Acrylic fiber treatment agent and use thereof

Abstract

The purpose of the present invention is to provide: an acrylic fiber treatment agent; an acrylic fiber for carbon fiber production using the acrylic fiber treatment agent; and a method for producing carbon fibers using the acrylic fiber treatment agent. This acrylic fiber treatment agent is capable of improving the bundling property of an acrylic fiber for carbon fiber production in a fire-resistant step of the acrylic fiber for carbon fiber production. This treatment agent for acrylic fibers contains an amino-modified silicone (A) and at least one substance selected from the group consisting of a compound (B) having a five-membered ring structure containing a sulfur atom and a nitrogen atom and a derivative of the compound (B). The acrylic fiber for carbon fiber production according to the present invention is a fiber obtained by adhering the acrylic fiber treatment agent for acrylic fibers according to the present invention to the raw material acrylic fiber of the acrylic fiber for carbon fiber production.

Description

Technical Field

[0001] The present invention relates to a treatment agent for acrylic fibers and its use. More specifically, it relates to a treatment agent used in the production of acrylic fibers, acrylic fibers (hereinafter also referred to as precursors) for carbon fiber production using the treatment agent, and a method for producing carbon fibers using the treatment agent. Prior art

[0002] Carbon fibers are widely used in aerospace, sports, and general industrial applications as reinforcing fibers for composite materials with plastics called matrix resins, taking advantage of their excellent mechanical properties.

[0003] As for the method of manufacturing carbon fiber, first, acrylic fiber (also called precursor) for carbon fiber manufacturing is manufactured (the manufacturing process of this precursor is also called spinning process). In the general method, this precursor is converted into a refractory fiber in an oxidizing atmosphere of 200 to 300°C (hereinafter, this process is sometimes referred to as a refractory treatment process), and then it is carbonized in an inert atmosphere of 300 to 2,000°C (hereinafter, this process is sometimes referred to as a carbonization treatment process) (hereinafter, the refractory treatment process and the carbonization treatment process are sometimes collectively referred to as a calcination process). In the manufacture of this precursor, it will go through a stretching process in which it is stretched to a higher ratio than general acrylic fibers. At this time, it is easy to produce adhesion between the fibers and it is not possible to uniformly stretch at a high ratio, so that it becomes an uneven precursor. The carbon fiber obtained by calcining this precursor will have the problem of not being able to obtain sufficient strength. In addition, when the precursor is calcined, fusion between the single fibers will occur, which will reduce the quality and grade of the obtained carbon fiber.

[0004] With regard to the treatment agent applied to the precursor in order to prevent adhesion of the precursor and fusion of the carbon fibers, a number of technologies have been proposed, including applying silicone-based treatment agents that reduce fiber-fiber friction when wet and in high-temperature environments, and amino-modified silicone-based treatment agents that can improve anti-fusion properties to the precursor (see patent documents 1 to 2).

[0005] Prior art literature

[0006] Patent Literature

[0007] Patent Document 1: Japanese Patent Application Publication No. 2001-172879

[0008] Patent Document 2: Japanese Patent Application Publication No. 2002-129481 Summary of the invention

[0009] Problems to be solved by the invention

[0010] However, when the precursor to which such a treatment agent has been applied is subjected to refractory treatment, there is a problem that the bundling property of the precursor is reduced due to the peeling effect of silicone and the effect of reducing the friction between fibers. Therefore, in the refractory treatment process and the carbonization treatment process, the fiber bundle is disordered and stretched unevenly due to insufficient bundling property, which may cause the processability, process passability, and quality of carbon fiber to be reduced.

[0011] Therefore, an object of the present invention is to provide an acrylic fiber treating agent, acrylic fiber for carbon fiber production using the treating agent, and a method for producing carbon fiber using the treating agent, wherein the treating agent can improve the bundling properties of the acrylic fiber for carbon fiber production in the pyrolysis process of the acrylic fiber for carbon fiber production.

[0012] Means of solving problems

[0013] As a result of intensive studies conducted by the present inventors to solve the above-mentioned problems, it was found that an acrylic fiber treating agent containing amino-modified silicone (A) and at least one compound (B) selected from a compound having a 5-membered ring structure containing a sulfur atom and a nitrogen atom and a derivative of the compound (B) can improve the bundling property of the precursor in the refractory process of acrylic fibers for carbon fiber production, thereby completing the present invention.

[0014] That is, the acrylic fiber treating agent of the present invention includes the following embodiments.

[0015] <1> An acrylic fiber treating agent comprising an amino-modified silicone (A) and at least one selected from a compound (B) having a five-membered ring structure containing a sulfur atom and a nitrogen atom, and a derivative of the compound (B).

[0016] <2> The acrylic fiber treating agent according to <1>, wherein the compound (B) comprises at least one selected from the group consisting of a compound represented by the following general formula (1) and a compound represented by the following general formula (2);

[0017]

[0018] (In formula (1), R 1 is an alkyl group, an aralkyl group or a hydrogen atom having 1 to 12 carbon atoms, and X and Y are independently a hydrogen atom or a halogen atom);

[0019]

[0020] (In formula (2), R 2 is an alkyl group having 1 to 8 carbon atoms or a hydrogen atom).

[0021] <3> The acrylic fiber treating agent according to <1> or <2>, further comprising a bronsted acid compound (C).

[0022] <4> The acrylic fiber treating agent according to <3>, wherein the Bronsted acid compound (C) comprises at least one selected from the group consisting of carboxylic acid compounds, inorganic acids, sulfonic acid compounds, phosphoric acid ester compounds, sulfate ester compounds, and phosphonic acid compounds.

[0023] <5> The acrylic fiber treating agent according to <3> or <4>, wherein a molar ratio of the Bronsted acid compound (C) to the amino group of the amino-modified silicone (A) is 0.01 to 5.0.

[0024] <6> The acrylic fiber treating agent according to any one of <3> to <5>, wherein the total weight of the compound (B) and the derivative of the compound (B) is 0.01 to 50 parts by weight based on 100 parts by weight of the Bronsted acid compound (C).

[0025] <7> The acrylic fiber treating agent according to any one of <1> to <6>, further comprising a hydrophilic solvent (D), wherein the hydrophilic solvent (D) comprises at least one selected from a compound represented by the following general formula (3) and an aprotic nitrogen-containing organic compound.

[0026]

[0027] (In formula (3), AO is an oxyalkylene group having 2 to 4 carbon atoms, and n is an integer from 1 to 3).

[0028] <8> The acrylic fiber treating agent according to any one of <1> to <7>, wherein the weight ratio of the amino-modified silicone (A) in the non-volatile matter of the treating agent is 20 to 90% by weight.

[0029] <9> The acrylic fiber processing agent according to any one of <1> to <8>, further comprising a nonionic surfactant (E).

[0030] <10> An acrylic fiber for producing carbon fiber, the acrylic fiber being obtained by allowing the acrylic fiber treating agent according to any one of <1> to <9> to adhere to a raw material acrylic fiber of the acrylic fiber for producing carbon fiber.

[0031] <11> A method for producing carbon fiber, comprising: a refractory treatment step of converting the acrylic fiber for carbon fiber production described in <10> into a refractory fiber in an oxidizing atmosphere at 200 to 300°C; and a carbonization treatment step of further carbonizing the refractory fiber in an inert atmosphere at 300 to 2,000°C.

[0032] Effects of the Invention

[0033] When using acrylic fibers for carbon fiber production produced by imparting a treatment agent, the treatment agent for acrylic fibers of the present invention can improve the bundling property of acrylic fibers for carbon fiber production in the refractory process, and can improve the fiber bundle disorder and uneven stretching caused by insufficient bundling property. If the acrylic fibers for carbon fiber production of the present invention are used, the fiber bundle disorder and uneven stretching can be improved by improving the bundling property in the refractory treatment process, and the processability and process passability can be improved. If the method for producing carbon fiber of the present invention is followed, the fiber bundle disorder and uneven stretching can be improved by improving the bundling property, and the processability and process passability can be improved, and high-quality carbon fiber can be obtained. DETAILED DESCRIPTION

[0034] Each component of the acrylic fiber treating agent of the present invention is described.

[0035] [Amino modified silicone (A)]

[0036] The treatment agent of the present invention contains amino-modified silicone (A). The amino group (including an organic group having an amino group) belonging to the modifying group of the amino-modified silicone may be bonded to the side chain of the silicone belonging to the main chain, may be bonded to the terminal, or may be bonded to both, but from the perspective of protecting the fiber in the refractory treatment process, it is preferred to bond to the side chain (the side chain has an amino group). In addition, the amino group may be any of a monoamine type, a diamine type, and a polyamine type, or both may coexist in one molecule, but from the perspective of uniformly imparting the treatment agent to the inside of the fiber bundle in the refractory treatment process and coating the treatment agent to protect the fiber, a monoamine type or a diamine type is preferred. In addition, the amino-modified silicone may also include an aminopolyether-modified silicone. An aminopolyether-modified silicone refers to a silicone having at least one amino group and a polyether group in its structure.

