JPH11107048A - Sheath-core type polyester textile excellent in dyeability and ultraviolet screening effects and production of the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain the subject textile manifesting improved thread breakage caused from uneven stretching, looping, piling, etc., excellent in dyeability, ultraviolet screening effects, hand and drape useful for sporting clothes, etc., by spinning a specific polyester, etc., from a spinning nozzle forming a sheath-core cross section under a specific condition. SOLUTION: A polyester comprising 1 to 20 wt.% of a polyester containing inorganic particles such as titanium oxide, zinc oxide, etc., having average particle size of 0.1 to 5 μm and having ultraviolet screening effects as the core component and a polyester as the sheath component, is spun from a spinning nozzle forming a sheath-core cross section textile under the spinning condition satisfying formulae I to III in the same time where Q; discharging rate of single nozzle (g/minute), L; area of a single nozzle (mm<2> ), M; Q/L, G; inlet diameter of heating zone (mm), V; spinning rate (m/minute), D; denier of a single yarn after drawing, N; number of filaments at drawing speed >=4000 m/minutes, once cooled below glass transition point and, heat drawing to obtain the objective sheath-core type polyester textile having elongation of <=50%, degree of shrinkage in boiling water of <=6.5%, and U% of <=0.65.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a polyester fiber having excellent ultraviolet shielding properties and excellent thread quality and a method for producing the same, such as blouses, summer suits, sports clothing, curtains, parasols, canvas, automobile covers, and the like. And a fiber suitably used for clothing and industrial materials.

[0002]

2. Description of the Related Art Conventionally, there has been known a resin composition which absorbs light having a wavelength of 380 nm or less almost completely and substantially shields ultraviolet rays. It is used for preventing deterioration of chemicals, liquid crystals, etc., or for window glass. Conventionally, additives that impart the ability to absorb or block ultraviolet rays include organic ultraviolet absorbers, organic dyes and pigments, and inorganic particles such as zinc oxide, titanium dioxide, talc, kaolin, and sodium carbonate. ing.

[0003]

Some of the conventional organic ultraviolet absorbers have excellent ultraviolet absorbing ability and a high melting point, so they are melted and kneaded into a high melting point thermoplastic resin for molding. Although it is possible to provide it, the kneading resin is conspicuously colored because it generally absorbs visible light well, and these are used only when high-concentration coloring is allowed, and resin molding that requires whiteness is used. It has the drawback that it is not suitable for an object or that attention is required because the object or decomposition products may cause skin damage. This point can be solved by using white inorganic fine particles.However, in the conventional method, even when the spinning condition at the time of spinning is poor due to the aggregation of the particles or the aggregation is not a problem, the particles are not removed. Since the fibers were contained in the fibers, the yarn had no physical properties. In particular, when the amount of inorganic particles is increased in order to improve the ultraviolet ray cutting effect, not only the fiberization processability is deteriorated, but also the physical properties are remarkably reduced, the feeling and dyeing are not satisfied, and the use is extremely limited.

[0004]

Means for Solving the Problems As a result of intensive studies to solve the above problems, the present inventors have limited the type and amount of fine particles to be contained in the polyester, and made the fiber cross section a core-sheath structure. Furthermore, it was found that by adopting a specific method as a spinning method, a polyester fiber having excellent dyeing properties, ultraviolet shielding function, mechanical properties, dyeing properties, and feeling was also obtained.

