JPWO2014050639A1 - Acrylic fiber treatment agent for carbon fiber production and its use - Google Patents

Abstract

An object of the present invention is to provide an acrylic fiber treatment agent for carbon fiber production that can achieve both fusion prevention between fibers and stable operability in carbon fiber production, and can further suppress fiber breakage and fluff generation. Another object of the present invention is to provide an acrylic fiber for producing carbon fiber using the treatment agent, a method for producing the same, and a method for producing carbon fiber using the treatment agent. This invention is the acrylic fiber processing agent for carbon fiber manufacture containing the sulfur-containing ester compound (A1) shown by following General formula (1), surfactant, and water. (In the formula, m and n are each independently an integer of 1 to 4, and R1 and R2 are each independently a hydrocarbon group having 12 to 16 carbon atoms.)

Description

  The present invention relates to an acrylic fiber treatment agent for producing carbon fiber and its use. More specifically, a treatment agent (hereinafter sometimes referred to as a precursor treatment agent) used when producing an acrylic fiber for carbon fiber production (hereinafter sometimes referred to as a precursor), and a precursor using the treatment agent. The present invention relates to a fiber, a manufacturing method thereof, and a carbon fiber manufacturing method using the treatment agent.

Carbon fibers are widely used for aerospace applications, sports applications, general industrial applications and the like as reinforcing fibers for composite materials with plastics called matrix resins, utilizing their excellent mechanical properties.
As a method for producing carbon fiber, a method is generally used in which a precursor is converted to a flame-resistant fiber in an oxidizing atmosphere at 200 to 300 ° C., and subsequently carbonized in an inert atmosphere at 300 to 2000 ° C. At the time of firing by these high heats, there is a problem that fusion of single fibers occurs and the quality and quality of the obtained carbon fibers are deteriorated.

  In order to prevent this fusion, a precursor of a silicone treating agent having excellent heat resistance and excellent peelability due to smoothness between fibers, particularly an amino-modified silicone treating agent capable of further improving heat resistance by a crosslinking reaction. A number of techniques to be applied to the above have been proposed (for example, Patent Document 1) and widely used industrially.

However, on the other hand, the silicone treatment agent that has been subjected to adhesion treatment drops off from the fiber to become an adhesive, which accumulates on a drying roller, a guide, etc. in the precursor manufacturing process, and the fibers are seized or broken. There was a problem of causing a decrease in sex. In addition, when silicon oxide is partly used in the oxidizing atmosphere of the flameproofing process and nitrogen is used as an inert gas in the inert atmosphere of the carbonizing process, silicon nitride is generated and these scales are deposited. However, there has been a problem that the operability and operability are deteriorated and the firing furnace is damaged.
Furthermore, the excellent releasability due to the fiber-to-fiber smoothness of the silicone treatment agent works effectively to prevent fusion between single fibers, while a large number of fiber bundles run simultaneously in parallel. In this case, the width of each fiber bundle expands due to the smoothness of the silicone treatment agent, so that the distance between adjacent fiber bundles is narrowed, and in some cases, there is a disadvantage that fluff is generated due to the interference.

  In order to avoid these problems, treatment agents with a reduced content of silicone compounds, treatment agents that do not use silicone compounds, and the like have been proposed. For example, a treating agent (for example, Patent Document 2) in which a bisphenol A aromatic compound and amino-modified silicone are combined, or a treating agent (for example, a patent containing a fatty acid ester of an alkylene oxide adduct of bisphenol A) as a main component. Reference 3).

  However, these treatment agents are effective in suppressing the above-mentioned problems such as operability caused by the silicone compound, but in the treatment agent composition, there is a suspicion that they correspond to endocrine disrupting substances (so-called environmental hormones). There existed a fault that it was inferior to the safety on use of containing a certain bisphenol A type compound. Moreover, in the processing agent which has the fatty acid ester of the alkylene oxide adduct of bisphenol A as a main component, there is a problem in that the fiber-metal friction is too high, and fiber breakage and fluff are generated.

Japanese Unexamined Patent Publication No. 2002-371477 Japanese Unexamined Patent Publication No. 2005-89884 Japanese Unexamined Patent Publication No. 2004-143645

  In view of such a conventional technical background, the object of the present invention is a treatment agent that does not use a component corresponding to or suspected of an endocrine disrupting substance, and prevents fusion between fibers in carbon fiber production and stable operability. The acrylic fiber treatment agent for carbon fiber production that can further suppress fiber breakage and fluff generation, the acrylic fiber for carbon fiber production using the treatment agent, its production method, and the treatment It is providing the manufacturing method of carbon fiber using an agent.

  As a result of intensive studies to solve the above-mentioned problems, the present inventors have found that the above-mentioned problems can be solved if the acrylic fiber treatment agent for producing carbon fibers contains a specific ester compound, a surfactant and water. And reached the present invention.

  That is, the acrylic fiber treatment agent for producing carbon fibers of the present invention contains a sulfur-containing ester compound (A1) represented by the following general formula (1), a surfactant and water.

（式中、ｍ及びｎは、それぞれ独立して、１〜４の整数であり、Ｒ^１及びＲ^２は、それぞれ独立して、炭素数１２〜１６の炭化水素基である。）

(In the formula, m and n are each independently an integer of 1 to 4, and R ¹ and R ² are each independently a hydrocarbon group having 12 to 16 carbon atoms.)

  The treating agent of the present invention preferably further contains a sulfur-containing ester compound (A2) represented by the following general formula (2).

（式中、ｍ及びｎは、それぞれ独立して、１〜４の整数であり、Ｒ^３は炭素数１２〜１６の炭化水素基である。）

(In the formula, m and n are each independently an integer of 1 to 4, and R ³ is a hydrocarbon group having 12 to 16 carbon atoms.)

  The weight ratio (A1 / A2) between the sulfur-containing ester compound (A1) and the sulfur-containing ester compound (A2) is preferably 99.9 / 0.1 to 50/50.

  The total weight ratio of the sulfur-containing ester compound (A1) and the sulfur-containing ester compound (A2) in the nonvolatile content of the treatment agent or the sulfur-containing ester compound ( The weight ratio of A1) is preferably 30 to 98.9% by weight. Similarly, the weight ratio of the surfactant is preferably 1 to 40% by weight.

  The treating agent of the present invention can further contain a modified silicone (B) having a modifying group containing a nitrogen atom.

  Does not include the sulfur-containing ester compound (A1) and the weight ratio (A1 + A2) / B) of the sum of the sulfur-containing ester compound (A2) and the modified silicone (B), or the sulfur-containing ester compound (A2). In this case, the weight ratio (A1 / B) between the sulfur-containing ester compound (A1) and the modified silicone (B) is preferably 99.9 / 0.1 to 50/50.

  The modified silicone (B) is preferably an amino-modified silicone.

  The treatment agent of the present invention is preferably an emulsion dispersed in water.

  The acrylic fiber for producing carbon fiber of the present invention is produced by attaching the above-mentioned treatment agent to the raw acrylic fiber for producing acrylic fiber for carbon fiber.

  The method for producing an acrylic fiber for producing carbon fiber of the present invention includes a yarn production step of producing a yarn by attaching the above-mentioned treatment agent to the raw acrylic fiber of the acrylic fiber for producing carbon fiber.

  The carbon fiber production method of the present invention includes a spinning process in which the above-mentioned treatment agent is attached to a raw acrylic fiber for producing carbon fiber to produce the acrylic fiber for producing carbon fiber, and carbon fiber production after the adhesion treatment. A flameproofing process for converting the acrylic fiber for use into a flameproofed fiber in an oxidizing atmosphere at 200 to 300 ° C., and a carbonizing process for carbonizing the flameproofed fiber in an inert atmosphere at 300 to 2000 ° C. Is included.

The acrylic fiber treatment agent for producing carbon fiber of the present invention achieves both fusion prevention and stable operability in carbon fiber production without using a component that corresponds to or is suspected to be an endocrine disrupting substance. In addition, fiber breakage and fluff generation can be suppressed.
By using the acrylic fiber for carbon fiber production of the present invention and the acrylic fiber for carbon fiber production obtained in the production method thereof, it is possible to achieve both the prevention of fusion between fibers and stable operability in the production of carbon fiber, Further, fiber breakage and fluff generation can be suppressed.
The carbon fiber manufacturing method of the present invention can achieve both fusion prevention between fibers and stable operability, and can further suppress fiber breakage and fluff generation. In addition, high-strength carbon fibers can be produced.

