JP2002266239A - Carbon fiber precursor acrylic fiber and method for producing the same and oil agent composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an oil agent capable of preventing occurrence of silicon oxide, etc., during bonding among fibers, fluffing, flameproofing, etc., operating efficiency and process passableness, a carbon fiber precursor acrylic fiber and a method for producing the acrylic fiber. SOLUTION: This oil agent composition for producing the carbon fiber precursor acrylic fiber comprises 80-95 mass% of a both-terminal higher fatty acid esterified substance of an ethylene oxide adduct and/or a propylene oxide adduct to bisphenol A represented by formula (1), 1.0-15.0 mass% of an amino-modified silicone represented by formula (2) and 0.5-10.0 mass% of an antioxidant. The oil agent composition comprises the oil agent composition and a nonionic surfactant having <=1.0 mass% of residual ratio after heating at 250 deg.C for 2 h in (85:15) to (65:35) mass ratio of the oil agent composition to the nonionic surfactant. The carbon fiber precursor acrylic fiber comprises the oil agent composition sticking thereto. The method for producing the carbon fiber precursor acrylic fiber is provided. Symbols in the formulas are defined in the specification.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an oil composition which is used to prevent the occurrence of fusion between single fibers in a flame-proofing step in which carbon fiber precursor acrylic fibers are converted into flame-resistant fibers. The present invention relates to a carbon fiber precursor acrylic fiber which is suitable for producing carbon fiber having excellent quality and physical properties and has improved processability in producing carbon fiber, and a method for producing the same.

[0002]

2. Description of the Related Art Conventionally, acrylic fibers have been widely used as precursors for producing carbon fibers. 20 acrylic fibers
It is converted into oxidized fiber by heat treatment in an oxidizing atmosphere at 0 to 400 ° C., and subsequently at least 1000 ° C.
Is generally used as a method for producing carbon fibers in an inert atmosphere. The carbon fiber thus obtained is widely used as a suitable reinforcing fiber of a fiber-reinforced resin composite material due to its excellent physical properties.

On the other hand, in the above-described method for producing carbon fibers, fusion between single fibers occurs in a flame-proofing step of converting carbon fiber precursor acrylic fibers into flame-resistant fibers, resulting in non-uniform firing, fluff and bundles. Failures such as disconnection occur. In order to avoid this fusion, it is known that it is important to select an oil agent to be applied to the carbon fiber precursor acrylic fiber before flame resistance, and many oil agents have been studied.

For example, silicone oils are often used as oils for carbon fiber precursors because they have high heat resistance and effectively suppress fusion.
No. 40821). However, when a silicone oil agent is used, silicon oxide and the like derived from silicone are generated in the flame resistance and carbonization process, and the silicon oil adheres and accumulates on a firing furnace wall or an exhaust gas treatment line, thereby lowering operability. In addition, silicon oxide or the like derived from silicone may adhere to guide rollers in the firing step to reduce the processability, or may adhere to the process yarn to deteriorate carbon fiber quality.

[0005] On the other hand, a carbon fiber precursor oil containing no amino-modified silicone is advantageous from the viewpoint that silicone-derived silicon oxide and the like are not generated at the time of firing and the raw material is inexpensive. Since it does not have the heat resistance of an oil agent, fusion during firing becomes a problem, and the performance of carbon fibers is inferior. Therefore, the opportunity for use in the production of a carbon fiber precursor is limited. The method of reducing the scattering of silicon oxide and the like while utilizing the heat resistance of the silicone-based oil agent includes reducing the amount of the oil agent containing amino-modified silicone as a main component, reducing the mixing ratio of the amino-modified silicone in the oil agent, and the like. There is a way,
There were problems in both the process passability and the carbon fiber performance, such as occurrence of fusion and deterioration of bunching in the spinning process. In addition, for example, in Japanese Patent Application Laid-Open No. 58-137508, a water-swelled acrylic fiber is provided with a nonionic activator and / or a cationic activator, and after a dry densification treatment, a silicone compound (or a nonionic (A mixture with an activator, etc.) suppresses the adhesion of the carbon fiber precursor in the spinning step and the high-temperature baking treatment, thereby producing a high-strength acrylic carbon fiber. Even with this method, it is possible to suppress scattering of silicon oxide or the like derived from silicone.
However, this method is still insufficient to suppress the adhesion of the carbon fiber precursor, and the deterioration of the carbon fiber performance due to the adhesion of the carbon fiber precursor was inevitable.

