JP2903773B2 - Core-sheath composite fiber with excellent comfort - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a polyester fiber having excellent moisture absorption properties, and more particularly to a polyester fiber which can be used particularly suitably for clothing materials such as innerwear, middle clothing, sports clothing and the like. The present invention relates to an excellent core-sheath type polyester composite fiber.

[0002]

2. Description of the Related Art Polyester fibers represented by polyethylene terephthalate or polybutylene terephthalate have excellent mechanical strength, chemical resistance and heat resistance.
Widely used mainly for clothing and industrial purposes.
However, since these polyester fibers have extremely low hygroscopicity, when used in the field where they are worn directly on the skin or near the skin side, such as inners, inner garments, and sports clothing, Perspiration from the skin causes stuffiness, stickiness, and the like, and the comfort is inferior to natural fibers. Therefore, the actual situation in these fields is limited. For this reason, for example, Japanese Patent Publication No. 60-47
No. 5, JP-B-60-40612, or JP-A-60-215835, various types of mixed fibers with a fiber having a high equilibrium moisture content (moisture absorption),
Attempts have been made to obtain comfort as a fabric by knitting, drawing and the like. Although the comfort is certainly improved by using these methods, the effect is not sufficient.On the other hand, when dyed, the polyester is stained by the disperse dye which dyes the polyester, the color is inferior, and the physical properties of the polyester are deteriorated. There is a problem that the characteristic is lost. In addition, a method is known in which acrylic acid or methacrylic acid is graft-polymerized to polyester fibers, and a method of imparting hygroscopicity by substituting the carboxyl groups with alkali metals after the graft polymerization is known. It has not been put to practical use because it is a material that is difficult to dye, and has a potential for deterioration in dyeing fastness, light resistance, fiber physical properties, texture, and the like.

[0003] As described above, the method of imparting hygroscopicity in the post-processing stage has various problems at the time of dyeing or in the properties of the obtained fabric. To eliminate moisture, the moisture absorption rate is 1
Japanese Patent Laid-Open No. 2-996 discloses a core-sheath type conjugate fiber in which a core portion is made of a hygroscopic resin of 0% or more, and the core portion is covered with polyester as a sheath portion.
No. 12 has proposed this. However, in this method, the sheath part is distorted due to the difference in water swelling between the core part and the sheath part due to moisture absorption and water absorption due to the high moisture absorption rate of the core part during hot water treatment such as dyeing, and the fiber surface is cracked or cracked This causes disadvantages such as not only lowering the commercial value but also causing process troubles. In addition, since the compatibility between the thermoplastic resin of the core and the sheath is poor, there has been a problem that exfoliation occurs at the interface and the commercial value is impaired.

[0004]

SUMMARY OF THE INVENTION It is an object of the present invention to overcome the above-mentioned problems of the prior art, to provide high-order workability without any process trouble, high commercial value, good moisture absorption properties, and clothing. It is another object of the present invention to provide a polyester fiber having excellent wearing comfort.

[0005]

SUMMARY OF THE INVENTION An object of the present invention is to provide a core-sheath composite fiber having a thermoplastic resin core and a fiber-forming polyester resin as a sheath. The thermoplastic resin is a mixture of the polyetheresteramide and another thermoplastic resin, and is 5 to 5 times the total weight of the composite fiber.
It can be achieved by a core-sheath conjugate fiber excellent in hygroscopicity, wherein 50% by weight is a polyetheresteramide.

[0006] The polyetheresteramide 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 polyetheresters comprising dicarboxylic acids and poly (alkylene oxide) glycols It is a block copolymer polymer obtained by subjecting the forming component (B) to a polycondensation reaction. Examples of the polyamide-forming component (A) of the polyetheresteramide of the present invention include caprolactam, enantholactam, 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, etc.
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
Salt.

On the other hand, the polyetherester component (B) constituting the soft segment of the polyetheresteramide
Consists of a dicarboxylic acid having 4 to 20 carbon atoms and a poly (alkylene oxide) glycol. Carbon number 4 ~ 2
Examples of the dicarboxylic acid of 0 include aliphatic dicarboxylic acids such as succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, sebacic acid, and dodecadic acid; Examples thereof include alicyclic dicarboxylic acids such as dicarboxylic acid and 1,4-cyclohexanedicarboxylic acid, which can be used alone or in combination of two or more. Preferred dicarboxylic acids are adipic acid, polyamides such as seba polyglycine,
It is a general-purpose thermoplastic resin such as polyester and polyolefin, such as succinic acid, dodecadic acid, terephthalic acid, and isophthalic acid. Further, poly (alkyleneoxy) or a mixture of two or more kinds can be used. Preferred dicarboxylic acids are adipic acid, sebacic acid, dodecadic acid, terephthalic acid, and isophthalic acid. , Poly (1, 2
-And 1,3-propylene oxide) glycol, poly (tetramethylene oxide) glycol, poly (hexamethylene oxide) glycol, random or block copolymerization of ethylene oxide with propylene oxide or tetrahydrofuran, etc., with polyethylene glycol being particularly preferred. . The number average molecular weight of the poly (alkylene oxide) glycol can be used in the range of 300-10000, preferably 500-4000.

