Short fiber treatment agent and method for producing nonwoven fabric

Abstract

The present invention addresses the problem of providing: a short fiber treatment agent which enables the improvement of the stability of an emulsion containing the short fiber treatment agent and enables the improvement of friction reduction properties of fibers when the short fiber treatment agent is applied to the fibers; and others. The short fiber treatment agent comprises: a component (A) which is a hydroxy acid and / or an alkali metal salt thereof; a component (B) which is a quaternary ammonium compound and / or an imidazoline compound; and a component (C) which includes a compound obtained by adding ethylene oxide and / or propylene oxide to a monovalent or divalent C8-22 fatty acid. The quaternary ammonium compound is of an imidazolinium type, a mono-long-chain skeleton type, a di-long-chain skeleton type, and / or a polyoxyalkylene aliphatic amine type. The imidazoline compound is an imidazoline having a C1-24 alkenyl group and / or an imidazoline having a C1-24 alkyl group.

Description

Treatment agent for short fibers and method for producing nonwoven fabric

[0001] The present invention relates to a treatment agent for short fibers and a method for producing a nonwoven fabric.

[0002] Synthetic fibers are generally used as the raw material fibers for nonwoven fabrics. For example, to produce nonwoven fabrics, staple fibers, which are short synthetic fibers, are first prepared and then the staple fibers are passed through a carding machine to produce a web. Therefore, by applying a short fiber treatment agent to the synthetic fibers, functions such as friction reduction are imparted. Webs obtained by passing the staple fibers through a carding machine are used in a wide range of fields, including industrial fields such as automotive interior materials, agriculture, hygiene materials, medicine, and construction / civil engineering.

[0003] Conventionally, a treatment agent for short fibers is known as disclosed in Patent Document 1. Patent Document 1 discloses a water permeability imparting agent for fibers used in the production of nonwoven fabrics, which contains component (A): gluconic acid, component (B): alkyl phosphate, alkyl phosphate salt, or the like, and component (C): an ester of an aliphatic carboxylic acid with at least one selected from monohydric alcohols, polyhydric alcohols, and alkylene oxide adducts thereof.

[0004] Japanese Patent Application Laid-Open No. 2021-172927

[0005] In addition to providing the short fiber treatment agent with the function of reducing friction on the short fibers, it is also necessary to improve the stability of the emulsion containing the short fiber treatment agent that is prepared at the time of use.

[0006] As a result of research aimed at solving the above problems, the present inventors have found that a composition containing a predetermined organic acid, a quaternary ammonium compound, and a polyoxyalkylene compound is suitable.

[0007] The following describes various aspects of the treatment agent for short fibers that solves the above-mentioned problems. The treatment agent for short fibers in aspect 1 is characterized by containing the following component (A), the following component (B), and the following component (C).

[0008] The component (A) is at least one selected from the group consisting of hydroxy acids and alkali metal salts of hydroxy acids, and the component (B) is at least one selected from the group consisting of quaternary ammonium compounds (B1) and imidazoline compounds (B2).

[0009] The quaternary ammonium compound (B1) is at least one selected from the following imidazolinium-type quaternary ammonium (B1a), the following mono-long chain skeleton-type quaternary ammonium (B1b), the following di-long chain skeleton-type quaternary ammonium (B1c), and the following polyoxyalkylene aliphatic amine-type quaternary ammonium (B1d).

[0010] The imidazolinium-type quaternary ammonium (B1a) is at least one selected from a quaternized imidazoline compound and a salt thereof. The mono-long-chain skeleton-type quaternary ammonium (B1b) is at least one selected from a quaternary ammonium having an aliphatic carbon skeleton having from 12 to 22 carbon atoms in the molecule and a salt thereof.

[0011] The dilong-chain skeleton-type quaternary ammonium (B1c) is at least one selected from quaternary ammonium having two aliphatic carbon skeletons with 12 to 22 carbon atoms in the molecule, and salts thereof.

[0012] The polyoxyalkylene aliphatic amine-type quaternary ammonium (B1d) is at least one selected from quaternary ammonium having, in the molecule, one aliphatic carbon skeleton having from 12 to 22 carbon atoms and two polyoxyalkylene skeletons having oxyalkylene structural units, and salts thereof.

[0013] The imidazoline compound (B2) is at least one selected from imidazolines having an alkenyl group with 1 to 24 carbon atoms and imidazolines having an alkyl group with 1 to 24 carbon atoms.

[0014] The component (C) is at least one selected from the group consisting of a compound obtained by adding at least one selected from ethylene oxide and propylene oxide to a mono- or di-valent fatty acid having from 8 to 22 carbon atoms, and a compound obtained by adding at least one selected from ethylene oxide and propylene oxide to a mono- or tri-valent aliphatic alcohol having from 3 to 22 carbon atoms.

[0015] In Aspect 2, in the short fiber treatment agent according to Aspect 1, the component (A) is at least one selected from gluconic acid and alkali metal salts of gluconic acid. In Aspect 3, in the short fiber treatment agent according to Aspect 1 or 2, the component (C) is at least one selected from a compound obtained by adding 3 to 50 moles in total of at least one selected from ethylene oxide and propylene oxide to 1 mole of a mono- or di-functional fatty acid having from 12 to 20 carbon atoms, and a compound obtained by adding 3 to 50 moles in total of at least one selected from ethylene oxide and propylene oxide to 1 mole of a mono- to tri-functional aliphatic alcohol having from 8 to 18 carbon atoms.

[0016] In Aspect 4, in the treatment agent for short fibers according to any one of Aspects 1 to 3, the treatment agent contains the component (A) in an amount of 1% by mass or more and 20% by mass or less, the component (B) in an amount of 1% by mass or more and 60% by mass or less, and the component (C) in an amount of 30% by mass or more and 90% by mass or less, where the total content of the component (A), the component (B), and the component (C) is 100% by mass.

[0017] The method for producing a nonwoven fabric of Aspect 5 is characterized by the following steps 1 to 3: Step 1: A step of adhering the short fiber treating agent according to any one of Aspects 1 to 4 to synthetic fibers.

[0018] Step 2: A step of obtaining a web by passing the synthetic fibers to which the staple fiber treatment agent has been applied in Step 1 through a carding machine. Step 3: A step of needle-punching the web obtained in Step 2 to obtain a nonwoven fabric.

[0019] Aspect 6 is the method for producing a nonwoven fabric according to aspect 5, wherein the synthetic fibers are polyester-based synthetic fibers.

[0020] According to the present invention, it is possible to improve the stability of an emulsion containing a treatment agent for short fibers, and also to improve the friction reducing properties of fibers to which the treatment agent for short fibers has been applied.

