JPS62299516A - Antistatic polyester conjugated fiber - Google Patents

Abstract

PURPOSE:A fiber resistant to lowering of electrical conductivity and to fibrillation, comprising a conductive polyamide component containing conductive carbon black and a polyester component copolymerized with an isophthalic acid component having a metal sulfonate group, wherein the polyamide component and polyester component are connected with each other in the direction of the axis of the fiber. CONSTITUTION:An antistatic conjugated fiber comprises a conductive polyamide component B containing 15-50wt% conductive carbon black and a non- conductive polyester component A copolymerized with 0.7-6.0mol% isophthalic acid component containing a metal sulfonate group. The polyamide component B and polyester component A are connected with each other in the direction of the axis of the fiber. The non-conductive polyester is preferably further copolymerized with a glycol component having a molecular weight of 90-6,000. In addition, the edge of the connected interface of the components A and B are preferably exposed to the surface of said fiber.

Description

Detailed Description of the Invention 3. Detailed Description of the Invention [Field of Industrial Application] The present invention is an improvement of an antistatic composite fiber made by bonding a conductive polyamide and a non-conductive polyester in the fiber axis direction. Regarding. In particular, it relates to the conductivity of a composite structure in which the interface end of the bond between non-conductive polyester and conductive polyamide is exposed on the fiber surface, and to improvements in single-component fibers.

[Prior Art] Composite fibers containing a layer made of a conductive thermoplastic synthetic polymer containing conductive carbon black (hereinafter referred to as a conductive layer) are used as cable materials that provide antistatic properties to textile products such as carpets and clothing. It has been widely used as Typical composite forms include a double core/sheath type with a conductive layer as the core (Japanese Patent Publication No. 31450/1983), and a triple core/sheath type with a conductive layer as the middle layer (1j1).
7/-J (!1 Yuki), partial encircling bonding type in which a conductive layer and a non-conductive layer are bonded so as to partially surround a conductive layer (Japanese Patent Publication No. 53-44579, etc.); A through-joint type in which a conductive layer is sandwiched between non-conductive layers so that only both ends of the elongated conductive layer are exposed on the fiber surface.
37322, etc.), or a multiple exposed bonding type in which the conductive layer is divided into a plurality of parts and arranged symmetrically on the fiber surface (Japanese Patent Application Laid-open No. 134117/1982).

Fibers with a composite structure in which a conductive layer is completely surrounded by a non-conductive layer (for example, the above-mentioned double core-sheath type or triple core-sheath type composite fibers) are suitable for antistatic use when mixed in IIi textile products. It is useful as a flexible material and is widely used for carpets, etc.

However, fibers with a composite structure in which a conductive layer is completely surrounded by a non-conductive layer have a high level of conductive performance (for example, the applied voltage Ratio resistance value at 100V is 1X
For these applications, composite fibers with a composite structure in which the conductive layer is exposed on the fiber surface, and composite fibers with a composite structure in which the conductive layer is exposed on the fiber surface, Conductive fibers with relatively high conductivity, such as coated fibers coated with conductive substances, have been used. Among these highly conductive fibers, the use of composite fibers with exposed conductive layers is recommended due to their superior uniformity in fineness and ease of handling during post-processing.

On the other hand, among thermoplastic polymers, polyester has excellent chemical resistance, heat resistance, light resistance, and dimensional stability, as well as high Young's modulus. It is suitably used as a material for clothing. Therefore, for these applications, the antistatic fiber used in the mixture is also required to be a polyester fiber.
This polyester fiber is generally manufactured by combining a non-conductive polyester and a conductive polymer.

However, since polyester has poor compatibility with conductive carbon black, it is difficult to finely and uniformly mix conductive carbon black into polyester. Moreover, even if carbon black is mixed into polyester, if it is allowed to remain in a molten state, hydrolysis and the resulting decrease in viscosity will be large, and the fiber forming ability will be significantly deteriorated.

Therefore, it is difficult to manufacture composite fibers from conductive polyester mixed with carbon black in actual industrial production.

Therefore, polyamide, polyethylene, etc. are generally used as base polymers for conductive polymers. In other words, when manufacturing polyester conductive fibers,
As the conductive polymer, polyamide-based or polyethylene-based conductive components are used, and among them, polyamide-based conductive components are generally used.

In the case of polyester composite fibers containing conductive polyamide as one component, due to poor bonding between both polymers,
Peeling phenomenon that creates holes at the bonding interface is likely to occur. This peeling phenomenon is particularly noticeable in the case of composite forms in which the bonded interface edges of both polymers are exposed on the fiber surface, such as in the case of dustproof clothing that is repeatedly washed under harsh conditions during use. Due to the peeling phenomenon that occurs with repeated washing,
This causes a decrease in conductive performance and fibrillation, which may cause problems in practical use.
This has become a major problem.

