Fiber treatment agent for nonwoven fabric and nonwoven fabric

Abstract

The present invention provides a synthetic fiber treating agent capable of improving the heat-resistant hydrophilicity of a nonwoven fabric to which the synthetic fiber treating agent has been applied, and a nonwoven fabric to which the synthetic fiber treating agent has been applied. [Solution] The fiber treatment agent for nonwoven fabric of the present invention is characterized by containing an alkenyl sulfonic acid compound (A) represented by the following general formula (1) and a hydroxyalkyl sulfonic acid compound (B) represented by the following general formula (2). (chemical 1) JPEG0007825318000019.jpg1094 (In equation (1), R 1 : an alkenyl group having 8 to 18 carbon atoms. M 1 : a hydrogen atom, an alkali metal, an alkaline earth metal, an ammonium, a phosphonium, or an organic amine. (Case 2) JPEG0007825318000020.jpg1294 (In equation (2), R 2 : A hydroxyalkyl group having 8 to 18 carbon atoms. 2 : a hydrogen atom, an alkali metal, an alkaline earth metal, an ammonium, a phosphonium, or an organic amine.

Description

[Technical Field]

[0001] The present invention relates to a fiber treating agent for nonwoven fabrics and a nonwoven fabric to which the fiber treating agent for nonwoven fabrics is attached. [Background technology]

[0002] Generally, synthetic fibers are used as raw fibers for nonwoven fabrics. For example, nonwoven fabrics are manufactured using synthetic fibers composed of thermoplastic resins such as polyolefins and polyesters. Functionality such as hydrophilicity is imparted to the raw fibers used for the nonwoven fabric or to the nonwoven fabric by applying a treatment agent to the nonwoven fabric. Nonwoven fabrics imparted with functionalities such as hydrophilicity are utilized in a wide range of fields, including hygiene products, medical care, agriculture, and civil engineering.

[0003] Conventionally, fiber treatment agents for nonwoven fabrics are known, as disclosed in Patent Documents 1 and 2. Patent Document 1 discloses a hydrophilic agent for fibers containing an anionic surfactant and an ester compound formed by condensing an alcohol having five or more carbon atoms with a fatty acid. Patent Document 2 discloses a water permeability agent containing gluconic acid as component (A), an alkylsulfonic acid, an alkylsulfonate salt, or the like as component (B), and an ester of a monohydric alcohol and an aliphatic carboxylic acid, or the like as component (C). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] International Publication No. 2022 / 163716 [Patent Document 2] Japanese Patent Publication No. 2021-172927 Summary of the Invention [Problem to be solved by the invention]

[0005] However, conventional fiber treating agents for nonwoven fabrics have the problem that the heat-resistant hydrophilicity of nonwoven fabrics to which the agent for synthetic fibers has been applied is poor. [Means for solving the problem]

[0006] As a result of research conducted by the present inventors to solve the above-mentioned problems, they found that a fiber treatment agent for nonwoven fabrics containing a specified alkenyl sulfonic acid compound (A) and a specified hydroxyalkyl sulfonic acid compound (B) is suitable.

[0007] Various aspects for solving the above problems will be described. The fiber treatment agent for nonwoven fabrics of the first aspect contains an alkenyl sulfonic acid compound (A) represented by the following general formula (1) and a hydroxyalkyl sulfonic acid compound (B) represented by the following general formula (2): When the total content of the alkenyl sulfonic acid compound (A) and the hydroxyalkyl sulfonic acid compound (B) is taken as 100% by mass, the alkenyl sulfonic acid compound (A) is contained in an amount of 40% by mass or more and 90% by mass or less, and the hydroxyalkyl sulfonic acid compound (B) is contained in an amount of 10% by mass or more and 60% by mass or less. It is characterized by:

[0008] [ka]

[0009] (In formula (1), R 1 : an alkenyl group having 8 to 18 carbon atoms. M 1 :a Cadmium metal or Ammoniu Hmm. )

[0010] [ka]

[0011] (In formula (2), R 2 : A hydroxyalkyl group having 8 to 18 carbon atoms. M 2 :a Cadmium metal or Ammoniu Hmm.)

[0012] Aspects 2 is the aspect 1 The fiber treating agent for nonwoven fabrics described in 1. above further contains a nonionic surfactant (C). Aspects 3 is the aspect 2 In the fiber treating agent for nonwoven fabric described in 1. above, the nonionic surfactant (C) has an ester bond.

[0013] Aspects 4 is the aspect 2 or 3 In the fiber treatment agent for nonwoven fabrics described in 1. above, when the total content of the alkenyl sulfonic acid compound (A), the hydroxyalkyl sulfonic acid compound (B), and the nonionic surfactant (C) is taken as 100% by mass, the alkenyl sulfonic acid compound (A) is contained in an amount of 20% by mass or more and 60% by mass or less, the hydroxyalkyl sulfonic acid compound (B) is contained in an amount of 5% by mass or more and 40% by mass or less, and the nonionic surfactant (C) is contained in an amount of 15% by mass or more and 55% by mass or less.

[0014] Aspects 5 is the aspect 2 or 3 The fiber treatment agent for nonwoven fabrics described in 1. above further contains the following secondary sulfonic acid compound (D). Secondary sulfonic acid compound (D): At least one selected from secondary sulfonic acid compounds (D1) represented by the following general formula (3) and secondary sulfonic acid compounds (D2) represented by the following general formula (4).

[0015] [ka]

[0016] (In formula (3), R 3 ,R 4 : an aliphatic hydrocarbon group having 1 to 16 carbon atoms. 3 and R 4 The total number of carbon atoms is 7 or more and 17 or less. M 3 : a hydrogen atom, an alkali metal, an alkaline earth metal, an ammonium, a phosphonium, or an organic amine.

[0017] [ka]

[0018] (In formula (4), R 5 ,R 6 : an aliphatic hydrocarbon group having 1 to 17 carbon atoms. 5 and R 6 The total number of carbon atoms is 8 or more and 18 or more. M 4 : a hydrogen atom, an alkali metal, an alkaline earth metal, an ammonium, a phosphonium, or an organic amine. Aspects 6 is the aspect 5 In the fiber treatment agent for nonwoven fabrics described in 1. above, when the total content of the alkenyl sulfonic acid compound (A), the hydroxyalkyl sulfonic acid compound (B), the nonionic surfactant (C), and the secondary sulfonic acid compound (D) is taken as 100% by mass, the fiber treatment agent for nonwoven fabrics contains the alkenyl sulfonic acid compound (A) in an amount of 10% by mass or more and 45% by mass or less, the hydroxyalkyl sulfonic acid compound (B) in an amount of 5% by mass or more and 40% by mass or less, the nonionic surfactant (C) in an amount of 15% by mass or more and 45% by mass or less, and the secondary sulfonic acid compound (D) in an amount of 10% by mass or more and 40% by mass or less.

