Treatment agent for synthetic fibers, aqueous liquid of treatment agent for synthetic fibers, synthetic fibers, and method for producing nonwoven fabric

Abstract

Provided are a treating agent for synthetic fibers, an aqueous solution of the treating agent for synthetic fibers, synthetic fibers, and a method for producing a nonwoven fabric, which can improve the functions of durable hydrophilicity, processability, and wetting prevention for fibers to which the treating agent for synthetic fibers is applied. **Solution**: The treating agent for synthetic fibers of the present invention is characterized by containing the following sulfate (A), the following organic phosphate ester (B), and polyhydric alcohol fatty acid ester (C). The sulfate (A) is at least one selected from polyhydric alcohol fatty acid ester sulfates and salts thereof. The organic phosphate ester (B) is at least one selected from organic phosphate esters having a linear hydrocarbon group with 8 to 24 carbon atoms and salts thereof.

Description

Technical Field

[0001] The present invention relates to a treating agent for synthetic fibers, an aqueous solution of the treating agent for synthetic fibers, synthetic fibers to which the treating agent for synthetic fibers is attached, and a method for producing a nonwoven fabric using the synthetic fibers.

Background Art

[0002] For example, synthetic fibers are used as raw material fibers for nonwoven fabrics. For nonwoven fabrics, for example, after producing staples which are short fibers of synthetic fibers, the staples are passed through a carding machine to produce a web. Further, by applying a treating agent for synthetic fibers to the synthetic fibers, functions such as hydrophilicity are imparted. Nonwoven fabrics made from synthetic fibers to which functions such as hydrophilicity are imparted are utilized in a wide range of fields such as the sanitary material field, the medical field, and the civil engineering field.

[0003] For example, conventionally, treating agents for synthetic fibers disclosed in Patent Documents 1 to 3 are known. Patent Document 1 discloses a water permeability-imparting agent containing a polyhydric alcohol fatty acid ester sulfate salt and a compound organic phosphate ester compound or an organic sulfonic acid compound having a hydrocarbon group having 6 to 10 carbon atoms. Patent Document 2 discloses a water permeability-imparting agent containing an alkyl sulfate having an alkyl group having 8 to 22 carbon atoms, an alkyl phosphate salt having an alkyl group having 4 to 18 carbon atoms, and the like. Patent Document 3 discloses a fiber treating agent for nonwoven fabrics containing an alkyl phosphate ester salt and a predetermined polyhydric alcohol fatty acid ester and the like.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Patent Document 2

Patent Document 3

Summary of the Invention

Problems to be Solved by the Invention

[0005] By the way, for the treating agent for synthetic fibers, improvement in each function of durable hydrophilicity, process passing property, and prevention of wetting back has been demanded for the fibers to which the treating agent for synthetic fibers is applied.

Means for Solving the Problems

[0006] As a result of research to solve the above problems, the inventors have found that a treating agent for synthetic fibers containing a specific sulfate, an organic phosphate ester, and a polyhydric alcohol fatty acid ester is exactly suitable.

[0007] Each aspect for solving the above problems will be described. The treating agent for synthetic fibers according to Aspect 1 contains the following sulfate (A), the following organic phosphate ester (B), and a polyhydric alcohol fatty acid ester (C) (Excluding esters in which at least one hydroxyl group of a condensate of a polyoxyalkylene group-containing hydroxy fatty acid polyhydric alcohol ester and a dicarboxylic acid is blocked with a fatty acid) and is characterized by that.

[0008] Sulfate (A): At least one selected from polyhydric alcohol fatty acid ester sulfates and salts thereof. Organic phosphate ester (B): At least one selected from organic phosphate esters having a linear hydrocarbon group having 8 to 24 carbon atoms and salts thereof.

[0009] Aspect 2 is the treating agent for synthetic fibers according to Aspect 1, wherein the hydrocarbon group of the organic phosphate ester (B) has 12 to 18 carbon atoms. Aspect 3 is the treating agent for synthetic fibers according to Aspect 1 or 2, wherein the polyhydric alcohol fatty acid ester (C) is a triglyceride.

[0010] Aspect 4 is a treatment agent for synthetic fibers according to any one of Aspects 1 to 3. When the total content ratio of the sulfate (A), the organic phosphate ester (B), and the polyhydric alcohol fatty acid ester (C) is 100% by mass, the sulfate (A) is 5% by mass or more and 70% by mass or less, the organic phosphate ester (B) is 10% by mass or more and 75% by mass or less, and the polyhydric alcohol fatty acid ester (C) is contained in a ratio of 10% by mass or more and 85% by mass or less.

[0011] Aspect 5 is a treatment agent for synthetic fibers according to any one of Aspects 1 to 4, further containing the following organic phosphate ester (D). Organic phosphate ester (D): at least one selected from organic phosphate esters having a branched hydrocarbon group having 6 to 10 carbon atoms and salts thereof.

[0012] Aspect 6 is a treatment agent for synthetic fibers according to Aspect 5. When the total content ratio of the sulfate (A), the organic phosphate ester (B), the polyhydric alcohol fatty acid ester (C), and the organic phosphate ester (D) is 100% by mass, the sulfate (A) is 10% by mass or more and 60% by mass or less, the organic phosphate ester (B) is 10% by mass or more and 60% by mass or less, the polyhydric alcohol fatty acid ester (C) is 10% by mass or more and 70% by mass or less, and the organic phosphate ester (D) is contained in a ratio of 10% by mass or more and 30% by mass or less.

[0013] The aqueous solution of the treatment agent for synthetic fibers of Aspect 7 is characterized by containing the treatment agent for synthetic fibers according to any one of Aspects 1 to 6 in a ratio of 0.1% by mass or more and 10% by mass or less. The synthetic fiber of Aspect 8 is characterized in that the treatment agent for synthetic fibers according to any one of Aspects 1 to 6 is adhered thereto.

[0014] Aspect 9 is the synthetic fiber according to Aspect 8, wherein the synthetic fiber is an olefin-based synthetic fiber. The method for manufacturing a non-woven fabric of Aspect 10 is characterized by subjecting the synthetic fiber according to Aspect 8 or 9 to a heat fusion treatment to obtain a non-woven fabric.