[0037] The kinematic viscosity of the amino-modified silicone (A) at 25° C. is preferably 50 to 20,000 mm / s from the viewpoint of uniform adhesion to the fiber, suppression of scattering of the treatment agent, and imparting bundling properties to the fiber. 2 The upper limit of the kinematic viscosity is 15,000 mm 2 / s is more preferred, with 10,000mm 2 / s is more preferably 8,000mm 2 On the other hand, the lower limit of the kinematic viscosity is 100 mm 2 / s is more preferred, with 150mm 2 / s is further preferred, with 200mm 2 / s is particularly preferred. In addition, for example, 200 to 10,000 mm2 / s is more preferred, with 200mm 2 / s to 8,000 mm 2 / s is further preferred.

[0038] From the viewpoint of preventing adhesion and fusion between fibers, the amino equivalent of the amino-modified silicone (A) is preferably 300 to 10,000 g / mol. The upper limit of the amino equivalent is more preferably 9,500 g / mol, further preferably 9,000 g / mol, and particularly preferably 8,000 g / mol. On the other hand, the lower limit of the amino equivalent is more preferably 500 g / mol, further preferably 1,000 g / mol, and particularly preferably 1,500 g / mol. In addition, for example, 500 to 9,000 g / mol is more preferred, and 1,000 g / mol to 8,000 g / mol is further preferred.

[0039] Here, amino equivalent means the mass of the siloxane skeleton per amino or ammonium group. The unit of g / mol is a value converted per 1 mole of amino or ammonium group. Therefore, the smaller the amino equivalent value, the higher the ratio of amino or ammonium groups in the molecule.

[0040] The amino-modified silicone (A) may be used in combination with a plurality of amino-modified silicones having different amino equivalents and kinematic viscosities (25° C.). When two or more amino-modified silicones are used, the amino equivalent means the amino equivalent of the entire amino-modified silicone (mixture), and the kinematic viscosity at 25° C. means the kinematic viscosity of the entire amino-modified silicone (mixture).

[0041] Examples of the amino-modified silicone include compounds represented by the following general formula (4).

[0042]

[0043] (In formula (4), R 3 represents an alkyl group or an aryl group having 1 to 20 carbon atoms. 4 is a group represented by the following general formula (5). 5 For R 3 , R 4 OR 11 (R 11 is a hydrogen atom or an alkyl group having 1 to 6 carbon atoms). p is 5≤p≤10,000, and q is 0≤q≤1,000. However, when q=0, R 5 At least one of them is a group represented by the following general formula (5).

[0044] In formula (4), R 3 represents an alkyl group or an aryl group having 1 to 20 carbon atoms. 3An alkyl group or an aryl group having 1 to 10 carbon atoms is preferred, an alkyl group having 1 to 5 carbon atoms is more preferred, and a methyl group is further preferred. 3 Can be the same or different. 4 is a group represented by the following general formula (5). 5 For R 3 , R 4 OR 11 The group represented by R 3 In addition, the multiple R in formula (4) 11 Can be the same or different.

[0045] R 11 is a hydrogen atom or an alkyl group having 1 to 6 carbon atoms, preferably a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, more preferably a hydrogen atom or a methyl group. p is a number from 5 to 10,000, preferably from 30 to 5,000, more preferably from 50 to 2,000. q is a number from 0 to 1,000, preferably from 0.1 to 500, more preferably from 0.2 to 100.

[0046]

[0047] In formula (5), R 6 and R 8 Each of R is independently an alkylene group having 1 to 6 carbon atoms, preferably an alkylene group having 1 to 3 carbon atoms. 7 , R 9 and R 10 Each of them is independently a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, or an aryl group, preferably a hydrogen atom or an alkyl group having 1 to 5 carbon atoms, and more preferably a hydrogen atom. r is a number from 0 to 6, preferably from 0 to 3, and more preferably from 0 to 1.

[0048] [Compound (B) having a 5-membered ring structure containing a sulfur atom and a nitrogen atom, and a derivative of compound (B)]

[0049] The treatment agent of the present invention contains at least one selected from a compound (B) having a five-membered ring structure containing a sulfur atom and a nitrogen atom (hereinafter sometimes referred to as compound (B)) and a derivative of compound (B).

[0050] The compound (B) is not particularly limited as long as it is a compound having a 5-membered ring structure containing a sulfur atom and a nitrogen atom. However, from the viewpoint of improving the bundling property of the fiber bundle by the treatment agent in the flame retardant step, it is preferred that the compound (B) has a bond between heteroatoms in the 5-membered ring because the crosslinking reaction of the amino-modified silicone (A) is further promoted and the bundling property of the fiber bundle is improved. It is preferred that the compound (B) has a nitrogen-sulfur bond in the 5-membered ring because the crosslinking reaction is further promoted and the bundling property of the fiber bundle is improved. It is particularly preferred that the compound (B) contains at least one compound selected from the group consisting of the following general formula (1) and the following general formula (2) because the crosslinking reaction is further promoted and the bundling property of the fiber bundle is improved.

[0051] The derivative of compound (B) is not particularly limited as long as it is a derivative of the above-mentioned compound (B), and examples thereof include a product obtained by forming a salt of compound (B) and a reaction product of compound (B) and a nucleophilic compound.

[0052] The factors that further improve the bundling of the fiber bundle are believed to be as follows: if there is a bond between heteroatoms in the 5-membered ring structure, the bond between the heteroatoms is broken by heat, and the free radicals generated by the break further promote the crosslinking reaction of the amino-modified silicone (A). In addition, it is believed that when the bond between the heteroatoms has a nitrogen-sulfur bond, the breakage of the bond between the heteroatoms is further promoted. If it is a compound represented by the following general formula (1) and the following general formula (2), the breakage of the bond between the heteroatoms is particularly promoted. The factors that further improve the bundling of the fiber bundle by the derivative of compound (B) are believed to be as follows: it is decomposed by heat, and the free radicals generated by the decomposition promote the crosslinking reaction of the amino-modified silicone (A).

[0053] The compound (B) may be contained alone or in combination of two or more. However, from the viewpoint of excellent scratch resistance, it is more preferable to contain two or more kinds.

[0054]

[0055] In order to exert the effect of this case, it is preferred that in formula (1), R 1 is an alkyl group having 1 to 12 carbon atoms, an aralkyl group or a hydrogen atom, and X and Y are independently a hydrogen atom or a halogen atom.

[0056] R 1 An alkyl group having 1 to 10 carbon atoms, an aralkyl group or a hydrogen atom is more preferred, and an alkyl group having 1 to 8 carbon atoms or a hydrogen atom is particularly preferred.

[0057] R 1Specific examples include: methyl, ethyl, isopropyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, nonyl, decyl, undecyl, dodecyl, phenyl and hydrogen atom. From the viewpoint of compatibility with amino-modified silicone, methyl, ethyl, isopropyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, nonyl, decyl or hydrogen atom is more preferred, and methyl, ethyl, isopropyl, propyl, butyl, pentyl, hexyl, heptyl, octyl or hydrogen atom is particularly preferred.

[0058] In formula (1), X and Y are each independently a hydrogen atom, a chlorine atom or a bromine atom, and more preferably a hydrogen atom or a chlorine atom.

[0059] When at least one of X and Y is a hydrogen atom, R 1 A methyl group, an ethyl group, an isopropyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a heptyl group, an octyl group, a nonyl group, a decyl group or a hydrogen atom is more preferred, and a methyl group, an ethyl group, an isopropyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a heptyl group, an octyl group or a hydrogen atom is further preferred.

[0060]

[0061] In terms of the effect of this case, in formula (2), R 2 An alkyl group having 1 to 8 carbon atoms or a hydrogen atom is preferred, an alkyl group having 1 to 6 carbon atoms or a hydrogen atom is more preferred, and an alkyl group having 1 to 4 carbon atoms is particularly preferred.

[0062] R 2 Specific examples include: methyl, ethyl, isopropyl, propyl, butyl, pentyl, hexyl, heptyl, octyl and hydrogen atom. From the viewpoint of compatibility with amino-modified silicone, methyl, ethyl, isopropyl, propyl, butyl, pentyl, hexyl or hydrogen atom is more preferred, and methyl, ethyl, isopropyl, propyl, butyl or hydrogen atom is particularly preferred.

[0063] Examples of the compound (B) include thiazoles, thiadiazoles, and the like in addition to the compounds represented by the general formula (1) and the general formula (2).

[0064] Examples of the thiazoles include 4-bromothiazole, 4-methylthiazole, 2,4-bicyclothiazole, 2-methyl-4-methylthiazole, 2-isopropyl-4-methylthiazole, 2-methyl-4-methylthiazole, 2-mercaptothiazole, 2-aminothiazole, 2-methylthiazole, 2-ethylthiazole, 2-propionylthiazole, 2-acetylthiazole, 5-methylthiazole, 2,5-dibromothiazole, and 5-(2-hydroxyethyl)-4-methylthiazole.

[0065] Examples of the thiadiazoles include 2-amino-1,3,4-thiadiazole, 1,3,4-thiadiazole-2-thiol, 1,3,4-thiadiazole-2,5-diamine, 2-amino-5-mercapto-1,3,4-thiadiazole, and 5-methyl-1,3,4-thiadiazole-2-thiol.

