JPH055216A - Polyester conjugate fiber excellent in light resistance - Google Patents

Abstract

PURPOSE:To provide the subject conjugate fiber composed of the core component of polyethylene terephthalate and the sheath component of a thermoplastic polymer having >=a prescribed value of the light reflectance in a specified wavelength region, excellent in color and light-fastness and useful for a car sheet, etc. CONSTITUTION:An objective conjugate fiber belonging to a sheath-core conjugated fiber in which the core component (A) and the sheath component (B) are respectively composed of polyethylene terephthalate and a thermoplastic polymer showing >=30% degree of light reflection in a region of 290-330nm wavelength, e.g. polyethylene-2,6-naphthalene. In addition, the ratio of the sheath component is preferably <=15vol%.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a polyester composite fiber having excellent light fastness.

[0002]

2. Description of the Related Art Polyethylene terephthalate (hereinafter referred to as P
Fibers (referred to as ET) are widely used for clothing and industrial materials. The reason is that it not only has sufficient strength and appropriate flexibility and drapeability, but also has good heat setting properties and is suitable for a wide range of applications, and it is mass produced and the raw material cost is relatively low. And so on. Further, it is one of the advantages that the PET fiber has good light fastness as compared with other fibers, but in recent years,
Demand for improved light resistance is stricter, mainly for automobile applications,
The improvement is needed. Even with PET fiber,
Since the strength is reduced and the dyed product is discolored and faded due to the influence of sunlight, especially ultraviolet rays, it is becoming difficult to meet the high requirements.

Various attempts have been made so far to improve the light fastness of synthetic fibers such as PET. For example, there is a method of adding an ultraviolet absorber such as a benzophenone type or a benzotriazole type. Additives are generally easily decomposed by heat and deteriorated in the process of melt spinning at high temperature, resulting in a decrease in UV absorption capacity, yellowing of the obtained fiber, and adverse effects on the hue after dyeing. .. Further, Japanese Patent Laid-Open No. 1-77623 and Japanese Patent Laid-Open No. 3-1
Japanese Patent No. 4621 discloses that a particle obtained by coating a manganese compound particle on a particle of 0.1 μm or less or a zinc oxide particle is added to a sheath of a composite fiber to protect a core component by utilizing the property that the particle absorbs or reflects ultraviolet rays. Composite fibers have been proposed. However, since particles are added in these techniques, there are problems that the color of the fiber is limited to grayish brown or white, and that the ultraviolet light cannot be completely covered and the light fastness does not reach a satisfactory level. ..

[0004]

SUMMARY OF THE INVENTION An object of the present invention is to provide a polyester fiber having excellent light fastness and good color tone.

[0005]

The above-mentioned object of the present invention is, in a core-sheath composite fiber, a core component consisting of PET,
The sheath component has a light reflectance of 30 in the wavelength range of 290 to 330 nm.
This can be achieved by a polyester composite fiber having a good light resistance composed of a thermoplastic polymer whose content is at least%. PET is known to absorb ultraviolet light. FIG. 1 shows the transmittance of the PET film with respect to the wavelength of light. The transmittance with respect to ultraviolet rays sharply decreases from 330 nm to a shorter wavelength, and the transmittance becomes almost 0% at around 310 nm. Considering together with the reflection spectrum of PET shown in FIG. 2,
It can be seen that the transmission spectrum represents the absorption of ultraviolet light by PET. On the other hand, in the wavelength range of sunlight on the ground, there is almost no component below 290 nm because it is absorbed by the atmosphere. Therefore, in order to prevent the PET from absorbing the light and decomposing the molecular chain or discoloring the dye, it can be achieved by protecting the PET from the light in the wavelength range of 290 to 330 nm.

The present invention is characterized in that, as a PET protective layer, a thermoplastic polymer that reflects sunlight in this wavelength range at a reflectance of 30% or more is used. In the present invention, the term “reflectance” means that a thermoplastic polymer film having a thickness of 10 μm is prepared, and using a U-3200 spectrophotometer manufactured by Hitachi, Ltd., 60 mmφ for incident light having a beam diameter of 10 mm.
The intensity of the reflected light received by the integrating sphere is detected by a photomultiplier tube, and it is determined by the specific intensity with respect to a standard white plate (calcium sulfate).