Advantages of the Invention

[0015] According to the present invention, for fibers to which a treating agent for synthetic fibers is applied, it is possible to improve each function of durable hydrophilicity, process passability, and wetting prevention.

Embodiments for Carrying Out the Invention

[0016] <First Embodiment> Hereinafter, a first embodiment in which a treating agent for synthetic fibers (hereinafter, also simply referred to as a treating agent) of the present invention is embodied will be described. The treating agent of this embodiment contains the following sulfate (A), organic phosphate ester (B), and polyhydric alcohol fatty acid ester (C) (Excluding esters in which at least one hydroxyl group of a condensate of a polyoxyalkylene group-containing hydroxy fatty acid polyhydric alcohol ester and a dicarboxylic acid is blocked with a fatty acid) and contains. The treating agent may further contain the following organic phosphate ester (D).

[0017] (Sulfate (A)) The sulfate (A) provided in this embodiment is at least one selected from polyhydric alcohol fatty acid ester sulfates and salts thereof. By the treating agent containing the sulfate (A), the durable hydrophilicity of the fibers to which the treating agent is applied can be improved.

[0018] Specific examples of the polyhydric alcohol that is a raw material for the sulfate (A) include, for example, ethylene glycol, diethylene glycol, polyethylene glycol, propylene glycol, dipropylene glycol, polypropylene glycol, 1,3 - propanediol, 1,2 - butanediol, 1,3 - butanediol, 1,4 - butanediol, 2 - methyl - 1,2 - propanediol, 1,5 - pentanediol, 1,6 - hexanediol, 2,5 - hexanediol, 2 - methyl - 2,4 - pentanediol, 2,3 - dimethyl - 2,3 - butanediol, glycerin, diglycerin, triglycerin, polyglycerin, 2 - methyl - 2 - hydroxymethyl - 1,3 - propanediol, trimethylolpropane, sorbitan, pentaerythritol, sorbitol, and the like.

[0019] As the fatty acid that is a raw material for the sulfate (A), it may be a saturated fatty acid or an unsaturated fatty acid. Also, it may be linear or have a branched-chain structure. Further, it may be a monovalent fatty acid or a polyvalent carboxylic acid (polybasic acid).

[0020] Specific examples of saturated fatty acids include, for example, formic acid, acetic acid, propionic acid, butyric acid, valeric acid, hexanoic acid (caproic acid), octylic acid (2-ethylhexanoic acid), octanoic acid (caprylic acid), nonanoic acid, decanoic acid (capric acid), dodecanoic acid (lauric acid), tetradecanoic acid (myristic acid), hexadecanoic acid (palmitic acid), octadecanoic acid (stearic acid), eicosanoic acid (arachidic acid), docosanoic acid (behenic acid), tetracosanoic acid, and the like.

[0021] Specific examples of unsaturated fatty acids include, for example, crotonic acid, myristoleic acid, palmitoleic acid, oleic acid, vaccenic acid, eicosenoic acid, linoleic acid, α-linolenic acid, γ-linolenic acid, arachidonic acid, and the like.

[0022] Specific examples of polyvalent carboxylic acids (polybasic acids) include, for example, (1) dibasic acids such as succinic acid, fumaric acid, maleic acid, adipic acid, and sebacic acid, (2) tribasic acids such as aconitic acid, (3) aromatic dicarboxylic acids such as terephthalic acid, isophthalic acid, and 2,6-naphthalenedicarboxylic acid, (4) aromatic tricarboxylic acids such as trimellitic acid, (5) aromatic tetracarboxylic acids such as pyromellitic acid, and the like.

[0023] As the sulfate (A), a sulfate ester of animal or vegetable oil or a salt thereof may be used. Specific examples of animal or vegetable oils include, for example, castor oil, sesame oil, tall oil, soybean oil, sunflower oil, rapeseed oil, palm oil, beef tallow, whale oil, fish oil, and the like.

[0024] Examples of salts of polyhydric alcohol fatty acid ester sulfates include amine salts, metal salts, ammonium salts, and the like. Examples of the metal salt include alkali metal salts and alkaline earth metal salts. Specific examples of the alkali metal constituting the alkali metal salt include, for example, sodium, potassium, lithium, and the like. Examples of the alkaline earth metal constituting the alkaline earth metal salt include metals corresponding to Group 2 elements, such as calcium, magnesium, beryllium, strontium, barium, and the like.

[0025] The amine constituting the amine salt may be any of primary amines, secondary amines, and tertiary amines. Specific examples of the amine constituting the amine salt include, for example, (1) aliphatic amines such as methylamine, dimethylamine, trimethylamine, ethylamine, diethylamine, triethylamine, N-N-diisopropylethylamine, butylamine, dibutylamine, 2-methylbutylamine, tributylamine, octylamine, dimethyllaurylamine, etc., (2) aromatic amines or heterocyclic amines such as aniline, N-methylbenzylamine, pyridine, morpholine, piperazine, and their derivatives, etc., (3) alkanolamines such as monoethanolamine, N-methylethanolamine, diethanolamine, triethanolamine, isopropanolamine, diisopropanolamine, triisopropanolamine, dibutylethanolamine, butyldiethanolamine, octyldiethanolamine, lauryldiethanolamine, etc., (4) arylamines such as N-methylbenzylamine, etc., (5) polyoxyalkylene alkylaminoethers such as polyoxyethylene laurylaminoether, polyoxyethylene stearylaminoether, etc., (6) ammonia, etc.

[0026] These sulfates (A) may be used alone or in appropriate combination of two or more. Specific examples of the sulfate (A) include, for example, sodium castor oil sulfate, sodium tallow sulfate, potassium rapeseed oil sulfate, potassium palm oil sulfate, sodium oleic acid triglyceride sulfate, and the like.