That is, according to the present invention, the average particle diameter is 0.1%.
A core-sheath type polyester fiber having a core component of polyester containing 1 to 20 wt% of inorganic fine particles of 1 to 5 μm and having a sheath component of polyester, having an elongation of 50% or less, a boiling water shrinkage of 6.5% or less, and a U% Is a core-sheath type polyester fiber having excellent dyeing properties and ultraviolet shielding properties, which is 0.65 or less, and a polyester containing 1 to 20 wt% of inorganic fine particles having an average particle diameter of 0.1 to 5 μm and having an ultraviolet shielding effect. As a core component, using polyester as a sheath component, melt-spinning is performed from a spinneret forming a core-sheath cross section, the spun yarn is once cooled to a temperature below the glass transition temperature, and then is run in a heating zone and subjected to drawing heat treatment. When applying an oil agent and winding at a take-up speed of 4000 m / min or more, the spinning conditions were as follows: spinneret single-hole discharge amount Q (g / min), spinneret single-hole area L (mm)
² ) When Q / L is M, the inlet diameter of the heating zone is G
(Mm), the spinning speed V (m / min), the denier of the single yarn after stretching is D, and the number of filaments is N, the following formulas (1) to (3)
This is a method for producing a core-sheath type polyester fiber which is excellent in dyeing property and ultraviolet ray shielding property to be spun under a condition satisfying simultaneously. 30 ≦ M + 5D ≦ 80 (1) −10 ≦ G−0.2N ≦ 5 (2) −65 ≦ M−0.02V ≦ −35 (3)

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The core-sheath type polyester fiber of the present invention has an average particle diameter of 0.1 to 5 in the core polyester.
1 to 20 w of inorganic fine particles having an ultraviolet shielding effect of μm
t%. If the content is less than 1% by weight, a sufficient ultraviolet shielding effect cannot be obtained, and if it exceeds 20% by weight, the viscosity during spinning is remarkably reduced, and the core-sheath viscosity balance is deteriorated, resulting in poor spinning condition. Further, even when the spinning condition does not become abnormal, the cross-sectional formation of the core-sheath becomes poor.

The average particle diameter of the inorganic fine particles contained in the core-side polyester is preferably 0.1 to 5 μm. More preferably, it is 0.3 to 1 μm. If the particle size is less than 0.1 μm, thermal aggregation is likely to occur at the stage of polyester polymerization, and filter clogging is likely to occur in the spinning process. On the other hand, if it exceeds 5 μm, the filter will be clogged and the spinning condition will be poor.

[0008] Furthermore, in the present invention, it is important that the cross section is a core sheath. By adding inorganic fine particles to the core-side polyester, during fiberization, fluff breakage hardly occurs due to contact with a guide or the like, and the fiber properties are maintained by the sheath polymer.

Examples of the inorganic fine particles used in the present invention include substances having an ultraviolet shielding property such as titanium oxide, zinc oxide, aluminum oxide and cerium oxide. One of these substances may be used alone, or two or more of them may be used in combination. . Of these, titanium oxide and / or zinc oxide are particularly preferably used.

The method of adding the inorganic fine particles is not particularly limited, and it is sufficient that the inorganic fine particles are added at an arbitrary stage from preparation of polyester polymerization to immediately before spinning. However, in the case of using a slurry containing zinc oxide in the present invention, the addition time must be immediately before spinning.For example, when added during the preparation of polyester polymerization or during the reaction, aggregation of zinc oxide particles occurs violently, which is preferable. Absent. The term “immediately before spinning” in the present invention should be understood as an arbitrary stage from after the completion of substantial polymerization to when the polymer is discharged from the spinning nozzle.

As the polyester forming the core component and the sheath component in the present invention, polyesters such as polyethylene terephthalate and polybutylene terephthalate,
Terephthalic acid, isophthalic acid, naphthalene 2,6-dicarboxylic acid, phthalic acid, α, β- (4-carboxyphenoxy) ethane, 4,4′-dicarboxydiphenyl 5-
Aromatic dicarboxylic acids such as sodium sulfoisophthalic acid, or aliphatic dicarboxylic acids such as adipic acid and sebacic acid or ester-forming derivatives thereof, and ethylene glycol, diethylene glycol, 1,4-butanediol, neopentyl glycol, cyclohexanedimethanol , A fiber-forming polyester synthesized from a diol compound such as polyethylene glycol or polytetramethylene glycol, wherein at least 80 mol% of its constituent units are polyethylene terephthalate units or polybutylene terephthalate units. Certain polyesters are preferred and have a melting point of 200
It is desirable that the temperature is not less than ° C. If the melting point is low, the heat resistance is insufficient and the use as a fiber for clothing is limited, which is not preferable. Further, the polyester may contain a small amount of additives such as an antioxidant, a flame retardant, an antibacterial agent, a deodorant, a fluorescent brightener, a stabilizer and the like.