Therefore, the reflectance of the present invention includes luminescence in addition to ordinary reflected light. Since UV light can reach the core component regardless of whether it is normal reflected light or luminescence, this protective layer shields the UV light and protects the polymer substrate without impairing the intrinsic properties of PET fiber. It is possible to suppress deterioration in strength and discoloration due to deterioration, and to improve light fastness.

The present invention will be described in detail below. The characteristics of the present invention will be described with reference to the drawings. FIG. 2 shows PET having the same thickness and polyethylene 2,6 naphthalate (hereinafter referred to as 2,6-
The reflection spectrum of the film (referred to as PEN) is shown. As can be seen from FIG. 2, the reflectance of PET is smaller at 330 nm or less, while the reflectance of 2,6-PEN is gradually higher in this wavelength range as the wavelength becomes shorter.
It can be seen that the reflectance is extremely high at 80% or more at 310 nm or less where the absorption of PET approaches 100%.

As the sheath component of the present invention, the above-mentioned 2,6-P is used.
A thermoplastic polymer having a naphthalene ring such as EN,
For example, a thermoplastic polymer containing an organic phosphor is used. In order to prevent peeling of the core-sheath interface of the composite fiber, it is preferable to have an ester bond, and 2,6-PEN, polybutylene-2,6-naphthalate, or a polyester blended with these, ethylenenaphthalene-2,
6-dicarboxylate, butylene naphthalene-2,6
-Examples include polyesters obtained by copolymerizing dicarboxylate. These polyesters may be those obtained by copolymerizing one or more other components such as isophthalic acid, diphenyldicarboxylic acid or ethylene oxide, propylene glycol, butylene glycol, or containing additives. When using an organic phosphor, it is preferable to keep the addition amount to a necessary minimum because of a problem in heat resistance. In addition, the intrinsic viscosity [η] of 0.4 or more 2,
By using 6-PEN as the sheath component, the strength of the obtained core-sheath composite fiber can be made equal to that when polyethylene terephthalate as the core component is spun alone, which is preferable. In the present invention, PET refers to polyester having ethylene terephthalate as a main repeating unit. In this case, copolymerization of other components in an amount of 15 mol% or less is also within the scope of the present invention, but copolymerization generally lowers the level of light fastness, and thus high light resistance is required. It is preferable that the copolymerization component is not positively added for use. Further, the PET of the present invention may contain a small amount of additives such as a light stabilizer and a matting agent. The PET of the present invention preferably has a high degree of polymerization with an intrinsic viscosity [η] of 0.8 or more in a field requiring not only light fastness but also high strength and high elastic modulus such as a seat belt. Used. In this case, the sheath component is 2,6
With -PEN, the high elastic modulus peculiar to 2,6-PEN can also be used, so that the present invention becomes more effective.

The composite ratio of the core-sheath composite fiber of the present invention is not particularly limited, but if the ratio of the sheath component is high, the moderately soft texture peculiar to the PET fiber is impaired, so the ratio of the sheath component is 30% by volume. The following is preferable, and 15% by volume or less is more preferable. On the other hand, if the ratio of the sheath component is too low, the stability of the composite state during spinning will be problematic.
Volume% or more is preferable and 1 volume% or more is more preferable.

In the core-sheath composite fiber of the present invention, PET is supplied as a core component, and a thermoplastic polymer having a reflectance of 30% or more in a wavelength range of 290 to 330 nm is supplied as a sheath component,
It can be obtained by ordinary core-sheath composite melt spinning. The take-up method is also not particularly limited, but high-speed spun fibers with a take-up speed of 5000 m / min or more can be preferably applied to raising applications in which the raising process is simplified and a good soft texture can be obtained. Car seats and the like that are required to have good properties are suitable for the use of the present invention.

The core-sheath composite fiber of the present invention is required to have a high degree of color fading fastness, such as car seats, interior panels and other automobile interior materials, curtains, carpets and other interior materials, and a high light resistance retention rate. It can be used for applications such as seat belts.

