JP3145796B2 - Core-sheath composite fiber - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a core-sheath type composite fiber having excellent peel resistance and elastic properties.

[0002]

2. Description of the Related Art Polyester fibers have hitherto been widely used for clothing, industrial use, interior use and the like. However, recently, with the rapid expansion of uses of polyester fibers, depending on the use, it is the present situation that conventional polyester fibers cannot provide sufficiently satisfactory fiber products. For example, when fabrics are manufactured using polyester fibers, it is possible to impart a certain degree of elasticity by improving the structure and the fiber material of the fabrics. However, these fabrics have good elastic properties, such as elastic recovery properties. Was extremely difficult to provide. Attempts have been made to compensate for such disadvantages by using an elastomer such as rubber having good elastic properties as a fiber material.However, it is extremely difficult to fiberize an elastomer such as rubber, and it is possible to temporarily spin. However, the fibers are completely stuck together by winding, and even if an oil agent is applied to the fiber surface to prevent the stuck, not only can the stuck not be sufficiently prevented, but the dye is easy to come off and the dyeing durability is low. It was inferior and could not be put to practical use.

[0003]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a core-sheath type composite fiber having excellent elastic properties and peel resistance.

[0004]

That is, the present invention relates to a conjugate fiber in which two kinds of thermoplastic polymers are arranged in a core-sheath shape over the entire length of the fiber. Conjugated diene polymer block B having a hydrogenation ratio of 80% or more
And a block copolymer comprising an aromatic vinyl polymer block A, wherein the block A accounts for 10 to 50% by weight, and the sheath component is a fiber having a difference in solubility parameter from the block copolymer of 1 or more. A core-sheath type composite fiber, which is a formable thermoplastic polymer and contains an olefinic compound in a core component or a sheath component at a ratio of 20% by weight or less. In the present invention, the solubility parameter (SP value) refers to A. J. Small, J.M. A
ppl. Chem. , 3, 71, (1953).

The block copolymer constituting the core component in the core-sheath type conjugate fiber of the present invention comprises a polymer block A mainly composed of an aromatic vinyl compound and a polymer block B mainly composed of a conjugated diene compound. Hydrogenate the block copolymer and 80% of the conjugated diene-based aliphatic double bonds
Above, preferably 90% or more, particularly preferably 95% or more is a saturated bond, preferably a block copolymer having a number average molecular weight of 30,000 to 200,000. If the hydrogenation rate (hydrogenation rate) is less than 80%, thermal degradation is likely to occur during melt spinning, and the weather resistance of the resulting fiber is also unfavorable.

Examples of the aromatic vinyl compound constituting the polymer block A include styrene, α-methylstyrene, 1-vinylnaphthalene, 2-vinylnaphthalene,
-Methylstyrene, 4-propylstyrene, 4-cyclohexylstyrene, 4-dodecylstyrene, 2-ethyl-4benzylstyrene, 4- (phenylbutyl) styrene, etc., with styrene being most preferred. One block of the aromatic vinyl polymer block A is 4000
Number average molecular weight of ５０50,000, especially 5,000 to 4,000
It is preferable that the polymer has a number average molecular weight of 0. If the block length is small, the cohesive force of the polymer decreases, rubber-like elasticity becomes insufficient, and the desired fiberization tends to be difficult. On the other hand, if the block length is too long, the melt viscosity of the block copolymer will be too high, and the thermoplasticity will be impaired, making spinning difficult. And the content of block A is 10-50
%, Preferably in the range of 10 to 50%. If the styrene content is less than 10%, the moldability and heat resistance are inferior. On the other hand, if the content of the block A exceeds 50% by weight, the stretchability,
The flexibility is reduced and the object of the present invention cannot be achieved.

The block B of the block copolymer used in the present invention includes 1,3-butadiene,
Although there is a block composed of isoprene, pentadiene, hexadiene and the like, in the present invention, isoprene or isoprene-butadiene is preferably used in combination. The block composed of isoprene is 1,4 depending on polymerization conditions and the like.
The bond is mainly composed of 1,2 bonds or 3,4 bonds. However, in the present invention, the isoprene block having 1,4 bonds of 70% or more is desirable from the viewpoint of heat resistance. It is. When the isoprene-butadiene is used in combination, the form of the block B may be random, block or tapered. Block B
It is preferable to consider the adhesiveness with the other component constituting the conjugate fiber of the present invention. For example, when polyethylene is selected as polyethylene as the other thermoplastic polymer, butadiene should be 20% by weight or more. It is preferable to use an isoprene-butadiene mixed-type block B, and in the case of polypropylene, it is preferable to use an isoprene-butadiene mixed type containing 10% by weight or less of butadiene or a block B of isoprene alone. . The number average molecular weight of one of the blocks B is 100
About 00 to 150,000, especially 15000 to 13000
A value of about 0 is preferable, and a value outside this range tends to result in poor yarn-making properties.