Next, the manufacturing method of the present invention will be described. In the present invention, a polyester containing 1 to 20% by weight of the inorganic fine particles having the above-mentioned specific particle diameter is used as the polyester constituting the core of the fiber, and a polyester is used as the sheath component to form a normal core-sheath cross section. Melt spinning from a spinneret, the spun yarn is once cooled to a temperature below the glass transition point,
Next, after running in a tube-type heating device and performing a stretching heat treatment, an oil agent is applied and wound at a take-up speed of 4000 m / min or more. The sheath component polymer may be any polyester as described above, and may be a regular polyester, a third component-added polyester or a copolymerized polyester.

The melt spinning temperature and melt spinning speed in this case are not particularly limited, and the melt spinning can be performed under the same conditions as those usually used for producing polyester fibers. (The melting point of polyester + 20 ° C.)
(For example, about 280 to 300 in the case of polyethylene terephthalate).
° C) and the melt spinning speed (melt spinning amount) is about 20 to
It is preferable to set the amount to about 50 g / spinning hole 1 mm 2 · minute because a good quality polyester fiber can be obtained with good spinning processability.

The size and number of the spinning holes and the shape of the spinning holes in the spinneret are not particularly limited, and can be adjusted according to the single fiber fineness of the target polyester fiber, the total denier number, the cross-sectional shape and the like. it can. Spinning hole (single hole)
Is desirably about 0.018 to 0.07 mm ² .

Then, the polyester fiber melt-spun as described above is once cooled to a temperature lower than its glass transition point, preferably 10 ° C. or lower than the glass transition temperature. The cooling method and the cooling device in this case are not particularly limited as long as the method and the device can cool the spun polyester fiber to the glass transition temperature or lower, but are not particularly limited. It is preferable that a cooling air blowing device is provided, and cooling air is blown onto the spun polyester fiber to cool the polyester fiber to a temperature lower than the glass transition temperature.

At this time, the cooling conditions such as the temperature and humidity of the cooling air, the blowing speed of the cooling air, and the angle at which the cooling air is blown onto the spun fibers are not particularly limited, and the polyester fibers spun from the die are converted into fibers. Any condition may be used as long as the condition allows rapid and uniform cooling to the glass transition temperature or lower while preventing shaking or the like. Among them, the temperature of the cooling air is about 20-30 ° C and the humidity of the cooling air is 2
0-60%, the blowing speed of cooling air is 0.4-1.0m
It is preferable to perform cooling of the spun polyester fiber with the blowing direction of the cooling air to the spun fiber being perpendicular to the spinning direction at about / sec, since a high-quality polyester fiber can be smoothly obtained. .

When cooling is performed under the above-mentioned conditions using a cooling air blowing cylinder, the length is about 80 to 120 with a slight or no interval directly below the spinneret.
It is preferable to arrange a cooling air blowing cylinder of about cm.

Next, the polyester fiber cooled to the glass transition temperature or lower is subsequently directly introduced into the heating zone and drawn. The temperature of the heating zone may vary depending on the type of the polyester, etc., but if the temperature is set at 40 ° C. or higher than the glass transition temperature of the polyester, the physical properties of the obtained polyester fiber can be made practically satisfactory. For example, in the case of polyethylene terephthalate fiber, the temperature of the heating zone is preferably set to about 100 ° C. or higher.

The upper limit temperature of the heating zone may be any temperature at which fusion between fibers, breakage of yarn, breakage of single yarn, etc. does not occur in the heating zone. The type and structure of the heating zone are such that the polyester fiber traveling in the heating zone can be heated without contacting the heating means in the heating zone, and the yarn traveling in the heating zone and the air surrounding it can be heated. Any structure can be used as long as the resistance can be generated between them and the yarn tension can be increased, and the fiber can be drawn. Among them, as the heating zone, a tubular heating zone is preferably used, and in particular, the inner diameter where the tube wall itself is a heater is about 2 mm.
A pipe heater of about 0 to 50 mm is preferable.

