Fiber treatment agent for nonwoven fabric, aqueous liquid of fiber treatment agent for nonwoven fabric, and fiber

Abstract

The present invention addresses the problem of reducing the change rate of friction of a synthetic fiber to which a fiber treatment agent for nonwoven fabric is adhered even after long-term storage of the synthetic fiber, and to improve the wet friction characteristic of the synthetic fiber to which the fiber treatment agent for nonwoven fabric is adhered, and the emulsion stability and the antifoaming property of the fiber treatment agent for nonwoven fabric. The fiber treatment agent for nonwoven fabric contains a specific phosphoric acid compound and an alcohol. In P nuclear NMR measurement when an alkali over-neutralization pretreatment is performed, provided that a total of P nuclear NMR integration ratios attributed to specific phosphate esters P1, P2, P3, P4, and P5, orthophosphoric acid, and a salt thereof is 100%, P nuclear NMR integration ratios attributed to P4 and P5 are between 20% and 65% (both inclusive), between 20% and 45% (both inclusive) respectively, a value obtained by equation (1) is 8 or less, a pH at 25 °C of the 1 mass% water diluted solution is between 5.0 and 8.0 (both inclusive), and an acid value per nonvolatile content is 5 or more and less than 60.

Description

Fiber treatment agent for nonwoven fabric, aqueous solution of fiber treatment agent for nonwoven fabric, and fiber

[0001] The present invention relates to a fiber treatment agent for nonwoven fabric, an aqueous solution of the fiber treatment agent for nonwoven fabric, and fibers.

[0002] It is generally known that the manufacturing process of nonwoven fabrics involves a spinning and drawing step of synthetic fibers, a finishing step, etc. Furthermore, in the spinning and drawing step, finishing step, etc., a treatment is sometimes carried out to attach a synthetic fiber treating agent to the surface of the synthetic fibers in order to reduce friction, etc. of the synthetic fibers and improve antistatic properties, etc.

[0003] Conventionally, synthetic fiber treatment agents are known, as disclosed in Patent Documents 1 to 3. Patent Document 1 describes a fiber treatment agent for nonwoven fabric production that contains a specific alkyl phosphate ester and has an acid value (mg KOH / g) of less than 100 in the nonvolatile content.

[0004] Patent Document 2 describes a treatment agent for polyolefin synthetic fibers that contains a specific organic acid, an alkyl phosphate ester salt, and a polyoxyalkylene derivative.

[0005] Patent Document 3 describes that a fiber treatment agent for short fibers contains a specific alkyl phosphate ester.

[0006] International Publication No. 2023 / 149326 Japanese Patent Application Laid-Open No. 2017-210693 Japanese Patent Application Laid-Open No. 2020-73741

[0007]

[0003] Synthetic fiber treatment agents used in nonwoven fabrics, i.e., fiber treatment agents for nonwoven fabrics, are required to exhibit a small rate of change in friction of the synthetic fibers even after long-term storage of the synthetic fibers to which the treatment agent is applied. Further improvements are also required in the wet friction characteristics of the synthetic fibers to which the fiber treatment agent is applied, the emulsion stability of the fiber treatment agent for nonwoven fabrics, and the foam suppression properties.

[0008] As a result of research aimed at solving the above-mentioned problems, the present inventors have found that a fiber treatment agent for nonwoven fabrics containing a specific phosphoric acid compound and an alcohol is exactly suitable. Various aspects for solving the above-mentioned problems will now be described.

[0009] A fiber treatment agent for nonwoven fabrics in Aspect 1 contains the following phosphoric acid compound (A) and the following alcohol (B): when the fiber treatment agent for nonwoven fabrics is pretreated by alkaline overneutralization, in P-nuclear NMR measurement, when the sum of the P-nuclear NMR integral ratios attributable to phosphate ester P1 represented by formula (1) below, phosphate ester P2 represented by formula (2) below, phosphate ester P3 represented by formula (3) below, phosphate ester P4 represented by formula (4) below, phosphate ester P5 represented by formula (5) below, and orthophosphoric acid and a salt thereof is taken as 100%, the P-nuclear NMR integral ratio attributable to phosphate ester P4 is 20% or more and 65% or less, the P-nuclear NMR integral ratio attributable to phosphate ester P5 is 20% or more and 45% or less, and the value calculated by formula (1) below is 8 or less; when a 1% by mass aqueous dilution of the fiber treatment agent for nonwoven fabrics is 100%, the pH at 25°C is 5.0 or more and 8.0 or less; The fiber treatment agent for nonwoven fabrics is characterized in that the acid value per nonvolatile content is 5 KOH-mg / g or more and less than 60 KOH-mg / g.

[0010] The phosphoric acid compound (A) contains phosphoric acid ester P3, phosphoric acid ester P4, phosphoric acid ester P5, and orthophosphoric acid, and optionally further contains at least one selected from phosphoric acid ester P1 and phosphoric acid ester P2.

[0011]

[0012] In formula (1), M １ , M ２ , M ３ are each a hydrogen atom, an alkali metal, an alkaline earth metal (1 / 2), an organic amine, ammonium, or phosphonium.

[0013]

[0014] In formula (2), R １ represents an alkyl or alkenyl group having 8 to 12 carbon atoms; M ４ , M ５ are each a hydrogen atom, an alkali metal, an alkaline earth metal (1 / 2), an organic amine, ammonium, or phosphonium.

[0015]

[0016] In formula (3), R ２ , R ３ each represents an alkyl or alkenyl group having 8 to 12 carbon atoms, M ６ is a hydrogen atom, an alkali metal, an alkaline earth metal (1 / 2), an organic amine, ammonium, or phosphonium.

[0017]

[0018] In formula (4), R ４ represents an alkyl or alkenyl group having 8 to 12 carbon atoms; M ７ , M ８ are each a hydrogen atom, an alkali metal, an alkaline earth metal (1 / 2), an organic amine, ammonium, or phosphonium.

[0019]

[0020] In formula (5), R ５ , R ６ each represents an alkyl or alkenyl group having 8 to 12 carbon atoms, M ９ is a hydrogen atom, an alkali metal, an alkaline earth metal (1 / 2), an organic amine, ammonium, or phosphonium.

[0021]

[0022] The alcohol (B) is an aliphatic alcohol having a carbon number of 8 to 18. In embodiment 2, in the fiber treatment agent for nonwoven fabric of embodiment 1, the value calculated by the above formula (1) is 3.5 or less.

[0023] In Aspect 3, the fiber treating agent for nonwoven fabrics according to Aspect 1 or 2 has a P NMR integral ratio attributable to the phosphate ester P3 of 6.5% or more and 40% or less. In Aspect 4, the fiber treating agent for nonwoven fabrics according to any one of Aspects 1 to 3 has a P NMR integral ratio attributable to the phosphate ester P2 and the phosphate ester P3 of more than 0% and less than 20%.

[0024] Aspect 5 is the fiber treatment agent for nonwoven fabrics according to any one of Aspects 1 to 4, wherein the phosphoric acid compound (A) is contained in an amount of 85% by mass or more and 99.9% by mass or less, and the alcohol (B) is contained in an amount of 0.1% by mass or more and 15% by mass or less, relative to the total amount of the phosphoric acid compound (A) and the alcohol (B) taken as 100% by mass.

[0025] Aspect 6 is the fiber treatment agent for nonwoven fabric according to any one of Aspects 1 to 5, which satisfies at least one of the following two conditions: Condition 1: The fiber treatment agent for nonwoven fabric according to Aspect 6 contains two or more alcohols (B) having different carbon numbers.

