Treatment agents for synthetic fibers and synthetic fibers

Abstract

Compared to conventional technologies, this technology suppresses tar generation and improves the bundling properties of the resulting synthetic fibers. [Solution] The solution comprises a sulfosuccinate ester compound (A), which is at least one compound selected from the group consisting of sulfosuccinate esters, alkali metal salts of sulfosuccinate esters, and ammonium salts of sulfosuccinate esters, which are esters of a polyoxyalkylene ether, which is an adduct obtained by adding one or more types of alkylene oxides having 2 to 4 carbon atoms to an aliphatic alcohol having 3 to 18 carbon atoms in a molar ratio of 1:1 to 1:15, and sulfosuccinate ester, and a nonionic surfactant (B), wherein the proportion of sulfosuccinate ester compound (A) in the nonvolatile content is greater than 0% by mass and less than 10% by mass.

Description

[Technical Field]

[0001] This invention relates to a treatment agent for synthetic fibers and synthetic fibers. [Background technology]

[0002] A commonly used method for manufacturing carbon fibers involves spinning a fibrous material and then firing it; this fibrous material is called a carbon fiber precursor. In some cases, carbon fiber precursors are used that have a carbon fiber precursor treatment agent applied to the surface of a fibrous material such as a polymer. Such treatment agents are used to improve the handling of the carbon fiber precursor in various processes during carbon fiber manufacturing. As in this example, various synthetic fiber treatment agents that can improve the handling of synthetic fibers may be used in the handling of synthetic fibers.

[0003] For example, Japanese Patent Publication No. 2019-7097 (Patent Document 1) discloses an acrylic fiber treatment agent containing an amino-modified silicone and an ether carboxylic acid compound. According to the invention described in Patent Document 1, static electricity and gum-up that occur in the manufacturing process of acrylic fibers for carbon fiber production can be suppressed. [Prior art documents] [Patent Documents]

[0004] [Patent Document 1] Japanese Patent Publication No. 2019-7097 [Overview of the project] [Problems that the invention aims to solve]

[0005] The invention described in Patent Document 1 also considers suppressing tar generated during the manufacturing process of acrylic fibers for carbon fiber production, but its tar suppression effect was not sufficient. Furthermore, there was room for improvement in the bundling properties of the resulting acrylic fibers.

[0006] Therefore, there is a need for a synthetic fiber treatment agent that can suppress tar generation compared to conventional technology and improve the bundling properties of the resulting synthetic fibers, as well as for the realization of synthetic fibers treated with said synthetic fiber treatment agent. [Means for solving the problem]

[0007] The synthetic fiber treatment agent according to the present invention comprises a sulfosuccinate ester compound (A), which is at least one compound selected from the group consisting of a sulfosuccinate ester (an ester of a polyoxyalkylene ether, which is an adduct obtained by adding one or more types of alkylene oxides having 2 to 4 carbon atoms to an aliphatic alcohol having 3 to 18 carbon atoms in a molar ratio of 1:1 to 1:15), an alkali metal salt of the sulfosuccinate ester, and an ammonium salt of the sulfosuccinate ester, and a nonionic surfactant (B), wherein the proportion of the sulfosuccinate ester compound (A) in the nonvolatile content is greater than 0% by mass and less than 10% by mass.

[0008] This configuration allows for the suppression of tar generation compared to conventional technologies, and also improves the bundling properties of the resulting synthetic fibers.

[0009] In one embodiment, the synthetic fiber treatment agent according to the present invention preferably contains a secondary alcohol nonionic surfactant (B1), which is an adduct obtained by adding ethylene oxide to a secondary alcohol having 4 to 18 carbon atoms in a molar ratio of 1:1 to 1:30.

[0010] This configuration tends to result in particularly high bundleability of the resulting synthetic fibers.

[0011] In one embodiment, the synthetic fiber treatment agent according to the present invention preferably contains an oxypropylene-based nonionic surfactant (B2), which is an adduct obtained by adding propylene oxide, or a mixture of two or more alkylene oxides having 2 to 4 carbon atoms and containing 1 mol% or more of propylene oxide, to an alcohol having 4 to 18 carbon atoms in a molar ratio of 1:1 to 1:100.

[0012] This configuration is particularly effective in both suppressing tar and improving its convergence.

[0013] In one embodiment, the treatment agent for synthetic fibers according to the present invention preferably further comprises an amino-modified silicone compound (C).

[0014] This configuration tends to result in synthetic fibers with higher strength.

[0015] In one embodiment, the synthetic fiber treatment agent according to the present invention preferably has the following characteristics: the total proportion of the sulfosuccinate ester compound (A), the nonionic surfactant (B), and the amino-modified silicone compound (C) in the nonvolatile content is 100% by mass, the proportion of the sulfosuccinate ester compound (A) is 0.001% by mass or more and less than 10% by mass, the proportion of the nonionic surfactant (B) is 8% by mass or more and 35% by mass or less, and the proportion of the amino-modified silicone compound (C) is 65% by mass or more and 92% by mass or less.

[0016] This configuration tends to result in particularly high strength in the resulting synthetic fibers.

[0017] The synthetic fiber according to the present invention is characterized in that the above-mentioned treatment agent for synthetic fibers is attached to the fiber material.

[0018] This configuration allows for the suppression of tar generation compared to conventional technologies, and also improves the bundling properties of the resulting synthetic fibers.

[0019] The synthetic fiber according to the present invention preferably has a fiber material that is a carbon fiber precursor.

[0020] According to this configuration, a carbon fiber precursor with good handleability in the flame resistance process can be obtained.

