JP4820153B2 - Multifilament for splitting with crimpability - Google Patents

Description

  The present invention relates to a multifilament for splitting having an atypical cross section obtained by using a single polymer, and provides crimpability in a fiber production process without imparting crimps in a subsequent process after fiber production. The present invention relates to a multifilament for splitting provided, and further relates to a monofilament obtained by splitting a multifilament.

In recent years, the technology for splitting multifilaments has been widely used not only for clothing but also for general industrial materials, and the range of application of the technology has been expanded.
There is also an increasing need for a split monofilament subjected to crimping treatment obtained by splitting a multifilament for splitting after post-processing.
Examples of a method for imparting crimps to the multifilament for splitting in a later step include false twisting, but the crimping process is a low-speed process and increases the cost. A special technique is required for the splitting.

  In addition, as a spinning technique for crimping fibers without providing a post-process, two or more types of thermoplastic resins having different heat shrinkage rates are used, and these two types of polymers are used on both sides of the fiber cross section. A side-by-side conjugate spinning technique is mentioned. This technology requires special spinning equipment, which increases capital investment costs and causes problems such as separation of the polymer bonding surface in the fiber separation process, fibrillation, and reduced fiber separation workability. It was.

The present invention has found that when a flat cross-section fiber is applied in the production of a fabric exhibiting visibility or light shielding properties, the cover factor of the fibers constituting the fabric is increased, and the visibility prevention effect and light shielding effect are improved. On the other hand (see Japanese Patent Application Laid-Open No. 2004-162194), the crimping performance, which is a latent property of the flat cross-section fiber found derivatively, is used.
JP 2004-162194 A

  The present invention solves the above-mentioned problems of the prior art, and uses a single polymer, has a crimp without passing through a post-process, and has excellent splitting properties. It is to provide a monofilament.

  As a result of intensive studies in order to solve the above problems, the present inventor has produced anisotropic cooling in the case of fibers having a flatness in a specific range during melt spinning of a thermoplastic resin, and the flat cross-section fibers It has been found that crimping performance can be imparted, and the invention has been completed.

That is, the invention according to claim 1 is a modified cross-section fiber obtained by using a single type of thermoplastic polymer, and the diameter ratio between the circumscribed circle of the section and the maximum diameter of the inscribed circle is 3 to 3. 15 to 1 range, single yarn fineness is 5 to 55 dtex, and the number of crimps per meter of fiber length after 1.1-fold drawing at 120 ° C. is 50 to 200 folds. Multifilament for use.

  Here, the single type of thermoplastic polymer includes not only a homopolymer but also a copolymer copolymerized homogeneously. In short, in the present invention, it is a feature of the present invention that there is no need to apply a composite structure composed of a combination of plural kinds of different polymers, which is the mainstream of the prior art.

Further, if the diameter ratio between the circumscribed circle of the cross section and the maximum diameter of the inscribed circle is 3 to 15, the cross section may be triangular or quadrilateral. The present invention utilizes an anisotropic cooling effect based on an atypical / flat shape when a thermoplastic resin is discharged from a melt spinning nozzle. In principle, it can be applied to a wide flat fiber or film yarn.

Invention relating to claim 2 is a monofilament minute繊用multifilament according obtained by dividing fiber in 請 Motomeko 1.

  According to the present invention, flat cross-section fibers exhibiting crimpability can be obtained from a single polymer without needing to bond plural kinds of different polymers to the side-by-side type. In the present invention, not only can melt spinning be easily carried out, but the equipment is as simple as usual, the workability is good, and there is almost no failure, so maintenance of the equipment is also easy. Moreover, there is an advantage that the production cost is low.

  Furthermore, in the splitting, the flat crimped fiber of the present invention is less peeled at the joint surface than the one in which a different polymer is bonded to the side-by-side type, and thus there is no concern about fibrillation, and workability at the time of splitting. Is good.

Hereinafter, embodiments of the present invention will be described in detail.
The multifilament provided in the present invention is formed from a thermoplastic resin such as polyester or polyamide. Specifically, there are polyethylene terephthalate, polybutylene terephthalate, polytrimethylene terephthalate, etc. The appropriate one is used.

In order to obtain a multifilament for splitting having this crimp, the single yarn fineness is 5 to 55 dtex (preferably 11 to 33 dtex), the single yarn cross-sectional shape is an irregular cross-sectional fiber, and the circumscribed circle of the cross section And the ratio of the diameter of the inscribed circle to the maximum diameter is 3 to 15: 1. The irregular cross-section fiber can be selected from a rectangular shape and an elliptical shape, and the shape ratio of the flat cross section is 3-15 to 1 in the ratio of the diameter between the circumscribed circle of the cross section and the maximum diameter of the inscribed circle. sell. Moreover, this flat cross-section fiber can also select what has two or more constricted parts as the cross-sectional shape.

In the present invention, by defining the cross-sectional shape as described above, when the polymer melt-spun from the spinneret is cooled, a difference occurs in the cooling rate in the fiber cross-sectional direction, resulting in the orientation in the fiber cross-sectional direction. A difference is born, resulting in a crimped yarn. The percentage of the diameter of the maximum diameter of the circumscribed circle and inscribed circle is not obtained almost crimpable when if less than 3. Further, if the ratio of the diameter between the circumscribed circle and the maximum diameter of the inscribed circle exceeds 15, the yarn-making property is deteriorated, and it is difficult to produce such ultra-flattened flat fibers with high productivity.

