JP2012046831A - Spinning method and spinning apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a spinning method and a spinning apparatus enabling necking drawing by controlling a necking position and capable of producing uniform yarns with small variation in diameter by controlling necking stability.SOLUTION: In a spinning method, tension is applied to a filament and a portion of the tension applied filament is heated from the temperature at which the diameter of the filament does not change substantially to the temperature at which a necking is caused in the filament so as to perform necking drawing to the filament to spin the filament. Preferably, after the temperature is reduced to the one at which a necking is not caused by cooling means, the temperature is raised to the one at which a necking is caused by heating means.

Description

  The present invention relates to a spinning method and a spinning device.

  Conventionally, in the spinning of polymer fibers, a stretching process for stretching a filamentous material that has been melt-extruded has been performed. For example, a polymer is melted and extruded from a spinneret to form a filament, and the filament is wound up as an unstretched yarn once cooled and solidified in a cooling tank having a cooling liquid, and the unstretched yarn is further heated. The drawing process is performed after heating through a water tank, a hot oil tank, a steam tank, a heated air tank or the like.

  And in drawing in spinning, there is a drawing method called necking drawing. The necking stretching is a stretching method in which necking (necking) occurs in a narrow range of the filamentous body and the filamentous body is stretched. Since the necking stretching is performed in a narrow range of the filamentous body, there is an advantage that a device used for stretching can be reduced in size and simplified.

However, in the necking stretching, it is difficult to control the position and stability of the necking.
In the necking stretching, the position of the necking usually cannot be controlled, and the position of the necking is moved to a site where the roll for conveying and applying tension and the thread-like body are in contact with each other. There is a problem that the yarn is cut and the yarn cannot be manufactured stably. Therefore, it is desired that the position of the necking can be controlled.
Further, if the stability of the necking cannot be controlled, draw resonance is likely to occur, and there is a problem that a yarn having a uniform cross-sectional shape and average diameter cannot be produced. Therefore, it is desired that the stability of the necking can be controlled.

With respect to the necking stretching, in order to obtain a product in the form of a film, a hot plate is used, and a temperature gradient is provided from a low temperature portion on the film inlet side stretched on the hot plate to a high temperature portion on the film delivery side, and There has been proposed a technique in which necking that occurs in a film accompanying stretching is performed at the low temperature portion of the hot plate and the drawing is completed at the high temperature portion of the hot plate (for example, Patent Document 1).
However, in this proposal, since the temperature of the film that causes the necking is not studied, even if this technique is applied to spinning, the position of the necking cannot be controlled, and as a result, the position of the necking moves, and the filamentous body There was a problem that was cut off. Further, even when this technique is applied to spinning, the stability of the necking cannot be sufficiently controlled, and there is a problem that a yarn having a uniform cross-sectional shape, average diameter and the like cannot be produced.

By the way, various devices have been made to improve the functionality and aesthetics of the yarn. For example, a heat-insulating and metallic glossy yarn made of only a polymer having crystallinity and having a cavity inside, and a method for producing the yarn have been proposed (for example, Patent Document 2). And as an example of the manufacturing method of the thread | yarn which has this cavity, manufacturing the thread | yarn which has a cavity inside is produced by producing necking.
However, in this proposal, since the temperature of the filamentous body that causes the necking is not studied, the position of the necking cannot be controlled, and as a result of the movement of the necking position, there is a problem that the filamentous body breaks. . Further, there is a problem that the stability of the necking cannot be sufficiently controlled, and a yarn having a uniform cross-sectional shape, average diameter and the like cannot be manufactured.

Further, as a technique for improving the functionality of the yarn, for example, there is a technology for improving water absorption by changing the cross-sectional shape of the yarn. In addition, a technique has been proposed in which a void is created inside the yarn to produce a soft texture or to improve lightness (for example, Patent Document 3). In addition, as a technique for improving the aesthetics of the yarn, for example, a technique for expressing structural coloring by alternately laminating two types of polymers having different refractive indexes and coating them with a protective layer to form a composite yarn Has been proposed (for example, Patent Document 4).
These yarns are usually stretched during the production process. In this stretching, if the necking stretching is used, the apparatus used for stretching can be reduced in size and simplified.
However, even when the necking drawing is used for the production of these yarns, there is a problem that the position of the necking cannot be controlled and the yarn cannot be produced stably. Further, the stability of necking cannot be controlled, the cross-sectional shape becomes non-uniform, the voids inside the yarn become non-uniform, and the laminated state of the composite yarn cannot be controlled. And when cross-sectional shape becomes non-uniform | heterogenous, there exists a problem that the water absorption of the thread | yarn obtained becomes non-uniform | heterogenous. Further, when the gaps inside the yarn are non-uniform, there is a problem that the texture and lightness of the resulting yarn become non-uniform. Further, if the laminated state of the composite yarn cannot be controlled, there is a problem that the color developability of the structural color development is not stable.

  Accordingly, there is a need to provide a spinning method and a spinning device that can control necking position to perform necking drawing and can control the necking stability to produce a uniform yarn with small variation in diameter. Is the current situation.

Japanese Patent Laid-Open No. 5-104619 JP 2009-191382 A JP 2005-256243 A Japanese Patent No. 3356438

  An object of the present invention is to solve the above-described problems and achieve the following objects. That is, the present invention provides a spinning method and a spinning device that can perform necking stretching by controlling the position of necking, and can control the stability of necking to produce a homogeneous yarn with small variation in diameter. With the goal.

Means for solving the problems are as follows. That is,
<1> By applying tension to the filamentous body and raising a part of the tensioned filamentous body from a temperature at which the diameter of the filamentous body does not substantially change to a temperature at which necking occurs in the filamentous body. The spinning method is characterized by spinning the filamentous body by necking and stretching the filamentous body.
<2> Tension is applied to the filamentous body, and a part of the tensioned filamentous body is brought to a temperature at which the diameter of the filamentous body does not substantially change by the cooling means, and then necked to the filamentous body by the heating means. The spinning method according to <1>, wherein the filamentous body is necked and stretched by raising the temperature to such a temperature that causes the filamentous body to be spun.
<3> The cooling means is a coolable member, the heating means is a heatable member,
The spinning method according to <2>, wherein tension is applied in a state where the filamentous body is in contact with the cooling unit and the heating unit.
<4> The spinning method according to any one of <2> to <3>, wherein the cooling temperature by the cooling unit is equal to or lower than the glass transition point of the filamentous body.
<5> The spinning method according to any one of <1> to <4>, wherein the half-width of the crystalline peak in X-ray diffraction of the filamentous body is less than 9 ° as 2θ.
<6> The spinning method according to any one of <1> to <5>, wherein an average diameter of the filamentous body is 10 μm to 500 μm.
<7> The obtained yarn has cavities oriented in the drawing direction inside, the average length of the cavities is L (μm), and the average of the cavities in the direction orthogonal to the orientation direction of the cavities The spinning method according to any one of <1> to <6>, wherein the L / r ratio when the diameter is r (μm) is 10 or more.
<8> The spinning method according to any one of <1> to <7>, wherein the obtained yarn is composed of only a crystalline polymer.
<9> The spinning method according to any one of <1> to <8>, wherein the obtained yarn has a reflectance of 40% to 90%.
<10> Necking is generated in the filament that has been heated to a temperature at which necking occurs, and the filament is necked and stretched, and the position of the necking is maintained at a temperature at which the diameter of the filament does not substantially change. The spinning method according to any one of <1> to <9>, wherein the spinning is performed in the vicinity of the filament and fixed.
<11> Necking is generated in the filament that has been heated to a temperature at which necking is generated by the heating means, the filament is necked and stretched, and the diameter of the filament is substantially changed by the cooling means. The spinning method according to any one of <1> to <10>, wherein the spinning is performed in the vicinity of the filament maintained at a temperature that is not performed and fixed.
<12> tension applying means for applying tension to the filamentous body;
And necking generating means for raising the temperature of a part of the thread-like body to which tension is applied by the tension applying means from a temperature at which the diameter of the thread-like body does not substantially change to a temperature at which necking of the thread-like body occurs. Spinning device.
<13> Cooling means for cooling a part of the filamentous body to which tension is applied to a temperature at which the diameter of the filamentous body does not substantially change, and heating for raising the temperature to a temperature at which necking occurs in the filamentous body. The spinning device according to <12>, further comprising: means.
<14> The spinning device according to <13>, wherein the cooling unit is a coolable member, and the heating unit is a heatable member.

