JP2007332518A - Oil agent composition, carbon fiber precursor acrylic fiber bundle and its production method, and carbon fiber bundle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an oil agent composition capable of preventing or reducing damage of a fiber surface which is caused by friction in production of a carbon fiber precursor acrylic fiber bundle. <P>SOLUTION: This oil gent composition containing ≥40 and ≤90 mass% compound expressed by formula (1) [wherein, R<SP>1</SP>, R<SP>2</SP>are each independently a 11-17C alkyl group; A<SP>1</SP>, A<SP>2</SP>are each independently ethylene or propylene group: and (m) (n) are each independently 1 to 2] is attached to the carbon fiber precursor acrylic fiber bundle having a multiple number of acrylic fibers. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  INDUSTRIAL APPLICABILITY The present invention prevents the occurrence of fusion between single fibers in a flameproofing process in which a carbon fiber precursor acrylic fiber bundle is converted to a flameproof fiber, and is suitable for producing a carbon fiber bundle having excellent quality and physical properties. Thus, the present invention relates to a carbon fiber precursor acrylic fiber bundle having improved process passability in the production of the carbon fiber bundle, a method for producing the same, and an oil agent composition attached thereto.

  Conventionally, acrylic fibers have been widely used as precursors for the production of carbon fibers. Specifically, acrylic fibers are converted to flame-resistant fibers by heat treatment in an oxidizing atmosphere at 200 to 400 ° C., and the obtained flame-resistant fibers are treated at a temperature up to about 700 ° C. in an inert atmosphere. It is common as a method for producing carbon fibers to perform pre-carbonization and subsequent carbonization at a temperature of at least 1000 ° C. in an inert atmosphere. The carbon fibers thus obtained are widely used as suitable reinforcing fibers for fiber-reinforced resin composite materials due to their excellent physical properties. In particular, the carbon fiber bundle is often used in the form of a bundle of carbon fibers.

  On the other hand, in the above method for producing a carbon fiber bundle, fusion between single fibers occurs in the flameproofing step of converting the carbon fiber precursor acrylic fiber bundle into a flameproofed fiber bundle, and firing (carbonization) becomes uneven. Failures such as fluff and bunches occur. In order to avoid this fusion, it is known that it is important to select an oil agent to be applied to the carbon fiber precursor acrylic fiber bundle before flame resistance, and many oil agents have been studied.

  Oiling is usually applied to a fiber bundle in a gel state before drying and densification (hereinafter, abbreviated as a fiber bundle in a “water-swelled state”) in which the spinning solvent is replaced with water in the washing step after spinning. Against. In order to prevent potential defects in the fiber and adhesion between single fibers, which cause troubles in the firing process and deterioration of the physical properties of the carbon fiber bundle, this oil agent has thermal stability, bundling and scratch resistance. It is important to have both. The oil agent used in the oil bath treatment often uses a substance having excellent thermal stability such as amino-modified silicone and epoxy-modified silicone as a main component (Patent Document 1, etc.).

  Currently, it is a silicone-based oil that is widely used, but has some drawbacks. First of all, there are a roll gum up problem, a process trouble associated with silica scattering in the firing process, a problem of carbon fiber quality deterioration, and a price problem, but in addition to these, there is a problem of scratch resistance. In general, silicone oil is widely used in the field of lubricating oil because it has excellent heat resistance and releasability. Although it has excellent scratch resistance, which is a necessary characteristic of lubricating oil, it is known that scratch resistance (extreme pressure) under high load is inferior to that of mineral oil. This is related to the fact that the cohesive force (intermolecular force) of the silicone oil is small, and the oil film on the friction surface is broken and the lubricating force is lost. The friction resistance of silicone fluids is not a problem with low load friction when used in textile fluids such as clothing, but the purpose is to increase production volume and reduce costs in the manufacture of carbon fiber precursor acrylic fiber bundles. As a result, the surface of the carbon fiber precursor acrylic fiber bundle and the rolls, guides, etc. contacted the surface of the fiber bundle under high load, and the abrasion of the fiber bundle surface became severe. In the near future, various troubles due to damage to the fiber bundle surface are expected. In addition, this phenomenon becomes apparent at the stage of producing a high-performance carbon fiber bundle, and the physical properties and quality of the carbon fiber bundle may be deteriorated. For this reason, there is an urgent need to develop an oil agent for producing a carbon fiber precursor acrylic fiber bundle having improved scratch resistance.

  Although it has been widely recognized that damage to the fiber bundle substrate that occurs during the manufacturing process of the carbon fiber precursor acrylic fiber bundle affects the physical properties of the carbon fiber bundle, this can be achieved by improving the fretting resistance (extreme pressure) of the oil agent. There has been no report in the past regarding studies to reduce damage and improve fiber bundle physical properties.

