JP2011042916A - Lubricant composition for carbon fiber precursor acrylic fiber, carbon fiber precursor acrylic fiber bundle, and method for producing the fiber bundle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a lubricant composition for carbon fiber precursor acrylic fiber, which effectively prevents fusings among single carbon fibers in the production process for carbon fiber bundles, suppresses operability decline, and is capable of obtaining in high productivity the well-bundled carbon fiber precursor acrylic fiber bundles and the carbon fiber bundles of excellent mechanical properties, and to provide the carbon fiber precursor acrylic fiber bundles, and to provide a method for producing the fiber bundles. <P>SOLUTION: The lubricant composition for carbon fiber precursor acrylic fiber includes: an aromatic ester compound of formula (I) having a residual mass rate (r<SP>1</SP>) at 300°C of 90-100 mass%, determined by thermogravimetric analysis in the presence of steam, and a residual mass rate (r<SP>2</SP>) at 500°C of not more than 10 mass%, determined by thermogravimetric analysis in a nitrogen gas atmosphere; and an aromatic ester compound of formula (II) having a residual mass rate (r<SP>1</SP>) of 70-80 mass% in, and a residual mass rate (r<SP>2</SP>) of not more than 3. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to an oil composition for carbon fiber precursor acrylic fibers, a carbon fiber precursor acrylic fiber bundle, and a method for producing the same.

  Conventionally, as a method for producing a carbon fiber bundle, a carbon fiber precursor fiber bundle made of acrylic fiber or the like (hereinafter also referred to as “precursor fiber bundle”) is heat-treated in an oxygen-existing atmosphere at 200 to 400 ° C. There is known a method of obtaining a carbon fiber bundle by converting into a flame resistant fiber bundle (flame resistance process) and subsequently carbonizing in an inert atmosphere at 1000 ° C. or higher (carbonization process). Carbon fiber bundles obtained by this method are widely used industrially as reinforcing fibers for composite materials because of their excellent mechanical properties.

  However, in the process of manufacturing the carbon fiber bundle, fusion occurs between the single fibers in the flameproofing process, and the flameproofing process and the subsequent carbonization process (hereinafter referred to as the “firing process” In some cases, process failures such as fluff and bundle breakage may occur. As a method for preventing fusion between single fibers in the flameproofing process, a method of applying an oil agent composition to the surface of the precursor fiber bundle (oil agent treatment) is known, and many oil agent compositions have been studied. I came.

As the oil composition, a silicone-based oil mainly composed of silicone has been generally used so far. From the viewpoint of ease of compatibility with the precursor fiber bundle and fixing property, modified silicones having reactive groups such as amino, epoxy, and polyether have been generally used.
However, the modified silicone-based oils are heated to undergo a cross-linking reaction to increase the viscosity, and the adhesive is easily deposited on the surface of fiber precursor rollers and guides used in the precursor fiber bundle manufacturing process and flameproofing process. It was. For this reason, process failures such as the precursor fiber bundle and the flameproof fiber bundle being wound or caught by the fiber conveying roller or the guide are generated, and the operability may be lowered.
Moreover, the precursor fiber bundle to which the silicone-based oil agent was applied easily generated silicon compounds such as silicon oxide, silicon carbide, and silicon nitride in the firing step. The formation of silicon compounds leads to industrial productivity and product quality degradation.

Therefore, an oil composition having a reduced silicone content has been proposed for the purpose of reducing the silicon content of the precursor fiber bundle treated with the oil. For example, an oil agent composition containing 40 to 100% by weight of an emulsifier containing 50 to 100% by weight of a polycyclic aromatic compound to reduce the silicone content has been proposed (see Patent Document 1).
Further, an oil agent composition has been proposed in which 80 to 95% by mass of both-end higher fatty acid esterified products of ethylene oxide and / or propylene oxide adducts of bisphenol A are contained (see Patent Document 2). . Similarly, as a compound having a bisphenol A skeleton, a reaction product of a saturated aliphatic dicarboxylic acid and a bisphenol A ethylene oxide and / or a monoalkyl ester of a propylene oxide adduct is added to reduce the silicone content. The thing is proposed (refer patent document 3).
Moreover, the oil agent composition which combined the heat resistant resin whose residual rate after heating at 250 degreeC in the air for 2 hours is 80 mass% or more and silicone is proposed (refer patent document 4).
Furthermore, an oil composition containing 10% by mass or more of a compound having a reactive functional group and not containing a silicone compound, or containing a silicone compound, in a range not exceeding 2% by mass in terms of silicon mass is proposed. (See Patent Document 5).

  On the other hand, an oil agent composition containing a compatibilizer has been proposed for the purpose of having an affinity between a silicone compound and a non-silicone compound in an oil agent composition having a reduced silicone content. (See Patent Documents 6 and 7).

  In recent years, an oil agent composition having an ester compound having three or more ester groups in the molecule and a silicone compound as essential components has been proposed (see Patent Document 8). According to this oil agent composition, the silicone content can be reduced by the ester compound, and both fusion prevention between single fibers in carbon fiber production and stable operability can be achieved.

JP 2005-264384 A JP 2002-266239 A JP 2003-55881 A JP 2000-199183 A JP 2005-264361 A JP 2004-149937 A JP 2004-169198 A International Publication No. 07/0666517 Pamphlet

However, although the oil composition described in Patent Document 1 has a high emulsifier content, the stability of the emulsion is increased, but the bundle of precursor fibers to which this oil composition is adhered tends to have a low convergence and is high. It was not suitable for manufacturing with production efficiency. Furthermore, there is a problem that it is difficult to obtain a carbon fiber bundle excellent in mechanical properties.
In addition, although the oil agent compositions described in Patent Documents 2 and 3 use bisphenol A aromatic ester as a heat-resistant resin, the heat resistance is extremely high, but the effect of preventing fusion between single fibers is not sufficient. There wasn't. Furthermore, there has been a problem that it is difficult to stably obtain a carbon fiber bundle excellent in mechanical properties.

Moreover, since the oil agent composition described in Patent Document 4 forms a film on the fiber surface at 250 ° C to 300 ° C, diffusion of oxygen into the fiber in the flameproofing process is inhibited, and flameproofing is performed uniformly. As a result, there has been a problem that it is difficult to stably obtain a carbon fiber bundle excellent in mechanical properties. Furthermore, due to the high heat resistance, there has been a problem that the oil agent composition or a modified product thereof is deposited on the inside of the furnace or the transport roller in the flameproofing process, resulting in a process hindrance.
Furthermore, although the oil agent composition of patent document 5 can improve oil agent adhesiveness by raising the oil agent viscosity in 100-145 degreeC, since the viscosity is high, the precursor fiber bundle after an oil agent process is a fiber. Occasionally, process troubles such as wrapping around a conveyance roller or the like were caused, and operability was sometimes lowered.

On the other hand, in the oil agent composition using the compatibilizing agent described in Patent Documents 6 and 7, although a certain compatibilizing effect is obtained, the compatibilizing agent is inferior in affinity to the silicone compound. It was necessary to contain at least mass%. Further, the decomposition product of the compatibilizing agent may become tarred during the firing process, which may impede the process.
Moreover, when the oil agent composition described in Patent Document 8 was applied to the precursor fiber, the operability was stable, but the heat resistance was low, so that the fiber bundle was not sufficiently converged in the flameproofing step. Further, the mechanical properties of the obtained carbon fiber bundle tended to be inferior to that of silicone-based oils mainly composed of silicone.

As described above, the oil agent composition having a reduced silicone content may cause a decrease in operability. Moreover, compared with silicone type oil agent, there existed a tendency for the anti-fusing property, the convergence property of the precursor fiber bundle treated with the oil agent to deteriorate, and the mechanical properties of the carbon fiber bundle to be inferior. Therefore, it has been difficult to stably obtain a high-quality carbon fiber bundle.
On the other hand, silicone oils that have been widely used in the past have suffered from problems such as a decrease in operability due to an increase in viscosity and a decrease in industrial productivity due to the formation of silicon compounds.
In other words, the problem of lowering the operability and industrial productivity due to the oil composition containing silicone as a main component, the anti-fusing property due to the oil composition having a reduced silicone content, the convergence of the precursor fiber bundle, The problem of the deterioration of the mechanical properties of the carbon fiber bundle has a two-sided relationship, and the conventional technology has not solved all the problems.

  The present invention has been made in view of the above circumstances, and effectively prevents fusion between single fibers in a carbon fiber bundle manufacturing process, suppresses operability deterioration, and has good convergence properties. It is an object of the present invention to provide an oil agent composition for a carbon fiber precursor acrylic fiber capable of obtaining an acrylic fiber bundle and a carbon fiber bundle excellent in mechanical properties with high productivity, a carbon fiber precursor acrylic fiber bundle, and a method for producing the same. .

  As a result of intensive studies by the present inventor, as described above, by using together aromatic ester compounds having different heat resistance characteristics under certain conditions, or by combining aromatic ester compounds having different structures and specifying the ratio thereof, It has been found that both the problem of the oil composition containing silicone as a main component and the problem of the oil composition having a reduced silicone content can be solved, and the present invention has been completed.

That is, the carbon fiber precursor acrylic fiber oil composition of the present invention has a residual mass ratio (r ¹ ) at 90 ° C. of 90 to 100% by mass in a nitrogen gas atmosphere in a thermal mass analysis in the presence of water vapor. In the thermal mass analysis of the aromatic ester compound (I) having a residual mass ratio (r ² ) at 500 ° C. of 10% by mass or less, the residual mass ratio (r ¹ ) is 70 to 80% by mass, And an aromatic ester compound (II) having a residual mass ratio (r ² ) of 3% by mass or less.
This oil composition preferably contains an amino-modified silicone.
Furthermore, it is preferable that the aromatic ester compound (I) is an aromatic ester compound having a bisphenol A skeleton, and the aromatic ester compound (II) is a monocyclic aromatic ester compound.

  Moreover, the oil agent composition for carbon fiber precursor acrylic fiber of this invention is 10-40 mass% of aromatic ester compounds of the structure shown by the following formula (1), and the aromatic structure of the following formula (2). It comprises 10 to 40% by mass of an ester compound and 1 to 10% by mass of an amino-modified silicone having a structure represented by the following formula (3).

In the formula (1), R ¹ and R ² are each independently a hydrocarbon group having 7 to 21 carbon atoms, and “m” and “n” are each independently 1 to 5.

In Formula (2), R ^{3 to} R ⁵ are each independently a hydrocarbon group having 8 to 14 carbon atoms.

  In the formula (3), “o” is 5 to 300, and “p” is 1 to 5.

Moreover, it is preferable that the oil agent composition for acrylic fibers of a carbon fiber precursor of the present invention contains 1 to 10% by mass of a compatibilizer having a polydimethylsiloxane structure.
Furthermore, the surfactant used to disperse the above oil composition in water contains 10 to 10 block copolymerized polyethers composed of a propylene oxide unit having a structure represented by the following formula (4) and an ethylene oxide unit. It is preferable to contain 30 mass%.