The schematic diagram explaining the measuring method of F / F frictional force.

  The acrylic fiber treatment agent for carbon fiber production (precursor treatment agent) of the present invention is a treatment agent intended to be applied to acrylic fibers (carbon fiber precursors) used for carbon fiber production, and is a specific sulfur-containing ester. It contains the compound (A1), a surfactant and water. First, each component which comprises a precursor processing agent is demonstrated.

[Sulfur-containing ester compound (A1)]
A sulfur-containing ester compound (A1) is a compound shown by the said General formula (1), and is an essential component of the precursor processing agent of this invention. The sulfur-containing ester compound (A1) is a component that can improve operability during firing while maintaining operability during yarn production in the production of carbon fiber. By using this sulfur-containing ester compound (A1), the fiber-to-fiber friction can be increased, and the convergence of the fiber bundle can be improved. As a result, good operability during firing is realized.

In the general formula (1), R ¹ and R ² are each independently a hydrocarbon group having 12 to 16 carbon atoms. R ¹ and R ² may be the same or different. R ¹ and R ² may be either linear or branched, but are preferably branched from the viewpoints of convergence and operability during firing. Examples of the hydrocarbon group include an alkyl group, an alkenyl group, and an alkynyl group, and an alkyl group is preferable. Carbon number of a hydrocarbon group is 12-16, and 14-16 are preferable. When the carbon number is less than 12, the fiber-metal friction is increased, and single fiber breakage and fluff are generated. On the other hand, if the number of carbons exceeds 16, a large amount of tarred product is generated during firing, and the fibers are fused.

  In the formula of the general formula (1), m and n are each independently an integer of 1 to 4, and preferably 2 to 3. When m or n exceeds 4, the fiber-to-fiber friction is lowered, the convergence is insufficient, and the operability during firing may be deteriorated.

  Specific examples of the linear hydrocarbon group include n-dodecyl group, n-tridecyl group, n-tetradecyl group, n-pentadecyl group, n-hexadecyl group and the like. Specific examples of the branched hydrocarbon group include an isododecyl group, an isotridecyl group, an isotetradecyl group, an isopentadecyl group, an isohexadecyl group, and a 2-hexyldecyl group. Among these, n-dodecyl group and 2-hexyldecyl group are preferable from the viewpoint of convergence and operability during firing.

Examples of the sulfur-containing ester compound (A1) include di (n-dodecyl) thiodietanate, di (n-tridecyl) thiodietanate, di (n-tetradecyl) thiodietanate, di (n-pentadecyl) thiodietanate, and di (n-hexadecyl). Thiodietanate di-linear esters such as thiodietanate; di (isododecyl) thiodietanate, di (isotridecyl) thiodietanate, di (isotetradecyl) thiodietanate, di (isopentadecyl) thiodietanate, di (isohexadecyl) thiodietanate, di (2 Thiodietanic acid dibranched esters such as -hexyldecyl) thiodietanate; di (n-dodecyl) thiodipropionate, di (n-tridecyl) thiodipropionate, di (n-tetradecyl) thiodipropionate Di (n-pentadecyl) thiodipropionate, di (n-hexadecyl) thiodipropionate, etc., thiodipropionic acid di-linear ester; di (isododecyl) thiodipropionate, di (isotridecyl) thiodiprote Thion such as pionate, di (isotetradecyl) thiodipropionate, di (isopentadecyl) thiodipropionate, di (isohexadecyl) thiodipropionate, di (2-hexyldecyl) thiodipropionate Dipropionic acid dibranched ester; di (n-dodecyl) thiodibutanate, di (n-tridecyl) thiodibutanate, di (n-tetradecyl) thiodibutanate, di (n-pentadecyl) thiodibutanate, di (n-hexadecyl) thiodibutanate, etc. Thiodibutanoic acid di linear ester; Thiodibutanoic acid dibranched types such as dodecyl) thiodibutanate, di (isotridecyl) thiodibutanate, di (isotetradecyl) thiodibutanate, di (isopentadecyl) thiodibutanate, di (isohexadecyl) thiodibutanate, di (2-hexyldecyl) thiodibutanate Esters; di (n-dodecyl) thiodipentanate, di (n-tridecyl) thiodipentanate, di (n-tetradecyl) thiodipentanate, di (n-pentadecyl) thiodipentanate, di (n- Hexadecyl) thiodipentanate and other thiodipentanoic acid di-linear esters; di (isododecyl) thiodipentanate, di (isotridecyl) thiodipentanate, di (isotetradecyl) thiodipentanate, di (isopentadecyl) ) Thiodipentanate, And thiodipentanoic acid dibranched esters such as di (isohexadecyl) thiodipentanate and di (2-hexyldecyl) thiodipentanate. Among these, thiodipropionic acid di-linear ester and thiodipropionic acid di-branched ester are preferable from the viewpoint of convergence and operability during firing, and di (n-dodecyl) thiodipropionate, di ( 2-Hexyldecyl) thiodipropionate is more preferred.
These sulfur-containing ester compounds (A1) can be used alone or in combination of two or more.

  A method for producing the sulfur-containing ester compound (A1) is not particularly limited, and a known method can be employed. For example, it can be produced by performing an esterification reaction of thiodipropionic acid and an aliphatic alcohol. As a specific example, there is a method in which an esterification reaction is performed while removing generated water at a charging ratio of 2 to 2.5 moles of aliphatic alcohol with respect to thiodipropionic acid.

  As esterification conditions, for example, the esterification reaction temperature is usually 120 to 250 ° C, preferably 130 to 230 ° C. Moreover, as reaction time, it is 1 to 10 hours normally, and 2 to 8 hours are preferable. The reaction may be performed without a catalyst or may be performed using an esterification catalyst described later.

Specific examples of the aliphatic alcohol include n-dodecanol, n-tridecanol, n-tetradecanol, n-pentadecanol, n-hexadecanol, isododecanol, isotridecanol, isotetradecanol, iso Examples include pentadecanol, isohexadecanol, and 2-hexyldecanol. Among these, n-dodecanol and 2-hexyldecanol are preferable.
These aliphatic alcohols can be used alone or in combination of two or more.

  Examples of esterification catalysts include Lewis acids and sulfonic acids. More specifically, examples of Lewis acids include aluminum derivatives, tin derivatives, and titanium derivatives, and examples of sulfonic acids include p-toluenesulfonic acid, metasulfonic acid, and sulfuric acid. Among these, titanium derivatives and sulfonic acids are preferable. The amount used is preferably about 0.05 to 5% by weight with respect to the total weight of the raw materials.

In the esterification reaction, the produced water may be distilled off azeotropically outside the system using a water entraining agent such as benzene, toluene, xylene, cyclohexane or the like, if necessary.
After completion of the esterification reaction, excess aliphatic alcohol is distilled off under reduced pressure or normal pressure, depending on the reaction, and conventional purification methods such as washing with water, distillation under reduced pressure, purification of adsorbents such as activated carbon are performed. Thiodipropionic acid diester can be obtained.

[Sulfur-containing ester compound (A2)]
The precursor treating agent of the present invention preferably further contains a sulfur-containing ester compound (A2) represented by the general formula (2). By containing the sulfur-containing ester compound (A2) in addition to the sulfur-containing ester compound (A1) described above, the fiber-metal friction can be effectively reduced while maintaining the fiber-fiber friction. As a result, it is possible to improve the bundleability of the fiber bundle and further suppress single fiber breakage and fluff generation. Furthermore, the emulsification stability when the treatment agent is water-based emulsified is improved, and the treatment agent can be uniformly attached to the fibers.

In the general formula (2), R ³ is a hydrocarbon group having 12 to 16 carbon atoms, and may be either linear or branched, but from the viewpoint of convergence and operability during firing, branched chain The shape is preferred. Examples of the hydrocarbon group include an alkyl group, an alkenyl group, and an alkynyl group, and an alkyl group is preferable. Carbon number of a hydrocarbon group is 12-16, and 14-16 are preferable. If the number of carbon atoms is less than 12, the fiber-to-fiber friction is lowered, the convergence is insufficient, and the operability during firing may be deteriorated. On the other hand, if the number of carbon atoms exceeds 16, a large amount of tarred product may be generated during firing and the fibers may be fused.
Specific examples of the straight-chain hydrocarbon group and the branched-chain hydrocarbon group are the same as the examples described in the items of R ¹ and R ² described above.

