DE2046121A1 - Process for the production of polyester fibers with improved properties - Google Patents

Description

dr. W. Schalk dipl.-inc. P. Wirth dipl.-ing. G. Dannenberg

DR.V. SCHMIED-KOWARZIK DR. P. WEINHOLD DR. D. GUDEL

8/25 I97O 6 FRANKFURT AM MAIN

CR. ESCHtNHEIMBK STKASSE 39

Case D, 11 [Z

HOIiTEGATIIiI EDISON S.p.A. Foro Buonaparte 31 Milan / Italy

Process for the production of polyester fibers with improved properties

The present invention relates to a process for the production of polyethylene torephthalate fibers with improved Properties and in particular with greater resistance to so-called "pilling" (see further below).

In the previously known method for the production of polyethyleneterephthalate fibers the polymer is made by transesterification of dimethyl terephthalate rait ethylene glycol and subsequent Polycondensation of the monomeric Μπ-2-hydroxyäthylterephthalat obtained and obtained by spinning converted from the melt into fibers.

Besides, he is. known that the polyethylene terephthalate Melt pre-spun can only be grounded if the viscosity des Polyaerioatof) in the molten state is greater than 500 pn is, but preferred wines between 800 and 3000 po lies.

Polyfitbylenteronhthalat fibers have the disadvantage that those made from them. Textiles are subject to an appearance that is referred to as "pilling". On the Textil-Ciebiet \ iiv <\ under "Pilling" a phonon protruded,

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that occurs when a garment is continuous Rubbing either with yourself or with another material or with the body - v / ie it when wearing or Washing of the same is done - is subjected. The fibers protruding from the surface are broken into small ones Matted globules or "pills" that remain anchored to the tissue.

This phenomenon is undesirable because it gives the fabric an unsightly appearance. It is formed on the surface of textiles made from both natural and synthetic fibers. The formation of "pills" on textiles made from natural fibers, however, does not represent a serious disadvantage in all cases, since these "pills ¹¹ tend to detach from the surface with a certain ease and the surface of the fabric remains unchanged On the other hand, the formation of "pills" ¹¹ on textiles made of synthetic fibers is usually a serious problem, since the "pills" are more difficult to detach from the surface due to their own inherent properties, such as tensile strength, elongation at break, etc.

According to the known methods, the tendency to "pilling" by introducing weak points into the fibers through strong mechanical crimping. be reduced or even eliminated. In doing so, however, the fibers are damaged irregularly and during their processing There is a high degree of fiber breakage in yarns with the formation of spinning fly (fly ash from the fibers) instead of.

The most commonly used general process for the production of pilling-resistant polyethylene terephthalate fanorn beotoht in the reduction of the molecular weight " the polycondensates au fourth corresponding to one

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Grensviskositätssahl [mJ ³ - ⁿ to decrease at 30 ⁰ C, between about 0.35 and 0.45 dl / g, so the strength of the fibers obtained o-chlorophenol.

However, the polyethylene having such a molecular weight range is in the molten] condition at 280 ⁰ G an absolute viscosity of about 200-500 of PE, and this is, as mentioned above, a ert ro lower T. ^T, that the melt spinning and in very hard some Cases even become impossible to implement. In fact, during spinning, the threads emerging from the spinneret break under their own weight without being able to freeze beforehand.

Various polycondensates with an increased viscosity in the molten state have already been produced by adding copolymerizing compounds which contain 3 or more functional alcohol groups (glycerol, pentaerythritol, etc.) to the transesterification between ethylene glycol and dimethyl terephthalate or to the direct esterification of ethylene glycol and terephthalic acid. ) or carboxyl groups (Tri-Carbally! acid, pyromellitic include trimesic etc.), or with alcohols or glycols with low molecular weights to get their esters thus partially branched poly λ merisate.

These modified polycondensates, although they have a low molecular weight and a sufficiently high viscosity value own in the melted hatred show different anyway Disadvantage. Due to the relatively high amounts (2-3 Gow .- $) of necessary modifier, undesirable Side effects occur to a greater extent, such as a reduction in the melting point of the polymer, formation of gels or particles that are difficult to filter, lower resistance to degradation, inhomogeneity in the polymer and thus irregularities in the titer of the fibers,

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unwanted coloring, etc.

It has now surprisingly been found that Pasern and endless filaments of polyethylene terephthalate with considerably improved resistance to pilling and excellent serimetric properties can be obtained by a process including the following steps:

a) Melt spinning of a polyethylene terephthalate with a limiting viscosity number of less than 0.5 dl / g, which - based on dimethyl terephthalate or terephthalic acid - 0.4 to Contains 1.5 moles of copolymerized trimethylol propane.

b) drawing the threads obtained in this way at a temperature of 100 ^° C. or less at a drawing ratio of not more than 1: 6;

c) repeated drawing of the already drawn threads at a temperature of at least 100 ° C. at a drawing ratio of 1: 1.5 or more, and

d) Heat treatment of the threads drawn in this way in the event of prevented shrinkage or a shrinkage up to a maximum of 3 $ at a temperature which is higher than the temperature used for the second drawing, but ^{must not exceed 160 °} C., for a time between 30 seconds

_ announce up to 5 minutes.