[0026] Condition 2: The fiber treatment agent for nonwoven fabrics according to any one of Aspects 1 to 6 further contains a nonionic surfactant (D) described below.

[0027] The nonionic surfactant (D) is at least one selected from a compound in which a total of 5 to 100 moles of alkylene oxide having 2 to 4 carbon atoms are added to 1 mole of a monohydric aliphatic alcohol having 22 to 50 carbon atoms, and an ester compound of a polyglycerol having a condensation degree of 3 to 12 and a saturated fatty acid having 12 to 18 carbon atoms.

[0028] In aspect 8, the fiber treatment agent for nonwoven fabrics according to aspect 7 contains the phosphoric acid compound (A) in an amount of 20% by mass or more and 80% by mass or less, the alcohol (B) in an amount of 0.1% by mass or more and 10% by mass or less, and the nonionic surfactant (D) in an amount of 10% by mass or more and 75% by mass or less, where the total amount of the phosphoric acid compound (A), the alcohol (B), and the nonionic surfactant (D) is 100% by mass.

[0029] Aspect 9 of the present invention relates to an aqueous solution of a fiber treatment agent for nonwoven fabric, wherein the fiber treatment agent for nonwoven fabric according to any one of aspects 1 to 8 has a nonvolatile content concentration of 0.1% by mass or more and 10% by mass or less.

[0030] A tenth aspect of the present invention relates to a fiber having adhered thereto the fiber treatment agent for nonwoven fabric according to any one of aspects 1 to 8. A eleventh aspect of the present invention relates to a fiber having adhered thereto the fiber according to aspect 10, which is a polyolefin-based synthetic fiber.

[0031] According to the present invention, it is possible to reduce the rate of change in friction of synthetic fibers to which a fiber treatment agent for nonwoven fabric has been applied, even after long-term storage of the synthetic fibers, and to improve the wet friction characteristics of the synthetic fibers to which the fiber treatment agent for nonwoven fabric has been applied, as well as the emulsion stability and foam suppression properties of the fiber treatment agent for nonwoven fabric.

[0032] First Embodiment A first embodiment of the fiber treatment agent for nonwoven fabrics (hereinafter simply referred to as the treatment agent) of the present invention will be described below. The treatment agent of this embodiment contains the following phosphoric acid compound (A) and the following alcohol (B).

[0033] (Phosphate Compound (A)) The phosphoric acid compound (A) contains a phosphoric acid ester P3 represented by the following formula (3), a phosphoric acid ester P4 represented by the following formula (4), a phosphoric acid ester P5 represented by the following formula (5), and orthophosphoric acid, and optionally further contains at least one selected from a phosphoric acid ester P1 represented by the following formula (1) and a phosphoric acid ester P2 represented by the following formula (2):

[0034]

[0035] In formula (1), M １ , M ２ , M ３ are each a hydrogen atom, an alkali metal, an alkaline earth metal (1 / 2), an organic amine, ammonium, or phosphonium.

[0036]

[0037] In formula (2), R １ represents an alkyl or alkenyl group having 8 to 12 carbon atoms; M ４ , M ５ are each a hydrogen atom, an alkali metal, an alkaline earth metal (1 / 2), an organic amine, ammonium, or phosphonium.

[0038]

[0039] In formula (3), R ２ , R ３each represents an alkyl or alkenyl group having 8 to 12 carbon atoms, M ６ is a hydrogen atom, an alkali metal, an alkaline earth metal (1 / 2), an organic amine, ammonium, or phosphonium.

[0040]

[0041] In formula (4), R ４ represents an alkyl or alkenyl group having 8 to 12 carbon atoms; M ７ , M ８ are each a hydrogen atom, an alkali metal, an alkaline earth metal (1 / 2), an organic amine, ammonium, or phosphonium.

[0042]

[0043] In formula (5), R ５ , R ６ each represents an alkyl or alkenyl group having 8 to 12 carbon atoms, M ９ is a hydrogen atom, an alkali metal, an alkaline earth metal (1 / 2), an organic amine, ammonium, or phosphonium.

[0044] (Alkali metal) In the phosphate compound (A), M １ ~M ９ The alkali metal constituting the compound is not particularly limited, and examples thereof include sodium, potassium, and lithium.

[0045] (alkaline earth metal) M １ ~M ９ The alkaline earth metal constituting the element (I) is not particularly limited, and examples thereof include calcium, magnesium, beryllium, strontium, and barium.

[0046] The above-mentioned "alkaline earth metal (1 / 2)" means that the alkaline earth metal is divalent, and therefore M １ ~M ９ (organic amine) M １ ~M ９The organic amine constituting the formula (I) is not particularly limited, and examples thereof include primary amines such as methylamine, ethylamine, butylamine, octylamine, laurylamine, octadecylamine (also called stearylamine), octadecenylamine, and coconut amine.

[0047] (phosphonium) M １ ~M ９ The phosphonium constituting the formula (I) is not particularly limited, and examples thereof include quaternary phosphoniums such as tetramethylphosphonium, tetraethylphosphonium, tetrabutylphosphonium, tetraoctylphosphonium, dibutyldihexylphosphonium, trihexyltetradecylphosphonium, triethyloctylphosphonium, trioctylmethylphosphonium, and triphenylmethylphosphonium.

[0048] The above M １ ~M ９ The alkali metals, alkaline earth metals, organic amines, ammonium, and phosphonium constituting the compound (I) may be used singly or in appropriate combination of two or more.

[0049] (Alkyl group having 8 to 12 carbon atoms) R １ ~R ６ The alkyl group having 8 to 12 carbon atoms constituting the alkyl group is not particularly limited and may be a straight-chain alkyl group or a branched-chain alkyl group. By making the alkyl group have 8 to 12 carbon atoms, it is possible to prevent a decrease in the wet friction characteristics of the synthetic fiber to which the treating agent is attached due to an insufficient number of carbon atoms, and a decrease in the emulsion stability of the treating agent due to an excessive number of carbon atoms.

[0050] Specific examples of linear alkyl groups include octyl, nonyl, decyl, undecyl, and dodecyl groups. Specific examples of branched alkyl groups include isooctyl, isononyl, isodecyl, isoundecyl, and isododecyl groups.

[0051] (Alkenyl group having 8 to 12 carbon atoms) R １ ~R ６The alkenyl group having from 8 to 12 carbon atoms constituting the group is not particularly limited and may be a straight-chain alkenyl group or a branched-chain alkenyl group. By making the alkenyl group have from 8 to 12 carbon atoms, it is possible to prevent a decrease in the wet friction characteristics of the synthetic fiber to which the treatment agent is attached due to an insufficient number of carbon atoms, and a decrease in the emulsion stability of the treatment agent due to an excessive number of carbon atoms.

[0052] Specific examples of linear alkenyl groups include octenyl, nonenyl, decenyl, undecenyl, and dodecenyl groups. Specific examples of branched alkenyl groups include isooctenyl, isononenyl, isodecenyl, isoundecenyl, and isododecenyl groups.

[0053] The above R １ ~R ６ The alkyl group and alkenyl group each having 8 to 12 carbon atoms may be used alone or in appropriate combination of two or more kinds.

[0054] The orthophosphoric acid contained in the phosphoric acid compound (A) may form a salt. Examples of the salt of orthophosphoric acid include salts with the above-mentioned alkali metals and alkaline earth metals.

