Synthetic fiber treatment agents, synthetic fibers, and methods for producing synthetic fiber treatment agents.

Abstract

The invention addresses the proposed problem: a treatment agent for synthetic fibers, which is capable of improving tar removal properties while having low fume emission properties; and similar. The invention proposes a treatment agent for synthetic fibers, which contains an ester compound (A) and is characterized by the fact that the measured peroxide value in the treatment agent for synthetic fibers is 100 meq / kg or less.

Description

Treatment agent for synthetic fibers, synthetic fibers, and method for producing treatment agent for synthetic fibers

[0001] The present invention relates to a synthetic fiber treating agent that can improve tar cleaning properties and reduce smoke generation, synthetic fibers, and a method for producing the synthetic fiber treating agent.

[0002] For example, in the spinning and drawing process of synthetic fibers, a fiber treatment agent may be applied to the surface of the fibers to improve smoothness, antistatic properties, etc. Conventional synthetic fiber treatment agents are disclosed in Patent Documents 1 to 3. Patent Document 1 discloses a lubricating treatment composition for synthetic fibers to be subjected to a hot processing process, containing a specific alkylene oxide adduct of bisphenol A. Patent Document 2 discloses a synthetic fiber treatment agent containing an ester compound of at least one selected from organic acids having a sulfur element in the molecule and ester-forming derivatives of organic acids having a sulfur element in the molecule with a Guerbet alcohol having 6 to 22 carbon atoms. Patent Document 3 discloses a synthetic fiber treatment agent containing an ester compound having a specific thioether bond, an acid value of 0.2 to 10 mgKOH / g, and an ash content of 0.01 to 0.5 mass %.

[0003] JP 52-155299 A JP 2020-094304 A JP 2018-150665 A

[0004] However, conventional synthetic fiber treatment agents have been required to have improved tar cleaning properties and low smoke generation.

[0005] As a result of research aimed at solving the above-mentioned problems, the present inventors have found that a treatment agent for synthetic fibers having a structure in which the peroxide value detected from the treatment agent for synthetic fibers is defined within a predetermined range is suitable.

[0006] The present invention relates to a synthetic fiber treatment agent that contains an ester compound (A) and has a peroxide value of 100 meq / kg or less.

[0007] In Aspect 2, the synthetic fiber treating agent according to Aspect 1 has a peroxide value of 50 meq / kg or less. In Aspect 3, the synthetic fiber treating agent according to Aspect 1 or 2 has an ester compound (A1) having a thioether bond in the molecule.

[0008] In Aspect 4, in the treatment agent for synthetic fibers according to any one of Aspects 1 to 3, the ester compound (A) includes a complete ester compound (A2) of a trihydric or greater but tetrahydric polyhydric alcohol and a fatty acid.

[0009] Aspect 5 is the synthetic fiber treating agent according to any one of Aspects 1 to 4, further comprising an ionic surfactant (B). Aspect 6 is the synthetic fiber treating agent according to Aspect 5, wherein the ionic surfactant (B) comprises a sulfonic acid compound (B1).

[0010] Aspect 7 is the synthetic fiber treating agent according to any one of Aspects 1 to 6, further comprising a nonionic surfactant (C). Aspect 8 is the synthetic fiber treating agent according to Aspect 7, wherein the nonionic surfactant (C) comprises a compound (C1) in which an alkylene oxide is added to a primary organic amine.

[0011] Aspect 9 is a synthetic fiber having adhered thereto the synthetic fiber treating agent according to any one of Aspects 1 to 8. Aspect 10 is a method for producing the synthetic fiber treating agent according to any one of Aspects 1 to 8, characterized in that the filling rate calculated from the following formula (1) at atmospheric pressure and 25°C is 60% by volume or more and 100% by volume or less.

[0012]

[0013] According to the present invention, it is possible to improve the tar cleaning property and reduce the smoke generation.

[0014] First Embodiment A first embodiment of the synthetic fiber treating agent (hereinafter also referred to as treating agent) of the present invention will be described below. The treating agent of this embodiment contains an ester compound (A), and the peroxide value detected from the treating agent is 100 meq / kg or less.

[0015] (Ester Compound (A)) The ester compound (A) is not particularly limited as long as it can be used as a smoothing agent in the field of treatment agents, and examples thereof include ester compounds produced from a fatty acid and an alcohol. The ester compound (A) may be produced, for example, from a fatty acid having an odd or even hydrocarbon group, as described below, and an alcohol. The fatty acid that is the raw material for the ester compound is not particularly limited in terms of the number of carbon atoms, whether or not it is branched, or the valence, and may be, for example, a higher fatty acid, a fatty acid having a cyclo ring, or a fatty acid having an aromatic ring. The alcohol that is the raw material for the ester compound is not particularly limited in terms of the number of carbon atoms, whether or not it is branched, or the valence, and may be, for example, a higher alcohol, an alcohol having a cyclo ring, or an alcohol having an aromatic ring.

[0016] The ester compound (A) preferably contains an ester compound (A1) having a thioether bond in the molecule. By containing the ester compound (A1), an increase in the peroxide value described below can be suppressed, and the tar cleaning ability can be improved and smoke generation can be reduced.

[0017] Specific examples of the ester compound (A1) having a thioether bond in the molecule include dioctyl thiodipropionate, diisolauryl thiodipropionate, dilauryl thiodipropionate, diisopalmityl thiodipropionate, diisostearyl thiodipropionate, dioleyl thiodipropionate, diisotetracosyl thiodipropionate, di(2-decyl-1-tetradecanol)thiodipropionate, di(2-dodecyl)thiodipropionate, di(2-octyl-1-decanol) thiodipropionate, di(2-ethylhexyl-1-hexadecanol) thiodipropionate, 2-ethylhexyl (lauryl thiopropionate), octyl thiodipropionate, isolauryl thiodipropionate, lauryl thiodipropionate, isopalmityl thiodipropionate, isostearyl thiodipropionate, oleyl thiodipropionate, isotetracosyl thiodipropionate, and the like.

[0018] Among the ester compounds (A1), it is preferable to include a thiodipropionic acid ester, more specifically, an ester compound of thiodipropionic acid with a Guerbet alcohol having from 24 to 32 carbon atoms. By including such an ester compound, it is possible to achieve particularly low smoke generation.

[0019] In the treatment agent, the lower limit of the content of the ester compound (A1) is preferably 0.5% by mass or more, more preferably 1% by mass or more. The upper limit of the content of the ester compound (A1) is preferably 30% by mass or less, more preferably 25% by mass or less, and particularly preferably 5% by mass or less. By specifying the content within this range, the effects of the present invention can be further improved. Any combination of the above upper and lower limits is also contemplated.