It is also a problem that an evaluation method for scuff resistance (extreme pressure) of an oil agent for producing a carbon fiber precursor acrylic fiber bundle has not been established. Although the technology (patent document 2) which prevents the damage of the fiber by contact with a process roller etc. by coat | covering the carbon fiber precursor acrylic fiber bundle surface with an organic polymer is published, the hardness ( (Pencil hardness) is used as an evaluation standard, and there is no correlation with scratch resistance.
JP 58-214517 A JP-A-9-176923

  An object of the present invention is to provide an oil composition that can prevent or reduce damage to the fiber surface due to abrasion in the production of a carbon fiber precursor acrylic fiber bundle.

  The present invention employs the following means in order to solve the above problems.

  An oil agent composition to be attached to an acrylic fiber bundle having a plurality of acrylic fibers, wherein the oil agent composition contains 40% by mass or more and 90% by mass or less of a compound represented by the following formula (1).

(In Formula (1), R ¹ and R ² are each independently an alkyl group having 11 to 17 carbon atoms, A ¹ and A ² are each independently an ethylene group or a propylene group, and m and n are Each is independently 1-2.)
A carbon fiber precursor acrylic fiber bundle obtained by attaching the oil composition to an acrylic fiber bundle having a plurality of acrylic fibers. Moreover, it is a manufacturing method of the carbon fiber precursor acrylic fiber bundle characterized by having the process of making the said oil agent composition adhere to the acrylic fiber bundle which has multiple acrylic fibers.

  It is a carbon fiber bundle obtained by flameproofing and carbonizing the carbon fiber precursor acrylic fiber bundle.

  According to the present invention, in the production of a carbon fiber precursor acrylic fiber bundle, it is possible to prevent or reduce damage to the fiber surface due to abrasion, and to produce a carbon fiber precursor acrylic fiber bundle and a carbon fiber bundle excellent in quality and physical properties. it can.

  The present inventors have solved the above-mentioned problems of the prior art, and can prevent or reduce damage due to abrasion of the fiber surface in the production process of the acrylic fiber bundle for carbon fiber precursor, such as fluff during firing. As a result of intensive studies on an oil agent for producing a carbon fiber precursor acrylic fiber bundle for preventing generation and deterioration of physical properties of the carbon fiber bundle, it has been found that an oil agent composition containing a specific scratch resistance improving component is effective.

  The present invention is described in detail below.

  In the present invention, a known acrylic fiber can be used as the acrylic fiber constituting the carbon fiber precursor acrylic fiber bundle before the oil agent is applied, and the composition thereof is not particularly limited. However, the acrylonitrile unit and the acrylonitrile are not limited. An acrylic fiber obtained by spinning an acrylonitrile copolymer comprising a polymerizable vinyl monomer unit is preferred. In this acrylonitrile copolymer, it is preferable that the acrylonitrile unit does not fall below 95% by mass, and the vinyl monomer unit copolymerizable with acrylonitrile does not exceed 5% by mass. Examples of vinyl monomers copolymerizable with acrylonitrile include acrylic acid, methacrylic acid, itaconic acid, or alkali metal salts or ammonium salts thereof, and one or more monomers selected from monomer groups such as acrylamide. A monomer is preferable for promoting the flameproofing reaction. The method for producing such an acrylic fiber bundle having a plurality of acrylic fibers is not particularly limited, and any of known wet, dry and dry and wet spinning methods can be employed.

  The oil agent composition used in the present invention will be described.

  The oil agent composition of this invention contains the compound shown by following formula (1) used as a rub resistance improvement component.

(In Formula (1), R ¹ and R ² are each independently an alkyl group having 11 to 17 carbon atoms, A ¹ and A ² are each independently an ethylene group or a propylene group, and m and n are Each is independently 1-2.)
The same structure as the above formula (1), wherein R ¹ and R ² are each independently an alkyl group having 7 to 21 carbon atoms, and m and n are each independently within a range of 1 to 5. Is excellent in terms of heat resistance and smoothness under a light load. Among them, when R ¹ and R ² are each independently an alkyl group having 11 to 17 carbon atoms, and m and n are each independently 1 to 2, heat resistance and smoothness under a light load are obtained. In addition, it has excellent scratch resistance under high loads. When a plurality of A ¹ and / or A ² are present, an ethylene group and a propylene group may be mixed. The compound represented by Formula (1) may be used alone or in combination of two or more. The compound represented by the formula (1) may include a mixture of a plurality of compounds in which R ¹ and R ² and A ¹ and A ² are the same, and m and / or n may not be an integer. . In that case, for each of the plurality of compounds, m and n may not be independently 1-2, and R ¹ and R ² and a mixture of a plurality of compounds in which A ¹ and A ² are the same As an average value, m and n may be 1-2 independently. m and n may each independently be 1 or 2.