The use of triraethylolpropane as a comonomer is one of the essential conditions for obtaining fibers with excellent pilling resistance. Indeed are made by using other tri-functional monomers, such as 1,2,4-butanetriol-tris-hydroxymethylolpropane, 1,2,6-hexanetriol; triethanolamine, hemimellitic acid, Trimellitic acid etc., instead of trimethylolpropane, fibers with good mechanical properties are obtained

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but have good resistance to "pilling".

The Copoly.7ierisates both have excellent spinning properties as well as excellent "anti-pilling" properties achieved when the composition of the polymer is suitably adjusted. As mentioned above, the crowd is supposed to des I'riinethylolpropano in Copolyraerisat between 0.4 and 1.5 liol-v, based on dimethyl terephthalate or terephthalic acid , amount.

Trimethylolpropane can be added both before the start of the | Transesterification or direct esterification as well as after completion of the same take place before the start of the polycondensation. However, the comonomer is preferably used at the beginning of the transesterification or added to the direct esterification.

The transesterification is carried out by the known methods at atmospheric pressure, at temperatures between 150 and 230 ° C. and under a nitrogen atmosphere. The direct esterification is carried out at the same temperatures. The polycondensation is carried out with an increase in the temperature from 230 ° bin 2 & j ~ ?. ^c J0 ⁰ G within 60 minutes and while reducing the pressure to 0.2-0.5 mm Hg and maintaining the said temperature and pressure values are carried out to achieve the desired viscosity. The polymer is then on; removed from the reactor, granulated and then dried to a water content of less than 200 pr ::. to reach.

. Ronz7i:;; the (:: .- i "i tUtriH.'ihl dor polycondensates is determined at 3O ⁰ O ur 'under Terweiuiung a Lorning that 1 g of the poly-o-meviufit'iu in Chlorphohol contains dissolved. by the Jjö-Bun ₍ ; ::. Tii. ttf; I to 1UO cc :: i iiufgofilllt is. Dio durotign-led icho have shown that dlo Anwuoonhoit of trlinothylol-

Oo - /
ui ηLi: 'lUmoiviV im Po lyäthylonteropii thaJ.at aim:

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- b -

'Essential condition for the manufacture of fibers nit high resistance to pilling and excellent eerimetric properties, but only for that not enough. It is to achieve this viz still required that the tri-methylolpropane-containing polycondensates by special processes spun the melt and determined the thread obtained and subjected to well-defined treatments.

It has been found that the normal and customary processes , which provide for drawing the threads in a single stage, with subsequent heat treatment at high temperatures, generally higher than 160.degree. C., being possible, are practically unsuitable for the production of threads with excellent anti-pilling properties and seriiaetric properties. This goal can be achieved only if zv ei successive Verstreekun ^ s are made /: first, the less is carried out at a temperature of 100 ⁰ C or higher, and a second which is performed at a temperature of at least 100 ⁰ G, whereupon thermal treatment at a temperature not exceeding 160 ° C follows. The first stretching is preferably; 'a3aer in hot \\ at temperatures between 90 and 100 ⁰ C and with a Vcrstreckungsverlriltnis of 1: 2 to 1: 5 _f is preferably between 1: 5 and 1: 4 is performed. D _a second Verstrocken s is either in hot air, on a hot plate or hot V'alzen at 100-120 ⁰ C at a Verstreckimgsverhältnis of between 1: 1.5 and 1: 2.5, preferably zwiochen 1: 1.7 and 1: 2.3.

Projecting stretched fiber is then for 30 seconds to 5 minutes hol a temperature "wipe 120 and treated 150 ⁰ C, the Faner is held under tension," or to give 1 - 3 # nchr.uraprt.-n gel is.

Feeding, the auu him üopolymeren bekehrIebenon above prepared

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_ * 7 -

and spun using the invention-based method show excellent physiometric properties and good resistance to pilling.

Measuring the tilling was done using a "Raiidom-TrabXer-Pilling-Tester" according to ABKi 1375-Standardveriahren on fabrics with 10 rows / cm and 1: 1 weave, made from a yarn of 36 Hn and 500 Z twist are made from a wool / polyester / fiber mix Exist in a ratio of 45/55,

According to this method, the "pilling" is expressed by a number between. 1 and 5, where 1 is understood to mean a sample without "pills" ub & under 5 a sample fully covered with "pills". The measurement of the "pills" was repeated every 20 minutes ijataend for a period between 20 to 120 minutes.

