JPS60252716A - Production of polyester fiber with latent shrinkability and modified cross section - Google Patents

Abstract

PURPOSE:Two kind of polyester polymers different in melt viscosity are extruded from specific spinning nozzles to give polyester fibers of triangular cross section, having latent shrinkage and beautiful luster. CONSTITUTION:Two kinds of polyesters different in melt viscosity are melt extruded through the spinneret having nozzles which have 3 slits with circular ends arranged in radiation from the center O so that polymer 1 of high viscosity comes out of slit L1 and polymer 2 of low viscosity through slits L2 and L3. The ratio of polymer 1 to polymer 2 is 40/60-60/40, and the orifices satisfy the following: 0.5<=r<=1.0(mm.); 0.15<=W1/r<=0.45; 0.3<=W1/d1, W2/d2, W3/d3<=0.9; 0.6<= d1<2>/(d2<2>+d3<2>)<=1.4; 0.6<=W1/(W2+W3)<=1.4; d2= d3, W2=W3; theta12=theta23=theta31=120 deg..

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention has a triangular cross-sectional shape that is latent crimp and exhibits a graceful external luster. ff This relates to a method for producing IJ ester fiber.

Conventional Technology A known method for imparting silk-like elegant luster to polyester fibers is to make the cross-sectional shape of the fibers triangular! 5 (USP 2939201.

USP 3097416 etc.), 'Industrially, for example, 8r! A method of melt-spinning a polyester polymer using a spinneret having discharge holes as shown in Figure 2 has been adopted (for example, Kagaku Dojinsha's "Fiber Formation and Structure Expression OID").
P5). However, it is very difficult to obtain the desired cross-sectional shape as shown in Figure 1 in polyester fibers made by applying two types of polyester polymers in a side-to-side manner to give the candy latent crimp properties. It is. That is, using a spinneret having the discharge holes shown in Fig. 2, the degree of polymerization was varied.
When different types of polyethylene terephthalate are laminated side-by-side at a ratio of approximately 1:1 and introduced into the discharge hole in the arrangement shown in Figure 3 (6) and (b), Figure 4 (a) respectively.
) and (b) Only the fiber cross-sectional shapes shown in VC can be obtained.

Purpose of the Invention The purpose of the present invention is to provide a method for producing polyester fiber having a triangular cross-sectional shape as shown in FIG. There is a particular thing.

Components of the Invention That is, the present invention provides a method for manufacturing polyester fibers with irregular cross-sections having latent crimp properties by composite spinning two types of polyester polymers having different melt viscosities in a side-by-side type. It is a spinneret having a cross-sectional discharge hole in which three slits are arranged radially from a center point O, and the widths of the three slits L1, L2, and L are expressed as ω1, ω, and O3, respectively. a), The diameter of the hole at the tip of each slit is d1, d2, d, (sn), respectively, and the center of the circular hole is 01, 0.・0. Then, the radius of the arc centered on the center point O and connecting 01, O7, and 03 is r (mn)
, slit LI and L2・Lt (!: Take L3・Ls, and let the angle between them be θ, 2・θt・θsI (degrees), then the following formula 〇) ~ (g) 0.5≦r≦ 1.0 (I'll), fi)0.15
5shi≦0.45 1...(b) d2 = dB, w! =ωs (-=-(to)θ1
．． = θ, 3 = θ51 = zzo (rl) · ()) In order to introduce the two types of molten polyester polymers to the discharge holes, a spinneret with a high melt viscosity is used. The component A is slit, and the component B, which has a lower melt viscosity, is discharged from the circular hole at the tip of the slit El! s L12 and its tip are arranged so that they are discharged from each circular hole, and component A and component B (ID ratio 40:60 to 60
: This is a method for producing latent crimp polyester fiber with a modified cross section, aiming at a percentage of 4Q.

Means to solve problems The present invention will be explained in more detail below with reference to the drawings.

FIG. 1 shows an example of the cross-sectional shape of the latent crimpable polyester fiber obtained by the present invention. Among the two types of polyester, the component with the higher melt viscosity is t''!
Component B, which has a lower melt viscosity, is placed in the second part, and both components are joined to the single fiber cross section in a tesite-by-side type.

In order to impart latent crimpability to the polyester fibers, these two types of 4-lyesters must have different thermal shrinkage behavior by, for example, making a difference in the degree of polymerization. The same objective can also be achieved by using a polyester polymer obtained by copolymerizing one of the polyesters with a copolymer component such as isophthalic acid, asobic acid, sodium isophthalate sulfonate, or butanol.

