistance can be observed. This example clearly shows that this is actually the case. It is interesting that this is chosen Amount of polycarbodiimide already at a noticeable Crosslinking of the polyester seems to result, as from the significant increase in intrinsic viscosity values can be. Generally, such networking is with thread-forming polymers only within narrow limits permissible if it is strictly reproducible and none Difficulty in spinning or difficulty in drawing the threads made from it are to be expected.
• Example 1 The procedure according to Example 1 or Example 2 was repeated, but now amounts of monocarbodiimide were added, resulting from the stoichiometric calculated value or a 20% excess Monocarbodiimide result. Even those preserved here Results are shown in the table below.
• a run 4a was exactly the stoichiometrically required Amount of monocarbodiimide added while in one run 4b an excess of 1.3 meq / kg of monocarbodiimide was used.
• the relative residual strengths found after a Treatment at 135 ° C in a steam atmosphere after a Time of 80 hours not state of the art. An excess of approx.
• Example 1 was repeated, but this time, in addition to monocarbodiimide, a polycarbodiimide was also used according to the invention. In this experiment, 0.4% by weight of monocarbodiimide and 0.32% by weight of polycarbodiimide, based on polyester, were added.
• the monofilament thus produced was used to manufacture Paper machine screens are ideally suited.

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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)
• Polyesters Or Polycarbonates (AREA)
• Paper (AREA)
• Compositions Of Macromolecular Compounds (AREA)
• Macromolecular Compounds Obtained By Forming Nitrogen-Containing Linkages In General (AREA)

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Publications (2)

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• 1991
  • 1991-11-28 JP JP31474991A patent/JP3228977B2/ja not_active Expired - Fee Related
• 1992
  • 1992-02-01 TW TW081100834A patent/TW212820B/zh active
  • 1992-03-02 EP EP92103536A patent/EP0503421B1/de not_active Expired - Lifetime
  • 1992-03-02 ES ES92103536T patent/ES2113384T3/es not_active Expired - Lifetime
  • 1992-03-02 DE DE59209093T patent/DE59209093D1/de not_active Expired - Fee Related
  • 1992-03-02 AT AT92103536T patent/ATE161903T1/de not_active IP Right Cessation
  • 1992-03-12 FI FI921068A patent/FI104568B/fi active
  • 1992-03-12 KR KR1019920004037A patent/KR100209864B1/ko not_active Expired - Fee Related
  • 1992-03-13 CA CA002063023A patent/CA2063023A1/en not_active Abandoned
  • 1992-03-13 RU SU925011051A patent/RU2094550C1/ru active
  • 1992-03-13 IE IE082992A patent/IE920829A1/en unknown
  • 1992-03-13 MX MX9201124A patent/MX9201124A/es not_active IP Right Cessation
  • 1992-03-13 BR BR9200867-4A patent/BR9200867A/pt not_active IP Right Cessation
• 1996
  • 1996-10-25 US US08/735,317 patent/US5885709A/en not_active Expired - Fee Related

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