JPS6147807A - Crimped porous hollow fiber and production therefor - Google Patents

Abstract

PURPOSE:To enlarge the anisotropy of fiber cross-sectional direction and soften the feeling, by quenching the one side of porous hollow fibers extruded from slits connecting hollow extrusion holes. CONSTITUTION:Extrusion holes for forming the hollow part are connected in the form of a straight line or extrusion holes for forming the hollow part are connected in the form of a ring to extrude porous hollow fibers in the cross-sectional form having joined fibers having the hollow part, and one side thereof is quenched. Thus, the aimed cross-sectional anisotropy can be imparted to the resultant fibers, and crimped porous hollow fibers having improved three-dimensional crimps and good heat insulating properties and soft feeling are obtained.

Description

Detailed Description of the Invention (Industrial Application Field) The present invention provides a crimped porous hollow material that exhibits highly excellent three-dimensional shrinkage, excellent bulkiness, snow recovery performance, heat retention, and flexible texture. Concerning delicacies and their manufacturing methods. Furthermore, the carpet in detail.

High pile - moquette and clothing fabric I! The present invention relates to a crimped porous hollow fiber that exhibits an excellent prickly-like characteristic when used in stuffing, etc., and a method for producing the same.

(Prior Art) Methods for imparting three-dimensional crimp to fibers by melt spinning have been proposed in the past, but it is difficult to achieve practical titration. That is, there is a method in which two types of polymers with different shrinkage properties are composite-spun into a bimetal type or a core sheath base with an eccentric core component. This method has the drawbacks that the spinning operation is quite difficult, it is difficult to obtain a product with stable quality, and the spinning equipment is complicated, so the installation cost is high.

(2) There is a method of heating one side of the solution-spun yarn to impart anisotropy in the cross-sectional direction, for example (see Japanese Patent Publication No. 13351/1983). This method involves heating each single ta fiber during the spinning operation. It is difficult to obtain a satisfactory product due to the occurrence of intermittent @ deposition.

(Q) A method of creating a non-uniform structure in the cross-sectional direction of the fiber by creating a certain angle between the direction in which the polymer is discharged from the nozzle and the direction in which the discharged yarn is taken (for example, Japanese Patent Publication No. 43-2
(Refer to Publication No. 7539). This method has drawbacks such as extremely poor spinning performance and very low operability since the flow state of the polymer at the nozzle outlet is extremely disturbed.

■ There is a method to obtain three-dimensional crimped fibers by blowing a cooling air stream onto the yarn immediately after discharge and imparting birefringence anisotropy in the cross-sectional direction (for example, see Japanese Patent Publication No. 38-7511). As an improvement on this, a method is proposed in which a single hollow portion is provided at the substantial center or eccentric position of the fiber cross section to further increase the anisotropy, as reported in Special Committee No. 1844-20497 Bulletin, No. 45-36.
It is described in Japanese Patent No. 330 and Japanese Patent No. 56-29007.

Furthermore, the cross-sectional shape is approximately quadrangular.

A method of rapidly cooling the cross section of a nylon discharged yarn having four hollow portions is described in Japanese Patent Laid-Open No. 112242/1983.

However, with the rolled fibers obtained by these methods, it is not possible to obtain rolled fibers that exhibit sufficiently satisfactory bulk, bulk recovery, heat retention, and texture, and the range of optimal conditions is extremely low. It's small and has low productivity.

(Object of the invention) The present invention has been made against the background of the above circumstances,
The aim is to create a crimped porous hollow lug that exhibits highly superior three-dimensional crimp, and exhibits excellent bulk, bulk recovery, heat retention, and flexible texture! An object of the present invention is to provide a Ji fiber and a method for producing it.

(Structure) As a result of studies to achieve the above-mentioned objective structure, the present inventors discovered that a porous hollow fiber is discharged from a slit in which hollow discharge holes capable of forming at least one hollow portion are connected via a slit. The inventors have discovered that by rapidly cooling one side of the fiber, the anisotropy in the cross-sectional direction of the fiber is expanded and the texture of the resulting crimp Rm becomes soft, and the present invention has been achieved.

That is, the present invention provides a crimped porous hollow fiber made of a thermoplastic polymer and having a plurality of hollow portions continuous in the longitudinal direction, which is formed by a curved line at the outer periphery in a cross section of the fiber. It is a crimped porous hollow fiber having a plurality of concave portions and having plane anisotropy as a 4I characteristic, and when melt spinning a porous hollow fiber made of a thermoplastic polymer, the porous hollow gL fiber is The yarn is discharged from a spinneret in which a nozzle in which a plurality of hollow discharge holes forming at least one hollow portion are connected via slits is disposed, and one side of the discharged yarn is then Crimp characterized by cooling by blowing cooling air having a wind speed of 0.2 m/sec or more from a direction substantially perpendicular to the running direction, and then stretching the obtained porous hollow undrawn yarn and then subjecting it to a heat treatment. This is a method for producing porous hollow fibers.

