JP7098210B1 - Treatment agents for carbon fiber precursors and carbon fiber precursors - Google Patents

Abstract

A carbon fiber precursor treatment agent and a carbon fiber precursor capable of reducing fluffiness of flame-resistant fibers are provided. The carbon fiber precursor treatment agent of the present invention comprises a smoothing agent (A) containing an ester compound (A1) of glycerin and a fatty acid containing the following fatty acid (X), and (poly)oxyalkylene The ratio of the total mass of fatty acids having 16 to 24 carbon atoms derived from the ester compound (A1) to the total mass of fatty acids derived from the ester compound (A1) in the carbon fiber precursor treatment agent containing the derivative (B) It is characterized by being 50% by mass or more. Fatty acid (X): A fatty acid having 16 or more and 24 or less carbon atoms. [Selection figure] None

Description

The present invention relates to a treatment agent for a carbon fiber precursor capable of reducing fluffing of flame-resistant fibers and a carbon fiber precursor obtained thereby.

Generally, carbon fiber is widely used in various fields such as building materials and transportation equipment as a carbon fiber composite material or a flame-retardant / flame-retardant material combined with a matrix resin, for example. For example, carbon fiber is produced as a carbon fiber precursor through, for example, a step of spinning acrylic fiber, a step of stretching the fiber, a flame resistance step, and a carbonization step. As the carbon fiber precursor, a treatment agent for a carbon fiber precursor may be used in order to impart concentrating property in the spinning process of the carbon fiber precursor.

Conventionally, a treatment agent for a carbon fiber precursor disclosed in Patent Document 1 is known. Patent Document 1 describes a predetermined poly such as a polyoxyalkylene block copolymer obtained by addition-polymerizing an alkylene oxide to an aliphatic hydroxy compound having a hydroxyl group, and an oil / fat containing glyceride having a fatty acid residue having 12 to 22 carbon atoms as a main component. A treatment agent for an acrylic synthetic fiber containing an oxyethylene glycol alkenyl ether or the like in a predetermined ratio is disclosed.

Japanese Unexamined Patent Publication No. 2002-88654

However, the conventional treatment agent for carbon fiber precursor has a problem that the effect of reducing the fluff of the flame-resistant fiber after the flame-resistant treatment of the carbon fiber precursor to which the treatment agent for carbon fiber precursor is applied is insufficient. was there.

As a result of research to solve the above-mentioned problems, the present inventors have found that a treatment agent for a carbon fiber precursor containing a predetermined ester compound and a (poly) oxyalkylene derivative is just suitable.

In order to solve the above problems, in the treatment agent for a carbon fiber precursor according to one aspect of the present invention, a smoothing agent (A) containing an ester compound (A1) of glycerin and a fatty acid containing the following fatty acid (X). , And the (poly) oxyalkylene derivative (B), and the composition ratio of the fatty acid (X) determined from the following formula 1 is 50% by mass or more.

Fatty acid (X): A fatty acid having 16 or more and 24 or less carbon atoms.

前記炭素繊維前駆体用処理剤において、前記数式１から求められる脂肪酸（Ｘ）の構成割合が、７０質量％以上であってもよい。

In the treatment agent for carbon fiber precursor, the composition ratio of the fatty acid (X) determined from the formula 1 may be 70% by mass or more.

In the treatment agent for a carbon fiber precursor, the (poly) oxyalkylene derivative (B) has 2 carbon atoms with respect to an ester compound of an alcohol having a monovalent or more and trivalent or less and a monovalent fatty acid having 16 or more and 24 or less carbon atoms. A compound to which an alkylene oxide of 4 or more is added may be contained.

Assuming that the total content of the smoothing agent (A) and the (poly) oxyalkylene derivative (B) in the treatment agent for carbon fiber precursor is 100% by mass, the smoothing agent (A) is 10% by mass. 90% by mass or more, and the (poly) oxyalkylene derivative (B) may be contained in a proportion of 10% by mass or more and 90% by mass or less.

The treatment agent for a carbon fiber precursor may further contain a condensed hydroxy fatty acid (C).
When the total content of the smoothing agent (A), the (poly) oxyalkylene derivative (B), and the condensed hydroxy fatty acid (C) in the treatment agent for carbon fiber precursor is 100% by mass, the smoothing is performed. The agent (A) is 9.9% by mass or more and 89.9% by mass or less, the (poly) oxyalkylene derivative (B) is 10% by mass or more and 90% by mass or less, and the condensed hydroxy fatty acid (C) is 0.1. It may be contained in a proportion of mass% or more and 50% by mass or less.

The treatment agent for a carbon fiber precursor may further contain an ionic component (D).
The treatment agent for a carbon fiber precursor may further contain a condensed hydroxy fatty acid (C) and an ionic component (D).

In the treatment agent for carbon fiber precursor, the total content ratio of the smoothing agent (A), the (poly) oxyalkylene derivative (B), the condensed hydroxy fatty acid (C), and the ionic component (D) is added. Assuming 100% by mass, the smoothing agent (A) is 9.9% by mass or more and 89.9% by mass or less, and the (poly) oxyalkylene derivative (B) is 9.9% by mass or more and 89.9% by mass or less. The condensed hydroxy fatty acid (C) may be contained in an amount of 0.1% by mass or more and 50% by mass or less, and the ionic component may be contained in a proportion of 0.1% by mass or more and 10% by mass or less.

In order to solve the above problems, the gist of the carbon fiber precursor of another aspect of the present invention is that the treatment agent for the carbon fiber precursor is attached.

According to the present invention, it is possible to reduce the fluff of the flame-resistant fiber after the carbon fiber precursor to which the treatment agent for the carbon fiber precursor is applied is treated to be flame-resistant.

<First Embodiment>
Hereinafter, the first embodiment in which the treatment agent for a carbon fiber precursor of the present invention (hereinafter, also simply referred to as a treatment agent) is embodied will be described. The treatment agent of the present embodiment contains a smoothing agent (A) containing the following ester compound (A1) and a (poly) oxyalkylene derivative (B).

(Smoothing agent (A))
The smoothing agent (A) used in the present embodiment contains an ester compound (A1) of glycerin and a fatty acid containing the following fatty acid (X). The fatty acid (X) is a fatty acid having 16 or more and 24 or less carbon atoms. As the fatty acid constituting the ester compound (A1), a known fatty acid can be appropriately adopted, and it may be a saturated fatty acid or an unsaturated fatty acid. Further, it may be linear or may have a branched chain structure. Further, the fatty acid may be a monovalent carboxylic acid or a polyvalent carboxylic acid. Further, it may be an oxycarboxylic acid having a hydroxyl group.

Specific examples of the saturated fatty acid include hexadecanoic acid (palmitic acid), octadecanoic acid (stearic acid), eicosanoic acid (arachidic acid), docosanoic acid (bechenic acid), tetracosanoic acid and the like. Specific examples of unsaturated fatty acids include palmitoleic acid, oleic acid, vaccenic acid, eicosenoic acid, linoleic acid, α-linolenic acid, gamma-linolenic acid, arachidonic acid and the like. Specific examples of the oxycarboxylic acid include ricinoleic acid and the like.

In the ester compound (A1), the composition ratio of the fatty acid (X) determined from the following formula is 50% by mass or more, preferably 70% by mass or more. By defining in such a numerical range, the effect of the present invention can be further improved.

