JPH06136618A - Sheath-core type conjugate fiber excellent in hygroscopicity - Google Patents

Abstract

PURPOSE:To obtain the subject conjugate fibers high in and good in comfortableness when worn, thus usable as a material with comfortableness for underwear or sports wear in the form of knitted fabrics, etc. CONSTITUTION:The objective conjugate fibers excellent in moistureproofness are made up of a thermoplastic resin as core and fiber-forming polyamide resin as sheath. In this case, the thermoplastic resin consists mainly of polyether esteramide and the core accounting for 5-50wt.% of the whole weight of the final conjugate fibers.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a polyamide fiber having excellent hygroscopicity, and more particularly to a hygroscopicity which can be suitably used for a material for clothing such as innerwear, inner garments and sports clothing. The present invention relates to an excellent core-sheath type polyamide composite fiber.

[0002]

2. Description of the Related Art Polyamide fibers represented by nylon 6 and nylon 66 are used in many clothing applications because of their excellent yarn strength, abrasion resistance, deep dyeability, and ease of high-order processing. There is. However, these polyamide fibers have relatively high hygroscopicity among synthetic fibers, but are inferior to natural fibers, so that they may come into direct contact with the skin, such as innerwear, inner garments, and sports clothing, or on the skin side. When it is used in a field worn in a close condition, it has a drawback that it is inferior in comfort as compared with natural fiber due to stuffiness and stickiness caused by sweating from the skin.

For the purpose of improving hygroscopicity and antistatic property, Japanese Patent Publication No. 44-10488 discloses a technique of compounding a polyamide and an aliphatic block polyetheramide. When a large amount of composite is added to impart hygroscopicity, the color tone of the composite fiber becomes more yellowish and the development application is limited. Further, since the block polyether amide has a high production cost, there is a limitation in this respect.

[0004]

SUMMARY OF THE INVENTION An object of the present invention is to provide a hygroscopic polyamide fiber which overcomes the above-mentioned problems of the prior art, has no process troubles, has good high-order processability, and has high commercial value. It is in.

[0005]

The above-mentioned object of the present invention is a core-sheath type composite fiber having a thermoplastic resin as a core portion and a fiber-forming polyamide resin as a sheath portion. The main component of the plastic resin is polyether ester amide, and the ratio of the core portion is 5 to 50% by weight based on the total weight of the composite fiber.

The polyether ester amide (hereinafter referred to as PEEA) in the present invention is a block copolymer having an ether bond, an ester bond and an amide bond in the same molecular chain. More specifically, one or more polyamide-forming components (A) selected from lactams, aminocarboxylic acids, salts of diamines and dicarboxylic acids, and polyether esters composed of dicarboxylic acids and poly (alkylene oxide) glycols. It is a block copolymer polymer obtained by polycondensation reaction of the forming component (B).
The polyamide-forming component (A) of PEEA of the present invention includes caprolactam, enantolactam, dodecanolactam,
Lactams such as undecanolactam, ω-aminocarboxylic acids such as aminocaproic acid, 11-aminoundecanoic acid and 12-aminododecanoic acid, and diamines which are precursors of nylon 66, nylon 610, nylon 612 and the like.
There are nylon salts of dicarboxylic acids, and these can be used alone or in combination of two or more. Preferred polyamide-forming components are ε-caprolactam, nylon 66
It is salt. On the other hand, the polyether ester-forming component (B) forming the soft segment of PEEA has 4 to 4 carbon atoms.
It is composed of 20 dicarboxylic acids and poly (alkylene oxide) glycol. Examples of the dicarboxylic acid having 4 to 20 carbon atoms include succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, sebacic acid, dodecadiic acid and other aliphatic dicarboxylic acids, terephthalic acid, isophthalic acid, 2,
Aromatic dicarboxylic acids such as 6-naphthalenedicarboxylic acid,
Examples thereof include alicyclic dicarboxylic acids such as 1,4-cyclohexanedicarboxylic acid, which may be used alone or in combination of two or more. Preferred dicarboxylic acids are adipic acid, sebacic acid, dodecadic acid, terephthalic acid, isophthalic acid. Further, as the poly (alkylene oxide) glycol, polyethylene glycol, poly (1,2)
-And 1,3-propylene oxide) glycol, poly (tetramethylene oxide) glycol, poly (hexamethylene oxide) glycol, a random or block copolymer of ethylene oxide and propylene oxide or tetrahydrofuran, and the like. preferable. The number average molecular weight of the poly (alkylene oxide) glycol is preferably 300 to 10,000, more preferably 500 to 4,000. If the molecular weight is lower than 300, it tends to scatter out of the system during the polycondensation reaction, while 100
If it is higher than 00, it is difficult to copolymerize and it is difficult to obtain a stable block copolymer.

