Treatment agent for carbon fiber precursor, and carbon fiber precursor

Abstract

This treatment agent for a carbon fiber precursor is characterized by containing a saturated monoalcohol (A), a nonionic surfactant (B), and a smoothing agent (C), and the smoothing agent (C) contains silicone (C1). The treatment agent for the carbon fiber precursor can prevent dross from adhering to a roller, improve the bundling property of the carbon fiber precursor, and improve the stability of an emulsion.

Description

Technical Field

[0001] The present invention relates to a treating agent for a carbon fiber precursor and a carbon fiber precursor. Background Art

[0002] As a method for manufacturing carbon fiber, a method of spinning a fibrous material and then firing the material is generally adopted. The fibrous material is called a carbon fiber precursor. As a carbon fiber precursor, a carbon fiber precursor in which a carbon fiber precursor treatment agent is attached to the surface of a fiber material such as a polymer is sometimes used. The treatment agent is used to improve the operability of the carbon fiber precursor in each step when manufacturing carbon fiber.

[0003] International Publication No. 2018 / 163739 (Patent Document 1) discloses an acrylic fiber treatment agent containing amino-modified silicone, a Bronsted acid compound, and an acetylene surfactant. Acrylic fibers for carbon fiber production produced by applying the treatment agent described in Patent Document 1 are not easily degraded even when stored for a long time.

[0004] Prior art literature

[0005] Patent Literature

[0006] Patent Document 1: International Publication No. 2018 / 163739 Summary of the invention

[0007] Problem that the invention aims to solve

[0008] The carbon fiber precursor is usually wound on a winding device such as a winder after continuously going through the steps of spinning, stretching, drying and applying a treatment agent. In this continuous step, the carbon fiber precursor passes through each step while being guided by a guide such as a roller. In terms of preventing scum from adhering to the roller and improving the bundling of the wound carbon fiber precursor, there is room for improvement in the carbon fiber precursor to which the treatment agent described in Patent Document 1 is applied. In addition, the dispersion (emulsion) of the treatment agent described in Patent Document 1 has low mechanical stability, and sometimes causes problems such as gelation in the oil supply bath. Therefore, there is a situation that hinders the continuous production of the carbon fiber precursor.

[0009] Therefore, there is a demand for a carbon fiber precursor treating agent that can prevent scum from adhering to a roll, improve the bundling property of the carbon fiber precursor, and improve the emulsion stability, and a carbon fiber precursor provided with the treating agent.

[0010] Solutions to the problem

[0011] The treatment agent for a carbon fiber precursor of the present invention is characterized by comprising a saturated monoalcohol (A), a nonionic surfactant (B) and a smoothing agent (C), wherein the smoothing agent (C) contains silicone (C1).

[0012] The carbon fiber precursor of the present invention is characterized in that a carbon fiber precursor treating agent is adhered thereto.

[0013] According to these structures, it is possible to prevent scum from adhering to the roller, improve the bundling property of the carbon fiber precursor, and improve the stability of the emulsion. In addition, a carbon fiber precursor with good friction characteristics can be obtained.

[0014] Hereinafter, preferred embodiments of the present invention will be described. However, the scope of the present invention is not limited by the examples of preferred embodiments described below.

[0015] In one embodiment of the treatment agent for a carbon fiber precursor of the present invention, the saturated monool (A) preferably has 8 or more and 26 or less carbon atoms.

[0016] According to this structure, scum is particularly unlikely to be generated.

[0017] In one embodiment of the treatment agent for a carbon fiber precursor of the present invention, the saturated monoalcohol (A) preferably has a branch at the β-position of the hydroxyl group.

[0018] According to this structure, the emulsion stability of the carbon fiber precursor treating agent is further improved.

[0019] In one embodiment of the treatment agent for a carbon fiber precursor of the present invention, it is preferable that the ratio of the saturated monoalcohol (A) in the non-volatile component is 0.1 mass % or more and 20 mass % or less.

[0020] According to this structure, the bundling property of the carbon fiber precursor is further improved.

[0021] In one embodiment of the treatment agent for a carbon fiber precursor of the present invention, the silicone (C1) preferably contains an amino-modified silicone.

[0022] According to this configuration, the friction characteristics of the carbon fiber precursor to which the carbon fiber precursor treating agent is applied are further improved.

[0023] In one embodiment of the treatment agent for a carbon fiber precursor of the present invention, preferably, the nonionic surfactant (B) comprises an alkylene oxide adduct (B1) of a monoalcohol having a branch at the β-position of the hydroxyl group.

[0024] According to this structure, the emulsion stability of the carbon fiber precursor treating agent is further improved.

[0025] The treatment agent for carbon fiber precursor of the present invention, as a mode, preferably, in the non-volatile component, the proportion of the above-mentioned saturated monoalcohol (A) is greater than 0.1 mass % and less than 20 mass %, the proportion of the above-mentioned nonionic surfactant (B) is greater than 10 mass % and less than 70 mass %, and the proportion of the above-mentioned smoothing agent (C) is greater than 29.9 mass % and less than 89.9 mass %.

