JP2010202999A - Acrylic carbon fiber precursor fiber bundle package and method for producing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a carbon fiber precursor fiber bundle package good in wound shape and having few problems of getting out of wound shape and package edge face swelling, etc. despite being extremely low in an oil pickup amount and moisture content as compared with a conventional package, and to provide a method for producing the package slight in fiber damage despite being extremely low in lubricant use levels in the production process. <P>SOLUTION: In producing the carbon fiber precursor fiber bundle package, oiling steps for the fiber bundle is divided into two; the oil pickup amount is under control at a specific level; and a drying step is subjected prior to the winding step. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a bobbin package of an acrylic carbon fiber precursor fiber bundle having an oil agent adhesion amount and a moisture amount that are extremely lower than those of conventional ones and having a good packing form, and a method for producing the same.

  Carbon fibers have superior specific strength and specific modulus compared to other fibers. Carbon fiber is widely used industrially as a reinforcing fiber to be combined with resin by utilizing its light weight and excellent mechanical properties.

  In recent years, industrial applications of composite materials using carbon fibers are spreading in many fields. Particularly in the sports / leisure field and the aerospace field, demands for higher performance (higher strength, higher elasticity) are increasing. In order to pursue high performance in the composite of carbon fiber and resin, it is essential to improve the physical properties of the carbon fiber itself rather than the physical properties of the resin.

  Currently, the production process of polyacrylonitrile (hereinafter also referred to as PAN) -based carbon fiber includes a process (pre-process) of manufacturing a PAN-based carbon fiber precursor fiber (hereinafter also simply referred to as precursor fiber), In general, the process is divided into a process (post-process) in which the precursor fiber is fired to produce carbon fiber. The reason is that the speed at which the precursor fiber is produced by spinning the polymer stock solution and the speed at which the precursor fiber is fired to produce the PAN-based carbon fiber are remarkably different (particularly, the precursor fiber). The flame-proofing process when baking is the most rate-determining). Therefore, in the production of PAN-based carbon fibers, the precursor fibers obtained in the previous step are generally temporarily stored due to the difference in speed in each step. As a method for preserving the precursor fibers, a method is generally employed in which the precursor fibers are wound around a bobbin and stored in the form of a package.

  In order to roll up the bobbin package in a good form without causing collapse of the bobbin package or end face swelling, it is necessary to improve the convergence of the precursor fiber bundle. In order to improve convergence, it is common to attach an oil agent to a coagulated fiber bundle as in the above production method.

  Patent Document 1 describes a method in which an oil agent is attached to a fiber bundle after wet heat drawing at 0.5 to 2.0 mass%. In such a method, it is described that the fiber bundle is not sufficiently converged when the oil agent adhesion amount is less than 0.5% by mass. In the case where the bundle property of the fiber bundle is low, when the bobbin package mass is increased, there arises a problem that the winding collapse occurs or the winding shape is deteriorated.

  On the other hand, the use of a large amount of oil increases the production cost of the precursor fiber bundle. Further, in the firing step, the silicone oil contained in the oil agent is thermally decomposed to generate silicon oxide and silicon nitride, which contaminates the flameproofing furnace and the firing furnace. Furthermore, if silicon remains as a foreign substance inside the fiber, the quality of the carbon fiber finally obtained is reduced.

  As a method for improving the converging property of the precursor fiber bundle, there is a method of imparting moisture to the precursor fiber bundle in addition to a method of attaching an oil agent to the precursor fiber bundle. Patent Document 2 describes a method of winding a precursor fiber bundle having a moisture content of 5 to 20% by mass into a package. According to this method, it is described that when the moisture content is less than 5% by mass, the convergence property of the precursor fiber bundle is poor, and the end face swelling of the package becomes large, causing problems such as winding collapse. Moreover, bacteria are generated in the fiber bundle having a high moisture content or the moisture content fluctuates, so that the quality of the finally obtained carbon fiber is not stable. Further, extra energy is required to evaporate a large amount of water in the subsequent drying step.