  In the formula of the general formula (2), m and n are each independently an integer of 1 to 4, and preferably 2 to 3. When m or n exceeds 4, the fiber-to-fiber friction is lowered, the convergence is insufficient, and the operability during firing may be deteriorated.

Examples of the sulfur-containing ester compound (A2) include thiodietanic acid mono (n-dodecyl) ester, thiodiethanic acid mono (n-tridecyl) ester, thiodiethanic acid mono (n-tetradecyl) ester, and thiodietanic acid mono (n-pentadecyl). Esters, thiodietanic acid mono (n-hexadecyl) esters, etc .; thiodietanic acid mono (isododecyl) esters, thiodiethanic acid mono (isotridecyl) esters, thiodiethanic acid mono (isotetradecyl) esters, thiodietanic acid monoesters (Isopentadecyl) ester, thiodiethanic acid mono (isohexadecyl) ester, thiodiethanic acid mono (2-hexyldecyl) ester and other thiodietanic acid monobranched esters; thiodipropionic acid mono (n- Decyl) ester, thiodipropionic acid mono (n-tridecyl) ester, thiodipropionic acid mono (n-tetradecyl) ester, thiodipropionic acid mono (n-pentadecyl) ester, thiodipropionic acid mono (n-hexadecyl) Thiodipropionic acid mono linear ester such as ester; thiodipropionic acid mono (isododecyl) ester, thiodipropionic acid mono (isotridecyl) ester, thiodipropionic acid mono (isotetradecyl) ester, thiodipropionic acid mono Thiodipropionic acid mono-branched ester such as (isopentadecyl) ester, thiodipropionic acid mono (isohexadecyl) ester, thiodipropionic acid mono (2-hexyldecyl) ester; thiodibutanoic acid mono (n-dodecyl) ) Ester, Thiodi Thiodibutanoic acid mono linear esters such as tanoic acid mono (n-tridecyl) ester, thiodibutanoic acid mono (n-tetradecyl) ester, thiodibutanoic acid mono (n-pentadecyl) ester, thiodibutanoic acid mono (n-hexadecyl) ester; thiodibutane Acid mono (isododecyl) ester, thiodibutanoic acid mono (isotridecyl) ester, thiodibutanoic acid mono (isotetradecyl) ester, thiodibutanoic acid mono (isopentadecyl) ester, thiodibutanoic acid mono (isohexadecyl) ester, thiodibutanoic acid mono (2 -Hexyldecyl) ester thiodibutanoic acid mono-branched ester; thiodipentanoic acid mono (n-dodecyl) ester, thiodipentanoic acid mono (n-tridecyl) ester, thiodipentanoic acid mono (n-tetra) Decyl) ester, thiodipentanoic acid mono (n-pentadecyl) ester, thiodipentanoic acid mono linear ester such as thiodipentanoic acid mono (n-hexadecyl) ester; thiodipentanoic acid mono (isododecyl) ester, thiodipentanoic acid mono (isotridecyl) ester, thiodipentane Thiodipentanoic acid mono-branched esters such as acid mono (isotetradecyl) ester, thiodipentanoic acid mono (isopentadecyl) ester, thiodipentanoic acid mono (isohexadecyl) ester, thiodipentanoic acid mono (2-hexyldecyl) ester; Is mentioned. Among these, thiodipropionic acid mono-linear ester and thiodipropionic acid mono-branched ester are preferable from the viewpoint of convergence and operability during firing, and thiodipropionic acid mono (n-dodecyl) ester, thio Dipropionic acid mono (2-hexyldecyl) ester is more preferred.
These sulfur-containing ester compounds (A2) can be used alone or in combination of two or more.

A method for producing the sulfur-containing ester compound (A2) is not particularly limited, and a known method can be employed. For example, it can be produced by performing an esterification reaction of thiodipropionic acid and an aliphatic alcohol. As a specific example, there may be mentioned a method in which an equimolar amount of an aliphatic alcohol is charged with respect to thiodipropionic acid, an esterification reaction is performed while removing generated water, and distillation / purification is performed.
In addition, as for the preparation amount of aliphatic alcohol, it is preferable to add 1-1.2 times mole with respect to thiodipropionic acid with a preparation ratio. The esterification conditions, specific examples of the aliphatic alcohol, esterification catalyst, and the like are the same as those described in the item of the method for producing the sulfur-containing ester compound (A1).

  The sulfur-containing ester compound (A1) and the sulfur-containing ester compound (A2) may be prepared by using an ester compound by the above-described method, respectively, and an esterification reaction between thiodipropionic acid and an aliphatic alcohol is performed. An ester mixture containing the ester compound (A1) and the sulfur-containing ester compound (A2) may be prepared and used.

Examples of the method for preparing the ester mixture of the sulfur-containing ester compound (A1) and the sulfur-containing ester compound (A2) include the following methods.
1) When the esterification reaction between thiodipropionic acid and an aliphatic alcohol is carried out, the molar ratio of the aliphatic alcohol to the thiodipropionic acid is 1.5 to 1.99 times mol, preferably 1.8 to The method of performing 1.9 times mole preparation esterification reaction is mentioned. The esterification conditions, specific examples of the aliphatic alcohol, esterification catalyst, and the like are the same as those described in the item of the method for producing the sulfur-containing ester compound (A1).
2) In the method for producing the sulfur-containing ester compound (A1) described above, there is a method in which the esterification reaction is terminated in the middle so that the ester mixture has a desired total acid value.

  The weight ratio between the sulfur-containing ester compound (A1) and the sulfur-containing ester compound (A2) in the ester mixture can be calculated by the following method. The obtained ester mixture is analyzed by gas chromatography analysis, the content of thiodipropionic acid as a raw material is measured, and the acid value derived from thiodipropionic acid in the ester mixture is determined. Next, the total acid value of the ester mixture is measured. From the value obtained by subtracting the acid value derived from thiodipropionic acid from the total acid value and the molecular weight of the sulfur-containing ester compound (A2), the weight ratio of the sulfur-containing ester compound (A1) and the sulfur-containing ester compound (A2) in the ester mixture Can be calculated.

  In order to exert the effect of the present invention more, the sulfur-containing ester compound (A1) and the sulfur-containing ester compound (A2) are not only used in combination, but also the sulfur-containing ester compound (A1) and the sulfur-containing ester compound (A2). Are preferably used together in a specific ratio. The weight ratio (A1 / A2) between the sulfur-containing ester compound (A1) and the sulfur-containing ester compound (A2) is preferably 99.9 / 0.1 to 50/50, and 99.9 / 0.1 to 70/30. Is more preferable, 99/1 to 80/20 is more preferable, and 98/2 to 90/10 is particularly preferable. When the weight ratio is more than 99.9 / 0.1, the fiber-metal friction increases, and fiber breakage or fluff may occur. Furthermore, the emulsion stability of the emulsion when water-based emulsified may deteriorate. On the other hand, when the weight ratio is less than 50/50, the fiber-to-fiber friction is lowered, the convergence is insufficient, and the operability during firing may be deteriorated.

[Surfactant]
The precursor treatment agent of the present invention contains a surfactant. The surfactant is used as an emulsifier, and makes it possible to emulsify and disperse the above-described sulfur-containing ester compound (A1), sulfur-containing ester compound (A2), modified silicone described later, and the like in water. The surfactant is not particularly limited, and a known one can be appropriately selected from nonionic surfactants, anionic surfactants, cationic surfactants and amphoteric surfactants. Surfactant may use together 1 type (s) or 2 or more types.

