JPH09250029A - Sheath-core type nylon-polyester conjugated fiber - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain sheath-core type nylon-polyester conjugated fiber which gives clear dyed colors with excellent fastness to light and washing and has increased sheath-core peeling strength against friction. SOLUTION: This sheath-core type nylon-polyester conjugated fiber comprises the sheath made of poly (hexamethylene adipamide) which contains at least 1wt.% of ε-caporlactam as a copolymer and has a relative viscosity >=3.0 in sulfuric acid and the core made or polyethylene terephthalate containing sodium 5-sulfoisopthalate as a copolymerization component and having a copolymerization rate (K) represented by formula (I). In addition, the conjugate ratio of the core R (in wt.%) satisfies the formula (II). 5.2-0.08R<=K<=9.2-0.08R (I), 15<=R<=40(II).

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a core-sheath type nylon-polyester composite which is capable of obtaining a dye of a vivid color, excellent in light fastness and wash fastness of the dye, and having improved core-sheath peeling strength against friction. It is about fibers.

[0002]

BACKGROUND OF THE INVENTION Polyamide fibers are used in many clothing applications because of their excellent strength, abrasion resistance, dyeability and resin processability. However, due to the diversification of fashion in recent years, clear colors are required for ski wear, swimwear, casual wear, etc., and polyamide fibers can be dyed in deep colors with acid dyes, and it is not possible to dye them in clear colors. However, when it is dyed in a clear color, it is considered to be difficult to put it into practical use for applications such as ski wear, swimwear, and casual wear because the color fading due to light is remarkable and the dyeing fastness is poor.

On the other hand, polyester fibers typified by polyethylene terephthalate are dyed mainly with disperse dyes, and their light-emitting property and migration sublimation property have been improved, but in the depth of vivid color, they still reach the level of polyamide fibers. There are some points that are not present, and due to the molecular structure and chemical structure of the polyester itself, it is vulnerable to abrasion and resin processability is not sufficient. However, regarding the dyeability of the polyester fiber, as described in Japanese Patent Publication No. 34-10497, a modified polyester obtained by copolymerizing a sulfonated aromatic dicarboxylic acid component is prepared, and this is dyed with a cationic dye to obtain a clear color. It has become possible to color it. However, the above-mentioned drawbacks inherent to polyester fibers such as insufficient abrasion resistance and resin processability have not been improved.

Many proposals have been made for the composite spinning of polyamide and polyester to utilize the advantages of both, but in this case, the dyeing is carried out by using a disperse dye capable of dyeing both or by using an acid dye. It is said to be necessary to use cationic dyes or mixed dyes with disperse dyes. However, when dyed with the former disperse dye,
The polyamide component has insufficient wash fastness, and when dyed with a mixed dye, the lightfastness of the polyamide component dyed in a clear color is poor, so that none of them has reached a practical level.

As a composite fiber that solves the above problems,
The applicant of the present invention previously disclosed in Japanese Patent Laid-Open No. 199392/1993,
We proposed a core-sheath type composite fiber in which polyamide was used as the sheath and sulfonated aromatic dicarboxylic acid-modified polyester was used as the core, and only the cationic dye was dyed as the dye. Moreover, the dyeing fastness and wash fastness can be made excellent.

However, the core-sheath type composite fiber of the above-mentioned proposal causes peeling between the core part and the sheath part when a forced frictional force or the like is applied in a higher-order processing step in the subsequent examination. However, it has been found that the peeling of the core-sheath causes the cloth to have a vertical streak-like appearance, thus degrading the quality of the cloth.

[0007]

SUMMARY OF THE INVENTION The object of the present invention is to obtain a dye of vivid color and to have excellent light fastness and wash fastness of the dye and to improve the core-sheath peeling strength against friction. It is to provide a core-sheath type nylon-polyester composite fiber.

[0008]

The present invention which achieves the above-mentioned object is a sheath of polyhexamethylene adipamide in which at least 1% by weight or more of ε-caprolactam is copolymerized and the relative viscosity of sulfuric acid is 3.0 or more. In the core, polyethylene terephthalate copolymerized with sodium 5-sulfoisophthalate satisfying the copolymerization rate K (mol%) represented by the following formula (I) is placed in the core, and the composite ratio R of the core is R. It is characterized by core-sheath type nylon-polyester composite fibers (% by weight) satisfying the following formula (II).

5.2-0.08R ≦ K ≦ 9.2-0.08R (I) 15 ≦ R ≦ 40 (II)

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION The core-sheath type composite fiber of the present invention is composed of a modified polyethylene terephthalate (hereinafter referred to as a modified polyester) obtained by copolymerizing sodium 5-sulfoisophthalate which can be dyed in a bright color with a cationic dye. And the circumference of this core is polyhexamethylene adipamide (hereinafter nylon 66) that is not dyed with a cationic dye.
(It is called) has a structure that the sheath is covered.

