JPH07238419A - Readily dyeable polyester hollow fiber excellent in color development and gloss - Google Patents

Abstract

PURPOSE:To obtain a readily dyable polyester fiber produced from a specified modified polyester so as to have a specified structure, excellent in color development, gloss, lightweight properties and heat-insulating properties, resistive to collapse of the fiber cross section and useful as a light-weight material, a heat-insulating material, a light and heat-insulating material for general closing and industrial construction. CONSTITUTION:A polyalkylene glycol having 500 to 4000 number-average molecular weight is copolymerized in an amount of 5.0 to 10.0wt.% based on the whole polyester and a modified polyester (having >=0.70 intrinsic viscosity) containing <=0.1wt.% delustering agent is prepared from the resultant copolymer. From the obtained modified polyester, the objective readily dyeable polyester hollow fiber in which the cross section has a circular outer shape and a triangular hollow part in the central part is formed. The thickness (NA) (mum) of the thinnest part of the layer except the hollow part is >=2.1Xd<1/2> when the fineness of the fiber is represented by (d) and the percentage of hollowness of the hollow part is 10 to 5%. This polyester hollow fiber is suitable for combination with wool, formation of union cloth with wool and formation of union knit fabric with wool.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a highly dyeable polyester hollow fiber having good color development and gloss. More specifically, as a lightweight material or heat insulating material or lightweight / heat insulating material for general clothing and industrial equipment construction, it has better color development, gloss and high dyeability than ever before, and is lightweight and excellent in heat retention. The present invention relates to a high-quality polyester hollow fiber whose fiber cross section is hard to be crushed.

[0002]

2. Description of the Related Art Polyester fibers are widely used for general clothing and industrial construction due to their excellent properties such as mechanical properties, chemical properties, easy care and gloss. In particular, recently, a unique product which is not found in other fibers has been developed by applying the excellent properties of polyester fiber. In addition, various performances of higher quality, such as lighter products, textile products with more heat-retaining function or brighter products, in response to diversifying consumer needs and individualized sensitivity needs, It has been demanded.

In order to supplement the functionalities such as low strength, wash and wear properties, pleating properties, insect repellency, and mold proof which are the defects of wool while maintaining the texture and color of wool, the functionality which is the defect of wool is added. It has been practiced to mix excellent polyesters. However, polyester is difficult to dye as compared with wool, and therefore, when it is dyed under the dyeing condition of wool, that is, under normal pressure, the color becomes light and the polyester is not dyed in the same color as wool. On the other hand, when wool is dyed at 130 to 135 ° C. which is the usual dyeing temperature of polyester, the wool and polyester are dyed in the same color, but there is a problem that the texture and strength of the wool are significantly reduced. Therefore, there have been proposed some techniques of polyester which can be dyed at a so-called normal pressure, in which the dyeing temperature is set to a wool dyeing condition, that is, a low temperature.

In order to reduce the dyeing cost, there have been proposed some techniques of polyester which can be dyed under normal pressure or a condition close to normal pressure. For example, JP-A-60-
88190, JP-A-61-34022 and the like disclose the technology of basic dye-dyeable polyester obtained by copolymerizing 5-sodium sulfoisophthalic acid in an amount of 5 mol% or more. However, the polyesters of these techniques have drawbacks such as high dyeability but low yarn strength, hard texture, and low stretchability.

Further, in JP-A-59-59911, JP-A-58-13739, etc., there is disclosed a technique for a dyeable polyester fiber in which the internal structure is changed by a special drawing method or high-speed spinning at 4000 m / min or more. Is disclosed. However, the polyesters of these techniques are more easily dyeable than conventional polyesters, but they are not completely normal pressure dyeable types, and for dyeing deep colors, they are in a so-called pressure state of 110 ° C or higher. Dyeing temperature is required.

Further, Japanese Patent Publication No. 57-25646 and Japanese Patent Publication No. 57-30169 disclose the technique of atmospheric pressure dyeable polyester obtained by copolymerizing polyalkylene oxide.

