JP2001348730A - Method for producing polypropylene terephthalate fiber - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for producing a polypropylene terephthalate fiber by which the staining of the spinneret surface and the inside of a housing is prevented, and improved operability and stabilized quality are provided. SOLUTION: This method for producing a polypropylene terephthalate fiber is characterized in that when melt-spinning the polypropylene terephthalate fiber while sucking a volatilized product by a sucking device installed between the spinneret surface and a cooling device, the sucking device is installed at the position of 30-200 mm below the spinneret surface, and the sucking wind velocity is 5-50 m/min.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a method for producing polypropylene terephthalate fiber. More specifically, the present invention relates to a method for producing polypropylene terephthalate fiber in which melt spinning is performed while sucking volatile substances with a suction device below the surface of the die in order to prevent contamination on the die surface and the inside of the housing and to produce a stable polypropylene terephthalate fiber. .

[0002]

2. Description of the Related Art Polypropylene terephthalate fibers are:
It has excellent elongation elastic recovery, low Young's modulus, good dyeability, and is chemically stable, as shown in JP-A-52-5320 and JP-A-52-8124. It has been known for a long time. However, the raw materials
Since propanediol is relatively expensive, it has not been used as a synthetic fiber until now.

[0003] In recent years, a low-cost method for producing 1,3 propanediol has been found, and various studies have been made on the industrialization of polypropylene terephthalate fibers.

[0004] However, polypropylene terephthalate is liable to be thermally decomposed.
A large amount of toxic gas such as low-polymerized polymer, that is, monomer or oligomer gas, is generated from the yarn immediately after spun from the die, so that the die surface is significantly stained and the housing below the die surface is left in the housing. Monomers and oligomers precipitate and cause yarn breakage, so continuous spinning for a long time cannot be performed, and frequent cleaning of the die is required, resulting in reduced workability and stable quality of the obtained fiber. There was a problem in manufacturing on an industrial level due to lack.

[0005] For this reason, in order to prevent the contamination of the die surface by suppressing the precipitation of oligomers, see, for example,
Japanese Patent No. 11177 discloses a polypropylene terephthalate resin having a reduced oligomer content. Certainly, according to the publication, it is possible to suppress the precipitation of oligomers to some extent, but it is not enough to reduce the amount of oligomers in the polymer in spinning for a long time. Precipitation in the housing could not be prevented.

[0006]

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned conventional problems. In the production of polypropylene terephthalate fiber, the surface of the base and the inside of the housing are prevented from being stained to improve workability. An object of the present invention is to provide a method for producing polypropylene terephthalate fiber having stable quality.

[0007]

According to the present invention, there is provided a method for producing a polypropylene terephthalate fiber, wherein a volatile substance is sucked from a polypropylene terephthalate fiber by a suction device provided between a die surface and a cooling device. When the melt spinning is performed, the suction device is set at 30 to
It is installed between 200mm, and the suction wind speed is 5
It is characterized by 50 m / min.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The polypropylene terephthalate of the present invention comprises a 1,3-propanediol component and a terephthalic acid component, but ethylene glycol, diethylene glycol,
Trimethylene glycol, cyclohexanediol, bisphenol A, bisphenol sulfone, an EO adduct of bisphenol A, an EO adduct of bisphenol sulfone, 1,4-butanediol, ε-caprolactone,
Isophthalic acid, phthalic anhydride, phthalic acid, succinic acid, adipic acid, 2,6-naphthalenedicarboxylic acid, sebacic acid, 5-sodium sulfoisophthalic acid, 5-sodium sulfoterephthalic acid, 5-potassium sulfoisophthalic acid, 5- Potassium sulfoterephthalic acid, 5-lithium sulfoisophthalic acid, sodium 3,5-di (carbo-β-hydroxyethoxy) benzenesulfonate, 3,5-
Potassium di (carbo-β-hydroxyethoxy) benzenesulfonate, lithium 3,5-di (carbo-β-hydroxyethoxy) benzenesulfonate, dimethyl 5-sodium sulfoisophthalate, dimethyl 5-potassium sulfoisophthalate, 5- Lithium dimethyl sulfoisophthalate may be copolymerized.

As a matting agent, titanium dioxide, silica or alumina fine particles as a lubricant, and as an antioxidant,
Hindered phenol derivatives, coloring pigments and the like can be added as needed.

The polypropylene terephthalate fiber of the present invention is a fiber comprising at least 45% or more of the above-mentioned polypropylene terephthalate, and a polyester such as polyethylene terephthalate or polybutylene terephthalate in a range of less than 55%.
Alternatively, a polyamide such as nylon 6, nylon 66, or nylon 610 may be compounded or blended.