The polyetheresteramide block copolymer of the present invention can be 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 less coloring, for example, antimony oxide, titanic acid It is preferable to add an ester or the like as a polycondensation catalyst and phosphoric acid, a phosphate or the like as a coloring inhibitor. The weight ratio of (A) to (B) in the polyetheresteramide is 99: 1.
5 to 95, preferably 80:20 to 10:90.

[0009] The polyetheresteramide is the main moisture-absorbing component of the present invention, and is arranged in the core of the core-sheath conjugate fiber by mixing with another thermoplastic resin. The amount of the polyetheresteramide in the total weight of the composite fiber must be 5 to 50% by weight. It is preferably from 7 to 45% by weight, more preferably from 10 to 40% by weight. If the amount is less than the above range, it is not preferable because sufficient moisture absorption properties cannot be obtained.If the amount is more than the above range, high-order workability such as cracking of the fiber surface due to swelling under hot water atmosphere such as dyeing is likely to be reduced. Not preferred.

[0010] Here, the hygroscopic property referred to in the present invention is 30%.
Moisture absorption rate in an environment of 90 ° C, 90% RH and 20 ° C, 65% RH
H is the difference in moisture absorption rate from the moisture absorption rate in an environment of H (ΔM), and the core-sheath conjugate fiber of the present invention needs to have a ΔM value of 1.2% or more. Heretofore, the comfort of a fiber material has been discussed at most in terms of moisture absorption under an environment of 20 ° C. and 65% RH, that is, under a standard condition. However, according to the study of the present inventors, the clothing has already reached the moisture absorption rate in the standard state when normally worn, so when discussing comfort during wearing, light to medium work or light to medium exercise It was found that it was necessary to pay attention to the driving force that quickly released the moisture in the clothes to the outside air when performing the training. The index of this driving force is the absorption rate difference (ΔM) of the present invention, and the environment in clothes represented by 30 ° C. and 90% RH when performing light-medium work or light-medium exercise and 20 ° C. This is a difference in moisture absorption from the outside air environment represented by 65% RH. If ΔM is less than 1.2%, sufficient wearing comfort cannot be obtained.

The thermoplastic resin other than the polyetheresteramide forming the core of the core-sheath type composite fiber in the present invention includes, for example, polyamides such as nylon 66, nylon 6, nylon 4, and nylon 2T, polyesters, and polyolefins. And one or more of them. Particularly, a modified polyethylene terephthalate obtained by copolymerizing nylon 66, nylon 6, or a sulfonate compound is preferable because it has good compatibility with polyetheresteramide, can be finely dispersed in each other, and has relatively small swelling due to hot water. Preferred sulfonate compounds as a copolymer component of the modified polyester include 5-sodium sulfoisophthalic acid, 5- (tetraalkyl) phosphonium sulfoisophthalic acid and ester derivatives thereof, sodium p-hydroxyethoxybenzenesulfonate, 2,5- And potassium bis (hydroxyethoxy) benzenesulfonate. The copolymerization amount of the sulfonate compound is preferably from 0.1 to 7 mol%, more preferably from 0.2 to 6 mol%, based on the acid component in consideration of the compatibility with the polyetheresteramide and the physical properties of the obtained blend fiber. And particularly preferably 0.5 to 5 mol%.

In the present invention, the fiber-forming polyester resin forming the sheath is not particularly limited. For example, terephthalic acid, 2,6-naphthalenedicarboxylic acid or an ester thereof is used as a main dicarboxylic acid component, and ethylene glycol or tetramethylene is used. Polyethylene terephthalate having glycol as a main glycol component,
A linear polyester such as polybutylene terephthalate or polyethylene 2,6 naphthalate is preferred, and polyethylene terephthalate is particularly preferred.

A part of the dicarboxylic acid component of the linear polyester is converted to a dicarboxylic acid such as adipic acid, isophthalic acid, 5-sodium sulfoisophthalic acid or an ester thereof, p-oxybenzoic acid, p-β-oxyethoxybenzoic acid. An oxycarboxylic acid such as an acid or an ester thereof may be substituted, and a part of the aliphatic glycol may be replaced with, for example, 1,4-bis (β-oxyethoxy) benzene, bisglycol ether of bisphenol A, polyalkylene glycol, or the like. It may be replaced by glycol. Further, a small amount of a chain branching agent such as pentaerythritol, trimethylolpropane, trimellitic acid and trimesic acid may be used.