  When the content of the compound of the formula (1) in the oil composition of the present invention is 40% by mass or more and 90% by mass or less, the effect of blending the above-described scratch resistance improving component can be obtained. When the ratio of the component is less than 40% by mass, the scratch resistance is insufficient, and therefore the carbon fiber performance such as strand strength tends to be lowered. On the other hand, when the amount is more than 90% by mass, there is a problem in terms of the particle size of the aqueous emulsion dispersed with the following emulsifier and the stability over time. Preferably, they are 60 mass% or more and 80 mass% or less. In this case, when the following emulsifier, antioxidant, and silicone component are blended, in addition to scratch resistance, there is an effect in suppressing inter-single fiber adhesion in the spinning process and fusion in the flame resistance process.

  The oil agent composition of this invention contains 10 mass% or more and 60 mass% or less of components other than the said abrasion resistance improving component. Examples of components other than the scratch resistance improving component include emulsifiers, antioxidants, and silicone components. These components can be appropriately used according to the purpose, but are preferably used as follows.

  The emulsifier is suitably used to form a water-based emulsion used when the above-described scratch resistance improving component is applied to the acrylic fiber bundle in a water-swelled state. As the emulsifier, it is preferable to use a nonionic surfactant. The emulsifier may be used alone or in combination of two or more.

  Nonionic surfactants include polyoxyalkylene glycol fatty acid esters, alkylene oxide adducts of aliphatic alcohols, and the like. The hydrophobic alkyl chain may be linear or branched. The HLB of the nonionic surfactant is preferably 6 to 16, and more preferably 8 to 13. Moreover, since it is preferable that the nonionic surfactant does not remain in the flameproofed yarn or carbonized yarn as a heating residue in the firing step, the residue ratio after heating at 250 ° C. in air for 2 hours is 1.0% by mass or less. It is preferably 0.5% by mass or less. The number of repeating oxyalkylene units, the type of oxyalkylene units, and the form of repeating oxyalkylene units, which are hydrophilic parts of such a nonionic surfactant, are appropriately determined so that the aqueous dispersion of the mixture becomes a stable aqueous emulsion. You can choose.

  The content of the emulsifier in the oil composition of the present invention is preferably in the range of 9 to 35% by mass, more preferably 15% by mass to 30% by mass. If the amount is less than 9% by mass, the stability of the water-based emulsion tends to be reduced and uneven adhesion to the fibers (unevenness) tends to occur. There is.

  Antioxidants may be effective in suppressing inter-single fiber adhesion and fusion in the drying process and flameproofing process of carbon fiber precursor fiber bundles after application of the oil composition, depending on the spinning conditions and firing conditions. Can be blended. Antioxidants include pentaerythrityl-tetrakis [3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate], triethylene glycol-bis [3- (3-t-butyl-5- Methyl-4-hydroxyphenyl) propionate], octadecyl-3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate, 1,3,5-tris (4-tert-butyl-3-hydroxy-) 2,6-dimethylbenzyl) isocyanuric acid, 2,2-thio-diethylenebis [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate], 4,4′-butylidenebis (3-methyl) -6-t-butylphenyl-ditridecyl phosphite) and the like are preferably used. The antioxidant may be one kind or a combination of two or more kinds.

  The content of the antioxidant in the oil composition of the present invention is preferably 14.0% by mass or less, more preferably 1% by mass or more and 5% by mass or less. Even if it exceeds 14.0% by mass, the effect of improving the heat resistance is not changed, and the antioxidant may remain as a heating residue in the flame-resistant yarn or the carbonized yarn, or the stability of the aqueous emulsion may be lowered.

  Although the silicone component has the problem of scratch resistance as described above, it suppresses adhesion and fusion between single fibers in the drying process and flame resistance process of the carbon fiber precursor fiber bundle after the oil agent composition is applied. Since it may be effective, it can be blended according to spinning conditions and firing conditions. In addition, as is well known, the coefficient of friction of the fiber, especially under light loads, is reduced, so that, for example, when the tension applied to the fiber bundle is small (for example, unraveling from the bobbin), it prevents process damage and damage during contact.・ It may be effective for mitigation. The silicone component can be appropriately selected from dimethyl silicone, amino-modified silicone having epoxy group, epoxy-modified silicone, polyether-modified silicone, etc. Among them, amino-modified silicone having excellent affinity for fibers is preferably used. One silicone component may be used, or two or more silicone components may be used in combination.