  In the formula (4), “x”, “y”, and “z” are each independently 1 to 200.

Moreover, the carbon fiber precursor acrylic fiber bundle of the present invention is formed by adhering the oil agent composition for carbon fiber precursor acrylic fibers in an amount of 0.1 to 2.0 mass% with respect to the dry fiber mass.
In the method for producing a carbon fiber precursor acrylic fiber bundle of the present invention, the oil agent composition for carbon fiber precursor acrylic fibers is dispersed in water to form micelles having an average particle diameter of 0.01 to 0.50 μm. A step of applying the aqueous emulsion solution to the precursor fiber bundle in a water-swelled state, and a step of drying and densifying the precursor fiber bundle to which the aqueous emulsion solution is applied.

According to the present invention, a carbon fiber precursor acrylic fiber bundle and mechanical properties that effectively prevent fusion between single fibers in the carbon fiber bundle manufacturing process, suppress deterioration in operability, and have good convergence. An oil composition for a carbon fiber precursor acrylic fiber that can obtain a carbon fiber bundle excellent in productivity with high productivity, a carbon fiber precursor acrylic fiber bundle, and a method for producing the same.
In addition, according to the present invention, it is possible to suppress a decrease in operability and the convergence property of the carbon fiber precursor acrylic fiber bundle is good. Therefore, the industrial productivity of the carbon fiber bundle is increased, and the quality is stably high. A carbon fiber bundle can be obtained.

Hereinafter, the present invention will be described in detail.
[Oil agent composition for carbon fiber precursor acrylic fiber]
<First embodiment>
The oil composition for carbon fiber precursor acrylic fibers of the present invention (hereinafter also referred to as “oil agent composition”) is a carbon fiber precursor acrylic fiber bundle (hereinafter referred to as “precursor fiber bundle”) before the oil agent treatment described below. And is also used in combination with aromatic ester components having different heat resistance characteristics.

The aromatic ester component is effective for preventing fusion and imparting convergence in the flame resistance process of the carbon fiber precursor acrylic fiber bundle described later.
In the present invention, as an aromatic ester component, in the thermal mass analysis in the presence of water vapor, the residual mass ratio (r ¹ ) at 300 ° C. is 90 to 100% by mass, and in the thermal mass analysis in a nitrogen gas atmosphere, The aromatic ester compound (I) having a residual mass ratio (r ² ) at 500 ° C. of 10% by mass or less, the residual mass ratio (r ¹ ) is 70 to 80% by mass, and the residual mass ratio (r ² ) Is used in combination with an aromatic ester compound (II) having a content of 3% by mass or less.

r ¹ and r ² can be measured by the following method.
Using a thermal mass measuring device (trade name: micro thermogravimetric measuring device TGA-50 manufactured by Shimadzu Corporation) capable of circulating gas, the aromatic ester was set in the device at room temperature, and the initial mass at this time was set to W ₀ . After that, while flowing N ₂ gas (purity 99.9999%), it was heated to 150 ° C. at a heating rate of 10 ° C./min, and at 150 ° C., N ₂ and water vapor were mixed at a ratio of 4: 1 (volume ratio). Switch to the selected gas line. Further, the mass when heated to 300 ° C. at a temperature increase rate of 10 ° C./min is defined as W ₁ . Thereafter, the flow gas line is returned to N _2, and the mass when heated to 500 ° C. at a rate of temperature increase of 10 ° C./min is defined as W ₂ . At this time, it is important that the gas flow rate is a flow rate at which the atmosphere in the apparatus can be purged, and it is necessary to start after the inside of the furnace is sufficiently replaced with N ₂ gas before the temperature rise is started. The gas line containing water vapor is preferably kept at 150 ° C. or higher using a ribbon heater or the like in order to avoid the water vapor from condensing.
r ¹ and r ² are obtained by the following formulas (i) and (ii).
r ¹ [mass%] = (W ₁ / W ₀ ) × 100 (i)
r ² [% by mass] = (W ₂ / W ₀ ) × 100 (ii)

By using together the aromatic ester compound (I) and the aromatic ester compound (II) as the aromatic ester component, it is possible to obtain the convergence in the flameproofing process and the anti-fusion effect. Specifically, the aromatic ester compound (I) retains the convergence in the flameproofing process, and the aromatic ester compound (II) exhibits an anti-fusing effect and exhibits good mechanical properties of the carbon fiber. It shall be
If r ¹ and r ² of the both aromatic ester compounds are out of the above ranges, it becomes impossible to maintain a good balance of fusing prevention, bundling properties, and carbon fiber mechanical strength.

As the aromatic ester compound (I), an aromatic ester compound having a bisphenol A skeleton is preferable.
Examples of aromatic ester compounds having a bisphenol A skeleton include polyoxyethylene bisphenol A diacrylate, polyoxypropylene bisphenol A diacrylate, polyoxyethylene bisphenol A dialchelate, polyoxypropylene bisphenol A dialchelate, and polyoxyethylene bisphenol A. Examples include dimethacrylate, polyoxypropylene bisphenol A dimethacrylate, bisphenol A diacetate, and bisphenol A glycerolate diacetate.
Among these, as the aromatic ester compound having a bisphenol A skeleton, an aromatic ester compound having a structure represented by the following formula (1) is preferable because it is particularly excellent in heat resistance.

In formula (1), R ¹ and R ² are each independently a hydrocarbon group having 7 to 21 carbon atoms. If the number of carbon atoms of the hydrocarbon group is 7 or more, the heat resistance of the aromatic ester compound (I) can be maintained satisfactorily, so that a sufficient anti-fusion effect can be obtained in the flameproofing step. On the other hand, if the carbon number of the hydrocarbon group is 21 or less, an emulsion of the oil agent composition containing the aromatic ester compound (I) can be easily prepared, and the oil agent composition adheres uniformly to the precursor fiber bundle. As a result, a sufficient fusion prevention effect can be obtained in the flameproofing process, and the convergence of the carbon fiber precursor acrylic fiber bundle is improved. As for carbon number of a hydrocarbon group, 9-15 are preferred.
R ¹ and R ² may have the same structure or may have independent structures.

  As the hydrocarbon group, a saturated hydrocarbon group is preferable, and among them, a saturated chain hydrocarbon group is particularly preferable. Specifically, heptyl group, octyl group, nonyl group, decyl group, undecyl group, lauryl group (dodecyl group), tridecyl group, tetradecyl group, pentadecyl group, hexadecyl group, heptadecyl group, octadecyl, nonadecyl group, icosyl group ( And alkyl groups such as eicosyl group) and heicosyl group (heneicosyl group).

Moreover, in Formula (1), "m" and "n" are 1-5 each independently. When the values of “m” and “n” exceed the above range, the heat resistance of the aromatic ester compound (I) is lowered, and fusion between single fibers may occur in the flameproofing process.
The aromatic ester represented by the formula (1) may be a mixture of a plurality of compounds, and therefore “m” and “n” may not be integers. Further, the hydrocarbon group forming R ¹ and R ² may be one kind or a mixture of plural kinds.

On the other hand, the aromatic ester compound (II) is preferably a monocyclic aromatic ester compound. Here, “monocyclic” means having one aromatic ring in one molecule.
Examples of monocyclic aromatic ester compounds include benzoic acid alkylate, phthalic acid alkylate, isophthalic acid alkylate, terephthalic acid alkylate, hemimellitic acid alkylate, trimellitic acid alkylate, pyromellitic acid alkylate, trimesic acid Examples thereof include alkylates, merophanic acid alkylates, planitic acid alkylates, mellitic acid alkylates, and toluic acid alkylates.
Among these, as the monocyclic aromatic ester compound, an aromatic ester compound having a structure represented by the following formula (2) is preferable because it is particularly excellent in thermal decomposability.

In formula (2), R ^{3 to} R ⁵ are each independently a hydrocarbon group having 8 to 14 carbon atoms. If the number of carbon atoms of the hydrocarbon group is 8 or more, the heat resistance of the aromatic ester compound (II) can be maintained satisfactorily, so that a sufficient anti-fusion effect can be obtained in the flameproofing step. On the other hand, if the carbon number of the hydrocarbon group is 14 or less, an emulsion of the oil agent composition containing the aromatic ester compound (II) can be easily prepared, and the oil agent composition adheres uniformly to the precursor fiber bundle. As a result, a sufficient fusion prevention effect can be obtained in the flameproofing process, and the convergence of the carbon fiber precursor acrylic fiber bundle is improved. R ^{3 to} R ⁵ are preferably a saturated hydrocarbon group having 8 to 12 carbon atoms in terms of easy preparation of an emulsion of a uniform oil composition, and having 10 to 14 carbon atoms in terms of excellent heat resistance in the presence of water vapor. Saturated hydrocarbon groups are preferred.
R ^{3 to} R ⁵ may have the same structure or may have independent structures.

  The hydrocarbon group is preferably a saturated hydrocarbon group such as a saturated chain hydrocarbon group or a saturated cyclic hydrocarbon group. Specific examples include alkyl groups such as octyl group, nonyl group, decyl group, undecyl group, lauryl group (dodecyl group), tridecyl group, and tetradecyl group.

It is preferable that 10-40 mass% of aromatic ester compounds (I) are contained in 100 mass% of oil agent compositions. If the content of the aromatic ester compound (I) is 10% by mass or more, the heat resistance of the oil composition is good, and the carbon fiber precursor acrylic fiber bundle maintains sufficient bundling properties until the flameproofing process is completed. it can. On the other hand, if the content of the aromatic ester compound (I) is 40% by mass or less, the mechanical properties of the obtained carbon fiber bundle are not easily lowered.
As for content of aromatic ester compound (I), 10-30 mass% is more preferable.

When the aromatic ester compound (I) is an aromatic ester compound having the structure represented by the above formula (1), the content is preferably 10 to 40% by mass in 100% by mass of the oil composition.
Since the aromatic ester compound having the structure represented by the above formula (1) is particularly excellent in heat resistance, the heat resistance of the oil composition is also improved, and the carbon fiber precursor acrylic fiber bundle is sufficiently focused until the flameproofing process is completed. Can retain sex. If content is 10 mass% or more, the effect mentioned above will fully be acquired. However, since the aromatic ester compound having the structure represented by the formula (1) remains in the fiber bundle until the carbonization step, the mechanical properties of the obtained carbon fiber bundle may be lowered. Therefore, when the aromatic ester compound (I) is an aromatic ester compound having a structure represented by the above formula (1), the upper limit of the content is preferably 40% by mass or less.
As for content of the aromatic ester compound of the structure shown by the said Formula (1), 10-30 mass% is more preferable.

