KR101405817B1 - A technical polyester fiber with high tenacity and low shrinkage and its manufacturing process - Google Patents

Abstract

INDUSTRIAL APPLICABILITY The present invention relates to a polyester fiber for high strength and low shrinkage industries and a method for producing the polyester fiber for industrial use, wherein the industrial polyester fiber produced by the method of the present invention satisfies the following conditions and properties.

    (1) Polymer viscosity: I.V. 0.95 to 1.00

    (2) Strength: 9.0 g / d or more

    (3) Deduction: 21-25%

    (4) Dry heat shrinkage: 3% or less

    (5) Winding speed 3500m / min

    (6) Yarn viscosity: I.V. 0.77 to 0.90

Industrial polyester fibers according to the present invention are used for industrial poses such as tarpaulins and truck cover sheets.

Industrial polyester fiber, stretching ratio, relaxation rate, shrinkage ratio, high strength, low shrinkage

Description

Technical Field [0001] The present invention relates to a high-strength low-shrinkage industrial polyester fiber,

The present invention relates to an industrial polyester fiber having a higher level of strength while maintaining the same level of shrinkage as an existing industrial polyester yarn, and a method for producing the same. More particularly, the present invention relates to an industrial polyester fiber having an appropriate level A polyester fiber for high strength and low shrinkage industrial manufactured by optimizing spinning conditions and winding conditions so as to produce an industrial polyester yarn having a higher level of strength while maintaining a low shrinkage characteristic and a method for producing the same .

In general, polyester fibers are widely used as industrial fibers because they have excellent physical properties such as excellent strength, initial elastic modulus and dimensional stability, but the demand for yarns having higher strength is continuously increasing.

The method of producing such a high-strength yarn can be considered in various directions. In the polymeric dimension, it is possible to consider a method of modifying the polymeric material itself or modifying the direction of using the additive, and a radiator or a facility. Investment costs are incurred to reduce the economic benefits that can be obtained when technology is achieved.

Some of the technologies that have already been released include:

U.S. Patent No. 4195052 discloses that the physical properties of a yarn prepared by stretching to 97% of its maximum stretching ratio are expressed at a strength of 8.54 g / d and a shrinkage rate of about 5.0% (175 ° C). In actual manufacturing processes, such a high stretching ratio And the claim of this invention limits the scope of right to 7.5 g / d or more, so that the level of the property that can be stably produced seems to be about 8.0 g / d.

Japanese Patent Publication No. 64 -68515 small in intrinsic viscosity of 0.8 or more, and to use the polymer introduces techniques for producing the yarn of 3% or less, contraction ratio in strength of 9.5g / d, 150 ℃, carried out as one example strength 10.4g / d and a shrinkage factor of 2.6% are introduced. However, this is a technique which is somewhat distant from the actual high-speed melt spinning process because it is a process of stretching an undrawn yarn after a post-treatment to a swelling agent for a certain period of time.

Japanese Patent Application Laid-open No. Hei 3 -76810 discloses a technique for producing a yarn having a strength of 9.2 g / d or more and a shrinkage at 150 ° C. using a polymer having an intrinsic viscosity of 0.91 to 1.05. Here, It is not economical to add a device for applying a high-temperature steam at a temperature of 450 DEG C in the opening process by introducing an end blocker into the melt.

Japanese Patent Laid-open No. Hei 2 -61109 discloses a method of producing a yarn having a strength of 8.0 g / d or more and a shrinkage ratio at 200 ° C of 3.5% or less by using a polymer having an intrinsic viscosity of 0.70 to 1.05. The strength of the yarn is 8.9 g / d and the shrinkage rate is 3.3%. In this embodiment, however, there is a problem of energy and equipment remodeling cost in actual application.

U.S. Patent Nos. 5238740 and 6015616 disclose a technique for producing a high strength yarn by stretching an unstretched yarn in a separate stretching device. However, since the increase in shrinkage due to the increase in strength can not be overcome, the yarn properties are respectively 8.74g / d and 177 ° C Of the shrinkage rate of 10.2%, the strength of 9.50 g / d, and the shrinkage rate at 177 ° C of 6.8%.