[Problems to be Solved by the Invention] The present invention has good adhesion at the composite interface, and even when used under harsh conditions, it does not cause interfacial peeling, resulting deterioration in conductive performance, or fibrillation. can be significantly suppressed,
Can be used in good condition for a long period of time,
The main purpose is to provide polyester/polyamide conductive fibers.

[Means and effects for solving the problem] In order to achieve this object, the conductive polyester composite fiber according to the present invention contains 15 to 50% by weight of non-conductive polyester.
A conductive composite fiber formed by joining a conductive polyamide containing conductive carbon black in the fiber axis direction, wherein the non-conductive polyester contains 0.7 to 6.0 moles of a metal sulfonate group-containing isophthalic acid component. % copolymerized polyester, preferably a polyester having a molecular weight of 90% along with the metal sulfonate group-containing isophthalic acid component.
It is characterized in that it is a polyester formed by copolymerizing 10% by weight or less of a glycol component of ~6000.

The non-conductive polyester component used in the composite fiber according to the present invention is a normal polyester such as polyethylene terephthalate or polybutylene terephthalate, and an isophthalic acid component containing a metal sulfonate group of 0.7 to 6.0%.
It is a modified polyester obtained by copolymerizing 10% by mole or less of a glycol component having a molecular weight of 90 to 6,000.

If the copolymerization of the metal sulfonate group-containing isophthalic acid component is too small, the adhesion to the polyester component cannot be sufficiently improved. On the other hand, if the amount is too large, the melt viscosity of the polymer becomes extremely high, making it difficult to perform melt spinning in a satisfactory manner. Its blending amount is 1.0 to 3.0
Mol% is preferred.

This metal sulfonate group-containing isophthalic acid component has the following formula: n is an integer of 2 or more) is used, specifically dimethyl (5
-sodium sulfo) isophthalate, bis-2-hydroxyethyl (5-sodium sulfo) isophthalate, bis-2-hydroxybutyl (5-sodium sulfo) isophthalate, and the like.

In addition to the metal sulfonate group-containing isophthalic acid component,
Furthermore, it is preferable to copolymerize a glycol component, and this glycol component needs to have a molecular weight of 90 to 6,000, preferably 100 to 4,000.
The roughness is preferably 100 to 900.

The glycol components include neopentyl glycol, 1,4-butanediol, 1,5-bentanediol, and 1,6-hexanediol.

] 4-Cyclohexanediol 1.4-Cyclohexane dimetatool, a bisphenol-ethylene oxide adduct, a polyalkylene glycol represented by the following formula, and the like are used.

A(CnH2,0)InH (However, A is C42 days 2.2+10 or OH.

α is 1 to 10. n is 2-5 and m is 2-65. ) This modified polyester is known as basic dye dyeable polyester, and is disclosed in Japanese Patent Application Laid-Open No. 57-21.
It can be obtained by polymerization using the methods described in JP-A-59-26521 and the like. That is, the addition of the above-mentioned copolymer component causes the ``!'' of the polyester to be added to the polyester. ! A
It may be added at any stage up to the completion of the reaction, but it is preferably added at a stage before the initial stage of the polycondensation reaction.

For conductive composite fibers, it is particularly preferable to use dimethyl (5-sodium sulfo) isophthalate as the isophthalic component and polyalkylene glycol as the glycol component.

Note that the modified polyester used in the present invention may contain copolymer components other than those mentioned above within a range that does not impede its excellent properties.

In general, antistatic improvers such as polyether polyamides, N-alkyl polyamides, and derivatives thereof may be blended into this non-conductive polyester component, or ordinary textile additives may be blended. Good too. Further, in order to suppress the black color of carbon black, a matting agent such as titanium oxide may be added.

On the other hand, conductive polyamide is nylon 6 and nylon 66.
An ordinary conductive polyamide component obtained by mixing and finely dispersing about 15 to 50% by weight of ordinary conductive carbon black in an ordinary polyamide, such as, may be used.

The composite structure and composite spinning method are not particularly limited, but composite fibers in which non-conductive polyester and conductive polyamide are directly bonded and the interface edge of the bond is exposed on the fiber surface, such as , a triple core-sheath composite fiber with a partially exposed conductive layer, in which a conductive sheath layer is formed around a non-conductive core layer, and an outermost layer is formed to partially cover the outer periphery of the conductive layer. The present invention is particularly effective for $11 (see Figures 1-3). In the case of this antistatic fiber having a composite structure, the composite ratio of the conductive layer is preferably about 10 to 25%. Also. In order to suppress filament crimp, improve post-processability, and increase yarn strength, the non-conductive core layer should be as large as possible; for example, the ratio of the core layer to the total non-conductive component should be 40% or more. It is preferable.

Since the conductive polyester composite fiber according to the present invention uses the above-mentioned specific polyester as the non-conductive polyester, the adhesion with the conductive polyamide is greatly improved, and peeling at the bonding interface is greatly suppressed. be done.