エステル化合物（Ａ１）の具体例としては、例えばヒマシ油（上記数式の値は１００質量％）、ナタネ油（上記数式の値は１００質量％）、ゴマ油（上記数式の値は１００質量％）、パーム油（上記数式の値は９９質量％）、アマニ油（上記数式の値は１００質量％）、ヒマワリ油（上記数式の値は１００質量％）、グリセリンと、リシノール酸及び他の脂肪酸とのエステル化合物であって上記数式の値が５０質量％以上のもの、グリセリンと、パルミチン酸及び他の脂肪酸とのエステル化合物であって上記数式の値が５０質量％以上のもの、グリセリンと、オレイン酸及び他の脂肪酸とのエステル化合物であって上記数式の値が５０質量％以上のもの等が挙げられる。

Specific examples of the ester compound (A1) include castor oil (value in the above formula is 100% by mass), rapeseed oil (value in the above formula is 100% by mass), sesame oil (value in the above formula is 100% by mass), and the like. Palm oil (value in the above formula is 99% by mass), flaxseed oil (value in the above formula is 100% by mass), sunflower oil (value in the above formula is 100% by mass), glycerin, and ricinolic acid and other fatty acids. Ester compounds having a value of 50% by mass or more in the above formula, ester compounds of glycerin with palmitic acid and other fatty acids having a value of 50% by mass or more in the above formula, glycerin and oleic acid. And ester compounds with other fatty acids such as those having a value of 50% by mass or more in the above formula.

These ester compounds (A1) may be used alone or in combination of two or more.
The lower limit of the content ratio of the ester compound (A1) in the treatment agent is appropriately set, but is preferably 5% by mass or more, more preferably 10% by mass or more. When the content ratio is 5% by mass or more, the fluff of the flame-resistant fiber after the carbon fiber precursor to which the treatment agent is applied is treated to be flame-resistant can be further reduced. The upper limit of the content ratio of the ester compound (A1) is appropriately set, but is preferably 90% by mass or less, more preferably 85% by mass or less. When the content ratio is 90% by mass or less, the stability of the treatment agent can be improved. A range in which the above upper limit and lower limit are arbitrarily combined is also assumed.

The smoothing agent (A) may contain other smoothing components other than the ester compound (A1) as long as the effects of the present invention are not impaired. The other smoothing component is not particularly limited, and a known smoothing agent used as a treatment agent can be used. Examples of known smoothing agents include silicone oils, mineral oils, polyolefins, ester compounds other than the above, and the like. In addition, silicone oil may contaminate the firing furnace by using it. Therefore, the silicone oil in the treatment agent is preferably 5% by mass or less, more preferably 1% by mass or less, and further preferably not blended. The content ratio of the ester compound (A1) in the smoothing agent (A) is appropriately set within a range that does not impair the effect of the present invention, and is, for example, 50% by mass or more and 100% by mass or less, and 80% by mass or more and 100% by mass. It is as follows. A range in which the above upper limit and lower limit are arbitrarily combined is also assumed.

These smoothing agents (A) may be used alone or in combination of two or more.
((Poly) oxyalkylene derivative (B))
The (poly) oxyalkylene derivative (B) provided in the present embodiment improves each function as a treatment agent by improving the stability of the treatment agent as a surfactant.

The (poly) oxyalkylene derivative (B) has, for example, an alcohol or a carboxylic acid having an alkylene oxide added to the (poly) oxyalkylene structure, or an alkylene oxide added to an ester compound of the carboxylic acid and the polyhydric alcohol. An ether ester compound having a (poly) oxyalkylene structure, an amine compound having an alkylene oxide added to an aliphatic amine, and a fatty acid amide having an alkylene oxide added (). Examples thereof include those having a poly) oxyalkylene structure, a block copolymer of a polyoxyethylene chain and a polyoxypropylene chain, and the like.

Specific examples of the alcohols used as the raw material of the (poly) oxyalkylene derivative (B) include (1) methanol, ethanol, propanol, butanol, pentanol, hexanol, octanol, nonanol, decanol, undecanol, dodecanol, and the like. Tridecanol, tetradecanol, pentadecanol, hexadecanol, heptadecanol, octadecanol, nonadecanol, eikosanol, heneicosanol, docosanol, tricosanol, tetracosanol, pentacosanol, hexacosanol, heptacosanol, octacosanol , Nonacosanol, Triacontanol and other linear alkyl alcohols, (2) Isopropanol, Isobutanol, Isohexanol, 2-Ethylhexanol, Isononanol, Isodecanol, Isoddecanol, Isotridecanol, Isotetradecanol, Isotriacon Tanol, Isohexadecanol, Isoheptadecanol, Isooctadecanol, Isononadecanol, Isoeicosanol, Isoheneicosanol, Isodocosanol, Isotricosanol, Isotetracosanol, Isopentacosa Branched alkyl alcohols such as Noll, Isohexacosanol, Isoheptacosanol, Isooctacosanol, Isononacosanol, Isopentadecanol, (3) Linear alkenyl alcohols such as Tetradecenol, Hexadesenol, Heptadesenol, Octadesenol, Nonadesenol, (4). ) Branched alkenyl alcohols such as isohexadecenol and isooctadecenol, (5) cyclic alkyl alcohols such as cyclopentanol and cyclohexanol, (6) phenols, nonylphenols, benzyl alcohols, monostyrene phenols and distyrenes. Examples thereof include aromatic alcohols such as phenol and tristyrene phenol.

Specific examples of the carboxylic acids used as the raw material of the (poly) oxyalkylene derivative (B) include (1) octyl acid, nonanoic acid, decanoic acid, undecanoic acid, dodecanoic acid, tridecanoic acid, tetradecanoic acid and pentadecanoic acid. , Hexadecanoic acid, heptadecanoic acid, octadecanoic acid, nonadecanoic acid, eikosanoic acid, heneikosanoic acid, docosanoic acid and other linear alkylcarboxylic acids, (2) 2-ethylhexanoic acid, isododecanoic acid, isotridecanoic acid, isotetradecanoic acid, isohexadecane. Branched alkyl carboxylic acids such as acids and isooctadecanoic acids, (3) linear alkenyl carboxylic acids such as octadecenoic acid, octadecadienoic acid and octadecatrienoic acid, (4) aromatic carboxylic acids such as benzoic acid, (5). ) Hydroxycarboxylic acids such as recinolic acid and the like can be mentioned.

As the alkylene oxide used as a raw material for forming the (poly) oxyalkylene structure of the (poly) oxyalkylene derivative (B), an alkylene oxide having 2 or more carbon atoms and 4 or less carbon atoms is preferable. Specific examples of the alkylene oxide include ethylene oxide, propylene oxide, butylene oxide and the like. The number of moles of alkylene oxide added is appropriately set, but is preferably 0.1 mol or more and 250 mol or less, more preferably 1 mol or more and 200 mol or less, and further preferably 2 mol or more and 150 mol or less. A range in which the above upper and lower limits are arbitrarily combined is also assumed. The number of moles of alkylene oxide added indicates the number of moles of alkylene oxide with respect to 1 mole of the compound to be added in the raw material to be charged. As the alkylene oxide, one kind of alkylene oxide may be used alone, or two or more kinds of alkylene oxides may be used in combination as appropriate. When two or more kinds of alkylene oxides are applied, the addition form thereof may be any of block addition, random addition, and a combination of block addition and random addition, and is not particularly limited.

