EP0034740B1 - Process for simultaneously dyeing and coating sewing silk of polyester filaments - Google Patents

Description

The present invention relates to a process for the simultaneous dyeing and bonding of sewing silk consisting of filaments of linear polyesters, in which the twisted multifilament is continuously padded with an aqueous dispersion containing a thermally crosslinkable binder system during the rewinding, dried before rewinding and then subjected to a heat treatment becomes.

As a rule, twisted endless threads (multifilament) are used as sewing silk. On the part of the sewing silk processing industry, this article requires, among other things, good running properties at high sewing speeds. At the usual high sewing speeds, which cannot be compared with those of household sewing machines, high mechanical stresses due to friction and heating occur at the thread guide points, but especially in the eye of the needle. As a result, care must be taken to ensure that the sewing silk is not damaged during sewing; H. that above all there is no splicing of the twisted thread into individual filaments.

For this reason, sewing silk provided for such purposes, which consists of endless, synthetic individual threads and whose twist caused in the course of twisting is stabilized by a heat treatment, is provided by impregnation with a synthetic resin film which completely envelops the thread surface. To produce this additional fixation in the form of a non-adhesive, thin coating which has no stiffening properties but at the same time allows adjacent threads or thread layers to adhere to one another, the single thread is passed through a bath containing the coating material in solution or dispersion and then subjected to a drying and curing process (DE-B-1 265109 and DE-A-1 635437).

To protect against the aforementioned harmful influences in the course of their practical application, z. B. sewing silk made of polyamide material with a plastic film bonded (coated) and at the same time dyed with acid dyes by the acid shock process. Sewing silks made of polyamide filaments, however, have the disadvantage that they soften at a relatively low temperature and then stretch or even melt, which then leads to thread breakage.

From this point of view, sewing silks made of polyester filaments are therefore in great demand due to their outstanding technological properties. The particular advantage over sewing silk made of polyamide filaments is the higher softening or melting point of the polyester material and the lower stretch when sewing on machines. Both factors therefore allow higher sewing speeds.

However, no method for simultaneously bonding and dyeing polyester filament for sewing silk has become known. The bonding products and dyes used for this purpose on polyamide material cannot be used for polyester material.

From DE-A-26 38 237 a method is known, according to which thread coulters which are intended for the production of technical bands or seat belts and which consist of polyester monofilament are dyed with dispersion dyes with the aid of a synthetic resin covering according to a thermosol process . In this case, the synthetic resin covering mainly serves the purpose of protecting the disperse dye, which has not yet been fixed but has already been applied to the threads, above all against abrasion during the weaving of the tapes. The actual fixation of textile goods together with the applied dyes takes place only after the weaving through the thermosol process.

• a) Die Nähseide (aus Polyesterfilament) soll echt gefärbt sein. Das kann bei Polyestermaterial nur mit Dispersionsfarbstoffen erfolgen. Die Färbung muß außerdem reduktiv nachgereinigt werden, um oberflächlich auf den Fäden abgelagerten Farbstoff zu entfernen.
• b) Die Einzelfilamente der Nähseide müssen entsprechende technologische Eigenschaften aufweisen, d. h. sie müssen ein vorgegebenes Schrumpf- und Dehnungsverhalten aufzeigen. Diese Qualifikationen können nur durch einen Hitzefixierprozess verliehen werden.
• c) Die Nähseide muß die hohen mechanischen Beanspruchungen beim Nähen aushalten und dafür bestimmte Beschaffenheit besitzen. Vor allem muß man das Aufspleißen der gezwirnten Seide in Einzelfilamente, z. B. beim Reißen eines einzelnen Fadens im Multifilament, verhindern. Ferner soll das sogenannte Krinkeln, d. h. die Entstehung kleiner Schlingen beim Bilden der Nahtverschlingung, vermieden werden. Es soll außerdem keine statische Aufladung der Filamente auftreten, die Reibung soll herabgesetzt und die Fadenfestigkeit nicht vermindert sein. Bondieren verleiht der Nähseide diese gewünschten Eigenschaften.