On the other hand, the aromatic ester compound (II) is preferably contained in an amount of 10 to 40% by mass in 100% by mass of the oil composition. When the content of the aromatic ester compound (II) is 10% by mass or more, the mechanical properties of the obtained carbon fiber bundle can be improved. On the other hand, if the content of the aromatic ester compound (II) is 40% by mass or less, the carbon fiber precursor acrylic fiber bundle can sufficiently maintain the convergence even in the flameproofing step.
As for content of aromatic ester compound (II), 20-40 mass% is more preferable.

When the aromatic ester compound (II) is an aromatic ester compound having the structure represented by the above formula (2), the content is preferably 10 to 40% by mass in 100% by mass of the oil composition.
Since the aromatic ester compound having the structure represented by the above formula (2) is particularly excellent in thermal decomposability, it is easily decomposed or scattered in the flameproofing process and hardly remains on the surface of the fiber bundle. Therefore, the mechanical properties of the carbon fiber bundle can be improved. If content is 10 mass% or more, the effect mentioned above will fully be acquired. However, since the aromatic ester compound having the structure represented by the above formula (2) is slightly inferior in heat resistance, if the content is increased, the carbon fiber precursor acrylic fiber bundle is difficult to maintain sufficient convergence in the flameproofing step. Become. Therefore, when the aromatic ester compound (II) is an aromatic ester compound having the structure represented by the above formula (2), the upper limit of the content is preferably 40% by mass or less.
As for content of the aromatic ester compound of the structure shown by the said Formula (2), 20-40 mass% is more preferable.

  The oil agent composition of the present invention preferably contains an amine-modified silicone in addition to the aromatic ester compounds (I) and (II) described above. The amino-modified silicone has good compatibility with the precursor fiber bundle and is effective in improving the affinity and heat resistance of the oil composition with the precursor fiber bundle.

The amino-modified silicone is preferably an amino-modified silicone having a kinematic viscosity at 25 ° C. of 50 to 500 mm ² / s and an amino equivalent of 2000 to 6000 g / mol.
When the kinematic viscosity is less than 50 mm ² / s, the heat resistance of the obtained oil agent composition is lowered, and it becomes difficult to sufficiently prevent fusion between single fibers in the flameproofing step. On the other hand, when the kinematic viscosity exceeds 500 mm ² / s, it becomes difficult to prepare an emulsion of the oil composition. Moreover, the stability of the emulsion of the oil composition is lowered, and it is difficult to uniformly adhere to the precursor fiber bundle. As a result, it becomes difficult to sufficiently prevent the fusion between the single fibers in the flameproofing process, and the convergence of the carbon fiber precursor acrylic fiber bundle is likely to be lowered.
The kinematic viscosity at 25 ° C. is preferably 50 to 300 mm ² / s.

  The kinematic viscosity of the amino-modified silicone is a value measured according to JIS-Z-8803 or ASTM D 445-46T, and can be measured using, for example, a Ubbelohde viscometer.

  The amino equivalent of the amino-modified silicone is preferably 2000 to 6000 g / mol, more preferably 4000 to 6000 g / mol, from the viewpoint of good compatibility with the precursor fiber bundle and the thermal stability of the silicone. When the amino equivalent is less than 2000 g / mol, the number of amino groups in one molecule of the silicone is excessively increased, the thermal stability of the amino-modified silicone is lowered, and the process is hindered. On the other hand, when the amino equivalent exceeds 6000 g / mol, the number of amino groups in one silicone molecule becomes too small, and the conformity with the precursor fiber bundle becomes worse, and the oil agent composition becomes difficult to adhere uniformly. In some cases, it becomes difficult to sufficiently prevent the fusion between the two, and the convergence of the carbon fiber precursor acrylic fiber bundle may be deteriorated.

  As such an amino-modified silicone, an amino-modified silicone having a structure represented by the following formula (3) is preferable.

In the formula (3), “o” is 5 to 300, and “p” is 1 to 5. When “o” and “p” are out of the above ranges, the performance and heat resistance of the carbon fiber bundle are likely to be lowered. In particular, when “o” is less than 5, the heat resistance tends to decrease or it becomes difficult to prevent fusion between single fibers. On the other hand, when “o” exceeds 300, it is very difficult to disperse the oil composition in water, making it difficult to prepare an emulsion. Moreover, stability of an emulsion falls and it becomes difficult to adhere to a precursor fiber bundle uniformly.
On the other hand, when “p” is less than 1, the affinity with the precursor fiber bundle is lowered, so that it becomes difficult to effectively prevent fusion between single fibers. On the other hand, if “p” exceeds 5, the heat resistance of the oil composition itself is lowered, and it becomes difficult to prevent fusion between single fibers.
“O” is preferably 10 to 200, and “p” is preferably 1 to 3.
The amino-modified silicone having the structure represented by the formula (3) may be a mixture of a plurality of compounds. Thus, “o” and “p” may not each be an integer.

“O” and “p” in the formula (3) can be estimated as an estimated value from the kinematic viscosity and amino equivalent of the amino-modified silicone.
The procedure for obtaining “o” and “p” is as follows. First, the kinematic viscosity of the amino-modified silicone is measured, and A.V. J. et al. The molecular weight is calculated according to the Barry equation (log η = 1.00 + 0.0123 M ^0.5 , (η: kinematic viscosity at 25 ° C., M: molecular weight)). Next, the average number of amino groups “p” per molecule is determined from this molecular weight and amino equivalent. The value of “o” can be determined by determining the molecular weight and “p”.

  The content of the amino-modified silicone is preferably 1 to 10% by mass and more preferably 5 to 10% by mass in 100% by mass of the oil agent composition. When the content of the amino-modified silicone is less than 1% by mass, it is difficult to completely prevent fusion between single fibers, and it becomes difficult to obtain a carbon fiber bundle excellent in mechanical properties. On the other hand, when the content of amino-modified silicone exceeds 10% by mass, there is a problem that industrial productivity is lowered due to a process failure caused by a silicon compound generated in the flameproofing process.

The oil agent composition of the present invention preferably contains a compatibilizing agent having a polydimethylsiloxane structure.
As for content of a compatibilizing agent, 1-10 mass% is preferable in 100 mass% of oil agent compositions, More preferably, it is 2-5 mass%. If the content of the compatibilizer is 1% by mass or more, the amino-modified silicone and the aromatic ester compounds (I) and (II) are easily adapted to each other, and each oil component is unevenly distributed when applied to the fiber. It becomes possible to adhere more evenly to the fiber surface without. On the other hand, if the content of the compatibilizing agent is 10% by mass or less, there is little generation of silicon compounds derived from the polydimethylsiloxane structure of the compatibilizing agent in the firing step, and there is a problem of lowering industrial productivity. It becomes difficult to do.

  As the compatibilizing agent, at least one unit selected from the group consisting of units represented by the following formula (5), units represented by the following formulas (6), (7) and (8), and optionally the following A modified polydimethylsiloxane containing a unit represented by the formula (9) is preferable.

In formula (5), xa is 7-15.
In Formula (6), ma is 0-3 and ya is 5-15.
In formula (7), mb is 0-3 and yb is 1-5.
In formula (8), mc is 0 to 3, yc + yd is 5 to 15, and ethylene oxide (EO) and propylene oxide (PO) are block copolymers or random copolymers.
In Formula (9), na is 1-5 and za is 3-60.

  The structure of the above-mentioned modified polydimethylsiloxane can be exemplified by the following three patterns in which combinations of the above units are roughly classified as a more preferable form.

(Combination 1)
The modified polydimethylsiloxane preferably has at least one unit represented by the above formulas (5), (6) and (9), and has a kinematic viscosity at 25 ° C. of 500 to 1000 mm ² / s ( Hereinafter, it is referred to as modified polydimethylsiloxane 1).
The alkyl chain of the modified polydimethylsiloxane 1 is familiar with oils and fats, and due to the effect of this site, the modified polydimethylsiloxane 1 is dissolved in both the amino-modified silicone and the aromatic ester compounds (I) and (II). Demonstrate the compatibilizing effect. This alkyl chain has xa = 7 to 15 in the above formula (5). Preferably, xa = 11. When xa is 7 or more, the solubility in fats and oils is good, and when it is 15 or less, stability is improved when the oil composition is dispersed in water.

  The polyethylene oxide chain of the modified polydimethylsiloxane 1 is familiar with water and has a function of stabilizing micelles when the oil composition is dispersed in water. The number of ethylene oxides in the polyethylene oxide chain is set to ya = 5 to 15 in the above formula (6). Preferably ya = 9. When ya is 5 or more, the affinity with water is good and the stability when it is made into an emulsion is good. Moreover, thermal stability is good in it being 15 or less. Also, there may be an alkyl group between polyethylene oxide and polydimethylsiloxane, and the range is ma = 0-3. Preferably ma = 0. If ma is 3 or less, the dispersibility in water is good and the stability of the emulsion does not decrease.

Moreover, when the modified polydimethylsiloxane 1 has a polydimethylsiloxyalkyl chain, the solubility in amino-modified silicone is increased. The alkyl part of the polydimethylsiloxyalkyl chain is a saturated hydrocarbon having na of 1 to 5 in the above formula (9). Preferably na = 2. When na is 5 or less, the balance of solubility in the aromatic ester and amino-modified silicone is good, and a compatibilizing effect is exhibited. The length of the polydimethylsiloxy part is determined by the overall balance, za in the formula (9) is in the range of 3 to 60, and the kinematic viscosity at 25 ° C. is a value that satisfies the range of 500 to 1000 mm ² / s. . Preferably it is 5-30. When za is 3 or more, the solubility in amino-modified silicone is good and a compatibilizing effect is exhibited. If it is 60 or less, the solubility in amino-modified silicone does not become too high, and the balance of compatibilization is good.

  Moreover, it is preferable that the number of units shown by said Formula (5), (6) and (9) is the range of 2-5, respectively. If it exists in this range, the balance between each performance mentioned above about each unit will be good, and compatibilizing ability will become favorable. When there are two or more units represented by the above formulas (5), (6) and (9), the values of xa, ya, za, ma and na may be the same or different depending on each unit. Good.

The modified polydimethylsiloxane 1 preferably has a kinematic viscosity at 25 ° C. of 500 to 1000 mm ² / s. More preferably, it is 600-800 mm < ² > / s. When the kinematic viscosity is 500 mm ² / s or more, the molecular weight does not become too small, so that the polyethylene oxide chain and the alkyl chain can be uniformly put in the structure, and the thermal stability is improved. On the other hand, when the kinematic viscosity is 1000 mm ² / s or less, it is easy to emulsify, the stability of the obtained emulsion is good, and in the drying step after applying the oil composition to the precursor fiber bundle, a highly viscous substance is present. The operability does not deteriorate due to precipitation on the drying roll.
The kinematic viscosity of the modified polydimethylsiloxane 1 can be measured in the same manner as the kinematic viscosity of the amino-modified silicone.

