JPS61231227A - Undrawn continuous fiber of thermoplastic polymer - Google Patents

Abstract

PURPOSE:To produce the titled fiber having high maximum draw ratio and spinnable even by decreasing the rate of extrusion per one extrusion orifice, by quenching the fiber immerdiately after extrusion from an orifice and collecting the fibers in a zone separated by a relatively short distance from the spinneret. CONSTITUTION:The extrusion cross-sectional area of an extrusion orifice is <=1.5X10<-4>cm<2>, the atmospheric temperature in a zone separated from the spinneret downward by 1-3cm is ajusted to <=200 deg.C, and the just spun fibers are collected in a zone separated from the spinneret downward by 10-150cm. An undrawn fiber having a single fiber fineness D (denier) and a maximum draw ratio X(%) satisfying the formulas 0.05<=100D/(X+100)<=0.15 and 10<=X<=350 can be produced and a drawing fiber having a single fiber fineness of <=0.15 denier can be produced therefrom.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an undrawn continuous thermoplastic polymer fiber and a method for producing the same. More specifically, it is obtained by a normal melt spinning method (a melt spinning method as defined later, hereinafter referred to as "direct melt spinning method"), and the single fiber fineness is 0.37-' by oriented drawing. The present invention relates to an undrawn continuous fiber that can be less than 100 mL and a method for producing the margin below. This thermoplastic polymer undrawn continuous fiber can be produced industrially advantageously, and if drawn, it can be woven into ultra-fine fibers that can be woven in conventional knitting and weaving processes and the resulting knitted fabrics are of high quality. ″・
In recent years, knitted fabrics made of ultrafine fibers with a single fiber fineness of around 1 denier and their surface-raised products (synthetic leather) have been actively manufactured and sold because they have a soft, suede-like texture. It is known that when ultra-fine fibers with a smaller single fiber fineness of 0.30 denier or less are used, knitted fabrics with extremely soft and desirable textures and products with raised surfaces thereof can be obtained. However, the conventionally known ultra-fine fibers of 0.3 deniers or less,
There are drawbacks such as the impossibility of knitting, the complicated dyeing process for knitted fabrics, or the poor quality of the knitted fabrics, as well as the difficulty in that the manufacturing process is complicated and cannot be produced industrially. Therefore, it has been desired to develop ultra-fine fibers that do not have such drawbacks and can be produced industrially advantageously by a simple method.

Conventionally, the following four methods are known as methods for producing ultrafine thermoplastic polymer fibers having a single fiber fineness of 0.30 denier or less.

a. Sea-island fiber (multifilament composite fiber) method (for example,
8-25362): An undrawn fiber having a seabird-like cross section is spun, and the undrawn fiber is drawn at a drawing ratio within the natural drawing region of its island component. Thereafter, the sea portion is dissolved and removed using a solvent to obtain the island component as ultrafine fibers. It is also possible to further draw this to make a thinner and stronger fiber.

b. Polymer blend fiber method: A mixture of two thermoplastic polymers with different solubility and poor compatibility is melt-spun to obtain sea-island fibers in which one polymer is finely dispersed in the other.

After stretching this, the sea part is dissolved and removed with a solvent in the same manner as in a above, and the high part is obtained as ultra-fine short fibers.

C. Super draw method (for example, Japanese Patent Application Laid-Open No. 51-5542
0): I-lyester undrawn fibers consisting of single tn fibers of 2 to 3 deniers are subjected to O-stretching without molecular orientation, and then oriented stretching (neck stretching) with molecular orientation. By doing so, polyester ultrafine fibers are obtained by drawing at a high drawing ratio.

d, easily splittable fiber method (for example, JP-A-51-13031
(Refer to 7): A composite fiber made of multiple thermoplastic polymers with poor compatibility is spun, and the resulting fiber is made into a knitted fabric, which is then mechanically or chemically divided into ultra-fine fibers. do.

Both methods a and b have the disadvantage of requiring solvent treatment, and furthermore, with ordinary solvent treatment, a small amount of sea components remains on the fiber surface and the fiber surface is attacked. Further, long fibers cannot be obtained from b. Since C is a special drawing method, it is inevitably disadvantageous in terms of process, and the resulting fibers have extremely poor uniformity, making them impossible to use for clothing. Since the fibers obtained in d are composed of a plurality of polymers, the dyeing process is complicated and dye stains may occur. As described above, the existing methods are disadvantageous in terms of process compared to normal melt spinning technology (direct melt spinning method), and the obtained fibers are inferior in quality. Despite these disadvantages, such a complicated method was devised because ultra-thin woven fibers have not yet been obtained from a single polymer by direct melt spinning.