[0066] Examples of salts of compound (B) that are derivatives of compound (B) include sodium salts, potassium salts, calcium salts, and amine salts. Examples of nucleophilic compounds that generate derivatives of compound (B) include compounds having at least one selected from a thiol group, an amino group, and an alkoxy group, specifically organic thiol compounds, organic amine compounds, organic alcohol compounds, and amino acid compounds, and examples of these organic groups include alkyl groups, alkenyl groups, and aryl groups.

[0067] 〔Brønsted acid compound (C)〕

[0068] From the viewpoint of inhibiting the decomposition of compound (B) and its derivatives over time and improving the strength of carbon fibers, the fiber treatment agent of the present invention preferably contains a Bronsted acid compound (C). Bronsted acid compound (C) refers to a proton donor, and examples thereof include carboxylic acid compounds, inorganic acids, sulfonic acid compounds, phosphate compounds, sulfate compounds, and phosphonic acid compounds.

[0069] The carboxylic acid compound refers to a compound having a carboxyl group in its molecular structure. The carboxylic acid compound is not particularly limited, and examples thereof include aliphatic monocarboxylic acids, alkyl ether carboxylic acids, aliphatic polycarboxylic acids, aromatic monocarboxylic acids, aromatic polycarboxylic acids, and amino acids.

[0070] Examples of the aliphatic monocarboxylic acid include acetic acid, lactic acid, butyric acid, crotonic acid, valeric acid, caproic acid, heptanoic acid, caprylic acid, nonanoic acid, capric acid, lauric acid, myristic acid, myristoleic acid, pentadecanoic acid, palmitic acid, palmitoleic acid, isocetyl acid, heptadecanoic acid, stearic acid, isostearic acid, oleic acid, trans-oleic acid, vaccenic acid, linoleic acid, linolenic acid, arachidic acid, isoeicosanoic acid, gadoleic acid, eicosenoic acid, behenic acid, isodocosanoic acid, erucic acid, lignoceric acid, isotetracosanoic acid, nervonic acid, cerotic acid, montanic acid, and melissic acid.

[0071] Examples of the alkyl ether carboxylic acid include those having an alkyl group with 8 to 18 carbon atoms and a polyoxyalkylene group with 1 to 50 moles of added moles. Examples of the alkyl group include octyl, nonyl, decyl, undecyl, dodecyl, tridecyl, isotridecyl, tetradecyl, pentadecyl, hexadecyl, heptadecyl, and octadecyl. Examples of the polyoxyalkylene group include polyoxyethylene, polyoxypropylene, and polyoxypolypropylene.

[0072] Examples of the aliphatic polycarboxylic acid include oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, undecanedioic acid, dodecanedioic acid, tridecanedioic acid, tetradecanedioic acid, pentadecanedioic acid, and derivatives thereof.

[0073] Examples of the aromatic monocarboxylic acid include benzoic acid, cinnamic acid, naphthoic acid, toluic acid, and derivatives thereof.

[0074] Examples of the aromatic polycarboxylic acid include phthalic acid, isophthalic acid, terephthalic acid, trimellitic acid, pyromellitic acid, and derivatives thereof.

[0075] Amino acids refer to compounds having both an amino group and a carboxyl group in their molecular structure, and examples thereof include alanine, valine, leucine, isoleucine, phenylalanine, tryptophan, methionine, proline, glycine, tyrosine, serine, threonine, cysteine, asparagine, glutamine, lysine, arginine, histidine, aspartic acid, and glutamic acid.

[0076] Inorganic acids are acids containing non-metal atoms as components. Examples of inorganic acids include sulfuric acid, nitric acid, phosphoric acid, and hydrochloric acid.

[0077] Examples of the sulfonic acid compound include alkylbenzenesulfonic acid, polyoxyalkylene alkyl ether sulfonic acid, higher fatty acid amide sulfonic acid, alkylsulfuric acid monoester, and polyoxyalkylenesulfuric acid monoester.

[0078] Examples of the phosphoric acid ester compound include alkyl phosphoric acid monoesters, alkyl phosphoric acid diesters, polyoxyalkylene alkyl ether phosphoric acid monoesters, polyoxyalkylene alkyl ether phosphoric acid diesters, polyoxyalkylene alkylphenyl ether phosphoric acid monoesters, and polyoxyalkylene alkylphenyl ether phosphoric acid diesters.

[0079] Examples of the sulfate ester compound include alkyl sulfate esters, polyoxyalkylene alkyl sulfate esters, alkylphenyl sulfate esters, and polyoxyalkylene alkylphenyl sulfate esters.

[0080] Examples of the phosphonic acid compound include alkylphosphonic acid, aromatic phosphonic acid, and polyoxyalkylene alkyl ether phosphonic acid.

[0081] The pKa of the Bronsted acid compound (C) is preferably 0 to 7, more preferably 1 to 6.5, and even more preferably 2 to 6 from the viewpoint of equipment corrosion and safety and suppression of temporal crosslinking caused by the amino group of the amino-modified silicone.

[0082] From the viewpoint of inhibiting the decomposition of the compound (B) and the derivative of the compound (B) over time, the Bronsted acid compound (C) preferably contains at least one selected from carboxylic acid compounds, phosphate compounds and inorganic acids, more preferably contains at least one selected from lactic acid, alkyl ether carboxylic acids, phosphate compounds, phosphoric acid and acetic acid, and further preferably contains at least one selected from alkyl ether carboxylic acids, phosphate compounds, acetic acid and phosphoric acid. One or more Bronsted acid compounds (C) can be used.

[0083] [Hydrophilic solvent (D)]

[0084] The acrylic fiber treating agent of the present invention preferably contains a hydrophilic solvent (D) from the viewpoint of improving the compatibility of the amino-modified silicone (A) with the compound (B) and the derivative of the compound (B) and improving the strength of carbon fibers.

[0085] The hydrophilic solvent (D) is not particularly limited as long as its solubility in water at 25°C is 0.05 g / ml or more, but it is more preferably a hydrophilic solvent (D) containing at least one selected from the group consisting of a compound represented by the following general formula (3) and an aprotic nitrogen-containing organic compound. One or more hydrophilic solvents (D) may be used.

[0086]

[0087] In the formula (3), AO is an oxyalkylene group having 2 to 4 carbon atoms, and n is an integer of 1 to 3.

[0088] From the viewpoint of improving the compatibility between the amino-modified silicone (A) and the compound (B) or the derivative of the compound (B) and making it easier to obtain the effect of the present invention, the compound represented by the general formula (3) is preferably at least one selected from ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, dipropylene glycol and tripropylene glycol, and more preferably at least one selected from ethylene glycol, diethylene glycol and propylene glycol. The compound represented by the general formula (3) may be used alone or in combination of two or more.

[0089] From the viewpoint of improving the compatibility between the amino-modified silicone (A) and the compound (B) or the derivative of the compound (B), the aprotic nitrogen-containing organic compound is preferably at least one selected from N,N-dimethylformamide, 1-methyl-2-pyrrolidone, N,N-dimethylacetamide and acetonitrile, and more preferably at least one selected from 1-methyl-2-pyrrolidone and N,N-dimethylformamide. One or more aprotic nitrogen-containing organic compounds may be used.

[0090] [Acrylic fiber treatment agent]

[0091] The acrylic fiber treating agent of the present invention contains the amino-modified silicone (A) and at least one selected from the compound (B) and a derivative of the compound (B), and may further contain at least one selected from the Bronsted acid compound (C) and a hydrophilic solvent (D).

[0092] The reason why the acrylic fiber treating agent of the present invention improves the bundling properties of acrylic fibers by containing amino-modified silicone (A) and at least one selected from compound (B) and a derivative of compound (B) is considered to be the following: the cross-linking reaction of amino-modified silicone (A) in the flame retardant step is appropriately promoted by compound (B) or a derivative of compound (B), and the molecular weight and viscosity of amino-modified silicone are increased in a well-balanced manner.

[0093] From the viewpoint of promoting the crosslinking reaction of amino-modified silicone in the flame retardant process, the total weight ratio of compound (B) and the derivative of compound (B) in the non-volatile matter of the treatment agent of the present invention is preferably 0.001 to 1% by weight. The upper limit of the weight ratio is more preferably 0.5% by weight, further preferably 0.1% by weight, particularly preferably 0.07% by weight, and most preferably 0.04% by weight. On the other hand, the lower limit of the weight ratio is more preferably 0.005% by weight, further preferably 0.008% by weight, particularly preferably 0.01% by weight, and most preferably 0.02% by weight. In addition, for example, 0.005 to 0.5% by weight is more preferred, and 0.008 to 0.04% by weight is further preferred.

[0094] From the viewpoint of imparting high bundling properties to the fiber bundle, the weight ratio of the amino-modified silicone (A) in the non-volatile matter of the treatment agent of the present invention is preferably 20 to 90 weight %. The upper limit of the weight ratio is more preferably 85 weight %, and 80 weight % is particularly preferred. On the other hand, the lower limit of the weight ratio is more preferably 30 weight %, more preferably 40 weight %, and particularly preferably 50 weight %. In addition, for example, 40 to 90 weight % is more preferred, and 50 to 90 weight % is further preferred.