  Examples of the nonionic surfactant include polyoxyalkylene linear alkyl ethers such as polyoxyethylene hexyl ether, polyoxyethylene octyl ether, polyoxyethylene decyl ether, polyoxyethylene lauryl ether, and polyoxyethylene cetyl ether; Polyoxyalkylene branched primary alkyl ethers such as polyoxyethylene 2-ethylhexyl ether, polyoxyethylene isocetyl ether, polyoxyethylene isostearyl ether; polyoxyethylene 1-hexyl hexyl ether, polyoxyethylene 1-octyl hexyl ether Polyoxyethylene 1-hexyl octyl ether, polyoxyethylene 1-pentyl heptyl ether, polyoxyethylene 1-heptylpentyl ether Polyoxyalkylene branched secondary alkyl ethers such as ter; polyoxyalkylene alkenyl ethers such as polyoxyethylene oleyl ether; polyoxys such as polyoxyethylene octyl phenyl ether, polyoxyethylene nonyl phenyl ether, polyoxyethylene dodecyl phenyl ether Alkylene alkyl phenyl ether; polyoxyethylene tristyryl phenyl ether, polyoxyethylene distyryl phenyl ether, polyoxyethylene styryl phenyl ether, polyoxyethylene tribenzyl phenyl ether, polyoxyethylene dibenzyl phenyl ether, polyoxyethylene benzyl phenyl ether Such as polyoxyalkylene alkyl aryl phenyl ether; Laurate, polyoxyethylene monooleate, polyoxyethylene monostearate, polyoxyethylene monomyristate, polyoxyethylene dilaurate, polyoxyethylene dioleate, polyoxyethylene dimyristate, polyoxyethylene distearate, etc. Polyoxyalkylene fatty acid esters; sorbitan esters such as sorbitan monopalmitate and sorbitan monooleate; polyoxyalkylene sorbitan fatty acid esters such as polyoxyethylene sorbitan monostearate and polyoxyethylene sorbitan monooleate; glycerin monostearate and glycerin monolaur Glycerin fatty acid ester such as rate and glycerin monopalmitate; Polyoxyalkylene sorbitol fatty acid ester; Sucrose fat Acid ester; polyoxyalkylene castor oil ether such as polyoxyethylene castor oil ether; polyoxyalkylene hardened castor oil ether such as polyoxyethylene hydrogenated castor oil ether; polyoxyalkylene alkyl such as polyoxyethylene lauryl amino ether and polyoxyethylene stearyl amino ether Amino ether; oxyethylene-oxypropylene block or random copolymer; oxyethylene-oxypropylene block or random copolymer terminal alkyl etherified product; oxyethylene-oxypropylene block or random copolymer terminal sucrose etherified product; Etc.

  Among these nonionic surfactants, polyoxyalkylene branched primary alkyl ethers, polyoxyalkylene branched secondary alkyl ethers, polyoxyalkylene alkenyl ethers are preferred because they are particularly excellent in aqueous emulsifying power of esters and silicone compounds. , Polyoxyalkylene alkyl phenyl ether, polyoxyalkylene fatty acid ester, oxyethylene-oxypropylene block copolymer, and terminal alkyl etherified product of oxyethylene-oxypropylene block copolymer are preferable. The terminal alkyl etherified product of oxyethylene-oxypropylene block copolymer or random copolymer or oxyethylene-oxypropylene block copolymer is Ri preferred.

  Examples of the anionic surfactant include fatty acids (salts) such as oleic acid, palmitic acid, sodium oleate, potassium palmitate, triethanolamine oleate; hydroxyacetic acid, potassium potassium hydroxyacetate, lactic acid, lactic acid Hydroxyl group-containing carboxylic acid (salt) such as potassium salt; polyoxyalkylene alkyl ether acetic acid (salt) such as polyoxyethylene tridecyl ether acetic acid (sodium salt); and many carboxyl groups such as potassium trimellitic acid and potassium pyromellitic acid Substituted aromatic compound salts; alkylbenzene sulfonic acid (salt) such as dodecylbenzene sulfonic acid (sodium salt); polyoxyalkylene alkyl ether sulfonic acid (salt) such as polyoxyethylene 2-ethylhexyl ether sulfonic acid (potassium salt); Higher fatty acid amide sulfonic acid (salt) such as theaeroylmethyl taurine (sodium), lauroyl methyl taurine (sodium), myristoyl methyl taurine N (sodium), palmitoyl methyl taurine (sodium); N- such as lauroyl sarcosine acid (sodium) Acyl sarcosine acid (salt); alkyl phosphonic acid (salt) such as octyl phosphonate (potassium salt); aromatic phosphonic acid (salt) such as phenyl phosphonate (potassium salt); 2-ethylhexyl phosphonate mono 2-ethylhexyl ester (potassium salt) Alkylphosphonic acid ester (salt) such as aminophosphonic acid (diethanolamine salt), etc .; alkyl such as 2-ethylhexyl sulfate (sodium salt); Acid esters (salts); polyoxyalkylene sulfates (salts) such as polyoxyethylene 2-ethylhexyl ether sulfate (sodium salt); long-chain sulfosuccinates such as sodium di-2-ethylhexyl sulfosuccinate and sodium dioctyl sulfosuccinate; Long-chain N-acyl glutamates such as sodium monosodium N-lauroyl glutamate and disodium N-stearoyl-L-glutamate;

  Examples of the cationic surfactant include lauryl trimethyl ammonium chloride, myristyl trimethyl ammonium chloride, palmityl trimethyl ammonium chloride, stearyl trimethyl ammonium chloride, oleyl trimethyl ammonium chloride, cetyl trimethyl ammonium chloride, behenyl trimethyl ammonium chloride, coconut oil alkyl trimethyl. Ammonium chloride, tallow alkyltrimethylammonium chloride, stearyltrimethylammonium bromide, coconut oil alkyltrimethylammonium bromide, cetyltrimethylammonium methosulfate, oleyldimethylethylammonium ethosulphate, dioctyldimethylammonium chloride, dill Alkyl quaternary ammonium salts such as ril dimethyl ammonium chloride, distearyl dimethyl ammonium chloride, octadecyl diethyl methyl ammonium sulfate; (polyoxyethylene) lauryl amino ether lactate, stearyl amino ether lactate, di (polyoxyethylene) lauryl Methylaminoether dimethyl phosphate, di (polyoxyethylene) laurylethylammonium ethosulphate, di (polyoxyethylene) -cured tallow alkylethylamine ethosulphate, di (polyoxyethylene) laurylmethylammonium dimethylphosphate, di (polyoxyethylene) stearyl (Polyoxyalkylene) alkylamino ether salts such as amine lactate; N- (2-hydroxyethyl)- , N-dimethyl-N-stearoylamidopropylammonium nitrate, lanolin fatty acid amidopropylethyldimethylammonium ethosulphate, acylamidoalkyl quaternary ammonium salts such as lauroylamidoethylmethyldiethylammonium methosulfate; dipalmityl polyethenoxyethyl Alkylethenoxy quaternary ammonium salts such as ammonium chloride and distearyl polyethenoxymethylammonium chloride; alkylisoquinolinium salts such as laurylisoquinolinium chloride; lauryldimethylbenzylammonium chloride, stearyldimethylbenzylammonium chloride and the like Benzalkonium salt; benzyldimethyl {2- [2- (p-1,1,3,3-tetramethylbutylphenol) Oxy) ethoxy] ethyl} ammonium chloride and other benzethonium salts; cetylpyridinium chloride and other pyridinium salts; oleyl hydroxyethyl imidazolinium etosulphate, imidazolinium salts such as lauryl hydroxyethyl imidazolinium etosulphate; N-cocoyl arginine ethyl Acyl basic amino acid alkyl ester salts such as ester pyrrolidone carboxylate and N-lauroyllysine ethyl ethyl ester chloride; Primary amine salts such as laurylamine chloride, stearylamine bromide, hardened beef tallow alkylamine chloride, rosinamine acetate; cetyl Methylamine sulfate, laurylmethylamine chloride, dilaurylamine acetate, stearylethylamine bromide, lauric Secondary amine salts such as rupropylamine acetate, dioctylamine chloride, octadecylethylamine hydroxide; dilaurylmethylamine sulfate, lauryldiethylamine chloride, laurylethylmethylamine bromide, diethanol stearylamide ethylamine trihydroxyethyl phosphate salt, stearylamide Examples include tertiary amine salts such as ethyl ethanolamine urea polycondensate acetate; fatty acid amidoguanidinium salts; alkyltrialkylene glycol ammonium salts such as lauryl triethylene glycol ammonium hydroxide.