In the method for producing polypropylene terephthalate fiber of the present invention, when producing polypropylene terephthalate fiber, a suction device is provided between the die surface and the cooling device. By installing a suction device between the die surface and the cooling device, it is possible to suck low-polymerized polymers, that is, monomers and oligomers, generated from the yarn immediately after spun from the die, and the die surface and below the die surface Can be prevented from depositing on the housing. If a suction device is not installed between the die surface and the cooling device, monomers and oligomers are deposited on the die surface and the housing below the die surface, resulting in a decrease in workability and inferior stability in the quality of the obtained fiber. It will be.

The suction device is installed at a position below the surface of the base in order to stabilize the quality of the obtained polypropylene terephthalate fiber, to attract monomers and oligomers, and to prevent deposition on the base surface and the housing below the base. ~ 200
mm. The installation position in the present invention refers to a distance L from the base surface to the suction start point of the suction device, that is, the upper portion of the suction port. When the installation position of the suction device is less than 30 mm below the surface of the base, suction properties of the monomer and oligomer are good, and contamination of the base surface and the housing under the base can be prevented. However, the temperature of the base surface is too close to the base surface. Is unstable, and stable quality polypropylene terephthalate fibers cannot be obtained. Conversely, if the installation position of the suction device exceeds 200 mm below the surface of the base, the suction effect of monomers and oligomers will be significantly reduced, so that the suction effect cannot be exhibited, and the stain on the surface of the base and the housing below the base is reduced. It cannot be prevented. In order to maintain the quality stability of polypropylene terephthalate fiber, the attraction of monomers and oligomers, and to prevent deposition on the base surface and the housing below the base surface, the suction device must be installed between 40 and 180 mm below the base surface. Is more preferred.

Further, the suction wind speed of the suction device is set at 5 to 50 m / min from the viewpoint of the quality stability of the polypropylene terephthalate fiber and the suction property of the monomer and oligomer. If the suction air velocity is less than 5 m / min, the monomer and oligomer cannot be sufficiently sucked, so that the surface of the base and the housing below the base cannot be prevented from being stained. Conversely, if the suction air velocity exceeds 50 m / min, the monomer and oligomer can be sufficiently sucked, so that the surface of the base and the housing below the base can be prevented from being stained.
Yarn shaking occurs, and it is impossible to obtain polypropylene terephthalate fiber of stable quality. The suction air velocity of the suction device is more preferably in the range of 10 to 40 m / min from the viewpoints of quality stability and suction properties of the monomer and oligomer.

In producing the polypropylene terephthalate fiber of the present invention, it is important to install the above-mentioned suction device. However, in order to suppress the generation of monomers and oligomers generated during spinning, the spinning temperature must be adjusted. The temperature is preferably 285 ° C or lower, more preferably 280 ° C or lower.

The present invention will be further described below with reference to the embodiments shown in the drawings.

FIG. 1 is a cross-sectional view showing one embodiment of the melt spinning apparatus of the present invention.

In FIG. 1, 1 is a spin block, 2 is a spin pack, 3 is a die, 4 is a suction device having an annular suction port A for sucking volatile matter, and 5 is a cooling device for the spun yarn Y. (Chimney).

The molten polymer is extruded from the pores of a base 3 attached to a lower part of a spin pack 2 mounted on a spin block. The spun yarn Y passes through the volatile matter suction device 4 and the cooling device 5 while being gradually cooled, and is wound up. Volatiles such as monomers and oligomers generated under the base are sucked from the suction device 4 through the suction port A.

The shape of the suction port A may be a shape in which suction is performed in one direction or a shape in which suction is performed in two directions, in addition to the annular shape shown in FIG. Therefore, it is preferable to use an annular suction port.

The thickness M of the suction portion of the suction port A is preferably 3 cm or more in order to suppress the deterioration of the suction effect with time due to precipitation of the sucked monomer or oligomer at the suction port. It is preferable to set it to 8 cm or less from the viewpoint of efficiency.

[0021]

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. Worcester spots (U%) USTER TESTER manufactured by Zellweger
The measurement was performed in the normal mode while supplying the yarn at a speed of 25 m / min using 1 Model C. C. Spinning property Using a polypropylene terephthalate having an intrinsic viscosity [η] of 1.12, using a spinneret having a hole diameter of 0.23 mmφ and 72 holes, a spinning temperature of 270 ° C. and a spinning speed of 3000 m.
The spinning was continuously performed for 72 hours at a discharge rate of 75 g / min / min.