[0021] The further features and advantages of the present invention will become more apparent from the following description of exemplary and non-limiting embodiments.

Embodiments for Carrying Out the Invention

[0022] Hereinafter, embodiments of the treatment agent for synthetic fibers and synthetic fibers according to the present invention will be described.

[0023] 〔Configuration of Treatment Agent for Synthetic Fibers〕 The treatment agent for synthetic fibers according to the present embodiment (hereinafter simply referred to as "treatment agent") includes a sulfosuccinic acid ester compound (A) and a nonionic surfactant (B). Further, the treatment agent according to the present embodiment preferably further includes an amino-modified silicone compound (C).

[0024] (Sulfosuccinic Acid Ester) The sulfosuccinic acid ester compound (A) is at least one compound selected from the group consisting of a sulfosuccinic acid ester, an alkali metal salt of the sulfosuccinic acid ester, and an ammonium salt of the sulfosuccinic acid ester.

[0025] The sulfosuccinic acid ester is an ester of a polyoxyalkylene ether, which is an adduct obtained by adding one or more kinds of alkylene oxides having 2 to 4 carbon atoms to an aliphatic alcohol having 3 to 18 carbon atoms in a molar ratio of 1:1 to 1:15, and sulfosuccinic acid, and can be a monoester represented by the following general formula (1), a diester represented by the following general formula (2), or a mixture of these monoesters and diesters. In any case, the number of types of monoesters and diesters contained in the sulfosuccinic acid ester is not limited. R 1 , R 11 , and R12 is an aliphatic hydrocarbon group having 3 to 18 carbon atoms. AO is one or more types of oxyalkylene groups having 2 to 4 carbon atoms, and n and m are both between 1 and 15. When there are multiple types of oxyalkylene groups AO, the addition configuration may be block-like or random. The diester represented by general formula (2) has two groups derived from the polyoxyalkylene ether, but these two groups may be the same group or different groups. That is, R 11 and R 12 n and m may be the same group or different groups, and n and m may be the same group or different groups. [ka]

[0026] The alkali metal salt of the sulfosuccinate ester may be the sodium salt or potassium salt of the sulfosuccinate ester. The sulfosuccinate ester compound (A) preferably contains the alkali metal salt of the sulfosuccinate ester, and more preferably consists only of the alkali metal salt of the sulfosuccinate ester.

[0027] Sulfosuccinate esters can be obtained, for example, by the steps of obtaining the adduct described above and obtaining an ester of the adduct with sulfosuccinate. The step of obtaining the adduct can be carried out, for example, by mixing an aliphatic alcohol and an alkylene oxide in a predetermined molar ratio and then reacting them in the presence of a basic catalyst. The step of obtaining an ester of the adduct with sulfosuccinate can be carried out, for example, by mixing the adduct with sulfosuccinate in a predetermined molar ratio and then reacting them under an acidic catalyst. Alkali metal salts of sulfosuccinate esters can be obtained, for example, by neutralizing the sulfosuccinate ester obtained by the above method with an aqueous solution of a predetermined alkali metal hydroxide. Ammonium salts of sulfosuccinate esters can be obtained, for example, by neutralizing the sulfosuccinate ester obtained by the above method with aqueous ammonia.

[0028] (Nonionic surfactant) As the nonionic surfactant (B), a nonionic surfactant that can be contained in known treating agents for synthetic fibers can be used. However, the nonionic surfactant (B) preferably contains at least one of the secondary alcohol nonionic surfactant (B1) and the oxypropylene-based nonionic surfactant (B2) shown below, and more preferably contains both of them.

[0029] The secondary alcohol nonionic surfactant (B1) is an adduct obtained by adding ethylene oxide to a secondary alcohol having 4 to 18 carbon atoms in a molar ratio of 1:1 to 1:30. Non-limiting examples of the secondary alcohol nonionic surfactant (B1) are represented by the following general formula (3). R 2 and R 3 are hydrocarbon groups, and the total number of carbon atoms of R 2 and R 3 is 3 or more and 17 or less. p is 1 or more and 30 or less. [Chemical formula]

[0030] When the nonionic surfactant (B) contains the secondary alcohol nonionic surfactant (B1), it is advantageous in that the bundling property of the synthetic fiber treated with the treating agent according to the present embodiment tends to be high.

[0031] Oxypropylene-based nonionic surfactants (B2) are adducts obtained by adding an alkylene oxide to an alcohol, and are compounds that essentially contain an oxypropylene group as the oxyalkylene group. Specifically, oxypropylene-based nonionic surfactants (B2) are adducts obtained by adding propylene oxide to an alcohol having 4 to 18 carbon atoms in a molar ratio of 1:1 to 1:100, or by adding a mixture of two or more alkylene oxides having 2 to 4 carbon atoms, containing 1 mol% or more of propylene oxide, in a molar ratio of 1:1 to 1:100 to an alcohol having 4 to 18 carbon atoms. In the latter case, the amount of the portion derived from propylene oxide in the adduct is preferably 1 to 30 times the molar ratio of the alcohol having 4 to 18 carbon atoms. A non-limiting example of the former is represented by the following general formula (4), and a non-limiting example of the latter is represented by the following general formula (5). PO is an oxypropylene group, EO is an oxyethylene group, and BO is an oxybutylene group. q is between 1 and 100. The sum of r, s, and t is greater than 1 and less than or equal to 100, with r being 1 or greater, and s and t not being 0 at the same time. Preferably, r is 30 or less. In general formula (5), the oxyalkylene groups are shown in a block-like arrangement for convenience, but the arrangement of the oxyalkylene groups may be block-like or random. [ka]

[0032] Including an oxypropylene-based nonionic surfactant (B2) in the nonionic surfactant (B) is advantageous in that it tends to increase the bundling properties of synthetic fibers treated with the treatment agent according to this embodiment.

