JPH0995816A - Production of polyester fiber suitable for hard twisting excellent in deep dyeing property - Google Patents

Abstract

PROBLEM TO BE SOLVED: To produce a polyester raw yarn, excellent in deep color properties, good in creping properties and suitable for hard twisting by utilizing high-draft spinning. SOLUTION: The spinning draft when extruding a polyester through discharge holes is regulated to at least >=5,000 and drawing and heat-treating conditions are regulated so as to provide >=1.5g/de and <3.5g/de stress at 10% elongation of polyester fibers, >=0.20g/de thermal stress thereof and <=10% shrinkage factor in boiling water in production of the polyester fibers by melting the polyester, extruding the molten polyester through the discharge holes, cooling and solidifying the extruded yarn, then applying an oil to the resultant yarn, taking off the oiled yarn and subsequently drawing and heat-treating the yarn.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a polyester fiber suitable for strong twisting, and more specifically, it has excellent dark color properties, for example, when a strong twist is made into a weft of a woven fabric using a new synthetic fiber. The present invention relates to a method for producing a polyester fiber excellent in dark color and suitable for strong twisting, which is capable of obtaining a high-quality textured woven or knitted fabric with no color difference from the new synthetic fiber.

[0002]

2. Description of the Related Art A textured woven or knitted fabric using strong twisted yarn is used in various fields in the field of Japanese clothes and Western clothes because of its unique characteristics in the texture and appearance of the product. In order to develop good grain, it is necessary to maximize the latent untwisting torque of the strongly twisted yarn in the fabric. In order to achieve this, the contraction rate of the fiber is reduced as much as possible, the restraining force of the warp and the weft in the fabric is reduced, the tension of the amorphous part is increased in the fiber structure, and the density of the amorphous part is increased. Is generally used to increase the thermal stress. As such prior art, there are Japanese Patent Publication No. 51-23619 and Japanese Patent Publication No. 56-8140. According to these technologies,
Although a fabric having good texture can be obtained, there is room for improvement from the viewpoint of dark colorability during dyeing. That is, according to these techniques, the obtained polyester fiber has high crystallinity, and the structure of the amorphous part thereof has a high tension state and the density thereof is also high, so that the disperse dye can be sufficiently incorporated. However, the dyeability was inferior.

Fibers having high crystallinity and excellent dyeability are drawn at a high spinning speed of 3,500 to 4,500 m / min, then drawn and then wound at a speed of about 6,000 m / min. Directly without adding a method or stretching operation,
It can be obtained by utilizing so-called high-speed spinning, which winds at a speed of 5,000 m / min or more. However, in this case, since the structure of the amorphous portion of the obtained fiber is loose, the value of thermal stress is small, and it is not possible to obtain a fabric excellent in wrinkle rising. On the other hand, when the above-mentioned direct-spinning spinning speed is decreased, the value of thermal stress increases, but on the other hand, the dyeability is deteriorated and it is not possible to achieve both.

On the other hand, various attempts have been made to manufacture a raw yarn for strong twist by changing the drawing operation method itself. Japanese Patent Laid-Open No. 59-71414 proposes an energy-saving manufacturing method by changing the stretching operation to a conventional heating roller system and passing a heating zone provided between the rollers. However, also in this case, the thermal stress was not sufficiently high and the wrinkle rising property was not sufficient.
As described above, in the conventional fiber forming technology, there has not been a technology that achieves both dyeability and graininess. Since a method for improving this is difficult with ordinary polymers, various modified polymers, for example, a method for imparting fine irregularities to the fiber surface after alkali reduction is typical. However, in this case, the fine unevenness was abraded in the dyeing process, so-called "atari" was generated, and there was room for improvement.

[0005]

DISCLOSURE OF THE INVENTION The present invention solves the above problems and provides a yarn capable of obtaining a fabric excellent in dyeability, high in thermal stress and excellent in wrinkle rising. It is an object of the present invention to provide a new method for producing a strong twisting raw yarn, which goes beyond the conventional concept.