[0026] According to this configuration, it is possible to achieve, at a high level, prevention of scum adhesion on the roller, improvement in bundling properties of the carbon fiber precursor, and improvement in emulsion stability.

[0027] Further characteristics and advantages of the invention will become clearer from the following description of exemplary and non-limiting embodiments. DETAILED DESCRIPTION

[0028] Embodiments of the carbon fiber precursor treatment agent and carbon fiber precursor of the present invention are described. Hereinafter, an example of applying the carbon fiber precursor treatment agent (hereinafter sometimes simply referred to as "treatment agent") of the present invention to the treatment of a carbon fiber precursor is described.

[0029] [Structure of the treatment agent for carbon fiber precursor]

[0030] The carbon fiber precursor treatment agent of this embodiment contains a saturated monoalcohol (A), a nonionic surfactant (B) and a smoothing agent (C) as nonvolatile components. It should be noted that the nonvolatile components of the treatment agent refer to components that do not volatilize and remain when the treatment agent is heated at 105°C for 2 hours in a hot air dryer.

[0031] (Saturated monoalcohol)

[0032] The saturated monoalcohol (A) is a saturated monoalcohol compound as indicated by its name. That is, the saturated monoalcohol (A) is a compound in which one hydrogen atom of a saturated hydrocarbon is replaced by a hydroxyl group. It should be noted that the saturated monoalcohol (A) may be a single saturated monoalcohol compound or a mixture of multiple saturated monoalcohol compounds.

[0033] The saturated monoalcohol (A) preferably has a carbon number of 8 or more and 26 or less. When the carbon number of the saturated monoalcohol (A) is 8 or more, it is preferred that roller scum is not easily generated in the spinning step of spinning the carbon fiber precursor. It is also preferred that the carbon number of the saturated monoalcohol (A) is 26 or less because roller scum is not easily generated. The carbon number of the saturated monoalcohol (A) is more preferably 12 or more. The carbon number of the saturated monoalcohol (A) is more preferably 24 or less. When the saturated monoalcohol (A) is a mixture of a plurality of saturated monoalcohol compounds, it is preferred that the carbon number of at least one of the saturated monoalcohol compounds constituting the mixture is within the above range, and it is more preferred that the carbon number of all the saturated monoalcohol compounds is within the above range.

[0034] Preferably, the saturated monoalcohol (A) has a branch at the β-position of the hydroxyl group. That is, the saturated monoalcohol (A) in a preferred embodiment is represented by the following general formula (1).

[0035]

[0036] In the general formula (1), R 1 and R 2 is a saturated alkyl group. 1 The number of carbon atoms n and R 2 The total number of carbon atoms m (n+m) is 6 or more and 24 or less. 1 and R 2 Preferably, at least one is a saturated chain alkyl group, and more preferably, both are saturated chain alkyl groups. When the saturated monoalcohol (A) is a mixture of a plurality of saturated monoalcohol compounds, preferably, at least one of the saturated monoalcohol compounds constituting the mixture is represented by the general formula (1), and more preferably, the carbon number of all the saturated monoalcohol compounds is represented by the general formula (1).

[0037] Non-limiting examples of the saturated monoalcohol (A) include 2-(1,3,3-trimethylbutyl)-5,7,7-trimethyl-1-octanol (carbon number 18, n=9, m=7), 2-(4-methylhexyl)-8-methyl-1-decanol (carbon number 18, n=9, m=7), 2-hexyl-1-decanol (carbon number 16, n=8, m=6), 2-octyl-1-decanol (carbon number 18, n=8, m=8), 2-hexyl-1-dodecanol (carbon number 18, n=10, m=6), 2-octyl-1-dodecanol (carbon number 20, n=10, m=8), 2-ethyl-1-hexanol (carbon number 8, n=4, m=2), 2-butyl-1-octanol (carbon number 16, n=8, m=6 ... 12, n=6, m=4), 2-decyl-1-tetradecanol (24 carbon atoms, n=12, m=10), 2-(4-methylnonyl)-7-methyl-1-tetradecanol (25 carbon atoms, n=13, m=10), 2-dodecyl-1-hexadecanol (28 carbon atoms, n=14, m=12), 2-tetradecyl-1-octadecanol (32 carbon atoms, n=16, m=14), 16-methyl-1-heptadecanol (18 carbon atoms), 1-dodecanol (12 carbon atoms), 1-nonanol (9 carbon atoms), 3,5,5-trimethyl-1-hexanol (9 carbon atoms), 1-octadecanol (18 carbon atoms), 1-hexanol (6 carbon atoms) and cyclohexanol (6 carbon atoms). The compounds having the values ​​of n and m in the above-exemplified saturated monoalcohol compounds are examples of the saturated monoalcohol (A) represented by the general formula (1). A mixture of a plurality of saturated monoalcohol compounds selected from the above-exemplified compound group is also an example of the saturated monoalcohol (A).

