Treatment agent for polyester-based synthetic fiber, first treatment agent for polyester-based synthetic fiber, second treatment agent for polyester-based synthetic fiber, and polyester-based synthetic fiber

Abstract

The present invention addresses the problem of providing: a treatment agent for a polyester-based synthetic fiber, which makes it possible to improve the quality of fibers having the treatment agent attached thereto; and a polyester-based synthetic fiber obtained using the treatment agent. This treatment agent for a polyester-based synthetic fiber is characterized by comprising a smoothing agent (A), an antistatic agent (B), and a nonionic surfactant (C), the nonionic surfactant (C) comprising a (poly)oxyalkylene derivative (C1) of an aromatic alcohol. The (poly)oxyalkylene derivative (C1) of the aromatic alcohol is a compound having a structure that at least one alkylene oxide selected from ethylene oxide and propylene oxide, in a total amount of 1 mol to 100 mol inclusive are added per 1 mole of an alcohol represented by the following general formula (1). In the general formula (1), R1 represents a hydrocarbon group having 10-20 carbon atoms.

Description

Treatment agent for polyester synthetic fibers, first treatment agent for polyester synthetic fibers, second treatment agent for polyester synthetic fibers, and polyester synthetic fibers

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

[0002] For example, in the spinning and drawing process and finishing process of polyester synthetic fibers, a treatment for attaching a synthetic fiber treating agent to the surface of the fiber may be carried out from the viewpoint of reducing friction of the fiber, improving antistatic properties, and improving bundling properties.

[0003] For example, known treatment agents for polyester synthetic fibers are disclosed in Patent Documents 1 and 2. Patent Document 1 discloses a spinning oil composition for polyester fibers that contains a potassium salt of an alkyl phosphate ester having a specified alkyl group, a phosphoric acid neutralized product of an ethylene oxide adduct of a specified alkylamine or substituted alkylamine, and an alkylene oxide adduct of a specified aromatic alcohol.

[0004] Patent Document 2 discloses a treatment agent for polyester synthetic fibers, which contains an alkali metal salt of an alkyl phosphate ester having a predetermined alkyl group, a surfactant such as a polyoxyalkylene alkyl ether, and a metal phosphate such as a dimetal hydrogen phosphate in predetermined proportions, wherein the alkali metal salt of the alkyl phosphate ester has an acid value of 0.1 to 90 KOHmg / g.

[0005] Japanese Patent Application Laid-open No. 60-224868 Patent No. 5796922

[0006] However, conventional polyester synthetic fiber treatment agents have the problem that the smoothness and antistatic properties of the fibers to which they are applied are insufficient, resulting in a decrease in the quality of the produced fibers.Furthermore, there is a problem that components in the treatment agent bleed out, causing adhesion on the fiber surface, resulting in a decrease in fiber quality.

[0007] As a result of research aimed at solving the above-mentioned problems, the present inventors have found that a treatment agent for polyester synthetic fibers containing a (poly)oxyalkylene derivative of a specific aromatic alcohol as a nonionic surfactant is exactly suitable.

[0008] The following describes various aspects of the treatment agent for polyester synthetic fibers that solve the above-mentioned problems. Aspect 1 of the treatment agent for polyester synthetic fibers contains a smoothing agent (A), an antistatic agent (B), and a nonionic surfactant (C), and is characterized in that the nonionic surfactant (C) contains a (poly)oxyalkylene derivative (C1) of an aromatic alcohol.

[0009] The (poly)oxyalkylene derivative (C1) of an aromatic alcohol is a compound obtained by adding 1 mole or more and 100 moles or less in total of at least one alkylene oxide selected from ethylene oxide and propylene oxide to 1 mole of an alcohol represented by the following general formula (1):

[0010] In general formula (1), R １ represents a hydrocarbon group having from 10 to 20 carbon atoms. Aspect 2 is the treating agent for polyester synthetic fibers according to Aspect 1, wherein the smoothing agent (A) contains an organic phosphate ester (A1) which is at least one selected from phosphate esters of aliphatic alcohols having from 12 to 20 carbon atoms and salts thereof.

[0011] In Aspect 3, in the treatment agent for polyester synthetic fibers according to Aspect 2, the treatment agent for polyester synthetic fibers contains the organic phosphate ester (A1) in a proportion of 16% by mass or more, relative to the total content of the smoothing agent (A), the antistatic agent (B), and the nonionic surfactant (C) being 100% by mass.

[0012] In Aspect 4, in the treatment agent for polyester synthetic fibers according to any one of Aspects 1 to 3, the total content of the smoothing agent other than the organic phosphate ester is 40% by mass or less, relative to 100% by mass of the total content of the smoothing agent (A), the antistatic agent (B), and the nonionic surfactant (C). The organic phosphate ester is at least one selected from the group consisting of a phosphate ester of an aliphatic alcohol, a phosphate ester of an aliphatic alcohol having an oxyalkylene group, and salts thereof.

[0013] Aspect 5 is the treating agent for polyester-based synthetic fibers according to any one of Aspects 1 to 4, wherein the antistatic agent (B) comprises an inorganic phosphate compound (B1) which is at least one selected from dimetal hydrogen phosphates and trimetal phosphates.

[0014] In Aspect 6, in the treatment agent for polyester synthetic fibers according to Aspect 5, the treatment agent for polyester synthetic fibers contains the inorganic phosphate compound (B1) in an amount of 20 mass% or less, relative to the total content of the smoothing agent (A), the antistatic agent (B), and the nonionic surfactant (C) being 100 mass%.

[0015] Aspect 7 is the treating agent for polyester synthetic fibers according to any one of Aspects 1 to 6, wherein the nonionic surfactant (C) comprises a (poly)oxyalkylene amino ether (C2) that is at least one selected from (poly)oxyalkylene alkyl amino ethers and (poly)oxyalkylene alkenyl amino ethers.

[0016] In Aspect 8, in the treatment agent for polyester synthetic fibers according to any one of Aspects 1 to 7, the treatment agent for polyester synthetic fibers contains the (poly)oxyalkylene derivative of aromatic alcohol (C1) in a proportion of 5% by mass or more and 80% by mass or less, relative to the total content of the smoothing agent (A), the antistatic agent (B), and the nonionic surfactant (C) being 100% by mass.

[0017] Aspect 9 is the treatment agent for polyester-based synthetic fibers according to any one of Aspects 1 to 8, wherein, when the total content of the smoothing agent (A), the antistatic agent (B), and the nonionic surfactant (C) is taken as 100 mass%, the treatment agent for polyester-based synthetic fibers contains the smoothing agent (A) and the antistatic agent (B) in a total amount of 20 mass% to 80 mass% and the nonionic surfactant (C) in a proportion of 20 mass% to 80 mass%.

[0018] In Aspect 10, the treatment agent for polyester synthetic fibers according to any one of Aspects 1 to 9 is configured as a set including a first treatment agent for polyester synthetic fibers containing the smoothing agent (A) and the antistatic agent (B), and a second treatment agent for polyester synthetic fibers containing the nonionic surfactant (C).

[0019] Aspect 11 of the present invention relates to a first treating agent for polyester synthetic fibers, which is used in combination with a second treating agent for polyester synthetic fibers containing a nonionic surfactant (C) including an aromatic alcohol (poly)oxyalkylene derivative (C1), and which contains a smoothing agent (A) and an antistatic agent (B). The aromatic alcohol (poly)oxyalkylene derivative (C1) is a compound in which a total of 1 to 100 moles of at least one alkylene oxide selected from ethylene oxide and propylene oxide are added to 1 mole of an alcohol represented by the following general formula (1):

[0020] In general formula (1), R １represents a hydrocarbon group having from 10 to 20 carbon atoms. Aspect 12 of the second treating agent for polyester synthetic fibers is a second treating agent for polyester synthetic fibers used in combination with a first treating agent for polyester synthetic fibers containing a smoothing agent (A) and an antistatic agent (B), and is characterized by containing a nonionic surfactant (C) containing a (poly)oxyalkylene derivative (C1) of an aromatic alcohol. The (poly)oxyalkylene derivative (C1) of an aromatic alcohol is a compound in which a total of from 1 mole to 100 moles of at least one alkylene oxide selected from ethylene oxide and propylene oxide is added to 1 mole of an alcohol represented by the following general formula (1):

[0021] In general formula (1), R １ represents a hydrocarbon group having from 10 to 20 carbon atoms. A polyester synthetic fiber according to Aspect 13 is characterized in that the treating agent for polyester synthetic fibers according to any one of Aspects 1 to 10 is adhered to the polyester synthetic fiber.

[0022] In Aspect 14, the polyester synthetic fiber according to Aspect 13 is a polyester staple fiber. In Aspect 15, the polyester synthetic fiber according to Aspect 13 is used in spun yarn.

[0023] According to the present invention, the quality of fibers to which a processing agent for polyester synthetic fibers is applied can be improved.

[0024] First Embodiment A first embodiment of the treatment agent for polyester synthetic fibers (hereinafter simply referred to as the treatment agent) of the present invention will be described below. The treatment agent of this embodiment contains a smoothing agent (A), an antistatic agent (B), and a nonionic surfactant (C).