U.S. Patent No. 5,277,885 discloses a technique capable of producing a yarn having a strength of 7.2 g / d or more and a shrinkage ratio of 2.0% or less at 177 ° C, but the shrinkage rate is 3.3% at 8.56 g / In order to secure the retention time of the yarn in the region, the process speed is determined to be lower and the speed of the final roller stays at 2200 m / min.

Korean Patent No. 0088316 discloses a method for producing a polyester yarn having a strength of 8.0 g / d or more and a shrinkage ratio of 1.5% or less (150 ° C × 30 minutes) using a blending chip prepared by adding 6 to 35 wt% of a thermotropic liquid crystal polymer However, there is an economical disadvantage in that a process for manufacturing a blending chip is added.

In Korean Patent No. 0070464, a stretched non-drawn filament yarn is stretched at a stretching ratio of 0.9 to 1.3 times the natural stretching ratio using a contact type heating plate having a stretching temperature of 180 to 210 DEG C, However, even when the equipment is added, the strength to be exhibited is low and the shrinkage ratio is also high.

Korean Patent No. 0101332 discloses a technique for producing a yarn having a shrinkage of less than 2% at not less than 7.0 g / d at 175 ° C for 30 minutes by stretching the unstretched yarn by multi-stage stretching using a transverse stretching method. Step process, which is not economical in terms of manufacturing cost.

Korean Patent No. 0101325 discloses a yarn manufacturing technique using a polymer having an intrinsic viscosity of 0.9 or more and having a strength of 8.0 g / d or more and a shrinkage ratio of 1% (177 ° C, 0.22 g / d load) have. Similarly, there is the following technique which introduces the technique of manufacturing the yarn in the transverse stretching machine after preparing the untreated shrine.

Korean Patent No. 0086089 discloses a method of producing a polyester fiber by stretching and heat-treating the polyethylene terephthalate polymer in a multi-stage by containing a side chain agent at 1 to 10 wt% in a high-speed spinning state. In Korean Patent No. 0084416, a transverse stretching method A process for producing an industrial polyester fiber having a strength of 8.0 g / d or more, a dry heat shrinkage of less than 2% and an elongation of 15 to 25% by optimizing the process conditions has been introduced in the production of polyester yarn.

Korean Patent No. 0084226 discloses a polyester unstretched yarn having a birefringence of 0.02 or less and a ratio of a maximum value and a minimum value of a single yarn area of 1.5 or less to an unstretched yarn by multi-step stretching by a transverse stretching method, heat treatment, and relaxation to give a strength of 9.5 g / And a shrinkage ratio at 175 DEG C of 2% or less.

In order to solve the problems and disadvantages of the prior art mentioned above, it is an object of the present invention to select an appropriate polymerized material without using a facility modification, a polymeric material modification or an additive, and then optimize spinning conditions and winding conditions, And an object of the present invention is to provide an industrial polyester fiber exhibiting a high level of strength while having characteristics of low shrinkage of the fiber and a method for producing the same.

The present invention relates to a process for producing a high-strength, low-shrinkage polyester fiber excellent in workability without modification of facilities or modification of a polymer or an additive, wherein a polymer having an appropriate level of viscosity capable of exhibiting an appropriate level of strength, As shown in Fig. 1, polyester resin unstretched yarn filaments were melt-spun with ester chips, and a conventional spinning oil (Kiss Roller or Jet Oiler) was applied before the godet roller, and then the multi- Stretching, heat fixation and relaxation, followed by a stretch process, and then a winding process.