[0021] First Embodiment A first embodiment of the treatment agent for short fibers (hereinafter simply referred to as the treatment agent) according to the present invention will be described.

[0022] The treatment agent of this embodiment contains, as component (A), at least one selected from hydroxy acids and alkali metal salts of hydroxy acids; as component (B), at least one selected from quaternary ammonium compounds (B1) and imidazoline compounds (B2); and as component (C), at least one selected from compounds in which at least one selected from ethylene oxide and propylene oxide is added to a mono- or di-valent fatty acid having from 8 to 22 carbon atoms, and compounds in which at least one selected from ethylene oxide and propylene oxide is added to a mono- or di-valent aliphatic alcohol having from 3 to 22 carbon atoms.

[0023] (Component (A)) Component (A) used in the treatment agent of this embodiment is at least one selected from the group consisting of hydroxy acids and alkali metal salts of hydroxy acids, as described above. By including component (A) in the treatment agent, the stability of the emulsion containing the treatment agent can be improved.

[0024] Examples of hydroxy acids include organic acids having a hydroxy group and aliphatic carboxylic acids having a hydroxy group. The aliphatic carboxylic acids are not particularly limited with respect to whether they are branched or not, and may be, for example, higher fatty acids or carboxylic acids having a cyclo ring. They may also be saturated or unsaturated fatty acids. The number of carbon atoms in the hydroxy acid is not particularly limited, but is preferably 1 to 20, more preferably 2 to 18, and even more preferably 3 to 12.

[0025] Specific examples of hydroxy acids include gluconic acid, citric acid, lactic acid, tartaric acid, glycolic acid, malic acid, ricinoleic acid, hydroxybutyric acid, glyceric acid, etc. Naturally occurring fatty acids may be used as the hydroxy acids, but when fatty acids other than hydroxy acids are also contained, the hydroxy acids should account for 80% by mass or more of the total fatty acids. Specific examples of naturally occurring fatty acids include castor oil and hydrogenated castor oil, which contain ricinoleic acid.

[0026] Specific examples of the alkali metal constituting the alkali metal salt include sodium, potassium, lithium, etc. These components (A) may be used alone or in appropriate combination of two or more.

[0027] Among these components (A), gluconic acid and alkali metal salts of gluconic acid are preferred from the viewpoint of further improving stability when hard water is used as a solvent. The lower limit of the content of component (A) in the non-volatile content of the solvent-free treatment agent can be set appropriately, but is preferably 0.5% by mass or more, more preferably 1% by mass or more. When such a content is 0.5% by mass or more, stability can be further improved when hard water is used as a solvent. The upper limit of the content of component (A) can be set appropriately, but is preferably 30% by mass or less, more preferably 20% by mass or less. When such a content is 30% by mass or less, carding ability of the fibers to which the treatment agent is applied can be further improved. Note that ranges obtained by arbitrarily combining the above upper and lower limits are also contemplated. In this specification, the non-volatile content refers to the bone-dry matter obtained by heat-treating the target object at 105°C for 2 hours to thoroughly remove volatile substances.

[0028] (Component (B)) The component (B) used in the treatment agent of this embodiment is at least one selected from the quaternary ammonium compound (B1) and the imidazoline compound (B2), as described above. By including component (B) in the treatment agent, the friction reduction properties of the short fibers to which the treatment agent is applied can be improved. In particular, fiber / metal friction can be reduced.

[0029] The quaternary ammonium compound (B1) preferably contains at least one selected from the following imidazolinium-type quaternary ammonium (B1a), the following mono-long chain skeleton-type quaternary ammonium (B1b), the following di-long chain skeleton-type quaternary ammonium (B1c), and the following polyoxyalkylene aliphatic amine-type quaternary ammonium (B1d). Use of these quaternary ammonium compounds (B1) can further improve antistatic properties.

[0030] The imidazolinium-type quaternary ammonium (B1a) is at least one selected from a compound obtained by quaternizing an imidazoline compound and a salt thereof. Examples of the imidazolinium-type quaternary ammonium (B1a) include quaternary ammonium salts represented by the following general formula (1):

[0031]

[0032] In general formula (1), R １ is an alkyl or alkenyl group having 1 to 24 carbon atoms, and R ２ is an alkyl group or alkenyl group having 1 to 24 carbon atoms. n is an integer of 1 to 20. X － Examples of the anion include sulfate ions such as alkyl sulfate ions, phosphate ions such as alkyl phosphate ions, sulfonate ions such as alkyl sulfonate ions, and anions such as chloride ions.

[0033] The imidazoline compound used as a raw material for the imidazolinium-type quaternary ammonium (B1a) is a compound represented by the general formula (1) in which the substituent R ２ Examples of the tertiary amine include imidazoline compounds having no structure.

[0034] The imidazoline compound (B2) is at least one selected from imidazolines having an alkenyl group having 1 to 24 carbon atoms and imidazolines having an alkyl group having 1 to 24 carbon atoms.

[0035] Specific examples of the imidazoline compound (B2) include 1-(2-hydroxyethyl)-2-alkenylimidazolines such as 1-(2-hydroxyethyl)-2-oleylimidazoline, and 1-(2-hydroxyethyl)-2-alkylimidazolines such as 1-(2-hydroxyethyl)-2-stearylimidazoline.

[0036] The quaternized imidazoline compound or its salt includes, for example, a reaction product of an imidazoline compound with a dialkyl sulfate, a trialkyl phosphate, or an alkyl sulfonate. Specific examples of the dialkyl sulfate include dimethyl sulfate and diethyl sulfate.

[0037] Specific examples of the imidazolinium-type quaternary ammonium (B1a) include alkyl sulfates of 1-ethyl-2-(heptadecenyl)-4,5-dihydro-3-(2-hydroxyethyl)-1H-imidazolinium, alkyl sulfates of 1-methyl-2-(heptadecenyl)-4,5-dihydro-3-(2-hydroxyethyl)-1H-imidazolinium, and alkyl sulfates of 1-ethyl-2-(heptadecenyl)- Examples include alkyl sulfates of 4,5-dihydro-3-(2-hydroxyethyl)-1H-imidazolinium, alkyl sulfates of 1-ethyl-2-(isoheptadecyl)-4,5-dihydro-3-(2-hydroxyethyl)-1H-imidazolinium, and alkyl sulfates of 1-ethyl-2-(pentadecyl)-4,5-dihydro-3-(2-hydroxyethyl)-1H-imidazolinium.

