Treatment Agent for Synthetic Fibers and Synthetic Fibers

Abstract

Suppress the generation of tar and improve the bundling property of the resulting synthetic fiber as compared with the prior art. 【Solution means】A sulfosuccinic acid ester which is an ester of a polyoxyalkylene ether which is an adduct obtained by adding one or more 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, an alkali metal salt of the sulfosuccinic acid ester, and an ammonium salt of the sulfosuccinic acid ester, a sulfosuccinic acid ester compound (A) which is at least one compound selected from the group consisting of, and a nonionic surfactant (B), wherein the proportion of the sulfosuccinic acid ester compound (A) in the nonvolatile matter exceeds 0% by mass and is less than 10% by mass.

Description

Technical Field

[0001] The present invention relates to a treatment agent for synthetic fibers and synthetic fibers.

Background Art

[0002] As a method for producing carbon fibers, a method of spinning a fibrous material and then firing the material is widely used, and this fibrous material is called a carbon fiber precursor. As the carbon fiber precursor, a material in which a treatment agent for carbon fiber precursor adheres to the surface of a fiber material such as a polymer may be used. Such a treatment agent is used for the purpose of improving the handleability of the carbon fiber precursor in various processes when producing carbon fibers. As in this example, in the handling of synthetic fibers, various treatment agents for synthetic fibers that can improve the handleability of synthetic fibers may be used.

[0003] For example, Japanese Patent Application Laid-Open 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, it is possible to suppress static electricity and gumming generated in the production process of acrylic fibers for carbon fiber production.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] In the invention described in Patent Document 1, although suppressing tar generated in the production process of acrylic fibers for carbon fiber production is also considered, the tar suppressing effect is not sufficient. In addition, there is still room for improvement in the bundling property of the obtained acrylic fibers.

[0006] Therefore, there is a desire to provide a treating agent for synthetic fibers that can suppress the generation of tar as compared with the prior art and can improve the bundling property of the obtained synthetic fibers, and to realize synthetic fibers treated with the treating agent for synthetic fibers.

Means for Solving the Problems

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

[0008] According to this configuration, the generation of tar can be suppressed as compared with the prior art, and the bundling property of the obtained synthetic fibers can be improved.

[0009] As one aspect, the treating agent for synthetic fibers according to the present invention preferably includes 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 as the nonionic surfactant (B).

[0010] According to this configuration, the bundling property of the obtained synthetic fibers is particularly likely to be high.

[0011] In one aspect, the treatment agent for synthetic fibers 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 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, as the nonionic surfactant (B).

[0012] According to this configuration, particularly high effects are easily obtained in both suppressing tar and improving the bundling property.

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

[0014] According to this configuration, the strength of the obtained synthetic fibers tends to be high.

[0015] In one aspect, for the treatment agent for synthetic fibers according to the present invention, with the total proportion of the sulfosuccinic acid ester compound (A), the nonionic surfactant (B), and the amino-modified silicone compound (C) in the nonvolatile content being 100% by mass, the proportion of the sulfosuccinic acid 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, which is preferable.

[0016] According to this configuration, the strength of the obtained synthetic fibers particularly tends to be high.

[0017] The synthetic fibers according to the present invention are characterized in that the above treatment agent for synthetic fibers adheres to the fiber material.

[0018] According to this configuration, the generation of tar can be suppressed compared to the prior art, and the bundling property of the obtained synthetic fibers can be improved.

[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 clearer from the following description of exemplary and non-limiting embodiments.

Embodiments for Carrying Out the Invention

[0022] Hereinafter, embodiments of a 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 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 、およびR12 is an aliphatic hydrocarbon group having 3 to 18 carbon atoms. AO is one or more kinds of oxyalkylene groups having 2 to 4 carbon atoms, and n and m are both 1 to 15. When there are multiple kinds of oxyalkylene groups AO, the addition mode may be block-like or random. The diester represented by the general formula (2) has two groups derived from polyoxyalkylene ether, and these two groups may be the same group or different groups. That is, R 11 and R 12 may be the same group or different groups, and n and m may be the same or different.