On the other hand, although it is possible to some extent by increasing the bulkiness of the yarns or devising the structure of the woven or knitted material in order to achieve weight reduction and heat retention, fibers can be further reduced in weight. It is necessary to reduce the weight itself. Hollow fibers, which are apparently lightweight, are used as one of the means.
Hollow fibers have been known for a long time. For example, Japanese Examined Patent Publication (Kokoku) No. 42-2928 discloses a method for producing hollow fibers having a hollow ratio of 50% or less, and many other patent publications disclose hollow fibers and hollow fibers. Is disclosed. For example, in JP-A-55-107510, a polyoxyalkylene glycol having a number average molecular weight of 4000 or more or a derivative thereof is contained in a polyester as an independent phase, and the independent phase is eluted with water or an alkaline aqueous solution to absorb water or sweat. Hollow fiber technology for imparting properties is disclosed. Further, JP-A-3-8806 discloses a technique of a soft antistatic polyester hollow fiber having a number average molecular weight of 6000 or more and an ionic antistatic agent, which is soft and excellent in fibril resistance. It is disclosed. One of the problems with hollow fibers is that a dyed product looks lighter than a solid fiber product having the same yarn, and in particular, a fiber having a high hollow ratio tends to look lighter. Therefore, hollow fibers having high color developability are desired.

As described above, the technique of highly dyeable polyester, the technique of hollow fiber, the technique of using a special polymer for the hollow fiber, etc. are well known. Actually, we have not obtained high-quality polyester hollow fibers that use normal pressure dyeable polyester, have better color development and gloss than before, are lightweight, have excellent heat retention, and have a fiber cross-section that does not easily collapse. Is.

[0009]

SUMMARY OF THE INVENTION As described above, the object of the present invention is to use a polyester hollow fiber and a highly easily dyeable polyester, which has better color development and luster than ever before, and is lightweight and heat-retaining. An object is to provide a high-quality polyester hollow fiber that is excellent and has a fiber cross-section that is not easily crushed.

[0010]

The above-mentioned object of the present invention is to provide a polyalkylene glycol having a number average molecular weight of 500 to 4000 with respect to the total polyester of 5.0 to 10.0.
% By weight, and the intrinsic viscosity (IV) is 0.70 or more,
It is made of a modified polyester with a matting agent content of 0.1% or less, the cross section of the fiber is circular, and the central part of the fiber cross section has a triangular hollow portion, not the hollow portion. The thickness of the thinnest part (NA) satisfies the following formula, and the hollow ratio of the hollow part is 10 to 50%, which is good dyeability with good coloring and luster. This can be achieved with polyester hollow fibers. NA (micron) ≧ 2.1 × d ^1/2 where NA = thickness of the thinnest part in the non-hollow part (micron) d = fineness of fiber (denier)

The present invention will be described in detail below. The highly easily dyeable polyester hollow fiber of the present invention has a number average molecular weight of 500.
〜4000 polyalkylene glycol is copolymerized with 5.0 to 10.0% by weight based on the total polyester, the intrinsic viscosity (IV) is 0.70 or more, and the matting agent content is 0.1%.
It must be formed of a modified polyester consisting of:

The modified polyester used in the present invention is a polyalkylene glycol having a number average molecular weight of 500 to 4000 copolymerized in an amount of 5.0 to 10.0% by weight based on the whole polyester. If a polyalkylene glycol of less than 500 is used, the dye exhaustion rate is lowered and the dyeability becomes poor, which is not good. Further, when a polyalkylene glycol having a number average molecular weight of more than 4000 is used, the light resistance, especially the fastness to discoloration, is unsatisfactory. Therefore, its number average molecular weight is preferably 600 to 3000,
More preferably, it is 800 to 2000.

When the copolymerization amount of the polyalkylene glycol is less than 5.0% by weight, stable high dyeability cannot be imparted, and the amount is required to be 5.0% by weight or more. When it is 6.0% by weight or more, the dyeability under normal pressure can be exhibited, which is preferable. Also,
When the copolymerization amount exceeds 10.0% by weight, the dyeability is sufficient, but the light fastness is poor, which is not good. Therefore, the copolymerization amount is preferably 6.0 to 9.0% by weight.

Examples of the polyalkylene glycol used in the present invention include polyethylene glycol, polypropylene glycol, polytrimethylene glycol and polytetramethylene glycol. Among these, polyethylene glycol is particularly preferable from the viewpoint of the effect of improving color developability.

Further, the modified polyester used in the present invention tends to have a lower resistance to oxidative decomposition as compared with ordinary polyesters, and therefore it is preferable to add an antioxidant, and the hindered antioxidant is used. Phenolic compounds are preferred. Further, the blending amount thereof is 0.05 to polyester based on the balance between oxidative decomposition resistance and spinneret stain.
1.0 wt% is preferable, and 0.1 to 0.5 wt% is more preferable.