[0055] (Method for Producing Phosphoric Acid Compound (A)) The method for producing phosphoric acid compound (A) is not particularly limited, and known production methods can be used. For example, phosphoric acid compound (A) can be produced by reacting a starting aliphatic alcohol with phosphoric anhydride such as diphosphorus pentoxide to obtain a phosphoric acid oxide (hereinafter also referred to as a phosphorylation reaction), and then neutralizing the obtained phosphoric acid oxide. By such a production method, phosphoric acid compound (A) is produced so as to contain at least phosphoric acid esters P3, P4, and P5.

[0056] The aliphatic alcohol is １ ~R ６An alcohol having an alkyl or alkenyl group having 8 to 12 carbon atoms can be used. The aliphatic alcohol is preferably dehydrated in advance. If the alcohol is dehydrated in advance, decomposition of phosphoric anhydride due to water in the raw material can be easily suppressed.

[0057] The reaction atmosphere between the aliphatic alcohol and phosphoric anhydride is not particularly limited, and a nitrogen atmosphere, an air atmosphere, or the like can be adopted. A nitrogen atmosphere is preferred because it makes it easier to suppress decomposition of phosphoric anhydride due to moisture in the reaction atmosphere.

[0058] The conditions for the phosphorylation reaction are not particularly limited, but the reaction is preferably carried out, for example, at a temperature of 65°C to 85°C for 1 hour to 6 hours. It is also preferable to prevent the synthesized phosphoric acid compound from coming into contact with moisture. If the phosphoric acid compound comes into contact with moisture, the phosphoric acid esters P2 and P3 are likely to be decomposed.

[0059] The conditions for the neutralization are not particularly limited, but it is preferable to carry out the neutralization for 3 to 9 hours at a temperature of 85 to 95° C. If the neutralization temperature is less than 85° C., the content of the phosphate ester P2 tends to be high.

[0060] (Alcohol (B)) The alcohol (B) is an aliphatic alcohol having from 8 to 18 carbon atoms. Specific examples of the alcohol (B) include octanol, nonanol, decanol, undecanol, dodecanol (lauryl alcohol), tridecanol, tetradecanol, pentadecanol, hexadecanol (cetyl alcohol), heptadecanol, and octadecanol (stearyl alcohol).

[0061] The alcohol (B) may be a linear aliphatic alcohol or a branched aliphatic alcohol. As the alcohol (B), one type of alcohol (B) may be used alone, or two or more types of alcohols (B) may be used in appropriate combination.

[0062] The alcohol (B) preferably contains two or more types of alcohol (B) having different carbon numbers. When two or more types of alcohol (B) having different carbon numbers are contained, the foam-suppressing property of the treatment agent can be further improved.

[0063] (Ratio of Phosphoric Acid Compound (A) and Alcohol (B)) The ratio of the phosphoric acid compound (A) and the alcohol (B) in the treatment agent is not particularly limited. When the total ratio of the phosphoric acid compound (A) and the alcohol (B) in the treatment agent is taken as 100 mass%, the treatment agent preferably contains 85 mass% or more and 99.9 mass% or less of the phosphoric acid compound (A) and 0.1 mass% or more and 15 mass% or less of the alcohol (B).

[0064] When the content ratio of the phosphoric acid compound (A) and the alcohol (B) in the treatment agent is within the above range, the initial hydrophilicity of the synthetic fiber to which the treatment agent is applied can be further improved.

[0065] (P nuclear NMR integral ratio) In P nuclear NMR measurement of the treatment agent after alkaline overneutralization pretreatment, when the sum of the P nuclear NMR integral ratios attributable to phosphate ester P1, phosphate ester P2, phosphate ester P3, phosphate ester P4, phosphate ester P5, and orthophosphoric acid and its salts is taken as 100%, the P nuclear NMR integral ratio attributable to phosphate ester P4 is 20% to 65% and the P nuclear NMR integral ratio attributable to phosphate ester P5 is 20% to 45%. By setting the respective ratios of phosphate ester P4 and phosphate ester P5 within the above ranges, it is possible to prevent a decrease in the foam-inhibiting ability of the treatment agent due to an excess of phosphate ester P4 and a decrease in the emulsification stability of the treatment agent due to an excess of phosphate ester P5.

[0066] The value calculated by the following formula (1) is 8 or less, and preferably 3.5 or less.

[0067]

[0068] When the value obtained from the formula (1) is 8 or less, the rate of change in friction of the synthetic fiber can be reduced even after the synthetic fiber with the treatment applied thereto is stored for a long period of time. Furthermore, when the value obtained from the formula (1) is 3.5 or less, the rate of change in friction can be further reduced.

[0069] The frictional properties of synthetic fibers coated with a treatment agent are thought to be significantly affected by the increase in orthophosphoric acid due to the decomposition of phosphate esters P1 and P2 over time. Two moles of orthophosphoric acid are produced from one mole of phosphate ester P1 through decomposition. Similarly, one mole of phosphate ester P2 through decomposition produces one mole of orthophosphoric acid. Therefore, the rate of change in friction of synthetic fibers can be evaluated using the above formula (1), taking into account the effect of orthophosphoric acid production.

[0070] Here, the term "alkaline superneutralization pretreatment" refers to a pretreatment in which an excess amount of alkali is added to the phosphate ester and orthophosphoric acid contained in the phosphoric acid compound (A). Specific examples of the alkali include alkali metal hydroxides. The alkali may be the same as or different from the alkali used in synthesizing the phosphate ester salt. Specific examples of alkali metal hydroxides include sodium hydroxide and potassium hydroxide. In P-nuclear NMR measurement, by performing alkaline superneutralization pretreatment, the peaks assigned to the phosphate esters P1 to P5 and orthophosphoric acid and its salts can be clearly separated. The method for measuring the P-nuclear NMR integral ratio will be described later.

[0071] The P NMR integral ratio attributable to phosphate ester P3 is preferably 6.5% or more and 40% or less, and the sum of the P NMR integral ratios attributable to phosphate ester P2 and phosphate ester P3 is preferably more than 0% and less than 20%.

[0072] When the P-NMR integral ratio attributable to phosphate ester P3 is 6.5% or more and 40% or less, emulsion stability can be further improved. Furthermore, when the sum of the P-NMR integral ratios attributable to phosphate ester P2 and phosphate ester P3 is more than 0% and less than 20%, friction between the synthetic fiber to which the treatment agent is applied and the metal in a wet state can be further reduced. In other words, wet friction characteristics can be further improved.

[0073] (pH of Treatment Agent) The pH of a 1% by mass water dilution of the treatment agent is 5.0 or more and 8.0 or less at 25° C. A pH of 5.0 or more and 8.0 or less is weakly acidic to neutral, and therefore when a nonwoven fabric containing fibers to which the treatment agent is attached is used as a sanitary material or the like that comes into contact with the skin, irritation to the skin can be reduced.

[0074] The method for adjusting the pH of the treatment agent is not particularly limited. For example, the pH can be adjusted by adjusting the acid value of the treatment agent. The pH of the treatment agent can also be adjusted by using a pH adjuster as the other component (E) described below.

[0075] The method for measuring pH is not particularly limited, and can be measured using, for example, a known pH meter (tabletop pH meter F-72 manufactured by Horiba, Ltd.). (Acid value of treatment agent) The acid value per non-volatile content of the treatment agent is 5 KOH-mg / g or more and less than 60 KOH-mg / g. When the acid value per non-volatile content of the treatment agent is within the above numerical range, the emulsion stability of the treatment agent can be improved.