The "direct melt spinning method" in the present invention refers to the steps of: (1) preparation of a molten polymer, (2) measuring and spinning of the molten polymer, (2) cooling under the spinneret and forming fibers, and (2) taking or winding the fibers. refers to a method of obtaining undrawn fibers. FIG. 1 shows a specific example of a device that realizes this. In the apparatus shown in FIG. 1, polymer chips in a hopper 1 are cross-melted in a melt extruder and discharged from a spinneret 5 via a metering tube 4. The spun fiber 7 is passed through a yarn guide duct 11, an oil application device 12,
The fibers are sequentially passed through take-up rolls 13 and wound up as undrawn fibers 14. In the present invention, the undrawn fibers are blown with cold air 10 by a cold air blowing device equipped with a cold air rectifier 9 so as to maintain the atmosphere 6 directly below the spinneret 5 at a relatively low temperature. by focusing with a focusing guide, such as a Snell guide, placed a relatively short predetermined distance from the center. The undrawn fibers obtained by melt spinning are usually oriented and drawn using a drawing apparatus as illustrated in FIG. 2 to obtain drawn fibers for practical use. That is, the undrawn fiber 14 is
It passes through a supply roll 16, contacts the surface of a hot plate 17, is heated, and is stretched, passes through a stretching roll 18, and is wound up as a stretched fiber 19. All of the above-mentioned four methods of producing ultrafine fibers are outside the scope of direct melt spinning.

In producing ultra-fine fibers with a single yarn denier of 0.30 d or less, the present inventors
We investigated the possibility of stably obtaining ultrafine fibers of high practical value by improving the conventional direct melt-spinning method, which does not have the process disadvantages and quality defects seen in .

It is said that ultra-fine fibers with a single fiber fineness of less than 0.7 denier cannot be obtained by simply obtaining undrawn fibers by direct melt spinning and orienting them (for example, Chemical Fiber Monthly Report 19).
July 1977 issue 57-! -ji).

It has been found that the main reason why such ultrafine fibers cannot be obtained by the conventional direct melt spinning method is as follows. In other words, in order to obtain good fibers using the direct melt spinning method, undrawn fibers should be spun with the polymer discharge amount per discharge orifice of the spinneret as small as possible, and then oriented and drawn at the highest possible drawing ratio. However, when the discharge rate per discharge orifice of the spinneret is gradually lowered and the discharge rate reaches approximately 0.15 g/min, yarn breakage begins to occur directly under the spinneret under normal spinning conditions. Undrawn continuous fibers whose single fiber fineness after drawing should be less than 0.30 denier cannot be obtained.

Therefore, the present inventors have devised a spinning method that can produce fibers that can be spun even if the discharge rate of one discharge orifice of a spinneret is reduced as much as possible, and the maximum draw ratio of the resulting undrawn continuous fibers is large. I thought it was necessary and researched it extensively. As a result, they discovered that it is effective to rapidly cool the fibers immediately after they are spun from the orifice and to focus them at a relatively short distance from the spinneret, and have completed the present invention.

The following margins, that is, the first invention of the present invention is ro, 05≦1
00D/(X+100)<o, 3 and 10≦X≦7
00. A thermoplastic polymer undrawn continuous fiber characterized by being 0.00. However, D: Fineness (denier) of single fiber, X: Maximum draw ratio (%). The second invention is to use a spinneret with a discharge cross-sectional area of 3.5 x 10 cd or less at the discharge orifice, maintain the atmospheric temperature at 1 to 3 cIrL below the spinneret at 200°C or less, and 10
A method for producing undrawn continuous fibers of a thermoplastic polymer, characterized in that all single fibers are bundled at ~250 degrees. ”.

The term "thermoplastic polymer" in the present invention refers to a melt-spun fiber-forming polymer such as polyester, polyamide, or polyolefin. Of course, these polymers may also contain small amounts of additives, such as matting agents, colorants, heat stabilizers, flame retardants, antistatic agents, and the like.

In the above formula in the present invention, (X+100)/10
Since 0 corresponds to the stretching ratio when oriented and stretched until breakage, 100D/(X+100) generally corresponds to the fineness (limit fineness) reached when oriented and stretched until broken. Therefore, the formula 0.05≦100D/(X+10
0 ) < 0.30 means that the single fiber fineness is 0 due to oriented stretching.
．． This means that it can be a drawn fiber of 0.05 denier or more and less than 0.30 denier. To help understand this inequality, it will be explained with reference to FIG. In the same figure,
The horizontal axis represents the maximum drawing ratio X (%), and the vertical axis represents the single fiber fineness D (denier) t- of the undrawn fibers. Inequality 0.
05≦100 D/(X+100)<0.30 is transformed to 5XIO-'X+0.05<D<3.0X10
-5X+0.30. The range that satisfies this relationship is
Straight line 1 in Figure 3 (D = 5.OX 10=X+0.
05) and straight line n (D=3, OX 10””X+0.
30). Therefore, the range showing the characteristics of the undrawn continuous fiber of the present invention is the four straight lines 1. It, IV (X=700) and V
(X=10). Similarly, as in the above-mentioned literature, the fact that fibers with a single fiber fineness of 0.7 denier or less cannot be obtained is expressed as the straight line D=7X10
This means that the lower range of X+0.70 was not obtained.

That is, conventionally, the straight line lit (D= 7.0X10-
5X+0.70) (the area marked with a hatched line parallel to the vertical axis) only undrawn continuous fibers were present. Although it is preferable that the single fiber fineness after drawing is as small as possible, undrawn continuous fibers satisfying 0.05>100D/(X+100) cannot be obtained even by the above-mentioned special cooling and focusing method.

The term "undrawn continuous fiber" refers to a substantially infinitely long fiber that has not been subjected to any drawing operation after being discharged from an orifice and solidified and can be continuously wound.