  Examples of amphoteric surfactants include 2-undecyl-N, N- (hydroxyethylcarboxymethyl) -2-imidazoline sodium, 2-cocoyl-2-imidazolinium hydroxide-1-carboxyethyloxy disodium salt, and the like. Imidazoline-based amphoteric surfactants; 2-heptadecyl-N-carboxymethyl-N-hydroxyethylimidazolium betaine, lauryldimethylaminoacetic acid betaine, alkylbetaines, amide betaines, sulfobetaine, and other betaine-based amphoteric surfactants; N- Amino acid type amphoteric surfactants such as lauryl glycine, N-lauryl β-alanine, N-stearyl β-alanine and the like can be mentioned.

  Among these surfactants, nonionic surfactants are excellent because they are excellent in stability over time and also in the emulsifying power of sulfur-containing ester compounds (A1), sulfur-containing ester compounds (A2), and modified silicones. Agents are preferred. Compared with nonionic surfactants, ionic surfactants have the advantage of excellent antistatic properties that can suppress fiber bundle fluctuations due to the generation of static electricity, so they should be used in combination with nonionic surfactants. Is preferred. Examples of the ionic surfactant include the above-mentioned anionic surfactants, cationic surfactants, and amphoteric surfactants. Among these, cationic surfactants are preferable, and among the cationic surfactants. Alkyl quaternary ammonium salts, (polyoxyalkylene) alkyl amino ether salts, acylaminoalkyl quaternary ammonium salts, alkylethenoxy quaternary ammonium salts, primary amine salts, secondary amine salts, tertiary More preferred are secondary amine salts and the like.

[Modified silicone (B) having a modifying group containing a nitrogen atom]
The precursor treating agent of the present invention can further contain a modified silicone (B) having a modifying group containing a nitrogen atom. Since the precursor treating agent of the present invention contains the above-described sulfur-containing ester compound (A1), the fiber-to-fiber friction can be increased without increasing the fiber-to-metal friction. By preventing the spread, the generation of fluff due to the interference of the fiber bundle can be effectively reduced. That is, the precursor treatment agent of the present invention containing the sulfur-containing ester compound (A1) can suppress problems caused by the modified silicone (B) and can be used in combination with the modified silicone (B).

  In order to exhibit such an effect more, not only the modified silicone (B) is used in combination, but also the sum of the sulfur-containing ester compound (A1) and the sulfur-containing ester compound (A2) and the modified silicone (B) Or when the sulfur-containing ester compound (A2) is not included, the sulfur-containing ester compound (A1) and the modified silicone (B) are preferably used in a specific ratio. The weight ratio ((A1 + A2) / B) of the sum of the sulfur-containing ester compound (A1) and the sulfur-containing ester compound (A2) to the modified silicone (B), or when the sulfur-containing ester compound (A2) is not included The weight ratio (A1 / B) between the sulfur-containing ester compound (A1) and the modified silicone (B) is preferably 99.9 / 0.1 to 50/50, more preferably 95/5 to 60/40, 90 / 12-70 / 30 is more preferable. When the weight ratio is more than 99.9 / 0.1, the fiber-metal friction increases, and fiber breakage or fluff may occur. Furthermore, the emulsion stability of the emulsion when water-based emulsified may deteriorate. On the other hand, when the weight ratio is less than 50/50, the fiber-to-fiber friction becomes low, resulting in insufficient convergence and operability during firing may be deteriorated.

  The modified silicone (B) is not particularly limited as long as it is a modified group containing a nitrogen atom. Examples of the modifying group containing a nitrogen atom include a modifying group containing an amino bond or an imino bond (ie, an amino group), a modifying group containing an amide bond (ie, an amide group), and the like. A modified group having a plurality of different bonds may be used. The modifying group containing a nitrogen atom may be bonded to the side chain of silicone as the main chain, may be bonded to the terminal, or may be bonded to both. Moreover, you may have a polyoxyalkylene group (For example, a polyoxyethylene group, a polyoxypropylene group, a polyoxybutylene group etc.) in the molecule | numerator.

  Examples of the modified silicone (B) having a modified group containing a nitrogen atom include amino-modified silicone, amino polyether-modified silicone, amide-modified silicone, amide-polyether-modified silicone, and the like. Alternatively, a plurality of modified silicones may be used in combination.

  Further, the content of nitrogen atom in the modified silicone (B) is preferably 0.35 to 3.2% by weight, more preferably 0.37 to 2.2% by weight, and 0.40 to 1.3% by weight. Further preferred. When the content of nitrogen atoms is lower than 0.35% by weight, the emulsion stability of the emulsion may deteriorate when aqueous emulsification is performed. On the other hand, when the content of nitrogen atoms is higher than 3.2% by weight, the adhesiveness of the modified silicone (B) increases due to thermal crosslinking, which causes gum up.

  Of these modified silicones (B), amino-modified silicones are preferred because they are excellent in emulsion stability when water-based emulsified and have excellent effects when used in combination with the sulfur-containing ester compound (A1).

  When the modified silicone (B) is an amino-modified silicone, the structure of the amino-modified silicone is not particularly limited. That is, the amino group that is a modifying group may be bonded to the side chain of silicone that is the main chain, may be bonded to the terminal, or may be bonded to both. The amino group may be a monoamine type or a polyamine type, and both may be present in one molecule.

The amino group (NH ₂ ) content in the amino-modified silicone (hereinafter referred to as “amino weight%”) is preferably 0.4 to 3.7% by weight, more preferably 0.42 to 2.5% by weight, 0.46 to 1.5% by weight is more preferable. When amino weight% is lower than 0.4 weight%, the emulsion stability of the emulsion may deteriorate when aqueous emulsification is performed. On the other hand, when the content is higher than 3.7% by weight, the tackiness of the amino-modified silicone becomes high due to thermal crosslinking, which causes gum-up.

The viscosity of the amino-modified silicone at 25 ° C. is not particularly limited, but if the viscosity is too low, the treatment agent is likely to scatter, and the emulsion stability of the emulsion deteriorates when emulsified with water, and the treatment agent is converted into fibers. It becomes impossible to apply uniformly. As a result, fiber fusion may not be prevented. On the other hand, if the viscosity is too high, gum-up due to adhesiveness may be a problem. From the standpoint of preventing these problems, the viscosity at 25 ° C. of an amino-modified silicone is preferably 100~15,000mm ² / s, more preferably 500~10,000mm ² / s, 1,000~5,000mm ² / s is more preferable.

[Other ingredients]
The precursor treatment agent of the present invention may contain components other than the above-described components as long as the effects of the present invention are not impaired. Other components include acid phosphate esters, phenolic, amine-based, sulfur-based, phosphorus-based and quinone-based antioxidants; sulfates of higher alcohols and higher alcohol ethers, sulfonates, higher alcohols and higher alcohols Antistatic agents such as phosphate salts of alcohol ethers, quaternary ammonium salt type cationic surfactants, amine salt type cationic surfactants; smoothing agents such as alkyl esters of higher alcohols, higher alcohol ethers, waxes, etc. Antibacterial agents; antiseptics; rust preventives; and hygroscopic agents.

The antioxidant is a component that effectively suppresses thermal decomposition of the precursor treatment agent by heating in the flameproofing treatment step and enhances the effect of preventing fusion between fibers.
Although there is no limitation in particular as antioxidant, From a viewpoint of baking furnace contamination prevention, an organic antioxidant is preferable. Examples of organic antioxidants include 4,4′-butylidenebis (3-methyl-6-tert-butylphenol, trioctadecyl phosphite, N, N′-diphenyl-p-phenylenediamine, triethylene glycol bis [3- (3-t-butyl-4-hydroxy-5-methylphenyl) propionate], dioleyl-thiodipropionate, etc. These organic antioxidants may be used alone or in combination of two or more. Good.

  Moreover, the precursor treating agent of the present invention may contain a silicone component other than the modified silicone (B) having a modifying group containing a nitrogen atom as long as the effects of the present invention are not inhibited. Specifically, dimethyl silicone, epoxy-modified silicone, alkylene oxide-modified silicone (polyether-modified silicone), epoxy polyether-modified silicone (see, for example, Japanese Patent No. 4616934), carboxy-modified silicone, carbinol-modified silicone, alkyl-modified silicone, Examples include phenol-modified silicone, methacrylate-modified silicone, alkoxy-modified silicone, and fluorine-modified silicone.