[0076] The acid value per unit of nonvolatile content of the treatment agent is a value calculated from the following formula by dissolving the nonvolatile content of the treatment agent in a mixed solvent of ethanol / xylene = 1 / 2 (volume ratio), setting it in a potentiometric titrator, and titrating it with a 0.1 mol / L potassium hydroxide methanol standard solution.

[0077] Acid value (KOH-mg / g) = (R x f x 56.11 x 0.1) / S In this formula, f is the factor of the 0.1 mol / L potassium hydroxide methanol standard solution, S is the amount of sample collected (g, converted into solid content), and R is the amount (mL) of the 0.1 mol / L potassium hydroxide methanol standard solution used up to the inflection point.

[0078] The non-volatile content of the treatment agent refers to the mass of the bone-dry product obtained by heat-treating the treatment agent at 105°C until it reaches a constant weight and then thoroughly removing volatile substances. (Fatty Acid (C) Having 12 to 20 Carbon Atoms) The treatment agent may contain a fatty acid (C) having 12 to 20 carbon atoms.

[0079] Specific examples of the fatty acid (C) include dodecanoic acid (lauric acid), tridecanoic acid, tetradecanoic acid (myristic acid), pentadecanoic acid, hexadecanoic acid (palmitic acid), heptadecanoic acid, octadecanoic acid (stearic acid), nonadecanoic acid, and icosanoic acid.

[0080] The fatty acid (C) may be a single type of fatty acid (C) or a suitable combination of two or more types of fatty acids (C). When the treatment agent contains a fatty acid (C) having from 12 to 20 carbon atoms, the foam-suppressing properties of the treatment agent can be further improved.

[0081] The content of the fatty acid (C) is not particularly limited, but is preferably 0% by mass or more and 2% by mass or less of the nonvolatile content of the treatment agent. The treatment agent preferably satisfies at least one of the following two conditions:

[0082] Condition 1: The treatment agent contains two or more alcohols (B) having different carbon numbers. Condition 2: The treatment agent contains a fatty acid (C) having from 12 to 20 carbon atoms. When the treatment agent satisfies at least one of conditions 1 and 2, the foam-suppressing properties of the treatment agent can be further improved.

[0083] (Nonionic Surfactant (D)) The treatment agent preferably further contains at least one selected from the following nonionic surfactants (D).

[0084] Specific examples of the nonionic surfactant (D) include a compound in which a total of 5 to 100 moles of alkylene oxide having 2 to 4 carbon atoms are added to 1 mole of a monohydric aliphatic alcohol having 22 to 50 carbon atoms, and an ester compound of a polyglycerol having a condensation degree of 3 to 12 and a saturated fatty acid having 12 to 18 carbon atoms.

[0085] When the treatment agent contains the nonionic surfactant (D), the durable hydrophilicity of the synthetic fiber to which the treatment agent is attached can be further improved. (Contents of the Phosphate Compound (A), the Alcohol (B), and the Nonionic Surfactant (D)) The contents of the phosphate compound (A), the alcohol (B), and the nonionic surfactant (D) in the treatment agent are not particularly limited. When the total content of the phosphate compound (A), the alcohol (B), and the nonionic surfactant (D) in the treatment agent is taken as 100% by mass, the treatment agent preferably contains the phosphate compound (A) in an amount of 20% by mass to 80% by mass, the alcohol (B) in an amount of 0.1% by mass to 10% by mass, and the nonionic surfactant (D) in an amount of 10% by mass to 75% by mass.

[0086] When the contents of the phosphoric acid compound (A), the alcohol (B), and the nonionic surfactant (D) in the treatment agent are within the above-mentioned numerical ranges, it becomes easy to adjust the acid value of the treatment agent and the value calculated by formula (1) within the above-mentioned numerical ranges.

[0087] (Other Components (E)) The treatment agent may contain other components (E). Examples of other components (E) include components typically used in treatment agents, such as stabilizers, antistatic agents, binders, antioxidants, ultraviolet absorbers, surfactants other than the nonionic surfactant (D), pH adjusters, and alcohols other than the alcohol (B).

[0088] Specific examples of the other component (E) include lactic acid, dioctyl sulfosuccinate sodium salt, dodecyl sulfonate sodium salt, polyether-modified silicone, and the like.

[0089] The content of the other component (E) in the nonvolatile content of the treatment agent is preferably 15% by mass or less, more preferably 10% by mass or less, and even more preferably 5% by mass or less. The content of the other component (E) may be 0% by mass.

[0090] (Storage form) The treatment agent may be configured as a one-component treatment agent containing the above-mentioned components (A) to (E), or from the viewpoint of improving the formulation stability, it may be configured as a two-component treatment agent or a three-component treatment agent.

[0091] (Solvent) The treatment agent of the present embodiment is prepared as a fiber treatment agent-containing composition for nonwoven fabric (hereinafter also referred to as a "treatment agent-containing composition") by mixing it with a solvent as necessary, and may be stored or distributed in the form of a treatment agent-containing composition.

[0092] 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 water include ion-exchanged water, distilled water, hard water, and soft water. Among these, it is preferable to use ion-exchanged water or distilled water.

[0093] 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 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.

[0094] <Actions and Effects of First Embodiment> (1-1) The treatment agent of the first embodiment contains the phosphoric acid compound (A) and alcohol (B) described above. Furthermore, the P-nucleus NMR integral ratio attributable to the phosphoric acid ester P4 is 20% to 65% and the P-nucleus NMR integral ratio attributable to the phosphoric acid ester P5 is 20% to 45%. The value calculated by Equation (1) is 8 or less. Furthermore, the acid value per nonvolatile content of the treatment agent is 5 KOH-mg / g or more and less than 60 KOH-mg / g. Therefore, even after long-term storage of synthetic fibers to which the treatment agent is applied, the rate of change in friction of the synthetic fibers can be reduced. Furthermore, the wet friction characteristics, initial hydrophilicity, durable hydrophilicity, emulsion stability, and foam suppression properties of the synthetic fibers to which the treatment agent is applied can be improved.

[0095] (1-2) Furthermore, by containing the nonionic surfactant (D) described above, the durable hydrophilicity of the synthetic fiber to which the treating agent is attached can be further improved. (1-3) By using the treating agent of the first embodiment, it is possible to produce a nonwoven fabric that can be suitably used for final products such as diapers and wet tissues as sanitary goods.

[0096] Second Embodiment Next, a second embodiment of the aqueous liquid fiber treatment agent for nonwoven fabrics (hereinafter also simply referred to as aqueous liquid) of the present invention will be described, focusing on the differences from the first embodiment.

[0097] The aqueous liquid of this embodiment contains the treatment agent and water. The aqueous liquid is used as an emulsion by mixing the treatment agent and water. Specific examples of water that can be used are the same as the water used as the solvent.

[0098] The method for preparing the aqueous liquid is not particularly limited, and examples thereof include a method in which a predetermined amount of the treatment agent is added to a pre-measured amount of water.Furthermore, the aqueous liquid can also be prepared by a known mechanical emulsification method using a known homomixer, homogenizer, or the like.

[0099] The concentration of the treatment agent in the aqueous liquid is not particularly limited. For example, the concentration of the treatment agent is preferably 0.1% by mass or more and 10% by mass or less in terms of the nonvolatile content of the treatment agent. When the concentration of the treatment agent in the aqueous liquid is in the above range, emulsion stability is easily improved.

