DE1710605B1 - Process for producing crimped polypropylene threads - Google Patents

Description

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The invention relates to a method for at 135 ° C and at a concentration of 0.1g / Manufacture of crimped polypropylene threads. The 100 ml) used. That for the present invention Attempts to date in this direction are more normal - polypropylene to be used must also have a poly type of substantially crystalline polypropylene degree of merization of less than 2.0, preferably of the end. Have 5 less than 1.5 to make it spin

From the Austrian patent specification 241 010 this is suitable.

Manufacture of crimped polypropylene threads. The degree of depolymerization is defined as follows:

knows, the propylene at a spin head degree of depolymerization = fysp / Ch / blsp / Qs. temperature from 175 to 320 ° C with a spinning In this formula, [y $ p / C] p means the reduced

speed of more than 600 m / min, spun io viscosity of the polymer obtained by polymerizing PoIywird and the threads at up to 14O ⁰ C and stretched mers and [r \ SPLC] _s, the reduced viscosity of the PoIyschließlich be relaxed. While according to this mers, when it is used as a raw material for spinning process, about 20 crimps per 2.54 cm is obtained.

In contrast, according to the invention, if the degree of depolymerization exceeds 2.0,

50 pimples per 2.54 cm can be achieved. 15 cannot obtain suitable crimped fibers

The process of making crimped will be, even if the other features of the Polypropylene threads, whereby crystalline polypropylene invention are adhered to, at a temperature at the spinneret from 260 to. Various additives can be used for polypropylene

280 ⁰ C at a spinning speed of more than thermal stabilizers, such as 2,6-di-t-butyl-t-cresol 600 m / min, spun, the filaments at 120 to 15O ⁰ C 20 (0.1 weight percent), light stabilizers such as 2-Hyerhitzt, then stretched at 110 to 15O ⁰ C and closing droxy-4-octoxybenzophenone (0.3 weight percent), are lent relaxed, characterized stabilizers against discoloration by gas, unloading _Λ according to the invention in that crystalline Polypropylene used with gloss agents, such as titanium dioxide, fluorescent \ a degree of depolymerization less than 2.0, bleach, pigments, crystalline nuclei. 25 substances, such as sodium benzoate and various Λ

According to the method according to the invention, there are types of substances which promote the ability to be dyed crimped polypropylene threads have zen, such as poly (aminotriazole), (5 to 20 percent by weight) surprisingly use a much higher curl number and; all these additives are known a much smaller crimp size than known The conditions under which the polypropylene

crimped polypropylene threads. When melt spun such as these, crimped polypropylene filaments are very important and must be carefully controlled for a long time afterwards. The spinning temperature keeps stretching under tension, for example when the should be 260 to 280 ° C at the spinneret. ^{If threads are wound around the draw} bobbin for several days at temperatures more than 10 0 C higher or lower, the crimp number decreases compared to when this range is applied. even if the tension is held. Even then, sufficient slack in the other process steps according to the invention cannot be carried out in these cases. The temperature at the spinneret, if the filaments of the heat treatment can only be measured easily and precisely, will be exposed after the relaxation, so that a small bore in the spinneret will not give a satisfactory result. 40 surface mounts and a thermistor

If, on the contrary, the one according to the invention, introduces into this hole.

crimped fibers or threads for more than 2 days. The spinning speed also affects the

remain wrapped around the draw out bobbin, however, the crimping properties of the resultant fibers, same extremely fine crimp within Although a slight crimp at a Spinnge- ά be obtained of about 2 minutes, such as when 45 speed of less than 600 m / min, to receive the threads relaxed immediately after stretching. can be, it is necessary for the invention A even with a heat treatment after a certain desired very fine crimps, a 'storage period fine crimps can get a higher spinning speed than 600 m / min, and maintain the degree of fineness of the crimps.

changes little even if the threads subsequently 5 ° It is also necessary that the conditions under be heat treated. which the unstretched threads of the heat treatment