[0095] From the viewpoint of promoting the crosslinking reaction of amino-modified silicone in the flame retardant process, the total weight of compound (B) and the derivative of compound (B) is preferably 0.001 to 5 parts by weight relative to 100 parts by weight of amino-modified silicone (A). The upper limit of the weight is more preferably 1.0 parts by weight, further preferably 0.5 parts by weight, and particularly preferably 0.25 parts by weight. On the other hand, the lower limit of the weight is more preferably 0.003 parts by weight, further preferably 0.005 parts by weight, and particularly preferably 0.007 parts by weight. In addition, for example, 0.003 to 0.5 parts by weight is more preferably, and 0.003 to 0.25 parts by weight is further preferred.

[0096] When the treatment agent of the present invention further contains a Bronsted acid compound (C), from the viewpoint of the storage stability of the treatment agent, the molar ratio of the Bronsted acid compound (C) to the amino group of the amino-modified silicone (A) is preferably 0.01 to 5.0. The upper limit of the ratio is more preferably 4.5, further preferably 4.0, particularly preferably 3.5, and most preferably 2.5. On the other hand, the lower limit of the ratio is more preferably 0.05, further preferably 0.1, particularly preferably 0.2, and most preferably 0.3. In addition, for example, 0.05 to 4.5 is more preferred, and 0.1 to 4.0 is further preferred. The molar ratio of the Bronsted acid compound (C) to the amino group of the amino-modified silicone (A) refers to the ratio of the total number of moles of the Bronsted acid compound (C) to the total number of moles of the amino group of the amino-modified silicone (A) contained in the treatment agent.

[0097] From the viewpoint of inhibiting the decomposition of compound (B) and the derivative of compound (B) over time, the total weight of compound (B) and the derivative of compound (B) is preferably 0.01 to 50 parts by weight relative to 100 parts by weight of the Bronsted acid compound (C). The upper limit of the weight is more preferably 30 parts by weight, further preferably 20 parts by weight, and particularly preferably 10 parts by weight. On the other hand, the lower limit of the weight is more preferably 0.05 parts by weight, further preferably 0.1 parts by weight, and particularly preferably 0.3 parts by weight. In addition, for example, 0.05 to 30 parts by weight is more preferred, and 0.1 to 20 parts by weight is further preferred.

[0098] From the viewpoint of inhibiting the decomposition of the compound (B) and the derivative of the compound (B) over time, the weight ratio of the Bronsted acid compound (C) in the non-volatile matter of the treatment agent of the present invention is preferably 0.02 to 30 weight %. The upper limit of the weight ratio is more preferably 26 weight %, more preferably 20 weight %, and particularly preferably 15 weight %. On the other hand, the lower limit of the weight ratio is more preferably 0.05 weight %, more preferably 0.1 weight %, and particularly preferably 0.3 weight %. In addition, for example, 0.05 to 15 weight % is more preferably, and 0.1 to 15 weight % is further preferred.

[0099] When the treatment agent of the present invention further contains a hydrophilic solvent (D), from the viewpoint of improving the compatibility of the amino-modified silicone (A) with at least one selected from the compound (B) and the derivative of the compound (B), the weight ratio of the hydrophilic solvent (D) in the non-volatile matter of the treatment agent of the present invention is preferably 0.05 to 10 weight %. The upper limit of the weight ratio is more preferably 7 weight %, more preferably 5 weight %, and particularly preferably 3 weight %. On the other hand, the lower limit of the weight ratio is more preferably 0.07 weight %, more preferably 0.1 weight %, and particularly preferably 0.15 weight %. In addition, for example, 0.05 to 7 weight % is more preferred, and 0.07 to 5 weight % is further preferred.

[0100] [Nonionic surfactant (E)]

[0101] From the viewpoint of being able to improve emulsification, it is preferred that the treatment agent of the present invention further contains a nonionic surfactant (E). In addition, examples of the nonionic surfactant (E) include: polyoxyalkylene linear alkyl ethers, polyoxyethylene hexyl ether, polyoxyethylene heptyl ether, polyoxyethylene octyl ether, polyoxyethylene decyl ether, polyoxyethylene lauryl ether, polyoxyethylene tridecyl ether, polyoxyethylene tetradecyl ether, polyoxyethylene hexadecyl ether and the like; polyoxyalkylene branched primary alkyl ethers, such as polyoxyethylene 2-ethylhexyl ether, polyoxyethylene isohexadecyl ether, polyoxyethylene isostearyl ether; polyoxyethylene 1-hexylhexyl ether, polyoxyethylene 1-octylhexyl ether, polyoxyethylene Polyoxyethylene secondary alkyl ethers such as 1-hexyloctyl ether, polyoxyethylene 1-pentylheptyl ether, polyoxyethylene 1-heptylpentyl ether, polyoxyethylene 1-hexylheptyl ether, polyoxyethylene 1-heptylhexyl ether, polyoxyethylene 1-pentyloctyl ether, polyoxyethylene 1-octylpentyl ether; polyoxyethylene alkenyl ethers such as polyoxyethylene oleyl ether; polyoxyethylene alkyl phenyl ethers such as polyoxyethylene octylphenyl ether, polyoxyethylene nonylphenyl ether, polyoxyethylene dodecylphenyl ether; polyoxyethylene tristyryl phenyl ether, polyoxyethylene distyryl phenyl ether, polyoxyethylene Polyoxyalkylene alkylarylphenyl ethers such as ethyl styrylphenyl ether, polyoxyethylene tritylphenyl ether, polyoxyethylene diphenylmethylphenyl ether, and polyoxyethylene benzylphenyl ether; acetylenic surfactants obtained by adding alkylene oxide to acetylenic alcohol or acetylenic diol; polyoxyalkylene fatty acid esters such as polyoxyethylene monolaurate, polyoxyethylene monooleate, polyoxyethylene monostearate, polyoxyethylene monomyristate, polyoxyethylene dilaurate, polyoxyethylene dioleate, polyoxyethylene dimyristate, and polyoxyethylene distearate; sorbitan monopalmitate, sorbitol Sorbitan esters such as polyoxyethylene sorbitan monooleate; polyoxyalkylene sorbitan fatty acid esters such as polyoxyethylene sorbitan monostearate and polyoxyethylene sorbitan monooleate; glycerol fatty acid esters such as glycerol monostearate, glycerol monolaurate and glycerol monopalmitate; polyoxyalkylene sorbitan fatty acid esters; sucrose fatty acid esters; polyoxyalkylene castor oil ethers such as polyoxyethylene castor oil ether; polyoxyalkylene hydrogenated castor oil ethers such as polyoxyethylene hydrogenated castor oil ether; oxyethylene-oxypropylene block or random copolymers; terminal sucrose ethers of oxyethylene-oxypropylene block or random copolymers, etc.

[0102] From the viewpoint of emulsification stability, it is preferred that the surfactant contains at least one selected from the group consisting of polyoxyalkylene linear primary alkyl ethers, polyoxyalkylene linear secondary alkyl ethers, polyoxyalkylene branched primary alkyl ethers, polyoxyalkylene branched secondary alkyl ethers, polyoxyalkylene alkyl phenyl ethers, polyoxyalkylene alkyl aryl phenyl ethers and acetylenic surfactants, and it is preferred that the surfactant contains at least one selected from the group consisting of polyoxyalkylene linear primary alkyl ethers, polyoxyalkylene linear secondary alkyl ethers, polyoxyalkylene branched primary alkyl ethers and polyoxyalkylene branched secondary alkyl ethers.

[0103] The weight average molecular weight of the nonionic surfactant (E) is preferably 2,000 or less, more preferably 200 to 1,800, more preferably 300 to 1,500, and further preferably 500 to 1,000. The nonionic surfactant may be used alone or in combination of two or more.

[0104] When the treatment agent of the present invention contains a nonionic surfactant (E), from the viewpoint of emulsification stability, the weight ratio of the nonionic surfactant (E) in the nonvolatile matter of the treatment agent is preferably 5 to 75 weight %. The upper limit of the weight ratio is more preferably 60 weight %, more preferably 50 weight %, and particularly preferably 40 weight %. On the other hand, the lower limit of the weight ratio is more preferably 10 weight %, more preferably 15 weight %, and particularly preferably 20 weight %. In addition, for example, 5 to 50 weight % is more preferably, and 10 to 40 weight % is further preferred.

[0105] 〔Other surfactants〕

[0106] The acrylic fiber treatment agent of the present invention may contain surfactants other than the above-mentioned nonionic surfactant and the Bronsted acid compound (C) within the range not impairing the effects of the present invention. The surfactant may be used as an emulsifier, an antistatic agent, etc. There are no particular limitations on other surfactants, and known surfactants may be appropriately selected from anionic surfactants, cationic surfactants, and amphoteric surfactants. The surfactant may be used alone or in combination of two or more.

