JPH11189920A - Polyester hollow fiber and its production - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a high quality polyester hollow fiber little in the change of properties during after-processes or on wearing, causing the collapse of hollow parts at less degree than a conventional hollow fiber when used as a material for clothes, especially as a material for sportswear, good in gloss, light in weight, excellent in warmth-keeping property, easily dyeable and having good softness, and to provide a method for producing the same. SOLUTION: This polyester hollow fiber comprises a polyester polymer composed of terephthalic acid as an acid component and trimethylene glycol in an amount of 280 mol.% as a glycol component, and has a hollow ratio of 10-60%, a density of 1.32-1.45 g/cm<3> and a birefringence (Δn) of 0.05-0.08. The process for producing the polytrimethylene terephthalate hollow fiber comprises melt spinning of the polyester polymer having an intrinsic viscosity [η] of 0.4-1.4, winding up of the spun yarn under quick cooling by keeping the atmospheric temperature at 1 m directly below the spinneret at <=100 deg.C, subsequent drawing, and thermal treatment at 90-200 deg.C.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hollow polyester fiber having little property change during a high-order processing step or wearing. More specifically, as a material for apparel, especially a material for sports apparel, the hollow portion is less crushed than before, the gloss is good, the weight is excellent, the heat retention is excellent, and the high-quality polyester hollow is excellent in easy dyeing and softness. About fibers.

[0002]

2. Description of the Related Art Polyester fibers are widely used for general clothing because of their excellent properties such as mechanical properties, chemical properties, easy care properties and glossiness. In particular, recently, it has attracted attention as a material for sports clothing, and has been used in all sports fields. Lightening of clothing has been desired as one of the needs in the past, and there has been a strong demand for weight reduction from the point of easiness of exercise in sports clothing, and in winter clothing, one that retains heat retention is desired. . As a means for reducing the weight of clothing, it is possible to some extent by increasing the bulkiness of the yarn or devising the structure of the woven or knitted fabric. However, in order to further reduce the weight, it is necessary to reduce the weight of the fiber itself. As a means for this, apparently lightweight hollow fibers are used. Hollow fibers have been known for a long time. For example, Japanese Patent Publication No. 42-2828 discloses a method for producing polyethylene terephthalate hollow fibers having a hollow ratio of 50% or less. However, hollow fibers are used in the manufacturing process, higher processing steps or product use (wearing).
There is a drawback that the hollow portion is liable to be crushed at times, and useful properties as a hollow fiber are easily impaired. In particular, the higher the hollow fiber, the greater the tendency. In particular, since sports clothing is more intensely handled than other clothing, the hollow portion is likely to collapse. When the hollow portion is crushed, the hollow ratio naturally decreases, and not only does the lightness and the heat retention of the product decrease, but also a streaky gloss unevenness occurs.

As means for improving the collapse of the hollow portion, Japanese Patent Application Laid-Open No. 6-228815 has proposed a polyethylene terephthalate hollow fiber having a triangular hollow portion. However, according to the study of the present inventors, when the hollow portion has a triangular shape, although a certain degree of crush resistance is obtained,
Since the polyethylene terephthalate fiber has a small elongation at the yield point when deformed, it is crushed when bent at a certain angle or more, and the crush resistance cannot be sufficiently improved. When hollow fibers are used, the outer diameter of the fibers is larger than that of the same denier solid fibers, and a soft feel cannot be obtained.

[0004] Sports clothing is also desired to have a soft feel and easy movement. Also in this regard, the polyethylene terephthalate hollow fiber has a larger outer diameter than the solid fiber when trying to obtain a fiber having the same strength (that is, a fiber having the same denier). It becomes a stiff texture. When the fiber diameter is reduced to obtain a soft feel, it becomes extremely difficult to increase the hollow ratio. Examples of the soft-feel fiber include a polytrimethylene terephthalate fiber disclosed in JP-A-52-5320. Because the fibers disclosed here have a low modulus of elasticity,
Cloths such as clothing obtained from these fibers have a very soft feel. However, it is difficult to obtain a fiber having a high hollow ratio even if a spinning method such as that generally used for polyethylene terephthalate is used.