The following examples illustrate the present invention, albeit limiting it. In the following examples, the viscosity in the molten state was determined using a capillary viscometer which had a diameter of 2 mm and a length of 35 cm and in which the first notch (rake) was 5 mm from the lower end and | two other notches (A and B) were 20 and 50 ma away from the same egg.

The Polyätlijlenterephthalat, which was contained in a special viskosimetrisehen test tube was dried for 4 hours under Yafaium and at 150 ⁰ C. This twin tube was then immersed in a bath of molten salt thermally regulated to 280 ° C + 0.2 ° C (the temperature at which the viscosity is to be measured *). The measurement was carried out by immersing the capillary Vis Ironi.neter In the molten polyethylene terephthalate to z \ rr first notch and pressure exerted within the Testrobrchens some nitrogen to the '. ■

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Allow polymer to rise within the capillary. The ZcitV (in seconds) that the melted polyethylene * terephthalate needed, ura. between the notch A and the Creeping up Notch B was measured.

The viscosity in the molten state (expressed in poises (ps)) was given by the formula

= 106.K.P.t

calculated, where P d'en means corrected pressure in mm Hg. This is achieved by subtracting the back pressure value, which is caused by the rising pressure in the capillary Liquid is exerted, from the pressure exerted on the inside of the test tube (read on the pressure gauge), obtain. K is a capillary constant

K =

v / orin (j means the cross section of the capillary (can be calculated by weighing it with mercury) and h. and hp are the distances of the notches A and B from the end of the capillary.

example 1

Polyethylene terephthalate containing 0.75 mol ¹ / trimethylolpropane with an intrinsic viscosity of 0.47 dl / g and a viscosity in the molten state at 280 ° C. of 1250 poises was prepared by the known processes at 235 ° C. This modified polyethylene terephthalate was spun at a temperature of 285 ° C using a conventional machine. The spinning head used had 70 holes, each 0.3 × 0.6 mm in size, and the winding speed of the threads was 52 μm / min.

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The co-compliant kid an nit one:] Titer of 18 den vrurdev: in 00 ⁰ G Heilem Nasser with a stretching ratio of 1: 3.2 ν "a \ - .; stretches (outflow speed: 90 m / min .. Then v. 'ere a sv / eites J'ial sin at 110 0 at a Verstree]: ^ungsvern: lltnis of 1: stretched 1.7 and then passed through einon hot air oven of 130 ⁰ C, in which they at a residence time of 3.5 Hinuten Prevented shrinkage v / 'iXTiob ehanö el t.

The threads obtained had a titer of 3 dtex and ^

the following serimetric properties:

Strength: 3.9 g / dtex

Elongation at break: $ 24.

The threads are crimped and cut into staple fibers with a wool cut ("v / oölon cut"). These were then stained in disperse dyes, by immersing for 1 hour in a bath maintained at 130 ⁰ C and quenched by addition of Essigcüure a P ^ -Vert of 5 accommodated Rlrbebad. Dan Mrbebad had the following composition;

1.2% Saraaron yellow 5 G O ₁ W / i Samaron pink FBL 0.4 $ Sainaron blue FBL

1 g / lt dispersant Ernulson Ii.L, U.

Dar; l'a. "ür: i'ii .-. O.-Ratio was 1:10.,

DJf-- rei ' ^: irbtciv and dry clay staple fibers vnirden nil V.'o?!: (FcJiU.f; it: ?,' J-? A) gou'u.o'it, v / oboi das Vorh? iltnJ «Polyester · .. V / o" I Io ^{ yj> t \ b ! ioU'ug. The GorrrLi; oh v / urd e anschlj oiiumi kardif-r ". Uii'i (Iftan after the UbI i.ehojx Verlutu'en spun, after which eir. (Aurii : .ii. T the following Eigonso adhere v / urd ο:

Hetrinciu- TUkr lim: 36

Zwirrnm / ,; ijOO Umdrehuri'-on / nt ".

Hi ι. fiji -. 'ier.t üurn was'J > in P&L with 10 horizon I.-U en

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Mosohcnreilion / cm produced. The "Pilling" was on DICR; c: G ¹ VK) Ik: Rait einera "Iiandom-tumbler" pilling ~ 'i'ester''by de D-13713 Vcrfahren measured and resulted in the following Ir.

gfibriioaen: To 20th There. 1 13th ti 40 η, 1 , 2 Il 60 Il 1 , 3 Il 80 It 1 • 5 120 dd 1 , 2.

The same modified polymer was described as above spun, but only a single stretching carried out at 95 ° G at a draw ratio of 1: 4.5 became. The threads obtained had the following seriinetric properties:

StrengthJ 2.2 g / dtex Bruohd eung: 1 Bf «

and the following "Anti-Pilling ^ values:

After 20 min. 3

5
5

4.5 1.5.