(Combination 2)
The modified polydimethylsiloxane preferably has 1 to 20 units represented by the above formulas (5), (7) and (9), and has a kinematic viscosity at 25 ° C. of 3000 to 5000 mm ² / s. (Hereinafter referred to as modified polydimethylsiloxane 2).
The alkyl chain of the modified polydimethylsiloxane 2 is familiar with oils and fats. Due to the effect of this site, the modified polydimethylsiloxane 2 is dissolved in both the amino-modified silicone and the aromatic ester compounds (I) and (II), Demonstrates solubilizing effect. This alkyl chain has xa = 7 to 15 in the above formula (5). Preferably xa = 11. When xa is smaller than 7, the solubility in fats and oils is reduced, and when it is larger than 15, the stability is lowered when the oil composition is dispersed in water.

  The polyglycerin chain of the modified polydimethylsiloxane 2 is familiar with water and has a function of stabilizing micelles when the oil composition is dispersed in water. The polyglycerin chain is set to yb = 1 to 5 in the above formula (7). Preferably yb = 3. If yb is less than 1, the affinity with water is low and the stability of the emulsion is lowered, and if it is greater than 5, the thermal stability is lowered. Further, there may be alkyl between polyglycerin and polydimethylsiloxane, and the range is mb = 0-3. Preferably mb = 0. When mb exceeds 3, the dispersibility to water will become low and the stability of an emulsion will fall.

Moreover, when the modified polydimethylsiloxane 2 has a polydimethylsiloxyalkyl chain, the solubility in amino-modified silicone is increased. The alkyl part of the polydimethylsiloxyalkyl chain is a saturated hydrocarbon of na = 1 to 5 in the above formula (9). Preferably na = 2. When na is more than 5, the balance of solubility in the aromatic ester and amino-modified silicone is lost, and the compatibilizing effect is lowered. The length of the polydimethylsiloxy part is determined by the overall balance, za in the above formula (9) is in the range of 3-60, and the kinematic viscosity at 25 ° C. is a value satisfying the range of 3000-5000 mm ² / s. . Preferably it is 5-30. When za is lower than 3, the solubility in amino-modified silicone is low and the compatibilizing effect is lowered, and when it exceeds 60, the solubility in amino-modified silicone is increased and the balance of compatibilization is lowered.

The modified polydimethylsiloxane 2 preferably has a kinematic viscosity at 25 ° C. of 3000 to 5000 mm ² / s. More preferably, it is 3500-4500 mm < ² > / s. When the kinematic viscosity is smaller than 3000 mm ² / s, the molecular weight is inevitably small, and the polyglycerin chain and the alkyl chain cannot be uniformly put in the structure, and the thermal stability is lowered. Moreover, when kinematic viscosity is larger than 5000 mm < ² > / s, emulsification is difficult, stability of the obtained emulsion also falls, and also a substance with high viscosity in the drying process after providing an oil agent composition to a precursor fiber bundle Is deposited on the drying roll and the operability is lowered.
The kinematic viscosity of the modified polydimethylsiloxane 2 can be measured in the same manner as the kinematic viscosity of the amino-modified silicone.

The modified polydimethylsiloxane 2 has 1 to 20 units represented by the above formulas (5), (7) and (9). Preferably it is 2-5. If it is in this range, the balance between the respective units will be improved, and the target compatibilizing ability will be good. When there are two or more units represented by the above formulas (5), (7), and (9), the values of xa, yb, za, mb, and na may be the same or different depending on each unit. Good.
The modified polydimethylsiloxane 2 may contain a unit represented by the following formula (10).

  In Formula (10), md is 0-3 and ye is 1-5.

(Combination 3)
The modified polydimethylsiloxane has 1 to 20 units represented by the above formulas (5) and (8), respectively, and preferably has a kinematic viscosity at 25 ° C. of 500 to 1500 mm ² / s (hereinafter, modified). Polydimethylsiloxane 3).
The alkyl chain of the modified polydimethylsiloxane 3 is well-familiar with fats and oils, and due to the effect of this site, the modified polydimethylsiloxane 3 is dissolved in both the amino-modified silicone and the aromatic ester compounds (I) and (II). Demonstrates solubilizing effect. This alkyl chain has xa = 7 to 15 in the above formula (5). Preferably, xa = 9-13. When xa is smaller than 7, the solubility in fats and oils is reduced, and when it is larger than 15, the stability is lowered when the oil composition is dispersed in water.

  The polyether chain of the modified polydimethylsiloxane 3 is familiar with water and has a function of stabilizing micelles when the oil composition is dispersed in water. The number of ethylene oxide and propylene oxide in the polyether chain is in the range of yc + yd = 5 to 15 in the above formula (8). Preferably, yc + yd = 8-12. When yc + yd is less than 5, the affinity with water is low and the stability of the emulsion is lowered. When yc + yd is greater than 15, the thermal stability is lowered. Also, there may be alkyl between the polyether chain and polydimethylsiloxane, and the range is mc = 0-3. Preferably, mc = 0. When mc exceeds 3, the dispersibility in water becomes low, and the stability of the emulsion decreases.

The modified polydimethylsiloxane 3 preferably has a kinematic viscosity at 25 ° C. of 500 to 1500 mm ² / s. More preferably, it is 800-1200 mm < ² > / s. When the kinematic viscosity is smaller than 500 mm ² / s, the molecular weight is inevitably small, and the polyether chain and the alkyl chain cannot be uniformly placed in the structure, and the thermal stability is lowered. Moreover, when kinematic viscosity is larger than 1500 mm < ² > / s, emulsification is difficult, stability of the emulsion obtained also falls, and also a substance with high viscosity in the drying process after giving an oil agent composition to a precursor fiber bundle Is deposited on the drying roll and the operability is lowered.
The kinematic viscosity of the modified polydimethylsiloxane 3 can be measured in the same manner as the kinematic viscosity of the amino-modified silicone.

  The modified polydimethylsiloxane 3 has 1 to 20 units represented by the above formulas (5) and (8). Preferably it is 2-5. If it is in this range, the balance between the respective units will be improved, and the target compatibilizing ability will be good. When there are two or more units represented by the above formulas (5) and (8), the values of xa, yc, yd and mc may be the same or different depending on each unit.

The oil composition of the present invention preferably contains a surfactant. By containing the surfactant, the oil agent composition can be easily dispersed in water.
As the surfactant, various known substances can be used, but nonionic surfactants are preferred.
Nonionic surfactants include, for example, higher alcohol ethylene oxide adducts, alkylphenol ethylene oxide adducts, aliphatic ethylene oxide adducts, polyhydric alcohol aliphatic ester ethylene oxide adducts, higher Polyethylene glycol-type nonionic surfactants such as alkylamine ethylene oxide adducts, aliphatic amide ethylene oxide adducts, fat and oil ethylene oxide adducts, polypropylene glycol ethylene oxide adducts; glycerol aliphatics Esters, aliphatic esters of pentaerythrol, aliphatic esters of sorbitol, aliphatic esters of sorbitan, aliphatic esters of sucrose, alkyl ethers of polyhydric alcohols, fatty acid amides of alkanolamines Polyhydric alcohol type non-io Sex surfactants, and the like.
These surfactants may be used alone or in combination of two or more.

  Among these, as the nonionic surfactant, a block copolymer type polyether composed of a propylene oxide (PO) unit having a structure represented by the following formula (4) and an ethylene oxide (EO) unit is preferable.

In formula (4), “x”, “y”, and “z” are each independently 1 to 200, preferably 10 to 100.
Further, the ratio (x + z: y) of “x” and “z” to “y” is preferably 90:10 to 50:50.

The block copolymer polyether preferably has a number average molecular weight of 2,000 to 10,000. When the number average molecular weight is within the above range, it is possible to have both thermal stability and water dispersibility required for an oil composition.
Furthermore, the block copolymer polyether preferably has a kinematic viscosity at 100 ° C. of 10 to 500 mm ² / s. If the kinematic viscosity is within the above range, the permeation of the oil composition to the inside of the fiber is prevented, and in the drying step after being applied to the precursor fiber bundle, the single fiber is fed to the conveying roller or the like due to the viscosity of the oil composition. Process failure such as wrapping around is less likely to occur.
The kinematic viscosity of the block copolymer type polyether can be measured in the same manner as the kinematic viscosity of the amino-modified silicone.

  10-30 mass% is preferable in 100 mass% of oil agent compositions, and, as for content of a block copolymerization type polyether, More preferably, it is 10-20 mass%. When the content of the block copolymer polyether is 10% by mass or more, it becomes easy to disperse other oil agent compositions in water, and the dispersion becomes stable. On the other hand, if the content of the block copolymer polyether is 30% by mass or less, an aqueous emulsified solution in which the oil agent composition is dispersed in water does not deteriorate without lowering the mechanical properties of the carbon fiber bundle. It is possible to suppress the occurrence of adhesion spots on the fiber bundle.

The oil agent composition of the present invention is charged for the purpose of improving operability and improving the stability and adhesion characteristics of the oil agent composition depending on the equipment and use environment for adhering to the precursor fiber bundle. You may contain additives, such as an inhibitor, antioxidant, and an antibacterial agent.
Moreover, when the oil agent composition of this invention contains an antibacterial agent, although mentioned later in detail, when disperse | distributing an oil agent composition to water and making it an oil agent processing liquid, the deterioration can also be prevented.

A known substance can be used as the antistatic agent. Antistatic agents are broadly classified into ionic types and nonionic types, and ionic types include anionic, cationic and amphoteric, and nonionic types include polyethylene glycol type and polyhydric alcohol type. From the viewpoint of antistatic, ionic type is preferable, among them aliphatic sulfonate, higher alcohol sulfate ester salt, higher alcohol ethylene oxide adduct sulfate ester, higher alcohol phosphate ester salt, higher alcohol ethylene oxide adduct sulfate phosphate ester salt, Quaternary ammonium salt type cationic surfactants, betaine type amphoteric surfactants, higher alcohol ethylene oxide adducts polyethylene glycol fatty acid esters, polyhydric alcohol fatty acid esters and the like are preferably used.
These antistatic agents may be used alone or in combination of two or more.

  1.0-5.0 mass% is preferable in 100 mass% of oil agent compositions, and, as for content of an antistatic agent, 1.0-3.0 mass% is more preferable. When the content of the antistatic agent is less than 1.0% by mass, it is difficult to sufficiently obtain the antistatic effect. As a result, the carbon fiber precursor acrylic fiber bundle is charged and spreads in the process after the oil agent composition adheres, particularly in the firing process, and merges with adjacent fiber bundles or winds around a roll for transportation. May happen. On the other hand, when the content of the antistatic agent exceeds 5.0% by mass, the aqueous emulsified solution at the time of applying the oil composition to the precursor fiber bundle is likely to foam, or the antistatic agent is decomposed in the firing step, In some cases, the decomposition product accumulates in the furnace in the firing process, which causes a process failure.