[0038] The treatment agent of this embodiment preferably has a ratio of saturated monoalcohol (A) in the non-volatile component of 0.1 mass % or more and 20 mass % or less. When the ratio of saturated monoalcohol (A) is 0.1 mass % or more, it is preferred in that roller scum is not easily generated. When the ratio of saturated monoalcohol (A) is 20 mass % or less, the bundling property of the carbon fiber precursor tends to be high. More preferably, the ratio of saturated monoalcohol (A) in the non-volatile component is 1 mass % or more and 20 mass % or less, and further preferably, 1 mass % or more and 18 mass % or less.

[0039] (Nonionic surfactant)

[0040] The nonionic surfactant (B) may be any nonionic surfactant commonly used in the art. The nonionic surfactant (B) may be a single compound or a mixture of multiple compounds.

[0041] The nonionic surfactant (B) may be, for example, an alkylene oxide adduct of a compound having a hydroxyl group or a derivative thereof (e.g., an esterified product, etc.). Preferably, the nonionic surfactant (B) comprises an alkylene oxide adduct (B1) of a monoalcohol having a branch at the β position of the hydroxyl group (hereinafter sometimes referred to as a nonionic surfactant (B1)).

[0042] The nonionic surfactant (B1) of a preferred embodiment is represented by the following general formula (2).

[0043]

[0044] In the general formula (2), R 3 and R 4 is any hydrocarbon group, R 5 is an alkylene oxide residue. 3 and R 4 Preferably, at least one of them is a saturated alkyl group, and more preferably, both of them are saturated alkyl groups. 3 and R 4 Preferably, at least one of them is a chain alkyl group, and more preferably, both of them are chain alkyl groups. 3 and R 4 Both are saturated chain alkyl groups.

[0045] Preferably, R 5 Includes one or both of an ethylene oxide residue (-(C2H4O)x-) and a propylene oxide residue (-(C3H6)x-).

[0046] When the nonionic surfactant (B) is a mixture of multiple nonionic surfactants, preferably, at least one of the nonionic surfactants constituting the mixture is a nonionic surfactant (B1) (general formula (2)), and more preferably, all of the nonionic surfactants are nonionic surfactants (B1) (general formula (2)).

[0047] In the case where the nonionic surfactant (B) is an alkylene oxide adduct of a compound having a hydroxyl group, non-limiting examples are shown. The compounds listed as non-limiting examples of the above-mentioned saturated monoalcohol (A) are all examples of compounds having a hydroxyl group that can be provided to the nonionic surfactant (B). That is, as a compound having a hydroxyl group, 2-(1,3,3-trimethylbutyl)-5,7,7-trimethyl-1-octanol, 2-(4-methylhexyl)-8-methyl-1-decanol, 2-hexyl-1-decanol, 2-octyl-1-decanol, 2-hexyl-1-dodecanol, 2-octyl-1-dodecanol, 2-ethyl-1-hexanol, 2-butyl-1-octanol, 2-dodecyl-1-tetradecanol, 2-(4-methylnonyl)-7-methyl-1-tetradecanol, 2-dodecyl-1-hexadecanol, 2-tetradecyl-1-octadecanol, 16-methyl-1-heptadecanol, 1-dodecanol, 1-nonanol, 3,5,5-trimethyl-1-hexanol, 1-octadecanol, 1-hexanol and cyclohexanol can be exemplified. In addition, other examples of the compound having a hydroxyl group include 11-methyl-undecanol, tetradecanol, tridecanol, dodecanol, secondary tetradecanol, secondary tridecanol, tristyrenated phenol, distyrenated phenol, and bisphenol A. Non-limiting examples of alkylene oxides include ethylene oxide and propylene oxide.

[0048] Therefore, the nonionic surfactant (B) may be, for example, a compound obtained by reacting one or more of the above-exemplified compounds having a hydroxyl group with one or more of the above-exemplified alkylene oxides at a predetermined molar ratio. In the nature of the addition reaction of alkylene oxides, the product of the above reaction is generally a mixture of a plurality of compounds having different numbers of alkylene oxide additions. Therefore, the nonionic surfactant (B) may be determined according to the types of the hydroxyl group-containing compound and the alkylene oxide used as the substrate and their molar ratio.

[0049] The nonionic surfactant (B) may be an alkylene oxide adduct of an amine compound or a derivative thereof (for example, an esterified product). As a non-limiting example in this case, an ethylene oxide adduct of dodecylamine can be exemplified.

[0050] The treatment agent of the present embodiment preferably has a nonionic surfactant (B) in the non-volatile component that has a ratio of 10% by mass or more and 70% by mass or less. When the ratio of the nonionic surfactant (B) is 10% by mass or more and 70% by mass or less, it is preferred in that emulsification becomes easier. More preferably, the ratio of the nonionic surfactant (B) in the non-volatile component is 15% by mass or more and 70% by mass or less, and further preferably 20% by mass or more and 70% by mass or less. It should be noted that when the nonionic surfactant (B) is a mixture of multiple nonionic surfactants, the ratio of the nonionic surfactant (B) in the non-volatile component represents the total ratio of the multiple nonionic surfactants.