The installation position of the heating zone from the spinneret, the length of the heating zone, etc. depend on the type of polyester fiber, the amount of polyester spun, the cooling temperature of the polyester fiber, the running speed of the polyester fiber, the temperature of the heating zone, and the heating zone. It can be adjusted according to the inner diameter of the zone, etc., but the distance from immediately below the spinneret to the entrance of the heating zone is about 0.5 to 3.0 m, and the length of the heating zone is about 1.0 to 2.0 m. When,
This is desirable because the polyester fiber can be heated and uniformly drawn in the heating zone. Then, an oil agent is applied to the polyester fiber drawn in the heating zone as needed, and then the polyester fiber is drawn at a high speed.

In the present invention, it is necessary to carry out the process for producing a stretched polyester fiber comprising the above-mentioned series of processes at a polyester fiber take-off speed of 4000 m / min or more. Preferably it is. The take-up speed of the polyester fiber is 4000m /
If it is less than minutes, the drawing of the fiber in the heating zone will not be performed sufficiently, the mechanical properties of the obtained polyester fiber will be reduced, and the method of the present invention comprising the above series of steps will not be performed smoothly, especially Fluctuations in the tension in the heating zone, overheating, etc., occur, making it difficult to perform uniform stretching.

In practicing the present invention, the spinning conditions are as follows: Q / L is M when the discharge amount of the single-hole die is Q (g / min) and the area of the single-hole die is L (mm ² ). When the inlet diameter is G (mm), the spinning speed V (m / min), the denier of the single yarn after drawing is D, and the number of filaments is N, the following expressions (1) to (3) must be satisfied at the same time. There is. 30 ≦ M + 5D ≦ 80 (1) −10 ≦ G−0.2N ≦ 5 (2) −65 ≦ M−0.02V ≦ −35 (3)

If the value of M + 5D in the formula (1) is less than 30, the back pressure of the nozzle is low, which causes a sectional defect or a thread breakage caused by a discharge failure. On the other hand, the value of M + 5D is 80
When the pressure exceeds, the back pressure of the nozzle is too high, resulting in melt fracture and poor uniformity of the cross section. More preferably 45
≦ M + 5D ≦ 60.

Next, if the value of G-0.2N in the expression (2) is less than -10, the diameter of the inlet of the heating zone becomes too small with respect to the number of filaments during spinning, and single yarn breakage due to guide resistance is likely to occur. This deteriorates the processability. On the other hand, if the value of G-0.2N exceeds 5, the inlet diameter of the heating zone becomes too large, and the temperature in the heating zone is cooled, so that the drawing and heat treatment of the yarn are not sufficiently performed and the fiber properties are satisfactory. I can't get it. The exit diameter of the heating zone is desirably as small as possible in terms of quality, but considering the workability of lowering the yarn at the time of yarn introduction and the like, 8 mm to 15 mm is appropriate depending on the brand such as the number of filaments.

Further, regarding the M value and the spinning speed V in the equation (3), M
If the value of -0.02V is less than -65, the back pressure of the nozzle becomes insufficient, and if the value of -0.02V exceeds -35, the back pressure of the nozzle becomes too high. Cause. By satisfying the formulas (1) to (3), yarn breakage, loops, fluff, and the like due to unevenness in drawing caused by fluctuations in the running speed of the yarn and the tension applied to the running yarn are improved, and mass production can be performed with good processability.

The single fiber fineness and the total denier of the polyester fiber finally obtained in the present invention are not particularly limited.
Although it can be appropriately adjusted depending on the use of the polyester fiber, etc., the method of the present invention particularly has a single fiber fineness of 0.5 to
It is suitable for producing polyester fibers having a denier of 6 and a total denier of 20 to 200 denier.