Various known substances can be used as the antioxidant, and phenol-based and sulfur-based antioxidants are suitable.
Specific examples of the phenolic antioxidant include 2,6-di-t-butyl-p-cresol, 4,4′-butylidenebis- (6-t-butyl-3-methylphenol), 2,2′- Methylene bis- (4-methyl-6-tert-butylphenol), 2,2′-methylene bis- (4-ethyl-6-tert-butylphenol), 2,6-di-tert-butyl-4-ethylphenol, 1, 1,3-tris (2-methyl-4-hydroxy-5-t-butylphenyl) butane, n-octadecyl-3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate, tetrakis [methylene -3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate] methane, triethylene glycol bis [3- (3-tert-butyl-4-hydroxy-5-methyl) Eniru) propionate], tris (3,5-di -t- butyl-4-hydroxybenzyl) isocyanurate.
Specific examples of the sulfur-based antioxidant include dilauryl thiodipropionate, distearyl thiodipropionate, dimyristyl thiodipropionate, and ditridecyl thiodipropionate.
These antioxidants may be used alone or in combination of two or more.

  The antioxidant preferably acts on both the aromatic ester compounds (I) and (II) and the amino-modified silicone. Among the above, tetrakis [methylene-3- (3,5-di- t-butyl-4-hydroxyphenyl) propionate] methane and triethylene glycol bis [3- (3-t-butyl-4-hydroxy-5-methylphenyl) propionate] are preferred.

  0.5-3.0 mass% is preferable in 100 mass% of oil agent compositions, and, as for content of antioxidant, 0.5-2.0 mass% is more preferable. When the content of the antioxidant is less than 0.5% by mass, it is difficult to sufficiently obtain the antioxidant effect. Therefore, when the oil agent composition contains amino-modified silicone, when the amino-modified silicone in the oil agent composition attached to the precursor fiber bundle in the process of producing the precursor fiber bundle is heated by a hot roll or the like to become a resin There is. When the amino-modified silicone is converted into a resin, it is likely to be deposited on the surface of a roll or the like, and the precursor fiber bundle is wound to cause a process failure, resulting in a decrease in operability. On the other hand, when the content of the antioxidant exceeds 3.0% by mass, the antioxidant is difficult to uniformly disperse in the oil composition.

A known substance can be used as the antibacterial agent. For example, 5-chloro-2-methyl-4-isothiazolin-3-one, 2-methyl-4-isothiazolin-3-one, 1,2-benzisothiazolin-3-one, Nn-butyl-1,2- Benzisothiazolin-3-one, 2-n-octyl-4-isothiazolin-3-one, 4,5-dichloro-2-n-octyl-4-isothiazolin-3-one, 2-methyl-4,5-trimethylene Isothiazoline-based compounds such as -4-isothiazolin-3-one; 2-bromo-2-nitropropane-1,3-diol, 2,2-dibromo-2-nitroethanol, 2,2-dibromo-3-nitrilopropion Organic bromine compounds such as amide, 1,2-dibromo-2,4-dicyanobutane, hexabromodimethylsulfone; formaldehyde, glutaral Aldehyde compounds such as hydride and o-phthalaldehyde; 3-methyl-4-isopropylphenol, 2-isopropyl-5-methylphenol, o-phenylphenol, 4-chloro-3,5-dimethylphenol, 2,4, Phenolic compounds such as 4′-trichloro-2′-hydroxydiphenyl ether and 4,4′-dichloro-2′-hydroxydiphenyl ether; 8-oxyquinoline, 2,3,5,6-tetrachloro-4- (methylsulfonyl) ) Pyridine compounds such as pyridine, bis (2-pyridylthio-1-oxide) zinc, (2-pyridylthio-1-oxide) sodium; N, N ′, N ″ -trishydroxyethylhexahydro-S-triazine, Triazines such as N, N ′, N ″ -trisethylhexahydro-S-triazine Compounds; Anilide compounds such as 3,4,4′-trichlorocarbanilide and 3-trifluoromethyl-4,4′-dichlorocarbanilide; Thiazoles such as 2- (4-thiocyanomethylthio) benzimidazole Compound; Imidazole compounds such as 2- (4-thiazolyl) -benzimidazole and methyl 2-benzimidazolecarbamate; 1-[[2- (2,4-dichlorophenyl) -4-n-propyl-1,3- Dioxolan-2-yl] methyl] -1H-1,2,4-triazole, (RS) -2- (2,4-dichlorophenyl) -1- (1H-1,2,4-triazol-1-yl) hexane -2-ol, α- [2- (4-chlorophenyl) ethyl] -α- (1,1-dimethylethyl) -1H-1,2,4-triazole-1 Ethanol, α- (chlorophenyl) -α- (1-cyclopropylethyl) -1H-1,2,4-triazole-1-ethanol, 1-[[2- (2,4-dichlorophenyl) -1,3- Triazole compounds such as dioxolan-2-yl] methyl-1H-1,2,4-triazole; 2,4,5,6-tetrachloroisophthalonitrile, 5-chloro-2,4,6-trifluoroisothiol Nitrile compounds such as talonitrile; Organochlorine compounds such as 4,5-dichloro-1,2-dithiolane-3-one and 3,3,4,4-tetrachlorotetrahydrothiophene-1,1-dioxide; 3 -Iodo-2-propynylbutyl carbamate, diiodomethyl-p-tolylsulfone, 2,3,3-triiodoallyl alcohol, etc. Thing, and the like. Of these, isothiazoline antibacterial agents are preferred.
These antibacterial agents may be used alone or in combination of two or more.

  The content of the antibacterial agent is preferably 100 to 10,000 ppm and more preferably 1000 to 5000 ppm in 100% by mass of the oil composition. When the content of the antibacterial agent is less than 100 ppm, it is difficult to sufficiently obtain the antibacterial effect. On the other hand, when the content of the antibacterial agent exceeds 10,000 ppm, the antibacterial agent or the decomposed product of the antibacterial agent may damage the fiber bundle in the firing step, and the quality of the obtained carbon fiber bundle may be deteriorated.

The oil agent composition of the present invention described above contains two types of aromatic ester compounds that exhibit the necessary thermal behavior in measurement under certain specific conditions, so that the flameproofing step can be achieved even if the proportion of the silicone component is reduced. It is possible to effectively prevent fusion between the single fibers while maintaining the convergence property. In addition, since the ratio of the silicone component can be reduced, the generation of silicon compounds can be reduced, and as a result, operability deterioration and process failure are reduced, and industrial productivity can be maintained. Therefore, it is possible to obtain a carbon fiber bundle having excellent mechanical properties by a stable continuous operation.
Thus, according to the oil agent composition of the present invention, it is possible to solve both of the problems of conventional oil agent compositions mainly composed of silicone and the problem of oil agent compositions having a reduced silicone content.

<Second Embodiment>
The oil agent composition of the present invention contains an aromatic ester component and a silicone component.
The aromatic ester component is effective for preventing fusion and imparting convergence in the flame resistance process of the carbon fiber precursor acrylic fiber bundle described later.
In the present invention, as the aromatic ester component, the aromatic ester compound having the structure represented by the above formula (1) and the aromatic ester compound having the structure represented by the above formula (2) explained in the first embodiment. Use together.

The aromatic ester compound having the structure represented by the above formula (1) has high heat resistance and is effective in maintaining the bundling property of the carbon fiber precursor acrylic fiber bundle until the flameproofing process is completed. There is work to improve. However, since it remains in the fiber bundle until the carbonization step, the mechanical properties of the carbon fiber may be lowered.
On the other hand, the aromatic ester compound having the structure represented by the above formula (2) is easily decomposed or scattered in the flameproofing process and hardly remains on the surface of the fiber bundle, so that the mechanical properties of the carbon fiber bundle are maintained in high quality. It becomes possible. However, since the heat resistance is slightly inferior, it is difficult for the carbon fiber precursor acrylic fiber bundle to maintain the bundling property in the flameproofing process with this material alone.
Therefore, in the present invention, it is important to use together the aromatic ester compound having the structure represented by the above formula (1) and the aromatic ester compound having the structure represented by the above formula (2).

  Content of the aromatic ester compound of the structure shown by said Formula (1) is 10-40 mass% in 100 mass% of oil agent compositions, and 10-30 mass% is preferable. If content is 10 mass% or more, while being able to provide sufficient convergence to a carbon fiber precursor acrylic fiber bundle, operativity improves. On the other hand, if the content is 40% by mass or less, a carbon fiber bundle having good mechanical properties can be obtained.

  Content of the aromatic ester compound of the structure shown by said Formula (2) is 10-40 mass% in 100 mass% of oil agent compositions, and 20-40 mass% is preferable. If the content is 10% by mass or more, a carbon fiber bundle having good mechanical properties can be obtained. On the other hand, if the content is 40% by mass or less, sufficient convergence can be imparted to the carbon fiber precursor acrylic fiber bundle.

As the silicone component, the amino-modified silicone having the structure represented by the above formula (3) described in the first embodiment is used. The amino-modified silicone preferably has a kinematic viscosity at 25 ° C. is 50 to 500 mm ² / s, more preferably 50 to 300 mm ² / s. Moreover, it is preferable that an amino equivalent is 2000-6000 g / mol, and it is more preferable that it is 4000-6000 g / mol.

  The content of the amino-modified silicone having the structure represented by the above formula (3) is 1 to 10% by mass, preferably 5 to 10% by mass, in 100% by mass of the oil composition. When the content of the amino-modified silicone is less than 1% by mass, it is difficult to completely prevent fusion between single fibers, and it becomes difficult to obtain a carbon fiber bundle excellent in mechanical properties. On the other hand, when the content of amino-modified silicone exceeds 10% by mass, there is a problem that industrial productivity is lowered due to a process failure caused by a silicon compound generated in the flameproofing process.

It is preferable that the oil agent composition of this invention contains 1-10 mass% of compatibilizers which have a polydimethylsiloxane structure, More preferably, it is 2-5 mass%.
Examples of the compatibilizer include the compatibilizer described in the first embodiment.

Moreover, it is preferable that the oil agent composition of this invention contains a nonionic surfactant as surfactant. Examples of the nonionic surfactant include the surfactant described in the first embodiment, and among them, a propylene oxide (PO) unit having a structure represented by the above formula (4) and an ethylene oxide (EO) unit. The block copolymer type polyether consisting of is preferable.
10-30 mass% is preferable in 100 mass% of oil agent compositions, and, as for content of a block copolymerization type polyether, More preferably, it is 10-20 mass%.

In addition, the oil composition of the present invention is intended to improve operability or improve the stability and adhesion characteristics of the oil composition depending on the equipment and use environment for adhering to the precursor fiber bundle. In addition, additives such as an antistatic agent, an antioxidant, and an antibacterial agent may be contained.
Examples of the antistatic agent, antioxidant, and antibacterial agent include the antistatic agent, antioxidant, and antibacterial agent described in the first embodiment. These contents are the same as those in the first embodiment.