[0100] <Functions and Effects of Second Embodiment> In addition to the functions and effects of the first embodiment, the second embodiment has the following functions and effects.

[0101] (2-1) The aqueous liquid of the second embodiment contains the treatment agent and water. Therefore, the treatment agent can be applied to the synthetic fibers for the nonwoven fabric in the form of an emulsion. Furthermore, the inclusion of water as a solvent improves the handleability of the aqueous liquid.

[0102] Third Embodiment Next, a third embodiment of the fiber of the present invention will be described. The fiber of this embodiment is a treated fiber having the treatment agent of the first embodiment adhered to its surface. By adhering the treatment agent to the fiber surface, a fiber exhibiting the effects of the present invention can be obtained.

[0103] The type of fiber is not particularly limited, and examples thereof include (1) polyester fibers such as polyethylene terephthalate (PET), polytrimethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polyethylene terephthalate isophthalate, polyether polyester, polylactic acid, and composite fibers containing these polyester resins, (2) polyamide fibers such as nylon 6 and nylon 66, (3) polyacrylic fibers such as polyacrylic and modacrylic, and (4) polyolefin fibers such as polyethylene and polypropylene. Among these, polyolefin fibers (hereinafter also referred to as polyolefin synthetic fibers) are preferred.

[0104] The polyolefin synthetic fiber may be a composite fiber with a core-sheath structure. That is, the composite fiber may be a composite fiber in which either or both of the core and sheath are polyolefin fibers. Specifically, the composite fiber may be a polyethylene / polypropylene composite fiber in which the sheath is polyethylene and the core is polypropylene, or a polyethylene / polyester composite fiber in which the sheath is polyethylene and the core is polyester.

[0105] The treatment agent of this embodiment is applied to nonwoven fabric applications. As long as a treated nonwoven fabric having the treatment agent of this embodiment adhered to its surface can be obtained, the treatment agent may be adhered to the fiber surface before the nonwoven fabric is produced, or the treatment agent may be adhered to the fiber surface after the nonwoven fabric is produced.

[0106] The length of the fibers is not particularly limited, and the present invention can be applied to either short fibers or long fibers, but is preferably applied to short fibers. That is, the polyolefin synthetic fibers of the present embodiment are preferably polyolefin short fibers.

[0107] The 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 the technical field, but is, for example, 100 mm or less, preferably 30 mm to 70 mm.

[0108] (Treatment Agent Application Treatment) There are no particular restrictions on the proportion of the treatment agent of the first embodiment applied to the fiber. The treatment agent is applied so that the non-volatile content of the treatment agent is preferably 0.01% by mass or more and 10% by mass or less, more preferably 0.1% by mass or more and 3% by mass or less, relative to the fiber. This configuration allows the efficacy of each component to be effectively exerted. There are also no particular restrictions on the method for applying the aqueous liquid, and known methods can be used depending on the type, shape, and application of the fiber, such as roller oiling, guide oiling using a metering pump, immersion oiling, and spray oiling. When the immersion oiling method is used, the immersion time is preferably 1 minute or more and 5 minutes or less.

[0109] The fibers to which the aqueous liquid has been applied may be dried or heat-treated using a known method. The drying or heat-treatment volatilizes the solvent, such as water, to obtain fibers to which the components contained in the treatment agent are attached. The fibers to which the components of the treatment agent are attached can effectively exhibit the efficacy for use in nonwoven fabrics.

[0110] (Method of manufacturing nonwoven fabric) The type of nonwoven fabric is not particularly limited, but examples thereof include spunbond nonwoven fabrics produced by the spunbond method. Furthermore, examples of web formation methods other than the spunbond method include, for example, dry methods such as carding and airlaid methods when the raw material fibers are short fibers, and wet methods such as papermaking methods. Furthermore, examples of methods of interfiber bonding include chemical bonding, thermal bonding, needle punching, spunlace, and stitch bonding.

[0111] The polyolefin synthetic fiber of this embodiment may be used to produce a nonwoven fabric by the following method. Specifically, the nonwoven fabric can be obtained through the following steps: Step 1: A step of adhering the treatment agent of the first embodiment to the polyolefin synthetic fiber.

[0112] Step 2: The polyolefin synthetic fibers to which the treatment agent has been applied in Step 1 are passed through a roller carding machine to obtain a roller carded web. Step 2 is also called the carding step. Step 3: The roller carded web obtained in Step 2 is subjected to a hot air treatment to fuse the fibers together to produce a nonwoven fabric. Step 3 is also called the air-through step.

[0113] A nonwoven fabric can be manufactured through the above steps. The nonwoven fabric obtained through the air-through process is also called a thermal-bonded nonwoven fabric. <Actions and Effects of the Third Embodiment> (3-1) The treatment agent of the first embodiment is adhered to the polyolefin synthetic fiber. Therefore, even after long-term storage, the rate of change in friction is small. In addition, the wet friction characteristics of the polyolefin synthetic fiber are improved.

[0114] 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 explanations of the examples and comparative examples, parts mean parts by mass.

[0115] Test Section 1 (Preparation of Fiber Treatment Agent for Nonwoven Fabric) (Example 1) As shown in Table 1, 23.2 parts (mass%) of the phosphate compound (A) shown in Table 2 (A-1) and 16 parts (mass%) of the phosphate compound (A-2), 0.28 parts (mass%) of lauryl alcohol (B-1) as the alcohol (B), and 0.28 parts (mass%) of octyl alcohol (B-2), 0.24 parts (mass%) of stearic acid (C-2) as the fatty acid (C), 30 parts (mass%) of polyoxyethylene (40 mol) triacontyl ether (D-1) and 30 parts (mass%) of polyoxyethylene (50 mol) tetracontyl ether (D-2) as the nonionic surfactant (D), a total of 100 parts (mass%) was diluted with 900 parts of hot water at 70 ° C. in a beaker. Stirring was performed until uniform, and a 10% by mass aqueous solution of the fiber treatment agent for nonwoven fabric of Example 1 was prepared.

[0116] (Examples 2 to 25, Comparative Examples 1 to 14) The treatment agents of Examples 2 to 25 and Comparative Examples 1 to 14 were prepared in the same manner as the treatment agent of Example 1, so as to contain the phosphoric acid compound (A), alcohol (B), fatty acid (C), nonionic surfactant (D), and other component (E) in the proportions shown in Table 1.

[0117] The type and content of the phosphoric acid compound (A), the type and content of the alcohol (B), the type and content of the fatty acid (C), the type and content of the nonionic surfactant (D), and the type and content of the other component (E) are shown in the "Phosphate Compound (A)," "Alcohol (B)," "Fatty Acid (C)," "Nonionic Surfactant (D)," and "Other (E)" columns of Table 1. In addition, the value calculated by formula (1), the acid value per nonvolatile content of the treatment agent, and the pH of a 1% by mass water dilution of the treatment agent at 25°C are shown in the "Value of Formula 1," "Acid Value of Treatment Agent," and "pH" columns of Table 1.

[0118]

[0119] Details of the phosphoric acid compound (A) shown in Table 1 are as follows. <Phosphate Compound (A)> Phosphate compounds (A) A-1 to A-16 shown in Table 2 were used. The type of phosphoric acid compound (A) is shown in the "Type of phosphoric acid compound (A)" column of Table 2. The production conditions, acid value, and P-nucleus NMR integral ratio of the phosphoric acid compound (A) are shown in the "Production conditions (A / B / C / D)" column, the "Acid value of phosphoric acid compound (A)" column, and the "P-nucleus NMR integral ratio (%)" column of Table 2, respectively.