Specific examples of the polyhydric alcohol used as a raw material for the (poly) oxyalkylene derivative (B) include ethylene glycol, propylene glycol, 1,3-propanediol, 1,2-butanediol, and 1,3-butanediol. , 1,4-Butanediol, 2-methyl-1,2-propanediol, 1,5-pentanediol, 1,6-hexanediol, 2,5-hexanediol, 2-methyl-2,4-pentanediol , 2,3-dimethyl-2,3-butanediol, glycerin, 2-methyl-2-hydroxymethyl-1,3-propanediol, trimethylolpropane, sorbitane, pentaerythritol, sorbitol and the like.

Specific examples of the aliphatic amine used as a raw material for the (poly) oxyalkylene derivative (B) include methylamine, ethylamine, butylamine, octylamine, laurylamine, octadecylamine, octadecenylamine, and coconutamine.

Specific examples of the fatty acid amide used as a raw material for the (poly) oxyalkylene derivative (B) include octyl acid amide, lauric acid amide, palmitic acid amide, stearic acid amide, oleic acid amide, behenic acid amide, and lignoceric acid amide. And so on.

The block copolymer of a polyoxyethylene chain and a polyoxypropylene chain has a polyoxypropylene chain having low hydrophilicity and a polyoxyethylene chain having high hydrophilicity, and is not particularly limited as long as it has a surface active action. .. The number of polyoxyethylene chains and polyoxypropylene chains in the molecule is not particularly limited, and may be, for example, a block copolymer composed of one polyoxypropylene chain and one polyoxyethylene chain, or may be a polyoxypropylene chain. It may be a poloxamer-based surfactant composed of two polyoxyethylene chains sandwiching the same. The number of moles of ethylene oxide that forms a polyoxyethylene chain is not particularly limited, and examples thereof include 5 mol and 200 mol or less. The number of moles of propylene oxide that forms a polyoxypropylene chain is not particularly limited, and examples thereof include 5 mol and 100 mol or less.

Among these, a compound obtained by adding an alkylene oxide having 2 or more and 4 or less carbon atoms to an ester compound of a monohydric alcohol or a trihydric polyhydric alcohol and a monohydric fatty acid having 16 or more and 24 or less carbon atoms is preferable. By using such a compound, the stability of the treatment agent can be further improved.

Specific examples of the (poly) oxyalkylene derivative (B) include ω-hydroxy (polyoxyethylene) (n = 7: the number of moles of ethylene oxide added (the same applies hereinafter)) castor oil and ω-hydroxy (poly). Oxyethylene) (n = 20) hardened castor oil, hydroxy (polyoxypropylene polyoxyethylene) (m = 13: indicates the number of moles of propylene oxide added (the same applies hereinafter), n = 10) castor oil, hydroxy (polyoxy). Propylene polyoxyethylene) (m = 12, n = 12) Hardened ethylene oxide, a fat ethylene oxide adduct obtained by addition-polymerizing ethylene oxide at a ratio of 200 mol per mol of castor oil, α-dodecyl-ω-hydroxy (polyoxy) Ethylene) (n = 7), a polyoxyalkylene block copolymer having a number average molecular weight of 5000 obtained by addition-polymerizing ethylene oxide and propylene oxide to ethylene glycol in a block shape, wherein the polyoxyalkylene group is an oxyethylene unit /. A polyoxyalkylene block copolymer composed of an oxypropylene unit = 30/70 (molar ratio), a polyoxyalkylene having a number average molecular weight of 10000 obtained by addition-polymerizing ethylene oxide and propylene oxide in a block shape to ethylene glycol. A polyoxyalkylene block copolymer having a polyoxyalkylene group having a ratio of oxyethylene unit / oxypropylene unit = 70/30 (molar ratio), which is a block copolymer, and the number of repetitions of the oxyethylene unit. Examples thereof include polyoxyethylene glycol octadecenyl ether having a value of 20.

For these (poly) oxyalkylene derivatives (B), one kind of (poly) oxyalkylene derivative may be used alone, or two or more kinds of (poly) oxyalkylene derivatives may be used in combination as appropriate. May be good.

The lower limit of the content ratio of the (poly) oxyalkylene derivative (B) in the treatment agent is appropriately set, but is preferably 5% by mass or more, more preferably 10% by mass or more. When the content ratio is 5% by mass or more, the stability of the treatment agent can be further improved. The upper limit of the content ratio of the (poly) oxyalkylene derivative (B) is appropriately set, but is preferably 95% by mass or less, more preferably 90% by mass or less. When the content ratio is 95% by mass or less, the fluff of the flame-resistant fiber after the carbon fiber precursor to which the treatment agent is applied is treated to be flame-resistant can be further reduced. A range in which the above upper limit and lower limit are arbitrarily combined is also assumed.

Assuming that the total content of the smoothing agent (A) and the (poly) oxyalkylene derivative (B) in the treatment agent is 100% by mass, the smoothing agent (A) is 10% by mass or more and 90% by mass or less, and (poly). ) The oxyalkylene derivative (B) is preferably contained in a proportion of 10% by mass or more and 90% by mass or less. By defining in such a range, the effect of the present invention can be further improved.

(Condensed hydroxy fatty acid (C))
The condensed hydroxy fatty acid (C) provided in the present embodiment can improve the focusing property of the flame-resistant fiber after the carbon fiber precursor to which the treatment agent has been applied is subjected to the flame-resistant treatment.

Condensed hydroxy fatty acid (C) is prepared by, for example, using one or a mixture of two or more hydroxy fatty acids as a raw material under a stream of an inert gas such as nitrogen gas at 100 ° C. or higher and 200 ° C. or lower for 30 minutes or longer and 12 hours or shorter. It is obtained by a dehydration condensation reaction. Specific examples of hydroxy fatty acids include, for example, 12-hydroxy-9-octadecenoic acid (ricinoleic acid), 12-hydroxystearic acid, 16-hydroxyhexadecanoic acid (uniperic acid), 18-hydroxyoctadecanoic acid, 9-hydroxystearic acid, and the like. Examples thereof include 10-hydroxystearic acid, 12-hydroxydecanoic acid (savinic acid), 9,10-dihydroxyoctadecanoic acid, castor oil fatty acid, hydrogenated castor oil fatty acid and the like. The degree of condensation of the condensed hydroxy fatty acid is appropriately set, but is preferably a dimer or more and a hexamer or less.

Specific examples of the condensed hydroxy fatty acid (C) include condensed 12-hydroxystearic acid hexamer, condensed castor oil fatty acid dimer, condensed castor oil fatty acid trimer, condensed castor oil fatty acid tetramer, and condensed castor oil. Examples thereof include fatty acid pentamer and condensed castor oil fatty acid hexamer.

As these condensed hydroxy fatty acids (C), one kind of condensed hydroxy fatty acid may be used alone, or two or more kinds of condensed hydroxy fatty acids may be used in combination as appropriate.

The lower limit of the content ratio of the condensed hydroxy fatty acid (C) in the treatment agent is appropriately set, but is preferably 0.1% by mass or more, more preferably 0.3% by mass or more. When the content ratio is 0.1% by mass or more, the focusing property of the flame-resistant fiber after the flame-resistant treatment of the carbon fiber precursor to which the treatment agent is applied can be further improved. The upper limit of the content ratio of the condensed hydroxy fatty acid (C) is appropriately set, but is preferably 60% by mass or less, more preferably 50% by mass or less. When the content ratio is 60% by mass or less, the stability of the treatment agent can be improved. A range in which the above upper limit and lower limit are arbitrarily combined is also assumed.