  Therefore, there is a demand for a bobbin package of a precursor fiber bundle having a good winding shape and a large winding weight while lowering the oil agent adhesion amount and moisture amount than before.

JP 2006-274472 A JP 2004-123296 A

  The object of the present invention is to provide a precursor fiber that has a good winding shape and less problems such as collapse and package end face swell, despite the fact that the amount of oil attached to the precursor fiber bundle and the amount of water in the precursor fiber bundle are extremely low. It is to provide a bundle package. Another object of the present invention is to provide a method for producing a precursor fiber bundle package with little damage to the fiber, although the amount of oil used in the production process of the precursor fiber bundle is extremely small.

  As a result of studying the above problems, the present inventor divided the oil agent application step into two steps, controlled the amount of oil agent adhesion of the precursor fiber bundle to a specific amount, and passed the drying step before winding, so that the precursor It was found that a bobbin package with good winding shape and less problems such as collapse and package end face swell while maintaining the amount of oil agent adhesion and moisture content of the body fiber bundle at a level lower than that of the conventional bobbin package. The invention has been completed.

The present invention for achieving the above object is described below.
[1] A package comprising a bobbin and an acrylic carbon fiber precursor fiber bundle wound around the bobbin, wherein the acrylic carbon fiber precursor fiber bundle contains a silicone oil agent with respect to 100 parts by mass. An acrylic carbon fiber precursor fiber bundle package containing 0.10 to 0.50 parts by mass and 0.10 to 2.0 parts by mass of water.
[2] 0.03 to 0.40 parts by mass of a silicone-based oil agent is attached to a coagulated fiber bundle obtained by spinning the spinning dope with respect to 100 parts by mass of the coagulated fiber bundle. The adhering coagulated yarn fiber bundle is dried with hot air, then the hot air dried fiber bundle is subjected to steam stretching, and then silicone oil is added to 0.05 to 0.40 with respect to 100 parts by mass of the steam stretched fiber bundle. Mass parts (however, the total adhesion amount of the silicone-based oil is 0.10 to 0.50 parts by mass with respect to 100 parts by mass of the acrylic carbon fiber precursor fiber bundle). The method for producing a package according to [1], wherein the water content is set to 0.10 to 2.0 parts by mass with respect to 100 parts by mass of the fiber precursor fiber bundle, and then wound on a bobbin.

  The precursor fiber bundle package of the present invention has a good winding shape, and has very few problems such as unwinding and package end face swelling. In addition, since the precursor fiber bundle has a small amount of oil agent adhesion, the content of foreign matters derived from the oil agent in the acrylic carbon fiber obtained by carbonizing the precursor fiber bundle becomes low. Furthermore, since the amount of water is small, problems such as generation of bacteria do not occur.

  According to the method for producing a precursor fiber bundle package of the present invention, since the drying step in the first oil agent application step dries the fiber with hot air, the amount of the oil agent used is small, but the damage to the fiber is extremely small. Further, the obtained precursor fiber bundle package has a good winding shape, and there are very few problems such as winding collapse and package end face swelling.

It is process drawing which shows an example of the manufacturing method of the bobbin package of this invention. It is a perspective view which shows an example of the one end side of the bobbin package of this invention. It is a perspective view which shows an example of the one end side of the conventional bobbin package.

  Hereinafter, the present invention will be described in detail.

  FIG. 1 is a process diagram showing an example of a bobbin package manufacturing method according to the present invention.

  In the figure, 1 is a spinning stock solution, and this spinning stock solution 1 is spun into a coagulating solution 3 through a spinneret 2 to obtain a coagulated yarn fiber bundle 4a. The coagulated yarn fiber bundle 4 a is washed with the washing liquid 6 in the washing tank 5. Thereafter, the washed coagulated fiber bundle 4b is sent to the first oil agent application step, and a predetermined amount of oil 8 is adhered in the oil agent application tank 7 to obtain the oil agent-attached coagulated fiber fiber bundle 4c. It is dried with a dryer 9. Next, the hot air-dried coagulated fiber bundle 4d is heated and drawn by the steam drawing machine 11 to obtain a steam drawn fiber bundle 4e.

