JPS6221817A - Ultra-high speed spinning of polyester fiber - Google Patents

Abstract

PURPOSE:To obtain the titled fiber having not too small residual elongation and usable for clothes, etc., by dispersing a specific amount of a polymer having specific solubility parameter and melt index in a polyester, melting the composition, and taking up the molten mixture at an ultra-high speed. CONSTITUTION:A polymer (e.g. polymethyl methacrylate) having a solubility parameter (SP) of 9-12 and a melt index (MI) of <=4 is dispersed in a polyester phase constituting the base of a polyester composition. The amount of the polymer is 0.5-5wt% based on the whole composition. The obtained polyester composition is melted, extruded through a spinneret and taken up at a rate of 9,000-13,000m/min to obtain the objective fiber. The polyester used as the base is preferably polyethylene terephthalate and the maximum temperature in the melt-spinning process is preferably >=300 deg.C.

Description

[Detailed description of the invention] a. Field of use The present invention relates to a method for ultra-high speed spinning of polyester fibers.

More specifically, the present invention is 9000, ? I/min or more 130
The present invention relates to a high-speed spinning method for polynisdel that achieves excellent spinnability at ultra-high speeds of 00 m/min or less.

b. Prior Art Polyester, represented by polyethylene terephthalate, has many excellent properties, so it has been used for a variety of purposes.
Polyester fibers are widely used in textiles.
Up until now, it has been used to melt-spun at a low spinning speed of around 1000 m/min and then heat-treat it by stretching at a temperature higher than K°C. On the other hand, recent advances in yarn spinning technology have made it possible to increase the take-up speed during melt spinning from the conventional 1000 to 2000 m/min to 5000 m/min. Especially 2500~50'O
The intermediately oriented yarn obtained by 0m/min is usually directly subjected to stretching, false twisting and crimping, which is becoming the mainstream of yarn spinning technology. (For example, see Chemical Fiber Monthly Vol. 37, No. 6, pages 44-49.) Furthermore, the take-up speed should be 5000 m/min or more.

So-called ki high-speed spinning has also been attempted in order to obtain fibers with sufficient mechanical properties without going through a drawing process. However, with such ultra-high speed spinning, yarn breakage occurs frequently during spinning, and in addition, the spinning speed is reduced to 650.
If you reduce the speed by 1% at 0 m/min or more, the degree of orientation and strength will change.

There are five problems when crystallinity etc. deteriorate.

In order to solve this problem, spinning conditions such as spinning temperature,
Attempts were made to optimize the cooling air volume and cooling air temperature, and to improve the structure of the spinning tube, spinneret nozzle, etc., but these measures had their limits and no significant improvement could be expected.

Furthermore, when the drawing speed is set to 9000 m7 minutes or more, the residual elongation of the drawn fiber is usually 20. %, and there was a problem in using it for clothing and other normal uses.

C4 Purpose of the Invention The purpose of the present invention is to achieve excellent spinnability at ultra-high speeds of 9000 yn/min or higher by not only improving the above-mentioned spinning conditions, but also improving the chemical composition of polyester at the same time. The purpose is to provide a method.

Another object of the present invention is to produce a polyester fiber that does not have an excessively low residual elongation even during ultra-high speed spinning of 9,000 m/min or higher and can be used for ordinary clothing applications. Our goal is to provide the following.

d0 Constitution of the Invention According to the present invention, 0.5 of the total amount of a polymer having a solubility parameter (SP) of 9 or more and 12 or less and a melt index (MI) of 4 or less is added to the polyester phase serving as a paste. The polyester composition obtained by dispersing ~5 weight is melted and the speed is 9,000 m/min or more.
A method for ultra-high speed spinning of polyester fibers is provided that takes off at a speed of less than fflZ minutes.

The polyester referred to in the present invention has terephthalic acid as the main acid component, and has a small amount of glycol, preferably ethylene glycol.

The main targets are polyesters whose main glycol component is at least 1a fullylene glycol selected from trimethylene glycol and tetraethylene glycol, especially polyethylene terephthalate (
PET).

It may also be a polyester in which part of the terephthalic acid component is replaced with another difunctional carboxylic acid component, and/
Alternatively, it may be a polyester in which part of the glycol fraction is replaced with the above-mentioned glycol group or other diol component other than the main component.