Therefore, when this composite fiber is dyed with a cationic dye, the modified polyester in the core is sufficiently dyed, but the nylon 66 in the sheath is undyed. However, even if it is dyed in this way, it has sufficiently vivid color development. This is because even if the nylon 66 in the sheath is not dyed, the dye particles easily move inside the sheath, so even if the dye concentration should be the same, the dye that should originally be dyed to nylon 66 is the modified polyester of the core. Be absorbed into the core to enhance the color development of the core, and the color development of the core is recognized as the color development of the entire composite fiber without being substantially hindered by the nylon 66 containing no dye particles. Therefore, a sufficient level of vivid color is developed.

Further, the above dyeing exhibits sufficiently excellent light fastness and washing fastness. This is nylon 6 in the sheath
This is because, since 6 is not dyed, there is no possibility that the dye in nylon 66 will fade due to light irradiation or washing, resulting in poor dyeing fastness. Therefore, the light fastness and the wash fastness of a bright color dyeing can be made to a level that cannot be achieved by the polyamide fiber itself.
Further, by covering the surface of the modified polyester with nylon 66 having a low refractive index, the surface reflection is reduced and the depth of color can be increased.

Another feature of the core-sheath type composite fiber of the present invention is that the relative viscosity of sulfuric acid of nylon 66 in the sheath portion is set to a specific level, a specific amount of ε-caprolactam is copolymerized, and the core is In the modified polyester of 5 parts
The copolymerization rate of sodium sulfoisophthalate is set in a certain range in relation to the composite ratio of the core, and the composite ratio of the core is set in a certain range.

Due to the above characteristics, the peel strength between the sheath portion and the core portion is increased, and peeling does not occur even if frictional force or the like is applied in a high-order processing step or the like. That is, it is possible to solve the problem that the peeling of the core-sheath causes a white turbid vertical stripe on the fabric, which deteriorates the quality of the product. In the present invention, the amount of ε-caprolactam copolymerized with nylon 66 of the sheath portion is at least 1% by weight or more, preferably 2 to 5% by weight. The nylon 66 of the sheath portion has a relative viscosity of sulfuric acid of 3.0 or more, preferably in the range of 3.0 to 3.2.

The .epsilon.-caprolactam copolymerized with nylon 66 enhances the peel strength between the sheath portion and the core portion and enhances the color developability. The copolymerization amount of ε-caprolactam is 1
If it is less than wt%, the effect of improving the peel strength between the sheath and the core becomes insufficient. However, if the copolymerization amount of ε-caprolactam is too large to exceed 10% by weight, peeling is likely to occur, which is not preferable.

Further, when the relative viscosity of sulfuric acid of nylon 66 in the sheath is less than 3.0, the effect of improving the peel strength between the sheath and the core cannot be seen. However, if the relative viscosity of sulfuric acid becomes too high, the spinnability and drawability deteriorate, and it becomes difficult to obtain the desired composite fiber. Therefore, it is desirable to set the upper limit of the relative viscosity of sulfuric acid to 4.8. In the present invention, the relative viscosity of sulfuric acid of nylon 66 is a value measured by the following measuring method.

That is, a sample was dissolved in 98% sulfuric acid to form a solution having a concentration of 1% by weight, and the solution was measured with an Ostwald viscometer to measure 2
Flow time is measured under a constant temperature of 5 ° C. The ratio of the flow-down time of the sample solution to the flow-down time of sulfuric acid is converted into a specific viscosity using a standard sample, and this is taken as a 98% sulfuric acid viscosity. Nylon 66 of the sheath portion may contain a matting agent such as titanium oxide, but in order to sufficiently transmit the dyed color of the modified polyester of the core portion to obtain excellent color developability,
It is desirable that these matting agents and other pigments are not substantially contained. Further, the nylon 66 may contain additives such as an antistatic agent, a heat resistance agent, and a light resistance agent as long as the amount of light transmission is not significantly reduced.