[0020] The ester compound (A) preferably contains a complete ester compound (A2) of a trivalent or greater and tetravalent or less polyhydric alcohol with a fatty acid. When the ester compound (A) contains the ester compound (A2), the ester compound (A) can be made less fuming.

[0021] Specific examples of the trihydric to tetrahydric polyhydric alcohol that can be used as a raw material for the completely esterified compound (A2) include glycerin, pentaerythritol, trimethylolpropane, 2-methyl-2-hydroxymethyl-1,3-propanediol, 1,2,3-butanetriol, 1,2,4-butanetriol, erythritol, 1,2,3-pentatriol, and 1,2,4-pentatriol.

[0022] As the fatty acid used as the raw material for the completely esterified compound (A2), known fatty acids can be appropriately used, and may be saturated or unsaturated fatty acids. Furthermore, they may be linear or have a branched chain structure. Furthermore, they may be monovalent fatty acids or polycarboxylic acids (polybasic acids). Specific examples of fatty acids include: (1) linear alkyl fatty acids such as octanoic acid, nonanoic acid, decanoic acid, undecanoic acid, dodecanoic acid, tridecanoic acid, tetradecanoic acid, pentadecanoic acid, hexadecanoic acid, heptadecanoic acid, octadecanoic acid, nonadecanoic acid, icosanoic acid, henicosanoic acid, docosanoic acid, and tetracosanoic acid; (2) 2-ethylhexanoic acid, isododecanoic acid, isotridecanoic acid, isotetradecanoic acid, and isohexadecanoic acid; (3) straight-chain alkenyl fatty acids such as crotonic acid, myristoleic acid, palmitoleic acid, oleic acid, vaccenic acid, eicosenoic acid, linoleic acid, α-linolenic acid, γ-linolenic acid, and arachidonic acid; and (4) naturally occurring fatty acids such as castor oil fatty acid, sesame oil fatty acid, tall oil fatty acid, soybean oil fatty acid, rapeseed oil fatty acid, palm oil fatty acid, palm kernel fatty acid, and coconut oil fatty acid.

[0023] Specific examples of the complete ester compound (A2) include glycerin trioleate, trimethylolpropane trilaurate, pentaerythritol tetraoctate, a triester of trimethylolpropane and a mixed acid (a mixture of palm kernel fatty acid and vegetable oleic acid), a triester of trimethylolpropane and rapeseed oil fatty acid, a triester of trimethylolpropane and coconut oil fatty acid, a tetraester of pentaerythritol and palm oil fatty acid, coconut oil, rapeseed oil, sunflower oil, soybean oil, castor oil, sesame oil, and animal and vegetable oils such as fish oil.

[0024] In the treating agent, the lower limit of the content of the completely esterified compound (A2) is preferably 10% by mass or more, more preferably 20% by mass or more. The upper limit of the content of the completely esterified compound (A2) is preferably 70% by mass or less, more preferably 60% by mass or less. By specifying the content within this range, it is possible to achieve even lower smoke generation. Any combination of the above upper and lower limits is also contemplated.

[0025] Specific examples of the ester compound (A) other than the ester compound (A1) and the completely esterified compound (A2) include, for example, (1) ester compounds of aliphatic monoalcohols and aliphatic monocarboxylic acids, such as butyl stearate, octyl stearate, oleyl laurate, oleyl oleate, isopentacosanyl isostearate, octyl palmitate, oleyl erucinate, and isotridecyl stearate, and ester compounds of aliphatic monocarboxylic acids with (poly)oxyalkylene adducts in which alkylene oxides having from 2 to 4 carbon atoms are added to aliphatic monoalcohols; (2) 1,(3) Complete ester compounds of aliphatic monoalcohols and aliphatic monocarboxylic acids, such as 6-hexanediol didecanoate, (4) (5) (6) (7) (8) (9) (10) (11) (12) (13) (14) (15) (16) (17) (18) (19) (20) (21) (22) (23) (24) (25) (26) (27) (28) (29) (30) (31) (32) (33) (34) (35) (40) Ester compounds of aliphatic polyalcohols and aliphatic monocarboxylic acids, such as 6-hexanediol didecanoate, (35) (46) (47) (58) Ester compounds of aromatic monoalcohols and aliphatic monocarboxylic acids, such as benzyl oleate, benzyl laurate, and polyoxypropylene benzyl stearate, and aromatic monoalcohols. (5) ester compounds of aliphatic monocarboxylic acids with (poly)oxyalkylene adducts in which alkylene oxides having from 2 to 4 carbon atoms are added to an aromatic polyhydric alcohol, such as bisphenol A dilaurate and polyoxyethylene bisphenol A dilaurate; complete ester compounds of aliphatic monocarboxylic acids with (poly)oxyalkylene adducts in which alkylene oxides having from 2 to 4 carbon atoms are added to an aromatic polyhydric alcohol; (6) complete ester compounds of aliphatic monoalcohols with aromatic polycarboxylic acids, such as bis 2-ethylhexyl phthalate, diisostearyl isophthalate and trioctyl trimellitate; and complete ester compounds of aromatic polycarboxylic acids with (poly)oxyalkylene adducts in which alkylene oxides having from 2 to 4 carbon atoms are added to an aliphatic monoalcohol.

[0026] These ester compounds (A) may be used alone or in appropriate combination of two or more ester compounds. The lower limit of the content of the ester compound (A) in the treatment agent is preferably 25% by mass or more, more preferably 30% by mass or more. When the content is 25% by mass or more, the smoothness of the fiber to which the treatment agent is applied can be further improved. The upper limit of the content of the ester compound (A) is preferably 80% by mass or less, more preferably 70% by mass or less. When the content is 80% by mass or less, the stability of the treatment agent can be further improved. Any combination of the above upper and lower limits is also contemplated.

[0027] (Other Smoothing Agents) The treating agent may contain other smoothing agents besides the ester compound (A) for the purpose of improving the smoothness of synthetic fibers, within the range that does not impair the effects of the present invention. Examples of such smoothing agents include mineral oil (kinematic viscosity of 5 mm at 40°C) and ２ / s or more), polyolefins, etc.

[0028] Examples of mineral oils include aromatic hydrocarbons, paraffinic hydrocarbons, naphthenic hydrocarbons, etc. More specifically, examples include spindle oil, liquid paraffin, etc.

[0029] The polyolefin used is a poly-α-olefin used as a smoothing component. Specific examples of polyolefins include poly-α-olefins obtained by polymerizing 1-butene, 1-hexene, 1-decene, etc. Commercially available poly-α-olefins can be used as appropriate.

[0030] (Ionic surfactant (B)) The treatment agent may further contain an ionic surfactant (B). By including the ionic surfactant (B) in the treatment agent, the tar cleaning properties in particular can be further improved. As the ionic surfactant (B), any known surfactant can be appropriately used. Examples of the ionic surfactant (B) include anionic surfactants, cationic surfactants, and amphoteric surfactants.