The present invention relates to a polyester having an intrinsic viscosity of 0.95 to 1.00 dl / g in order to produce a high-strength polyester fiber at a winding speed of 3500 m / min, while maintaining a low shrinkage characteristic of 3% A solid-state polymerized chip is used to melt-spin the cylinder at a temperature of 300 to 315 ° C, and then passed through a multi-stage godet roller until it is wound on a winder and subjected to a stretching-heat fixing-relaxation-stretching-winding process. Industrial grade yarns having a low stretching ratio of 5.9 to 6.2 and a relaxation zone temperature of 245 to 250 ° C and a relaxation rate of 10 to 13% on a multistage godet roller, And a method of producing polyester fibers at a winding speed of 3500 m / min.

The present invention relates to a process for producing a polyester polyolefin by melt-spinning and cooling solidification using a polyester solid state polymer having an intrinsic viscosity of 0.95 to 1.00 dl / g, treating the resulting polyester undrawn with a conventional emulsion, The polyester fiber for use in the high strength and low shrinkage industries produced by the stretching process, the heat fixation, the relaxation process and the stretching process using the multi-stage stretching roller with the ester non-stretched polyester yarn has a higher shrinkage ratio and a strength of not less than 9.0 g / Can be produced.

Further, a wide range of industrial poses such as tarpaulins, truck cover sheets, and billboards manufactured using the polyester yarn according to the present invention exhibit high resistance to external loads and shape stability, thereby increasing the added value of products using the same.

Hereinafter, the present invention will be described in more detail.

In the present invention, the polyester melt which is obtained by melting the polymerizate having an intrinsic viscosity of 0.95 to 1.00 dl / g and transferring it to the spinneret is in a state where the polyester is not cooled before the first godet roller.

The polyester undrawn yarn is stretched by a multi-stage roller, then subjected to a heat fixing process on the rollers, followed by a relaxation process on a roller rotating at a high speed, and is subjected to a stretching process before final winding.

Here, considering the characteristics of the solid-phase-polymerized polyester chips each having an intrinsic viscosity of 0.95 to 1.00 dl / g, melt spinning was carried out at an appropriate spinning temperature, and the low shrinkage characteristics of conventional industrial polyester yarns While producing superior industrial polyester yarns that exhibit even higher levels of high strength properties.

In the present invention, the intrinsic viscosity of the polyethylene terephthalate chip is preferably from 0.95 to 1.00 dl / g, and when the intrinsic viscosity is less than 0.95 dl / g, the strength is hardly expressed and the heat resistance is lowered. There is a problem that it is difficult to control the orientation crystallization because the radiation tension is increased on the radiation line.

The cylinder temperature of the extruder is preferably in the range of 300 to 315 ° C. If the cylinder temperature is less than 300 ° C., the melting temperature is low relative to the viscosity of the polymeric compound, There is a problem that the extensibility of the unstretched yarn is increased and the extensibility is lowered. When the cylinder temperature exceeds 315 ° C, pyrolysis of the polyester melt accelerates and the physical properties at the target level are difficult to manifest. Thereafter, the radiation beam, the hood, the gear pump temperature and the cooling conditions can be carried out according to ordinary conditions.

The unstretched sheet prepared under such conditions is passed through a multi-stage godet roller and subjected to a stretching-heat fixing-relaxation-stretching-winding process.

When the stretching ratio is less than 5.9, the fiber orientation is low and the strength development is difficult. When the stretching ratio is more than 6.2, the stretching ratio is excessively increased and the yarn outer appearance is bad If this situation persists, full envoys will occur.

The relaxation rate is preferably from 10 to 13%, and if it is less than 10%, the shrinkage rate is difficult to manifest. If the ratio exceeds 13%, the relaxation area retention time due to high speed winding is relatively decreased, The vibration of the roller on the roller becomes severe and the workability can not be ensured.

If the temperature is less than 245 DEG C, the heat transfer amount to the yarn is insufficient and the relaxation efficiency is low to achieve the shrinkage rate. When the temperature exceeds 250 DEG C, the yarn is thermally decomposed The strength is lowered and the generation of tar on the roller is increased to lower the workability.

The above conditions were optimized to match the winding speed of 3,500 m / min.

