JPWO2018163739A1 - Acrylic fiber treatment agent and use thereof - Google Patents

Abstract

A treatment agent for acrylic fiber capable of suppressing deterioration of an acrylic fiber for carbon fiber production when the acrylic fiber for carbon fiber production produced by applying a treatment agent is stored for a long period of time, an acrylic fiber for carbon fiber production using the treatment agent And a method of producing carbon fibers using the treatment agent. The acrylic fiber treatment agent of the present invention comprises an amino-modified silicone (A), a Bronsted acid compound (B) and an acetylenic surfactant (C). The acrylic fiber for carbon fiber production of the present invention is obtained by adhering the acrylic fiber treatment agent of the present invention to raw material acrylic fiber of acrylic fiber for carbon fiber production.

Description

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

Carbon fibers are widely used in aerospace applications, sports applications, general industrial applications, etc., as reinforcing fibers for composite materials with plastics called matrix resins, taking advantage of their excellent mechanical properties.
As a method for producing carbon fibers, first, acrylic fibers for producing carbon fibers (sometimes referred to as "precursors") are produced (the process for producing the precursors may be referred to as a yarn production process). This precursor is converted to a flameproofed fiber in an oxidizing atmosphere at 200 to 300 ° C. (this process may be hereinafter referred to as a flameproofing step) and subsequently carbonized in an inert atmosphere at 300 to 2000 ° C. (This step is hereinafter sometimes referred to as a carbonization treatment step) is a general method (hereinafter, a combination of a flameproofing step and a carbonization treatment step may be referred to as a firing step). The precursor is manufactured through a drawing process which is drawn at a high magnification as compared with ordinary acrylic fibers. At that time, the fibers are easily stuck to each other, and the high magnification stretching is not uniformly performed, so that it becomes a non-uniform precursor. There is a problem that carbon fibers obtained by firing such a precursor can not obtain sufficient strength. In addition, at the time of firing of the precursor, there is a problem that fusion between single fibers occurs and the quality and quality of the obtained carbon fiber are lowered.

As a treating agent to be applied to the precursor for preventing sticking of the precursor and preventing fusion of carbon fiber, a silicone-based treating agent having excellent peelability and low fiber-fiber friction under wet condition and high temperature environment, especially A number of techniques have been proposed for applying to the precursor an amino-modified silicone-based treatment agent capable of further improving the heat resistance by a crosslinking reaction with heat (see Patent Documents 1 and 2).
When a precursor produced by applying such a treatment agent is stored for a long period of time, there is a problem of causing the precursor to deteriorate with time. Therefore, when a carbon fiber is manufactured by firing a precursor stored for a long period of time, fuzz is generated in the firing step, and there is a problem such as a decrease in carbon fiber strength after firing.

Japanese Patent Application Laid-Open No. 2001-172879 Japanese Patent Application Laid-Open No. 2002-129481

  In view of such conventional technical background, an object of the present invention is to treat acrylic fibers which can suppress deterioration of acrylic fibers for carbon fiber production when the acrylic fibers for carbon fiber production which are produced by adding a treating agent are stored for a long period of time An agent, an acrylic fiber for producing carbon fibers using the treating agent, and a method for producing a carbon fiber using the treating agent.

  As a result of intensive studies to solve the above problems, the inventors of the present invention have found that deterioration when a precursor prepared by adding a treating agent is stored for a long time is caused by the amino group of amino-modified silicone contained in the treating agent. It has been found that this is due to the penetration of the emulsifying agent used to emulsify the amino-modified silicone into the interior of the fiber. And, if amino-modified silicone (A), Br ス テ ッ ド nsted acid compound (B) and acetylenic surfactant (C) are used in combination, the deterioration of the precursor due to the amino group and the permeation of the emulsifier into the fiber are caused. It has been found that deterioration of the precursor can be suppressed, and the present invention has been achieved.

  That is, the acrylic fiber treatment agent of the present invention comprises an amino-modified silicone (A), a Bronsted acid compound (B) and an acetylene-based surfactant (C).

  It is preferable that the ratio of a Bronsted-acid compound (B) is 0.01-2.5 molar equivalent with respect to 1 mol of amino groups of the said amino modified silicone (A).

  The proportion of the acetylene-based surfactant (C) is preferably 0.1 to 12 parts by weight with respect to 100 parts by weight of the amino-modified silicone (A).

  The acetylene-based surfactant (C) is selected from acetylene alcohol (C1), acetylene diol (C2), compound (C3) obtained by adding alkylene oxide to acetylene alcohol and compound (C4) obtained by adding alkylene oxide to acetylene diol Or at least one selected from the group consisting of

  The acetylene alcohol (C1) is preferably a compound represented by the following general formula (1). The acetylene diol (C2) is preferably a compound represented by the following general formula (2). It is preferable that the compound (C3) which added the alkylene oxide to the said acetylene alcohol is a compound represented by following General formula (3). It is preferable that the compound (C4) which added the alkylene oxide to the said acetylene diol is a compound represented by following General formula (4).

（式（１）中、Ｒ^１及びＲ²は、それぞれ独立して炭素数１〜８のアルキル基である。）

(In formula (1), R ¹ and R ² are each independently an alkyl group having 1 to 8 carbon atoms.)

（式（２）中、Ｒ^３、Ｒ^４、Ｒ^５及びＲ^６は、それぞれ独立して炭素数１〜８のアルキル基である。）

(In formula (2), R ³ , R ⁴ , R ⁵ and R ⁶ are each independently an alkyl group having 1 to 8 carbon atoms.)

（式（３）中、Ｒ^１及びＲ²は、それぞれ独立して炭素数１〜８のアルキル基である。Ｒ^７は水素原子、または炭素数１〜５のアルキル基である。ＡＯは炭素数２〜４のオキシアルキレン基を示す。ｎは１〜５０の数である。）

(In Formula (3), R ¹ and R ² are each independently an alkyl group having 1 to 8 carbon atoms. R ⁷ is a hydrogen atom or an alkyl group having 1 to 5 carbon atoms. AO is carbon 2 to 4 represents an oxyalkylene group, n is a number of 1 to 50.)

（式（４）中、Ｒ^３、Ｒ^４、Ｒ^５及びＲ^６は、それぞれ独立して炭素数１〜８のアルキル基である。Ｒ^７は水素原子、または炭素数１〜５のアルキル基である。なお、式（４）における複数のＲ^７は、同一であってもよく異なっていてもよい。ＡＯは炭素数２〜４のオキシアルキレン基を示す。ｍ、ｎはそれぞれ独立して１〜５０の数である。）

(In formula (4), R ³ , R ⁴ , R ⁵ and R ⁶ are each independently an alkyl group having 1 to 8 carbon atoms. R ⁷ is a hydrogen atom or an alkyl group having 1 to 5 carbon atoms In addition, a plurality of R ⁷ in the formula (4) may be the same or different, and AO represents an oxyalkylene group having 2 to 4 carbon atoms, and m and n are each independently. It is a number of 1 to 50.)

  It is preferable that the weight ratio of the said amino modified silicone (A) to the non volatile matter of a processing agent is 40 to 95 weight%.

  The treatment agent for acrylic fiber of the present invention preferably further contains a polyoxyalkylene alkyl ether (D)

  It is preferable that the said polyoxyalkylene alkyl ether (D) contains the compound shown by following General formula (5).