[0038] The mono-long-chain skeleton quaternary ammonium (B1b) is at least one selected from quaternary ammonium having one aliphatic carbon skeleton having from 12 to 22 carbon atoms in the molecule, and salts thereof. Examples of ions constituting the salt form include sulfate ions such as alkyl sulfate ions, phosphate ions such as alkyl phosphate ions, sulfonate ions such as alkyl sulfonate ions, and anions such as chloride ions.

[0039] Examples of the aliphatic carbon skeleton having 12 to 22 carbon atoms include saturated hydrocarbon groups, unsaturated hydrocarbon groups, straight-chain hydrocarbon groups, and branched-chain hydrocarbon groups. Specific examples of aliphatic carbon skeletons having 12 to 22 carbon atoms include (1) linear saturated hydrocarbon groups such as dodecyl, tridecyl, tetradecyl, pentadecyl, hexadecyl, heptadecyl, octadecyl, icosyl, and docosyl groups; (2) branched saturated hydrocarbon groups such as isododecyl, isotridecyl, isotetradecyl, isopentadecyl, isohexadecyl, isoheptadecyl, isooctadecyl, isoicosyl, and isodocosyl groups; and (3) linear unsaturated hydrocarbon groups having one double bond in the hydrocarbon group such as dodecenyl, tridecenyl, tetradecenyl, pentadecenyl, hexadecenyl, heptadecenyl, octadecenyl, icosenyl, and docosenyl groups.

[0040] The mono-long chain skeleton type quaternary ammonium (B1b) includes, for example, a reaction product of a tertiary amine having one aliphatic carbon skeleton having from 12 to 22 carbon atoms with a dialkyl sulfate, a trialkyl phosphate, or an alkyl sulfonate. Specific examples of dialkyl sulfates include dimethyl sulfate and diethyl sulfate.

[0041] Specific examples of tertiary amines having one aliphatic carbon skeleton having from 12 to 22 carbon atoms include N-stearyl-N,N-bis(2-hydroxyethyl)amine, N-[3-(dimethylamino)propyl]stearamide, and N-[3-(dimethylamino)propyl]lauroylamide.

[0042] Specific examples of quaternary ammonium having one aliphatic carbon skeleton having from 12 to 22 carbon atoms in the molecule include lauryltrimethylammonium, stearyltrimethylammonium, eicosenyltriethylammonium, oleyltrimethylammonium, di(hydroxyethyl)stearylmethylammonium, di(hydroxyethyl)oleylmethylammonium, ethyldimethyl(stearoylamino)propaneammonium, ethyldimethyl(lauroylamino)propaneammonium, and tallow alkyltrimethylammonium.

[0043] Specific examples of the mono-long chain skeleton type quaternary ammonium (B1b) include, for example, alkyl sulfates of N-stearyl-N,N-bis(2-hydroxyethyl)-N-methylammonium, N-oleyl-N,N-bis(2-hydroxyethyl)-N-methylammonium chloride, alkyl sulfates of N-ethyl-N,N-dimethyl-3-(stearoylamino)propaneammonium, alkyl sulfates of N-ethyl-N,N-dimethyl-3-(lauroylamino)propaneammonium, and tallow alkyltrimethylammonium chloride.

[0044] The dilong-chain skeleton quaternary ammonium (B1c) is at least one selected from quaternary ammonium having two aliphatic carbon skeletons with 12 to 22 carbon atoms in the molecule, and salts thereof. Examples of ions constituting the salt form include sulfate ions such as alkyl sulfate ions, phosphate ions such as alkyl phosphate ions, sulfonate ions such as alkyl sulfonate ions, and anions such as chloride ions.

[0045] Examples of the aliphatic carbon skeleton having from 12 to 22 carbon atoms include saturated hydrocarbon groups, unsaturated hydrocarbon groups, linear hydrocarbon groups, and branched hydrocarbon groups. Specific examples thereof are the same as those given above as specific examples of the aliphatic carbon skeleton having from 12 to 22 carbon atoms in the mono-long chain skeleton-type quaternary ammonium (B1b).

[0046] The dilong-chain skeleton quaternary ammonium (B1c) includes, for example, a reaction product of a tertiary amine having two aliphatic carbon skeletons having from 12 to 22 carbon atoms with a dialkyl sulfate, a trialkyl phosphate, or an alkyl sulfonic acid. Specific examples of dialkyl sulfates include dimethyl sulfate and diethyl sulfate.

[0047] Specific examples of quaternary ammonium having two aliphatic carbon skeletons with 12 to 22 carbon atoms include dilauryldimethylammonium, dioctadecyldimethylammonium, and dimethyldioleylammonium.

[0048] A specific example of the dilong-chain skeleton-type quaternary ammonium (B1c) is dioctadecyldimethylammonium chloride. The polyoxyalkylene aliphatic amine-type quaternary ammonium (B1d) is at least one selected from quaternary ammonium having one aliphatic carbon skeleton having from 12 to 22 carbon atoms and two polyoxyalkylene skeletons having oxyalkylene structural units in the molecule, and salts thereof. Examples of ions that constitute the salt form include sulfate ions such as alkyl sulfate ions, phosphate ions such as alkyl phosphate ions, sulfonate ions such as alkyl sulfonate ions, and anions such as chloride ions.

[0049] Examples of the aliphatic carbon skeleton having from 12 to 22 carbon atoms include saturated hydrocarbon groups, unsaturated hydrocarbon groups, linear hydrocarbon groups, and branched hydrocarbon groups. Specific examples thereof are the same as those given above as specific examples of the aliphatic carbon skeleton having from 12 to 22 carbon atoms in the mono-long chain skeleton-type quaternary ammonium (B1b).

[0050] The polyoxyalkylene aliphatic amine quaternary ammonium (B1d) includes, for example, a reaction product of a tertiary amine formed by adding an alkylene oxide to an aliphatic amine having from 12 to 22 carbon atoms with a dialkyl sulfate, a trialkyl phosphate, or an alkyl sulfonic acid. Specific examples of dialkyl sulfates include dimethyl sulfate and diethyl sulfate.

[0051] Specific examples of aliphatic amines include laurylamine, octadecylamine, octadecenylamine, stearylamine, oleylamine, etc. Specific examples of the reaction product of a tertiary amine and a dialkyl sulfuric acid include a reaction product of a compound obtained by adding 5 moles of ethylene oxide to 1 mole of stearylamine with dimethyl sulfate, and a reaction product of a compound obtained by adding 5 moles of ethylene oxide and 3 moles of propylene oxide to 1 mole of oleylamine with diethyl sulfate.