On the other hand, the modified polyester of the core is a copolymer of sodium 5-sulfoisophthalate with a part of the chain or terminal of polyethylene terephthalate, and can be dyed with a cationic dye in a clear color. . This type of modified polyester is disclosed, for example, in Japanese Patent Publication No. 34-
No. 10497. In the modified polyester constituting the core, the copolymerization amount of sodium 5-sulfoisophthalate with respect to polyethylene terephthalate is
From the relationship with the composite ratio R (% by weight) of the core, the following formula (I)
It is necessary to satisfy the copolymerization rate K (mol%) represented by

5.2-0.08R ≦ K ≦ 9.2-0.08R ... (I) 15 ≦ R ≦ 40 (II) The copolymerization rate K of sodium 5-sulfoisophthalate is When it is less than the lower limit (5.2-0.08R), the color developability when dyed with a cationic dye becomes insufficient, and it becomes difficult to improve the core-sheath peeling strength. On the other hand, when the copolymerization amount is larger than the upper limit (9.2-0.08R), the crystal structure of the modified polyester is disturbed and the mechanical properties are significantly lowered.

The modified polyester may contain an antistatic agent, a weather resistance agent, a heat resistance agent, a matting agent and the like. However, it is not preferable to add sodium 5-sulfoisophthalate to the modified polyester because it deteriorates the spinnability. If the composite ratio R of the core is less than 15% by weight, the desired clear color development due to the dyeing with the cationic dye cannot be sufficiently exhibited, and the nylon 66 coating on the sheath also becomes thick, resulting in the color of the modified polyester. Is blocked, and it becomes difficult to obtain the desired color development. On the other hand, when the composite ratio R of the core exceeds 40% by weight, the nylon 66 coating on the sheath becomes thin and the peel strength between the core and the sheath decreases.

In the core-sheath type composite fiber of the present invention, the arrangement of the sheath portion and the core portion is basically desired to be a concentric core-sheath shape, but eccentricity and It may be multi-core. Further, as long as the modified polyester of the core can be covered with nylon 66 of the sheath, a deformed yarn can be used. The core-sheath type composite fiber of the present invention can be produced by a conventional method, or by further dyeing, and a desired product may be obtained by knitting, weaving, dyeing and post-processing.

For example, nylon 66 and modified polyester are separately melted, spun as a composite fiber from a core-sheath spinneret, cooled, refueled, and then taken at a predetermined speed to form an undrawn yarn into a package. Roll up. Then, the undrawn yarn is released from this package and drawn by a draw twister according to a conventional method. This drawing may be carried out continuously after the spun yarn is taken up and not once wound. It is also possible to take a method of obtaining desired fiber performance all at once by taking off at a high speed of 4000 m / min or more.

As the direct spinning and drawing method, for example, a spun yarn is drawn at 1000 to 5000 m / min, and then 3000 is continuously drawn.
A method of stretching and heat-setting at ˜5500 m / min can be mentioned.
The obtained conjugate fiber is then dyed with a cationic dye at any stage, that is, at the stage of a filament yarn or a fabric such as a woven or knitted fabric. Examples of cationic dyes include “Alzen Cathilon” (Hodogaya Chemical Co., Ltd.) and “Kayac
"ryl" (Nippon Kayaku Co., Ltd.), "Estrol Sumiacryl" (Sumitomo Chemical Co., Ltd.), "Diacryl" (Mitsubishi Kasei Co., Ltd.)
), "Maxilon" (manufactured by Ciba Geigy) and "As"
Examples include dyes with a generic name such as trazon ”(manufactured by Bayer Japan Co., Ltd.), but are not limited to these.
Any cationic dye can be used. Also,
Other dyes can be used in combination with the cationic dye as long as the amount is within a small range that does not impair the effects of the present invention.

The core-sheath type nylon-polyester composite fiber according to the present invention is dyed in a bright color with a cationic dye, and the dyeing can be excellent in light fastness and washing fastness. Furthermore, because the peel strength between the sheath and core is extremely high, conventional core-sheath polyamide
Frosting found in polyester composite fibers can be eliminated. That is, when it is made into a cloth, white turbid stripes do not occur.

Further, the core-sheath type nylon-polyester composite fiber of the present invention has excellent abrasion resistance inherent to polyamide fiber and ease of resin processing. In addition, since it has a modulus intermediate between polyester and polyamide, it is possible to impart favorable tension and stiffness to the fabric, and as a secondary effect, improvement of dimensional stability against water, which is a drawback of polyamide. The effect and the wrinkle-proof effect can be obtained.

The core-sheath type nylon-polyester composite fiber of the present invention is suitable for clothing due to the above-mentioned excellent properties, and is particularly suitable for sportswear, outerwear and the like which require a vivid color. Of course, it can also be used for interior products such as carpets and car seats.

[0027]

EXAMPLE Among polyethylene terephthalate raw materials consisting of ethylene glycol and terephthalic acid, sodium 5-sulfoisophthalate having a copolymerization rate (mol%) shown in Table 1 and a catalyst were added to terephthalic acid, and a catalyst was added according to a conventional method. Polymerization gave a modified polyester.

