DE1961004A1 - Method of making elastic yarn - Google Patents

Description

DR. MOLLER-BORE DIPI.-ING. GRALFS ' // DIPL-PHYS. DR. MANITZ DIPL.-CHEM. DR. DEUFEL 1961004 7 PATENT LAWYERS

*H. Dec, 1969

Lo / Sv - 0? 1026

Toyo Boseki Kabushiki Kaisha 8, Dojima Hamadori 2-ckome, Kita-ku, Osaka,

Japan

Process "for the production of elastic

yarn

Priority: Japan of December 4, 1968, No. 89224/68

The invention relates to a process for the production of elastic threads or fibers and in particular to an improvement in the production of elastic fibers or threads from a polyester-polyether block copolymer which have excellent, rubber-like elasticity.

It is already known to produce an elastic polyester-polyether block copolymer, which consists of polyester, such as polyethylene terephthalate ,, as hard seps and polyethers, such as polytetramethylene glycol, as soft segments, which has rubber elasticity, and elastic threads or from such an elastic copolymer To manufacture fibers.

009825/1968 BAD OWG.NAL

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TELEX 522050 MIPAT

For example, according to the ÜSA patent specification 3,023,192 a c © polymerized polyether polyester, elasticity comprises a polyether having a molecular weight from 350 to 6000, which is represented by the general formula will:

HO (RO) _n H

where H is a divalent organic radical and η is a whole Number, and a polyester-forming material. According to the US patent, elastic south through Extruding the molten copolymer into threads that being stretched and then relaxed.

However, these and other common, elastic! Threads were made of Polyester-polyether block copolymers (copolyether ester) unsatisfactory in terms of elastic properties, particularly in terms of performance at high Strain. For example, it is a phenomenon that 'the The tension-elongation curve varies greatly depending on the speed at which the thread is subjected to elongation becomes, i.e. the higher the stretching speed, the more gerir ^ r is the breaking strength and the elongation at break, but especially the elongation at break.

Furthermore, the elastic recovery from a high degree of elongation and the breaking strength are unsatisfactory. As a result of this deficiency, elastic polyester bottoms became lyether threads or yarns as rubber yarns or spandex yarns (highly elastic Threads based on polyurethane) underneath considered.

In Fig. 1 of the drawing, a diagram is reproduced which shows the stress-strain curves of various elastic Reproduces threads made of oopolyesterether / so-called stretch threads.

_ 2 -

ί · ■

a 3

The differences in the properties of copolyester ether yarns from rubber yarns and spandex yarns can also be evident the one in Big. 1 reproduced stress-strain curves are explained, here shows the stress-strain curve a conventional polyether polyether yarn (Mr. 1) a practically uniform increase in tension with an increase in elongation. In the case of a typical, commercially available Spandex yarn (e.g., the trademark "lycra"), the curve can be divided into a section in which the Tension teeth due to elongation are very low and into a part in which the tension increases relatively becomes strong. The spawning elongation curve of "lycra" is typically characteristic of a rubber-like one Elastomer in which the soft segments crystallize when stretched. The comparatively slightly curved one Part in the first half is a zone of low tension in which the soft segments are gradually stretched or stretched and the freedom of movement decreases. the sharp increase in tension in the second half means that the soft segments, which by the hard segments be firmly connected, approaching a fully stretched state, with the soft segments partially crystallizing and the stress on the hard segments very strong increases. Therefore, the fact that such a stress-strain curve of a typical rubbery elastomer does not mean in the conventional copolyetherester yarns it is found that they are imperfect in the internal structure as an elastic thread.

It was previously believed that such an imperfection is based on the properties of the polyester-polyether block copolymers (copolyether esters).

Surprisingly, it has now been found that elastic polyester Po lyäther threads or yarns, which have an excellent

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have rubber-like elasticity, are obtained, by performing a special stretching (warping) and subsequent shrinking after the thread formation will. . ■

The invention provides a method for the production of elastic threads, which is characterized in that an elastic Polyestor-polyether Bloekcopolymerisat having hard segments composed mainly or entirely consist of polyethylene terephthalate ", and soft segments of a polyalkylene glycol having a molecular weight of 1,000 to 6,000 to is melt-spun form of elastic threads, the threads of the animal times or more of their length are not stretched greater than 80 ° at a temperature 0 and then the filaments are relaxed in a freely shrinkable state under heating.

-The essential feature of the invention is therefore 'that Drawing or warping of the elastic copolyetherester threads perform in an unexpectedly higher ratio than is already known, and then the threads to relax under warming.