[0013]

EXAMPLES The present invention will be described in detail below with reference to examples. Each characteristic value in the examples was determined according to the following method. A. Strong elongation, Young's modulus Orientec tensile tester 200mm sample length,
A strength-elongation curve was obtained under the condition of a pulling speed of 200 mm / min, and a strength-elongation at break and an initial Young's modulus were obtained. B. Fastness to discoloration and fading Irradiation was carried out at 83 ° C. for 300 hours with a fade meter, and fastness to discoloration and fading was evaluated by grade determination on a gray scale. C. Intensity retention rate Six fluorescent lamps FL20SE for Toshiba Health Line, which emits ultraviolet rays having a peak at 313 nm, were used, and the sample was rotated and irradiated from all around with six lamps. The ambient temperature in the apparatus during irradiation was 65 ° C. Irradiation for 24 hours,
The strength retention was determined.

Example 1, Comparative Example 1 o-Chlorophenol Intrinsic viscosity [η] measured at 25 ° C.
Of 2,6-PEN of 0.60 and titanium oxide of 0.
PET containing 5 wt% of intrinsic viscosity [η] of 0.70 was melted with a 40 mmφ extruder and introduced into a composite spinning pack, and the sheath was 2,6-PE from the core-sheath composite spinneret.
Composite melt spinning was carried out with N and PET as PET and the sheath component ratio of 15% by volume. A die having a discharge hole diameter of 0.3 mm and a number of holes of 36 was used. 2,6-PEN is 305 ℃, PET
Were melted at 290 ° C. and the spinning hack was spun at 295 ° C. Provide a 15cm heat insulating atmosphere under the base,
Immediately below it, it was cooled by a direct flow of cooling air. Then, after applying the oil agent, the oil agent was taken up by a pair of take-up rolls rotating at a speed of 3000 m / min and wound up. The obtained undrawn yarn was drawn at a ratio of 1.6 times between the first hot roll at 140 ° C and the second hot roll at 160 ° C to obtain 75 denier 3
A drawn yarn of 6 filaments was obtained. As Comparative Example 1, a drawn yarn of 75 denier 36 filaments was obtained in the same manner as in Example 1 except that the discharge of the sheath component was stopped by the same spinning machine to perform the PET single component spinning. The light fastness of the obtained drawn yarn is shown in Table 1. The composite fiber of the present invention has a high elongation,
The Young's modulus is almost the same as that of ordinary PET fiber, and the color fastness to discoloration is extremely excellent.

Example 2 and Comparative Example 2 A composite high-speed spun fiber of 75 denier 36 filaments was obtained in the same manner as in Example 1 except that the spinning take-up speed was set to 6000 m / min, and the winding step was omitted. (Example 2) As Comparative Example 2, 75 denier 3 was prepared in the same manner as in Example 2 except that the same spinning machine as in Example 2 was used to stop the discharge of the sheath component and perform PET single-component spinning.
A 6 filament composite high speed spun fiber was obtained. The light fastness of the resulting composite high-speed spun fiber is shown in Table 1. The composite fiber of the present invention has strength and elongation and Young's modulus which are almost the same as those of ordinary PET fiber, and has extremely excellent fastness to discoloration and fading.

Further, when a tricot-brushed product was made using these fibers and the light fastness was measured, it showed the same tendency as that of the raw yarn, and Example 2 showed extremely excellent light resistance as compared with Comparative Example 2. Indicated.

[0017]

[Table 1]

[0018]

EFFECTS OF THE INVENTION Since a thermoplastic polymer having a reflectance of 30% or more in the ultraviolet wavelength range of 290 to 330 nm is arranged on the outer circumference, PET is prevented from being deteriorated by ultraviolet rays, and light resistance of conventional PET is fast. It is possible to obtain polyester fibers that greatly exceed the degree. The core-sheath composite fiber of the present invention is used for automobile interior materials such as car seats and interior panels, interior materials such as curtains and carpets, and other applications requiring a high degree of color fastness, or for maintaining high light resistance such as seat belts. It can be suitably used for applications requiring a high rate.

[Brief description of drawings]

FIG. 1 shows a transmission spectrum of PET.

FIG. 2 shows the reflection spectra of PET and 2,6-PEN.

Claims (1)

Claim: What is claimed is: 1. A core-sheath composite fiber comprising polyethylene terephthalate as a core component and 290-330 as a sheath component.
A polyester conjugate fiber having good light resistance, which is made of a thermoplastic polymer having a light reflectance of 30% or more in a wavelength range of nm. 2. A polyester composite fiber having good light resistance according to claim 1, wherein the sheath component is polyethylene-2,6-naphthalate.