  According to the present invention, it is possible to solve the above-mentioned problems in the prior art, to perform necking stretching by controlling the position of necking, and to control the stability of necking to obtain a uniform yarn with small variation in diameter. A spinning method and a spinning device that can be manufactured can be provided.

FIG. 1 is a diagram showing an outline of necking. FIG. 2A is a diagram for specifically explaining the aspect ratio, and is a perspective view of a yarn. FIG. 2B is a diagram for specifically explaining the aspect ratio, and is a cross-sectional view taken along line A-A ′ of the yarn in FIG. 2A. FIG. 2C is a diagram for specifically explaining the aspect ratio, and is a cross-sectional view taken along the line B-B ′ of the yarn in FIG. 2A. FIG. 3 is a schematic view of an embodiment of the spinning device of the present invention. FIG. 4 is a schematic view of an embodiment of the spinning device of the present invention. FIG. 5 is a schematic view of an embodiment of the spinning device of the present invention. FIG. 6 is a schematic view of an embodiment of the spinning device of the present invention. FIG. 7 is a schematic view of an embodiment of the spinning device of the present invention. FIG. 8 is a schematic view of the spinning device used in the reference example.

(Spinning method and spinning device)
The spinning method of the present invention includes at least a stretching step, and further includes other steps as necessary.
The stretching step is a step of stretching the filamentous body and includes at least a tension applying process and a necking generating process, and further includes other processes as necessary.
The spinning device of the present invention has at least a drawing machine and, if necessary, other equipment.
The stretching machine has at least a tension applying unit and a necking generating unit, and further includes other units as necessary.
In the spinning method of the present invention, the stretching step can be performed by the stretching machine. The tension applying process can be performed by the tension applying means. The necking generation process can be performed by the necking generating means.

<Filament>
There is no restriction | limiting in particular as a material of the said filament, It can select suitably according to the objective, For example, a thermoplastic resin is mentioned.
The filamentous body may contain a heat stabilizer, an antioxidant, an organic lubricant, a nucleating agent, a dye, a pigment, a dispersant, a coupling agent, and the like. Moreover, you may contain cavity forming agents, such as an inorganic fine particle and resin which is incompatible, for producing a cavity in the thread | yarn obtained after extending | stretching.
There is no restriction | limiting in particular as said thermoplastic resin, According to the objective, it can select suitably, For example, a crystalline polymer and an amorphous polymer are mentioned. Among these, the crystalline polymer is preferable in that a thread having a cavity can be obtained without using a cavity forming agent such as inorganic fine particles or incompatible resin.

-Crystalline polymer-
In general, polymers are classified into crystalline polymers and amorphous (amorphous) polymers, but even crystalline polymers are not 100% crystalline, and long chain molecules are regularly formed in the molecular structure. It includes aligned crystalline regions and non-regularly arranged amorphous (amorphous) regions.
Therefore, the crystalline polymer only needs to include at least the crystalline region in the molecular structure, and the crystalline region and the amorphous region may be mixed.

  There is no restriction | limiting in particular as said crystalline polymer, According to the objective, it can select suitably, For example, polyolefin (for example, low density polyethylene, high density polyethylene, polypropylene, etc.), polyamides (PA) (for example, Nylon-6), polyacetals (POM), polyesters (eg, PET, PEN, PTT, PBT, PPT, PHT, PBN, PES, PBS, etc.), syndiotactic polystyrene (SPS), polyphenylene sulfide ( PPS), polyether ether ketones (PEEK), liquid crystal polymers (LCP), fluororesin, isotactic polypropylene (isoPP) and the like. Among these, polyolefins, polyesters, syndiotactic polystyrene (SPS), and liquid crystal polymers (LCP) are preferable, and polyolefins and polyesters are more preferable from the viewpoints of durability, mechanical strength, production, and cost. Two or more kinds of these polymers may be blended or copolymerized.

The melt viscosity of the crystalline polymer is not particularly limited and may be appropriately selected depending on the intended purpose, but is preferably 50 Pa · s to 700 Pa · s, more preferably 70 Pa · s to 500 Pa · s, and more preferably 80 Pa · s. s to 300 Pa · s is particularly preferable. When the melt viscosity is in the preferred range, the shape of the melt discharged from the melt extrusion die (nozzle) at the time of melt extrusion is stable, which is advantageous in that it becomes easy to form a filament having a uniform diameter. A particularly preferable range is advantageous in that the above-described effect becomes remarkable.
Here, the melt viscosity can be measured by a plate type rheometer or a capillary rheometer.

There is no restriction | limiting in particular as intrinsic viscosity (IV) of the said crystalline polymer, Although it can select suitably according to the objective, 0.4-1.3 are preferable and 0.6-1.0 are more preferable. 0.7 to 0.9 is particularly preferable. When the IV is in the preferred range, the resulting filamentous body has a high tensile strength and is advantageous in that it can be efficiently stretched. In the particularly preferred range, the effect becomes remarkable. Is advantageous.
Here, the IV can be measured by an Ubbelohde viscometer.

There is no restriction | limiting in particular as melting | fusing point (Tm) of the said crystalline polymer, Although it can select suitably according to the objective, 40 to 350 degreeC is preferable, 100 to 300 degreeC is more preferable, 100 to 260 degreeC is preferable. ° C is particularly preferred. When the melting point is in the preferred range, it is easy to keep the diameter in the temperature range expected for normal use, and even without special techniques required for processing at high temperatures, it is uniform. It is advantageous in that it can be spun smoothly, and if it is in the particularly preferred range, it is advantageous in that the effect becomes remarkable.
Here, the melting point can be measured by a differential thermal analyzer (DSC).

--- Polyester resin--
The polyesters (hereinafter referred to as “polyester resin”) mean a generic term for polymers having an ester bond as the main bond chain of the main chain. Therefore, as the polyester resin suitable as the crystalline polymer, the exemplified PET (polyethylene terephthalate), PEN (polyethylene naphthalate), PTT (polytrimethylene terephthalate), PBT (polybutylene terephthalate), PPT (polypenta). Methylene terephthalate), PHT (polyhexamethylene terephthalate), PBN (polybutylene naphthalate), PES (polyethylene succinate), PBS (polybutylene succinate), as well as by polycondensation reaction of dicarboxylic acid component and diol component All the resulting polymers are included.

  The dicarboxylic acid component is not particularly limited and may be appropriately selected depending on the intended purpose. Examples thereof include aromatic dicarboxylic acids, aliphatic dicarboxylic acids, alicyclic dicarboxylic acids, oxycarboxylic acids, and polyfunctional acids. Can be mentioned.

  Examples of the aromatic dicarboxylic acid include terephthalic acid, isophthalic acid, diphenyldicarboxylic acid, diphenylsulfone dicarboxylic acid, naphthalenedicarboxylic acid, diphenoxyethanedicarboxylic acid, and 5-sodium sulfoisophthalic acid. Among these, terephthalic acid, isophthalic acid, diphenyldicarboxylic acid, and naphthalenedicarboxylic acid are preferable, and terephthalic acid, diphenyldicarboxylic acid, and naphthalenedicarboxylic acid are more preferable.

  Examples of the aliphatic dicarboxylic acid include oxalic acid, succinic acid, eicoic acid, adipic acid, sebacic acid, dimer acid, dodecanedioic acid, maleic acid, and fumaric acid. Examples of the alicyclic dicarboxylic acid include cyclohexane dicarboxylic acid. Examples of the oxycarboxylic acid include p-oxybenzoic acid. Examples of the polyfunctional acid include trimellitic acid and pyromellitic acid. Among the aliphatic dicarboxylic acids and alicyclic dicarboxylic acids, succinic acid, adipic acid, and cyclohexanedicarboxylic acid are preferable, and succinic acid and adipic acid are more preferable.

  There is no restriction | limiting in particular as said diol component, According to the objective, it can select suitably, For example, aliphatic diol, alicyclic diol, aromatic diol, diethylene glycol, polyalkylene glycol etc. are mentioned. Of these, aliphatic diols are preferred.

Examples of the aliphatic diol include ethylene glycol, propane diol, butane diol, pentane diol, hexane diol, neopentyl glycol, and triethylene glycol. Among these, propanediol, butanediol, pentanediol, and hexanediol are particularly preferable.
Examples of the alicyclic diol include cyclohexanedimethanol.
Examples of the aromatic diol include bisphenol A and bisphenol S.

