JP2001064824A - Highly oriented undrawn yarn of polypropylene terephthalate and its production - Google Patents

Abstract

PROBLEM TO BE SOLVED: To produce a highly oriented undrawn yarn of polypropylene terephthalate capable of suppressing problems in a conventional two-step method for the highly oriented undrawn yarn of the polypropylene terephthalate, i.e., a change in filaments with time after spinning, imparting flexibility to the production and improving productivity and to provide a method for producing the yarn. SOLUTION: This highly oriented undrawn yarn of polypropylene terephthalate comprises polyester filaments in which at least 90 mol% of polymer components forming the filaments are composed of propylene terephthalate units and satisfies the following formulae (1) to (4): (1) strength ST (g/d): 2.0<=ST, (2) birefringence Δn (10-3): 30<=Δn<=60, (3) elongation EL (%): 80<=EL<=250 and (4) shrinkage percentage in boiling water SW (%): 3<=SW<=15.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a highly oriented unstretched yarn of polypropylene terephthalate and a method for producing the same.
More specifically, the present invention relates to a highly oriented unstretched polypropylene terephthalate yarn having excellent fiber physical property stability and process passability, and a method for producing the same.

[0002]

2. Description of the Related Art Polyester fibers have various excellent properties including mechanical properties, and are therefore widely used in apparel applications and other industrial materials.

Conventionally, in order to obtain polyester fibers, a so-called two-step method in which a polymer is melt-spun and then stretched has been generally used. Such a fiber that has only been melt-spun has not developed the internal structure of the fiber and has poor mechanical properties and dimensional stability. Therefore, it is necessary to form and fix the structure by stretching in a separate process. Was.

On the other hand, polypropylene terephthalate fibers are disclosed in JP-A-52-5320 and JP-A-52-812.
It has been known for a long time as seen in No. 4
It has excellent elongation elastic recovery, low Young's modulus, good dyeability, and is chemically stable, and is a fiber suitable for clothing.

However, since 1,3 propanediol as a raw material is relatively expensive, it has not been used as a synthetic fiber until now.

In recent years, US Pat. No. 5,304,691
As disclosed in the specification, a novel method for synthesizing 1,3 propanediol has been found, and an inexpensive polypropylene terephthalate fiber has become possible and its value has been reviewed.

However, according to the study of the present inventors, when the conventional two-step production method of polyethylene terephthalate is applied as it is to the polypropylene terephthalate highly oriented undrawn yarn, the internal structure starts to change from the stage of melt spinning and winding, It was found that the so-called time-dependent changes in the fiber properties changing with the day were severe.

The fact that the change with time is severe indicates that a fiber having stable physical properties cannot be obtained unless the conditions in the subsequent steps, for example, the drawing and false twisting steps, are changed depending on the number of days from spinning to drawing. .

For this reason, when producing, it is necessary to control the number of days from spinning to drawing and to precisely control the storage state, and there is a problem that the burden on the producer is large.

In order to solve this problem, Japanese Patent Laid-Open Publication No. Sho 52
There is also a method using a one-step method typified by DSD in which spinning and drawing steps are continuously performed as shown in JP-8123-A, but a two-step method is known as polyethylene terephthalate and the like. However, the fiber has low toughness, and is not suitable for applications requiring high performance, and it is not possible to obtain a raw yarn to be fed by a draw false twist method or the like.

[0011]

DISCLOSURE OF THE INVENTION The present invention is to solve the above-mentioned conventional problems, and there is a problem in a two-step method for a highly oriented unstretched polypropylene terephthalate yarn,
That is, an object of the present invention is to provide a highly oriented unstretched polypropylene terephthalate yarn capable of suppressing a change with time of a fiber after spinning, giving flexibility to production and improving productivity, and a method for producing the same.

[0012]

In order to achieve the above object, the highly oriented unstretched polypropylene terephthalate yarn of the present invention comprises at least 90% of the polymer component constituting the fiber.
Molar% is a polyester fiber composed of propylene terephthalate units, and satisfies the following formulas (1) to (4).

(1) Strength ST (g / d): 2.0 ≦ ST (2) Birefringence Δn (10 ⁻³ ): 30 ≦ Δn ≦ 60 (3) Elongation EL (%): 80 ≦ EL ≦ 200 (4) Boiling water shrinkage ratio WS (%): 3 ≦ WS ≦ 15 In the method for producing a highly oriented unstretched polypropylene terephthalate yarn of the present invention, at least 90 mol% of the polymer component constituting the fiber is propylene terephthalate unit. When producing the constituted polyester highly oriented undrawn yarn, it is characterized in that it is heat-treated while being taken up at a spinning speed of 2500 to 4500 m / min, and is taken up.