[0006]

DISCLOSURE OF THE INVENTION The present invention solves the above-mentioned problems of the prior art, and comprises a step of forming a carbon fiber precursor acrylic fiber in a fiber-forming step and a step of oxidizing the carbon fiber precursor acrylic fiber in a flame-proofing step. Suppress adhesion, therefore, can prevent fluff, breakage of bundles or uneven firing, and suppress generation of silicon oxide, etc. in flame resistance and carbonization process,
Accordingly, an object of the present invention is to provide an oil agent which can prevent deterioration in operability, processability, and carbon fiber quality, and a carbon fiber precursor acrylic fiber and a method for producing the same.

[0007]

Means for Solving the Problems The inventors of the present invention carry out the application of the oil agent to the carbon fiber precursor acrylic fiber in a plurality of times, particularly, the application of the non-silicone oil agent before the yarn is dried and densified. (1st stage), and before the winding or baking, diligently study the two-stage application of applying a silicone oil agent (2nd stage), in terms of spinning process passability, baking stability, carbon fiber performance, cost, etc. Therefore, in the first stage, a low silicone oil containing a small amount of an amino-modified silicone is applied, and in the second stage, a silicone oil containing an amino-modified silicone as a main component is applied to reduce the amount of scattered silica and the like during firing. The inventors have found that a carbon fiber performance comparable to that of a carbon fiber precursor acrylic fiber treated with only a silicone-based oil agent is exhibited while reducing the amount, and completed the present invention.

That is, the present invention provides the following equation (1)

[0009]

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(In the formula (1), R ¹ and R ² are each independently an alkyl group having 7 to 21 carbon atoms, and A ¹ O and A ² O are each independently an ethylene oxide residue or a propylene oxide residue. And m and n each independently represent an integer of from 1 to 5).
95% by mass, Formula (2)

[0011]

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(In the equation (2), j is 10 to 1000
An integer of 0, and k represents an integer of 1 to 100), in an amount of 1.0 to 15.0% by mass, and 0.5 to 10.0% by mass of an antioxidant. Oil composition for producing a carbon fiber precursor acrylic fiber (hereinafter referred to as oil composition (1)).

[0013] The present invention also relates to the above oil agent composition at 250 ° C.
A nonionic surfactant having a residue ratio after heating for 2 hours of 1.0% by mass or less, and the mass ratio of the oil agent composition to the nonionic surfactant is 85:15 to 65:35. (Hereinafter referred to as "oil composition (2)").

The present invention includes an oil-treated carbon fiber precursor acrylic fiber. That is, the present invention provides a carbon fiber precursor acrylic fiber in which the oil composition (1) is attached in an amount of 0.1 to 1.0% by mass, and the oil composition (2) is 0.1 to 1.0 mass%. It is a carbon fiber precursor acrylic fiber which is attached by 1.0% by mass.

Further, in the present invention, 0.1 to 1.0% by mass of the oil agent composition (2) is applied to an acrylic fiber in a water-swelled state (referred to as first oil agent application), and the mixture is dried and densified. Later, equation (2)

[0016]

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(In the equation (2), j is 10 to 1000
(An integer of 0 and k represents an integer of 1 to 100), or an oil composition containing the amino-modified silicone (hereinafter referred to as "second oil agent application").
A method for producing a carbon fiber precursor acrylic fiber, characterized in that:

In the method for producing a carbon fiber precursor acrylic fiber of the present invention, the amount of the oil agent composition applied in the first oil agent application and the amino-modified silicone or the oil agent containing the amino-modified silicone in the second oil agent application The total amount of the composition and the applied amount is preferably 0.3 to 2.0% by mass.

[0019]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail.