  There is no restriction | limiting in particular as melt viscosity of the said polyester resin, Although it can select suitably according to the objective, 50 Pa.s-700 Pa.s are preferable, 70 Pa.s-500 Pa.s are more preferable, 80 Pa.s ˜300 Pa · s is particularly preferred. The higher the melt viscosity, the easier it is to develop cavities during stretching, but when the melt viscosity is within the above preferred range, it is easier to extrude from the die during melt extrusion, or the resin flow stabilizes and stays. It becomes difficult and the quality is stabilized, the stretching tension is properly maintained at the time of stretching, it becomes easy to stretch uniformly, it is difficult to break, and the form of the polymer discharged from the die at the time of extrusion This is advantageous in terms of improving physical properties such as being easy to maintain, enabling stable spinning, and making the product difficult to break. It is.

  There is no restriction | limiting in particular as intrinsic viscosity (IV) of the said polyester resin, Although it can select suitably according to the objective, 0.4-1.3 are preferable, 0.6-1.0 are more preferable, 0.7 to 0.9 is particularly preferable. When the IV is larger, cavities are more likely to develop during stretching. However, if the IV is within the preferred range, extrusion from the die becomes easier during melt extrusion, and the resin flow is more stable and less likely to stay. Therefore, it is advantageous in that the quality is stabilized, and in the particularly preferable range, it is advantageous in that the effect becomes remarkable. Furthermore, when the IV is within the preferable range, the stretching tension is appropriately maintained at the time of stretching, so that it is easy to stretch uniformly, and it is advantageous in that the load is not easily applied to the apparatus. If it exists, it is advantageous at the point from which the said effect becomes remarkable. In addition, when the IV is in the preferred range, it is advantageous in that the product is less likely to be damaged and the physical properties are increased, and in the particularly preferred range, it is advantageous in that the effect is remarkable. .

  There is no restriction | limiting in particular as melting | fusing point of the said polyester resin, Although it can select suitably according to the objective, From viewpoints, such as heat resistance, 70 to 300 degreeC is preferable and 90 to 270 degreeC is more preferable.

  In addition, as said polyester resin, the said dicarboxylic acid component and the said diol component may respectively superpose | polymerize with 1 type, and may form the polymer, and the said dicarboxylic acid component and / or the said diol component are 2 or more types. A polymer may be formed by copolymerization. Further, as the polyester resin, two or more kinds of polymers may be blended and used.

  In the blend of two or more kinds of polymers, the polymer added to the main polymer has a melt viscosity and an intrinsic viscosity that are close to those of the main polymer, and the addition amount is smaller, the physical properties at the time of melt extrusion are smaller. It is preferable in terms of increasing and facilitating extrusion.

  In addition, for the purpose of improving the flow characteristics of the polyester resin, controlling light transmittance, and improving the adhesion with the coating solution, a resin other than polyester may be added to the polyester resin.

  It is preferable that the full width at half maximum of the crystalline peak can be confirmed in the filamentous body by X-ray diffraction. As a half value width, 2θ is preferably less than 9 °, more preferably 7 ° or less, and particularly preferably 5 ° or less. When the half width is 9 ° or more, it is difficult to obtain a thread having a cavity. When the half-value width is in a particularly preferable range, it is advantageous in that a yarn having a cavity having an appearance with excellent glitter can be produced with stable quality.

  The half width can be measured by, for example, an X-ray diffractometer (for example, RINT TTR III, manufactured by Rigaku Corporation).

  There is no restriction | limiting in particular as an average diameter of the said filamentous body, Although it can select suitably according to the objective, It is preferable that it is 10 micrometers-500 micrometers, It is more preferable that they are 20 micrometers-200 micrometers, It is 20 micrometers-50 micrometers. It is particularly preferred. When the average diameter is less than 10 μm, yarn breakage is likely to occur, and it may be difficult to stably and continuously manufacture. In addition, the difference in the cooling rate between the surface and the inside of the yarn becomes small, and when producing a yarn having a cavity, voids are less likely to occur. When the thickness exceeds 500 μm, the resulting yarn is rigid. Therefore, when processed into a woven fabric or the like, the texture may get worse and the shape may be difficult to follow when secondary processing such as insert molding is performed on the woven fabric obtained by processing the yarn. . When the average diameter is in the particularly preferable range, it is advantageous in that the obtained yarn is excellent in flexibility, workability, and texture.

  The average diameter of the filamentous body is, for example, a digital dimension measuring instrument (LS-7600 (controller part), LS-7010M (measuring part)) manufactured by Keyence Corporation, or a digital micrometer (293-230MDC-25MJ manufactured by Mitutoyo Corporation). It is an average value when the diameter of the filament is measured at 20 points.

There is no restriction | limiting in particular as a manufacturing method of the said filament, It can select suitably according to the objective, For example, melt spinning, dry spinning, etc. are mentioned.
Examples of the melt spinning include a method in which a raw material is melted using a melt extruder, and then the raw material is extruded from a die having a circular cross-sectional shape and solidified in a cooling water tank while being taken up.

<Tension applying treatment and tension applying means>
The tension applying process can be performed by the tension applying means.

-Tensioning means-
The tension applying unit is not particularly limited as long as it is a unit that applies tension to the filament, and can be appropriately selected according to the purpose. For example, a tension applying unit having a low speed roll and a high speed roll. And tension applying means having a roll and a winder, tension applying means having an endless belt and a winder, and tension applying means having an orifice for extruding a filament and a winder. Among these, a tension applying means having a low speed roll and a high speed roll is preferable in that a stable tension can be applied to the filamentous body.

  For example, in the conveyance of the filamentous body using the low-speed roll and the high-speed roll, the application of tension by the tension applying unit including the low-speed roll and the high-speed roll is performed on the upstream side in the conveyance direction of the filamentous body. The high-speed roll is arranged on the downstream side, the filamentous body is conveyed so as to be in contact with these rolls, and the circumferential speed difference between these rolls is used.

There is no restriction | limiting in particular as a conveyance speed of the said filament, It can select suitably according to the objective.
The conveyance speed of the filamentous body at the position in contact with the low-speed roll is not particularly limited as long as it is lower than the conveyance speed of the filamentous body at the position in contact with the high-speed roll, and can be appropriately selected according to the purpose. However, 0.1 to 200 m / min is preferable, 0.5 to 100 m / min is more preferable, and 1 to 20 m / min is particularly preferable. When the conveyance speed is less than 0.1 m / min, speed unevenness is likely to occur, and when producing a thread having a cavity, voids may not be stably generated, and the conveyance speed is Since it is slow, it may be inferior in productivity, and when it exceeds 200 m / min, the position of necking stretching may not be stable and thread breakage may easily occur. When the conveying speed is in the particularly preferable range, it is advantageous in that stable necking stretching can be performed with high productivity.
The conveyance speed of the filamentous body at the position in contact with the high-speed roll is not particularly limited as long as it is higher than the conveyance speed of the filamentous body at the position in contact with the low-speed roll, and can be appropriately selected according to the purpose. However, 0.5 to 2,000 m / min is preferable, 50 to 1,500 m / min is more preferable, and 100 to 1,000 m / min is particularly preferable. When the conveyance speed is less than 0.5 m / min, cavities may not be stably produced when producing a yarn having a cavity, and when it exceeds 2,000 m / min, necking stretching may occur. The position may not be stable and thread breakage may occur easily. When the conveyance speed is in the particularly preferable range, it is advantageous in that high-speed stretching can be stably performed.

  Here, the conveyance speed of the filament in the position in contact with the low-speed roll can be obtained from the peripheral speed of the low-speed roll because it is the same speed as the peripheral speed of the low-speed roll. Moreover, since the conveyance speed of the filament at the position in contact with the high-speed roll is the same as the peripheral speed of the high-speed roll, it can be obtained from the peripheral speed of the high-speed roll.

  The ratio (h / l) between the conveyance speed (l) of the filamentous body at the position in contact with the low-speed roll and the conveyance speed (h) of the filamentous body at the position in contact with the high-speed roll may exceed 1.0. If there is no restriction | limiting in particular, Although it can select suitably according to the objective, (h / l) = 2-20 are preferable, 4-15 are more preferable, and 4-10 are especially preferable. When the ratio is less than 2, cavities (voids) are less likely to be generated when a yarn having cavities is produced, and when it exceeds 20, yarn breakage may easily occur. When the ratio is within the particularly preferable range, it is advantageous in that stable and continuous production is possible.

  The tension applying means having the low speed roll and the high speed roll preferably further has a nip roll. Tension can be stably applied to the filamentous body by nipping the filamentous body between the nip roll and any one of the low-speed roll and the high-speed roll.