A small amount of the polyetheresteramide of the present invention may be mixed in the polyester, but is preferably controlled to 10% by weight or less.

In addition, 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, and polyvinyl alcohol. Further, a moisture-absorbing / water-absorbing substance such as a copolymer thereof, polyacrylamide and its copolymer, a crosslinked polyethylene oxide polymer, and a general-purpose thermoplastic resin may be contained to such an extent that the object of the present invention is not hindered. The thermoplastic resin forming the core and the fiber forming polyester resin forming the sheath include pigments such as titanium oxide and carbon black, as well as conventionally known antioxidants, coloring inhibitors, light stabilizers, and antistatic agents. Of course, it may be added.

The core-in-sheath type conjugate fiber of the present invention is obtained by disposing a fiber-forming polyester resin in a sheath portion and a thermoplastic resin containing polyetheresteramide as a main component having good moisture absorption properties in a core portion. is there. Since the polyester resin disposed in the sheath is hydrophobic, it has extremely low hygroscopicity. Therefore, even in a high humidity environment, the fiber surface is always smooth, and there is little discomfort due to stickiness, and the wearing comfort is good. In addition, as a core component, a mixture of polyetheresteramide with very good hygroscopic property and other thermoplastic resin is used and also covered with polyester resin, so that swelling during hot water treatment is maintained without impairing hygroscopic property. Since it can be suppressed, high-order workability such as dyeing is improved. Further, since the adhesiveness between the ester bond existing in the polyetheresteramide and the polyester of the sheath is enhanced, there is an effect that the core-sheath interface is hardly peeled off. In the core-sheath composite fiber of the present invention, the core-sheath composite ratio and the ratio of the polyetheresteramide in the core and the other thermoplastic resin can be arbitrarily selected. As described above, it is necessary to be 5 to 50% by weight based on the total weight of the conjugate fiber. Here, the weight ratio of the polyester resin in the sheath portion is preferably 30% or more because it is easy to handle in a high-order processing of the polyester fiber such as an alkali weight reduction treatment and a dyeing treatment, and the development application is widened. The weight ratio of polyetheresteramide / thermoplastic resin in the core is preferably 90/10 to 10/90, and is preferably 80/20 to 10/90.
20/80 is more preferred.

The core-sheath shape of the core-sheath type conjugate fiber of the present invention may be concentric or eccentric as long as the fiber surface does not crack or crack.
Irregular cross sections such as H type and Π type may be used. Furthermore, it is also possible to provide a hollow portion inside the core-sheath type composite fiber.
Further, the filamentous form of the core-sheath composite fiber is a filament,
Any of staples may be used and can be obtained by a conventional method. The fabric form can be appropriately selected depending on the purpose, such as a woven fabric, a knitted fabric, or a nonwoven fabric.

[0018]

The present invention will be described in more detail with reference to the following examples. In addition, each characteristic value in an Example was calculated | required by the following method. A. Intrinsic viscosity of polyester [η] An orthochlorophenol solution was determined at 25 ° C. B. Difference in moisture absorption rate of fiber △ M
From the weight change with the weight after being left for 24 hours in a thermo-hygrostat (PR-2G manufactured by Tabai) in an atmosphere of 65 ° C., 65% RH or 30 ° C., 90% RH, it was determined by the following formula. Moisture absorption rate (%) = (weight after moisture absorption-weight when absolutely dry) 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), a difference in moisture absorption rate ΔM (%) = M2−M1 is obtained.
This ΔM is used as a parameter as a scale for evaluating moisture absorption characteristics. C. Evaluation of cracking in hot water atmosphere 2 g of tubular knitted fabric and 200 ml of water were placed in a pressure-resistant pot, heated to 130 ° C., kept as it was for 70 minutes, cooled, taken out and air-dried. The cross section of the composite yarn constituting this tubular knitted fabric was sampled in a flake shape, and the presence or absence of cracks was observed for each single yarn using a microscope. The case where there was no single yarn having cracks in the 24 filaments was evaluated as ○, the case where 1 to 3 single yarns with cracks was Δ, and the case where 4 or more single yarns with cracks was ×.