Such fibers include both filaments and tows. X is the maximum stretching ratio measured by Tensilon at 21° C., RH 65%, and a yarn length of 1 OcrIL and a tensile speed of 50 crn/min. Its unit is expressed in gloss cents relative to the original length. X varies greatly depending mainly on the spinning speed, but in the direct melt spinning method, it would be difficult to spin at a spinning speed that gives X outside of 10≦X≦700. Normally, industrially adopted spinning speed is 500 to 3,500 m7
In minutes, a suitable numerical value is 60≦X≦500.

When producing the undrawn continuous fibers of the present invention by the direct melt spinning method, the ambient temperature at 1 to 3 crrL directly below the spinneret is kept at a low temperature of 200°C or less, and the discharge cross-sectional area of the discharge orifice is set to 3.5 10=, 2 spinnerets are used and the as-spun fiber is placed under the spinneret lO~2
It is manufactured by a method that focuses on combining the conditions of convergence at 50 degrees Fahrenheit. With this combination, the amount of polymer discharged per orifice discharged under the spinning rod can be reduced to O,
It has become possible to spin at 15 P/min or less, and it has become possible to stably obtain ultrafine continuous fibers with a single fiber fineness of 0.30 denier or less after drawing. In particular, it has become possible to spin fibers with a discharge rate of 0.085 L/min or less per discharge orifice of a spinneret, and to obtain fibers with a single fiber fineness of 0.2 denier or less.

In direct melt spinning of thermoplastic polymers, a method is generally used in which spinning is carried out while maintaining the atmosphere directly below the spinneret at a high temperature over a certain range.

In that case, the atmospheric temperature at 1 to 3 cm directly below the spinneret is at least 200°C, preferably 250°C or higher. In this way, the reason for increasing the atmospheric temperature directly below the spinneret is to keep the spinneret warm, prevent slabs and single fiber breakage, and promote relaxation of fiber orientation, thereby increasing the drawing ratio in the drawing process. It's for the sake of doing it.

However, when reducing the discharge amount per discharge orifice of the spinneret to obtain fibers with a single fiber fineness of 0.30 denier or less, if the area directly below the spinneret is kept in a high temperature atmosphere, the yarn is likely to break υ, and vice versa. The effect appears, so place 1 directly below the spinneret.
It is necessary to keep the ambient temperature at ~3α below 200°C. If the temperature exceeds 200°C, single filament breakage occurs frequently and a stable spinning state cannot be obtained. For the purpose of stably spinning, promoting sufficient orientation relaxation, and increasing the residual elongation of undrawn fibers, the preferable range of the ambient temperature at 1 to 3 crIL immediately below the spinneret is 120 to 190°C.

Another feature in the production of undrawn continuous fibers is to bundle all single fibers after spinning at a distance of 10 to 250 cm below the spinneret. The first advantage of performing such focusing is that if the fibers are not focused near the nozzle as described above, single fiber breakage will occur under the spinneret due to air resistance, resulting in continuous undrawn fibers. However, when the fibers are converged within a distance of the nozzle, this single fiber breakage is eliminated and continuous undrawn continuous fibers can be stably obtained. The second advantage is that the maximum stretching ratio of the undrawn fibers becomes larger than that in the case where the fibers are not converged near the nozzle as described above, and therefore, thinner drawn fibers can be obtained. All single line m? The reason for this effect is thought to be that by converging at a short distance from the nozzle, air resistance is reduced and the tension applied to the fibers is reduced, which makes the orientation easier to relax.

Although any known method may be used to bundle the fibers immediately after spinning, it is preferable to use a guide that has a small degree of contact with the fibers, such as a Snell guide. In addition, the first advantage mentioned above is greater as the convergence position is closer to the spinneret, but since the spun fibers are not solidified within 1 OcIrL below the spinneret, the fusion of single fibers and contact with guides may cause Easy to cause cuts. Therefore, the position must be at least 10 cm below the spinneret. Furthermore, the above-mentioned second advantage is observed only in the region within 25 OcIrL below the spinneret. Therefore, the focusing position is 10-250 cm below the spinneret, with a preferred range of 20-200 cWL.

Another feature of the invention is that it requires a spinneret with a relatively small discharge cross-sectional area per discharge orifice. If the cross-sectional area of the discharge nozzle is 3.5 x 10 or less, it is possible to obtain drawn fibers with a single fiber fineness of 0.30 denier or less by selecting conditions such as polymer discharge amount, spinning speed, and drawing ratio. is possible, but 3.5X 10"-'cIr
This is not possible beyond L2. In particular, Q. To obtain fibers of 2 denier or less, 2 X 10-'crI? It is necessary to use the following: The cross-sectional shape of the discharge orifice may be of a different shape, such as a Y-shape, a pentagon, a flattened shape, or a C-shape, in addition to the circular shape.

For the orientation and stretching of the undrawn fibers of the present invention, it is preferable to use a known stretching device such as a draw twister, a drawer twister, a stretch false twister, or a tow stretcher. Depending on the type of thermoplastic polymer, either hot stretching or cold stretching is selected, and multistage stretching is also possible if necessary.