The polyetheresteramide block copolymer of the present invention is obtained by polycondensing the above-mentioned polyamide-forming component (A) and polyetherester-forming component (B). An industrially preferable method is a method in which (A) and (B) are heated and polycondensed under reduced pressure. In this case, in order to obtain a polymer having a high degree of polymerization and little coloring, for example, antimony oxide or titanic acid is used. It is preferable to add an ester or the like as a polycondensation catalyst and phosphoric acid, a phosphoric acid ester or the like as a color preventing agent. PEEA
The weight ratio of (A) and (B) therein is preferably 99: 1 to 5:95, and more preferably 80:20 to 10:90. If the ratio of (A) is large, or conversely small, the hygroscopicity is lowered. The PEEA is the main moisture absorbing component of the fiber of the present invention, and is placed in the core of the core-sheath type composite fiber. The main component of the core is PEEA, and the core is 5 to 5 of the total weight of the composite fiber.
It should be 0% by weight. It is preferably 10 to 40% by weight, more preferably 15 to 30% by weight.
If it is less than 5% by weight, sufficient hygroscopicity cannot be obtained, which is not preferable.
It is not preferable because high-order workability is deteriorated.

The polyamide of the sheath portion in the core-sheath type composite yarn of the present invention is nylon 6, nylon 66, nylon 46, nylon 9, nylon 610, nylon 1
1, nylon 12, nylon 612, etc., or compounds having an amide-forming functional group with them, such as laurolactam, sebacic acid, terephthalic acid, isophthalic acid, 5-
Copolymerized polyamides containing a copolymerization component such as sodium sulfoisophthalic acid can be mentioned. Of these, nylon 6 and nylon 66 are particularly preferable. A small amount of PEEA of the present invention may be mixed in the polyamide,
It is preferably 10% by weight or less.

The thermoplastic resin forming the core of the present invention includes sodium polyacrylate, poly-N-vinylpyrrolidone,
Polyacrylic acid and its copolymer, polymethacrylic acid and its copolymer, polyvinyl alcohol and its copolymer, polyacrylamide and its copolymer,
A moisture-absorbing / water-absorbing substance such as a cross-linked polyethylene oxide-based polymer or a general-purpose thermoplastic resin such as polyamide, polyester, or polyolefin may be contained to such an extent that the object of the present invention is not impaired. The thermoplastic resin forming the core and the fiber-forming polyamide resin forming the sheath include, in addition to pigments such as titanium oxide and carbon black, conventionally known antioxidants, anti-coloring agents, light stabilizers, antistatic agents. Etc. may be added.

In the core-sheath type composite fiber of the present invention, a fiber-forming polyamide resin is arranged in the sheath part, and a hygroscopic PE is formed in the core part.
It has a thermoplastic resin containing EA as a main component.
Since the fiber-forming polyamide resin arranged in the sheath portion is relatively hydrophobic, it has low hygroscopicity. Therefore, even in an environment of high humidity, the surface of the fiber is always smooth, and the discomfort due to stickiness is small, and the wearing comfort is good. Further, since PEEA having a relatively high moisture absorption rate is used as a core component and is also covered with a polyamide resin, swelling during hot water treatment can be suppressed without impairing hygroscopicity, and thus high-order processability such as dyeing is good. Becomes Further, since the amide bond existing in PEEA and the polyamide of the sheath have a high affinity with the resin, the core-sheath interface is less likely to peel off.