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail.

The polypropylene terephthalate of the present invention is a polyester obtained by using terephthalic acid as a main acid component and 1,3 propanediol as a main glycol component. However, it may contain a copolymer component capable of forming another ester bond at a ratio of 10 mol% or less. Examples of the copolymerizable compound include diphthalic acids such as isophthalic acid, succinic acid, cyclohexanedicarboxylic acid, adipic acid, dimeric acid, and sebacic acid.On the other hand, examples of the glycol component include ethylene glycol and diethylene glycol. , Butanediol, neopentyl glycol, cyclohexanedimethanol, polyethylene glycol, polypropylene glycol, and the like, but are not limited thereto.

[0016] Titanium dioxide as a matting agent, silica or alumina fine particles as a lubricant, hindered phenol derivatives, coloring pigments and the like as antioxidants can be added as required.

It is important that the polypropylene terephthalate highly oriented undrawn yarn of the present invention simultaneously satisfies the following formulas (1) to (4).

(1) Strength ST (g / d): 2.0 ≦ ST (2) Birefringence Δn (10 ⁻³ ): 30 ≦ Δn ≦ 60 (3) Elongation EL (%): 80 ≦ EL ≦ 200 (4) Boiling water shrinkage ratio WS (%): 3 ≦ WS ≦ 15 First, when the strength is less than 2.0 g / d, the processability such as the stretching process and the false twisting process is deteriorated, and the productivity is reduced. . More preferably, the strength is 2.5 g / d or more. Also, aging is large after spinning the birefringence Δn is below 30 × 10 ^-3, and fluff during stretching since the lower crystallinity, becomes trouble such as with the single yarn is likely to occur, also 60 × 10 ^{- If} it exceeds ³ , even if it is stretched, the improvement in birefringence is so small that no improvement in strength can be expected. Birefringence Δn is 40-50 × 1
0 ^-3 is more preferable.

Further, if the elongation is less than 80%, the film is drawn at a low magnification, and yarn unevenness is liable to occur in the drawing step or false twisting step. If it exceeds 200%, troubles such as fluffing and winding of a single yarn during drawing may occur. More likely to occur. On the other hand, if the boiling water shrinkage is less than 3%, the yarn is easily sagged when heat is applied in the drawing step, etc., and the processability is poor. If it exceeds 15%, the effect of suppressing the secular change is small. Deterioration of physical properties and unevenness are likely to occur. Boiling water shrinkage is 5% ~
10% is more preferred.

The method for producing a highly oriented unstretched polypropylene terephthalate yarn of the present invention comprises the steps of: producing a highly oriented unstretched polyester yarn in which at least 90 mol% of the polymer component constituting the fiber is composed of propylene terephthalate units; It is important to perform a heat treatment while winding at 2500 to 4500 m / min and wind up.

When the spinning speed is lower than 2500 m / min, the birefringence Δn becomes as low as 30 × 10 ⁻³ or less, and the fiber is not fluffed during stretching.
Single yarn winding is likely to occur. On the other hand, if it exceeds 4500 m / min, the structure becomes close to that of the so-called drawn yarn, and it is not expected that the structure is stabilized and the strength is improved by drawing.

It is important that the heat treatment is performed while the fiber is being taken. By performing the heat treatment and the heat treatment successively, the fiber structure is stabilized by the heat treatment, and the change with time after winding is suppressed. Thus, it is possible to avoid unevenness of the end face period of the fiber and a difference in inner and outer layers due to fiber shrinkage due to a change with time of the wound yarn.

The heat treatment may be either dry heat or wet heat treatment, but preferably 70-160 ° C. for dry heat treatment, and 70-140 ° C. for wet heat treatment. Temperature 100 ~ for heat treatment
The temperature is 135 ° C., and the temperature is 100 to 130 ° C. in the case of wet heat treatment.

In the present invention, it is preferable that the highly oriented undrawn yarn after the oil agent is applied and before the heat treatment is subjected to a entanglement treatment by a high-speed airflow. Using a confounding nozzle, processing pressure pneumatic 0.05
More preferably, it is -0.4 MPa. By performing the entanglement treatment by the high-speed airflow, uniform heat treatment is facilitated, so that the heat treatment time can be shortened. In this treatment, the CF value which is the degree of entanglement of the obtained highly oriented undrawn yarn is 3 or more,
More preferably, it is performed to the extent of 5 to 15.