The crystalline polypropylene serving as the raw material for the present development and the drawing conditions of the present invention can be carefully controlled. If the heat treatments are retained, if the usual way of polishing the unstretched fibers is omitted or, in the case of propylene, in the presence of a catalyst for the production of isotactic polypropylene poly range of 120 to 150 ⁰ C is carried out at a temperature lower than the prescribed, gets merized. The by-product is not either no crimp or a very poor crystalline polypropylene may be obtained by extracting with ripple, even if the distances are in the n-heptane or a similar solvent corresponds prescribed range of 110 to 15O ⁰ C durchfernt. For the purposes of the present 60 leads and then the fibers or threads are used. Crystalline polypropylene is then tensioned. The heat treatment of the unstretched with less than 20%> preferably less than 10% threads in the prescribed temperature range of constituents which can be extracted with n-heptane. This obviously affects the increase in crimps, and polypropylene used for spinning must have a permeability of the filaments, as can be seen from the fact that the crimp is achieved even then for melt-spinning. For this purpose, a polymer, may be with if one carries out the stretching at a reduced viscosity (r _S p / C) of 0.8 to 3.0, temperature of 110 to 150 ⁰ C. One has preferably from 1.4 to 2.5 (measured in tetralin, namely previously assumed that with such a high

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Stretching temperature no crimp can be achieved or become entangled. The ripple can

can. under the tension exerted on the

The temperature and duration of the heat treated fibers exerted during knitting

ment are in inverse proportion to one another.

in relationship, d. H. around the same effect of heat- 5 The "crimp elongation" shown in the following

To achieve treatment at a higher temperature, examples given, is defined as follows:

the duration of the heat treatment should be shorter. L - S

For example, a heat treatment will result in crimp elongation = - 100 (%)

at 130 ^c C and a duration of about 30 minutes the ^ o

Achieve the same as at 12O ⁰ C and a duration of OK Comments:

of more than an hour. The duration of heat- ^s ° . ^{Length of the} crimped threads after an initial

,,,,,,. ,. ,, "". load of 1 mg / den has been applied.

treatment typically varies from about 10 micro _{L of the same length of crimped} yarn, as long as a

utes up to 2 hours. Load of 100 mg / den is applied.

If you try to use the

the heat treated fibers at a temperature 15 B e i s ρ i e 1 1 to stretch that is lower than the prescribed one

Range of 110 to 15O ⁰ C, so the stretching is not using titanium trichloride and diethyl or with only a low draw ratio possible. aluminum chloride as catalysts as well as a small amount of hydrogen is not acceptable for modifying the molecular bar, since this leads to insufficient crimping of the 20 weight propylene was polymerized in η-hexane; Fibers leads. the polymer has been worked up in the usual manner. If stretching is carried out at the prescribed, using polypropylene powder at a reduced temperature, the stretching ratio is not limited to viscosity of 2.0 and n-heptane content of, but it is usually 1.1-4.0, 2.1%.

preferably 2.0 to 3.5. As a thermal stabilizer, 0.1% 2,6-di-Wenn were added to the threads at a temperature within t-butyl-p-cresol; this mixture was stretched in the prescribed range, a tabletting device is given, whereby not only a crimp is possible, but polymer granules with a reduced viscosity of also an extremely fine crimp, which so far obtained 1.8, are obtained. The degree of depolymerization was 1.1. with conventional methods, without subsequent heat- 30 For spinning, a normal melt treatment was never achieved. Rather, under spinning machine consisting of extruder and gearwheel such conditions the result is a pump used. The temperature at the spinneret feingekräuseltes yarn with a crimpability was 265 ⁰ C. The spinneret had 24 holes, each with the even is not lower when the yarn mm a diameter of 0.45. The squeezed out leaves under tension for a long time. As soon as the 35 thread was ^{cooled with 20 0} C cold air. The stretched fibers are relaxed, the spinning develops with a take-up speed, so that a heat treatment after 800 m / min, the relaxation is not absolutely necessary. The undrawn threads were treated at 140 ° C for 1 hour while they were on bobbins from the thread denier. A particularly fine 40 wraps were. These unstretched threads were crimps, which were stretched in the customary manner using the process according to the invention. The stretched that can be achieved are more than 40 crimps of thread bundles of 70 denier / 24 threads were at a per 25 mm in the case of a single 1-den to 5-den draw temperature of 140 ⁰ C, a draw ratio of thread as it is for garments is used, of 3.0 and a stretching speed of 400 m / and about 25 crimps per 25 mm, even in the case of 45 minutes.

