DE2130451A1 - Process for making yarn from polytetramethylene terephthalate - Google Patents

Description

DR.-ING, FROM KREISLER DR.-ING. SCHÖNWALD DR.-ING. TH. MEYER DR. FUES DiPL.-CHEM. ALEK VON KREISLER . DIPL.-CHEM. CAROLA KELLER DR.-ING. KLÖPSCH

COLOGNE 1, DEICHMANNHAUS

Cologne, June 17th, 1971 Ke / Ax / Hz

Fiber Industries, Inc., Charlotte , North Carolina (U.S.A.),

Process for the production of yarn from polytetramethylene

terenhthalate

Polytetramethylene terephthalate yarn is due to its excellent strength properties and its excellent dyeability is very valuable. The invention relates to discloses a new method of spinning and drawing a yarn composed of at least 85% by weight polytetramethylene terephthalate consists.

In normal processing of melt-spun polymers For fibers, it is advisable to keep the tension in the threads emerging from the nozzle as low as possible and still wind the material on a spinning bobbin, because the use of low voltages improves the evenness and keeps the orientation of the freshly spun threads low, and a low orientation the freshly spun threads enable relatively high tail ratios and increased production output. A typical teaching of the prior art in this regard is given, for example, in the United States patent 5 361 859 given.

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It has surprisingly been found that polymers that at least 85% by weight of polytetramethylene terephthalate exist, not under the conditions previously used for the processing of polyethylene terephthalates, for example were valid, can be processed. If the first-named polymer under conditions (which are to take into account Differences in melting points have been corrected) normally applied for the latter polymer is melt-spun, for example the produced yarn crystallizes on the bobbin, causing the thread becomes longer and eventually slides off the spool. Such a bobbin can only be used with extreme difficulty and cumbersome handling. If the material is handled and tried carefully, to complete the drawing process, the yarn becomes longer, when it is heated. Stretching with hot delivery rolls is then impossible because the spun material is too hot Roll backwards, creating a tangle and tangle that leads to catastrophic ruptures of the Thread material leads. Using a cold delivery roll alone is limited to processes in which with a low draw ratio (less than about 1.6) is worked because a cold drawing with higher ratios of thick and thin parts in the yarn and too results in an uneven product. Other stretching methods, e.g. the use of steam jets or stretching with hot air require special equipment and are cumbersome on a large scale. The usage For example, steam jets are disadvantageous because they are expensive, a large amount of heat and noise occurs and the yarn becomes crystallized to the point where it does not texturize effectively can be. If, for example, a heated shoe is used, the method is very difficult to carry out. The use of a steam conditioning tube during spinning prevents crystallization on the bobbin,

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does not necessarily allow the material to be withdrawn from a hot delivery roller.

The invention is a simple economical process for spinning and stretching of polymers which are at least 35 wt -.% Consist of polytetramethylene to yarns. The method according to the invention for the production of yarn that at least. 85 wt .-% consists of polytetramethylene terephthalate, with a total titer of the freshly spun material of about 80 to 700 den is characterized by the following levels:

1) At least 85% by weight are made of polytetramethylene terephthalate existing polymer that has a relative viscosity of about 10 to 50,

2) about 5 to 70 threads of this polymer are pressed through a spinneret, v / ob ei

a) the spinning temperature is about 24-0 to 280 ° C and

b) the extruded threads are pulled off at a winding speed of about 305 to 3050 m / minute be, and

3) subsequently drawn the filaments at a stretching ratio of about 1.0 to · 5 »0, wherein passing the filaments during drawing a held at about 60 to 180 ⁰ C feed roll,

with the proviso that the tension of the extruded individual threads (measured at a distance of about 178 cm from the exit surface of the spinneret) is at least 0.09 g / thread and the total tension of the spun material (ie the tension of the yarn bundle) at least -0.4 + 0.00174 (total titre of the freshly spun yarn) + 0.052 (relative viscosity of the polymer) - 0.0366 (spinning temperature in ⁰ G) + 0.1414 (number of threads squeezed out) + 0.00381 (winding-

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speed in feet) - 0.000000332 (winding speed

'P-

in feet). ,

It has surprisingly been found that a relatively high tension exerted on the spun material in connection with the others described here Process conditions a yarn with excellent strength properties, excellent dyeability and good uniformity is formed. The product made by the method according to the invention also has good evenness at high winding speeds. This is unexpected given the behavior of polyethylene terephthalate, in which the quality of the yarn produced increases with increasing winding speeds becomes significantly worse. The method according to the invention thus has at least two differences the process of making polyethylene terephthalate yarn: it is made with relatively high tensions, the are exerted on the spun threads, and carried out at relatively high winding speeds. With this procedure, a polyethylene terephthalate yarn would be produced in the spinning and drawing of polyethylene terephthalate obtained with poor properties, while resulting in a polytetramethylene terephthalate yarn with excellent Properties leads.