[0005]

DISCLOSURE OF THE INVENTION The present invention is directed to a sports field in which the above-mentioned drawbacks of the conventional polyester hollow fiber are improved, the light weight, the heat retention, the ease of dyeing are excellent, and the soft feeling is hard to be crushed. The present invention relates to a useful polyester fiber and a stable production method thereof.

[0006]

Means for Solving the Problems The present inventors have made intensive studies to solve the above-mentioned drawbacks, and as a result, by using a specific hollow fiber made of a specific polyester polymer,
Polyester fibers which are excellent in lightness, heat retention, ease of dyeing, and clarity, are hard to be crushed, and have a soft feel, and are useful for sports fields and the like have been provided. That is, the first aspect of the present invention is a polyester polymer containing terephthalic acid as an acidic component and containing at least 80 mol% of trimethylene glycol as a glycol component, and having a hollow ratio of 1%.
It is a polyester hollow fiber characterized by having a density of 0 to 60%, a density of 1.32 to 1.45 g / cm ³ , and a birefringence (Δn) of 0.05 to 0.08.

A second aspect of the present invention is that, when melt-spinning a polyester polymer containing terephthalic acid as an acidic component and at least 80 mol% of trimethylene glycol as a glycol component, an intrinsic viscosity [η] of 0.4 to 1 is used. Polyester methylene terephthalate, characterized in that it is rapidly cooled to a temperature of 100 ° C. or less immediately below the spinneret and wound up using a polyester polymer of 0.4 and stretched and then heat-treated at a temperature of 90 to 200 ° C. Hollow fiber manufacturing method,
It is. The hollow fiber of the present invention needs to be composed of a polyester polymer containing trimethylene glycol as a glycol component in an amount of 80 mol% or more. Normally, hollow fibers tend to have low sharpness due to irregular reflection of light on the inner surface of the fibers. However, the polymer used in the present invention has a high refractive index, so that even if it is a hollow fiber, the sharpness does not easily decrease.

In the present invention, the trimethylene glycol is selected from 1,3-propanediol, 1,2-propanediol, 1,1-propanediol, 2,2-propanediol or a mixture thereof. However, 1,3-propanediol is particularly preferred from the viewpoint of stability. The content of trimethylene glycol must be at least 80 mol% of the glycol component. If the amount is less than 80 mol%, not only the crush resistance, color development and softness, which are the objects of the present invention, cannot be achieved, but also the ease of dyeing and sharpness are reduced, and the objects of the present invention are not achieved. Preferably, it is 90 mol% or more.

In the polytrimethylene terephthalate used in the present invention, if necessary, isophthalic acid, succinic acid, adipic acid, 2,6-naphthalenedicarboxylic acid, etc. may be used as long as the effects of the present invention are not impaired. A glycol component such as ethylene glycol, 1,4-butanediol, 1,6-hexanediol, or polyoxyalkylene glycol may be copolymerized as the glycol component. If necessary, various additives such as a matting agent, a heat stabilizer, a flame retardant, an antistatic agent, and an antifoaming agent may be copolymerized or mixed. The polymer used in the present invention can be polymerized by a known polyester polymerization method.

It is considered that the crush resistance of the hollow fiber is determined by the thickness of the polymer portion, the difficulty of deformation of the polymer, and the ease of recovery when the polymer is deformed. In order to make fibers with lightness, heat retention, softness, and resistance to crushing suitable for sports clothing, while having an appropriate hollow ratio,
It is preferable to have an appropriate fineness. This allows the polymer portion of the hollow fiber to have an appropriate thickness.
The hollow fiber of the present invention needs to have a hollow ratio of 10 to 60%. When the hollow ratio exceeds 60%, the polymer portion becomes thin, and the crush resistance, which is the object of the present invention, cannot be exhibited. On the other hand, if the hollow ratio is less than 10%, the features of the present invention, such as light weight and heat retention, cannot be exhibited. The preferred hollow ratio is 15 to from the viewpoint of lightness, heat retention, and difficulty in crushing.
It is in the range of 50%, more preferably 20-40%.