Assuming that the total content of the smoothing agent (A), the (poly) oxyalkylene derivative (B), and the condensed hydroxy fatty acid (C) in the treatment agent is 100% by mass, the smoothing agent (A) is 9.9% by mass. % To 89.9% by mass, (poly) oxyalkylene derivative (B) 10% by mass or more and 90% by mass or less, and condensed hydroxy fatty acid (C) 0.1% by mass or more and 50% by mass or less. It is preferable to do so. By defining in such a range, the effect of the present invention can be further improved.

(Ionic component (D))
The ionic component (D) provided in the present embodiment can improve the focusing property of the flame-resistant fiber after the carbon fiber precursor to which the treatment agent has been applied is subjected to the flame-resistant treatment. In addition, the antistatic property of the flame-resistant fiber can be improved. Examples of the ionic component (D) include an anionic component, a cationic component, and the like.

Examples of the anionic component include anionic compounds, such as acids and salts thereof.
Examples of the acid include inorganic acids, organic acids, fatty acids, alkylsulfonic acids, alkyl sulfates, polyoxyalkylene alkyl sulfates, alkyl phosphate esters, polyoxyalkylene alkyl phosphate esters, fatty acid sulfate esters, fat and oil sulfate esters, and the like. Salt and the like.

Specific examples of the inorganic acid or a salt thereof include hydrochloric acid, sulfuric acid, phosphoric acid, nitrate, carbonic acid, sodium hydrogensulfate, sodium dihydrogen phosphate, disodium hydrogen phosphate, sodium hydrogencarbonate and the like.

Specific examples of the organic acid include citric acid, tartrate acid, lactic acid, malic acid, succinic acid, fumaric acid, maleic acid, gluconic acid, glucuronic acid, benzoic acid and the like.
As the fatty acid, a known one can be appropriately adopted, and it may be a saturated fatty acid or an unsaturated fatty acid. Further, it may be linear or may have a branched chain structure. Further, it may be a monovalent fatty acid or a polyvalent carboxylic acid (polybasic acid).

Specific examples of saturated fatty acids include formic acid, acetic acid, propionic acid, butyric acid, valeric acid, hexanic acid (caproic acid), octyl acid (2-ethylhexanoic acid), octanoic acid (caprilic acid), nonanoic acid and decanoic acid. (Caproic acid), dodecanoic acid (lauric acid), tetradecanoic acid (myristic acid), hexadecanoic acid (palmitic acid), octadecanoic acid (stearic acid), eicosanoic acid (arachidic acid), docosanoic acid (bechenic acid), tetracosanoic acid, etc. Can be mentioned.

Specific examples of unsaturated fatty acids include crotonic acid, myristoleic acid, palmitoleic acid, oleic acid, vaccenic acid, eicosenoic acid, linoleic acid, α-linolenic acid, γ-linolenic acid, and arachidonic acid.

Specific examples of the polyvalent carboxylic acid (polybasic acid) include (1) dibasic acids such as succinic acid, fumaric acid, maleic acid, adipic acid and sebacic acid, and (2) tribasic acids such as aconitic acid. (3) Aromatic dicarboxylic acids such as benzoic acid, terephthalic acid, isophthalic acid and 2,6-naphthalenedicarboxylic acid, (4) aromatic tricarboxylic acids such as trimellitic acid, and (5) aromatic tetra such as pyromellitic acid. Examples include carboxylic acid.

Specific examples of the alkyl sulfonic acid include, for example, lauryl sulfonic acid (dodecyl sulfonic acid), myristyl sulfonic acid, cetyl sulfonic acid, oleyl sulfonic acid, stearyl sulfonic acid, tetradecane sulfonic acid, dodecylbenzene sulfonic acid, and secondary alkyl sulfonic acid ( C13 to 15) and the like can be mentioned.

Specific examples of the alkyl sulfuric acid include lauryl sulfate ester, oleyl sulfate ester, stearyl sulfate ester and the like.
Specific examples of the polyoxyalkylene alkyl sulfate include, for example, polyoxyethylene lauryl ether sulfate ester, polyoxyalkylene (polyoxyethylene, polyoxypropylene) lauryl ether sulfate ester, polyoxyethylene dodecyl ether sulfate ester, and polyoxyethylene oleyl ether. Sulfate ester and the like can be mentioned.

Specific examples of the alkyl phosphate ester include lauryl phosphate ester, cetyl phosphate ester, octyl phosphate ester, oleyl phosphate ester, stearyl phosphate, 2-ethylhexyl phosphate and the like.

Specific examples of the polyoxyalkylene alkyl phosphate ester include, for example, polyoxyethylene lauryl ether phosphate, polyoxyethylene cetyl ether phosphate, polyoxyethylene oleyl ether phosphate, polyoxyethylene stearyl ether phosphate, and the like. Can be mentioned.

Specific examples of fatty acid sulfate esters include pine oil fatty acid sulfate ester, sesame oil fatty acid sulfate ester, tall oil fatty acid sulfate ester, soybean oil fatty acid sulfate ester, rapeseed oil fatty acid sulfate ester, palm oil fatty acid sulfate ester, and pig fat fatty acid sulfate ester. Examples thereof include beef fat fatty acid sulfate ester and whale oil fatty acid sulfate ester.

Specific examples of oil and fat sulfate esters include castor oil sulfate ester, sesame oil sulfate ester, tall oil sulfate ester, soybean oil sulfate ester, rapeseed oil sulfate ester, palm oil sulfate ester, and pig fat sulfate ester. Examples thereof include sulfuric acid ester of beef fat and sulfuric acid ester of whale oil.

Examples of the salt include ammonium salt, amine salt, metal salt and the like. Examples of the metal salt include an alkali metal salt and an alkaline earth metal salt. Specific examples of the alkali metal constituting the alkali metal salt include sodium, potassium, lithium and the like. Examples of the alkaline earth metal constituting the alkaline earth metal salt include metals corresponding to Group 2 elements such as calcium, magnesium, beryllium, strontium, and barium.

The amine constituting the amine salt may be any of a primary amine, a secondary amine, and a tertiary amine. Specific examples of the amine constituting the amine salt include (1) methylamine, dimethylamine, trimethylamine, ethylamine, diethylamine, triethylamine, NN-diisopropylethylamine, butylamine, dibutylamine, 2-methylbutylamine and tributylamine. , Octylamine, aliphatic amines such as dimethyllaurylamine, (2) aniline, N-methylbenzylamine, pyridine, morpholine, piperazine, aromatic amines such as derivatives thereof or heterocyclic amines, (3) monoethanolamine. , N-methylethanolamine, diethanolamine, triethanolamine, isopropanolamine, diisopropanolamine, triisopropanolamine, dibutylethanolamine, butyldiethanolamine, octyldiethanolamine, lauryldiethanolamine and other alkanolamines, (4) N-methylbenzylamine and the like. , (5) Polyoxyethylene laurylamino ether, polyoxyalkylene alkylamino ether such as polyoxyethylene sterylamino ether, (6) ammonia and the like.

For example, among the above-mentioned anionic components, metal salts of fatty acids and the like constitute an anionic surfactant. Therefore, an anionic surfactant may be applied as an anionic component.
Examples of the cationic component include cationic surfactants and organic amines.

Specific examples of the cationic surfactant include lauryltrimethylammonium chloride, cetyltrimethylammonium chloride, stearyltrimethylammonium chloride, behenyltrimethylammonium chloride, didecyldimethylammonium chloride, 1,2-dimethylimidazole and the like.