Chemical formula

[0026] The alkali metal salts of sulfosuccinic acid esters can be sodium salts, potassium salts, etc. of sulfosuccinic acid esters. The sulfosuccinic acid ester compound (A) preferably contains an alkali metal salt of sulfosuccinic acid ester, and more preferably consists only of an alkali metal salt of sulfosuccinic acid ester.

[0027] The sulfosuccinic acid ester can be obtained, for example, through the steps of obtaining the above adduct and obtaining an ester of the adduct and sulfosuccinic acid. 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 in the presence of a basic catalyst. The step of obtaining an ester of the adduct and sulfosuccinic acid can be carried out, for example, by mixing the adduct and sulfosuccinic acid in a predetermined molar ratio and then reacting under an acidic catalyst. The alkali metal salts of sulfosuccinic acid esters can be obtained, for example, by neutralizing the sulfosuccinic acid esters obtained by the above method with an aqueous solution of a hydroxide of a predetermined alkali metal. The ammonium salts of sulfosuccinic acid esters can be obtained, for example, by neutralizing the sulfosuccinic acid esters obtained by the above method with aqueous ammonia.

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

[0029] The secondary alcohol nonionic surfactant (B1) is an adduct in which ethylene oxide is added 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] The oxypropylene-based nonionic surfactant (B2) is an adduct obtained by adding an alkylene oxide to an alcohol, and is a compound that essentially contains an oxypropylene group as an oxyalkylene group. Specifically, the oxypropylene-based nonionic surfactant (B2) is an adduct 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 a mixture of two or more alkylene oxides having 2 to 4 carbon atoms containing 1 mol% or more of propylene oxide with respect to an alcohol having 4 to 18 carbon atoms, and the adduct is added in a molar ratio of 1:1 to 1:100. 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 with respect to the alcohol having 4 to 18 carbon atoms. The former non-limiting example is represented by the following general formula (4), and the latter non-limiting example 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 1 or more and 100 or less. r, s, and t have a total of more than 1 and 100 or less, r is 1 or more, and s and t are not 0 at the same time. r is preferably 30 or less. In the general formula (5), for the sake of convenience, a mode in which each oxyalkylene group is added in a block form is shown, but the addition mode of the oxyalkylene group may be block or random. [Chemical formula]

[0032] When the nonionic surfactant (B) contains the oxypropylene-based nonionic surfactant (B2), it is advantageous in that the bundling property of the synthetic fiber treated with the treatment agent according to the present embodiment tends to be high.

[0033] (Amino-modified silicone) As the amino-modified silicone compound (C), a known amino-modified silicone compound that can be contained in a treatment agent for synthetic fibers can be used. The amino-modified silicone compound (C) has a kinematic viscosity at 25°C of, for example, 100 mm 2 / s or more and 60,000 mm2 It may be as follows. The kinematic viscosity of the amino-modified silicone compound (C) can be measured with a Cannon-Fenske viscometer. Also, the amino-modified silicone compound (C) may have an amino equivalent of 800 g / mol or more and 40,000 g / mol or less. The amino equivalent of the amino-modified silicone compound (C) can be calculated from the value (KOH-mg / g) of the total amine value measured by titrating 1 g accurately weighed against a mixed solution of 60 mL of acetone and 20 mL of normal hexane with a perchloric acid solution of known concentration. However, the numerical values of the kinematic viscosity and amino equivalent of the amino-modified silicone compound (C) described here are merely examples.

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

[0035] (Other components) The treatment agent according to this embodiment may contain components other than the sulfosuccinic acid ester 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 specified by the ratio in the nonvolatile matter. The nonvolatile matter of the treatment agent refers to the components that remain without volatilizing after heating the treatment agent in a hot air dryer at 105°C for 2 hours.

[0037] In the treatment agent according to this embodiment, the proportion of the sulfosuccinic acid ester compound (A) in the non-volatile matter exceeds 0% by mass and is less than 10% by mass. The inventors of the present invention discovered that synthetic fibers treated with a treatment agent in which the proportion of the sulfosuccinic acid ester compound (A) is within the above range are less likely to generate tar during firing, and thus completed the present invention. The proportion of the sulfosuccinic acid ester compound (A) is preferably 0.001% by mass or more, more preferably 0.1% by mass or more. The proportion of the sulfosuccinic acid ester compound (A) is preferably 5% by mass or less, more preferably 2% by mass or less.