The core-sheath type composite fiber of the present invention can be obtained by the following method. For example, polyamide (sheath part) and PEEA (core part) are separately melted, introduced into a spinning pack part, and then a composite flow is formed by a usual method so as to have a core-sheath structure and spun from a nozzle. The spun filament yarn is taken up and oiled at a predetermined speed, and then wound up in a package. Next, to obtain the desired strength and elongation,
The wound yarn is drawn by a draw twister in the usual manner. This drawing may be carried out continuously after winding the spun yarn without winding and winding up. In addition, a method may be adopted in which the fiber is taken out at a high speed of 4000 m / min or more and the desired fiber performance is obtained all at once. Examples of the direct spinning / drawing method include a method in which the spun yarn is drawn at 1000 to 5000 m / min, subsequently drawn, and drawn and heat set at 3000 to 5500 m / min.

The core-sheath shape of the core-sheath type composite fiber of the present invention may be concentric, eccentric, or multi-island as long as the surface of the fiber is not cracked or cracked. A modified cross section such as a polygonal shape, an H shape, or a π shape may be used. Further, it is possible to provide a hollow portion inside the core-sheath type composite fiber. The filament form of the core-sheath type composite fiber may be either filament or staple and can be obtained by a conventional method. As the fabric form, woven fabric, knitted fabric,
A non-woven fabric or the like can be appropriately selected according to the purpose.

[0013]

EXAMPLES The present invention will now be described in more detail by way of examples. Each characteristic value in the examples was determined by the following method. A. Difference in moisture absorption rate of fiber ΔM The moisture absorption rate is 20% and 20% of the weight when the fiber is made into a tube knitted fabric.
It was determined by the following formula from the weight change with the weight after standing for 24 hours in a thermo-hygrostat (PR-2G manufactured by Tabai) under an atmosphere of ℃, 65% RH or 30 ℃, 90% RH. Moisture absorption rate (%) = (weight after moisture absorption-weight at absolute dryness) x
100 20 ° C., 65% RH and 30 ° C., 90% measured above
From the moisture absorption rate under the condition of RH (M1 and M2, respectively), the moisture absorption rate difference ΔM (%) = M2-M1 is obtained.
Here, the moisture absorption rate difference ΔM is a driving force for obtaining comfort by releasing moisture in clothes when the clothes are worn to the outside, and when light-moderate work or light-moderate exercise is performed. Is the difference in moisture absorption rate between the temperature inside clothes represented by 30 ° C. and 90% RH and the outside temperature humidity represented by 20 ° C. and 65% RH. In the present invention, this ΔM is used as a parameter for the evaluation of hygroscopicity, and the larger ΔM corresponds to the higher hygroscopicity and the better wearing comfort. At least 2.5% is required for a polyamide fiber that is practically comfortable to wear.

B. Evaluation of cracking in hot water atmosphere Put 2 g of tubular knitted fabric and 200 ml of water in a pressure resistant pot,
Heat to 90 ° C, hold for 70 minutes, then cool,
The tubular knit fabric was taken out and air-dried. The cross section of the composite fiber constituting the tubular knitted fabric was sampled in a thin piece shape, and the presence or absence of cracks was observed for each single yarn by a microscope. The evaluation was as follows. If there are no single filaments with cracks in 24 filaments: ○ 1 to 3 single filaments with cracks: △ 4 or more single filaments with cracks: ×