In the present invention, the cross-sectional shape of the polyester fiber is not particularly limited, and may be any shape such as a circle or a triangle as long as the core-sheath can be formed, and the outer shape of the core and the sheath may be the same. Good, no problem even if different. It can be appropriately selected according to the intended use, physical properties and feeling.

The core-sheath type polyester fiber of the present invention obtained by the above method has an elongation of 50% or less and a shrinkage of boiling water of 6.5%.
Hereinafter, a core-sheath type polyester fiber having excellent dyeing properties and ultraviolet shielding properties with U% of 0.65 or less, for example, a polyester containing a high concentration of titanium oxide as a core component and a regular polyester as a sheath component. The core-sheath type polyester fiber of the present invention not only has good functionality and mechanical properties, but also has excellent dyeability with a disperse dye, dyeing a much deeper color than conventional drawn yarns. In addition, when polyester having a high concentration of titanium oxide added to the core and polyester having a metal sulfonate group in the sheath are used, it has an ultraviolet shielding effect, a mechanical property, and a further anti-transparent effect, but also has a dyeability with a cationic dye. Very excellent.

[0029]

EXAMPLES The present invention will be specifically described below with reference to examples and the like, but the present invention is not limited thereto. The following examples illustrate the measurement method.

<Intrinsic Viscosity> The intrinsic viscosity was measured at 30 ° C. with an equal weight of a mixed solvent of phenol and tetrachloroethane. <Strength and elongation of fiber> Determined from a load-elongation curve obtained using an Instron type tensile tester. <Boiling water shrinkage ratio WSr> Measured according to JIS-L1013. <Uniformity of polyester fiber (Worcester spots: U%)> The yarn is passed between the electrodes at a constant speed by using a Worcester spot tester manufactured by Zellberger (yarn speed 100 m / min, range ± 12.
(5%, chart speed 10 cm / min) A change in electric capacity proportional to a change in cross section was continuously measured, and an average deviation coefficient U% of a constant length of the yarn was measured. <Evaluation of yarn production process> Good mass production process (〇), level of mass production just now (産), no mass production (×) <Dyeing / feel evaluation> Use the obtained polyester fiber as warp and weft. Weaving the fabric, normal weight loss dyeing,
Finishing was performed to obtain a woven fabric. This was evaluated by panelists and indicated as extremely good (（), good (○), now one step (△), and poor (×). <Measurement of Ultraviolet Transmittance> The knitted fabric of the fiber of the present invention is covered on the sensor part of the ultraviolet intensity integrator, and at the same time, the ultraviolet light is measured without attaching a sample to the other sensor part. The transmittance was determined. It is determined that the smaller this value, the better the ultraviolet shielding performance. UV transmittance (%) = (U / Uo) × 100 ‥‥‥ (4) U: amount of ultraviolet light on the sample side, Uo: amount of ultraviolet light on the non-sample side

Example 1 10 wt% of titanium oxide having an average particle diameter of 0.4 μm was used as a core component.
% Of intrinsic viscosity [η] = 0.70 polyester (FD10-PET) and sheath [η] = 0.68 regular semi-dal polyester (SD-PET), with a core / sheath discharge ratio of 1/1 And 36 holes (0.18 mm holes)
φ) Spinneret temperature 295 ° C, single hole discharge amount 1.04g
/ Min. Then temperature 25 ℃, humidity 6
After the temperature of the spun yarn is reduced to 70 ° C. or less at a rate of 0% cooling air of 0.5 m / sec, the spun yarn is placed at a position 1.2 m below the die, having a length of 1.0 m, an inlet diameter of 5 mmφ, and an outlet. Caliber 10
mmφ, inner diameter 30mmφ, tube heater (internal temperature 18
0 ° C.) and stretched in a tube heater. After that, the yarn coming out of the tube heater is lubricated with a crow mouth guide and wound up at a speed of 4500 m / min via two take-up rollers at 75 d / 36 f. Was obtained. Tables 1 and 2 show the spinning conditions at that time and the structural properties of the resulting fibers and the results of the evaluation of dyeing, hand and UV transmittance.