[0038] In the treatment agent according to this embodiment, with the total proportion of the sulfosuccinic acid ester compound (A), nonionic surfactant (B), and amino-modified silicone compound (C) in the non-volatile matter being 100% by mass, the proportion of the sulfosuccinic acid 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. This is preferable. 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 is likely to be high.

[0039] 〔Method for producing treatment agent for synthetic fiber〕 The treatment agent according to this embodiment can be obtained, for example, by dissolving the sulfosuccinic acid ester compound (A) and nonionic surfactant (B), as well as optionally added amino-modified silicone compound (C) and other components, in a solvent. The solvent can be, for example, water. The apparatus, conditions, method, etc. for dissolving components such as the sulfosuccinic acid ester compound (A) in the solvent are arbitrary. As an example, at a temperature of 10°C or higher and 90°C or lower, while stirring the components such as the previously weighed sulfosuccinic acid ester compound (A), water is added over 5 hours to obtain a uniform aqueous solution, and the treatment agent according to this embodiment can be obtained.

[0040] 〔Synthetic fiber〕 The synthetic fiber according to this embodiment is characterized in that the above-mentioned treatment agent is adhered to the fiber material. The fiber material may be any fiber material, for example, a carbon fiber precursor. In this case, carbon fibers can be produced by firing the synthetic fiber according to this embodiment. Further, when carbon fibers are produced using a carbon fiber precursor to which the treatment agent according to this embodiment is adhered, it becomes easy to suppress tar generated during production, and the carbon fiber precursor and carbon fibers during the process are likely to converge, so the productivity of carbon fibers is likely to be improved.

[0041] As a method for adhering the treatment agent to the fiber material, a method usually used in the art for adhering this type of 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 applying each method, the treatment agent can be appropriately diluted with a solvent such as water.

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

[0043] 〔Other Embodiments〕 Regarding other configurations as well, it should be understood that the embodiments disclosed in this specification are illustrative in all respects, and the scope of the present invention is not limited thereby. Those skilled in the art will easily understand that appropriate modifications can be made without departing from the spirit of the present invention. Therefore, other embodiments modified without departing from the spirit of the present invention are naturally included in the scope of the present invention.

Examples

[0044] Hereinafter, the present invention will be further described with reference to examples. However, the following examples do not limit the present invention.

[0045] 〔Preparation of Treatment Agent for Synthetic Fiber〕 The treating agents of Examples 1 to 27 and Comparative Examples 1 to 6 shown in Tables 2 to 4 below were obtained by the following method.

[0046] (1) Reagents (1-1) Sulfosuccinic acid ester compounds The sulfosuccinic acid ester compounds A-1 to A-18 and ra-1 used in the examples and comparative examples will be described in order. Among these, the sulfosuccinic acid ester compounds A-1 to A-18 correspond to the sulfosuccinic acid ester compound (A) according to the above embodiment. In the following, examples of the production method of each compound are shown, but each production method is only an example, and even if the compound is produced by a method different from the methods exemplified below, the results of the examples and comparative examples will not change.

[0047] The sulfosuccinic acid ester compound A-1 is the sodium salt of the ester of an adduct obtained by adding ethylene oxide to tridecanol at a molar ratio of 1:3 and sulfosuccinic acid. After reacting tridecanol and ethylene oxide at a molar ratio of 1:3 to obtain an adduct, the adduct and sulfosuccinic acid were reacted to obtain a sulfosuccinic acid ester. Subsequently, the sulfosuccinic acid ester was neutralized with an aqueous sodium hydroxide solution to obtain the sulfosuccinic acid ester compound A-1.

[0048] The sulfosuccinic acid ester compounds A-2 to A-9 are compounds that differ in the alcohol moiety and the molar ratio of the alcohol moiety to ethylene oxide, respectively, in comparison with the sulfosuccinic acid ester compound A-1. Table 1 shows the alcohol moiety of each of these compounds and the molar ratio of the alcohol moiety to ethylene oxide. The production methods of each of these compounds are substantially the same as the production method of the sulfosuccinic acid ester compound A-1, except for the type of alcohol used and the molar ratio of the alcohol to ethylene oxide.