[0031] As the anionic surfactant, known surfactants can be appropriately used. Specific examples of anionic surfactants include (1) phosphate salts of aliphatic alcohols, such as lauryl phosphate salts, cetyl phosphate salts, octyl phosphate salts, oleyl phosphate salts, and stearyl phosphate salts; (2) phosphate salts of aliphatic alcohols to which at least one alkylene oxide selected from ethylene oxide and propylene oxide has been added, such as polyoxyethylene lauryl ether phosphate salts, polyoxyethylene oleyl ether phosphate salts, and polyoxyethylene stearyl ether phosphate salts; (3) aliphatic sulfonates or aromatic sulfonates, such as lauryl sulfonate, myristyl sulfonate, cetyl sulfonate, oleyl sulfonate, stearyl sulfonate, tetradecane sulfonate, dodecylbenzene sulfonate, secondary alkyl sulfonate (having 13 to 15 carbon atoms), secondary alkyl sulfonate (having 11 to 14 carbon atoms), and α-olefin sulfonate; and (4) lauryl sulfate salts, oleyl sulfate salts, and stearyl sulfate salts. (5) sulfates of fatty alcohols to which at least one alkylene oxide selected from ethylene oxide and propylene oxide is added, such as polyoxyethylene lauryl ether sulfate, polyoxyalkylene (polyoxyethylene, polyoxypropylene) lauryl ether sulfate, and polyoxyethylene oleyl ether sulfate; (6) castor oil fatty acid sulfate, sesame oil fatty acid sulfate, and tall oil fatty acid sulfate; (6) sulfates of natural fats and oils such as castor oil sulfate, sesame oil sulfate, tall oil sulfate, soybean oil sulfate, rapeseed oil sulfate, and palm oil sulfate; (7) sulfates of natural fats and oils such as castor oil sulfate, sesame oil sulfate, tall oil sulfate, soybean oil sulfate, rapeseed oil sulfate, and palm oil sulfate; (8) fatty acid salts such as laurates, oleates, and stearates; and (9) sulfosuccinate salts of fatty alcohols such as dioctyl sulfosuccinate.Examples of counter ions of anionic surfactants include alkali metal salts such as potassium salts and sodium salts, ammonium salts, and alkanolamine salts such as triethanolamine salts, (poly)oxyalkylene alkylamine salts, and dibutylethanolamine salts.

[0032] From the viewpoint of further improving tar cleaning properties, the anionic surfactant preferably contains a sulfonic acid compound (B1) such as an aliphatic sulfonate. When the sulfonic acid compound (B1) is contained as the anionic surfactant, it is preferably used in combination with a thiodipropionic acid ester as the ester compound (A), more specifically, an ester compound of a Guerbet alcohol having from 24 to 32 carbon atoms and thiodipropionic acid. This configuration further improves the effects of the present invention.

[0033] In the treatment agent, the lower limit of the content of the sulfonic acid compound (B1) is preferably 0.1 mass% or more, more preferably 0.5 mass% or more. The upper limit of the content of the sulfonic acid compound (B1) is preferably 5 mass% or less, more preferably 3.5 mass% or less. By specifying the content within this range, the tar cleaning ability can be further improved. Note that ranges that combine the above upper and lower limits are also contemplated.

[0034] Specific examples of cationic surfactants include lauryltrimethylammonium chloride, cetyltrimethylammonium chloride, stearyltrimethylammonium chloride, behenyltrimethylammonium chloride, and didecyldimethylammonium chloride.

[0035] Specific examples of amphoteric surfactants include betaine-type amphoteric surfactants, etc. These ionic surfactants (B) may be used alone as one type of ionic surfactant, or as an appropriate combination of two or more types of ionic surfactants.

[0036] In the treatment agent, the lower limit of the content of the ionic surfactant (B) is preferably 0.1% by mass or more, more preferably 1% by mass or more. The upper limit of the content of the ionic surfactant (B) is preferably 10% by mass or less, more preferably 6% by mass or less. By specifying the content within this range, the tar cleaning ability can be further improved. Note that ranges that combine the above upper and lower limits are also contemplated.

[0037] (Nonionic surfactant (C)) The treatment agent may further contain a nonionic surfactant (C). By including a nonionic surfactant (C) in the treatment agent, the stability of the appearance of the treatment agent can be improved, and it becomes possible to use solvents with different polarities, such as water and / or organic solvents, as diluents when applying the treatment agent to synthetic fibers.

[0038] Examples of the nonionic surfactant (C) include compounds having a (poly)oxyalkylene structure in which alkylene oxide is added to alcohols or carboxylic acids, ether / ester compounds having a (poly)oxyalkylene structure in which alkylene oxide is added to an ester compound of carboxylic acids and polyhydric alcohols, compounds in which alkylene oxide is added to natural fats and oils or compounds in which such compounds are esterified with carboxylic acids, and amine compounds such as compounds (C1) having a (poly)oxyalkylene structure in which alkylene oxide is added to primary organic amines, compounds having a (poly)oxyalkylene structure in which alkylene oxide is added to fatty acid amides, amide compounds in which amine compounds and carboxylic acids are condensed, and partial ester compounds of carboxylic acids and polyhydric alcohols. Among these, from the viewpoint of further improving tar cleaning properties, it is preferable to include compounds (C1) in which alkylene oxide is added to primary organic amines.

[0039] Specific examples of alcohols used as raw materials for the nonionic surfactant (C) include: (1) linear alkyl alcohols such as methanol, ethanol, propanol, butanol, pentanol, hexanol, octanol, nonanol, decanol, undecanol, dodecanol, tridecanol, tetradecanol, pentadecanol, hexadecanol, heptadecanol, octadecanol, nonadecanol, eicosanol, heneicosanol, docosanol, tricosanol, tetracosanol, pentacosanol, hexacosanol, heptacosanol, octacosanol, nonacosanol, and triacontanol; (2) isopropanol, isobutanol, isohexanol, 2-ethylhexanol, isononanol, isodecanol, isododecanol, isotridecanol, isotetradecanol, isotriacontanol, and isoheptadecanol; (3) branched alkyl alcohols such as tetradecenol, hexadecanol, heptadecanol, octadecanol, isonodecanol, isoeicosanol, isoheneicosanol, isodocosanol, isotricosanol, isotetracosanol, isopentacosanol, isohexacosanol, isoheptacosanol, isooctacosanol, isononacosanol, and isopentadecanol; (4) branched alkenyl alcohols such as isohexadecenol and isooctadecenol; (5) cyclic alkyl alcohols such as cyclopentanol and cyclohexanol; and (6) aromatic alcohols such as phenol, nonylphenol, benzyl alcohol, monostyrenated phenol, distyrenated phenol, and tristyrenated phenol.