Ultrafine fibers obtained by oriented drawing of undrawn continuous fibers have little fuzz and denier unevenness, and can be sufficiently knitted in conventional knitting and weaving processes, and the resulting knitted fabrics have no dyeing unevenness and are of high quality. In addition, the raised surface of knitted fabrics is soft,
It has an excellent texture and is very similar to natural suede. Moreover, among the undrawn continuous fibers of the present invention, X≦20
0 can be stretched and false-twisted using a known stretching and false-twisting machine.
A false twisted yarn that can be knitted and woven was obtained.

Hereinafter, the present invention will be explained in more detail with reference to Examples, but the present invention is not limited to these Examples.
Example 1 Below, using a spinning machine and a stretching/twisting machine as shown in Figs. 1 and 2, polyethylene terephthalate having an intrinsic viscosity [η) = 0.65 was spun and drawn. At that time, various combinations of the polymer discharge amount and the ambient temperature at 1 to 3 cIrL below the spinneret were set as shown in Table 1, and the spinning conditions at that time and the single fiber denier of the obtained drawn fibers were investigated. The results were as shown in Table 1.

Other manufacturing conditions are as follows.

Spinning conditions Spinneret Number of holes 144 Hole cross-sectional area (circular) 0.78X10 crl Spinning temperature
300℃ spinning speed 12
50m/min Focusing position Below the spinneret 30crrL (by Snell guide) Smoking conditions Supply roll temperature 75℃ Hot plate temperature
140℃ spreading and fast smoking
500rr+/drawing ratio Set so that the elongation at break of the drawn fibers is around 25% for each spinning condition.If the atmospheric temperature at 1 to 3 cm below the spinneret is 200°C or less, the polymer discharge rate is 0.1 s. It can be spun under the conditions of y-7 minutes and 1 nozzle, and fibers with a single fiber fineness of 0.30 denier or less can be obtained at 0.135 L/min and orifice or less. In addition, the U% of the obtained drawn fibers was 2.0.
% or less.

Below is a margin Example 2 Using a spinning machine as shown in Fig. 1, polyethylene terephthalate with an intrinsic viscosity [η] = 0.65 was melt-spun by varying the focusing position under the following spinning conditions to obtain an undrawn continuous fiber. I got it. Table 2 shows the spinning state and the maximum draw ratio (3) at this time.

The effect of the focusing position on X is 10~250c below the spinneret.
It is noticeable among WL.

Spinning conditions Number of spinneret holes: 72 Hole cross-sectional area: 3 x 10 cal Output amount
0.073fI-7min・Orifice spinning temperature 290'C Spinning speed
1.200 m/f + focusing method
Margin below Snell guide Table 2 Focusing position and its effect Example 3 Using a spinning machine as shown in Figure 1, intrinsic viscosity [η] = 0.6
Polyethylene terephthalate No. 5 was spun by setting various combinations of discharge amount and discharge nozzle cross-sectional area. The maximum draw ratio of the obtained undrawn fiber was measured and was 100D/(X+
100) was calculated. Spinning state and 100D/(X+
1. Table 3 shows the values of OO). The results show that when the nozzle cross-sectional area is 3.5×10 ad or less, it is 0.3 denier or less, and when it is 2.0×10 crl or less, it is 0.2 denier or less.

Spinning conditions Number of spinneret holes 144 (circular nozzle) Spinning temperature 295°C Atmospheric temperature at spinneret bottom 1 to 3α 180°C Spinning speed 1,250 m/min Smoking supply roll speed 75°C Hot plate temperature 140°C Spreading and twisting Rapid smoldering 500 m/min or less Margin Example 4 Using the spinning machine shown in Figure 1, polyethylene terephthalate (PET) with an intrinsic viscosity [η] = 0.65 and sulfuric acid were prepared using nylon with a relative viscosity η = 2.3. 6 was melt-spun under the following conditions and stretched with a drawing/twisting machine to obtain ultra-fine fibers.

Table 4 shows their single fiber denier, physical properties, etc.