[0049] The sulfosuccinic acid ester compound A-10 is the sodium salt of the ester of sulfosuccinic acid and an adduct obtained by adding ethylene oxide and propylene oxide to octyl alcohol. The addition mode of ethylene oxide and propylene oxide in the sulfosuccinic acid ester compound A-10 is in a block form, and the molar ratio of octyl alcohol, ethylene oxide, and propylene oxide is 1:2:8. After reacting octyl alcohol and ethylene oxide at a molar ratio of 1:2, subsequently, propylene oxide eight times the molar ratio with respect to octyl alcohol is added and reacted to obtain an adduct, and the adduct and sulfosuccinic acid are reacted to obtain a sulfosuccinic acid ester. Subsequently, the sulfosuccinic acid ester is neutralized with an aqueous sodium hydroxide solution to obtain the sulfosuccinic acid ester compound A-10.

[0050] The sulfosuccinic acid ester compound A-11 is the sodium salt of the ester of sulfosuccinic acid and an adduct obtained by adding ethylene oxide and propylene oxide to hexadecanol. The addition mode of ethylene oxide and propylene oxide in the sulfosuccinic acid ester compound A-11 is in a block form, and the molar ratio of hexadecanol, ethylene oxide, and propylene oxide is 1:8:2. After reacting hexadecanol and ethylene oxide at a molar ratio of 1:8, subsequently, propylene oxide twice the molar ratio with respect to hexadecanol is added and reacted to obtain an adduct, and the adduct and sulfosuccinic acid are reacted to obtain a sulfosuccinic acid ester. Subsequently, the sulfosuccinic acid ester is neutralized with an aqueous sodium hydroxide solution to obtain the sulfosuccinic acid ester compound A-11.

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

[0052] The sulfosuccinic acid ester compound A-13 is the ammonium salt of the ester of sulfosuccinic acid and an adduct obtained by adding ethylene oxide to dodecanol at a molar ratio of 1:3. The sulfosuccinic acid ester obtained by the same method as the production method of the sulfosuccinic acid ester compound A-1 was neutralized with aqueous ammonia to obtain the sulfosuccinic acid ester compound A-13.

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

[0054] Sulfosuccinic acid ester compounds A-15 to A-18 are compounds in which the alcohol moiety and the molar ratio of the alcohol moiety to ethylene oxide are different from those of sulfosuccinic acid ester compound A-14, respectively, in comparison with sulfosuccinic acid ester compound A-14. Table 1 shows the alcohol moiety of each of these compounds and the molar ratio of the alcohol moiety to ethylene oxide. The production method of each of these compounds is substantially the same as the production method of sulfosuccinic acid ester compound A-14 (the production method of the precursor ester of sulfosuccinic acid 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 distinction between the alcohol moiety, the alkylene oxide moiety, the molar ratio of the alcohol moiety to the alkylene oxide moiety, and the ester, alkali metal salt, and ammonium salt of sulfosuccinic acid ester compounds A-1 to A-18. Note that all of sulfosuccinic acid ester compounds A-1 to A-18 are mixtures of monoester forms and diester forms.

[0056] Table 1: Sulfosuccinic acid ester compounds

Table 1

[0057] Also, as an example not corresponding to the sulfosuccinic acid ester compound (A) according to the above embodiment, sulfosuccinic acid ester compound ra-1 was used. Sulfosuccinic acid ester compound ra-1 is dioctyl sodium sulfosuccinate commercially available as a reagent.

[0058] (1-2) Nonionic surfactant 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. Among these, the nonionic surfactants B1-1 to B1-11 correspond to the secondary alcohol nonionic surfactant (B1) according to the above embodiment, and the nonionic surfactants B2-1 to B2-7 correspond to the oxypropylene-based nonionic surfactant (B2) according to the above embodiment. In the following, examples of the production methods for each compound are shown, but each production method is only an example, and even if the compound is produced by a method different from the methods exemplified below, the results of the examples and comparative examples will not change.

[0059] The nonionic surfactant B1-1 is an adduct in which ethylene oxide is added to 2-dodecanol at a molar ratio of 1:5. 2-Dodecanol and ethylene oxide were reacted at a molar ratio of 1:5 to obtain the nonionic surfactant B1-1.