Further, the fineness of the hollow fiber of the present invention is preferably such that the single fiber fineness is 0.1 to 10 denier. With a hollow fiber having a fineness of less than 0.1 denier, it is difficult to make the hollow ratio within the range of the present invention. Also, if the fineness exceeds 10 denier, the hollow ratio is increased and the hollow fiber is easily crushed, and the fiber having a low hollow ratio is difficult to bend. It doesn't feel good. The fineness of the single yarn is preferably in the range of 0.2 to 5 denier, and more preferably 0.1 to 5 denier.
It is in the range of 5 to 3 denier.

[0012] A fiber having a high hollow ratio and a soft feel,
There is a need to increase the ease of recovery when the polymer is deformed. For this purpose, it is necessary to use the polymer of the present invention and also to increase the degree of crystallinity and the degree of orientation of molecules in the fiber axis direction. By increasing the degree of crystallinity and the degree of orientation, the elongation at the yield point, which is the area where the deformed fiber returns to the original shape, and the stress at that time (yield point stress) can be increased, making the hollow fiber hard to collapse. Can be.

The fiber of the present invention has a density of 1.32.
It is important that it is １1.45 g / cm ³ . When the density is less than 1.32 g / cm ³ , the crystallinity of the fiber is low, and only a fiber that is easily broken can be obtained. Since the crystal density of the polymer of the present invention is 1.45 g / cm ³ or less, the fiber density does not substantially exceed 1.45 g / cm ³ . The density of the fibers is preferably in the range of 1.35~1.4g / cm ^3.

In the fiber of the present invention, the birefringence (Δn), which is an index of the degree of orientation of the fiber, needs to be 0.05 to 0.08. If Δn is less than 0.05, the yield point elongation of deformation becomes low because the orientation of the fiber is not sufficient,
Only fragile fibers can be obtained. If Δn exceeds 0.08, the degree of orientation is too high, so that fluffing and yarn breakage frequently occur during stretching or post-processing. Δ
n is preferably in the range of 0.055 to 0.075, more preferably 0.06 to 0.07.

The second invention of the present invention is a production method for stably providing the hollow fiber of the first invention, wherein terephthalic acid is used as an acid component and trimethylene glycol is 80 mol% as a glycol component. When the polyester polymer contained above is melt-spun, a polyester polymer having an intrinsic viscosity [η] of 0.4 to 1.4 is used, and the spinning is performed at an ambient temperature of 1 cm immediately below the spinneret at 100 ° C. or lower. This is a method for producing polytrimethylene terephthalate hollow fibers. Here, the intrinsic viscosity [η] is obtained by dividing the viscosity at 35 ° C. of a diluted solution of polytrimethylene terephthalate dissolved in o-chlorophenol having a purity of 98% or more by the viscosity of the solvent itself measured at the same temperature. And is defined as the relative viscosity.

In the production method of the present invention, the intrinsic viscosity [η] of polytrimethylene terephthalate needs to be 0.4 to 1.4. If the intrinsic viscosity [η] exceeds 1.4, no matter how high the spinning temperature is, the melt viscosity will increase and not only will it be difficult to extrude with a normal spinning machine, but also because the extruded polymer will have high elasticity. As a result, the hollow fibers having a hollow ratio of 10% or more cannot be manufactured stably. When the intrinsic viscosity is less than 0.4, the mechanical properties such as the strength of the hollow fiber are reduced, and only the fiber which is inferior in the collapse of the hollow portion can be obtained. A preferred intrinsic viscosity [η] is 0.5 to 0.5.
9 is in the range.

The melt spinning temperature of the hollow fiber of the present invention is 24
The range is from 0 ° C to 320 ° C, preferably from 245 ° C to 300 ° C, and more preferably from 250 ° C to 280 ° C. 240 ° C
If it is less than 5, the melt viscosity becomes high, and extrusion becomes difficult. On the other hand, when the temperature exceeds 320 ° C., the decomposition of the polymer becomes severe, and coloring and remarkable decrease in strength occur. In the production method of the present invention, it is important that the spinning is performed by rapidly cooling the ambient temperature 1 cm immediately below the spinneret to 100 ° C. or less. By quenching, not only the solidification of the polymer can be accelerated and the hollow ratio can be increased to 10% or more, but also the crystallization after extrusion can be suppressed by quenching. It is possible to achieve a high density and a high degree of orientation. In order to suppress the solidification and crystallization of the polymer, it is better that the ambient temperature 1 cm immediately below the spinneret is lower, but from the viewpoint of spinning stability and yarn unevenness, the temperature is preferably 30 ° C to 90 ° C. If the temperature of the atmosphere 1 cm immediately below the spinning mouth exceeds 100 ° C., it is difficult to stably obtain hollow fibers having a hollow ratio of 10% or more and excellent in crush resistance.