[0040] Specific examples of carboxylic acids used as raw materials for the nonionic surfactant (C) include: (1) linear alkyl carboxylic acids such as octylic acid, nonanoic acid, decanoic acid, undecanoic acid, dodecanoic acid, tridecanoic acid, tetradecanoic acid, pentadecanoic acid, hexadecanoic acid, heptadecanoic acid, octadecanoic acid, nonadecanoic acid, eicosanoic acid, heneicosanoic acid, and docosanoic acid; (2) branched alkyl carboxylic acids such as 2-ethylhexanoic acid, isododecanoic acid, isotridecanoic acid, isotetradecanoic acid, isohexadecanoic acid, and isooctadecanoic acid; (3) linear alkenyl carboxylic acids such as octadecenoic acid, octadecadienoic acid, and octadecatrienoic acid; (4) aromatic carboxylic acids such as benzoic acid; and (5) hydroxycarboxylic acids such as ricinoleic acid.

[0041] The alkylene oxide used as a raw material for forming the (poly)oxyalkylene structure of the nonionic surfactant (C) is preferably an alkylene oxide having 2 to 4 carbon atoms. Specific examples of alkylene oxide include ethylene oxide, propylene oxide, and butylene oxide. The number of moles of alkylene oxide added is set appropriately, but is preferably 0.1 to 250 moles, more preferably 1 to 200 moles, and even more preferably 2 to 150 moles. Any combination of the above upper and lower limits is also possible. The number of moles of alkylene oxide added indicates the number of moles of alkylene oxide per mole of the compound to be added in the charged raw material. As the alkylene oxide, one type of alkylene oxide may be used alone, or two or more types of alkylene oxides may be used in appropriate combination. When two or more types of alkylene oxide are used, the addition form may be any of block addition, random addition, and a combination of block addition and random addition, and is not particularly limited.

[0042] Specific examples of polyhydric alcohols used as raw materials for the nonionic surfactant (C) include ethylene glycol, propylene glycol, 1,3-propanediol, 1,2-butanediol, 1,3-butanediol, 1,4-butanediol, 2-methyl-1,2-propanediol, 1,5-pentanediol, 1,6-hexanediol, 2,5-hexanediol, 2-methyl-2,4-pentanediol, 2,3-dimethyl-2,3-butanediol, glycerin, diglycerin, 2-methyl-2-hydroxymethyl-1,3-propanediol, trimethylolpropane, sorbitan, pentaerythritol, and sorbitol.

[0043] Specific examples of the aliphatic amine or primary organic amine used as a raw material for the nonionic surfactant (C) include methylamine, ethylamine, butylamine, octylamine, laurylamine, octadecylamine (stearylamine), octadecenylamine, and coconut amine.

[0044] Specific examples of fatty acid amides used as raw materials for the nonionic surfactant (C) include octylic acid amide, lauric acid amide, palmitic acid amide, stearic acid amide, oleic acid amide, behenic acid amide, and lignoceric acid amide.

[0045] Specific examples of the compound (C1) in which an alkylene oxide is added to a primary organic amine include, for example, 3 moles of ethylene oxide (hereinafter referred to as EO) added to 1 mole of laurylamine, 10 moles of EO added to 1 mole of laurylamine, 10 moles of EO added to 1 mole of stearylamine, and 15 moles of EO added to 1 mole of stearylamine. The number of moles of alkylene oxide added in the compound (C1) can be appropriately set, but is preferably 1 mole or more and 25 moles or less, more preferably 3 moles or more and 20 moles or less. Ranges in which the above upper and lower limits are arbitrarily combined are also contemplated.

[0046] In the treating agent, the lower limit of the content of the compound (C1) obtained by adding an alkylene oxide to a primary organic amine is preferably 0.1% by mass or more, more preferably 1% by mass or more. The upper limit of the content of such compound (C1) is preferably 10% by mass or less, more preferably 5% by mass or less. By specifying the content within this range, the tar cleaning ability can be further improved. Note that ranges that combine the above upper and lower limits are also contemplated.

[0047] Specific examples of the nonionic surfactant (C) other than those mentioned above include a compound obtained by adding 10 moles of EO to 1 mole of stearyl alcohol, a compound obtained by adding 10 moles of EO to 1 mole of isotridecanol, a compound obtained by randomly adding 10 moles of EO and 10 moles of propylene oxide (hereinafter referred to as PO) to 1 mole of isotridecanol, a compound obtained by adding 10 moles of EO to 1 mole of hydrogenated castor oil, a compound obtained by esterifying a compound obtained by adding 20 moles of EO to 1 mole of hydrogenated castor oil with 3 moles of oleic acid, a compound obtained by crosslinking a compound obtained by adding 25 moles of EO to 1 mole of hydrogenated castor oil with adipic acid and terminally esterifying it with stearic acid (mass average molecular weight 5000), sorbitan monolaurate, a compound obtained by adding 10 moles of EO to 1 mole of sorbitan trioleate, an ester of 1 mole of diglycerin and 2 moles of isostearic acid, a diester of polyethylene glycol (mass average molecular weight 600) and lauric acid, a diester of polyethylene glycol (mass average molecular weight 600) and oleic acid, and oleyl diethanolamide.

[0048] These nonionic surfactants (C) may be used singly or in combination of two or more. The lower limit of the content of the nonionic surfactant (C) in the treatment agent is preferably 20% by mass or more, more preferably 25% by mass or more. The upper limit of the content of the nonionic surfactant (C) is preferably 70% by mass or less, more preferably 65% ​​by mass or less. By specifying the content within this range, the stability of the appearance of the treatment agent can be improved, and solvents of different polarities, such as water and / or organic solvents, can be used as diluents when applying the treatment agent to synthetic fibers. Any combination of the above upper and lower limits is also contemplated.

[0049] The synthetic fiber treatment agent of the present invention preferably contains 15% by mass or more and 80% by mass or less of the smoothing agent (A), 0.1% by mass or more and 15% by mass or less of the ionic surfactant (B), and 15% by mass or more and 80% by mass or less of the nonionic surfactant (C), assuming the total content of the smoothing agent (A), ionic surfactant (B), and nonionic surfactant to be 100% by mass. By specifying the content within these ranges, the effects of the present invention can be further improved.

[0050] (Peroxide Value) The peroxide value detected from the treatment agent is 100 meq / kg or less, preferably 50 meq / kg or less, and more preferably 20 meq / kg or less. Even if an increase in the peroxide value is observed during storage and exceeds 0 meq / kg, as long as it is within this range, tar cleaning performance can be improved and low smoke generation can be achieved. The peroxide value in the treatment agent can be measured by potentiometric titration in accordance with the measurement method (peroxide value (chloroform method)) in the "Standard Methods for the Analysis of Fats, Oils and Related Materials" established by the Japan Oil Chemists' Society.