There is no restriction | limiting in particular as a structure and a magnitude | size of the said low speed roll, the said high speed roll, and the said nip roll, Although it can select suitably according to the objective, A roll with a big curvature is preferable.
There is no restriction | limiting in particular as a shape of the said low speed roll, the said high speed roll, and the said nip roll, According to the objective, it can select suitably, For example, a column shape is mentioned.
The material of the low-speed roll, the high-speed roll, and the nip roll is not particularly limited and can be appropriately selected according to the purpose. For example, a metal-plated metal, stainless steel, silicon rubber, nitrile rubber , Urethane rubber, NBR, and various elastomers.

  Moreover, it is preferable that the tension | tensile_strength provision means which has the said low speed roll and a high speed roll further has an auxiliary roll. By having the auxiliary roll, tension can be uniformly applied to the filamentous body.

There is no restriction | limiting in particular as tension | tensile_strength provided to the said filament by the said tension | tensile_strength provision process, Although it can select suitably according to the objective, 5MPa-40MPa is preferable, 10MPa-30MPa is more preferable, 10MPa-20MPa Particularly preferred. When the tension is less than 5 MPa, stretching unevenness is likely to occur, and when it exceeds 40 MPa, yarn breakage may easily occur. When the tension is within the particularly preferable range, it is advantageous in that high-speed stretching can be stably performed.
Here, the tension indicates the tension of the filamentous body.

<Necking generation processing and necking generation means>
The necking generation process can be performed by the necking generation means.

Here, necking is a constriction that occurs in a narrow range of the filamentous body during stretching. An outline of necking is shown in FIG. In FIG. 1, W ₀ represents the diameter of the filamentous body, W represents the diameter of the thread (the thread after stretching), and L ₀ is the length of the range of the filamentous body in which necking has occurred. Usually, in the neck stretching, the length of _{L 0} is a 1 mm to 5 mm.

-Necking generating means-
As the necking generating means, any means can be used as long as the temperature of a part of the filamentous body to which tension is applied is increased from a temperature at which the diameter of the filamentous body does not substantially change to a temperature at which necking occurs in the filamentous body. There is no restriction | limiting, According to the objective, it can select suitably.

--Temperature at which filament diameter does not change substantially--
The temperature at which the diameter of the filamentous body does not substantially change is a temperature at which the diameter of the filamentous body does not substantially change in the state where the tension is applied, for example, below the glass transition point (Tg) of the filamentous body. Temperature.
There is no particular limitation on the method for setting the temperature so that the diameter of the filamentous body does not substantially change, and it can be appropriately selected according to the purpose. For example, the diameter of the filamentous body is substantially reduced by using a cooling means. There is a method of keeping the temperature unchanged.
By cooling to a temperature at which the diameter of the filamentous body does not substantially change by the cooling means, the position of necking is moved to the vicinity of the filamentous body maintained at a temperature at which the diameter of the filamentous body does not substantially change and fixed. Can be made.
Here, that the diameter of the filamentous body does not substantially change means that the rate of change of the average diameter of the filamentous body is 3% or less.
Here, the glass transition point (Tg) can be measured by a differential thermal analyzer (DSC) (for example, DSC220 manufactured by SII).

--- Cooling means ---
The cooling means is not particularly limited as long as it is a means that can cool the filaments to which the tension is applied to a temperature at which the diameter of the filaments does not substantially change, and can be appropriately selected according to the purpose. For example, a coolable member, a cold air generating device, and the room itself in which the spinning device is installed may be set to a cooling temperature. Among these, a coolable member is preferable from the viewpoint of being small and capable of reliably cooling the filamentous body.

The member that can be cooled is not particularly limited as long as the member itself can be cooled to cool the filament, and can be appropriately selected according to the purpose. Examples thereof include an aluminum block that is easily slipped with a resin, an inorganic member in which a refrigerant circulates inside, an inorganic member to which a cooling element using electronic cooling is attached, and the like.
There is no restriction | limiting in particular as a material of the said inorganic member, Although it can select suitably according to the objective, Brass, copper, aluminum, iron, and stainless steel are preferable at the point that heat conductivity is high and it is cheap. Further, ceramic is preferable from the viewpoint of excellent slipperiness and wear resistance.
There is no restriction | limiting in particular as said refrigerant | coolant, According to the objective, it can select suitably, For example, the cooled gas, liquid, etc. are mentioned. An example of the cooled gas is cooled air. Examples of the cooled liquid include cooled water and antifreeze.
The filamentous body can be cooled by the coolable member by, for example, transporting the filamentous body in contact with the coolable member.

There is no restriction | limiting in particular as a magnitude | size of the said member which can be cooled, a structure, and a material, According to the objective, it can select suitably.
The shape of the coolable member is not particularly limited and can be appropriately selected according to the purpose. However, the coolable member having a substantially arcuate convex surface can easily contact the filamentous body. This is preferable because the temperature of the filamentous body can be easily controlled.

  The coolable member having the substantially arcuate convex surface is not particularly limited and may be appropriately selected depending on the purpose. However, as shown in FIGS. 4 and 6, the end of the substantially arcuate convex surface However, a coolable member having a structure that does not contact the filamentous body is preferable in that it can prevent the filamentous body from coming into contact with the end portion.

  When the coolable member is used, it is preferable that the filamentous body is in contact with the coolable member because the temperature of the filamentous body can be easily controlled.

The cold air generating device is not particularly limited as long as it is a device that can apply cold air to the filament, and can be appropriately selected according to the purpose.
The cold air generator preferably has a dustproof filter. By providing the dustproof filter, dust, dust and the like contained in the cold air can be removed, and a clean thread free from dust and dirt can be produced.
The cooling of the filamentous body by the cold air generating device can be performed, for example, by spraying dry cold air on a part of the filamentous body being conveyed.

  The cooling temperature of the filaments cooled by the cooling means is not particularly limited as long as the diameter of the filaments does not substantially change, and can be appropriately selected according to the purpose. The glass transition point of the filamentous body is preferably 10 ° C. or more lower than the glass transition point of the filamentous body, more preferably from 80 ° C lower than the glass transition point of the filamentous body to 10 ° C lower than the glass transition point of the filamentous body. Temperature is particularly preferred. When the cooling temperature exceeds the glass transition point of the filamentous material, the necking stretching position may be disengaged from the heating device, and yarn breakage may occur. When the cooling temperature is in the particularly preferable range, it is advantageous in that necking stretching can be stably performed on a heating device.

--Temperature at which necking occurs--
The temperature at which necking occurs is a temperature at which necking occurs in the filamentous body in the state where the tension is applied. For example, the temperature at which the necking occurs is 80 ° C. lower than the glass transition point of the filamentous body and 50 ° C. from the glass transition point of the filamentous body. The temperature is in the high temperature range.
There is no restriction | limiting in particular as the method of making the said necking temperature, It can select suitably according to the objective, For example, the method of making it the temperature which necking with a heating means is mentioned.

--- Heating means ---
The heating means is not particularly limited as long as it is a means capable of heating the filamentous body to which tension is applied to a temperature at which necking occurs, and can be appropriately selected according to the purpose. Examples include heated gas and carbon dioxide laser. Among these, the heatable member is preferable.

The heatable member is not particularly limited as long as the member can be heated by heating the member itself and bringing the filamentous body into contact with the member, and is appropriately selected according to the purpose. Examples thereof include a heating device using eddy current, an electric heater, and a metal member in which a heat medium circulates.
There is no restriction | limiting in particular as said heat medium, According to the objective, it can select suitably, For example, the heated gas, liquid, etc. are mentioned. Examples of the heated gas include heated air. Examples of the heated liquid include heated water and heat transfer oil.

There is no restriction | limiting in particular as a magnitude | size of the said member which can be heated, a structure, and a material, According to the objective, it can select suitably.
Further, the shape of the heatable member is not particularly limited and can be appropriately selected according to the purpose. However, the heatable member having a substantially arcuate convex surface is easily contacted with the filamentous body. This is preferable because the temperature of the filamentous body can be easily controlled.

  The heatable member having the substantially arc-shaped convex surface is not particularly limited and can be appropriately selected according to the purpose. However, as shown in FIGS. 3 and 4, the end of the substantially arc-shaped convex surface. However, a heatable member having a structure that does not come into contact with the filamentous body is preferable in that the filamentous body can be prevented from coming into contact with the end portion.

  When the heatable member is used, it is preferable that the filamentous body is in contact with the heatable member in terms of facilitating control of the temperature of the filamentous body and stabilizing the necking start point. .

  The heating gas is not particularly limited as long as it is a gas capable of heating the filaments, and can be appropriately selected according to the purpose. Examples thereof include hot air. The hot air can be generated by, for example, a hot air furnace.