As a method of keeping the atmospheric temperature 1 cm directly below the spinneret at 100 ° C. or lower, for example, a method of covering the lower surface except for the discharge surface of the spine with a heat insulating plate having excellent heat insulating properties, or a method of blowing cooling air just below the spinneret A method such as direct spraying is adopted. More preferably, these are combined. Although the shape of the spout is not particularly limited, a triangular shape, a square shape, a square shape, etc. may be mentioned, but it is preferable to use a spout having a C-shaped discharge hole as shown in FIG. . In that case, θ indicating the size of the C-shaped opening is 30 to 120 °, preferably 45 °.
It is preferable from the viewpoint of the form stability of the hollow fiber that can obtain ~ 90 °.

[0019] In addition, the ratio of the diameter φ _A and the thickness W of the spinneret "φ _A /
W "determines the hollow ratio. φ _A / W is preferably in the range of 5 to 20. When the spinning of the C-shaped discharge hole is used, it is desirable to arrange all the openings of the discharge hole in one direction and to blow cooling air toward the openings. By blowing the cooling air toward the opening, it is easy to obtain a uniform hollow fiber. Of course, other than this, a spinner having concentric ejection holes divided into two or more may be used.

The fiber bundle discharged from the spinneret and quenched immediately below the spinneret is taken up, wound up as an undrawn yarn, and drawn by a conventionally known method. At the time of collection, the fiber bundles are bundled, and a known lubrication or pre-entanglement is applied. The winding speed of the undrawn yarn is preferably from 1,000 to 5,000 m / min, and particularly preferably 1500 from the viewpoint of strength development.
３3500 m / min range. Spinning speed 5000
If it exceeds m / min, the crystallization of the molecules proceeds too much in the spinning process, making it difficult to achieve sufficient orientation and stretching in the subsequent stretching, and the yarn diameter unevenness increases. Further, when the spinning speed is less than 1000 m / min, the degree of orientation of the undrawn yarn does not become so high, so that it is difficult to sufficiently orient the molecules in subsequent drawing, and the hollow fiber which is the object of the present invention, which is hard to collapse, is obtained. It becomes difficult.

The hollow fiber of the present invention may be stretched after winding the undrawn yarn once, or may be stretched continuously between two or more godet rolls without winding. The stretching ratio is usually preferably 1.5 to 3.5 times. The stretching ratio varies depending on the winding speed of the undrawn yarn, the cooling temperature, and the yarn type, but it is preferable that the stretching is performed at 70 to 99% of the breaking stretching ratio.

The stretching temperature is in the range of 30 ° C. to 80 ° C., preferably 35 ° C. to 70 ° C., and more preferably 45 ° C. to 60 ° C. When the stretching temperature is lower than 35 ° C., yarn breakage occurs frequently at the time of stretching, and continuous stretching cannot be performed. If the stretching temperature exceeds 80 ° C., the slipperiness with a stretching roll or the like is deteriorated, and single yarn breakage occurs frequently, making stable stretching difficult. The drawn yarn needs to be subjected to a heat treatment. Heat treatment after stretching is 90 ° C to 200 ° C.
C., preferably from 100.degree. C. to 190.degree.
If the heat treatment temperature is lower than 90 ° C., the crystallinity of the fiber cannot be sufficiently increased, and it is difficult to obtain the excellent crush-resistant fiber which is the object of the present invention. If the heat treatment temperature is 200 ° C. or higher, the fibers are likely to break, making it difficult to perform heat treatment continuously.