[0120]

[0121] Table 3 shows details of production conditions A to D for phosphoric acid compound (A) shown in Table 2. In Table 3, the "Alcohol dehydration" column indicates whether or not the raw material alcohol was dehydrated. The "Synthesis environment" column indicates the atmosphere for the phosphorylation reaction. The "Phosphorylation conditions" column indicates the temperature and time for the phosphorylation reaction. The "Water addition after phosphorylation" column indicates whether or not water was added after the phosphorylation reaction. The "Neutralization conditions" column indicates the temperature and time for neutralization of the phosphoric acid.

[0122]

[0123] Further details of production conditions A to D for phosphoric acid compound (A) are provided below. (Production Condition A) Under production condition A, the raw material alcohol used was one that had been dehydrated under reduced pressure at 105°C. The raw material alcohol was charged into a four-neck flask, and diphosphorus pentoxide was gradually added thereto under a nitrogen atmosphere. The resulting mixture was stirred at 70±3°C for 3 hours to carry out a phosphorylation reaction. The phosphoric acid oxide obtained in the phosphorylation reaction was gradually added to an aqueous potassium hydroxide solution, and the resulting mixture was stirred at 90±3°C for 6 hours to neutralize the phosphoric acid oxide, thereby synthesizing a phosphoric acid ester compound.

[0124] (Production Condition B) In production condition B, the raw material alcohol was used as it was after opening the reagent bottle. The phosphorylation reaction was carried out in the atmosphere. After opening the reagent bottle, diphosphorus pentoxide was left in the atmosphere (room temperature: about 27°C, relative humidity: about 80%) until the entire amount was added. It took about 30 minutes from the start to the end of adding diphosphorus pentoxide. Otherwise, the phosphate ester compound was synthesized under the same conditions as production condition A.

[0125] (Production Condition C) In production condition C, the raw material alcohol was used as is after opening the reagent bottle. The phosphorylation reaction was carried out under atmospheric pressure. After opening the reagent bottle, diphosphorus pentoxide was left in the atmosphere (room temperature: approximately 27°C, relative humidity: approximately 80%) until the entire amount was added. It took approximately 30 minutes from the start to the end of addition of diphosphorus pentoxide. The phosphorylation reaction was carried out by stirring at 70±3°C for 3 hours. The phosphorus oxide obtained in the phosphorylation reaction was gradually added to an aqueous potassium hydroxide solution, and the phosphorus oxide was neutralized by stirring at 70±3°C for 3 hours. A phosphate ester compound was synthesized under the same conditions as production condition A, except for the above.

[0126] (Production Condition D) In ​​production condition D, the raw material alcohol was used as is after opening the reagent bottle. The phosphorylation reaction was carried out under atmospheric pressure. After opening the reagent bottle, diphosphorus pentoxide was left in the atmosphere (room temperature: approximately 27°C, relative humidity: approximately 80%) until the entire amount was added. It took approximately 30 minutes from the start of addition of diphosphorus pentoxide to the end of addition. The phosphorylation reaction was carried out by stirring at 70±3°C for 3 hours. After completion of the phosphorylation reaction, water was added in an amount of 1.8% by mass of the total amount of the raw material alcohol and diphosphorus pentoxide, and the mixture was stirred at 70±3°C for 1 hour to obtain a phosphorus oxide. The obtained phosphorus oxide was gradually added to an aqueous potassium hydroxide solution and neutralized by stirring at 70±3°C for 3 hours. A phosphoric acid ester compound was synthesized under the same conditions as production condition A, except for the above.

[0127] In addition, under each of the production conditions A to D, the compounding ratio of the raw material alcohol to diphosphorus pentoxide, the conditions for neutralizing the phosphoric acid oxide, and the like may be further adjusted as appropriate within the scope of common general technical knowledge. By adjusting these conditions, the composition of the phosphate ester compound synthesized can be adjusted even under the same production conditions. In other words, the ratio of the phosphate esters P1 to P5 and orthophosphoric acid contained in the phosphate compound (A) can be adjusted.

[0128] The P-nucleus NMR integral ratios of the phosphoric acid compound (A) shown in Table 2 were measured by the following method. (Method for Measuring P-nucleus NMR Integral Ratio) The P-nucleus NMR integral ratio of the phosphoric acid compound (A) was measured by first pretreating the phosphoric acid compound (A) by adding excess KOH to the compound to adjust the pH to 12 or higher. This pretreatment allows the peaks assigned to phosphate ester P1, phosphate ester P2, phosphate ester P3, phosphate ester P4, phosphate ester P5, and orthophosphoric acid and its salts to be clearly separated in 31P-NMR measurement.

[0129] The P nucleus NMR integral ratio was measured using 31P-NMR (Mercury plus NMR Spectrometer System, 300 MHz, manufactured by Valian).

[0130] The solvent used was a mixed solvent of heavy water / tetrahydrofuran = 8 / 2 (volume ratio). Of the obtained signals, the integral value of a single signal appearing between -3 ppm and -7 ppm corresponds to the P atom in P1.

[0131] The sum of the integral value of the doublet signal appearing between -3 ppm and -7 ppm and the integral value of the doublet signal appearing between -7 ppm and -11 ppm corresponds to the P atom in P2. The integral value of the single signal appearing between -7 ppm and -14 ppm corresponds to the P atom in P3.

[0132] The integral value of the single signal appearing between 3 ppm and 7 ppm corresponds to the P atom in P4. The integral value of the single signal appearing between -1 ppm and 4 ppm corresponds to the P atom in P5.

[0133] The integral values ​​of the signals appearing between 4 ppm and 10 ppm correspond to the P atoms in orthophosphoric acid and its salts. However, if signals are detected in overlapping ranges within the above values, the signals derived from the P atoms corresponding to, in order from the lower magnetic field side, orthophosphoric acid and its salts, phosphate esters P4, P5, P2 (-3 ppm to -7 ppm), P1, P2 (-7 ppm to -11 ppm), and P3 are detected.

[0134] The value can be calculated by the above-mentioned formula (1), assuming that the sum of the P nucleus NMR integral ratios assigned to phosphate ester P1, phosphate ester P2, phosphate ester P3, phosphate ester P4, phosphate ester P5, and orthophosphoric acid and its salts is 100%.

[0135] The acid value of the phosphoric acid compound (A) shown in Table 2 was measured by the following method. (Method for measuring acid value) The phosphoric acid compound (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 standard solution of potassium hydroxide in methanol. The acid value was calculated using the same mathematical formula as used to measure the acid value of the treatment agent described above. The acid value of the phosphoric acid compound can be adjusted, for example, by the degree of neutralization when obtaining the phosphoric acid compound (see, for example, paragraph

[0044] of Japanese Patent No. 7055512).

[0136] (Method of Measuring pH) The treatment agent of each example was diluted with water to prepare a 1% by mass aqueous solution. The pH of the prepared 1% by mass aqueous solution at 25°C was measured in accordance with a conventional method using a known pH measuring device (desktop pH meter F-72 manufactured by Horiba, Ltd.).