Spinning conditions PET Nylon 6 Number of spinneret holes 144 144 Nozzle cross-sectional area IJ3X10-'CJ 1-8X10
-'c! Spinning speed 1,500 m 7 minutes 1
．． 500 m/min Thread temperature 295℃
270℃ discharge amount 9. Q
9.0 Smoking conditions PET nylon hot plate temperature 140℃ Room temperature 'A
Twisting speed 500 m/f + 500 m/% stretching ratio
2,00 1.63 or less Almost no fuzz was observed in the PET and nylon 6 ultrafine fibers shown in Table 4. In addition, the tube knitted fabric passed the stripe test.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram showing a specific example of a melt spinning apparatus and a diagram showing the relationship between the maximum stretching ratio X. Reference numbers in FIGS. 1 and 2 are as follows. 1... Chip hopper, 2... Melt extruder, 3...
- Molten polymer flow, 4... Measuring pump, 5... Spinneret, 6... Rapid cooling atmosphere, 7... Spun fiber, 8...
・Focusing guide, 9... Cold air rectifier, lO... Cooling air, 11... Yarn guide duct, 12... Oil agent applying device, 1
3... Take-back Shiroru, 14... Undrawn fiber, 15...
... Presser roll, 16... Supply roll, 17... Hot plate, 18... Stretch roll, 19... Stretched fiber. Figure 1 Figure 3 Procedural amendment March 10, 1986 Director of the Patent Office Michibu Uga 1, Indication of the case Patent submitted on February 8, 1986 2, Name of the invention ℃ Name (003) Asahi Kasei Corporation 5. Subject of amendment (1) Full text of specification (2) Drawing (Figure 3) 6. Contents of amendment (as per attached sheet 11 (2) As per attached sheet 7. List of attached documents (1) Full text 1 copy of the amended statement (
2) Drawings (Figure 3) 1 copy of the specification (no changes to the contents) Full text amended specification 1, title of the invention Thermoplastic polymer undrawn continuous fiber 2, claim 1, by direct melt spinning method The obtained undrawn continuous fibers are 0.05≦1000/(X +100)
An undrawn continuous fiber of a thermoplastic polymer, characterized in that ≦0.15 and 10≦X≦350. However, D: Single fiber fineness (denier)
．． 10 and 60≦X≦200
The thermoplastic polymer undrawn continuous fiber described in Section 1. 3. The thermoplastic polymer undrawn continuous fiber according to any one of claims 1 to 2, wherein the thermoplastic polymer is polyester or polyamide. 3. Detailed Description of the Invention [Field of Industrial Application] The present invention relates to an undrawn continuous fiber of a thermoplastic polymer. More specifically, the usual melt spinning method (melt spinning method as defined later, hereinafter referred to as "direct melt spinning method")
The single fiber fineness is 0.1 by oriented drawing.
It relates to undrawn continuous fibers that can have a denier of 5 or less. This thermoplastic polymer undrawn continuous fiber can be produced industrially advantageously, and by drawing it, it can be made into ultra-fine fibers that can be woven using conventional knitting and weaving processes and the resulting knitted fabrics have high quality. . [Conventional technology] In recent years, due to its soft and suede-like texture,
BACKGROUND OF THE INVENTION Knitted fabrics made of ultrafine fibers with a single fiber fineness of around 1 denier and their surface-raised products (synthetic leather) are being actively manufactured and sold. It is known that when ultra-fine fibers with a smaller single fiber fineness of 0.30 denier or less are used, knitted fabrics with extremely soft and desirable textures and products with raised surfaces thereof can be obtained. However, conventionally known ultrafine fibers of 0.3 deniers or less have disadvantages such as being impossible to knit or weave, the dyeing process of knitted fabrics is complicated, or the quality of knitted fabrics is poor. The problem was that it was complicated and could not be manufactured industrially. Therefore, it has been desired to develop ultra-fine fibers that do not have such drawbacks and can be produced industrially and advantageously by a simple method. Conventionally, the following four methods are known as methods for producing ultrafine thermoplastic polymer fibers having a single fiber fineness of 0.30 denier or less. a. Sea-island fiber (multifilament composite fiber) method (for example,
B-25362): An undrawn fiber with a seabird-shaped cross section is spun, and the undrawn fiber is drawn at a drawing ratio within the natural drawing region of its island component. Thereafter, the sea portion is dissolved and removed using a solvent to obtain the island component as ultrafine fibers. It is also possible to further draw this to make a thinner and stronger fiber. b. Polymer blend fiber method: A mixture of two thermoplastic polymers with different solubility and poor compatibility is melt-spun to obtain sea-island fibers in which one polymer is finely dispersed in the other. After stretching this, the sea part is dissolved and removed with a solvent in the same manner as in a above, and the high part is obtained as ultra-fine short fibers. C3 super draw method (for example, JP-A-51-5542
0): A polyester undrawn fiber consisting of a single fiber of 2 to 3 deniers is flow-stretched without molecular orientation, and then oriented (neck-stretched) with molecular orientation. Polyester ultrafine fibers are obtained by stretching at a certain stretching ratio. d, easily splittable fiber method (for example, JP-A-51-13031
(Refer to 7): A composite fiber made of multiple thermoplastic polymers with poor compatibility is spun, and the resulting fiber is made into a knitted fabric, which is then mechanically or chemically divided into ultra-fine fibers. do. Both methods a and b have the disadvantage of requiring solvent treatment, and furthermore, with ordinary solvent treatment, a small amount of the sea component remains on the fiber surface and the fiber surface is attacked. Further, long fibers cannot be obtained from b. C is a special drawing method, which is inevitably disadvantageous in the process, and the uniformity of the obtained fibers is extremely poor (and cannot be used for clothing).D is a method in which the obtained fibers are made of multiple polymers. Therefore, the dyeing process is complicated and dye stains may occur.As such, existing methods do not rely on normal melt-spinning technology (