（一般式（５）中、Ｒ^８は炭素数６〜２２のアルキル基を示す。ＡＯは炭素数２〜４のオキシアルキレン基を示す。ｊはそれぞれ独立して１〜５０の数である。）

In (formula (5), ^{R 8} is .AO represents an alkyl group having 6 to 22 carbon atoms is a number from 1 to 50 independently respectively .j showing an oxyalkylene group having 2 to 4 carbon atoms. )

  The ratio of the total of the acetylene-based surfactant (C) and the polyoxyalkylene alkyl ether (D) is preferably 5 to 50 parts by weight with respect to 100 parts by weight of the amino-modified silicone (A).

  The acrylic fiber for carbon fiber production of the present invention is obtained by adhering the above-mentioned acrylic fiber treatment agent to raw material acrylic fiber for acrylic fiber for carbon fiber production.

  The method for producing carbon fiber according to the present invention comprises a spinning step in which the above-mentioned fiber treatment agent is made to adhere to raw material acrylic fiber of acrylic fiber for carbon fiber production to produce a yarn, and flameproof fiber in an oxidizing atmosphere at 200 to 300 ° C. And a carbonization treatment step of carbonizing the above-mentioned flameproofed fibers in an inert atmosphere at 300 to 2000 ° C.

  The acrylic fiber treatment agent of the present invention can suppress deterioration of the acrylic fiber for carbon fiber production when the acrylic fiber for carbon fiber production which is produced by applying the treatment agent is stored for a long time. By using the acrylic fiber for carbon fiber production of the present invention, even when using an acrylic fiber bundle stored for a long time, generation of fluff in the firing step can be suppressed, and carbon fiber with high strength and high quality can be obtained. According to the method for producing a carbon fiber of the present invention, even when using an acrylic fiber bundle stored for a long time, generation of fluff in the firing step can be suppressed, and high strength and high quality carbon fiber can be obtained.

(Amino-modified silicone (A))
The treatment agent of the present invention essentially contains an amino-modified silicone (A). An amino group (including an organic group having an amino group) which is a modifying group of amino-modified silicone may be bonded to a side chain of silicone which is a main chain, or may be bonded to an end, or It may be bonded to both, but from the viewpoint of fiber protection in the flameproofing step, it is preferable to be bonded to the side chain (having an amino group in the side chain). The amino group may be any of monoamine type, diamine type and polyamine type, and both may coexist in one molecule, but the treatment agent is extended to the inside of the fiber bundle in the flameproofing step. A monoamine type or a diamine type is preferred from the viewpoint of uniform application and coating of the treatment agent to protect the fibers. The amino-modified silicone (A) may be used alone or in combination of two or more.

The kinematic viscosity of the amino-modified silicone (A) at 25 ° C. is preferably 50 to 30,000 mm ² / s from the viewpoint of exerting the effect of the present invention. If the kinematic viscosity is less than 50 mm ² / s, the treatment agent is likely to scatter, and when aqueous emulsion is made, the solution stability of the emulsion may deteriorate, and the treatment agent may not be able to be uniformly applied to the fibers. . As a result, fusion of fibers may not be prevented. When the kinematic viscosity is more than 30000 mm ² / s, gum-up due to the tackiness may be a problem. The upper limit value of the kinematic viscosity is preferably 25000 mm ² / s, 20000 mm ² / s, 10000 mm ² / s, 5000 mm ² / s, 4000 mm ² / s, 3000 mm ² / s, 2500 mm ² / s in this order.

  The amino equivalent of the amino-modified silicone (A) is preferably 300 to 10000 g / mol, more preferably 500 to 10000 g / mol, and still more preferably 1000 to 9000 g / mol, from the viewpoint of preventing sticking and fusion between fibers. When the amino equivalent is less than 300 g / mol, the treatment agent may be thermally crosslinked at the beginning of the flameproofing step, so that the treatment agent may not be uniformly applied to the inside of the fiber bundle. In addition, when the amino equivalent is 10000 g / mol or more, the fibers may not be protected because thermal crosslinking of the treating agent does not occur at a later stage of the flameproofing step. Here, the amino equivalent means the mass of the siloxane skeleton per amino group or ammonium group. The g / mol of the indicated unit is a value converted per mol of amino group or ammonium group. Therefore, the smaller the value of the amino equivalent, the higher the proportion of amino groups or ammonium groups in the molecule.

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

  As said amino modified silicone, the compound shown by following General formula (6) can be mentioned, for example.

（式（６）中、Ｒ^９は炭素数が１〜２０のアルキル基又はアリール基を示す。Ｒ^１０は下記化学式（７）で示される基である。Ｒ^１１は、Ｒ^９、Ｒ^１０又は−ＯＲ^１７（Ｒ^１７は水素原子又は炭素数が１〜６のアルキル基）である。ｐは１０≦ｐ≦１００００、ｑは０．１≦ｑ≦１０００である。）

Wherein R ⁹ represents an alkyl group having 1 to 20 carbon atoms or an aryl group, and R ¹⁰ represents a group represented by the following chemical formula (7): R ¹¹ represents R ⁹ , R ¹⁰ or -OR ¹⁷ (R ¹⁷ is a hydrogen atom or an alkyl group having 1 to 6 carbon atoms), p is 10 ≦ p ≦ 10000, and q is 0.1 ≦ q ≦ 1000.

Wherein (6), ^{R 9} represents an alkyl or aryl group having 1 to 20 carbon atoms. R ⁹ is preferably an alkyl group having 1 to 10 carbon atoms or an aryl group, more preferably an alkyl group having 1 to 5 carbon atoms, and still more preferably a methyl group. In addition, several R < ⁹ > in Formula (6) may be same or different. R ¹⁰ is a group represented by the following general formula (7). R ¹¹ is a group represented by R ⁹ , R ¹⁰ or -OR ¹⁷ , preferably R ⁹ . In addition, several R < ¹¹ > in Formula (6) may be same or different.
R ¹⁷ 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, and more preferably a hydrogen atom or a methyl group. p is a number of 10 to 10000, preferably 50 to 5000, and more preferably 100 to 2000. q is a number of 0.1 to 1000, preferably 0.5 to 500, and more preferably 1 to 100.

In formula (7), R ¹² and R ¹⁴ are each independently an alkylene group having 1 to 6 carbon atoms, preferably an alkylene group having 1 to 3 carbon atoms. R ¹³ , R ¹⁵ and R ¹⁶ each independently represent 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 further Preferably it is a hydrogen atom. r is a number of 0 to 6, preferably 0 to 3, and more preferably 0 to 1.

(Brensted acid compound (B))
The fiber treatment agent of the present invention essentially contains a Bronsted acid compound (B). When the Bronsted acid (B) is not used, it is not possible to suppress the temporal crosslinking due to the amino group of the amino-modified silicone, even when the acetylene-based surfactant (C), which is an essential component, is used. The Bronsted acid compound (B) is a proton donor, and includes carboxylic acid compounds, inorganic acids, sulfonic acid compounds, phosphonic acid compounds and the like. The Bronsted acid compound (B) may be used alone or in combination of two or more.

  A carboxylic acid compound means the compound which contains a carboxyl group in molecular structure. Although it does not specifically limit as a carboxylic acid compound, Aliphatic monocarboxylic acid, aliphatic polycarboxylic acid, aromatic carboxylic acid, aromatic polycarboxylic acid, an amino acid etc. are mentioned.

  Examples of aliphatic monocarboxylic acids include acetic acid, lactic acid, butyric acid, crotonic acid, valeric acid, caproic acid, enanthate, caprylic acid, pelargonic acid, capric acid, lauric acid, myristic acid, myristoleic acid, pentadecanoic acid and palmitic acid Palmitoleic acid, isocetylic acid, margaric acid, stearic acid, isostearic acid, oleic acid, elaidic acid, bacicic acid, linoleic acid, linolenic acid, arachidic acid, isoeicoic acid, gaderic acid, eicosenic acid, docosanoic acid, isodocosanoic acid, eruka Examples of the acid include tetracosanoic acid, isotetracosanoic acid, nervonic acid, cerotic acid, montanic acid, melisic acid, polyoxyalkylene monocarboxylic acid, polyoxyalkylene alkyl ether monocarboxylic acid and the like.