[0051] (Smoothing Agent)

[0052] The lubricant (C) contains silicone (C1). The lubricant (C) may be a single compound or a mixture of multiple compounds. When the lubricant (C) contains multiple compounds, it may be a mixture of multiple silicones (C1) or a mixture of one or more silicones (C1) and one or more non-silicone lubricants (C2). The lubricant (C) preferably contains more than 15% by mass of silicone (C1).

[0053] Silicone (C1) can be determined based on the kinematic viscosity at 25° C. measured by a Cannon-Fenske viscometer. The kinematic viscosity of silicone at 25° C. may be 80 mm 2 / s or more and 2000mm 2 / s or less.

[0054] Silicone (C1) preferably contains amino-modified silicone. The modification method of amino-modified silicone is arbitrary. Therefore, amino-modified silicone can be a compound obtained by introducing an amino group into the end of the silicone main chain, the side chain, or both. In addition, when an amino group is introduced into the end of the silicone main chain, the amino group can be introduced into both ends or only into one end. In addition, the introduced amino group is also arbitrary and can be a monoamine, a diamine, an amino polyether, etc. In addition, when the terminal group is not modified, the terminal group can be a hydroxyl group, a methoxy group, etc.

[0055] The amino-modified silicone can be determined based on the amino equivalent (g / mol) calculated from the total amine value (KOH-mg / g). The total amine value is determined by accurately weighing 1 g of a mixed solution of 60 mL acetone and 20 mL n-hexane and titrating it with a perchloric acid solution of known concentration. The amino equivalent of the amino-modified silicone can be 2000 or more and 8000 or less.

[0056] Silicone (C1) may be a modified silicone other than amino-modified silicone. Examples of the modified silicone include polyether-modified silicone, carboxyl-modified silicone, hydroxyl-modified silicone, and alkyl-modified silicone.

[0057] The non-silicone smoothing agent (C2) may be any non-silicone smoothing agent commonly used in the art. As non-limiting examples of the non-silicone smoothing agent (C2), there may be exemplified a reaction product of polybutenyl succinic anhydride and triethylenetetramine, a reaction product of polybutenyl-modified phenol, formaldehyde and triethylenetetramine, and mineral oil.

[0058] The treatment agent of this embodiment preferably has a ratio of the smoothing agent (C) in the non-volatile component of 29.9 mass % or more and 89.9 mass % or less. When the ratio of the smoothing agent (C) is 29.9 mass % or more, it is preferred in terms of friction characteristics. When the ratio of the smoothing agent (C) is 89.9 mass % or less, it is preferred in terms of emulsification. More preferably, the ratio of the smoothing agent (C) in the non-volatile component is 29.9 mass % or more and 80 mass % or less, and further preferably 29.9 mass % or more and 75 mass % or less. In addition, when the smoothing agent (C) contains multiple compounds, the ratio of the smoothing agent (C) in the non-volatile component represents the total ratio of the multiple compounds.

[0059] (Other ingredients)

[0060] The treatment agent of this embodiment may also contain other components besides the saturated monoalcohol (A), the nonionic surfactant (B) and the smoothing agent (C). Examples of such other components include, but are not limited to, preservatives, antistatic agents, antioxidants, ultraviolet absorbers, defoaming agents, and the like.

[0061] In addition, as a typical method for treating a carbon fiber precursor by providing a treatment agent, a method of diluting a non-volatile component such as a saturated monoalcohol (A) with a diluent can be exemplified. The diluent is also an example of other components. As a diluent, water (tap water, industrial water, ion exchange water, distilled water, etc.), acetone, methyl ethyl ketone, N-methyl-2-pyrrolidone, etc. can be exemplified, but are not limited to these. In addition, the concentration of the non-volatile component in the treatment agent in the method of diluting the non-volatile component with a diluent is not particularly limited, and can be, for example, 10% by mass or more and 60% by mass or less. As described above, the non-volatile component of the treatment agent refers to the component that does not volatilize and remains after the treatment agent is heated at 105°C with a hot air dryer for 2 hours, and its concentration refers to the ratio of the mass of the non-volatile component in the treatment agent to the mass of the treatment agent.

[0062] [Method for producing a treatment agent for carbon fiber precursor]

[0063] The treatment agent of this embodiment can be obtained by mixing a saturated monoalcohol (A), a nonionic surfactant (B), a smoothing agent (C) and any added components by a known method. For example, it can be prepared by adding water to the saturated monoalcohol (A), a nonionic surfactant (B), a smoothing agent (C) and any added components while stirring at 20° C. to 90° C. for 5 hours.