[0006]

In order to solve the above problems, the inventors of the present invention have made earnest studies from the viewpoint of fiber forming technology, and as a result, the fibers have a relatively uniform distribution of molecular chains in terms of fiber structure. It has been considered that the object of the present invention can be achieved by obtaining a structure, especially when the structure has a structure in which the degree of tension of the molecular chain of the amorphous portion is not so high, but the distribution thereof is relatively uniform. That is, the low degree of tension of the molecular chain in the amorphous portion is effective in increasing the dyeability and is disadvantageous in terms of increasing the thermal stress.

However, from the viewpoint of the concept of distribution of molecular chains, the tension of the molecular chains as an average value is not so high, but if the structure has a relatively uniform distribution, thermal stress Even thought that you could get a high one. In order to take such a fiber structure, as a result of deeply studying the fiber forming technology for its spinning and drawing,
It has been found that the spinning process, especially during fiber formation, ie the process from melting to solidification of the polymer, has a significant effect. That is, it was concluded that in this process, a fiber forming technique for increasing elongational viscosity and elongational stress is important. Furthermore, as a result of deep investigations, it was reached the present invention that the object of the present invention can be achieved when the spinning draft at the time of extrusion from the discharge hole is set to a certain value or more.

That is, according to the present invention, in the production of polyester fiber in which polyester is melted and extruded through a discharge hole, cooled and solidified, an oil agent is applied and then taken out, and then drawing heat treatment is performed, at least a spinning draft at the time of extruding through the discharge hole 5,000 or more, and the stress at 10% elongation of the polyester fiber (hereinafter also referred to as "10% elongation stress") during the drawing heat treatment is 1.5 g / de or more and 3.5 g / de or more.
In the method for producing a polyester fiber having excellent dark color and suitable for strong twist, the stretching heat treatment condition is such that the heat stress is 0.20 g / de or more and the boiling water shrinkage is 10% or less. is there.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described in detail below.
In the present invention, first, the spinning draft when extruding from the discharge hole is at least 5,000 or more, preferably 8,
000 or more, more preferably 10,000 or more. When the spinning draft is less than 5,000, the molten polymer cannot sufficiently increase the extensional viscosity and the extensional stress during the solidification process, and the desired fiber structure cannot be obtained. That is, when the extensional viscosity and the extensional stress are sufficiently increased, rapid deformation occurs from the melting process to the thinning process, and at that time, uniform alignment of molecular chains occurs. If the spinning draft is less than 5,000,
For example, the spinning temperature can be lowered, and the extensional viscosity can be increased by using a polymer having a high melt viscosity. However, since the spinning stress cannot be sufficiently increased due to the low spinning stress, stretching and drawing of the molten polymer can be performed. Does not work well, and does not have the desired structure. At this time, the so-called
It becomes a fiber such as'weak yarn 'which has low strength and elongation and inferior mechanical properties. Moreover, many yarn breakages occur during spinning,
It is not preferable in terms of production technology. The spinning draft is 5,
When it is 000 or more, a higher value gives a preferable result, but when it exceeds 300,000, the number of yarn breakages during spinning increases, so it is preferable to suppress it to 300,000 or less.
It is preferable from the viewpoint of production technology.

Next, in the fiber drawn at a spinning draft of 5,000 or more, the 10% elongation stress of the polyester fiber obtained in the drawing heat treatment step is 1.5 g / de or more and less than 3.5 g / de, The thermal stress is preferably 2.0 g / de or more and less than 3.5 g / de and the thermal stress is 0.20 g / de
It is important to carry out a stretching heat treatment so that the boiling water shrinkage rate is not less than de and not more than 10%. When the 10% elongation stress of the polyester fiber is less than 1.5 g / de, the polyester fiber obtained has too low a tension of the molecular chain of the amorphous part and the dyeability is good, but the thermal stress value is sufficiently large. In addition, the texture obtained from the fiber becomes unsatisfactory in terms of graininess, which is not preferable. On the other hand, when the 10% elongation stress of the polyester fiber is 3.5 g / de or more, the polyester fiber obtained has too high a tension of the molecular chain of the amorphous part, and the fabric obtained from the fiber has a good wrinkle rising property. However, it is not preferable because the dyeability is insufficient.