  The heating temperature of the filamentous body heated by the heating means is not particularly limited as long as necking occurs in the filamentous body and can be appropriately selected according to the purpose, but the glass transition point of the filamentous body. A temperature in the range of 80 ° C. to 50 ° C. higher than the glass transition point of the filamentous body is preferable, and a temperature in the range of 20 ° C. lower than the glass transition point of the filamentous body to 40 ° C. higher than the glass transition point of the filamentous body. Temperature is more preferred. When the heating temperature is less than 80 ° C. lower than the glass transition point of the filamentous body, necking may occur and the yarn may be easily broken. When the heating temperature exceeds 50 ° C. higher than the glass transition point of the filamentous body, necking occurs. It may be stretched without causing. When the heating temperature is within the more preferable range, it is advantageous in that necking is likely to occur and voids are likely to occur when a yarn having a cavity is produced.

--- Temperature difference--
In the necking generation process, the absolute value of the temperature difference (B−A) between the temperature (A) at which the diameter of the filamentous body does not substantially change and the temperature (B) at which necking occurs in the filamentous body is particularly limited. However, it is preferably selected according to the purpose, preferably 5 ° C to 100 ° C, more preferably 10 ° C to 50 ° C, and particularly preferably 20 ° C to 40 ° C. If the temperature difference is less than 5 ° C., the starting point of necking may become unstable and uneven, and if it exceeds 100 ° C., the filamentous body may be easily cut or necking may be difficult to develop. . When the temperature difference is within the particularly preferable range, it is advantageous in that necking occurs stably.
Moreover, when the material of the said filament is a polyester resin, as said temperature difference, 40 to 80 degreeC is preferable, 40 to 60 degreeC is more preferable, and 10 to 40 degreeC is especially preferable. If the temperature difference is less than 10 ° C, the starting point of necking may not be stable, and the resulting yarn diameter may be likely to vary. If the temperature difference exceeds 80 ° C, frequent cutting or necking may occur. May be difficult. When the temperature difference is within the particularly preferable range, it is advantageous in that necking stretching can be stably performed.

In the necking generation process, necking is generated in the filaments that have been heated to a temperature at which necking occurs, the filaments are necked and stretched, and the position of the necking is a temperature at which the diameter of the filaments does not substantially change. It is preferable to move it to the vicinity of the filamentous body maintained in place and fix it from the viewpoint of easily controlling the position of necking.
As a method of moving and fixing the position of necking in the vicinity of the filamentous body maintained at a temperature at which the diameter of the filamentous body does not substantially change, for example, necking is caused on the downstream side in the conveyance direction of the filamentous body. After that, the position of necking is gradually closer to the vicinity of the filamentous body, which is upstream of the necking position in the conveyance direction of the filamentous body and maintained at a temperature at which the diameter of the filamentous body does not substantially change. And a method of fixing the necking position at that position.

Here, an example of a method of using the spinning device of FIG. 4 to move and fix the necking position in the vicinity of the filamentous body maintained at a temperature at which the diameter of the filamentous body does not substantially change will be described.
The spinning device in FIG. 4 includes a low speed roll 3, a high speed roll 4, a coolable member (cooling means) 5, a heatable member (heating means) 6 a, a nip roll 7, and an auxiliary roll 8. The coolable member 5 has a substantially arc-shaped convex surface, and is a metal member through which a coolant circulates. The substantially arc-shaped convex surface is in contact with the filament 2, but the substantially arc-shaped convex surface The end has a structure that does not contact the filament 2. The heatable member 6a is a metal member having a substantially arc-shaped convex surface, in which a heat medium circulates, and the substantially arc-shaped convex surface is in contact with the filament 2 but the substantially arc-shaped convex surface. The end portion of this is not in contact with the filament 2.

As a method of moving and fixing the position of the necking in the vicinity of the filamentous body maintained at a temperature at which the diameter of the filamentous body does not substantially change, first, the filamentous body 2 is moved to the low-speed roll 3 and the high-speed roll 4. Transport between the two. At this time, by making the peripheral speed of the high-speed roll 4 faster than the low-speed roll 3, the filament 2 is conveyed from the low-speed roll 3 side to the high-speed roll 4 side. Further, tension is applied to the filament 2 by the difference in peripheral speed between the low-speed roll 3 and the high-speed roll 4. The thread 2 is nipped by the low-speed roll 3 and the nip roll 7, and the thread 2 is nipped by the high-speed roll 4 and the nip roll 7, whereby tension is stably applied to the thread 2. The
Subsequently, a part of the filament 2 that is being conveyed is brought into contact with the member 5 that can be cooled, thereby cooling the filament to a temperature at which the diameter of the filament does not substantially change. Subsequently, a part of the filament 2 cooled to a temperature at which the diameter of the filament does not substantially change is moved by the conveyance of the filament 2 and brought into contact with the heatable member 6a. The temperature is raised to the resulting temperature. By this temperature rise, necking occurs in the filament 2 and the filament 2 is necked and stretched.
At this time, necking occurs on the downstream side (position b in FIG. 4) in the conveying direction of the filament 2 and necking stretching starts. Then, when the necking extension is continued, the necking position is the upstream side in the conveying direction of the filament 2 and is maintained at a temperature at which the diameter of the filament is not substantially changed by the coolable member 5. It moves back to the vicinity of the filament 2 (position a in FIG. 4), and the necking position is fixed at the position (position a in FIG. 4).

<Thread>
The material of the yarn obtained by the spinning method is not particularly limited and may be appropriately selected depending on the purpose. For example, the yarn material may be composed of only a crystalline polymer, or other than the crystalline polymer. These components may be included. Among these, it is preferable that the yarn is composed only of the crystalline polymer because the obtained yarn is a yarn having a cavity and the yarn having the cavity can be produced with stable quality.

  Here, as long as the said thread | yarn which consists only of crystalline polymers is a component which does not contribute to expression of a cavity, other components other than the said crystalline polymer may be included as needed. Examples of the other components include a heat stabilizer, an antioxidant, an organic lubricant, a dye, a pigment, a dispersant, and a coupling agent. Whether or not the other component contributes to the development of the cavity can be determined by whether or not a component other than the crystalline polymer is detected in the cavity or at the interface portion of the cavity.

-Yarn with cavity-
The yarn having a cavity is a yarn having a cavity therein.

  The cavity means a domain in a vacuum state or a domain in a gas phase existing inside a yarn having the cavity. The cavity can be confirmed by a photograph taken with an optical microscope or a scanning electron microscope.

  The yarn having cavities preferably has the cavities oriented in the drawing direction, and the aspect ratio of the cavities is preferably in a specific range.

The aspect ratio is an L / r ratio when the average length of the cavities is L (μm) and the average diameter of the cavities in the direction orthogonal to the orientation direction of the cavities is r (μm) (hereinafter, “ It may be abbreviated as “aspect ratio”.)
There is no restriction | limiting in particular as said aspect-ratio, Although it can select suitably according to the objective, 10 or more are preferable, 15 or more are more preferable, and 20 or more are especially preferable.

  2A to 2C are diagrams for specifically explaining the aspect ratio, in which FIG. 2A is a perspective view of a yarn having a cavity, and FIG. 2B is an AA of the yarn having a cavity in FIG. 2A. 2 is a cross-sectional view, and FIG. 2C is a cross-sectional view taken along the line BB ′ of the yarn having a cavity in FIG. 2A.

  In the manufacturing process of the yarn having the cavity, the cavity is usually oriented along the drawing direction. Therefore, the “average length of the cavity (L (μm))” is in a cross section (BB ′ cross section in FIG. 2A) perpendicular to the surface 10a of the thread 10 having the cavity and parallel to the drawing direction. This corresponds to the average length L of the cavity 100 (see FIG. 2C). The “average diameter of the cavities (r (μm))” is the cavity 100 in a cross section (AA ′ cross section in FIG. 2A) perpendicular to the surface 10a of the thread 10 having cavities and perpendicular to the drawing direction. Corresponds to an average thickness r (see FIG. 2B).

  In the spinning method, since necking stretching is performed along the conveying direction of the filamentous body, this necking stretching direction corresponds to the stretching direction.

  Here, the average length (L (μm)) of the cavity can be measured by an image of an optical microscope or an electron microscope. Similarly, the average diameter (r (μm)) of the cavities can be measured by an image of an optical microscope or an electron microscope.

  The average number P of the cavities in the direction orthogonal to the orientation direction of the cavities is not particularly limited and may be appropriately selected according to the purpose, but is preferably 5 or more, more preferably 10 or more, 15 One or more is particularly preferred.