The key is to use a combination of polyesters that have different thermal shrinkage behavior and can provide latent crimpability.1. l IJ
In order to obtain excellent fiber performance of the ester, it is necessary that at least 85 moles or more of both components A and B consist of the structural unit of ethylene terephthalate.

In the present invention, in order to obtain a triangular cross-sectional shape as shown in FIG. 1, the cross-sectional shape of the discharge hole of the spinneret is extremely important. FIG. 5 illustrates the cross-sectional shape of the discharge hole of the spinneret used in the present invention. Three slits with widths ω1 and ω3 from the center point 0! L2 and L3 are provided radially, and the tip of each slit is located at a point OI on the circumference of a radius r centered on the point O.・It is located at 03, and has circular holes with diameters d1, d, and d3. In the present invention, r is 0.5 to 1.0, preferably 0.6 to 0.8.
It is necessary to be within the range of ta. If it is less than 0.5+m, the manufacturing precision of the discharge hole will be poor and the cross-sectional shape of the discharge hole will be non-uniform.

) If it exceeds 1.0 mm, large knealing may occur when the molten polyvarnish is discharged from the discharge hole, and intermittent bump-like fineness unevenness may occur in the longitudinal direction of the single fibers, which is not preferable. The ratio of ω1 and r ω1/r is 0.15 to 0.4
5, preferably in the range of 0.25 to 0.35 +7). If it is less than 0.15, the cross-sectional shape of the fiber will be rounded as a whole and will not have the desired triangular shape. On the other hand, if it exceeds 0.45, the cross-sectional shape of the fibers becomes clover-shaped, which results in a smaller bonded area between the two types of polyester polymers and a weaker latent crimp force, which is not preferable.

The ratio of ω1 and d, ωl/dl, The ratio of ω, and d, ω2/d
2. The ratio ω3/d3 of ω3 and d3 is 0.3 to 0.
9 preferably in the range of 0.4 to 0.8. If it is less than 0.3, as shown in Figure 6, only the corner of the part A occupied by the component A with higher melt viscosity will have a sharply protruding fiber cross-sectional shape, and if it exceeds 0.9, the fiber cross-sectional shape will be distorted as a whole. It curls up into a triangle and it's 0.
It needs to be in the range of 6 to 1.4, preferably 0.8 to 1.2. If it is less than 0.6 or more than 1.4, the fiber cross-sectional shape will become as shown in FIG. 7 (jL) or (b). That is, the area of the slit L1 and the circular hole at its tip becomes approximately equal to the sum of the areas of the slits L, , L, and the respective circular holes at the tip of the slit L1 until equations (e) and (e) are simultaneously satisfied. This enables the triangular fiber cross-sectional shape of the present invention.

In the present invention, in order to obtain a bilaterally symmetrical and uniform triangular fiber cross-sectional shape, d, = d3. ω2=ω3 and the angles θ and 2・θ formed by each of the 2 lits L, ・L, ・L3
23・θ, 1 is θ12=023=θg+=120 (degrees)
It is necessary that

Next, in the arrangement of the two types of melted polyester polymers in the present invention, the component A with higher melt viscosity is placed in the slit L1.
Component B, which has a lower melt viscosity, is discharged from the circular hole at the tip of the slit L, and is discharged from the circular hole at the tip of the slit L, L, and the circular hole at the tip thereof. is necessary. If the arrangement is reversed, the fiber cross-sectional shape will not be triangular as shown in FIG. Two types of 15-lyester polymer component A and component B
The ratio is 40:60 to 60:40, preferably 45:55
-55:45 is required. 40;6
When the ratio is less than 0 or more than 60:40, sufficient latent crimp force cannot be obtained.

In the present invention, the triangular fiber cross-sectional shape refers to a substantially isosceles triangle with each vertex rounded and each side concave inward, as shown in FIG. Take each vertex and mark it as M and N.The center point of the arc connecting M and N is 01. The radius of the arc is f: R, and the bottom points of each side concave from the center point O are x, y, and 2'. : When the distance to is expressed as r or r k + r Z. Therefore, Fig. 10 (a
None of the cross-sectional shapes shown in ) to (d) correspond to the triangular fiber cross-sectional shape that is the object of the present invention.

The present invention will be described in more detail below with reference to Examples.

