JPH10204726A - Latently crimpable polyester conjugate yarn - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain the subject conjugate yarn providing a spun yarn excellent in elasticity and handle, capable of developing spiral crimp, comprising a polyethylene terephthalate-based polyester and a polyethylene terephthalate-based copolyester containing a specific component which are eccentrically bonded. SOLUTION: This conjugate yarn comprises (A) a polyethylene terephthalate- based polyester and (B) a polyethylene terephthalate-based copolyester copolymerized with 1-9mol% of isophthalic acid and 1-5mol% of an adduct of ethylene oxide to bisphenol A which are eccentrically bonded. The amount of isophthalic acid and the adduct of ethylene oxide to bisphenol A satisfies equation I (Ma is mol% of the adduct of ethylene oxide to bisphenol A; Mb is mol% of isophthalic acid) and heat shrinkage characteristics satisfy equations of formula II to formula IV. The conjugate yarn has latent crimpable performance capable of developing spiral crimp of 50-300 crimps/2.5cm by free shrinkage heat treatment at 170 deg.C.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a latently crimpable polyester composite fiber suitable for obtaining a spun yarn or a nonwoven fabric for woven or knitted fabric which has excellent elasticity and excellent feeling.

[0002]

2. Description of the Related Art Polyester fiber has weather resistance, chemical resistance,
It has excellent properties such as wash and wear properties, and is used for various purposes such as clothing and industrial materials. In recent years, especially for sports apparel applications, fibers with high elasticity have been demanded from the functional aspect.

Hitherto, as a method for imparting elasticity to synthetic fibers, there have been proposed a number of methods for producing latent crimpable fibers in which polymers having different heat shrinkage properties are combined in a side-by-side or eccentric core-sheath structure. For example, Japanese Patent Publication No. 3-10737 and Japanese Patent Publication No. 4-5769 disclose a composite fiber of polyethylene terephthalate-based copolymerized polyester obtained by copolymerizing 5-sodium sulfoisophthalic acid component and polyethylene terephthalate. Also, Japanese Patent Application Laid-Open No. 7-5
No. 4216 discloses a polyethylene terephthalate-based copolymerized polyester obtained by copolymerizing 2 to 7 mol% of 2,2-bis [4- (2-hydroxyethoxy) phenyl] propane and 5 to 13 mol% of isophthalic acid, and polyethylene terephthalate. Are disclosed.

[0004] However, in these composite fibers, if heat treatment is performed under conditions that sufficiently develop latent crimps in order to impart good elasticity, the yarn hardens, and as a result, the hand feels worse. However, if heat treatment is performed under conditions that suppress the appearance of latent crimps in order to prioritize the number of crimps that develop, the number of crimps that develop will be insufficient, and consequently the elasticity will be insufficient.

[0005]

DISCLOSURE OF THE INVENTION The present invention solves the above-mentioned problems, and has a latent crimping property suitable for obtaining a spun yarn or nonwoven fabric for woven or knitted fabric which has excellent stretchability and excellent feeling. An object of the present invention is to provide a polyester composite fiber.

[0006]

Means for Solving the Problems The inventors of the present invention have conducted intensive studies to solve the above-mentioned problems, and as a result, have adopted a specific copolymerized polyester as a polymer to be composited with polyethylene terephthalate, and have set the heat shrinkage property to an appropriate value. The inventors have found that the above object can be achieved by setting the range, and arrived at the present invention. That is, the present invention relates to polyethylene terephthalate (PET) or polyester A
And PET-based copolymer polyester B obtained by copolymerizing 1 to 9 mol% of isophthalic acid (IPA) and 1 to 5 mol% of ethylene oxide adduct of bisphenol A (BA · EO)
Are eccentrically bonded composite fibers, IPA and BA
・ The copolymerization amount of EO satisfies the following equation, and the heat shrinkage property satisfies the following equation.
The gist of the present invention is a latently-crimpable polyester composite fiber having a latent-crimping property of exhibiting a spiral crimp of 50 to 300 pieces / 2.5 cm. 15 ≦ Xp ≦ 60 Xq ≦ 15 10 ≦ (Xp−Xq) ≦ 50 [wherein Ma represents the mol% of BA · EO with respect to all glycol components in the copolymerized polyester B, and Mb represents the molarity in the copolymerized polyester B. It shows the mole% of IPA based on the total acid component. Xp is the dry heat shrinkage (%) measured by the following P method and Xq is the following Q method. P method: Measure the yarn length L ₀ by applying an initial load of 50 mg / d to the fiber,
Next, remove the load and treat at 170 ° C x 15 minutes, then 50mg / d
Stretched in the load by measuring the yarn length L _1, it is calculated by the following equation. Xp (%) = [(L ₀ −L ₁ ) / L ₀ ] × 100 Q method: Measure the yarn length L ₂ by applying an initial load of 150 mg / d to the fiber, remove the load, and remove the load at 170 ° C. × 15 minutes 300m after processing with
stretched at a load of g / d were measured yarn length L _3, it is calculated by the following equation. Xq (%) = [(L ₂ −L ₃ ) / L ₂ ] × 100

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail.