[0033] (Amino-modified silicone) The amino-modified silicone compound (C) can be an amino-modified silicone compound that may be included in known synthetic fiber treatment agents. The amino-modified silicone compound (C) has a kinematic viscosity at 25°C, for example, 100 mm². 2 / s or more 60000mm2 It may be less than / s. The kinematic viscosity of amino-modified silicone compound (C) can be measured with a Cannon-Fenske viscometer. Furthermore, the amino equivalent of amino-modified silicone compound (C) may be between 800 g / mol and 40,000 g / mol. The amino equivalent of amino-modified silicone compound (C) can be calculated from the total amine value (KOH-mg / g) measured by accurately weighing 1 g in a mixed solution of 60 mL of acetone and 20 mL of n-hexane, and then titrating with a perchloric acid solution of known concentration. However, the values ​​for kinematic viscosity and amino equivalent of amino-modified silicone compound (C) described herein are merely examples.

[0034] If the treatment agent according to this embodiment further contains an amino-modified silicone compound (C), it is advantageous in that the strength of the synthetic fiber treated with the treatment agent tends to increase.

[0035] (Other ingredients) The treatment agent according to this embodiment may contain components other than the sulfosuccinate compound (A), the nonionic surfactant (B), and the amino-modified silicone compound (C) (hereinafter referred to as "other components"). Examples of such other components include, but are not limited to, solvents, preservatives, antistatic agents, antioxidants, ultraviolet absorbers, defoamers, and surfactants.

[0036] (Content of each component) The content of each component in the treatment agent according to this embodiment is determined by its proportion of the non-volatile content. The non-volatile content of the treatment agent refers to the components that remain without volatilizing after the treatment agent is heated in a hot air dryer at 105°C for 2 hours.

[0037] In the treatment agent according to this embodiment, the proportion of sulfosuccinate ester compound (A) in the nonvolatile content is greater than 0% by mass and less than 10% by mass. The inventors have discovered that synthetic fibers treated with a treatment agent in which the proportion of sulfosuccinate ester compound (A) is within the above range are less likely to produce tar during firing, and have completed the present invention. The proportion of sulfosuccinate ester compound (A) is preferably 0.001% by mass or more, and more preferably 0.1% by mass or more. The proportion of sulfosuccinate ester compound (A) is preferably 5% by mass or less, and more preferably 2% by mass or less.

[0038] In the treatment agent according to this embodiment, it is preferable that, with the total proportion of sulfosuccinate ester compound (A), nonionic surfactant (B), and amino-modified silicone compound (C) in the nonvolatile content being 100% by mass, the proportion of sulfosuccinate ester compound (A) is 0.001% by mass or more and less than 10% by mass, the proportion of nonionic surfactant (B) is 8% by mass or more and 35% by mass or less, and the proportion of amino-modified silicone compound (C) is 65% by mass or more and 92% by mass or less. When the content of each component satisfies the above conditions, it is advantageous in that the strength of the synthetic fiber treated with the treatment agent tends to be higher.

[0039] [Method for manufacturing treatment agents for synthetic fibers] The treatment agent according to this embodiment can be obtained, for example, by dissolving a sulfosuccinate compound (A), a nonionic surfactant (B), and optionally added amino-modified silicone compound (C) and other components in a solvent. The solvent may be, for example, water. The apparatus, conditions, and methods for dissolving components such as the sulfosuccinate compound (A) in the solvent are arbitrary. As an example, the treatment agent according to this embodiment can be obtained by adding water over 5 hours while stirring pre-weighed components such as the sulfosuccinate compound (A) at a temperature of 10°C to 90°C to obtain a homogeneous aqueous solution.

[0040] [Synthetic Fibers] The synthetic fiber according to this embodiment is characterized in that the above-mentioned treatment agent is attached to the fiber material. The fiber material may be any fiber material, but for example, it is a carbon fiber precursor. In this case, carbon fibers can be produced by firing the synthetic fiber according to this embodiment. Furthermore, when carbon fibers are produced using a carbon fiber precursor to which the treatment agent according to this embodiment is attached, it becomes easier to suppress the tar generated during production, and the carbon fiber precursor and carbon fibers become easier to bundle during the process, thus improving the productivity of carbon fibers.

[0041] For applying the treatment agent to the fiber material, methods commonly used in this field for applying this type of treatment agent to fiber material can be applied. Specifically, immersion lubrication, spray lubrication, roller lubrication, and guide lubrication methods may be employed. When applying each method, the treatment agent may be appropriately diluted with a solvent such as water.

[0042] In the synthetic fibers according to this embodiment, the amount of treatment agent attached is not particularly limited. For example, it is preferable that the amount of treatment agent attached is 0.3% by mass or more and 3% by mass or less of the total amount of synthetic fibers to which the treatment agent is attached.

[0043] [Other Embodiments] With regard to other configurations, the embodiments disclosed herein are illustrative in all respects, and it should be understood that the scope of the present invention is not limited thereto. Those skilled in the art will readily understand that modifications can be made as appropriate without departing from the spirit of the invention. Therefore, other embodiments modified without departing from the spirit of the invention are naturally included within the scope of the present invention. [Examples]

[0044] The present invention will be further described below with reference to examples. However, the following examples are not limiting to the present invention.