Further, a conventional winding method such as winding using a tension cut roll after the second body roll, or a roller bale driven winding of a winding machine, for performing low tension winding. When used together, the package shape can be further stabilized.

The intrinsic viscosity of the polypropylene terephthalate of the present invention is preferably from 0.5 to 1.2. If it is less than 0.5, it may be difficult to spin stably due to unevenness of fineness and thread breakage during spinning, or even if obtained, it may be inferior in practical use such as tensile strength and bending wear resistance. . In addition, if the intrinsic viscosity exceeds 1.2, the melt viscosity becomes too high, so that the measurement performance of a gear pump or the like is inferior,
In some cases, it is difficult to perform stable spinning due to poor discharge, or the texture of the obtained fiber tends to be hard, which is not preferable. More preferably, the intrinsic viscosity of PPT is 0.8 or more and 1.0 or less.

The cross-sectional shape of the single yarn of the fiber of the present invention is not particularly limited, and may be appropriately selected depending on the purpose of use, such as a circle, a triangle, a flat, a 3 to 8 multilobe, and a hollow.

[0028]

The present invention will be described in more detail with reference to the following examples. Each characteristic value in the examples was obtained by the following method. A. Intrinsic viscosity [η] 0.10 g of sample per 10 ml of orthochlorophenol
Was dissolved and measured at 25 ° C. using an Ostwald viscometer. B. Strong elongation Strong elongation and Young's modulus were measured using Orientec Tensilon UCT-100 according to JIS L1013. C. Birefringence Δn The birefringence Δn was determined from the retardation Γ and the optical path length d using an OLYMPUS BH-2 polarizing microscope.
= Γ / d. In addition, d was calculated from Γ at the fiber center and the fiber diameter. D. Boiling water shrinkage ratio 1/30 per denier using a measuring machine with a frame circumference of 0.5 m
An initial load of g is applied and the film is rewound at a speed of 60 turns / minute to form a small scab of 10 turns, and the scab length is measured by applying a load 20 times the initial load. Next, remove the load and set the sample at 100 ° C.
Was immersed in hot water for 15 minutes, taken out, air-dried, again applied a load of 20 times the initial load, measured the length of the hull, and calculated the hot water shrinkage ratio by the following equation.

Hot water shrinkage (%) = [(L0−L1) / L0] × 100 where L0: length before immersion (mm) L1: length after air drying (mm) Entanglement CF value Measured under the conditions shown in JIS L 1013 (Chemical Fiber Filament Yarn Test Method) 7.13 Entanglement Degree. The number of tests was set to 50 times, and a CF value (Coherence Factor) was calculated from the average value L (mm) of the confound length by the following formula.

CF value = 1000 / L Example 1 19.4 kg of dimethyl terephthalic acid
Using 15.2 kg of 3-propanediol and tetrabutyl titanate as catalysts, a transesterification reaction was carried out while distilling methanol at 140 ° C. to 230 ° C., and further polymerization was carried out at a constant temperature of 250 ° C. for 3 hours. A polypropylene terephthalate having an intrinsic viscosity [η] of 0.89 was obtained.