  Next, the process moves to the second oil agent application step. In the steam drawn fiber bundle 4e, the adhesion amount of the oil agent 14 is adjusted to a predetermined amount in the oil agent application tank 13. Next, the moisture amount of the second oil agent-attached fiber bundle 4 f to which the oil agent is attached is adjusted to a predetermined amount by the dry heat roller 15 to become the precursor fiber bundle 20. Then, the precursor fiber bundle 20 is wound up by the winder 17, and the bobbin package 19 which is this invention is obtained.

  Each step may be performed using a conventionally known method. Moreover, it does not prevent that another process intervenes between each process in the limit which does not prevent the effect of this invention.

  Hereinafter, an example of an embodiment of the present invention will be described more specifically.

<Preparation of spinning dope>
As the starting raw material spinning solution used in the production of the precursor fiber of this example, any conventionally known spinning solution can be used without limitation as long as it is a spinning raw solution for producing acrylic carbon fibers. Examples thereof include a spinning dope comprising a polyacrylonitrile obtained by polymerizing acrylonitrile alone or a copolymer obtained by polymerizing a monomer mixture containing 90% by mass or more, preferably 94% by mass or more of acrylonitrile. Examples of the monomer copolymerized with acrylonitrile include known monomers such as itaconic acid, methyl acrylate, ethyl acrylate, and acrylic acid.

  Examples of the polymerization method for the monomer include solution polymerization, suspension polymerization, and emulsion polymerization. Since the polymer solution can be spun as it is, solution polymerization is preferred, and solution polymerization using a zinc chloride solvent as the polymerization solvent is most preferred.

  The spinning dope is preferably a polymer solution obtained by polymerizing the above monomers using an aqueous zinc chloride solution as a solvent.

  The concentration of the spinning dope affects the specific gravity of the resulting precursor fiber. When using an aqueous zinc chloride solution as a solvent, the concentration of the spinning dope is preferably 10 to 40% by mass, and more preferably 20 to 30% by mass. When the concentration of the spinning dope is low, the specific gravity of the obtained precursor fiber is low, and a low specific gravity carbon fiber is obtained. On the other hand, if the concentration is high, there is a limit to the solubility of the polymer in the solvent, and the spinning dope becomes non-uniform, which is not preferable.

<Spinning process>
A spinning stock solution is spun into a coagulation liquid from a spinneret having preferably 1,000 to 30,000 spinning holes in one spinneret and solidified to obtain a coagulated fiber bundle. The spinning solution is spun into a coagulating bath containing a coagulating liquid (mixed liquid of solvent and water used for spinning) cooled to a low temperature. As this spinning method, a known wet spinning method, dry wet spinning method, or the like can be used. The wet spinning method is a method of spinning a spinning solution directly into a coagulation solution. On the other hand, the dry and wet spinning method is a method in which a spinning solution is discharged into the air, and then poured into a coagulation bath through a space of about 3 to 5 mm to coagulate. Since the finally obtained carbon fiber forms wrinkles on the surface and adhesion with the resin can be expected, the wet spinning method is more preferable. The coagulated yarn fiber bundle obtained by coagulation is washed with water by a known method.

<First oil agent application process>
In the first oil agent application step, the oil agent is adhered to the washed coagulated fiber bundle. Lubrication can be performed by a known method such as immersion lubrication, touch roller lubrication, or spray lubrication. The purpose of applying this oil agent is to prevent fusion between single fibers in the drying step before steam drawing (hereinafter also referred to as the first drying step) and the steam drawing step, and the coagulated yarn fibers washed with water. It is to improve the convergence of the bundle. The adhesion amount of the oil agent in the first oil agent application step is 0.03 to 0.40 parts by mass with respect to 100 parts by mass of the coagulated fiber bundle in the absolutely dry state, preferably 0.05 to 0.35 parts by mass, 0.06-0.30 mass part is more preferable. If the amount is less than 0.03 parts by mass, the single fibers are easily fused in the first drying step and the steam drawing step. Moreover, the convergence property of the coagulated yarn fiber bundle after application of the oil agent is poor, the precursor fiber bundle spreads in the first drying step and the steam drawing step, and the process is not stable. On the other hand, even if the amount exceeds 0.40 parts by mass, the effect on fusion and convergence is not increased in proportion to the amount of adhesion. Rather, impurities derived from the oil agent are mixed in the carbon fiber finally obtained, and the quality of the carbon fiber is deteriorated.