Reference Example 1 (Synthesis of polyetheresteramide block copolymer) 340 parts of ε-caprolactam
18 parts of terephthalic acid, 100 parts of polyethylene glycol having a number-average molecular weight of 1000, and “Irganox 1”
330 "(manufactured by Ciba-Geigy) and 0.1 part of trimethyl phosphate in a polymerization reactor, and heated and stirred at 240 ° C. for 1 hour under a nitrogen stream.
0.1 part of antimony trioxide was added, and a polymerization reaction was carried out at 250 ° C. and 0.5 mmHg or less for 4 hours under a heating / decompression program to obtain a polyetheresteramide block having a N6 component ratio of 45% by weight. A copolymer was obtained. Relative viscosity ηr at 25 ° C. of an orthochlorophenol solution (concentration: 0.5 g / 100 ml) of this copolymer
Was 2.05. M1 of the polymer alone is 6.2.
%, M2 was 15.2%, and ΔM was 9.0%.

Reference Example 2 (Synthesis of polyethylene terephthalate) Dimethyl terephthalate and ethylene glycol were transesterified by a conventional method using manganese acetate as a transesterification catalyst, antimony trioxide as a polymerization catalyst, and trimethyl phosphate as a coloring inhibitor. After the reaction, a polymerization reaction was performed to obtain polyethylene terephthalate. [Η] of this polymer was 0.62. The moisture absorption of this polymer alone was 0.4% for M1 and 0.4% for M2.
Was 0.5% and ΔM = 0.1%.

Example 1 70 parts by weight of the polyetheresteramide block copolymer synthesized in Reference Example 1 and 30 parts by weight of modified polyethylene terephthalate having an intrinsic viscosity of 0.56 obtained by copolymerizing 2.0 mol% of 5-sodium sulfoisophthalic acid were used as chips. And the polyethylene terephthalate synthesized in Reference Example 2 was used as a sheath component. The unstretched yarn was discharged from a concentric core / sheath composite die so that the core / sheath ratio (weight ratio) was 30/70. And then stretched and heat-treated,
A concentric core-sheath composite fiber of 75 denier and 24 filaments was obtained. The moisture absorption rate difference ΔM of the tubular knitted fabric after scouring was 2.8%, indicating that the tubular knitted fabric had good moisture absorption characteristics. After the tubular knitted fabric was subjected to the hot water treatment, the cross section of the single yarn was observed, and no crack was generated in any of the 24 filaments.

Examples 2 to 10 and Comparative Examples 1 to 4 In the same manner as in Example 1, a polyetheresteramide block copolymer and 2.0 mol% of 5-sodium sulfoisophthalic acid were copolymerized to have an intrinsic viscosity of 0.56 and a modification of 0.56. Various concentric core-sheath composite fibers were obtained in which the weight ratio or the core-sheath composite ratio of polyethylene terephthalate was changed. Table 1 shows the results of examining the properties of the fiber in the same manner as in Example 1. Examples 2 to 10 all have good moisture absorption properties,
Also, no cracks due to the hot water treatment were observed.
On the other hand, in Comparative Example 1, the hygroscopic property was low because the ratio of the polyetheresteramide as the core component was small, and in Comparative Examples 2 and 3, the hygroscopic property was high because the polyetheresteramide as the core component was used alone. Many cracks occurred on the fiber surface during the hot water treatment, and it was not practical. Also, even if the modified polyester is mixed with the core component as in Comparative Example 4, if the amount of polyetheresteramide is too large, a large number of cracks are generated on the fiber surface at the time of hot water treatment, but the fibers have high hygroscopicity and can be put to practical use. Did not.

[0023]

[Table 1]

[0024]

The core-in-sheath type composite fiber obtained by the present invention has a sufficient moisture absorbing property for obtaining wearing comfort.
In addition, since the sheath is made of polyester, it has a dry touch texture and high color fastness and light fastness.
In addition, since the fiber surface does not crack even under a severe atmosphere such as dyeing conditions, it can be used for a wide range of applications.

The core-sheath type composite fiber of the present invention comprises underwear, shirts / blouses, middle garments, sportswear, slacks,
It is extremely practical and suitable for bedding such as outer garments, linings, sheets and futon covers.

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-2-99612 (JP, A) JP-A-60-49029 (JP, A) JP-A-60-112826 (JP, A) JP-A-60- 53537 (JP, A) JP-A-4-361616 (JP, A) JP-A-61-289123 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , DB name) D01F 8/04-8 / 16

Claims (1)

(57) [Claims] 1. A core-sheath composite fiber having a thermoplastic resin as a core and a fiber-forming polyester resin as a sheath, wherein the thermoplastic resin forming the core comprises polyetheresteramide and another thermoplastic resin. A core-sheath type composite fiber excellent in hygroscopicity, which is a mixture with a resin, wherein 5 to 50% by weight of the total weight of the composite fiber is polyetheresteramide.