[Precursor treatment agent]
The precursor treating agent of the present invention essentially contains the aforementioned sulfur-containing ester compound (A1), a surfactant and water, and optionally contains a sulfur-containing ester compound (A2). The total weight ratio of the sulfur-containing ester compound (A1) and the sulfur-containing ester compound (A2) occupying the non-volatile content of the treating agent or the sulfur-containing ester compound (A1) when the sulfur-containing ester compound (A2) is not included. The weight ratio is preferably 30 to 98.9% by weight. It is more preferably 45 to 95% by weight, further preferably 55 to 85% by weight, and particularly preferably 65 to 75% by weight. When the weight ratio is less than 30% by weight, the fiber-to-fiber friction is lowered, the convergence is insufficient, and the operability during firing may be deteriorated. On the other hand, if it exceeds 98.9% by weight, the emulsion stability when emulsified with water may be deteriorated.

1-40 weight% is preferable, as for the weight ratio of surfactant to the non volatile matter of a processing agent, 5-30 weight% is more preferable, and 8-25 weight% is further more preferable. When the weight ratio is less than 1% by weight, good emulsification stability may be difficult to obtain. Moreover, when this weight ratio exceeds 40 weight%, the heat resistance of a processing agent falls and it may be unable to suppress the fusion | bonding of the carbon fiber in a baking process.
When the precursor treatment agent of the present invention contains the modified silicone (B), the weight ratio of the modified silicone (B) in the nonvolatile content of the treatment agent is more preferably 5 to 40% by weight, further 10 to 30% by weight. Preferably, 15 to 25% by weight is particularly preferable.

The precursor treating agent of the present invention contains a surfactant as an emulsifier, and emulsifies or disperses the sulfur-containing ester compound (A1), the sulfur-containing ester compound (A2), and the modified silicone in water, and disperses them in water. A state in which the emulsion is formed is preferable.
There is no particular limitation on the weight ratio of water and the weight ratio of non-volatile content in the entire precursor treatment agent. For example, what is necessary is just to determine suitably in consideration of the transport cost at the time of transporting the precursor processing agent of this invention, the handleability resulting from emulsion viscosity, etc. The weight ratio of water to the entire precursor treatment agent is preferably 0.1 to 99.9% by weight, more preferably 10 to 99.5% by weight, and particularly preferably 50 to 99% by weight. The weight ratio (concentration) of the non-volatile component in the entire precursor treatment agent is preferably 0.01 to 99.9% by weight, more preferably 0.5 to 90% by weight, and particularly preferably 1 to 50% by weight.

  The average particle size of the emulsion in the precursor treatment agent is preferably 0.05 to 0.30 μm, more preferably 0.06 to 0.20 μm, and further preferably 0.07 to 0.10 μm. When the average particle diameter is less than 0.05 μm, the treatment agent can easily penetrate into the fiber, and the strength of the obtained carbon fiber may be lowered. On the other hand, when the average particle diameter is more than 0.30 μm, the treatment agent cannot uniformly adhere to the fiber surface, and the strength of the obtained carbon fiber may be lowered. In addition, the average particle diameter as used in the field of this invention means the average value computed from the particle size distribution measured with the laser diffraction / scattering type particle size distribution measuring apparatus (LA-910 by Horiba).

  The precursor treating agent of the present invention can be produced by mixing the components described above. The method for emulsifying and dispersing the components described above is not particularly limited, and a known method can be employed. As such a method, for example, each component constituting the precursor treatment agent is charged into warm water under stirring and emulsified and dispersed, and each component constituting the precursor treatment agent is mixed, a homogenizer, a homomixer, Examples of the method include phase inversion emulsification by gradually adding water while applying a mechanical shearing force using a ball mill or the like.

  Moreover, a precursor and carbon fiber can be manufactured using the precursor processing agent of this invention. The method for producing a precursor and carbon fiber using the precursor treating agent of the present invention is not particularly limited, and examples thereof include the following production methods.

[Precursor and production method thereof, and production method of carbon fiber]
The acrylic fiber (precursor) for producing carbon fiber of the present invention is produced by attaching the above-mentioned precursor treating agent to the precursor acrylic fiber of the precursor. The method for producing a precursor according to the present invention includes a yarn-making process in which the precursor treatment agent is attached to the precursor acrylic fiber of the precursor to produce a yarn.
The carbon fiber production method of the present invention includes a spinning process in which the precursor treatment agent is attached to the precursor acrylic fiber of the precursor to produce the precursor, and the precursor produced in the spinning process is oxidized at 200 to 300 ° C. It includes a flameproofing treatment step for converting to flameproofing fiber in an atmosphere, and a carbonization treatment step for carbonizing the flameproofing fiber in an inert atmosphere at 300 to 2000 ° C.

The yarn making process is a process of making a precursor by attaching a precursor treating agent to the precursor acrylic fiber of the precursor, and includes an adhesion treatment process and a stretching process.
The adhesion treatment process is a process of adhering a precursor treatment agent after spinning precursor acrylic fiber. That is, the precursor treatment agent is adhered to the precursor raw acrylic fiber in the adhesion treatment step. The precursor raw acrylic fiber is stretched immediately after spinning, and the high-strength stretching after the adhesion treatment step is particularly called a “stretching step”. The stretching process may be a wet heat stretching method using high temperature steam or a dry heat stretching method using a hot roller.

  A precursor is comprised from the acrylic fiber which has as a main component the polyacrylonitrile obtained by copolymerizing at least 95 mol% or more of acrylonitrile and 5 mol% or less of a flame-resistant acceleration | stimulation component. As the flame resistance promoting component, a vinyl group-containing compound having copolymerizability with acrylonitrile can be suitably used. Although there is no limitation in particular about the single fiber fineness of a precursor, from the balance of a performance and manufacturing cost, Preferably it is 0.1-2.0 dTex. Further, the number of single fibers constituting the precursor fiber bundle is not particularly limited, but is preferably 1,000 to 96,000 from the balance between performance and production cost.

  The precursor treatment agent may be attached to the precursor raw acrylic fiber at any stage of the yarn production process, but it is preferably attached once before the drawing process. It may be attached at any stage before the stretching process, for example, immediately after spinning. Further, it may be reattached at any stage after the stretching process, for example, it may be reattached immediately after the stretching process, it may be reattached at the winding stage, or it may be reattached immediately before the flameproofing process. You may let them. As for the attachment method, it may be attached using a roller or the like, or may be attached by a dipping method, a spray method or the like.

  In the adhesion treatment process, the application rate of the precursor treatment agent obtains an anti-sticking effect between fibers and fibers and an anti-fusing effect, and prevents deterioration of the quality of the carbon fiber due to the tar product of the treatment agent in the carbonization treatment process. From the balance with this, it is preferably 0.1 to 2% by weight, more preferably 0.3 to 1.5% by weight, based on the weight of the precursor. When the application rate of the precursor treatment agent is less than 0.1% by weight, sticking and fusion between single fibers cannot be sufficiently prevented, and the strength of the obtained carbon fibers may be lowered. On the other hand, if the application rate of the precursor treatment agent exceeds 2% by weight, the precursor treatment agent covers more than necessary between the single fibers, so that the supply of oxygen to the fibers is hindered in the flameproofing treatment step, and the resulting carbon fiber The strength of the may decrease. In addition, the provision rate of a precursor processing agent here is defined with the percentage of the non volatile matter weight to which the precursor processing agent adhered with respect to the precursor weight.

  The flameproofing treatment step is a step of converting the precursor to which the precursor treating agent is attached to flameproofing fibers in an oxidizing atmosphere of 200 to 300 ° C. The oxidizing atmosphere is usually an air atmosphere. The temperature of the oxidizing atmosphere is preferably 230 to 280 ° C. In the flameproofing treatment step, the acrylic fiber after the adhesion treatment is applied for 20 to 100 minutes (preferably 30) while applying a tension ratio of 0.90 to 1.10 (preferably 0.95 to 1.05). Heat treatment is performed for ˜60 minutes. In this flameproofing treatment, a flameproof fiber having a flameproof structure is produced through intramolecular cyclization and oxygen addition to the ring.