[0025] (Smoothing Agent (A)) Examples of the smoothing agent used in this embodiment include silicone oil, mineral oil, polyolefin, ester, and the like.

[0026] The ester is not particularly limited, but examples thereof include organic phosphate esters produced from phosphoric anhydride and alcohol, and ester oils produced from fatty acids and alcohol. (Ester) Examples of organic phosphate esters include alkyl phosphate esters, alkenyl phosphate esters, and salts thereof. The alkyl or alkenyl group constituting the alkyl phosphate ester is not particularly limited, and may be, for example, linear or branched.

[0027] Alcohols that can be used as raw materials for organic phosphate esters include monohydric aliphatic alcohols. Specific examples of monohydric aliphatic alcohols 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; and (2) isopropanol, isobutanol, isohexanol, 2-ethylhexanol, isononanol, isodecanol, isododecanol, isotridecanol, and isotetradecanol. (3) branched alkyl alcohols such as tetradecenol, isopentadecanol, isohexadecanol, isoheptadecanol, isooctadecanol, isononadecanol, isoeicosanol, isoheneicosanol, isodocosanol, isotricosanol, isotetracosanol, 2-decyltetradecanol, isopentacosanol, isohexacosanol, isoheptacosanol, isooctacosanol, isononacosanol, and isotriacontanol; (4) linear alkenyl alcohols such as tetradecenol, hexadecenol, heptadecenol, octadecenol, oleyl alcohol, and nonadecenol; (4) branched alkenyl alcohols such as isohexadecenol and isooctadecenol; and (5) cyclic alkyl alcohols such as cyclopentanol and cyclohexanol.

[0028] The phosphoric acid constituting the organic phosphate ester is not particularly limited and may be orthophosphoric acid or a polyphosphoric acid such as diphosphoric acid. When an organic phosphate ester salt is used as the organic phosphate ester, examples of the salt include an amine phosphate salt and a metal phosphate salt.

[0029] Examples of metal salts include alkali metal salts and alkaline earth metal salts. Specific examples of alkali metals constituting alkali metal salts include sodium, potassium, and lithium. Examples of alkaline earth metals constituting alkaline earth metal salts include metals belonging to Group 2 elements, such as calcium, magnesium, beryllium, strontium, and barium.

[0030] The amine constituting the amine salt may be any of a primary amine, a secondary amine, and a tertiary amine. Specific examples of amines constituting the amine salt include: (1) aliphatic amines such as methylamine, dimethylamine, trimethylamine, ethylamine, diethylamine, triethylamine, N-N-diisopropylethylamine, butylamine, dibutylamine, 2-methylbutylamine, tributylamine, octylamine, and dimethyllaurylamine; (2) aromatic amines or heterocyclic amines such as aniline, N-methylbenzylamine, pyridine, morpholine, piperazine, and derivatives thereof; (3) alkanolamines such as monoethanolamine, N-methylethanolamine, diethanolamine, triethanolamine, isopropanolamine, diisopropanolamine, triisopropanolamine, dibutylethanolamine, butyldiethanolamine, octyldiethanolamine, and lauryldiethanolamine; (4) arylamines such as N-methylbenzylamine; (5) polyoxyalkylene alkylamino ethers such as polyoxyethylene laurylamino ether and polyoxyethylene sterylamino ether; and (6) ammonia.

[0031] Among these, the organic phosphate ester (A1) is preferably at least one selected from phosphate esters of aliphatic alcohols having from 12 to 20 carbon atoms and salts thereof. Use of such an organic phosphate ester (A1) can reduce adhesion on the fiber surface to which the treatment agent is applied.

[0032] Specific examples of organic phosphates include alkali metal salts of lauryl phosphate, alkali metal salts of stearyl phosphate, alkali metal salts of cetyl phosphate, alkali metal salts of arachidyl phosphate, and alkali metal salts of octyl phosphate.

[0033] These organic phosphate esters may be used alone or in appropriate combination of two or more. The acid value of the organic phosphate ester is appropriately set, but is preferably 0 to 100 KOH-mg / g, more preferably 0 to 30 KOH-mg / g. By specifying the acid value within this range, emulsion stability and product handleability can be improved.

[0034] The acid value of the organic phosphate ester is calculated from the following formula by dissolving the organic phosphate ester in a mixed solvent of ethanol / xylene = 1 / 2 (volume ratio), setting the solution in a potentiometric titrator, and titrating it with a 0.1 mol / L standard solution of potassium hydroxide in methanol:

[0035] Acid value (KOH-mg / g) = (R x f x 56.11 x 0.1) / S In the formula, f: factor of 0.1 mol / L potassium hydroxide methanol standard solution, S: amount of sample collected (g, converted into solid content), R: amount of 0.1 mol / L potassium hydroxide methanol standard solution used up to the inflection point (mL).

[0036] (Other Esters) Examples of ester oils include ester oils produced from fatty acids having odd or even hydrocarbon groups and alcohols.

[0037] The fatty acid used as a raw material for the ester oil is not particularly limited in terms of the number of carbon atoms, whether or not it is branched, its valence, etc., 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 used as a raw material for the ester oil is not particularly limited in terms of the number of carbon atoms, whether or not it is branched, its valence, etc., and may be, for example, a higher alcohol, an alcohol having a cyclo ring, or an alcohol having an aromatic ring.

[0038] Specific examples of ester oils include (1) ester compounds of aliphatic monoalcohols and aliphatic monocarboxylic acids, such as octyl palmitate, oleyl laurate, oleyl oleate, isotridecyl stearate, and isotetracosyl oleate; (2) complete ester compounds of aliphatic polyhydric alcohols and aliphatic monocarboxylic acids, such as 1,6-hexanediol didecanate, glycerin trioleate, trimethylolpropane trilaurate, and pentaerythritol tetraoctate; and (3) dioleyl azelate, dioleyl thiodipropionate, diisocetyl thiodipropionate, and diisostearyl thiodipropionate. (3) ester compounds of aromatic monoalcohols and aliphatic monocarboxylic acids such as benzyl oleate and benzyl laurate; (4) ester compounds of aromatic monoalcohols and aliphatic monocarboxylic acids such as benzyl oleate and benzyl laurate; (5) ester compounds of aromatic polyhydric alcohols and aliphatic monocarboxylic acids such as bisphenol A dilaurate; (6) ester compounds of aliphatic monoalcohols and aromatic polycarboxylic acids such as bis-2-ethylhexyl phthalate, diisostearyl isophthalate and trioctyl trimellitate; and (7) natural oils and fats such as coconut oil, rapeseed oil, sunflower oil, soybean oil, castor oil, sesame oil, fish oil and beef tallow.

[0039] These ester oils may be used alone or in appropriate combination of two or more. (Other Lubricating Agents) Specific examples of silicone oils are not particularly limited, but include, for example, dimethyl silicone, phenyl-modified silicone, amino-modified silicone, amide-modified silicone, polyether-modified silicone, aminopolyether-modified silicone, alkyl-modified silicone, alkylaralkyl-modified silicone, alkylpolyether-modified silicone, ester-modified silicone, epoxy-modified silicone, carbinol-modified silicone, mercapto-modified silicone, polyoxyalkylene-modified silicone, etc.

[0040] Examples of mineral oils include aromatic hydrocarbons, paraffinic hydrocarbons, naphthenic hydrocarbons, etc. More specifically, examples include spindle oil, liquid paraffin, etc. Commercially available products of these mineral oils can be used as appropriate.

[0041] 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.

[0042] These smoothing agents (A) may be used alone or in appropriate combination of two or more. The lower limit of the content of the smoothing agent (A) in the treatment agent is set appropriately, but is preferably 1% by mass or more, more preferably 2% by mass or more. When the content is 1% by mass or more, the smoothness of the fiber to which the treatment agent is applied can be improved. The upper limit of the content of the smoothing agent (A) is set appropriately, but is preferably 90% by mass or less, more preferably 85% by mass or less. When the content is 90% by mass or less, the stability of the treatment agent can be improved. Note that ranges obtained by arbitrarily combining the above upper and lower limits are also envisioned. In this embodiment, the content of the smoothing agent (A) in the treatment agent is, for example, 2% by mass or more, 3% by mass or more, 5% by mass or more, 8% by mass or more, 10% by mass or more, 12% by mass or more, 15% by mass or more, 16% by mass or more, 19% by mass or more, 20% by mass or more, 25% by mass or more, 29% by mass or more, 35% by mass or more, 40% by mass or more, 45% by mass or more, 47% by mass or more, 50% by mass or more, 55% by mass or more, 60% by mass or more, 65% by mass or more, 68% by mass or more, 70% by mass or more, 80% by mass or more, or 84% by mass or more. Similarly, the content of the smoothing agent (A) is, for example, 84% by mass or less, 80% by mass or less, 70% by mass or less, 68% by mass or less, 65% by mass or less, 60% by mass or less, 55% by mass or less, 50% by mass or less, 47% by mass or less, 45% by mass or less, 40% by mass or less. , 35% by mass or less, 29% by mass or less, 25% by mass or less, 20% by mass or less, 19% by mass or less, 16% by mass or less, 15% by mass or less, 12% by mass or less, 10% by mass or less, 8% by mass or less, 5% by mass or less, 3% by mass or less, or 2% by mass or less.