[0045] [Preparation of treatment agents for synthetic fibers] The treatment agents for Examples 1 to 27 and Comparative Examples 1 to 6, shown in Tables 2 to 4 below, were obtained using the following method.

[0046] (1) Reagents (1-1) Sulfosuccinate compounds The sulfosuccinate ester compounds A-1 to A-18 and ra-1 used in the examples and comparative examples will be described in order. Of these, sulfosuccinate ester compounds A-1 to A-18 correspond to sulfosuccinate ester compound (A) according to the above embodiment. While examples of manufacturing methods are shown below for each compound, each manufacturing method is merely an example, and the results of the examples and comparative examples will not change even if the compound is manufactured using a method different from those exemplified below.

[0047] Sulfosuccinate ester compound A-1 is the sodium salt of an ester formed by adding ethylene oxide to tridecanol in a molar ratio of 1:3 and sulfosuccinate. Tridecanol and ethylene oxide were reacted in a molar ratio of 1:3 to obtain an adduct, and then this adduct was reacted with sulfosuccinate to obtain a sulfosuccinate ester. Subsequently, the sulfosuccinate ester was neutralized with an aqueous sodium hydroxide solution to obtain sulfosuccinate ester compound A-1.

[0048] Sulfosuccinate ester compounds A-2 to A-9 are compounds that differ from sulfosuccinate ester compound A-1 in their alcohol portion and the molar ratio of the alcohol portion to ethylene oxide. The alcohol portion and the molar ratio of the alcohol portion to ethylene oxide for each of these compounds are shown in Table 1. The manufacturing methods for each of these compounds are substantially the same as those for sulfosuccinate ester compound A-1, except for the type of alcohol used and the molar ratio of alcohol to ethylene oxide.

[0049] Sulfosuccinate ester compound A-10 is the sodium salt of an ester of sulfosuccinate between an adduct obtained by adding ethylene oxide and propylene oxide to octyl alcohol and sulfosuccinate. In sulfosuccinate ester compound A-10, the addition of ethylene oxide and propylene oxide is in a block-like manner, and the molar ratio of octyl alcohol, ethylene oxide, and propylene oxide is 1:2:8. Octyl alcohol and ethylene oxide were reacted in a molar ratio of 1:2, and then propylene oxide was added in a molar ratio of 8 times that of octyl alcohol to obtain an adduct. This adduct was then reacted with sulfosuccinate to obtain a sulfosuccinate ester. Subsequently, the sulfosuccinate ester was neutralized with an aqueous sodium hydroxide solution to obtain sulfosuccinate ester compound A-10.

[0050] Sulfosuccinate ester compound A-11 is the sodium salt of an ester of sulfosuccinate between an adduct obtained by adding ethylene oxide and propylene oxide to hexadecanol and sulfosuccinate. In sulfosuccinate ester compound A-11, the addition of ethylene oxide and propylene oxide is in a block-like manner, and the molar ratio of hexadecanol, ethylene oxide, and propylene oxide is 1:8:2. After reacting hexadecanol and ethylene oxide in a molar ratio of 1:8, propylene oxide was subsequently added in a molar ratio of 2 to hexadecanol and reacted to obtain an adduct, which was then reacted with sulfosuccinate to obtain a sulfosuccinate ester. Subsequently, the sulfosuccinate ester was neutralized with an aqueous sodium hydroxide solution to obtain sulfosuccinate ester compound A-11.

[0051] Sulfosuccinate ester compound A-12 is the potassium salt of an ester of sulfosuccinic acid with an adduct formed by the addition of ethylene oxide and propylene oxide to octadecanol. The addition of ethylene oxide and propylene oxide in sulfosuccinate ester compound A-12 is random, and the molar ratio of octadecanol, ethylene oxide, and propylene oxide is 1:10:10. An adduct was obtained by reacting hexadecanol, ethylene oxide, and propylene oxide in a molar ratio of 1:10:10, and this adduct was reacted with sulfosuccinic acid to obtain a sulfosuccinate ester. Subsequently, the sulfosuccinate ester was neutralized with an aqueous potassium hydroxide solution to obtain sulfosuccinate ester compound A-12.

[0052] Sulfosuccinate ester compound A-13 is an ammonium salt of an ester of sulfosuccinate and an adduct obtained by adding ethylene oxide to dodecanol in a molar ratio of 1:3. Sulfosuccinate ester compound A-13 was obtained by neutralizing the sulfosuccinate ester obtained by the same method as for producing sulfosuccinate ester compound A-1 with aqueous ammonia.

[0053] Sulfosuccinate ester compound A-14 is an ester of sulfosuccinate and an adduct obtained by adding ethylene oxide to dodecanol in a molar ratio of 1:3. This ester was obtained as a precursor ester of sulfosuccinate ester compound A-1, and the method of production is as described in the section on sulfosuccinate ester compound A-1.

[0054] Sulfosuccinate ester compounds A-15 to A-18 are compounds that differ from sulfosuccinate ester compound A-14 in their alcohol portion and the molar ratio of the alcohol portion to ethylene oxide. The alcohol portion and the molar ratio of the alcohol portion to ethylene oxide for each of these compounds are shown in Table 1. The manufacturing methods for each of these compounds are substantially the same as those for sulfosuccinate ester compound A-14 (the manufacturing method for the precursor ester of sulfosuccinate ester compound A-1), except for the type of alcohol used and the molar ratio of the alcohol to ethylene oxide.