[0019] Aspects 7 The nonwoven fabric of the embodiment 1 to 6 The fiber treating agent for nonwoven fabric according to any one of the above aspects is attached to the nonwoven fabric. Aspects 8 is the aspect 7 In the nonwoven fabric described in 1, the fibers used in the nonwoven fabric include PLA fibers. [Effects of the Invention]

[0020] According to the present invention, the heat-resistant hydrophilicity of a nonwoven fabric to which a fiber treatment agent for nonwoven fabric has been applied can be improved. DETAILED DESCRIPTION OF THE INVENTION

[0021] First Embodiment A first embodiment of the fiber treatment agent for nonwoven fabrics (hereinafter also referred to as the treatment agent) of the present invention will be described below. The treatment agent of this embodiment contains an alkenyl sulfonic acid compound (A) represented by the following general formula (1) and a hydroxyalkyl sulfonic acid compound (B) represented by the following general formula (2). The treatment agent may further contain a nonionic surfactant (C) and a secondary sulfonic acid compound (D) described below.

[0022] (Alkenyl sulfonic acid compound (A)) The alkenyl sulfonic acid compound (A) used in the treatment agent of this embodiment is an alkenyl sulfonic acid compound (A) represented by the following general formula (1).

[0023] [ka]

[0024] (In formula (1), R 1 : an alkenyl group having 8 to 18 carbon atoms. M 1 : a hydrogen atom, an alkali metal, an alkaline earth metal, an ammonium, a phosphonium, or an organic amine. In addition, M 1 is R 1 -SO3 - This shows a cation that is ionic bonded to In the present invention, M 1 is an alkali metal or ammonium.

[0025] The alkenyl group constituting the alkenylsulfonic acid compound (A) may be a straight-chain alkenyl group or a branched-chain alkenyl group. Specific examples of the alkenyl group constituting the alkenyl sulfonic acid compound (A) include, for example, an octenyl group, a nonenyl group, a decenyl group, an undecenyl group, a dodecenyl group, a tridecenyl group, a tetradecenyl group, a pentadecenyl group, a hexadecenyl group, a heptadecenyl group, an octadecenyl group, an isooctenyl group, an isononenyl group, an isodecenyl group, an isoundecenyl group, an isododecenyl group, an isotridecenyl group, an isotetradecenyl group, an isopentadecenyl group, an isohexadecenyl group, an isoheptadecenyl group, and an isooctadecenyl group.

[0026] Specific examples of alkali metals include sodium, potassium, and lithium. Specific examples of alkaline earth metals include metals belonging to Group 2 elements. Specific examples of metals belonging to Group 2 elements include calcium, magnesium, beryllium, strontium, and barium.

[0027] Specific examples of the phosphonium include quaternary phosphoniums such as tetramethylphosphonium, tetraethylphosphonium, tetrabutylphosphonium, tetraoctylphosphonium, dibutyldihexylphosphonium, trihexyltetradecylphosphonium, triethyloctylphosphonium, trioctylmethylphosphonium, and triphenylmethylphosphonium.

[0028] The organic amine may be any of primary amines, secondary amines, and tertiary amines. Specific examples of the organic amine include (1) aliphatic amines such as methylamine, dimethylamine, trimethylamine, ethylamine, diethylamine, triethylamine, 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, and (5) polyoxyalkylene alkylamino ethers such as polyoxyethylene laurylamino ether and polyoxyethylene sterylamino ether.

[0029] Specific examples of the alkenyl sulfonic acid compound (A) include alkali metal salts of octenyl sulfonic acid, alkali metal salts of decenyl sulfonic acid, alkali metal salts of dodecenyl sulfonic acid, alkali metal salts of tetradecenyl sulfonic acid, alkali metal salts or ammonium salts of hexadecenyl sulfonic acid, and ammonium salts of octadecenyl sulfonic acid.

[0030] The alkenyl sulfonic acid compound (A) may be used alone or in appropriate combination of two or more kinds. The lower limit of the content of the alkenyl sulfonic acid compound (A) in the treatment agent can be set as appropriate, but is preferably 5% by mass or more, more preferably 10% by mass or more, and even more preferably 15% by mass or more. When the content is 5% by mass or more, the heat-resistant hydrophilicity of the nonwoven fabric to which the treatment agent is applied can be particularly improved. The upper limit of the content of the alkenyl sulfonic acid compound (A) can be set as appropriate, but is preferably 95% by mass or less, more preferably 90% by mass or less. When the content is 95% by mass or less, the heat-resistant hydrophilicity and initial hydrophilicity of the nonwoven fabric to which the treatment agent is applied can be particularly improved. Note that ranges that combine the above upper and lower limits are also contemplated.

[0031] (Hydroxyalkyl sulfonic acid compound (B)) The hydroxyalkyl sulfonic acid compound (B) used in the treatment agent of this embodiment is a hydroxyalkyl sulfonic acid compound (B) represented by general formula (2).

[0032] [ka]

[0033] (In formula (2), R 2 : A hydroxyalkyl group having 8 to 18 carbon atoms. M 2 : a hydrogen atom, an alkali metal, an alkaline earth metal, an ammonium, a phosphonium, or an organic amine. In addition, M 2 is R 2 -SO3 - This shows a cation that is ionic bonded to In the present invention, M 2 is an alkali metal or ammonium.

[0034] The hydroxyalkyl group constituting the hydroxyalkyl sulfonic acid compound (B) may be a straight-chain hydroxyalkyl group or a branched-chain hydroxyalkyl group.

[0035] Specific examples of the hydroxyalkyl group constituting the hydroxyalkyl sulfonic acid compound (B) include, for example, a hydroxyoctyl group, a hydroxynonyl group, a hydroxydecyl group, a hydroxyundecyl group, a hydroxydodecyl group, a hydroxytridecyl group, a hydroxytetradecyl group, a hydroxypentadecyl group, a hydroxyhexadecyl group, a hydroxyheptadecyl group, a hydroxyoctadecyl group, a hydroxyisooctyl group, a hydroxyisononyl group, a hydroxyisodecyl group, a hydroxyisoundecyl group, a hydroxyisododecyl group, a hydroxyisotridecyl group, a hydroxyisotetradecyl group, a hydroxyisopentadecyl group, a hydroxyisohexadecyl group, a hydroxyisoheptadecyl group, and a hydroxyisooctadecyl group.

[0036] M 2 is M in general formula (1) 1 is the same as: Specific examples of the hydroxyalkyl sulfonic acid compound (B) include alkali metal salts of hydroxytetradecyl sulfonic acid, alkali metal salts of hydroxyhexadecyl sulfonic acid, alkali metal salts of hydroxyoctyl sulfonic acid, alkali metal salts of hydroxydecyl sulfonic acid, alkali metal salts of hydroxydodecyl sulfonic acid, ammonium salts of hydroxyhexadecyl sulfonic acid, and ammonium salts of hydroxyoctadecyl sulfonic acid.

[0037] The hydroxyalkyl sulfonic acid compound (B) may be used alone or in appropriate combination of two or more kinds. The lower limit of the content of the hydroxyalkyl sulfonic acid compound (B) in the treatment agent can be set as appropriate, but is preferably 3% by mass or more, more preferably 4% by mass or more, and even more preferably 5% by mass or more. When the content is 3% by mass or more, the initial hydrophilicity of the nonwoven fabric to which the treatment agent is applied can be particularly improved. The upper limit of the content of the hydroxyalkyl sulfonic acid compound (B) can be set as appropriate, but is preferably 60% by mass or less, more preferably 50% by mass or less, and even more preferably 40% by mass or less. When the content is 60% by mass or less, the heat-resistant hydrophilicity of the nonwoven fabric to which the treatment agent is applied can be particularly improved. Note that ranges that combine the above upper and lower limits are also contemplated.

[0038] When the total content of the alkenyl sulfonic acid compound (A) and the hydroxyalkyl sulfonic acid compound (B) in the treatment agent is taken as 100 mass%, the alkenyl sulfonic acid compound (A) is contained in a proportion of 40 mass% to 90 mass% and the hydroxyalkyl sulfonic acid compound (B) is contained in a proportion of 10 mass% to 60 mass%. do. By specifying the range as described above, it is possible to further improve the heat-resistant hydrophilicity and initial hydrophilicity of the nonwoven fabric to which the treatment agent has been applied. Note that ranges that combine the above upper and lower limits are also contemplated.

[0039] The lower limit of the total content of the alkenyl sulfonic acid compound (A) and the hydroxyalkyl sulfonic acid compound (B) in the treatment agent can be set appropriately, but is preferably 30% by mass or more. When this content is 30% by mass or more, the heat-resistant hydrophilicity and initial hydrophilicity of the nonwoven fabric to which the treatment agent is applied can be particularly improved. The upper limit of the total content of the alkenyl sulfonic acid compound (A) and the hydroxyalkyl sulfonic acid compound (B) can be set appropriately, but is preferably 100% by mass or less. When this content is 100% by mass or less, the effects of the present invention can be further improved, for example, by increasing the blending ratio of the nonionic surfactant (C) and the secondary sulfonic acid compound (D) described below. Ranges combining the above upper and lower limits are also contemplated.

[0040] (Nonionic surfactant (C)) The treatment agent of this embodiment may further contain a nonionic surfactant (C). By containing the nonionic surfactant (C) in the treatment agent, the carding properties of the fibers to which the treatment agent is applied can be improved when they pass through a carding machine.

[0041] Examples of the nonionic surfactant (C) include compounds having a (poly)oxyalkylene structure in which alkylene oxide is added to alcohols or carboxylic acids, ether ester compounds having a (poly)oxyalkylene structure in which alkylene oxide is added to an ester compound of carboxylic acids and polyhydric alcohols, compounds obtained by further esterifying such ether ester compounds with fatty acids, compounds having a (poly)oxyalkylene structure in which alkylene oxide is added to an amine compound, partial ester compounds of carboxylic acids and polyhydric alcohols, amide compounds obtained by condensing an amine compound and a carboxylic acid, 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.

[0042] Among these, compounds having a (poly)oxyalkylene structure in which alkylene oxide is added to 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, and further compounds having an ester bond such as compounds obtained by esterifying fatty acids with such ether ester compounds, and partial ester compounds of carboxylic acids and polyhydric alcohols are preferred. The use of such compounds can improve the carding properties of fibers treated with the treatment when they pass through a carding machine.

[0043] Specific examples of alcohols used as raw materials for the nonionic surfactant (C) include: (1) linear alkyl alcohols such as methanol, ethanol, propanol, butanol, pentanol, hexanol, octanol, nonanol, decanol, undecanol, dodecanol, tridecanol, tetradecanol, pentadecanol, hexadecanol, heptadecanol, octadecanol, nonadecanol, eicosanol, heneicosanol, docosanol, tricosanol, tetracosanol, pentacosanol, hexacosanol, heptacosanol, octacosanol, nonacosanol, and triacontanol; (2) isopropanol, isobutanol, isohexanol, 2-ethylhexanol, isononanol, isodecanol, isododecanol, isotridecanol, isotetradecanol, isopentadecanol, isohexadecanol, and iso Branched alkyl alcohols such as heptadecanol, isooctadecanol, isononadecanol, isoeicosanol, isoheneicosanol, isodocosanol, isotricosanol, isotetracosanol, isopentacosanol, isohexacosanol, isoheptacosanol, isooctacosanol, 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; (6) aromatic alcohols such as benzyl alcohol; and (7) phenols such as phenol, nonylphenol, monostyrenated phenol, distyrenated phenol, tristyrenated phenol, and bisphenol A.

[0044] Specific examples of carboxylic acids used as raw materials for the nonionic surfactant (C) include: (1) linear alkyl carboxylic acids such as octylic acid, nonanoic acid, decanoic acid, undecanoic acid, dodecanoic acid, tridecanoic acid, tetradecanoic acid, pentadecanoic acid, hexadecanoic acid, heptadecanoic acid, octadecanoic acid, nonadecanoic acid, eicosanoic acid, heneicosanoic acid, and docosanoic acid; (2) branched alkyl carboxylic acids such as 2-ethylhexanoic acid, isododecanoic acid, isotridecanoic acid, isotetradecanoic acid, isohexadecanoic acid, and isooctadecanoic acid; (3) linear alkenyl carboxylic acids such as octadecenoic acid, octadecadienoic acid, and octadecatrienoic acid; (4) aromatic carboxylic acids such as benzoic acid; (5) hydroxycarboxylic acids such as lactic acid, citric acid, and ricinoleic acid; and (6) polycarboxylic acids such as adipic acid, sebacic acid, and tricarbaryl.

[0045] The alkylene oxide used as a raw material for forming the (poly)oxyalkylene structure of the nonionic surfactant (C) is preferably an alkylene oxide having 2 to 4 carbon atoms. Specific examples of alkylene oxide include ethylene oxide, propylene oxide, and butylene oxide. The number of moles of alkylene oxide added is appropriately set, but is preferably 0.1 to 60 moles, more preferably 1 to 40 moles, and even more preferably 2 to 30 moles. Any combination of the above upper and lower limits is also possible. The number of moles of alkylene oxide added refers to the number of moles of alkylene oxide per mole of the compound to be added in the 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.

[0046] Specific examples of polyhydric alcohols used as raw materials for the nonionic surfactant (C) include ethylene glycol, propylene glycol, 1,3-propanediol, 1,2-butanediol, 1,3-butanediol, 1,4-butanediol, 2-methyl-1,2-propanediol, 1,5-pentanediol, 1,6-hexanediol, 2,5-hexanediol, 2-methyl-2,4-pentanediol, 2,3-dimethyl-2,3-butanediol, glycerin, 2-methyl-2-hydroxymethyl-1,3-propanediol, trimethylolpropane, sorbitan, pentaerythritol, and sorbitol.

[0047] Specific examples of the aliphatic amine used as a raw material for the nonionic surfactant (C) include methylamine, ethylamine, butylamine, octylamine, laurylamine, octadecylamine, octadecenylamine, and coconut amine.

[0048] Specific examples of fatty acid amides used as raw materials for the nonionic surfactant (C) include octylic acid amide, lauric acid amide, palmitic acid amide, stearic acid amide, oleic acid amide, behenic acid amide, lignoceric acid amide, amides of fatty acids and diethanolamine, and amides of fatty acids and ethyleneamine.

[0049] Specific examples of the nonionic surfactant (C) include sorbitan monostearate, glycerin monostearate, a compound in which an alkylene oxide is added to sorbitan monostearate, a compound in which an alkylene oxide is added to sorbitan trioleate, a compound in which an alkylene oxide is added to coconut fatty acid, a compound in which an alkylene oxide is added to castor oil, a compound in which an alkylene oxide is added to hydrogenated castor oil, a compound in which an alkylene oxide is added to 1 mole of hydrogenated castor oil and then esterified with 3 moles of lauric acid, a compound in which an alkylene oxide is added to lauryl alcohol, a compound in which an alkylene oxide is added to stearyl alcohol, a compound in which an alkylene oxide is added to oleyl alcohol, a compound in which an alkylene oxide is added to laurylamine, and a compound in which an alkylene oxide is added to a branched alkyl alcohol having 12 or 13 carbon atoms.

[0050] The nonionic surfactant (C) may be used singly or in appropriate combination of two or more kinds. The lower limit of the content of the nonionic surfactant (C) in the treatment agent is set as appropriate, but is preferably 10% by mass or more, more preferably 15% by mass or more. When the content is 10% by mass or more, the carding property of fibers to which the treatment agent has been applied can be improved when they pass through a carding machine. The upper limit of the content of the nonionic surfactant (C) is set as appropriate, but is preferably 60% by mass or less, more preferably 55% by mass or less. When the content is 60% by mass or less, the carding property of fibers to which the treatment agent has been applied can be improved when they pass through a carding machine. Note that ranges that combine the above upper and lower limits are also contemplated.

[0051] In the treatment agent, when the total content of the alkenyl sulfonic acid compound (A), the hydroxyalkyl sulfonic acid compound (B), and the nonionic surfactant (C) is taken as 100% by mass, it is preferable that the alkenyl sulfonic acid compound (A) is contained in an amount of 20% by mass to 60% by mass, the hydroxyalkyl sulfonic acid compound (B) is contained in an amount of 5% by mass to 40% by mass, and the nonionic surfactant (C) is contained in an amount of 15% by mass to 55% by mass. By specifying these ranges, the effects of the present invention can be further improved. Note that ranges that arbitrarily combine the above upper and lower limits are also contemplated.

[0052] (Secondary sulfonic acid compound (D)) The treatment agent of this embodiment may further contain a secondary sulfonic acid compound (D) shown below. The secondary sulfonic acid compound (D) is at least one selected from the secondary sulfonic acid compound (D1) shown in the following general formula (3) and the secondary sulfonic acid compound (D2) shown in the following general formula (4). The incorporation of such a compound can further improve the initial hydrophilicity of the nonwoven fabric to which the treatment agent is applied.

[0053] [ka]

[0054] (In formula (3), R 3 ,R 4 : an aliphatic hydrocarbon group having 1 to 16 carbon atoms. 3 and R 4 The total number of carbon atoms is 7 or more and 17 or less. M 3 : a hydrogen atom, an alkali metal, an alkaline earth metal, an ammonium, a phosphonium, or an organic amine. In addition, M 3 is -SO3 - This shows a cation that is ionic bonded to

[0055] The aliphatic hydrocarbon group constituting the secondary sulfonic acid compound (D1) may be a saturated hydrocarbon group or an unsaturated hydrocarbon group, and may be a straight-chain hydrocarbon group or a branched-chain hydrocarbon group.

[0056] The unsaturated hydrocarbon group may be an alkenyl group having one double bond as an unsaturated carbon bond, an alkadienyl group or an alkatrienyl group having two or more double bonds, or an alkynyl group having one triple bond as an unsaturated carbon bond, or an alkadiynyl group having two or more triple bonds.

[0057] Specific examples of the aliphatic hydrocarbon group constituting the secondary sulfonic acid compound (D1) include a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a heptyl group, an octyl group, a nonyl group, a decyl group, an undecyl group, a dodecyl group, a tridecyl group, a tetradecyl group, a pentadecyl group, a hexadecyl group, an isobutyl group, an isopentyl group, an isohexyl group, an isoheptyl group, an isooctyl group, an isononyl group, an isodecyl group, an isoundecyl group, an isododecyl group, an isotridecyl group, an isotetradecyl group, an isopentadecyl group, and an isohexadecyl group.

[0058] M 3 is M in general formula (1) 1 is the same as: The secondary sulfonic acid compound (D1) may be used alone or in appropriate combination of two or more kinds.

[0059] The lower limit of the content of the secondary sulfonic acid compound (D1) in the treatment agent can be set as appropriate, but is preferably 5% by mass or more, more preferably 10% by mass or more. When the content is 5% by mass or more, the initial hydrophilicity of the nonwoven fabric to which the treatment agent is applied can be particularly improved. The upper limit of the content of the secondary sulfonic acid compound (D1) can be set as appropriate, but is preferably 45% by mass or less, more preferably 40% by mass or less. When the content is 45% by mass or less, the heat-resistant hydrophilicity of the nonwoven fabric to which the treatment agent is applied can be particularly improved. Note that ranges that combine the above upper and lower limits are also contemplated.

[0060] [ka]

[0061] (In formula (4), R 5 ,R 6 : an aliphatic hydrocarbon group having 1 to 17 carbon atoms. 5 and R 6 The total number of carbon atoms is 8 or more and 18 or more. M 4 : a hydrogen atom, an alkali metal, an alkaline earth metal, an ammonium, a phosphonium, or an organic amine. In addition, M 3 is -SO3 - This shows a cation that is ionic bonded to

[0062] The aliphatic hydrocarbon group constituting the secondary sulfonic acid compound (D2) may be a saturated hydrocarbon group or an unsaturated hydrocarbon group, and may be a straight-chain hydrocarbon group or a branched-chain hydrocarbon group.

[0063] The unsaturated hydrocarbon group may be an alkenyl group having one double bond as an unsaturated carbon bond, an alkadienyl group or an alkatrienyl group having two or more double bonds, or an alkynyl group having one triple bond as an unsaturated carbon bond, or an alkadiynyl group having two or more triple bonds.

[0064] Specific examples of the aliphatic hydrocarbon group constituting the secondary sulfonic acid compound (D2) include a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a heptyl group, an octyl group, a nonyl group, 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 isobutyl group, an isopentyl group, an isohexyl group, an isoheptyl group, an isooctyl group, an isononyl group, an isodecyl group, an isoundecyl group, an isododecyl group, an isotridecyl group, an isotetradecyl group, an isopentadecyl group, an isohexadecyl group, and an isoheptadecyl group.

[0065] M 4 is M in general formula (1) 1 is the same as: The secondary sulfonic acid compound (D2) may be used singly or in appropriate combination of two or more kinds.

[0066] The lower limit of the content of the secondary sulfonic acid compound (D2) in the treatment agent can be set as appropriate, but is preferably 5% by mass or more, more preferably 10% by mass or more. When the content is 5% by mass or more, the initial hydrophilicity of the nonwoven fabric to which the treatment agent is applied can be particularly improved. The upper limit of the content of the secondary sulfonic acid compound (D2) can be set as appropriate, but is preferably 45% by mass or less, more preferably 40% by mass or less. When the content is 45% by mass or less, the heat-resistant hydrophilicity of the nonwoven fabric to which the treatment agent is applied can be particularly improved. Note that ranges that combine the above upper and lower limits are also contemplated.

[0067] The lower limit of the total content of the secondary sulfonic acid compound (D1) and the secondary sulfonic acid compound (D2) in the treatment agent can be set appropriately, but is preferably 5% by mass or more, more preferably 10% by mass or more. When this content is 5% by mass or more, the initial hydrophilicity of the nonwoven fabric to which the treatment agent is applied can be particularly improved. The upper limit of the total content of the secondary sulfonic acid compound (D1) and the secondary sulfonic acid compound (D2) can be set appropriately, but is preferably 45% by mass or less, more preferably 40% by mass or less. When this content is 45% by mass or less, the heat-resistant hydrophilicity of the nonwoven fabric to which the treatment agent is applied can be particularly improved. Note that ranges that combine the above upper and lower limits are also contemplated.

[0068] In the treatment agent, when the total content of the alkenyl sulfonic acid compound (A), the hydroxyalkyl sulfonic acid compound (B), the nonionic surfactant (C), and the secondary sulfonic acid compound (D) is taken as 100% by mass, it is preferable to contain the alkenyl sulfonic acid compound (A) in an amount of 10% by mass to 45% by mass, the hydroxyalkyl sulfonic acid compound (B) in an amount of 5% by mass to 40% by mass, the nonionic surfactant (C) in an amount of 15% by mass to 45% by mass, and the secondary sulfonic acid compound (D) in an amount of 10% by mass to 40% by mass. By specifying these ranges, the effects of the present invention can be further improved. Ranges that combine the above upper and lower limits are also contemplated.

[0069] (solvent) The treatment agent of this embodiment may be mixed with a solvent, if necessary, to prepare a fiber treatment agent-containing composition for nonwoven fabrics (hereinafter referred to as a "treatment agent-containing composition") or a diluted solution of the fiber treatment agent for nonwoven fabrics (hereinafter referred to as a "diluted solution").

[0070] The solvent has a boiling point of 105°C or lower at one atmospheric pressure. 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.

[0071] In the treatment-containing composition, the treatment agent is prepared in an amount exceeding 10% by mass, assuming that the total content of the treatment agent and solvent is 100% by mass. In the diluted solution, the treatment agent is contained in an amount of 0.1% to 10% by mass, assuming that the total content of the treatment agent and solvent is 100% by mass.

[0072] (Effects of this embodiment) The effects of the treatment agent of the first embodiment will be described. (1-1) The treatment agent of the first embodiment is configured to contain the alkenyl sulfonic acid compound (A) represented by the general formula (1) and the hydroxyalkyl sulfonic acid compound (B) represented by the general formula (2). Therefore, the heat-resistant hydrophilicity and initial hydrophilicity of the nonwoven fabric to which the treatment agent is applied can be further improved.

[0073] (1-2) When the treatment agent of the first embodiment further contains a nonionic surfactant (C), the carding properties of the fibers to which the treatment agent is applied can be improved. In particular, the bundling properties can be improved by appropriate F / F friction, resulting in a high-quality nonwoven fabric.

[0074] (1-3) When the treatment agent of the first embodiment contains at least one secondary sulfonic acid compound (D) selected from the secondary sulfonic acid compound (D1) represented by the general formula (3) and the secondary sulfonic acid compound (D2) represented by the general formula (4), the initial hydrophilicity of the nonwoven fabric to which the treatment agent is applied can be particularly further improved.

[0075] Second Embodiment Next, a second embodiment of the nonwoven fabric of the present invention will be described. The nonwoven fabric of this embodiment is a treated nonwoven fabric having the treatment agent of Embodiment 1 adhered to its surface. By adhering the treatment agent to the surface of the nonwoven fabric, a nonwoven fabric exhibiting the effects of the present invention is obtained.

[0076] The type of fiber used for the nonwoven fabric is not particularly limited, but examples include (1) polyester fibers such as polyethylene terephthalate (PET), polytrimethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polyethylene terephthalate-isophthalate, polyether polyester, polylactic acid (PLA), and composite fibers containing these polyester resins, (2) polyamide fibers such as nylon 6 and nylon 66, (3) polyacrylic fibers such as polyacrylic and modacrylic, and (4) polyolefin fibers such as polyethylene and polypropylene. Among these, polyester fibers are preferred, and PLA fibers are more preferred.

[0077] The polyolefin synthetic fiber may be a composite fiber with a core-sheath structure. That is, the composite fiber may be a composite fiber in which either or both of the core and sheath are polyolefin fibers. Specifically, the composite fiber may be a polyethylene / polypropylene composite fiber in which the sheath is polyethylene and the core is polypropylene, or a polyethylene / polyester composite fiber in which the sheath is polyethylene and the core is polyester. The composite fiber may also be a coPLA / PLA composite fiber in which the sheath is copolymerized polylactic acid (coPLA) and the core is addition-polymerized polylactic acid (PLA).

[0078] The length of the fibers is not particularly limited, and can be either short fibers or long fibers. Short fibers are generally 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 it corresponds to short fibers in this technical field, but is, for example, 100 mm or less, preferably 30 mm to 70 mm.

[0079] Furthermore, if a treated nonwoven fabric having the treatment agent of this embodiment adhered to its surface can be obtained, the treatment agent may be adhered to the surface of raw fiber such as raw cotton before the nonwoven fabric is manufactured, or the treatment agent may be adhered to the surface of nonwoven fabric fibers after the nonwoven fabric has been manufactured.

[0080] (Treatment agent adhesion treatment) A dilution containing the treatment agent of the first embodiment and a solvent is applied to the fibers. There are no particular restrictions on the proportion of the treatment agent of the first embodiment applied to the fibers. The treatment agent is applied so that the non-volatile content of the treatment agent is preferably 0.01% by mass to 10% by mass, more preferably 0.1% by mass to 3% by mass, relative to the fibers. This configuration allows the efficacy of each component to be effectively exerted.

[0081] Examples of solvents used to prepare the diluted solution include those exemplified in the first embodiment. From the viewpoint of operability and the like, the diluted solution preferably has a treatment agent concentration of 0.1% by mass or more and 10% by mass or less. The method for applying the diluted solution is not particularly limited, and known methods can be used depending on the type, form, and application of the fiber, 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.

[0082] The fibers to which the dilution liquid has been applied may be dried or heat-treated using a known method. The drying or heat-treatment volatilizes the solvent, such as water, to obtain fibers to which the components contained in the treatment agent are attached. The fibers to which the components in the treatment agent are attached can effectively exhibit the efficacy for use in nonwoven fabrics.

[0083] (Nonwoven fabric manufacturing method) The type of nonwoven fabric is not particularly limited, but examples thereof include meltblown, flash spinning, and spunbond methods when the raw fibers are long fibers. Web formation methods other than spunbond methods include dry methods such as carding and airlaid methods, and wet methods such as papermaking methods when the raw fibers are short fibers. Examples of interfiber bonding methods include chemical bonding, thermal bonding, needle punching, spunlace, and stitch bonding.

[0084] Furthermore, the nonwoven fabric may be produced by the following method. Step 1: A step of attaching the treatment agent of the first embodiment to fibers. Step 2: A step of passing the fibers to which the treatment agent has been applied in step 1 through a roller carding machine to obtain a roller carded web. Step 2 is also called a carding step.

[0085] Step 3: A step of producing a nonwoven fabric by subjecting the roller-carded web obtained in Step 2 to a hot air treatment to fuse the fibers together. Step 3 is also called an air-through step. A nonwoven fabric can be produced through the above steps. The nonwoven fabric obtained through the air-through process is also called a thermal-bonded nonwoven fabric.

[0086] (Effects of this embodiment) (2-1) The nonwoven fabric of this embodiment has the treatment agent of the first embodiment attached thereto. Therefore, the nonwoven fabric can maintain its hydrophilicity even after being stored at high temperatures for a long period of time. In other words, the heat-resistant hydrophilicity of the nonwoven fabric can be improved. Furthermore, the initial hydrophilicity of the nonwoven fabric can be improved.

[0087] (Example of change) The above embodiment may be modified as follows: The above embodiment and the following modifications may be combined with each other within the scope of technical compatibility.

[0088] The treatment agents, compositions, or diluted solutions of the above embodiments may further contain other components commonly used in treatment agents, such as other solvents, stabilizers, antistatic agents, binders, antioxidants, UV absorbers, surfactants other than those listed above, organic acids, organic acid salts, inorganic acids, inorganic acid salts, and polyhydric alcohols, to maintain the quality of the treatment agents, compositions, or diluted solutions, as long as the effects of the present invention are not impaired. To ensure the efficacy of the present invention is efficiently achieved, the amount of other components commonly used in treatment agents other than solvents is preferably 20% by weight or less, and more preferably 10% by weight or less, of each treatment agent. Furthermore, these other components may be stored separately from the treatment agents described above.

[0089] The treatment agent of the above embodiment may contain unreacted materials or reaction by-products remaining after synthesis of the alkenyl sulfonic acid compound (A) or the hydroxyalkyl sulfonic acid compound (B). Examples of unreacted materials or reaction by-products include disulfonates and sulfate ions. The sulfate ion concentration in the treatment agent is preferably 1% by mass or less. [Example]

[0090] 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 examples and comparative examples, unless otherwise specified, parts mean parts by mass and % means % by mass.

[0091] Test Category 1 (Preparation of Treatment Agent) Example 1 As shown in Table 1, the treatment agent of Example 1 was prepared by uniformly mixing 30 parts of the alkenyl sulfonic acid compound (A-1) shown in Table 3 as the alkenyl sulfonic acid compound (A), 14 parts of the hydroxyalkyl sulfonic acid compound (B-1) shown in Table 4 as the hydroxyalkyl sulfonic acid compound (B), 29 parts of a compound (C-3) obtained by adding 20 moles of ethylene oxide (hereinafter referred to as EO) to 1 mole of sorbitan monostearate as the nonionic surfactant (C), 23 parts of the secondary sulfonic acid compound (D1-1) shown in Table 5 as the secondary sulfonic acid compound (D), and 0.3 parts of sodium sulfate (E-1), 1 part of sodium gluconate (E-5), 1 part of oleic acid (E-9), and 1.7 parts of ethylene glycol (E-11) as other components (E).

[0092] (Example 2 11,13,14,16~23,25,27~30,32,33, Reference example 12,15,24,26,31,34~37, Comparative Examples 1 to 7 Example 2 11,13,14,16~23,25,27~30,32,33, Reference example 12,15,24,26,31,34~37 The treatment agents of Comparative Examples 1 to 7 were prepared in the same manner as the treatment agent of Example 1, so as to contain an alkenyl sulfonic acid compound (A), a hydroxyalkyl sulfonic acid compound (B), a nonionic surfactant (C), a secondary sulfonic acid compound (D), and other components (E) in the proportions shown in Tables 1 and 2.

[0093] The type and content of alkenyl sulfonic acid compound (A), the type and content of hydroxyalkyl sulfonic acid compound (B), the type and content of nonionic surfactant (C), the type and content of secondary sulfonic acid compound (D), and the type and content of other components (E) are shown in the "Alkenyl sulfonic acid compound (A)" column, the "Hydroxyalkyl sulfonic acid compound (B)" column, the "Nonionic surfactant (C)" column, the "Secondary sulfonic acid compound (D)" column, and the "Other components (E)" column in Tables 1 and 2, respectively.

[0094] [Table 1]

[0095] [Table 2]

[0096] Details of the alkenyl sulfonic acid compound (A), hydroxyalkyl sulfonic acid compound (B), nonionic surfactant (C), secondary sulfonic acid compound (D), and other components (E) listed in Tables 1 and 2 are as follows.

[0097] <Alkenyl sulfonic acid compound (A)> The alkenylsulfonic acid compound (A) used was the compound of the general formula (1) shown in Chemical Formula 5. Specifically, A-1 to A-3, ra-1, and ra-2 shown in Table 3 below were used.

[0098] [Table 3]

[0099] <Hydroxyalkyl sulfonic acid compound (B)> The hydroxyalkyl sulfonic acid compound (B) used was the compound of the general formula (2) shown in Chemical Formula 6. Specifically, B-1 to B-3, rb-1, and rb-2 shown in Table 4 below were used.

[0100] [Table 4]

[0101] <Nonionic surfactant (C)> C-1: Sorbitan monostearate C-2: Glycerin monostearate C-3: Compound in which 20 moles of EO are added to 1 mole of sorbitan monostearate C-4: Compound in which 20 moles of EO are added to 1 mole of sorbitan trioleate C-5: Compound in which 9.5 moles of EO are added to 1 mole of coconut fatty acid C-6: Compound in which 12 moles of EO are added to 1 mole of castor oil C-7: Compound in which 20 moles of EO are added to 1 mole of hydrogenated castor oil C-8: A compound obtained by adding 25 moles of EO to 1 mole of hydrogenated castor oil and then esterifying it with 3 moles of lauric acid. C-9: Compound in which 5 moles of EO are added to 1 mole of lauryl alcohol C-10: A compound in which 15 moles of EO and 5 moles of propylene oxide (hereinafter referred to as PO) are added to 1 mole of stearyl alcohol. C-11: A compound in which 15 moles of EO are added to 1 mole of oleyl alcohol C-12: Compound in which 10 moles of EO are added to 1 mole of laurylamine C-13: A compound in which 10 moles of EO are added to 1 mole of branched alkyl alcohol with 12 or 13 carbon atoms. C-14: A compound in which 9 moles of EO and 9 moles of PO are added to 1 mole of branched alkyl alcohol with 12 or 13 carbon atoms. <Secondary sulfonic acid compound (D)> (Secondary sulfonic acid compound (D1)) The secondary sulfonic acid compound (D1) used was the compound of the general formula (3) shown in Chemical Formula 7. Specifically, D1-1, D1-2, rd1-1, and rd1-2 shown in Table 5 below were used.

[0102] [Table 5]

[0103] (Secondary sulfonic acid compound (D2)) The secondary sulfonic acid compound (D2) used was a compound of general formula (4) in Chemical Formula 8. Specifically, D2-1, D2-2, rd2-1, and rd2-2 shown in Table 6 below were used.

[0104] [Table 6]

[0105] <Other ingredients (E)> E-1: Sodium sulfate E-2: Potassium sulfate E-3: Ammonium sulfate E-4: Gluconic acid E-5: Sodium gluconate E-6: Potassium gluconate E-7: Citric acid E-8: Sodium citrate E-9: Oleic acid E-10: Potassium oleate E-11: Ethylene glycol E-12: Polyethylene glycol E-13: 1,4-butanediol E-14: Glucose Test Category 2 (treatment agent adhesion) CoPLA / PLA composite fibers were prepared, with a sheath made of copolymerized polylactic acid (coPLA) and a core made of addition-polymerized polylactic acid (PLA). The treatment agents prepared as described above were diluted with water to 0.35% by mass, and the diluted solution was applied to the coPLA / PLA composite fibers by spray oiling so that the amount of treatment agent attached (excluding solvent) was 0.35%. The fibers were then dried in a hot air dryer at 80°C for 1 hour to obtain treated coPLA / PLA composite fibers.

[0106] Test Category 3 (Nonwoven Fabric Creation) 100 g of the treated coPLA / PLA composite fiber treated cotton was conditioned for 24 hours in a temperature-controlled room at 20°C and 65% RH, and then subjected to a roller card (carding machine) to produce a fabric with a basis weight of 20 g / m. 2 The resulting carded web was heat-treated at 140°C for 10 seconds to prepare a sample for evaluation of initial hydrophilicity.

[0107] Test category 4 (initial hydrophilicity) The sample for initial hydrophilicity evaluation was conditioned for 24 hours in a thermostatic chamber at 20°C and 60% RH. It was then placed on a horizontal plate, and a 0.5 mL drop of water was dropped onto it from a height of 10 mm using a burette. The time required for the drop to be completely absorbed into the sample (time required for water penetration) was measured, and the sample was evaluated according to the following criteria. The results are shown in the "Initial Hydrophilicity" column in Tables 1 and 2.

[0108] Evaluation criteria for initial hydrophilicity 5 (Excellent): Water permeates in less than 0.5 seconds 4 (Excellent): Time required for water penetration is 0.5 seconds or more and less than 2.0 seconds 3 (Good): Time required for water penetration is 2.0 seconds or more and less than 5 seconds 2 (Acceptable): Time required for water to penetrate is 5 seconds or more but less than 10 seconds 1 (Not acceptable): It takes more than 10 seconds for water to penetrate Test category 5 (heat-resistant hydrophilicity) The sample for initial hydrophilicity evaluation was conditioned at 50°C for two weeks, and then conditioned in a thermostatic chamber at 20°C and 60% RH for 24 hours. It was then placed on a horizontal plate, and a 0.5 mL drop of water was dropped onto it from a height of 10 mm using a burette. The time required for the drop to be completely absorbed into the sample (time required for water penetration) was measured, and the sample was evaluated according to the following criteria. The results are shown in the "Heat-resistant hydrophilicity" column in Tables 1 and 2.

[0109] Evaluation criteria for heat resistance and hydrophilicity 5 (Excellent): Water permeates in less than 0.5 seconds 4 (Excellent): Time required for water penetration is 0.5 seconds or more and less than 2.0 seconds 3 (Good): Time required for water penetration is 2.0 seconds or more and less than 5 seconds 2 (Acceptable): Time required for water to penetrate is 5 seconds or more but less than 10 seconds 1 (Not acceptable): It takes more than 10 seconds for water to penetrate Test Category 6 (Card Passability) 20 g of treated synthetic fiber-treated cotton was conditioned for 24 hours in a thermostatic chamber at 20°C and 65% RH, and then subjected to a roller card (carding machine). The ratio of the amount discharged to the amount input was calculated and evaluated according to the following criteria. The results are shown in the "Carding Efficiency" column in Tables 1 and 2.

[0110] Card passability evaluation criteria 5 (Excellent): Emissions are 90% or more 4 (Excellent): Emissions are 85% or more and less than 90% 3 (Good): Emissions are 80% or more and less than 85% 2 (Acceptable): Emissions are 75% or more and less than 80% 1 (Not acceptable): Emissions are less than 75% As is clear from the evaluation results of each Example and Comparative Example in each table, the treatment agent of the present invention can improve the initial hydrophilicity and heat-resistant hydrophilicity of the nonwoven fabric to which the treatment agent is applied, and can also improve the carding properties of the fiber to which the treatment agent is applied.

Claims

1. The composition contains an alkenyl sulfonic acid compound (A) represented by the following general formula (1) and a hydroxyalkyl sulfonic acid compound (B) represented by the following general formula (2), A fiber treatment agent for nonwoven fabrics, characterized in that it contains the alkenyl sulfonic acid compound (A) in an amount of 40% by mass or more and 90% by mass or less, and the hydroxyalkyl sulfonic acid compound (B) in an amount of 10% by mass or more and 60% by mass or less, where the total content of the alkenyl sulfonic acid compound (A) and the hydroxyalkyl sulfonic acid compound (B) is taken as 100% by mass. 【Chemistry 1】 (In formula (1), R １ : an alkenyl group having 8 to 18 carbon atoms. M １ : Alkali metal or ammonium. 【Chemistry 2】 (In formula (2), R ２ : A hydroxyalkyl group having 8 to 18 carbon atoms. M ２ : Alkali metal or ammonium.

2. The fiber treatment agent for nonwoven fabrics according to claim 1, further comprising a nonionic surfactant (C).

3. 3. The fiber treatment agent for nonwoven fabrics according to claim 2, wherein the nonionic surfactant (C) has an ester bond.

4. 3. The fiber treatment agent for nonwoven fabrics according to claim 2, wherein the fiber treatment agent contains the alkenyl sulfonic acid compound (A) in an amount of 20% by mass or more and 60% by mass or less, the hydroxyalkyl sulfonic acid compound (B) in an amount of 5% by mass or more and 40% by mass or less, and the nonionic surfactant (C) in an amount of 15% by mass or more and 55% by mass or less, where the total amount of the alkenyl sulfonic acid compound (A), the hydroxyalkyl sulfonic acid compound (B), and the nonionic surfactant (C) is taken as 100% by mass.

5. The fiber treatment agent for nonwoven fabrics according to claim 2, further comprising the following secondary sulfonic acid compound (D): Secondary sulfonic acid compound (D): At least one selected from secondary sulfonic acid compounds (D1) represented by the following general formula (3) and secondary sulfonic acid compounds (D2) represented by the following general formula (4). 【Transformation 3】 (In formula (3), R ３ , R ４ : an aliphatic hydrocarbon group having 1 to 16 carbon atoms. ３ and R ４ The total number of carbon atoms is 7 or more and 17 or less. M ３ : a hydrogen atom, an alkali metal, an alkaline earth metal, an ammonium, a phosphonium, or an organic amine. 【Chemistry 4】 (In formula (4), R ５ , R ６ : an aliphatic hydrocarbon group having 1 to 17 carbon atoms. ５ and R ６ The total number of carbon atoms is 8 or more and 18 or more. M ４ : a hydrogen atom, an alkali metal, an alkaline earth metal, an ammonium, a phosphonium, or an organic amine.

6. 6. The fiber treatment agent for nonwoven fabrics according to claim 5, wherein the fiber treatment agent contains the alkenyl sulfonic acid compound (A) in an amount of 10% by mass or more and 45% by mass or less, the hydroxyalkyl sulfonic acid compound (B) in an amount of 5% by mass or more and 40% by mass or less, the nonionic surfactant (C) in an amount of 15% by mass or more and 45% by mass or less, and the secondary sulfonic acid compound (D) in an amount of 10% by mass or more and 40% by mass or less, where the total amount of the alkenyl sulfonic acid compound (A), the hydroxyalkyl sulfonic acid compound (B), the nonionic surfactant (C), and the secondary sulfonic acid compound (D) is taken as 100% by mass.

7. A nonwoven fabric having the fiber treatment agent for nonwoven fabric according to any one of claims 1 to 6 attached thereto.

8. The nonwoven fabric according to claim 7, wherein the fibers used in the nonwoven fabric include PLA fibers.

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