In the method according to the invention, the yarn to be spun and drawn consists of at least 85% by weight Polytetramethylene terephthalate. This polymer can diirch Implementation of terephthalic acid or its alkyl esters with a polymethylene glycol of the formula HO (GHp) OH, in the η is an integer from 2 to 8. At least 85% of this polymer comes from a glycol formed, in which η stands for 4 (1,4-butanediol). the the remaining 15% can be partly or wholly from ethylene glycol, Trimethylene glycol, 1,4-butanediol and the like. are formed. The polymethylene glycol, which is used to remove these residual

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lichen 15% can be partially or fully formed by other glycols, e.g. 1,4-cyclohexanedi-, methanol and 1,4-bis (2-hydroxyethyloxy) benzene will. Preferably no more than about 10% of the polymer is formed from a glycol other than polymethylene glycol is.

Other dicarboxylic acids and their esters can also be used for the preparation of the used in the process according to the invention Polymers are used. For example, about 1 to 10% by weight (based on the weight of the Preparation of the polymer used terephthalic acid or its dialkyl ester) of a dicarboxylic acid of the formula

COOH COOH

HOOC-R-COOH,

COOH

in which R is an alkylene radical having about 2 to 16 carbon atoms. When this dicarboxylic acid is used in the preparation of the polymer, its amount is preferably about 3 to 8% by weight. Examples of suitable dicarboxylic acids for the preparation of the polymer used in the process according to the invention are succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, phthalic acid and isophthalic acid. If one or more of these dicarboxylic acids are used, those of the formula HOOC-R'-COOH, in which R ^{1 is} an alkylene radical with about 4 to 10 carbon atoms, are preferred, acids of this formula in which R ^{1 is} an alkylene radical with 4 · C atoms are particularly preferred.

Subject to the above limitation (at least 85% by weight of the polymer consists of polytetramethylene terephthalate) can be the polymer used in the process according to the invention in addition to the above-mentioned compounds other compounds, e.g. additives for

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Improvement of the colorability, matting agents, antistatic agents and optical brighteners contain

In a preferred embodiment, this is the case Process according to the invention used polymers in. essentially, i.e. at least 95% by weight of polytetramethylene terephthalate ·

In the method according to the invention, yarns with a "total denier" of about 80 to 700 are preferably produced. The "total titer" is the weight of 9000 m of yarn in grams. The total linear density of the yarn produced according to the invention is preferably about 100 to 550 den, wherein a total titre of about 150 to 450 denier is particularly preferred will.

Process for the preparation of tetramethylene terephthalate polymers are known. For example, the polymer can be obtained by reacting terephthalic acid and 1,4-butanediol manufactured by the method of U.S. Patent 2,465,519 will. This is a "direct esterification process". The polymer can also, for example, by reacting Dimethyl terephthalate and 1,4-butanediol are produced. This is the "ester interchange process". The "relative viscosity" (i.e. the ratio of viscosity an 8% solution of polytetramethylene terephthalate in o-chlorophenol to the viscosity of o-chlorophenol alone, measured in equal units at 25 ° 0) of the polymer used in the process according to the invention should be about 10 to 50. However, polymers with are preferred a relative viscosity of about 15 to 40, being polymers having a relative viscosity of about 20 to 30 are particularly preferred.

In the method according to the invention about 5 to 70 threads of the polymers are extruded through a spinneret at a spinning temperature of about 240 to 280 ⁰ C. (The "spinning temperature ^11" is the temperature of the molten polymer

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before pressing). The extruded threads are drawn off at a "winding speed ¹¹ of about 305" to 3050 m / minute. Preferably about 10 to 50 threads of the polymer are spun at a spinning temperature of about 24-5 to 270.degree subtracted about 760 to 183O m / minute. In the particularly preferred embodiment of the invention, about 15 "to 40 threads of the polymer are pressed out at a spinning temperature of about 250 to 265 ° C. and drawn off at a take-up speed of about 910 to 1525 m / minute.