[0051] (Method for manufacturing the treatment agent) The treatment agent is filled into a product container after mixing the above-mentioned components. From the viewpoint of suppressing the peroxide value, the raw materials for the treatment agent are preferably stored at 80°C or lower, more preferably 10°C or higher and 50°C or lower, and even more preferably 20°C or higher and 30°C or lower. The filling rate of the treatment agent in the product container is preferably specified to be in the range of 60% by volume or higher and 100% by volume or lower, as calculated from the following formula (1) at atmospheric pressure and 25°C:

[0052]

[0053] By specifying the temperature within this range, the oxygen contacted by the treating agent is reduced, the increase in peroxide value is suppressed, and the tar cleaning properties can be improved while producing less smoke. The filling temperature of the treating agent into the product container is preferably 20°C or higher and 80°C or lower, and more preferably 50°C or lower. A filling temperature of 20°C or higher reduces the viscosity of the treating agent, improving handling properties, such as increasing the filling speed of the treating agent. A filling temperature of 80°C or lower reduces the reaction between oxygen and the treating agent, suppressing the increase in peroxide value. The storage temperature of the treating agent filled into the product container is preferably 80°C or lower, more preferably 10°C or higher and 50°C or lower, and even more preferably 20°C or higher and 30°C or lower, from the viewpoint of suppressing the increase in peroxide value. It is preferable to adjust the temperature of the treating agent to an appropriate temperature for each treating agent before use. When filling the treating agent into the product container, a method of pumping with nitrogen or using a pump is preferred, from the viewpoint of avoiding contact with oxygen and suppressing the increase in peroxide value.

[0054] It is preferable that the gas-liquid contact area of ​​the treatment agent in the product container / the volume of the treatment agent = 0 [1 / cm] or more and 0.1 [1 / cm] or less (25°C). By specifying this range, contact between the treatment agent and oxygen can be reduced, and an increase in the peroxide value can be suppressed.

[0055] (Others) The concentration of Cu ions in the treatment agent is preferably 50 ppm or less, more preferably 10 ppm or less, even more preferably 5 ppm or less, and particularly preferably 1 ppm or less. By specifying this concentration, an increase in smoke generation after long-term storage can be suppressed.

[0056] The concentration of Fe ions in the treatment agent is preferably 50 ppm or less, more preferably 10 ppm or less, even more preferably 5 ppm or less, and particularly preferably 1 ppm or less. By specifying this concentration, an increase in smoke generation after long-term storage can be suppressed.

[0057] In order to suppress an increase in Cu ions and Fe ions in the treatment agent, it is preferable to use equipment or devices made of aluminum, stainless steel, ceramic, fluororesin, or glass in the processes of product synthesis, storage, transportation, blending, neutralization, dissolution, filtration, purification, etc. Furthermore, the raw materials or treatment agent may be subjected to ion exchange, adsorption treatment using inorganic adsorbents, crystallization, etc. The concentrations of Cu ions and Fe ions in the treatment agent can be determined by ICP atomic emission spectrometry.

[0058] Further, as other components, the treatment agent may contain metal deactivators such as benzotriazole, dialkylmercaptothiadiazole, citric acid, tartaric acid, ascorbic acid, amino acids, etc.

[0059] The iodine value (IV) of the treatment agent is preferably 10 meq / kg or more and 60 meq / kg or less. When the iodine value (IV) is 10 meq / kg or more, the melting point of the treatment agent is lowered and stability at low temperatures is improved, eliminating the need to store the treatment agent at high temperatures. The handling properties of the treatment agent can also be improved. When the iodine value (IV) is 60 meq / kg or less, an increase in the peroxide value can be suppressed. Furthermore, problems in post-processing, such as deterioration of the treatment agent adhering to the yarn and poor unwinding, can also be resolved. The iodine value (IV) in the treatment agent can be measured in accordance with the measurement method (iodine value (Wiess-cyclohexane method)) in the "Standard Methods for the Analysis of Fats, Oils, and Related Materials" established by the Japan Oil Chemists' Society.

[0060] Furthermore, a radical scavenger such as a light stabilizer or a phenolic antioxidant may be added during or after the production of the treatment agent. The molecular weight of the light stabilizer or radical scavenger is preferably 300 g / mol or more, more preferably 450 g / mol or more, and even more preferably 600 g / mol or more, from the viewpoint of suppressing smoke generation from the added compound itself. The amount of other components used in combination can be specified within a range that does not impair the effects of the present invention.

[0061] Second Embodiment Next, a second embodiment of the synthetic fiber according to the present invention will be described. The synthetic fiber of this embodiment is coated with the treatment agent of the first embodiment. When the treatment agent is applied to the synthetic fiber, it may be in the form of a dilution diluted with a dilution solvent, such as an organic solvent solution or an aqueous liquid. From the viewpoint of the adhesion of the treatment agent to the fiber and economic efficiency, it is preferable to use a hydrocarbon having 10 to 15 carbon atoms and / or water as the dilution solvent. The dilution liquid, such as an aqueous liquid, is applied to the synthetic fiber during, for example, a spinning or drawing process. The dilution solvent applied to the synthetic fiber may be evaporated during a drawing or drying process. The process for applying the dilution liquid is not particularly limited as long as it is a spinning process. The effects of the present invention can be further enhanced by using the synthetic fiber in manufacturing equipment or processes that include a step of passing the synthetic fiber through rollers at 150°C or higher during the drawing or heat treatment process.

[0062] Specific examples of synthetic fibers to which the treatment agent of this embodiment can be applied include, but are not limited to, (1) polyester fibers such as polyethylene terephthalate (PET), polytrimethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polylactic acid, and composite fibers containing these polyester resins, (2) polyamide fibers such as nylon 6 and nylon 66, (3) polyacrylic fibers such as polyacrylic and modacrylic, and (4) polyolefin fibers such as polyethylene and polypropylene. Of these, the treatment agent is preferably applied to polyester fibers and polyamide fibers.

[0063] There are no particular restrictions on the proportion of the treatment agent applied to the synthetic fibers, but it is preferable to apply the treatment agent at a proportion of 0.1% by mass to 3% by mass (excluding solvents such as water) relative to the synthetic fibers. This configuration further improves the effects of the present invention. There are also no particular restrictions on the method for applying the treatment agent, and known methods such as roller oiling, guide oiling using a metering pump, immersion oiling, and spray oiling can be used.