Such polyesters may be synthesized by any method. For example, in the case of polyethylene terephthalate, usually terephthalic acid and ethylene glycol are directly esterified, a lower alkyl ester of terephthalic acid such as dimethyl terephthalate is transesterified with ethylene glyfur, or terephthalic acid and ethylene glycol are transesterified. The glycol ester and/or terephthalic acid is reacted with ethylene oxide to form a low polymer in the first step, and the reaction product in the first step is heated under reduced pressure to reach the desired degree of polymerization. It is produced by a two-step reaction in which 1klIB is combined until 1klIB is obtained.

In the present invention, the solubility parameter (SP) in the above base and the polyester is 9 or more and 12 or less,
It is necessary that a polymer having a melt index (Mr) of 4 or less be dispersed in a proportion of 0.5 to 51 Ftit% of the total amount.

This polymer preferably has a chemical structure different from that of the base polyester and does not chemically react with the polyester at 250°C to 400°C. If a chemical reaction occurs, random love lock or even graft copolymerization with polyester occurs during the melt spinning process, which deteriorates the m-quality of the polyester fiber and significantly deteriorates its drawability at ultra-high speeds.

Furthermore, the polymer dispersed in the polyester phase must have a solubility parameter (SP) of 9 or more and 12 or less. When the SP value is less than 9 or more than 12, the compatibility with polyester becomes low and the dispersed particles become coarse. In this case, the coarse dispersed particles act as foreign matter in the polyester composition, so the 9000 m
Ultra high speed spinning of more than 1/min becomes impossible. On the other hand, sp
When a is from 9 to 12, the mutual solubility with the matrix polyester is good, and the dispersed particles are finely divided, making ultra-high speed spinning possible. .

Typical examples of these dispersed polymers include polymethacrylate or its derivatives, polyacrylate or its derivatives, polystyrene or its derivatives, and the like.

Further, the dispersed polymer does not have to have a single chemical composition, and may be a copolymer of acrylic-styrene resin or the like. Among these polymers, especially polymethyl methacrylate)
(PMMA), polystyrene (PS), and acrylic-styrene resin (AS) are preferred examples. Furthermore, these dispersed polymers have a melt index (MI
) is 4 or less. Even if the SP value satisfies the above conditions, if the MI value exceeds 4, the ultrahigh-speed spinning stringability that is the object of the present invention cannot be achieved.

That is, only when the SP value is within the above conditions and the MI value is above or below, in other words, a polymer with low melt flowability is dispersed, spinning at a speed of 9000 m/min or higher is required. Therefore, it is possible to ensure the quality of the product.

It is necessary that the amount of these dispersed polymers is 0.5 to 11% of the total amount of the polyester composition.

If the amount added is less than 0.5 litres, spinnability will not be improved without the effects of the present invention. On the contrary, 5m: 1%
If the amount exceeds this value, the agglomeration of the rolled polymer becomes large and acts as a foreign substance, resulting in worsening of spinnability.

As described in the present invention, ultra-high-speed spinning take-off properties are significantly improved by performing a composition cross-drawing of a special polyester. They begin to offer and pray.

However, as the single filament of polyester yarn becomes thinner and the drawing speed becomes higher, the effect of air drag on the filament becomes stronger (the molecules in the filament are stretched and the crystals are destroyed. Since problems such as an increase in fiber shrinkage occur, it is desirable to employ a first-order spinning technique.

←) A length of 5 clI or more from the bottom surface of the spinneret is passed through a heating zone maintained at a temperature of 150° C. or more and 250° C. or less, and then cooled at room temperature or by a heated air stream.

(b) An air nozzle is provided between the spinneret and the first take-up device to collect the filament bundle. The initial take-off device can be a godet roller or a direct winder. Examples of air nozzles include interlace nozzles and false twist nozzles, and a plurality of these may be used.

(→ A lubricating nozzle guide is used between the spinneret and the first drawing device to lubricate and condense the filaments. It is preferable to install the oil supply nozzle guide upstream of the heel.Also, the number of oil supply nozzle guides is not limited to one, and a plurality of oil supply nozzle guides may be used.

b) The filament running length from the spinneret to the first take-off device shall be within 3 m.

(f) The maximum temperature during melt spinning shall be 300°C or higher.