[0027] The lower limit of the content ratio of the sulfate (A) in the treatment agent is appropriately set, but is preferably 3% by mass or more, more preferably 5% by mass or more. When such a content ratio is 3% by mass or more, the durable hydrophilicity of the fiber to which the treatment agent is applied can be further improved. The upper limit of the content ratio of such sulfate (A) is appropriately set, but is preferably 80% by mass or less, more preferably 70% by mass or less. When such a content ratio is 80% by mass or less, the process passability of the fiber to which the treatment agent is applied can be further improved. In addition, a range in which the above upper and lower limits are arbitrarily combined is also assumed.

[0028] (Organic phosphate ester (B)) In the present embodiment, the organic phosphate ester (B) used is at least one selected from organic phosphate esters having a linear hydrocarbon group having 8 to 24 carbon atoms and salts thereof. By the treatment agent containing the organic phosphate ester (B), the process passability of the fiber to which the treatment agent is applied can be improved.

[0029] Examples of the organic phosphate ester (B) include alkyl phosphate esters, alkenyl phosphate esters, alkyl phosphate esters or alkenyl phosphate esters to which a (poly)alkylene oxide chain is added, and salts thereof. Further, the organic phosphate ester (B) may be a monoester form, a diester form, or a triester form.

[0030] Specific examples of the alkyl group include, for example, octyl group, nonyl group, decyl group, undecyl group, dodecyl group, tridecyl group, tetradecyl group, pentadecyl group, hexadecyl group, heptadecyl group, octadecyl group, icosyl group, docosyl group and the like.

[0031] Specific examples of the alkenyl group include, for example, octenyl group, nonenyl group, decenyl group, undecenyl group, dodecenyl group, tridecenyl group, tetradecenyl group, pentadecenyl group, hexadecenyl group, heptadecenyl group, octadecenyl group, icosenyl group, docosenyl group and the like.

[0032] The number of carbon atoms in the hydrocarbon group is preferably 12 or more and 18 or less. By defining it within such a range, the process passability of the fiber to which the treatment agent is applied can be further improved. As the alkylene oxide used as a raw material for forming the (poly)oxyalkylene structure, an alkylene oxide having 2 or more and 4 or less carbon atoms is preferable. Specific examples of the alkylene oxide include, for example, ethylene oxide, propylene oxide, butylene oxide, and the like. The added molar number of the alkylene oxide is appropriately set, but is preferably 0.1 mol or more and 60 mol or less, more preferably 1 mol or more and 40 mol or less, and still more preferably 2 mol or more and 30 mol or less. Ranges arbitrarily combining the above upper and lower limits are also assumed. The added molar number of the alkylene oxide indicates the molar number of the alkylene oxide with respect to 1 mol of the compound to be added in the charged raw materials. The alkylene oxide may be used alone as one kind of alkylene oxide, or may be used by appropriately combining two or more kinds of alkylene oxides. When two or more kinds of alkylene oxides are applied, their addition forms may be any of block addition, random addition, and a combination of block addition and random addition, and there is no particular limitation.

[0033] The phosphoric acid constituting the organic phosphate ester (B) is not particularly limited, and may be orthophosphoric acid or a polyphosphoric acid such as diphosphoric acid. When an organic phosphate ester salt is applied as the organic phosphate ester (B), examples of the salt include a phosphate ester amine salt, a phosphate ester metal salt, and the like. Specific examples of the metal salt and the amine salt are those exemplified in the sulfate (A) column.

[0034] These organic phosphate esters (B) may be used alone as one kind, or may be used by appropriately combining two or more kinds. Specific examples of the organic phosphate ester (B) include, for example, lauryl phosphate ester or its salt, stearyl phosphate ester or its salt, polyoxyethylene lauryl phosphate ester or its salt, decyl phosphate ester or its salt, behenyl phosphate ester or its salt, polyoxyethylene octyl phosphate ester or its salt, octyl phosphate ester or its salt, and the like.

[0035] The lower limit of the content ratio of the organic phosphate ester (B) in the treatment agent is appropriately set, but is preferably 2% by mass or more, more preferably 5% by mass or more, and still more preferably 10% by mass or more. When such a content ratio is 2% by mass or more, the process passability of the fiber to which the treatment agent is applied can be further improved. The upper limit of the content ratio of such an organic phosphate ester (B) is appropriately set, but is preferably 75% by mass or less, more preferably 60% by mass or less. When such a content ratio is 75% by mass or less, the effects of the present invention can be further improved. In addition, the ranges obtained by arbitrarily combining the above upper and lower limits are also assumed.

[0036] Note that the content of the organic phosphate ester (B) in the treatment agent indicates the total content including not only the organic phosphate ester compound but also inorganic phosphate or its salt which is a reaction residue in the synthesis of the organic phosphate ester (B) (hereinafter the same).

[0037] (Polyhydric alcohol fatty acid ester (C)) When the treatment agent contains the polyhydric alcohol fatty acid ester (C), the wet regain prevention property of the fiber to which the treatment agent is applied can be improved.

[0038] Specific examples of the polyhydric alcohol that serves as a raw material for the polyhydric alcohol fatty acid ester (C) include, for example, ethylene glycol, diethylene glycol, polyethylene glycol, propylene glycol, dipropylene glycol, polypropylene glycol, 1,3-propanediol, 1,2-butanediol, 1,3-butanediol, 1,4-butanediol, 2-methyl-1,2-propanediol, 1,5-pentanediol, 1,6-hexanediol, 2,5-hexanediol, 2-methyl-2,4-pentanediol, 2,3-dimethyl-2,3-butanediol, glycerin, diglycerin, triglycerin, polyglycerin, 2-methyl-2-hydroxymethyl-1,3-propanediol, trimethylolpropane, sorbitan, pentaerythritol, sorbitol, and the like.

[0039] The fatty acid that serves as a raw material for the polyhydric alcohol fatty acid ester (C) may be a saturated fatty acid or an unsaturated fatty acid. Further, it may be linear or may have a branched-chain structure. Further, it may be a monovalent fatty acid or a polyvalent carboxylic acid (polybasic acid).