[0064] [Carbon fiber precursor]

[0065] The carbon fiber precursor of this embodiment is a method in which the treatment agent of this embodiment is attached to a fiber material commonly used as a carbon fiber precursor. The fiber material here refers to a fibrous material that becomes a carbon fiber after a sintering step, and can be polyacrylonitrile fiber, polyamide fiber, polyester fiber, polyolefin fiber, cellulose fiber, lignin fiber, phenolic resin, asphalt, etc. or a combination thereof.

[0066] As a method for attaching the treatment agent to the fiber material, a method commonly used in the art for attaching such a treatment agent to the fiber material can be applied. That is, an immersion oiling method, a spray oiling method, a roller oiling method, a guide oiling method, etc. can be adopted. In addition, when each method is applied, the treatment agent can be appropriately diluted with a solvent such as water.

[0067] In the carbon fiber precursor of the present embodiment, the amount of the treatment agent attached is not particularly limited, but preferably, the treatment agent is attached in an amount of 0.3% by mass or more and 3% by mass or less relative to the entire carbon fiber precursor to which the treatment agent is attached.

[0068] [Other embodiments]

[0069] For other structures, it should also be understood that the embodiments disclosed herein are exemplary in all respects, and the scope of the present invention is not limited thereto. Those skilled in the art can easily understand that, without departing from the scope of the present invention, appropriate changes can be made. Therefore, other embodiments that are changed within the scope of the present invention are certainly also included in the scope of the present invention.

[0070] [Example]

[0071] The present invention will be further described below with reference to the following examples. It should be noted that the present invention is not limited to the following examples.

[0072] [Preparation of a treatment agent for carbon fiber precursor]

[0073] The carbon fiber precursor treating agents of Examples 1 to 24 and Comparative Examples 1 to 4 shown in the following Tables 1 to 3 were obtained by the following method.

[0074] (1) Reagent (1-1) Alcohol

[0075] As alcohols, the following alcohols A-1 to A-18 and a-1 to a-3 are used. Among them, alcohols A-1 to A-18 are saturated monoalcohols. In addition, alcohols A-1 to A-11 are saturated monoalcohols represented by general formula (1). The meanings of the carbon number of each alcohol and the description of n and m are the same as those in the above embodiment.

[0076] A-1: 2-(1,3,3-trimethylbutyl)-5,7,7-trimethyl-1-octanol (carbon number 18, n=9, m=7)

[0077] A-2: 2-(4-methylhexyl)-8-methyl-1-decanol (carbon number 18, n=9, m=7)

[0078] A-3: 2-hexyl-1-decanol (carbon number 16, n=8, m=6)

[0079] A-4: a mixture of 2-octyl-1-decanol (carbon number 18, n=8, m=8) and 2-hexyl-1-dodecanol (carbon number 18, n=10, m=6) in a molar ratio of 50:50

[0080] A-5: 2-octyl-1-dodecanol (carbon number 20, n=10, m=8)

[0081] A-6: 2-ethyl-1-hexanol (carbon number 8, n=4, m=2)

[0082] A-7: 2-butyl-1-octanol (carbon number 12, n=6, m=4)

[0083] A-8: 2-decyl-1-tetradecanol (carbon number 24, n=12, m=10)

[0084] A-9: 2-(4-methylnonyl)-7-methyl-1-tetradecanol (carbon number 25, n=13, m=10)

[0085] A-10: 2-dodecyl-1-hexadecanol (carbon number 28, n=14, m=12)

[0086] A-11: 2-Tetradecyl-1-octadecyl alcohol (32 carbon atoms, n=16, m=14)

[0087] A-12: 16-methyl-1-heptadecanol (carbon number 18)

[0088] A-13: 1-dodecanol (carbon number 12)

[0089] A-14: 1-nonanol (carbon number 9)

[0090] A-15: 3,5,5-trimethyl-1-hexanol (carbon number 9)

[0091] A-16: 1-octadecyl alcohol (carbon number 18)

[0092] A-17: 1-Hexanol (carbon number 6)

[0093] A-18: Cyclohexanol (carbon number 6)

[0094] a-1:3,6-Dimethyl-4-octyne-3,6-diol

[0095] a-2: cis-9-octadecene-1-ol

[0096] a-3:9Z,12Z-octadecadien-1-ol

[0097] (1-2) Nonionic surfactant

[0098] As nonionic surfactants, the following nonionic surfactants B-1 to B-17 are used. Any nonionic surfactant meets the nonionic surfactant (B) of the above-mentioned embodiment, wherein nonionic surfactants B-1 to B-3 meet the nonionic surfactant (B1) represented by general formula (2). However, the manufacturing methods shown for various nonionic surfactants are all examples, and even if the nonionic surfactant is manufactured by a method different from the method illustrated below, the results of the examples and comparative examples will not change.

[0099] (Nonionic surfactant B-1)

[0100] 2-Hexyl-1-decanol and ethylene oxide were reacted at a molar ratio of 1:3 to obtain a nonionic surfactant B-1 which was an ethylene oxide adduct of 2-hexyl-1-decanol.