The block form of the block copolymer in the present invention is represented by A (BA) n and (AB) n. Here, A represents a block composed of an aromatic vinyl monomer, B represents a block composed of a conjugated diene-based monomer such as isoprene or isoprene-butadiene, and n is an integer of 1 or more. Of these, the ABA form is most preferably used. The copolymer comprising the block A and the block B can be produced by a known method. For example, a method described in JP-B-40-23798 may be used, and a lithium-based copolymer such as n-butyllithium may be used. It is possible to synthesize from the above vinyl aromatic compound and conjugated diene compound in an inert solvent using a catalyst or the like. The method of hydrogenating the block copolymer can be carried out by a known method, for example, a method described in JP-B-42-8704, JP-B-43-6636, or the like. The method is not particularly limited as long as the hydrogenation rate is 80% or more.

The sheath component constituting the core-sheath type composite fiber of the present invention has a solubility parameter (S
P value) is a fiber-forming thermoplastic polymer having a difference of 1 or more, and when such a polymer is used as a sheath component, 20% by weight or less of an olefin-based compound is used so that the core component and the sheath component do not peel off. Must be contained. The olefin compound may be contained in the above-mentioned block copolymer (core component), or may be contained in both the core and sheath components. In terms of block copolymer (core component)
Is more preferable. Examples of the thermoplastic polymer include polyethylene terephthalate, polybutylene terephthalate and, for example, isophthalic acid, naphthalene dicarboxylic acid, diphenyl dicarboxylic acid, diphenoxy ethane dicarboxylic acid, β-hydroxyethoxy benzoic acid, and 5-sodium sulfoisophthalic acid. , Adipic acid, sebacic acid, aromatic, aliphatic, alicyclic dicarboxylic acids such as 1,4-cyclohexanedicarboxylic acid, propylene glycol, butylene glycol, diethylene glycol, neopentyl glycol, cyclohexane 1,4 dimethanol, bisphenol A A polyester obtained by copolymerizing a third component such as bisphenol S;
Examples thereof include polyamides such as nylon 6 and nylon 66. The olefinic compound is not particularly limited as long as it is a compound that can improve the affinity between the core component and the sheath component, and examples thereof include polyethylene, polypropylene, polybutene, and block copolymers thereof. α
Copolymers of olefins with acrylic acid, methacrylic acid, maleic acid, etc .; and olefin polymers such as compounds (ionomers) obtained by neutralizing the copolymers with metal compounds. May be appropriately selected, for example, when polyester is used as the sheath component,
It is desirable to select, as the olefinic compound, an ionomer neutralized with metal ions such as sodium, potassium, magnesium, and zinc. Further, the compounding amount of the olefinic compound is preferably 20% by weight or less, particularly preferably 3% by weight to 10% by weight based on the whole fiber.
Conversely, it adversely affects the spinnability and the color tone of the fiber. Since the lower limit of the compounding amount varies depending on the combination of the sheath component and the selected olefin compound, it cannot be determined unconditionally. However, when polyester is used as the sheath component, it is preferable to use about 3% by weight or more of the olefin compound.

The weight ratio (core / sheath) of the core component and the sheath component in the core-sheath type composite fiber of the present invention is 80/20 to 20.
/ 80, and the block copolymer is preferably 80
If the content is more than 10% by weight, the processability of spinning, drawing and the like will be remarkably deteriorated. On the other hand, if the amount of the polymer is less than 20% by weight, sufficient elasticity cannot be obtained. Therefore, their weight ratio is 70/30
It is desirable to be で 40/60. The conjugate fiber of the present invention can be spun using an ordinary core-sheath type conjugate fiber melt spinning apparatus. The core-sheath form may be single-core or multi-core. The cross-sectional shape of the fiber is circular, elliptical, dog bone, tri-octagonal, multi-local, T
Various irregular cross-sections such as a letter shape may be used, and the single yarn denier is not particularly limited and may be selected according to the intended product, and is generally about 1 to 50 denier, preferably about 1.5 to 3 denier.
It is 0 denier. Various additives may be added to the conjugate fiber of the present invention as needed. For example, catalysts, coloring inhibitors, heat-resistant agents, flame retardants, antibacterial agents, deodorants, optical brighteners, matting agents, coloring agents, gloss improvers, antistatic agents, fragrances, inorganic fine particles, etc. are included. May be.

