JPS60194114A - Polyester fiber dyeable under normal pressure - Google Patents

Abstract

PURPOSE:To provide the titled fiber composed of polyethylene terephthalate, having flat cross-section, exhibiting X-shaped 4-spots interference pattern in small-angle X-ray scattering, having specific birefringence and specific flatness of the cross-section, and having excellent color fastness. CONSTITUTION:Molten polyehylene terephthalate is extruded, cooled, oiled, and wound. The wound filament is drawn and heat-treated with a slit heater to obtain the objective fiber exhibiting X-shaped 4-spots interference pattern in the small-angle X-raw scattering, having a birefringence (DELTAn) of the whole fiber of 0.08-0.12, and that of the amorphous region (DELTAna) of 0.015-0.06, and having a faltness of the cross-section of 200-600%.

Description

Detailed Description of the Invention (Field of Industrial Application) The present invention relates to polyester fibers, more specifically polyester fibers which have practically sufficient properties, can be dyed by atmospheric pressure dyeing, and have excellent color fastness. This invention relates to polyester fibers.

(Prior Art) Generally, polyester fibers, particularly polyethylene terephthalate fibers, have many excellent properties such as strength and dimensional stability, and are therefore used for various purposes. On the other hand, polyethylene terephthalate fibers must be dyed at high temperatures and pressures around 130 degrees Celsius, which requires special equipment, or when mixed with fibers such as wool and acrylic whose physical properties deteriorate due to high temperature and high pressure dyeing. It has drawbacks such as limitations.

Several attempts have been made to improve the dyeability of such polyethylene terephthalate fibers and make them dyeable under normal pressure.For example, a method of using a carrier during dyeing is known, but this method requires a special carrier. In addition, not only does waste liquid treatment require special consideration, but there is also the problem that it is difficult to completely remove the bad odor emitted by the carrier remaining in the dyed product.

In order to solve these problems, chemical modification methods are known, such as copolymerizing polyoxyalkylene f IJ cole or metal sulfonate groups into polyester to provide a dyeing seat. However, this method not only increases the production cost of the polymer, but also has drawbacks such as decreased spinning stability and poor color fastness. In addition, since the above-mentioned chemical modification of the polymer to facilitate dyeing involves copolymerizing the third component, which can serve as a dyeing seat, into the polymer, it is possible to avoid changing the original properties of polyethylene terephthalate. It can be said that there is no.

On the other hand, as a completely different method, polyester fibers are
A similar modification method, such as relaxation heat treatment at a high temperature of 00° C. or higher, has been proposed.

This method relaxes the molecular chains in the amorphous region of the fiber, reduces the cohesiveness of the molecular chains, and improves the diffusion of the dye into the fiber, thereby improving the dyeability without impairing the mechanical properties. Although it can be improved, there is a problem that streaks are likely to occur.

Further, as another method that does not involve chemical modification, for example, Japanese Patent Application Laid-Open No. 54-64133 describes the denier per filament and the intrinsic viscosity [η].

Flat yarns and tows are disclosed that specify relative disperse dye dyeing speed, modulus, modulus after wastewater treatment, amorphous modulus, water production shrinkage, shrinkage modulus, shrinkage value, etc. According to K, the stainability is certainly improved, but it has not yet reached the level where normal pressure staining is possible. In addition, Japanese Patent Application Laid-Open No. 55-1075+1 discloses that HI
Dual structure polyethylene terephthalate (which is said to have the same mechanical properties as Jli fibers, sufficient natural crimping, and dye adsorption properties) with an appropriate difference in birefringence between the outer layer and the inner layer. However, no concrete suggestions have been made regarding the effects and effects related to dyeability, particularly atmospheric dyeability, dyeing, and color fastness.

Furthermore, JP-A-57-121613 discloses the initial modulus and the peak temperature of the mechanical loss tangent.

Polyethylene terephthalate fibers with defined peak values are disclosed.

Such polyester fibers are obtained by spinning at ultra-high speeds of 7,000 m/min or more, but according to experiments by the present inventors, spinning speeds of 5,000 to 6,000 m/min
Although the dyeing is somewhat darker than that obtained by spinning at a speed of 1/2 min, it was still not possible to achieve sufficient dyeing by ordinary pressure dyeing. (Objective of the Invention) The object of the present invention is to provide a polyester fiber that can be dyed under normal pressure, which has not been possible before, that is, a polyester fiber that can be dyed satisfactorily by normal pressure dyeing without chemical modification.

(Structure of the Invention) The present inventors studied to achieve the above object, and found that
The dyeability is more than that which can be dyed sufficiently by normal pressure dyeing, and it goes without saying that the fine structure of the fiber has a great influence on the dyeing property, but also the fine structure and the flat cross-sectional shape of the single fibers. I learned that the shoulder dye has extremely good dyeability.