Preferably, the stretching is carried out in the vicinity of the normal temperature below 40 ^° C. If the stretching is carried out at a temperature as high as 80 ^° C. or higher, sufficient shrinkage will not occur in the subsequent relaxation or shrinkage step. The draw ratio should be 4 times or more, and it is preferably 5 to 12 times. The particularly preferred draw ratio is 6 to 10.

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The drawn elastic filaments are then relaxed in a shrinkable state with heating. At this stage, it is preferred that the filaments are allowed to shrink practically freely. Tails the shrinkage is unduly limited, the residual shrinkage would be correspondingly large, so that the resulting elastic yarns of the dimensional stability would regard to be inferior * It is necessary, for example to carry out this Entepannungsbehandlung at a temperature higher than 80 ⁰ O, but below the temperature at which begins the softening of the thread; if the temperature is lower, for example, in the range of normal temperature, sufficient shrinkage does not occur. Ba i over addition, the physical and before mixing properties of the filaments destroyed when the temperature is high. As a result, a temperature of 80 ° especially recommended to 16O ⁰ C · ^1st

Any heating medium which does not noticeably accelerate deterioration of the yarn (thread) can be used in this tension treatment, For example, water, steam, air or silicone oil can be used.

If the threads with such a high ratio in the * previous stage were stretched, allowed to shrink sufficiently with heating in this relaxation stage they will shrink in a high ratio. Usually the shrinkage ratio (the ratio Hg / Rx the peripheral speed Rp of the feed roller for the Feeding the threads to the shrinkage or relaxation zone at the peripheral speed R, the outlet orphan for the decrease of the threads from this zone) proportional to the Υθγβdrawung ratio in the one preceding the feed

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Stretching stage. If, therefore, the temperature for relaxation is constant, the resulting stretching ratio, which is obtained by dividing the initial stretching ratio by the drawing ratio, is practically constant (about 2) regardless of the initial stretching ratio. However, it varies depending on whether a Stretching and subsequent relaxation or shrinkage was carried out at a high ratio or not, since the tension-elongation behavior of the elastic fern obtained was noticeable. The elongation at the point at which the increase in tension begins to become steep with the elongation depends on the shrinkage ratio and therefore on the stretching ratio so that this can be approximately represented by: (Shrinkage ratio -1) x 100 %. Basically, it is believed that in the processes of drawing at a high ratio and shrinking or relaxing under heating, the polyester segments agglomerate and the internal structure of the thread approaches a more perfect shape like an elastic thread. The higher the shrinkage length and therefore the stretching ratio, the higher the consistency.

Therefore, according to the invention, by an "oil ca"? * Rbesee ~ modification of the internal structure of the thread as a result of the special stretching and subsequent wefting tasks, as explained above, an elwtfcMißa ·? thread be obtained both in terms of elastic

as well as
Recovery, / the breaking strength and elongation »uijeieiehnet is. Furthermore, this behavioral oscillation lowers the denier of the thread and the windability of the threads becomes so high that even if an agent to prevent sticking falls on the threads it is not necessary.

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is brought, this rewound without any difficulty. can be. .

Since the relaxation-C-vaccinationB-) treatment with heating only needs a very short time, the whole process, i.e. spinning - stretching - shrinking, can be carried out continuously.

The polyester-polyether block polymers (copolyether esters) to be used in the invention are known per se and no detailed explanation of this is required.

As is well known, the Bloekcopolynerisate consist of hard Segaenten τοη polyester (or copolyester) and soft segments made of polyalkylene glycol. In the invention, the polyester is polyethylene terephthalate and the copolyester is made from at least 80 Mo 1.96 ethylene terephthalate units and not more than 20 moles of other polyester-forming units, which are known per se, see for example U.S. Patent 3,023,192. The polyalkylene glycol, which the soft Representing segments of the block copolymer should have a molecular weight of 1000 to 6000. Examples for the polyalkylene glycol is polyethylene glycol with a molecular weight of 1000 to 6000 and polytetramethylene glycol with a molecular weight of 1000 to 4000, in particular 4500 to 3000, although there is no restriction to this is present. It is also possible to use irregular copolymers or block copolymers thereof.

The molar ratio of the terephthalic acid residue to the polyalkylene glycol is preferably approximately 3: 1 to 10: 1 in the case of polyethylene glycol and 5: 1 to 6: 1 in the PalIe of polytetramethylene glycol.

0 09 825/19 68

The preparation of such block copolymers can be carried out in a customary manner which is well known per se, see, for example, USA Patent 3,023,192. However, it is necessary that the copolymer obtained have a reduced specific viscosity of at least 2.0, measured at 30 ^° C. on a solution of 0.2 g of polymer dissolved in 100 ml of a mixed solvent of phenol and tetrachloroethane 6: 4. In general, the constituents forming the polyester and polyalkylene glycol are reacted together with heating, while the volatile by-products are distilled off In the final stage of this reaction or polycondensation, a high vacuum is applied, in which case a catalyst, matting agent, stabilizer, etc. can be added.