  Examples of aliphatic polycarboxylic acids include oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, speric acid, azelaic acid, sebacic acid, undencan diacid, dodecanedioic acid, tridecanedioic acid and tetradecanedioic acid And pentadecanedioic acid, polyoxyalkylene dicarboxylic acid, polyoxyalkylene alkyl ether dicarboxylic acid and derivatives thereof.

  Aromatic monocarboxylic acids include benzoic acid, cinnamic acid, naphthoic acid, toluic acid, and derivatives thereof.

  Examples of aromatic polycarboxylic acids include phthalic acid, isophthalic acid, terephthalic acid, trimellitic acid and pyromellitic acid, and derivatives thereof.

  An amino acid is a compound having both an amino group and a carboxyl group in the molecular structure, and alanine, valine, leucine, isoleucine, phenylalanine, tryptophan, methionine, proline, glycine, tyrosine, serine, threonine, cysteine, asparagine, glutamine , Lysine, arginine, histidine, aspartic acid, glutamic acid and the like.

An inorganic acid means an acid containing a nonmetal atom as a component. As the inorganic acid, sulfuric acid, nitric acid, phosphoric acid, hydrochloric acid and the like can be mentioned.
As a sulfonic acid compound, alkyl benzene sulfonic acid, polyoxyalkylene alkyl ether sulfonic acid, higher fatty acid amido sulfonic acid, alkyl sulfuric acid monoester, polyoxyalkylene sulfuric acid mono ester, etc. may be mentioned.
Examples of phosphonic acid compounds include alkyl phosphonic acid, aromatic phosphonic acid, polyoxyalkylene alkyl ether phosphonic acid, alkyl phosphonic acid alkyl phosphoric acid monoester, and the like.

  The pKa of the Bronsted compound (B) is preferably from 0 to 7, more preferably from 1 to 6.5, from the viewpoints of corrosion and safety of equipment and suppression of crosslinking with time due to amino groups of amino-modified silicones. Preferably, 2 to 6 are more preferable.

(Acetylene-based surfactant (C))
The acrylic fiber treatment agent of the present invention essentially contains an acetylenic surfactant (C). The use of a Bronsted acid compound (B) and an acetylenic surfactant (C) in combination with an amino-modified silicone suppresses the crosslinking with time due to the amino group of the amino-modified silicone, and the amino-modified silicone It is presumed that the emulsifier at the time of aqueous emulsification can be prevented from penetrating into the fiber structure, and as a result, deterioration of the precursor fiber when the precursor fiber is stored for a long period of time can be suppressed. When other surfactants are used without using the acetylene-based surfactant (C), the penetration of the emulsifier into the fiber structure is suppressed even when the Bronsted acid compound (B) is used. As a result, it is presumed that if carbon fibers are produced using precursor fibers when the precursor fibers are stored for a long period of time, the strength will be reduced. In addition, acetylene type surfactant means the compound which has hydrophilic groups, such as an acetylene group and a hydroxyl group, in molecular structure. The acetylene-based surfactant (C) may be used alone or in combination of two or more.

  The acetylene-based surfactant (C) is selected from acetylene alcohol (C1), acetylene diol (C2), compound (C3) obtained by adding alkylene oxide to acetylene alcohol, and compound (C4) obtained by adding alkylene oxide to acetylene diol Or at least one of them. Among these, a compound (C3) obtained by adding an alkylene oxide to an acetylene alcohol and a compound (C4) obtained by adding an alkylene oxide to an acetylene diol are preferable, and a compound (C4) obtained by adding an alkylene oxide to an acetylene diol is more preferable.

Acetylene alcohol (C1) is a compound having an acetylene group and one hydroxyl group in the molecular structure.
It is preferable that acetylene alcohol (C1) is a compound represented by the said General formula (1).

Acetylene diol (C2) is a compound which has an acetylene group and two hydroxyl groups in molecular structure.
It is preferable that acetylene diol (C2) is a compound represented by the said General formula (2).

The compound (C3) obtained by adding an alkylene oxide to an acetylene alcohol is a compound obtained by adding an alkylene oxide to a hydroxyl group of an acetylene alcohol.
The compound (C3) obtained by adding an alkylene oxide to an acetylene alcohol is preferably a compound represented by the above general formula (3).

The compound (C4) obtained by adding an alkylene oxide to an acetylene diol is a compound obtained by adding an alkylene oxide to at least one hydroxyl group of an acetylene diol.
It is preferable that the compound (C4) which added the alkylene oxide to acetylene diol is a compound represented by the said General formula (4).

In Formula (1) and Formula (3), R ¹ and R ² are each independently an alkyl group having 1 to 8 carbon atoms. The alkyl group may be linear or have a branched structure. Carbon number of the said alkyl group becomes like this. Preferably it is 1-7, More preferably, it is 1-6, More preferably, it is 1-5.
In formulas (2) and (4), R ³ , R ⁴ , R ⁵ and R ⁶ are each independently an alkyl group having 1 to 8 carbon atoms. The alkyl group may be linear or have a branched structure. Carbon number of the said alkyl group becomes like this. Preferably it is 1-7, More preferably, it is 1-6, More preferably, it is 1-5.

Equation (3) and in formula (4), ^{R 7} is a hydrogen atom or an alkyl group having 1 to 5 carbon atoms. Carbon number of the said alkyl group becomes like this. Preferably it is 1-4, More preferably, it is 1-3, More preferably, it is 1-2.
In Formula (3) and Formula (4), AO shows a C2-C4 oxyalkylene group. That is, it represents an oxyethylene group, an oxypropylene group or an oxybutylene group. The oxyalkylene group is preferably an oxyethylene group or an oxypropylene group, and more preferably an oxyethylene group. AO constituting (AO) _n or (AO) _m may be one type, or two or more types. In the case of two or more types, any of a block adduct, an alternate adduct, and a random adduct may be used.

In Formula (3), n is a number of 1 to 50. n is preferably 1 to 45, more preferably 1 to 40, and still more preferably 1 to 35.
In Formula (4), m and n are respectively independently the numbers of 1-50. Each of m and n is independently preferably 1 to 45, more preferably 1 to 40, and still more preferably 1 to 35.

  The HLB of the acetylene-based surfactant (C) is preferably 4 to 25, more preferably 5 to 20, and still more preferably 6 to 18 from the viewpoint of emulsifiability. The HLB in the present invention can be determined experimentally by the atlas method proposed by Griffin et al.

The acetylene-based surfactant (C) is a known compound and can be easily produced by a known method. For example, such a compound can be obtained by a method called Reppe reaction, in which acetylene is reacted with ketone or aldehyde in the presence of a catalyst such as an alkali or a metal compound under pressure.
The above compound (C3) or compound (C4) is an acetylene alcohol (C1) or an acetylene diol (C2), respectively, with an alkylene oxide (eg ethylene oxide and / or propylene oxide) as a catalyst such as an alkali or a metal compound. It can be obtained by addition polymerization in the presence.