[0043] The lower limit of the content of the organic phosphate ester (A1) in the treatment agent can be set as appropriate, but is preferably 2% by mass or more, more preferably 5% by mass or more. When the content is 2% by mass or more, adhesion on the fiber surface to which the treatment agent is applied can be further reduced. The upper limit of the content of the organic phosphate ester (A1) can be set as appropriate, but is preferably 85% by mass or less, more preferably 80% by mass or less. When the content is 85% by mass or less, the stability of the treatment agent can be improved. Note that ranges obtained by arbitrarily combining the above upper and lower limits are also contemplated. In this embodiment, the content of the organic phosphate ester (A1) in the treatment agent is, for example, 3% by mass or more, 5% by mass or more, 10% by mass or more, 12% by mass or more, 15% by mass or more, 16% by mass or more, 19% by mass or more, 25% by mass or more, 29% by mass or more, 40% by mass or more, 45% by mass or more, 47% by mass or more, 50% by mass or more, 55% by mass or more, 60% by mass or more, 63% by mass or more, 65% by mass or more, 68% by mass or more, 70% by mass or more, 80% by mass or more, or 84% by mass or more. Similarly, the content of the organic phosphate ester (A1) is, for example, 84% by mass or less, 80% by mass or less, 70% by mass or less, 68% by mass or less, 65% by mass or less, 63% by mass or less, 60% by mass or less, 55% by mass or less, 50% by mass or less, 47% by mass or less, 45% by mass or less, 40% by mass or less, 29% by mass or less, 25% by mass or less, 19% by mass or less, 16% by mass or less, 15% by mass or less, 12% by mass or less, 10% by mass or less, 5% by mass or less, or 3% by mass or less.

[0044] (Antistatic Agent (B)) Specific examples of the antistatic agent (B) used in this embodiment include, for example, (1) fatty acid salts or organic acid salts such as potassium acetate, potassium octylate, potassium oleate, and potassium lactate; (2) organic sulfonate salts such as decane sulfonate potassium salt, alkyl (having 12 to 15 carbon atoms) sulfonate sodium salt, tetradecane sulfonate sodium salt, and dodecylbenzene sulfonate sodium salt; (3) organic sulfate salts such as sodium dodecyl sulfate; and (4) polyoxyalkylene alkyl esters such as polyoxyalkylene lauryl phosphate potassium salt. (4) ammonium salts such as dimethyloctylammonium trimethylphosphate, dimethyldodecylammonium trimethylphosphate, trimethyloctylammonium chloride, and the like; (5) amphoteric compounds such as octyldimethylammonioacetate, N,N-bis(2-carboxyethyl)-octylamine sodium, and N-oleyl-N'-carboxylethyl-N'-hydroxyethyl-ethylenediamine sodium; (6) quaternary ammonium salts such as dimethyloctylammonium trimethylphosphate, dimethyldodecylammonium trimethylphosphate, and trimethyloctylammonium chloride; and (7) inorganic phosphate compounds such as dimetallic hydrogen phosphate and trimetallic phosphate.

[0045] These antistatic agents (B) may be used singly or in appropriate combination of two or more. Among these, at least one inorganic phosphate compound (B1) selected from dimetallic hydrogen phosphates and trimetallic phosphates is preferred. Use of the inorganic phosphate compound (B1) can reduce adhesion on the fiber surface to which the treatment agent is applied. Specific examples of dimetallic hydrogen phosphates include dipotassium hydrogen phosphate and disodium hydrogen phosphate. Specific examples of trimetallic phosphates include tripotassium phosphate and trisodium phosphate.

[0046] The lower limit of the content of the antistatic agent (B) in the treatment agent can be set as appropriate, but is preferably 0.5% by mass or more, more preferably 1% by mass or more. When the content is 0.5% by mass or more, the antistatic properties of the fiber to which the treatment agent is applied can be improved. The upper limit of the content of the antistatic agent (B) can be set as appropriate, but is preferably 90% by mass or less, more preferably 85% by mass or less. When the content is 90% by mass or less, the stability of the treatment agent can be improved. Any combination of the above upper and lower limits is also contemplated. In this embodiment, the content of the antistatic agent (B) in the treatment agent is, for example, 1% by mass or more, 2% by mass or more, 3% by mass or more, 5% by mass or more, 6% by mass or more, 7% by mass or more, 10% by mass or more, 12% by mass or more, 13% by mass or more, 15% by mass or more, 20% by mass or more, 25% by mass or more, 30% by mass or more, 35% by mass or more, 40% by mass or more, or 85% by mass or more. Similarly, the content of the antistatic agent (B) is, for example, 85% by mass or less, 40% by mass or less, 35% by mass or less, 30% by mass or less, 25% by mass or less, 20% by mass or less, 15% by mass or less, 13% by mass or less, 12% by mass or less, 10% by mass or less, 7% by mass or less, 6% by mass or less, 5% by mass or less, 3% by mass or less, 2% by mass or less, or 1% by mass or less.

[0047] The lower limit of the content of the inorganic phosphate compound (B1) in the treatment agent can be set as appropriate, but is preferably 0.5% by mass or more, more preferably 1% by mass or more. When the content is 0.5% by mass or more, the antistatic properties of the fiber to which the treatment agent is applied can be improved, and adhesion on the fiber surface can be further reduced. The upper limit of the content of the inorganic phosphate compound (B1) can be set as appropriate, but is preferably 80% by mass or less, more preferably 75% by mass or less. When the content is 80% by mass or less, the stability of the treatment agent can be improved. Any combination of the above upper and lower limits is also contemplated. In this embodiment, the content of the inorganic phosphate compound (B1) in the treatment agent is, for example, 1% by mass or more, 2% by mass or more, 3% by mass or more, 5% by mass or more, 7% by mass or more, 8% by mass or more, 10% by mass or more, 15% by mass or more, or 75% by mass or more. Similarly, the content of the inorganic phosphate compound (B1) in the treatment agent is, for example, 75% by mass or less, 15% by mass or less, 10% by mass or less, 8% by mass or less, 7% by mass or less, 5% by mass or less, 3% by mass or less, 2% by mass or less, or 1% by mass or less.

[0048] (Nonionic Surfactant (C)) The nonionic surfactant (C) used in this embodiment contains an aromatic alcohol (poly)oxyalkylene derivative (C1). The aromatic alcohol (poly)oxyalkylene derivative (C1) can reduce adhesion on the fiber surface to which the treatment agent is applied.

[0049] ((Poly)oxyalkylene Derivative (C1) of Aromatic Alcohol) The (poly)oxyalkylene derivative (C1) of aromatic alcohol is a compound in which a total of 1 mole or more and 100 moles or less of at least one alkylene oxide selected from ethylene oxide and propylene oxide is added to 1 mole of an alcohol represented by the following general formula (1):

[0050] In general formula (1), R １ represents a hydrocarbon group having 10 to 20 carbon atoms. １The hydrocarbon group constituting the formula (I) may be a saturated hydrocarbon group or an unsaturated hydrocarbon group. It may also be a linear hydrocarbon group or a branched hydrocarbon group. Among these, from the viewpoint of further reducing adhesion on the fiber surface to which the treatment agent is applied, a hydrocarbon group having 10 to 20 carbon atoms and one or more double bonds is preferred. The number of carbon atoms in the hydrocarbon group is 10 to 20, preferably 12 to 18, more preferably 14 to 16. Any combination of the above upper and lower limits is also contemplated.

[0051] The unsaturated hydrocarbon group may be an alkenyl group having one double bond as an unsaturated carbon bond, or an alkadienyl group or alkatrienyl group having two or more double bonds.

[0052] The unsaturated carbon bond may be an alkynyl group having one triple bond, or an alkadiynyl group having two or more triple bonds. Specific examples of the saturated hydrocarbon group include a decyl group, an undecyl group, a dodecyl group, a tridecyl group, a tetradecyl group, a pentadecyl group, a hexadecyl group, a heptadecyl group, an octadecyl group, and an icosyl group.

[0053] Specific examples of unsaturated hydrocarbon groups having one double bond in the hydrocarbon group include decenyl, undecenyl, dodecenyl, tridecenyl, tetradecenyl, pentadecenyl, hexadecenyl, heptadecenyl, octadecenyl, and icocenyl groups.

[0054] Specific examples of unsaturated hydrocarbon groups having two double bonds in the hydrocarbon group include decadienyl, undecadienyl, dodecadienyl, tridecadienyl, tetradecadienyl, pentadecadienyl, hexadecadienyl, heptadecadienyl, octadecadienyl, and icosadienyl groups.

[0055] Specific examples of unsaturated hydrocarbon groups having three double bonds in the hydrocarbon group include decatrienyl, undecatrienyl, dodecatrienyl, tridecatrienyl, tetradecatrienyl, pentadecatrienyl, hexadecatrienyl, heptadecatrienyl, octadecatrienyl, and icosatrienyl groups.