In the present invention, known acrylic fibers can be used as the acrylic fibers for the carbon fiber precursor before the oil agent is applied, and the composition thereof is not particularly limited, but the acrylonitrile unit is 95% by mass or more. Acrylic fibers obtained by spinning an acrylonitrile-based polymer comprising 5% by mass or less of a vinyl-based monomer unit copolymerizable with acrylonitrile are preferred. Further, as the copolymerizable vinyl monomer, acrylic acid, methacrylic acid, itaconic acid, or one or more monomers selected from a monomer group such as an alkali metal salt or an ammonium salt and acrylamide thereof. The body is preferred in promoting the anti-oxidation reaction. The method for producing the fiber bundle made of such acrylic fibers is not particularly limited, either, and a known wet, dry or dry-wet spinning method can be adopted.

In the esterified ester of higher fatty acid at both ends of the ethylene oxide and / or propylene oxide adduct of bisphenol A represented by the formula (1) in the present invention, R ¹ and R ² in the formula each independently have 7 carbon atoms.
Specific examples of the carboxylic acid which is an alkyl group of R ^{1 to} R 21 and forms R ¹ or R ² are preferably selected from higher fatty acids such as lauric acid, myristic acid, palmitic acid and stearic acid.

[0022]

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The number of moles m and n of ethylene oxide and / or propylene oxide added is preferably from 1 to 5.
When the added mole number exceeds this range, the heat resistance, which is an advantage of the compound of the formula (1), may be impaired. Further, the content of the compound of the formula (1) in the oil agent composition of the present invention is preferably in the range of 80 to 95% by mass. 80% by mass
If the amount is less than the above, the performance of the carbon fiber tends to decrease, and if the amount is more than 95% by mass, the effect of suppressing the adhesion in the spinning step or the high-temperature firing treatment of the carbon fiber precursor is insufficient.
It is not preferable because the process passability and the performance of the carbon fiber may be reduced.

In the amino-modified silicone represented by the formula (2), 10 ≦ j ≦ 10000 and 1 ≦ k ≦ 100, preferably 50 ≦ j ≦ 1000 and 1 ≦ k ≦ 10. If j and k are out of this range, the performance development and heat resistance of the carbon fiber are undesirably reduced.

[0025]

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The content of the compound of the formula (2) in the oil composition is preferably in the range of 1.0 to 15.0% by mass. If the amount is less than 1.0% by mass, the performance of the carbon fiber tends to decrease. If the amount is more than 15.0% by mass, the effect of improving the heat resistance does not change, and the convergence of the fiber bundle deteriorates. Increasing the content of the amino-modified silicone also defeats the object of the present invention of suppressing the generation of silicon oxide and the like during firing.

In the present invention, pentaerythrityl-tetrakis [3- (3,5-di-t) is used as an antioxidant.
-Butyl-4-hydroxyphenyl) propionate], triethylene glycol-bis [3- (3-t-
Butyl-5-methyl-4-hydroxyphenyl) propionate], octadecyl-3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate, 1,
3,5-tris (4-t-butyl-3-hydroxy-
2,6-dimethylbenzyl) isocyanuric acid, 2,2-
Thio-diethylenebis [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate], 4,
4'-butylidenebis (3-methyl-6-t-butylphenyl-ditridecyl phosphite) or the like is preferably used, and these may be used alone or in combination. The content of the antioxidant in the oil composition is 0.5 to 1%.
The content is preferably within the range of 0.0% by mass. If the amount is less than 0.5% by mass, the effect of heat resistance is not sufficient, and if added in excess of 10.0% by mass, the effect of improving heat resistance does not change. It is not preferable because it may remain on the yarn or the stability of the emulsion may be reduced when this oil agent is dispersed in water.

The carbon fiber precursor acrylic fiber of the present invention comprises:
Bisphenol A derivative represented by formula (1), formula (2)
Can be produced by providing an oil composition containing an amino-modified silicone represented by formula (1) and an antioxidant. Further, the carbon fiber precursor acrylic fiber of the present invention can be provided in the form of an emulsion in which a nonionic surfactant is mixed with the above mixture and dispersed in water.