In the present invention, PET is preferably used as the polyester A which constitutes one component of the latently crimpable polyester conjugate fiber. However, as long as the effects of the present invention are not impaired, IPA, 1,4- Butanediol,
It may contain a copolymer component such as 1,6-hexanediol, diethylene glycol, polyethylene glycol or the like, and may contain a stabilizer, a fluorescent agent, a pigment, a reinforcing material and the like.

On the other hand, the copolyester B constituting the other component of the conjugate fiber is mainly composed of ethylene terephthalate units and contains 1 to 9 mol% of IPA, preferably 1 to 9 mol%.
It is necessary to use a copolymer of about 4.5 mol% and 1-5 mol%, preferably 1-3 mol% of BA.EO. The sum of the copolymerization amounts of IPA and BA / EO is 3 to 10
Mol%, preferably 5 to 10 mol%. I
If the sum of the copolymerization amount of PA and BA / EO and the sum of the copolymerization amount of IPA and BA / EO is less than the above range, the crimping property becomes insufficient. The recovery rate is small, and a sufficient stretching function cannot be obtained. On the other hand, if the copolymerization amount exceeds this range, the fiber strength is remarkably reduced due to a decrease in the melting point, and the feeling becomes hard.
The BA.EO preferably has 2 to 10 mol, more preferably 2 to 5 mol of ethylene oxide added to 1 mol of bisphenol A.

The composite fiber of the present invention must have a dry heat shrinkage Xp by the P method of 15 to 60%, preferably 25 to 40%. If Xp is less than 15%, the stretching property is insufficient, and 60%
Exceeding the heat treatment undesirably reduces the height of the crimp peaks developed by the heat treatment, and the texture of the nonwoven fabric or woven / knitted fabric obtained from the composite fiber becomes paper-like.

Further, the composite fiber of the present invention needs to have a dry heat shrinkage Xq by the Q method of 15% or less, preferably 10% or less. If Xq exceeds 15%, the yarn is hardened, and the hand of the nonwoven fabric or woven or knitted fabric obtained from the composite fiber becomes undesirably hard.

Here, the significance of the dry heat shrinkage rate of the P method and the Q method will be described. A fiber with latent crimp has a strong shrinking force and cannot be expanded under the load (50mg / d) in the P method. Therefore, the high dry heat shrinkage of the P method means that the fiber has a strong shrinking force. It shows. In addition, since the fiber with latent crimp can be stretched by the load (300mg / d) in the Q method, the high dry heat shrinkage of the Q method means that the actual shrinkage of the fiber is high and the fiber is hardened. It shows that.

Further, the composite ester fiber of the present invention comprises:
(Xp-Xq) needs to be 10 to 50%, preferably 15 to 40%. When (Xp-Xq) is out of this range, the nonwoven fabric or woven or knitted fabric obtained from this fiber cannot have both the stretchability and the soft feel.

[0014] The dry heat shrinkage Xp by the P method is IPA or B
It can be adjusted by the copolymerization amount of A / EO, the stretching ratio in the stretching step, and the temperature of the tension heat treatment after the stretching. To increase Xp, operations such as increasing the copolymerization amount, increasing the draw ratio, and lowering the tension heat treatment temperature may be performed, and when decreasing Xp, the reverse operation may be performed. The copolymerization amount of IPA or BA / EO is adjusted within the above-mentioned range. The draw ratio is within the range where the residual elongation of the fiber is 30% to 60%, and the strain heat treatment temperature is 170 ° C.
Adjust at the following temperature. With this operation, Xp can be changed in the range of 15 to 60%.

The heat shrinkage characteristic Xq by the Q method is IPA
And the amount of BA / EO copolymerization and the heat treatment temperature during stretching. To increase Xq, the amount of copolymerization may be increased or the heat treatment temperature may be increased. To decrease Xq, the reverse operation may be performed. The copolymerization amount of IPA or BA / EO is adjusted within the above-mentioned range. Heat treatment temperature during stretching is 120 ° C ~ 19
Adjust within the range of 0 ° C. With this operation, Xq can be changed in the range of 0 to 15%.