[0107] Examples of anionic surfactants include fatty acids (salts) such as oleic acid, palmitic acid, sodium oleate, potassium palmitate, and triethanolamine oleate; carboxylic acids (salts) containing a hydroxyl group such as glycolic acid, potassium glycolate, lactic acid, and potassium lactate; polyoxyalkylene alkyl ether acetic acid (salts) such as polyoxyethylene tridecyl ether acetic acid (sodium salt); salts of carboxyl polysubstituted aromatic compounds such as potassium trimellitate and potassium pyromellitate; alkylbenzene sulfonic acid (salts) such as dodecylbenzene sulfonic acid (sodium salt); polyoxyethylene Polyoxyalkylene alkyl ether sulfonic acid (salt) such as 2-ethylhexyl ether sulfonic acid (potassium salt); higher fatty acid amide sulfonic acid (salt) such as stearoyl methyl taurine (sodium), lauroyl methyl taurine (sodium), myristoyl methyl taurine N (sodium), palmitoyl methyl taurine (sodium); N-acyl sarcosine (salt) such as lauroyl sarcosine (sodium); 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- Alkyl phosphonic acid alkyl phosphate esters (salts) such as ethylhexyl ester (potassium salt); nitrogen-containing alkyl phosphonic acid (salts) such as aminoethylphosphonic acid (diethanolamine salt); alkyl sulfate esters (salts) such as 2-ethylhexyl sulfate (sodium salt); polyoxyalkylene sulfate esters (salts) such as polyoxyethylene 2-ethylhexyl ether sulfate (sodium salt); alkyl phosphate esters (salts) such as lauryl phosphate (potassium salt), hexadecyl phosphate (potassium salt), and stearyl phosphate (diethanolamine salt); polyoxyethylene lauryl ether phosphate (potassium salt), polyoxyethylene Polyoxyalkylene alkyl (alkenyl) ether phosphates (salts) such as polyoxyethylene nonylphenyl ether phosphate (potassium salt) and polyoxyethylene dodecylphenyl ether phosphate (potassium salt); long-chain sulfosuccinates such as sodium di-2-ethylhexyl sulfosuccinate and sodium dioctyl sulfosuccinate, long-chain N-acyl glutamate salts such as monosodium N-lauroyl glutamate and disodium N-stearoyl-L-glutamate, etc.

[0108] From the viewpoint of emulsion stability, it is preferred that the polyoxyalkylene alkyl ether acetic acid (salt), polyoxyalkylene alkyl ether sulfonic acid (salt), alkylbenzene sulfonic acid (salt), polyoxyalkylene alkyl ether sulfonic acid (salt), and alkyl phosphate ester (salt) contain at least one selected from the group consisting of polyoxyalkylene alkyl ether acetic acid (salt), polyoxyalkylene alkyl ether sulfonic acid (salt) and alkyl phosphate ester (salt). It is preferred that the polyoxyalkylene alkyl ether acetic acid (salt), polyoxyalkylene alkyl ether sulfonic acid (salt) and alkyl phosphate ester (salt) contain at least one selected from the group consisting of polyoxyalkylene alkyl ether acetic acid (salt), polyoxyalkylene alkyl ether sulfonic acid (salt) and alkyl phosphate ester (salt).

[0109] Examples of the cationic surfactant include alkyl quaternary ammonium salts such as lauryl trimethyl ammonium chloride, myristyl trimethyl ammonium chloride, palmityl trimethyl ammonium chloride, stearyl trimethyl ammonium chloride, oleyl trimethyl ammonium chloride, hexadecyl trimethyl ammonium chloride, behenyl trimethyl ammonium chloride, coconut oil alkyl trimethyl ammonium chloride, tallow alkyl trimethyl ammonium chloride, stearyl trimethyl ammonium bromide, coconut oil alkyl trimethyl ammonium bromide, hexadecyl trimethyl ammonium methyl sulfate, oleyl dimethyl ethyl ammonium ethyl sulfate, dioctyl dimethyl ammonium chloride, dilauryl dimethyl ammonium chloride, distearyl dimethyl ammonium chloride, and octadecyl diethyl methyl ammonium sulfate; (polyoxyethylene) lauryl amino ether lactate, stearyl amino ether lactate, di(polyoxyethylene) lauryl methyl amino ether dimethyl phosphate, di(polyoxyethylene) ethyl sulfate ) lauryl ethyl ammonium, di(polyoxyethylene) hydrogenated tallow alkylethylamine ethylsulfate, di(polyoxyethylene) lauryl methyl ammonium dimethyl phosphate, di(polyoxyethylene) stearylamine lactate and other (polyoxyalkylene) alkylamino ether salts; acylamide alkyl quaternary ammonium salts such as N-(2-hydroxyethyl)-N,N-dimethyl-N-stearoyl amidopropyl ammonium nitrate, lanolin fatty acid amidopropyl ethyl dimethyl ammonium ethylsulfate, lauryl amidoethyl methyl diethyl ammonium methylsulfate; alkyl vinyloxy quaternary ammonium salts such as dipalmityl polyethyleneoxyethyl ammonium chloride and distearyl polyethyleneoxymethyl ammonium chloride; alkyl isoquinolinium salts such as lauryl isoquinolinium chloride; alkyl dimethylbenzyl ammonium salts such as lauryl dimethylbenzyl ammonium chloride and stearyl dimethylbenzyl ammonium chloride (benzalkonium salt); benzethonium salts such as benzyl dimethyl {2-[2-(p-1,1,3,3-tetramethylbutylphenoxy)ethoxy]ethyl} ammonium chloride; pyridinium salts such as cetylpyridinium chloride; imidazolium salts such as oleyl hydroxyethyl imidazolium ethyl sulfate and lauryl hydroxyethyl imidazolium ethyl sulfate; acyl basic amino acid alkyl ester salts such as N-cocoyl arginine ethyl ester pyrrolidone carboxylate and N-lauroyl lysine ethyl ethyl ester chloride; primary amine salts such as lauryl ammonium chloride, stearyl ammonium bromide, hydrogenated tallow alkyl ammonium chloride, and rosinamine acetate; cetyl methyl ammonium sulfate, lauryl methyl chloride Secondary amine salts such as octadecyl ethylamine, dilaurylamine acetate, stearyl ethylammonium bromide, laurylpropylammonium acetate, dioctyl ammonium chloride, and octadecyl ethylammonium hydroxide; tertiary amine salts such as dilauryl methylammonium sulfate, lauryl diethylammonium chloride, lauryl ethyl methylammonium bromide, diethanol stearyl amide ethylamine trihydroxyethyl phosphate, and stearyl amide ethylethanolamine urea polycondensate acetate; fatty acid amide guanidine salts; alkyl trialkylene glycol ammonium salts such as lauryl triethylene glycol ammonium hydroxide, etc.

[0110] Examples of the amphoteric surfactant include imidazoline-based amphoteric surfactants such as 2-undecyl-N,N-(hydroxyethylcarboxymethyl)-2-imidazolinium sodium and 2-cocoyl-2-imidazolinium hydroxide-1-carboxyethoxy disodium salt; betaine-based amphoteric surfactants such as 2-heptadecanyl-N-carboxymethyl-N-hydroxyethylimidazolinium betaine, lauryldimethylaminoacetic acid betaine, alkyl betaine, amide betaine, and sulfobetaine; and amino acid-based amphoteric surfactants such as N-laurylglycine, N-lauryl β-alanine, and N-stearyl β-alanine.

[0111] [Other ingredients]

[0112] The acrylic fiber treatment agent of the present invention may contain other components other than the above components within the range that does not impair the effects of the present invention. Other components include phenolic, amine, sulfur, phosphorus, quinone antioxidants, quaternary ammonium salt type cationic surfactants, amine salt type cationic surfactants and other antistatic agents, higher alcohol alkyl esters, higher alcohol ethers, waxes and other lubricants, antibacterial agents, preservatives, rust inhibitors and moisture absorbents.

[0113] In addition, the treatment agent of the present invention may contain modified silicones other than the above-mentioned amino-modified silicones within the range that does not impair the effects of the present invention. Examples of modified silicones include amide-modified silicones, amide polyether-modified silicones, epoxy-modified silicones, polyether-modified silicones, epoxy polyether-modified silicones (for example, see Japanese Patent No. 4616934), carbinol-modified silicones, alkyl-modified silicones, phenol-modified silicones, methacrylate-modified silicones, alkoxy-modified silicones, fluorine-modified silicones, and the like. One modified silicone may be used, or a plurality of modified silicones may be used in combination.

[0114] In addition, the treatment agent of the present invention may contain one or more low molecular weight silicones. Examples of low molecular weight silicones include, for example, linear or cyclic silicones having 2 to 7 silicon atoms. Specific examples of low molecular weight silicones include octamethylcyclotetrasiloxane, decamethylcyclopentasiloxane, dodecamethylcyclohexasiloxane, heptamethyloctyltrisiloxane, hexamethyldisiloxane, decamethyltetrasiloxane, dodecamethylpentasiloxane, etc. These low molecular weight silicones may be substituted by groups represented by the general formula (5) or the like. These low molecular weight silicones may be contained as trace components of the amino-modified silicone (A).

[0115] The content of the low-molecular silicone in the treatment agent of the present invention may be 15 parts by weight or less relative to 100 parts by weight of the amino-modified silicone (A).

[0116] The acrylic fiber treating agent of the present invention is preferably a state in which the amino-modified silicone (A), at least one selected from the compound (B) and the derivative of the compound (B), and optionally the Bronsted acid compound (C), the hydrophilic solvent (D) and the nonionic surfactant (E) are dissolved, solubilized, emulsified or dispersed in water.