In contrast to this, when bonding multifilament sewing silk, other circumstances must be taken into account, which at the same time outline the task for the present invention. The following conditions must be met:

• a) The sewing silk (made of polyester filament) should be really dyed. With polyester material, this can only be done with disperse dyes. The dyeing must also be reductively cleaned in order to remove dye deposited on the surface of the threads.
• b) The individual filaments of the sewing silk must have appropriate technological properties, ie they must show a given shrinkage and elongation behavior. These qualifications can only be obtained through a heat setting process.
• c) The sewing silk must be able to withstand the high mechanical stresses when sewing and must have a certain quality. Above all, one has to unravel the twisted silk into individual filaments, e.g. B. when tearing a single thread in the multifilament, prevent. Furthermore, the so-called crinkling, ie the formation of small loops when forming the seam interlacing, is to be avoided. In addition, there should be no static charging of the filaments, the friction should be reduced and the thread strength should not be reduced. Bonding gives the sewing silk these desired properties.

In summary, the present invention is based on the object of dyeing and bonding polyester filaments for use as sewing silk at the same time, the bonding not affecting the properties of the dyeing and, on the other hand, the requirements of the dyeing should not adversely affect the bonding.

• a) die eingesetzte Klotzflotte neben einem Bindersystem aus einer oder mehreren thermisch vernetzbaren, polymeren Acrylverbindungen sowie einem Vernetzungskatalysator, einen oder mehrere Dispersionsfarbstoffe enthält,
• b) die Flottenaufnahme 15-25 % (bezogen auf das Gewicht der trockenen Ware) beträgt,
• c) die Hitzebehandlung während 15-60 Sekunden Dauer mittels Heißluft bei 190-225 °C erfolgt und
• d) die so behandelte Nähseide daraufhin vor dem Wiederaufwickeln reduktiv nachgereinigt und abschließend wie üblich präpariert wird.

This object is achieved in that

• a) the padding liquor used contains, in addition to a binder system composed of one or more thermally crosslinkable, polymeric acrylic compounds and a crosslinking catalyst, one or more disperse dyes,
• b) the liquor intake is 15-25% (based on the weight of the dry goods),
• c) the heat treatment is carried out for 15-60 seconds using hot air at 190-225 ° C and
• d) the sewing silk treated in this way is then reductively cleaned before rewinding and finally prepared as usual.

• Man führt die Nähseide aus Polyesterfilamenten im Verlauf des Umspulens von einem Schärgatter oder Kettbaumträger kontinuierlich über einen Foulard, in dem die Klotzflotte mit z. B. einer Flottenaufnahme von ca. 20 % (vom Gewicht der trockenen Ware) aufgebracht wird, zum Trockner, vorteilhaft ein Zylindertrockner. Von dort fährt man mit den bei zumindest 110 °C getrockneten Fäden durch die Heißluftzone, in der gleichzeitig das Polyesterfilamentmaterial fixiert und stabilisiert wird, die Färbung fixiert und das Acrylharz ausgehärtet werden. Über Kühlwalzen, die auch zur Übernahme des Spannungsausgleichs vorgesehen wird, läuft die nun gefärbte und bondierte Nähseide der Nachbehandlung zu. Die Waschmaschine sollte 4 Bäder enthalten, je eines für die reduktive, alkalische Nachbehandlung, das Spülen und das Neutralisieren und für die Präparation. Danach wird das Substrat wieder getrocknet (Zylindertrockner oder Heißluftzone) und die fertig gefärbte und bondierte Nähseide schließlich aufgespult.

In practice, the procedure claimed is advantageously carried out as follows:

• You run the sewing silk from polyester filaments in the course of winding from a warping or warp beam continuously over a foulard in which the padding liquor with z. B. a liquor intake of about 20% (by weight of the dry goods) is applied to the dryer, advantageously a cylinder dryer. From there, the threads are dried at at least 110 ° C through the hot air zone, in which the polyester filament material is simultaneously fixed and stabilized, the dye is fixed and the acrylic resin is cured. The now dyed and bonded sewing silk runs to the aftertreatment via cooling rollers, which are also provided to take over the tension compensation. The washing machine should contain 4 baths, one each for the reductive, alkaline post-treatment, rinsing and neutralizing and for the preparation. The substrate is then dried again (cylinder dryer or hot air zone) and the finished colored and bonded sewing silk is finally wound up.