[0101] (Nonionic surfactant B-2)

[0102] 2-Hexyl-1-decanol and ethylene oxide were reacted at a molar ratio of 1:6 to obtain a nonionic surfactant B-2 which was an ethylene oxide adduct of 2-hexyl-1-decanol.

[0103] (Nonionic surfactant B-3)

[0104] 2-Hexyl-1-decanol and ethylene oxide were reacted at a molar ratio of 1:9 to obtain a nonionic surfactant B-3 which was an ethylene oxide adduct of 2-hexyl-1-decanol.

[0105] (Nonionic surfactant B-4)

[0106] Dodecanol and ethylene oxide were reacted at a molar ratio of 1:9 to obtain a nonionic surfactant B-4 which was an ethylene oxide adduct of dodecanol.

[0107] (Nonionic surfactant B-5)

[0108] 11-Methyl-undecanol and ethylene oxide were reacted at a molar ratio of 1:12 to obtain a nonionic surfactant B-5 which was an ethylene oxide adduct of 11-methyl-undecanol.

[0109] (Nonionic surfactant B-6)

[0110] Tetradecanol and ethylene oxide were reacted at a molar ratio of 1:7 to obtain the ethylene oxide adduct of tetradecanol, i.e., nonionic surfactant B-6.

[0111] (Nonionic surfactant B-7)

[0112] Tridecanol and ethylene oxide were reacted at a molar ratio of 1:15 to obtain a nonionic surfactant B-7 which is an ethylene oxide adduct of tridecanol.

[0113] (Nonionic surfactant B-8)

[0114] Dodecanol and ethylene oxide were reacted at a molar ratio of 1:20 to obtain a dodecanol ethylene oxide adduct, namely, a nonionic surfactant B-8.

[0115] (Nonionic surfactant B-9)

[0116] The secondary tetradecanol and ethylene oxide were reacted at a molar ratio of 1:10 to obtain the ethylene oxide adduct of the secondary tetradecanol, namely, the nonionic surfactant B-9.

[0117] (Nonionic surfactant B-10)

[0118] Secondary tridecanol and ethylene oxide were reacted at a molar ratio of 1:9 to obtain an ethylene oxide adduct of secondary tridecanol, namely, nonionic surfactant B-10.

[0119] (Nonionic surfactant B-11)

[0120] Dodecanol, ethylene oxide and propylene oxide were reacted at a molar ratio of 1:2:6 to obtain a nonionic surfactant B-11 which is a random adduct of ethylene oxide and propylene oxide to dodecanol.

[0121] (Nonionic surfactant B-12)

[0122] Tristyrenated phenol, ethylene oxide and propylene oxide were reacted at a molar ratio of 1:15:9 to obtain a nonionic surfactant B-12 which was a random adduct of ethylene oxide and propylene oxide to tristyrenated phenol.

[0123] (Nonionic surfactant B-13)

[0124] Distyrenated phenol, ethylene oxide and propylene oxide were reacted at a molar ratio of 1:18:5 to obtain a nonionic surfactant B-13 which was a random adduct of ethylene oxide and propylene oxide to distyrenated phenol.

[0125] (Nonionic surfactant B-14)

[0126] Bisphenol A and ethylene oxide were reacted at a molar ratio of 1:18 to obtain an ethylene oxide adduct of bisphenol A, namely, nonionic surfactant B-14.

[0127] (Nonionic surfactant B-15)

[0128] Tristyrenated phenol and ethylene oxide were reacted at a molar ratio of 1:30 to obtain a nonionic surfactant B-15 which was an ethylene oxide adduct of tristyrenated phenol.

[0129] (Nonionic surfactant B-16)

[0130] Dodecanol and ethylene oxide were reacted at a molar ratio of 1:6 to obtain the ethylene oxide adduct of dodecanol, namely, nonionic surfactant B-16.

[0131] (Nonionic surfactant B-17)

[0132] Dodecylamine and ethylene oxide were reacted at a molar ratio of 1:10 to obtain an ethylene oxide adduct of dodecylamine, namely, nonionic surfactant B-17.

[0133] (1-3) Smoothing agent

[0134] As the lubricant, the following silicones C1-1 to C1-11 and non-silicone lubricants C2-1 to C2-5 were used. Among them, silicones C1-1 to C1-7 were amino-modified silicones.

[0135] (Silicone C1-1)

[0136] The kinematic viscosity at 25°C is 80 mm 2 / s, amino equivalent of 4400, amino group is a side chain diamino type, both ends are blocked amino-modified silicone.

[0137] (Silicone C1-2)

[0138] The kinematic viscosity at 25°C is 800 mm2 / s, an amino equivalent of 3000, and an amino group of the side chain monoamino type, a double-end blocked amino-modified silicone.

[0139] (Silicone C1-3)

[0140] The kinematic viscosity at 25°C is 1200 mm 2 / s, amino equivalent of 5000, amino group of side chain diamino type, both terminal OH type amino-modified silicone.