The oil agent composition of the present invention described above can contain two kinds of aromatic ester compounds having a specific structure and a specific amount of amino-modified silicone having a specific structure, thereby reducing the ratio of the silicone component. The fusion between the single fibers can be effectively prevented while maintaining the convergence in the flameproofing process. In addition, since the ratio of the silicone component can be reduced, the generation of silicon compounds can be reduced, and as a result, operability deterioration and process failure are reduced, and industrial productivity can be maintained. Therefore, it is possible to obtain a carbon fiber bundle having excellent mechanical properties by a stable continuous operation.
Thus, according to the oil agent composition of the present invention, it is possible to solve both of the problems of conventional oil agent compositions mainly composed of silicone and the problem of oil agent compositions having a reduced silicone content.

[Method for producing carbon fiber precursor acrylic fiber bundle]
In the method for producing the carbon fiber precursor acrylic fiber bundle of the present invention, the above-described oil agent composition of the present invention was subjected to a step (oil agent treatment) for imparting the precursor fiber bundle in a water swollen state, and then the oil agent treatment was performed. A step of drying and densifying the precursor fiber bundle is performed.
Hereinafter, each process in the manufacturing method of a carbon fiber precursor acrylic fiber bundle is demonstrated in detail.

(spinning)
As the precursor fiber bundle before the oil agent treatment used in the present invention, an acrylic fiber bundle spun by a known technique can be used. Specifically, an acrylic fiber bundle obtained by spinning an acrylonitrile polymer can be used.
The acrylonitrile-based polymer is a polymer obtained by polymerizing acrylonitrile as a main monomer. The acrylonitrile-based polymer may be a homopolymer obtained only from acrylonitrile, or may be an acrylonitrile-based copolymer in which other monomers are used in addition to the main component acrylonitrile.

  The content of the acrylonitrile unit in the acrylonitrile-based copolymer is 96.0 to 98.5% by mass to prevent heat fusion of the fiber in the firing step, heat resistance of the copolymer, stability of the spinning dope, And more preferable from the viewpoint of the quality of the carbon fiber. When the acrylonitrile unit is 96% by mass or more, it is preferable because excellent quality and performance of the carbon fiber can be maintained without inducing the thermal fusion of the fiber in the firing step when converting to the carbon fiber. In addition, the heat resistance of the copolymer itself is not lowered, and adhesion between single fibers can be avoided in spinning the precursor fiber or in a process such as fiber drying or drawing with a heating roller or pressurized steam. On the other hand, when the acrylonitrile unit is 98.5% by mass or less, the solubility in the solvent is not lowered, the stability of the spinning stock solution can be maintained, and the precipitation solidification property of the copolymer is not increased. This is preferable because stable production of body fibers is possible.

As a monomer other than acrylonitrile in the case of using a copolymer, it can be appropriately selected from vinyl monomers copolymerizable with acrylonitrile, and acrylic acid or methacrylic acid having an action of promoting flameproofing reaction. , Itaconic acid, or an alkali metal salt or ammonium salt thereof, or a monomer such as acrylamide is preferable because flame resistance can be promoted.
As the vinyl monomer copolymerizable with acrylonitrile, carboxyl group-containing vinyl monomers such as acrylic acid, methacrylic acid and itaconic acid are more preferable. The content of the carboxyl group-containing vinyl monomer unit in the acrylonitrile copolymer is preferably 0.5 to 2.0% by mass.
These vinyl monomers may be used alone or in combination of two or more.

  At the time of spinning, the acrylonitrile polymer is dissolved in a solvent to form a spinning dope. The solvent used here can be appropriately selected from known solvents such as organic solvents such as dimethylacetamide, dimethylsulfoxide, dimethylformamide, and aqueous inorganic compounds such as zinc chloride and sodium thiocyanate. Among these, dimethylacetamide, dimethylsulfoxide and dimethylformamide having a high coagulation rate are preferable from the viewpoint of improving productivity, and dimethylacetamide is more preferable.

In order to obtain a dense coagulated yarn, it is preferable to adjust the spinning dope so that the polymer concentration of the spinning dope becomes a certain level or more. Specifically, the polymer concentration in the spinning dope is preferably adjusted to 17% by mass or more, more preferably 19% by mass or more.
Since the spinning dope requires proper viscosity and fluidity, the polymer concentration is preferably within a range not exceeding 25% by mass.

  Spinning methods are known, such as a wet spinning method in which the above-mentioned spinning solution is directly spun into a coagulation bath, a dry spinning method in which the solution is coagulated in the air, and a dry and wet spinning method in which the solution is once coagulated in the air and then coagulated in the bath. A spinning method can be appropriately employed, but a wet spinning method or a dry-wet spinning method is preferable for obtaining a carbon fiber bundle having higher performance.

The spinning shaping by the wet spinning method or the dry and wet spinning method can be performed by spinning the spinning solution into a coagulation bath from a nozzle having a hole having a circular cross section. As the coagulation bath, it is preferable to use an aqueous solution containing a solvent used in the spinning dope from the viewpoint of easy solvent recovery.
When an aqueous solution containing a solvent is used as the coagulation bath, the solvent concentration in the aqueous solution is such that there is no void and a dense structure can be formed to obtain a high-performance carbon fiber bundle, and stretchability can be ensured and productivity is excellent. From 50 to 85 mass%, the temperature of the coagulation bath is preferably 10 to 60 ° C.

(Extension process)
A coagulated yarn obtained by dissolving a polymer or copolymer in a solvent and discharging into a coagulation bath as a spinning dope into a fiber can be stretched in a coagulation bath or in a stretching bath. . Alternatively, it may be partially stretched in the air and then stretched in a bath, and the precursor fiber bundle in a water-swelled state can be obtained by washing with water before or after stretching or simultaneously with stretching.
Stretching in the bath is usually carried out in a water bath at 50 to 98 ° C. by dividing it into multiple stages once or twice, and the coagulated yarn so that the total ratio of in-air stretching and stretching in the bath becomes 2 to 10 times. It is preferable from the viewpoint of the performance of the obtained carbon fiber bundle.

(Oil treatment)
For application of the oil composition to the precursor fiber bundle, an aqueous emulsion solution (emulsion) in which the oil composition of the present invention is dispersed in water to form micelles having an average particle size of 0.01 to 0.50 μm. Is used.
If the average particle diameter of the micelle is within the above range, the oil agent composition can be uniformly applied to the surface of the precursor fiber bundle.
In addition, the average particle diameter of the micelle in the water-based emulsified solution can be measured using a laser diffraction / scattering particle size distribution measuring device (trade name: LA-910, manufactured by Horiba, Ltd.).

The aqueous emulsified solution can be prepared, for example, as follows. That is, while stirring an amino-modified silicone and a nonionic surfactant, an aromatic ester compound is added and dispersed therein, and water is added to obtain an aqueous emulsion solution in which the oil composition is dispersed in water. .
When the antioxidant is contained, it is preferable to dissolve the antioxidant in amino-modified silicone in advance. When an antistatic agent and / or an antibacterial agent is contained, it is preferable to add and agitate after adding water to obtain an aqueous emulsion solution.
Each component can be mixed or dispersed in water using a propeller, a homomixer, a homogenizer or the like. In particular, it is preferable to use an ultrahigh pressure homogenizer that can pressurize to 150 MPa or more.

  2-40 mass% is preferable, as for the density | concentration of the oil agent composition in a water-system emulsified solution, 10-30 mass% is more preferable, and 20-30 mass% is especially preferable. When the concentration of the oil agent composition is less than 2% by mass, it is difficult to apply a necessary amount of the oil agent composition to the precursor fiber bundle in the water-swelled state. On the other hand, when the concentration of the oil composition exceeds 40% by mass, the aqueous emulsified solution becomes unstable and the emulsion is easily broken.

When the oil agent composition of the present invention is applied to a precursor fiber bundle in a water-swollen state, it is preferable to add ion-exchanged water to the aqueous emulsified solution and dilute to a predetermined concentration.
The “predetermined concentration” is adjusted according to the state of the precursor fiber bundle during the oil agent treatment. Hereinafter, the dispersion having a predetermined concentration is referred to as “oil treatment liquid”.

Application of the oil composition to the precursor fiber bundle can be performed by applying an aqueous emulsion solution of the oil composition to the precursor fiber bundle in the water-swollen state after stretching in the bath described above.
When washing is performed after stretching in the bath, an aqueous emulsified solution of the oil composition can also be applied to the fiber swollen fiber bundle obtained after stretching and washing in the bath.

As a method for imparting the oil agent composition to the precursor fiber bundle in a water-swelled state, an oil agent treatment liquid is prepared by adding ion-exchanged water to a water-based emulsified solution in which the oil agent composition is dispersed in water and diluting to a predetermined concentration. Thereafter, a technique of attaching the precursor fiber bundle in a water-swollen state can be used.
As a method of attaching the oil treatment liquid to the precursor fiber bundle in the water swelling state, the lower part of the roller is immersed in the oil treatment liquid, and the precursor fiber bundle is brought into contact with the upper part of the roller. The guide adhesion method in which the oil treatment liquid is discharged from the guide and the precursor fiber bundle is brought into contact with the guide surface, the spray adhesion method in which a predetermined amount of the oil treatment liquid is sprayed onto the precursor fiber bundle from the nozzle, and the oil treatment liquid A known method such as a dip attachment method in which the precursor fiber bundle is dipped in and then squeezed with a roller or the like to remove the excess oil agent treatment liquid can be used.
Among these methods, from the viewpoint of uniform adhesion, the dip adhesion method in which the oil agent treatment liquid is sufficiently infiltrated into the precursor fiber bundle and the excess treatment liquid is removed is preferable. In order to adhere more uniformly, it is also effective to apply the oil agent application step in two or more stages and repeatedly apply it.

(Drying densification process)
The precursor fiber bundle to which the aqueous emulsified solution is applied is dried and densified in the subsequent drying step.
The temperature for drying and densification needs to be performed at a temperature exceeding the glass transition temperature of the fiber, but may be substantially different depending on the dry state from the water-containing state. For example, it is preferable to perform dense drying by a method using a heating roller having a temperature of about 100 to 200 ° C. At this time, the number of heating rollers may be one or plural.