It is disadvantageous in terms of process compared to the direct melt spinning method (direct melt spinning method), and the quality of the obtained fibers is inferior. Despite these disadvantages, such a complicated method was devised because ultrafine fibers have not yet been obtained from a single polymer by direct melt spinning. [Problems to be Solved by the Invention] The object of the present invention is to achieve a single yarn denier of 0.1 by oriented drawing.
It is an undrawn continuous fiber that can be made into an ultrafine fiber of 5 d or less, does not have the process disadvantages and quality defects seen in a, b, c, and d above, and can be produced industrially by direct melt spinning method. The object of the present invention is to provide an undrawn continuous fiber that can be advantageously produced. It is said that ultra-fine fibers with a single fiber fineness of less than 0.7 denier cannot be obtained by simply obtaining undrawn fibers by direct melt spinning and orienting them (for example, Chemical Fiber Monthly Report 19).
(July 1977 issue, page 57). It has been found that the main reason why such ultrafine fibers cannot be obtained by the conventional direct melt spinning method is as follows. In other words, in order to obtain good fibers using the direct melt spinning method, undrawn fibers should be spun with the polymer discharge amount per discharge orifice of the spinneret as small as possible, and then oriented and drawn at the highest possible drawing ratio. However, when the discharge rate per discharge orifice of the spinneret is gradually lowered and the discharge rate reaches approximately 0.15 g/min, under normal spinning conditions, yarn breakage begins to occur directly under the spinneret, and drawing The subsequent single fiber fineness is 0.3
Undrawn continuous fibers that should be less than 0 denier cannot be obtained. Therefore, the present inventors need a spinning method that can produce fibers that can be spun even if the discharge amount per discharge orifice of the spinneret is reduced as much as possible, and that can increase the maximum draw ratio of the resulting undrawn continuous fibers. I thought about it and researched it extensively. As a result, they discovered that it is effective to rapidly cool the fibers immediately after they are spun from the orifice and to focus them at a relatively short distance from the spinneret, and have completed the present invention. [Means for Solving the Problems] The above-mentioned object is to provide an undrawn continuous fiber of the present invention, that is, an undrawn continuous fiber obtained by a direct melt-spinning method, which has an undrawn continuous fiber of 0.05≦1000/(X +100 )≦0.1
5 and 10≦X≦350. However, D: Fineness of single fiber (denier), X: Maximum stretching rate (%
). The "direct melt spinning method" in the present invention includes the steps of: 1. Preparation of the molten polymer, 2. Measurement and spinning of the molten polymer, 2. Cooling under the spinneret and fiber formation, and 2. Taking or winding of the fiber. refers to a method of obtaining undrawn fibers. FIG. 1 shows an example of a device for realizing this. In the apparatus shown in FIG. 1, polymer chips in a hopper 1 are kneaded and dissolved in a melt extractor, and are discharged from a spinneret 5 via a metering pump 4. The spun fiber 7 is passed through a yarn guide duct 11, an oil application device 12,
The fibers are sequentially passed through take-up rolls 13 and wound up as undrawn fibers 14. In the present invention, the undrawn fibers are blown with cold air lO by a cold air blowing device equipped with a cold air rectifier 9 so as to maintain the atmosphere 6 directly below the spinneret 5 at a relatively low temperature. by focusing with a focusing guide, such as a Snell guide, placed a relatively short predetermined distance from the center. The undrawn fibers obtained by melt spinning are usually oriented and drawn using a drawing apparatus as illustrated in FIG. 2 to obtain drawn fibers for practical use. That is, the undrawn fiber 14 is
It passes through a supply roll 16, contacts the surface of a hot plate 17, is heated, and is stretched, passes through a stretching roll 18, and is wound up as a stretched fiber 19. The four ultrafine fiber manufacturing methods a, b, c, and d mentioned above are all outside the scope of direct melt spinning. In the present invention, "thermoplastic polymer" refers to polyester, polyamide, polyolefin, etc. A fiber-forming polymer that can be melt-spun. Of course, these polymers may also contain small amounts of additives, such as matting agents, colorants, heat stabilizers, flame retardants, antistatic agents, and the like. In the above formula in the present invention, (X+100)/10
Since 0 corresponds to the stretching ratio when oriented and stretched until breakage, 1000/(X +100) is generally the fineness (limit fineness) reached when oriented and stretched until breakage.
corresponds to Therefore, 20.05≦1ooo, /
(X +100 )≦0.15 means that by oriented drawing, a drawn fiber having a single fiber fineness of 0.05 denier or more and 0.15 denier or less can be obtained. To help understand this inequality, it will be explained with reference to FIG. In the figure, the horizontal axis represents the maximum drawing ratio X (%), and the vertical axis represents the single fiber fineness D (denier) of the undrawn fibers. Transforming the inequality 0.05≦1000/(X+100)≦0.15, 5 X 10-' X + 0.05≦D
≦1.5 xlO-'X +0.15. The range that satisfies this relationship is the straight line 1 (D = 5.
OXl0-'X +0.05> and straight line II (D=1