[0060] The nonionic surfactant B1-2 is an adduct in which ethylene oxide is added to 2-dodecanol at a molar ratio of 1:10. 2-Dodecanol and ethylene oxide were reacted at a molar ratio of 1:10 to obtain the nonionic surfactant B1-2.

[0061] The nonionic surfactant B1-3 is an adduct in which ethylene oxide is added to 2-dodecanol at a molar ratio of 1:15. 2-Dodecanol and ethylene oxide were reacted at a molar ratio of 1:15 to obtain the nonionic surfactant B1-3.

[0062] The nonionic surfactant B1-4 is an adduct in which ethylene oxide is added to 2-tridecanol at a molar ratio of 1:5. 2-Tridecanol and ethylene oxide were reacted at a molar ratio of 1:5 to obtain the nonionic surfactant B1-4.

[0063] Nonionic surfactant B1-5 is an adduct obtained by adding ethylene oxide to 2-tetradecanol at a molar ratio of 1:5. 2-Tetradecanol and ethylene oxide were reacted at a molar ratio of 1:5 to obtain nonionic surfactant B1-5.

[0064] Nonionic surfactant B1-6 is an adduct obtained by adding ethylene oxide to 2-dodecanol at a molar ratio of 1:1. 2-Dodecanol and ethylene oxide were reacted at a molar ratio of 1:1 to obtain nonionic surfactant B1-6.

[0065] Nonionic surfactant B1-7 is an adduct obtained by adding ethylene oxide to 2-dodecanol at a molar ratio of 1:13. 2-Dodecanol and ethylene oxide were reacted at a molar ratio of 1:13 to obtain nonionic surfactant B1-7.

[0066] Nonionic surfactant B1-8 is an adduct obtained by adding ethylene oxide to 2-dodecanol at a molar ratio of 1:30. 2-Dodecanol and ethylene oxide were reacted at a molar ratio of 1:30 to obtain nonionic surfactant B1-8.

[0067] Nonionic surfactant B1-9 is an adduct obtained by adding ethylene oxide to 2-octanol at a molar ratio of 1:4. 2-Octanol and ethylene oxide were reacted at a molar ratio of 1:4 to obtain nonionic surfactant B1-9.

[0068] Nonionic surfactant B1-10 is an adduct obtained by adding ethylene oxide to 2-hexadecanol at a molar ratio of 1:8. 2-Hexadecanol and ethylene oxide were reacted at a molar ratio of 1:8 to obtain nonionic surfactant B1-10.

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

[0070] Nonionic surfactant B2-1 is an adduct obtained by adding ethylene oxide and propylene oxide to 2-dodecanol. The addition modes of ethylene oxide and propylene oxide are in block form, and the molar ratio of 2-dodecanol, ethylene oxide, and propylene oxide is 1:40:18. After reacting 2-dodecanol with ethylene oxide at a molar ratio of 1:40, subsequently, propylene oxide with a molar ratio 18 times that of 2-dodecanol was reacted to obtain nonionic surfactant B2-1.

[0071] Nonionic surfactant B2-2 is an adduct obtained by adding ethylene oxide and propylene oxide to 2-dodecanol. The addition modes of ethylene oxide and propylene oxide are random, and the molar ratio of 2-dodecanol, ethylene oxide, and propylene oxide is 1:40:18. 2-Dodecanol, ethylene oxide, and propylene oxide were reacted at a molar ratio of 1:40:18 to obtain nonionic surfactant B2-2.

[0072] Nonionic surfactant B2-3 is an adduct obtained by adding ethylene oxide and propylene oxide to 2-dodecanol. The addition modes of ethylene oxide and propylene oxide are random, and the molar ratio of 2-dodecanol, ethylene oxide, and propylene oxide is 1:3:1. 2-Dodecanol, ethylene oxide, and propylene oxide were reacted at a molar ratio of 1:3:1 to obtain nonionic surfactant B2-3.

[0073] Nonionic surfactant B2-4 is an adduct obtained by adding ethylene oxide and propylene oxide to 1-dodecanol. The addition mode of ethylene oxide and propylene oxide is block-like, and the molar ratio of 1-dodecanol, ethylene oxide, and propylene oxide is 1:2:6. After reacting 1-dodecanol with ethylene oxide at a molar ratio of 1:2, subsequently, propylene oxide with a molar ratio 6 times that of 1-dodecanol was reacted to obtain nonionic surfactant B2-4.