In the method according to the invention it is critically important that the emerging threads are kept under a tension of at least 0.09 g / thread, preferably at least 0.19 g / thread (measured approximately 178 cm from the exit surface of the spinneret). The total tension exerted on the emerging threads (i.e. the Garri bundle as opposed to the individual threads forming the Garri bundle) is at least -0.4 + 0.00174 (total denier of the spun yarn) + 0.052 (relative viscosity of the polymer) - 0, 0366 (spinning temperature in ⁰ O) + 0.1414 (number of threads squeezed out) + 0.00381 (winding speed in feet) - 0.000000332 (winding speed in feet) ² .

After the spun threads have been drawn off, they are drawn up to a draw ratio of about 1.0 to 5 »0, preferably about 1.5 to 4.0. This can be done in one or two stages depending on the conditions used. Two-stage stretching is preferred when the equation below gives a value of 1,000 or more. If 1.603 - 0.0000174 (winding speed in feet) + 0.0001336 (spinning temperature in ⁰ C) + 0.003863 (temperature of the delivery roller in ⁰ G) - 0.02377 (relative viscosity of the polymer) + 0.0006562 (number of extruded threads) - 0.0919 (temperature of the delivery roller /

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relative viscosity) gives a value of more than 1,000, ought to be stretched in two stages. Is this value below 1,000, is preferably stretched in one step.

If stretching is carried out in two stages, the first stage is expediently a "cold stretching" in which the material is stretched at a stretching ratio of about 1.0 to 1.6 (preferably about 1.0 to 1.2), while it is stretched over a " cold "delivery roller is performed, which has a temperature between about room temperature and about 60 ° C. The second stage is "hot stretching" in which the material is drawn over a hot feed roll at a temperature of about 60 to 180 ° C 'at a stretching ratio of about 1.0 to 5 * 0. As with the single-stage stretching is the two-step process preferably the total draw ratio is about 1.5 to 4.5 and the temperature of the feed roller of the second stage about 70 to 15O ⁰ C, a temperature of the feed roller of the second stage of about 80 to 1JO C particularly is preferred. The stretching speed in hot stretching can be about 150 to 3050 m / hour. Since the method according to the invention comprises one-step and two-step drawing, the two-step operation including cold drawing, means in the description of FIG. Invention, the words "v threads / ground during the stretching at a temperature of about 60 to 180 ⁰ G over a heated" feed roll out "of the expression" during "the use of a heated feed roll at a temperature of about 60 to 180 ⁰ C. for one of the two parts of the stretching (two-stage stretching) or for practically the entire stretching (single-stage stretching).

If the above equation gives a value less than 1.000 and the spun threads are held under a tension of at least 0.19 g / thread, the tension being at least 0.16 + 0.0005 (temperature of

10 9 B G 3/16 0 0

Feed roller in ⁰ C) grams / thread, one-stage "hot stretching" can be used. This is the preferred stretching method. In single-stage stretching the filaments during drawing at a temperature of about 60 to 180 ⁰ C over a heated feed roll and a hot pin or hot plate be performed, but preferably the use of up to 150 ⁰ G, heated to about 70 feeding roller and a is particularly preferably to a temperature of about 80 to 130 ⁰ G heated feed roll. In this single-stage hot stretching, the threads are stretched at a stretching ratio of about 1.0 to 5 »0, preferably about 1.5 to 4.5.

The fabrics made from the yarns produced according to the invention have an excellent feel (softer than comparable substances made of polyethylene terephthalate), excellent colorability and uniformity of coloration »

In the method according to the invention, preferably stretched Yarns with a single denier of 0.6 to 10 den, in particular from about 1 to 8, are produced, with a single denier from about 1.2 to 6.5 is particularly preferred.

The orifices of the spinnerets through which the tetramethylene terephthalate polymer is spun, can have a diameter of about 0.127 to 1.27 mm «. In contrast to the Spinning of polyethylene terephthalate, in which with increasing Opening size, the birefringence of the spun thread increases and the stretching ratios become significantly smaller, are in the case of polytetramethylene terephthalate threads that are used in the same spinning temperature and the same winding speed up to, spun to the same single denier , the Uster values, the coefficients of the cross-sectional fluctuations, the birefringence and the maximum stretching ratios essentially the same regardless of the hole size used.