In the spinning method, the cavities are usually oriented along the drawing direction. Therefore, the “number of the cavities in the direction orthogonal to the orientation direction of the cavities” is a cross section perpendicular to the surface 10a of the yarn 10 having the cavities and perpendicular to the drawing direction (AA ′ cross section in FIG. 2A). This corresponds to the number of cavities 100 included in ().
Here, the average number P of the cavities in the direction orthogonal to the orientation direction of the cavities can be measured by an image of an optical microscope or an electron microscope.

  There is no restriction | limiting in particular as an average diameter of the said thread | yarn, Although it can select suitably according to the objective, It is preferable that they are 10 micrometers-500 micrometers, It is more preferable that they are 20 micrometers-200 micrometers, It is 20 micrometers-50 micrometers. Is particularly preferred. When the average diameter is less than 10 μm, yarn breakage tends to occur, and it may be difficult to stably and continuously manufacture. When the average diameter exceeds 500 μm, the yarn is rigid, and thus when processed into a woven fabric or the like. The texture may be harsh and the texture may be deteriorated, and the shape may be difficult to follow when the fabric obtained by processing the yarn is subjected to secondary processing such as insert molding. When the average diameter is within the particularly preferable range, it is advantageous in terms of excellent flexibility, workability, and texture.

  The average diameter of the yarn is, for example, a digital dimension measuring instrument (LS-7600 (controller part), LS-7010M (measuring part)) manufactured by Keyence Corporation or a digital micrometer (293-230MDC-25MJ) manufactured by Mitutoyo Corporation. It is an average value when the diameter of the yarn is measured at 20 points.

  The reflectance of the yarn is not particularly limited and may be appropriately selected depending on the purpose, but is preferably 40% to 90%, more preferably 40% to 80%, and more preferably 40% Particularly preferred is ˜60%. When the reflectance is within the particularly preferable range, it is advantageous in that a yarn having a metallic luster and a high-quality texture can be obtained.

  The reflectance is a reflectance at a wavelength of 550 nm when an integrating sphere is attached to JASCO Corporation (“V-570”; JASCO Corporation) and scanned in a wavelength range of 200 nm to 2500 nm. Moreover, the measured value of the standard white board attached to the apparatus was set to 100%. In addition, what measured the obtained thread | yarn in the shape of cloth by plain weaving was used as the measurement sample. When weaving, a load of about 100 g to 200 g per yarn was applied to sufficiently thicken the yarn.

<Other processes and other means>
As said other process, a static elimination process is mentioned, for example.
As said other means, a static elimination means is mentioned, for example.

-Static elimination process and static elimination means-
The neutralization step is not particularly limited as long as it can neutralize the yarn, and can be appropriately selected according to the purpose. For example, the yarn is discharged by blowing neutralization air onto the yarn using a neutralization unit. It is possible to remove the charge.
Examples of the static eliminating means include a direct current blower static eliminator (Kasuga Electric Co., Ltd., KD-730B).
Performing the static elimination step is advantageous in that the yarn can be wound while being kept clean.

Examples of the present invention will be described below, but the present invention is not limited to the following examples.

(Production Example 1)
<Manufacture of filamentous body A>
PBT (polybutylene terephthalate 100% resin) having an intrinsic viscosity (IV) = 0.71 was extruded from a die having a circular cross section at 245 ° C. using a melt extruder, and 14 ° C. while being drawn at a line speed of 20 m / min. Was solidified in a cooling water bath to obtain a filament A having an average diameter of 110 μm.
The obtained filament A had a glass transition point of 36 ° C.
The half width of the crystalline peak of the obtained filament A was 0.4 ° to 4.1 °.

<Measurement>
The glass transition point and crystallite size were measured by the following methods.
<< 1 >> Glass transition point (Tg)
The glass transition point (Tg) of the filament was measured by a differential thermal analyzer (DSC).

<< 2 >> Measurement of half width of crystalline peak The obtained filamentous body was pasted on a glass sample holder over a width of 25 mm, and the following measurement was performed using an X-ray diffractometer (RINT TTR III, manufactured by Rigaku Corporation). After measurement under the conditions, the peak separation of crystalline peak and amorphous peak (2θ = 20 °) was performed, and the half width of each peak was measured.
-Measurement conditions-
X-ray intensity: 50 kV-300 mA
Divergent slit: Open Divergent longitudinal slit: 10mm
Scattering slit: 0.05 mm
Light receiving slit: 0.15 mm
Scanning speed: 4 ° / min
Scan range: 2θ = 5 ° -60 °

(Production Example 2)
<Manufacture of filamentous body B>
PET (polyethylene terephthalate 100% resin) having an intrinsic viscosity (IV) = 0.90 was extruded from a die having a circular cross-sectional shape at 280 ° C. using a melt extruder, and taken at a line speed of 15 m / min. Solidified in a cooling water bath, a filament B having an average diameter of 120 μm was obtained.
The glass transition point of the obtained filament B was 72 ° C.
The full width at half maximum of the crystallinity peak of the obtained filament B was 4.0 ° to 7.0 °.

(Production Example 3)
<Manufacture of filamentous body C>
PBT (polybutylene terephthalate 100% resin) having an intrinsic viscosity (IV) = 0.72 was extruded from a die having a circular cross-sectional shape at 250 ° C. using a melt extruder, and was drawn at a line speed of 20 m / min. Solidified in a cooling water bath at 0 ° C., a filament C having an average diameter of 105 μm was obtained.
The glass transition point of the obtained filament C was 34 ° C.
The full width at half maximum of the crystalline peak of the obtained filament C was 10 °.

Example 1
<Stretching of filamentous body>
Using the spinning device shown in FIG. 3, the filament A was necked and stretched.
First, the conveyance speed of the filament A at a position in contact with the low speed roll 3 is 20 m / min, the conveyance speed of the filament A at a position in contact with the high speed roll 4 is 101 m / min, and the filament A is transferred to the low speed roll 3. Then, it was conveyed toward the high-speed roll 4. At this time, a tension of 17 MPa was applied to the filament A. Further, the filament A was conveyed so as to be in contact with the heatable member 6a.
While transporting the filament A, a part of the filament A is 25 ° C. upstream of the heatable member 6a in the transport direction of the filament A (the diameter of the filament changes substantially). Temperature). A part of the filament A at 25 ° C. was moved downstream in the conveyance direction by conveyance of the filament A, brought into contact with the heatable member 6a, and heated to 40 ° C. (temperature at which necking occurred).
By these treatments, necking occurred in the filament A. The position of necking was the position of b in FIG. 3 immediately after starting the necking stretching. However, when the necking stretching is continued, the position of FIG. 3 a (the temperature at which the diameter of the filaments does not substantially change). It moved back to the vicinity of the maintained filament A), fixed at that position, and then stopped moving.
During the necking drawing, the filament A did not break and could be spun stably.
The average diameter of the obtained yarn was 40 μm.
The following evaluation was performed on the obtained yarn. The evaluation results are shown in Table 1.
In addition, although the external appearance of the filament A was transparent, the external appearance of the thread | yarn which has the cavity obtained by extending | stretching was silver. Therefore, the position of necking can be easily confirmed by visually observing the appearance of the filamentous body being stretched.

<Evaluation>
<< 1 >> The average diameter of the filamentous body and the thread, and the variation in the diameter of the thread Using the digital dimension measuring instrument (LS-7600 (controller unit), LS-7010M (measurement unit)) manufactured by Keyence Corporation, the filamentous body and At arbitrary positions of the yarn, the diameter of the filament and the yarn was measured at 20 points every 20 cm, and the average value was taken as the average diameter. Further, the standard deviation (σ) was calculated from the measured values of the yarn diameter at 20 points.

<< 2 >> Presence / absence of cavities After exposing the cross-section of the thread embedded with the epoxy resin, which is an embedding resin, using a microtome, the photograph taken with a scanning electron microscope is observed to determine the presence / absence of cavities. confirmed.