Further, the conjugate fiber of the present invention must have a latent crimping ability to develop a spiral crimp of 50 to 300 pieces / 2.5 cm by a free shrink heat treatment at 170 ° C. When the number of crimps generated by the free shrinkage heat treatment is less than 50 pieces / 2.5 cm, the product has poor elasticity. On the other hand, when the number of crimps exceeds 300 pieces / 2.5 cm, the peak of the crimp becomes too small and the product becomes paper-like.

The conjugate fiber of the present invention is a conjugate fiber in which polyester A and copolyester B are eccentrically bonded, but eccentrically bonded is defined as an eccentric core-sheath spinneret or side-by-side spinning. It refers to a joining form obtained by using a die, and the joining form is not particularly limited as long as the joining form is biased in two components. Also,
The cross-sectional shape of the fiber may be an irregular shape such as a circular cross section, a flat cross section, a six-lobed shape, a triangular cross section, or a hollow cross section.

Further, when the conjugate fiber of the present invention is used as a short fiber to obtain a spun yarn or a nonwoven fabric, 8 to 18 fibers / powder are used in order to improve the passability in the spinning process and the carding process.
It is preferable to provide a mechanical crimp of 2.5 cm. The method for applying the mechanical crimp is not particularly limited, and a method using a push-in type crimping device or the like can be adopted.

[0019]

The present inventors believe that the latent crimpable polyester composite fiber which becomes a woven or knitted fabric or a nonwoven fabric having a good stretchability and a soft feel according to the present invention can be obtained as follows. That is, in the latently crimpable conjugate fiber having a normal eccentric structure, the crimp development performance is enhanced (by increasing the dry heat shrinkage by the P method) to improve the stretchability. If it is too large, the bulk will not be obtained (the dry heat shrinkage rate by the P method is too high), and if the fiber shrinks, the fiber will harden (the dry heat shrinkage rate by the Q method is too high) and the feeling as a product will be impaired. On the other hand, as in the present invention, when a specific copolyester is used as a polymer to be combined with PET and the heat shrinkage characteristics of the P method and the Q method are controlled, when the product is made into a spun yarn or a nonwoven fabric, This makes it possible to combine the elasticity by the expression of shrinkage with the soft feeling.

[0020]

Next, the present invention will be described in detail with reference to examples. The method for measuring the characteristic values is as follows.

[0021] The measurement was carried out at a concentration of 0.5% by weight and a temperature of 20 ° C, using an equal weight mixture of phenol and ethane tetrachloride as a solvent. (2) Fineness The fineness was measured by a method specified in JIS L-1015 7-5-1A. (3) Strength Measured according to the method specified in JIS L-1015 7-7. And 2g / d or more was judged as pass. (4) Number of crimps due to the appearance of latent crimps The stretched tow is cut to a length of 51 mm, heat-treated at 170 ° C for 5 minutes in a freely shrinkable state, and then subjected to JIS L-10.
The number of crimps was measured by the method specified in 157-21-1. (5) Dry heat shrinkage (P method and Q method) Measured by the method described above. (6) Non-woven fabric elongation recovery rate Cotton cut to 51 mm is made into a card web with a basis weight of 120 g / m ² , treated at 170 ° C for 1 minute, and then processed horizontally (perpendicular to the machine direction).
Prepare a 5mm, 150mm vertical (machine direction) sample. This is stretched in the machine direction at a speed of 100 mm / min to 50% of the breaking elongation.
The elongation I ₀ is measured. After maintaining the stretched state for 1 minute, return to the original state at a speed of 100 mm / min and leave it for 3 minutes. Stretched at a rate of once again 100 mm / min, to measure the elongation I ₁ until load is applied. The elongation recovery rate was calculated from the measured value by the following equation. Elongation recovery rate (%) = [(I ₀ −I ₁ ) / I ₀ ] × 100 Then, 20% or more was regarded as acceptable. (7) Hand of non-woven fabric The non-woven fabric prepared in the manner described in (6) was prepared and subjected to a sensory test with 30 panelists, and evaluated on a five-point scale. The evaluation criteria are as follows. 5 points: soft 4 points: slightly soft 3 points: normal 2 points: slightly hard 1 point: hard The average of 30 people was taken, and 4 or more were considered acceptable.

Example 1 PET having an intrinsic viscosity of 0.67 was used as polyester A, and copolyester having an intrinsic viscosity of 0.70 obtained by copolymerizing 4 mol% of IPA and 2 mol% of BA / EO added with 2 mol of ethylene oxide was used as copolymer polyester B. . After drying these two types of chips under reduced pressure by a conventional method, the spinning temperature is 290 ° C and the total discharge is performed using a spinneret having a round cross section of 0.45 mm in diameter and 344 pores using a conventional composite melt spinning device. Amount 23
At 0 g / min, the two components are side-by-side (weight ratio 1:
After spinning the composite yarn in 1) and cooling the spun yarn with air, 1000m
/ Min to obtain an undrawn yarn.