[0056] The ethylene oxide and propylene oxide added to the aromatic alcohol may be ethylene oxide alone, propylene oxide alone, or both ethylene oxide and propylene oxide. When two types of alkylene oxides 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. In addition to ethylene oxide or propylene oxide, butylene oxide or the like may also be added as the alkylene oxide.

[0057] The number of moles of alkylene oxide added is 1 mole or more and 100 moles or less. Any range combining the above upper and lower limits is also conceivable. The number of moles of alkylene oxide added indicates the number of moles of alkylene oxide per mole of aromatic alcohol in the charged raw material.

[0058] Specific examples of the (poly)oxyalkylene derivative (C1) of aromatic alcohol include compounds obtained by adding alkylene oxide to cardanol, 3-[(8Z,11Z)-8,11,14-pentadecatrienyl]phenol, etc. The aromatic monoalcohol used as the raw material may be chemically synthesized or may be a naturally occurring mixture such as cardanol obtained from cashew nut shell liquid.

[0059] These (poly)oxyalkylene derivatives (C1) of aromatic alcohols may be used alone or in appropriate combination of two or more. ((Poly)oxyalkylene Amino Ether (C2)) The nonionic surfactant (C) used in this embodiment preferably contains a (poly)oxyalkylene amino ether (C2). The (poly)oxyalkylene amino ether (C2) is at least one selected from a (poly)oxyalkylene alkyl amino ether and a (poly)oxyalkylene alkenyl amino ether. The (poly)oxyalkylene amino ether (C2) may form a salt with an inorganic acid or an organic acid. By including a (poly)oxyalkylene amino ether (C2) in the treatment agent, adhesion on the fiber surface to which the treatment agent is applied can be reduced.

[0060] The (poly)oxyalkylene amino ether (C2) can be obtained by adding an alkylene oxide to an alkylamine or alkenylamine. The alkyl or alkenyl group constituting the (poly)oxyalkylene amino ether (C2) is not particularly limited and may be, for example, linear or branched.

[0061] Specific examples of alkylamines or alkenylamines used as raw materials for the (poly)oxyalkylene amino ether (C2) include aliphatic amines such as methylamine, ethylamine, butylamine, octylamine, decylamine, laurylamine (dodecylamine), octadecylamine, octadecenylamine, and coconut amine.

[0062] The alkylene oxide used as a raw material for forming the (poly)oxyalkylene structure of the (poly)oxyalkylene amino ether (C2) 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 1 to 60 moles, more preferably 2 to 50 moles. Any combination of the above upper and lower limits is also contemplated. 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.

[0063] Specific examples of the (poly)oxyalkylene amino ether (C2) include a compound in which an alkylene oxide is added to decylamine, a compound in which an alkylene oxide is added to dodecylamine, an inorganic salt of a compound in which an alkylene oxide is added to dodecylamine, and a compound in which an alkylene oxide is added to octadecylamine.

[0064] These (poly)oxyalkylene amino ethers (C2) may be used singly or in appropriate combination of two or more. (Other Nonionic Surfactants (C3)) Furthermore, other nonionic surfactants (C3) than the above-mentioned aromatic alcohol (poly)oxyalkylene derivatives (C1) and (poly)oxyalkylene amino ethers (C2) may be blended into the treatment agent.

[0065] Examples of other nonionic surfactants (C3) 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, partial ester compounds of carboxylic acids and polyhydric alcohols, amide compounds in which amine compounds and carboxylic acids are condensed, compounds having a (poly)oxyalkylene structure in which alkylene oxide is added to fatty acid amides, and compounds having a polyoxyalkylene structure such as block copolymers having a polyoxyethylene chain and a polyoxypropylene chain.

[0066] Specific examples of alcohols that can be used as raw materials for the other nonionic surfactants (C3) 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 isohexadecanol; (3) branched alkyl alcohols such as tetradecenol, hexadecenol, heptadecenol, octadecenol, isonadecanol, isoeicosanol, isoheneicosanol, isodocosanol, isotricosanol, isotetracosanol, isopentacosanol, isohexacosanol, isoheptacosanol, isooctacosanol, isononacosanol, and isopentadecanol; (4) linear alkenyl alcohols such as isohexadecenol and isooctadecenol; (5) cyclic alkyl alcohols such as cyclopentanol and cyclohexanol; and (6) aromatic alcohols such as phenol, nonylphenol, p-decylphenol, benzyl alcohol, monostyrenated phenol, distyrenated phenol, and tristyrenated phenol.

[0067] Specific examples of carboxylic acids used as raw materials for the other nonionic surfactant (C3) 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.

[0068] The alkylene oxide used as a raw material for forming the (poly)oxyalkylene structure of the other nonionic surfactant (C3) 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 contemplated. 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. 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 oxides 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.

[0069] Specific examples of polyhydric alcohols used as raw materials for the other nonionic surfactants (C3) 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, 2-methyl-2-hydroxymethyl-1,3-propanediol, trimethylolpropane, sorbitan, pentaerythritol, and sorbitol.

[0070] Specific examples of fatty acid amides used as raw materials for the other nonionic surfactants (C3) include octylic acid amide, lauric acid amide, palmitic acid amide, stearic acid amide, oleic acid amide, behenic acid amide, and lignoceric acid amide.

[0071] The block copolymer of polyoxyethylene chains and polyoxypropylene chains is not particularly limited as long as it has a polyoxypropylene chain with low hydrophilicity and a polyoxyethylene chain with high hydrophilicity and has surfactant properties. The number of polyoxyethylene chains and polyoxypropylene chains in the molecule is not particularly limited, and may be, for example, a block copolymer consisting of one polyoxypropylene chain and one polyoxyethylene chain, or a poloxamer surfactant consisting of a polyoxypropylene chain and two polyoxyethylene chains sandwiching it. The number of moles of ethylene oxide added to form the polyoxyethylene chain is not particularly limited, and may be, for example, 5 to 200 moles. The number of moles of propylene oxide added to form the polyoxypropylene chain is not particularly limited, and may be, for example, 5 to 100 moles.

[0072] Specific examples of other nonionic surfactants (C3) include a compound in which an alkylene oxide is added to lauryl alcohol, a compound in which an alkylene oxide is added to an alcohol having from 12 to 13 carbon atoms, a compound in which an alkylene oxide is added to isotridecyl alcohol, a compound in which an alkylene oxide is added to oleyl alcohol, a compound in which an alkylene oxide is added to oleic acid, a compound in which an alkylene oxide is added to coconut fatty acid, a compound in which an alkylene oxide is added to p-nonylphenol, and a compound in which an alkylene oxide is added to p-decylphenol.

[0073] These other nonionic surfactants (C3) may be used alone or in appropriate combination of two or more. The lower limit of the content of the nonionic surfactant (C) in the treatment agent is set appropriately, but is preferably 5% by mass or more, more preferably 10% by mass or more, and even more preferably 20% by mass. When the content is 5% by mass or more, adhesion on the fiber surface to which the treatment agent is applied can be reduced. The upper limit of the content of the nonionic surfactant (C) is set appropriately, but is preferably 90% by mass or less, more preferably 85% by mass or less, and even more preferably 80% by mass or less. When the content is 90% by mass or less, adhesion on the fiber surface to which the treatment agent is applied can be reduced. Note that ranges obtained by arbitrarily combining the above upper and lower limits are also contemplated. In this embodiment, the content of the nonionic surfactant (C) in the treatment agent is, for example, 5% by mass or more, 10% by mass or more, 15% by mass or more, 30% by mass or more, 35% by mass or more, 40% by mass or more, 50% by mass or more, 55% by mass or more, 60% by mass or more, 65% by mass or more, 70% by mass or more, 74% by mass or more, 75% by mass or more, 80% by mass or more, 81% by mass or more, 82% by mass or more, 85% by mass or more, 88% by mass or more, or 90% by mass or more. Similarly, the content of the nonionic surfactant (C) is, for example, 90% by mass or less, 88% by mass or less, 85% by mass or less, 82% by mass or less, 81% by mass or less, 80% by mass or less, 75% by mass or less, 74% by mass or less, 7 0 mass% or less, 65 mass% or less, 60 mass% or less, 55 mass% or less, 50 mass% or less, 40 mass% or less, 35 mass% or less, 30 mass% or less, 15 mass% or less, 10 mass% or less, or 5 mass% or less.

[0074] In the treatment agent, when the total content of the smoothing agent (A), antistatic agent (B), and nonionic surfactant (C) is taken as 100% by mass, it is preferable that the total content of the smoothing agent (A) and antistatic agent (B) is 20% by mass or more and 80% by mass or less, and the nonionic surfactant (C) is 20% by mass or more and 80% by mass or less. By specifying these ranges, adhesion on the fiber surface to which the treatment agent is applied can be reduced.