[Acrylic fiber treatment agent]
The treating agent for acrylic fiber of the present invention contains the above-mentioned amino-modified silicone (A), a Bronsted acid compound (B) and an acetylene-based surfactant (C).
The weight ratio of the amino-modified silicone (A) to the non-volatile component of the treatment agent is preferably 40 to 95% by weight, more preferably 45 to 94% by weight, still more preferably 50 to 92% by weight, particularly preferably 55 to 90 It is weight%. If the weight ratio is less than 40% by weight, the heat resistance of the treating agent may be insufficient in the flameproofing step. On the other hand, when the weight ratio is more than 95% by weight, a stable aqueous emulsion may not be obtained when the treatment agent is emulsified in water.

  The weight ratio of the acetylene-based surfactant (C) in the non-volatile portion of the processing agent is preferably 0.1 to 20% by weight, more preferably 0.2 to 15% by weight, and still more preferably 0.3 to 13%. %, Particularly preferably 0.5 to 10% by weight. If the weight ratio is less than 0.1% by weight, the penetration of the emulsifier into the fiber structure may not be able to be suppressed. On the other hand, when the weight ratio is more than 20% by weight, stable operability may not be obtained.

  The ratio of the acetylenic surfactant (C) is 0.1 to 12 parts by weight with respect to 100 parts by weight of the amino-modified silicone (A) from the viewpoint of achieving both stable operability and storage stability of the precursor. Is preferred. The ratio is preferably 0.2 to 11 parts by weight, more preferably 0.2 to 10 parts by weight, and still more preferably 0.5 to 8 parts by weight. If the ratio is less than 0.1 parts by weight, it may not be possible to suppress the penetration of the emulsifier into the fiber structure. On the other hand, when the ratio is more than 12 parts by weight, stable operability may not be obtained.

  The proportion of the Bronsted acid compound (B) is 0.01 to 2 with respect to 1 mole of the amino group of the amino-modified silicone (A) from the viewpoint of suppressing the crosslinking with time caused by the amino group of the amino-modified silicone. It is preferable that the amount is 0.5 molar equivalent. The ratio is preferably 0.05 to 2.25 molar equivalents, more preferably 0.1 to 2.0 molar equivalents, and still more preferably 0.12 to 1.5 molar equivalents. If the ratio is less than 0.01 equivalent, it may not be possible to suppress the crosslinking with time due to the amino group of the amino-modified silicone. On the other hand, if the ratio is more than 2.5 equivalents, gum up in the process may be promoted and stable operability may not be obtained.

(Polyoxyalkylene alkyl ether (D))
The processing agent of the present invention preferably contains a polyoxyalkylene alkyl ether (D) from the viewpoint of enhancing the emulsifiability. The polyoxyalkylene alkyl ether is a compound having a structure in which an alkylene oxide is added to a saturated aliphatic alcohol, and in the above general formula (5), R ⁸ is an alkyl group and AO is an oxy having 2 to 4 carbon atoms. And an alkylene group, j is one or more. The polyoxyalkylene alkyl ether (D) may be used alone or in combination of two or more.

  As polyoxyalkylene alkyl ether, for example, polyoxyethylene hexyl ether, polyoxyethylene heptyl ether, polyoxyethylene octyl ether, polyoxyethylene decyl ether, polyoxyethylene lauryl ether, polyoxyethylene tridecyl ether, polyoxyethylene Polyoxyalkylene linear alkyl ethers such as tetradecyl ether and polyoxyethylene cetyl ether; Polyoxyalkylene branched primary alkyls such as polyoxyethylene 2-ethylhexyl ether, polyoxyethylene isocetyl ether, and polyoxyethylene isostearyl ether Ether; polyoxyethylene 1-hexylhexyl ether, polyoxyethylene 1-octylhexyl ether, polio Ethylene 1-hexyl octyl ether, polyoxyethylene 1-pentyl heptyl ether, polyoxyethylene 1-heptyl pentyl ether, polyoxyethylene 1-hexyl heptyl ether, polyoxyethylene 1-heptyl hexyl ether, polyoxyethylene 1- Examples thereof include polyoxyalkylene branched secondary alkyl ethers such as pentyl captyl ether and polyoxyethylene 1-captyl pentyl ether.

It is preferable that the polyoxyalkylene alkyl ether (D) essentially contains the compound represented by the above general formula (5) from the viewpoint of exerting the effect of the present invention. In the general formula (5), R ⁸ is an alkyl group having 6 to 22 carbon atoms. If R ⁸ carbon atoms in the hydrocarbon group and R ⁸ other than the alkyl group of 22 than by polyoxyalkylene alkyl ether is tar in the oxidization step, drawback of precursor is converted to flame-resistant structure As a result, the strength of the carbon fiber may be reduced. On the other hand, when the carbon number of R ⁸ is less than 6, the solution stability of the emulsion when the treatment agent is emulsified in water may be deteriorated. 8-20 are preferable, as for carbon number of R < ⁸ >, 10-18 are more preferable, and 10-16 are more preferable. The carbon number of R ⁸ may have a distribution, and R ⁸ may be linear or branched.

A shows a C2-C4 alkylene group and AO shows an oxyalkylene group. That is, it represents an oxyethylene group, an oxypropylene group or an oxybutylene group. The oxyalkylene group is preferably an oxyethylene group or an oxypropylene group, and more preferably an oxyethylene group. The number j of repetition of the oxyalkylene group, j, is a number of 1 to 50, preferably 2 to 40, and more preferably 3 to 30. When n is more than 30, when used in combination with the above amino-modified silicone, fusion may occur because the treatment agent can not be uniformly applied to the inside of the fiber bundle in the flameproofing step. The AO constituting the polyoxyalkylene group (AO) _j may be one type, or two or more types. In the case of two or more types, any of a block adduct, an alternate adduct, and a random adduct may be used. J of AO is the addition mole number of the oxyalkylene group.

  When the treating agent contains a polyoxyalkylene alkyl ether (D), the weight ratio of the polyoxyalkylene alkyl ether (D) to the non volatile matter of the treating agent is preferably 2 to 25% by weight, and 5 to 20 % By weight is more preferable, and 10 to 20% by weight is further preferable. When the weight ratio is less than 2% by weight, a stable aqueous emulsion may not be obtained when the treatment agent is emulsified in water. On the other hand, when the weight ratio is more than 25% by mass, the heat resistance of the treating agent may be insufficient in the flameproofing step.

  From the viewpoint of improving the long-term storage stability of the precursor, the ratio of the total of acetylenic surfactant (C) and polyoxyalkylene alkyl ether (D) is 5 to 50 with respect to 100 parts by weight of amino-modified silicone (A). It is preferable that it is a weight part. When the ratio is less than 5 parts by weight, the emulsion stability may be deteriorated. On the other hand, when the part by weight is more than 50 parts by weight, stable operability may not be obtained.

(Other surfactant)
The acrylic fiber treatment agent of the present invention may contain a surfactant other than the above-mentioned acetylenic surfactant (C) and the polyoxyalkylene alkyl ether (D) within the range not inhibiting the effect of the present invention. Surfactants are used as emulsifiers, antistatic agents and the like. The surfactant is not particularly limited, and nonionic surfactants other than the above-mentioned acetylenic surfactant (C) and polyoxyalkylene alkyl ether (D), anionic surfactants, cationic surfactants and Known amphoteric surfactants can be appropriately selected and used. The surfactant may be used alone or in combination of two or more.