[0141] (Silicone C1-4)

[0142] The kinematic viscosity at 25°C is 2000 mm 2 / s, an amino equivalent of 7000, and an amino group of a side chain diamino type amino-modified silicone with methoxy groups at both ends.

[0143] (Silicone C1-5)

[0144] The kinematic viscosity at 25°C is 250 mm 2 / s, an amino equivalent of 2000, and an amino group of the side chain diamino type, both ends of the amino-modified silicone blocked.

[0145] (Silicone C1-6)

[0146] The kinematic viscosity at 25°C is 1500 mm 2 / s, an amino equivalent of 8000, an amino group of a side chain monoamino type, and an amino-modified silicone of a mixed type of hydroxyl and methoxy groups.

[0147] (Silicone C1-7)

[0148] The kinematic viscosity at 25°C is 90 mm 2 / s, an amino equivalent of 2200, and an amino group of diamino type at both ends.

[0149] (Silicone C1-8)

[0150] The kinematic viscosity at 25°C is 300 mm 2 / s, a side chain type polyether modified silicone having a weight ratio of dimethyl silicone main chain / ethylene oxide / propylene oxide of 50 / 20 / 30.

[0151] (Silicone C1-9)

[0152] The kinematic viscosity at 25°C is 1000 mm 2 / s, ABn type polyether modified silicone with a weight ratio of dimethyl silicone main chain / ethylene oxide of 70 / 30.

[0153] (Silicone C1-10)

[0154] The kinematic viscosity at 25°C is 1000 mm 2 / s two-end blocked dimethyl silicone.

[0155] (Silicone C1-11)

[0156] The kinematic viscosity at 25°C is 80 mm 2 / s of dimethyl silicone with OH at both ends.

[0157] (Non-silicone smoothing agent C2-1)

[0158] A compound obtained by reacting polybutenyl succinic anhydride having a number average molecular weight of 2,000 in the polybutene part and triethylenetetramine was used.

[0159] (Non-silicone smoothing agent C2-2)

[0160] A compound obtained by reacting phenol modified with a polybutene group having a number average molecular weight of 1,500 in the polybutene portion, formaldehyde, and triethylenetetramine was used.

[0161] (Non-silicone smoothing agent C2-3)

[0162] The composition of aromatic component 0.5%, cycloparaffin component 25%, paraffin component 74.5% and kinematic viscosity at 30°C of 18 mm was used. 2 / s of mineral oil.

[0163] (Non-silicone smoothing agent C2-4)

[0164] The composition of aromatic component 2%, cycloparaffin component 40%, paraffin component 58% and kinematic viscosity at 30°C was 9 mm 2 / s of mineral oil.

[0165] (Non-silicone smoothing agent C2-5)

[0166] The composition of aromatic component 0.1%, cycloparaffin component 30%, paraffin component 69.9% and kinematic viscosity at 30°C of 46 mm was used. 2 / s of mineral oil.

[0167] (1-4) Other ingredients

[0168] As other ingredients, the following were used.

[0169] D-1: Acetic acid

[0170] D-2: Methyloctyl ammonium dimethyl phosphate

[0171] Diluent: Ion exchange water

[0172] (2) Preparation of Carbon Fiber Treatment Agent (Preparation of Example 1)

[0173] 10 parts by mass of alcohol A-1, 5 parts by mass of nonionic surfactant B-1, 5 parts by mass of nonionic surfactant B-4, 10 parts by mass of nonionic surfactant B-7, and 70 parts by mass of silicone C1-1 were weighed and poured into a beaker. After the above components were fully mixed, 233 parts by mass of ion exchange water were slowly added while stirring to prepare the carbon fiber precursor treatment agent of Example 1.

[0174] (Preparation of other examples and comparative examples)

[0175] Except for changing the type and mass fraction of the reagent to be mixed, the carbon fiber precursor treatment agent of each example was prepared in the same manner as in Example 1. The preparation conditions of all examples including Example 1 are shown in Tables 1 to 3 below.

[0176] [Evaluation of Treatment Agents for Carbon Fiber Precursors] (1) Preparation of Carbon Fibers (1-1) Preparation of Fiber Materials

[0177] A copolymer with an intrinsic viscosity of 1.80 composed of 95% by mass of acrylonitrile, 3.5% by mass of methyl acrylate and 1.5% by mass of methacrylic acid was dissolved in dimethylacetamide (DMAC) to prepare a spinning solution with a polymer concentration of 21.0% by mass and a viscosity of 500 poise at 60° C. The spinning solution was ejected from a spinneret with a hole diameter (inner diameter) of 0.075 mm and a hole number of 12,000 at a draft ratio of 0.8 into a coagulation bath of a 70% by mass aqueous solution of DMAC maintained at a spinning bath temperature of 35° C. The coagulated fibers were stretched 5 times while removing the solvent in a water washing tank to prepare acrylic fiber bundles in a water-swollen state.