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In the method according to the invention, the spun threads made of polytetramethylene terephthalate can according to any known methods can be cooled quickly. The cooling can for example with water and inflated air take place. When a cooling system is used, an air cooling system is used for the sake of simplicity and economy preferred, in which air is blown over the threads emerging from the nozzle. It has been found to be in use of such a system for polytetramethylene terephthalate, which has been produced according to Example 1, for example is, there is a certain optimal cooling rate for ■ any combination of spinning conditions at which the Orientation of the spun yarn is minimal »Under otherwise identical spinning conditions, the orientation of the spun yarn to a minimum with increasing flow rate of the cooling air, and with further increasing As the cooling speed increases, the orientation of the spun yarn increases. For example, in one experiment, yarns spun with a titer of 400 freshly spun, wound up at a speed of 1220 m / minute and stretched at a stretch ratio of 2.5. The elongations at break of the products obtained are given below.

Air outflow speed , m / minute

0 ι

7.9 15.2 24.4 29.3

Elongation at break of the product

$ 25

44 $ 40 ° /

From this observation, two important procedural implications emerge for a given Spinning process, there is an optimal flow rate of the cooling air to achieve maximum product performance. Since the curve of birefringence as a function of the

»: 1 -.- & 9 8 5 3/1890

Flow rate of cooling air "at this point If the minimum is reached, the process becomes less sensitive to small fluctuations in the cooling speed, so that a more uniform product is obtained «.

The invention is further illustrated by the following examples. All parts are parts by weight, unless otherwise stated.

example 1

0.2 mol of purified diphenylsilanediol are placed in a vessel which was equipped with a stirrer, an addition funnel and a short distillation adapter connected to a vacuum system. Within 2 minutes veräcn 0.4 mol of tetraisopropyl titanate added Here An exothermic reaction. The reactants are slowly heated to 65 ° C. with constant stirring. The isopropyl alcohol formed as a condensation product is removed quantitatively under reduced pressure (3 mm Hg absolute) within 3.5 hours. A viscous, slightly cloudy, tan-colored liquid product is obtained in a yield of 98 ^c / o . The titanium-silicon product formed in this reaction and its use as a catalyst are the subject of an earlier proposal by the applicants

11.34 kg of dimethyl terephthalate and 7.35 kg of 1,4-butanediol are placed in a melting vessel and liquefied, forming a solution in which the molar ratio of 1,4-butanediol to dimethyl terephthalate is 1.4 * 1. “The solution is transferred to an ester exchange vessel which is provided with a stirrer and a condensation system for the separation of distillates. 11.4 g of the silicon-titanium compound prepared in the manner described above are added to the solution = the reaction mixture is then heated to 2-4 ° C., whereupon the ester exchange reaction is allowed to proceed for 77 minutes until 3.63 kg of methanol ( 97 ^c a <dor theoretical amount of methanol) have been formed ,, Anr.ohlj ο kund v, '. I rd dan Hc.'jki j onr; /: emiHch in

10 9 8 5 3/1690

BATH

transferred to an autoclave, into which 11.4 g triphenyl phosphite as a sequestering agent and 11.4 g titanium dioxide are added as a matting agent. The temperature of the mixture is increased to 250 ^° C. while it is brought under an absolute pressure of about 0.08 to 0.35 mm Hg within 60 minutes. After this reduced pressure has been reached, the polycondensation is allowed to proceed for 140 minutes until a polymer with a relative viscosity of 25.4 has been formed.

The polymer is then dried and spun "at a temperature of about 255 ⁰ C and a winding speed of 1067 m / minute ,, During spinning filaments are cooled with the air that nr in an amount of 0.425 / minute is inflated ₀ The exiting spun material is held under a tension of about 0.19 g per extracted thread. 36 threads are spun »The spun yarn has a total denier of 430 denier, a birefringence of about 0.050 to 0.065 and a boiling water shrinkage of about 0 to $ 1. '

The spun yarn is drawn at a temperature of 110 C over a heated feed roll at a draw ratio of about 2.82, which the draw speed is 550 m / minute _o the drawn yarn has a titre of 150 to, a breaking strength of 3.4 g / den, an elongation of $ 35 and a shrinkage of about $ 13 in boiling water. The Uster value is $ 0.5 "The yarn can be dyed very evenly"

Example 2

Tetramethylene terephthalate is polymerized up to a relative viscosity of 21.1 using zinc acetate as a polymerization catalyst ο The chips are dried under vacuum. 36 filaments at a spinning temperature of 265 ⁰ C and a winding speed of 915 m / minute The exiting spun spun yarns are under a tension of 0.125 g held per filament. The spun product obtained is um