[0074] Nonionic surfactant B2-5 is an adduct obtained by adding ethylene oxide and propylene oxide to 1-dodecanol. The addition mode of ethylene oxide and propylene oxide is block-like, and the molar ratio of 1-dodecanol, ethylene oxide, and propylene oxide is 1:8:6. After reacting 1-dodecanol with ethylene oxide at a molar ratio of 1:8, subsequently, propylene oxide with a molar ratio 6 times that of 1-dodecanol was reacted to obtain nonionic surfactant B2-5.

[0075] Nonionic surfactant B2-6 is an adduct obtained by adding ethylene oxide and propylene oxide to 1-dodecanol. The addition mode of ethylene oxide and propylene oxide is block-like, and the molar ratio of 1-dodecanol, ethylene oxide, and propylene oxide is 1:6:2. After reacting 1-dodecanol with ethylene oxide at a molar ratio of 1:6, subsequently, propylene oxide with a molar ratio 2 times that of 1-dodecanol was reacted to obtain nonionic surfactant B2-6.

[0076] Nonionic surfactant B2-7 is an adduct obtained by adding ethylene oxide and propylene oxide to 1-dodecanol. The addition mode of ethylene oxide and propylene oxide is random, and the molar ratio of 1-dodecanol, ethylene oxide, and propylene oxide is 1:5:5. 1-Dodecanol, ethylene oxide, and propylene oxide were reacted at a molar ratio of 1:5:5 to obtain nonionic surfactant B2-7.

[0077] Nonionic surfactant B-1 is an adduct obtained by adding ethylene oxide to 1-dodecanol at a molar ratio of 1:5. 1-Dodecanol and ethylene oxide were reacted at a molar ratio of 1:5 to obtain nonionic surfactant B-1.

[0078] Nonionic surfactant B-2 is an adduct obtained by adding ethylene oxide to 1-dodecanol at a molar ratio of 1:10. 1-Dodecanol and ethylene oxide were reacted at a molar ratio of 1:10 to obtain nonionic surfactant B-2.

[0079] Nonionic surfactant B-3 is an adduct obtained by adding ethylene oxide to 1-dodecanol at a molar ratio of 1:15. 1-Dodecanol and ethylene oxide were reacted at a molar ratio of 1:15 to obtain nonionic surfactant B-3.

[0080] Nonionic surfactant B-4 is an adduct obtained by adding ethylene oxide to 1-tridecanol at a molar ratio of 1:5. 1-Tridecanol and ethylene oxide were reacted at a molar ratio of 1:5 to obtain nonionic surfactant B-4.

[0081] Nonionic surfactant B-5 is an adduct obtained by adding ethylene oxide to 1-tetradecanol at a molar ratio of 1:5. 1-Tetradecanol and ethylene oxide were reacted at a molar ratio of 1:5 to obtain nonionic surfactant B-5.

[0082] Nonionic surfactant B-6 is an adduct obtained by adding ethylene oxide to 1-dodecanol at a molar ratio of 1:1. 1-Dodecanol and ethylene oxide were reacted at a molar ratio of 1:1 to obtain nonionic surfactant B-6.

[0083] Nonionic surfactant B-7 is an adduct obtained by adding ethylene oxide to 1-dodecanol at a molar ratio of 1:13. 1-Dodecanol and ethylene oxide were reacted at a molar ratio of 1:13 to obtain nonionic surfactant B-7.

[0084] Nonionic surfactant B-8 is an adduct obtained by adding ethylene oxide to 1-dodecanol at a molar ratio of 1:30. 1-Dodecanol and ethylene oxide were reacted at a molar ratio of 1:30 to obtain nonionic surfactant B-8.

[0085] Nonionic surfactant B-9 is an adduct obtained by adding ethylene oxide to 1-octanol at a molar ratio of 1:4. 1-Octanol and ethylene oxide were reacted at a molar ratio of 1:4 to obtain nonionic surfactant B-9.

[0086] Nonionic surfactant B-10 is an adduct obtained by adding ethylene oxide to 1-hexadecanol at a molar ratio of 1:8. 1-Hexadecanol and ethylene oxide were reacted at a molar ratio of 1:8 to obtain nonionic surfactant B-10.