  Examples of nonionic surfactants other than the above-mentioned acetylenic surfactant (C) and polyoxyalkylene alkyl ether (D) include polyoxyalkylene alkenyl ethers such as polyoxyethylene oleyl ether; polyoxyethylene octyl phenyl ether Polyoxyalkylene alkyl phenyl ethers such as polyoxyethylene nonyl phenyl ether and polyoxyethylene dodecyl phenyl ether; polyoxyethylene tris-styryl phenyl ether, polyoxyethylene distyryl phenyl ether, polyoxyethylene styryl phenyl ether, polyoxyethylene triethyl phenyl ether Polyoxyal such as benzyl phenyl ether, polyoxyethylene dibenzyl phenyl ether, polyoxyethylene benzyl phenyl ether Alkyl alkyl aryl phenyl ether; polyoxyethylene monolaurate, polyoxyethylene monooleate, polyoxyethylene monostearate, polyoxyethylene monomyristylate, polyoxyethylene dilaurate, polyoxyethylene diolate, polyoxyethylene dimilli Styrates, polyoxyalkylene fatty acid esters such as polyoxyethylene distearate; sorbitan monopalmitate, sorbitan esters such as sorbitan monooleate; polyoxyalkylene sorbitan such as polyoxyethylene sorbitan monostearate, polyoxyethylene sorbitan monooleate Fatty acid ester; glycerin fatty acid ester such as glycerin monostearate, glycerin monolaurate, glycerin monopalmitate and the like Polyoxyalkylene sorbitol fatty acid ester; sucrose fatty acid ester; polyoxyalkylene castor oil ether such as polyoxyethylene castor oil ether; polyoxyalkylene cured castor oil ether such as polyoxyethylene hydrogenated castor oil ether; oxyethylene-oxypropylene block or random co Polymer; terminal-sucrose etherified product of oxyethylene-oxypropylene block or random copolymer; and the like can be mentioned. 2000 or less are preferable, as for the weight average molecular weight of nonionic surfactant, 200-1800 are more preferable, 300-1500 are more preferable, and 500-1000 are more preferable.

  Examples of anionic surfactants include fatty acid salts such as sodium oleate, potassium palmitate, triethanolamine oleate, hydroxyl group-containing carboxylates such as potassium hydroxyacetate, potassium lactate and the like; Polyoxyalkylene alkyl ether acetates such as sodium tridecyl ether acetate; Salts of carboxyl group-substituted aromatic compounds such as potassium trimellitate and potassium pyromellitic acid; alkyl benzene sulfonates such as sodium dodecylbenzene sulfonate Polyoxyalkylene alkyl ether sulfonates such as polyoxyethylene 2-ethylhexyl ether sulfonic acid potassium salt; stearoyl methyl taurine sodium, lauroyl methyl taurine sodium, myris Higher fatty acid amide sulfonates such as sodium ylmethyl taurine, palmitoyl methyl taurine sodium; N-acyl sarcosinates such as sodium lauroyl sarcosinate; alkyl phosphonates such as octyl phosphonate potassium salt; aromatics such as phenyl phosphonate potassium salt Phosphonates; alkylphosphonic acid alkyl phosphoric acid ester salts such as 2-ethylhexyl phosphonate mono 2-ethylhexyl ester potassium salt; nitrogen-containing alkyl phosphonic acid salts such as aminoethyl phosphonic acid diethanolamine salt; alkyls such as 2-ethylhexyl sulfate sodium salt Sulfate ester salt; Polyoxyalkylene sulfate ester salt such as polyoxyethylene 2-ethylhexyl ether sulfate sodium salt; Di-2-ethylhexyl Sodium Ruhokohaku acid, long chain sulfosuccinates such as sodium dioctylsulfosuccinate, N- lauroyl glutamate monosodium, can be exemplified such as long-chain N- acyl glutamates such as N- stearoyl -L- glutamate disodium.

  As a cationic surfactant, for example, lauryl trimethyl ammonium chloride, myristyl trimethyl ammonium chloride, palmityl trimethyl ammonium chloride, stearyl trimethyl ammonium chloride, oleyl trimethyl ammonium chloride, cetyl trimethyl ammonium chloride, behenyl trimethyl ammonium chloride, coconut oil alkyl trimethyl Ammonium chloride, tallow alkyl trimethyl ammonium chloride, stearyl trimethyl ammonium bromide, coconut oil alkyl trimethyl ammonium bromide, cetyl trimethyl ammonium methosulfate, oleyl dimethyl ethyl ammonium etho sulfate, dioctyl dimethyl ammonium chloride, dira Alkyl quaternary ammonium salts such as lyldimethyl ammonium chloride, distearyl dimethyl ammonium chloride, octadecyl diethyl methyl ammonium sulfate, etc .; (polyoxyethylene) lauryl amino ether lactate, stearyl amino ether lactate, di (polyoxyethylene) lauryl Methyl amino ether dimethyl phosphate, di (polyoxyethylene) lauryl ethyl ammonium ethosulfate, di (polyoxyethylene) hardened beef tallow alkyl ethylamine etho sulfate, di (polyoxyethylene) lauryl methyl ammonium dimethyl phosphate, di (polyoxyethylene) stearyl (Polyoxyalkylene) alkyl amino ether salts such as amine lactates; N- (2-hydroxyethyl)- Acylamidoalkyl quaternary ammonium salts such as N-dimethyl-N-stearoylamidopropylammonium nitrate, lanolin fatty acid amidopropylethyldimethylammonium ethosulfate, lauroylamidoethylmethyldiethylammonium methosulfate; dipalmitylpolyethenoxyethyl Alkyl ethenoxy quaternary ammonium salts such as ammonium chloride, distearyl polyethenoxymethyl ammonium chloride; alkyl isoquinolinium salts such as lauryl isoquinolinium chloride; lauryl dimethyl benzyl ammonium chloride, stearyl dimethyl benzyl ammonium chloride and the like Benzalkonium salt; benzyldimethyl {2- [2- (p-1,1,3,3-tetramethylbutyl fe] Benzium salts such as oxy) ethoxy] ethyl} ammonium chloride; pyridinium salts such as cetyl pyridinium chloride; imidazolinium salts such as oleyl hydroxyethyl imidazolinium ethosulfate, lauryl hydroxyethyl imidazolinium ethosulphate; N-cocoyl arginine ethyl Acyl basic amino acid alkyl ester salts such as ester pyrrolidone carboxylate, N-lauroyl lysine ethyl ester chloride; primary amine salts such as lauryl amine chloride, stearyl amine bromide, hardened beef tallow alkyl amine chloride, rosin amine acetate salt; cetyl Methylamine sulfate, lauryl methylamine chloride, dilaurylamine acetate, stearylethylamine bromide, lauri Secondary amine salts such as dipropylamine acetate, dioctylamine chloride and octadecylethylamine hydroxide; dilaurylmethylamine sulfate, lauryldiethylamine chloride, laurylethylmethylamine bromide, diethanolstearylamidoethylamine trihydroxyethyl phosphate salt, stearylamide Examples include tertiary amine salts such as ethyl ethanolamine urea polycondensate acetic acid salt; fatty acid amide guanidinium salts; alkyl trialkylene glycol ammonium salts such as lauryl triethylene glycol ammonium hydroxide and the like.

  Examples of amphoteric surfactants include sodium 2-undecyl-N, N- (hydroxyethylcarboxymethyl) -2-imidazoline, 2-cocoyl-2-imidazolinium hydroxide-1-carboxyethyloxydisodium salt and the like. Imidazoline based amphoteric surfactants; 2-heptadecyl-N-carboxymethyl-N-hydroxyethyl imidazolium betaines, lauryl dimethylaminoacetic acid betaines, alkyl betaines, amido betaines, sulfobetaines, and other betaine based amphoteric surfactants; N- Amino acid-type amphoteric surfactants such as lauryl glycine, N-lauryl β-alanine, N-stearyl β-alanine and the like can be mentioned.