：: no thread breakage Δ: slight thread breakage (1 to 3 times) ×: frequent thread breakage D. Stain on the mouthpiece Remove the mouthpiece that has been spun under the above conditions, observe the foreign matter deposited around the ejection hole with a microscope, and measure the average height from the mouth surface and the average width from the edge of the ejection hole (unit: μm)
Then, the size of the base stain was evaluated. Examples 1 to 5 and Comparative Examples 1 and 2 Transesterification reaction while distilling methanol at 140 ° C to 230 ° C using 97.0 kg of dimethyl terephthalic acid and 76.0 kg of 1,3-propanediol as a catalyst with tetrabutyl titanate as a catalyst After that, polymerization was further carried out for 4.0 hours at a constant temperature of 250 ° C. to obtain an intrinsic viscosity [η].
Of 1.12 was obtained.

A spinning temperature of 270 ° C. and a spinning speed of 3,000 using a polypropylene terephthalate obtained by the above method and a spinneret having a hole diameter of 0.23 mmφ and 72 holes.
Using the annular suction device (suction port thickness 5 cm) shown in FIG. 1 under the conditions of m / min and a discharge rate of 75 g / min, a suction speed of 25 m
/ Min, and change the installation position of the suction device as shown in Table 1 to 7
Continuous spinning was performed for 2 hours. Table 1 shows the results of the evaluation of the spinning properties, stains on the spinneret, and the quality (U%) of the obtained raw yarn.

In Examples 1, 3 and 4, the spinnerets were less contaminated, the yarn-making properties were good, and the quality of the obtained raw yarn (U
%) Was also good.

In Example 2, the installation position of the suction device was slightly shorter, 30 mm below the base, so that it was affected by the suction, and the U% of the obtained yarn was 1.1, which was slightly inferior to Example 1. However, there was little dirt on the mouthpiece, and the spinning property was good.

In the fifth embodiment, the installation position of the suction device is slightly longer, 200 mm below the base, so that the effect of the suction device for preventing the base from being stained is slightly reduced as compared with the first embodiment.
The quality of the obtained yarn was good.

On the other hand, in Comparative Example 1, although the spinneret dirt was small and the spinning property was good, the position of the suction device was too short, 20 mm, so that the U% of the original yarn obtained by the influence of suction was 1.
8 was bad and of poor quality.

In Comparative Example 2, since the installation position of the suction device was as long as 220 mm below the base, the effect of preventing the base from being stained by the suction device was reduced, and as a result, thread breakage occurred frequently. In Examples 6 to 9 and Comparative Examples 3 and 4, yarns were formed in the same manner as in Example 1 except that the suction speed was changed as shown in Table 2. Table 2 shows the results of evaluating the quality (U%) of the yarn.

In Examples 7 and 8, the spinneret is less stained, the yarn forming property is good, and the quality of the obtained raw yarn (U%) is obtained.
Was also good.

In the sixth embodiment, the suction speed of the suction device is 5 m
/ Min, the effect of preventing the base from being stained by the suction device was slightly reduced as compared with Example 1, but the quality of the obtained raw yarn was good.

In the ninth embodiment, the suction speed of the suction device is 50
m / min, which was slightly higher than that of Example 1, which was affected by the suction and the U% of the obtained yarn was 1.0, which was slightly inferior to that of Example 1. Met.

On the other hand, in Comparative Example 3, since the suction speed of the suction device was too low at 3 m / min, the effect of the suction device to prevent the cap from being stained was reduced, and as a result, thread breakage occurred frequently.

In Comparative Example 4, although the spinneret dirt was small and the spinning property was very good, the suction speed of the suction device was 60 m.
/ Min, which was too high to be affected by the suction, and the U% of the obtained yarn was as poor as 2.3, degrading the quality.

[0034]

[Table 1]

[0035]

[Table 2]

[0036]

According to the present invention, when a polypropylene terephthalate fiber is melt-spun while a volatile substance is sucked by a suction device provided between a die surface and a cooling device, the suction device is placed between 30 and 200 mm below the die surface. A method for producing polypropylene terephthalate fiber, wherein the fiber is installed between the fibers and has a suction air velocity of 5 to 50 m / min. Polypropylene terephthalate fiber with stable quality can be produced.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of one embodiment of a melt spinning apparatus used in a method for producing a polypropylene terephthalate fiber according to the present invention.

[Explanation of symbols]

 1: Spin block 2: Spin pack 3: Spinner 4: Suction device 5: Cooling device (chimney) A: Volatile suction port Y: Spun yarn L: Distance from the spinneret surface to the suction start point of the suction device M: Suction part thickness

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 4L035 BB32 4L045 AA05 BA03 BA60 CA25 CA29 CB09 CB13 CB31 DA28 DC03

Claims (1)

[Claims] (1) When melt-spinning polypropylene terephthalate fiber while sucking volatile substances by a suction device provided between a die surface and a cooling device, the suction device is installed between 30 and 200 mm below the die surface. And a suction air velocity of 5 to 50 m / min.