The block copolymer obtained is in a customary Melt-spun way to form elastic threads.

The invention is further illustrated a nh gnfl the following examples are described herein, the various yarn properties at 20 ° 0 is determined as follows. Furthermore, in the examples, all parts are given as parts by weight.

Breaking strength and elongation ;

A sample of 5 cm in length is taken at a speed stretched at 1000% / min. The breaking strength is called

Strength per denier (g / <3en) at the time of breakage

reproduced.

El _n Hn ti sch. e _ΐ_ r hc kng:

A sample 5 ca length is three times the length stretched and left standing for Ί0 minutes. Then the ! 'vine from the stretched state and relaxed for 10 minutes ctehe: jgeJessen. The length of the sample becomes 1 (cm)

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and the elastic recovery is calculated using the following formula:

Elastic recovery = -2 room χ 1OO (%)

Variation in denier number (Of %}:

The result of the measurement obtained by inserting a sample 300 m long at a speed of 25 m / min into a Uster equality meter Type C (Zellv / eger. Company) is divided equally into three blocks. The average in the three blocks of the difference between the average of the three maximum points (%) and the average of the three minimum points (%) of each block is expressed as a measure of the variation in denier in TJ%.

Ratio (G) of increasing modulus of elasticity by stretching at a high ratio:

A sample of 5 cm in length is taken at a speed stretched by 1Q00 # / min. The ratio of the increase in Young's modulus by stretching at a high ratio is represented by the difference G between the tension in g / äa ^ (äai means the original denier number) at the time of 425% draw and those at the time of 475% draw. It is a value that is used in place of the stress-strain curve of each sample The above-mentioned elongation or stretching range is a range in which the increase in tension is rapid in virtually all elastic threads. Hence there is »behavior to Time of stretching, the more rubber-like, the larger the Value of G is.

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Example 1

2800 parts of dimethyl terephthalate, 2200 parts of ethylene glycol and 7500 parts of polytetramethylene glycol (average molecular weight 2000) were reacted with one another in the presence of 5 parts of zinc formate, 5 parts of sermanium dioxide and 150 parts of titanium dioxide, a polyether-polyether block copolymer having a reduced epesifical viscosity of 3 , 08 was obtained. This copolymer was melted and passed through at 230.degree. Spi & nöf & ungen extruded into threads. Bann were drawn the filaments between, a first roll having a peripheral speed of H ₁ m / min and a second roll with ejLner peripheral speed of Rg m / min at room temperature of 3O ⁰ C to the H ₂ ZR ₁ -fold dor length. Immediately after the stretching the filaments in a Erhiteungazone were (heated by air at 8O ⁰ C, or by steam at 10O ⁰ C), the third between a roll with a peripheral speed of SU m / min and the second orphan was arranged allowed to shrink. In this case, the speed B was set so that as little tension as possible was applied to the threads. The properties of the elastic threads obtained under various treatment conditions are shown in Table I. Furthermore, the tension-behavior curves of some samples (Mr.: 1, 5 «ad?) Are in Ig. 1 shown. The shrinkage temperature is that of the thread immediately after leaving the heating zone. The shrinkage ratio has a value Ton ^R 2 ^ 3 * ^In d ⁶ * ⁶¹ * case, R _{1 was} 100 m / min. Trials 1, 2 and 4 are given for comparison purposes.

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00982B / 1960

No. Treatment toeding 30th ugly Table I. fracture
firm
speed Yarn properties U (%) 6th
(ES / the> 1 30th Shrinkage
relationship Elast.
recreation 12.0 0.100 2 em- Schruan- 80 1.6 strain ~ 84.0 - - 5 relationship
tempera-
tnr
C ⁰ C) 100 1.8 540 6.2 «Μ 5.0 0.140 ^ - 3.5 IOC: 3.1 325 5.6 93.0 19.0 0.100, 5 .χ 7th 100 1.7 540 5.9 85.2 5.8 0.112 to S. 7th 1OC 3.0 600 6.3 92.8 4.8 0.130 7th 3.8 3.8 580 6.6 93.5 4.9 0.135 '.a 5 4.7 570 93.0 cn S. 580 10

From these results it can be seen that the elastic

Recovery at a VerstreckungBverhältnis of about 3 »5 to 3.8 is low and that the threads have a strong variation in the denier, and is that, even if the increased Yerstreckungsverhältnis to 7 times at a shrinking temperature of 3O ⁰ G elongation is remarkably low. On the other hand, according to the invention (Nos. 3, 5, 6 and 7), when the draw ratio was increased and the heat shrinkage or relaxation treatment was carried out, the strength and the elastic recovery were improved while maintaining the excellent elongation and the fluctuation in denier -Number was very low. It can also be seen that the numerical value of the elastic recovery is substantially proportional to the value of the increasing ratio G of the modulus of elasticity by drawing at high elongation, and that the improvement in the elastic recovery is due to the improvements in the internal structure of the thread by the Treatment according to the invention.