[0040] Specific examples of the saturated fatty acid include, for example, formic acid, acetic acid, propionic acid, butyric acid, valeric acid, hexanoic acid (caproic acid), octylic acid (2-ethylhexanoic acid), octanoic acid (caprylic acid), nonanoic acid, decanoic acid (capric acid), dodecanoic acid (lauric acid), tetradecanoic acid (myristic acid), hexadecanoic acid (palmitic acid), octadecanoic acid (stearic acid), eicosanoic acid (arachidic acid), docosanoic acid (behenic acid), tetracosanoic acid, and the like.

[0041] Specific examples of the unsaturated fatty acid include, for example, crotonic acid, myristoleic acid, palmitoleic acid, oleic acid, vaccenic acid, eicosenoic acid, linoleic acid, α-linolenic acid, γ-linolenic acid, arachidonic acid, and the like.

[0042] Specific examples of the polyvalent carboxylic acid (polybasic acid) include, for example, (1) dibasic acids such as succinic acid, fumaric acid, maleic acid, adipic acid, and sebacic acid, (2) tribasic acids such as aconitic acid, (3) aromatic dicarboxylic acids such as terephthalic acid, isophthalic acid, and 2,6-naphthalenedicarboxylic acid, (4) aromatic tricarboxylic acids such as trimellitic acid, and (5) aromatic tetracarboxylic acids such as pyromellitic acid, etc.

[0043] As the polyhydric alcohol fatty acid ester (C), animal and vegetable oils may be used. Specific examples of the animal and vegetable oils include, for example, castor oil, sesame oil, tall oil, soybean oil, sunflower oil, rapeseed oil, palm oil, beef tallow, whale oil, fish oil, etc.

[0044] These polyhydric alcohol fatty acid esters (C) may be used alone or in appropriate combination of two or more kinds. As the polyhydric alcohol fatty acid ester (C), triglyceride is preferable. By using triglyceride, the wet regain prevention property of the fiber to which the treatment agent is applied can be further improved.

[0045] Specific examples of the polyhydric alcohol fatty acid ester (C) include, for example, triglyceride oleate, triglyceride stearate, diglyceride oleate, diglyceride laurate, monoglyceride oleate, sorbitan monostearate, hexaglycerin sesquistearate, etc.

[0046] The lower limit of the content ratio of the polyhydric alcohol fatty acid ester (C) in the treatment agent is appropriately set, but is preferably 5% by mass or more, more preferably 10% by mass or more. When such a content ratio is 5% by mass or more, the water repellency prevention property of the fiber to which the treatment agent is applied can be further improved. The upper limit of the content ratio of such a polyhydric alcohol fatty acid ester (C) is appropriately set, but is preferably 85% by mass or less, more preferably 80% by mass or less. When such a content ratio is 85% by mass or less, the initial hydrophilicity of the fiber to which the treatment agent is applied can be further improved. In addition, a range arbitrarily combining the above upper and lower limits is also assumed.

[0047] When the total content ratio of the sulfate (A), the organic phosphate ester (B), and the polyhydric alcohol fatty acid ester (C) is 100% by mass, the sulfate (A) is 5% by mass or more and 70% by mass or less, the organic phosphate ester (B) is 10% by mass or more and 75% by mass or less, and the polyhydric alcohol fatty acid ester (C) is preferably contained in a ratio of 10% by mass or more and 85% by mass or less. By defining it within such a range, the effects of the present invention can be further improved. In addition, a range arbitrarily combining the above upper and lower limits is also assumed.

[0048] (Organic phosphate ester (D)) The organic phosphate ester (D) provided in the present embodiment is at least one selected from an organic phosphate ester having a branched hydrocarbon group having 6 to 10 carbon atoms and a salt thereof. When the treatment agent contains the organic phosphate ester (D), the initial hydrophilicity of the fiber to which the treatment agent is applied can be improved.

[0049] Examples of the organic phosphate ester (D) include alkyl phosphate esters, alkenyl phosphate esters, alkyl phosphate esters or alkenyl phosphate esters to which a (poly)alkylene oxide chain is added, and salts thereof. The organic phosphate ester (D) may be a monoester form, a diester form, or a triester form.

[0050] Specific examples of the alkyl group include, for example, isopentyl group, isohexyl group, isoheptyl group, isooctyl group, isononyl group, isodecyl group, and the like. Specific examples of the alkenyl group include, for example, isopentene group, isohexene group, isoheptene group, isooctene group, isononene group, isodecene group, and the like.

[0051] As the (poly)oxyalkylene structure, the same structure as that described for the organic phosphate ester (B) can be adopted. The phosphoric acid constituting the organic phosphate ester (D) is not particularly limited, and may be orthophosphoric acid or polyphosphoric acid such as diphosphoric acid.

[0052] When an organic phosphate ester salt is applied as the organic phosphate ester (D), examples of the salt include phosphate ester amine salts, phosphate ester metal salts, and the like. Specific examples of the metal salts and amine salts include those exemplified in the sulfate (A) column.

[0053] These organic phosphate esters (D) may be used alone or in appropriate combination of two or more. Specific examples of the organic phosphate ester (D) include, for example, 2-ethylhexyl phosphate ester or its salt, isodecyl phosphate ester or its salt, and the like.

[0054] The lower limit of the content ratio of the organic phosphate ester (D) in the treatment agent is appropriately set, but is preferably 5% by mass or more, more preferably 10% by mass or more. When such a content ratio is 5% by mass or more, the initial hydrophilicity of the fiber to which the treatment agent is applied can be further improved. The upper limit of the content ratio of such an organic phosphate ester (D) is appropriately set, but is preferably 35% by mass or less, more preferably 30% by mass or less. When such a content ratio is 35% by mass or less, the anti-wicking property of the fiber to which the treatment agent is applied can be further improved. In addition, a range in which the above upper and lower limits are arbitrarily combined is also assumed.

[0055] Note that the content of the organic phosphate ester (D) in the treatment agent indicates the total content including not only the organic phosphate ester compound but also inorganic phosphate or its salt which is a reaction residue when synthesizing the organic phosphate ester (D) (hereinafter the same).