  As the amino-modified silicone, it is preferable to use one or more compounds represented by the following formula (2) or formula (3).

At the amino-modified portions in the formula (2), k is an integer of from 1 to 10, L is an integer of 1 to 10, p is an integer of 0 to 5, R ³ to R ⁵ is a hydrogen atom or an alkyl of 1 to 5 carbon atoms Group is preferable in terms of affinity for acrylic carbon fiber precursor and heat resistance, and aminopropyl group [—C ₃ H ₆ NH ₂ (k = 3, p = 0 in the amino-modified part of formula (2), R ⁴ and R ⁵ are hydrogen atoms)]], or N- (2-aminoethyl) aminopropyl group [—C ₃ H ₆ NHCH ₂ CH ₂ NH ₂ (k = 3 in the amino-modified part of the formula (2), L = 2 and p = 1, and R ³ , R ⁴ and R ⁵ are each preferably a hydrogen atom)].

  In the formula (2), i represents an integer of 10 to 10000, j represents an integer of 1 to 100, and preferably 50 ≦ i ≦ 1000 and 1 ≦ j ≦ 10. When i and j are out of this range, the performance and heat resistance of the carbon fiber may be deteriorated. If i <10, the heat resistance is low and the fusion between single yarns may not be prevented. If i> 10000, dispersion in water becomes difficult, and it may not be possible to uniformly apply to the fiber surface. If j = 0, sufficient heat resistance may not be exhibited, and fusion between single yarns may not be effectively prevented. On the other hand, if j> 100, the heat resistance of the oil itself is lowered, and it is sometimes impossible to prevent fusion between single yarns.

In the amino-modified moiety represented by Y in Formula (3), q is an integer of 1 to 10, r is an integer of 1 to 10, s is an integer of 0 to 5, R ^{3 to} R ⁵ are hydrogen atoms or carbon numbers 1 Is preferably an alkyl group of ˜5 in terms of affinity and heat resistance to the acrylic carbon fiber precursor, and aminopropyl group [—C ₃ H ₆ NH ₂ (q = 3 in Y of formula (3), s = 0) , R ⁷ and R ⁸ are hydrogen atoms)], or N- (2-aminoethyl) aminopropyl group [—C ₃ H ₆ NHCH ₂ CH ₂ NH ₂ (q = 3 in Y of formula (3), r = 2, s = 1, and R ⁶ , R ⁷ and R ⁸ are each preferably a hydrogen atom)].

  T in Formula (3) is an integer of 10 to 10000, and preferably 50 ≦ t ≦ 1000. If t is out of this range, the carbon fiber performance and heat resistance are lowered, which is not preferable.

  The content of the silicone component in the oil composition of the present invention is preferably 50% by mass or less, more preferably 2% by mass or more and 25% by mass or less. When it is more than 50% by mass, the expression of scratch resistance by the oil composition of the present invention may be inhibited. In addition, in the production of the carbon fiber precursor acrylic fiber bundle of the present invention, the convergence of the acrylic fiber bundle after the drying densification step is deteriorated, and the process passability is lowered.

  In the present invention, when each component in the oil composition and the mixing ratio thereof are selected from the components and ratios shown in Table 1, more preferable results are obtained.

  The oil agent composition of the present invention may appropriately contain an antistatic agent, a penetrating agent, an antifoaming agent, a preservative, and the like in order to improve the characteristics.

  The oil agent composition of the present invention is preferably in the form of a water-based emulsion in which the scratch resistance improving component and other compounding agents are dispersed in water in order to impart the water-swelled acrylic fiber bundle. For example, the water-based emulsion may contain an antioxidant as needed while stirring the scratch resistance improving component (bisphenol A derivative) represented by the formula (1) and the silicone component (for example, amino-modified silicone represented by the formula (2)). It can be prepared by adding the mixture while heating, adding an emulsifier (for example, a nonionic surfactant) to the mixture and stirring the mixture. Each component can be mixed or dispersed in water using a propeller, a homomixer, a homogenizer or the like.

  A water-swelled acrylic fiber bundle can be obtained, for example, by a wet spinning method. The wet spinning method is a method of preparing a spinning stock solution in which a raw material polymer is dissolved in a solvent, spinning the spinning stock solution from a nozzle immersed in a coagulation bath containing the coagulation solution, and fiberizing the solution. .