(Other ingredients)
The acrylic fiber treatment agent of the present invention may contain other components in addition to the components described above, as long as the effects of the present invention are not impaired. As other components, antioxidants such as acidic phosphates, phenols, amines, sulfurs, phosphoruss and quinones; sulfates of higher alcohols and higher alcohol ethers, sulfonates, higher alcohols and higher Antistatic agents such as phosphoric acid ester salts of alcohol ethers, quaternary ammonium salt type cationic surfactants, amine salt type cationic surfactants, etc .; Smoothing agents such as alkyl esters of higher alcohols, higher alcohol ethers, waxes Antibacterial agents; Antiseptics; Antirust agents; and Hygroscopic agents.

  In addition, the treatment agent of the present invention may contain a modified silicone other than the above-mentioned amino-modified silicone, as long as the effects of the present invention are not impaired. Examples of the modified silicone include aminopolyether modified silicone, amide modified silicone, amide polyether modified silicone, epoxy modified silicone, polyether modified silicone, epoxy polyether modified silicone (see, for example, patent 4616934), carbinol modified silicone And alkyl-modified silicones, phenol-modified silicones, methacrylate-modified silicones, alkoxy-modified silicones, fluorine-modified silicones, etc. One type of modified silicone may be used, or a plurality of modified silicones may be used in combination.

The acrylic fiber treatment agent of the present invention comprises an amino-modified silicone (A), a Bronsted acid compound (B), an acetylenic surfactant (C), and optionally a polyoxyalkylene alkyl ether (D) dissolved in water, It is preferable that it is in a solubilised, emulsified or dispersed state.
There is no limitation in particular about the weight ratio of water to the whole acrylic fiber processing agent, and the weight ratio of non volatile matter. For example, it may be appropriately determined in consideration of the transportation cost when transporting the acrylic fiber treatment agent of the present invention, the handleability attributable to the emulsion viscosity, and the like. 0.1 to 99.9 weight% is preferable, 10 to 99.5 weight% is further more preferable, and 50 to 99 weight% of the weight ratio of the water which occupies for the whole acrylic fiber processing agent is especially preferable. 0.01 to 99.9% by weight is preferable, 0.5 to 90% by weight is more preferable, and 1 to 50% by weight is particularly preferable as the weight ratio (concentration) of the non-volatile component in the entire acrylic fiber treatment agent.

  The acrylic fiber treatment agent of the present invention can be produced by mixing the components described above. It does not specifically limit about the method to emulsify and disperse | distribute the component demonstrated above, A well-known method is employable. As such a method, for example, a method of emulsifying and dispersing each component constituting an acrylic fiber treatment agent into warm water under stirring, or mixing each component constituting an acrylic fiber treatment agent, homogenizer, homogeniser There is a method of gradually introducing water while applying mechanical shear force using a mixer, a ball mill or the like to perform phase inversion emulsification.

  The acrylic fiber treatment agent of the present invention can be suitably used as a treatment agent (precursor treatment agent) for acrylic fiber (precursor) for carbon fiber production. You may use as a spinning oil agent of acrylic fibers other than a precursor.

  The viscosity at 25 ° C. of the non-volatile component of the acrylic fiber treatment agent of the present invention is preferably 10 to 50000 mPa · s, and the viscosity is 10 mPa, from the viewpoint of imparting good fiber bundle focusing properties in the precursor spinning process and the flameproofing process. If it is less than s, the bundling ability of the fiber bundle in the precursor spinning process and the flameproofing process may be deteriorated. When the viscosity exceeds 50000 mPa · s, the viscosity of the treating agent becomes too high, and the handleability of the treating agent is deteriorated, even if good fiber bundle focusing can be imparted in the precursor spinning process and the flameproofing step. There is a case. The viscosity is preferably in the order of 10 to 25,000 mPa · s, 10 to 15,000 mPa · s, 10 to 10,000 mPa · s, 10 to 5,000 mPa · s, and 50 to 1,000 mPa · s.

[Acrylic fiber for producing carbon fiber, method for producing the same, and method for producing carbon fiber]
The acrylic fiber (precursor) for carbon fiber production of the present invention is produced by attaching the above-mentioned acrylic fiber treatment agent to raw material acrylic fiber of a precursor. The method for producing a precursor of the present invention includes a yarn production step of producing a yarn by adhering the above-mentioned acrylic fiber treatment agent to raw material acrylic fiber of a precursor.
The method for producing carbon fiber according to the present invention comprises the steps of producing the precursor by adhering the above-mentioned acrylic fiber treatment agent to raw material acrylic fiber of the precursor, and spinning the precursor, and oxidizing the precursor produced in the spinning step at 200 to 300 ° C. And a carbonization treatment step of carbonizing the above-mentioned flameproofed fiber in an inert atmosphere at 300 to 2000C.
According to the method for producing carbon fiber of the present invention, since the acrylic fiber treatment agent of the present invention is used, the treatment agent can be uniformly applied to the inside of the fiber bundle at the initial stage of the flameproofing step, and the flameproofness can be achieved. Since the treatment agent can be formed into a film to protect the fibers later in the treatment process, it is possible to suppress the fusion between fibers and the generation of fluff, and to manufacture high quality carbon fibers.

The yarn production step is a step of attaching an acrylic fiber treatment agent to a raw material acrylic fiber of a precursor to produce a precursor, and includes an adhesion treatment step and a drawing step.
The adhesion treatment step is a step of adhering an acrylic fiber treatment agent after spinning the raw material acrylic fiber of the precursor. That is, the acrylic fiber treatment agent is attached to the raw material acrylic fiber of the precursor in the adhesion treatment step. In addition, although the raw material acrylic fiber of this precursor is drawn immediately after spinning, the high magnification drawing after the adhesion treatment step is particularly referred to as a "drawing step". The drawing process may be a wet heat drawing method using high temperature steam, or a dry heat drawing method using a heat roller.

  The precursor is composed of an acrylic fiber composed mainly of polyacrylonitrile obtained by copolymerizing at least 95% by mole or more of acrylonitrile and 5% by mole or less of the flameproofing promoting component. As the flame resistance promoting component, a vinyl group-containing compound having copolymerizability with acrylonitrile can be suitably used. The single fiber fineness of the precursor is not particularly limited, but is preferably 0.1 to 2.0 dTex from the balance of performance and manufacturing cost. Further, the number of single fibers constituting the fiber bundle of the precursor is not particularly limited, but is preferably 1,000 to 96,000 in terms of the balance between the performance and the manufacturing cost.

  The acrylic fiber treatment agent may be attached to the raw material acrylic fiber of the precursor at any stage of the yarn production process, but it is preferable to apply it once before the drawing process. It may be attached at any stage before the drawing process, for example, immediately after spinning. Furthermore, it may be attached again at any stage after the stretching process, for example, it may be deposited again immediately after the stretching process, or may be deposited again at the winding stage, and it is again deposited just before the flameproofing process. You may With regard to the adhesion method, it may be adhered using a roller or the like, or may be adhered by an immersion method, a spray method or the like.

  In the adhesion treatment step, the application rate of the acrylic fiber treatment agent prevents the deterioration of carbon fiber by obtaining the fiber-fiber adhesion preventing effect and the fusion preventing effect, and the tarification of the treatment agent in the carbonization treatment step. In view of the balance with the composition, it is preferably 0.1 to 2% by weight, more preferably 0.3 to 1.5% by weight, based on the weight of the precursor. When the application rate of the acrylic fiber treatment agent is less than 0.1% by weight, sticking and fusion between single fibers can not be sufficiently prevented, and the strength of the obtained carbon fiber may be lowered. On the other hand, if the application rate of the acrylic fiber treatment agent is more than 2% by weight, the acrylic fiber treatment agent covers between the single fibers more than necessary, so that the supply of oxygen to the fibers is hindered in the flameproofing treatment step. The strength of the carbon fiber may be reduced. Here, the application rate of the acrylic fiber treatment agent as used herein is defined as the percentage of the weight of the non-volatile component to which the acrylic fiber treatment agent adheres to the weight of the precursor.