, 5 Xl0-'X +0.15). Therefore, the range showing the characteristics of the undrawn continuous fiber of the present invention is the four straight lines 1. II, IV (X=3
50) and V (X=10). Similarly, as in the above-mentioned literature, the fact that fibers with a single fiber fineness of 0.7 denier or less cannot be obtained is expressed as the straight line D.
This means that the lower range of = 7 Xl0-"
' Although it is preferable that the single fiber fineness after drawing is as small as possible, undrawn continuous fibers satisfying 0.05>1000/(X+100) cannot be obtained even by the above-mentioned special cooling and focusing method. The term "undrawn continuous fiber" refers to a substantially infinitely long fiber that has not been subjected to any drawing operation after being discharged from an orifice and solidified and can be continuously wound. Such fibers include both filaments and tows. X is a yarn length of 10c by Tensilon at 21°C and RH 65%! II is the maximum stretching ratio measured under the condition of a pulling speed of 50 cm/min. Its unit is expressed as a percentage of the original length. X varies greatly depending mainly on the spinning speed, but in the direct melt spinning method,
It would be difficult to spin at a spinning speed that gives an X outside of 1OSX≦350. Usually, at an industrially employed spinning speed of 500 to 3,500 m/min, a suitable numerical value is 60≦X≦200. When producing the undrawn continuous fibers of the present invention by the direct melt spinning method, the ambient temperature at 1 to 3 cII+ directly below the spinneret is maintained at a low temperature of 200°C or less, and the discharge cross-sectional area per discharge orifice is maintained at a low temperature of 1.5 Using a spinneret of 10-'cnl and transferring the fibers immediately after spinning to
It is manufactured by a method that focuses on combining the conditions of focusing in the range of 0 to 150 cm. This combination makes it possible to perform spinning with a polymer discharge rate of 0.05 g/min or less per discharge orifice under the spinning rod, and to stably obtain ultrafine continuous fibers with a single fiber fineness of 0.15 denier or less after drawing. Now you can. In particular, it has become possible to perform spinning at a yield of 0.02 g/minute per discharge orifice of a spinneret, and to obtain fibers with a single fiber fineness of 0 and 1 denier. In direct melt spinning of thermoplastic polymers, a method is generally used in which spinning is carried out while maintaining the atmosphere directly below the spinneret at a high temperature over a certain range. In that case, the ambient temperature at a distance of 1 to 3 cm directly below the spinneret is at least 200°C, preferably 250°C or higher. In this way, the reason for increasing the atmospheric temperature directly below the spinneret is to keep the spinneret warm, prevent slabs and single fiber breakage, and promote relaxation of fiber orientation, thereby increasing the drawing ratio in the drawing process. This is to do so. However, when reducing the discharge amount per discharge orifice of the spinneret to obtain fibers with a single fiber fineness of 0.15 denier or less, if the area directly below the spinneret is kept in a high temperature atmosphere, the yarn is likely to break, which has the opposite effect. It will appear, so place 1 directly below the spinneret.
It is necessary to keep the ambient temperature at 200°C or less at ~3 cm. If the temperature exceeds 200°C, single filament breakage occurs frequently and a stable spinning state cannot be obtained. For the purpose of stably spinning, promoting sufficient orientation relaxation, and increasing the residual elongation of undrawn fibers, the preferable range of the ambient temperature at 1 to 3' cm directly below the spinneret is 120 to 190°C. Another feature in the production of undrawn continuous fibers is to bundle all single fibers after spinning at a distance of 10 to 150 cm below the spinneret. The first advantage of performing such focusing is that if the fibers are not focused near the nozzle as described above, single fiber breakage will occur under the spinneret due to air resistance, resulting in continuous undrawn fibers. However, if the fibers are bundled at a position within the distance from the nozzle, this single fiber breakage is eliminated and continuous undrawn continuous fibers can be stably obtained. The second advantage is that the maximum draw ratio of the undrawn fibers is greater than in the case where the fibers are not converged near the nozzle as described above, and therefore, thinner drawn fibers can be obtained. This effect is thought to be due to the fact that by converging all single fibers at a short distance from the nozzle, air resistance is reduced and the tension applied to the fibers is reduced, thereby making the orientation easier to relax. Although any known method may be used to bundle the fibers immediately after spinning, it is preferable to use a guide that has a small degree of contact with the fibers, such as a Snell guide. In addition, the first advantage mentioned above is greater as the convergence position is closer to the spinneret, but since the spun fibers are not solidified within 10 cm below the spinneret, the fusion of single fibers and contact with guides may cause Easy to cause cuts. Therefore, the location of the spinneret must be more than 10 countries away. Moreover, the above-mentioned second advantage is observed only in a region within 250 cm below the spinneret. therefore,
