JPH0369616A - Spinneret for hollow carbon yarn - Google Patents

Abstract

PURPOSE:To obtain the title spinneret providing hollow yarn for hollow carbon yarn having surface arrangement of carbon layer of onion-like section by introducing an insertion element equipped with plural spiral grooves on the outer peripheral surface and a gas feeding through hole at the central part to an inverted conic insertion element hole at the middle. CONSTITUTION:An insertion element fitting hole 11 of a spinneret main body 13 is introduced to the spinneret main body 13 equipped with a screw hole 10 of large diameter to be connected to a melt feed pipe at the top, an inverted conic insertion concentrically following the screw hole 10 at the middle and a melt delivery hole 12 concentrically following the insertion element fitting hole 11 at the bottom. An insertion element 14 provided with plural grooves or projections 16a and 16b of spiral arrangement on the outer peripheral surface and a small diameter part 14c into which the melt delivery hole 12 is inserted at the tip wherein a circular through hole 17 bore through the central part of shaft with tapering the tip and a gas feeding pipe 18 is connected to the top of the through hole 17 is introduced to the insertion hole 11 to give the objective spinneret 15.

Description

[Detailed description of the invention] (Industrial application field) The present invention relates to hollow carbon fiber spinnerets.

(Prior Art) Conventionally, in order to spin hollow carbon fibers, a gas blowing pipe 4 is inserted into a stock solution discharge hole 3 following an inverted conical stock solution introduction hole 2 of a spinneret body 1, as shown in FIG. A cap 5 is used.

(Problem to be Solved by the Invention) By the way, in the hollow carbon fiber spinneret 5, it was difficult to insert and hold the gas blowing pipe 4 concentrically in the stock solution discharge hole 3, and there were cases where the core was misaligned. .

Therefore, when spinning pitch with such a spinneret 5, the seventh
As shown in the figure, there was a problem in that a hollow system with non-uniform wall thickness in the circumferential direction was spun.

Furthermore, even if the gas blowing pipe 4 is inserted and held concentrically in the raw solution discharge hole 3 with the nozzle 5, when pitch is spun, the cross-sectional orientation of the hollow fiber 5 is parallel to the fiber axis, so the bottom of the hole and the graphite The hollow carbon fiber 6 shown in FIG. 8 shrinks due to the removal of volatile components, and as shown in the figure, it is easier to crank the fiber from the outer periphery toward the center, and sufficient strength and elastic modulus cannot be obtained.

Therefore, the present invention has developed a hollow carbon fiber spinneret that does not insert a gas blowing pipe into the raw solution discharge hole and that allows the spun hollow fibers to have a uniform wall thickness in the circumferential direction and a carbon layer surface with an onion-like cross-sectional orientation. This is what we are trying to provide.

(Means for Solving the Problems) A hollow carbon fiber spinneret of the present invention for solving the above problems has a large-diameter threaded hole in the upper part to which a raw solution supply pipe is connected, and a threaded hole in the middle to which the stock solution supply pipe is connected. Next, there is a cap body having an inverted conical introducer insertion hole at both ends thereof, and a stock solution discharge hole at the bottom following the introducer insertion hole at the center, and an introducer insertion hole of the mouthpiece body. The shaft is loaded into the shaft, has multiple grooves or protrusions arranged in a spiral pattern on the outer circumferential surface, has a small diameter part inserted into the stock solution discharge hole at the tip, and has a circular through hole in the center of the shaft with a small diameter tip. It consists of an introducer that is drilled through the hole and a gas blowing pipe is connected to the upper end of the hole.

(Function) When spinning pitch with the hollow carbon fiber spinneret of the present invention configured as described above, the pitch supplied from the stock solution supply pipe connected to the spinneret body is fed to the introducer insertion hole of the spinneret body. A spiral array of passages formed by the inner circumferential surface of the introducer and the grooves on the outer circumferential surface of the introducer, or the inner circumferential surface of the introducer insertion hole, the outer circumferential surface of the introducer, and a spiral protrusion provided on the outer circumferential surface. A rotational moment is applied through the screw-shaped passage formed by the introducer, and the solution enters the annular discharge hole formed by the small diameter portion at the tip of the introducer, and is discharged and spun from the tip. At the same time as this discharge spinning, gas is blown into the gas blowing pipe and blown out from the tip of the through hole in the center of the shaft of the introducer. As a result, the spun hollow fibers have a uniform thickness in the circumferential direction, and have an onion-like carbon layer plane arrangement in cross section. Therefore, the hollow carbon fiber obtained by firing and graphitizing this carbon fiber has high strength and elastic modulus without cracking on the outer periphery.

(Example) An example of the hollow carbon fiber spinneret of the present invention will be described with reference to the drawings. As shown in FIGS. 1a and 1b, there is a threaded hole 10 with a diameter of 26mm and a depth of 5mm in the upper part to which the stock solution supply pipe is connected, and a diameter of 10mm on both sides following the threaded hole 10 in the middle.
, has an inverted conical introducer insertion hole 11 consisting of a vertical part 11a with a depth of 1.0 mm and an inverted conical part 11b with an opening angle of 60 degrees and a depth of 8.2 mm, and a bottom part with a thickness of 0.8 mm. 2a and b in the introducer insertion hole 11 and the stock solution discharge hole 12 of the mouthpiece body 13, which has a stock solution discharge hole 12 with a diameter of 0.5 mm between the introducer insertion hole 11 and the stock solution discharge hole 12. The hollow carbon fiber spinneret 15 is constructed by inserting the introducer 14 shown in FIG. 3 as shown in FIGS. 3a and 3b.