   Industrial foams such as tarpaulins, truck cover sheets, and billboards can be produced by conventional methods using polyester fibers for high strength and low shrinkage as described above.

Hereinafter, the present invention will be described in more detail with reference to examples, but the scope and scope of the present invention are not limited thereto. In the embodiment, the following evaluation methods and measurement methods are utilized.

(a) intrinsic viscosity of the polymer:

 A 0.4% polyester / solvent solution was prepared with a 6: 4 mixed solvent of phenol / 1,1,2,2-tetrachloroethane to make a poly (vinylpyrrolidone) solution with a Canon Auto Visc II auto- The flow time of the ester / solvent solution was measured and then calculated by the Bill Meyer approximation of the following equation (1).

      [Equation 1]

(b) Strength and Strength of Yarn:

A 250 mm sample was fired at 80 times / meter on the basis of ASTM D885, and then subjected to tensile test at a rate of 300 mm / min. The strength of the measured yarn divided by the weight of the yarn 9,000 m was determined as the strength of the yarn.

(c) Shrinkage:

The percentage of the difference in length after the test sample was allowed to stand at 190 캜 for 15 minutes while applying a load of 0.01 g / d to the sample was determined.

  (d) The stretching ratio and the relaxation rate are defined by the following equations (2) and (3).

       Example 1;

Polyester solid state polymer chips having an intrinsic viscosity of 0.90 dl / g were used and the temperature of the cylinder of the extruder was kept at 295 DEG C while the gear pump temperature, the radiation beam temperature, the hood temperature and the cooling conditions were changed to a polyester non- , A stretch ratio of 5.80 at a winding speed of 3500 m / min, a relaxation rate of 11%, and a relaxation zone temperature of 245 DEG C to produce a 1,000 denier yarn of fineness of the final stretch yarn

Examples 2 to 6 and Comparative Examples 1 to 10;

The cylinder temperature, the stretching ratio, the relaxation rate, and the relaxation zone temperature of the extruder were varied using polyester chips having different intrinsic viscosities as shown in Tables 1 and 2.

[Table 1]

division

Example 1
Example 2
Example 3
Example 4
Example 5
Example 6
Chip intrinsic viscosity (dl / g)
0.95
1.00
0.97
0.97
0.95
1.00
Cylinder temperature (캜)
300
315
315
315
300
315
Stretching cost
5.9
6.1
5.9
6.2
5.9
6.0
Relaxation rate (%)
11
12
13
13
10
13
Relaxation zone temperature (캜)
245
250
245
250
250
250
Strength (g / d)
9.01
9.21
9.06
9.02
9.04
9.03
Doubt (%)
23.3
22.5
24.6
22.5
23.2
24.6
Shrinkage (%)
2.8
3.0
2.9
3.0
3.0
2.6
Intrinsic viscosity of yarn (dl / g)
0.77
0.81
0.79
0.75
0.76
0.80
Workability
Good
Good
Good
Good
Good
Good

[Table 2]

division
Comparative Example 1
Comparative Example 2
Comparative Example 3
Comparative Example 4
Comparative Example 5
Comparative Example 6
Chip intrinsic viscosity (dl / g)
0.88
0.98
0.93
0.90
0.95
0.90
Cylinder temperature (캜)
300
305
290
310
305
300
Stretching cost
5.7
5.8
5.8
5.7
5.6
6.1
Relaxation rate (%)
11
12
11
12
11
12
Relaxation zone temperature (캜)
245
250
250
245
250
250
Strength (g / d)
8.25
8.79
8.82
8.68
8.81
8.71
Doubt (%)
22.5
23.9
22.9
23.5
24.1
22.8
Shrinkage (%)
2.8
2.7
3.0
2.9
2.9
3.1
Intrinsic viscosity of yarn (dl / g)
0.72
0.86
0.86
0.71
0.84
0.76
Workability
Good
Bad
Bad
Bad
Good
Bad