[0117] There is no particular limitation on the weight ratio of water and the weight ratio of non-volatile matter in the overall acrylic fiber treatment agent. For example, it can be appropriately determined in consideration of the transportation cost when transporting the acrylic fiber treatment agent of the present invention, the handleability based on the viscosity of the emulsion, etc. The weight ratio of water in the overall acrylic fiber 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 non-volatile matter in the overall acrylic fiber 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.

[0118] The acrylic fiber treatment agent of the present invention can be produced by mixing the above-described components. The method for emulsifying / dispersing the above-described components is not particularly limited, and a known method can be used. Such methods include, for example, a method of emulsifying and dispersing the components constituting the acrylic fiber treatment agent by adding them to warm water under stirring; a method of mixing the components constituting the acrylic fiber treatment agent, and applying mechanical shear force using a homogenizer, a homomixer, a ball mill, etc., while slowly adding water to emulsify the phase. In addition, a method of emulsifying some components and then dissolving and dispersing the remaining components can also be used.

[0119] The acrylic fiber treating agent of the present invention can be suitably used as a treating agent (precursor treating agent) for acrylic fibers (precursors) for producing carbon fibers. In addition, it can also be used as a spinning oil agent for acrylic fibers other than precursors.

[0120] [Acrylic fiber for carbon fiber production, method for producing the same, and method for producing carbon fiber]

[0121] The acrylic fiber (precursor) for carbon fiber production of the present invention is made by attaching the above-mentioned acrylic fiber treatment agent to the raw acrylic fiber of the precursor and spinning. The manufacturing method of the precursor of the present invention includes a spinning step of attaching the above-mentioned acrylic fiber treatment agent to the raw acrylic fiber of the precursor and spinning.

[0122] The method for producing carbon fiber of the present invention comprises a refractory treatment step of converting a precursor to which the above-mentioned acrylic fiber treatment agent has been attached into a refractory fiber in an oxidative atmosphere at 200 to 300° C.; and a carbonization treatment step of further carbonizing the refractory fiber in an inert atmosphere at 300 to 2,000° C.

[0123] According to the method for producing carbon fiber of the present invention, by using the acrylic fiber treating agent of the present invention, the bundling property can be improved and the disorder and uneven stretching of the fiber bundle can be reduced, thereby producing high-quality carbon fiber.

[0124] The spinning step is a step of spinning the precursor by attaching an acrylic fiber treating agent to the raw acrylic fiber of the precursor, and preferably includes an attaching treatment step and a stretching step.

[0125] The attachment treatment process is a process of attaching an acrylic fiber treatment agent to the raw acrylic fiber of the precursor after the precursor is spun. That is, in the attachment treatment process, the acrylic fiber treatment agent is attached to the raw acrylic fiber of the precursor. In addition, when the raw acrylic fiber of the precursor is stretched immediately after spinning, the high-ratio stretching after the attachment treatment process is specifically referred to as a "stretching process". The stretching process may be a wet heat stretching method using high-temperature steam (steam) or a dry heat stretching method using a hot roller. The stretching ratio in the stretching process is preferably a total stretching ratio of 2 to 20 times relative to the raw acrylic fiber just after spinning.

[0126] The precursor is preferably composed of acrylic fibers having at least 95 mol % of acrylonitrile and 5 mol % or less of a flame retardant promoting component copolymerized to obtain polyacrylonitrile as the main component. The flame retardant promoting component can be suitably used as a vinyl-containing compound copolymerizable with acrylonitrile. There is no particular limitation on the single fiber fineness of the precursor, but from the perspective of the balance between performance and manufacturing cost, 0.1 to 2.0 dtex is preferred. In addition, although there is no particular limitation on the single fiber count of the fiber bundle constituting the precursor, from the perspective of the balance between performance and manufacturing cost, 1,000 to 96,000 is preferred.

[0127] Although the acrylic fiber treatment agent can be attached to the raw acrylic fiber of the precursor at any stage of the carbon fiber manufacturing process, it is preferred to attach it once before the stretching process. If it is a stage before the stretching process, it can be attached at any stage, for example, it can be attached immediately after spinning. In addition, it can also be attached at any stage after the stretching process, for example, it can be attached immediately after the stretching process, it can also be attached at the winding stage, and it can also be attached just before the refractory treatment process. Regarding the attachment method, it can be attached using a roller, etc., or it can be attached by dipping, spraying, etc.

[0128] In the attachment treatment process, from the perspective of the balance between "obtaining the effect of preventing adhesion between fibers and preventing fusion" and "preventing the quality of carbon fibers from being reduced by tar products of the treatment agent in the carbonization process", the imparting rate of the acrylic fiber treatment agent is preferably 0.1 to 5% by weight, and more preferably 0.3 to 1.5% by weight relative to the weight of the precursor. The imparting rate of the acrylic fiber treatment agent here is defined as the percentage of the weight of the non-volatile matter to which the acrylic fiber treatment agent is attached relative to the weight of the precursor.

[0129] The refractory treatment process is a process of converting the precursor to which the acrylic fiber treatment agent has been attached into a refractory fiber in an oxidizing atmosphere at 200 to 300° C. The oxidizing atmosphere can generally be an air atmosphere. The temperature of the oxidizing atmosphere is preferably 230 to 280° C. In the refractory treatment process, the acrylic fiber after the attachment treatment is subjected to a tension of 0.90 to 1.10 (preferably 0.95 to 1.05) and heat-treated for 20 to 100 minutes (preferably 30 to 60 minutes). In this refractory treatment, a refractory fiber having a refractory structure is manufactured through intramolecular cyclization and ring oxygen addition.

[0130] The carbonization treatment process is a process for further carbonizing the refractory fiber in an inert atmosphere of 300 to 2,000°C. In the carbonization treatment process, it is preferred to first perform a preliminary carbonization treatment process (first carbonization treatment process) in an inert atmosphere such as nitrogen and argon, in a sintering furnace with a temperature gradient of 300°C to 800°C, while applying a tension of a stretch ratio of 0.95 to 1.15 to the refractory fiber and heat treating it for several minutes. Then, in order to further carbonize and graphitize it, a second carbonization treatment process is performed in an inert atmosphere such as nitrogen and argon, while applying a tension of a stretch ratio of 0.95 to 1.05 relative to the first carbonization treatment process, and heat treating it for several minutes to carbonize the refractory fiber. Regarding the control of the heat treatment temperature in the second carbonization treatment process, the maximum temperature can be set to 1,000°C or more (preferably 1,000 to 2,000°C) while giving a temperature gradient. This maximum temperature is appropriately selected and determined according to the desired properties (tensile strength, elastic modulus, etc.) of the carbon fibers.

[0131] In the method for producing carbon fiber of the present invention, when carbon fiber having a higher elastic modulus is desired, a graphitization step may be performed after the carbonization step. The graphitization step is usually performed at a temperature of 2,000 to 3,000° C. in an inert atmosphere such as nitrogen or argon while applying tension to the fiber obtained by the carbonization step.

[0132] The carbon fiber obtained in this way can be subjected to surface treatment to improve the bonding strength with the matrix resin when it is made into a composite material, depending on the purpose. The surface treatment method can be gas phase or liquid phase treatment. From the perspective of productivity, liquid phase treatment with an electrolyte such as an acid or an alkali is preferred. In addition, various sizing agents with excellent compatibility can also be given to the matrix resin to improve the processability and handling of the carbon fiber.

[0133] Example

[0134] The present invention is described in more detail below with reference to the examples, but the present invention is not limited to the examples described herein. In addition, the percentages (%) and parts shown in the following examples represent "weight %" and "weight parts" unless otherwise specified. The measurement of each characteristic value is carried out according to the method shown below.

[0135] <Applying rate of treatment agent>

[0136] The precursor to which the treatment agent was applied was alkali-dissolved using potassium hydroxide / sodium butyrate, dissolved in water, and adjusted to pH 1 using hydrochloric acid. Sodium sulfite and ammonium molybdate were added to develop color, and the silicon content was determined by colorimetric quantification of silicon molybdenum blue (wavelength 815 μm). The silicon content obtained here and the value of the silicon content in the treatment agent obtained in advance by the same method were used to calculate the application rate (weight %) of the acrylic fiber treatment agent.

[0137] <Workability during firing (clustering)>

[0138] In the precursor calcining step, the passing state of the refractory fiber bundle immediately after passing through the refractory furnace was determined according to the following evaluation criteria.

[0139] ◎: The fiber bundle width does not increase, and there is no interference with adjacent fiber bundles, and the workability is particularly good.

[0140] ○: The fiber bundle width is slightly increased, but there is no interference with adjacent fiber bundles, and the workability is good.

[0141] ×: The fiber bundle width becomes wider, and there is interference with adjacent fiber bundles, and fluff may occur, resulting in poor workability.

[0142] <Abrasion resistance>

[0143] The precursor yarn strand (12 K) was rubbed 1,000 times (reciprocating speed 300 times / minute) at a tension of 50 g using a TM-200 friction cohesion tester (manufactured by Daiei Kagaku Seiki Co., Ltd.) through three mirror-finished chrome-plated stainless steel needles arranged in a zigzag pattern, and the fuzzing state of the precursor yarn strand was visually determined based on the following criteria.

[0144] ◎: No fuzzing was observed at all, similar to before rubbing, and the abrasion resistance was very good.