(Secondary stretching process)
It is preferable that the densely dried precursor fiber bundle is further subjected to a stretching treatment. As the stretching method, a known stretching technique such as steam stretching using pressurized or atmospheric steam, hot plate stretching, stretching using a heating roller, or the like can be used.
Among the above, a stretching process using a heating roller capable of stable uniform stretching is preferable. By the stretching treatment, the denseness and orientation degree of the obtained carbon fiber precursor acrylic fiber bundle can be further increased. In particular, the density of the obtained carbon fiber precursor acrylic fiber bundle is increased by 1.1 to 4.0 times by changing the roller speed while conveying the densely dried precursor fiber bundle with a heating roller. And the degree of orientation can be further improved.
The temperature of the heating roller is preferably about 150 to 200 ° C. If the temperature is lower than 150 ° C., plasticization becomes incomplete, fluff or the like occurs when stretched, fiber bundles are wound in the subsequent carbonization process, and process failure may be caused due to process failure. is there. On the other hand, when temperature exceeds 200 degreeC, an oxidation reaction, a decomposition reaction, etc. are started and the quality of the carbon fiber bundle obtained by baking a carbon fiber precursor acrylic fiber bundle may be reduced.

The carbon fiber precursor acrylic fiber bundle obtained through the dry densification treatment and the secondary stretching treatment is passed through a roll at room temperature, cooled to room temperature, and then wound around a bobbin with a winder or transferred into a can. Is done.
And a carbon fiber precursor acrylic fiber bundle is moved to a baking process, and becomes a carbon fiber bundle.

[Carbon fiber precursor acrylic fiber bundle]
In the carbon fiber precursor acrylic fiber bundle of the present invention thus obtained, the oil agent composition of the present invention is preferably adhered to 0.1 to 2.0% by mass relative to the dry fiber mass, more preferably. Is 0.5 to 1.5 mass%. When the adhesion amount of the oil composition is less than 0.1% by mass, it may be difficult to sufficiently develop the original function of the oil composition. On the other hand, when the adhesion amount of the oil agent composition exceeds 2.0% by mass, the excessively adhered oil agent composition may be polymerized in the firing step, which may cause adhesion between the single fibers.
The “dry fiber mass” refers to the dry fiber mass of the precursor fiber bundle after the dry densification treatment.

The adhesion amount of the oil composition is determined as follows.
In accordance with the Soxhlet extraction method using methyl ethyl ketone, the oil agent composition is extracted by immersing the carbon fiber precursor acrylic fiber bundle in 90 ° C. methyl ethyl ketone for 8 hours, and the mass w ₁ of the carbon fiber precursor acrylic fiber bundle before extraction, and after extraction of the mass w ₂ of the carbon fiber precursor acrylic fiber bundle were measured to determine the amount of adhered oil agent composition by the following formula (iii).
Adhering amount [mass%] of oil agent composition = (w ₁ −w ₂ ) / w ₂ × 100 (iii)

As described above, since the method for producing a carbon fiber precursor acrylic fiber bundle of the present invention uses the oil composition of the present invention, a carbon fiber precursor acrylic fiber bundle excellent in convergence can be produced with high productivity.
In addition, the carbon fiber precursor acrylic fiber bundle of the present invention is excellent in convergence because the oil agent composition of the present invention is uniformly attached. Furthermore, since fusion between single fibers can be prevented in the firing process, and generation of silicon compounds and scattering of silicone decomposition products can be suppressed, the operability and process passability are significantly improved.
In addition, the carbon fiber bundle obtained by firing the carbon fiber precursor acrylic fiber bundle of the present invention is excellent in mechanical properties, high quality, and reinforced fiber used in fiber reinforced resin composite materials used in various structural materials. It is suitable as.

Hereinafter, the present invention will be specifically described with reference to examples. However, the present invention is not limited to these.
Each component used in this example, various measurement methods, and evaluation methods are as follows.

[component]
<Aromatic ester compound>
A-1: polyoxyethylene bisphenol A dilaurate with 95% by mass of r ^{1 and} 7% by mass of r ² (trade name: EXCEPARL BP-DL, manufactured by Kao Corporation)
A-2: triisodecyl trimellitate with 75% by mass of r ^{1 and 1} % by mass of r ² (trade name: Trimex T-10, manufactured by Kao Corporation)
A-3: pentaerythritol tetrastearate with r ¹ of 88% by mass and r ² of 9% by mass (manufactured by NOF Corporation, product name: Unistar H-476)

Incidentally, r ¹ and r ² of the aromatic ester compound was measured as follows.
Using a thermal mass measuring device (trade name: Micro Thermogravimetric Measuring Device TGA-50, manufactured by Shimadzu Corporation) capable of circulating gas, about 50 mg of aromatic ester was set in the device at room temperature, and the initial mass at this time Was _designated as W0. Thereafter, _{N 2} gas (99.9999% purity) was heated at a flow rate of 200ml / min at a heating rate of 10 ° C. / min to 0.99 ° C. while circulating, _{N 2} and water vapor 4 at 0.99 ° C.: 1 (volume ratio ) Was switched to a mixed gas line. Furthermore, the mass when heated to 300 ° C. at a temperature increase rate of 10 ° C./min was defined as W ₁ . Thereafter, the flow gas line was returned to N ₂ and the mass when heated to 500 ° C. at a rate of temperature increase of 10 ° C./min was defined as W ₂ . Each mass _{W 0,} W 1, _{W 2} was measured, the following formula (i), was determined ^{r 1} and ^{r 2} by (ii).
r ¹ [mass%] = (W ₁ / W ₀ ) × 100 (i)
r ² [% by mass] = (W ₂ / W ₀ ) × 100 (ii)

<Amino-modified silicone>
B-1: Amino-modified silicone having a structure of the above formula (3) and a kinematic viscosity at 25 ° C. of 90 mm ² / s and an amino equivalent of 2500 g / mol (manufactured by Gelest, Inc., trade name: AMS-132)
B-2: Amino-modified silicone having a structure of the above formula (3) and a kinematic viscosity at 25 ° C. of 110 mm ² / s and an amino equivalent of 5000 g / mol (manufactured by Shin-Etsu Chemical Co., Ltd., trade name: KF-868) )
B-3: Amino-modified silicone having a structure of the above formula (3) and a kinematic viscosity at 25 ° C. of 450 mm ² / s and an amino equivalent of 5700 g / mol (manufactured by Shin-Etsu Chemical Co., Ltd., trade name: KF-8008) )
B-4: Amino-modified silicone having primary and secondary amines in the side chain with a kinematic viscosity at 25 ° C. of 10,000 mm ² / s and an amino equivalent of 7000 g / mol (Momentive Performance Materials Japan Joint (Product name: TSF4707)

<Surfactant>
C-1: PO / EO block copolymerized polyether having the structure of the above formula (4) and x = 75, y = 30, z = 75 (trade name: Pluronic PE6800, manufactured by BASF Japan Ltd.)
C-2: PO / EO block copolymerized polyether having a structure of the above formula (4) and x = 10, y = 20, z = 10 (trade name: Adeka Pluronic L-44, manufactured by ADEKA Corporation) )
C-3: Nonaethylene glycol dodecyl ether (Nikko Chemicals Corporation, trade name: NIKKOL BL-9EX)

<Compatibilizer>
D-1: Lauryl PEG-9 polydimethylsiloxyethyl dimethicone consisting of units of the above formulas (5), (6) and (9) (manufactured by Shin-Etsu Chemical Co., Ltd., trade name: KF-6038)
D-2: Lauryl polyglyceryl-3 polydimethylsiloxyethyl dimethicone (made by Shin-Etsu Chemical Co., Ltd., trade name: KF-6105) comprising the units of the above formulas (5), (7) and (9)
D-3: a modified silicone having a random copolymer side chain and an alkyl side chain of ethylene oxide and propylene oxide, comprising units of the above formulas (5) and (8) (made by Momentive Performance Materials Japan GK) (Product name: TSF4450)

[Measurement / Evaluation]
<Measurement of oil adhesion amount>
After drying the carbon fiber precursor acrylic fiber bundle at 105 ° C. for 1 hour, the oil composition adhered by soaking in 90 ° C. methyl ethyl ketone for 8 hours was extracted with a solvent in accordance with a Soxhlet extraction method using methyl ethyl ketone. The mass w ₁ of the carbon fiber precursor acrylic fiber bundle before extraction and the mass w ₂ of the carbon fiber precursor acrylic fiber bundle after extraction were measured, respectively, and the adhesion amount of the oil composition was determined by the following formula (iii). .
Adhering amount [mass%] of oil agent composition = (w ₁ −w ₂ ) / w ₂ × 100 (iii)

<Evaluation of operability>
When the carbon fiber precursor acrylic fiber bundle was continuously produced for 24 hours, the operability was evaluated based on the frequency with which the single yarn was wound around and removed from the transport roll. The evaluation criteria were as follows.
○: Number of removals (times / 24 hours) ≦ 1
Δ: Removal frequency (times / 24 hours) 2 to 5
×: Number of removals (times / 24 hours)> 5

<Evaluation of flame resistance and convergence>
The width of the flameproof fiber bundle on the roll immediately after the flameproofing process was measured with a digital caliper and subjected to evaluation.

<Measurement of the number of fusions between single fibers>
A carbon fiber bundle is cut to a length of 3 mm, dispersed in acetone, stirred for 10 minutes, and the total number of single fibers and the number of single fibers fused together (number of fusions) are calculated. The number of fusions per 100 pieces was calculated and evaluated according to the following evaluation criteria.
○: Number of fusions (pieces / 100 pieces) ≦ 1
×: Number of fusions (pieces / 100 pieces)> 1

<Measurement of strand strength>
Start production of carbon fiber bundles, sample carbon fiber bundles in a steady state, and measure strand strength of carbon fiber bundles according to the epoxy resin impregnated strand method specified in JIS-R-7608 did. The number of measurements was 10 times, and the average value was used as an evaluation target.

<Measurement of Si scattering amount>
The measurement of the amount of silica compound scattering from the silicone compound is calculated from the difference between the silicon (Si) content (A ₁ ) of the carbon fiber precursor acrylic fiber bundle and the Si content (A ₂ ) of the flameproof fiber bundle. The change in the amount of Si to be used was taken as the amount of Si scattering and used as an evaluation index.
Specifically, 50 mg of a sample obtained by finely pulverizing the carbon fiber precursor acrylic fiber bundle and the flameproof fiber bundle with a scissors was weighed into a sealed crucible, and 0.25 g each of powdered NaOH and KOH were added to the muffle furnace. And then thermally decomposed at 210 ° C. for 150 minutes. This was dissolved in distilled water and a constant volume of 100 mL was used as a measurement sample, and the Si content of each measurement sample was determined with an ICP emission analyzer (manufactured by Thermo Electron Co., Ltd., device name: IRIS Advantage AP). The amount of Si scattering was calculated from (iv).
Si scattering amount [mg / kg] = A ₁ −A ₂ (iv)

[Example 1]
<Preparation of aqueous emulsion solution of oil agent composition>
The aromatic ester compound was added to the amino-modified silicone while mixing and stirring the surfactant, and ion-exchanged water was further added so that the concentration of the oil composition was 30% by mass, followed by emulsification with a homomixer. The average particle size of the micelles in this state was measured using a laser diffraction / scattering particle size distribution measuring device (manufactured by Horiba, Ltd., device name: LA-910), and was about 3 μm.
Then, it further disperse | distributed until the average particle diameter of the micelle became 0.3 micrometer or less with the high voltage | pressure homogenizer, and obtained the water-system emulsified solution (emulsion) of the oil agent composition.
Table 1 shows the types and amounts (% by mass) of the components in the oil composition.