[0032]

[Table 1]

[Table 2]

Example 2 The amount of titanium oxide added to the core polyester was 15 wt.
%, And the spinning speed was set to 4000 m / min. Tables 1 and 2 show the spinning conditions and fiber evaluation results at that time.

Example 3 10 wt% of titanium oxide having an average particle diameter of 0.4 μm as a core component
And a polyester ([η] = 0.7) added with a total of 15 wt% of zinc oxide having an average particle diameter of 0.6 μm and 5 wt%.
0), the core / sheath discharge ratio was 1/1 using regular bright polyester (RB-PET [η] = 0.68) as the sheath component, and the spinning temperature was determined using a die having 48 holes (pore diameter 0.15 mmφ). Melt spinning was performed at 298 ° C. and a single hole discharge rate of 0.69 g / min. After that, the yarn was made in the same manner as in Example 1 and 40
At a speed of 00 m / min, a drawn yarn of 75d / 48f was obtained. Tables 1 and 2 show the spinning conditions and fiber evaluation results at that time.

Example 4 Polyester ([η] = 5%) was added to the core component in an amount of 5 wt% of titanium oxide having an average particle diameter of 0.4 μm and 5 wt% of aluminum oxide having an average particle diameter of 0.3 μm.
0.70), and using a regular bright polyester (RB-PET [η] = 0.68) as a sheath component to form a core /
With a sheath discharge ratio of 1/1, 48 holes (0.15 mmφ)
With a spinning temperature of 295 ° C. and a single hole discharge rate of 0.87 g /
min. Thereafter, the yarn was formed in the same manner as in Example 1 and wound at a speed of 5000 m / min to obtain a drawn yarn of 75d / 48f. Tables 1 and 2 show the spinning conditions and fiber evaluation results at that time.

Example 5 Using a polyester ([η] = 0.68) in which 5 wt% of titanium oxide having an average particle diameter of 0.4 μm was added to a core component, an isophthalic acid copolymer polyester (SIP2) having a metal sulfonate group in a sheath component was used. 0.5 mol% copolymerized PET: [η]
= 0.60), the core / sheath discharge ratio was 2/1, and the number of holes was 3
6 (hole diameter 0.18 mmφ) with a spinning temperature of 298 ° C,
Melt spinning was performed at a single hole discharge rate of 0.69 g / min. Thereafter, the yarn was formed in the same manner as in Example 1 to obtain a drawn yarn of 50d / 36f at a speed of 4500 m / min. Tables 1 and 2 show the spinning conditions and fiber evaluation results at that time.

Example 6 10 wt% of titanium oxide having an average particle size of 0.4 μm was used as a core component.
% Added polyester ([η] = 0.68)
5 wt% barium sulfate with an average particle diameter of 0.6 μm in the sheath component
% Of added SIP 2.5 mol% copolyester ([η] = 0.55), the core / sheath discharge ratio was 1/1, and the spinning temperature was 2 with a die having 36 holes (pore diameter 0.2 mmφ).
Melt spinning was performed at 95 ° C. and a single hole discharge rate of 1.04 g / min. Then, the yarn is formed in the same manner as in Example 1 and 75d / 36f
Was obtained. Tables 1 and 2 show the spinning conditions and fiber evaluation results at that time. This product was particularly excellent in high color development.

Comparative Example 1 Titanium oxide having an average particle diameter of 0.4 μm was added to the core component in an amount of 30 wt.
% Added [η] = 0.70 polyester (FD30
-PET) was used in the same manner as in Example 1, except that spinning properties were poor and satisfactory processability was not obtained.

Comparative Example 2 10 wt% of titanium oxide having an average particle diameter of 0.4 μm as a core component
And a polyester ([η] = 0.70) added with a total of 15 wt% of zinc oxide and 5 wt% of zinc oxide, and a regular bright polyester [η] = 0.68 as a sheath component. And the number of holes is 48 (pore diameter 0.2m
spinning temperature of 298 ° C, single hole discharge rate 0.87
It was melt spun at g / min. As a result, there were many section failures due to ejection failure, and the processability was insufficient.