  The carbonization treatment step is a step of carbonizing the flameproof fiber in an inert atmosphere of 300 to 2000 ° C. In the carbonization treatment step, first, in a firing furnace having a temperature gradient from 300 ° C. to 800 ° C. in an inert atmosphere such as nitrogen or argon, a tension ratio of 0.95 to 1.15 is applied to the flameproof fiber. It is preferable to carry out a pre-carbonization treatment step (first carbonization treatment step) by applying heat treatment for several minutes while applying. Thereafter, in order to further promote carbonization and advance graphitization, a tension ratio of 0.95 to 1.05 is applied to the first carbonization treatment step in an inert atmosphere such as nitrogen or argon. While being applied, heat treatment is performed for several minutes to perform the second carbonization treatment step, and the flame resistant fiber is carbonized. About control of the heat processing temperature in a 2nd carbonization process process, it is good to make maximum temperature into 1000 degreeC or more (preferably 1000-2000 degreeC), applying a temperature gradient. This maximum temperature is appropriately selected and determined according to the required characteristics (tensile strength, elastic modulus, etc.) of the desired carbon fiber.

  In the carbon fiber manufacturing method of the present invention, when a carbon fiber having a higher elastic modulus is desired, the graphitization treatment step can be performed subsequent to the carbonization treatment step. The graphitization treatment step is usually performed at a temperature of 2000 to 3000 ° C. while applying tension to the fiber obtained in the carbonization treatment step in an inert atmosphere such as nitrogen or argon.

  The carbon fiber thus obtained can be subjected to a surface treatment for increasing the adhesive strength with the matrix resin when made into a composite material, depending on the purpose. As the surface treatment method, gas phase or liquid phase treatment can be adopted, and from the viewpoint of productivity, liquid phase treatment with an electrolytic solution of acid, alkali or the like is preferable. Furthermore, various sizing agents having excellent compatibility with the matrix resin can be added to improve the processability and handleability of the carbon fiber.

  EXAMPLES Hereinafter, although an Example demonstrates this invention concretely, it is not limited to the Example described here. In addition, the percentage (%) and part shown in the following examples indicate “% by weight” and “part by weight” unless otherwise specified. Each characteristic value was measured based on the following method.

<Calculation method of weight ratio of sulfur-containing ester compound (A1) and sulfur-containing ester compound (A2) in ester mixture>
(1) Gas chromatography analysis The thiodipropionic acid content (S (g)) in 1 g of the ester mixture was quantified by an internal standard method. The analysis conditions of the gas chromatography analysis are shown below.
Equipment: GC-2010 manufactured by Shimadzu Corporation
Column: J & W TC-5 30m x 0.25m
Column temperature: 80 to 300 ° C. (temperature increase rate 10 ° C./min)
Injection temperature / detector temperature: 300 ° C / 300 ° C
Detector: FID
Carrier gas: acid value of thiodipropionic acid in helium (2) ester mixture (T (mg KOH / g))
S × 112220 / 178.21 = T
S: Thiodipropionic acid content (g) in 1 g of ester mixture determined by gas chromatography analysis
(3) The total acid value ester mixture was measured according to JIS K2501 (2003).
(4) Calculation method of weight ratio Sulfur-containing ester compound (A1): Sulfur-containing ester compound (A2)
= (100-X): X
X: (A−T) × M / 561.1
A: Total acid value of the ester mixture (mgKOH / g)
T: Acid value of thiodipropionic acid in the ester mixture (mgKOH / g)
M: Molecular weight of the sulfur-containing ester compound (A2)

<Average particle size (emulsification stability)>
The precursor treatment agent was diluted with water so that the transmittance was 90% or more, and the average value was calculated from the particle size distribution measured with a laser diffraction / scattering type particle size distribution analyzer (LA-910, manufactured by Horiba).

<Application rate of treatment agent>
The application rate of the precursor treatment agent was calculated by an ethanol extraction method using a Soxhlet extractor. However, about the Examples 11-16 containing a silicone type compound and the comparative example 1, the provision rate was computed with the following method.
The precursor after application of the treatment agent was alkali-melted with potassium hydroxide / sodium butyrate, dissolved in water, and adjusted to pH 1 with hydrochloric acid. This was added with sodium sulfite and ammonium molybdate to develop a color, and colorimetric determination (wavelength 815 mμ) of silicomomolybdenum blue was performed to determine the silicon content. Using the silicon content obtained here and the value of the silicon content in the treatment agent obtained in advance by the same method, the application rate (% by weight) of the precursor treatment agent was calculated.

<Friction between fiber and fiber>
Tension (g) when the carbon fiber strand was set in the fiber-fiber friction measuring machine shown in FIG. Was defined as a fiber-fiber friction force.

<Friction between fiber and metal>
After degreasing the carbon fiber strands, each treatment agent was applied so that the treatment agent application amount (OPU) was 1.0% by weight, and the tension (g) measured using a running yarn friction measuring machine was determined as fiber-metal. Frictional force was used.
<Measurement conditions>
Yarn speed: 50 m / min
Load: 50g
Friction body: satin chrome pin

<Abrasion resistance>
Using a TM-type friction conjugation force tester TM-200 (manufactured by Daiei Kagaku Seiki Co., Ltd.), carbon fiber strands were rubbed 1000 times with a tension of 50 g through three mirror-finished chrome-plated stainless needles arranged in a zigzag (reciprocating speed 300). Times / minute), and the state of fluff of the carbon fiber strand was visually determined according to the following criteria.
◎: No fluffing was observed as before rubbing ○: Several fluffs were seen but good scratch resistance △: Slightly fuzzed and slightly inferior in scratch resistance ×: Many fuzzed and marked single yarn breakage Seen poor scratch resistance

<Yarn operability (roller dirt)>
The degree of contamination (gum-up) of the drying roller after applying the treatment agent to 50 kg of the precursor was determined according to the following evaluation criteria.
◎: There is no roller contamination due to gum-up, and there is no problem with spinning operation ○: Little roller contamination due to gum-up and there is no problem with yarn-making operability △: Roller contamination due to gum-up is slightly inferior, x Roller contamination due to

<Fused prevention>
Twenty locations were selected at random from carbon fibers, 10 mm-long short fibers were cut out therefrom, the fused state was observed, and the following evaluation criteria were used.
◎: No fusion ○: Almost no fusion △: Less fusion ×: Many fusion

<Carbon fiber strength>
Measurement was performed according to the epoxy resin impregnated strand method defined in JIS-R-7601, and the average value of 10 measurements was defined as carbon fiber strength (GPa).

[Example 1]
The following ester compound a1 which is a sulfur-containing ester compound (A1) is converted into a nonionic surfactant (polyoxyethylene 7 mol addition alkyl ether (the alkyl group has 12 to 14 carbon atoms), polyoxyethylene 12 mol addition tristyrenated phenyl. Ether and ethylene oxide / propylene oxide (50/50) block copolymer) are water-based emulsified, and the treatment consists of a weight ratio of ester compound a1 / nonionic surfactant = 70/30 as a non-volatile composition of the treatment agent. An agent emulsion (precursor treatment agent) was obtained. The concentration of the treatment agent non-volatile content was 3.0% by weight.
This treating agent emulsion was attached to a precursor (single fiber fineness 0.8 dtex, 24,000 filaments) so as to give an application rate of 1.0% by weight, and dried at 100 to 140 ° C. to remove moisture. The precursor after adhering the treatment agent was flameproofed for 60 minutes in a 250 ° C flameproofing furnace, and then baked in a carbonization furnace having a temperature gradient of 300 to 1400 ° C in a nitrogen atmosphere to be converted into carbon fibers. Table 1 shows the evaluation results of the characteristic values.

[Examples 2 to 10 and Comparative Examples 1 to 7]
In Example 1, it was carried out similarly to Example 1 except having prepared the processing agent emulsion so that it might become the processing agent non-volatile composition (weight%) shown to Table 1, 2, 4, respectively. The evaluation results are shown in Tables 1, 2, and 4.

Example 11
The following ester mixture a5, which is an ester mixture of the sulfur-containing ester compound (A1) and the sulfur-containing ester compound (A2), and the following silicone compound b1 are mixed with a nonionic surfactant (polyoxyethylene 7 mol addition alkyl ether (carbon of alkyl group). The number is 12 to 14), polyoxyethylene 12 mol addition tristyrenated phenyl ether and ethylene oxide / propylene oxide (50/50) block copolymer) are water-based emulsified, and the treatment agent non-volatile composition is ester mixture a5 / silicone. The processing agent emulsion (precursor processing agent) which consists of a weight ratio of the compound b1 / nonionic surfactant = 50/20/30 was obtained. The concentration of the treatment agent non-volatile content was 3.0% by weight.
This treating agent emulsion was attached to a precursor (single fiber fineness 0.8 dtex, 24,000 filaments) so as to give an application rate of 1.0% by weight, and dried at 100 to 140 ° C. to remove moisture. The precursor after adhering the treatment agent was flameproofed for 60 minutes in a 250 ° C flameproofing furnace, and then baked in a carbonization furnace having a temperature gradient of 300 to 1400 ° C in a nitrogen atmosphere to be converted into carbon fibers. Table 3 shows the evaluation results of each characteristic value.