[0137] Details of the alcohols (B) shown in Table 1 are as follows: <Alcohols (B)> B-1: Lauryl alcohol B-2: Octyl alcohol B-3: Stearyl alcohol Details of the fatty acids (C) shown in Table 1 are as follows:

[0138] <Fatty Acid (C)> C-1: Lauric acid C-2: Stearic acid Details of the nonionic surfactant (D) shown in Table 1 are as follows.

[0139] <Nonionic surfactants (D)> D-1: Polyoxyethylene (40 mol) triacontyl ether D-2: Polyoxyethylene (50 mol) tetracontyl ether D-3: Pentaglycerin monooctadecanoate D-4: Tetraglycerin monooctadecanoate D-5: Polyoxyethylene (10 mol) octacosyl ether D-6: Polyoxyethylene (20 mol) oleyl ether D-7: Polyoxyethylene (10 mol) hydrogenated castor oil ether D-8: Polyoxyethylene (15 mol) sorbitan monolaurate D-9: Polyoxyethylene (20 mol) sorbitan stearate D-10: Polyoxyethylene (10 mol) coconut fatty acid ester D-11: Polyoxyethylene (15 mol) palm fatty acid ester Details of other components (E) shown in Table 1 are as follows.

[0140] <Other Components (E)> E-1: Lactic Acid E-2: Dioctyl Sulfosuccinate Sodium Salt E-3: Dodecyl Sulfonate Sodium Salt As other components (E), E-4 to E-6 (all polyether-modified silicones) shown in Table 4 were also used.

[0141]

[0142] In Table 4, "Me group" and "n-Bu group" mean methyl group and normal butyl group, respectively. "Si %" means the mass ratio of the portion obtained by excluding alkylene oxide from the mass average molecular weight of the polyether-modified silicone. "EO % (molar ratio)" means the molar ratio of ethylene oxide to alkylene oxide. For example, when the alkylene oxide contains ethylene oxide (hereinafter also referred to as EO) and propylene oxide (hereinafter also referred to as PO), the EO % (molar ratio) can be calculated using the following formula.

[0143] EO % (molar ratio) = (EO moles / (EO moles + PO moles)) × 100 Test Section 2 (Attachment of fiber treatment agent for nonwoven fabrics to polyolefin synthetic fiber) Polyolefin composite fiber (fineness 2.2 dtex, fiber length 51 mm) with a polyethylene sheath and a polyester core was prepared. A 10% by mass aqueous solution of each treatment agent prepared in Test Section 1 was further diluted with water to a 0.4% by mass aqueous solution, and this was attached to 100 g of this fiber by spraying so that the amount of attachment was 0.40% as nonvolatile matter. The fiber was dried in a hot air dryer at 80°C for 2 hours and then conditioned overnight in an atmosphere at 20°C and 65% RH to obtain a treatment-applied polyolefin composite fiber.

[0144] Test Section 3 (Preparation of Thermal Bonded Nonwoven Fabric) 100 g of polyolefin composite fiber with a treatment agent was conditioned for 24 hours in a thermostatic chamber at 20°C and 65% RH. After conditioning, the polyolefin composite fiber with the treatment agent was passed through a roller carding machine to form a fiber with a basis weight of 20 g / m. ２ The resulting carded web was subjected to a hot air treatment at 140°C for 10 seconds to obtain a thermal-bonded nonwoven fabric.

[0145] Test Section 4 (Initial Hydrophilicity) The thermal bonded nonwoven fabric obtained in Test Section 3 was conditioned for 24 hours in a thermostatic chamber at 20°C and 65% RH, then placed on a horizontal plate and a 0.4 mL drop of water was dropped on it from a height of 10 mm using a burette. The time required for the drop to be completely absorbed was measured and evaluated according to the following criteria.

[0146] Evaluation Criteria for Initial Hydrophilicity: 3 (Good): Water permeation time less than 3 seconds; 2 (Fair): Water permeation time 3 seconds or more but less than 6 seconds; 1 (Poor): Water permeation time 6 seconds or more. Test Section 5 (Durable Hydrophilicity): The thermobonded nonwoven fabric obtained in Test Section 3 was cut into 10 cm x 10 cm pieces and conditioned for 24 hours in a thermostatic chamber at 20°C and 65% RH. The conditioned thermobonded nonwoven fabric was placed on top of five stacked filter papers, and a 1 cm inner diameter cylinder with open ends was placed vertically in the center of the nonwoven fabric. 5 mL of 0.9% saline was poured into the cylinder. The time until the saline solution was completely absorbed into the thermobonded nonwoven fabric was measured. The thermobonded nonwoven fabric was then removed and air-dried at 40°C for 90 minutes. This procedure was repeated twice, and evaluation was performed according to the following criteria starting from the second time.

[0147] Evaluation criteria for durable hydrophilicity 3 (good): When the time required for saline solution to be absorbed is less than 5 seconds 2 (passable): When the time required for saline solution to be absorbed is 5 to 10 seconds 1 (unacceptable): When the time required for saline solution to be absorbed is 10 seconds or more Test category 6 (high temperature, high humidity treatment) The treatment agent-attached polyolefin composite fiber was aged for 48 hours in a constant temperature room at 70°C x 90% RH to obtain a treatment agent-attached polyolefin composite fiber that had been treated with high temperature and humidity (hereinafter also referred to as high temperature, high humidity treated fiber) simulating long-term storage. In the present invention, long-term storage means storage for 48 hours or more.

[0148] Test Section 7 (Friction Change Rate After Long-Term Storage) 20 g of fiber that had been subjected to high-temperature, high-humidity treatment and 20 g of polyolefin-based composite fiber with a treatment agent attached and not subjected to high-temperature, high-humidity treatment were each conditioned for 24 hours in a constant-temperature chamber at 20°C and 65% RH, and then fed into a miniature carding machine to produce a carded web. The produced carded web was fed into a miniature drawing frame to obtain a sliver with a grain weight of 3 g / m. For the slivers under the above two conditions, the draft force was measured when the sliver was drafted at a sliver speed of 1 m / min and a draft ratio of 1.5. The friction change rate with and without high-temperature, high-humidity treatment was calculated using the following formula and evaluated according to the following criteria. The results are shown in the "Friction Change Rate" column of Table 1.

[0149] [Friction change rate] = [Drafting force of polyolefin composite fiber with treatment agent attached and not subjected to high-temperature, high-humidity treatment] / [Drafting force of fiber subjected to high-temperature, high-humidity treatment] × 100 Evaluation criteria for friction change rate: 3 (Good): When the friction change rate is less than 5%; 2 (Acceptable): When the friction change rate is 5% or more but less than 10%; 1 (Fail): When the friction change rate is 10% or more. Test Category 8 (Emulsion Stability) Hard water with a hardness of 300 was prepared by dissolving 300 mg of calcium carbonate in 1 L of distilled water. Using the hard water with a hardness of 300, an aqueous solution of hard water containing 10% by mass of each treatment agent was prepared. This aqueous solution was further diluted with hard water to prepare an aqueous solution with a nonvolatile content of 0.3% by mass. The aqueous solution was kept at a constant temperature of 20°C for 24 hours, after which the condition of the aqueous solution was visually inspected and evaluated according to the following criteria. The results are shown in the "Emulsion Stability" column of Table 1.