<< 3 >> Aspect Ratio A cross section (see FIG. 2B) perpendicular to the surface of the yarn and perpendicular to the drawing direction (necking drawing direction), and perpendicular to the surface of the yarn and parallel to the drawing direction. The cross section (see FIG. 2C) was examined using a scanning electron microscope at an appropriate magnification of 300 to 3000 times, and a measurement frame was set in each cross-sectional photograph. This measurement frame was set so that 50 to 100 cavities were included in the measurement frame.
Next, the number of cavities included in the measurement frame is measured, and the number of cavities included in the measurement frame having a cross section perpendicular to the extending direction (see FIG. 2B) is m, and the measuring frame having a cross section parallel to the extending direction. The number of cavities included in (see FIG. 2C) is n.
Then, the measurement frame of a section perpendicular to the extending direction one by one thickness of the cavity included in (see FIG. 2B) (r _i) was measured and the thickness of the average and the average diameter r. Further, the length (L _i ) of each cavity included in the measurement frame (see FIG. 2C) having a cross section parallel to the stretching direction was measured, and the average length was defined as L.
That is, r and L can be represented by the following formulas (1) and (2), respectively.
r = (Σr _i ) / m (1)
L = (ΣL _i ) / n (2)
Then, L / r was calculated as an aspect ratio.

<< 4 >> Reflectance Reflectance at a wavelength of 550 nm was measured when an integrating sphere was attached to JASCO Corporation (“V-570”; JASCO Corporation) and scanned in a wavelength range of 200 nm to 2,500 nm. . Moreover, the measured value of the standard white board attached to the apparatus was set to 100%. In addition, what measured the obtained thread | yarn in the shape of cloth by plain weaving was used as the measurement sample. When weaving, a load of about 100 g to 200 g per yarn was applied to sufficiently thicken the yarn.

(Example 2)
<Stretching of filamentous body>
The filamentous body A was necked and stretched using the spinning device shown in FIG.
First, the conveyance speed of the filament A at a position in contact with the low speed roll 3 is 30 m / min, the conveyance speed of the filament A at a position in contact with the high speed roll 4 is 148 m / min, and the filament A is transferred to the low speed roll 3. Then, it was conveyed toward the high-speed roll 4. At this time, a tension of 19 MPa was applied to the filament A. Further, the filament A was conveyed so as to contact the coolable member 5 and the heatable member 6a.
While conveying the filament A, a part of the filament A was brought into contact with the coolable member 5 and cooled to 10 ° C. (temperature at which the diameter of the filament did not change substantially). A part of the cooled filament A was moved downstream in the conveyance direction by conveyance of the filament A, brought into contact with the heatable member 6b, and heated to 40 ° C. (temperature at which necking occurred).
By these treatments, necking occurred in the filament A. The position of necking was the position of b in FIG. 4 immediately after the start of necking stretching, but when necking stretching was continued, the position of FIG. 4 a (the temperature at which the diameter of the filaments does not change substantially). It moved back to the vicinity of the maintained filament A), fixed at that position, and then stopped moving.
During the necking drawing, the filament A did not break and could be spun stably.
The average diameter of the obtained yarn was 41 μm.
Evaluation similar to Example 1 was performed about the obtained thread | yarn. The evaluation results are shown in Table 1.

(Example 3)
<Stretching of filamentous body>
The filament A was necked and stretched using the spinning device shown in FIG. In the spinning device shown in FIG. 5, the distance between the low speed roll 3 and the high speed roll 4 was set to 20 cm. Moreover, the heating part 6b was installed so that the edge part might be installed in the position 5 cm away from the said low speed roll 3, and the said high speed roll 4 may be covered. The high speed roll 4 may be outside the heating unit 6b.
First, the conveyance speed of the filament A at the position in contact with the low-speed roll 3 is 48 m / min, the conveyance speed of the filament A in the position in contact with the high-speed roll 4 is 242 m / min, and the filament A is the low speed. It was conveyed from the roll 3 toward the high-speed roll 4. At this time, a tension of 16 MPa was applied to the filament A.
While conveying the filament A, a part of the filament A is moved to 15 ° C. (filament) outside the heating unit 6b and upstream of the heating unit 6b in the conveyance direction of the filament A. Temperature at which the body diameter does not change substantially). A part of the filament A at 15 ° C. was moved downstream in the conveyance direction by conveyance of the filament A, and the temperature was raised to 40 ° C. (temperature at which necking occurs) in the heating unit 6b.
By these treatments, necking occurred in the filament A. Necking occurred in the heating unit 6b, and the position of necking was fixed at a desired position in the heating unit 6b.
During the necking drawing, the filament A did not break and could be spun stably.
The average diameter of the obtained yarn was 38 μm.
Evaluation similar to Example 1 was performed about the obtained thread | yarn. The evaluation results are shown in Table 1.

Example 4
<Stretching of filamentous body>
The filamentous body A was necked and stretched using the spinning device shown in FIG. In the spinning device shown in FIG. 6, the interval between the low speed roll 3 and the high speed roll 4 was set to 20 cm. Moreover, the heating part 6b was installed so that the edge part might be installed in the position 5 cm away from the said low speed roll 3, and the said high speed roll 4 may be covered. The high speed roll 4 may be outside the heating unit 6b.
First, the conveyance speed of the filament A at the position in contact with the low-speed roll 3 is 85 m / min, the conveyance speed of the filament A in the position in contact with the high-speed roll 4 is 460 m / min, and the filament A is the low speed. It was conveyed from the roll 3 toward the high-speed roll 4. At this time, a tension of 17 MPa was applied to the filament A.
While conveying the filament A, a part of the filament A was brought into contact with the coolable member 5 and cooled to 10 ° C. (temperature at which the diameter of the filament did not change substantially). A part of the cooled filament A was moved downstream in the conveyance direction by conveyance of the filament A, and the temperature was raised to 40 ° C. (temperature at which necking occurs) in the heating unit 6b.
By these treatments, necking occurred in the filament A. Necking occurred in the heating unit 6b, and the position of necking was fixed at a desired position in the heating unit 6b.
During the necking drawing, the filament A did not break and could be spun stably.
The average diameter of the obtained yarn was 37 μm.
Evaluation similar to Example 1 was performed about the obtained thread | yarn. The evaluation results are shown in Table 1.

(Example 5)
<Stretching of filamentous body>
The filamentous body A was necked and stretched using the spinning device shown in FIG. In the spinning device shown in FIG. 7, the distance between the low speed roll 3 and the high speed roll 4 was set to 20 cm. Moreover, the heating part 6b was installed so that the edge part might be installed in the position 5 cm away from the said low speed roll 3, and the member 5 which can be cooled, and the said high speed roll 4 may be covered. The high speed roll 4 may be outside the heating unit 6b.
First, the conveying speed of the filament A at the position in contact with the low-speed roll 3 is 15 m / min, and the conveyance speed of the filament A in the position in contact with the high-speed roll 4 is 80 m / min. It was conveyed from the roll 3 toward the high-speed roll 4. At this time, a tension of 18 MPa was applied to the filament A.
While conveying the filament A, a part of the filament A was brought into contact with the coolable member 5 and cooled to 15 ° C. (temperature at which the diameter of the filament did not change substantially). A part of the cooled filament A was moved downstream in the conveyance direction by conveyance of the filament A, and the temperature was raised to 40 ° C. (temperature at which necking occurs) in the heating unit 6b.
By these treatments, necking occurred in the filament A. Necking occurred in the heating unit 6b, and the position of necking was fixed at a desired position in the heating unit 6b.
During the necking drawing, the filament A did not break and could be spun stably.
The average diameter of the obtained yarn was 38 μm.
Evaluation similar to Example 1 was performed about the obtained thread | yarn. The evaluation results are shown in Table 1.

(Example 6)
<Stretching of filamentous body>
In Example 2, the filament A was necked and stretched by the same method as in Example 2 except that the cooling temperature of the filament A by the coolable member 5 was set to 15 ° C.
The position of necking was the position of b in FIG. 4 immediately after the start of necking stretching, but when necking stretching was continued, the position of FIG. 4 a (the temperature at which the diameter of the filaments does not change substantially). It moved back to the vicinity of the maintained filament A), fixed at that position, and then stopped moving.
During the necking drawing, the filament A did not break and could be spun stably.
The average diameter of the obtained yarn was 41 μm.
Evaluation similar to Example 1 was performed about the obtained thread | yarn. The evaluation results are shown in Table 1.

(Example 7)
<Stretching of filamentous body>
In Example 4, the conveyance speed of the filament A at the position in contact with the low-speed roll 3 is 85 m / min, and the conveyance speed of the filament A in the position in contact with the high-speed roll 4 is 460 m / min. The filament A was necked and stretched by the same method as in Example 4 except that the cooling temperature of the filament A was 15 ° C.
Necking occurred in the heating unit 6b, and the position of necking was fixed at a desired position in the heating unit 6b.
During the necking drawing, the filament A did not break and could be spun stably.
The average diameter of the obtained yarn was 37 μm.
Evaluation similar to Example 1 was performed about the obtained thread | yarn. The evaluation results are shown in Table 1.