[Examples 12 to 16]
In Example 11, it was carried out similarly to Example 11 except having prepared the processing agent emulsion so that it might become the processing agent non-volatile composition (weight%) shown in Table 3, respectively. The evaluation results are shown in Table 3.

  In the following ester mixture examples and Tables 1 to 4, “A1: A2” represents the weight ratio (A1: A2) between the sulfur-containing ester compound (A1) and the sulfur-containing ester compound (A2), and “ “(A1 + A2): B” indicates a weight ratio ((A1 + A2): B) of the sulfur-containing ester compound (A1) and the sulfur-containing ester compound (A2) to the modified silicone (B).

[Sulfur-containing ester compound (A1)]
a1: Thiodipropionic acid di (n-dodecyl) ester a2: Thiodipropionic acid di (2-hexyldecyl) ester In Tables 1 to 4, the sulfur-containing ester compound (A1) is shown as an ester compound A1.

[Ester mixture of sulfur-containing ester compound (A1) and sulfur-containing ester compound (A2)]
a3: Mixture of thiodipropionic acid di (n-dodecyl) ester and thiodipropionic acid mono (n-dodecyl) ester (A1: A2 = 95: 5)
a4: Mixture of thiodipropionic acid di (2-hexyldecyl) ester and thiodipropionic acid mono (2-hexyldecyl) ester (A1: A2 = 99.6: 0.4)
a5: Mixture of thiodipropionic acid di (2-hexyldecyl) ester and thiodipropionic acid mono (2-hexyldecyl) ester (A1: A2 = 95: 5)
a6: Mixture of thiodipropionic acid di (2-hexyldecyl) ester and thiodipropionic acid mono (2-hexyldecyl) ester (A1: A2 = 85: 15)
a7: Mixture of thiodipropionic acid di (2-hexyldecyl) ester and thiodipropionic acid mono (2-hexyldecyl) ester (A1: A2 = 75: 25)
In Tables 1 to 4, the ester mixture of the sulfur-containing ester compound (A1) and the sulfur-containing ester compound (A2) is simply referred to as ester mixture A1 / A2.

[Modified silicone (B)]
b1: Amino-modified silicone (viscosity at 25 ° C .: 1300 mm ² / s, amino equivalent: 2000 g / mol, modified type: diamine)
b2: amino-modified silicone (25 ° C. viscosity: 4500 mm ² / s, amino equivalent: 1000 g / mol, modified type: diamine)
b3: amino-modified silicone (25 ° C. viscosity: 120 mm ² / s, amino equivalent: 5000 g / mol, modified type: monoamine)

[Ester compound (C)]
c1: Dilauryl ester of ethylene oxide 2 mol adduct of bisphenol A c2: Mixture of thiodipropionic acid di (n-octyl) ester and thiodipropionic acid mono (n-octyl) ester (diester to monoester and weight ratio is 95: 5)
c3: Mixture of thiodipropionic acid dioleyl ester and thiodipropionic acid monooleyl ester (weight ratio of diester to monoester is 95: 5)
c4: thiodipropionic acid di (n-octyl) ester c5: thiodipropionic acid dioleyl ester c6: thiodipropionic acid mono (2-hexyldecyl) ester

As shown in Tables 1 to 4, all of the carbon fibers treated with the precursor treating agents of the examples can achieve both fusion prevention between fibers and stable operability, and further, fiber breakage In addition, the generation of fuzz was suppressed, and the carbon fiber strength was very good.
On the other hand, the carbon fiber treated with the precursor treating agent of the comparative example has a relatively good carbon fiber strength as in the comparative example 1, but the roller dirt is generated and the stable operability cannot be obtained. As in Examples 2, 3, and 5, it can be seen that the fiber-metal friction is high, the scratch resistance is deteriorated, and the carbon fiber strength is inferior. In Comparative Examples 2 and 5, in particular, the average particle diameter is slightly large, so it is considered that the treatment agent could not be uniformly adhered to the fibers and the performance of the treatment agent could not be exhibited. In Comparative Examples 4, 6, and 7, the ester component was tarned to cause much fiber fusion, resulting in poor carbon fiber strength. In particular, in Comparative Example 7, it is considered that the fiber-to-fiber friction was low, the convergence was insufficient, and the performance of the treatment agent could not be exhibited.

  The acrylic fiber treatment agent for producing carbon fibers of the present invention is a treatment agent used when producing acrylic fibers for producing carbon fibers, and is useful for producing high-quality carbon fibers. The acrylic fiber for producing carbon fiber of the present invention is treated with the treatment agent of the present invention and is useful for producing high-quality carbon fiber. High quality carbon fibers can be obtained by the carbon fiber manufacturing method of the present invention.

1 Tension measuring instrument 2 Guide roller 3 Load 4 Carbon fiber strand

EXAMPLES Hereinafter, although an Example demonstrates this invention concretely, it is not limited to the Example described here. In addition, the percentage (%) and part shown in the following examples indicate “% by weight” and “part by weight” unless otherwise specified. Each characteristic value was measured based on the following method. Examples 1 and 2 are referred to as Reference Examples 1 and 2.

Claims (11)

The acrylic fiber processing agent for carbon fiber manufacture containing the sulfur-containing ester compound (A1) shown by following General formula (1), surfactant, and water.

(In the formula, m and n are each independently an integer of 1 to 4, and R ¹ and R ² are each independently a hydrocarbon group having 12 to 16 carbon atoms.) The processing agent of Claim 1 which further contains the sulfur-containing ester compound (A2) shown by following General formula (2).

(In the formula, m and n are each independently an integer of 1 to 4, and R ³ is a hydrocarbon group having 12 to 16 carbon atoms.)   The processing agent of Claim 2 whose weight ratio (A1 / A2) of the said sulfur-containing ester compound (A1) and the said sulfur-containing ester compound (A2) is 99.9 / 0.1-50 / 50.   The total weight ratio of the sulfur-containing ester compound (A1) and the sulfur-containing ester compound (A2) in the nonvolatile content of the treatment agent or the sulfur-containing ester compound ( The processing agent in any one of Claims 1-3 whose weight ratio of A1) is 30-98.9 weight%, and whose weight ratio of the said surfactant is 1-40 weight%.   The processing agent according to any one of claims 1 to 4, further comprising a modified silicone (B) having a modifying group containing a nitrogen atom.   Does not include the sulfur-containing ester compound (A1) and the weight ratio (A1 + A2) / B) of the sum of the sulfur-containing ester compound (A2) and the modified silicone (B), or the sulfur-containing ester compound (A2). In this case, the treatment agent according to claim 5, wherein a weight ratio (A1 / B) of the sulfur-containing ester compound (A1) to the modified silicone (B) is 99.9 / 0.1 to 50/50.   The processing agent according to claim 5 or 6, wherein the modified silicone (B) is an amino-modified silicone.   The processing agent according to any one of claims 1 to 7, which is an emulsion dispersed in water.   The acrylic fiber for carbon fiber manufacture which made the yarn by making the processing agent in any one of Claims 1-8 adhere to the raw material acrylic fiber of the acrylic fiber for carbon fiber manufacture.   The manufacturing method of the acrylic fiber for carbon fiber manufacture including the yarn-making process which makes the processing agent in any one of Claims 1-8 adhere to the raw material acrylic fiber of the acrylic fiber for carbon fiber manufacture, and produces a yarn.   A process for producing the carbon fiber-producing acrylic fiber by attaching the treatment agent according to any one of claims 1 to 8 to the raw acrylic fiber of the carbon fiber-producing acrylic fiber, and carbon produced by the yarn-making process. A flameproofing treatment step of converting acrylic fibers for fiber production into flameproofing fibers in an oxidizing atmosphere of 200 to 300 ° C, and a carbonization treatment step of carbonizing the flameproofing fibers in an inert atmosphere of 300 to 2000 ° C. The manufacturing method of carbon fiber containing these.

Images