[0064] In the present invention, the use of the synthetic fiber is not particularly limited, but synthetic fibers used in industrial materials are preferred, such as fibers for airbags, seat belts, tire cords, carpets, tents, advertising fabrics, fishing nets, conveyor belts, ropes, and other fields such as automobiles, construction, commerce, agriculture, fisheries, and civil engineering.

[0065] The effects of the treatment agent and synthetic fibers of the above embodiment will be described. (1-1) The treatment agent of the above embodiment contains an ester compound (A), and the peroxide value detected from the treatment agent is specified to be 100 meq / kg or less. Therefore, tar cleaning properties can be improved and low smoke generation can be achieved. In particular, even when the treatment agent is stored for a long period of time, deterioration of the components in the treatment agent is suppressed, and tar cleaning properties and low smoke generation can be maintained even after long-term storage.

[0066] <Reference Embodiment 1> The following describes an antioxidant according to Reference Embodiment 1. The following description focuses on the differences from the treatment agent described above.

[0067] The antioxidant of this embodiment contains a thiodipropionic acid ester, more specifically, an ester compound of a Guerbet alcohol having from 24 to 32 carbon atoms and thiodipropionic acid, and is used by being blended into a treatment agent. The antioxidant of this embodiment may also be used as a method for preventing oxidation of a treatment agent by blending a thiodipropionic acid ester, more specifically, an ester compound of a Guerbet alcohol having from 24 to 32 carbon atoms, into the treatment agent.

[0068] The effects of the antioxidant of the above embodiment will be described. (2-1) The antioxidant of this embodiment is used by blending it into a treatment agent and contains a thiodipropionic acid ester, more specifically, an ester compound of a Guerbet alcohol having 24 to 32 carbon atoms and thiodipropionic acid. This improves the long-term storage stability of the treatment agent. Furthermore, this eliminates the need for processes or measures, such as filling the product container with nitrogen to suppress the reaction between oxygen and the treatment agent, thereby improving work efficiency. Furthermore, this eliminates the need to store the treatment agent in a low-temperature environment, improving product handleability.

[0069] In particular, when the treatment agent contains vegetable oil or fish oil, which are prone to component deterioration due to oxidation, the deterioration of such components can be suppressed, and the function as a smoothing agent can be maintained. <Reference Embodiment 2> The smoke suppressant of Reference Embodiment 2 will be described below. The following description will focus on the differences from the treatment agent described above.

[0070] The smoke suppressant of this embodiment contains a thiodipropionic acid ester, more specifically, an ester compound of a Guerbet alcohol having from 24 to 32 carbon atoms and thiodipropionic acid, and is used in a fiber drawing process. The smoke suppressant of this embodiment may also be used as a smoke suppression method in which a thiodipropionic acid ester, more specifically, an ester compound of a Guerbet alcohol having from 24 to 32 carbon atoms and thiodipropionic acid is applied to a fiber before the drawing process.

[0071] The effects of the smoke suppressant of the above embodiment will be described. (3-1) The smoke suppressant of this embodiment is used by being blended into a treatment agent and contains a thiodipropionic acid ester, more specifically, an ester compound of a Guerbet alcohol having from 24 to 32 carbon atoms and thiodipropionic acid. Therefore, it is possible to reduce smoke generation while exhibiting a smoothing function, particularly in the process of passing through heated rollers, where smoke generation is likely to occur. The ester compound contained in such a smoke suppressant is less likely to decompose during long-term storage or to thermally decompose during spinning, thereby generating low-molecular-weight decomposition products that are likely to cause smoke generation.

[0072] The above embodiment may be modified as follows: The above embodiment and the following modifications may be combined with each other to the extent that they are not technically inconsistent. The treatment agent of the above embodiment may further contain components that are typically used in treatment agents, such as stabilizers, antistatic agents, binders, antioxidants, UV absorbers, defoamers, preservatives, and rust inhibitors, other than those mentioned above, during or after production of the treatment agent, to maintain the quality of the treatment agent, as long as the effects of the present invention are not impaired.

[0073] The treatment agent of the above embodiment does not necessarily contain the ionic surfactant (B) and the nonionic surfactant (C). The treatment agent may contain both the ionic surfactant (B) and the nonionic surfactant (C), or may contain either the ionic surfactant (B) or the nonionic surfactant (C).

[0074] Examples will be given below to more specifically explain the configuration and effects of the present invention, but the present invention is not limited to these examples. In the following explanation of the examples and comparative examples, parts mean parts by mass, and % means % by mass, unless otherwise specified.

[0075] Test Section 1 (Preparation of Treatment Agent) (Example 1) As shown in Table 1, the ester compound (A) was 5 parts (%) of di(2-decyl-1-tetradecanol) thiodipropionate (A1-1), 30 parts (%) of a triester of trimethylolpropane and a mixed acid (A2-1), 0.5 parts (%) of a sodium salt of secondary alkane sulfonate (B1-1) and 1 part (%) of an oleyl phosphate ester-dibutylethanolamine salt (B2-2) as ionic surfactants (B), 2.5 parts (%) of a compound (C1-2) in which 10 moles of EO are added to 1 mole of laurylamine, and 10 moles of EO are added to 1 mole of stearyl alcohol as nonionic surfactants (C). A treatment agent for Example 1 was prepared containing 10 parts (%) of (C2-1), 20 parts (%) of a compound (C2-3) obtained by randomly adding 10 moles of EO and 10 moles of PO to 1 mole of isotridecanol, 20 parts (%) of a compound (C2-5) obtained by esterifying a compound obtained by adding 20 moles of EO to 1 mole of hydrogenated castor oil with 3 moles of oleic acid, 5 parts (%) of sorbitan monolaurate (C2-7), 5 parts (%) of a diester (C2-11) of polyethylene glycol (mass average molecular weight 600) and oleic acid, and 1 part (%) of 4,4′-butylidenebis(6-tert-butyl-m-cresol) (D1-2) as another component (D).

[0076] The ester compound in Example 1 had been stored in a polyethylene container at 25°C so that the filling rate was 90% by volume and the gas-liquid contact area / treatment agent volume was 0.07 [1 / cm], and the compound had been in storage for less than two weeks since synthesis.

[0077] The compounds other than the ester compound were stored in polyethylene containers at 25°C with a filling rate of 90% by volume and a gas-liquid contact area / treatment agent volume of 0.07 [1 / cm], and were used within less than two weeks of synthesis.

[0078] The treating agents were prepared by adjusting the temperature of each raw material compound to 40°C in a water bath and then using them in a nitrogen atmosphere. (Examples 2 to 14, Comparative Examples 1 to 4) The treating agents of Examples 2 to 14 and Comparative Examples 1 to 4 were prepared in the same manner as the treating agent of Example 1, so as to contain the ester compound (A), ionic surfactant (B), nonionic surfactant (C), and other component (D) in the proportions shown in Table 1.