[0055] Table 1 shows the alcohol portion, alkylene oxide portion, molar ratio of the alcohol portion to the alkylene oxide portion, and distinction between esters, alkali metal salts, and ammonium salts for sulfosuccinate ester compounds A-1 to A-18. Note that all sulfosuccinate ester compounds A-1 to A-18 are mixtures of monoesters and diesters.

[0056] Table 1: Sulfosuccinate compounds [Table 1]

[0057] Furthermore, as an example that does not fall under the sulfosuccinate ester compound (A) of the above embodiment, sulfosuccinate ester compound ra-1 was used. Sulfosuccinate ester compound ra-1 is sodium dioctyl sulfosuccinate, which is commercially available as a reagent.

[0058] (1-2) Nonionic surfactants The nonionic surfactants B1-1 to B1-11, B2-1 to B2-7, and B-1 to B-18 used in the examples and comparative examples will be described in order. Of these, nonionic surfactants B1-1 to B1-11 correspond to the secondary alcohol nonionic surfactant (B1) according to the above embodiment, and nonionic surfactants B2-1 to B2-7 correspond to the oxypropylene-based nonionic surfactant (B2) according to the above embodiment. While examples of manufacturing methods are shown below for each compound, each manufacturing method is merely an example, and the results of the examples and comparative examples will not change even if the compound is manufactured using a method different from those exemplified below.

[0059] Nonionic surfactant B1-1 is an adduct obtained by adding ethylene oxide to 2-dodecanol in a molar ratio of 1:5. Nonionic surfactant B1-1 was obtained by reacting 2-dodecanol and ethylene oxide in a molar ratio of 1:5.

[0060] Nonionic surfactant B1-2 is an adduct obtained by adding ethylene oxide to 2-dodecanol in a molar ratio of 1:10. Nonionic surfactant B1-2 was obtained by reacting 2-dodecanol and ethylene oxide in a molar ratio of 1:10.

[0061] Nonionic surfactant B1-3 is an adduct obtained by adding ethylene oxide to 2-dodecanol in a molar ratio of 1:15. Nonionic surfactant B1-3 was obtained by reacting 2-dodecanol and ethylene oxide in a molar ratio of 1:15.

[0062] Nonionic surfactant B1-4 is an adduct obtained by adding ethylene oxide to 2-tridecanol in a molar ratio of 1:5. Nonionic surfactant B1-4 was obtained by reacting 2-tridecanol and ethylene oxide in a molar ratio of 1:5.

[0063] Nonionic surfactant B1-5 is an adduct obtained by adding ethylene oxide to 2-tetradecanol in a molar ratio of 1:5. Nonionic surfactant B1-5 was obtained by reacting 2-tetradecanol and ethylene oxide in a molar ratio of 1:5.

[0064] The nonionic surfactant B1-6 is an adduct obtained by adding ethylene oxide to 2-dodecanol in a molar ratio of 1:1. The nonionic surfactant B1-6 was obtained by reacting 2-dodecanol and ethylene oxide in a molar ratio of 1:1.

[0065] The nonionic surfactant B1-7 is an adduct obtained by adding ethylene oxide to 2-dodecanol in a molar ratio of 1:13. The nonionic surfactant B1-7 was obtained by reacting 2-dodecanol with ethylene oxide in a molar ratio of 1:13.

[0066] Nonionic surfactant B1-8 is an adduct obtained by adding ethylene oxide to 2-dodecanol in a molar ratio of 1:30. Nonionic surfactant B1-8 was obtained by reacting 2-dodecanol and ethylene oxide in a molar ratio of 1:30.

[0067] The nonionic surfactant B1-9 is an adduct obtained by adding ethylene oxide to 2-octanol in a molar ratio of 1:4. The nonionic surfactant B1-9 was obtained by reacting 2-octanol and ethylene oxide in a molar ratio of 1:4.

[0068] The nonionic surfactant B1-10 is an adduct obtained by adding ethylene oxide to 2-hexadecanol in a molar ratio of 1:8. The nonionic surfactant B1-10 was obtained by reacting 2-hexadecanol and ethylene oxide in a molar ratio of 1:8.

[0069] Nonionic surfactant B1-11 is a compound obtained by adding ethylene oxide to 2-octadecanol in a molar ratio of 1:10. Nonionic surfactant B1-11 was obtained by reacting 2-octadecanol with ethylene oxide in a molar ratio of 1:10.

[0070] Nonionic surfactant B2-1 is an adduct obtained by adding ethylene oxide and propylene oxide to 2-dodecanol. The addition of ethylene oxide and propylene oxide is in a block-like manner, and the molar ratio of 2-dodecanol, ethylene oxide, and propylene oxide is 1:40:18. Nonionic surfactant B2-1 was obtained by reacting 2-dodecanol with ethylene oxide in a molar ratio of 1:40, followed by reacting 2-dodecanol with propylene oxide in a molar ratio of 18:18.

[0071] Nonionic surfactant B2-2 is an adduct formed by the addition of ethylene oxide and propylene oxide to 2-dodecanol. The addition of ethylene oxide and propylene oxide is random, and the molar ratio of 2-dodecanol, ethylene oxide, and propylene oxide is 1:40:18. Nonionic surfactant B2-2 was obtained by reacting 2-dodecanol, ethylene oxide, and propylene oxide in a molar ratio of 1:40:18.

[0072] Nonionic surfactant B2-3 is an adduct formed by the addition of ethylene oxide and propylene oxide to 2-dodecanol. The addition of ethylene oxide and propylene oxide is random, and the molar ratio of 2-dodecanol, ethylene oxide, and propylene oxide is 1:3:1. Nonionic surfactant B2-3 was obtained by reacting 2-dodecanol, ethylene oxide, and propylene oxide in a molar ratio of 1:3:1.