The polytrimethylene terephthalate hollow fibers of the present invention can be used alone or in combination with other fibers as a fabric. Other fibers to be mixed include polyester, polyamide, cellulose, wool,
Any of cotton, silk, acetate, stretch fiber, etc.
Alternatively, these may be mixed. Examples of the mixing method include a woven fabric used for warp or weft, a woven fabric such as a reversible woven fabric, and a knitted fabric such as tricot and Russell. In addition, twisting, twining, and entanglement may be performed. In particular, the polyester hollow fibers of the present invention exhibit excellent performance when mixed with cellulose fibers. A characteristic feature is that good color developability can be obtained even when mixed with cotton, hemp, rayon, cuprammonium rayon, polynosic and the like as the cellulose fiber and dyed at 100 ° C. or lower.

[0024]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in more detail by way of examples, but the present invention is not limited to the examples. In addition, the main measurement value in an Example was measured by the following method. (1) Intrinsic viscosity [η] Intrinsic viscosity [η] is a value obtained based on the following definition formula.

(Equation 1) Ηr in the definition formula is a value obtained by dividing the viscosity at 35 ° C. of a diluted solution of polytrimethylene terephthalate dissolved in o-chlorophenol having a purity of 98% or more by the viscosity of the solvent itself measured at the same temperature, It is defined as relative viscosity. C is the solute weight value in grams in 100 ml of the solution.

(2) Birefringence (Δn) Using a light microscope and a compensator, the birefringence was determined from the retardation of polarized light observed on the fiber surface. (3) Density The density was measured using a density gradient tube made of carbon tetrachloride and toluene.

(4) Strength and elongation Using Orientec Co., Ltd. Tensilon, yarn length 20 c
m and the tensile speed were 20 cm / min. (5) Hollowness ratio and crush resistance Calculated by the following formula from a cross-sectional photograph of the fiber. Hollow ratio (%) = (cross-sectional area of hollow part / cross-sectional area of fiber) × 1
Further, the crushing of the hollow fibers was evaluated by the hollow ratio of the yarn after knitting into a tubular knit.

(6) Dyeability: exhaustion rate, deep chromaticity (K /
S)｝ The sample is a single-knit knitted fabric of a polyester-based composite fiber, scoured at 70 ° C. for 20 minutes using warm water containing 2 g / liter of score roll 400, dried with a tumbler dryer, and then pin-tentered. At 180 ° C.
The one subjected to heat setting for 30 seconds was used. The exhaustion rate is
After the temperature was raised from 40 ° C. to 110 ° C., the temperature was further maintained for 1 hour, and the evaluation was made based on the exhaustion rate. The dye used was Kayaron Polyester Blue 3RSF (manufactured by Nippon Kayaku Co., Ltd.).
% Owf, bath ratio 1:50. As a dispersant, 0.5 g / liter of Nikka San Salt 7000 (manufactured by Nikka Chemical Co., Ltd.) was used, and 0.25 ml / liter of acetic acid and 1 g / liter of sodium acetate were added to adjust the pH to 5.

The deep chromaticity, which indicates how deep the color was, was evaluated using K / S. This value was obtained by measuring the spectral reflectance R of the sampled cloth after dyeing and using the following Kubelka-Munk equation. K / S = (1−R) ² / 2R The larger this value, the greater the deep color effect, ie,
Indicates that the color is well developed. As R, the value at the maximum absorption wavelength of the dye was used.

Example 1 1,3-propanediol and dimethyl terephthalate were polymerized by a conventional method to obtain a polytrimethylene terephthalate polymer having an intrinsic viscosity [η] of 0.7. At a spinning temperature of 270 ° C., the C-shaped holes (W = 0.08, φ _A = 1.9, θ = 60 °) shown in FIG. Using a spinneret (FIG. 1B) in which the openings of the mold are all arranged in the same direction, the discharge amount is 23.1.
Extruded at g / min. Thickness around the spout other than the discharge surface is 1
The spun yarn was spun from the spinning part shielded by a 6 mm heat insulating plate, and the discharged yarn was cooled while blowing cooling air toward the opening of the C-shaped hole immediately below the spinning hole. At this time, the wind speed of the cooling air blown to the spinning surface was set to 0.4 m / sec, and the ambient temperature 1 cm immediately below the spinning nozzle was adjusted to 70 ° C. The cooled hollow undrawn yarn was bundled together by a bundle guide, and was wound at 1600 m / min to obtain an undrawn yarn. The spinnability was extremely stable without yarn breakage for about 24 hours.