division
Comparative Example 7
Comparative Example 8
Comparative Example 9
Comparative Example 10
Chip intrinsic viscosity (dl / g)
0.93
0.95
0.93
0.93
Cylinder temperature (캜)
300
305
300
300
Stretching cost
5.7
5.8
5.7
5.7
Relaxation rate (%)
9
14
13
13
Relaxation zone temperature (캜)
245
250
240
255
Strength (g / d)
8.81
8.65
8.77
8.54
Doubt (%)
23.8
24.8
24.1
24.6
Shrinkage (%)
3.2
2.5
3.2
2.6
Intrinsic viscosity of yarn (dl / g)
0.78
0.81
0.80
0.77
Workability
Good
Bad
Good
Bad

In Comparative Example 1, the physical properties desired by the present invention were not exhibited because the polymeric viscosity was low to exhibit a certain level of strength or more. In Comparative Example 2, the viscosity of the melt was high at the corresponding spinning temperature, And the degree of birefringence of the undrawn yarn was increased, resulting in poor ductility and poor workability.

In Comparative Example 3, although the physical properties of the yarn satisfied the target physical properties, the spinning temperature was set lower than the polymeric viscosity in Comparative Example 2. As a result, the extensibility due to the increase in spinning tension was lowered, The spinning temperature was excessively set relative to the viscosity of the polymer, and the thermal decomposition of the polymer in the melting process resulted in poor radioactivity and low strength and intrinsic viscosity of the yarn.

In Comparative Example 5, the strength of the final stretched yarn was low because the proper stretching ratio was not applied to develop yarn properties. On the other hand, in Comparative Example 6, the appearance of the remaining manufactured yarn was excessively applied after the stretching ratio was excessively applied, The level of envoys during the process was high.

 In Comparative Example 7, since the applied relaxation rate was low, the final yarn had a high level of strength, but the shrinkage ratio was not exhibited. In Comparative Example 8, a very high level of relaxation ratio was applied, But also the workability was not good.

In Comparative Example 9, the shrinkage ratio remained at a high level due to the insufficient amount of heat supplied to the yarn by setting the temperature of the relaxed region to a low level with respect to the applied relaxed ratio. In Comparative Example 10, the properties of the final yarn satisfied the target level of the present invention, The temperature was excessively set so that the tar on the rollers was severe during long-term operation, resulting in poor appearance and workability of the final product.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic view showing a production process of a polyester fiber for a high strength, low shrinkage industry according to the present invention. FIG.

Claims (4)

A polyester fiber prepared by melt-spinning a polyester chip having an intrinsic viscosity of 0.95 to 1.00 dl / g through a step of stretching-heat-fixing-relaxation-stretching-winding on a polyester undrawn yarn by a multi- (1) strength of 9.0 g / d or more (2) The shrinkage rate is 3% or less. (The shrinkage percentage is a percentage of the length difference after allowing the sample to stand at 190 ° C for 15 minutes under a load of 0.01 g / d.)     (3) The yarn viscosity is 0.77-0.90, which is a high strength, low shrinkage industrial polyester fiber. 1) melt spinning a polyester polymer having an intrinsic viscosity of 0.95 to 1.00 dl / g to produce a cold-agglomerated undrawn filament; 2) A method for producing a high strength, low shrinkage polyester fiber, characterized in that the non-drawn yarn is manufactured by a multi-stage stretching roller under the following conditions through stretching-heat fixing-relaxation-stretching-       (a) Drawing ratio: 5.9 to 6.2       (b) Relaxation rate: 10 to 13%       (c) Relaxation zone temperature: 245 to 250 DEG C       (d) Coiling speed: 3500 m / min The method of producing a polyester fiber for high strength, low shrinkage industrial according to claim 2, wherein the temperature of the cylinder is set to 300 to 315 DEG C in step (1). An industrial forge comprising one selected from the group consisting of tarpaulins and truck covers comprising the high strength, low shrinkage industrial polyester fibers prepared according to claim 1.

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