[0073] Nonionic surfactant B2-4 is an adduct obtained by adding ethylene oxide and propylene oxide to 1-dodecanol. The addition of ethylene oxide and propylene oxide is in a block-like manner, and the molar ratio of 1-dodecanol, ethylene oxide, and propylene oxide is 1:2:6. Nonionic surfactant B2-4 was obtained by reacting 1-dodecanol with ethylene oxide in a molar ratio of 1:2, followed by reacting 1-dodecanol with propylene oxide in a molar ratio of 6:1.

[0074] Nonionic surfactant B2-5 is an adduct obtained by adding ethylene oxide and propylene oxide to 1-dodecanol. The addition of ethylene oxide and propylene oxide is in a block-like manner, and the molar ratio of 1-dodecanol, ethylene oxide, and propylene oxide is 1:8:6. Nonionic surfactant B2-5 was obtained by reacting 1-dodecanol with ethylene oxide in a molar ratio of 1:8, followed by reacting 1-dodecanol with propylene oxide in a molar ratio of 6:1.

[0075] Nonionic surfactant B2-6 is an adduct obtained by adding ethylene oxide and propylene oxide to 1-dodecanol. The addition of ethylene oxide and propylene oxide is in a block-like manner, and the molar ratio of 1-dodecanol, ethylene oxide, and propylene oxide is 1:6:2. Nonionic surfactant B2-6 was obtained by reacting 1-dodecanol with ethylene oxide in a molar ratio of 1:6, followed by reacting 1-dodecanol with propylene oxide in a molar ratio of twice that of 1-dodecanol.

[0076] Nonionic surfactant B2-7 is an adduct formed by the addition of ethylene oxide and propylene oxide to 1-dodecanol. The addition of ethylene oxide and propylene oxide is random, and the molar ratio of 1-dodecanol, ethylene oxide, and propylene oxide is 1:5:5. Nonionic surfactant B2-7 was obtained by reacting 1-dodecanol, ethylene oxide, and propylene oxide in a molar ratio of 1:5:5.

[0077] Nonionic surfactant B-1 is an adduct obtained by adding ethylene oxide to 1-dodecanol in a molar ratio of 1:5. Nonionic surfactant B-1 was obtained by reacting 1-dodecanol and ethylene oxide in a molar ratio of 1:5.

[0078] Nonionic surfactant B-2 is an adduct obtained by adding ethylene oxide to 1-dodecanol in a molar ratio of 1:10. Nonionic surfactant B-2 was obtained by reacting 1-dodecanol and ethylene oxide in a molar ratio of 1:10.

[0079] Nonionic surfactant B-3 is an adduct obtained by adding ethylene oxide to 1-dodecanol in a molar ratio of 1:15. Nonionic surfactant B-3 was obtained by reacting 1-dodecanol and ethylene oxide in a molar ratio of 1:15.

[0080] Nonionic surfactant B-4 is an adduct obtained by adding ethylene oxide to 1-tridecanol in a molar ratio of 1:5. Nonionic surfactant B-4 was obtained by reacting 1-tridecanol with ethylene oxide in a molar ratio of 1:5.

[0081] Nonionic surfactant B-5 is an adduct obtained by adding ethylene oxide to 1-tetradecanol in a molar ratio of 1:5. Nonionic surfactant B-5 was obtained by reacting 1-tetradecanol and ethylene oxide in a molar ratio of 1:5.

[0082] Nonionic surfactant B-6 is an adduct obtained by adding ethylene oxide to 1-dodecanol in a molar ratio of 1:1. Nonionic surfactant B-6 was obtained by reacting 1-dodecanol and ethylene oxide in a molar ratio of 1:1.

[0083] Nonionic surfactant B-7 is an adduct obtained by adding ethylene oxide to 1-dodecanol in a molar ratio of 1:13. Nonionic surfactant B-7 was obtained by reacting 1-dodecanol and ethylene oxide in a molar ratio of 1:13.

[0084] Nonionic surfactant B-8 is an adduct obtained by adding ethylene oxide to 1-dodecanol in a molar ratio of 1:30. Nonionic surfactant B-8 was obtained by reacting 1-dodecanol and ethylene oxide in a molar ratio of 1:30.

[0085] Nonionic surfactant B-9 is an adduct obtained by adding ethylene oxide to 1-octanol in a molar ratio of 1:4. Nonionic surfactant B-9 was obtained by reacting 1-octanol and ethylene oxide in a molar ratio of 1:4.

[0086] Nonionic surfactant B-10 is an adduct obtained by adding ethylene oxide to 1-hexadecanol in a molar ratio of 1:8. Nonionic surfactant B-10 was obtained by reacting 1-hexadecanol and ethylene oxide in a molar ratio of 1:8.

[0087] Nonionic surfactant B-11 is an adduct obtained by adding ethylene oxide to 1-octadecanol in a molar ratio of 1:10. Nonionic surfactant B-11 was obtained by reacting 1-octadecanol and ethylene oxide in a molar ratio of 1:10.

[0088] Nonionic surfactant B-12 is an adduct obtained by adding ethylene oxide to oleic acid in a molar ratio of 1:5 moles. Nonionic surfactant B-12 was obtained by reacting oleic acid and ethylene oxide in a molar ratio of 1:5.