Among the above techniques, ni) (he) promotes the relaxation of molecular orientation, and (gu) (c) ←)... This is to suppress excessive orientation up. As a result, the residual elongation of the resulting high-speed drawn fibers can be ensured, and the spinnability at high speeds is also significantly improved.In the present invention, any method can be used to add and disperse the above-mentioned polymer into the polyester. can.

For example, it may be carried out during the polymerization process of polyester, and
It may be melt-blended with polyester, extruded, cooled, and then cut into chips. Furthermore, both may be mixed in the form of chips and then melt-spun as is. However, in this case, in order to increase the degree of kneading, it is preferable to use a screw type melt extruder +1 bird.

No matter which method you use, mix thoroughly and
It is necessary to take care to ensure that the added polymer is finely and uniformly dispersed and mixed in the polyester. If the kneading is insufficient and the added polymer is arranged in a sea-island pattern in the matrix polyester, it is necessary to mix it under ultra-high speed. The take-up property of the spinning material deteriorates.

e6 Functions and Effects of the Invention Why is the design of the polyester composition as in the present invention 9000?
It is not fully clear whether K improves the stringiness of ultra-high-speed spinning of 1 minute or more, but it is probably due to the high mutual solubility that results in uniform fine particle dispersion of the added polymer and the low melt index, that is, in the molten state. Since the fluidity is low, it is thought that the added polymer acts like a "flow" on the deformation of the polyester during the process from extensional flow during ultra-high speed spinning of polyester to immediately after necking roughening.

In fact, when the running filaments during ultra-high speed spinning are examined to examine the shape of neck thinning, neck thinning occurs rapidly in the case of ordinary polyester.1 The neck thinning of the polyester composition of the present invention It is observed that the shape of the change becomes significantly more gradual.

Through these processes, the polyester molecules use the fIJΣ-added polymer as "rollers" to cause a phenomenon similar to a kind of slippage, thereby suppressing oriented crystallization during the spinning process. As a result, it is thought that the cross-sectional non-uniformity peculiar to ultra-high speed spinning such as skin core A structure is alleviated, and the stringiness at ultra-high speeds is significantly improved.

At the same time, such an effect suppresses the increase in the orientation of the molecular chains, so that it is possible to prevent an excessive decrease in elongation even in ultra-high speed drawing of 9000 m/min or more.

Note that the melt index of the added polymer in the present invention was measured by the method of ASTM D1238.

f, Example low viscosity is 0.64, titanium oxide 0 as a matting agent
．． After drying polyethylene terephthalate (CPET) chips containing 3% at 160°C for 4 hours, polymethyl methacrylate (PMMA) (7 0.9) were mixed in various ratios in a chiffon, and melt-mixed at 310° C. in a screw-type melt extruder with a diameter of 25 tm to diffuse PMMA into PET. Then, it was discharged from a spinneret having 12 circular holes with a diameter of 0.35 m and kept at 305°C.

A multifilament of 37.5 denier/12 filaments was obtained by ultra-high speed spinning at a take-up speed of 950 OFF+ per minute. Furthermore, at this time.

Take the traveling yarn between 150I below the cap (warm the atmosphere to 200℃, and then cool the part between 20α and 90CII below the cap using cooling air at room temperature (wind speed about 15α/sec). The winding machine was installed at a position 3 m directly below the spinneret, and winding was performed directly after oiling with an oiling roller without using a godet roller.

Table 1 shows the mechanical properties, water yield rate, and high-speed spinning properties of the polyester fibers obtained as described above. The boiling water shrinkage rate is the shrinkage rate when heat treated in boiling water for 5 minutes in a free state.

Table 1: Spinnability standards (same in the following tables) ×: Yarn breakage within a few seconds after start of take-up Δ: Single yarn breakage occurs within tens of seconds ○: Single yarn breakage occurs within 1 to 2 minutes ◎: No single yarn breakage (2 minutes) *: Comparative example (also shown in the table below) In the case of implementation point 1, ordinary PET was used and the spinnability was poor. In addition, in the case of Arashi 7, the amount of PMMA added is too large, resulting in poor spinnability and low strength. On the other hand, in Arashi 2 to Seki 6, improvements in spinnability were observed, and improvements in strength and elongation were also observed.

Example 2 In the same manner as in Example 1, a polyester composition in which the amount of PMMA added was O weight S and 2.5 mt amount 6 was prepared, and then the following spinning was performed.

