TW201713808A - Elastic polyester multifilament which has excellent elastic recovery and can quickly return to the original length - Google Patents

Abstract

The invention relates to a method for manufacturing a thermoplastic elastic polyester multifilament and a thermoplastic elastic polyester multifilament manufactured by the method. The elastic polyester multifilament manufactured by the method of the invention has excellent elastic recovery and can quickly return to the original length when the external force is removed. The yarn and fabric produced by this elastic polyester multifilament have superb elasticity and elastic recovery.

Description

Polyester elastic multifilament

The present invention relates to a method for producing a thermoplastic polyester elastic multifilament and a thermoplastic polyester elastic multifilament obtained by the method. The polyester elastic multifilament obtained by the method of the present invention has an excellent elastic restoring force and can be quickly restored to its original length when the external force is released. The yarns and fabrics produced by using the polyester elastic multifilament have good elastic elasticity and elastic recovery.

PET is made up of terephthalic acid monomer and ethylene glycol monomer. Because of its good heat resistance and chemical stability, and high mechanical strength, PET fiber is widely used in clothing, furniture, industry. Use such as textile materials. However, the disadvantage of PET is that it has a high modulus and a high hardness, and its elastic recovery rate is far less than that of nylon 66. In order to improve the shortcomings of the difference in elastic recovery rate, it has been proposed to use 1,4-butanediol (1,4-BDO) monomer and 1,3-propanediol (1,3-BDO) single in the polymerization process. The body is polymerized with terephthalic acid monomer to produce PBT and PTT. The fiber produced by PBT and PTT is better than the fiber produced by PET, but the fiber elastic recovery rate is still insufficient compared with nylon 66 fiber (also known as PA66).

The present invention has been made in view of the problems in the prior art described above. SUMMARY OF THE INVENTION An object of the present invention is to provide a method for producing a polyester elastic multifilament which is low in production cost, high in production efficiency, and excellent in elastic recovery ratio, and a polyester elastic multifilament obtained by using the production method. The yarns and fabrics obtained by using the polyester elastic multifilament have good elastic elasticity and elastic recovery.

The invention provides a method for producing a polyester elastic multifilament, which comprises the steps of: heating and melting a thermoplastic polyester elastomer (also referred to as TPEE) raw material through a screw extruder, extruding from a spinning nozzle, and then cooling The air is cooled, solidified, stretched, heat set and relaxed to obtain a polyester stretch multifilament having elasticity.

The present invention also provides a polyester elastic multifilament obtained by the above production method.

The molecular structure of the thermoplastic polyester elastomer (TPEE) consists of two parts, a hard segment and a soft segment, wherein the hard segment is an aromatic polyester, such as polyethylene terephthalate (hereinafter also referred to as PET) or polybutylene terephthalate (hereinafter also referred to as PBT), the soft segment is a polyether ester, wherein the weight ratio of the hard segment to the soft segment ranges from 80:20 to 20:80, The number average molecular weight of the reactive monomer polyether diol ranges from 500 to 5,000, such as polytetramethylene ether glycol (hereinafter also referred to as PTMEG).

The thermoplastic polyester elastomer (TPEE) of the present invention may be a thermoplastic polyester elastomer having a hard segment of PBT type or a thermoplastic polyester elastomer having a hard segment of PET type. The composition of the thermoplastic polyester elastomer (TPEE) is schematically as follows:

1. TPA+1,4-BDO+PTMEG → PBT type TPEE

2. TPA+EG+PTMEG → PET type TPEE

The meaning of each abbreviation code is as follows: TPA: terephthalic acid

BDO: butanediol

PTMEG: polytetramethylene ether glycol

EG: ethylene glycol

PBT: polybutylene terephthalate

PET: polyethylene terephthalate

TPEE: Thermoplastic polyester elastomer

In a specific embodiment, the method for producing a polyester elastic multifilament of the present invention is characterized in that the method comprises the steps of: subjecting a thermoplastic polyester elastomer (referred to as TPEE) raw material to a screw extruder at 230 to 300 After heating and melting at °C, it is quantitatively extruded through a spinning nozzle at a spinning temperature of 230-300 ° C. After cooling and solidification by cooling air, the initial spinning speed (as-spun speed) is 100~3500 m/min, and the extension temperature is 40~. 180 ° C, stretching ratio of 1 to 10 times, the molding temperature of 70 ~ 210 ° C for spinning and extension, after relaxation treatment, coiling speed of 100 ~ 5000m / min, to obtain a stretchable polyester stretch extension wire.