[0178] (1-2) Preparation of carbon fiber precursor

[0179] The acrylic fiber bundles were impregnated with a 3% ion exchange aqueous solution of a carbon fiber precursor treatment agent in each example of the embodiment and the comparative example so that the amount of the treatment agent attached was 1% by mass (without solvent). The acrylic fiber bundles with the treatment agent attached were then dried and densified with a 150°C heating roller, and then stretched 1.7 times between 170°C heating rollers, and then wound on a silk tube to obtain a carbon fiber precursor.

[0180] (2) Evaluation of scum generation

[0181] For each of the treatment agents of the examples and comparative examples, the carbon fiber precursor was continuously prepared according to the step (1) above, and the presence and degree of scum accumulation on the heating roller in the drying and densification step were observed. The results of the observations were classified into the following three levels.

[0182] A: There is little scum accumulation on the heating roller, and it can operate continuously for more than 7 days without stopping due to wire breakage, etc.

[0183] B: Although a small amount of scum was deposited on the heating roller, the operation could be continued for more than 3 days and less than 7 days without stopping the operation due to wire breakage, etc.

[0184] C: There is a lot of scum accumulated on the heating roller, and the operation needs to be stopped due to wire breakage, etc. It needs to be cleaned within less than 3 days.

[0185] (3) Evaluation of winding bundling

[0186] The treatment agents of each example of the examples and comparative examples were classified into the following three levels according to the operation conditions when the carbon fiber precursor was wound on a winder.

[0187] A: There is almost no cracking and the winding can be continued without stopping the operation.

[0188] B: Although a small amount of cracking occurred, the winding could be continued without stopping the operation.

[0189] C: The wire is severely cracked and tangled, so the operation needs to be stopped.

[0190] (4) Emulsion stability

[0191] A 3% ion exchange aqueous solution of the treatment agent of each example of the embodiment and the comparative example was circulated in an oil supply bath by a pump, and the state of the aqueous solution was observed visually. Based on the observation results, it was classified into the following four levels.

[0192] A: After 7 days, no gel was found and the operation could be continued smoothly.

[0193] B: After 7 days, a small amount of gel was found, but the operation could be continued smoothly without cleaning the oil bath.

[0194] C: After 7 days, gel formation was observed and the gel in the oil bath needed to be cleaned and removed, but the operation could continue.

[0195] D: After 7 days, a lot of gel was generated and the operation had to be stopped to clean the oil supply bath.

[0196] (5) Friction characteristics

[0197] A 100 g tension was applied to a 12K (12,000 carbon fiber precursor bundle with 1% of a treatment agent attached thereto, and a 1 cm chrome pin was rotated at 200 rpm for 10 minutes to observe the carbon fiber precursor bundle. The results of the observation were classified into the following three levels.

[0198] A: No broken yarns or fuzz associated therewith were visually confirmed.

[0199] B: Broken silk and a small amount of fluff (1 to 10 pieces) were found.

[0200] C: Many broken threads and accompanying hairs were found (more than 11).

[0201] [result]

[0202] Tables 1 to 3 show the raw material composition of each example of the Examples and Comparative Examples and the results of each evaluation.

[0203] Table 1: Examples 1 to 12 [Table 1]

[0204]

[0205] Table 2: Examples 13 to 24 [Table 2]

[0206]

[0207] Table 3: Comparative Examples 1 to 4 [Table 3]

[0208]

[0209] [Industrial Applicability]

[0210] The present invention can be used, for example, in the production of carbon fiber precursors.

Claims

1. A treatment agent for a carbon fiber precursor, characterized in that: It contains a saturated monoalcohol (A), a nonionic surfactant (B) and a smoothing agent (C); The smoothing agent (C) contains silicone (C1).

2. The carbon fiber precursor treating agent according to claim 1, wherein The saturated monoalcohol (A) has 8 or more and 26 or less carbon atoms.

3. The carbon fiber precursor treating agent according to claim 1, wherein The saturated monoalcohol (A) has a branch at the β position of the hydroxyl group.

4. The carbon fiber precursor treating agent according to claim 1, wherein The ratio of the saturated monoalcohol (A) in the non-volatile component is 0.1 mass % or more and 20 mass % or less.

5. The carbon fiber precursor treating agent according to claim 1, wherein The silicone (C1) includes an amino-modified silicone.

6. The carbon fiber precursor treating agent according to claim 1, wherein The nonionic surfactant (B) comprises an alkylene oxide adduct (B1) of a monoalcohol having a branch at the β-position of a hydroxyl group.

7. The treating agent for carbon fiber precursor according to claim 1, wherein Among the non-volatile components, The proportion of the saturated monoalcohol (A) is 0.1% by mass or more and 20% by mass or less, The proportion of the nonionic surfactant (B) is 10% by mass or more and 70% by mass or less, and The ratio of the smoothing agent (C) is 29.9 mass % or more and 89.9 mass % or less.

8. A carbon fiber precursor, characterized in that: The carbon fiber precursor treating agent according to any one of claims 1 to 7 is adhered thereto.

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