[0087] Nonionic surfactant B-11 is an adduct obtained by adding ethylene oxide to 1-octadecanol at a molar ratio of 1:10. 1-Octadecanol and ethylene oxide were reacted at a molar ratio of 1:10 to obtain nonionic surfactant B-11.

[0088] Nonionic surfactant B-12 is an adduct obtained by adding ethylene oxide to oleic acid at a molar ratio of 1:5 mol. Oleic acid and ethylene oxide were reacted at a molar ratio of 1:5 to obtain nonionic surfactant B-12.

[0089] Nonionic surfactant B-13 is an adduct in which ethylene oxide is added to linoleic acid at a molar ratio of 1:1. Linoleic acid and ethylene oxide were reacted at a molar ratio of 1:1 to obtain nonionic surfactant B-13.

[0090] Nonionic surfactant B-14 is an adduct in which ethylene oxide is added to linoleic acid at a molar ratio of 1:15. Linoleic acid and ethylene oxide were reacted at a molar ratio of 1:15 to obtain nonionic surfactant B-14.

[0091] Nonionic surfactant B-15 is an adduct in which ethylene oxide is added to linolenic acid at a molar ratio of 1:1. Linolenic acid and ethylene oxide were reacted at a molar ratio of 1:1 to obtain nonionic surfactant B-15.

[0092] Nonionic surfactant B-16 is an adduct in which ethylene oxide is added to linolenic acid at a molar ratio of 1:15. Linolenic acid and ethylene oxide were reacted at a molar ratio of 1:15 to obtain nonionic surfactant B-16.

[0093] Nonionic surfactant B-17 is an adduct in which ethylene oxide is added to lauryl alcohol at a molar ratio of 1:10. Lauryl alcohol and ethylene oxide were reacted at a molar ratio of 1:10 to obtain nonionic surfactant B-17.

[0094] Nonionic surfactant B-18 is an adduct in which ethylene oxide is added to dodecyl acetic acid at a molar ratio of 1:10. Dodecyl acetic acid and ethylene oxide were reacted at a molar ratio of 1:10 to obtain nonionic surfactant B-18.

[0095] (1-3) silicone compound The silicone compounds C-1 to C-4, rc-1, and rc-2 used in the examples and comparative examples will be described in order. Among them, the 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 is an amino-modified silicone with a kinematic viscosity of 1200 mm 2 / s and an amino equivalent of 4000 g / mol. Silicone compound C-2 is an amino-modified silicone with a kinematic viscosity of 500 mm 2 / s and an amino equivalent of 1600 g / mol. Silicone compound C-3 is an amino-modified silicone with a kinematic viscosity of 40000 mm 2 / s and an amino equivalent of 20000 g / mol. Silicone compound C-4 is an amino-modified silicone with a kinematic viscosity of 250 mm 2 / s and an amino equivalent of 7600 g / mol.

[0097] Silicone compound rc-1 is a polyether-modified silicone with a kinematic viscosity of 500 mm 2 / 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] Silicone compound rc-2 is a dimethyl silicone with a kinematic viscosity of 100 mm 2 / s.

[0099] (1-4) Other components The following were used as other components. D-1: Permachem (registered trademark) OM-17 (manufactured by Permachem Asia Co., Ltd.) D-2: Permachem (registered trademark) OM-17 (manufactured by Permachem Asia Co., Ltd.) D-3: ACTITUDE LA (manufactured by Soh Japan Co., Ltd.) D-4: ACTITUDE LA2011 (manufactured by Soh-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 at the mass ratios shown below. Sulfosuccinic acid 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 putting each weighed component into a beaker and mixing well, ion-exchanged water was gradually added while stirring to make the non-volatile content concentration 30% by mass, and the treatment agent of Example 1 was prepared.

[0101] (Preparation of other examples and comparative examples) Except for changing the types and ratios of the 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 agent for synthetic fibers] (1) Production of carbon fiber precursor and carbon fiber Using the treatment agents of each example of the examples and comparative examples, carbon fiber precursors and carbon fibers were produced. Based on the states of each part of the production equipment during production and the physical properties of the obtained carbon fiber precursors and carbon fibers, the treatment agents of each example of the examples and comparative examples were evaluated.