  As the oil agent, an oil agent containing silicone is used. Silicone may be either unmodified silicone or modified silicone, but modified silicone is more preferable. Among the modified silicones, epoxy-modified silicone, ethylene oxide-modified silicone, polysiloxane, and amino-modified silicone are preferable, and amino-modified silicone is particularly preferable. Many known oils containing silicone are commercially available. It is preferable to use the oil agent in combination with a permeable oil agent having a hydrophilic group.

  The osmotic oil agent preferably has sulfinic acid, sulfonic acid, phosphoric acid, carboxylic acid, its alkali metal salt, ammonium salt or its derivative as a functional group. Among these penetrating oils, it is particularly preferable to use ammonium phosphate or a derivative thereof that easily penetrates.

<Drying step after the first oil agent application step>
The coagulated fiber bundle after the application of the oil agent is dried in the drying process (first drying process). This drying step is preferably a hot air drying method which is non-contact heating. Drying with a dry heat roller tends to cause fiber damage due to rubbing with the roller in the present invention in which the amount of the oil agent attached to the fiber bundle is small. Furthermore, it is easy to produce the fusion | bonding of the single fibers by thermocompression bonding. The drying temperature is preferably 70 to 150 ° C, more preferably 80 to 140 ° C. The drying time is preferably 1 to 10 minutes. By this hot air drying, the water adhesion amount in 100 parts by mass of the coagulated fiber bundle is 0.1 to 1.0 part by mass.

<Steam stretching process>
The dried coagulated yarn fiber bundle is heated and stretched by a steam stretching process. The steam stretching may be performed using a known method. The steam stretching conditions are preferably a temperature of 100 to 150 ° C. and a saturated steam pressure of 0.1 to 5.0 MPa (absolute pressure). The stretching ratio is preferably 10 to 15 times in terms of the total stretching ratio through washing, drying and steam stretching.

<Second oil agent application step>
It is considered that the distribution of the first oil agent film on the fiber surface becomes nonuniform in the steam-stretched fiber bundle after the steam stretching treatment. For this reason, the steam-stretched fiber bundle is inferior in converging property, and causes a winding shape defect such as collapse when the bobbin package described later is used. Therefore, an oil agent is made to adhere again to the steam drawn fiber bundle. The adhesion amount with respect to the steam stretched fiber bundle in this step is 0.05 to 0.40 part by mass with respect to 100 parts by mass of the fiber bundle in the absolutely dry state, preferably 0.10 to 0.35 part by mass, 0.15 -0.30 mass part is especially preferable. If the amount is less than 0.05 parts by mass, the fiber bundle is poorly converged and a bobbin package having a good winding shape cannot be obtained. Moreover, even if it makes it adhere exceeding 0.40 mass part, the effect with respect to convergence is an upper limit. Furthermore, the quality of the carbon fiber finally obtained becomes worse. In addition, the total amount of the adhesion amount of the oil agent in the first oil agent application step and the second oil agent application step is 0.10 to 0.50 parts by mass with respect to 100 parts by mass of the precursor fiber bundle, and is 0.20. -0.40 mass part is preferable. If the total amount of adhesion is less than 0.10 parts by mass, the fiber bundle is poorly converged and a bobbin package having a good winding shape cannot be obtained. Moreover, even if it makes it adhere exceeding 0.40 mass part, the effect with respect to convergence is not the upper limit, but there exists a possibility that the quality of the carbon fiber finally obtained may worsen.