The term "vIr plane anisotropy" in this tJA refers to the existence of physical property differences such as birefringence differences in the fiber cross-sectional direction.

The present invention will be explained using the drawings.

1 and 2 are cross-sectional shapes of the nozzle of the spinneret used in the present invention, FIG. 3 is the cross-sectional shape of the nozzle of the spinneret used in the conventional method, and FIGS. 4 to 6 are shown in FIGS. 1 to 3. The cross-sectional shapes of the crimped porous hollow fibers of the present invention obtained using the nozzles having the cross-sectional shapes shown in FIG.

In FIG. 1 (&), 5l-5s indicates a slit, and the hollow portions are formed by slits S, and St, and slits S,
In the present invention, such sulin) (81) (sm),
and slit (S, ) (St ) is slit (S, )
It is important that they are connected.

The fibers discharged from the nozzle shown in Figure 1 (&) are $
As shown in Figure 4 (-), fibers with a single hollow part (also or This makes it possible to impart anisotropy.

On the other hand, the single hollow fiber shown in Figure 6, which is obtained from the conventional round hollow fiber nozzle shown in Figure 3, is 1
Even if cooling air is blown to cool only one side, since the cooling air also flows around to the leeward side, it tends to be uniformly cooled, and a high degree of cross-sectional anisotropy cannot be imparted.

In addition, from the nozzle for porous hollow fibers shown in Japanese Patent Application Laid-Open No. 54-112242 shown in Fig. 3 (-), the nozzle shown in Fig. 6 (-) is
A porous hollow fiber having a substantially rectangular cross-sectional shape as shown in b) is obtained.

However, if a substantially rectangular @ surface shape can be obtained as shown in Figure G3 (b), even if cooling air is blown onto one side of the fiber, the amount of cooling air that wraps around to the lee side can be reduced, resulting in a fairly advanced cross section. Although anisotropy can be imparted, it is difficult to obtain such a substantially rectangular cross-sectional shape, and a substantially circular cross-sectional shape is likely to be obtained.

As for the nozzle shape used in the present invention, the hollow part forming discharge holes are connected in a straight line as shown in Fig. 1 (in addition to al, fs1 Fig. The crimped fiber of the present invention having the cross-sectional shape shown in (c), or in which hollow part forming discharge holes are connected in an annular manner as shown in FIG. It is preferable to obtain the crimped fiber of the present invention having the cross-sectional shape shown in Figure 4 (dl~(-)). Since a hollow portion (E) is formed, an extremely high degree of cross-sectional anisotropy can be imparted, which is preferable.

Alternatively, as shown in Fig. 1 (shown in Fig. 1), the hollow part forming discharge holes may be connected in a ring shape, and a plurality of such nozzles may be connected. A crimped fiber having such a cross-sectional shape cannot be obtained by conventional composite spinning.

Furthermore, as shown in FIG. 2 (1> to (k)), a nozzle in which hollow discharge holes capable of forming a plurality of hollow parts are connected may be used. F shown in trout
r? If-shaped fibers are obtained.

Next, in the present invention, in order to rapidly cool one side of the fiber having the cross-sectional shape shown in Figure 1 (&) and discharged from the nozzle shown in Figure 1 (&), the discharge yarn It is important to blow cooling air with a wind speed of 0.2 m/sec or more from a direction perpendicular to the running direction of the vehicle.

Here, the direction in which the cooling air is blown is significantly (slanted) with respect to the traveling direction of the discharged yarn, or the wind speed is 0.2 m/min.
If the cooling time is less than seconds, one side of the fiber cannot be rapidly cooled and a high degree of cross-sectional anisotropy cannot be imparted.

The direction in which the cooling air is blown may be any direction as long as it is orthogonal to the running direction of the discharged yarn, but it is preferably in the direction of the arrow shown in FIG. [Cross-sectional anisotropy can be further enhanced by spraying from the direction in which the protrusions on the surface are present.

In addition, the cooling air is blown closer to the spinneret surface to be more effective, but in order to maintain good operability, it is preferably 1 to 35 m below the spinneret surface.

Although air is the most economical gas for cooling air,
Any gas may be used as long as it is inert to the polymer melt, and the temperature is preferably as low as possible, but from an economical point of view, a temperature of 10 to 40° is preferable.

By stretching the yarn thus obtained and subjecting it to relaxation heat treatment, 1@ shrinkage can be achieved.