Specific examples of the organic amine include, for example, (1) methylamine, dimethylamine, trimethylamine, ethylamine, diethylamine, triethylamine, NN-diisopropylethylamine, butylamine, dibutylamine, 2-methylbutylamine, tributylamine, octylamine, and the like. Aliphatic amines such as laurylamine and dimethyllaurylamine, (2) aromatic amines or heterocyclic amines such as aniline, N-methylbenzylamine, pyridine, morpholine, piperazine and derivatives thereof, (3) monoethanolamine, Alkanolamines such as N-methylethanolamine, diethanolamine, triethanolamine, isopropanolamine, diisopropanolamine, triisopropanolamine, dibutylethanolamine, butyldiethanolamine, octyldiethanolamine, lauryldiethanolamine, and aryls such as (4) 3-aminopropene. Examples thereof include amines, (5) N, N-bis (polyoxyethylene) dodecaneamines (n = 10), polyoxyethylene laurylamino ethers, polyoxyalkylene alkylamino ethers such as polyoxyethylene steryl amino ethers, and the like.

As these ionic components (D), one kind of ionic component may be used alone, or two or more kinds of ionic components may be used in combination as appropriate.
The lower limit of the content ratio of the ionic component (D) in the treatment agent is appropriately set, but is preferably 0.05% by mass or more, more preferably 0.1% by mass or more. When the content ratio is 0.05% by mass or more, the focusing property of the flame-resistant fiber after the flame-resistant treatment of the carbon fiber precursor to which the treatment agent is applied can be further improved. The upper limit of the content ratio of the ionic component (D) is appropriately set, but is preferably 15% by mass or less, more preferably 10% by mass or less. When the content ratio is 15% by mass or less, the stability of the treatment agent can be improved. A range in which the above upper limit and lower limit are arbitrarily combined is also assumed.

When the total content of the smoothing agent (A), the (poly) oxyalkylene derivative (B), the condensed hydroxy fatty acid (C), and the ionic component (D) in the treatment agent is 100% by mass, the smoothing agent ( A) is 9.9% by mass or more and 89.9% by mass or less, (poly) oxyalkylene derivative (B) is 9.9% by mass or more and 89.9% by mass or less, and condensed hydroxy fatty acid (C) is 0.1% by mass. It is preferable to contain% or more and 50% by mass or less, and an ionic component in a proportion of 0.1% by mass or more and 10% by mass or less. By defining in such a range, the effect of the present invention can be further improved.

According to the treatment agent of the first embodiment, the following effects can be obtained.
(1-1) In the treatment agent of the first embodiment, a smoothing agent (A) containing an ester compound (A1) of glycerin and a fatty acid containing a fatty acid (X) having 16 or more and 24 or less carbon atoms, and (poly). ) Contains the oxyalkylene derivative (B). Then, the composition ratio of the fatty acid (X) obtained from the above formula was defined as 50% by mass or more. Therefore, it is possible to reduce the fluff of the flame-resistant fiber after the carbon fiber precursor to which the treatment agent has been applied is subjected to the flame-resistant treatment. In addition, the focusing property of the flame-resistant fiber can be improved. Further, by improving the stability of the treatment agent, each function as the treatment agent can be improved.

(1-2) In the treatment agent of the first embodiment, silicone oil is not blended as an essential component as a smoothing agent. Silicone oil may contaminate the firing pot when used. Therefore, when the treatment agent does not contain silicone oil, contamination of the firing furnace can be reduced. Further, even if silicone oil is not blended as a smoothing agent, the above-mentioned fluff can be reduced and the focusing property can be improved.

<Second Embodiment>
Next, a second embodiment embodying the carbon fiber precursor according to the present invention will be described. The treatment agent of the first embodiment is attached to the carbon fiber precursor of the present embodiment.

The carbon fiber precursor is preferably a synthetic fiber that becomes a carbon fiber through a carbonization treatment step described later. The fiber raw material constituting the carbon fiber precursor is not particularly limited, and is, for example, (1) polyester fibers such as polyethylene terephthalate, polypropylene terephthalate, and polylactic acid ester, and (2) polyamide fibers such as nylon 6 and nylon 66. Fibers, (3) polyacrylic fibers such as polyacrylic and modal acrylic, (4) polyolefin fibers such as polyethylene and polypropylene, (5) cellulose fibers, (6) lignin fibers, (7) phenol resins, (8) ) Pitch etc. can be mentioned. Further, the polyacrylic fiber is preferably composed of a fiber containing polyacrylonitrile as a main component, which is obtained by copolymerizing at least 90 mol% or more of acrylonitrile and 10 mol% or less of a flame resistance promoting component. .. As the flame resistance promoting component, for example, a vinyl group-containing compound having copolymerizability with acrylonitrile can be preferably used.

The ratio of the treatment agent of the first embodiment to the carbon fiber precursor is not particularly limited, but the treatment agent (without the solvent) is 0.1% by mass or more and 2% by mass or less with respect to the carbon fiber precursor. It is preferable that the fibers are adhered in such a manner, and it is more preferable that the fibers are adhered so as to be 0.3% by mass or more and 1.2% by mass or less.

As a method for adhering the treatment agent to the carbon fiber precursor, for example, a known method in the form of a treatment agent-containing composition containing the treatment agent and the solvent of the first embodiment, or a diluted solution further diluted with a solvent. For example, a method of adhering by a immersion method, a spray method, a roller method, a guide lubrication method using a measuring pump, or the like can be applied.

Next, a method for producing carbon fiber using the carbon fiber precursor of the present embodiment will be described.
The method for producing carbon fiber preferably goes through the following steps 1 to 3.
Step 1: A spinning step of spinning a raw material to be a carbon fiber precursor and attaching the treatment agent of the first embodiment.

Step 2: A flame-resistant treatment step of converting the carbon fiber precursor obtained in the above step 1 into flame-resistant fibers in an oxidizing atmosphere of preferably 200 ° C. or higher and 300 ° C. or lower, more preferably 230 ° C. or higher and 270 ° C. or lower.

Step 3: A carbonization treatment step of carbonizing the flame-resistant fiber obtained in the above step 2 in an inert atmosphere of more preferably 300 ° C. or higher and 2000 ° C. or lower, more preferably 300 ° C. or higher and 1300 ° C. or lower.

It is assumed that the firing step is composed of the above steps 2 and 3.
The treatment agent may be attached to the raw material fiber of the carbon fiber precursor at any stage of the spinning step, but it is preferable to attach the treatment agent once before the drawing step. Further, it may be reattached at any stage after the stretching step. For example, it may be reattached immediately after the stretching step, may be reattached at the winding step, or may be reattached immediately before the flame resistance treatment step.

The oxidizing atmosphere in the flame-resistant treatment step is not particularly limited, and for example, an air atmosphere can be adopted.
The inert atmosphere in the carbonization treatment step is not particularly limited, and for example, a nitrogen atmosphere, an argon atmosphere, a vacuum atmosphere, or the like can be adopted.

According to the carbon fiber precursor of the second embodiment, the following effects can be obtained.
(2-1) In the carbon fiber precursor of the second embodiment, the treatment agent of the first embodiment is attached. Therefore, it is possible to reduce the fluff of the flame-resistant fiber after the carbon fiber precursor is treated to be flame-resistant. Thereby, the yarn quality can be improved. In addition, the focusing property of the flame-resistant fiber can be improved. As a result, it is possible to reduce wrapping around the rollers in the firing process and improve manufacturing efficiency.