The modified polyester used in the present invention is required to have an intrinsic viscosity (IV) of 0.70 or more. When the intrinsic viscosity (IV) is less than 0.70, the strength and elongation of the fiber are lowered, and the fiber is produced. This is not good because many yarn breakages occur during the process and many problems such as fluffing and yarn breakage occur during the fiber product manufacturing process. It is preferably 0.72 or more, but if the intrinsic viscosity is too high, problems due to an increase in discharge pressure during melt spinning tend to occur, so the intrinsic viscosity is preferably less than 0.9.

Further, since the modified polyester used in the present invention cannot contain the desired glossy fiber when a large amount of the matting agent is contained therein, the matting agent of the present invention can be used in an amount of 0.
Use up to 1% by weight of polyester. The matting agent content is preferably 0.07% by weight or less, and more preferably 0.05% by weight or less.

The highly dyeable polyester hollow fiber of the present invention must have a circular cross section. If the outer shape of the cross section of the fiber is extremely irregular, yarn breakage easily occurs during spinning, and yarn breakage or fluffing easily occurs during drawing. The circular shape is most preferably a perfect circle, but is not necessarily a perfect circle and may be a substantially perfect circle. Specifically, the diameter of a circle or an ellipse may change between a long diameter and a short diameter. 10%
In the present invention, the relation between the distance R1 to the point on the outer circumference farthest from the yarn center of gravity and the distance R2 to the point on the outer circumference closest to the yarn center of gravity is [(R1-R2)].
/ R1] × 100 ≦ 10 may be satisfied.

Furthermore, the highly dyeable polyester hollow fiber of the present invention must have a triangular hollow portion at the center of the fiber cross section. That is, it means that the hollow portion does not exist eccentrically. The presence of the hollow portion makes it possible to reduce the weight of the woven or knitted fabric by that amount. Moreover, good gloss can be obtained by forming the hollow portion into a triangular hollow fiber.
The reason why good gloss is obtained is not clear, but when the hollow fiber is exposed to light, most of the light enters the hollow part due to the small amount of the matting agent content, and the light has a triangular shape. It is considered that the inner wall of the hollow portion is reflected again to enhance the gloss, and this is considered to express good gloss.
Further, since the hollow portion is located at the center of the fiber and the hollow portion has a triangular shape, the hollow portion is less likely to be crushed, that is, the hollow ratio is not lowered at the time of stretching and the higher-order processing step. Generally, in the production of hollow fiber and its higher-order processing steps, the hollow fiber is subjected to lateral pressure on the fiber due to the contact pressure with the rollers, frictional force in the guides or other external force It collapses into an elliptical shape or a flat shape and the hollow rate decreases.
This phenomenon is more likely to occur in hollow fibers having a higher hollow ratio. In addition, when the hollow ratio exceeds a certain level, it tends to occur when the outer shape of the fiber and the hollow portion are circular. Further, if the hollow portion is not located at the center of the fiber and is eccentric, that is, if the hollow portion is partially present, it tends to occur. On the other hand, the polyester hollow fiber of the present invention has a triangular hollow portion in the central portion of the fiber cross section as described above, and thus is difficult to be crushed. Regarding the triangular shape of the hollow portion of the highly easily dyeable polyester hollow fiber of the present invention,
This will be described with reference to FIG. Let three apexes of a triangular shape be a, b and c, respectively, and let three sides of a triangle connecting three points be straight lines be ab, bc and ca. Perpendicular line c from point c to side ab
Let d be the intersection with the hollow wall on the extension of the perpendicular cd. A perpendicular line is drawn from the point a and the point b to the side bc and the side ca, respectively, and points f, g, h, and i are determined as shown in the drawing. The hollow portion of the hollow fiber of the present invention has a triangular shape as a whole, preferably an equilateral triangle, but may be a rice ball shape as shown in FIG. 1 and the shape is as follows. (1) The lengths of the line segments ab, bc, and ca on the sides are preferably equal, but may change within 20%. (2) The respective values of the line segment ag / line segment af, the line segment bi / line segment bh, and the line segment ce / line segment cd are preferably in the range of 1.0 to 1.3, more preferably 1.0 to 1.3. It is in the range of 1.2.