The nonionic surfactant used in the present invention is not particularly limited, but preferred examples thereof include polyoxyalkylene glycol fatty acid esters, alkylene oxide adducts of aliphatic alcohols and alkylene oxide adducts of alkyl-substituted phenols. The alkyl chain of the hydrophobic portion may be linear or branched. The nonionic surfactant preferably has an HLB of 6 to 16. In addition, since it is not preferable that these nonionic surfactants remain on the oxidized yarn or the carbonized yarn as a heating residue in the firing step, the residue ratio after heating at 250 ° C. in air for 2 hours is 1.0% or less. Is preferably, and more preferably 0.5% or less. The number of repetitions of the oxyalkylene unit in the hydrophilic part of such a nonionic surfactant, the type of the oxyalkylene unit, and the form of the repetition of the oxyalkylene unit are appropriately selected so that the aqueous dispersion of the oil agent becomes a stable emulsion. be able to.

The mixing ratio between the oil composition and the nonionic surfactant is preferably in the range of 85:15 to 65:35 by mass. If the proportion of the nonionic surfactant is less than 15% by mass, the stability of the emulsion tends to decrease, and there is a tendency that spots (unevenness) adhere to fibers.
If it is more than 35% by mass, the performance of the carbon fiber tends to decrease.

The method for preparing the oil composition of the present invention includes:
Various known oil agent preparation methods can be applied, and a bisphenol A derivative represented by the formula (1), an amino-modified silicone represented by the formula (2), and an antioxidant can be mixed and used as an oil agent. Further, this mixture can be dispersed in water mixed with a nonionic surfactant.
Further, a nonionic surfactant can be further mixed with the bisphenol A derivative represented by the formula (1), the amino-modified silicone represented by the formula (2), and the antioxidant, and these can be dispersed in water.

For example, an antioxidant is added to the bisphenol A derivative represented by the formula (1) while heating, if necessary, with stirring, and an emulsifier (nonionic surfactant) and a compound represented by the formula (2) are added to the mixture. The aqueous emulsion of the oil composition is obtained by adding and stirring the amino-modified silicone to be dispersed in water.

The mixing or dispersion of each component in water can be carried out using a propeller agitator, a homomixer, a homogenizer or the like. It is also possible to separately emulsify the bisphenol A derivative and the amino-modified silicone and mix them before attaching the fibers.

It should be noted that an antistatic agent, a penetrant, an antifoaming agent, a preservative, and the like may be appropriately added to the oil composition comprising these components in order to improve its properties.

When the oil composition of the present invention is attached to acrylic fibers, it is applied as a water-based emulsion by a known method such as roller oiling and dipping. The oil composition can be directly attached to the acrylic fiber without forming an emulsion, but in this case, the fiber bundle needs to be dried.

The applied amount of the oil composition comprising the above components is as follows:
The range of 0.1 to 2.0% by mass, preferably 0.2 to 1.0% by mass, based on the dry mass of the fiber is good. Cannot suppress the fluff / bundle breakage and the adhesion between the single fibers, and if the amount exceeds 2.0%, the amount of thermally degraded products in the flame-proofing step increases, which is not preferable.

The carbon fiber precursor acrylic fiber of the present invention comprises:
A water-swelled acrylic fiber before drying and densification is applied with the oil agent composition containing the above-mentioned bisphenol A derivative as a main component as an aqueous dispersion, dried and densified, and then subjected to a second oil agent application step. Is done. In the second oil agent application step,
Equation (2)

[0038]

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(In the equation (2), j is 10 to 1000
An integer of 0, and k represents an integer of 1 to 100) or an oil composition containing the amino-modified silicone.

When the second oil agent is applied, the amino-modified silicone may be applied directly, or a nonionic surfactant which can be used in the oil agent composition and the amino-modified silicone dispersed in water is used as an application liquid. You can also. When the amino-modified silicone and the nonionic surfactant are used for imparting the second oil agent, the ratio of the amino-modified silicone may be 70% by mass or more based on the total amount of the amino-modified silicone and the nonionic surfactant. desirable. It should be noted that an antistatic agent, a penetrant, an antifoaming agent, a preservative, and the like may be appropriately added to the oil composition to be provided by the second oil agent application in order to improve its properties. The second oil agent application can be performed from immediately after drying and densification to immediately before baking, and the amino-modified silicone or the oil agent composition containing the amino-modified silicone is supplied by a known method such as roller oiling or dipping. Can be granted.