[0089] Nonionic surfactant B-13 is an adduct obtained by adding ethylene oxide to linoleic acid in a molar ratio of 1:1. Nonionic surfactant B-13 was obtained by reacting linoleic acid and ethylene oxide in a molar ratio of 1:1.

[0090] Nonionic surfactant B-14 is an adduct obtained by adding ethylene oxide to linoleic acid in a molar ratio of 1:15. Nonionic surfactant B-14 was obtained by reacting linoleic acid and ethylene oxide in a molar ratio of 1:15.

[0091] Nonionic surfactant B-15 is an adduct obtained by adding ethylene oxide to linolenic acid in a molar ratio of 1:1. Nonionic surfactant B-15 was obtained by reacting linolenic acid and ethylene oxide in a molar ratio of 1:1.

[0092] Nonionic surfactant B-16 is an adduct obtained by adding ethylene oxide to linolenic acid in a molar ratio of 1:15. Nonionic surfactant B-16 was obtained by reacting linolenic acid and ethylene oxide in a molar ratio of 1:15.

[0093] Nonionic surfactant B-17 is an adduct obtained by adding ethylene oxide to lauryl alcohol in a molar ratio of 1:10. Nonionic surfactant B-17 was obtained by reacting lauryl alcohol and ethylene oxide in a molar ratio of 1:10.

[0094] Nonionic surfactant B-18 is an adduct obtained by adding ethylene oxide to dodecylacetic acid in a molar ratio of 1:10. Nonionic surfactant B-18 was obtained by reacting dodecylacetic acid and ethylene oxide in a molar ratio of 1:10.

[0095] (1-3) Silicone compounds The silicone compounds C-1 to C-4 and rc-1 and rc-2 used in the examples and comparative examples will be described in order. Of these, silicone compounds C-1 to C-4 correspond to the amino-modified silicone compound (C) according to the above embodiment. The kinematic viscosity of each silicone compound is the value at 25°C.

[0096] Silicone compound C-1 has a kinematic viscosity of 1200 mmHg. 2 It is an amino-modified silicone with a viscosity of / s and an amino equivalent of 4000 g / mol. Silicone compound C-2 has a kinematic viscosity of 500 mm². 2 It is an amino-modified silicone with a viscosity of / s and an amino equivalent of 1600 g / mol. Silicone compound C-3 has a kinematic viscosity of 40000 mm². 2 It is an amino-modified silicone with a viscosity of / s and an amino equivalent of 20,000 g / mol. Silicone compound C-4 has a kinematic viscosity of 250 mm². 2 It is an amino-modified silicone with a density of / s and an amino equivalent of 7600 g / mol.

[0097] Silicone compound rc-1 has a kinematic viscosity of 500 mmHg. 2 It is a polyether-modified silicone with a molecular weight of / s. In silicone compound rc-1, the mass ratio of the silicone chain to the polyether chain is 1:1, and the polyether chain contains oxyethylene groups and oxypropylene groups in a molar ratio of 1:1.

[0098] The silicone compound rc-2 has a kinematic viscosity of 100 mmHg. 2 It is dimethyl silicone with a temperature of / s.

[0099] (1-4) Other ingredients The following other ingredients were used: D-1: Permakem® OM-17 (manufactured by Permakem Asia Co., Ltd.) D-2: Permakem® OM-17 (manufactured by Permakem Asia Co., Ltd.) D-3: ACTITUDE LA (manufactured by So Japan Co., Ltd.) D-4: ACTITUDE LA2011 (manufactured by So Japan Co., Ltd.) D-5: PROXEL GXL (manufactured by Lonza Japan Co., Ltd.)

[0100] (2) Preparation of treatment agent (Preparation of Example 1) Each component was weighed in the mass ratio shown below. Sulfosuccinate ester compound A-1 1% by mass Nonionic surfactant B1-1 3% by mass Nonionic surfactant B2-3 5% by mass Nonionic surfactant B2-7 3% by mass Silicone compound C-1 77.9% by mass Silicone compound rc-1 10% by mass After weighing each component and placing it in a beaker and mixing thoroughly, deionized water was gradually added while stirring to achieve a non-volatile content concentration of 30% by mass, thus preparing the treatment agent for Example 1.

[0101] (Preparation of other examples and comparative examples) Except for changing the types and proportions of reagents to be mixed, the treatment agents for each example were prepared in the same manner as in Example 1. The preparation conditions for all examples, including Example 1, are shown in Tables 2 to 4 below.

[0102] [Evaluation of treatment agents for synthetic fibers] (1) Production of carbon fiber precursors and carbon fibers Carbon fiber precursors and carbon fibers were produced using the treatment agents from each of the examples and comparative examples. The treatment agents from each of the examples and comparative examples were evaluated based on the condition of each part of the manufacturing equipment during production, as well as the physical properties of the obtained carbon fiber precursors and carbon fibers.

[0103] (First step) A copolymer with an intrinsic viscosity of 1.80, consisting 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 stock with a polymer concentration of 21.0% by mass and a viscosity of 500 poise at 60°C. The spinning stock was extruded at a draft ratio of 0.8 through a spinneret with a pore size (inner diameter) of 0.075 mm and 12,000 holes into a coagulation bath of a 70% by mass aqueous solution of DMAC maintained at a spinning bath temperature of 35°C. The coagulated yarn was desolvated and simultaneously stretched five times in a water rinsing tank to create water-swollen acrylic fiber strands.