[0075] The lower limit of the content of the aromatic alcohol (poly)oxyalkylene derivative (C1) in the treatment agent can be set as appropriate, but is preferably 1 mass% or more, more preferably 5 mass% or more. When the content is 1 mass% or more, adhesion on the fiber surface to which the treatment agent is applied can be reduced. The upper limit of the content of the aromatic alcohol (poly)oxyalkylene derivative (C1) can be set as appropriate, but is preferably 90 mass% or less, more preferably 80 mass% or less. When the content is 90 mass% or less, adhesion on the fiber surface to which the treatment agent is applied can be reduced. Note that ranges that combine the above upper and lower limits in any way are also contemplated. In this embodiment, the content of the aromatic alcohol (poly)oxyalkylene derivative (C1) in the treatment agent is, for example, 1% by mass or more, 2% by mass or more, 3% by mass or more, 4% by mass or more, 5% by mass or more, 8% by mass or more, 9% by mass or more, 10% by mass or more, 15% by mass or more, 20% by mass or more, 25% by mass or more, 26% by mass or more, 30% by mass or more, 35% by mass or more, 40% by mass or more, 50% by mass or more, 60% by mass or more, 62% by mass or more, 76% by mass or more, 80% by mass or more, 81% by mass or more, 82% by mass or more, 85% by mass or more, or 90% by mass or more. Similarly, the content of the (poly)oxyalkylene derivative (C1) of the aromatic alcohol is, for example, 90% by mass or less, 85% by mass or less, 82% by mass or less, 81% by mass or less, 80% by mass or less, 76% by mass or less, 62% by mass or less, 60% by mass or less, 50% by mass or less, 40% by mass or less mass% or less, 35 mass% or less, 30 mass% or less, 26 mass% or less, 25 mass% or less, 20 mass% or less, 15 mass% or less, 10 mass% or less, 9 mass% or less, 8 mass% or less, 5 mass% or less, 4 mass% or less, 3 mass% or less, 2 mass% or less, or 1 mass% or less.

[0076] The treatment agent preferably contains the (poly)oxyalkylene derivative (C1) of an aromatic alcohol in a proportion of 5 to 80 mass % relative to the total content of the smoothing agent (A), the antistatic agent (B), and the nonionic surfactant (C) taken as 100 mass %. By specifying this range, adhesion on the fiber surface to which the treatment agent is applied can be reduced.

[0077] The lower limit of the content of the (poly)oxyalkylene amino ether (C2) in the treatment agent is set as appropriate, but is preferably 3% by mass or more, more preferably 5% by mass or more. When the content is 3% by mass or more, adhesion on the fiber surface to which the treatment agent is applied can be reduced. The upper limit of the content of the (poly)oxyalkylene amino ether (C2) is set as appropriate, but is preferably 80% by mass or less, more preferably 70% by mass or less. When the content is 80% by mass or less, adhesion on the fiber surface to which the treatment agent is applied can be reduced. Note that ranges that combine the above upper and lower limits in any desired manner are also contemplated.

[0078] The organic phosphate ester (A1) is preferably contained in a proportion of 16% by mass or more relative to the total content of the smoothing agent (A), the antistatic agent (B), and the nonionic surfactant (C) taken as 100% by mass. When the content is 16% by mass or more, adhesion on the fiber surface to which the treatment agent is applied can be further reduced.

[0079] The inorganic phosphate compound (B1) is preferably contained in an amount of 20% by mass or less, relative to the total content of the smoothing agent (A), the antistatic agent (B), and the nonionic surfactant (C) being 100% by mass. When the content is 20% by mass or less, the sizing ability of the fibers to which the treatment agent is applied can be improved.

[0080] When the total content of the smoothing agent (A), the antistatic agent (B), and the nonionic surfactant (C) is taken as 100% by mass, the total content of the smoothing agent other than the organic phosphate ester is preferably 40% by mass or less. The smoothing agent other than the organic phosphate ester refers to a smoothing agent other than aliphatic alcohol phosphate ester, aliphatic alcohol phosphate ester having an oxyalkylene group, and salts thereof, and more specifically, mineral oil, polyolefin, and ester oil. When the content of such a smoothing agent other than the organic phosphate ester is 40% by mass or less, the sizing ability of the fibers to which the treatment agent is applied can be improved. The content of the smoothing agent other than the organic phosphate ester is, for example, 2% by mass or more, 3% by mass or more, 5% by mass or more, 8% by mass or more, 10% by mass or more, 12% by mass or more, 15% by mass or more, 20% by mass or more, 25% by mass or more, 45% by mass or more, or 60% by mass or more, and for example, 60% by mass or less, 45% by mass or less, 25% by mass or less, 20% by mass or less, 15% by mass or less, 12% by mass or less, 10% by mass or less, 8% by mass or less, 5% by mass or less, 3% by mass or less, or 2% by mass or less.

[0081] (Storage form) The treatment agent may be configured as a one-component type containing the above-mentioned smoothing agent (A), antistatic agent (B), and nonionic surfactant (C), or, from the viewpoint of improving the formulation stability, may be configured as a two-component type treatment agent as shown below.

[0082] The two-component treatment agent is configured as a set including a first treatment agent for polyester-based synthetic fibers (hereinafter referred to as the "first treatment agent") containing a smoothing agent (A) and an antistatic agent (B), and a second treatment agent for polyester-based synthetic fibers (hereinafter referred to as the "second treatment agent") containing a nonionic surfactant (C).

[0083] The two-component treatment agent is composed of a first treatment agent and a second treatment agent, which is prepared as a separate agent from the first treatment agent, before use, for example, during storage or distribution. The two-component treatment agent is prepared as a mixture of the first treatment agent and the second treatment agent when used.

[0084] (Solvent) The treatment agent of the present embodiment is mixed with a solvent, if necessary, to prepare a treatment-agent-containing composition for polyester-based synthetic fibers (hereinafter referred to as "treatment-agent-containing composition"). The treatment agent may be stored or distributed in the form of a treatment-agent-containing composition.

[0085] The solvent preferably has a boiling point of 105°C or lower at atmospheric pressure. In this specification, atmospheric pressure refers to standard atmospheric pressure (101,325 Pa = 1 atm). Examples of the solvent include water and organic solvents. Specific examples of organic solvents include lower alcohols such as ethanol and propanol, and low-polarity solvents such as hexane. These solvents may be used alone or in appropriate combination of two or more. Among these, polar solvents such as water and lower alcohols are preferred from the viewpoint of excellent dispersibility or solubility of each component, and water is more preferred from the viewpoint of excellent handleability.

[0086] In the treatment-agent-containing composition, the treatment agent is preferably contained in an amount of 10 parts by mass or more, assuming that the total content of the treatment agent and the solvent is 100 parts by mass. The effects of the treatment agent of the first embodiment will be described.

[0087] (1-1) The treatment agent of the first embodiment contains a smoothing agent (A), an antistatic agent (B), and the nonionic surfactant (C) described above. Therefore, the quality of fibers to which the treatment agent is applied can be improved. More specifically, the smoothness of fibers to which the treatment agent is applied can be improved. This reduces fiber-metal friction and fiber damage. Furthermore, the charging of fibers to which the treatment agent is applied can be prevented. This improves the processability of fibers and improves the spinning characteristics of the fibers. Furthermore, the bleed-out of components in the treatment agent can be suppressed, reducing adhesion of the fiber surface. This suppresses winding around equipment, particularly during the spinning process, and improves spinning characteristics. Furthermore, the unevenness of the quality of the produced yarn can be reduced.

[0088] (1-2) The treatment agent of the first embodiment can be configured as a set including a first treatment agent containing a smoothing agent (A) and an antistatic agent (B) and a second treatment agent containing a nonionic surfactant (C). This configuration can improve the formulation stability, particularly storage stability, of the treatment agent.

[0089] Second Embodiment Next, a second embodiment of the first treatment agent of the present invention will be described, focusing on the differences from the above embodiment.

[0090] The first treatment agent of this embodiment contains a smoothing agent (A) and an antistatic agent (B). When used, the first treatment agent is used in combination with a second treatment agent containing a nonionic surfactant (C) including an aromatic alcohol (poly)oxyalkylene derivative (C1). That is, when used, the first treatment agent and the second treatment agent are mixed to prepare a mixture as a treatment agent.

[0091] The smoothing agent (A), antistatic agent (B), and nonionic surfactant (C) are the same as those described in the first embodiment. The contents of the smoothing agent (A), organic phosphate ester (A1), antistatic agent (B), inorganic phosphate compound (B1), nonionic surfactant (C), (poly)oxyalkylene derivative of aromatic alcohol (C1), and (poly)oxyalkylene amino ether (C2) in the treatment agent are also the same as those described in the first embodiment.

[0092] The effects of the first treatment agent of the second embodiment will be described. In addition to the effects of the above embodiments, the second embodiment has the following effects. (2-1) The first treatment agent of the second embodiment contains a smoothing agent (A) and an antistatic agent (B), and is used in combination with a second treatment agent containing a nonionic surfactant (C) including an aromatic alcohol (poly)oxyalkylene derivative (C1). This improves the formulation stability, particularly storage stability, of the first treatment agent. Furthermore, by adjusting the mixing ratio with the second treatment agent, the components of the resulting treatment agent can be adjusted. Furthermore, the first treatment agent alone can be distributed as a separate agent from the second treatment agent.

[0093] Third Embodiment Next, a third embodiment of the second treatment agent of the present invention will be described, focusing on the differences from the above-described embodiments.