Example 2

3270 parts of dimethyl terephthalate, 2620 parts of ethylene glycol and 7500 parts of polytetramethylene glycol (average molecular weight 2000) were reacted together in the presence of 5.6 parts of zinc format, 5-6 parts of germanium dioxide and 170 parts of titanium dioxide, a polyester-polyether block copolymer having a reduced specific viscosity of 3> 12 was obtained. This Copolyierisat was melted at 240 ⁰ C and extruded through spinning orifices to form elastic yarns. The filaments obtained were drawn in the same manner as in Example 1 and shrunk, except that R ^, was set to 20 m / min and that the shrinkage treatment was performed in a silicone oil bath at 140 ⁰ ™ C. The results are shown in Table II together with a control test (No. 8) as a comparison.

• Table II Shrink
f-
terapera-
door Shrinkage
behaved-
never strain "T
1961004 Elast.
recreation a
(g / den _o ) Treatment conditions 30th 1.8 650 Yarn properties 33.0 0.06 No. r Stretched
kungsver
ratio 2.7 630 Fracture-
featig-
coit 91.5 0.09 8th 3.2 k _t * 609 5.2 92.5 O, 12 9 5 Λ0 5.0 630 5.8 ■ 92.5 O ₁ -2 10 8th 6.2 11th '! θ 6 k

Example 3

The same polymer as in Example 1 was melt-spun into threads in the same way. The threads would then be stretched at room temperature at Hyj ■ 100 m / min and R ₂ = 1000 m / min and then shrunk in a non-tensioned state in boiling water for various times. The results are given in Table III. The same experiment was repeated under the same conditions except that only the shrinkage treatment was carried out in air at room temperature for 2400 seconds at a shrinkage ratio of 2.2. This resulted in threads with an elongation of only 250 % .

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0 0 9 8 2 5/19 6 8

Treatment s-
conditions Tabel III 4th Yarn properties 0.135 Shrinkage. Shrinkage.
Duration behaves-
(lake) EIaBt. G
Recovery / - / ^ _6n . 0.135 No. 1 4.7 Deh
tion
(96) fracture
firm
speed
(g / den) 93.5 0.130 12th 600 4.8 570 6.6 93.7 13th 2400 4.9 565 6.4 93.2 14th 585 6.5 example

A block copolymer was prepared in the same manner as in Example 1, except that a copolyether (molecular weight 2000) of tetrahydrofuran and ethylene oxide (90:10) was used in place of E-olytetramethylene glycol. The reduced specific viscosity of the Blockicopolymerisates was 3 ₅ 15 · The block copolymer was melt-spun in the same manner as in Example 1, and the threads formed were in the 8-times the length at room temperature, stretched and then to shrink in steam at 100 ⁰ C relaxed . The shrinkage ratio was 3.8. The elastic yarn obtained had an elongation of 610 #, a breaking strength of 6.0 g / ee ^, an elastic recovery of 94.0 %, an O value of 4.8 % and a G value of 0.135 ·

- claims

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Claims (6)

Patent claims 1. A process for the production of elastic .Fäden ¹ - by melt "pinning cause an elastic Polyeater-polyether Blo.Qkcopolymerisates which ethylene of hard segments of poly · or contains a copolyester of 80 mol% Jtthylenphthalateinheiten least, and soft segments ^. consists of polyalkylene glycol with a molecular weight of 1000 to 6000, inter formation of elastic threads, thereby known that the elastic threads formed are pre-stretched to 4 times or more times the length at a ^{temperature not exceeding 80 0} C and then in a shrinkable state under Heating to be subjected to relaxation. 2. The method according to claim 1, characterized in that that folytetramethylene glycol with a molecular weight of 1500 to 3000 is used as the polyalkylene glycol. 3 «Method according to claim 2, characterized in that that "a block copolymer is used in which the ratio of terephthalic acid residues to polytetramethylene glycol 3i1 to 6: 1. 4. The method according to claim 1, characterized in that that the threads are 5 to 12 times, preferably that 6 to 10 times the length can be stretched. 5. The method according to claim 1, characterized in that that the relaxation is carried out in a state in which the threads can shrink practically freely. 6. The method according to claim 1, characterized in that the Ent voltage; is carried out at a Temperotur above 80 ⁰ C, but below 160 ° C. - 15 - 009825 / 19ff BAD ORlQiNAt Blank page