JPH0551822A - Polyester-based conjugate fiber excellent in fastness - Google Patents

Abstract

PURPOSE:To obtain the subject fiber, suitable as a raw material for nonwoven fabrics according to a hot bonding method and dyeable with a disperse dye by using a polyester as a core component and polyethylene as a sheath component and regulating the thickness of the sheath component to a prescribed value or below and the residual elongation to a prescribed value or above. CONSTITUTION:The objective fiber is core-sheath type conjugate fiber containing (A) a core component of a polyester and (B) a sheath component of polyethylene. The thickness of the polyethylene which is the component (B) is <=15mum and the residual elongation is >=20%. The above-mentioned fiber is dyeable with a disperse dye.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a heat-adhesive conjugate fiber which is preferably used as a raw material for a nonwoven fabric by a heat-adhesion method and which can be easily dyed with a disperse dye and has excellent fastness. Regarding fibers.

[0002]

2. Description of the Related Art Conventionally, many colored fibers used as raw materials for nonwoven fabrics are produced by a stock solution coloring method. But,
This method is not suitable for small-quantity production because a large amount of loss occurs in the replacement of the resin in the spinning device when a fiber having a different color from the conventional one is produced. Although there is a method of directly printing a dye on the surface of a non-woven fabric, its use is limited because a product with a good texture cannot be obtained. Therefore, a method of arbitrarily dyeing a nonwoven fabric using dyeable heat-adhesive conjugate fibers is most preferable. However, such a fiber has not existed because the polyolefin generally used as the adhesive component of the heat-adhesive conjugate fiber is hardly dyeable.

[0003]

SUMMARY OF THE INVENTION The present invention overcomes the above-mentioned conventional technical problems and provides economically a thermoadhesive conjugate fiber which can easily dye an arbitrary amount in an arbitrary color and has excellent fastness. There is something to do.

[0004]

Means for Solving the Problems As a result of earnest research for solving the above problems, the present inventor has found that in a core-sheath type composite fiber using polyester as a core component and polyethylene as a sheath component, polyethylene as a sheath component is used. And the residual elongation of 20% or more can be dyed by a conventional method using a disperse dye, and the dyeing fastness after being formed into a nonwoven fabric is excellent, and the present invention is completed. Came to. The polyester used in the present invention may be a copolymer such as polyethylene (terephthalate / isophthalate) other than polyethylene terephthalate, which is a thermoplastic polyester generally used as a fiber raw material, and has a melting point of 2
Those having an intrinsic viscosity of 50 to 260 ° C. and an inherent viscosity of 0.5 to 1.2 (30 ° C. in phenol / tetrachloroethane) are preferably used. Examples of polyethylene used in the present invention include high-density polyethylene, linear low-density polyethylene, low-density polyethylene, and ethylene-vinyl acetate copolymer, but high-density polyethylene capable of dyeing in various colors is preferable. Good melt flow rate of 8 to 2
No. 8 (190 ° C., 2.16 Kgf) is more preferably used.

The polyester and polyethylene described above are composite-spun into a sheath-core type so that the core is made of polyester and the sheath is made of polyethylene and the core is completely covered with the sheath. By doing so, the polyethylene of the sheath prevents the disperse dye from coming off after dyeing, and the friction fastness and the wash fastness are remarkably improved. However, it is necessary to control the thickness of the polyethylene film so as not to hinder the dyeing of the disperse dye inside the polyester, and as a result of experience, the thickness of the film must be 15 μm or less. When the thickness of the polyethylene film is within the range of this condition, the core polyester can be adjusted to a required fiber diameter according to the application of the composite fiber. The residual elongation of the composite fiber is closely related to the crystallinity of the polyester, and generally, as the crystallinity increases, the residual elongation decreases. In the present invention, it was found that the dyeability deteriorates when the residual elongation decreases, and the residual elongation was set to 20% or more as a standard showing good dyeability.

The disperse dye used in the present invention is generally a commercially available disperse dye for polyester fibers. For example, Miket
on Polyester Navy Blue RRS
F (Mitsui Toatsu Co., Ltd .: trade name) can be exemplified. The conventional high-temperature dyeing method for polyester can be applied as is to the dyeing method. However, considering the texture of the subsequent non-woven fabric, the melting point and softening point of the high-density polyethylene used as the raw material, 13
0 ° C or less is desirable. After dyeing, it can be processed in the same way as ordinary polyester fibers by a dyeing and finishing process using an ordinary finishing agent. Further, after the raw cotton is processed into a nonwoven fabric in advance, it can be dyed by the same method.

[0007]

EXAMPLES The present invention will be described in more detail with reference to the following examples and comparative examples. The evaluation method in each example is shown below. Residual elongation: Measured with a constant-speed extension type tensile tester according to JIS L 1015-77. Friction fastness: Tested in a dry state and a wet state in accordance with JIS L 0849, and judged by a gray scale for contamination of JIS L 0801. Washing fastness: According to JIS L 0844 A-2,
Each white cloth made of cotton, nylon and polyester was tested for contamination, and the coloration of the test liquid was also judged. Dyeing property: The state of the residual liquid in the dyeing bath is visually observed, and when it becomes almost transparent (⊚), when some color remains (∘), when the residual liquid shows a clear residual color. (Δ), those that were hardly dyed were indicated as (x), and those of (⊚) and (∘) were judged to be practically acceptable.

[0008]

Examples 1 to 4 and Comparative Examples 1 to 3 Polyester having an intrinsic viscosity of 0.65 at an extrusion temperature of 300 ° C. and MFR (190 ° C.)
20 high-density polyethylene was spun out from a composite spinneret with 100 holes at a discharge temperature of 200 ° C. so as to have the fiber diameters set in Table 1 and Table 2, drawn 2.5 times, and wound. It was crimped and cut into 51 mm to obtain staples. Disperse dye Mik in 5 liters of 0.1% sodium acetate solution
Eton Polyester Navy Blue
100 g of the above staples were dipped in a dye bath in which 2 g of RRSF (Mitsui Toatsu) was melted, and the temperature was raised from 50 ° C to 125 ° C.
The temperature was raised at .degree. C./min, then kept at 125.degree. C. for 1 hour, then washed with water for 3 minutes, and then soaped with potassium dodecyl phosphate. This cotton was carded into a web having a basis weight of 50 g / m ² and heat-treated with a suction dryer at 135 ° C. to obtain a nonwoven fabric. The friction fastness and the wash fastness of this nonwoven fabric were measured. The results are shown in Table 1.
Shown in.

[0009]

[Table 1]

[0010]

Examples 5 to 6 and Comparative Example 4 Using the above polyester and polyethylene, melt spinning was performed in the same manner to obtain an unstretched yarn, and the stretching ratio was adjusted so as to obtain a predetermined residual elongation. Fiber was obtained. The same test as in Example 1 was performed on these conjugate fibers. The results are shown in Table 2.

[0011]

[Table 2]

[0012]

Industrial Applicability According to the method of the present invention, it is possible to economically provide a polyester-based heat-fusible fiber which can be easily dyed by a commonly used dispersion dyeing method and has high fastness.

Claims (1)

[Claims] 1. A core-sheath type composite fiber in which the core component is polyester and the sheath component is polyethylene, wherein the polyethylene of the sheath component has a thickness of 15 μm or less and a residual elongation of 20.
% Or more, a polyester-based conjugate fiber that can be dyed with a disperse dye.