The thus obtained core-in-sheath type conjugate fiber of the present invention has excellent elastic properties and can be used in various applications, and can be used as short fibers or long fibers such as woven fabric, knitted fabric and non-woven fabric. And is useful as a textile product such as sports clothing, stockings, socks, bandages, cataplasms, pile products, and the like. It is also suitable as a product. In particular, a pile product using the conjugate fiber of the present invention for a pile yarn can obtain a product having excellent set resistance with a set rate of 3% or less as seen in the following examples.

[0012]

EXAMPLES The present invention will be described below in detail with reference to examples, but the present invention is not limited to these examples. In addition, the hair fall property test in an Example was performed as follows. Hair fall property test: A pile fabric using the composite fiber of the present invention as a pile yarn is prepared, and the height of the pile is measured to be L0. A load of 40 g / m @ 2 was applied to this pile fabric,
After leaving at 0 ° C. for 2 hours and removing the weight, the pile height is measured, and when this is defined as L1, the sag rate is determined by the following equation. Set rate (%) = {(L0−L1) / L0} × 100

Example 1 As a block copolymer, a solubility composed of a block B having a styrene block A content of 30% by weight, a 1,4 bond content of an isoprene block of 95%, and a hydrogenation rate of 98%. AB having a number-average molecular weight of 50,000 having a parameter of 8.1 and a melt viscosity at 285 ° C. of 500 poise.
A triblock type polymer was used, and 5% by weight of an ionomer “Himilan” manufactured by Dupont-Mitsui Polychemicals Co., Ltd. was blended with the polymer as a core component. On the other hand, polyethylene terephthalate having an intrinsic viscosity [η] of 0.63 dl / g and a solubility parameter of 10.8 was used as a sheath component, and the composite ratio was 50:50 at 285 ° C. from a round cross-section die hole by a conventional composite melt spinning apparatus. 60 concentric circles
A wound undrawn yarn was obtained at a discharge rate of 0 g / min and a speed of 1000 m / min. After bundling this undrawn yarn, drawing at a draw ratio of 3 and a drawing temperature of 75 ° C., a heat treatment at a tension heat treatment temperature of 180 ° C., and mechanical crimping by an indentation type crimping device,
The fiber was cut into 51 mm to obtain short fibers having a single denier of 2 dr.
Using this fiber, a spun yarn having a cotton count of 20/2 was obtained by an ordinary spinning method. When this spun yarn was observed, no separation between the core component and the sheath component was observed. Next, this spun yarn is dyed, and the pile basis weight is 320 g /
A moquette with m ↑ 2 and a pile height of 4 mm was prepared, and a pile falling test was performed using this moquette. As a result, the pile using the composite fiber of the present invention has a set rate of 3
%, Which was excellent.

Example 2 Short fibers were produced in the same manner as in Example 1 except that the core / sheath ratio was 70/30 and the content of the olefinic compound was 10% by weight, and a moquette was prepared. Evaluation was performed in the same manner as in Example 1. The pile set rate of this moquette was 2%, and it had very good elastic properties.

[0015]

Comparative Example 1 Short fibers were produced and spun under the same conditions as in Example 1 except that no olefinic compound was added, but the core component and sheath component of many fibers were peeled off in the carding process. The obtained spun yarn having poor spinnability was extremely poor in quality.

Comparative Example 2 Short fibers were produced in the same manner as in Example 1 except that a block copolymer having a hydrogenation ratio of 50% was used as a core component, and a moquette was formed from the short fibers. Although the short fibers were produced, the short fibers were strongly colored at the time of fiberization, and the deterioration with time was conspicuous, so that a practical moquette could not be obtained.

Claims (1)

(57) [Claims] 1. A composite fiber in which two kinds of thermoplastic polymers are arranged in a core-sheath shape over the entire length of the fiber, wherein the thermoplastic polymer constituting the core component is a conjugated diene having a hydrogenation ratio of 80% or more. The block copolymer is composed of a base polymer block B and an aromatic vinyl polymer block A, wherein the block A accounts for 10 to 50% by weight, and the sheath component has a difference in solubility parameter from the block copolymer. Is one or more fiber-forming thermoplastic polymers, and the olefin-based compound is contained in the core component or the sheath component in a ratio of 20% by weight or less (based on the weight of the fiber). Composite fiber.