The amount of the oil agent attached in the second oil agent application is:
If the amount of the oil agent adhered in the first stage is appropriate, it is preferable to adhere as little as possible evenly. Even if the amount of adhesion is large, there is no problem as long as no process troubles due to adhesion spots (unevenness) occur, but the amino-modified silicone adheres much, and the object of the present invention is to suppress the generation of silicon oxide and the like during firing. Contrary to The total amount of the oil agent applied in the first and second oil agent application is desirably 0.3 to 2.0% by mass based on the dry mass of the fiber before the oil agent adheres.

[0042]

EXAMPLES The present invention will be described below more specifically with reference to examples, but the oil agent for a carbon fiber precursor of the present invention is not limited thereto. In addition, the nonionic surfactant heating residue, the number of fusions between single fibers, the processability before the oxidization process, the amount of silicone oil agent decomposed matter scattered, and the carbon fiber strand strength were evaluated by the following methods.

[Non-Surfactant Heating Residue] Nonionic surfactant 2.0 g was precisely weighed on an aluminum dish (diameter 60 mm, depth 10 mm), and the residue after heating at 250 ° C. in air for 2 hours was measured. The residue ratio was calculated. The higher the heating residue ratio, the greater the possibility that the thermally degraded nonionic surfactant remains on the flame-resistant yarn or carbonized yarn.

[Number of fusion between single fibers (number of fusion)] The tow of the carbonized yarn was cut into a length of 3 mm, dispersed in acetone, stirred with a magnetic stirrer for 10 minutes, and fused with the total number of single fibers. The number of adhesions was counted, and the number of fusions per 100 fibers was calculated. The evaluation criteria are as follows. ：: Number of fusions (pieces / 100 pieces) ≦ 1 ×: Number of fusions (pieces / 100 pieces)> 1 [Permeability before process of oxidization process (processability)] Using acrylic fiber of carbon fiber precursor The amount of fluff and thread breakage at the stage of the precursor acrylic fiber, depending on the number of windings around the rolls etc. at the stage of the carbon fiber precursor acrylic fiber before the flameproofing step when manufacturing carbon fibers continuously for one week Was evaluated. The evaluation criteria are as follows. ：: Number of windings (times / day) ≦ 1 △: <Number of windings (times / day) ≦ 10 ×: Number of windings (times / day)> 10 [Scattering amount of silicone oil agent decomposed product (silica scattering)] The amount of decomposition of the silicone oil agent in the oxidizing furnace was expressed by the cleaning frequency of the oxidizing furnace when carbon fibers were continuously produced for one week. Cleaning was performed by interrupting the firing when the filter for trapping silica in the air circulation line of the oxidation furnace became clogged and the pressure loss of the circulation pump became large. The evaluation criteria for silica scattering are as follows. ：: Number of cleaning times (times / week) ≦ 1 ×: Number of cleaning times (times / week)> 1 [Carbon fiber strand strength (CF strength)] JIS-R-
It is a value measured according to the epoxy resin-impregnated strand method specified in 7601. (Note that the number of measurements was 10
And the physical property values are indicated by the average values. (Examples 1 to 9) The preparation of the oil emulsion was carried out by the following method.

An ester of ethylene oxide and / or propylene oxide of bisphenol A represented by the formula (1) and a higher fatty acid ester at both terminals (component A in Table 1) and an amino-modified silicone represented by the formula (2) (component B) ,
Ion-exchanged water was added to a mixture of the antioxidant (component C) and the nonionic emulsifier (component D) at the ratio (% by mass) shown in Table 1 (the total concentration of components A to D was adjusted to 25% by mass),
Emulsify with a homomixer, and further with a high-pressure homogenizer,
Secondary emulsification was performed at 30 MPa to obtain an oil emulsion.

The oil compositions shown in Table 1 are based on components A, B, and C.
Are set to be 100. The “D mass ratio” is a ratio of the component D to the total amount of the components A to D, expressed in mass%.