As a result of further studies based on this knowledge, the present inventors have found that the polyester fiber has a t11KO microstructure in which dyes can easily diffuse, and the cross-sectional shape of the single fiber is 20 mm.
It was discovered that a material having an aspect ratio of 0 to 600 can have a dyeing rate of 66 or more stripes at normal pressure, and the present invention was achieved.

That is, the present invention provides a fiber having a flat cross section that is substantially composed of polyethylene terephthalate alone, in which the small-angle X-ray scattering pattern of the fiber exhibits an X-shaped four-point interference pattern, and Birefringence (△n) is 0.08~
0.12, birefringence (△na) of amorphous region is 0.015
~0.06, and the oblateness of the fiber cross section is 20
0~600<+t, 7qmf, -a! i tin - +) X bone +1rn! It is an AFTa6fflII ester fiber.

In addition, the oblateness referred to in the present invention refers to the long axis where the single fiber cross-sectional length is the longest value (g), and the short axis which is perpendicular to the long axis and where the length is the maximum length (b). The ratio C(L, /W)Xi
o o (a)].

Moreover, the dyeing rate is measured by the residual liquid colorimetric method shown below.

Namely, disperse dye 1) ispereol Fast 5c
arlet B (IC1 Co., Ltd.) was used, and Monogen (Daiichi Kogyo Co., Ltd. product name) was used as a dispersant in o, s, 9/
l plus 4'G owf, 10 at a bath ratio of 1:100
Staining was carried out in a bottom tumblet staining machine at 0°C.

The dyeing rate is determined by collecting the dye solution after 90 minutes, calculating the amount of dye in the remaining solution from the absorbance, and subtracting this from the dye used for dyeing. ) was calculated.

Dyeing rate"' (IDx/Do) x 100 (%)
Dx: Absorbance of the residual solution Do: Absorbance of the dye solution before dyeing The sample is a 10-knitted fabric of raw yarn, scoured with 100 times distilled water at 70°C for 30 minutes, and after drying, the sample is in a standard state (20
℃×65%RH)t.

I used something similar.

The polyethylene terephthalate used in the present invention is essentially a polyethylene terephthalate homopolymer, but it is a polyester copolymerized with a third component in a range that does not essentially change the properties of polyethylene terephthalate, that is, at a mole ratio of 10 or less. There is no problem even if it is a copolymer.

Such third components include, for example, isophthal ft, 5-sodium sulfoiphthal i, 216-naphthalene dicarboxylic acid, adipine M, oxalic acid, trimellitic acid, pyromellitic rf, p-oxybenzoic acid, diethylene glycol, and Examples include robylene glycol, butylene glycol, polyochene glycol, cyclohexanedimethanol, and functional rust conductors thereof.

These polyesters may contain small amounts of modifiers such as matting agents, stabilizers, flame retardants, antistatic agents or fillers.

The present invention will be explained with reference to the drawings.

FIG. 81 is a schematic diagram showing the small-angle XIs scattering pattern of the polyester fiber of the present invention, and FIG. 2 is a schematic diagram showing the small-angle XIs scattering pattern of the conventional polyester fiber.

The polyester fiber of the present invention is required to exhibit a unique X-shaped four-point interference pattern in the small-angle scattering pattern trap of X-rays, as shown in FIG. Figure 2 shows the small-angle scattering pattern of a conventional polyester fiber, that is, a drawn yarn that is suitable for practical use by being wound up at a winding speed of 5 oom/min and hot-stretched in a drawing machine. It is clearly different from the one shown. A fiber exhibiting a unique X-shaped four-point interference pattern as shown in FIG. 1 means that the repetition period of crystalline parts in the internal structure of the fiber is long and has a large distribution. On the contrary, this indicates that the amorphous portion has an extremely long structure in the fiber axis direction, and means that the length distribution is also large. Polyester #j with such a structure! 1
The dyeability of fibers is very good because the amorphous part of the fiber has extremely high mobility against heat. Additionally, when the dye has penetrated inside the fiber, the heat during dyeing causes the highly mobile amorphous portion to crystallize and become incorporated into the crystalline portion, so once the dye has penetrated into the fiber, it is trapped. As a result, it is believed that the stain resistance is sufficient for practical use.

On the other hand, a fiber exhibiting a small-angle X-ray scattering pattern as shown in Figure 2 has a short and dense repetition period of crystalline parts in its internal structure, so the amorphous part is extremely short in the fiber axis direction. , its length distribution is also small.

The amorphous part of the 4a fibers with this structure has extremely low -C mobility to heat, and the dye cannot sufficiently penetrate into the amorphous part at the temperature of normal pressure dyeing, so it is impossible to achieve dull color at normal pressure. .