Further, to the salt of hexamethylenediamine and adipic acid (AH salt), ε-caprolactam was added in an amount shown in Table 1 and polymerized according to a conventional method to give a sulfuric acid relative viscosity shown in Table 1. And nylon 66 containing no titanium oxide was obtained. The modified polyester was used as the core part, and the nylon 66 was used as the sheath part. By performing composite spinning and drawing so that the composite ratio (% by weight) of the core part was the value shown in Table 1, 20 shown in Table 1 was obtained. Types of core-sheath composite fibers (N
o.1-20) was produced.

The composite spinning conditions are as follows: using an extruder type composite spinning machine, the spun yarn is drawn at 1500 m / min, subsequently drawn without winding once, and heated with a drawing heat roller at 160 ° C. After being set, the condition of winding at 4000 m / min and drawing yarn of 70 denier and 24 filament was adopted in common. Next, each of the obtained 20 types of conjugate fibers was used as a warp and a weft, and the warp density was 118 yarns / 2.54 cm and the weft density was 85 yarns / 2.5.
A plain fabric of 4 cm was woven, and the plain fabric was desizing-refined, dried, and intermediate set at 170 ° C. to obtain a sample fabric for dyeing.

Then, each of the sample cloths was treated with the cationic dye "Ka
Using yacryl-Black "R-ED (manufactured by Nippon Kayaku Co., Ltd.), dyeing temperature 105 ° C, 45 minutes, dye concentration 10% ow
f, dyeing was carried out under the condition that the bath ratio was 1: 100, followed by drying at 130 ° C. and finishing setting at 170 ° C. The results of evaluating the properties of each of the obtained dyed fabrics by the following methods are as shown in Table 1.

[Frosting resistance (core sheath peeling resistance)]
When a load of 1 kg was applied to the cloth and the cloth was rubbed 10,000 times, the state of cloudy vertical streaks appearing on the cloth was classified and evaluated into the following grades. (The higher the grade is, the better the frosting resistance is.) ◎ ... 4 to 5 grade, ◯ ... 4 grade, Δ ... 3 grade, × ... 1-2 grade [Strength] Strength measured by JIS L1013 Was evaluated according to the following criteria.

∘: 4 g / d or more, ∘: 3 g / d, Δ: 2
g / d, x ... 1 g / g or less. [Coloring property (black L value)] The L value of the black dyeing of the dyed fabric was measured under the conditions of a multi-light source spectrocolorimeter (manufactured by Suga Test Instruments Co., Ltd.) and a C light source of 65 °. It evaluated by the standard of. A: 12, O: 13, A: 14, X: 15 or more.

[Coloring property (vivid color)] Orange dyeing L value 5
The saturation at 0 was measured under the same conditions as above and evaluated according to the following criteria. ◎ ... 80, ◯ ... 70, Δ ... 65, × ... 60.

[0034]

[Table 1]

As is clear from the results of Table 1, the composite fiber of the present invention (No. 1, 2, 7, 9, 10, 11, 12)
It can be seen that in each case, the peel strength between the sheath portion and the core portion is high, and the strength and the color developability are excellent. On the other hand, it is understood that the composite fiber of Comparative Example (No. 3, 4, 5, 8, 13 to 20) cannot exert the effect of the present invention.

[0036]

As described above, according to the core-sheath type nylon / polyester composite fiber of the present invention, it is possible to obtain a coloring property which is dyed in a vivid color and is excellent in light fastness and washing fastness of the dyeing. Moreover, since the peel strength between the sheath portion and the core portion is improved, excellent wear resistance can be obtained.

Claims (3)

[Claims] 1. At least 1% by weight of ε-caprolactam is copolymerized and polyhexamethylene adipamide having a relative sulfuric acid viscosity of 3.0 or more is used as a sheath, and the following formula (I) is used.
A polyethylene terephthalate copolymerized with sodium 5-sulfoisophthalate satisfying a copolymerization rate K (mol%) represented by the following is arranged in the core part, and the composite ratio R (wt%) of the core part is represented by the following formula ( A core-sheath type nylon / polyester composite fiber that satisfies II). 5.2-0.08R ≦ K ≦ 9.2-0.08R (I) 15 ≦ R ≦ 40 (II) 2. The core-sheath type nylon-polyester composite fiber according to claim 1, wherein the sheath does not substantially contain a matting agent such as titanium oxide. 3. The core-sheath nylon according to claim 1, which is dyed with a cationic dye, and the cationic dye is dyed on the core portion and is not substantially dyed on the sheath portion. Polyester composite fiber.