(Example 8)
<Stretching of filamentous body>
In Example 2, the thread B was necked and stretched by the same stretching method as in Example 2 except that the types of filaments, the cooling temperature, and the heating temperature were the conditions shown in Table 1.
The position of necking was the position of b in FIG. 4 immediately after the start of necking stretching, but when necking stretching was continued, the position of FIG. It moved back to the vicinity of the maintained filament A), fixed at that position, and then stopped moving.
During the necking drawing, the filament A did not break and could be spun stably.
The average diameter of the obtained yarn was 43 μm.
Evaluation similar to Example 1 was performed about the obtained thread | yarn. The evaluation results are shown in Table 1.

Example 9
<Stretching of filamentous body>
In Example 4, the thread B was necked and stretched by the same stretching method as in Example 4 except that the type of filament, cooling temperature, and heating temperature were the conditions shown in Table 1.
Necking occurred in the heating unit 6b, and the position of necking was fixed at a desired position in the heating unit 6b.
During the necking drawing, the filament A did not break and could be spun stably.
The average diameter of the obtained yarn was 42 μm.
Evaluation similar to Example 1 was performed about the obtained thread | yarn. The evaluation results are shown in Table 1.

(Reference Example 1)
<Stretching of filamentous body>
The filamentous body A was necked and stretched using the spinning device shown in FIG.
First, the conveyance speed of the filament A at the position in contact with the low speed roll 3 is 20 mm / min, the conveyance speed of the filament A in the position in contact with the high speed roll 4 is 99 mm / min, and the filament A is transferred to the low speed roll 3. Then, it was conveyed toward the high-speed roll 4. At this time, a tension of 20 MPa was applied to the filament A.
While conveying the filament A, a part of the filament A was heated to 40 ° C. (temperature at which necking occurs) by the preheating roll 9. A part of the heated filament A was moved downstream in the conveyance direction by conveyance of the filament A, and was kept in contact with the heatable member 6a at 40 ° C. (temperature at which necking occurs).
By these treatments, necking occurred in the filament A.
While the necking is being stretched, the necking state is unstable, and as a result of the movement of the necking to the part that contacts the low-speed roll, the filament A often breaks, and stable spinning cannot be performed. It was.
Evaluation similar to Example 1 was performed about the obtained thread | yarn. The evaluation results are shown in Table 1.

(Reference Example 2)
<Stretching of filamentous body>
The filamentous body B was necked and stretched using the spinning device shown in FIG.
First, the conveyance speed of the filament B at a position in contact with the low speed roll 3 is 30 m / min, the conveyance speed of the filament B in a position in contact with the high speed roll 4 is 148 m / min, and the filament B is moved to the low speed roll 3. Then, it was conveyed toward the high-speed roll 4. At this time, a tension of 51 MPa was applied to the filament B. The filament B was conveyed so as to be in contact with the heatable member 6a.
While transporting the filamentous body B, a part of the filamentous body B was set to 80 ° C. upstream of the heatable member 6a in the transporting direction of the filamentous body B. A part of the filament B at 80 ° C. was moved downstream in the conveyance direction by conveyance of the filament B, and contacted with the heatable member 6a to maintain 80 ° C.
By these treatments, the filament B was stretched but no necking occurred. Further, during the stretching, the stretched state was unstable and the filament B was frequently cut, and stable spinning could not be performed.
Evaluation similar to Example 1 was performed about the obtained thread | yarn. The evaluation results are shown in Table 1.

(Reference Example 3)
<Stretching of filamentous body>
The filament C was drawn using the spinning device shown in FIG.
First, the conveyance speed of the filament C at a position in contact with the low speed roll 3 is 30 m / min, the conveyance speed of the filament C in a position in contact with the high speed roll 4 is 148 m / min, and the filament C is moved to the low speed roll 3. Then, it was conveyed toward the high-speed roll 4. At this time, a tension of 19 MPa was applied to the filament C. Further, the filament C was conveyed so as to contact the coolable member 5 and the heatable member 6a.
While transporting the filament C, a part of the filament C was brought into contact with the coolable member 5 and cooled to 10 ° C. A part of the cooled filament C was moved downstream in the conveyance direction by conveyance of the filament C, brought into contact with the heatable member 6b, and heated to 40 ° C.
By these treatments, the filament C was stretched but no necking occurred.
The average diameter of the obtained yarn was 39 μm.
Evaluation similar to Example 1 was performed about the obtained thread | yarn. The evaluation results are shown in Table 1.

Nine crystalline peaks were observed in the X-ray diffraction of the filament A, and their half-value widths were in the range of 0.4 ° to 4.1 °.
Five crystalline peaks were observed in the X-ray diffraction of the filament B, and their half-value widths were within the range of 4.0 ° to 7.0 °.
In the yarn of Reference Example 2, although there were cavities, the cavities were not uniform and were mottled.
Since Reference Example 2 and Reference Example 3 could not be stably spun, their average diameter, diameter variation, and aspect ratio could not be measured.
The yarns obtained by the stretching methods of Examples 1 to 9 had small diameter variations and high reflectivity.

  The spinning method and spinning device of the present invention can be suitably used, for example, for producing a yarn having a cavity.

2 Filament 3 Low-speed roll 4 High-speed roll 5 Coolable member (cooling means)
6a Heatable member (heating means)
6b Heating part (heating means)
7 Nip roll 8 Auxiliary roll 9 Preheating roll 10 Yarn having cavity 10a Surface 100 Cavity L Length of cavity in orientation direction of cavity r Thickness of cavity in direction orthogonal to orientation direction of cavity

Claims (14)

  By applying a tension to the filamentous body and raising the temperature of a part of the filamentous body to which the tension is applied from a temperature at which the diameter of the filamentous body does not substantially change to a temperature at which necking occurs in the filamentous body, A spinning method comprising spinning the filamentous body by necking and stretching the body.   The temperature at which necking of the filamentous body is caused by the heating means after applying tension to the filamentous body and setting a part of the tensioned filamentous body to a temperature at which the diameter of the filamentous body is not substantially changed by the cooling means. The spinning method according to claim 1, wherein the filamentous body is spun by stretching the filamentous body by heating the filamentous body. The cooling means is a coolable member, the heating means is a heatable member,
The spinning method according to claim 2, wherein tension is applied in a state where the filamentous body is in contact with the cooling means and the heating means.   The spinning method according to any one of claims 2 to 3, wherein a cooling temperature by the cooling means is not higher than a glass transition point of the filamentous body.   The spinning method according to any one of claims 1 to 4, wherein the full width at half maximum of the crystalline peak in X-ray diffraction of the filamentous body is less than 9 ° as 2θ.   The spinning method according to any one of claims 1 to 5, wherein an average diameter of the filamentous body is 10 µm to 500 µm.   The resulting yarn has cavities oriented in the drawing direction inside, the average length of the cavities is L (μm), and the average diameter of the cavities in the direction orthogonal to the orientation direction of the cavities is r The spinning method according to any one of claims 1 to 6, wherein the L / r ratio in the case of (µm) is 10 or more.   The spinning method according to any one of claims 1 to 7, wherein the yarn obtained comprises only a crystalline polymer.   The spinning method according to any one of claims 1 to 8, wherein the obtained yarn has a reflectance of 40% to 90%.   Necking occurs in the filament that has been heated to the temperature at which necking occurs, and the filament is necked and stretched, and the position of the necking is maintained in the vicinity of the filament where the diameter of the filament does not change substantially. The spinning method according to any one of claims 1 to 9, wherein the spinning method is moved to a fixed position and fixed.   Necking is generated in the filament that has been heated to a temperature at which necking occurs by the heating means, the filament is necked and stretched, and the position of the necking is adjusted to a temperature at which the diameter of the filament does not change substantially by the cooling means. The spinning method according to any one of claims 1 to 10, wherein the spinning method is moved to the vicinity of the maintained filament and fixed. Tension applying means for applying tension to the filament,
And necking generating means for raising the temperature of a part of the thread-like body to which tension is applied by the tension applying means from a temperature at which the diameter of the thread-like body does not substantially change to a temperature at which necking of the thread-like body occurs. Spinning device.   Necking generating means is a cooling means for cooling a part of the filamentous body to which tension is applied to a temperature at which the diameter of the filamentous body does not substantially change, and a heating means for raising the temperature to a temperature at which necking occurs in the filamentous body. The spinning device according to claim 12.   The spinning device according to claim 13, wherein the cooling means is a coolable member, and the heating means is a heatable member.