  The oil agent to be attached may be the same oil agent as the oil agent used in the first oil agent application step or a different oil agent.

<Drying step after the second oil agent application step>
The second oil agent-attached fiber bundle is then subjected to a drying step, whereby a precursor fiber bundle is obtained. This drying step is preferably performed by a contact heating method using a dry heat roller with good thermal efficiency because the processing speed of the fiber bundle is high. It is necessary to adjust the drying conditions so that the water content is 0.10 to 2.0 parts by mass with respect to 100 parts by mass of the precursor fiber bundle. When the amount is less than 0.10 parts by mass, there is no particular problem, but extra heat energy is required, which is uneconomical. When the amount exceeds 2.0 parts by mass, bacteria are generated and the amount of water varies between the inside and outside of the precursor fiber bundle, so that the quality of the finally obtained carbon fiber is not stable. Although what is necessary is just to adjust suitably about drying temperature, 70-240 degreeC is preferable and 90-220 degreeC is especially preferable. Although what is necessary is just to adjust suitably about drying time, 1 to 20 second is preferable.

<Winding process>
The precursor fiber bundle obtained by the above treatment is wound around a bobbin using a known winder device, becomes a bobbin package, and is stored. As the bobbin material, known materials such as paper, plastic, and fiber reinforced plastic can be used. Moreover, when winding up to such a package, you may wind up, after combining several several precursor fiber bundles.

<Baking>
The precursor fiber bundle is flameproofed at 230 to 260 ° C. in heated air for 30 to 100 minutes. By this flameproofing treatment, a cyclization reaction of the acrylic fiber is caused, and the oxygen bond amount is increased to obtain a flameproof fiber. In general, the flameproofing treatment is preferably performed in a range of a draw ratio of 1.00 to 1.20. By this flameproofing treatment, a flameproofed fiber bundle having a fiber density of 1.33 to 1.36 g / cm3 is obtained. The tension at the time of flame resistance is not particularly limited as long as it does not exceed the range of the draw ratio.

  The flame-resistant fiber bundle can be carbonized using a conventionally known method. For example, a temperature gradient is gradually applied in a firing furnace (first carbonization furnace) at 300 to 800 ° C. in a nitrogen atmosphere, and the tension of the flame-resistant fiber bundle is controlled to perform first-stage carbonization under the tension (first Carbonization treatment). In order to further promote carbonization and promote graphitization, that is, high crystallization of carbon, the temperature is raised in an inert gas atmosphere such as nitrogen, and a temperature gradient is gradually applied in a firing furnace (second carbonization furnace). Then, the tension of the fiber bundle after the first carbonization treatment is controlled, and firing is performed under a relaxation condition (second carbonization treatment). About baking temperature, a temperature gradient is applied in a 2nd carbonization furnace, Preferably it is 800-2500 degreeC in a maximum temperature range, More preferably, it bakes at 1100-2100 degreeC.

  The fiber bundle after the second carbonization treatment is preferably subsequently subjected to surface oxidation treatment. The surface oxidation treatment can be performed by a gas phase or a liquid phase treatment, but a liquid phase treatment is preferable from the viewpoint of easy process control and productivity. Among the liquid phase treatments, electrolytic treatment using an electrolytic solution is preferable from the viewpoint of liquid safety and stability. Examples of the electrolytic solution used for the electrolytic oxidation treatment include inorganic acids such as sulfuric acid, nitric acid, and hydrochloric acid, inorganic hydroxides such as sodium hydroxide and potassium hydroxide, and inorganic salts such as ammonium sulfate, sodium carbonate, and sodium bicarbonate. Can be mentioned.

  The fiber bundle after the surface oxidation treatment is subjected to sizing treatment as necessary. The sizing method can be performed by a conventionally known method. The sizing agent is preferably used after changing the composition as appropriate according to the application, and after uniformly depositing the sizing agent.

  Hereinafter, the present invention will be described more specifically with reference to examples and comparative examples. Moreover, the processing method in each Example and a comparative example, and the evaluation method about the physical property of the fiber bundle after a steam extending process, a flame-resistant fiber, and carbon fiber were implemented with the following method.