In a specific embodiment, the method for manufacturing the polyester elastic multifilament of the present invention can also be obtained by first forming a partial forward yarn, and then stretching, heat setting and relaxing in a discontinuous manner to obtain a stretchable shape. Elastic polyester extends the multifilament.

The polyester elastically stretched multifilament of the present invention may be in the form of continuous long fibers or short fibers.

The polyester elastically extending multifilament of the present invention may have a circular cross section or a non-circular cross section.

In the process of manufacturing the aforementioned polyester elastic extension multifilament, the invention may add other functional additives such as a flame retardant, a heat storage heat retaining agent, a heat resistant agent, an ultraviolet resist, an antistatic agent, a fluorescent whitening agent, Antibacterial agents, matting agents, etc.

According to the polyester elastic multifilament of the present invention, a long fiber product or a staple fiber product having good stretch elasticity and elastic recovery can be produced as needed.

The present invention utilizes the polyester elastic multifilaments prepared as described above to produce related fabrics by known textile techniques.

The invention is further described in the following examples, but the examples are only intended to illustrate the method of the invention and are not intended to limit the scope of the invention.

First, the measurement method of the physical properties of the polyester elastic multifilament of the present invention will be described in detail.

(1) Intrinsic viscosity IV

The ultimate viscosity was determined according to the specifications of ASTM D2857-01.

(2) Relative viscosity RV (relative viscosity)

Prepare the sample of the polyamide material to be tested, the water content of which is less than 2800 ppm. If the water content exceeds the above water content, the polyamine material pellet to be tested must be dried at a temperature of 90 ° C in a vacuum to be less than 2800 ppm. A sample of polyamido granules having a standard moisture content was dissolved in 96% sulfuric acid. After all the dissolution, the flow time was measured by a trigeminal viscosity meter, and compared with the solvent, the relative viscosity (RV) was calculated according to the following formula.

Relative viscosity (RV) = dripping time of the sample (seconds) / dripping time of the solvent (seconds)

(3) Yarn breaking strength and elongation at break:

The measurement was carried out according to the specifications of ASTM D 885 using a STATIMAT 4 automatic tensile tester (Textechno Inc, Germany).

(4) boiling water shrinkage rate:

Take 10 turns of the sample on the length measuring instrument, hang the sample with a load of 2g/D, measure the length at this time as L ₀ , and put the sample with the load into the boiling water at 98 ° C. The boiling water treatment was carried out for 15 minutes, and the sample was taken out and dried, and the length after the measurement was L. The boiling water shrinkage rate was calculated according to the following formula.

Boiling water shrinkage rate (%) = [(L0-L) / L0] × 100%

(5) Elastic recovery rate of fixed load yarn:

Take 3 samples of yarn length 60cm long, fix one end of the sample to the upper fixed clip, hang the 0.01g/De preload on the other end, and mark at 50cm interval, the length of this time Recorded as L0. Then, the load of 3.6 g/De was hung, and after one hour, the length between the marks was measured, and the length at this time was recorded as L1. Then, the load was removed, and the 0.01 g/De preload was hung for 30 seconds and 1 hour, and the length between the marks was measured, and the length was recorded as L2. Repeat the above measurement 3 times. The yarn elastic recovery rate was obtained by the following formula. The test results were expressed by three average values after leaving the load for 30 seconds and for one hour.

Yarn elastic recovery rate (%) = [(L1-L2) / (L1-L0)] × 100%

(6) Elastic recovery rate of fixed elongation yarn:

Take 3 samples of yarn length 60cm long, first fix one end of the sample to the upper fixed clip, and the other end with 0.01g/De preload and mark at 50cm interval. And clamped with a chuck, so that the distance between the specimen fixing clips is 50cm (length is L0), then stretched by 20% (length L1) at a tensile speed of 50cm/min, and the sample is placed for 1min, then Restore to the original position at the same speed, and then place it for 3 minutes. After repeated stretching for 5 times according to the above method, open the chuck and then hang the preload, measure the length (length is L2), and find the elastic recovery of the yarn by the following formula. rate. The test results are expressed in an average of three times.

Yarn elastic recovery rate (%) = [(L1-L2) / (L1-L0)] × 100%

Example

Example 1

Using a screw extruder, a PET type thermoplastic elastomer (PET-TYPE TPEE) of IV=1.4 was heated and melted at a melting temperature of 255 to 275 ° C, and then discharged by a metering pump to a spinning temperature of 275 ° C. The wire box is extruded from the spinning nozzle assembly, cooled by cooling air and oiled by the oil tanker. The as-spun speed is 700m/min, the extension temperature is 80°C, the setting temperature is 180°C, and the length is 180°C. A draw ratio of 4.0, a relaxation ratio of 10%, and a take-up speed of 2520 m/min were taken up to obtain a 420De/48F polyester elastically stretched multifilament. The breaking strength, elongation at break, boiling water shrinkage, elastic recovery rate of the fixed weight yarn, and elastic recovery rate of the fixed elongation yarn of the polyester elastically stretched multifilament were measured in accordance with the above measurement methods, and the results are shown in Table 1.