Of particular importance in the new process is the amount and composition of the dispersion of the crosslinkable, polymeric acrylic compounds. In general, 200-400 g / l of these resin-forming substances are used, preferably a copolymer of ethyl acrylate, N-methylolacrylamide and acrylonitrile.

According to the invention, substances of the alkylolamine hydrochloride type, in particular aminopropanol hydrochloride, are used as the crosslinking catalyst which is only acidic in the heat.

With this high amount of crosslinkable acrylic compounds used, it was surprising that the hardening actually expected due to resin formation does not impair the suppleness of the sewing silk - but that the desired bonding effect, i. H. the individual filaments are bonded without reducing the flexibility of the fibers. Furthermore, it could not have been foreseen that this bonding would not suffer any damage as a result of the subsequent reductive aftertreatment of the dyed goods carried out in a strongly alkaline medium at a higher temperature for reasons of authenticity of the dyeing, and that the desired smoothing and gluing of the individual filaments would be retained.

The technological properties of the finished sewing silk largely depend on the precise monitoring of the drying and fixing conditions. Depending on the titer of the individual filaments and their number in the sewing silk, the dwell times of 15-60 seconds must be adjusted.

Another important factor is the choice of a suitable preparation for the good running properties of the sewing silk when sewing. Plasticizers based on oleyl sarcoside, paraffin oil emulsions and products based on silicone oil, or mixtures of these products, have proven successful in this regard.

example 1

• 600 g/I einer wäßrigen, 40 %igen Dispersion eines Copolymerisats aus
• 84 % Äthylacrylat,
• 11 % N-Methyloacrylamid und
• 5 % Acrylnitril, (Prozentzahlen bedeuten Gewichtsprozent)
• 30 g/I Aminopropanol-Hydrochlorid (Katalysator),
• 9,7 g/I des Dispersionsfarbstoffes 2,6-Dicyan-4-nitro-2'-acetylamino-4'-diäthylaminoazobenzol,
• 4,14 g/I des Dispersionsfarbstoffs der Formel
  

und 10,68 g/I des Dispersionsfarbstoffes der Formel

150 kg of twisted multifilament from dtex 226 f 64 x 3 made of linear polyesters (sewing silk) on bobbins of 2.5 kg each are placed in a warping machine, warmed in the course of unwinding and on a foulard at room temperature and with 20% liquor absorption (from the weight of the goods) padded with an aqueous liquor of the following composition:

• 600 g / l of an aqueous, 40% dispersion of a copolymer
• 84% ethyl acrylate,
• 11% N-methyloacrylamide and
• 5% acrylonitrile, (percentages mean percent by weight)
• 30 g / l aminopropanol hydrochloride (catalyst),
• 9.7 g / l of the disperse dye 2,6-dicyan-4-nitro-2'-acetylamino-4'-diethylaminoazobenzene,
• 4.14 g / l of the disperse dye of the formula
  

and 10.68 g / l of the disperse dye of the formula

• 24 cm³ Natronlauge (32,5 %ig)
• 24 g Natriumdithionit und
• 6 g eines Waschmittels auf Basis eines mit 20 Mol AeO per Mol oxäthylierten Nonylphenols.

After padding, the moist thread material is dried on drying cylinders at approx. 110 ° C and then subjected to hot air treatment at 210 ° C for 25 seconds. The dyeing thus obtained is continuously cleaned after cooling on cooling rollers. The bath temperature of the reductive post-cleaning bath used is 85 ° C; the following are to be used per 1 kg of polyester filament in liters of water:

• 24 cm ³ sodium hydroxide solution (32.5%)
• 24 g sodium dithionite and
• 6 g of a detergent based on a nonylphenol oxyethylated with 20 moles of AeO per mole.