  The flameproofing step is a step of converting the precursor to which the acrylic fiber treatment agent is adhered to a flameproofed fiber in an oxidizing atmosphere at 200 to 300 ° C. The oxidizing atmosphere may usually be an air atmosphere. The temperature of the oxidizing atmosphere is preferably 230 to 280 ° C. In the flameproofing step, tension of a stretching ratio of 0.90 to 1.10 (preferably 0.95 to 1.05) is applied to the acrylic fiber after adhesion treatment for 20 to 100 minutes (preferably 30). Heat treatment is carried out for 60 minutes. In this flameproofing treatment, through intramolecular cyclization and oxygenation to the ring, a flameproofed fiber having a flameproofed structure is produced.

  The carbonization treatment step is a step of further carbonizing the flameproofed fiber in an inert atmosphere at 300 to 2000 ° C. In the carbonization treatment step, first, in a baking furnace having a temperature gradient from 300 ° C. to 800 ° C. in an inert atmosphere of nitrogen, argon, etc., a tension ratio of 0.95 to 1.15 with respect to the flame resistant fiber It is preferable to heat-process for several minutes, and to perform a pre-carbonization process (1st carbonization process process), Thereafter, in order to promote carbonization and graphitization, a tension of 0.95 to 1.05 is applied to the first carbonization treatment step in an inert atmosphere such as nitrogen or argon. Heat treatment is carried out for a few minutes while the second carbonization treatment step is performed to carbonize the flame-resistant fiber. About control of the heat processing temperature in a 2nd carbonization process process, it is good to make maximum temperature 1000 degreeC or more (preferably 1000-2000 degreeC), applying a temperature gradient. The maximum temperature is appropriately selected and determined in accordance with the required characteristics (tensile strength, elastic modulus, etc.) of the desired carbon fiber.

  In the method for producing carbon fibers of the present invention, if carbon fibers having a still higher elastic modulus are desired, it is possible to carry out the graphitization treatment step following the carbonization treatment step. The graphitization treatment step is usually performed at a temperature of 2000 to 3000 ° C. in an inert atmosphere of nitrogen, argon or the like while applying tension to the fibers obtained in the carbonization treatment step.

  The carbon fibers obtained in this manner can be subjected to surface treatment to increase the adhesive strength with the matrix resin when made into a composite material according to the purpose. As the surface treatment method, gas phase or liquid phase treatment can be adopted, and from the viewpoint of productivity, liquid phase treatment with an electrolytic solution such as acid or alkali is preferable. Furthermore, in order to improve the processability and the handleability of the carbon fiber, various sizing agents having excellent compatibility with the matrix resin can also be provided.

  Hereinafter, the present invention will be specifically described by way of examples, but the present invention is not limited to the examples described herein. Unless otherwise specified, percentages (%) and parts shown in the following examples indicate "wt%" and "parts by weight". The measurement of each characteristic value was performed based on the method shown below.

<Applying rate of treatment agent>
The precursor after application of the treating agent was alkali-melted with potassium hydroxide / sodium butyrate, then dissolved in water and adjusted to pH 1 with hydrochloric acid. Sodium sulfite and ammonium molybdate were added thereto to develop a color, and colorimetric determination (wavelength: 815 mμ) of silica blue was performed to determine the content of silicon. The application rate (% by weight) of the acrylic fiber treatment agent was calculated using the silicon content obtained here and the value of the silicon content in the treatment agent previously obtained by the same method.

<Anti-fusion property>
Twenty points were randomly selected from carbon fibers, short fibers having a length of 10 mm were cut out therefrom, and the fused state was observed and judged according to the following evaluation criteria.
:: No fusion ○: Almost no fusion :: Less fusion ×: More fusion

Precursor strand hardness
The hardness of the precursor strand (length: about 50 cm) was measured with a texture tester (HANDLE-O-METERHOM-2 manufactured by Daiei Kagaku Seiki Mfg. Co., Ltd., slit width 5 mm). The measurement was performed 10 times, and it was judged that the precursor strand was more flexible as the average value was smaller. In the evaluation, a precursor immediately after production (within 7 days after production) and a precursor stored for 12 months at normal temperature after production (indicated as after storage in the table) were used.

<Abrasion resistance>
The precursor strand (12 K) is rubbed 1000 times with 50 g of tension via three specular chrome-plated stainless steel needles arranged in a zigzag by TM type friction conjugation tester TM-200 (made by Daiei Scientific Seiki Co., Ltd.) (reciprocation The speed of 300 times / min) and the state of fuzzing of the precursor strand were visually determined according to the following criteria. In the evaluation, a precursor immediately after production (within 7 days after production) and a precursor stored for 12 months at normal temperature after production were used.
:: No fuzzing was observed as in the case before scratching ○: Several fuzz were observed but scratch resistance was good. :: fuzzing was slightly high and a little scratch resistance poor x: much fuzzing, significant single thread breakage Poor abrasion resistance seen

<Carbon fiber strength>
It measured according to the epoxy resin impregnation strand method prescribed | regulated to JIS-R-7601, and made the average value of the measurement frequency | count 10 times the carbon fiber strength (GPa). In the evaluation, a precursor immediately after production (within 7 days after production) and a precursor stored for 12 months at normal temperature after production were used.

Example 1
The amino-modified silicone water-based emulsion was obtained by mixing the amino-modified silicone A1, Bronsted acid compound B1, polyoxyethylene alkyl ether D1 and water so as to have a non-volatile content of the treatment agent shown in Table 1 and conducting water-based emulsification. Acetylene-based surfactant C1 is added to the product, and the weight ratio of amino-modified silicone A1 to non-volatile content of processing agent is 80% by weight, the weight ratio of Bronsted acid compound B1 is 0.7% by weight, acetylene-based surfactant A treating agent (precursor treating agent) was prepared in which the proportion by weight of the agent C1 was 2% by weight and the proportion by weight of the polyoxyethylene alkyl ether D1 was 17.3% by weight. The concentration of non-volatile components in the treatment agent was 20% by weight.
Then, the adjusted treating agent was further diluted with water to obtain a treating solution having a nonvolatile content concentration of 3.0% by weight.
It adheres to the raw material acrylic fiber of the precursor obtained by copolymerizing a processing liquid with 97 mol% of acrylonitrile and 3 mol% of itaconic acid so as to give an application rate of 1.0%, and a stretching step (steam stretching, stretching ratio A precursor was produced (single fiber fineness 0.8 dtex, 24,000 filaments) through 2.1 times). The precursor was subjected to a stabilization treatment for 60 minutes in a stabilization furnace at 250 ° C., and then was calcined in a carbonization furnace having a temperature gradient of 300 to 1400 ° C. in a nitrogen atmosphere to convert it into carbon fibers. The evaluation results of each characteristic value are shown in Table 1.

[Examples 2 to 22, Comparative Examples 1 to 17]
A precursor and carbon fibers after adhesion of the treating agent were obtained in the same manner as in Example 1 except that the treating liquid was adjusted to have the composition of the non-volatile components of treating agents shown in Tables 2 to 4 in Example 1. The evaluation results of the respective characteristic values are shown in Tables 1 to 4.