The area occupied by the hollow portion in the fiber cross section of the highly dyeable polyester hollow fiber of the present invention, that is, the hollow ratio is 1
It must be in the range of 0 to 50%. When the hollow ratio is less than 10%, the effect of reducing the weight of clothing is small and the effect of retaining heat is small. The warmth of the woven or knitted fabric can be increased to a certain extent by using a structure that contains air between fibers or tissues as described above, but if a structure that contains too much air is used, the air warmed by body temperature will be Convection occurs and heat retention decreases. Since the hollow fiber encloses air in the fiber itself, there is no convection and heat retention can be improved. The higher the hollowness, the greater the effect of weight reduction and the effect of heat retention, which is preferable.However, if the hollowness of the fiber is too high, the fiber cross-section is likely to be crushed in the high-order processing step, and the fiber becomes less Since the hollowness cannot be maintained and the fiber cross section is likely to be crushed even while wearing clothing, the hollowness is 50%.
Must be: It is more preferably from 15 to 40% from the viewpoints of the effect of weight reduction, the effect of heat retention, and the crushability of the fiber cross section during wearing. Further, the wall thickness (NA) of the thinnest portion of the fiber cross section of the highly easily dyeable polyester hollow fiber of the present invention needs to satisfy the following formula. NA (micron) ≧ 2.1 × [fiber fineness (denier)] ^1/2 For example, in the case of 3 denier fiber, it is necessary that it is 3.6 microns or more. The wall thickness means the length of the fiber upper portion in the line segment connecting the center of gravity of the hollow fiber and the fiber surface. The wall thickness of the non-hollow part is determined by the fineness of the hollow fiber, the hollow ratio and the shape of the hollow part, but in any case, it is necessary to prevent the collapse of the fiber cross section by the wall thickness satisfying the above formula. .

Further, in the highly dyeable polyester hollow fiber of the present invention, the presence or absence of fluff at the stage of the raw yarn, that is, the fluff of the yarn which is drawn and wound, is greatly related to the quality of the high-order processability. The effect is greater than that of conventional polyester fiber. Therefore, the number of fluffs of the wound thread is 0.20 / 10,000 m
The number is preferably below, more preferably 0.10 pieces / 10,000 m or less, still more preferably 0.05 pieces / 10,000 m or less. In the highly easily dyeable polyester hollow fiber of the present invention, for example, polyethylene glycol having a number average molecular weight of 1200 as polyalkylene glycol is used in the polyester production step (direct polymerization) to be 5.0 to 10.0.
The polyester obtained by adding in the range of wt% (the content of the matting agent is, for example, 0.05 wt%) is shown in FIG. 2a.
Is obtained by melt spinning from a die having a three-slit type polymer discharge hole, applying an oil agent to obtain an unstretched yarn, and temporarily winding the unstretched yarn or continuously stretching it. At this time, in the forced cooling of the melt-spun yarn, it is preferable to start blowing the cooling air at a distance of 3 to 15 cm below the surface of the spinneret in order to reduce the variation in hollow ratio. Further, at the time of stretching, a method of using a hot roll-hot roll type stretching machine, preheating to 75 to 100 ° C. with the first hot roll, and stretching with the second hot roll reduces the generation of fluff. Preferred for. The temperature of the second hot roll may be appropriately set so as to match the target shrinkage characteristic of the yarn to be obtained. The cross section of the resulting fiber is almost equivalent to that shown in Figure 3a.

The method of producing the modified polyester used in the present invention is not particularly limited, but a method of producing by a direct polymerization method is preferable in view of reduction of production cost and quality stability between production lots.

The highly dyeable polyester hollow fiber of the present invention can be utilized as a material for clothing, a material for interior products, a material for vehicle interiors or a material for bedding. In particular, it is particularly preferable and effective to be applied as a mixed fiber with wool, a woven fabric with wool, and a knitted fabric with wool from the viewpoint of dyeability under normal pressure.

As described above, by containing a specific amount of a polyalkylene glycol having a specific number average molecular weight and a delusterant consisting of a modified polyester in a specific amount or less, and by using a specialized hollow fiber, It is possible to provide a high-quality polyester hollow fiber which has a good color developability and good luster that conventional hollow fibers do not have, is lightweight, has excellent heat retention, and has a fiber cross-section that does not easily collapse.