[0145] ○: Some fuzz was seen, but the scratch resistance was good.

[0146] △: There is some fuzzing and the abrasion resistance is slightly poor.

[0147] ×: There is a lot of fuzzing, single yarn breakage is obviously seen, and the abrasion resistance is poor.

[0148] <Carbon fiber strength>

[0149] The carbon fiber strength (GPa) was measured by the epoxy resin impregnated yarn method specified in JIS-R-7601, and the average value of 10 measurements was taken as the carbon fiber strength (GPa).

[0150] [Example 1]

[0151] An amino-modified silicone A1, nonionic surfactants E1 and E2, antioxidants F1 and F2, and water are mixed and aqueous-emulsified in such a manner as to obtain a nonvolatile composition of the treatment agent shown in Table 1, and then compounds B2 and B3 having a 5-membered ring structure containing sulfur atoms and nitrogen atoms, a Bronsted acid compound C2, a hydrophilic solvent D4, and an antistatic agent are dissolved and dispersed therein to prepare a treatment agent for acrylic fibers having a nonvolatile concentration of 30% by weight. Among the non-volatile matter of the treatment agent, the weight ratio of amino-modified silicone A1 is 85 weight%, the weight ratio of compounds B2 and B3 having a 5-membered ring structure containing sulfur atoms and nitrogen atoms is 0.02 weight%, the weight ratio of Bronsted acid compound C2 is 2.5 weight%, the weight ratio of hydrophilic solvent D4 is 0.18 weight%, the weight ratio of nonionic surfactant E1 is 3 weight%, the weight ratio of nonionic surfactant E2 is 5.3 weight%, the antistatic agent is 3 weight%, and the total weight ratio of antioxidants F1 and F2 is 1 weight%.

[0152] Next, the prepared treatment agent was further diluted with water to obtain a diluted solution having a nonvolatile matter concentration of 3.0% by weight.

[0153] The diluent was attached to the raw material acrylic fiber of the precursor obtained by copolymerization of 97 mol% acrylonitrile and 3 mol% itaconic acid in such a manner that the non-volatile matter of the treatment agent was given at a rate of 1.0 wt%, and a precursor (single fiber fineness 0.8 dtex, 24,000 filaments) was prepared by a stretching process (steam stretching, stretching ratio 2.1 times). This precursor was subjected to refractory treatment in a 250°C refractory furnace for 60 minutes, and then calcined in a carbonization furnace with a temperature gradient of 300 to 1,400°C in a nitrogen atmosphere to convert it into carbon fiber. The evaluation results of each characteristic value are shown in Table 1.

[0154] [Examples 2 to 83, Comparative Examples 1 to 40]

[0155] In Example 1, the same operation as in Example 1 was performed except that the treatment liquid was prepared so as to have the non-volatile composition of the treatment agent shown in Tables 1 to 12, thereby obtaining a precursor and carbon fibers to which the treatment agent was attached. The evaluation results of the various characteristic values ​​are shown in Tables 1 to 12.

[0156] In addition, the non-volatile components in Tables 1 to 12 are described in detail below.

[0157] <Amino-modified silicone (A)>

[0158] Amino modified silicone A1: 25℃ kinematic viscosity: 90mm 2 / s, amino equivalent: 3,900 g / mol, diamine type (manufactured by Dow Toray, trade name DOWSIL (registered trademark) BY 16-205)

[0159] Amino modified silicone A2: 25℃ kinematic viscosity: 60mm 2 / s, amino equivalent: 2,700 g / mol (manufactured by Dow Toray, trade name DOWSIL (registered trademark) BY 16-213)

[0160] Amino modified silicone A3: 25℃ kinematic viscosity: 1,200 mm 2 / s, amino equivalent: 600 g / mol, diamine type (manufactured by Dow Toray, trade name DOWSIL (registered trademark) BY 16-849 Fluid)

[0161] Amino modified silicone A4: 25℃ kinematic viscosity: 1,500 mm 2 / s, amino equivalent: 7,500 g / mol, diamine type (manufactured by Dow Toray, trade name DOWSIL (registered trademark) BY 16-879B)

[0162] Amino modified silicone A5: 25℃ kinematic viscosity: 220mm 2 / s, amino equivalent: 1,700 g / mol, diamine type (manufactured by Dow Toray, trade name DOWSIL (registered trademark) FZ-3760)

[0163] Amino modified silicone A6: 25℃ kinematic viscosity: 3,500 mm 2 / s, amino equivalent: 6,000 g / mol, diamine type (manufactured by Dow Toray, trade name DOWSIL (registered trademark) FZ-3785)

[0164] Amino modified silicone A7: 25℃ kinematic viscosity: 250mm 2 / s, amino equivalent: 7,600g / mol, diamine type (manufactured by Shin-Etsu Chemical Co., Ltd., trade name KF-860)

[0165] Amino modified silicone A8: 25℃ kinematic viscosity: 3,500mm 2 / s, amino equivalent: 2,000g / mol, diamine type (manufactured by Shin-Etsu Chemical Co., Ltd., trade name KF-861)

[0166] Amino modified silicone A9: 25℃ kinematic viscosity: 1,700mm 2 / s, amino equivalent: 3,800g / mol, monoamine type (manufactured by Shin-Etsu Chemical Co., Ltd., trade name KF-864)

[0167] Amino modified silicone A10: 25℃ kinematic viscosity: 1,300mm 2 / s, amino equivalent: 1,700g / mol, diamine type (manufactured by Shin-Etsu Chemical Co., Ltd., trade name KF-867S)

[0168] Amino modified silicone A11: 25℃ kinematic viscosity: 1,500mm 2 / s, amino equivalent: 3,800g / mol, diamine type (manufactured by Shin-Etsu Chemical Co., Ltd., trade name KF-869)

[0169] Amino modified silicone A12: 25℃ kinematic viscosity: 7,000mm 2 / s, amino equivalent: 4,000 g / mol (manufactured by Asahi Kasei Wacker Silicone Co., Ltd., trade name WACKER (registered trademark) FINISH WT 1200)

[0170] Amino modified silicone A13: 25℃ kinematic viscosity: 200mm 2 / s, amino equivalent: 4,000 g / mol (manufactured by Asahi Kasei Wacker Silicone Co., Ltd., trade name WACKER (registered trademark) FINISH WT 1270)

[0171] Amino modified silicone A14: 25℃ kinematic viscosity: 75 mm 2 / s, amino equivalent: 8,300 g / mol (manufactured by Asahi Kasei Wacker Silicone Co., Ltd., trade name WACKER (registered trademark) L653)

[0172] Amino modified silicone A15: 25℃ kinematic viscosity: 25mm2 / s, amino equivalent: 800 g / mol (manufactured by Asahi Kasei Wacker Silicone Co., Ltd., trade name WACKER (registered trademark) L656)

[0173] Amino modified silicone A16: 25℃ kinematic viscosity: 3,300mm 2 / s, amino equivalent: 1,800g / mol (manufactured by Shin-Etsu Chemical Co., Ltd., trade name X-22-3939A)

[0174] Amino modified silicone A17: 25℃ kinematic viscosity: 15,000mm 2 / s, amino equivalent: 3,600g / mol, diamine type

[0175] Amino modified silicone A18: 25℃ kinematic viscosity: 9,000mm 2 / s, amino equivalent: 9,000g / mol, diamine type

[0176] <Compound (B) and derivatives of compound (B)>

[0177] Compound B1: R in formula (1) 1 A compound in which octyl is present and X and Y are hydrogen atoms

[0178] Compound B2: R in formula (1) 1 A compound in which X is a chlorine atom and Y is a hydrogen atom

[0179] Compound B3: R in formula (1) 1 A compound wherein X and Y are hydrogen atoms

[0180] Compound B4: R in formula (2) 1 Compounds containing hydrogen atoms

[0181] Compound B5: R in formula (2) 1 Butyl compounds

[0182] Compound B6: 4-bromothiazole

[0183] Compound B7: 2-amino-1,3,4-thiadiazole

[0184] Compound B8: Reaction product of B1 and cysteine ​​(molar ratio 1:1)

[0185] Compound B9: Sodium salt of B4

[0186] <Components other than compound (B) and derivatives of compound (B)>

[0187] Compound B'1: 1,4-thiazine

[0188] Compound B'2: 3-methylthiophene

[0189] Compound B'3: Indole

[0190] <Brønsted acid compound (C)>

[0191] Bronsted acid compound C1: acetic acid

[0192] Bronsted acid compound C2: phosphoric acid

[0193] Bronsted acid compound C3: Benzoic acid

[0194] Brønsted acid compound C4: Arginine

[0195] Bronsted acid compound C5: C12 alkyl ether acetic acid to which 4.5 mol of ethylene oxide have been added (manufactured by Kao Corporation, trade name KAO AKYPO (registered trademark) RLM-45)

[0196] Bronsted acid compound C6: alkyl ether acetic acid having 12 carbon atoms to which 6 moles of ethylene oxide have been added (produced by Taikwang Oil & Fat Chemical Industry Co., Ltd., trade name Taipolsoft ECA-490)