[Adhesion amount of silicone oil]
The oil agent adhesion amount of the fiber bundle was measured by a method defined in JIS L 1015.

[amount of water]
By the method specified in JIS L 0105, the mass of the precursor fiber bundle after winding is Ww, the absolute dry mass of the precursor is Wd, and the following formula: Water content (mass%) = 100 × (Ww−Wd ) / Ww
Calculated by

[Bulge width of package end face]
On the end face of the package, the width of the outermost part and the maximum swollen part was measured along the circumference at three points, and the average was taken as the swollen width.

[Problem occurrence rate when solving]
When the precursor fiber bobbin package is unpacked and sent to the flameproofing process, it represents the frequency of cutting due to trouble due to the form of the package such as Ringer, and the following formula trouble occurrence rate (%) = 100 × Number of cuts (pieces) / Number of throws (pieces)
Calculated with

[Amount of silicon falling off during flame resistance and carbonization]
When 1000 kg of the obtained precursor fiber was flameproofed and carbonized using a known apparatus and method, the amount of silicon dropped into the furnace was evaluated according to the following criteria.
A: Almost no observation in the furnace.
B: Confirmed in part of the furnace.
C: Confirmed throughout the furnace.
D: It is confirmed in the entire furnace and is deposited on a part of the inner wall of the furnace.
E: The state confirmed in the entire furnace and deposited on the inner wall of the furnace.

[Carbon fiber tensile strength]
The resin-impregnated strand strength of the carbon fiber was measured by the method defined in JIS R7601.

[Example 1]
A copolymer spinning stock consisting of 95% by mass of acrylonitrile / 4% by mass of methyl acrylate / 1% by mass of itaconic acid was passed through a spinneret having 3000 spin holes in one spinneret, and a 25% by mass aqueous zinc chloride solution at 6 ° C. It was spun in and coagulated to obtain a coagulated yarn fiber bundle. After washing this fiber bundle with water, it was led to an oil agent application tank, and an amino-modified silicone oil was added as an oil agent in the amount shown in Table 1 (first oil agent application step). The fiber bundle was dried at 140 ° C. through a hot air dryer, and then subjected to steam drawing at a temperature of 120 ° C. so that the draw ratio was 6 times. Thereafter, the amount of amino-modified silicone oil agent shown in Table 1 was applied to the fiber bundle (second oil agent application step), and further dried with a dry heat roller at 165 ° C. to obtain a single fiber fineness of 1.1d, filaments Several 3000 precursor fiber bundles were obtained. The obtained precursor fiber bundle had an oil agent adhesion amount of 0.38 parts by mass and a water content of 0.9 parts by mass per 100 parts by mass of the precursor fiber bundle. This precursor fiber bundle was wound up on a paper tube having a length of 720 mm and an outer diameter of 160 mm until the winding thickness reached 300 mm. Subsequently, carbon fiber was obtained by baking said precursor fiber bundle by a well-known method.

[Examples 2 to 4]
Except having changed the oil agent adhesion amount in Example 1, it processed similarly to Example 1 and obtained the precursor fiber bundle and carbon fiber of the physical property shown in Table 1.

[Comparative Example 1]
A precursor fiber bundle having the physical properties shown in Table 1 was processed in the same manner as in Example 1 except that the second oil agent application step in Example 1 was omitted and the oil agent adhesion amount in the first oil agent application step was changed. And carbon fibers were obtained. The obtained precursor fiber bundle is thought to be due to poor convergence, but compared with Example 1, there were more troubles such as ringers, fluffing, and yarn breakage during bobbin unwinding.

[Comparative Examples 2 and 5]
A precursor fiber bundle having the physical properties shown in Table 1 was processed in the same manner as in Example 1 except that the second oil agent application step in Example 1 was omitted and the oil agent adhesion amount in the first oil agent application step was changed. And carbon fibers were obtained. The obtained precursor fiber bundle had a large package end face swelling, and the collection was completed when the winding thickness was 100 mm. In addition, there were many troubles such as ringers, fluffing and thread breakage during bobbin unwinding.