[0047]

[Table 1]

[0048]

[Table 2]

(1) to (1) in components A to D in the table
5) represents the following substances. (1) A dilauryl ester of bisphenol A ethylene oxide 2 mol adduct. m = 1, n = 1 (2) Dilauryl ester of ethylene oxide 4 mol adduct of bisphenol A. m = 2, n = 2 (3) Dilauryl ester of an adduct of bisphenol A with 2 moles of ethylene oxide and 2 moles of propylene oxide.
m = 2, n = 2 (4) Dilauryl ester of ethylene oxide 12 mol adduct of bisphenol A. m = 7, n = 6 (5) Amino-modified silicone (j = 60, k = 1) (6) Amino-modified silicone (j = 300, k = 8) (7) Amino-modified silicone (j = 2000, k = Fifteen
0) (8) Pentaerythrityl-tetrakis [3- (3,5
-Di-t-butyl-4-hydroxyphenyl) propionate] (9) Triethylene glycol-bis [3- (3-t-
Butyl-5-methyl-4-hydroxyphenyl) propionate] (10) 1,3,5-tris (4-t-butyl-3-hydroxy-2,6-dimethylbenzyl) isocyanuric acid (11) polyoxyethylene lauryl Ether [EO
(Ethylene oxide): 10 mol, HLB: 14.
0] Heated residue (mass after heating at 250 ° C. for 2 hours) 0.4 mass% (12) Polyoxyethylene lauryl ether [EO:
5 mol, HLB: 10.8] Heating residue (mass after heating at 250 ° C. for 2 hours) 0.6 mass% (13) Polyoxyethylene tridecyl ether [E
O: 10 mol, HLB: 13.7] Heated residue (mass after heating at 250 ° C. for 2 hours) 0.7 mass% (14) Palm fatty acid reduced alcohol ethylene oxide adduct [EO: 9 mol, HLB: 13.1] Heating residue (mass after heating at 250 ° C. for 2 hours) 5.0% by mass (15) Polyoxyethylene hydrogenated castor oil [EO: 10
Mol, HLB: 12.5] Heating residue (mass after heating at 250 ° C. for 2 hours) 15% by mass Acrylonitrile copolymer (97.1 mass ratio of acrylonitrile unit / methacrylic acid unit / acrylamide unit)
/0.9/2.0) in dimethylacetamide,
A spinning solution having a polymer concentration of 21% by mass and a viscosity of 500 poise at 60 ° C. was prepared, and a pore diameter (diameter) was placed in a coagulation bath filled with a 69% by mass aqueous dimethylacetamide solution at 35 ° C.
A coagulated yarn was discharged from a spinneret having a diameter of 0.75 mm and a number of holes of 12,000. The coagulated yarn is desolvated in the washing tank and
It was drawn twice to obtain an acrylic fiber in a water-swelled state.

(Application of First Oil Agent) The acrylic fiber in the water-swelled state is guided to an oil bath filled with an aqueous dispersion of the oil agent composition shown in Table 1, and the surface of the oil solution is applied. Drying and densification were performed with a heating roll at a temperature of 130 ° C., and further 1.7 times stretching was performed between heating rolls at a surface temperature of 170 ° C. to obtain a precursor acrylic fiber.

This precursor acrylic fiber has a single yarn fineness of 1.
2dtex, tensile strength 7g / dtex, elongation 10.5
%, The amount of the oil agent attached to the fibers was 0.8% by mass.
(Example 9) is a mixture in which a higher fatty acid ester of both ends of an ethylene oxide adduct of bisphenol A, an amino-modified silicone, and an antioxidant were mixed in the ratio (% by mass) shown in Table 1, and dispersed in water. Then, the mixture was heated and subjected to adhesion treatment in the same manner as the aqueous dispersion of the oil composition.

(Application of a second oil agent) 85% by mass of amino-modified silicone (j = 300, k = 8 in the formula (2))
And polyoxyethylene lauryl ether (EO: 10
Mol) of 15% by mass was emulsified in the same manner as in the application of the first oil agent to prepare a 1.0% by mass aqueous dispersion. Acrylic fiber that has finished applying one oil agent and drying and densifying,
A second oil agent was applied, followed by drying treatment with a heating roll having a surface temperature of 130 ° C. to obtain a carbon fiber precursor acrylic fiber of the present invention. The total amount of the oil agent compositions of the first and second stages attached to the fibers was 1.1% by mass.

This carbon fiber precursor acrylic fiber was
The mixture was passed through an oxidizing furnace having a temperature gradient of 0 to 270 ° C. over 60 minutes, and further fired in a carbonizing furnace having a temperature gradient of 300 to 1300 ° C. in a nitrogen atmosphere to obtain carbon fibers.