[0197] Bronsted acid compound C7: C12 alkyl ether acetic acid to which 10 mol of ethylene oxide have been added (manufactured by Kao Corporation, trade name KAO AKYPO (registered trademark) RLM-100)

[0198] Bronsted acid compound C8: a C18 alkyl ether phosphate to which 3 mol of ethylene oxide have been added (manufactured by Toho Chemical Industry Co., Ltd., trade name Phosphanol (registered trademark) RL-310)

[0199] Bronsted acid compound C9: secondary alkyl ether phosphate having 12 to 15 carbon atoms to which 3 moles of ethylene oxide have been added (manufactured by Toho Chemical Industry Co., Ltd., trade name Phosphanol (registered trademark) RS-410)

[0200] Bronsted acid compound C10: secondary alkyl ether phosphate having 12 to 15 carbon atoms to which 9 moles of ethylene oxide have been added (manufactured by Toho Chemical Industry Co., Ltd., trade name Phosphanol (registered trademark) RS-710)

[0201] <Hydrophilic solvent (D)>

[0202] Hydrophilic solvent D1: monoethylene glycol

[0203] Hydrophilic solvent D2: diethylene glycol

[0204] Hydrophilic solvent D3: Propylene glycol

[0205] Hydrophilic solvent D4: tripropylene glycol

[0206] Hydrophilic solvent D5: N,N-dimethylformamide

[0207] Hydrophilic solvent D6: 1-methyl-2-pyrrolidone

[0208] <Nonionic surfactant (E)>

[0209] Nonionic surfactant E1: a C12 alkyl ether to which 3 mol of ethylene oxide have been added (manufactured by Kao Corporation, trade name EMULGEN (registered trademark) 103)

[0210] Nonionic surfactant E2: C12 alkyl ether to which 6 mol of ethylene oxide have been added (manufactured by Kao Corporation, trade name EMULGEN (registered trademark) 108)

[0211] Nonionic surfactant E3: C18 alkyl ether to which 13 mol of ethylene oxide have been added (manufactured by Kao Corporation, trade name EMULGEN (registered trademark) 320P)

[0212] Nonionic surfactant E4: polyoxyethylene trityl phenyl ether (manufactured by Kao Corporation, trade name EMULGEN (registered trademark) B-66)

[0213] Nonionic surfactant E5: acetylene-based surfactant (manufactured by Nissin Chemical Industry Co., Ltd., trade name Olfine (registered trademark) E1010)

[0214] Nonionic surfactant E6: acetylene-based surfactant (manufactured by Nissin Chemical Industry Co., Ltd., trade name Olfine (registered trademark) EXP-4123)

[0215] Nonionic surfactant E7: acetylene-based surfactant (manufactured by Nissin Chemical Industry Co., Ltd., trade name Olfine (registered trademark) PD-001)

[0216] Nonionic surfactant E8: acetylene-based surfactant (manufactured by Nissin Chemical Industry Co., Ltd., trade name Surfynol (registered trademark) 104E)

[0217] Nonionic surfactant E9: acetylene-based surfactant (manufactured by Nissin Chemical Industry Co., Ltd., trade name Surfynol (registered trademark) 440)

[0218] Nonionic surfactant E10: acetylene-based surfactant (manufactured by Nissin Chemical Industry Co., Ltd., trade name Surfynol (registered trademark) 485)

[0219] Nonionic surfactant E11: a secondary alkyl ether having 12 to 14 carbon atoms to which 5 mol of ethylene oxide have been added (manufactured by Nippon Shokubai Co., Ltd., trade name Softanol (registered trademark) 50)

[0220] Nonionic surfactant E12: a secondary alkyl ether having 12 to 14 carbon atoms to which 9 mol of ethylene oxide have been added (manufactured by Nippon Shokubai Co., Ltd., trade name Softanol (registered trademark) 90)

[0221] Nonionic surfactant E13: a secondary alkyl ether having 12 to 14 carbon atoms to which 12 mol of ethylene oxide have been added (manufactured by Nippon Shokubai Co., Ltd., trade name Softanol (registered trademark) 120)

[0222] Nonionic surfactant E14: polyoxyethylene polyoxypropylene butyl ether (manufactured by Sanyo Chemical Industries, Ltd., trade name Newpol (registered trademark) 50-HB)

[0223] Nonionic surfactant E15: polyoxyethylene polyoxypropylene glycol (manufactured by Sanyo Chemical Industries, Ltd., trade name Newpol (registered trademark) MAP-4000)

[0224] Nonionic surfactant E16: polyoxyethylene polyoxypropylene glycol (manufactured by Sanyo Chemical Industries, Ltd., trade name Newpol (registered trademark) PE-64)

[0225] Nonionic surfactant E17: Polyoxyalkylene branched decyl ether (manufactured by Daiichi Industrial Seiyaku Co., Ltd., trade name NOIGEN (registered trademark) XL-41)

[0226] Nonionic surfactant E18: Polyoxyalkylene branched decyl ether (manufactured by Daiichi Industrial Pharmaceutical Co., Ltd., trade name NOIGEN (registered trademark) XL-80)

[0227] Nonionic surfactant E19: nonylphenyl ether to which 3 mol of ethylene oxide have been added (manufactured by Aoki Oil & Fats Industry Co., Ltd., trade name BLAUNON (registered trademark) BNP-30A)

[0228] Nonionic surfactant E20: C16 alkyl ether to which 3 mol of ethylene oxide have been added (manufactured by Aoki Oil & Fats Industry Co., Ltd., trade name BLAUNON (registered trademark) CH-313)

[0229] Nonionic surfactant E21: nonylphenyl ether to which 5 mol of ethylene oxide have been added (manufactured by Aoki Oil & Fats Industry Co., Ltd., trade name BLAUNON (registered trademark) N-505)

[0230] <Other ingredients>

[0231] Antioxidant F1: Triethylene glycol-bis-3-(3-tert-butyl-4-hydroxy-5-methylphenyl) propionate

[0232] Antioxidant F2: Dioleyl thiodipropionate

[0233] Antistatic agent: Ethylene bis(hydroxyethyl)octadecyl ammonium ethyl sulfate

[0234]

[0235]

[0236]

[0237]

[0238]

[0239]

[0240]

[0241]

[0242]

[0243]

[0244]

[0245]

[0246] As can be seen from Tables 1 to 12, the acrylic fiber treating agent of the embodiment can obtain high-quality carbon fibers with excellent bundling properties in the manufacturing process and refractory process of acrylic fibers for carbon fiber manufacturing, compared with the treating agent of the comparative example which does not contain amino-modified silicone (A) and / or compound (B).

Claims

1. An acrylic fiber treating agent comprising an amino-modified silicone (A) and at least one selected from a compound (B) having a five-membered ring structure containing a sulfur atom and a nitrogen atom, and a derivative of the compound (B).

2. The acrylic fiber treating agent according to claim 1, wherein The compound (B) comprises at least one selected from the group consisting of a compound represented by the following general formula (1) and a compound represented by the following general formula (2); In formula (1), R 1 is an alkyl group, an aralkyl group or a hydrogen atom having 1 to 12 carbon atoms, and X and Y are independently a hydrogen atom or a halogen atom; In formula (2), R 2 It is an alkyl group having 1 to 8 carbon atoms or a hydrogen atom.

3. The acrylic fiber treating agent according to claim 1 or 2, further comprising a Bronsted acid compound (C).

4. The acrylic fiber treating agent according to claim 3, wherein The Bronsted acid compound (C) includes at least one selected from the group consisting of carboxylic acid compounds, inorganic acids, sulfonic acid compounds, phosphoric acid ester compounds, sulfuric acid ester compounds, and phosphonic acid compounds.

5. The acrylic fiber treating agent according to claim 3 or 4, wherein The molar ratio of the Bronsted acid compound (C) to the amino group of the amino-modified silicone (A) is 0.01 to 5.

0.

6. The acrylic fiber treating agent according to any one of claims 3 to 5, wherein The total weight of the compound (B) and the derivative of the compound (B) is 0.01 to 50 parts by weight relative to 100 parts by weight of the Bronsted acid compound (C).

7. The acrylic fiber treating agent according to any one of claims 1 to 6, further comprising a hydrophilic solvent (D), wherein the hydrophilic solvent (D) comprises at least one selected from the group consisting of a compound represented by the following general formula (3) and an aprotic nitrogen-containing organic compound; In the formula (3), AO is an oxyalkylene group having 2 to 4 carbon atoms, and n is an integer of 1 to 3.

8. The acrylic fiber treating agent according to any one of claims 1 to 7, wherein The weight ratio of the amino-modified silicone (A) in the non-volatile matter of the treatment agent is 20 wt % to 90 wt %. 9 . The acrylic fiber treating agent according to claim 1 , further comprising a nonionic surfactant (E). 10 . Acrylic fibers for carbon fiber production, obtained by allowing the acrylic fiber treating agent according to claim 1 to adhere to acrylic fibers as a raw material of the acrylic fibers for carbon fiber production.

11. A method for producing carbon fiber, comprising: A refractory treatment step of converting the acrylic fiber for carbon fiber production according to claim 10 into a refractory fiber in an oxidative atmosphere at 200° C. to 300° C.; and The step of carbonizing the fire-resistant fiber is further performed in an inert atmosphere at 300°C to 2000°C.

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