The thermal stress must be 0.20 g / de or more, preferably 0.23 g / de or more. When the thermal stress is less than 0.20 g / de, the latent untwisting torque when the strong twisted yarn is made small, and a fabric having good wrinkle rising cannot be obtained, which is not preferable. However, if the thermal stress becomes too large, the shrinkage rate of boiling water tends to become large, so it is preferable to stop at about 0.8 g / de at most. Further, it is necessary to perform heat treatment in the stretching heat treatment step so that the boiling water shrinkage rate of the polyester fiber is 10% or less. This has a boiling water shrinkage of 10%
When a fiber having a number of more than 10 is used as a fabric, the binding force between the warp and the weft becomes large, and the potential of the potential untwisting torque cannot be sufficiently exhibited, and as a result, a fabric having good wrinkle rising cannot be obtained, which is preferable. Absent. However, when the polyester fiber does not shrink at all in boiling water or causes self-expansion (that is, when the shrinkage rate of boiling water is 0% or less), untwisting torque cannot be expressed, which is not preferable.

In the present invention, the polyester is preferably polyethylene terephthalate, but may be a polyester obtained by copolymerizing and / or blending other components within a range not impairing the characteristics thereof. Examples of the copolymerization component include dibasic acids such as isophthalic acid and 5-sodium sulfoisophthalic acid, and glycols such as propylene glycol and butylene glycol. The blend may contain various inorganic substances and various organic / inorganic pore forming agents that form fine irregularities or streaky morphology on the fiber surface by alkali weight loss. The intrinsic viscosity of the polyester used in the present invention is not particularly limited, but since it is a clothing material, it is often used in the range of 0.50 to 0.75.

The shape of the discharge hole used in the present invention is not particularly limited, and various shapes can be used, but in the case where the spinning draft exceeds 10,000, the shape is such that the cross-sectional area continuously expands. Gives particularly favorable results. Further, as the apparatus used for the stretching heat treatment of the present invention, a conventionally existing apparatus can be used. Further, in the present invention, other fibers are present in the polyester fiber,
It may be a so-called spun mixed fiber. The spun mixed fiber may be a different polymer cospan in which another polymer is present.

Polyester fiber having the above characteristics,
Apply strong twist. The degree of strong twist generally depends on the target quality of the woven fabric and the fineness (denier) of the filaments constituting the polyester fiber, but is usually 2,000 to
A twist of about 4,000 turns / m is sufficient. In addition, prior to the strong twist, gluing the polyester fiber in advance may be adopted. As the sizing agent, a starch-based, polyvinyl alcohol-based, or acrylic-based sizing agent that is easily desized with warm water is preferable. The strongly twisted polyester fiber is then treated with dry heat and wet heat at 70 to 130 ° C. to make the twisting torque latent.

The strongly twisted and textured polyester fiber for knitting and knitting produced as described above is used for weaving as warp and / or weft. The cloth after weaving is dipped in hot water according to a conventional method and is embossed. By such an operation, an excellent textured fabric can be obtained. When applied to a knitted product, a product having an excellent appearance and touch can be obtained. Also, the quality of the texture after weaving can be judged after actually making the cloth, but the manifestation torque at the fiber stage (particularly the torque when untwisting the strong twist in boiling water) is
It has a strong correlation with the appearance of wrinkles in the fabric. That is, when the value of the untwisting torque in the boiling water of the twisted polyester fiber is large, the cloth has excellent wrinkles. The polyester fiber obtained by the method of the present invention has a large value of the untwisting torque of the twisted polyester fiber in boiling water, and
Since it has the remarkable property of high darkness during dyeing,
It has an advantage that its characteristics can be easily determined.

[0016]

EXAMPLES The present invention will be described in more detail with reference to examples. The measurement values used in the present invention were measured by the following method. (1) Intrinsic Viscosity [η] Polyethylene terephthalate was dissolved in o-chlorophenol and measured at a temperature of 35 ° C. by an Ubbelohde viscometer by a conventional method. (2) Spinning draft It was calculated from the ratio (V ₂ / V ₁ ) of the average extrusion speed V ₁ of the molten polyester extruded from the discharge hole of the spinneret and the take-up speed V ₂ of the polyester fiber.