[0079] The ester compounds used in Examples 7, 9, 10, and 14 were placed in a glass beaker (inner diameter 4.5 cm) so that the gas-liquid contact area / volume was 0.25 [1 / cm] and stored at 70°C for 2 weeks.

[0080] The ester compounds in the examples other than those described above were stored in polyethylene containers at 25°C so that the filling rate was 90% by volume and the gas-liquid contact area / treatment agent volume = 0.07 [1 / cm], and were used within two weeks of synthesis.

[0081] The ester compound used in Comparative Example 1 was placed in a glass beaker (inner diameter 4.5 cm) so that the gas-liquid contact area / volume was 0.25 [1 / cm], and stored at 70°C for 4 weeks.

[0082] In Comparative Example 2, an ester compound immediately after synthesis was used, and the prepared treating agent was placed in a glass beaker (inner diameter 4.5 cm) so that the gas-liquid contact area / volume ratio was 0.5, and the beaker was stored at 70°C for 6 weeks.

[0083] The compounds other than the ester compound were stored in polyethylene containers at 25°C with a filling rate of 90% by volume and a gas-liquid contact area / treatment agent volume of 0.07 [1 / cm], and were used within two weeks of synthesis.

[0084] The treating agent was prepared by adjusting the temperature of each raw material compound to 40° C. in a water bath under a nitrogen atmosphere. The type and content of the ester compound (A), the type and content of the ionic surfactant (B), the type and content of the nonionic surfactant (C), and the type and content of the other component (D) are shown in the "Ester compound (A)" column, the "Ionic surfactant (B)" column, the "Nonionic surfactant (C)" column, and the "Other component (D)" column in Table 1, respectively.

[0085] The peroxide value in each treatment agent was measured using potentiometric titration in accordance with the measurement method (peroxide value (chloroform method)) in the "Standard Test Methods for the Analysis of Fats, Oils and Related Materials" established by the Japan Oil Chemists' Society. The peroxide value values ​​of the treatment agents are shown in the "Peroxide Value" column of Table 1.

[0086] The iodine value (IV) of each treatment agent was measured in accordance with the measurement method (iodine value (Wijs-cyclohexane method)) in the "Standard Test Methods for the Analysis of Fats, Oils and Related Materials" established by the Japan Oil Chemists' Society. The iodine value (IV) values ​​of the treatment agents are shown in the "Iodine Value" column of Table 1.

[0087] The Fe and Cu contents in all the prepared treatment agents were measured by ICP-AES and confirmed to be 1 ppm or less. For ICP-AES, an ICPE-9000 (manufactured by Shimadzu Corporation) was used, and a solution prepared by diluting 0.5 g of sample with ultrapure water to a total volume of 100 mL was used for analysis.

[0088]

[0089] Details of the ester compound (A), ionic surfactant (B), nonionic surfactant (C), and other component (D) shown in Table 1 are as follows. <Ester Compounds (A)> (Ester compounds (A1) having a thioether bond in the molecule) A1-1: di(2-decyl-1-tetradecanol) thiodipropionate A1-2: di(2-dodecyl-1-hexadecanol) thiodipropionate A1-3: dioleyl thiodipropionate A1-4: di(2-octyl-1-decanol) thiodipropionate A1-5: 2-ethylhexyl (lauryl thiopropionate) (Complete ester compounds (A2) of a trivalent or greater but tetravalent polyhydric alcohol and a fatty acid) A2-1: triester of trimethylolpropane and a mixed acid (a mixture of palm kernel fatty acid and plant-based oleic acid, in a mass ratio of 4:6) A2-2: rapeseed oil (Other ester compounds (A)) A3-1: dioleyl adipate A3-2: oleyl erucinate (Other lubricating agents) rA-1: mineral oil (40 mPa·s at 40°C) <Ionic surfactants (B)> (Sulfonic acid compounds (B1)) B1-1: secondary alkane sulfonate sodium salt (C=11 or more and 14 or less) B1-2: dioctyl sulfosuccinate sodium salt B1-3: α-olefin sulfonate sodium salt (Other ionic surfactants (B)) B2-1: oleic acid potassium salt B2-2: oleyl phosphate ester-dibutylethanolamine salt B2-3: isocetyl phosphate ester-triethanolamine salt <Nonionic surfactants (C)> (compounds (C1) in which alkylene oxide is added to primary organic amine) C1-1: 3 moles of EO added to 1 mole of laurylamine C1-2: 10 moles of EO added to 1 mole of laurylamine C1-3: 10 moles of EO added to 1 mole of stearylamine C1-4: 15 moles of EO added to 1 mole of stearylamine (other nonionic surfactants (C)) C2-1: 10 moles of EO added to 1 mole of stearyl alcohol C2-2: 10 moles of EO added to 1 mole of isotridecanol C2-3: 10 moles of EO and 10 moles of PO randomly added to 1 mole of isotridecanolC2-4: A compound obtained by adding 10 moles of EO to 1 mole of hydrogenated castor oil. C2-5: A compound obtained by esterifying a compound obtained by adding 20 moles of EO to 1 mole of hydrogenated castor oil with 3 moles of oleic acid. C2-6: A compound obtained by adding 25 moles of EO to 1 mole of hydrogenated castor oil with adipic acid and terminally esterifying with stearic acid (mass average molecular weight 5000). C2-7: Sorbitan monolaurate. C2-8: A compound obtained by adding 10 moles of EO to 1 mole of sorbitan trioleate. C2-9: An ester of 1 mole of diglycerin and 2 moles of isostearic acid. C2-10: A diester of polyethylene glycol (mass average molecular weight 600) and lauric acid. C2-11: A diester of polyethylene glycol (mass average molecular weight 600) and oleic acid. C2-12: Oleyl diethanolamide. <Other components (D)> D1-1: Tris(3,5-di-tert-butyl-4-hydroxybenzyl isocyanurate) D1-2: 4,4'-butylidenebis(6-tert-butyl-m-cresol) D1-3: Tris(4-tert-butyl-3-hydroxy-2,6-dimethylbenzyl isocyanurate) D1-4: 2,2'-methylenebis(4-ethyl-6-tert-butylphenol) Test Section 2 (Evaluation of Tar Cleaning Ability) Immediately after preparation, each treatment agent was diluted with an organic solvent (a mixed solvent of hexane and ethanol) to give a 15% diluted treatment solution. The diluted solution was applied to an unoiled polyethylene terephthalate fiber having 1000 dtex, 126 filaments, and an intrinsic viscosity of 0.93 using the guided oiling method so that the amount applied was 5.0% as nonvolatile content. The fibers were run at an initial tension of 1.5 kg and a yarn speed of 0.1 m / min in contact with a matte chrome pin having a surface temperature of 240°C. The brown tar adhering to the fiber run location and its surroundings was rubbed at 180°C with a cotton swab impregnated with a glycerin solution prepared to be 5% NaOH, and the number of times it was rubbed until the brown tar disappeared was counted. Tar cleanability was evaluated according to the following criteria. The results are shown in the "Tar cleanability" column of Table 1.