[0052] Examples of alkylene oxides used as raw materials for constituting the polyoxyalkylene skeleton include ethylene oxide, propylene oxide, and butylene oxide. The number of moles of alkylene oxide added is set appropriately, but is preferably 2 to 60 moles, more preferably 3 to 50 moles, and even more preferably 4 to 50 moles. Ranges combining the above upper and lower limits are also contemplated. The number of moles of alkylene oxide added indicates the number of moles of alkylene oxide per mole of the compound to be added in the charged raw material. As the alkylene oxide, one type of alkylene oxide may be used alone, or two or more types of alkylene oxides may be used in appropriate combination. When two or more types of alkylene 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.

[0053] Specific examples of the polyoxyalkylene aliphatic amine-type quaternary ammonium (B1d) include alkyl sulfates of alkylene oxide adducts of N-stearyl-N,N-bis(2-hydroxyethyl)-N-methylammonium, and alkyl sulfates of alkylene oxide adducts of N-oleyl-N,N-bis(2-hydroxyethyl)-N-ethylammonium.

[0054] These components (B) may be used singly or in appropriate combination of two or more. The lower limit of the content of component (B) in the non-volatile content of the solvent-free treatment agent is set appropriately, but is preferably 0.5% by mass or more, more preferably 1% by mass or more. When this content is 1% by mass or more, the friction reduction properties for the short fibers to which the treatment agent is applied can be further improved. In particular, fiber / metal friction can be further reduced. The upper limit of the content of component (B) is set appropriately, but is preferably 65% ​​by mass or less, more preferably 60% by mass or less. When this content is 65% by mass or less, the carding ability can be further improved. Note that ranges obtained by arbitrarily combining the above upper and lower limits are also envisioned.

[0055] (Component (C)) Component (C) used in the treatment agent of this embodiment is at least one selected from the group consisting of a compound obtained by adding at least one selected from ethylene oxide and propylene oxide to a mono- or di-valent fatty acid having from 8 to 22 carbon atoms, and a compound obtained by adding at least one selected from ethylene oxide and propylene oxide to a mono- or tri-valent aliphatic alcohol having from 3 to 22 carbon atoms. The treatment agent can improve the friction reduction properties of the short fibers to which it is applied. In particular, it can reduce fiber / metal friction.

[0056] Specific examples of fatty acids used as a raw material for component (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 oleic acid, octadecenoic acid, octadecadienoic acid, octadecatrienoic acid, and erucic acid; (4) hydroxycarboxylic acids such as 12-hydroxystearic acid and ricinoleic acid; and (5) polycarboxylic acids such as sebacic acid. Among these, mono- or di-valent fatty acids having 12 to 20 carbon atoms are preferably used from the viewpoint of further improving the stability of the emulsion containing the treating agent.

[0057] Specific examples of monohydric aliphatic alcohols used as raw materials for component (C) include, for example, (1) linear alkyl alcohols such as propanol, butanol, pentanol, hexanol, octanol, nonanol, decanol, undecanol, dodecanol, tridecanol, tetradecanol, pentadecanol, hexadecanol, heptadecanol, octadecanol, nonadecanol, eicosanol, heneicosanol, and docosanol; (2) isopropanol, isobutanol, isohexanol, 2-ethylhexanol, isononanol, isodecanol, isododecanol, and isopropyl alcohols; (3) branched alkyl alcohols such as sotridecanol, isotetradecanol, isopentadecanol, isohexadecanol, isoheptadecanol, isooctadecanol, isononadecanol, isoeicosanol, isoheneicosanol, and isodocosanol; (4) straight-chain alkenyl alcohols such as oleyl alcohol, tetradecenol, hexadecenol, heptadecenol, octadecenol, and nonadecenol; (4) branched alkenyl alcohols such as isohexadecenol and isooctadecenol; and (5) cyclic alkyl alcohols such as cyclopentanol and cyclohexanol.

[0058] Specific examples of polyhydric alcohols used as a raw material for component (C) include 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, 1,10-decanediol, glycerin, 2-methyl-2-hydroxymethyl-1,3-propanediol, and trimethylolpropane.

[0059] Among these, monovalent to trivalent aliphatic alcohols having 8 to 18 carbon atoms are preferred from the viewpoint of further improving the stability of emulsions containing a treating agent. Examples of alkylene oxides used as raw materials for component (C) include ethylene oxide and propylene oxide. The number of moles of alkylene oxide added is set appropriately, but is preferably 1 to 60 moles, more preferably 3 to 50 moles. Any combination of the above upper and lower limits is also contemplated. The number of moles of alkylene oxide added indicates the number of moles of alkylene oxide per mole of the compound to be added in the charged raw material. As for the alkylene oxide, one type of alkylene oxide may be used alone, or two or more types of alkylene oxides may be used in appropriate combination. When two or more types of alkylene 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.

[0060] Among these, component (C) is preferably at least one selected from a compound obtained by adding 3 to 50 moles in total of at least one selected from ethylene oxide and propylene oxide to 1 mole of a mono- or di-functional fatty acid having from 12 to 20 carbon atoms, and a compound obtained by adding 3 to 50 moles in total of at least one selected from ethylene oxide and propylene oxide to 1 mole of a mono- to tri-functional aliphatic alcohol having from 8 to 18 carbon atoms. Use of these compounds can further improve the stability of emulsions containing a treating agent.

[0061] Specific examples of component (C) include a compound in which ethylene oxide is added to oleic acid, a compound in which ethylene oxide and propylene oxide are randomly added to a branched alkyl alcohol having 12 or 13 carbon atoms, a compound in which ethylene oxide is added to lauryl alcohol, a compound in which ethylene oxide is added to stearic acid, a compound in which ethylene oxide is added to lauric acid, a compound in which ethylene oxide and propylene oxide are block-added to a branched alkyl alcohol having 8 to 10 carbon atoms, a compound in which propylene oxide and ethylene oxide are block-added to myristic acid, a compound in which propylene oxide and ethylene oxide are block-added to 2-ethylhexanol, a compound in which ethylene oxide is added to 12-hydroxystearic acid, and oleyl alcohol. Examples of the ethylene oxide-added glycerin include a compound in which ethylene oxide is added to 1,10-decanediol, a compound in which ethylene oxide is added to 1,10-decanediol, a compound in which ethylene oxide is added to sebacic acid, a compound in which ethylene oxide is added to 2-ethylhexanoic acid, a compound in which ethylene oxide is added to erucic acid, a compound in which ethylene oxide is added to 1-docosanol, a compound in which ethylene oxide is added to glycerin, a compound in which ethylene oxide and propylene oxide are randomly added to propylene glycol, a compound in which propylene oxide and ethylene oxide are block-added to propylene glycol, a compound in which ethylene oxide and propylene oxide are block-added to oleic acid, and a compound in which ethylene oxide is added to 2-ethylhexanol.