(3) Strength and Elongation of Polyester Fiber Tensilon (UTM-III) manufactured by Toyo Sokki Co., Ltd. is used,
The stress (g) -elongation (%) curve of the polyester fiber was obtained at room temperature, and the value obtained by dividing the maximum stress (g) by the fineness (denier) of the polyester fiber was taken as the strength (g / de). The elongation at the point of maximum stress was taken as the elongation (%). (4) 10% elongation stress of polyester fiber Elongation 10 in the above stress (g) -elongation (%) curve
The value obtained by dividing the stress (g) at the% point by the fineness (denier) of the polyester fiber was taken as 10% elongation stress (g / de).

(5) Shrinkage rate of boiling water (BWS) (%) The polyester fiber was treated in boiling water for 30 minutes under no load, and the change in length before and after the treatment was calculated from the following formula. (BWS) (%) = [(L ₀ −L ₁ ) / L ₀ ] × 100 where L ₀ : length before processing L ₁ : length after processing

(6) Thermal stress (T _MAX , F _MAX ) Thermal stress manufactured by Kanebo Engineering Co., Ltd. is measured at a temperature rising rate of 300 ° C./120 seconds, and the temperature at which the stress (F) is maximum is measured. _{Was set} as T _MAX . Further, F _MAX was calculated from the following formula. F _MAX (g / de) = maximum stress (g) / {2 × fineness (de)} The measurement was performed twice, and the average value was obtained.

(7) Boiling water torque (T / m) Twisting of 2500 times / m was applied to the multifilament, and twist setting was performed for 30 minutes in the dry heat of 85 ° C. Collected and 5mg / d in the center
After applying the load of e, put both ends together and put in boiling water for 30
After soaking for a minute, it was dried and the number of double twists (T / 50 cm) generated at this time was determined, and the value was converted to a value of 1 m. The boiling water torque (T / m) value is preferably 700 or more.

(6) Dark-colored multifilament is tubularly knitted, and
Stained at 60 ° C for 60 minutes. Dyeing conditions Dye Eastman Polyester B
lue GLF Dye concentration 4% owf Bath ratio 1/100 Dispersant Disper VG (manufactured by Meisei Chemical Co., Ltd.)
5g / 1 Acetic acid 0.2g / 1

Subsequently, bisphenol [manufactured by Yatasha Yushi Kogyo Co., Ltd.] in an aqueous solution of 2 g / l at 80.degree.
It was subjected to reduction cleaning treatment for minutes, washed with water and dried. The obtained dyed tubular knitting was set in a dry heat of 170 ° C. for 1 minute to obtain a measurement sample. This sample is quadrupled and Macbeth MS202
L ^* was measured with a 0 spectrophotometer. The value of L ^* is 26.
When it was less than 0, it was determined to have dark color.

Examples 1-5, Comparative Examples 1-7 Polyethylene terephthalate having an intrinsic viscosity [η] of 0.64 and containing 0.07% by weight of titanium oxide as a delustering agent was melted at 300 ° C. After extruding from a spinneret in which 16 circular holes each having a hole diameter of 10φ (mm) at a discharge portion, which are continuously expanded, are extruded, and after cooling and solidifying, an oil agent is applied,
After the first roller heated to a surface temperature of 120 ° C turned 8 times, the second roller heated to a surface temperature of 190 ° C turned 8 times to draw and heat-treat, and then wound, 64 denier / 16 filament To obtain polyethylene terephthalate multifilament. At this time, the second
The peripheral speed of the roller was changed to prepare polyethylene terephthalate multifilaments having different elongations. Table 1 shows the results
(Comparative Examples 1-2, Examples 1-5).