The focusing position is 10 to 150 cn+ below the spinneret, with a preferred range of 20 to 100 am. Another feature of the invention is that it requires a spinneret with a relatively small discharge cross-sectional area per discharge orifice. The cross-sectional area of the discharge nozzle is 1.5 x 10-'cm? If it is below, it is possible to obtain drawn fibers with a single fiber fineness of 0.15 denier or less by selecting conditions such as polymer discharge amount, spinning speed, and drawing ratio, but 1.5 × 10-' crl It is impossible if it exceeds. In particular, in order to obtain fibers with a denier of O.1 or less, it is necessary to use fibers with a diameter of 1X10-'cJA or less. The cross-sectional shape of the discharge orifice may be of a different shape such as a Y-shape, a pentagon, a flat shape, or a C-shape, in addition to the circular shape. For the orientation and stretching of the undrawn fibers of the present invention, it is preferable to use a known stretching device such as a draw twister, a drawer twister, a stretch false twister, or a tow stretcher. Depending on the type of thermoplastic polymer, either hot stretching or cold stretching is selected, and multistage stretching is also possible if necessary. Ultrafine fibers obtained by oriented drawing of undrawn continuous fibers have little fuzz and denier unevenness, and can be sufficiently knitted in conventional knitting and weaving processes, and the resulting knitted fabrics have no dyeing unevenness and are of high quality. In addition, the raised surface of knitted fabrics is soft,
It has an excellent texture and is very similar to natural suede. Moreover, among the undrawn continuous fibers of the present invention, X≦20
0 can be stretched and false-twisted using a known stretching and false-twisting machine.
A temporarily processed yarn that can be knitted and woven was obtained. Example C] Hereinafter, the present invention will be described in more detail with reference to Examples, but the present invention is not limited to these Examples. Example 1 A spinning machine and a spinning machine as shown in FIGS. 1 and 2 and a spinning machine as shown in FIGS. Polyethylene terephthalate having an intrinsic viscosity [η) of 0.65 was spun and drawn using eight machines. At that time, the polymer discharge amount and the atmospheric temperature at 1 to 3 cIIl below the spinneret are shown in Table 1.
Various combinations were set as follows, and the spinning conditions at that time and the single fiber denier of the obtained drawn fibers were investigated. The results are shown in Table 1. Other manufacturing conditions are as follows. Juku Mujosho spinning nozzle Number of holes 144 Hole cross-sectional area (circular) 0.78X10-'cnl Spinning temperature 300℃ Spinning speed 1250m/min Focusing position
Bottom of the spinneret 30cm (by Snell guide) Smoldering hole supply roll temperature 75℃ Hot plate temperature 140℃ Smoldering speed 5QOm/min Stretching ratio The elongation at break of the drawn fibers should be around 25% for each spinning condition. Set the ambient temperature 1 to 3 cm below the spinneret to 200°.
If it is less than C, a fiber with a single fiber fineness Q of less than 15 denier can be obtained at less than 0.05 g/min/orifice. In addition, the obtained drawn fibers all had high uniformity with a U% of 2.0% or less. Margin below *l Discharge amount per spinneret orifice *2 Atmospheric temperature at 1 to 3ω below the spinneret Spinning condition: ○ Fine pore x Unable to spin, frequent breakage Example 2 Using a spinning machine as shown in Fig. 1, the intrinsic viscosity [η ]=0.65
Polyethylene terephthalate was spun by setting various combinations of discharge amount and discharge nozzle cross-sectional area. The maximum draw ratio of the obtained undrawn fiber was measured and was 1000/(X
+100) was calculated. Spinning state and 1000/(X
+100) values are shown in Table 3. From the results, when the nozzle cross-sectional area is 3.5 x 10-'am or less, 0.3
Less than denier, 2. When less than OX ltl'cm,
It can be seen that it can be 0.2 denier or less. Spinning conditions Number of spinneret holes: 144 (circular nozzle) Spinning temperature: 295°C Spinneret bottom 1-3c
Ambient temperature at 180'C spinning speed
1,250 m/min Focusing method and focusing Snell guide, position 20 cm below the spinneret Smoking feed roll speed 75°C Hot plate temperature 140°C Rolling speed Smoking
500 m/min 4, Brief description of the drawings Fig. 1 is a schematic diagram showing an example of a one-piece melt spinning apparatus,
FIG. 2 is a schematic diagram showing a specific example of a stretching device;
The figure shows the relationship between the single fiber fineness of undrawn continuous fibers and the maximum drawing ratio X. Reference numbers in FIGS. 1 and 2 are as follows. ■...chimp hopper, 2...melt extruder, 3
...melted polymer flow, 4.metering pump, 5.
... Spinneret, 6... Rapid cooling atmosphere, 7...
・Spun fiber, 8... Focusing guide, 9...
Cold air rectifier, 10... Cooling air, 11... Thread path duct, 12... Oil agent application device, 13...
Take-up roll, 14... undrawn fiber, 15...
Presser roll, 16... Supply roll, 17...
Hot plate, 1 day...Stretching roll, 19...
Stretched fiber. Figure 3 Procedural Amendment (Spontaneous) Date of 1985 Michibe Uga, Commissioner of the Patent Office1, Case description 1985 Patent Application No. 0249232, Name of invention Thermoplastic polymer unstretched continuous Textile 3, Relationship with the person making the amendment Patent applicant name (003) Asahi Kasei Industries Co., Ltd. 4, Agent address: 10-5, Toranomon-8-chome, Minato-ku, Tokyo 105
Target of amendment: Full text of the amended specification attached to the procedural amendment submitted dated March 10, 1986 6, Contents of the amendment: Engraving of the full text of the amended specification (no change in content) 7, List of attached documents

Claims (1)

[Scope of Claims] 1. An undrawn continuous fiber of a thermoplastic polymer, characterized in that 0.05≦100D/(X+100)<0.30 and 10≦X≦700. However, the thermoplastic polymer undrawn continuous fiber according to claim 1, wherein D: single fiber fineness (denier) X: maximum drawing ratio (%) 2.60≦X≦500. 3. The thermoplastic polymer undrawn continuous fiber according to claim 1, wherein 0.05≦100D/(X+100)<0.25 and 60≦X≦350. 4. The thermoplastic polymer undrawn continuous fiber according to any one of claims 1 to 3, wherein the thermoplastic polymer is polyester or polyamide.