• 6 g/I Oleylsarkosid sowie
• 2 g/I einer emulgierbaren Mineralölparaffinzubereitung.

Then the dyeing is rinsed with hot water at 70 ° C, neutralized with acetic acid and prepared in the last bath. The preparation bath contains in liters of water:

• 6 g / l oleyl sarcoside as well
• 2 g / l of an emulsifiable mineral oil paraffin preparation.

The circulation of this preparation is 20% of the product weight. The dyed and bonded polyester filaments are then dried and wound up.

A black-colored sewing silk is obtained with good sewing properties, good strength and sufficient stretch.

Example 2

• 4,85 g/l des Dispersionsfarbstoffes 2,6-Dicyan-4-nitro-2'-acetylamino-4'-diäthylaminoazobenzol
• 2,07 g/I des Dispersionsfarbstoffes der Formel
  
• 5,34 g/I des Dispersionsfarbstoffes der Formel
  
• 6,75 g/l des Dispersionsfarbstoffes der Formel
  

und verfährt sonst genau so wie in Beispiel 1 beschrieben, dann erhält man eine dunkelblaue Nähseide mit guten Gebrauchseigenschaften.If the following dye combination is used instead of the dyes from Example 1:

• 4.85 g / l of the disperse dye 2,6-dicyan-4-nitro-2'-acetylamino-4'-diethylaminoazobenzene
• 2.07 g / l of the disperse dye of the formula
  
• 5.34 g / l of the disperse dye of the formula
  
• 6.75 g / l of the disperse dye of the formula
  

and otherwise proceeds exactly as described in Example 1, then a dark blue sewing silk with good usage properties is obtained.

Example 3

• 1 g/I des Farbstoffes Disperse Blue 56 mit der C.I-Nr. 63285
• 4 g/I des Dispersionsfarbstoffes mit der Formel
  
• 6 g/I des Dispersionsfarbstoffes mit der Formel
  

The procedure is exactly the same as in Example 1, but the following dyes are used instead of the dye combination mentioned there:

• 1 g / l of the Disperse Blue 56 dye with CI no. 63285
• 4 g / I of the disperse dye with the formula
  
• 6 g / I of the disperse dye with the formula
  

After dyeing, bonding and post-treatment, you get a brown sewing silk with the required behavior when sewing.

The same result as in Examples 1 to 3 is obtained if instead of polyester multifilament of dtex 226 f 64, twisted three times, one with the same titer and number of threads, but twisted twice, is used here.

Corresponding results can also be achieved if sewing silk from the multifilament of dtex 74 f 16 / or. f 24, 2 or 3-ply twisted or dtex 455 f 96, 2 or 3-ply twisted and subjected to hot air treatment for 15 or 60 seconds to fix it.

Claims (4)

1. A process for the simultaneous dyeing and bonding of sewing silk consisting of filaments of linear polyesters, wherein the twisted multifilament is continuously padded during a rewinding operation, with an aqueous dispersion which contains a thermally cross-linkable binder system, is dried before winding it up again and subsequently subjected to a heat treatment, which process is characterized in that

a) the padding liquor used is containing one or more disperse dyestuffs in addition to a binder system of one or more thermally cross-linkable, polymeric acrylic acid derivatives and a catalyst which promotes cross-linking,

b) a liquor pick-up of 15 to 25 % (relative to the weight of the dry material) is observed,

c) the heat treatment of the padded and dried twisted multifilament is performed with hot air of from 190° to 225 °C for a time of from 15 to 60 seconds, and subsequently

d) the sewing silk is continuously afterscoured by reduction before winding it up again and finally a usual fiber preparation is applied onto it.

2. A process according to claim 1, wherein 200 to 400 g/I of the cross-linkable polymeric acrylic acid derivatives are used in the padding liquor.

3. A process according to claim 1 or 2, wherein a copolymer of ethyl acrylate, methylol acrylamide and acrylnitrile is used as the cross-linkable polymeric acrylic acid derivative.

4. A process according to claims 1 to 3, wherein an alkylolamine hydrochloride is used as the catalyst promoting cross linking.