Next, in the present invention, the birefringence (△n) of the entire fiber is 0.
．． It is necessary that the value is between 0.08 and 0.12. Here, △n
If it is less than 18, it will not be able to have enough structural stability and mechanical properties to be used as a fiber, and on the other hand, if it exceeds 0.12, there will be a problem that the dyeing rate will decrease. At the same time, the birefringence (△na) of the amorphous region
is required to be 0.015 to 0.06. If Δna is less than 0.015, the dyeing properties are considered to be good. However, the fixation of the dye inside the fiber, that is, the fastness of the dyeing is reduced. On the other hand, when Δna exceeds 0.06, the orientational cohesiveness of the amorphous molecular chains is too high (1), so that the dye easily diffuses into the fiber and it is difficult to achieve uniform dispersion.

On the other hand, the physical property values of the previous Rj, that is, the small-angle X-ray scattering pattern of the polyester fiber, Δn and Δna, are all determined by the present invention.
Even if the polyester fiber satisfies the hilum of 111, the cross-sectional shape of the single fiber is round or triangular.

Dyeing under normal pressure is less than 8<crab 8G, and sufficient dyeing cannot be performed under normal pressure.

In this regard, in the present invention, the small-angle X-ray scattering pattern, Δn, and Δna of the polyester fiber has a fiber fine structure that has sufficient mechanical properties to be used as a fiber and that allows dyes to easily diffuse into the fiber. By flattening the single fiber cross-sectional shape and creating a porous surface structure with many dye adsorption points as described later, the dyeing rate at normal pressure was increased to 86qb.
I was able to do more than that.

Here, if the cross-sectional shape of the single fiber is a flat cross section of less than 200 cm, the dyeing rate at normal pressure is less than 86%, so high temperature and high pressure conditions are required to dye the fiber sufficiently.

On the other hand, when a single fiber has an oblateness of more than 600 inches, its mechanical strength is significantly reduced, and the texture of a woven or knitted fabric made of such a single fiber becomes rough and hard.

The reason why the fiber made of single 411 fibers with a flat cross section of the present invention has extremely good dyeability is presumed to be as follows.

In other words, in general, when the spun yarn that has been melted and discharged reaches a temperature range where the crystallization rate is high during cooling, the oriented crystallization of the spun yarn rapidly progresses due to the elongation internal stress during spinning. At the same time, thinning occurs during spinning.

At this time, if the cross section of the single fiber is flat, the heat dissipation is greater than that of a single fiber with a round cross section, and as a result, purification occurs more rapidly and stress is concentrated on the fiber surface, making it easier for dye to enter the fiber surface. This is thought to be due to the porous structure.

As described above, polyester fibers that can achieve the objects of the present invention have a small-angle X-ray scattering pattern, a birefringence index (
Δn and Δna) all satisfy the range specified in the present invention, the cross-sectional shape is flat and 200 to 6
It has a flat plan of section 00.

Polyester fibers having both a fine structure and a flat cross section as in the present invention are disclosed in the above-mentioned JP-A-54-64133, JP-A-55-107511 and JP-A-57-1.
Nothing is disclosed in any of the 21613 publications, and it is completely new and previously unknown.

The cross-sectional shape of the single fibers constituting the polyester fiber of the present invention may be any shape as long as it satisfies the flatness specified in the present invention, and the cross-sectional shape may have rounded end faces or slightly bulge end faces. It may be.

Such polyester fibers of the present invention can be obtained by the melt spinning method shown below, but the present invention is not limited to this method.

fil The intrinsic viscosity of the supplied polyester polymer is made higher than that of polymers used in general clothing filaments.

That is, it is preferable that the intrinsic viscosity [η]≧0.62.

(2) Increase the spinning temperature, increase the ambient temperature directly below the spinneret, and increase the length of the atmosphere maintained at that ambient temperature as long as possible.

That is, it is preferable that the spinning temperature is 3,00° C. or higher, the temperature of the atmosphere below the die is 250° C. or higher, and the length of the atmosphere maintained at such atmospheric temperature is 130 mm or higher.

(3) Set the cooling air temperature as low as possible.

(4) Flat discharge hole provided in the cap ((0,25~0
．． 40) X (0.05 to 0.20), preferably rectangular, is arranged so that its long axis is parallel to the direction of the cooling air.

(5) The winding speed is 4700 m/min or more, preferably 5
000m/min or more.

(6) It is preferable that the cooling air particularly strongly cools the position where spinning necking occurs.

It goes without saying that in such 77I melt spinning, it is preferable to select the optimum conditions by appropriately adjusting the denier of the fiber to be obtained.

(Function) The polyester fiber of the present invention has, in its fine structure,
The crystalline portion and the amorphous portion are moderately oriented, the amorphous portion is extremely long in the fiber axis direction, and has a large length distribution, and also has a porous surface structure due to the flattened cross section. It is something.