[0062] These components (C) may be used alone or in appropriate combination of two or more. The lower limit of the content of component (C) in the non-volatile content of the solvent-free treatment agent is set appropriately, but is preferably 5 mass% or more, more preferably 15 mass% or more, and even more preferably 30 mass% or more. When this content is 5 mass% or more, the friction reduction properties of the short fibers to which the treatment agent is applied can be improved. In particular, fiber / metal friction can be reduced. The upper limit of the content of component (C) is set appropriately, but is preferably 95 mass% or less, more preferably 90 mass% or less. When this content is 95 mass% or less, the friction reduction properties of the short fibers to which the treatment agent is applied can be improved. In particular, fiber / metal friction can be reduced. Note that ranges obtained by arbitrarily combining the above upper and lower limits are also envisioned.

[0063] In the non-volatile content of the treatment agent not containing the solvent, when the total content of the components (A), (B), and (C) is taken as 100% by mass, the component (A) is preferably contained in an amount of 1% by mass to 20% by mass, the component (B) is preferably contained in an amount of 1% by mass to 60% by mass, and the component (C) is preferably contained in an amount of 30% by mass to 90% by mass. By specifying the content within these ranges, the carding property can be further improved. In addition, the friction reduction property of the short fibers to which the treatment agent is applied can be further improved. In particular, fiber / metal friction can be further reduced. In addition, the stability of the treatment agent against hard water can be further improved.

[0064] (Solvent) The treatment agent of this embodiment may be mixed with a solvent as needed to prepare a treatment-agent-containing composition for short fibers (hereinafter referred to as the "treatment-agent-containing composition"), and the composition may be stored or distributed in this form. This configuration improves the homogeneity and stability of the mixture when it is further diluted with a solvent at the time of use.

[0065] The solvent has a boiling point of 105°C or less at 1 atmosphere. Examples of the solvent include water and organic solvents. Specific examples of the organic solvent 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.

[0066] In the treatment-agent-containing composition, the treatment agent is preferably contained in an amount of 10 parts by mass or more, assuming that the total content of the treatment agent and solvent is 100 parts by mass. (Effects of this embodiment) The effects of the treatment agent of the first embodiment will be described.

[0067] (1-1) The treatment agent of the first embodiment contains the above-mentioned components (A), (B), and (C). Therefore, the stability of the emulsion containing the treatment agent can be improved, and the friction reduction properties of the fibers to which the treatment agent is applied can be improved. In particular, fiber / metal friction can be reduced. Furthermore, the antistatic properties and carding properties of the fibers to which the treatment agent is applied can be improved. Furthermore, the stability of the treatment agent against hard water can be improved. As a result, scum can be reduced.

[0068] Second Embodiment A second embodiment of the method for producing a nonwoven fabric according to the present invention will be described below. The nonwoven fabric obtained in this embodiment has the treatment agent of the first embodiment adhered thereto.

[0069] The method for producing a nonwoven fabric of this embodiment involves the following steps 1 to 3: Step 1: A step of applying the treatment agent of the first embodiment to synthetic fibers. Step 2: A step of passing the synthetic fibers to which the treatment agent has been applied in step 1 through a carding machine to obtain a web.

[0070] Step 3: A step of needle-punching the web obtained in Step 2 to obtain a nonwoven fabric. (Synthetic Fibers) Specific examples of synthetic fibers include: (1) polyolefin synthetic fibers such as polyethylene fibers, polypropylene fibers, and polybutene fibers; (2) polyester synthetic fibers such as polyethylene terephthalate, polybutylene terephthalate, polyethylene terephthalate isophthalate, and polyether polyester; (3) polyamide synthetic fibers such as nylon 6 and nylon 66; and (4) composite fibers, including core-sheath composite fibers in which either the core or the sheath, or both, are polyolefin fibers, such as polyethylene / polypropylene composite fibers or polyethylene / polyester composite fibers in which the sheath is polyethylene fiber, or polyethylene / polyester composite fibers or polyethylene / polyester composite fibers having a side-by-side structure. Here, polyolefin synthetic fibers refer to synthetic fibers synthesized using olefins or alkenes as monomers.

[0071] (Use of Fiber) The use of the fiber to which the treatment agent is attached is as short 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.

[0072] (Treatment of applying treatment agent) There is no particular restriction on the proportion of the treatment agent of the first embodiment applied to the synthetic fiber, but it is preferable to apply a solvent-free treatment agent so that it is 0.1% by mass or more and 2% by mass or less relative to the synthetic fiber, and it is more preferable to apply it so that it is 0.3% by mass or more and 1.2% by mass or less.

[0073] The treatment agent can be applied to synthetic fibers by a known method, such as a dipping method, a spraying method, a roller method, or a guide oiling method using a metering pump, using, for example, a treatment agent-containing composition containing the treatment agent of the first embodiment and water, or a diluted solution obtained by further diluting the treatment agent with a solvent.

[0074] (Effects of this embodiment) The effects of the method for producing a nonwoven fabric of the second embodiment will be described. (2-1) In the second embodiment, a nonwoven fabric is produced using fibers to which the treatment agent containing the above-mentioned components (A), (B), and (C) is attached. This reduces fiber-to-metal friction of the fibers to which the treatment agent is applied. In addition, the carding properties of the fibers to which the treatment agent is applied can be improved. This improves the manufacturing characteristics and quality of the nonwoven fabric obtained by needle punching.

[0075] (Modifications) The above embodiment can be modified as follows: The above embodiment and the following modifications can be combined with each other within the scope of technical compatibility.

[0076] The manufacturing method of the nonwoven fabric of the above embodiment is not particularly limited, and a manufacturing method of a nonwoven fabric using a carding machine other than the above may be adopted when a reduction in friction is required. The above-mentioned treatment agent or composition may contain components commonly used in treatment agents, such as stabilizers for maintaining the quality of the treatment agent or composition, antistatic agents, smoothing agents, surfactants other than those mentioned above, antistatic agents, antistatic aids such as polyhydric alcohols, binders, antioxidants, UV absorbers, and defoamers, within the range that does not impair the effects of the present invention. Note that, from the viewpoint of efficiently exerting the efficacy of the present invention, the other components commonly used in treatment agents other than the solvent are preferably 40% by mass or less, and more preferably 20% by mass or less, of each treatment agent.

[0077] Examples will be given below to more specifically explain the configuration and effects of the present invention, but the present invention is not limited to these examples. In the following explanation of the examples and comparative examples, unless otherwise specified, parts mean parts by mass and % means % by mass.

[0078] Test Section 1 (Preparation of Treatment Agent) (Example 1) As shown in Table 1, 5 parts (%) of sodium gluconate (A-1) as component (A), 10 parts (%) of 1-ethyl-2-(heptadecenyl)-4,5-dihydro-3-(2-hydroxyethyl)-1H-imidazolinium ethyl sulfate (B-1) as component (B), 77 parts (%) of a compound (C-1) in which 10 moles of ethylene oxide were added to 1 mole of oleic acid as component (C), 5 parts (%) of a compound (C-3) in which 7 moles of ethylene oxide were added to 1 mole of lauryl alcohol as component (C), and 3 parts (%) of ethylene glycol (D-1) as component (D) were weighed and added to a container. 20°C water was added to the container and stirred to mix uniformly, making a total of 500 parts, to prepare a 20% aqueous solution (treatment-containing composition) of the treatment agent of Example 1.

[0079] (Examples 2 to 47, Comparative Examples 1 to 8) The treatment agents of Examples 2 to 47 and Comparative Examples 1 to 8 were prepared in the same manner as the treatment agent-containing composition of Example 1, so as to contain component (A), component (B), component (C), and other component (D) in the proportions shown in Tables 1 and 2.

[0080] The type and content of component (A), the type and content of component (B), the type and content of component (C), and the type and content of other component (D) are shown in the “Component (A)” column, the “Component (B)” column, the “Component (C)” column, and the “Other component (D)” column in Tables 1 and 2, respectively.

[0081]

[0082]

[0083] Details of the components (A), (B), (C), and other components (D) shown in Tables 1 and 2 are as follows. <Component (A): Hydroxy acid or alkali metal salt thereof> A-1: ​​Sodium gluconate A-2: Potassium gluconate A-3: Gluconic acid A-4: Sodium citrate A-5: Citric acid A-6: Potassium lactate A-7: Lactic acid a-1: Zinc gluconate a-2: Chlorhexidine gluconate <Component (B): Quaternary ammonium compound (B1) or imidazoline compound (B2)> (Imidazolinium-type quaternary ammonium (B1a)) B-1: Ethyl sulfate of 1-ethyl-2-(heptadecenyl)-4,5-dihydro-3-(2-hydroxyethyl)-1H-imidazolinium B-2: Methyl sulfate of 1-methyl-2-(heptadecenyl)-4,5-dihydro-3-(2-hydroxyethyl)-1H-imidazolinium B-3: Ethyl sulfate of 1-ethyl-2-(heptadecyl)-4,5-dihydro-3-(2-hydroxyethyl)-1H-imidazolinium (Polyoxyalkylene aliphatic amine type quaternary ammonium (B1d)) B-4: Methyl sulfate of ethylene oxide 3 mole adduct of N-stearyl-N,N-bis(2-hydroxyethyl)-N-methylammonium B-5: Ethyl sulfate of ethylene oxide 3 mole / propylene oxide 3 mole adduct of N-oleyl-N,N-bis(2-hydroxyethyl)-N-ethylammonium (Mono long chain skeleton type quaternary ammonium (B1b)) B-6: Methyl sulfate of N-stearyl-N,N-bis(2-hydroxyethyl)-N-methylammonium B-7: N-oleyl-N,N-bis(2-hydroxyethyl)-N-methylammonium chloride B-8: Ethyl sulfate of N-ethyl-N,N-dimethyl-3-(stearoylamino)propane ammonium B-9: N-ethyl-N,ethyl sulfate of N-dimethyl-3-(lauroylamino)propanammonium, B-10: tallow alkyltrimethylammonium chloride (dilong chain skeleton type quaternary ammonium (B1c)), B-11: dioctadecyldimethylammonium chloride (imidazoline compound (B2)), B-12: 1-(2-hydroxyethyl)-2-oleyl imidazoline, B-13: 1-(2-hydroxyethyl)-2-stearyl imidazoline <Component (C): Polyoxyalkylene type nonionic surfactant> C-1: a compound in which 10 moles of ethylene oxide are added to 1 mole of oleic acid, C-2: a compound in which 6 moles of ethylene oxide and 2 moles of propylene oxide are randomly added to 1 mole of branched alkyl alcohol having 12 and 13 carbon atoms, C-3: a compound in which 7 moles of ethylene oxide are added to 1 mole of lauryl alcohol, C-4: a compound in which 40 moles of ethylene oxide are added to 1 mole of stearic acid. C-5: A compound obtained by adding 10 moles of ethylene oxide to 1 mole of lauric acid. C-6: A compound obtained by block-adding 3 moles of ethylene oxide and 4 moles of propylene oxide to 1 mole of branched alkyl alcohol having 8 to 10 carbon atoms. C-7: A compound obtained by block-adding 4 moles of propylene oxide and 3 moles of ethylene oxide to 1 mole of myristic acid. C-8: A compound obtained by block-adding 3 moles of propylene oxide and 12 moles of ethylene oxide to 1 mole of 2-ethylhexanol. C-9: A compound obtained by adding 8 moles of ethylene oxide to 1 mole of 12-hydroxystearic acid. C-10: A compound obtained by adding 20 moles of ethylene oxide to 1 mole of oleyl alcohol. C-11: 1,C-12: A compound obtained by adding 15 moles of ethylene oxide to 1 mole of 10-decanediol. C-13: A compound obtained by adding 4 moles of ethylene oxide to 1 mole of 2-ethylhexanoic acid. C-14: A compound obtained by adding 10 moles of ethylene oxide to 1 mole of erucic acid. C-15: A compound obtained by adding 25 moles of ethylene oxide to 1 mole of 1-docosanol. C-16: A compound obtained by adding 10 moles of ethylene oxide to 1 mole of glycerin. C-17: A compound obtained by randomly adding 30 moles of ethylene oxide and 30 moles of propylene oxide to 1 mole of propylene glycol. C-18: A compound obtained by block-adding 30 moles of propylene oxide and 30 moles of ethylene oxide to 1 mole of propylene glycol. C-19: A compound obtained by block-adding 10 moles of ethylene oxide and 45 moles of propylene oxide to 1 mole of oleic acid. C-20: A compound in which 2 moles of ethylene oxide are added to 1 mole of 2-ethylhexanol <Other Components (D)> D-1: Ethylene glycol D-2: Propylene glycol D-3: Dimethyl silicone (10 cst, 30°C) D-4: Polyethylene glycol (mass average molecular weight 400) D-5: 1,3-propanediol D-6: Glucose D-7: Coconut oil fatty acid amidopropyl betaine D-8: Octyl phosphate potassium salt D-9: Dioctyl sulfosuccinate sodium salt D-10: A compound in which 20 moles of ethylene oxide are added to 1 mole of sorbitan trioleate D-11: A compound in which 20 moles of ethylene oxide are added to 1 mole of hydrogenated castor oil Test Section 2 (Production of Synthetic Fibers and Nonwoven Fabrics) Synthetic fibers and nonwoven fabrics were produced using the treatment-containing compositions prepared in Test Section 1.

[0084] Polyethylene terephthalate fibers were used as synthetic fibers. These synthetic fibers were short fibers (staple) with a fineness of 6.6 dtex and a length of 64 mm. A 20% aqueous solution of the prepared treatment agent was further diluted with distilled water to a 0.3% diluted solution, and sprayed onto 100 g of the synthetic fibers. The solids content (excluding solvent) relative to the staple was 0.3%. The synthetic fibers with the treatment agent applied were dried in a hot air dryer at 80°C for 1 hour to prepare short fiber samples. The emulsion stability was evaluated using each treatment agent-containing composition obtained as described above. Furthermore, antistatic properties, card passability, and fiber / metal friction were evaluated using the short fiber samples with the treatment agent applied. Furthermore, hard water stability was evaluated using each treatment agent obtained by uniformly mixing the components.

[0085] The amount of treatment agent attached to the treated nonwoven fabric was calculated by extracting the treated nonwoven fabric with methanol using a rapid extractor. Test Section 3 (Evaluation of Antistatic Properties) 20 g of the above-mentioned short fiber sample was passed through a miniature roller carding machine at a temperature of 25°C and a humidity of 40% to form a web, and the static voltage generated on the web at the exit of the carding machine was measured to evaluate the antistatic properties according to the following criteria. The results are shown in the "Antistatic Properties" column in Tables 1 and 2.

[0086] Evaluation criteria for antistatic properties ⊚ (good): static electricity generated is less than 300V ○ (passable): static electricity generated is 300V or more and less than 1kV × (poor): static electricity generated is 1kV or more Test section 4 (evaluation of carding ability) 20g of the above short fiber sample was conditioned for 24 hours under conditions of a temperature of 25°C and a humidity of 65%. Thereafter, it was passed through a miniature roller carding machine, and the ratio of the amount discharged from the carding machine to the amount input was calculated and evaluated according to the following evaluation criteria. The results are shown in the "carding ability" column of Tables 1 and 2.

[0087] Evaluation criteria for card passability: ◎ (Good): When the discharge amount is 80% or more ○ (Fair): When the discharge amount is 60% or more but less than 80% × (Poor): When the discharge amount is less than 60% Test Category 5 (Stability Evaluation) The 20% aqueous solution of the treatment agent prepared in each example was further diluted with distilled water to prepare a 5% diluted solution. Each diluted solution was kept at a constant temperature of 20°C and 60% RH for 24 hours, after which the appearance of the diluted solution was evaluated according to the following criteria. The results are shown in the "5% emulsion stability" column in Tables 1 and 2.

[0088] Stability Evaluation Criteria ⊚ (Good): No precipitate or separation observed in the diluted solution ◯ (Fair): Very slight precipitate or separation observed in the diluted solution × (Poor): Precipitation or separation observed in the diluted solution Test Category 6 (Hard Water Stability Evaluation) 300 mg of calcium carbonate was dissolved in 1 L of pure water to prepare hard water with a hardness of 300. Each treatment agent was added to this to prepare a hard water dilution with a nonvolatile content of 1%. Dilutions of the same concentration were also prepared using ion-exchanged water. After preparation, the dilutions were left to stand for 6 hours at a temperature of 25°C and a humidity of 65%, and then the appearance of the dilutions was checked for any difference between the hard water and the ion-exchanged water, and each was evaluated according to the following criteria. The results are shown in the "Hard Water Stability" column in Tables 1 and 2.

[0089] - Evaluation criteria for hard water stability ◎ (Good): When there is no difference in appearance between the sample prepared with hard water and the sample prepared with ion-exchanged water ○ (Fair): When there is a slight difference in appearance between the sample prepared with hard water and the sample prepared with ion-exchanged water, but when no precipitate is observed in the sample prepared with hard water × (Poor): When precipitate is observed in the sample prepared with hard water Test category 7 (Evaluation of fiber / metal friction (F / M friction)) The friction characteristics between fiber and metal during the needle punching process were evaluated by the following method.

[0090] Preparation of needle-punched nonwoven fabric for F / M friction evaluation Polyethylene terephthalate short fibers prepared for evaluation of antistatic properties and carding properties were carded to a thickness of 150 g / m ２ After forming a web of 45 times / cm ２ The nonwoven fabric for testing was prepared by needle punching.

[0091] F / M Friction Evaluation: A rectangular plate-shaped weight measuring 30 mm long, 90 mm wide, and 45 mm high, weighing 1 kg, was prepared. A needle-punched nonwoven fabric of the same size as the bottom of the weight was attached using double-sided tape. A matte-finished SUS304 stainless steel plate was prepared, and the weight was placed on it with the bottom side, where the nonwoven fabric was attached, facing downwards. A tensile test was conducted using a tensile tester (Shimadzu Corporation, Autograph Model AGS-X) equipped with a load cell with a maximum load capacity of 50 N, at a horizontal speed of 100 mm / min, under an atmosphere of 20°C and 60% RH. The M / N ratio was calculated as the ratio of the friction force N measured using fibers treated with the treatment agent of Comparative Example 1, which does not contain component (B), to the friction force M measured using fibers treated with the treatment agents of each Example. A higher value indicates poorer passability in the needle-punching process. F / M friction was evaluated according to the following criteria. The results are shown in the "F / M friction" column of Tables 1 and 2.

[0092] Evaluation criteria for F / M friction: ⊚ (Good): When the M / N ratio is 0.98 or less; ∘ (Fair): When the M / N ratio is greater than 0.98 and less than 0.99; × (Poor): When the M / N ratio is greater than 0.99. As is clear from the evaluation results of each example compared to the comparative examples in Tables 1 and 2, the treatment agent of the present invention can improve emulsion stability and hard water stability. Furthermore, synthetic fibers to which the treatment agent is applied can improve antistatic properties and card passability. Furthermore, synthetic fibers to which the treatment agent is applied can reduce F / M friction.

[0093] The present disclosure also includes the following aspects: (Appendix 1) A treatment agent for short fibers, characterized by containing the following component (A), the following component (B), and the following component (C).

[0094] Component (A): at least one selected from hydroxy acids and alkali metal salts of hydroxy acids. Component (B): at least one selected from quaternary ammonium compounds (B1) and imidazoline compounds (B2).

[0095] Component (C): At least one selected from a compound obtained by adding at least one selected from ethylene oxide and propylene oxide to a mono- or di-valent fatty acid having from 8 to 22 carbon atoms, and a compound obtained by adding at least one selected from ethylene oxide and propylene oxide to a mono- or tri-valent aliphatic alcohol having from 3 to 22 carbon atoms.

[0096] (Appendix 2) The short fiber treating agent according to Appendix 1, wherein the component (A) is at least one selected from gluconic acid and alkali metal salts of gluconic acid.

[0097] (Appendix 3) The treatment agent for short fibers according to Appendix 1, wherein the component (B) is the quaternary ammonium compound (B1), and the quaternary ammonium compound (B1) contains at least one selected from the following imidazolinium-type quaternary ammonium (B1a), the following mono-long chain skeleton-type quaternary ammonium (B1b), the following di-long chain skeleton-type quaternary ammonium (B1c), and the following polyoxyalkylene aliphatic amine-type quaternary ammonium (B1d).

[0098] Imidazolinium-type quaternary ammonium (B1a): at least one selected from compounds obtained by quaternizing the imidazoline compound (B2) and salts thereof. Mono-long chain skeleton-type quaternary ammonium (B1b): at least one selected from quaternary ammonium having one aliphatic carbon skeleton having from 12 to 22 carbon atoms in the molecule and salts thereof.

[0099] Dilong-chain skeleton type quaternary ammonium (B1c): At least one selected from quaternary ammonium having two aliphatic carbon skeletons with 12 to 22 carbon atoms in the molecule, and salts thereof.

[0100] Polyoxyalkylene aliphatic amine-type quaternary ammonium (B1d): At least one selected from quaternary ammonium having one aliphatic carbon skeleton having 12 to 22 carbon atoms in the molecule and two polyoxyalkylene skeletons having oxyalkylene as structural units, and salts thereof.

[0101] (Appendix 4) The short fiber treatment agent according to Appendix 1, wherein the component (C) is at least one selected from the group consisting of a compound in which a total of 3 to 50 moles of at least one selected from ethylene oxide and propylene oxide are added to 1 mole of a mono- or di-valent fatty acid having from 12 to 20 carbon atoms, and a compound in which a total of 3 to 50 moles of at least one selected from ethylene oxide and propylene oxide are added to 1 mole of a mono- to tri-valent aliphatic alcohol having from 8 to 18 carbon atoms.

[0102] (Appendix 5) The treatment agent for short fibers according to Appendix 1, containing the component (A) in an amount of 1% by mass or more and 20% by mass or less, the component (B) in an amount of 1% by mass or more and 60% by mass or less, and the component (C) in an amount of 30% by mass or more and 90% by mass or less, where the total content of the component (A), the component (B), and the component (C) is 100% by mass.

[0103] (Appendix 6) A method for producing a nonwoven fabric, comprising the following steps 1 to 3: Step 1: A step of adhering the staple fiber treating agent according to any one of Appendices 1 to 5 to synthetic fibers.

[0104] Step 2: A step of obtaining a web by passing the synthetic fibers to which the staple fiber treatment agent has been applied in Step 1 through a carding machine. Step 3: A step of needle-punching the web obtained in Step 2 to obtain a nonwoven fabric.

[0105] (Appendix 7) The method for producing a nonwoven fabric according to Appendix 6, wherein the synthetic fiber is a polyester-based synthetic fiber.

Claims

1. A treatment agent for short fibers, comprising the following components (A), (B), and (C): Component (A): at least one selected from hydroxy acids and alkali metal salts of hydroxy acids; Component (B): at least one selected from the following quaternary ammonium compounds (B1) and imidazoline compounds (B2); Component (C): at least one selected from compounds obtained by adding at least one selected from ethylene oxide and propylene oxide to a mono- or divalent fatty acid having from 8 to 22 carbon atoms, and compounds obtained by adding at least one selected from ethylene oxide and propylene oxide to a mono- or divalent aliphatic alcohol having from 3 to 22 carbon atoms. Quaternary ammonium compound (B1): at least one selected from the following imidazolinium-type quaternary ammonium (B1a), the following mono-long chain skeleton-type quaternary ammonium (B1b), the following di-long chain skeleton-type quaternary ammonium (B1c), and the following polyoxyalkylene aliphatic amine-type quaternary ammonium (B1d). Imidazolinium-type quaternary ammonium (B1a): at least one selected from a compound obtained by quaternizing an imidazoline compound, and a salt thereof. Mono-long chain skeleton-type quaternary ammonium (B1b): at least one selected from a quaternary ammonium having one aliphatic carbon skeleton with 12 to 22 carbon atoms in the molecule, and a salt thereof. Di-long chain skeleton-type quaternary ammonium (B1c): at least one selected from a quaternary ammonium having two aliphatic carbon skeletons with 12 to 22 carbon atoms in the molecule, and a salt thereof. Polyoxyalkylene aliphatic amine type quaternary ammonium (B1d): at least one selected from quaternary ammonium having one aliphatic carbon skeleton having 12 to 22 carbon atoms in the molecule and two polyoxyalkylene skeletons having oxyalkylene as a structural unit, and salts thereof. Imidazoline compound (B2): at least one selected from imidazolines having an alkenyl group having 1 to 24 carbon atoms, and imidazolines having an alkyl group having 1 to 24 carbon atoms.

2. The agent for treating short fibers according to claim 1, wherein said component (A) is at least one selected from the group consisting of gluconic acid and alkali metal salts of gluconic acid.

3. The treatment agent for short fibers according to claim 1, wherein component (C) is at least one selected from the group consisting of a compound in which a total of 3 to 50 moles of at least one selected from ethylene oxide and propylene oxide are added to 1 mole of a mono- or divalent fatty acid having 12 to 20 carbon atoms, and a compound in which a total of 3 to 50 moles of at least one selected from ethylene oxide and propylene oxide are added to 1 mole of a mono- or divalent aliphatic alcohol having 8 to 18 carbon atoms.

4. The short fiber treatment agent according to claim 1, wherein the component (A) is contained in an amount of 1% by mass or more and 20% by mass or less, the component (B) is contained in an amount of 1% by mass or more and 60% by mass or less, and the component (C) is contained in an amount of 30% by mass or more and 90% by mass or less, assuming that the total content of the components (A), (B), and (C) is 100% by mass.

5. A method for producing a nonwoven fabric, comprising the steps of: Step 1: applying the short fiber treatment agent according to any one of claims 1 to 4 to synthetic fibers; Step 2: passing the synthetic fibers to which the short fiber treatment agent has been applied in step 1 through a carding machine to obtain a web; Step 3: needle-punching the web obtained in step 2 to obtain a nonwoven fabric.

6. The method for producing a nonwoven fabric according to claim 5, wherein the synthetic fibers are polyester-based synthetic fibers.

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