[Comparative Examples 3, 4, 8]
The precursor of the physical property shown in Table 1 is processed in the same manner as in Example 1 except that in addition to the method of Example 1, moisture was applied just before winding, and the adhesion amount and winding amount of the oil agent were changed. Fiber bundles and carbon fibers were obtained. When the obtained precursor fiber bundle was fired, it was considered that it was caused by the generation of mold and bacteria, but the strength of the carbon fiber was lower than that in Example 1.

[Comparative Example 6]
Except having dried by the dry heat roller system in the first drying step after the first oil agent application step in Example 1, the same treatment as in Example 1 was performed to obtain a precursor fiber bundle having physical properties shown in Table 1. It was. The obtained carbon fiber precursor fiber bundle is thought to be due to poor convergence, but the package end face swelled greatly, and there were many troubles such as ringers, fluffing, and yarn breakage during bobbin unwinding. Furthermore, although it is considered that the fiber surface was damaged by contact heating, the carbon fiber strength was lower than that of Example 1.

[Comparative Examples 7 and 9]
Except having changed the oil agent adhesion amount in Example 1, it processed similarly to Example 1 and obtained the precursor fiber bundle of the physical property shown in Table 1. When carbon fiber was produced using the obtained precursor fiber bundle, silicon was frequently dropped during flame resistance and carbonization.

[Comparative Example 10]
The physical properties shown in Table 1 are the same as those in Example 1, except that the amount of oil attached in Example 1 is changed and dried by the dry heat roller method in the first drying step after the first oil applying step. A precursor fiber bundle was obtained. When carbon fiber was produced using the obtained precursor fiber bundle, silicon was frequently dropped during flame resistance and carbonization.

100 Manufacturing process 1 of bobbin package of the present invention Spinning stock solution 2 Spinneret 3 Coagulating liquid 4a Coagulated fiber bundle 4b Washed coagulated fiber bundle 4c Oil agent-attached coagulated fiber bundle 4d Hot air dried coagulated fiber bundle 4e Steam Stretched fiber bundle 4f Second oil agent-attached fiber bundle 5 Cleaning tank 6 Cleaning liquid 7 First oil agent application tank 8 Oil agent 9 Hot air dryer 11 Steam drawing machine 13 Second oil agent application tank 14 Oil agent 15 Dry heat roller 17 Winder 19 Bobbin package 20 Precursor fiber 200 One end side 21 of bobbin package of the present invention 21 Bobbin 23 Carbon fiber precursor fiber bundle 300 wound around bobbin 300 One end side 31 of conventional bobbin package Bobbin 33 Carbon fiber precursor fiber bundle wound around bobbin

Claims (2)

A package comprising a bobbin and an acrylic carbon fiber precursor fiber bundle wound around the bobbin, wherein the acrylic carbon fiber precursor fiber bundle contains 0.10 silicone oil with respect to 100 parts by mass. An acrylic carbon fiber precursor fiber bundle package containing ˜0.50 parts by mass and 0.10 to 2.0 parts by mass of water. To a coagulated fiber bundle obtained by spinning the spinning dope, 0.03 to 0.40 parts by mass of a silicone-based oil agent is attached to 100 parts by mass of the coagulated fiber bundle, and then the coagulated fiber is attached with the oil. The bundle is dried with hot air, and then the hot air-dried fiber bundle is steam-stretched, and then the silicone-based oil agent is added in an amount of 0.05 to 0.40 parts by mass (provided that 100 parts by mass of the steam-stretched fiber bundle (provided that The total adhesion amount of the silicone-based oil is 0.10 to 0.50 parts by mass with respect to 100 parts by mass of the acrylic carbon fiber precursor fiber bundle.) The acrylic carbon fiber precursor fiber bundle is adhered and dried. The method for producing a package according to claim 1, wherein the content of water with respect to 100 parts by mass is set to 0.10 to 2.0 parts by mass and then wound on a bobbin.

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