Example 2

A 420De/48F polyester elastically stretched multifilament was produced in the same manner except that the PBT type thermoplastic polyester elastomer (PBT-TYPE TPEE) of IV = 1.4 was used instead of the PET type thermoplastic polyester elastomer of Example 1. The breaking strength, elongation at break, boiling water shrinkage, elastic recovery rate of the fixed weight yarn, and elastic recovery rate of the fixed elongation yarn of the polyester elastically stretched multifilament were measured in accordance with the above measurement methods, and the results are shown in Table 1.

Comparative example 1

Using a screw extruder, the PET of 0.4=0.64 was heated and melted by a screw extruder at a melting temperature of 280 to 290 ° C, and then discharged by a metering pump to a spinning box having a spinning temperature of 290 ° C, from a spinning jet. The wire hole assembly is extruded, cooled by cooling air and oiled by the oil tanker, with an as-spun speed of 700 m/min, an extension temperature of 90 ° C, a setting temperature of 180 ° C, a stretching ratio of 4.0, a relaxation rate of 10% and The take-up speed was 2520 m/min for winding, and a 420De/48F PET extended multifilament was obtained. The breaking strength, elongation at break, boiling water shrinkage, elastic recovery rate of the fixed weight yarn, and elastic recovery rate of the fixed elongation yarn of the polyester elastically stretched multifilament were measured in accordance with the above measurement methods, and the results are shown in Table 1.

Comparative example 2

Using a screw extruder, the PA66 with RV=2.4 is heated and melted by a screw extruder at a melting temperature of 280 to 290 ° C, and then discharged through a metering pump to enter the spinning temperature. The spinning box of 290 °C is extruded from the spinning nozzle assembly, cooled by cooling air and oiled by the oil tanker, and has an as-spun speed of 700 m/min, an extension temperature of 90 ° C, and a setting temperature. The 420De/48F PA66 extended multifilament was obtained by coiling at 180 ° C, a stretching ratio of 4.0, a relaxation ratio of 10% (relax = 0.90), and a take-up speed of 2520 m/min. The breaking strength, elongation at break, boiling water shrinkage, elastic recovery rate of the fixed weight yarn, and elastic recovery rate of the fixed elongation yarn of the polyester elastically stretched multifilament were measured in accordance with the above measurement methods, and the results are shown in Table 1.

According to the above Table 1, it is understood that the elastic recovery ratio of the fixed weight yarn and the elastic recovery ratio of the fixed elongation yarn of the extended multifilament yarn produced according to the present invention are significantly superior to those of the PET extended multifilament yarn. Moreover, the elastic recovery rate and the elastic recovery rate of the fixed elongation yarn of the extended multifilament yarn prepared according to the present invention are not only comparable to those of PA66, but even better than PA66.

Claims (10)

A method for producing a polyester elastic multifilament, characterized in that the method comprises the steps of: heating and melting a thermoplastic polyester elastomer (hereinafter referred to as TPEE) raw material through a screw extruder, extruding from a spinning nozzle, and then cooling The air is cooled and solidified, oiled, extended, heat set and relaxed to obtain a polyester elastic multifilament. The method of claim 1, wherein the thermoplastic polyester elastic system is selected from the group consisting of PET type TPEE or PBT type TPEE. The method of claim 2, wherein the thermoplastic polyester elastic system is selected from the group consisting of PBT type TPEE. The method of claim 1, wherein the polyester elastic multifilament is obtained by continuously performing a continuous manner of spinning extension, heat setting and relaxation. The method of claim 1, wherein the polyester elastic multifilament yarn is obtained by first producing a partial directional filament, followed by a discontinuous manner of stretching, heat setting and relaxation. The method of claim 1, wherein the fiber is a long fiber or a short fiber. A polyester elastic multifilament obtained by the production method according to any one of claims 1 to 6. A use of a thermoplastic polyester elastomer for the manufacture of a polyester elastic multifilament. The use of claim 8 wherein the thermoplastic polyester elastomer is selected from the group consisting of PET type TPEE or PBT type TPEE. The use of claim 9 wherein the thermoplastic polyester elastomer is selected from the group consisting of PBT type TPEE.