On the other hand, a round hole 1 having a hole diameter of 0.40 φ (mm)
A polyethylene terephthalate multifilament was prepared in the same manner by using 6 spinnerets arranged. In this case, the surface temperature of the first roller was initially 120 ° C., but since the yarn swayed on the roller was large and winding could not be performed, it was carried out at 100 ° C. The results are also shown in Table 1 (Comparative Examples 3 to 7). In addition, Table 2 shows the yarn characteristics and dyeing results (dark color) of the obtained polyethylene terephthalate multifilament.

[0025]

[Table 1]

[0026]

[Table 2]

In the case of Examples 1 to 5, which reflects the characteristics of the present invention, it was found that they were high twist raw yarns having a high boiling water torque and an excellent wrinkle rising property. The result was excellent in dark color. In contrast, Comparative Example 1
Had extremely good dark colorability, but the thermal stress was too low, and as a result, the thermal stress value did not increase and the boiling water torque value decreased, which was not preferable. In Comparative Example 2, the 10% elongation stress was too high and the dyeability was insufficient, and Comparative Examples 3 to
No. 5 had some dyeability, but the value of boiling water torque was small, which was not preferable. In Comparative Examples 6 to 7, the value of the boiling water torque was increased to some extent, but the dyeability was deteriorated, which was not preferable.

Examples 6 to 11 and Comparative Examples 8 to 10 Using spinnerets having various changes in the hole diameter of round holes, 64 denier / in the same manner as in Examples 1 to 5 and Comparative Examples 1 to 7.
A 16-filament polyethylene terephthalate multifilament was obtained. The results are shown in Table 3. Yarn characteristics of the obtained polyethylene terephthalate multifilament
Table 4 shows the staining results (dark color).

[0029]

[Table 3]

[0030]

[Table 4]

Examples 6 to 11 were excellent in the desired dark coloration, had a high boiling water torque, and had characteristics suitable for a strong twist woven fabric. On the other hand, Comparative Examples 8 to 10 had a low spinning draft, and did not have characteristics capable of satisfying both dark color properties and boiling water torque.

Examples 12 to 16 and Comparative Examples 11 to 12 64 denier / 1 in the same manner as in Example 3 except that the surface temperature of the second roller was changed under the conditions of Example 3.
A 6-filament polyethylene terephthalate multifilament was obtained. Table 5 shows the results. Table 6 shows the yarn characteristics and dyeing result (dark color) of the obtained polyethylene terephthalate multifilament.

[0033]

[Table 5]

[0034]

[Table 6]

Examples 12 to 16 had the characteristic that both dark color and boiling water torque were compatible. On the other hand, Comparative Examples 11 to 1
Sample No. 2 had a high boiling water shrinkage ratio and a low thermal stress, and thus had a low boiling water torque.

[0036]

EFFECTS OF THE INVENTION The conventional polyester fiber for strong twist has a problem in its dyeability (dark color) because it is manufactured by a method in which heat treatment is strengthened. Therefore, dyeability (dark color)
In order to improve the above, polyester having unevenness on the surface is used, but its use is limited due to'attari 'in the dyeing process.

The polymer used in the present invention does not necessarily require a modified polymer, and even when it is used, the addition amount of the pore-forming agent that forms the fine irregularities can be greatly reduced, so that the attrition There is no problem with the problem of saying '. The present invention solves the above problems, provides a raw yarn that is excellent in dyeability, and can obtain a fabric having high heat stress and excellent wrinkle rising property, which is beyond the conventional concept. It is possible to provide a new method for producing a yarn for strong twist, and its industrial significance is extremely great.

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Toshimasa Kuroda 3-4-1, Amihara, Ibaraki-shi, Osaka Teijin Limited Osaka Research Center

Claims (1)

[Claims] 1. In the production of polyester fiber in which polyester is melted, extruded from a discharge hole, cooled and solidified, an oil agent is applied and then taken out, and then drawn and heat treated, a spinning draft at the time of extruding from the discharge hole is at least 5,000 or more. And, during the stretching heat treatment, 10% of the polyester fiber
% Stretching stress is 1.5 g / de or more and less than 3.5 g / de, the thermal stress is 0.20 g / de or more, and the boiling water shrinkage is 10% or less. A method for producing a polyester fiber excellent in color and suitable for strong twisting.