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cold stretched and then additionally retained on a "at 115 C to 250 roller $ verstreckto The drawn product has a good tensile strength and an excellent uniformity of dyeing ₀

Example 3

Tetramethylene terephthalate is obtained in the manner described in Example 2 " "polymerized up to a relative viscosity of 23.9 ο The polymer is at a spinning temperature of 255 ° C and a winding speed of 762 m / minute. »The emerging threads are held under a tension of less than about 0.09 grams per filament. After about 15 minutes the thread will start on the Crystallize coil, thereby preventing further drawdown and use of the material on the coil will"

Example 4

In the manner described in Example 2, tetramethylene terephthalate is polymerized to a relative viscosity of 25.4. The polymer will be at a spinning temperature of 255 ⁰ C dried under vacuum "24 threads and a winding speed of 1370 m / minute spun" The exiting filaments are maintained under a tension of 0.28 g / filament. The total denier of the extruded threads is 82 _denier. The yarn is pre-stretched by $ 1 on a cold roller and then stretched by $ 203 ^{on a roller heated to 110 ° C} have a good appearance and good dimensional stability, are knitted "

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Claims (1)

Claims (IJ A process for the production of yarn to at least '85 wt -.% Of polytetramethylene terephthalate and is an N- total titre has to 700 g immediately after spinning of about 80, characterized in that successively a) a polymer, which produces at least 85 wt -% consists of polytetramethylene terephthalate and has a relative viscosity of about 10 to 50. b) from about 5 to 70 squeezes threads from this polymer through a spinneret, wherein the spinning temperature is about 240 to 28O ⁰ C, and are subtracted the squeezed filaments having a Aufwiekelgeschwindigkeit of about 305 to 3050m / minute, and c) then the threads are drawn at a draw ratio of about 1.0 to 5 * 0, the threads being drawn passes over a heated feed roll during stretching at a temperature of about 60 to 180 ° C, with the proviso that during spinning the emerging threads under a tension (measured at a distance of about 178 cm from the exit side of the spinneret) of at least 0.09 g per thread and the yarn bundle under a total tension of at least -0.4 + 0.00174 (total titre of the freshly spun yarn) + 0.052 (relative viscosity of the polymer) - 0.0366 (spinning temperature in ⁰ C) + 0.1414 (number of threads spun) + 0.00381 (winding speed in feet) - 0, 000000332 (winding speed in feet) ² holds. 2. The method according to claim 1, characterized in that a) the value from 1.603 - 0.0000174 (winding speed in feet / minute) + 0.0001336 (spinning temperature in ° C) + 0.003863 (temperature of the feed value in ° C) 0.02377 (relative viscosity of the polymer) + 0.0006562 109853/1690 (Number of threads squeezed out) - 0.09l9 (temperature of the feed roller / relative viscosity) is smaller than 1,000, b) the threads are drawn in one stage at a draw ratio of about 1.0 to 5 * 0 while they are passed over a heated feed roller at a temperature of about 60 to 180 ° C, and c) the threads emerging from the nozzle under a tension of at least 0.19 g per thread and of at least 0.16 + 0.0005 (temperature of the feed roller in ° C) grams per thread can be maintained. 5. The method according to claim 1 and 2, characterized in that that he a) a yarn with a total denier of about 100 to 550 den manufactures, b) produces a polymer with a relative viscosity of about 15 to 40 and presses about 10 to 50 threads of the polymer through a spinneret, keeping the spinning temperature between about 245 and 27O ⁰ C and the pressed threads with a winding speed of about 762 to subtracts l8j50 m / minute, and c) then the threads are drawn in a single stage at a draw ratio of about 1.5 to 4.5, while they are passed over a heated feed ^{roller at a temperature of about 70 to 150 ° C.} 4. The method according to claim 1 to ~ 5, characterized in that one a) a yarn with a total denier of about 150 to 450 manufactures, - b) a polymer with a relative viscosity of 109853/1 630 used about 20 to J50 and about 15 to 40 threads of the
Polymers are extruded through a spinneret, the spinning temperature being kept between about 250 and 265 ° C. and
pulls off the pressed threads at a winding speed of about 914 to 1524 m / minute and c) then the threads are drawn while they are at a temperature of about 80 to 130 ⁰ C over a
heated feed roller leads. 109853/1690