Bione results clearly lament the HotwencU ^ ielt de ^ awoiiaaugen stretching ^ to fibers with excellent and ei'v / unshaken aer.imetriacheil Eigonfschaftoii and ^H Anti-Pilli.iu; "

obtain.

η 40 Il η 60 H η 80 η ti ion η

} ivi Use of PolyHthylonterephthalat with a size: .vi

from O, f> u dt / g and a Yiakonifcufc in gp γοή 284U poi3eo al »AWQ tuyt was, JWQh dep» above öp.liwverfahj'un χλ \%

qitfoloudei 'oo ^ liuc triöüh.qi \

Strength: 5.7 g / dtex Elongation at break: 23 $.

These pasera- showed after they were further processed in tissue the following undesirable

ilach 20th Min. 3.7 Il 40 Il 5 It 60 It LfN Il 80 It 5 It -f 20th Il 5.

EeJn T) Xel 2

? Polyethylene terephthalate containing 0.5 mole "Trimetbylolpropan containing un; l a viscosity in the molten state at 280 ⁰ C of C-50 poises and a Grenaviskositätssahl CtjJ of 0.45 dl / g possessed of Example 1 was spun according to the method .

The threads obtained showed the following serimetric Own chaxt c. u:

Titer: 3 dtex, strength: 4.1 g / dtex, elongation at break: 22 $.

The results of the "Pilling ^TI measurements were:

ilach 20th There. 2.3 It 40 Il 3.2 M. 60 Il 2.5 Il 80 ti 1.8 It 100 It 1.5 It 120 Il 1.2.

After only one stretching at 95 ° C and at

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With a draw ratio of 1: 4.5, the fibers showed the following serimetric properties:

Strength: 2.8 g / dtex Elongation at break:

The "pilling" -vj ^r erte were very bad:

To 20th Min. 5 It 40 dd 5 ti 60 » 5 Il 80 dd 4.5 Il 100 4th Il 120 dd 3. Example 3

Polyethylene terephthalate containing triraethylolpropane and having a viscosity in the molten state at 280 ° C. of 1350 poises and a maximum viscosity number ßft J of 0.48 dl / g was spun according to the method of Example 1.

The threads obtained showed the following serimetric properties:

Titer: 3.1 'dtex, strength 3.6 g / dtex, elongation at break: 20 $.

The values of the "pilling" measurements were as follows:

To 20th Hm. 1.3 Il 40 It 1.2 Il 60 ti 1.2 ■ Ii 80 It 1.2 ti 100 It 1.2 It 120 It 1.2.

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After a single brace at 95 G and one Yerstrecl ratio of 1: 4.5 showed the fibers the the following sorimetric properties:

Strength: 2.2 g / dtex Elongation at break: 17 $.

The "Pilling" Yers are very bad:

After 20 Hin. 4th

3.5 3.5 3

3 2.

ti 40 Il Il 60 Il Il 80 It Il 100 It It 120 It

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Claims (1)

Claims 1) Method of producing polyester fibers with excellent serimetric properties and improved resistance to "pilling", characterized in that that he a) a polyethylene terephthalate with an intrinsic viscosity number of less than 0.5 dl / g, based on the dimethyl terephthalate or terephthalic acid of 0.4 to 1.5 mol-Jo copolymerized trimethylolpropane contains, spun from the melt, b) the threads thus obtained are drawn at a temperature of 100 ⁰ O or less at a draw ratio of not more than 1: 6, c) the threads thus drawn at a temperature of at least 100 0 with one draw ratio stretched again by 1: 1.5 or more, and ". d) the twice-drawn threads with a prevented shrinkage or a shrinkage up to a maximum of 3 / ί at a temperature which is higher than the temperature used for the second drawing, but ^{does not exceed 160 0} O, for a time between 30 seconds to 5 seconds Minutes of heat treatment. 2) The method according to claim 1, characterized in that the first stretching is carried out at a temperature between 90 and 100 ⁰ C and a stretching ratio of 1: 2 to 1: 5 tons, preferably from 1: 3 to 1: 4 _tons . . ■ 109813/1815 5) Method according to claim 1-2, characterized in that the second stretching "at a temperature between .1CO and 12O ⁰ G and a stretching ratio = from 1: 1.5 to 1: 2.5, preferably from 1: 1, 7 to 1: 2.5. 4) Method according to claim 1 - 3, characterized in that the drawn * fibers are heat-treated with a prevented shrinkage or a shrinkage of 1 to 3 $ "at a temperature of 120 to 150 ⁰ C for between 30 seconds and 5 minutes. 5) The textile fibers produced by the method according to claims 1-4 with excellent serimetric properties and improved resistance to pilling ¹¹ The patent attorney S chm i ^ d-Eowarz Ϊ1 109813/1815