The obtained undrawn yarn is passed through a hot roll 55
, A hot plate at 140 ° C, a stretching ratio of 2.6 times, and a stretching speed of 800 m / min.
A 6-filament drawn yarn was obtained. The hollow fiber has a hollow ratio of 32.
%, Strength 4.2 g / d and elongation 32%. At this time, the density of the hollow fiber was 1.353 g / cm ³ , and Δn was 0.0
66. The hollow ratio after hollow knitting of this hollow fiber was 31%, and it was a fiber that was very hard to collapse. Moreover, the obtained tubular knitted fabric had a very soft feeling. The dye exhaustion at 100 ° C. of the ultrafine multifilament of this example was 86%, and the K / S was 21.5. This result shows that when a multifilament made of polyethylene terephthalate having the same single fiber fineness is dyed at 130 ° C. for 60 minutes, the dye exhaustion rate is 91% and the K / S is 21, so that it is extremely easy to dye and has high coloring properties. Is good.

Examples 2 to 5 and Comparative Examples 1 to 4 Hollow fibers were obtained in the same manner as in Example 1 except that the spinning conditions (winding speed, stretching ratio, heat treatment temperature) were changed. The results are shown in Table 1. Hollow fibers within the scope of the present invention had good crush resistance, sharpness, and softness. On the other hand, hollow fibers out of the range of the present invention could not obtain satisfactory ones such as crushability.

[0032]

[Table 1]

(Comparative Example 5) The temperature of the hot roll was 30 ° C
Polymerization and spinning were carried out in the same manner as in Example 1, except that During drawing, yarn breakage frequently occurred, and fibers could not be obtained continuously. (Comparative Example 6) Polymerization and spinning were carried out in the same manner as in Example 1 except that the temperature of the hot roll was changed to 85 ° C. Single yarn breakage occurs frequently because the yarn is fused to the hot roll during drawing,
The resulting fibers were fluffy.

Comparative Example 7 A hot plate temperature of 21
Polymerization and spinning were performed in the same manner as in Example 1 except that the temperature was set to 0 ° C. The fibers broke at the hot plate and could not be stretched. (Comparative Example 8) Polymerization was carried out from ethylene glycol and dimethyl terephthalate by an ordinary method to obtain a polyethylene terephthalate polymer having an intrinsic viscosity [η] of 0.7. Using this polymer, spinning and stretching were performed in the same manner as in Example 1 to obtain hollow fibers. However, this hollow fiber was easily crushed by tubular knitting.

[0035]

The polyester hollow fiber obtained by the present invention improves the drawbacks of the conventional hollow fiber, is excellent in lightness, heat retention, and easy dyeability, and is hard to be crushed during a post-processing step or wearing clothes, and is soft. It is useful in the sports field, etc., with a good hand.

[Brief description of the drawings]

FIG. 1 (a) shows C in producing the hollow fiber of the present invention.
The top view of an example of a mold discharge hole. (B) is a layout view of an example of a C-shaped discharge hole when producing the hollow fiber of the present invention.

[Explanation of symbols]

W: thickness of the C-shaped discharge hole φ _A : diameter of the C-shaped discharge hole θ: opening angle (°) of the opening of the C-shaped discharge hole

Claims (2)

[Claims] 1. A terephthalic acid is used as an acidic component, and trimethylene glycol is 80 mol% as a glycol component.
It consists of the polyester polymer contained above, has a hollow ratio of 10 to 60%, a density of 1.32 to 1.45 g / cm ³ ,
Polyester hollow fibers having a birefringence (Δn) of 0.05 to 0.08. 2. Terephthalic acid is used as an acidic component, and trimethylene glycol is 80 mol% as a glycol component.
In melt-spinning the polyester polymer contained above, a polyester polymer having an intrinsic viscosity [η] of 0.4 to 1.4 is used, and an atmosphere temperature of 1 cm immediately below the spinneret is set to 100 ° C.
After quenching and winding, stretching is performed below,
A method for producing a polytrimethylene terephthalate hollow fiber, comprising heat-treating at a temperature of ° C.