Example relative viscosity (metacresol; 25°C) is 1.65 and 1
．． Two types of polyethylene terephthalate having a relative viscosity of 1.65 were prepared using a side-width composite spinneret shown in FIG. 11 having the spinning discharge hole shown in FIG. 5.
The polyester with a relative viscosity of 1.55 is discharged from the slit LI and the circular hole at its tip, and the polyester with a relative viscosity of 1.55 is discharged from the slit L! r Guide to the spinning discharge hole so that the yarn is discharged from each circular hole in the Ls and its tip, and follow the usual method 2
Melt spinning at 90°C and winding at a yarn speed of 1000 m/min.
An undrawn polyester yarn of denier 15 filaments was obtained. Preester with relative viscosity 1.65 and relative viscosity 1.55
Nobori ester was weighed using a gear pump so that the ratio was 50:50. Spinning discharge hole no.r,0)H shown in FIG.
' 6) 2 ” 6) 3, dl ” d2 ” d
3,01! "θ7.・θ3° and the specifications of the cross-sectional shape of the undrawn yarn obtained thereby are shown in Table 1. When the polyester drawn fiber 6 of 60 denier 15 filaments obtained by drawing 3.5 times at a plate temperature of 120° C. was continuously steam-treated in the relaxation heat treatment device 7 shown in FIG. A moon-resester fiber having a high gloss and a graceful luster was obtained.

Comparative Example ° d8 of the spinneret used in the example. Fibers were spun under the same conditions as in the examples using a spinneret having a spinning discharge hole shown in FIG. 13 with a change in ω.

The specifications of the cross-sectional shape of the obtained undrawn yarn are also listed in Table-1.

Margin Table-1 Effects of the Invention According to the invention configured as described above, a soft texture derived from latent crimpability and a silk-like graceful luster derived from the cross-sectional shape of the fibers, which are suitable for high-class clothing, can be achieved. This provides an exceptional effect in that it is possible to obtain a ester fiber having the following properties.

[Brief explanation of the drawing]

FIG. 1 shows the cross-sectional shape of polyester fibers obtained by the method of the present invention. FIG. 2 shows the shape of the discharge hole of a spinneret in the prior art. FIGS. 3(IL) and (b) each show a typical example of the arrangement of two types of polymers when composite spinning is performed using the spinneret shown in FIG. 2. Figures 4(a) and (b) correspond to figures 3(a) and (g), respectively.
The m-shape of the fiber obtained by the arrangement is shown. FIG. 5 shows the shape of the spinneret used in the present invention. FIG. 6, FIG. 7 (ω, 载) and FIG. 8 show the cross-sectional shapes of fibers spun by a method other than the method of the present invention, respectively. FIG. 9 is an explanatory diagram for explaining the shape of fibers obtained by the method of the present invention. FIGS. 10(a) to 10(d) show cross-sectional shapes of fibers that are not covered by the present invention. FIGS. 11(a) and 11(b) are side cross-sectional and plan views of a spinneret showing the positional relationship of two types of polyester polymers with respect to each discharge hole slit in an example of the present invention. FIG. 12 is a schematic diagram of a relaxation heat treatment apparatus used in an example of the present invention. FIG. 13 shows the shape of the discharge hole of the spinneret used as a comparative example. 1...Polyester polymer with higher melt viscosity, 2.
・Polyester polymer with lower melt viscosity, 6...
, J? lJ ester fiber, 7... Relaxation heat treatment device. Figure 3 (Q) (b) Figure 4 Figure 7 Figure 10 Figure 11 Figure 12 Figure 13

Claims (1)

[Claims] A method for producing polyester fibers with irregular cross-sections having latent crimp properties by side-by-side composite spinning of two types of 4-lyester polymers having different melt viscosities; The spinneret has a cross-sectional discharge hole in which three slits are arranged radially from a center point O, and the widths of the three slits L, .・ω, -1 The diameter of the hole in each slit slit is d, ・d, ・ds (w+), and the center of the circular hole is OI・0!・0. Then, centering on the center point 0, O
l・0.・The radius of the arc connecting Os is r (m), the angle between the slits L, -L, -L, and slits is θ1. When ・θ, ・θal (jJD), the following formulas (a) to (g) 0.5≦r≦1.0 (m) ... (a) ω1 0.15≦ -≦0.45 ... (b) ω1 0.6□ ≦1.4 ... (e) ωminoiω3 d, = d,, ω, = ω, (-... (f) θ1.=
θ8. −〇, 1=120 (υβ−) ... Melt viscosity when using a spinneret having a discharge hole that satisfies (g) and guiding two types of molten polyester polymers to the discharge hole. Component A, which has a higher melt viscosity, is discharged from the slit L and the circular hole at its tip, and component B, which has a lower melt viscosity, is discharged from the slit L2. L, arranged so that it is discharged from each circular hole at its tip,
A method for producing a latent crimp polyester fiber with a modified cross section, which further comprises adjusting the ratio of component A to component B to be in the range of 40:60 to 60:40.