<Manufacture of carbon fiber precursor acrylic fiber bundle>
A precursor fiber bundle to which the oil agent composition was adhered was prepared by the following method. Acrylonitrile copolymer (composition ratio: acrylonitrile / acrylamide / methacrylic acid = 96.5 / 2.7 / 0.8 (mass ratio)) is dissolved in dimethylacetamide to prepare a spinning dope, with a concentration of 60% by mass, It was discharged from a spinning nozzle having a pore diameter (diameter) of 50 μm and a pore number of 50000 into a coagulation bath filled with a dimethylacetamide aqueous solution at a temperature of 35 ° C. to obtain a coagulated yarn. The coagulated yarn was desolvated in a water washing tank and stretched 5.5 times to obtain a precursor fiber bundle in a water swollen state.
A water-based emulsified solution of the oil agent composition obtained above was diluted with ion-exchanged water, and water was added to the oil agent treatment tank filled with the oil agent treatment liquid adjusted so that the concentration of the oil agent composition was 1.7% by mass. A swollen precursor fiber bundle was guided to give an aqueous emulsion solution.
Thereafter, the precursor fiber bundle to which the aqueous emulsified solution is applied is dried and densified with a roll having a surface temperature of 180 ° C., and then stretched 1.5 times using a roll having a surface temperature of 190 ° C. Got.
The oil agent adhesion amount of the obtained carbon fiber precursor acrylic fiber bundle was measured, and the operability during production was evaluated. The results are shown in Table 1.

<Manufacture of carbon fiber bundles>
The obtained carbon fiber precursor acrylic fiber bundle was passed through a flame-proofing furnace having a temperature gradient of 220 to 260 ° C. to make the flame-resistant fiber bundle. The convergence of the obtained flame resistant fiber bundle was evaluated, and the amount of Si scattering in the flame resistance process was measured. The results are shown in Table 1.
Subsequently, the flame-resistant fiber bundle was baked in a carbonization furnace having a temperature gradient of 400 to 1400 ° C. in a nitrogen atmosphere to obtain a carbon fiber bundle. The number of fusions between single fibers and the strand strength of the obtained carbon fiber bundle were measured. The results are shown in Table 1.

[Examples 2 to 10]
A water-based emulsified solution of the oil agent composition was prepared in the same manner as in Example 1 except that the types and blending amounts of the components constituting the oil agent composition were changed as shown in Table 1, and the carbon fiber precursor acrylic fiber bundle was prepared. And carbon fiber bundles were manufactured, and each measurement and evaluation was performed. The results are shown in Table 1.
In Examples 8 to 10, the compatibilizer was dispersed in amino-modified silicone in advance, and then an aqueous emulsion solution of the oil agent composition was prepared in the same manner as in Example 1.

[Comparative Examples 1 to 7]
A water-based emulsified solution of the oil agent composition was prepared in the same manner as in Example 1 except that the types and blending amounts of the components constituting the oil agent composition were changed as shown in Table 1, and the carbon fiber precursor acrylic fiber bundle was prepared. And carbon fiber bundles were manufactured, and each measurement and evaluation was performed. The results are shown in Table 1.

As is clear from Table 1, in the case of each example, the amount of oil agent adhered was an appropriate amount. In addition, the operability in the production process of the carbon fiber precursor acrylic fiber bundle was good.
Moreover, the convergence after the flameproofing process in each Example was as favorable as 19-22 mm. Furthermore, the amount of Si scattered in the flameproofing process was small, and the operability in the firing process was good.

The carbon fiber bundles obtained in each example had substantially no number of fusions between single fibers, showed a high strand strength, and were excellent in mechanical properties. In particular, the content of polyoxyethylene bisphenol A dilaurate (A-1) is less than the content of triisodecyl trimellitate (A-2), and the content of amino-modified silicone is 5 to 10% by mass Examples 2, 7, 8, 9, and 10 showed higher strand strength values compared to the other examples.
In Examples 2, 3, and 7, the content of amino-modified silicone was 10% by mass, and in Examples 8, 9, and 10, modified polydimethylsiloxane was used as a compatibilizing agent. Although the amount of Si scattering in the flameproofing process was larger than that in each of the other examples, it was not a problem in terms of industrial continuous operation.

On the other hand, in the case of Comparative Example 1 in which only pentaerythritol tetrastearate (A-3) was used as the aromatic ester component, the operability was slightly poor despite the fact that the oil agent adhesion amount was appropriate, and the carbon fiber precursor. In continuous production of acrylic fiber bundles for 24 hours, the single yarn was wound around the transport roll several times. Furthermore, the flame resistance and sizing properties were also poor, and the obtained carbon fiber bundle was confirmed to have many fusions, and the strand strength was lower than in each example.
In Comparative Example 2 where only pentaerythritol tetrastearate (A-3) is used as an aromatic ester component, no amino-modified silicone is contained, and no PO / EO block copolymer polyether is contained, an amino-modified silicone is contained. Therefore, the amount of Si scattering in the flameproofing process was substantially absent, but all other evaluation items were significantly inferior to those of the examples.

  In Comparative Example 3 in which polyoxyethylene bisphenol A dilaurate (A-1) and pentaerythritol tetrastearate (A-3) were used as aromatic ester components, each of the operations was performed in terms of operability, flameproofing convergence, and Si scattering amount. Although it was the same as the example, the carbon fiber bundle had a large number of fusions, and the strand strength was not at a satisfactory level.

Using only polyoxyethylene bisphenol A dilaurate (A-1) as an aromatic ester component, amino-modified silicone has a viscosity of 10000 mm ² / s and an amino equivalent of 7000 g / mol. In the case of Comparative Example 4 using the amino-modified silicone (B-4), the phenomenon that the single yarn is wound around the transport roll many times in the continuous operation of the carbon fiber precursor acrylic fiber bundle for 24 hours is observed. Sex was remarkably bad. Further, the obtained carbon fiber bundle had a large number of fusions, and the strand strength was not satisfactory.

  In Comparative Example 5 in which triisodecyl trimellitate (A-2) and pentaerythritol tetrastearate (A-3) were used as aromatic ester components, the number of carbon fiber precursor acrylic fiber bundles was 24 hours in continuous operation. The phenomenon that the single yarn was wound around the transport roll was observed, and the operability was inferior compared with each example. Moreover, the number of fusions of the obtained carbon fiber bundle was large.

Using only triisodecyl trimellitate (A-2) as an aromatic ester component, amino-modified silicone has a viscosity of 10000 mm ² / s and an amino equivalent of 7000 g / mol of primary and secondary amines in the side chain. Also in Comparative Example 6 using the amino-modified silicone (B-4) possessed in the above, the operability was inferior, and fusion was confirmed in the obtained carbon fiber bundle.

  In Comparative Example 7, which does not contain an aromatic ester component and contains 90% by mass of amino-modified silicone, the operability, flameproofing convergence, number of fusions, and strand strength were the same as in each Example. The amount of scattered Si was extremely large, which was an obstacle to industrial continuous baking.

The oil composition for carbon fiber precursor acrylic fibers of the present invention can effectively suppress fusion between single fibers in the firing step. Furthermore, the carbon fiber precursor acrylic fiber bundle which can suppress the operativity fall which generate | occur | produces when using the oil agent composition which has silicone as a main component, and has favorable convergence can be obtained. From the carbon fiber precursor acrylic fiber bundle, a carbon fiber bundle excellent in mechanical properties can be produced with high productivity.
The carbon fiber bundle obtained from the carbon fiber precursor acrylic fiber bundle of the present invention can be formed into a composite material after prepreg. In addition, the composite material using the carbon fiber bundle can be suitably used for sports applications such as golf shafts and fishing rods, and as a structural material for automobiles, aerospace applications, and various gas storage tank applications. .

Claims (8)

In the thermal mass analysis in the presence of water vapor, the residual mass ratio (r ¹ ) at 300 ° C. is 90 to 100% by mass, and in the thermal mass analysis in a nitrogen gas atmosphere, the residual mass ratio (r ² ) at 500 ° C. is The aromatic ester compound (I) that is 10% by mass or less, the aromatic mass ester that the residual mass ratio (r ¹ ) is 70 to 80% by mass, and the residual mass ratio (r ² ) is 3% by mass or less. A carbon fiber precursor acrylic agent oil composition comprising a compound (II).   The oil composition for carbon fiber precursor acrylic fibers according to claim 1, comprising an amino-modified silicone.   The carbon fiber precursor according to claim 1 or 2, wherein the aromatic ester compound (I) is an aromatic ester compound having a bisphenol A skeleton, and the aromatic ester compound (II) is a monocyclic aromatic ester compound. Oil composition for body acrylic fiber. 10 to 40% by mass of an aromatic ester compound having a structure represented by the following formula (1), 10 to 40% by mass of an aromatic ester compound having a structure represented by the following formula (2), and represented by the following formula (3) An oil agent composition for an acrylic fiber for a carbon fiber precursor comprising 1 to 10% by mass of an amino-modified silicone having a structure.

(In Formula (1), R ¹ and R ² are each independently a hydrocarbon group having 7 to 21 carbon atoms, and “m” and “n” are each independently 1 to 5).

(In formula (2), R ^{3 to} R ⁵ are each independently a hydrocarbon group having 8 to 14 carbon atoms.)

(In Formula (3), “o” is 5-300, and “p” is 1-5.)   The oil agent composition for carbon fiber precursor acrylic fibers according to any one of claims 1 to 4, comprising 1 to 10% by mass of a compatibilizing agent having a polydimethylsiloxane structure. Carbon fiber precursor as described in any one of Claims 1-5 which contains the block copolymer type polyether which consists of a propylene oxide unit of the structure shown by following formula (4), and an ethylene oxide unit 10-30 mass%. Oil composition for body acrylic fiber.

(In Formula (4), “x”, “y”, and “z” are each independently 1 to 200.)   The carbon fiber precursor acrylic fiber bundle to which the oil agent composition for carbon fiber precursor acrylic fibers as described in any one of Claims 1-6 adhered 0.1-2.0 mass% with respect to the dry fiber mass. A method for producing a carbon fiber precursor acrylic fiber bundle according to claim 7,
The step of applying an aqueous emulsified solution in which the oil agent composition for carbon fiber precursor acrylic fiber is dispersed in water to form micelles having an average particle diameter of 0.01 to 0.50 μm to the precursor fiber bundle in a water-swollen state. And a step of drying and densifying the precursor fiber bundle to which the aqueous emulsified solution is applied, and a method for producing a carbon fiber precursor acrylic fiber bundle.