That is, the polymer was dried by a conventional method and heated at 160°C for 4 hours.
After melting and discharging at a maximum temperature of 320°C using a spinneret with 8 circular spinning holes with a hole diameter of 0.4 mm, ultra-high speed spinning is performed at a take-up speed of 9,000 m/min to 13,000 m/min. A multifilament of 37.5 tenier/8 filaments was obtained.

At this time, the lower part of the spindle 12α -1 is heated so that the temperature of the atmosphere surrounding the running yarn reaches 220℃, and then
Using warm air at 0°C (wind speed approximately 100/sec), lower the base 150
A portion of 1 to 85 cm was cooled. Furthermore, the base is 0
A lubrication nozzle guide is installed at the bottom 80cIP position to focus the multifilament and lubricate it.

Cooling was performed. Further, the winding machine was installed at a position 2.5 m directly below the spinneret, and the winding was carried out immediately after oiling with an oiling roller without passing through a godet roller.

Table 2 shows changes in high-speed spinnability and fiber properties at this time.

Spinnability level XX: No spinnability at all In the case of Arashi 6 to 8 where there is no addition and dispersion of PMMA, spinnability is perfect (
It is defective. To this, PMMA is added.
In the case of No. 5, the spinnability was significantly improved and the strong elongation was satisfactory.Example 3 Polystyrene (PS) was used as the added dispersion polymer (product name: Styron 475-D manufactured by Asahi Tau; SP value "1 + MI").
Five multifilaments of 37.5 denier/8 filaments were obtained by high-speed spinning at a take-up speed of 9000 m/min using a 37.5 denier/8 filament. Note that other conditions are the same as in Example 2. Table 3 shows the changes in high-speed spinnability at this time.

Table 3 In the case of the present invention, improvement in spinnability was observed.

Example 4 Various acrylic-styrene copolymer side fIFI(AS) (
When a high-speed spinning test similar to Example 3 was conducted using Asahi Dow #783, #767゜#769), the fourth
Obtained the results in the table.

Table 4 Case 4 is a case of ordinary PET, and its spinnability is poor. Although As is added and mixed in 10,000, Na2, and Na3, the spinnability is not improved at all because the MI value is still low. On the other hand, positive 1 is based on the present invention and not only improves spinnability but also improves mechanical properties.

Claims (11)

[Claims] (1) A polymer having a solubility parameter (SP) of 9 or more and 12 or less and a melt index (MI) of 4 or less is dispersed in the base polyester phase in an amount of 0.5 to 5% by weight based on the total amount. 1. A method for ultra-high-speed spinning of polyester fibers, which comprises melting a polyester composition and taking it off at a speed of 9,000 m/min or more and 13,000 m/min or less. (2) The polymer to be dispersed has a chemical structure different from that of the base polyester, and
The method for ultra-high speed spinning of polyester fibers according to claim (1), which does not chemically react with each other at temperatures between 400°C and 400°C. (3) The ultrahigh-speed spinning method for polyester fibers according to claim (1) or (2), wherein the polymer to be dispersed is polymethyl methacrylate or a derivative thereof. (4) The method for ultra-high speed spinning of polyester fibers according to claim (1) or (2), wherein the polymer to be dispersed is polystyrene or a derivative thereof. (5) The method for ultra-high speed spinning of polyester fibers according to claim (1) or (2), wherein the polymer to be dispersed is an acrylic-styrene resin. (6) The method for ultra-high speed spinning of polyester fibers according to claim (1), wherein the polyester is polyethylene terephthalate. (7) The polyester fiber according to claim (1), wherein the spun yarn is passed through a heating zone maintained at a temperature of 150°C or more and 250°C or less over a length of 5 cm or more from the bottom surface of the spinneret. ultra-high speed spinning method. (8) The method for ultra-high speed spinning of polyester fibers according to claim (1), wherein an air nozzle is provided between the spinneret and the first take-off device to collect the spun yarn. (9) The method for ultra-high-speed spinning of polyester fibers according to claim (1), in which a lubricating nozzle guide is used between the spinneret and the first take-off device to lubricate and condense the filaments. (10) The ultrahigh-speed spinning method for polyester fibers according to item (8) or item (9), wherein the filament running length from the spinneret to the first take-off device is within 3 m. (11) The method for ultra-high speed spinning of polyester fibers according to claim (1), wherein the maximum temperature of melt spinning is 300°C or higher.