The number of fusions and carbon fiber strand strength of the carbonized yarn obtained here, evaluation of the passability of the pre-oxidation process, and the amount of scattered silicone decomposed matter in the anti-oxidation process (evaluated by the number of times of furnace cleaning) were evaluated. The results are shown in Table 1.

(Comparative Examples 1 to 12) As comparative examples of the present invention, carbon fibers were produced in the same manner as in Example 1 except that the oil agent composition used for applying the first oil agent was changed to the components shown in Table 1.
evaluated. As shown in Table 1, the number of carbonized yarn fusions,
Either (or all items) of the process passability and the CF strength were inferior to those of the examples. In addition, regarding the example in which the process passability was poor, the evaluation regarding the scattering of silica was not performed. When the amino-modified silicone ratio of the first-stage oil agent in the first oil agent application is increased (Comparative Example 5)
Although the number of fusions and the CF strength were the same as those of the example, the scattering of silica increased, and the frequency of cleaning of the oxidation furnace increased.

[0056]

Since the oil composition for a carbon fiber precursor of the present invention has good heat resistance, the oil composition or the carbon fiber precursor acrylic fiber provided with the emulsion thereof is
At the stage of the carbon fiber precursor, there is no adhesion between single yarns, substantially no fluff is present, and when a carbon fiber is produced using this carbon fiber precursor acrylic fiber, the fluff of the precursor fiber in the flame-proofing step, Thread breakage and fusion between single yarns are effectively suppressed, and carbon fibers excellent in quality and physical properties can be produced.
In addition, since the amount of the silicone decomposed matter scattered in the oxidization process and the carbonization process is small, the operability and processability in the oxidization process and the carbonization process are significantly improved. Further, a production method capable of suitably producing such an excellent carbon fiber precursor acrylic fiber has been provided.

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme court ゛ (Reference) // D06M 101: 28 D06M 101: 28 (72) Inventor Yoshitaka Kageyama 20-1 Miyukicho, Otake City, Hiroshima Prefecture Mitsubishi Rayon Co., Ltd. Central Research Laboratory F-term (reference) 4J002 CH022 CH052 CP091 EH026 EH046 EJ017 EU197 EV067 FD077 FD312 GK02 HA05 4L033 AA05 AC09 AC15 BA21 CA64

Claims (6)

[Claims] (1) Formula (1) (In the formula (1), R ¹ and R ² are each independently an alkyl group having 7 to 21 carbon atoms, A ¹ O and A ² O are each independently an ethylene oxide residue or a propylene oxide residue; And n are each independently 1 to
A bisphenol A ethylene oxide and / or propylene oxide adduct of both ends higher fatty acid ester represented by the formula (2) represented by the formula (2): (In the formula (2), j is an integer of 10 to 10000, k
Is an integer of 1 to 100), containing 1.0 to 15.0% by mass of an amino-modified silicone and 0.5 to 10.0% by mass of an antioxidant. Oil composition for producing body acrylic fiber. 2. The oil agent composition according to claim 1, comprising a nonionic surfactant having a residue ratio of 1.0% by mass or less after heating at 250 ° C. for 2 hours, wherein the oil agent composition and the nonionic interface An oil agent composition for producing a carbon fiber precursor acrylic fiber, wherein the mass ratio of the activator is 85:15 to 65:35. 3. The oil agent composition according to claim 1, wherein
A carbon fiber precursor acrylic fiber, wherein 1.0% by mass of carbon fiber is attached. 4. The oil agent composition according to claim 2, wherein
A carbon fiber precursor acrylic fiber, wherein 1.0% by mass of carbon fiber is attached. 5. An oil agent composition according to claim 2, which is applied to the acrylic fiber in a water-swelled state in an amount of 0.1 to 1.0% by mass,
After drying and densification, it is further treated with the formula (2) (In the formula (2), j is an integer of 10 to 10000, k
Wherein the amino-modified silicone or an oil composition containing the amino-modified silicone is provided. 6. An applied amount of the oil agent composition according to claim 2,
The total amount of the amino-modified silicone or the oil agent composition containing the amino-modified silicone is 0.3 to
The method according to claim 5, wherein the amount is 2.0% by mass.