[0090] Evaluation criteria for tar cleaning performance: ⊚ (Good): Less than 100 times; ◯ (Acceptable): 100 to 200 times; × (Unacceptable): 200 or more times. Test Section 3 (Smoke Generation Evaluation): Each prepared treatment agent was uniformly diluted with ion-exchanged water or an organic solvent (a mixed solvent of hexane and ethanol) as needed to prepare a 15% diluted treatment agent solution. The diluted solution was applied to an unoiled polyethylene terephthalate fiber having 1000 dtex, 126 filaments, and an intrinsic viscosity of 0.93 using an oiling roller oiling method, so that the amount applied was 1.0% as nonvolatile matter. The diluted solution was then dried to prepare a test yarn. This was brought into contact with a heated roller at 220°C at a yarn speed of 300 m / min, and the smoke generation observed around the heated roller was evaluated according to the following criteria. The results are shown in the "Smoke Generation" column in Table 1.

[0091] Evaluation criteria for smoke generation ⊚ (good): no smoke generation observed ◯ (pass): slight smoke generation observed × (poor): clear smoke generation observed As is clear from the results in Table 1, the treatment agents of each example were evaluated as pass or better in both tar cleaning ability and smoke generation. According to the present invention, it is possible to improve tar cleaning ability and reduce smoke generation, particularly in processes such as spinning synthetic fibers.

[0092] The present disclosure also encompasses the following aspects: (Appendix 1) A synthetic fiber treatment agent containing an ester compound (A) and used in a spinning or drawing process, characterized in that the peroxide value detected from the synthetic fiber treatment agent is 100 meq / kg or less.

[0093] (Appendix 2) The synthetic fiber treating agent according to Appendix 1, wherein the peroxide value detected from the synthetic fiber treating agent is 50 meq / kg or less.

[0094] (Appendix 3) The synthetic fiber treating agent according to Appendix 1, wherein the ester compound (A) comprises an ester compound (A1) having a thioether bond in the molecule.

[0095] (Appendix 4) The synthetic fiber treating agent according to Appendix 1, wherein the ester compound (A) comprises a complete ester compound (A2) of a trihydric or more and tetrahydric or less polyhydric alcohol with a fatty acid.

[0096] (Appendix 5) The synthetic fiber treatment agent according to Appendix 1, further comprising an ionic surfactant (B). (Appendix 6) The synthetic fiber treatment agent according to Appendix 5, wherein the ionic surfactant (B) comprises a sulfonic acid compound (B1).

[0097] (Appendix 7) The synthetic fiber treatment agent according to Appendix 1, further comprising a nonionic surfactant (C). (Appendix 8) The synthetic fiber treatment agent according to Appendix 7, wherein the nonionic surfactant (C) comprises a compound (C1) in which an alkylene oxide is added to a primary organic amine.

[0098] (Appendix 9) A synthetic fiber having the synthetic fiber treating agent according to any one of Appendices 1 to 8 adhered thereto.

[0099] (Appendix 10) A method for producing the synthetic fiber treatment agent according to any one of Appendices 1 to 8, characterized in that the filling rate calculated from the following formula (1) at atmospheric pressure and 25°C is 60% by volume or more and 100% by volume or less:

[0100]

[0101] (Appendix 11) A synthetic fiber treatment agent containing an ester compound, characterized in that the concentration of Cu ions and the concentration of Fe ions in the synthetic fiber treatment agent are each 50 ppm or less.

[0102] (Appendix 12) A synthetic fiber treatment agent comprising an ester compound of a Guerbet alcohol having from 24 to 32 carbon atoms and thiodipropionic acid, and a sulfonic acid compound.

[0103] (Appendix 13) A synthetic fiber treatment agent containing an ester compound, characterized in that a peroxide value detected from the synthetic fiber treatment agent is 100 meq / kg or less, and the synthetic fiber treatment agent further contains a radical scavenger or a metal deactivator.

[0104] (Appendix 14) A synthetic fiber treatment agent containing an ester compound, characterized in that a peroxide value detected from the synthetic fiber treatment agent is 100 meq / kg or less, and an iodine value is 10 meq / kg or more and 60 meq / kg or less.

[0105] (Appendix 15) A synthetic fiber treatment agent containing an ester compound, wherein the ester compound includes a thiodipropionic acid ester, and the concentrations of Cu ions and Fe ions in the synthetic fiber treatment agent are each 50 ppm or less.

[0106] (Appendix 16) A treatment agent for synthetic fibers containing an ester compound (A), wherein the ester compound (A) comprises an ester compound (A1) having a thioether bond in the molecule, the treatment agent for synthetic fibers contains the ester compound (A1) having a thioether bond in the molecule in a proportion of 0.5% by mass or more and 5% by mass or less, and the concentrations of Cu ions and Fe ions in the treatment agent are each 50 ppm or less.

Claims

1. A synthetic fiber treatment agent containing an ester compound (A), characterized in that the peroxide value detected from the synthetic fiber treatment agent is 100 meq / kg or less.

2. The synthetic fiber treating agent according to claim 1, wherein the peroxide value detected from the synthetic fiber treating agent is 50 meq / kg or less.

3. The synthetic fiber processing agent according to claim 1, wherein the ester compound (A) comprises an ester compound (A1) having a thioether bond in the molecule.

4. The synthetic fiber treatment agent according to claim 1, wherein the ester compound (A) comprises a complete ester compound (A2) of a trihydric or more and tetrahydric or less polyhydric alcohol with a fatty acid.

5. The synthetic fiber treating agent according to claim 1, further comprising an ionic surfactant (B).

6. The synthetic fiber treatment agent according to claim 5, wherein the ionic surfactant (B) contains a sulfonic acid compound (B1).

7. The synthetic fiber treating agent according to claim 1, further comprising a nonionic surfactant (C).

8. The synthetic fiber treatment agent according to claim 7, wherein the nonionic surfactant (C) comprises a compound (C1) in which an alkylene oxide is added to a primary organic amine.

9. Synthetic fibers characterized by having the synthetic fiber treatment agent according to any one of claims 1 to 8 adhered thereto.

10. A method for producing a synthetic fiber treatment agent according to any one of claims 1 to 8, characterized in that the filling rate calculated from the following formula (1) at atmospheric pressure and 25°C is 60% by volume or more and 100% by volume or less: