Method for producing synthetic fiber treatment agent-containing composition, synthetic fiber, and nonwoven fabric

Abstract

The present invention provides a method for producing a synthetic fiber treatment agent-containing composition, synthetic fibers, and nonwoven fabrics that can improve the stability of the synthetic fiber treatment agent-containing composition and reduce foaming properties. [Solution] The synthetic fiber treatment agent-containing composition of the present invention is a synthetic fiber treatment agent-containing composition comprising a synthetic fiber treatment agent comprising the following ester compound (A) and a surfactant (B) such as an anionic surfactant, and a solvent (S) having a boiling point of 105°C or less at one atmosphere, and further characterized by containing a component (C) such as an inorganic acid. Ester compound (A): An ester copolymer with a mass average molecular weight of 1000 to 15000 formed from the following constituent unit 1 and constituent unit 2, etc. Constituent unit 1: Contains constituent units such as dicarboxylic acid. Constituent unit 2: Contains constituent units such as alkylene glycol having 2 to 6 carbon atoms.

Description

[Technical Field]

[0001] The present invention relates to a composition containing a synthetic fiber treatment agent, synthetic fibers treated with the synthetic fiber treatment agent, and a method for producing a nonwoven fabric using synthetic fibers. [Background technology]

[0002] For example, synthetic fibers are known as raw materials for papermaking, nonwoven fabrics, and staple fibers. For instance, applying a synthetic fiber treatment agent to synthetic fibers imparts functions such as hydrophilicity. Papermaking, nonwoven fabrics, stuffing, and batting made from synthetic fibers with these added functions are utilized in a wide range of fields, including clothing, bedding, tea bags, and other daily necessities.

[0003] For example, a synthetic fiber treatment agent disclosed in Patent Document 1 is known. Patent Document 1 discloses a synthetic fiber treatment agent for use in synthetic fibers used in the papermaking process, comprising a predetermined polyether polyester, a predetermined ionic surfactant, and a predetermined silicone compound, in a proportion of 50 to 98.99% by mass of the polyether polyester, 1 to 49.99% by mass of the ionic surfactant, and 0.01 to 20% by mass of the silicone compound, such that the total content of the predetermined polyether polyester, a predetermined ionic surfactant, and a predetermined silicone compound is 100% by mass. [Prior art documents] [Patent Documents]

[0004] [Patent Document 1] Japanese Patent Publication No. 2018-123465 [Overview of the Initiative] [Problems that the invention aims to solve]

[0005] Incidentally, conventional synthetic fiber treatment agents have problems such as poor stability in the composition of the synthetic fiber treatment agent-containing composition mixed with a solvent, and inability to adequately suppress foaming. [Means for solving the problem]

[0006] As a result of research conducted to solve the above-mentioned problems, the present inventors have found that a synthetic fiber treatment agent containing a predetermined ester compound (A) and a surfactant (B), and a synthetic fiber treatment agent-containing composition containing a predetermined solvent (S), etc., are indeed suitable.

[0007] The following describes various methods for solving the above problems. The synthetic fiber treatment agent-containing composition of Embodiment 1 is a synthetic fiber treatment agent-containing composition comprising the following ester compound (A) and the following surfactant (B), and the following solvent (S), and further comprising the following component (C). A synthetic fiber treatment agent-containing composition, wherein the nonvolatile content of the synthetic fiber treatment agent-containing composition contains the ester compound (A) in an amount of 40% to 98% by mass, the surfactant (B) in an amount of 1% to 50% by mass, and the component (C) in an amount of 0.01% to 10% by mass. It is characterized by the following:

[0008] Ester compound (A): An ester copolymer formed from the following constituent unit 1 and constituent unit 2, or from the following constituent unit 1, constituent unit 2, and constituent unit 3, with a mass-average molecular weight of 1000 or more and 15000 or less.

[0009] Constituent unit 1: A constituent unit formed from at least one selected from dicarboxylic acids and ester-forming derivatives of dicarboxylic acids. Constituent unit 2: A constituent unit formed from at least one selected from alkylene glycol having 2 to 6 carbon atoms and (poly)alkylene glycol having a (poly)oxyalkylene group composed of oxyalkylene units having 2 to 6 carbon atoms.

[0010] Constituent unit 3: A constituent unit formed from at least one selected from the compound represented by the following general formula (1), the compound represented by the following general formula (2), and the compound represented by the following general formula (3).

[0011] [ka] (In Chemistry 1, R 1 A hydrocarbon group having 1 to 24 carbon atoms. A 1O: An oxyalkylene group having 2 to 4 carbon atoms (however, when there are a plurality of such oxyalkylene groups, they can be of one kind alone or of two or more kinds). n: An integer of 0 or more and 100 or less. )

[0012]

Chemical formula

[0013]

Chemical formula

[0014] Component (C): At least one selected from inorganic acids, inorganic acid salts, organic acids, carboxylates having 1 to 6 carbon atoms, and amine compounds. Solvent (S): A solvent having a boiling point of 105 °C or less at one atmosphere.

[0015] Aspect 2is, 1 In the synthetic fiber treatment agent-containing composition described above, the surfactant (B) is at least one selected from organic phosphate salts, organic sulfonates, organic sulfate salts, polyoxyalkylene fatty acid esters, polyhydric alcohol fatty acid esters, polyoxyalkylene polyhydric alcohol fatty acid esters, and polyoxyalkylene alkyl ethers.

[0016] manner 3 This is aspect 1 or 2 In the synthetic fiber treatment agent-containing composition described above, the synthetic fiber treatment agent further contains silicone (D). manner 4 The synthetic fibers are, in embodiment 1~ 3 The synthetic fiber treatment agent described in any one embodiment is attached to the material.

[0017] manner 5 is, 4 In the synthetic fiber described above, the synthetic fiber is for papermaking. manner 6 is, 4 In the synthetic fiber described above, the synthetic fiber is intended for use as stuffing.

[0018] manner 7 is, 4~6 In the synthetic fiber according to any one embodiment, the synthetic fiber is a polyester fiber or a polyolefin fiber. manner 8 The method for manufacturing nonwoven fabric is, 5 The method is characterized by dispersing the synthetic fibers described above in water and then making paper. [Effects of the Invention]

[0019] According to the present invention, the stability of the synthetic fiber treatment agent-containing composition can be improved, and foaming properties can be reduced. [Modes for carrying out the invention]

[0020] <First Embodiment> The following describes a first embodiment of the synthetic fiber treatment agent-containing composition of the present invention (hereinafter simply referred to as the treatment agent-containing composition). The treatment agent in this embodiment contains a synthetic fiber treatment agent (hereinafter simply referred to as the treatment agent) comprising an ester compound (A) and a surfactant (B), which will be described later, and a solvent (S). The treatment agent-containing composition further contains a component (C), which will be described later. The treatment agent-containing composition may further contain silicone (D).

[0021] (Ester compound (A)) Ester compound (A) is an ester copolymer formed from the following constituent unit 1 and constituent unit 2, or constituent unit 1, constituent unit 2, and constituent unit 3, with a mass-average molecular weight of 1000 to 15000.

[0022] Constituent unit 1 includes a constituent unit formed from at least one selected from dicarboxylic acids and ester-forming derivatives of dicarboxylic acids. Specific examples of dicarboxylic acids and ester-forming derivatives of dicarboxylic acids include, for example, aliphatic dicarboxylic acids such as oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, fumaric acid, and maleic acid; ester-forming derivatives of aliphatic dicarboxylic acids such as dimethyl oxalate, dimethyl malonate, dimethyl succinate, dimethyl glutarate, dimethyl adipate, bis(2-hydroxyethyl) adipate, dimethyl fumarate, and dimethyl maleate; aromatic dicarboxylic acids such as terephthalic acid, isophthalic acid, 2,6-naphthalenedicarboxylic acid, and 5-sulfoisophthalic acid; and ester-forming derivatives of aromatic dicarboxylic acids such as dimethyl terephthalate, dimethyl isophthalate, 2,6-naphthalenedicarboxylic acid, and 5-sulfoisophthalate-1,3-dimethyl.

[0023] Constituent unit 2 includes a constituent unit formed from at least one selected from alkylene glycols having 2 to 6 carbon atoms and (poly)alkylene glycols having (poly)oxyalkylene groups composed of oxyalkylene units having 2 to 6 carbon atoms. One type of alkylene glycol may be used alone, or two or more types may be used in appropriate combinations. When two or more types of alkylene glycols are applied, their addition methods may be block addition, random addition, or a combination of block addition and random addition, and there are no particular restrictions.

[0024] Specific examples of such alkylene glycols and (poly)alkylene glycols include alkylene glycols having 2 to 6 carbon atoms, such as ethylene glycol, propylene glycol, butylene glycol, and 1,6-hexanediol; and (poly)alkylene glycols having a (poly)oxyalkylene group composed of oxyalkylene units having 2 to 6 carbon atoms, such as polyethylene glycol, polypropylene glycol, polybutylene glycol, and poly-1,6-hexanediol. Specific examples include, for instance, ethylene glycol (monoethylene glycol manufactured by Mitsui Chemicals), polyethylene glycol (PEG-4000S manufactured by Sanyo Chemical Industries), polyethylene glycol (PEG-2000 manufactured by Sanyo Chemical Industries), polyethylene glycol (PEG-1000 manufactured by Sanyo Chemical Industries), polyethylene glycol (PEG-400 manufactured by Sanyo Chemical Industries), and polyoxyethylene (70 mol%) polyoxypropylene (30 mol%) block copolymer (mass-average molecular weight 4000).

[0025] Constituent unit 3 includes a constituent unit formed from at least one selected from the compound represented by the following general formula (1), the compound represented by the following general formula (2), and the compound represented by the following general formula (3).

[0026] [ka] (In Chemical Formula 4, R 1A hydrocarbon group having 1 to 24 carbon atoms. A 1 O: Oxyalkylene group having 2 to 4 carbon atoms (however, if multiple oxyalkylene groups are present, one type or two or more types may be used). n: An integer between 0 and 100 (inclusive). The hydrocarbon group constituting formula 4 may be a saturated hydrocarbon group or an unsaturated hydrocarbon group. It may also be a straight-chain hydrocarbon group or a branched-chain hydrocarbon group. Furthermore, it may be an aromatic hydrocarbon group such as a phenyl group or an aliphatic hydrocarbon group.

[0027] Examples of oxyalkylene groups having 2 to 4 carbon atoms that constitute formula 4 include oxyethylene groups, oxypropylene groups, and oxybutylene groups. One type of oxyalkylene group may be used alone, or two or more types may be used in appropriate combinations. When two or more types of oxyalkylene groups are applied, their addition form may be block addition, random addition, or a combination of block addition and random addition, and there are no particular restrictions.

[0028] [ka] (In Chemistry 5, R 2 ,R 3 A hydrocarbon group having 1 to 24 carbon atoms. A 2 O: Oxyalkylene group having 2 to 4 carbon atoms (however, if multiple oxyalkylene groups are present, one type or two or more types may be used). p: An integer between 0 and 100 (inclusive). The hydrocarbon group and the oxyalkylene group having 2 to 4 carbon atoms that make up Formula 5 can have the same configuration as in Formula 4.

[0029] [ka] (In Chemical Formula 6, R4 ,R 5 ,R 6 A hydrocarbon group having 1 to 24 carbon atoms. A 3 O: Oxyalkylene group having 2 to 4 carbon atoms (however, if multiple oxyalkylene groups are present, one type or two or more types may be used). X - : An organic acid having an alkyl group with 1 to 4 carbon atoms. q: An integer between 1 and 100 (inclusive). The hydrocarbon group and the oxyalkylene group having 2 to 4 carbon atoms that make up formula 6 can have the same configuration as in formula 4.

[0030] X - Examples include alkyl sulfates, alkyl sulfonates, alkyl phosphates, and carboxylates. In ester compound (A), it is preferable to include structural unit 3. By adopting such a configuration, the hydrophilicity of the synthetic fibers to which the treatment agent has been applied, particularly papermaking dispersibility and cotton ball settling hydrophilicity, can be further improved. Furthermore, in structural unit 3, it is preferable that the hydrocarbon groups constituting chemicals 4 to 6 include aromatic rings. By adopting such a configuration, the hydrophilicity of the synthetic fibers to which the treatment agent has been applied, particularly durable hydrophilicity, can be further improved.

[0031] The composition ratio of constituent units 1, 2, and 3 in ester compound (A) is preferably 10-60 / 20-85 / 0-35 as a molar ratio, and more preferably 15-50 / 30-80 / 0-25. By specifying within this range, the problem can be solved without impairing the hydrophilicity (papermaking dispersibility, cotton ball settling hydrophilicity) of the synthetic fibers to which the treatment agent has been applied. It should be noted that ranges by arbitrarily combining the above upper and lower limits are also conceivable.

[0032] The mass-average molecular weight of the ester compound (A) is 1,000 to 15,000, preferably 2,000 to 12,000, and more preferably 3,000 to 10,000. By defining it within this range, the problem can be solved without impairing the hydrophilicity (papermaking dispersibility, cotton ball settling hydrophilicity) of the synthetic fibers to which the treatment agent has been applied.

[0033] The measurement conditions for the mass-average molecular weight of ester compound (A) are as follows: Model: HLC-8120GPC (Liquid chromatograph manufactured by Tosoh Corporation) Column: TSK gel Super H4000, TSK gel Super H3000, and TSK gel Super H2000 (all product names manufactured by Tosoh Corporation) Column temperature: 40℃ Detector: RI (Refractive Index) Solvent: tetrahydrofuran Flow rate: 0.5mL / min Sample concentration: 0.25% by mass Injection volume: 10μL These ester compounds (A) may be used individually or in combination of two or more as appropriate.

[0034] In the nonvolatile content of the treatment agent-containing composition, the lower limit of the ester compound (A) content is set as appropriate, but is preferably 30% by mass or more, more preferably 40% by mass or more, and even more preferably 45% by mass or more. When the content is 30% by mass or more, the hydrophilicity of the synthetic fiber to which the treatment agent is applied can be further improved. The upper limit of the ester compound (A) content is set as appropriate, but is preferably 99% by mass or less, more preferably 98% by mass or less. When the content is 99% by mass or less, the stability can be further improved. It should be noted that ranges by arbitrarily combining the above upper and lower limits are also conceivable.

[0035] The non-volatile content is determined from the mass of the oven-dried material obtained by heat-treating the object at 105°C for 2 hours to thoroughly remove volatile substances (the same applies hereafter). (Surfactant (B)) Surfactant (B) is at least one selected from anionic surfactants (excluding carboxylates having 1 to 6 carbon atoms) and nonionic surfactants.

[0036] (Anionic surfactant) As an anionic surfactant, any known one can be used as appropriate. Specific examples of anionic surfactants include, for example, (1) phosphate ester salts of aliphatic alcohols such as butyl phosphate salt, octyl phosphate salt, 2-ethylhexyl phosphate salt, lauryl phosphate salt, cetyl phosphate salt, octyl phosphate salt, oleyl phosphate salt, and stearyl phosphate salt; (2) phosphate ester salts obtained by adding at least one alkylene oxide selected from ethylene oxide and propylene oxide to aliphatic alcohols such as polyoxyethylene lauryl ether phosphate salt, polyoxyethylene oleyl ether phosphate salt, and polyoxyethylene stearyl ether phosphate salt; (3) aliphatic sulfonates or aromatic sulfonates such as lauryl sulfonate, myristyl sulfonate, cetyl sulfonate, oleyl sulfonate, stearyl sulfonate, tetradecane sulfonate, dodecylbenzene sulfonate, and secondary alkanesulfonic acid (C13-15) salts; and (4) aliphatic alcohols such as lauryl sulfate salt, oleyl sulfate salt, and stearyl sulfate salt. (5) Sulfate salts of aliphatic alcohols to which at least one alkylene oxide selected from ethylene oxide and propylene oxide has been added, such as (6) Castor oil fatty acid sulfate, sesame oil fatty acid sulfate, tall oil fatty acid sulfate, soybean oil fatty acid sulfate (7) Sulfate salts of fatty acids such as sterol salts, rapeseed oil fatty acid sulfate salts, palm oil fatty acid sulfate salts, lard fatty acid sulfate salts, beef tallow fatty acid sulfate salts, whale oil fatty acid sulfate salts, etc., (8) Sulfate salts of fats and oils such as castor oil sulfate salts, sesame oil sulfate salts, tall oil sulfate salts, soybean oil sulfate salts, rapeseed oil sulfate salts, palm oil sulfate salts, lard sulfate salts, beef tallow sulfate salts, whale oil sulfate salts, etc., (8) Fatty acid salts such as laurate, oleate, and stearate,(9) Examples include sulfosuccinate salts of aliphatic alcohols such as dioctyl sulfosuccinate. Examples of counterions for anionic surfactants include alkali metal salts such as potassium salts and sodium salts, ammonium salts, and alkanolamine salts such as triethanolamine.

[0037] (Nonionic surfactant) Examples of nonionic surfactants include compounds having a (poly)oxyalkylene structure obtained by adding alkylene oxide to alcohols or carboxylic acids, ether ester compounds having a (poly)oxyalkylene structure obtained by adding alkylene oxide to ester compounds of carboxylic acids and polyhydric alcohols, amine compounds such as compounds having a (poly)oxyalkylene structure obtained by adding alkylene oxide to primary organic amines, partial ester compounds of carboxylic acids and polyhydric alcohols, amide compounds obtained by condensing amine compounds and carboxylic acids, compounds having a (poly)oxyalkylene structure obtained by adding alkylene oxide to fatty acid amides, and compounds having a polyoxyalkylene structure such as block copolymers having polyoxyethylene chains and polyoxypropylene chains.

[0038] Specific examples of alcohols used as raw materials for nonionic surfactants include, for example, (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, heptadecanol, octacosanol, nonacosanol, triacontanol, and (2) isopropanol, isobutanol, isohexanol, 2-ethylhexanol, isononanol, isodecanol, isododecanol, isotridecanol, isotetradecanol, isopentadecanol, isohexa Examples include branched alkyl alcohols such as decanol, isoheptadecanol, isooctadecanol, isononadecanol, isoeicosanol, isoheneicosanol, isodocosanol, isotricosanol, isotetracosanol, isopentacosanol, isohexacosanol, isoheptacosanol, isooctactasanol, isononacosanol, and isotriacontanol; (3) linear alkenyl alcohols such as tetradecenol, hexadecenol, heptadecenol, octadecenol, and nonadecenol; (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, monostylenide, distylenide, and tristylenide.

[0039] Specific examples of carboxylic acids used as raw materials for nonionic surfactants include, for example, (1) linear alkyl carboxylic acids such as octic 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; (5) hydroxycarboxylic acids such as lactic acid, citric acid, and ricinoleic acid; and (6) polycarboxylic acids such as adipic acid, sebacic acid, and tricarbaryl.

[0040] As the alkylene oxide used as a raw material for forming the (poly)oxyalkylene structure of nonionic surfactants, alkylene oxides having 2 to 4 carbon atoms are preferred. Specific examples of alkylene oxides include ethylene oxide, propylene oxide, and butylene oxide. The number of moles of alkylene oxide to be added is set as appropriate, but is preferably 0.1 moles to 60 moles, more preferably 1 mole to 40 moles, and even more preferably 2 moles to 30 moles. Ranges arbitrarily combining the above upper and lower limits are also conceivable. The number of moles of alkylene oxide to be added indicates the number of moles of alkylene oxide per mole of the compound to be added in the raw materials. One type of alkylene oxide may be used alone, or two or more types of alkylene oxide may be used in appropriate combination. When two or more types of alkylene oxide are applied, their addition method may be block addition, random addition, or a combination of block addition and random addition, and is not particularly limited.

[0041] Specific examples of polyhydric alcohols used as raw materials for nonionic surfactants include, for example, 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.

[0042] Specific examples of aliphatic amines used as raw materials for nonionic surfactants include methylamine, ethylamine, butylamine, octylamine, laurylamine, octadecylamine, octadecenylamine, and coconutamine.

[0043] Specific examples of fatty acid amides used as raw materials for nonionic surfactants include, for example, octylic acid amide, lauric acid amide, palmitic acid amide, stearic acid amide, oleic acid amide, behenic acid amide, lignoceric acid amide, amides of fatty acids and diethanolamine, and amides of fatty acids and ethyleneamine.

[0044] Compounds having a polyoxyalkylene structure are not particularly limited as long as they have surfactant properties. The number of polyoxyethylene chains and / or polyoxypropylene chains in the molecule is not particularly limited. The number of moles of ethylene oxide added to form the polyoxyethylene chain is not particularly limited, for example, 3 moles to 200 moles. The number of moles of propylene oxide added to form the polyoxypropylene chain is not particularly limited, for example, 3 moles to 100 moles.

[0045] Among nonionic surfactants, polyoxyalkylene fatty acid esters may produce monoesters with 1 mole of fatty acid added to the polyoxyalkylene chain and diesters with 2 moles of fatty acid added, through synthesis methods such as reacting a polyoxyalkylene chain with a fatty acid. In such cases, the ratio of monoester to diester is not particularly limited. Preferably, the ratio of the produced monoester to diester is monoester:diester = 30:70 to 70:30 by mass. In such cases, the stability of the treatment agent-containing composition can be further improved.

[0046] Specific examples of nonionic surfactants include compounds obtained by adding alkylene oxide to octyl alcohol, compounds obtained by adding alkylene oxide to branched alcohols with 12 or 13 carbon atoms, compounds obtained by adding alkylene oxide to branched alcohols with 14 or 15 carbon atoms, compounds obtained by adding alkylene oxide to lauryl alcohol, compounds obtained by adding alkylene oxide to stearyl alcohol, compounds obtained by adding alkylene oxide to oleic acid, compounds obtained by adding alkylene oxide to hydrogenated castor oil, compounds obtained by adding alkylene oxide to sorbitan monooleate, compounds obtained by adding alkylene oxide to beef tallow-derived fatty acids, compounds obtained by adding alkylene oxide to stearic acid, compounds obtained by adding alkylene oxide to sorbitan monooleate and stearylamide, and compounds obtained by adding alkylene oxide to laurylamine.

[0047] These surfactants (B) may be used individually or in combination of two or more as appropriate. Among these, the surfactant (B) is preferably at least one selected from organic phosphate salts, organic sulfonates, organic sulfate salts, polyoxyalkylene fatty acid esters, polyhydric alcohol fatty acid esters, polyoxyalkylene polyhydric alcohol fatty acid esters, and polyoxyalkylene alkyl ethers. By applying such compounds, stability can be further improved.

[0048] In the nonvolatile content of the treatment agent-containing composition, the lower limit of the surfactant (B) content is 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, stability can be further improved. The upper limit of the surfactant (B) content is set as appropriate, but is preferably 70% by mass or less, more preferably 60% by mass or less, and even more preferably 50% by mass or less. When the content is 70% by mass or less, the hydrophilicity of the synthetic fiber to which the treatment agent has been applied can be further improved. It should be noted that a range of arbitrary combinations of the above upper and lower limits is also conceivable.

[0049] (Component (C)) Component (C) is at least one selected from inorganic acids, inorganic acid salts, organic acids, organic acid salts, and amine compounds.

[0050] Specific examples of inorganic acids include hydrochloric acid, sulfuric acid, phosphoric acid, nitric acid, and carbonic acid. Examples of salts that make up inorganic salts include metal salts and ammonium salts. Examples of metal salts include alkali metal salts and alkaline earth metal salts. Specific examples of alkali metals that make up alkali metal salts include sodium, potassium, and lithium. Examples of alkaline earth metals that make up alkaline earth metal salts include metals belonging to Group 2 elements, such as calcium, magnesium, beryllium, strontium, and barium.

[0051] Specific examples of inorganic salts include, for example, dipotassium phosphate, disodium phosphate, ammonium chloride, ammonium sulfate, and calcium carbonate. As the organic acid constituting the organic acid and organic acid salt, a carboxylic acid is preferred. Furthermore, the number of carbon atoms in such an organic acid is preferably between 1 and 6. This configuration can further improve stability. Specific examples of carboxylic acids include citric acid, tartaric acid, lactic acid, malic acid, succinic acid, fumaric acid, maleic acid, gluconic acid, glucuronic acid, and benzoic acid. Specific examples of organic acid salts include disodium citrate, sodium acetate, and sodium gluconate. In the present invention, a carboxylate salt with 1 to 6 carbon atoms is used as the organic acid salt.

[0052] The amine compound may be a primary amine, a secondary amine, or a tertiary amine. Specific examples of amine compounds include, for example, (1) aliphatic amines such as methylamine, dimethylamine, trimethylamine, ethylamine, diethylamine, triethylamine, NN-diisopropylethylamine, butylamine, dibutylamine, 2-methylbutylamine, tributylamine, octylamine, and dimethyllaurylamine; (2) aromatic amines or heterocyclic amines such as aniline, N-methylbenzylamine, pyridine, morpholine, piperazine, and their derivatives; (3) alkanolamines such as monoethanolamine, N-methylethanolamine, diethanolamine, triethanolamine, isopropanolamine, diisopropanolamine, triisopropanolamine, dibutylethanolamine, butyldiethanolamine, octyldiethanolamine, and lauryldiethanolamine; (4) arylamines such as N-methylbenzylamine; and (5) polyoxyalkylene alkylamino ethers such as polyoxyethylene laurylamino ether and polyoxyethylene sterylamino ether.

[0053] These components (C) may be used individually or in combination of two or more as appropriate. Among these, inorganic acids, inorganic salts, and amine compounds are preferred from the viewpoint of further improving stability.

[0054] In the nonvolatile content of the treatment agent-containing composition, the lower limit of the content of component (C) is set as appropriate, but is preferably 0.01% by mass or more, more preferably 0.1% by mass or more. When the content is 0.01% by mass or more, stability and the hydrophilicity of the synthetic fiber to which the treatment agent has been applied can be further improved. In particular, stability at high temperatures and the hydrophilicity of the synthetic fiber to which the treatment agent has been applied at high temperatures can be further improved. The upper limit of the content of component (C) is set as appropriate, but is preferably 15% by mass or less, more preferably 10% by mass or less. When the content is 15% by mass or less, stability and the hydrophilicity of the synthetic fiber to which the treatment agent has been applied can be further improved. In particular, stability at high temperatures and the hydrophilicity of the synthetic fiber to which the treatment agent has been applied at high temperatures can be further improved. It should be noted that a range of arbitrary combinations of the above upper and lower limits is also conceivable.

[0055] In the nonvolatile content of the treatment agent-containing composition, it is preferable that the ester compound (A) is contained in an amount of 40% to 98% by mass, the surfactant (B) in an amount of 1% to 50% by mass, and component (C) in an amount of 0.01% to 10% by mass. In the present invention, such a blending amount is applied. By defining the range in this way, the effects of the present invention can be further improved. It should be noted that ranges obtained by arbitrarily combining the above upper and lower limits are also conceivable.

[0056] (Silicone (D)) The treatment agent-containing composition may further contain silicone (D). By incorporating silicone (D), the foaming properties of the treatment agent-containing composition can be further reduced.

[0057] Specific examples of silicone (D) are not particularly limited, but include 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. The viscosity of silicone (D) at 25°C is not particularly limited, but is preferably 10 mPa·s or more and 100,000 mPa·s or less.

[0058] These silicones (D) may be used individually or in combination of two or more as appropriate. In the nonvolatile content of the treatment agent-containing composition, the lower limit of the silicone (D) content is set as appropriate, but is preferably 0.01% by mass or more, more preferably 0.02% by mass or more. When the content is 0.01% by mass or more, foaming can be further reduced. The upper limit of the silicone (D) content is set as appropriate, but is preferably 1% by mass or less, more preferably 0.5% by mass or less. When the content is 1% by mass or less, the effects of the present invention can be further improved. It should be noted that ranges obtained by arbitrarily combining the above upper and lower limits are also conceivable.

[0059] (Solvent (S)) The solvent (S) is a solvent whose boiling point at one atmosphere is 105°C or lower. Examples of solvents 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 (S) may be used individually or in appropriate combinations 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 handling.

[0060] In the treatment agent-containing composition, the content of solvent (S) is set appropriately depending on the purpose, etc., but for example, a content of 10 parts by mass or more and 1000 parts by mass or less per 100 parts by mass of treatment agent is possible.

[0061] (pH) In a composition containing a treatment agent, the pH of a diluted solution containing 1% by mass of the treatment agent at 25°C is preferably 3 to 10, and more preferably 4 to 9. By specifying this range, the stability of each component can be further improved. It should be noted that ranges arbitrarily combining the above upper and lower limits are also conceivable.

[0062] (Effects of this embodiment) The effects of the treatment agent-containing composition of the first embodiment will be described. (1-1) The treatment agent-containing composition of the first embodiment contains a treatment agent comprising the ester compound (A) and surfactant (B) described above, and the solvent (S) and component (C) described above. Therefore, the stability of the treatment agent-containing composition, particularly its emulsification stability, can be improved. Furthermore, the stability during high-temperature storage, particularly its emulsification stability during high-temperature storage, can be improved. In addition, the foaming properties of the treatment agent-containing composition or its diluted solution can be reduced. As a result, the usability characteristics of the treatment agent-containing composition or its diluted solution can be improved.

[0063] Furthermore, the hydrophilicity of synthetic fibers treated with the treatment agent can be improved, especially after high-temperature storage. In particular, when the synthetic fibers are in the form of papermaking, the dispersibility during papermaking can be improved. This can improve the quality of the resulting paper. In addition, the durable hydrophilicity of synthetic fibers treated with the treatment agent can be improved. This can improve the washing characteristics of products using synthetic fibers treated with the treatment agent.

[0064] (1-2) Furthermore, if the treatment agent-containing composition contains silicone (D), the foaming properties of the treatment agent-containing composition can be further reduced. <Second Embodiment> A second embodiment of the synthetic fiber according to the present invention will now be described. The synthetic fiber of this embodiment is a treated synthetic fiber in which the treatment agent of the first embodiment is attached to the surface. By attaching the treatment agent to the surface of the synthetic fiber, a synthetic fiber with various functions is obtained.

[0065] (Uses of synthetic fibers) The uses of synthetic fibers are not particularly limited and include, for example, papermaking, nonwoven fabrics, spinning, yarn manufacturing, and stuffing. Papermaking uses are not particularly limited and include filtration membranes and tea bags. Stuffing uses are not particularly limited and include bedding such as futons, pillows, and cushions, clothing such as quilts and down jackets, and stuffed animals. The fiber length is also not particularly limited and can be applied to both short and long fibers. Short fibers generally refer to what are called staples and do not include long fibers generally called filaments. Furthermore, the length of short fibers is not particularly limited as long as they qualify as short fibers in this art, but is preferably 100 mm or less, and more preferably 30 mm to 70 mm.

[0066] (Synthetic fiber) Specific examples of synthetic fibers include (1) polyolefin fibers such as polyethylene fibers, polypropylene fibers, and polybutene fibers; (2) polyester fibers such as polyethylene terephthalate, polybutylene terephthalate, polyethylene terephthalate-isophthalate, and polyether polyester; (3) polyamide fibers such as nylon 6 and nylon 66; and (4) composite fibers, specifically composite fibers with a core-sheath structure in which either the core, sheath, or both are polyolefin fibers, such as polyethylene / polypropylene composite fibers or polyethylene / polyester composite fibers where the sheath is polyethylene fiber, or polyethylene / polypropylene composite fibers or polyethylene / polyester composite fibers having a side-by-side structure. Among these, polyester fibers and polyolefin fibers are preferred.

[0067] (Application of treatment agent) There are no particular restrictions on the proportion of the treatment agent of the first embodiment that is applied to the synthetic fibers, but it is preferable to apply the solvent-free treatment agent in an amount of 0.1% to 2% by mass relative to the synthetic fibers, and more preferably in an amount of 0.2% to 1.2% by mass.

[0068] As a method for attaching the treatment agent to synthetic fibers, for example, known methods such as immersion, spraying, rolling, or guided lubrication using a metering pump can be applied using the treatment agent-containing composition of the first embodiment, or a dilution obtained by further diluting with a solvent.

[0069] (Method of manufacturing nonwoven fabrics) Nonwoven fabrics may be manufactured using the synthetic fibers of this embodiment by the following methods. The type of nonwoven fabric is not particularly limited, but examples include dry methods such as the airlaid method, wet methods such as the papermaking method, carding, and spunbond. Furthermore, when the raw material fibers are long fibers, examples include the meltblown method and the flash spinning method. Examples of interfiber bonding methods include the chemical bond method, the thermal bond method, the needle punch method, the spunlace method, and the stitch bond method. In the case of a papermaking method, the synthetic fibers of the above embodiment are dispersed in water and paper is made. More specific papermaking methods can be manufactured using known methods.

[0070] (Effects of this embodiment) The effects of the synthetic fiber of the second embodiment will now be described. In addition to the effects of the above embodiment, the second embodiment has the following effects.

[0071] (2-1) In the synthetic fibers of the second embodiment, the treatment agent of the first embodiment is attached. Therefore, the hydrophilicity of the synthetic fibers to which the treatment agent has been applied, especially the hydrophilicity after high-temperature storage, can be improved. Thus, it can be suitably applied to nonwoven fabrics, stuffing cotton, and other applications where improved functionality is required.

[0072] (Example of change) The above embodiment may be modified as follows. The above embodiment and the following modifications can be combined and implemented to the extent that they do not contradict each other technically.

[0073] The processing agents, processing agent-containing compositions, or diluents of the above embodiments may further contain other components commonly used in processing agents, such as other solvents, stabilizers, antistatic agents, binders, ultraviolet absorbers, surfactants other than those mentioned above, pH adjusters, higher alcohols, polyhydric alcohols such as polyethylene glycol, etc., as long as they do not impede the effects of the present invention. The other components commonly used in processing agents, other than solvents, are preferably present in 20% by mass or less, and more preferably 10% by mass or less, in each processing agent from the viewpoint of efficiently exhibiting the efficacy of the present invention. Furthermore, the other components may be stored as separate agents from the processing agents described above.

[0074] • Each of the above embodiments of the treatment agent, treatment agent-containing composition, or diluent may contain preservatives, antioxidants, etc., to maintain the quality of each treatment agent, etc. Specific examples of preservatives include, for example, 1,2-benzothiazolin-3-one. Specific examples of antioxidants include, for example, 1,1,3-tris(2-methyl-4-hydroxy-5-t-butylphenyl)butane, pentaerythritol=tetrakis[3-(3',5'-di-t-butyl-4'-hydroxyphenyl)propionate], 3,9-bis(2,6-di-t-butyl-4-methylphenoxy)-2,4,8,10-tetraoxa-3,9-diphosphaspiro[5.5]undecane, ditridecane-1-yl=3,3'-sulfandiyldipropanoate, etc. From the viewpoint of enabling each additive to exert its function, these components are preferably present in a composition containing the treatment agent at a concentration of 0.01% by mass or more and 1% by mass or less.

[0075] • The treatment agent-containing composition of the above embodiment may contain the catalyst used when synthesizing the ester compound (A). Examples of catalysts include zinc acetate, calcium acetate, anhydrous sodium acetate, antimony trioxide, phosphorous acid, phosphoric acid, and titanium tetrabutoxide. The amount of catalyst in the treatment agent-containing composition is preferably 0.1% by mass or less. The treatment agent-containing composition may also contain unreacted products and reaction by-products after synthesizing the ester compound (A). Examples of unreacted products or reaction by-products include polyethylene glycol, dimethyl terephthalate, isomethyl terephthalate, ethylene glycol, phenyl-polyethylene glycol, 5-sulfoisophthalic acid, adipic acid, and their reaction products. [Examples]

[0076] The following examples illustrate the structure and effects of the present invention in more detail, but the present invention is not limited to these examples. In the following examples and comparative examples, "parts" refers to parts by mass, and "%" refers to mass percent.

[0077] Test category 1 (Preparation of treatment agent) (Example 1) 900g of water at 20°C was weighed into a 1000mL beaker, and 4.98g of polyoxyethylene (3mol) lauryl ether sulfate triethanolamine (B-1), 0.09g of dimethyl silicone (D-1) with a viscosity of 300mPa·s at 25°C, 0.20g of dipotassium phosphate (C-1), 0.09g of triethanolamine (C-10), and 0.20g of 1,2-benzothiazolin-3-one (Q-1) were added. While stirring with a homomixer (4000rpm), 94.44g of ester compound (A-1), which had been molten at 150°C beforehand, was added, and the mixture was stirred for 10 minutes (4000rpm) to prepare a treatment agent-containing composition (Example 1) with a treatment agent concentration of 30%.

[0078] (Example 2~ 25, Reference example 26~ 28. Comparative Examples 1-7) Example 2~ 25, Reference example 26~Each of the treatment agents for 28 and Comparative Examples 1-7 was prepared using the components shown in Table 1, in the same manner as in Example 1. However, the melting temperature was the melting temperature of each ester compound (A), and the amount used was the proportion shown in Table 1.

[0079] The types and content of ester compounds (A), surfactants (B), components (C), silicones (D), water as a solvent (S), and other components in the treatment agent for each example are shown in the "Ester Compounds (A)", "Surfactants (B)", "Components (C)", "Silicones (D)", "Solvents (S)", and "Other Components" columns of Table 1, respectively. Note that the solvent (S) content is shown in parts per 100 parts of the treatment agent-containing composition.

[0080] (pH) The treatment agent-containing compositions for each example were diluted with water to make a 1% dilution, and the pH was measured at 25°C. The results are shown in Table 1. * indicates that the treatment agent was insoluble in water and therefore not measured.

[0081] [Table 1] The details of the ester compounds (A), surfactants (B), components (C), silicones (D), solvents (S), and other components listed in Table 1 are as follows.

[0082] <Ester compound (A)> Ester compounds (A) used were A-1 to A-15, as shown in Table 2 below. The types of constituent units 1 to 3 and their mass-average molecular weights for ester compound (A) are shown in the "Constituent Unit 1" to "Constituent Unit 3" columns and the "Mass-Average Molecular Weight" column in Table 2, respectively. Furthermore, constituent unit 3 represents one of the above formulas 4 to 6, with formula 4 having one substituent R, formula 5 having two substituents R, and formula 6 having three substituents R. In Table 2, "R", "AO", "Number of Moles", and "X" are shown. -The symbols " and " indicate the composition of the compounds in formulas 4-6. In Table 2, "EO" represents an ethylene oxy group and "PO" represents a propylene oxy group.

[0083] (Ester compound (A-1)) First, 821.2 g of a compound obtained by adding 69 moles of ethylene oxide to 1 mole of phenol, 179.2 g of dimethyl terephthalate, 19.9 g of dimethyl isophthalate, 158.7 g of ethylene glycol, 0.36 g of zinc acetate dihydrate, and 0.10 g of antimony trioxide were charged into a reaction vessel. Next, the reaction was carried out for 6 hours under a nitrogen atmosphere at 150-220°C while distilling off methanol, and it was confirmed that approximately the theoretical amount of methanol had distilled off. Subsequently, a polycondensation reaction was carried out at 220-250°C for 60 minutes under reduced pressure of 20 mmHg, and then at 250-260°C for 6 hours under further reduced pressure of 0.5-1.0 mmHg. As a result, an ester compound (A-1) was obtained having 24 mol% of constituent units formed from dimethyl terephthalate and 2.7 mol% of constituent units formed from dimethyl isophthalate (total 26.7 mol%) as constituent unit 1, 66.5 mol% of constituent units formed from ethylene glycol as constituent unit 2, and 6.8 mol% of constituent unit 3, which was obtained by adding 69 moles of ethylene oxide to 1 mole of phenol. The mass-average molecular weight of ester compound (A-1) was 5659. The measurement conditions for the mass-average molecular weight are as described in the column for ester compound (A) (the same applies hereafter).

[0084] (Ester compounds (A-2) to (A-13)) Ester compounds (A-2) to (A-13) were prepared using the components shown in Table 2, in the same manner as ester compound (A-1).

[0085] (Ester compound (A-14)) 1000g of A-2 was placed in a reaction vessel. Next, under a nitrogen atmosphere, 18.3g of diethyl sulfuric acid was gradually added dropwise at 60-80°C. After the addition was complete, the reaction was carried out at 70-90°C for 2 hours. As a result, ester compound (A-14) was obtained. The mass-average molecular weight of ester compound (A-14) was 8190.

[0086] (Ester compound (A-15)) 1000g of A-6 was placed in a reaction vessel. Next, under a nitrogen atmosphere, 25g of dibutylsulfuric acid was gradually added dropwise at 60-80°C. After the addition was complete, the reaction was carried out at 70-90°C for 2 hours. As a result, an ester compound (A-15) was obtained. The mass-average molecular weight of the polyether polyester (A-15) was 8249.

[0087] [Table 2] Types of constituent unit 1: The ester-forming derivatives of dicarbons or dicarboxylic acids that form constituent unit 1 in Table 2 are shown below.

[0088] 1-1: Dimethyl terephthalate 1-2: Dimethyl isophthalate 1-3:5-Sulfoisophthalate-1,3-dimethyl 1-4: Bis(2-hydroxyethyl) adipate Types of constituent unit 2: The following are (poly)alkylene glycols having (poly)oxyalkylene groups composed of (poly)oxyalkylene units having 2 to 6 carbon atoms that form constituent unit 2 in Table 2.

[0089] 2-1: Ethylene glycol (monoethylene glycol manufactured by Mitsui Chemicals, Inc.) 2-2: Polyethylene glycol (PEG-4000S manufactured by Sanyo Chemical Industries, Ltd.) 2-3: Polyethylene glycol (PEG-2000 manufactured by Sanyo Chemical Industries, Ltd.) 2-4: Polyethylene glycol (PEG-1000 manufactured by Sanyo Chemical Industries, Ltd.) 2-5: Polyethylene glycol (PEG-400 manufactured by Sanyo Chemical Industries, Ltd.) 2-6: Polyoxyethylene (70 mol%) polyoxypropylene (30 mol%) block copolymer (mass-average molecular weight 4000) <Surfactant (B)> (Anionic surfactant) B-1: Polyoxyethylene (3 molar) lauryl ether sulfate triethanolamine (acid value: 0.7 KOH mg / g) B-2: Sodium dioctyl sulfosuccinate (acid value: 0.4KOH mg / g) B-3: Sodium lauryl sulfate salt (Acid value: 0KOH mg / g) B-4: Potassium butyl phosphate salt (a mixture of 19% monoester, 26% diester, 18% polyester, and 37% diphosphate esters; acid value: 0 KOH mg / g) B-5: Octyl phosphate esters and their potassium salts (a mixture of 39% monoesters, 51% diesters, 9% polyesters, and 1% diphosphate esters; acid value: 29 KOH mg / g) B-6: 2-Ethylhexyl phosphate ester and its potassium salt (mixture of monoester 50%, diester 28%, polyester 5%, and diphosphate esters 17%, acid value: 33 KOH mg / g) B-7: Lauryl phosphate esters and their potassium salts (a mixture of 53% monoesters, 30% diesters, and 17% diphosphate esters; acid value: 77 KOH mg / g) (Nonionic surfactant) B-8: A compound obtained by adding 5 moles of ethylene oxide to 1 mole of octyl alcohol (Conol 10WS, manufactured by Shin Nippon Rika Co., Ltd.). B-9: A compound obtained by adding 10 moles of ethylene oxide to 1 mole of a branched alcohol with 12 or 13 carbon atoms (SAFOL23, manufactured by SASOL). B-10: A compound obtained by randomly adding 39 moles of ethylene oxide and 13 moles of propylene oxide to 1 mole of a branched alcohol with 14 or 15 carbon atoms (NEODOL45, manufactured by Shell Chemicals). B-11: A compound obtained by block adding 13 moles of ethylene oxide and 16 moles of propylene oxide in that order to 1 mole of a branched alcohol with 14 or 15 carbon atoms (NEODOL45, manufactured by Shell Chemicals). B-12: A compound obtained by adding 10 moles of ethylene oxide to 1 mole of lauryl alcohol (Kao Corporation's Calcol 2098). B-13: A compound obtained by adding 18 moles of ethylene oxide to 1 mole of stearyl alcohol (Kao Corporation's Calcol 8688). B-14: A compound obtained by adding 8 moles of ethylene oxide to 1 mole of oleic acid (PM200, manufactured by Miyoshi Oil & Fat Co., Ltd.). B-15: A compound obtained by adding 10 moles of ethylene oxide to 1 mole of oleic acid (PM200, manufactured by Miyoshi Oil & Fat Co., Ltd.). B-16: A compound obtained by randomly adding 9 moles of ethylene oxide and 9 moles of propylene oxide to 1 mole of hydrogenated castor oil (hydrogenated castor oil manufactured by Ito Oil Co., Ltd.). B-17: A compound obtained by adding 18 moles of ethylene oxide to 1 mole of hydrogenated castor oil (hydrogenated castor oil manufactured by Ito Oil Co., Ltd.). B-18: A compound obtained by adding 20 moles of ethylene oxide to 1 mole of sorbitan monooleate (nonionic OP-80R, manufactured by NOF Corporation). B-19: A compound obtained by adding 20 moles of ethylene oxide to 1 mole of sorbitan monostearate (Kao Corporation's Rheodol SP-S10V). B-20: A compound obtained by adding 30 moles of propylene oxide and 15 moles of ethylene oxide to 1 mole of fatty acid derived from beef tallow. B-21: A compound obtained by adding 25 moles of propylene oxide to 1 mole of fatty acid derived from beef tallow. B-22: A compound obtained by adding 5 moles of ethylene oxide to 1 mole of stearic acid (Lunaq S-70V, manufactured by Kao Corporation). B-23: Sorbitan Monooleate (Nonionic OP-80R manufactured by NOF Corporation) B-24: A compound obtained by adding 3 moles of ethylene oxide to 1 mole of stearylamide (ArmoSlip HT powder, manufactured by Lion Specialty Chemicals). B-25: A compound obtained by adding 10 moles of ethylene oxide to 1 mole of laurylamine (Farmin CS, manufactured by Kao Corporation). <Ingredient (C)> C-1: Dipotassium phosphate C-2: Disodium phosphate C-3: Ammonium chloride C-4: Ammonium sulfate C-5: Calcium carbonate C-6: Disodium citrate C-7: Sodium acetate C-8: Sodium gluconate C-9: Diethanolamine C-10: Triethanolamine <Silicone (D)> D-1: Dimethyl silicone (viscosity 300 mPa·s(cP), 25℃) D-2: Dimethyl silicone (viscosity 350 mPa·s(cP), 25℃) D-3: Dimethyl silicone (viscosity 1000 mPa·s(cP), 25℃) (Viscosity measurement conditions) Model: RB80L (Viscometer manufactured by Toki Sangyo Co., Ltd.) Measurement temperature: 25℃, Container: Height approximately 13.5cm 300 mL tall beaker Sample volume: 250 mL <Other ingredients> Q-1: 1,2-Benzothiazolin-3-one Q-2: Polyethylene glycol (mass-average molecular weight 20,000) Q-3: 1,1,3-Tris(2-methyl-4-hydroxy-5-t-butylphenyl)butane Q-4: Pentaerythritol = tetrakis[3-(3',5'-di-t-butyl-4'-hydroxyphenyl)propionate] Q-5:3,9-bis(2,6-di-t-butyl-4-methylphenoxy)-2,4,8,10-tetraoxa-3,9-diphosphaspiro[5.5]undecane Q-6: Ditridecane-1-yl=3,3'-sulfandiyldipropanoate Test category 2 (Emulsification stability) Each example of the treatment agent-containing composition was diluted with water to obtain a 1% diluted solution of the treatment agent. 10 mL of this diluted solution was placed in a test tube and allowed to stand at 25°C for 24 hours. The stability after 24 hours was determined by visual observation according to the following criteria. The results are shown in the "Emulsification Stability" column of Table 1.

[0090] • Evaluation criteria for emulsification stability 4 (Excellent): No precipitate is observed at all. 3 (Good): A small amount of precipitate is observed, but it is resolved in less than 5 seconds by stirring with a stirring blade at 300 rpm. 2 (Acceptable): A small amount of precipitate is observed, but the precipitate is resolved within 5 to 15 seconds by stirring with a stirring blade at 300 rpm. 1 (Unacceptable): If a large amount of precipitate is observed and the precipitate does not disappear even after stirring with a stirring blade at 300 rpm for 15 seconds or more. Test category 3 (Emulsification stability after high temperature and time) The treatment agent-containing compositions for each example were allowed to stand at 50°C for two weeks, and then diluted with water to obtain a 1% diluted solution of the treatment agent. 10 mL of this diluted solution was placed in a test tube and allowed to stand at 25°C for 24 hours. The stability after 24 hours was determined by visual observation according to the following criteria. The results are shown in the "Emulsification Stability" column, "After High Temperature Time" column, in Table 1.

[0091] • Evaluation criteria for emulsification stability after high temperature exposure 3 (Good): No precipitate is observed. 2 (Acceptable): When a small amount of precipitate is observed. 1 (Not acceptable): When a large amount of precipitate is observed. Test category 4 (Paper dispersibility (immediately after)) • Adhesion of treatment agent to synthetic fiber bundles Each example of the treatment agent-containing composition was diluted with water to prepare a 1% diluted solution as the treatment agent. 2 g of the diluted solution was applied by spraying to 10 g of raw material synthetic fiber (polyethylene terephthalate short fiber with a fineness of 1.3 dtex and a length of 10 mm), and dried in an 80°C dryer for 1 hour. The papermaking properties were evaluated using the obtained short fiber samples as follows.

[0092] • Method for evaluating variance (immediately after the event) 1000 mL of 25°C water and 0.1 g of the short fiber sample were placed in a 2000 mL beaker and stirred for 1 minute at a speed of 200 rpm using a 4 cm diameter, 4-bladed propeller. The dispersion state of the polyester short fibers was then visually observed and evaluated according to the following criteria. The results are shown in the "Immediately After" column of the "Papermaking Dispersibility" section in Table 1. Note that "**" in the table indicates that the treatment agent is insoluble in water and therefore could not be emulsion-lubricated to the synthetic fibers, and thus was not evaluated (the same applies hereafter).

[0093] • Evaluation criteria for variance (immediately after the event) 3 (Good): Short fibers are completely and uniformly dispersed, and no short fiber bundles are detected at all. 2 (Acceptable): Short fibers are uniformly dispersed, but the presence of short fiber bundles is slightly noticeable. 1 (Unacceptable): When the short fibers are not dispersed very uniformly and many bundles of short fibers are observed. Test category 5 (Papermaking dispersibility after high temperature and time) • Adhesion of treatment agent to synthetic fiber bundles The treatment agent-containing compositions for each example were allowed to stand at 50°C for two weeks, and then diluted with water to prepare a 1% diluted solution as the treatment agent. 2 g of the diluted solution was applied to 10 g of raw material synthetic fiber (polyethylene terephthalate short fibers with a fineness of 1.3 dtex and a length of 10 mm) by spraying, and dried in an 80°C dryer for one hour. The papermaking properties were evaluated using the obtained short fiber samples as follows.

[0094] • Method for evaluating papermaking dispersibility after high temperature and time elapsed 1000 mL of 25°C water and 0.1 g of the short fiber sample were placed in a 2000 mL beaker and stirred for 1 minute at a speed of 200 rpm using a 4 cm diameter, four-bladed propeller. The dispersion state of the polyester short fibers was then visually observed and evaluated according to the following criteria. The results are shown in the "Papermaking Dispersibility" column, "After High Temperature Time" column, in Table 1.

[0095] • Evaluation criteria for papermaking dispersibility after high temperature and time. 3 (Good): Short fibers are completely and uniformly dispersed, and no short fiber bundles are detected at all. 2 (Acceptable): Short fibers are uniformly dispersed, but the presence of short fiber bundles is slightly noticeable. 1 (Unacceptable): When the short fibers are not dispersed very uniformly and many bundles of short fibers are observed. Test category 6 (low foaming) Each example of the treatment agent-containing composition was diluted with water to obtain a 1% diluted solution of the treatment agent. 10 g of this diluted solution was placed in a 25 mL stoppered graduated cylinder and shaken vigorously for 30 seconds. After standing for 5 minutes, the foaming state was visually observed and evaluated according to the following criteria. The results are shown in the "Low Foaming" column of Table 1.

[0096] • Evaluation criteria for low foaming properties 3 (Good): No foaming is observed at all. 2 (Acceptable): When slight foaming is observed. 1 (Not acceptable): When excessive foaming is observed. Test category 7 (Hydrophilicity of cotton ball sedimentation (immediately after)) • Adhesion of treatment agent to short fibers The treatment agent-containing compositions for each example were diluted with water to obtain a 0.35% diluted solution as the treatment agent. 5 g of the diluted solution was applied to 5 g of raw material synthetic fiber (polyethylene terephthalate short fiber with a fineness of 1.3 dtex and a length of 38 mm) by spraying, and dried in an 80°C dryer for 1 hour. The hydrophilicity of the obtained short fiber samples was evaluated as follows.

[0097] • Evaluation method for the hydrophilicity of cotton ball sedimentation (immediately after application) (1) Pack 5 g of the short fiber sample described above evenly into a wire basket as described in section 5.1 of STANDARD PROCEDURE:NWSP 010.1.R0(15) in "NONWOVENS STANDARD PROCEDURES 2015 EDITION" (published by EDANA (European Disposables And Nonwovens Association)).

[0098] (2) Weigh 1000g of water at 25°C ± 1°C into a 1L beaker. (3) The wire basket containing the short fiber sample is dropped into the water from a height of 25 mm above the liquid surface.

[0099] (4) Measure the time it takes for the entire wire basket to sink below the liquid level. (5) Remove the short fiber sample from the wire basket, dehydrate it until the moisture content is 50%, and then dry it at 80°C for 1 hour.

[0100] (6) Repeat steps (2) to (5) until the wire basket no longer sinks within 5 seconds. The number of repetitions was counted and evaluated according to the following criteria. The results are shown in the "Immediately After" column of the "Cotton Ball Sinking Hydrophilicity" column in Table 1.

[0101] • Evaluation criteria for the hydrophilicity of cotton ball sedimentation (immediately after) 4 (Excellent): The entire wire basket sinks into the water 6 or more times within 5 seconds. 3 (Good): The entire wire basket sinks into the water four or more times but less than six times within 5 seconds. 2 (OK): If the entire wire basket sinks into the water two or more times but less than four times within 5 seconds. 1 (Not acceptable): If the entire wire basket sinks into the water less than twice within 5 seconds. Test category 8 (Hydrophilicity of cotton ball sedimentation after high temperature exposure) • Adhesion of treatment agent to short fibers The treatment agent-containing compositions for each example were left to stand at 50°C for two weeks, then diluted with water to obtain a 0.35% diluted solution as the treatment agent. 5 g of the diluted solution was applied to 5 g of raw material synthetic fiber (polyethylene terephthalate short fiber with a fineness of 1.3 dtex and a length of 38 mm) by spraying, and dried in an 80°C dryer for one hour. The hydrophilicity of the obtained short fiber samples was evaluated as follows.

[0102] • Method for evaluating the hydrophilicity of cotton ball sedimentation after high temperature and time intervals. (1) Pack 5 g of the short fiber sample described above evenly into the wire basket described in section 5.1 of "STANDARD PROCEDURE:NWSP 010.1.R0(15)".

[0103] (2) Weigh 1000g of water at 25°C ± 1°C into a 1L beaker. (3) The wire basket containing the short fiber sample is dropped into the water from a height of 25 mm above the liquid surface.

[0104] (4) Measure the time it takes for the entire wire basket to sink below the liquid level. (5) Remove the short fiber sample from the wire basket, dehydrate it until the moisture content is 50%, and then dry it at 80°C for 1 hour.

[0105] (6) Repeat steps (2) to (5) until the wire basket no longer sinks within 5 seconds. The number of repetitions was counted and evaluated according to the following criteria. The results are shown in the "After high temperature time" column of the "Cotton ball sedimentation hydrophilicity" column in Table 1.

[0106] • Evaluation criteria for the hydrophilicity of cotton ball sedimentation after high temperature and time. 4 (Excellent): The entire wire basket sinks into the water 6 or more times within 5 seconds. 3 (Good): The entire wire basket sinks into the water four or more times but less than six times within 5 seconds. 2 (OK): If the entire wire basket sinks into the water two or more times but less than four times within 5 seconds. 1 (Not acceptable): If the entire wire basket sinks into the water less than twice within 5 seconds. From the results in the table above, the present invention can improve the stability and low foaming properties of the treatment agent-containing composition. Furthermore, it can improve the hydrophilicity of synthetic fibers to which the treatment agent has been applied.

Claims

1. A synthetic fiber treatment agent containing the following ester compound (A) and surfactant (B), and a synthetic fiber treatment agent containing the following solvent (S), Furthermore, the synthetic fiber treatment agent-containing composition contains the following component (C), characterized in that, in the nonvolatile content of the synthetic fiber treatment agent-containing composition, the ester compound (A) is contained in an amount of 40% by mass or more and 98% by mass or less, the surfactant (B) in an amount of 1% by mass or more and 50% by mass or less, and component (C) in an amount of 0.01% by mass or more and 10% by mass or less. Ester compound (A): An ester copolymer formed from the following constituent unit 1 and constituent unit 2, or from the following constituent unit 1, constituent unit 2, and constituent unit 3, with a mass-average molecular weight of 1000 or more and 15000 or less. Constituent unit 1: A constituent unit formed from at least one selected from dicarboxylic acids and ester-forming derivatives of dicarboxylic acids. Constituent unit 2: A constituent unit formed from at least one selected from alkylene glycol having 2 to 6 carbon atoms and (poly)alkylene glycol having a (poly)oxyalkylene group composed of oxyalkylene units having 2 to 6 carbon atoms. Constituent unit 3: A constituent unit formed from at least one selected from the compound represented by the following general formula (1), the compound represented by the following general formula (2), and the compound represented by the following general formula (3). 【Chemistry 1】 (In Chemistry 1, R １ : A hydrocarbon group having 1 to 24 carbon atoms. A １ O: An oxyalkylene group having 2 to 4 carbon atoms (however, if multiple oxyalkylene groups are present, one type alone or two or more types may be used). n: An integer between 0 and 100 (inclusive). 【Chemistry 2】 (In Chemistry 2, R ２ , R ３ : A hydrocarbon group having 1 to 24 carbon atoms. A ２ O: An oxyalkylene group having 2 to 4 carbon atoms (however, if multiple oxyalkylene groups are present, one type alone or two or more types may be used). p: An integer between 0 and 100 (inclusive). 【Transformation 3】 (In Chemistry 3, R ４ , R ５ , R ６ : A hydrocarbon group having 1 to 24 carbon atoms. A ３ O: An oxyalkylene group having 2 to 4 carbon atoms (however, when there are a plurality of such oxyalkylene groups, they can be of one kind alone or two or more kinds). X － : An organic acid having an alkyl group with 1 to 4 carbon atoms. q: An integer between 1 and 100 (inclusive). Surfactant (B): At least one selected from anionic surfactants (excluding carboxylates with 1 to 6 carbon atoms) and nonionic surfactants. Component (C): At least one selected from inorganic acids, inorganic acid salts, organic acids, carboxylates having 1 to 6 carbon atoms, and amine compounds. Solvent (S): A solvent whose boiling point at one atmosphere is 105°C or lower.

2. The synthetic fiber treatment agent-containing composition according to claim 1, wherein the surfactant (B) is at least one selected from organic phosphate salts, organic sulfonates, organic sulfate salts, polyoxyalkylene fatty acid esters, polyhydric alcohol fatty acid esters, polyoxyalkylene polyhydric alcohol fatty acid esters, and polyoxyalkylene alkyl ethers.

3. The synthetic fiber treatment agent-containing composition according to claim 1, wherein the synthetic fiber treatment agent further contains silicone (D).

4. A synthetic fiber characterized by having the synthetic fiber treatment agent described in any one of claims 1 to 3 attached to it.

5. The synthetic fiber according to claim 4, wherein the synthetic fiber is for papermaking.

6. The synthetic fiber according to claim 4, wherein the synthetic fiber is for stuffing purposes.

7. The synthetic fiber according to claim 4, wherein the synthetic fiber is a polyester fiber or a polyolefin fiber.

8. A method for producing a nonwoven fabric, characterized by dispersing the synthetic fibers described in claim 5 in water and then making paper.

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