Using this polymer, the spinning temperature is 260 ° C. by a spinning machine having a steam heat treatment machine 6 installed between the first godet roll 5 and the second godet roll 7 of the spinning machine as shown in FIG.
Using a ferrule having a discharge hole diameter of 0.3 mmφ × 36 holes, a heat treatment at 110 ° C. was performed by a steam heat treatment machine 6 while discharging at a discharge amount of 35.0 g / min and spinning speed of 3000 m / min. The drawn yarn was wound up. Refueling device 2
Was used as a water emulsion with an active ingredient of 10%, and the amount of adhesion was 0.8% based on the weight of the yarn. The physical properties of this yarn are shown in Table 1, and the delayed shrinkage is shown in FIG. In Table 1, the value immediately after spinning is a value measured within 12 hours after winding. The highly oriented undrawn yarn had a stable winding shape and little change in physical properties with time. Example 2 A polypropylene terephthalate having an intrinsic viscosity [η] of 0.89 obtained in the same manner as in Example 1 was spun using a spinning machine shown in FIG.
Using a base having a diameter of 36 mmφ × 36 holes, discharge at a discharge rate of 35.0 g / min.
Dry heat treatment was performed with the second godet roll 15 heated to 10 ° C., and the highly oriented undrawn yarn was wound up. In the same manner as in Example 1, the oil supply by the oil supply device 10 and the entanglement processing by the high-speed airflow by the entanglement nozzle 12 were performed. The physical properties of this yarn are shown in Table 1, and the delayed shrinkage is shown in FIG. This highly oriented undrawn yarn is
As in Example 1, the winding shape was stable, and there was little change over time in the physical properties. Example 3 A highly oriented undrawn yarn was wound in the same manner as in Example 2 except that the entanglement treatment by a high-speed airflow was not performed. Table 1 shows the physical properties of this yarn. Comparative Example 1 A polypropylene terephthalate having an intrinsic viscosity [η] of 0.89 obtained in the same manner as in Example 1 was spun at a spinning temperature of 260 ° C. and a discharge hole diameter of 0.3 mmφ × 36 using the ordinary spinning machine shown in FIG. The discharge amount is 35.0 by using a hole base.
g / min, and the highly oriented undrawn yarn was wound at a spinning speed of 3000 m / min. In the same manner as in the first embodiment, the oil supply by the oil supply device 18 and the entanglement processing by the high-speed airflow by the entanglement nozzle 20 were performed. The physical properties of this yarn are shown in Table 1, and the delayed shrinkage is shown in FIG. The highly oriented unstretched yarn became unstable in the form of a standing edge several hours after the winding, and the physical properties were greatly changed with time.

[0032]

[Table 1]

[0033]

EFFECTS OF THE INVENTION According to the present invention, there is a problem in the two-step method of a highly oriented unstretched polypropylene terephthalate yarn, that is, a polypropylene which can suppress the change with time of the fiber after spinning, give flexibility to production and improve productivity. It is possible to provide a highly oriented unstretched terephthalate yarn and a method for producing the same.

[Brief description of the drawings]

FIG. 1 is a diagram showing the amount of delayed shrinkage of a highly oriented unstretched polypropylene terephthalate yarn.

FIG. 2 is a process diagram showing an example of a spinning apparatus in which a steam heating device is installed between first and second god rolls.

FIG. 3 is a process diagram showing an example of a spinning apparatus in which a hot roll is incorporated in a second godet roll.

FIG. 4 is a process diagram showing an example of a conventional spinning apparatus for obtaining a highly oriented undrawn yarn.

[Explanation of symbols]

 1, 9, 17: spinning block 2, 10, 18: lubricating device 3, 11, 19: undrawn yarn 4, 12, 20: entangled nozzle 5, 13, 21: first god roll 6: steam heat treatment machine 7, 22 : Second god roll 8, 14, 23: Winding machine 15: Second god roll (hot roll) 16: Separate roll

Continued on the front page F term (reference) 4L035 BB33 BB40 BB59 CC02 CC05 CC11 EE01 EE02 EE08 EE20 HH10 4L036 MA05 MA26 PA01 PA18 PA19 PA42 UA25

Claims (6)

[Claims] (1) a polyester fiber in which at least 90 mol% of a polymer component constituting the fiber is a propylene terephthalate unit and satisfies the following formulas (1) to (4); Drawn yarn. (1) Strength ST (g / d): 2.0 ≦ ST (2) Birefringence Δn (10 ⁻³ ): 30 ≦ Δn ≦ 60 (3) Elongation EL (%): 80 ≦ EL ≦ 250 (4) ) Boiling water shrinkage ratio SW (%): 3 ≦ SW ≦ 15 2. The highly oriented unstretched polypropylene terephthalate yarn according to claim 1, wherein a entanglement treatment is performed and the entanglement degree CF value is 3 or more. 3. A process for producing a highly oriented undrawn polyester yarn in which at least 90 mol% of a polymer component constituting a fiber is composed of a propylene terephthalate unit is subjected to a heat treatment while being taken up at a spinning speed of 2500 to 4500 m / min. A method for producing a highly oriented undrawn yarn of polypropylene terephthalate, comprising: 4. The method for producing a highly oriented unstretched polypropylene terephthalate yarn according to claim 3, wherein the heat treatment is a dry heat treatment at 70 to 160 ° C. 5. The method for producing a highly oriented unstretched polypropylene terephthalate yarn according to claim 3, wherein the heat treatment is a wet heat treatment at 70 to 140 ° C. 6. The highly oriented polypropylene terephthalate according to claim 3, wherein when the highly oriented undrawn yarn is taken off, oil supply and entanglement treatment are performed after spinning cooling and before the heat treatment. Method for producing undrawn yarn.