  As the polymer that is a raw material, an acrylonitrile-based copolymer is used as described above. As a solvent for preparing the spinning dope, for example, dimethylacetamide, dimethyl sulfoxide, dimethylformamide, nitric acid, aqueous rhodium soda, aqueous zinc chloride and the like can be used. The concentration of the acrylic copolymer in the spinning dope is preferably 15 to 35% by mass, and more preferably 18 to 28% by mass.

  As the coagulation liquid to be put into the coagulation tank, it is common to use a mixed liquid of a solvent and water used for preparing the spinning dope.

  The number of holes provided in the nozzle to be used may be selected appropriately depending on the number of filaments of the target carbon fiber precursor acrylic fiber bundle and the presence or absence of division. If the pitch between holes is narrow, the spinnability may be reduced and fluff may be generated. Therefore, it is preferable to use a material having a wide pitch between holes as much as possible. Usually, the pitch between holes is 0.4 to 0.9 mm.

  The obtained fiber (coagulated yarn) is desolvated in a water washing tank and becomes in a water-swelled state. At this time, the film can be stretched 2 to 6 times.

  A water-based emulsion is given to the acrylic fiber bundle in the water-swelled state. Application of the water-based emulsion to the water-swelled acrylic fiber bundle can be performed by a known method such as roller oiling or dipping. The water-swelled acrylic fiber bundle to which the water-based emulsion is applied is subsequently subjected to treatments such as drying densification and stretching to become a carbon fiber precursor acrylic fiber bundle to which the oil composition is adhered.

  Dry densification is a process of evaporating the moisture in the swollen acrylic fiber bundle, crushing the voids, and densifying. The temperature for drying and densification is usually 110 to 200 ° C., and the time is about 1 to 5 minutes.

  The stretching after drying and densification can be performed by a heating roll or a pressure steam treatment apparatus. The temperature at the time of extending | stretching can be about 110-150 degreeC, and can be performed by 150-500 kPa (gauge pressure) by extending | stretching by a pressurized steam processing apparatus. A draw ratio can be 1.5-6 times, for example.

  Then, the evaluation / selection method of the oil agent composition containing the scratch resistance improving component of the present invention will be described.

  When the fiber is damaged due to the lack of scratch resistance of the carbon fiber precursor acrylic fiber bundle, single yarn breakage (fluff generation) in the firing process, deterioration of physical properties of the carbon fiber bundle (increased ratio of low-strength fibers), etc. One method is to perform an evaluation analysis based on these process data and quality. However, since these are information including a firing process factor, it may be difficult to extract the oil agent factor. If the scratch resistance (potential damage occurrence factor) at the stage of the carbon fiber precursor acrylic fiber bundle can be evaluated, it is considered that the characteristics of the oil composition can be grasped more accurately. Moreover, if it can evaluate in the stage of a carbon fiber precursor acrylic fiber bundle, it will be thought that there is a big merit also at the point of quality control.

  Since the scratch resistance of the carbon fiber precursor acrylic fiber bundle becomes apparent at the time of firing, necessary data cannot be obtained even if the carbon fiber precursor acrylic fiber bundle is observed and evaluated as it is. Further, if any number of fiber damages can be easily detected, it is not suitable as a firing raw material. An object of the present invention is to find an oil composition excellent in a function of protecting a fiber surface substrate against abrasion under high load, and to produce a carbon fiber precursor acrylic fiber bundle provided with such an oil composition. It is a thing. Since the observation and evaluation of the fiber itself are limited, the present inventors have studied an accelerated test and a severe test method for evaluating the abrasion resistance of the carbon fiber precursor acrylic fiber bundle. Evaluation of damage caused by rubbing between fiber bundles or between fiber bundles and another object is, for example, rubbing with a constant contact load and measuring the time until the fiber bundle breaks or the number of abrasions. Quantitative data can be obtained by measuring the tensile strength and elongation of the fiber bundle or the single fiber constituting the fiber bundle after being rubbed a certain number of times under a specific load, and the carbon fiber precursor (including oil) The relationship with the body acrylic fiber bundle manufacturing conditions can also be grasped.

  The apparatus for performing such a fretting model test is not particularly limited as long as the above data can be obtained, but the present inventors have used a ring spinning machine used for spinning ordinary textile fibers. evaluated. In the case of garment fibers, it goes through a pre-process specific to staple spinning, but in the present invention, the properties of the oil composition can be easily obtained by evaluating the scratch resistance with a spinning machine with the carbon fiber precursor acrylic fiber bundle as it is. I can grasp. Ring spinning, especially spinning tests where metal parts and fibers are in contact at high speeds usually determines the spinning conditions and improves the fiber substrate by evaluating abrasion damage such as processability of fibers for textiles, abnormal dyeing, falling off of white powder, etc. Although it is a well-known method utilized for the selection test of a fiber processing agent (oil agent), the present inventors used this test method as an evaluation apparatus of the abrasion resistance of a carbon fiber precursor acrylic fiber bundle.