[0104] (Second process) The prepared acrylic fiber strands were lubricated by immersion using a 3% ion-exchange aqueous solution of the treatment agent from each example and comparative example, so that the amount of treatment agent adhering to them was 1% by mass (excluding solvent). Subsequently, the acrylic fiber strands with the treatment agent adhering to them were dried and densified using heated rollers at 150°C, and then stretched 1.7 times between heated rollers at 170°C before being wound onto a thread tube to obtain a carbon fiber precursor.

[0105] (Third step) In each of the examples and comparative examples, yarn was unwound from the carbon fiber precursors, subjected to flame-retardant treatment for 1 hour in an air atmosphere in a flame-retardant furnace with a temperature gradient of 230 to 270°C, and then wound onto a thread tube to obtain flame-retardant yarn. Furthermore, yarn was unwound from this flame-retardant yarn, calcined in a nitrogen atmosphere in a carbonization furnace with a temperature gradient of 300 to 1300°C to convert it into carbon fibers, and then wound onto a thread tube to obtain carbon fibers.

[0106] (2) Tar cleaning properties In the third step described above, tar buildup occurs at the outlet of the flame-retardant furnace. It is necessary to remove the tar before the amount of buildup reaches a level that interferes with the operation of the flame-retardant furnace (specifically, before it causes yarn breakage). In this evaluation, continuous operation was started using a flame-retardant furnace without tar buildup, and the following four levels were evaluated based on the period until yarn breakage occurred. A: No yarn breakage occurred for more than three weeks after the start of operations. B: Yarn breakage occurred between two and three weeks after the start of operations. C: Yarn breakage occurred between one and two weeks after the start of operations. D: Yarn breakage occurred less than one week after the start of operations.

[0107] (3) Convergence In the second step described above, the convergence state of the acrylic fiber strands coated with the treatment agent as they passed through the heated roller was visually observed and evaluated on the following four levels. A: The strands are sufficiently bundled and do not wrap around the heating rollers. B: There may be very slight strand unraveling, but no breakage occurs, and there are no operational problems. C: Strands may unravel, but no breakage occurs, and no operational problems arise. D: Frequent strand unraveling occurs, leading to yarn breakage and disrupting operations.

[0108] (4) Strength The tensile strength of the obtained carbon fibers was measured according to JIS R 7606:2000. Based on the measured tensile strength, the fibers were classified into the following four levels. A: The tensile strength is 4.5 GPa or higher. B: The tensile strength is 4.0 GPa or higher and less than 4.5 GPa. C: Tensile strength is 3.5 GPa or more and less than 4.0 GPa. D: The tensile strength is less than 3.5 GPa.

[0109] (5) Antistatic properties In the second step described above, the electricity generated when the acrylic fiber strands coated with the treatment agent passed through the heating roller was measured using a current collector type potential meter. Based on the measured values, the following two levels were classified. A: The generated electricity is 0.5kV or less. D: The generated electricity is greater than 0.5kV.

[0110] 〔result〕 The composition and evaluation results of each treatment agent for the examples and comparative examples are shown in Tables 2 to 4. In each table, sulfosuccinate compounds are abbreviated as "Component A," nonionic surfactants as "Component B," and silicone compounds as "Component C."

[0111] Table 2: Examples [Table 2]

[0112] Table 3: Examples [Table 3]

[0113] Table 4: Comparative Examples [Table 4] [Industrial applicability]

[0114] This invention can be used in the production of synthetic fibers such as carbon fiber precursors.

Claims

1. A sulfosuccinate ester compound (A) is at least one compound selected from the group consisting of a polyoxyalkylene ether, which is an adduct obtained by adding one or more types of alkylene oxides having 2 to 4 carbon atoms to an aliphatic alcohol having 3 to 18 carbon atoms in a molar ratio of 1:1 to 1:15, and sulfosuccinate ester, an alkali metal salt of the sulfosuccinate ester, and an ammonium salt of the sulfosuccinate ester, A nonionic surfactant (B) is included, A treatment agent for synthetic fibers, characterized in that the proportion of the sulfosuccinate ester compound (A) in the nonvolatile content is greater than 0% by mass and less than 10% by mass.

2. The synthetic fiber treatment agent according to claim 1, wherein the nonionic surfactant (B) comprises a secondary alcohol nonionic surfactant (B1), which is an adduct obtained by adding ethylene oxide to a secondary alcohol having 4 to 18 carbon atoms in a molar ratio of 1:1 to 1:

30.

3. The synthetic fiber treatment agent according to claim 1, wherein the nonionic surfactant (B) is an oxypropylene-based nonionic surfactant (B2) which is an adduct obtained by adding propylene oxide, or a mixture of two or more alkylene oxides having 2 to 4 carbon atoms and containing 1 mol% or more of propylene oxide, to an alcohol having 4 to 18 carbon atoms in a molar ratio of 1:1 to 1:

100.

4. The synthetic fiber treatment agent according to claim 1, further comprising an amino-modified silicone compound (C).

5. The sum of the proportions of the sulfosuccinate ester compound (A), the nonionic surfactant (B), and the amino-modified silicone compound (C) in the nonvolatile content is set to 100% by mass. The proportion of the sulfosuccinate ester compound (A) is 0.001% by mass or more and less than 10% by mass, The proportion of the nonionic surfactant (B) is 8% by mass or more and 35% by mass or less, The synthetic fiber treatment agent according to claim 4, wherein the proportion of the amino-modified silicone compound (C) is 65% by mass or more and 92% by mass or less.

6. A synthetic fiber characterized in that the synthetic fiber treatment agent described in any one of claims 1 to 5 is attached to the fiber material.

7. The synthetic fiber according to claim 6, wherein the fibrous material is a carbon fiber precursor.

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