As a result of dyeing the polyester fiber of the present invention under normal pressure, the dye becomes a porous A-structured monomer. i) J (If the coating surface is easily absorbed and then diffused uniformly into the amorphous part, it can be dyed under normal pressure to obtain a mulberry coating of 86 coefficient V. The dye fastness can also be improved because the dye is absorbed into the crystal part by the heat during dyeing.

(Effects of the Invention) The polyester fiber of the present invention has good dyeability, fixability, and mechanical properties, so it can be easily made into thread-like, cotton-like, and coarse fabrics by using disperse dyes after being made into a woven or knitted fabric. Since it can be dyed under normal pressure, it is possible to use normal non-carrier voile dyeing, and it is possible to use conventional voile dyeing.
Dyeing costs can be significantly reduced compared to K.

Furthermore, there is no trouble during weaving and knitting, and the final product has excellent durability. Therefore, the fibers of the present invention can be widely used in the fields of clothing, innoterifs, industrial materials, etc.

(Example) The present invention will be further explained in detail with reference to Examples. However, the present invention is not limited to this in any way.

The method for measuring each characteristic value used in this example is as follows.

X #i! Small-angle scattering noter/D-9C manufactured by Rigaku Denki, based on normal small-angle X-ray scattering photography.
A WXM generator was used, and the X-ray source was CuKα (N+ filter), 35 KV, and 20 mA. Photographs were taken under reduced pressure with an exposure time of 60 minutes.

Birefringence of the entire υ fiber 〇80〇 is the initial refraction 71 (n, ) for light polarized at right angles to the fiber axis, and the refraction for light polarized parallel to the fiber axis. The difference from I fold trillion (n, , ), that is, △
It is expressed as n=n, , -n. The measurement was carried out using an interference microscope manufactured by Carl Zeiss Jena and MR Interfaf, using white light with a wavelength of 550 mμ, and iodine and diamethylene as the immersion liquid.
Using α-bromnaphthalene and a mixture thereof, Δn was first measured over the entire inner, middle, and outer layers at equal intervals in the cross-sectional direction of the fiber, and the average value was calculated.

Birefringence Δna of the amorphous region Δna is a parameter that indicates the orientation of molecular chains in the amorphous region, and is expressed by Publication No.)
Calculate using the following formula.

Example: Polyethylene terephthalate having an intrinsic viscosity [η) = o, e s was spun at a spinning temperature of 305°C, and was spun from a spinneret having 36 rectangular spinning holes with the lengths of the major axis and intellectual axis listed in Table 1. Then, it is passed through an air zone below the mouthpiece with the strength and length listed in Table 1, and then cooled with cooling air at the temperature listed in Table 1, refueled, and then wound. A polyester fiber of 75 denier and 36 filaments was obtained by winding at 8 degrees and 5000 m/min. The cooling Jt linear velocity was 0.4 rn/sec.

However, the winding speeds of A117 and Fu 18 in Table 1 were set to 4 (100 m/min and 43 oom/min).

Also, the winding speeds of /619 and 20 in Table 1 are both 1
The winding speed was 500 m/min, and both the wound yarns were drawn at 809C. It was heat treated with a slit heater of I8fl'(2).The stretching ratio at that time was 300% at 19.

It was 200 regrets for Hawk '20.

Small-angle X-ray scattering pattern of the obtained polyester fiber, △
n, Δna, flatness, and dyeing rate were measured and shown in Table 1.

At the same time, we also conducted an IF value for color fastness to light in accordance with JIS L 1044, and reported defective items to that effect on the first page.
Note 411JK is listed in the table. Furthermore, for mechanical property evaluation, raw yarn was woven, and the fabric in a specified manner was stretched with a specified appendage, and the recovery of the fabric was visually judged. Regarding this, I wrote ``knee removal'' (tsu) in the notes column of Table 1.

As is clear from the first paragraph, the dyeing release at normal pressure is 86% or more, and the fibers satisfy the dye N fastness and mechanical properties.It satisfies the characteristics specified in the present invention. It is something.

[Brief explanation of drawings]

FIG. 1 is a schematic diagram showing the small-angle X-ray scattering pattern of the polyester fiber of the present invention, and FIG. 2 is a schematic diagram showing the small-angle X-ray scattering pattern of the conventional polyester fiber. Patent applicant Teijin Ltd. Figure 1 Figure 2

Claims (1)

[Claims] A fiber that is substantially composed of polyethylene terephthalate alone and has a flat cross section, the small-angle X-ray scattering pattern of the fiber exhibits an X-shaped four-point interference pattern, and the birefringence (△n) of the entire fiber is is 0.08 to 0.12. A polyester fiber capable of being dyed under normal pressure, characterized in that the birefringence (Δna) of the amorphous region is 0.015 to 0.06, and the flatness of the cross section of the fiber is 200 to 600 inches.