  Here, an RY type spinning machine (manufactured by TOYODA) was used in a laboratory where the temperature and humidity were controlled (temperature 20 ° C., humidity 65% RH). If the number of single fibers constituting the carbon fiber precursor acrylic fiber bundle is large, it cannot be attached to the spinning machine. Therefore, in order to make the thickness of the fiber bundle passing through the spinning test machine, here, the carbon fiber precursor acrylic fiber bundle of 100 filaments is used. Used for evaluation. The conditions for conducting the rubbing model test with the fine spinning machine were set such that the spindle rotation number was 16000 rpm and the twist number was 665 T / m.

  The rubbing resistance of an oil agent can be evaluated relative to the degree of damage when rubbing under the same conditions. The evaluation can be performed based on various spinning data and the physical properties / appearance of the carbon fiber precursor acrylic fiber bundle and single fiber after rubbing. Here, the time until thread breakage (or traveler breakage) due to rubbing with the traveler fixed to the ring rail was compared. The reason why it cuts in a short time is that the fiber substrate and the traveler rub against each other directly (or in a situation close to it) without using an oil film, and although it is indirect, it can be an index of oil film strength and scratch resistance. Although it is undeniable that factors different from the production of ordinary carbon fiber precursor acrylic fiber bundles are included in the evaluation by this method, it can be evaluated at the stage of carbon fiber precursor acrylic fiber bundles. Since it can be used, it can be applied to quality control by evaluation of scratch resistance and screening of oil agent components.

  In ring spinning under the above conditions, the longer the time until the 100-filament carbon fiber precursor acrylic fiber bundle breaks, the better, but if it does not break for more than 30 minutes, contact between the fiber substrate and the metal part via the oil coating Was considered to be stable, so the scratch resistance was judged to be good. More preferably, it is not cut for more than 45 minutes.

  Needless to say, multi-dimensional evaluation of the carbon fiber precursor acrylic fiber bundle and the oil composition by aligning the scratch resistance evaluation data described here with the firing data such as passability of the firing process and carbon fiber bundle physical properties.・ Analysis is possible and more useful information can be obtained.

  The present invention will be described more specifically with reference to the following examples. However, the present invention is not limited to these examples.

  In addition, as an evaluation of the scratch resistance of the carbon fiber precursor acrylic fiber bundle, the yarn breakage (or traveler breakage) when the 100 filament carbon fiber precursor acrylic fiber bundle was spun at high speed with an RY type spinning machine (manufactured by TOYODA). ) Was measured. Each sample was measured three times and compared with the average value. At this time, the spindle rotation speed was fixed at 16000 rpm, and the number of twists was fixed at 665 T / m.

  As a performance evaluation of the carbon fiber bundle, the carbon fiber strand strength was measured according to the epoxy resin impregnated strand method defined in JIS-R-7601. The number of measurements was 10 and the average value was shown.

  The adhesion amount of the oil agent composition on the carbon fiber precursor acrylic fiber bundle was measured by a thermal decomposition method based on SACMA method SRM14-90.

Example 1
An aqueous emulsion containing the oil composition was prepared by the following method.

As the scratch resistance improving component, in formula (1), A ¹ and A ² are both ethylene groups, m = 1, n = 1, and both carboxylic acids forming R ¹ and R ² are lauric acid. Compound (i) and polyoxyethylene lauryl ether [EO (ethylene oxide) unit number of 0.4% by mass as a nonionic emulsifier, heated residue (mass after heating at 250 ° C. for 2 hours): 10, HLB: 14 0.0] (iv) and pentaerythrityl-tetrakis [3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate] (v) as an antioxidant in 75: 23: 2. Ion exchange water was added to the oil composition mixed at a mass ratio to adjust the total concentration of each component to 25% by mass. Thereafter, the mixture was emulsified with a homomixer and further subjected to secondary emulsification at 30 MPa with a high-pressure homogenizer to obtain an aqueous emulsion.