[0094] The second treatment agent of this embodiment contains a nonionic surfactant (C) containing an aromatic alcohol (poly)oxyalkylene derivative (C1). The second treatment agent is used in combination with a first treatment agent containing a smoothing agent (A) and an antistatic agent (B). That is, the first treatment agent and the second treatment agent are mixed together to prepare a treatment mixture.

[0095] The smoothing agent (A), antistatic agent (B), and nonionic surfactant (C) are the same as those described in the first embodiment. The contents of the smoothing agent (A), organic phosphate ester (A1), antistatic agent (B), inorganic phosphate compound (B1), nonionic surfactant (C), (poly)oxyalkylene derivative of aromatic alcohol (C1), and (poly)oxyalkylene amino ether (C2) in the treatment agent are also the same as those described in the first embodiment.

[0096] The effects of the second treatment agent of the third embodiment will be described. In addition to the effects of the above embodiments, the third embodiment has the following effects. (3-1) The second treatment agent of the third embodiment contains a nonionic surfactant (C) including an aromatic alcohol (poly)oxyalkylene derivative (C1), and is used in combination with a first treatment agent containing a smoothing agent (A) and an antistatic agent (B). This improves the formulation stability, particularly storage stability, of the second treatment agent. Furthermore, by adjusting the mixing ratio with the first treatment agent, the components of the resulting treatment agent can be adjusted. Furthermore, the second treatment agent can be distributed separately from the first treatment agent.

[0097] Fourth Embodiment Next, a fourth embodiment of the polyester-based synthetic fiber (hereinafter referred to as "synthetic fiber") of the present invention will be described.

[0098] The synthetic fiber of this embodiment has the treatment agent of the first embodiment adhered to it. According to this embodiment, a treated synthetic fiber is provided, which includes a synthetic fiber and a treatment agent adhered thereto. When the treatment agent is a one-component type, the method for producing the synthetic fiber of this embodiment includes a step of applying a dilution containing a solvent and the treatment agent of the first embodiment to the polyester synthetic fiber. The dilution can be prepared, for example, by adding the treatment agent or treatment agent-containing composition of the first embodiment to a solvent. The dilution is preferably prepared by adding the treatment agent of the first embodiment to water.

[0099] When the treatment agent is a two-component type, the synthetic fiber manufacturing method of this embodiment is characterized by applying a diluted solution of the treatment agent containing a solvent, the first treatment agent of the second embodiment, and the second treatment agent of the third embodiment to polyester-based synthetic fibers. The diluted solution can be prepared, for example, by adding the first treatment agent and the second treatment agent to a solvent. The diluted solution is preferably prepared by adding the first treatment agent and the second treatment agent to water. The ratio of the content of the first treatment agent to the second treatment agent, expressed as the mass ratio of the nonvolatile components, is preferably 95 / 5 to 5 / 95 (first treatment agent / second treatment agent). By specifying the content within this range, operability can be improved. In this specification, the term "nonvolatile components" refers to the residue, i.e., the bone-dry product, remaining after heat-treating an object at 105°C for two hours to thoroughly remove volatile substances.

[0100] Examples of the solvent used to prepare the diluted solution include those exemplified in the first embodiment. From the viewpoint of operability, the diluted solution preferably has a concentration of the treatment agent of 0.1% by mass or more and 10% by mass or less.

[0101] When the first and second treatment agents are used in combination, the mixing ratio of each agent can be changed as desired, making it easy to fine-tune the mixing ratio and prepare a treatment agent or dilution solution that always provides optimal fiber properties or fiber production characteristics, even under different production conditions, such as different production facilities or different climates (temperature, humidity, etc.).

[0102] To emulsify the treating agents, each treating agent may be mixed with a solvent and stirred using a known stirrer, such as a homomixer, homogenizer, colloid mill, line mixer, etc. The method for treating synthetic fibers is a method in which the diluted solution obtained as described above is applied to synthetic fibers in at least one of the steps of spinning, drawing, and finishing polyester synthetic fibers.

[0103] Examples of synthetic fibers to which the treatment agent is applied include polyester synthetic fibers, such as polyethylene terephthalate (PET), polytrimethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polylactic acid, and composite fibers containing these polyester resins.

[0104] The uses of synthetic fibers are not particularly limited, and examples include spinning, spun yarn production, nonwoven fabrics, and wadding. Synthetic fibers may be short fibers or long fibers. Short fibers generally refer to those called staple fibers, and do not include long fibers generally called filaments. The length of the short fibers is not particularly limited as long as they fall under the category of short fibers in this technical field, but is, for example, 100 mm or less. Among these, the dilution solution of the present invention is preferably applied to polyester short fibers and polyester-based synthetic fibers for spun yarn production.

[0105] There are no particular restrictions on the proportion of the diluent applied to the synthetic fibers, but the diluent is applied so that the final solids content is preferably 0.01% by mass or more and 10% by mass or less, more preferably 0.1% by mass or more and 3% by mass or less, relative to the synthetic fibers. This configuration allows the efficacy of each component to be effectively exerted. There are also no particular restrictions on the method for applying the diluent, and known methods can be used depending on the type, shape, and application of the synthetic fibers, such as roller oiling, guide oiling using a metering pump, immersion oiling, and spray oiling. When the immersion oiling method is used, the immersion time is preferably 1 minute or more and 5 minutes or less.

[0106] The synthetic fibers to which the dilution liquid has been applied may be dried or heated by a known method, which volatilizes the solvent such as water, yielding synthetic fibers to which the treatment agent, or the components contained in the first treatment agent and the second treatment agent, have adhered.

[0107] The effects of the synthetic fiber of the fourth embodiment will be described. In addition to the effects of the above embodiments, the fourth embodiment has the following effects. (4-1) The synthetic fiber of the fourth embodiment has the treatment agent of the first embodiment adhered thereto. Therefore, smoothness and antistatic properties are improved, and the quality of the fiber can be improved by reducing adhesion on the fiber surface.

[0108] Furthermore, in the case of multi-component formulations, the first and second treatment agents are prepared by adding them to a solvent immediately before use, allowing the treatment agents to be applied to fibers in a state of good emulsion stability, thereby enabling each component of the treatment agent to effectively exert its efficacy for spinning, spun yarn production, staple fiber, filament fiber, nonwoven fabric, wadding, etc.

[0109] 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. Each treatment agent, composition, or dilution solution of the above embodiment may further contain other components used in conventional treatment agents, such as other solvents, stabilizers, antistatic agents, binders, antioxidants, UV absorbers, organic acids, and surfactants other than those mentioned above, to maintain the quality of each treatment agent, as long as the effects of the present invention are not impaired. From the perspective of efficiently demonstrating the efficacy of the present invention, the other components used in conventional treatment agents, other than solvents, are preferably present in an amount of 10% by mass or less in each treatment agent. Furthermore, the other components may be stored as a separate agent from the above-mentioned treatment agents.

[0110] Examples will be given below to more specifically illustrate the configuration and effects of the present invention, but the present invention is not limited to these examples. In the following explanations of the examples and comparative examples, parts mean parts by mass, and % means % by mass.

[0111] Test Section 1 (Preparation of Treatment Agent) (Example 1-1) 50 parts of potassium lauryl phosphate (acid value 70 KOH-mg / g) (A1-1) as the smoothing agent (A), 10 parts of dipotassium hydrogen phosphate (B1-1) as the antistatic agent (B), and 30 parts of a compound (C1-2) in which 5 moles of ethylene oxide (hereinafter referred to as EO) have been added to 1 mole of cardanol B and 10 parts of a compound (C2-1) in which 10 moles of EO have been added to 1 mole of decylamine, as the nonionic surfactant (C), were prepared, and these were added to a beaker and mixed well to prepare the treatment agent of Example 1-1.

[0112] Examples 1-2 to 1-50, Comparative Examples 1 to 7 The treating agents of Examples 1-2 to 1-50 and Comparative Examples 1 to 7 were prepared using the components shown in Tables 1 and 2 in the same manner as in Example 1-1.

[0113] The type and content of the smoothing agent (A), the type and content of the antistatic agent (B), and the type and content of the nonionic surfactant (C) in each example of the treatment agent are as shown in the "Smoothing agent (A)" column, the "Antistatic agent (B)" column, and the "Nonionic surfactant (B)" column in Tables 1 and 2, respectively.