[0025]

The present invention will be described in more detail with reference to the following examples. The physical properties in the examples were measured as follows.

A. Hollow ratio 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
00

B. Coloring property The sample yarn was knitted on a tubular knitting machine with a 27-gauge tubular knitting machine, boiled and scoured by a conventional method, washed with water, dried, dyed under the following conditions, reduced and washed by a conventional method, washed with water, and dried. After that, seven tubular knitted fabrics dyed with an SM color computer (manufactured by Suga Test Instruments Co., Ltd.) were overlaid and the L value was measured and used as an index of color developability. The darker the L value, the smaller the value and the greater the color developability. <Dyeing conditions> Dianix Black BG-FS 10% owf (disperse dye manufactured by Mitsubishi Kasei Co., Ltd.) Nikkasan Salt # 1200 0.5 g / l (manufactured by Nichika Chemical Industry Co., Ltd.) in an aqueous solution of a dyeing bath PH 6. Dyeing was carried out at a bath ratio of 1:50 at 98 ° C. for 60 minutes.

C. Intrinsic Viscosity (IV) 0.8 g of a sample that has been thoroughly washed to remove oils and the like and sufficiently dried is dissolved in 10 cc of orthochlorophenol,
It measured at 25 degreeC with the Ostwald viscometer.

D. Light resistance (fastness to light) A fade meter was used to visually irradiate carbon arc light for 10 hours to perform photobleaching, and the degree of fading was visually judged. Grades with almost no discoloration were classified as grade 5, and grades with extremely discolored color were classified as grade 1, and displayed in 5 levels.

E. Glossiness The standard value was adjusted using a magnesium oxide standard gloss plate under the conditions of 45 ° irradiation and 44 ° light reception using an automatic colorimetric color difference meter manufactured by Suga Test Instruments, and then the fiber axis was applied to the sample yarn wound on the aluminum plate. The glossiness was measured by irradiating and receiving light in the direction.

F. Using a multi-fly counter type F of Toray Engineering Co., Ltd., five drawn yarns were run at about 400 m / min to measure 50,000 m each, and the number of fluff was calculated from the total number counted. Number of fluff (pieces / 10,000 m) = (total count / 250,000 m) ×
10,000

Example 1 Polyethylene glycol having a number average molecular weight of 1000 (P
EG) was added in the production process of polyester by direct polymerization of terephthalic acid and ethylene glycol by changing the weight% relative to the total polyester to obtain 5 levels of modified polyester (matting agent (titanium dioxide) content Is 0.0
5% by weight, intrinsic viscosity adjusted to 0.74)
2 at the spinning temperature of 285 ° C.
After discharging from the four caps, cooling is performed by applying cooling air at a speed of 30 m / min at a position 8 cm below the surface of the cap, and a highly smooth oil agent is controlled so that the oil adhesion amount becomes 1.1%. After being applied, it was wound at a spinning speed of 1650 m / min.

The obtained undrawn yarn is preheated by a hot roll-hot roll type drawing machine with the first hot roll set to 88 ° C. and the drawn yarn elongation between the second hot roll and the hot roll is 35.
While being drawn at a draw ratio of ± 2%, heat treatment was performed at a second hot roll temperature of 145 ° C. and a 75 denier 24 filament hollow fiber yarn was wound at a winding speed of 800 m / min. The obtained yarn was knitted into a tubular knitted fabric and dyed black. The cross section of the obtained fiber was the same as that of FIG. 3a, and the hollow portion was triangular and the center portion of the fiber was present. The thickness of the non-hollow portion was 4.6 μm in the thinnest portion. The number of fluffs of the obtained fiber yarn was 0.10 pieces / 10,000 m or less at all levels.

The hollowness of the obtained fiber was in the range of 20 to 23%. Table 1 shows the evaluation results of the glossiness of the obtained yarn and the color developability of the obtained tubular knitted fabric.

[0035]

[Table 1] Experiment No. of the present invention. The fibers of Nos. 2 to 4 had good glossiness of 70% or more, and the knitted fabric had a good dye exhaustion rate under normal pressure, and thus had good color developability (small L value). The light resistance was also good. Experiment No. The fiber of No. 1 (Comparative Example) had a poor coloring property due to a small amount of PEG. Experiment No. The fiber of No. 5 (Comparative Example) had a poor light resistance due to the large amount of PEG, and had many yarn breakages during spinning, resulting in poor spinnability. Intrinsic viscosity of fiber (I
V) was in the range of 0.71 to 0.73 at all levels.