a single 15 denier thread. The number of with within 30 minutes were the most stretched

crimps obtained up to now usual method is threads processed into strands, whereby an extreme

less than half of the stated values. fine ripple developed, and then became rapid

When the yarn reaches a state of equilibrium immediately after drawing. The properties

be relaxed, an extremely fine crimp 5 ° of the crimped fibers were as follows:

developed practically immediately. On the other hand, when the crimp elongation is 120 »/ 0

Fibers or thread on the bobbin for more than 2 days. _{Number of} crimps 51/25 mm

remain wound up, reach the stretched thread

nevertheless almost a state of equilibrium within- After these strands were steamed for 30 minutes

half of 2 minutes after relaxing. In addition, 55 were treated at 120 ° C, they showed only one

the same fine crimp is obtained as when there is little difference compared to the untreated

the threads are untangled immediately after stretching; they had the following characteristics:

tense. The crimp which at room temperature crimp elongation 125%

Achieved equilibrium shows little change, the _{number of} crimps 51/25 mm

even with a subsequent heat treatment, 60

d. that is, subsequent heating and de-Example 2 tension to achieve crimps

is necessary, but can sometimes be useful, A after the polymerization process of the Beium the crimp obtained even further to stabilize game I obtained crystalline polypropylene with a sate. 65 reduced viscosity of 2.5 was 2.0% Da the crimped threads according to the invention 2,6-di-t-butyl-p-cresol as a thermal stabilizer The puckers can develop their puckering quickly. This mixture was stretched into a tablet Threads are fed directly from a stretching bobbin; a polymer was obtained with

a reduced viscosity of 2.0. This polymer was used as a raw material for spinning. The degree of depolymerization of this polymer was 1.25. The by spinning this polymer obtained non stretched filaments at a spinning nozzle temperature of 275 ⁰ C door and a spinning speed of 1000 m / min for 30 minutes was subjected to a heat treatment at 130 ⁰ C for. The treated in the heat filaments were drawn at a ratio of 3.0 at 135 ⁰ C to obtain stretched yarn bundle of monofilaments of 15 received the. The strands made into strands quickly reached equilibrium within 30 minutes after drawing. The curled fibers had the following properties:

Crimp elongation 90%

Number of crimps 35/25 mm

When the drawn threads are wound around the draw bobbin at room temperature for 1 week left, the crimp reached equilibrium in about 2 minutes. The threads had the following properties:

Crimp elongation 80%

Number of crimps 30/25 mm ^a5

When this yarn was ^{treated with steam at 120 °} C., the following crimp values were measured:

Crimp elongation 83%

Number of crimps 32/25 mm

Example 3

3 kg of trioctylamine and 3 kg of precipitated calcium carbonate with an average grain diameter of 0.05 μ were mixed with 94 kg of granulated polypropylene with a reduced viscosity of 2.0 and a degree of depolymerization of 1.25; the polypropylene was obtained by following the procedure of Example 2. The granular polymer was used for spinning (spinning head temperature 265 ⁰ C;. Spinning speed of 900 m / min). The threads were ^{treated at 135 °} C. for 20 minutes.

The heat-treated, unstretched threads were stretched 2.3 times ^{at 140 ° C.} Thread bundles of 100 denier / 24 threads were obtained. These drawn threads were made into strands after drawing in minutes. An extremely fine crimp was obtained, with equilibrium being reached in 1 minute. The properties of the crimped threads were as follows:

Crimp elongation 115%

Number of crimps 48/25 mm

When these threads were steamed at 120 ° C for 30 minutes, the fibers had curled fibers following properties:

Crimp elongation 120%

Number of crimps 50/25 mm

Claims (2)

Patent claims: 1. A process for the manufacture of crimped polypropylene fibers, said crystalline polypropylene at a temperature of the spinneret 260-280 ° C at a spinning speed greater than 600 m / min spun, heats the filaments to 120 to 15O ⁰ C, then at 110 to 150 ⁰ C and finally relaxed, characterized in that crystalline polypropylene with a degree of depolymerization of less than 2.0 is used. 2. The method according to claim 1, characterized in that a crystalline polypropylene with a reduced viscosity of 0.8 to 3.0, measured in tetralin at 135 ⁰ C and at a concentration of 0.1 g / 100 ml, is used.