[0114]

[0115]

[0116] Details of the smoothing agent (A), antistatic agent (B), and nonionic surfactant (C) shown in Tables 1 and 2 are as follows. <Smoothing Agent (A)> (Organic Phosphate Ester (A1)) A1-1: Lauryl phosphate potassium salt (acid value 70 KOH-mg / g) A1-2: Lauryl phosphate potassium salt / stearyl phosphate potassium salt = 30 / 70 (mass ratio) (acid value 30 KOH-mg / g) A1-3: Cetyl phosphate potassium salt (acid value 12.5 KOH-mg / g) A1-4: Cetyl phosphate potassium salt / stearyl phosphate potassium salt = 30 / 70 (mass ratio) (acid value 0 KOH-mg / g) A1-5: Cetyl phosphate potassium salt / stearyl phosphate potassium salt = 30 / 70 (mass ratio) (acid value 12.5 KOH-mg / g) A1-6: Cetyl phosphate potassium salt / stearyl phosphate potassium salt = 70 / 30 (mass ratio) (acid value 0 KOH-mg / g) A1-7: Cetyl phosphate potassium salt / stearyl phosphate potassium salt = 70 / 30 (mass ratio) (acid value 12.5 KOH-mg / g) A1-8: Stearyl phosphate potassium salt (acid value 10 KOH-mg / g) A1-9: Stearyl phosphate potassium salt (acid value 25 KOH-mg / g) A1-10: Arachidyl phosphate potassium salt (acid value 10 KOH-mg / g) (Other smoothing agents (A2)) A2-1: Polydimethylsiloxane A2-2: Paraffin wax A2-3: Hydrogenated castor oil A2-4: Octyl phosphate potassium salt (acid value 50 KOH-mg / g) <Antistatic agents (B)> (Inorganic phosphate compounds (B1)) B1-1: Dipotassium hydrogen phosphate B1-2: Tripotassium phosphate B1-3: Disodium hydrogen phosphate (Other antistatic agents (B2)) B2-1: Sodium dodecylbenzenesulfonate B2-2: Trimethyloctylammonium chloride B2-3: Potassium octylate B2-4: Potassium lactate B2-5: Potassium phosphate salt of an adduct of 5 moles of EO to 1 mole of lauryl alcohol (acid value 45 KOH-mg / g) <Nonionic surfactants (C)> ((Poly)oxyalkylene derivatives of aromatic alcohols (C1))C1-1: A compound obtained by adding 1 mole of EO to 1 mole of cardanol A. C1-2: A compound obtained by adding 5 moles of EO to 1 mole of cardanol B. C1-3: A compound obtained by adding 10 moles of EO to 1 mole of cardanol A. C1-4: A compound obtained by adding 100 moles of EO to 1 mole of cardanol B. C1-5: A compound obtained by adding 5 moles of propylene oxide (hereinafter referred to as PO) to 1 mole of cardanol A. C1-6: A compound obtained by randomly adding 6 moles of EO and 2 moles of PO to 1 mole of cardanol B. C1-7: A compound obtained by randomly adding 4 moles of EO and 2 moles of PO to 1 mole of cardanol A, and then adding 2 moles of EO. C1-8: A compound obtained by adding 5 moles of PO to 1 mole of cardanol B, and then further adding 15 moles of EO. C1-9: A compound prepared by adding 300 parts of EO to 100 parts of cashew nut shell liquid (the number of moles of EO added per mole of alcohol represented by the general formula (1) above is approximately 10 moles). Note: Cardanol A was LB-7000 (a mixture of 90% by mass of cardanol and 10% by mass of cardol) manufactured by Tohoku Kako Co., Ltd. The hydrocarbon groups in the cardanol side chains consist of 5% by mass of pentadecyl groups with zero unsaturated bonds, 35% by mass of pentadecenyl groups with one unsaturated bond, 20% by mass of pentadecadienyl groups with two unsaturated bonds, and 40% by mass of pentadecatrienyl groups with three unsaturated bonds. The content of (poly)oxyalkylene derivative (C1) listed in Tables 1 and 2 indicates the content ratio of the compound derived from the general formula (1) above.

[0117] Cardanol B used was LB-7250 (a mixture of 95% by mass of cardanol and 5% by mass of cardol) manufactured by Tohoku Kako Co., Ltd. The hydrocarbon groups in the side chains of cardanol consisted of 5% by mass of pentadecyl groups with zero unsaturated bonds, 35% by mass of pentadecenyl groups with one unsaturated bond, 20% by mass of pentadecadienyl groups with two unsaturated bonds, and 40% by mass of pentadecatrienyl groups with three unsaturated bonds. The content of the (poly)oxyalkylene derivative (C1) listed in Tables 1 and 2 indicates the content ratio of the compound derived from the general formula (1) above.

[0118] The cashew nut shell liquid used was CNSL (a mixture of 82% by mass of cardanol and 18% by mass of cardol in the monomers) manufactured by Tohoku Kako Co., Ltd. The hydrocarbon groups in the cardanol side chains consisted of 5% by mass of pentadecyl groups with zero unsaturated bonds, 35% by mass of pentadecenyl groups with one unsaturated bond, 20% by mass of pentadecadienyl groups with two unsaturated bonds, and 40% by mass of pentadecatrienyl groups with three unsaturated bonds. The content of (poly)oxyalkylene derivative (C1) listed in Tables 1 and 2 indicates the content ratio of the compound derived from the general formula (1) above.

[0119] ((Poly)oxyalkylene amino ethers (C2)) C2-1: A compound obtained by adding 10 moles of EO to 1 mole of decylamine C2-2: A compound obtained by adding 10 moles of EO to 1 mole of dodecylamine C2-3: A compound obtained by adding 15 moles of EO to 1 mole of dodecylamine C2-4: A compound obtained by randomly adding 8 moles of EO and 2 moles of PO to 1 mole of dodecylamine C2-5: A phosphate salt of a compound obtained by adding 12 moles of EO to 1 mole of dodecylamine C2-6: A compound obtained by adding 10 moles of EO to 1 mole of octadecylamine C2-7: A compound obtained by adding 10 moles of EO to 1 mole of octadecylamine and further adding 5 moles of PO (Other nonionic surfactants (C3)) C3-1: A compound obtained by adding 10 moles of EO to 1 mole of lauryl alcohol C3-2: A compound in which 6 moles of EO and 2 moles of PO have been added randomly to 1 mole of an alcohol having from 12 to 13 carbon atoms. C3-3: A compound in which 3 moles of PO have been added to 1 mole of isotridecyl alcohol, and further 7 moles of EO have been added. C3-4: A compound in which 5 moles of PO have been added to 1 mole of oleyl alcohol. C3-5: A compound in which 3 moles of EO have been added to 1 mole of oleic acid. C3-6: A compound in which 200 parts by mass of EO have been added to 100 parts by mass of coconut fatty acid. C3-7: A compound in which 10 moles of EO have been added to 1 mole of p-nonylphenol. C3-8: A compound in which 8 moles of EO have been added to 1 mole of p-decylphenol. Test Section 2 (Evaluation of Smoothness) Each of the treatment agents prepared in Test Section 1 was diluted with warm water of about 70°C to prepare a 0.5% diluted solution as a treatment agent. The treatment agent described in each example was applied to polyester cotton (1.2 mm × 38 mm) that had not been treated with the treatment agent, so that the amount of the applied treatment agent was 0.15% based on the polyester cotton. The polyester cotton to which the treatment agent had been applied was dried in a dryer at 80°C for 2 hours and then conditioned overnight in an atmosphere of 25°C × 40% RH. Ten kilograms of the treated polyester cotton was passed through a flat card (manufactured by Howa Kogyo Co., Ltd.) in an atmosphere of 25°C × 40% RH to obtain a carded sliver. The obtained carded sliver was examined using a scanning electron microscope (manufactured by JEOL Ltd.). Ten or more polyester fibers constituting the carded sliver were examined, and the smoothness was evaluated based on the number of friction damages on the fiber surface according to the following criteria. The results are shown in the "Smoothness" column of Tables 1 and 2.

[0120] Evaluation criteria for smoothness: ○ (Acceptable): Fewer than 3 scratches on the fiber surface per fiber on average; × (Unacceptable): 3 or more scratches on the fiber surface on average per fiber. Test Section 3 (Evaluation of Antistatic Properties) In Test Section 2, the carded web was visually inspected when the polyester cotton was passed through the flat card. Antistatic properties were evaluated based on the sagging of the carded web due to static electricity, according to the following criteria. The results are shown in the "Antistatic Properties" column of Tables 1 and 2.

[0121] Antistatic Evaluation: Good (Acceptable): No sagging of the card web was observed. Bad (Not Acceptable): Sagging of the card web was observed. Test Section 4 (Adhesion Evaluation): Five grams of a standard adhesive test treatment agent, different from the treatment agents described in each example, was uniformly applied to one side of a 10 cm x 10 cm polyester film that had not been treated with any treatment agent. Six standard adhesive test samples were prepared using six treatment agents with different levels of adhesiveness using the procedure described above. The standard adhesive test samples were ranked in descending order of adhesiveness, from most adhesive to least adhesive, as follows: 0-point standard sample, 1-point standard sample, 2-point standard sample, 3-point standard sample, 4-point standard sample, and 5-point standard sample. The standard adhesive test samples were repeatedly calibrated by 10 evaluators, and selected so that the order of adhesiveness was consistent among the 10 evaluators. Five grams of the treatment agents described in the Examples and Comparative Examples in Tables 1 and 2 were uniformly applied to one side of a 10 cm x 10 cm polyester film that had not been treated with any treatment agent. The samples were conditioned at 25°C x 40% RH for 24 hours, and the treatment-coated surface was then touched with a hand to check for adhesion. The adhesion check was conducted without disclosing the type of treatment applied. Ten evaluators who had undergone the above calibration checked the adhesion, and each selected a standard adhesion test sample that had the closest adhesion level. The average scores for the standard adhesion test samples selected by the ten evaluators were calculated, and the adhesion was evaluated according to the following criteria. The results are shown in the "Adhesion" column of Tables 1 and 2.