[0056] When the total content ratio of the sulfate (A), the organic phosphate ester (B), the polyhydric alcohol fatty acid ester (C), and the organic phosphate ester (D) is 100% by mass, the sulfate (A) is 10% by mass or more and 60% by mass or less, the organic phosphate ester (B) is 10% by mass or more and 60% by mass or less, the polyhydric alcohol fatty acid ester (C) is 10% by mass or more and 70% by mass or less, and the organic phosphate ester (D) is preferably contained in a ratio of 10% by mass or more and 30% by mass or less. By defining it within such a range, the effects of the present invention can be further improved. In addition, ranges obtained by arbitrarily combining the above upper and lower limits are also assumed.

[0057] (Solvent) The treatment agent of the present embodiment may be mixed with a solvent as necessary to prepare an aqueous solution of the treatment agent. The aqueous solution of the treatment agent does not prevent the inclusion of solvents other than water. The solvent is a solvent having a boiling point of 105°C or lower at one atmosphere. Examples of the solvent include 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.

[0058] The content of the treatment agent in the aqueous solution of the treatment agent is preferably contained in a ratio of 0.1% by mass or more and 10% by mass or less. By defining it within such a range, the adhesion characteristics to synthetic fibers and the stability of the aqueous solution can be further improved.

[0059] (Effects of the present embodiment) The effects of the treatment agent of the first embodiment will be described. (1-1) In the treatment agent of the above-described first embodiment, it is configured to contain the above-described sulfate (A), organic phosphate ester (B), and polyhydric alcohol fatty acid ester (C). Therefore, it is possible to improve each function of the durable hydrophilicity, process passability, wet regain prevention property, and initial hydrophilicity of the fiber to which the treatment agent is applied.

[0060] (1-2) Further, when the treatment agent contains an organic phosphate ester (D), the initial hydrophilicity of the fiber to which the treatment agent is applied can be further improved. <Second Embodiment> A second embodiment embodying the synthetic fiber according to the present invention will be described. The synthetic fiber of this embodiment is a synthetic fiber to which the treatment agent of the first embodiment is attached. By attaching the treatment agent to the surface of the synthetic fiber, a synthetic fiber having various functionalities can be obtained.

[0061] (Use of Synthetic Fiber) The use of the synthetic fiber is not particularly limited, and examples include short fibers, spun yarns, non-woven fabrics, etc. It can be applied to both short fiber and long fiber applications, but it is preferably applied to short fibers. The short fibers correspond to what is generally called staple and do not include long fibers generally called filaments. Also, the length of the short fibers is not particularly limited as long as it corresponds to short fibers in the technical field, but is preferably 100 mm or less, for example.

[0062] (Synthetic Fiber) Specific examples of the synthetic fiber include: (1) polyolefin fibers such as polyethylene fiber, polypropylene fiber, and polybutene fiber; (2) polyester fibers such as polyethylene terephthalate, polybutylene terephthalate, polyethylene terephthalate / isophthalate, and polyether polyester; (3) polyamide fibers such as nylon 6 and nylon 66; and (4) among composite fibers, composite fibers having a core-sheath structure where either one or both of the core and sheath portions are polyolefin fibers, for example, polyethylene / polypropylene composite fibers where the sheath portion is polyethylene fiber, polyethylene / polyester composite fibers, or polyethylene / polypropylene composite fibers having a side-by-side structure, polyethylene / polyester composite fibers, etc. Among these, polyolefin fibers such as polyethylene fiber, polypropylene fiber, and polybutene fiber, and composite fibers having a core-sheath structure where either one or both of the core and sheath portions are polyolefin fibers, for example, polyethylene / polypropylene composite fibers where the sheath portion is polyethylene fiber, polyethylene / polyester composite fibers, or polyethylene / polypropylene composite fibers having a side-by-side structure, polyethylene / polyester composite fibers, etc., are preferably polyolefin synthetic fibers. Here, the polyolefin synthetic fiber means a synthetic fiber synthesized using olefin or alkene as a monomer.

[0063] (Adhesion treatment of the treatment agent) There is no particular limitation on the ratio of attaching the treatment agent of the first embodiment to the synthetic fiber, but it is preferably attached so as to be 0.1% by mass or more and 2% by mass or less with respect to the synthetic fiber as a treatment agent not containing a solvent, and more preferably attached so as to be 0.2% by mass or more and 1.2% by mass or less.

[0064] As a method for attaching the treatment agent to the synthetic fiber, for example, a known method such as an immersion method, a spray method, a roller method, or a guide oil supply method using a metering pump can be applied using an aqueous solution of the treatment agent of the first embodiment and a treatment agent containing water.

[0065] (Method for manufacturing non-woven fabric) Using the synthetic fiber of the present embodiment, a nonwoven fabric may be further manufactured by the following method. It is obtained by going through a step of attaching a treatment agent to a synthetic fiber configured as the composite fiber described above, for example, a short fiber, and a step of performing a heat fusion treatment to obtain a nonwoven fabric. More specifically, it is obtained by going through the following steps.

[0066] Step 1: A step of attaching the treatment agent of the first embodiment to the synthetic fiber. Step 2: A step of passing the synthetic fiber to which the treatment agent has been attached in Step 1 through a carding machine to obtain a web.

[0067] Step 3: A step of performing a heat fusion treatment on the web obtained in Step 2 to obtain a nonwoven fabric. By going through the above steps, a nonwoven fabric can be manufactured. Since the fibers are heat-fused to each other, it can be rephrased as a thermal bond nonwoven fabric.

[0068] When a nonwoven fabric is manufactured from synthetic fibers, it is preferable to apply polyolefin-based synthetic fibers as the synthetic fibers from the viewpoints of excellent productivity and use characteristics. The temperature of the heat fusion treatment is appropriately set according to the type of synthetic fiber, treatment time, etc. For example, 100°C or higher and 180°C or lower, preferably 120°C or higher and 160°C or lower are adopted. The time of the heat fusion treatment is appropriately set according to the type of synthetic fiber, treatment temperature, etc. For example, 1 second or longer and 60 seconds or shorter, preferably 5 seconds or longer and 20 seconds or shorter are adopted.

[0069] (Effect of the present embodiment) The effect of the synthetic fiber of the second embodiment will be described. In the second embodiment, in addition to the effects of the above embodiment, it has the following effects.