As shown in FIGS. 2a and 2b, the introducer 14 has a vertical part 14a with a diameter of 10 mm and a height of 2 mm, an included angle of 60 degrees, and a height of 8.4 mm.
The inverted conical part 14b of the plate and its tip have a diameter of 0.3M and a length of 1
．． 0 mm vertical small diameter portion 14c, and four openings having a width of 0.3 mm at equal angular intervals on the outer peripheral surface of the vertical portion 14a;
A vertical groove 16a having an inverted trapezoidal cross section with a depth of 0.3 mm and a base width of 0.1 mm is provided, followed by grooves 16b of the same size in a spiral arrangement on the outer peripheral surface of the inverted conical portion 14b. A circular through hole 17 with an inner diameter of 2 mm is penetrated through the center of the shaft of the introducer 14 with the tip tapered to an inner diameter of 0.1 m, and the upper end of the through hole 17 has an outer diameter of 2.5 mm. Rib, inner diameter 2.0m
m gas blowing pipes 18 are continuous.

When spinning pitch using the hollow carbon fiber spinneret 15 of the embodiment shown in FIGS. 3a and 3b constructed in this way, a stock solution supply is connected to the spinneret body 13 as shown by the chain line in FIG. 3a. The pitch supplied from the pipe 19 is between the inner peripheral surface of the inverted conical introducer insertion hole 11 of the mouthpiece body 13 and the introducer 1.
A rotational moment is applied through the passage 20 formed by the grooves 16a and 16b on the outer peripheral surface of the undiluted solution discharge hole 1, which is formed into an annular shape by the small diameter portion 14c at the tip of the introducer 14.
2 while rotating, and discharge spun from the tip. At the same time as this discharge spinning, air was blown into the gas blowing pipe 18 and blown out from the tip of the through hole 17 at the center of the shaft of the introducer 14. As a result, the spun yarn had an outer diameter of φ0.05 mm and an inner diameter of φ
The 0.02 mm hollow fiber had a uniform thickness in the circumferential direction as shown in FIG. 4, and the cross section had an onion-like carbon layer plane arrangement. Therefore, the hollow carbon fibers obtained by firing and graphitizing the carbon fibers do not have cranks on the outer periphery and have high strength and elastic modulus.

Incidentally, in the above embodiment, grooves 16a, 16 are formed on the outer peripheral surface of the introducer 14.
b to form a spiral passage 20 between the inner circumferential surface of the introducer insertion hole 11, and as shown in FIG. Provide this protrusion 2
1, the outer circumferential surface of the introducer 14, and the inner circumferential surface of the introducer insertion hole 11 to form a screw-shaped passage 22, it is possible to discharge and spin hollow fibers in the same manner as described above.

(Effects of the Invention) As can be seen from the above explanation, according to the hollow carbon fiber spinneret of the present invention, hollow fibers having a uniform wall thickness in the circumferential direction and an onion-like cross-sectional carbon layer plane arrangement can be spun. Therefore, if this is fired and graphitized, hollow carbon fibers with high strength and elastic modulus can be obtained.

[Brief explanation of drawings]

FIG. 1 shows a spinneret body in one embodiment of the hollow carbon fiber spinneret of the present invention, in which a is a longitudinal sectional view, b is a plan view, and FIG. 2 is an introduction to be charged into the spinneret body of FIG. 1. Fig. 3 shows an embodiment of the hollow carbon fiber spinneret of the present invention, a is a longitudinal sectional view, b is a plan view, and Fig. 4 is a side view, b is a bottom view. The figure is a cross-sectional view of a hollow fiber discharged and spun from the hollow carbon fiber spinneret shown in FIGS. Figure 7 is a longitudinal cross-sectional view of a main part showing a conventional hollow carbon fiber spinneret, Figure 7 is a cross-sectional view showing defects in hollow fibers spun from a conventional hollow carbon fiber spinneret, and Figure 8 is a cross-sectional view of a conventional hollow fiber. FIG. 2 is a cross-sectional view of a hollow carbon fiber obtained by firing and graphitizing.

Claims (1)

[Claims] 1. It has a large-diameter screw hole at the top to which the stock solution supply pipe is connected, a concentric inverted conical introducer insertion hole following the screw hole in the middle, and the introducer insertion hole at the bottom. The cap body has a concentric liquid discharge hole following the inlet hole, and the introducer is inserted into the introducer insertion hole of the cap body, and a plurality of grooves or protrusions are provided in a spiral arrangement on the outer peripheral surface, and the tip An introducer having a small diameter part inserted into the stock solution discharge hole, a circular through hole in the center of the shaft with a small diameter tip, and a gas blowing pipe connected to the upper end of the through hole. Consisting of hollow carbon fiber spinneret.