As the stretching conditions at this time, it is preferable to adopt conditions in which the high degree of cross-sectional anisotropy imparted in the spinning process is sufficiently maintained, that is, a low temperature and low stretching ratio.

To specifically describe such stretching conditions in the case of polyester m-fiber, the stretching temperature is Tg±20'O (Tg:
The temperature is preferably within the range of the glass transition point of polyester), and the stretching ratio is preferably the highest stretching ratio of 65 to 95 inches.

The stretching method may be any method such as liquid bath stretching or pin stretching.

Further, the relaxation pre-heat treatment process is performed by making each single ffl fiber constituting the stretched yarn as unrestrained as possible, and then heat-treating it. Heat treatment temperature is 100-23
0°C is preferred. Such relaxation heat treatment may be performed in any state such as a filament shape, multifilament shape, stable shape, etc., and mechanical shrinkage may be applied before the relaxation heat treatment.

The hollowness ratio of the crimped porous hollow fiber obtained in this way is 5~
60 inches is preferable.

The term "hollowness ratio" as used herein refers to the ratio of the total area of the hollow portions in the cross section of the fiber to the area surrounded by the outer periphery of the cross section. To explain specifically using FIG. 4 (・), the total area of the hollow part (Sg) is
l-4), and the area surrounded by the outer periphery of the cross section (ST) is the hollow area area (Sv)
and the area occupied by the high molecular weight polymer (SP). That is, the hollowness ratio is expressed by the following formula.

R Hollowness ratio (1%) = 6 - + - 5 × 100 If the hollowness ratio exceeds 6096, the hollow part tends to be easily deformed, and if there are no 5-inch grooves, the anisotropy in the cross-sectional direction cannot be sufficiently maintained. There is a tendency that it cannot be granted.

In the present invention, the thermoplastic polymer refers to a polymer that can be melt-spun, and examples of such polymers include polyesters such as polyethylene terephthalate and polybutylene terephthalate, and polyolefins such as polyethylene and polypropylene. fAI knife 6. These are polyamides such as Naipun 66, and copolymers and polymer mixtures mainly made of these. In particular, it is preferable to use a polyester having 85 molti or more of ethylene terephthalate units because it has good thermal properties. And such polyester is 25
It is preferable that the rA limiting viscosity calculated from the viscosity measured in °0-chlorphenol is 0.35 to 0.90.

Incidentally, the polymer may contain additives such as a matting agent, an adhesive, an antistatic agent, and a flame retardant.

(Function) The conventionally known method of cooling one side of the fiber discharged from the nozzle shown in Fig. 3 (a) and (b) cannot sufficiently impart new surface anisotropy, so stuffing Unless physical T8 crimp processing such as a box or a fluid treatment nozzle is used in combination, sufficient crimp cannot be obtained.

In this regard, in the present invention, the cross-sectional shape of the discharged fibers is made into a shape that makes it difficult to be uniformly cooled by the cooling air.
Since it is difficult for the cooling air to go around to the leeward side, the temperature difference between the windward side and the leeward side of the fiber cross section can be made significantly larger than that of conventional ones, and the cross-sectional anisotropy is higher than that of conventional ones. It is possible to have a sexual nature.

Then, as a result of subjecting such am to relaxation heat treatment to develop crimp, it can exhibit large crimp and exhibit excellent bulkiness and bulk recovery properties.

Since it is a porous hollow fiber, it can exhibit good heat retention and a soft texture.

Moreover, since the range of optimal conditions for obtaining crimped fibers with good uniformity can be set wider than in conventional methods, productivity can be improved and production costs can be reduced.

(Effects of the Invention) The crimped fibers obtained by the production method of the present invention can be used for carpet +/S pile, moquette, clothing paper, silk, etc.
Particularly when used for word lines, a product is obtained that exhibits excellent characteristics of prickly hair.

(Example) Furthermore, the present invention will be further explained by examples.

Examples 1-3. Comparative Example 1 Polyethylene terephthalate having an intrinsic viscosity of 0.65 as measured in 25°00-courophenol was melted and discharged at 280°0 from a nozzle having the cross-sectional shape shown in Table 1.
The yarn was wound in a length of 0 ml and 1 m to obtain a single fiber drawn yarn with an atR degree of 25 denier. Cooling in the east of the discharge prefecture is 1.5 to 1 s below the mouth surface.
1.0 yt of cooling air at 25°0 at position tM1
This was done by blowing from a direction perpendicular to the direction in which the yarn advances at a flow rate of /sec. The undrawn yarn thus obtained was bundled into a tow of 700,000 deniers, which was stretched 3.5 times in a water bath at 65°0 and then dried in a 130°0 atmosphere. A relaxation heat treatment was performed, and the fibers were cut at 64 points after the appearance of crimp. The thus obtained staple fiber was passed through the card to make a kuetsubu, which was used as futon cotton, and its performance was measured. The results are also shown in Table 1.