[0070] (2-1) In the synthetic fiber of the second embodiment, the treatment agent of the first embodiment is attached. Therefore, a synthetic fiber with improved functions of durable hydrophilicity, anti-wicking, and initial hydrophilicity can be obtained. Thus, it can be suitably applied to applications in the fields of sanitary materials and medical fields where improvement of those functions is required.

[0071] (2-2) Also, when obtaining a nonwoven fabric using such synthetic fibers, the process passability in the carding machine can be improved. Thereby, a nonwoven fabric with excellent quality can be efficiently obtained. (Modification example) Note that the above embodiment may be modified as follows. The above embodiment and the following modification examples can be implemented in combination with each other within a range where there is no technical contradiction.

[0072] · In the treatment agent or aqueous liquid of the above embodiment, within a range that does not inhibit the effects of the present invention, for maintaining the quality of the treatment agent and the like, as other components, other solvents, stabilizers, antistatic agents, linking agents, antioxidants, ultraviolet absorbers, surfactants other than the above, pH adjusters, components usually used in treatment agents such as silicone, etc. may be further blended. Note that other components usually used in treatment agents other than solvents are preferably 10% by mass or less in each treatment agent from the viewpoint of efficiently exerting the efficacy of the present invention. Also, the other components may be stored as separate agents from the above-described treatment agents.

Examples

[0073] Hereinafter, in order to make the configuration and effects of the present invention more specific, examples and the like are given, but the present invention is not limited to these examples. In the following examples and comparative examples, "parts" means parts by mass, and "%" means mass%.

[0074] Test category 1 (Preparation of treatment agent) (Example 1) As sulfate (A), 15.0 g of castor oil sodium sulfate salt (A-1), as organic phosphate ester (B), 15.0 g of lauryl phosphate ester and its potassium salt (B-1), as polyhydric alcohol fatty acid ester (C), 15.0 g of triglyceride oleate (C-1), and as organic phosphate ester (D), 5.0 g of 2-ethylhexyl phosphate ester and its potassium salt (D-1) were mixed, 950.0 g of water was added, and stirred to obtain an aqueous dispersion, and a 5.0% aqueous liquid of the treatment agent of Example 1 was obtained.

[0075] (Examples 2 to 24, Comparative Examples 1 to 7) 5.0% aqueous solutions of each treatment agent of Examples 2 to 24 and Comparative Examples 1 to 7 were prepared in the same manner as in Example 1 using the respective components shown in Table 1.

[0076] The type and content of sulfate (A), the type and content of organic phosphate ester (B), the type and content of polyhydric alcohol fatty acid ester (C), the type and content of organic phosphate ester (D), and the type and content of other components in the treatment agent of each example are as shown in the columns of "Sulfate (A)", "Organic Phosphate Ester (B)", "Polyhydric Alcohol Fatty Acid Ester (C)", "Organic Phosphate Ester (D)", and "Other Components" in Table 1, respectively.

[0077]

Table 1

[0078] Details of the sulfate (A), organic phosphate ester (B), polyhydric alcohol fatty acid ester (C), organic phosphate ester (D), and other components described in Table 1 are as follows.

[0079] (Sulfate (A)) As the sulfate (A), the following components A-1 to A-5 and a-1 were used. The acid value in each component notation was measured by the method shown below.

[0080] (Method for Measuring Acid Value) The sulfate (A) was dissolved in a mixed solvent of ethanol / xylene = 1 / 2 (volume ratio), set in a potentiometric titrator, and titrated with a 0.1 mol / L potassium hydroxide methanol standard solution, and calculated from the following formula.

[0081] Acid value (KOH - mg / g) = (R × f × 56.11 × 0.1) / S In the formula, f: Factor of 0.1 mol / L potassium hydroxide methanol standard solution S: Sampling amount (g, solid content converted amount) R: Amount of 0.1 mol / L potassium hydroxide methanol standard solution used until the inflection point (mL) A-1: Sodium salt of castor oil sulfate (acid value: 28 KOH-mg / g) A-2: Sodium salt of beef tallow sulfate (acid value: 37 KOH-mg / g) A-3: Potassium salt of rapeseed oil sulfate (acid value: 7 KOH-mg / g) A-4: Potassium salt of palm oil sulfate (acid value: 50 KOH-mg / g) A-5: Sodium salt of oleic acid triglyceride sulfate (acid value: 5 KOH-mg / g) a-1: Sodium salt of behenyl sulfate (acid value: 12 KOH-mg / g) (Organic phosphate ester (B)) For the organic phosphate ester (B), the following components B-1 to B-7 and b-1 were used. The P nuclear NMR integration ratio in each component notation was measured by the method shown below. The acid value was determined by the same method as the method described in the sulfate (A) column. The blending amount of each organic phosphate ester (B) in Table 1 indicates the total content of each component of the inorganic substance, monoester form, diester form, and diphosphate esters.

[0082] (Method for measuring P nuclear NMR integration ratio) The P nuclear NMR integration ratio of the phosphate compound (A) was pretreated by first adding an excess of KOH to the phosphate compound (A) to make the pH 12 or higher. The P nuclear NMR integration ratio was 31 measured using P-NMR (MERCURY plus NMR Spectrometor System, manufactured by Varian, 300 MHz, the same below). As the solvent, a mixed solvent of heavy water / tetrahydrofuran = 8 / 2 (volume ratio) was used.

[0083] The P nuclear NMR integration ratio shown in each component indicates the P nuclear NMR integration ratio of each component when the total of the P nuclear NMR integration ratios attributed to the inorganic substance, monoester form, diester form, and diphosphate esters is set to 100%.

[0084] B-1: Lauryl phosphate and its potassium salt (acid value: 70 KOH-mg / g, P nuclear NMR integration ratio: inorganic substance 31.67%, monoester form 51.85%, diester form 16.48%, diphosphate esters 0%) B-2: Stearyl phosphate and its potassium salt (acid value: 18 KOH-mg / g, P nuclear NMR integration ratio: inorganic substance 3.5%, monoester form 49.71%, diester form 38.72%, diphosphate esters 7.92%) B-3: Polyoxyethylene (2 moles) lauryl phosphate and its potassium salt (acid value: 5 KOH-mg / g, P nuclear NMR integration ratio: inorganic substance 15.36%, monoester form 32.33%, diester form 37.76%, diphosphate esters 14.55%) B-4: Decyl phosphate and its potassium salt (acid value: 33 KOH-mg / g, P nuclear NMR integration ratio: inorganic substance 4.21%, monoester form 40.33%, diester form 39.15%, diphosphate esters 16.31%) B-5: Behenyl phosphate and its potassium salt (acid value: 8 KOH-mg / g, P nuclear NMR integration ratio: inorganic substance 2.93%, monoester form 47.2%, diester form 39.98%, diphosphate esters 9.89%) B-6: Polyoxyethylene (3 moles) octyl phosphate and its potassium salt (acid value: 4 KOH-mg / g, P nuclear NMR integration ratio: inorganic substance 10.21%, monoester form 35.43%, diester form 32.59%, diphosphate esters 21.77%) B-7: Octyl phosphate and its potassium salt (acid value: 26 KOH-mg / g, P nuclear NMR integration ratio: inorganic substance 2.07%, monoester form 41.89%, diester form 44.3%, diphosphate esters 11.76%) b-1: Hexyl phosphate and its potassium salt (acid value: 44 KOH-mg / g, P nuclear NMR integration ratio: inorganic substance 8.96%, monoester form 41.5%, diester form 33%, diphosphate esters 16.54%) (Polyhydric alcohol fatty acid ester (C)) C-1: Triglyceride oleate C-2: Tristearin C-3: Diglycerol oleate C-4: Diglycerol laurate C-5: Monoglycerol oleate C-6: Sorbitan monostearate C-7: Hexaglycerol sesquistearate (Organic phosphate ester (D)) For the organic phosphate ester (D), the following D-1, D-2, and d-1 components were used. The P nuclear NMR integration ratio and acid value in the notation of each component were measured by the same method as shown in the column of the above organic phosphate ester (B). Note that the blending amount of each organic phosphate ester (D) in Table 1 indicates the total content of each component of the inorganic substance, monoester form, diester form, and diphosphate esters.

[0085] D-1: 2-Ethylhexyl phosphate ester and its potassium salt (acid value: 29 KOH-mg / g, P nuclear NMR integration ratio: inorganic substance 5.3%, monoester form 40.78%, diester form 35.24%, diphosphate esters 18.68%) D-2: Isodecyl phosphate ester and its potassium salt (acid value: 65 KOH-mg / g, P nuclear NMR integration ratio: inorganic substance 20.3%, monoester form 49.08%, diester form 25.23%, diphosphate esters 5.39%) d-1: Isocetyl phosphate ester and its potassium salt (acid value: 12 KOH-mg / g, P nuclear NMR integration ratio: inorganic substance 5.4%, monoester form 48.79%, diester form 37.77%, diphosphate esters 8.04%) (Other components) E-1: Sodium dioctyl sulfosuccinate E-2: Ester obtained by blocking 1 molar equivalent of the hydroxyl group of the maleic acid condensate of polyoxyethylene (20 moles) hydrogenated castor oil with 1 molar equivalent of stearic acid (iodine value 6) E-3: Sodium distearyl sulfosuccinate E-4: Polyether-modified silicone 1 E-5: Ester blocked with 3 molar equivalents of oleic acid per 1 molar equivalent of hydroxyl groups of hydrogenated castor oil polyoxyethylene (25 moles) E-6: Polyether-modified silicone 2 E-7: Polyether-modified silicone 3 Polyether-modified silicones 1 to 3 show the components described in Table 2 below. In Table 2, "Si%" indicates the mass ratio of the part excluding alkylene oxide from the mass average molecular weight of the polyether-modified silicone. "EO% (molar ratio)" in Table 2 means the molar ratio of ethylene oxide in alkylene oxide. For example, when alkylene oxide contains ethylene oxide (EO) and propylene oxide (PO), EO% (molar ratio) can be obtained by the following formula.

[0086] EO% (molar ratio) = (number of moles of EO / (number of moles of EO + number of moles of PO)) × 100

[0087]

Table 2

[0088] Test section 2 (Preparation of polyolefin synthetic fiber-treated cotton) As the polyolefin synthetic fiber, a polyolefin composite fiber with a sheath part made of polyethylene, a core part made of polyester, a fineness of 2.2 decitex, and a fiber length of 51 mm was used. The aqueous solution of the treatment agent of each example prepared in Test section 1 was adhered to the polyolefin composite fiber by spray oiling so that the adhesion amount (excluding the solvent) was 0.35% by mass, and dried with a hot air dryer at 80 °C for 1 hour to obtain treated polyolefin synthetic fiber-treated cotton.

[0089] Test section 3 (Durable hydrophilicity) 100 g of the treated polyolefin synthetic fiber-treated cotton obtained in Test section 2 was conditioned at 20 °C and 65% RH in a constant temperature chamber for 24 hours, and then subjected to a roller card (carding machine) to obtain a basis weight of 20 g / m 2A card web was produced. The obtained card web was subjected to hot air treatment at 140 °C for 10 seconds to obtain a sample for evaluating durable hydrophilicity. This sample was cut into small pieces of 10 cm × 10 cm and conditioned in a constant temperature chamber at 20 °C and 60% RH for 24 hours. The conditioned non-woven fabric was placed on 5 stacked filter papers, and a cylinder with an inner diameter of 1 cm and both ends open was vertically placed in the center on top of it. 10 mL of 0.9% physiological saline was injected into this cylinder, and the time until the physiological saline was completely absorbed by the non-woven fabric was measured. Then, the non-woven fabric was taken out and dried by blowing air at 40 °C for 90 minutes. The same operation was repeated a total of 3 times, and the evaluation was made based on the following evaluation criteria from the time of the third time. The results are shown in the "Durable Hydrophilicity" column of Table 1.

[0090] · Evaluation criteria for durable hydrophilicity 4 (Excellent): The time required for the complete absorption of physiological saline is less than 3 seconds 3 (Good): The time required for the complete absorption of physiological saline is 3 seconds or more and less than 5 seconds 2 (Fair): The time required for the complete absorption of physiological saline is 5 seconds or more and less than 8 seconds 1 (Poor): The time required for the complete absorption of physiological saline is 8 seconds or more Test category 4 (Process passability) After conditioning 20 g of the above-mentioned treated polyolefin-based synthetic fiber treated cotton in a constant temperature chamber at 20 °C and 65% RH for 24 hours, it was fed into a roller card (carding machine). The ratio of the discharged amount to the input amount was calculated and evaluated based on the following evaluation criteria. The results are shown in the "Process passability" column of Table 1.

[0091] · Evaluation criteria for card passability 4 (Excellent): The discharge amount is 90% or more 3 (Good): The discharge amount is 80% or more and less than 90% 2 (Fair): The discharge amount is 60% or more and less than 80% 1 (Poor): The discharge amount is less than 60% Test category 5 (Water repellency prevention) The sample for the above-mentioned durability hydrophilicity evaluation was cut into small pieces of 10 cm × 10 cm and conditioned in a constant temperature chamber at 20°C and 65% RH for 24 hours. A non-woven fabric piece of 10 cm × 10 cm was cut from the outermost non-woven fabric material of a commercially available paper diaper, and the conditioned 10 cm × 10 cm small piece was attached to the cut portion to obtain a wetting return prevention evaluation sample. The wetting return prevention evaluation sample was placed horizontally so that the attached small piece faced upward, a cylinder with an inner diameter of 6 cm and both ends open was vertically placed at the center of the small piece, 80 mL of water was poured into this cylinder, and it was left standing for 5 minutes to allow the water to be absorbed into the paper diaper. The total mass of 15 stacked filter papers was measured, the mass increase rate was calculated, and the evaluation was performed according to the following evaluation criteria. The results are shown in the "Wetting Return Prevention Property" column of Table 1.

[0092] · Evaluation criteria for wetting return prevention property 4 (Excellent): Mass increase rate is less than 1% 3 (Good): Mass increase rate is 1% or more and less than 2% 2 (Fair): Mass increase rate is 2% or more and less than 3% 1 (Poor): Mass increase rate is 3% or more Test category 6 (Initial hydrophilicity) The sample for the above-mentioned durability hydrophilicity evaluation was conditioned in a constant temperature chamber at 20°C and 65% RH for 24 hours. Then, it was placed on a horizontal plate, and a 0.5 mL water droplet was dropped from a height of 10 mm using a burette, and the time required until the water droplet was completely absorbed into the sample (time required until water penetration) was measured, and the evaluation was performed according to the following evaluation criteria. The results are shown in the "Initial Hydrophilicity" column of Table 1.

[0093] · Evaluation criteria for initial hydrophilicity 4 (Excellent): Time required until water penetration is less than 0.5 seconds 3 (Good): Time required until water penetration is 0.5 seconds or more and less than 1.0 second 2 (Fair): Time required until water penetration is 1.0 second or more and less than 2.0 seconds 1 (Poor): Time required until water penetration is 2.0 seconds or more From the results in the above table, according to the present invention, the durability hydrophilicity, process passing property, wetting return prevention property, and initial hydrophilicity of the fibers to which the treatment agent is applied can be improved respectively.

Claims

1. A treatment agent for synthetic fibers, comprising the following sulfate (A), the following organic phosphoric acid ester (B), and a polyhydric alcohol fatty acid ester (C) (excluding an ester of a condensate of a polyoxyalkylene group-containing hydroxy fatty acid polyhydric alcohol ester and a dicarboxylic acid, at least one hydroxyl group of which is blocked with a fatty acid). Sulfate (A): At least one selected from polyhydric alcohol fatty acid ester sulfates and salts thereof. Organic phosphate (B): At least one selected from organic phosphates having a linear hydrocarbon group having 8 to 24 carbon atoms, and salts thereof.

2. 2. The agent for treating synthetic fibers according to claim 1, wherein the hydrocarbon group of said organic phosphate ester (B) has from 12 to 18 carbon atoms.

3. 2. The agent for treating synthetic fibers according to claim 1, wherein the polyhydric alcohol fatty acid ester (C) is a triglyceride.

4. 2. The treatment agent for synthetic fibers according to claim 1, wherein the treatment agent contains the sulfate (A) in an amount of 5% by mass or more and 70% by mass or less, the organic phosphoric acid ester (B) in an amount of 10% by mass or more and 75% by mass or less, and the polyhydric alcohol fatty acid ester (C) in an amount of 100% by mass or more.

5. 2. The synthetic fiber treating agent according to claim 1, further comprising the following organic phosphate ester (D): Organic phosphate ester (D): At least one selected from organic phosphate esters having a branched hydrocarbon group having 6 to 10 carbon atoms, and salts thereof.

6. 6. The treatment agent for synthetic fibers according to claim 5, wherein the treatment agent contains the sulfate (A) in an amount of 10% by mass or more and 60% by mass or less, the organic phosphate (B) in an amount of 10% by mass or more and 60% by mass or less, the polyhydric alcohol fatty acid ester (C) in an amount of 10% by mass or more and 70% by mass or less, and the organic phosphate (D) in an amount of 10% by mass or more and 30% by mass or less, when the total content of the sulfate (A), the organic phosphate ester (B), the polyhydric alcohol fatty acid ester (C), and the organic phosphate ester (D) is taken as 100% by mass.

7. 7. An aqueous solution of a synthetic fiber treating agent, comprising the synthetic fiber treating agent according to claim 1 in an amount of 0.1% by mass to 10% by mass.

8. A synthetic fiber having the synthetic fiber treating agent according to any one of claims 1 to 6 adhered thereto.

9. The synthetic fiber according to claim 8, wherein the synthetic fiber is an olefin-based synthetic fiber.

10. A method for producing a nonwoven fabric, comprising subjecting the synthetic fiber according to claim 8 to a heat fusion treatment to obtain a nonwoven fabric.

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