[Example] Dimethyl (5-sodium sulfo) isophthalate
．． Non-conductive polyester A is prepared by adding 0.05% by weight of titanium oxide to polyethylene terephthalate, which is obtained by copolymerizing 3% by mole of polyethylene glycol and 1.0% by weight of polyethylene glycol with a molecular weight of 1600, and sulfuric acid with a relative viscosity of 2.0% by weight. 3
5% nylon 6 with 35% conductive carbon black
290% conductive polyamide B dispersed therein, respectively.
' After melting and filtration at C, the composite spinneret shown in Figure 2.3 (
The composite ratio (cross-sectional area ratio) of the core layer, conductive inner sheath layer, and non-conductive core layer is 45:
Composite spinning at 15:40, cooling and refueling at 70
It was wound up at 0 m/min. The obtained undrawn yarn was stretched 3.4 times with a hot pin at 115°C and a hot plate at 155°C, and
One piece of 0.0 denier, 3 filament composite fiber yarn. The 1σ composite fiber had a composite structure as shown in FIG. 1, and the ratio of the circumferential length exposed to the fiber surface to the outer circumferential length of the conductive inner sheath layer was 38% (Example).

On the other hand, as a comparative example, as non-conductive polyester A,
Composite fibers were produced using ordinary polyethylene terephthalate under the same conditions as in the examples (comparative example).

The specific resistance values of the conjugated fiber threads obtained by the jq process were as shown in Table 1.

Measuring method of specific resistance value of yarn: After deoiling with carbon tetrachloride, bundle it to make a sample bundle of 1QOO denier, cut it so that the measurement length is 1Qcm, apply conductive resin to both ends to use as an electrode, 20'C165%RH
The resistance value when 100 V DC was applied was measured in an atmosphere of 1, and was converted to specific resistance (Ωcm).

Table 1 Next, these two types of composite fibers were made using polyethylene terephthalate yarn with a warp and weft of 100 denier and 48 filaments, respectively, with a weaving density of 112 yarns/inch in the warp and 88 yarns/inch in the weft. During the weaving process, vertically,
The fabric was woven in a J1 shape with 6mm width spacing.

The obtained fabric was washed in a washer type washing machine (Asahi, W
EIII-10V), 4 times at 70'C hot water.
The 0 minute wash test was repeated.

The surface resistance and degree of fibrillation of this fabric were measured, and the results are shown in Table 2.

This surface resistance was determined by placing electrodes on a sample fabric placed on an insulating sheet at 5 cm intervals in the horizontal direction of the fabric, and measuring the electrical resistance value when 100V was applied.

Also, what is the degree of fibrillation? Relative R based on 1 and 2 observations
Judging by degrees.

[Effects of the Invention] Although the antistatic polyester composite fiber according to the present invention uses conductive polyamide, it has good adhesion at the bonding interface between both polymers, so washing (E) is not repeated. Even when used under harsh conditions such as products that
The composite form can be well maintained, excellent antistatic performance can be maintained over a long period of time, and fibrillation is less likely to occur.

In general, since polyester is used as the non-conductive polymer, it has excellent chemical resistance, and since polyamide is used as the base polymer for the conductive component, composite spinning can be easily performed using normal methods. Can be done.

The polyester composite fiber according to the present invention is useful for applications that particularly require chemical resistance and wash resistance, such as dust-proof clothing, explosion-proof clothing, and electrically conductive clothing.

[Brief explanation of the drawing]

FIG. 1 is a fiber cross-sectional view showing an example of a composite structure that can be formed by the polyester composite fiber according to the present invention. FIG. 2 is a partial vertical sectional view schematically showing a composite spinneret capable of producing fibers with the composite structure. Figure 3 shows
It is a top view of the lower spinneret plate 3 of the composite spinneret. [Explanation of symbols] A: Non-conductive polyester component B: Conductive polyamide component

Claims (3)

[Claims] (1) A conductive composite fiber formed by bonding a non-conductive polyester and a conductive polyamide containing 15 to 50% by weight of conductive carbon black in the fiber axis direction, wherein the non-conductive polyester is a metal sulfonate. An antistatic polyester composite fiber characterized by being a polyester obtained by copolymerizing 0.7 to 6.0 mol % of a group-containing isophthalic acid component. (2) The non-conductive polyester contains 0.7 to 6.0 mol% of a metal sulfonate group-containing isophthalic acid component and 10% by weight of a glycol component with a molecular weight of 90 to 6000.
The antistatic polyester composite fiber according to claim 1, which is a polyester obtained by copolymerizing the following: (3) The antistatic polyester composite according to claim 1, wherein the composite structure is such that the interface end of the bond between the non-conductive polyester and the conductive polyamide is exposed on the fiber surface. fiber.