  An acrylonitrile copolymer (acrylonitrile unit / methacrylic acid unit / acrylamide unit mass ratio 97.1 / 0.9 / 2.0) was dissolved in dimethylacetamide, and the acrylonitrile copolymer concentration was 21% by mass and the viscosity at 60 ° C. A 500 poise spinning stock solution was prepared. This spinning dope was discharged from a spinneret having a pore diameter (diameter) of 75 μm and a pore number of 100 into a coagulation bath filled with a 69 mass% dimethylacetamide aqueous solution at 35 ° C. to obtain a coagulated yarn. The coagulated yarn was desolvated in a water washing tank and stretched 5 times to obtain an acrylic fiber bundle in a water swollen state.

  The acrylic fiber bundle in the water-swelled state was led to an oil bath filled with a diluent prepared by adding ion exchange water to the aqueous emulsion to adjust the active ingredient concentration to 1.0% by mass, and the oil agent composition was adhered. Then, it dried and densified with the heating roll with a surface temperature of 130 degreeC, and also it extended | stretched 1.7 times between the heating rolls with a surface temperature of 170 degreeC, and obtained the carbon fiber precursor acrylic fiber bundle. This carbon fiber precursor acrylic fiber bundle had a single yarn fineness of 1.2 dtex, a tensile strength of 7 g / dtex, and an elongation of 10.5%, and the amount of the oil composition deposited was 0.9% by mass.

  The scratch resistance of the carbon fiber precursor acrylic fiber bundle was evaluated. Here, a part of a 100-filament carbon fiber precursor acrylic fiber bundle was used for evaluation as it was.

  A part of the carbon fiber precursor acrylic fiber bundle not subjected to the rubbing test was fired to produce a carbon fiber bundle. Specifically, it is passed through a flameproof furnace having a temperature gradient of 230 to 270 ° C. over 60 minutes, and further baked in a carbonization furnace having a temperature gradient of 300 to 1300 ° C. in a nitrogen atmosphere to obtain a carbon fiber bundle. .

  Table 2 shows the scratch resistance test results of the carbon fiber precursor acrylic fiber bundle and the strand strength of the carbon fiber bundle.

(Example 2)
As the scratch resistance improving component, in Formula (1), A ¹ and A ² are both a mixture of ethylene group and propylene group (molar ratio 50/50), m = 2, n = 2, R ¹ , R An aqueous emulsion was prepared in the same manner as in Example 1 except that the compound (ii) in which both of the carboxylic acids forming ² were palmitic acid was used. A carbon fiber precursor acrylic fiber bundle and a carbon fiber bundle were obtained in the same manner as in Example 1 except that this aqueous emulsion was used. Table 2 shows the scratch resistance test results of the carbon fiber precursor acrylic fiber bundle and the strand strength of the carbon fiber bundle.

(Example 3)
As the amino-modified silicone, a substance in which k = 3, L = 2, p = 1 in formula (2), R ³ , R ⁴ , R ⁵ are hydrogen atoms, i = 60, j = 1 (vi ), And the same as in Example 1 except that the scratch resistance improving component, nonionic emulsifier, antioxidant, and amino-modified silicone are mixed at a mass ratio of 71: 23: 2: 4. An aqueous emulsion was prepared by this method. A carbon fiber precursor acrylic fiber bundle and a carbon fiber bundle were obtained in the same manner as in Example 1 except that this aqueous emulsion was used. Table 2 shows the scratch resistance test results of the carbon fiber precursor acrylic fiber bundle and the strand strength of the carbon fiber bundle.

Example 4
As the amino-modified silicone, q = 3, s = 0, R ⁷ and R ⁸ in the formula (3) are hydrogen atoms, and the same as in Example 3 except that (vii) where t = 60 is used. An aqueous emulsion was prepared by this method. A carbon fiber precursor acrylic fiber bundle and a carbon fiber bundle were obtained in the same manner as in Example 1 except that this aqueous emulsion was used. Table 2 shows the scratch resistance test results of the carbon fiber precursor acrylic fiber bundle and the strand strength of the carbon fiber bundle.

(Example 5)
A water-based emulsion was prepared in the same manner as in Example 3, except that the scratch resistance improving component, nonionic emulsifier, antioxidant, and amino-modified silicone were mixed at a mass ratio of 65: 23: 2: 10. . A carbon fiber precursor acrylic fiber bundle and a carbon fiber bundle were obtained in the same manner as in Example 1 except that this aqueous emulsion was used. Table 2 shows the scratch resistance test results of the carbon fiber precursor acrylic fiber bundle and the strand strength of the carbon fiber bundle.

(Comparative Example 1)
An aqueous emulsion was prepared in the same manner as in Example 3 except that the scratch resistance improving component, nonionic emulsifier, antioxidant, and amino-modified silicone were mixed at a mass ratio of 20: 23: 2: 55. . A carbon fiber precursor acrylic fiber bundle and a carbon fiber bundle were obtained in the same manner as in Example 1 except that this aqueous emulsion was used. Table 2 shows the scratch resistance test results of the carbon fiber precursor acrylic fiber bundle and the strand strength of the carbon fiber bundle.