Example 2 Experiment No. 1 of Example 1 A hollow fiber yarn having a changed hollow ratio was obtained in the same manner as in Example 1, except that the polymer of Example 3 was used and the die having the inner diameter of the slit arranged in a ring shape at the die discharge hole of FIG. 2a was changed. . The number of fluffs of the obtained yarn is 0.
The number was 10 pieces / 10,000 m or less. Further, the thickness of the thinnest portion in the non-hollow portion is in the range of 3.4 to 6.0 μm, and the experiment No. No. 11 has a diameter of 3.7 μm, and the experiment No. 12 was the thinnest at 3.4 microns. The results of evaluation of the obtained hollow fiber yarn according to Example 1 are shown in Table 2.

[0037]

[Table 2] Experiment No. The knitted fabric of No. 6 (Comparative Example) had a small hollow ratio and a small effect of lightness, and was not much different from the ordinary round cross-section yarn. Experiment N
o. In the knitted fabric of No. 10 (Comparative Example), the fibers were often crushed during knitting, and the hollow ratio of the knitted fabric was small. In addition, the thickness (micron) of the thinnest part of the non-hollow part is less than 2.1 × 3 ^1/2 = 3.6 (micron), and the crushing degree of the fiber is frequent and the crushing degree is high. It was great. The color developability was good at all levels, and the light resistance was good at grade 4 or higher.

Experiment No. 1 of the present invention is advantageous in terms of lightness and shape retention of the fiber cross section in post-processing. The 7, 8 and 9 fibers can be effectively utilized.

Example 3 According to the same manner as in Example 1 except that the polymer of Example 2 was used and the die having the die discharge holes of FIGS. 2b and 2c was used, a hollow fiber yarn having a modified fiber cross section was obtained. evaluated. The cross section of the obtained fiber is shown in FIGS. 3b and 3c. The experimental results are shown in Experiment No. 1 of Example 1. The results are shown in Table 3 in comparison with No. 3.

A hollow fiber yarn having a trilobal outer shape as shown in Fig. 3b (Experiment No. 11 (comparative example), hollow ratio 15.2%)
The number of yarn breakages during spinning was 16 times per ton, the number of fluffs during stretching was 3.8 k / 10,000 m, and the yarn breakage rate was 13
It was as high as%.

The hollow fiber yarn having the eccentric hollow portion shown in FIG. 3c (Experiment No. 12 (comparative example)) has a hollow ratio of 20.
Although it was 5%, the change in the cross section was large when the knitted fabric was formed, and the fibers were crushed, and the hollow ratio was lowered to 13.2%.

[0042]

[Table 3] Example 4 According to Example 1, except that the polymer of Example 2 was used, the die having the die discharge holes of FIGS. 2a and 2d was used, and the hollow rate was adjusted to about 35%, the shapes of the hollow portions of the fibers were compared. The obtained hollow fiber yarn was obtained and evaluated. The cross section of the resulting fiber is shown in Figure 3a,
It is equivalent to that shown in FIG. 3d. The experimental results are shown in Table 4.

The hollow fiber yarn in which the shape of the hollow portion shown in FIG. 3d is almost perfect (Experiment No. 14 (Comparative Example)) had a hollow ratio of 36.1%, but the change in cross section when formed into a knitted fabric. Was large and the fibers were crushed, and the hollow ratio was reduced to 26.2%. In the knitted fabric, streak-like unevenness was generated in the crushed portion of the fiber, and the quality of the knitted fabric was extremely poor.

The hollow fiber yarn (experiment No. 13 (invention)) having a substantially hollow shape shown in FIG. 3a had a hollow ratio of 35.2%, but the fiber collapsed even when knitted. The hollow ratio was almost 33.8% and the quality of the woven fabric was good.

[0045]

[Table 4] Example 5 Modified polyester obtained by adding four kinds of polyalkylene glycol shown in Table 5 to 7.5% by weight based on the total polyester (the content of the matting agent (titanium dioxide) is 0.05% by weight). %), Hollow fiber yarns were obtained and evaluated in the same manner as in Example 1. The hollowness of the obtained fiber was in the range of 20 to 23%. The evaluation results are shown in Table 5.