[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 dope with a polymer concentration of 21.0% by mass and a viscosity of 500 poise at 60°C. The spinning dope was discharged from a spinneret with a pore diameter (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 with a draw ratio of 0.8. The coagulated yarn was stretched 5-fold simultaneously with solvent removal in a water washing tank to prepare an acrylic fiber strand in a water-swelled state.

[0104] (Second step) For the prepared acrylic fiber strands, a 3% ion-exchanged aqueous solution of the treatment agent for each example of the examples and comparative examples was oiled by the dipping method so that the adhesion amount of the treatment agent was 1% by mass (excluding the solvent). Thereafter, the acrylic fiber strands with the treatment agent attached were subjected to a drying densification treatment with a heating roller at 150°C, and further stretched 1.7 times between heating rollers at 170°C, and then wound onto a yarn bobbin to obtain a carbon fiber precursor.

[0105] (Third step) The yarns were unwound from the carbon fiber precursors of each example of the examples and comparative examples, and subjected to a flame retardant treatment in an air atmosphere for 1 hour in a flame retardant furnace having a temperature gradient of 230 to 270°C, and then wound onto a yarn bobbin to obtain flame retardant yarns. Further, the yarns were unwound from the flame retardant yarns, fired in a carbonization furnace having a temperature gradient of 300 to 1300°C in a nitrogen atmosphere to be converted into carbon fibers, and wound onto a yarn bobbin to obtain carbon fibers.

[0106] (2) Tar detergency In the above third step, tar adheres to the outlet of the flame retardant furnace. Before the adhesion amount of this tar reaches a level that hinders the operation of the flame retardant furnace (specifically, before causing yarn breakage), it is necessary to perform an operation to remove the tar. In this evaluation, continuous operation was started using a flame retardant furnace without tar adhesion, and the following four levels were evaluated based on the period until yarn breakage occurred. A: No yarn breakage occurred for more than 3 weeks from the start of operation. B: Thread breakage occurred within more than two weeks and less than three weeks from the start of operation. C: Thread breakage occurred within more than one week and less than two weeks from the start of operation. D: Thread breakage occurred within less than one week from the start of operation.

[0107] (3) Convergence The convergence state of the acrylic fiber strand with the treatment agent attached when passing through the heating roller in the above second step was visually observed and evaluated at the following four levels. A: The strand is sufficiently converged and does not wrap around the heating roller. B: The strand may slightly disperse, but no thread breakage occurs and there are no operational problems. C: The strand may disperse, but no thread breakage occurs and there are no operational problems. D: The strand disperses significantly, thread breakage occurs, and there are operational obstacles.

[0108] (4) Strength The tensile strength of the obtained carbon fiber was measured according to JIS R 7606:2000. According to the measured value of the tensile strength, it was classified into the following four levels. A: The tensile strength is 4.5 GPa or more. B: The tensile strength is 4.0 GPa or more and less than 4.5 GPa. C: The 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 property The generated electricity when the acrylic fiber strand with the treatment agent attached passes through the heating roller in the above second step was measured using an electrostatic voltmeter. Based on the measured value, it was classified into the following two levels. A: The generated electricity is 0.5 kV or less. D: The generated electricity is greater than 0.5 kV.

[0110] 〔Results〕 The compositions and evaluation results of the respective treatment agents according to the examples and comparative examples are shown in Tables 2 to 4. In each table, the sulfosuccinic acid ester compound is abbreviated as "Component A", the nonionic surfactant as "Component B", and the silicone compound 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] The present invention can be used in the production of synthetic fibers such as carbon fiber precursors.

Claims

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

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

30.

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

100.

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

5. When the total proportion of the sulfosuccinate compound (A), the nonionic surfactant (B), and the amino-modified silicone compound (C) in the nonvolatile content is taken as 100 mass%, The ratio of the sulfosuccinate 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 synthetic fiber treating agent according to claim 4, wherein the proportion of the amino-modified silicone compound (C) is from 65% by mass to 92% by mass.

6. A synthetic fiber comprising a fiber material having the synthetic fiber treating agent according to any one of claims 1 to 5 adhered thereto.

7. The synthetic fiber of claim 6, wherein the fiber material is a carbon fiber precursor.

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