(Comparative Example 2)
A water-based emulsion was prepared in the same manner as in Example 1 except that the oil composition was prepared by mixing the scratch resistance improving component (i) and the nonionic emulsifier (iv) at a mass ratio of 91: 9. A carbon fiber precursor acrylic fiber bundle and a carbon fiber bundle were obtained in the same manner as in Example 1 except that this aqueous emulsion was used. Table 2 shows the scratch resistance test results of the carbon fiber precursor acrylic fiber bundle and the strand strength of the carbon fiber bundle.

(Comparative Example 3)
As the scratch resistance improving component, in formula (1), A ¹ and A ² are both ethylene groups, m = 6, n = 6, and both carboxylic acids forming R ¹ and R ² are lauric acid. An aqueous emulsion was prepared in the same manner as in Example 1 except that the compound (iii) was used. A carbon fiber precursor acrylic fiber bundle and a carbon fiber bundle were obtained in the same manner as in Example 1 except that this aqueous emulsion was used. Table 2 shows the scratch resistance test results of the carbon fiber precursor acrylic fiber bundle and the strand strength of the carbon fiber bundle.

(Comparative Example 4)
A water-based emulsion was prepared in the same manner as in Example 1 except that the oil composition was prepared by mixing nonionic emulsifier (iv) and amino-modified silicone (vi) at a mass ratio of 15:85. A carbon fiber precursor acrylic fiber bundle and a carbon fiber bundle were obtained in the same manner as in Example 1 except that this aqueous emulsion was used. Table 2 shows the scratch resistance test results of the carbon fiber precursor acrylic fiber bundle and the strand strength of the carbon fiber bundle.

(I) to (vii) in the components in Table 2 represent the following compounds.
(I) Dilauryl ester of adduct of 2 moles of ethylene oxide of bisphenol A (number of moles relative to 1 mole of bisphenol A, the same applies hereinafter). m = 1, n = 1.
(Ii) Dipalmityl ester of 2 mol of ethylene oxide and 2 mol of propylene oxide adduct of bisphenol A. m = 2, n = 2.
(Iii) Dilauryl ester of bisphenol A ethylene oxide 12 mol adduct. m = 6, n = 6.
(Iv) Polyoxyethylene lauryl ether [EO (ethylene oxide) unit number: 10, HLB: 14.0, heating residue: 0.4% by mass]. The heating residue was determined from the mass of a residue obtained by accurately weighing 2.0 g of a nonionic surfactant in an aluminum petri dish (diameter 60 mm, depth 10 mm) and heating in air at 250 ° C. for 2 hours.
(V) Pentaerythrityl-tetrakis [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate].
(Vi) Amino-modified silicone [in formula (2), k = 3, L = 2, p = 1, R ³ , R ⁴ , R ⁵ are hydrogen atoms, i = 60, j = 1].
(Vii) amino-modified silicone [in formula (3), q = 3, s = 0, R ⁷ and R ⁸ are hydrogen atoms, t = 60].

  As shown in Table 2, the scuff resistance of the carbon fiber precursor acrylic fiber bundles in the examples was superior to the comparative examples. The strand strength of the carbon fiber bundle in the examples was the same as or superior to that of the comparative example. Even if there is no problem from the current production conditions of carbon fiber bundles and the required characteristics of carbon fiber bundles, when abrasion is applied to the fiber surface under high load due to high speed, multiple spindles, etc. in the future, This suggests the possibility of problems in process passability and quality, and is attracting attention.

Claims (4)

An oil agent composition to be attached to an acrylic fiber bundle having a plurality of acrylic fibers, wherein the oil agent composition comprises 40% by mass or more and 90% by mass or less of a compound represented by the following formula (1).

(In Formula (1), R ¹ and R ² are each independently an alkyl group having 11 to 17 carbon atoms, A ¹ and A ² are each independently an ethylene group or a propylene group, and m and n are Each is independently 1-2.)   A carbon fiber precursor acrylic fiber bundle obtained by adhering the oil composition according to claim 1 to an acrylic fiber bundle having a plurality of acrylic fibers.   A method for producing a carbon fiber precursor acrylic fiber bundle, comprising a step of attaching the oil agent composition according to claim 1 to an acrylic fiber bundle having a plurality of acrylic fibers.   A carbon fiber bundle obtained by flameproofing and carbonizing the carbon fiber precursor acrylic fiber bundle according to claim 2.