The above embodiment can be modified and implemented as follows. The above embodiment and the following modified examples can be implemented in combination with each other within a technically consistent range.
-In the treatment agent of the present embodiment, only one of the condensed hydroxy fatty acid (C) and the ionic component (D) may be blended, or both may be blended.

-The above-mentioned treatment agent, treatment agent-containing composition, and diluent are used as stabilizers and antistatic agents for maintaining quality, oily components other than the above, and other than the above, as long as the effects of the present invention are not impaired. It may contain commonly used components such as surfactants, antistatic agents, binders, antioxidants, UV absorbers and defoamers. The other components other than the solvent are preferably 20% by mass or less, more preferably 10% by mass or less in the treatment agent from the viewpoint of efficiently exerting the efficacy of the present invention.

Hereinafter, examples and the like will be given in order to make the configuration and effects of the present invention more specific, but the present invention is not limited to these examples. In the following Examples and Comparative Examples, "parts" means "parts by mass" and "%" means "% by mass".

Test category 1 (preparation of treatment agent and diluent)
(Example 1)
The treatment agent of Example 1 contained 60 parts (%) of castor oil (A-1) and 20 parts (%) of castor oil (A-6) as the smoothing agent (A), and a (poly) oxyalkylene derivative (B). ) As ω-hydroxy (polyoxyethylene) (n = 7) castor oil (B-1) in 14 parts (%) and condensed hydroxy fatty acid (C) as condensed 12-hydroxystearic acid hexamer (C-1). 5 parts (%) and 1 part (%) of sodium dodecylbenzenesulfonate (D-1) as an ionic component (D) were added to the beaker and mixed well to prepare the treatment agent of Example 1. Next, ion-exchanged water was gradually added so that the solid content concentration became 25% while continuing stirring to prepare a treatment agent-containing composition containing 25% of the treatment agent of Example 1.

(Examples 2 to 19, Comparative Examples 1 to 7)
Each of the treatment agents of Examples 2 to 19 and Comparative Examples 1 to 7 was prepared by the same method as in Example 1 using each component shown in Table 1.

The type and content of the smoothing agent (A), the type and content of the (poly) oxyalkylene derivative (B), the type and content of the condensed hydroxy fatty acid (C), and the ionic component (D) in the treatment agent of each example. ) Is listed in the “Smoothing agent (A)” column, “(Poly) oxyalkylene derivative (B)” column, “Condensed hydroxy fatty acid (C)” column, and “Ionic component (D)” in Table 1. As shown in the column. Each ester compound (A1) contained in the smoothing agents (A-7) to (A-9) was synthesized by the method shown below.

Test category 2 (Synthesis of smoothing agents (A-7) to (A-9))
(Smoothing agent (A-7))
92.1 g of glycerin, 160.3 g of lauric acid and 617.1 g of ricinoleic acid were placed in a 2 L four-necked flask equipped with a thermometer, a vacuum pump, a nitrogen introduction tube, a stirrer, and a cooling trap. Next, 3.3 g of p-toluenesulfonic acid monohydrate and 1.1 g of a 50% phosphinic acid aqueous solution were charged as catalysts. The four-necked flask was heated in an oil bath and reacted at 130 ° C. for 2 hours under a nitrogen stream, and then reacted at 150 ° C. and 2 kPa for 12 hours. The water produced by the reaction was distilled off from the system. The acid value after completion of the reaction was 3.5 mgKOH / g. After cooling the reaction solution to 60 ° C., a 5% aqueous sodium hydroxide solution in an amount capable of completely neutralizing the residual fatty acid and the acid catalyst was added to the reaction solution, and the mixture was stirred for 30 minutes. To the reaction solution under stirring, 100% ion-exchanged water with respect to the amount of the reaction solution was added, and the mixture was further stirred for 30 minutes. After stopping the stirring, the mixture was allowed to stand for 1 hour to remove the aqueous layer separated into the lower layer. Next, 100% ion-exchanged water with respect to the amount of the reaction solution was added, the mixture was stirred at 60 ° C. for 10 minutes, allowed to stand for 2 hours, and then the operation of removing the separated aqueous layer was repeated twice. Then, it was dehydrated at 100 ° C. and 2 kPa. Activated clay was added to the obtained crude product as a 2% adsorbent, and the mixture was stirred at 80 ° C. and 5 kPa for 1 hour, and then the adsorbent was removed to obtain an ester compound. This ester compound was used as a smoothing agent (A-7). The proportions of fatty acids constituting this ester compound were lauric acid 27% and ricinoleic acid 73%.

The proportion of fatty acids constituting the obtained ester compound was measured by the following method.
<Creation of calibration curve>
In order to convert the fatty acid ratio of each sample into mass, a sample was prepared by adding various fatty acids and margaric acid as a standard substance in an arbitrary amount. Fatty acid methyl esters were prepared according to the methyl esterification method (boron trifluoride methanol method) in the "Standard Oil and Fat Analysis Test Method" edited by the Japan Oil Chemists' Society. The prepared sample was analyzed by gas chromatography under the following conditions.

<Analysis conditions for gas chromatography>
Equipment: GC-2010Plus manufactured by Shimadzu Corporation
Column: DB-1 30m x 0.25mm x 0.25μm (manufactured by Agilent J & W)
Carrier gas: Nitrogen 1 mL / min
Injector: Split (1:50), T = 300 ° C.
Detector: FID, T = 300 ° C
Oven temperature: 50 ° C, 10 min holding → 5 ° C / min temperature rise → 280 ° C, 10 min
From the results of gas chromatography, a calibration curve of the concentration and peak area ratio of various fatty acid methyls was prepared.

<Measurement of fatty acid ratio of smoothing agent>
1 g of a smoothing agent and 100 ml of a 2N sodium hydroxide-methanol solution were added to the flask, heated in a water bath at 60 ° C., and stirred for 30 minutes to carry out saponification decomposition. The saponified and decomposed sample was cooled to room temperature and then put into a separating funnel. After adding 100% ion-exchanged water with respect to the amount of liquid and allowing it to stand for 2 hours, the operation of removing the separated aqueous layer was repeated twice. Then, it was dehydrated at 100 ° C. and 2 kPa to obtain fatty acid. A sample was prepared by adding an arbitrary amount of margaric acid as a standard substance to the obtained fatty acid. The prepared sample was prepared as a fatty acid methyl ester sample according to the methyl esterification method (boron trifluoride methanol method) in the "Standard Oil and Fat Analysis Test Method" edited by the Japan Oil Chemists' Society. The prepared fatty acid methyl ester sample was analyzed by gas chromatography under the above conditions. From the obtained gas chromatography results, the composition ratio of each fatty acid was calculated by obtaining the peak area ratio of the standard substance and various fatty acid methyl esters.

(Smoothing agent (A-8))
It was synthesized in the same manner as the smoothing agent (A-7) except that 92.1 parts of glycerin, 144.2 parts of octanoic acid and 512.8 parts of palmitic acid were used as raw materials. The ratio of fatty acids constituting the ester compound contained in the smoothing agent (A-8) is shown in Table 2 below.

(Smoothing agent (A-9))
It was synthesized in the same manner as the smoothing agent (A-7) except that 92.1 parts of glycerin, 300.5 parts of lauric acid and 423.8 parts of oleic acid were used as raw materials. The ratio of fatty acids constituting the ester compound contained in the smoothing agent (A-9) is shown in Table 2 below.