Next, the obtained yarn is bundled, made into a 100,000-denier tow, stretched at a temperature of 70 ° C. and a magnification of 3.72 times.
Tensile heat treatment at a temperature of 160 ° C. was performed, and a mechanical crimp of 12 pieces / 2.5 cm was applied by a press-type crimping machine, and then cut into 51 mm to obtain short fibers. The short fibers obtained above were made into a card web having a basis weight of 120 g / m ² and heat-treated at 170 ° C. for 1 minute to obtain a nonwoven fabric.

Examples 2-6, Comparative Examples 1-6 Short fibers and copolymers were prepared in the same manner as in Example 1 except that the copolymerization amount of IPA and BA / EO constituting the copolyester B was changed as shown in Table 1. A non-woven fabric was obtained.

Table 1 shows the evaluation results of the composite fibers and nonwoven fabrics obtained in Examples 1 to 6 and Comparative Examples 1 to 6.

Comparative Example 7 Short fibers and a nonwoven fabric were obtained in the same manner as in Example 1 except that the stretched fiber was subjected to a tension heat treatment at a temperature of 180 ° C.

Table 1 shows the evaluation results of the composite fibers and nonwoven fabrics obtained in Examples 1 to 6 and Comparative Examples 1 to 7.

[0028]

[Table 1]

As is clear from Table 1, the fibers obtained in Examples 1 to 6 have excellent crimp development performance while maintaining sufficient fiber strength. Had excellent elongation recovery rate and texture.

On the other hand, in the copolyester B of Comparative Example 1, IPA was excessively copolymerized, so that the strength of the obtained fiber was low, and the feeling of the nonwoven fabric using this fiber was hard. . Next, the copolyester B of Comparative Example 2
Was insufficient in the copolymerization ratio of IPA, and the copolymerized polyester B of Comparative Example 3 was insufficient in the copolymerization amount of BA / EO, and in each case, only a nonwoven fabric with a poor elongation recovery rate was obtained.
Further, the copolyester B of Comparative Example 4 was BA.EO.
Of the copolymerized polyester B of Comparative Example 5
Was excessive in the sum of the copolymerization amounts of IPA and BA / EO. In each case, the fibers obtained had low strength and the hand of the nonwoven fabric was hard. Next, the copolyester B of Comparative Example 6
Is insufficient in the sum of the copolymerization amounts of IPA and BA / EO,
Therefore, only a nonwoven fabric having a poor elongation recovery rate was obtained. In Comparative Example 7, since the tension heat treatment temperature was too high, X
Only a fiber with a small p was obtained, and the nonwoven fabric from this fiber had a poor elongation recovery rate and a slightly hard feel.

[0031]

According to the present invention, the heat-treated fiber has excellent elasticity, and has excellent elasticity and a good crimpability. A polyester composite fiber is provided.

Claims (1)

[Claims] 1. Polyethylene terephthalate or a polyester A containing the same as a main component, and a polyethylene terephthalate copolymer polyester B obtained by copolymerizing 1 to 9 mol% of isophthalic acid and 1 to 5 mol% of an ethylene oxide adduct of bisphenol A. An eccentrically bonded conjugate fiber, in which the copolymerization amount of ethylene oxide adduct of isophthalic acid and bisphenol A satisfies the following formula, the heat shrinkage property satisfies the following formulas and A latently-crimpable polyester composite fiber having a latent-crimping property of exhibiting a spiral crimp of up to 300 pieces / 2.5 cm. 3 ≦ (Ma + Mb) ≦ 10 15 ≦ Xp ≦ 60 Xq ≦ 15 10 ≦ (Xp−Xq) ≦ 50 [wherein Ma represents the mole% of the ethylene oxide adduct of bisphenol A with respect to all the glycol components in the copolyester B. In the formula, Mb represents the mole% of isophthalic acid based on the total acid components in the copolyester B. Also Xp
Is the dry heat shrinkage (%) measured by the following P method and Xq is the following Q method. P method: Measure the yarn length L ₀ by applying an initial load of 50 mg / d to the fiber,
Next, remove the load and treat at 170 ° C x 15 minutes, then 50mg / d
Stretched in the load by measuring the yarn length L _1, it is calculated by the following equation. Xp (%) = [(L ₀ −L ₁ ) / L ₀ ] × 100 Q method: Measure the yarn length L ₂ by applying an initial load of 150 mg / d to the fiber, remove the load, and remove the load at 170 ° C. × 15 minutes 300m after processing with
stretched at a load of g / d were measured yarn length L _3, it is calculated by the following equation. Xq (%) = [(L ₂ −L ₃ ) / L ₂ ] × 100