[0046]

[Table 5] Experiment No. The fiber of No. 15 (Comparative Example) was poor in color developability because the molecular weight of polyethylene glycol was small and the dye exhaustion rate was drastically reduced. In addition, due to the low molecular weight, the amount of polyethylene glycol scattered out of the system during polymerization was large and the amount of polyethylene glycol was poorly adjusted, resulting in uneven dyeing on the tubular knitted fabric.

Experiment No. In the fiber of No. 20 (Comparative Example), the molecular weight of polyethylene glycol was large and the dye exhaustion rate was drastically reduced, and the color development was poor, and the light resistance was extremely poor.

Experiment No. of the present invention. 16, 17, 18, 1
The fibers of 9, 21, 22, and 23 were good in both color development and light resistance. Among them, the level of addition of polyethylene glycol was better than those of other polyalkylene glycols added. Example 6 The experiment No. 1 of Example 1 was used. The intrinsic viscosity (IV) is changed by changing the conditions at the time of polymerization with the polyester composition of 3,
Hollow fiber yarn was obtained and evaluated according to Example 1 except that the spinning temperature was changed so that melt spinning could be normally performed. The evaluation results are shown in Table 6.

[0049]

[Table 6] Experiment No. 1 having a low intrinsic viscosity (IV). No. 24 had many yarn breakages during spinning and poor drawability, and had a large number of filament fluffs of 3.8 pieces / 10,000 m. Moreover, the hollow rate was slightly low. Experiment No. Nos. 25 to 27 had no significant problems in hollow ratio and yarn formability, but Experiment No. No. 27, which has a high melt viscosity during spinning, is difficult to spin for a long time and is not preferable in production. The other properties such as color developability and light resistance were all satisfactory.

[0050]

As described above, in the highly dyeable polyester hollow fiber of the present invention, the polyalkylene glycol is copolymerized in a specific amount so that the intrinsic viscosity becomes a specific value or more, and the matting agent becomes a specific amount or less. Made of high quality polyester and made into a specialized hollow fiber, it has good color development and good gloss that conventional hollow fibers do not have, is lightweight and has excellent heat retention, and the fiber cross section is difficult to collapse. A high-quality polyester hollow fiber can be provided.

The highly dyeable polyester hollow fiber of the present invention can be utilized as a material for clothing, a material for interior products, a material for vehicle interiors or a material for bedding. In particular, it is particularly preferable and effective to be applied as a mixed fiber with wool, a woven fabric with wool, and a knitted fabric with wool from the viewpoint of dyeability under normal pressure.

[Brief description of drawings]

FIG. 1 is a model diagram for explaining the shape of the hollow portion of the polyester hollow fiber of the present invention.

FIG. 2 is a schematic view of discharge holes of a spinneret when producing the polyester hollow fiber of the present invention.

3 is a cross-sectional view of a fiber manufactured from the die of FIG.

[Explanation of symbols]

a: Triangular apex of hollow fiber hollow part b: Triangular apex of hollow fiber hollow part c: Triangular apex of hollow fiber hollow part d: Subtraction from point c to side ab of the above triangle An intersection of a vertical line and side ab h: An intersection of a vertical line drawn from point b to side a of the above triangle and side ac f: A vertical line drawn from point a to side b of the above triangle and side bc E: intersection of the extension line of the above-mentioned triangle line segment cd and the hollow wall g: intersection of the above-mentioned triangle line segment af and the hollow wall i: extension line of the above-mentioned triangle line segment bh and the hollow wall Intersection with

Claims (1)

[Claims] 1. A polyalkylene glycol having a number average molecular weight of 500 to 4000, based on the total polyester, of 5.0 to
10.0% by weight is copolymerized and the intrinsic viscosity (IV) is 0.70.
As described above, the polyester is formed of a modified polyester having a matting agent content of 0.1% or less, the cross-section of the fiber has a circular outer shape, and the central portion of the fiber has a triangular hollow portion,
Thickness of the thinnest part (NA) of the part that is not hollow
Is a highly dyeable polyester hollow fiber having good colorability and gloss, wherein the hollow part has a hollowness of 10 to 50%. NA (micron) ≧ 2.1 × d ^1/2 where NA = thickness of the thinnest part in the non-hollow part (micron) d = fineness of fiber (denier)