表１に記載する平滑剤（Ａ）、（ポリ）オキシアルキレン誘導体（Ｂ）、縮合ヒドロキシ脂肪酸（Ｃ）、イオン性成分（Ｄ）の詳細は以下のとおりである。

The details of the smoothing agent (A), the (poly) oxyalkylene derivative (B), the condensed hydroxy fatty acid (C), and the ionic component (D) shown in Table 1 are as follows.

(Smoothing agent (A))
A-1: Sunflower oil A-2: Rapeseed oil A-3: Sesame oil A-4: Palm oil A-5: Amani oil A-6: Sunflower oil A-7: Ester of glycerin and lauric acid and ricinoleic acid Compound (composition ratio of fatty acid is lauric acid 27%, ricinoleic acid 73%)
A-8: Ester compound of glycerin and caprylic acid and palmitic acid (the composition ratio of fatty acid is 33% caprylic acid and 67% palmitic acid).
A-9: Ester compound of glycerin and lauric acid and oleic acid (the composition ratio of fatty acid is 50% lauric acid and 50% oleic acid).
rA-1: Palm oil rA-2: Palm kernel oil Composition ratio of fatty acids constituting the ester compound (A1) contained in each smoothing agent (A) of A-1 to A-9, rA-1 and rA-2. (%) Is shown in the "Oil" column of Table 2 below. The ratio (%) of the fatty acid (X) having 16 or more and 24 or less carbon atoms to the total mass of the fatty acids constituting the ester compound (A1) is shown in the “Constituent ratio of fatty acid (X)” column of Table 2.

（（ポリ）オキシアルキレン誘導体（Ｂ））
Ｂ－１：ω－ヒドロキシ（ポリオキシエチレン）（ｎ＝７）ヒマシ油
Ｂ－２：ω－ヒドロキシ（ポリオキシエチレン）（ｎ＝２０）硬化ヒマシ油
Ｂ－３：ヒドロキシ（ポリオキシプロピレンポリオキシエチレン）（ｍ＝１３、ｎ＝１０）ヒマシ油
Ｂ－４：ヒドロキシ（ポリオキシプロピレンポリオキシエチレン）（ｍ＝１２、ｎ＝１２）硬化ヒマシ油
Ｂ－５：ヒマシ油１モル当たりエチレンオキサイドを２００モルの割合で付加重合した油脂エチレンオキサイド付加物
Ｂ－６：α－ドデシル－ω－ヒドロキシ（ポリオキシエチレン）（ｎ＝７）
Ｂ－７：エチレングリコールにエチレンオキサイドとプロピレンオキサイドとをブロック状に付加重合した数平均分子量５０００のポリオキシアルキレンブロック共重合体であって、そのポリオキシアルキレン基がオキシエチレン単位／オキシプロピレン単位＝３０／７０（モル比）の割合から成るものであるポリオキシアルキレンブロック共重合体
Ｂ－８：エチレングリコールにエチレンオキサイドとプロピレンオキサイドとをブロック状に付加重合した数平均分子量１００００のポリオキシアルキレンブロック共重合体であって、そのポリオキシアルキレン基がオキシエチレン単位／オキシプロピレン単位＝７０／３０（モル比）の割合から成るものであるポリオキシアルキレンブロック共重合体
Ｂ－９：オキシエチレン単位の繰り返し数が２０であるポリオキシエチレングリコールオクタデセニルエーテル
（縮合ヒドロキシ脂肪酸（Ｃ））
Ｃ－１：縮合１２－ヒドロキシステアリン酸６量体
Ｃ－２：縮合ヒマシ油脂肪酸４量体及び５量体の混合物
Ｃ－３：縮合ヒマシ油脂肪酸６量体
Ｃ－４：縮合ヒマシ油脂肪酸２量体
ｒｃ－１：ジエチレントリアミンのジステアリン酸アミド１モル当たりエチレンオキサイドを７モルの割合で付加重合したポリオキシアルキレン変性脂肪酸アミド
ｒｃ－２：ヒマシ油脂肪酸
ｒｃ－３：１２－ヒドロキシステアリン酸
ｒｃ－４：イソステアリン酸
（イオン性成分（Ｄ））
Ｄ－１：ドデシルベンゼンスルホン酸ナトリウム
Ｄ－２：２－エチルヘキシルホスフェートカリウム
Ｄ－３：酢酸カリウム
Ｄ－４：Ｎ，Ｎ－ビス（ポリオキシエチレン）（ｎ＝１０）ドデカンアミン酢酸塩
Ｄ－５：ポリオキシエチレングリコール（オキシエチレン単位の繰り返し数１６）モノセチルエーテルリン酸エステルカリウム塩であって、モノリン酸エステル塩／ジリン酸エステル塩＝１／１（モル比）の割合から成る有機リン酸エステル塩
試験区分３（炭素繊維前駆体及び炭素繊維の製造）
試験区分１で調製した処理剤を含有する希釈液を用いて、炭素繊維前駆体及び炭素繊維を製造した。

((Poly) oxyalkylene derivative (B))
B-1: ω-hydroxy (polyoxyethylene) (n = 7) castor oil B-2: ω-hydroxy (polyoxyethylene) (n = 20) hardened castor oil B-3: hydroxy (polyoxypropylene polyoxy) Ethylene) (m = 13, n = 10) castor oil B-4: hydroxy (polyoxypropylene polyoxyethylene) (m = 12, n = 12) hardened castor oil B-5: ethylene oxide per mol of castor oil Addition-polymerized oil / fat ethylene oxide adduct at a ratio of 200 mol B-6: α-dodecyl-ω-hydroxy (polyoxyethylene) (n = 7)
B-7: A polyoxyalkylene block copolymer having a number average molecular weight of 5000 obtained by addition-polymerizing ethylene oxide and propylene oxide to ethylene glycol in a block shape, wherein the polyoxyalkylene group is oxyethylene unit / oxypropylene unit =. Polyoxyalkylene block copolymer composed of a ratio of 30/70 (molar ratio) B-8: Polyoxyalkylene block having a number average molecular weight of 10000 obtained by addition-polymerizing ethylene oxide and propylene oxide to ethylene glycol in a block shape. Polyoxyalkylene block copolymer B-9: of oxyethylene unit, which is a copolymer and the polyoxyalkylene group thereof is composed of a ratio of oxyethylene unit / oxypropylene unit = 70/30 (molar ratio). Polyoxyethylene glycol octadecenyl ether with 20 repeats (condensed hydroxy fatty acid (C))
C-1: Condensed 12-hydroxystearic acid hexamer C-2: Condensed castor oil fatty acid tetramer and pentamer mixture C-3: Condensed castor oil fatty acid hexamer C-4: Condensed castor oil fatty acid 2 Quant: rc-1: Polyoxyalkylene-modified fatty acid amide obtained by addition-polymerizing ethylene oxide at a ratio of 7 mol per mol of distearate amide of diethylenetriamine rc-2: Himashi oil fatty acid rc-3: 12-hydroxystearic acid rc-4 : Isostearic acid (ionic component (D))
D-1: Sodium dodecylbenzenesulfonate D-2: 2-Ethylhexyl phosphate potassium D-3: Potassium acetate D-4: N, N-bis (polyoxyethylene) (n = 10) dodecaneamine acetate D-5 : Polyoxyethylene glycol (repeated number of oxyethylene units: 16) Monocetyl ether phosphate potassium salt, organic phosphate consisting of monophosphate ester salt / diphosphate ester salt = 1/1 (molar ratio) Ester salt test category 3 (manufacture of carbon fiber precursor and carbon fiber)
A carbon fiber precursor and carbon fiber were produced using the diluted solution containing the treatment agent prepared in Test Category 1.