In addition, the detail of the non volatile matter composition of Tables 1-4 is the following.
<Amino-modified silicone (A)>
Amino-modified silicone A1 (25 ° C. viscosity: 250 mm ² / s, amino equivalent: 7600 g / mol, diamine type)
Amino-modified silicone A2 (25 ° C. viscosity: 1300 mm ² / s, amino equivalent: 1700 g / mol, diamine type)
Amino-modified silicone A3 (25 ° C viscosity: 1700 mm ² / s, amino equivalent: 3800 g / mol, monoamine type)
Amino-modified silicone A4 (25 ° C viscosity: 20000 mm ² / s, amino equivalent: 1800 g / mol, diamine type)
Amino-modified silicone A5 (25 ° C viscosity: 1500 mm ² / s, amino equivalent: 3800 g / mol, diamine type)

<Brensted acid compound (B)>
Carboxylic acid compound B1: acetic acid carboxylic acid compound B2: benzoic acid carboxylic acid compound B3: arginine carboxylic acid compound B4: phosphoric acid

<Acetylene-based surfactant (C)>
Acetylene surfactant C1: ethylene oxide 20 molar adduct of 2,4,7,9-tetramethyl-5-decyne-4,7-diol (in the formula (4), R ³ and R ⁵ are both methyl groups , R ⁴ and R ^{6 each} represent an isobutyl group, R ⁷ represents a hydrogen atom, AO represents ethylene oxide, and n + m = 20.)
Acetylene surfactant C2: ethylene oxide 5-mole adduct of 2,4,7,9-tetramethyl-5-decyne-4,7-diol (in the formula (4), R ³ and R ⁵ are both methyl groups , R ⁴ and R ^{6 each} represent an isobutyl group, R ⁷ represents a hydrogen atom, AO represents ethylene oxide, and n + m = 5).
Acetylene-based surfactant C3: ³ , 6-dimethyl-4-octin- ³ , 6-diol (in the formula (2), R ³ and R ⁵ are both methyl groups, R ⁴ and R ⁶ are both ethyl groups, R ⁷ is a hydrogen atom.)
Acetylene-based surfactant C4: 2,4,7,9-tetramethyl-5-decyne-4,7-diol (in Formula (2), R ³ and R ⁵ are both methyl groups, R ⁴ and R ⁶ are Both are isobutyl and R ⁷ is a hydrogen atom.)

<Polyoxyalkylene alkyl ether (D)>
Polyoxyethylene alkyl ether D1: alkyl ether having 12 to 14 carbons to which 5 moles of oxyethylene group have been added polyoxyethylene alkyl ether D2: alkyl ether having 12 to 14 carbon atoms having 7 mole of oxyethylene group added Polyoxyethylene alkyl ether D3: C12-C14 alkyl ether to which 9 moles of oxyethylene group is added

  In Tables 1 to 4, the numerical values in the parentheses of the Br ス テ ッ ド nsted acid compound (B) indicate the molar equivalents of the Br ス テ ッ ド nsted acid compound (B) with respect to 1 mole of the amino group of the amino-modified silicone (A). The numerical value in the parenthesis of the acetylene-based surfactant (C) indicates the weight ratio of the acetylene-based surfactant (C) when the amino-modified silicone (A) is 100 parts by weight. In addition, the numerical values in parentheses after storage of the strand hardness and the carbon fiber strength show the rate of change with respect to the numerical values immediately after production.

  As apparent from Tables 1 to 4, the acrylic fiber treatment agent of the example is compared with the acrylic fiber treatment agent of the comparative example which does not contain the Bronsted acid compound (B) and / or the acetylenic surfactant (C). Therefore, it is understood that it is excellent in the temporal deterioration suppression of the acrylic fiber for carbon fiber manufacture.

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

Claims (11)

  A processing agent for acrylic fiber, comprising an amino-modified silicone (A), a Bronsted acid compound (B) and an acetylene-based surfactant (C).   The treatment agent for acrylic fibers according to claim 1, wherein the ratio of the Br ス テ ッ ド nsted acid compound (B) is 0.01 to 2.5 molar equivalents with respect to 1 mole of the amino group of the amino-modified silicone (A). .   The processing agent for acrylic fibers of Claim 1 or 2 whose ratio of the said acetylene type surfactant (C) is 0.1-12 weight part with respect to 100 weight part of said amino modified silicones (A).   The acetylene-based surfactant (C) is selected from acetylene alcohol (C1), acetylene diol (C2), compound (C3) obtained by adding alkylene oxide to acetylene alcohol, and compound (C4) obtained by adding alkylene oxide to acetylene diol The processing agent for acrylic fibers according to any one of claims 1 to 3, which is at least one selected from the group consisting of The acetylene alcohol (C1) is a compound represented by the following general formula (1), the acetylene diol (C2) is a compound represented by the following general formula (2), and an alkylene oxide is added to the acetylene alcohol And the compound (C4) obtained by adding an alkylene oxide to the acetylene diol is a compound represented by the following general formula (4). The processing agent for acrylic fibers as described in 4.

(In formula (1), R ¹ and R ² are each independently an alkyl group having 1 to 8 carbon atoms.)

(In formula (2), R ³ , R ⁴ , R ⁵ and R ⁶ are each independently an alkyl group having 1 to 8 carbon atoms.)

(In Formula (3), R ¹ and R ² are each independently an alkyl group having 1 to 8 carbon atoms. R ⁷ is a hydrogen atom or an alkyl group having 1 to 5 carbon atoms. AO is carbon 2 to 4 represents an oxyalkylene group, n is a number of 1 to 50.)

(In formula (4), R ³ , R ⁴ , R ⁵ and R ⁶ are each independently an alkyl group having 1 to 8 carbon atoms. R ⁷ is a hydrogen atom or an alkyl group having 1 to 5 carbon atoms In addition, a plurality of R ⁷ in the formula (4) may be the same or different, and AO represents an oxyalkylene group having 2 to 4 carbon atoms, and m and n are each independently. It is a number of 1 to 50.)   The processing agent for acrylic fibers in any one of Claims 1-5 whose weight proportion of the said amino modified silicone (A) to the non volatile matter of a processing agent is 40 to 95 weight%.   Furthermore, the processing agent for acrylic fibers in any one of Claims 1-6 containing polyoxyalkylene alkyl ether (D). The processing agent for acrylic fibers of Claim 7 in which the said polyoxyalkylene alkyl ether (D) contains the compound shown by following General formula (5).

In (formula (5), ^{R 8} is .AO represents an alkyl group having 6 to 22 carbon atoms is a number from 1 to 50 independently respectively .j showing an oxyalkylene group having 2 to 4 carbon atoms. )   The ratio of the total of the acetylene-based surfactant (C) and the polyoxyalkylene alkyl ether (D) is 5 to 50 parts by weight with respect to 100 parts by weight of the amino-modified silicone (A). The processing agent for acrylic fibers as described in 8. The acrylic fiber for carbon fiber manufacture which makes the acrylic fiber processing agent in any one of Claims 1-9 adhere to the raw material acrylic fiber of the acrylic fiber for carbon fiber manufacture.   A spinning process in which a fiber treatment agent according to any one of claims 1 to 9 is attached to raw material acrylic fiber for producing acrylic fiber for carbon fiber production, and a fiber-stabilized fiber in an oxidizing atmosphere at 200 to 300 ° C. A method for producing a carbon fiber, comprising the step of converting to a flameproofing step, and the step of carbonizing the carbonized fiber to be further carbonized in an inert atmosphere at 300 to 2000 ° C.