[0122] Evaluation of Adhesion ◎◎◎: Average score of 4.0 points or more ◎◎○: Average score of 3.5 points or more but less than 4.0 points ◎◎: Average score of 3.0 points or more but less than 3.5 points ◎○: Average score of 2.5 points or more but less than 3.0 points ◎: Average score of 2.0 points or more but less than 2.5 points ○: Average score of 1.5 points or more but less than 2.0 points ×: Average score less than 1.5 points Test Section 5 (Evaluation of Bundling Ability) In Test Section 2, the diameter of the card sliver was measured when the polyester cotton passed through the flat card. Bundling ability was evaluated according to the following criteria based on the tightness of the card sliver due to bundle ability. The results are shown in the "Bundling Ability" column in Tables 1 and 2.

[0123] Evaluation of convergence ◎ (Good): Card sliver diameter was less than 4.0 cm ○ (Acceptable): Card sliver diameter was 4.0 cm or more and less than 6.0 cm × (Unacceptable): Card sliver diameter was 6.0 cm or more Test category 6 (Preparation of first treatment agent of two-component treatment agent) (First treatment agent (I-1)) As shown in Table 3, a first treatment agent (I-1) was prepared containing 83.33 parts of potassium lauryl phosphate (acid value 70 KOH-mg / g) (A1-1) as the smoothing agent (A) and 16.67 parts of dipotassium hydrogen phosphate (B1-1) as the antistatic agent (B).

[0124] (First treatment agents (I-2) to (I-45)) First treatment agents (I-2) to (I-45) were prepared in the same manner as the first treatment agent (I-1), except that they contained the smoothing agent (A) and the antistatic agent (B) in the proportions shown in Tables 3 and 4.

[0125] The type and content of the smoothing agent (A) and the type and content of the antistatic agent (B) are shown in the "smoothing agent (A)" and "antistatic agent (B)" columns of Tables 3 and 4, respectively.

[0126]

[0127]

[0128] Test Section 7 (Preparation of Second Treatment Agent of Two-Part Treatment Agent) (Second Treatment Agent (II-1)) As shown in Table 5, a second treatment agent (II-1) was prepared containing, as the nonionic surfactant (C), 75 parts of a compound (C1-2) in which 5 moles of EO were added to 1 mole of cardanol B, and 25 parts of a compound (C2-1) in which 10 moles of EO were added to 1 mole of decylamine.

[0129] (Second treatment agents (II-2) to (II-40)) Second treatment agents (II-2) to (II-40) were prepared in the same manner as second treatment agent (II-1), except that they contained the nonionic surfactant (C) in the proportions shown in Table 5.

[0130] The type and content of the nonionic surfactant (C) are shown in the "Nonionic surfactant (C)" column of Table 5.

[0131]

[0132] Test Section 8 (Preparation of Treatment Agent from First Treatment Agent and Second Treatment Agent) (Example 2-1) As shown in Table 6, the treatment agent of Example 2-1 was prepared by mixing 60% (parts) of the first treatment agent (I-1) and 40% (parts) of the second treatment agent (II-1).

[0133] Examples 2-2 to 2-47 In the same manner as in Example 2-1, the first treating agent and the second treating agent were mixed as shown in Table 6 to prepare the treating agents of each example.

[0134] The types and mass ratios of the first treatment agent and the types and mass ratios of the second treatment agent are shown in the "First treatment agent (I)" and "Second treatment agent (II)" columns of Table 6, respectively.

[0135]

[0136] Test Section 9 (Evaluation of Two-Part Treatment Agents) Using the treatment agents obtained in each example, smoothness, antistatic properties, and adhesion were evaluated in the same manner as for the treatment agent in Example 1. The results are shown in the "Smoothness," "Antistatic Properties," and "Adhesion" columns of Table 6, respectively.

[0137] The results in the above table show that the present invention can improve the smoothness of fibers to which a treatment agent has been applied. It can also prevent static buildup on fibers to which a treatment agent has been applied. It can also suppress bleeding out of the components in the treatment agent, reducing adhesion on the fiber surface.

Claims

1. A polyester synthetic fiber treatment agent containing a smoothing agent (A), an antistatic agent (B), and a nonionic surfactant (C), characterized in that the nonionic surfactant (C) contains an aromatic alcohol (poly)oxyalkylene derivative (C1), the aromatic alcohol (poly)oxyalkylene derivative (C1) being a compound in which at least one alkylene oxide selected from ethylene oxide and propylene oxide is added in a total amount of 1 mol to 100 mol to 1 mol of alcohol represented by the following general formula (1): In the general formula (1), R １ represents a hydrocarbon group having 10 to 20 carbon atoms, a treatment agent for polyester-based synthetic fibers.

2. The treatment agent for polyester synthetic fibers according to claim 1, wherein the smoothing agent (A) contains an organic phosphate ester (A1) which is at least one selected from phosphate esters of aliphatic alcohols having 12 to 20 carbon atoms and their salts.

3. The treatment agent for polyester-based synthetic fibers according to claim 2, wherein the organic phosphate ester (A1) is contained in an amount of 16% by mass or more when the total content of the smoothing agent (A), the antistatic agent (B), and the nonionic surfactant (C) is taken as 100% by mass.

4. The treatment agent for polyester-based synthetic fibers according to claim 1, wherein the total content of smoothing agents other than organic phosphate esters is 40% by mass or less when the total content of the smoothing agent (A), the antistatic agent (B), and the nonionic surfactant (C) is taken as 100% by mass, and the organic phosphate ester is at least one selected from the group consisting of aliphatic alcohol phosphate esters, aliphatic alcohol phosphate esters having an oxyalkylene group, and salts thereof.

5. The agent for treating polyester synthetic fibers according to claim 1, wherein the antistatic agent (B) contains an inorganic phosphate compound (B1) which is at least one selected from dimetal hydrogen phosphates and trimetal phosphates.

6. The treatment agent for polyester-based synthetic fibers according to claim 5, wherein the inorganic phosphate compound (B1) is contained in an amount of 20 mass% or less when the total content of the smoothing agent (A), the antistatic agent (B), and the nonionic surfactant (C) is taken as 100 mass%.

7. The treatment agent for polyester synthetic fibers according to claim 1, wherein the nonionic surfactant (C) contains at least one (poly)oxyalkylene amino ether (C2) selected from the group consisting of (poly)oxyalkylene alkyl amino ethers and (poly)oxyalkylene alkenyl amino ethers.

8. The treatment agent for polyester-based synthetic fibers according to claim 1, wherein the (poly)oxyalkylene derivative (C1) of an aromatic alcohol is contained in an amount of 5% by mass or more and 80% by mass or less, assuming that the total content of the smoothing agent (A), the antistatic agent (B), and the nonionic surfactant (C) is 100% by mass.

9. The treatment agent for polyester-based synthetic fibers according to claim 1, wherein the total content of the smoothing agent (A) and the antistatic agent (B) is 20% by mass or more and 80% by mass or less, and the nonionic surfactant (C) is 20% by mass or more and 80% by mass or less, assuming that the total content of the smoothing agent (A), the antistatic agent (B), and the nonionic surfactant (C) is 100% by mass.

10. The treatment agent for polyester-based synthetic fibers according to claim 1, which is composed of a set including a first treatment agent for polyester-based synthetic fibers containing the smoothing agent (A) and the antistatic agent (B), and a second treatment agent for polyester-based synthetic fibers containing the nonionic surfactant (C).

11. A first treatment agent for polyester synthetic fibers used in combination with a second treatment agent for polyester synthetic fibers containing a nonionic surfactant (C) including an aromatic alcohol (poly)oxyalkylene derivative (C1), characterized in that it contains a smoothing agent (A) and an antistatic agent (B), and the aromatic alcohol (poly)oxyalkylene derivative (C1) is a compound in which a total of 1 to 100 moles of at least one alkylene oxide selected from ethylene oxide and propylene oxide are added to 1 mole of alcohol represented by the following general formula (1): In the general formula (1), R １ A first treatment agent for polyester synthetic fibers, wherein represents a hydrocarbon group having 10 to 20 carbon atoms.

12. A second treatment agent for polyester synthetic fibers used in combination with a first treatment agent for polyester synthetic fibers containing a smoothing agent (A) and an antistatic agent (B), characterized in that it contains a nonionic surfactant (C) containing an aromatic alcohol (poly)oxyalkylene derivative (C1), said aromatic alcohol (poly)oxyalkylene derivative (C1) being a compound in which at least one alkylene oxide selected from ethylene oxide and propylene oxide is added in a total amount of 1 mole or more and 100 moles or less to 1 mole of alcohol represented by the following general formula (1): In the general formula (1), R １ represents a hydrocarbon group having 10 to 20 carbon atoms, 13. A polyester synthetic fiber having the treatment agent for polyester synthetic fiber according to any one of claims 1 to 10 adhered thereto.

14. The polyester synthetic fiber according to claim 13, which is a polyester staple fiber.

15. The polyester-based synthetic fiber according to claim 13, which is applied to spun yarn.

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