As shown in Table 1, compared to Comparative Example 1, the futon cotton using the fiber obtained by the method of the present invention has a specific volume of fi110cd.
/19 or more, compression rate of 60 inches or more, recovery rate of 90% or more, excellent bulkiness, smooth texture and soft texture. In Examples 1 to 3, the spinning condition was good, but in the comparative example, spun single fiber breakage occurred.

The number of crimp shown in Table 1 is the value measured according to JIS-L1074, and the specific volume, compression ratio, and recovery rate are according to JIS-L1074.
1097.

Example 4. Comparative Example-2 Intrinsic viscosity measured in 25°Cm-cresol is 1.1
26 through the nozzle shown in Figure 1(h).
Melt and discharge at 0'O, take off at 1500H@/mt, single fiber #! An undrawn yarn having a fineness of 30 denier was obtained. The cross section of this undrawn yarn was a porous hollow cross section as shown in FIG. 4(h). The discharged yarn is cooled by blowing 25°C cooling air at a flow rate of 0.8 m/s6c from a direction perpendicular to the yarn traveling direction at a position 1.5 to 10 α below the mouth surface. went.

The spinning condition was perfect (there were no problems. This undrawn yarn consisted of 70 single fibers, and after live-stretching this undrawn yarn by 3.5 times at a drawing temperature of 50°0, It was subjected to a relaxation heat treatment in an atmosphere and then wound up continuously.The crimp performance of the obtained stretching heat treatment system was measured according to JIS-L1074, and the number of crimps was 12.5/25 tx, and the crimp elasticity was y4.
It had a good crimp of 90 inches. Furthermore, when the nozzle shown in Fig. 3 (b) was used to similarly rapidly cool one side, and after stretching, the material was subjected to relaxation heat treatment. It was something. Furthermore, single QM breakage occurred during spinning.

[Brief explanation of drawings]

Figures 1 and 2 show the cross-sectional shape of the nozzle of the spinneret used in the present invention, Figure 3 shows the cross-sectional shape of the nozzle of the spinneret used in the conventional method, and Figures 4 to 6 show the nozzle shape shown in Figures 1 to 3. The cross-sectional shapes of the fibers obtained using the nozzles having the cross-sectional shapes shown in FIG. First cause (CL> (bj
(Pressure) (e) (1) (cl)<h) Fig. 8 (-°) Fig. 3 (a) (O) Fig. 4 ()) (h) Fig. 5 (k) Figure 6

Claims (9)

[Claims] (1) A crimped porous hollow fiber made of a thermoplastic polymer and having a plurality of hollow parts continuous in the longitudinal direction,
A crimped porous hollow fiber characterized in that a cross section of the fiber has a plurality of curved concave portions on the outer periphery and an anisotropic cross section. (2) The total area of the hollow portion in the cross section of the crimped porous hollow fiber is 5 to 6 with respect to the area surrounded by the outer periphery of the cross section.
0% crimped porous hollow fiber according to claim (1). (3) The crimped porous hollow fiber according to claim (1), wherein the thermoplastic polymer is polyethylene terephthalate. (4) When melt-spinning porous hollow fibers made of thermoplastic polymer, a nozzle is arranged in which a plurality of hollow discharge holes forming at least one hollow part of the porous hollow fibers are connected via slits. The yarn is discharged from a spinneret, and then one side of the discharged yarn is cooled by blowing cooling air having a wind speed of 0.2 m/sec or more from a direction substantially perpendicular to the running direction of the discharged yarn. A method for producing crimped porous hollow fibers, which comprises stretching the resulting porous hollow undrawn fibers and then subjecting them to relaxation heat treatment. (5) The total area of the hollow portion in the cross section of the crimped porous hollow fiber is 5 to 6 with respect to the area surrounded by the outer periphery of the cross section.
0% of the method for producing a crimped porous hollow fiber according to claim (4). (6) A method for producing a crimped porous hollow fiber according to claim (4), wherein the hollow discharge holes are connected in a straight line. (7) A method for producing a crimped porous hollow fiber according to claim (1), wherein the hollow discharge holes are connected in an annular manner. (8) A method for producing a crimped porous hollow fiber according to claim (4), in which the hollow discharge hole can form a plurality of hollow parts. (9) The method for producing crimped porous hollow fibers according to claim (4), wherein the thermoplastic polymer is polyethylene terephthalate.