C. Color tone The degree of coloring of the tubular knitted fabric was judged by visual inspection.

Reference Example 1 (Synthesis of Polyether Esteramide Block Copolymer) 340 parts of ε-caprolactam, 18 parts of terephthalic acid, polyethylene glycol 100 having a number average molecular weight of 1000
Part, further “Irganox 1330” (manufactured by Ciba Geigy) and 0.1 part and trimethyl phosphate 0.0
Charge 1 part with the polymerization reaction vessel and put it under a nitrogen stream for 24 hours.
After heating and stirring for 1 hour at 0 ° C., antimony trioxide 0.1
Part was added and the temperature was raised under reduced pressure program at 250 ° C. and 0.5 m.
By carrying out the polymerization reaction for 4 hours under the condition of mHg or less,
A polyether ester amide block copolymer having a nylon 6 component ratio of 45% by weight was obtained. Ortho-chlorophenol solution of this copolymer (concentration: 0.5 g / 10
0 ml) had a relative viscosity ηr at 25 ° C. of 2.05. In addition, the polymer alone has M1 of 6.2% and M2 of 15.2
ΔM was 9.0% in%.

Example 1 The polyether ester amide block copolymer synthesized in Reference Example 1 was used as a core component, and the relative viscosity in sulfuric acid was 2.80.
Nylon 6 which is a sheath component is discharged from the concentric core-sheath composite die to a core / sheath ratio (weight ratio) = 8/92 to obtain an unstretched yarn, which is then stretched and heat treated. A concentric core-sheath type composite fiber of 75 denier 24 filaments was obtained. Moisture absorption difference ΔM of the tubular knitted fabric after scouring is 3.4%
And had good hygroscopicity.

Examples 2 to 4 and Comparative Examples 1 to 2 In the same manner as in Example 1, various core-sheath composite ratios of the polyether ester amide block copolymer and the polyamide were changed as shown in Table 1. A concentric core-sheath type composite fiber was obtained. Table 1 shows the results obtained by evaluating the properties of this fiber in the same manner as in Example 1. All of Examples 2 to 4 had good hygroscopicity, and no cracks were observed due to hot water treatment. On the other hand, in Comparative Example 1, the percentage of PEEA in the core is low, so the hygroscopicity is low, and in Comparative Example 2, the percentage of PEEA in the core is high, so the hygroscopicity is high, but on the fiber surface during hot water treatment. Many cracks occurred and it was not practical.

Example 5 PEEA as the core component and the weight ratio of nylon 6 were 80: 2.
A core-sheath type conjugate fiber was obtained in the same manner as in Example 1 except that the mixture of 0 was used to change the core ratio to 30% by weight. The hygroscopicity was good and no cracking occurred during hot water treatment.

Comparative Example 3 Polyetheramide obtained by polycondensing polyethylene glycol (average molecular weight 1000) having a diamine at the end as a core component, adipic acid salt and ε-caprolactam at 240 ° C. (45% by weight of nylon 6 component) , Relative viscosity ηr = 1.8
A core-sheath type composite fiber was obtained in the same manner as in Example 3 except that 8) was used. The hygroscopicity was good and no cracking occurred during hot water treatment, but the color tone was strong yellow.

[0021]

[Table 1]

[0022]

EFFECT OF THE INVENTION The core-sheath type composite fiber of the present invention has sufficient hygroscopicity to obtain wearing comfort, and since the polyamide is arranged in the sheath, it has high hygroscopicity without impairing the texture. Holding In addition, since the fiber surface does not crack even under a severe atmosphere such as dyeing conditions, and the color tone is good, it can be applied to a wide range of applications. The core-sheath type composite fiber of the present invention is extremely practical and suitable for underwear, shirts / blouses, inner garments, sportswear, slacks, outer garments, linings, and even bedding such as sheets and futon covers. It is expensive.

Claims (1)

[Claims] 1. A core-sheath type composite fiber comprising a thermoplastic resin as a core portion and a fiber-forming polyamide resin as a sheath portion, wherein the main component of the thermoplastic resin forming the core portion is a polyether ester amide. The core-sheath type composite fiber having excellent hygroscopicity, characterized in that the ratio of the core portion is 5 to 50% by weight based on the total weight of the composite fiber.