That is, in the present invention, using a single type of thermoplastic polymer made of polyester or polyamide for clothing and industrial materials, it is a modified cross-section fiber obtained by melt spinning from a modified cross-section nozzle, A flat cross-section fiber having a diameter ratio of a circumscribed circle of the cross section and a maximum diameter of the inscribed circle of 3 to 15 to 1 and a single yarn fineness of 5 to 55 dtex is manufactured by a usual means. The flat cross-section fiber has a crimping frequency of 50 to 200 crests after crimping 1.1 times at 120 ° C. A multifilament crimped by one melt spinning can be efficiently produced, and the multifilament can be divided with good workability to obtain a high-quality monofilament.

Hereinafter, the present invention will be described in more detail with reference to examples. In addition, the evaluation described in the examples was measured by the following method.
(1) Crimpability After the split sample is stretched 1.1 times in a dry heat atmosphere at 120 ° C. at a yarn speed of 10 m / min, the number of peaks with a sample yarn length of 20 cm in an unloaded state is measured five times. And expressed as crimpability per meter.
(2) Separation property The percentage of 50 drum-shaped packages wound up on a 10 kg bag was separated into four monofilaments at a separation speed of 600 m / min without breaking the yarn.

[Example 1]
A polyethylene terephthalate having an intrinsic viscosity of 0.64 is spun at a spinning temperature of 290 ° C. from a base whose diameter ratio between the circumscribed circle and the maximum diameter of the inscribed circle shown in FIG. Then, after winding at a spinning speed of 900 m / min, the film is stretched under the conditions of a preheating temperature of 90 ° C., a heat setting temperature of 120 ° C. and a stretching ratio of 4.0 without winding once, and wound into a drum at a speed of 3500 m / min. A multifilament made of a modified cross-section fiber of the present invention having a total fineness of 66 dtex, a filament number of 4 and a single yarn fineness of 15 dtex was obtained.
Table 1 shows the results of evaluating the obtained multifilaments by the following methods.

[Example 2]
In Example 1, the spinneret was changed, and the diameter ratio of the circumscribed circle and the maximum diameter of the inscribed circle in the cross section shown in FIG. To obtain monofilaments. The results are shown in Table 1.

[Example 3]
In Example 1, the spinneret is changed, and the cross-sectional shape shown in FIG. 3 is a flat cross-sectional yarn having two constricted portions, and the ratio of the diameter between the circumscribed circle of the cross section and the maximum diameter of the inscribed circle is 4. A multifilament for splitting was obtained in the same manner as in Example 1 except that the monofilament was obtained by splitting them. The results are shown in Table 1.

[Comparative Example 1 and Comparative Example 2]
In Example 1, except that the spinneret was changed and changed as shown in Table 1, multifilaments for separating fibers were obtained in the same manner as in Example 1, and they were separated to obtain monofilaments. The results are shown in Table 1.

[Comparative Example 3]
A multifilament for splitting was obtained in the same manner as in Example 1 from a die in which polyethylene terephthalate having intrinsic viscosities of 0.64 and 0.45 was bonded with a side-by-side conjugate and the fiber cross section was a round cross section. . The results are summarized in Table 1.

  According to the present invention, flat cross-section fibers exhibiting crimpability can be obtained from a single polymer without needing to bond plural kinds of different polymers to the side-by-side type. In the present invention, not only can melt spinning be easily carried out, but the equipment is as simple as usual, the workability is good, and there is almost no failure, so maintenance of the equipment is also easy. Moreover, there is an advantage that the production cost is low.

  Furthermore, in the splitting, the flat crimped fiber of the present invention is less peeled at the joint surface than the one in which a different polymer is bonded to the side-by-side type, and thus there is no concern about fibrillation, and workability at the time of splitting. Is good.

It is an illustration of the flat cross section fiber used as the Example of this invention, Comprising: It is a figure which shows typically the relationship between the ratio of the diameter of the circumscribed circle of a fiber cross section, and the maximum diameter of an inscribed circle . It is an illustration of the triangular cross-section fiber used as the Example of this invention, Comprising: The relationship between the circumscribed circle diameter (A) and inscribed circle diameter (B) of a fiber cross section is shown as a schematic diagram. It is an example of the flat cross-section fiber which has four constrictions used as the Example of this invention, Comprising: The relationship between the diameter ratio of the circumscribed circle of a fiber cross section and the maximum diameter of an inscribed circle is shown typically.

Maximum diameter of A fiber cross Menmata maximum diameter or inscribed circle of triangle cross-sectional fiber of the inscribed circle of the circumscribed circle diameter B fiber cross section of a triangular cross-section fibers

Claims (2)

A modified cross-section fiber obtained by using a single type of thermoplastic polymer, the diameter ratio of the circumscribed circle of the cross section and the maximum diameter of the inscribed circle being in the range of 3 to 15: 1, single yarn A multifilament for splitting having a fineness of 5 to 55 dtex and a crimping property of 50 to 200 crimps per meter of fiber length after 1.1 times stretching at 120 ° C. A monofilament having a flat cross section obtained by dividing the multifilament for splitting according to claim 1 .