First, as step 1, the acrylic resin was wet-spun. Specifically, a copolymer having an extreme viscosity of 1.80 consisting of 95% acrylonitrile, 3.5% methyl acrylate, and 1.5% methacrylic acid is dissolved in dimethylacetamide (DMAC) to have a polymer concentration of 21. A spinning stock solution at 0% and a viscosity at 60 ° C. of 500 poise was prepared. The undiluted spinning solution was discharged into a coagulation bath of a 70% aqueous solution of DMAC kept at a spinning bath temperature of 35 ° C. from a spinneret having a pore diameter (inner diameter) of 0.075 mm and a hole number of 12,000 at a draft ratio of 0.8.

Acrylic fiber strands (carbon fiber precursors) in a water-swelled state were prepared by stretching the coagulated yarn five times in a washing tank at the same time as desolving. The treatment agent-containing composition prepared in Test Category 1 was further diluted with ion-exchanged water to prepare a diluted solution of 4% of the treatment agent. The acrylic fiber strand was lubricated with a 4% diluted solution by a dipping method so that the amount of solid content adhered to the acrylic fiber strand was 1% (solvent-free). After that, the acrylic fiber strands are dried and densified with a heating roller at 130 ° C., further stretched 1.7 times between the heating rollers at 170 ° C., and then carbon is applied to the yarn tube using a winding device. The fiber precursor was wound up.

Next, as step 2, the yarn is unwound from the wound carbon fiber precursor, and the yarn is flame-resistant in a flame-resistant furnace having a temperature gradient of 230 to 270 ° C. for 1 hour under an air atmosphere, and then the transfer roller. A flame-resistant yarn (flame-resistant fiber) was obtained by winding it around a yarn tube via the above.

Next, as step 3, the yarn is unwound from the wound flame-resistant yarn, fired in a carbonization furnace having a temperature gradient of 300 to 1300 ° C. in a nitrogen atmosphere, converted into carbon fibers, and then made into a yarn tube. Carbon fiber was obtained by winding.

Test category 4 (evaluation)
The stability of the treatment agents of each Example and Comparative Example, and the fluff and sizing property of the flame-resistant fiber were evaluated. The procedure for each test is shown below.

(Fluff)
The flame-resistant fiber was measured by a fluff counting device installed immediately before the winding device. The number of fluffs per hour was evaluated according to the following criteria. The test results are shown in the "fluff" column of Table 1.

・ Evaluation criteria for fluff ◎ ◎ (excellent): 0 or more and 5 or less fluff ◎ (good): 6 or more and 10 or less fluff ○ (possible): 11 or more and 20 or less fluff × ( Impossible): 21 or more fluffs (focusing)
With respect to the flame-resistant fiber, the focusing state before winding was visually observed, and the focusing property was evaluated according to the following criteria. The test results are shown in the "Focusability" column of Table 1.

・ Evaluation criteria for focusing ◎ ◎ (excellent): When focused and toe width is constant ◎ (Good): When it is generally focused but toe width is sometimes not constant ○ (possible): Generally When focused but the toe width is not constant × (impossible): When there is space in the fiber bundle and it is not focused (stability)
After producing the treatment agent, 100 g was placed in a 100 ml vertically long sedimentation tube. The appearance after standing at 25 ° C. for 72 hours was visually observed, and the difference in concentration between the upper layer and the lower layer of the treatment agent was measured, and the stability was evaluated according to the following criteria. A certain amount of the concentration difference was collected from the portion near the upper surface of the treatment agent and the portion near the bottom of the settling tube, and dried at 105 ° C. for 2 hours. The concentration was determined from the obtained solid content. The test results are shown in the "Stability" column of Table 1.

・ Stability evaluation criteria ◎ ◎ ◎ (Very excellent): When there is no change in appearance even after standing ◎ ◎ (Excellent): Separation is seen, and the concentration difference between the upper layer and the lower layer is 5% or less. However, if it returns to the original state by stirring ◎ (Good): Separation is seen, and the concentration difference between the upper layer and the lower layer is more than 5% and 10% or less, but if it returns to the original state by stirring ○ (OK): Separation When the concentration difference between the upper layer and the lower layer exceeds 10%, but it returns to the original state by stirring × (impossible): When separation is seen and the concentration does not return to the original level even after stirring. According to the above, the fluff reducing effect and the focusing property of the flame-resistant fiber can be improved. In addition, the stability of the treatment agent can be improved.

Claims (10)

It contains a smoothing agent (A) containing an ester compound (A1) of glycerin and a fatty acid containing the following fatty acid (X), and a (poly) oxyalkylene derivative (B).
A treatment agent for a carbon fiber precursor, characterized in that the composition ratio of the fatty acid (X) obtained from the following formula 1 is 50% by mass or more.
Fatty acid (X): A fatty acid having 16 or more and 24 or less carbon atoms.

The treatment agent for a carbon fiber precursor according to claim 1, wherein the composition ratio of the fatty acid (X) obtained from the formula 1 is 70% by mass or more. The (poly) oxyalkylene derivative (B) is obtained by adding an alkylene oxide having 2 or more and 4 or less carbon atoms to an ester compound of an alcohol having a monovalent or more and trivalent or less and a monovalent fatty acid having 16 or more and 24 or less carbon atoms. The treatment agent for a carbon fiber precursor according to claim 1, which comprises a compound. Assuming that the total content of the smoothing agent (A) and the (poly) oxyalkylene derivative (B) is 100% by mass, the smoothing agent (A) is 10% by mass or more and 90% by mass or less, and the above (poly). ) The treatment agent for a carbon fiber precursor according to claim 1, which contains the oxyalkylene derivative (B) in a proportion of 10% by mass or more and 90% by mass or less. The treatment agent for a carbon fiber precursor according to claim 1, further comprising a condensed hydroxy fatty acid (C). Assuming that the total content of the smoothing agent (A), the (poly) oxyalkylene derivative (B), and the condensed hydroxy fatty acid (C) is 100% by mass, the smoothing agent (A) is 9.9% by mass. 89.9% by mass or less, 10% by mass or more and 90% by mass or less of the (poly) oxyalkylene derivative (B), and 0.1% by mass or more and 50% by mass or less of the condensed hydroxy fatty acid (C). The treatment agent for a carbon fiber precursor according to claim 5. The treatment agent for a carbon fiber precursor according to claim 1, further comprising an ionic component (D). The treatment agent for a carbon fiber precursor according to claim 1, further comprising a condensed hydroxy fatty acid (C) and an ionic component (D). Assuming that the total content of the smoothing agent (A), the (poly) oxyalkylene derivative (B), the condensed hydroxy fatty acid (C), and the ionic component (D) is 100% by mass, the smoothing agent ( A) is 9.9% by mass or more and 89.9% by mass or less, the (poly) oxyalkylene derivative (B) is 9.9% by mass or more and 89.9% by mass or less, and the condensed hydroxy fatty acid (C) is 0. The treatment agent for a carbon fiber precursor according to claim 8, which contains 1% by mass or more and 50% by mass or less, and 0.1% by mass or more and 10% by mass or less of the ionic component. A carbon fiber precursor to which the treatment agent for a carbon fiber precursor according to any one of claims 1 to 9 is attached.