Comparative Example 3 0.5 wt. Of titanium oxide having an average particle diameter of 0.4 μm was used as a core component.
% Added [η] = 0.68 polyester, and a regular bright polyester (RB-PET [η] =
0.68), the core / sheath discharge ratio is 1/1, and the number of holes is 3
6 (hole diameter 0.18mmφ) with a spinning temperature of 295 ° C,
Melt spinning was performed at a single hole discharge rate of 0.61 g / min. Thereafter, the yarn was formed in the same manner as in Example 1 and wound at a speed of 4000 m / min to obtain a drawn yarn of 50d / 36f. Tables 1 and 2 show the spinning conditions and fiber evaluation results at that time.

Comparative Example 4 A yarn was produced in the same manner as in Example 1 except that the spinning speed was changed to 3400 m / min, to obtain a 75d / 36f drawn yarn. Tables 1 and 2 show the spinning conditions and fiber evaluation results at that time. When the spinning speed was low, unsatisfactory physical properties were obtained.

Comparative Example 5 In the same manner as in Example 1, FD10-PET was used for the core component and SD-PET was used for the sheath component, and the film was once wound at a spinning speed of 1000 m / min. The yarn was formed by a conventional method to obtain a drawn yarn of 75d / 36f. Tables 1 and 2 show the spinning conditions and fiber evaluation results at that time. The dyeability of the product obtained by the conventional method was lighter than that of the product obtained by the spinning method of the present invention, and the appearance was unsatisfactory.

The products obtained in Examples 1 to 6 were all good in process condition and satisfactory in physical properties, dyeing and feeling. In particular, according to the present invention, in addition to the examples, by examining the type of sheath component polymer and the addition of functional particles in a range that does not impair spinnability, prevention of sheer, UV cut properties, good dyeability Can also provide new functionality and feel. On the other hand, in Comparative Examples 1 to 5, the particle amount and the spinning conditions were out of the range of the present invention, and no processability was obtained, or even if the processability was obtained, none of the physical properties and fiber evaluation were satisfactory.

Claims (3)

[Claims] A core-sheath type polyester fiber comprising a polyester containing 1 to 20 wt% of inorganic fine particles having an average particle diameter of 0.1 to 5 μm as a core component and a polyester as a sheath component, and having an elongation of 50%. A core-sheath type polyester fiber excellent in dyeability and ultraviolet shielding property, having a boiling water shrinkage of 6.5% or less and a U% of 0.65 or less. 2. An inorganic fine particle comprising titanium oxide, zinc oxide,
The core-sheath type polyester fiber according to claim 1, which is at least one kind of inorganic fine particles having an ultraviolet shielding effect selected from the group consisting of aluminum oxide and cerium oxide. 3. A spinneret forming a core-sheath cross section using a polyester containing 1-20 wt% of inorganic fine particles having an average particle diameter of 0.1 to 5 μm and having an ultraviolet shielding effect as a core component and a polyester as a sheath component. After melt spinning, the spun yarn is once cooled to a temperature lower than the glass transition point, and then is stretched and heat-treated by running in a heating zone.
When winding at a take-up speed of 000 m / min or more, the spinning conditions are as follows: Q / L is M when the discharge amount of the single-hole die is Q (g / min) and the area of the single-hole die is L (mm ² ). When the inlet diameter is G (mm), the spinning speed V (m / min), the denier of the single yarn after drawing is D, and the number of filaments is N, the dyeing is performed under the conditions that simultaneously satisfy the following expressions (1) to (3). Of core-sheath type polyester fiber excellent in water resistance and ultraviolet ray shielding property 30 ≦ M + 5D ≦ 80 {(1) -10 ≦ G−0.2N ≦ 5} (2) −65 ≦ M-0. 02V ≦ -35３５ (3)