[0150] Evaluation criteria for emulsion stability 3 (good): no precipitate or particles 2 (passable): no precipitate but particles present 1 (unacceptable): precipitate present Test section 9 (wet friction properties) A ​​0.35 mass% aqueous solution was prepared by diluting the 10 mass% aqueous solution of the treatment agent prepared in test section 1 with ion-exchanged water. 80 mL of the prepared 0.35 mass% aqueous solution was placed in a metal tray measuring 60 mm length x 230 mm width x 20 mm height.

[0151] A rectangular plate-shaped weight measuring 30 mm in length, 90 mm in width, and 45 mm in height and weighing 1 kg was prepared. A polyester spunbond nonwoven fabric of the same size as the bottom of the weight was attached to the bottom surface of the weight using double-sided tape. The weight was placed in the pad containing the 0.35% by mass aqueous liquid, with the bottom surface with the attached polyester spunbond nonwoven fabric facing downwards.

[0152] A tensile test was conducted using a tensile testing machine (Shimadzu Corporation, Autograph Model AGS-X) equipped with a load cell with a maximum load capacity of 50 N, in which the weight was pulled at a horizontal speed of 100 mm / min in an atmosphere of 20°C x 60% RH.

[0153] The frictional properties between the fiber and metal in a wet state were evaluated using the above method. Specifically, the frictional properties between the fiber and a metal roller in the spinning process and drawing process were evaluated using the above method. The evaluation of the frictional properties was carried out within 12 hours after preparing the 0.35 mass% aqueous solution. When the treatment agent of Comparative Example 1 was used, the friction between the fiber and metal in a wet state was relatively large, so the evaluation was carried out using the following evaluation criteria with Comparative Example 1 as the standard. The results are shown in the "Wet Friction" column of Table 1.

[0154] Evaluation criteria for wet friction properties: 3 (Good): The M / N ratio, which is the ratio of the friction N measured using the 0.35% by mass aqueous solution of Comparative Example 1 to the friction M measured using the 0.35% by mass aqueous solution of each example, was 0.98 or less. 2 (Acceptable): The M / N ratio was greater than 0.98 and less than 0.99. 1 (Fail): The M / N ratio was greater than 0.99. Test Section 10 (Foam Inhibition) A 10% by mass aqueous solution of the treatment agent prepared in Test Section 1 was diluted with ion-exchanged water to prepare a 0.25% by mass aqueous solution. 25 g of the prepared aqueous solution was placed in a 100 mL graduated cylinder with a stopper, shaken vigorously 30 times over 30 seconds, allowed to stand for 30 seconds, and then shaken vigorously again 30 times over 30 seconds. After allowing to stand for 5 minutes, the height H1 from the water surface to the top of the foam was measured. Evaluation was based on the following criteria. The results are shown in the "Foam Inhibition" column of Table 1.

[0155] Evaluation criteria for foam suppression: 3 (good): H1≦10.0 cm 2 (pass): 10.0 cm

[0156] Test Section 12 (pH of Treatment Agent) The treatment agent of each example was diluted to prepare a 1% by mass aqueous solution of the treatment agent. The pH of the prepared 1% by mass aqueous solution at 25°C was measured using a known pH meter (desktop pH meter F-72, manufactured by Horiba, Ltd.).

[0157] ​As shown in Table 1, the treatment agent of Comparative Example 1 did not contain alcohol (B) and had an acid value outside the range of the present invention, confirming poor anti-foaming properties. The treatment agents of Comparative Examples 2 and 3 did not contain alcohol (B) and the phosphoric acid compound (A) did not contain phosphate ester P3. Furthermore, the integral ratio of phosphate ester P4 was outside the range of the present invention. Furthermore, the acid value was outside the range of the present invention, confirming poor emulsion stability, wet friction properties, and anti-foaming properties.

[0158] The value calculated by the formula (1) for the treatment agent of Comparative Example 4 was outside the range of the present invention, and it was confirmed that the treatment agent of Comparative Example 4 had poor friction change rate. The treatment agent of Comparative Example 5 did not contain alcohol (B), and it was confirmed that the treatment agent of Comparative Example 5 had poor foam suppression properties.

[0159] The treatment agents of Comparative Examples 6 and 7 did not contain the alcohol (B) and the phosphoric acid compound (A) did not contain the phosphoric acid ester P3. Furthermore, the integral ratio of the phosphoric acid ester P4 was outside the range of the present invention, and it was confirmed that the treatment agents were inferior in emulsion stability and foam suppression.

[0160] The treatment agent of Comparative Example 8 had an acid value outside the range of the present invention, and was confirmed to have poor wet friction properties.The treatment agent of Comparative Example 9 had phosphoric acid esters P3 to P5 contained in the phosphoric acid compound (A) with alkyl group carbon numbers outside the range of the present invention, and was confirmed to have poor emulsion stability, initial hydrophilicity, and durable hydrophilicity.

[0161] The treatment agent of Comparative Example 10 did not contain alcohol (B), and the integral ratio of the phosphoric acid ester P5 contained in the phosphoric acid compound (A) was outside the range of the present invention. Furthermore, the acid value was outside the range of the present invention, and it was confirmed that the treatment agent was inferior in wet friction characteristics, foam suppression, and durable hydrophilicity.

[0162] In the treatment agent of Comparative Example 11, the phosphoric acid compound (A) did not contain phosphoric acid ester P3. The integral ratio of phosphoric acid ester P4 was outside the range of the present invention. Furthermore, the acid value was outside the range of the present invention, and it was confirmed that the treatment agent had poor emulsion stability, wet friction characteristics, and foam suppression properties.

[0163] The treatment agent of Comparative Example 12 had an acid value outside the range of the present invention, and was therefore confirmed to have poor emulsion stability. The treatment agent of Comparative Example 13 had a carbon chain of the phosphate compound (A) with less than 8 carbon atoms, and was therefore confirmed to have poor wet friction properties, initial hydrophilicity, and durable hydrophilicity.

[0164] The treatment agent of Comparative Example 14 had a carbon chain containing more than 12 carbon atoms in the phosphoric acid compound (A), and was found to be inferior in emulsion stability, initial hydrophilicity, and durable hydrophilicity. On the other hand, the treatment agent of the present invention can improve the rate of change in friction after long-term storage, emulsion stability, wet friction characteristics, and foam suppression. It can also improve initial hydrophilicity and durable hydrophilicity. Furthermore, nonwoven fabrics containing fibers to which the treatment agent is attached can be suitably used as sanitary materials, etc.

Claims

1. A fiber treatment agent for nonwoven fabrics containing the following phosphoric acid compound (A) and the following alcohol (B), wherein, in P-nuclear NMR measurement of the fiber treatment agent for nonwoven fabrics after alkaline overneutralization pretreatment, when the sum of the P-nuclear NMR integral ratios attributable to phosphate ester P1, phosphate ester P2, phosphate ester P3, phosphate ester P4, phosphate ester P5, orthophosphoric acid and its salts is taken as 100%, the P-nuclear NMR integral ratio attributable to phosphate ester P4 is 20% to 65% and the P-nuclear NMR integral ratio attributable to phosphate ester P5 is 20% to 45% and the value calculated by the following mathematical formula (1) is 8 or less, and the pH of a 1% by mass aqueous dilution of the fiber treatment agent for nonwoven fabrics at 25°C is 5.0 to 8.0, and a fiber treatment agent for nonwoven fabrics, characterized in that the fiber treatment agent for nonwoven fabrics has an acid value per nonvolatile content of 5 KOH-mg / g or more and less than 60 KOH-mg / g. Phosphate compound (A): A fiber treatment agent for nonwoven fabrics containing a phosphate ester P3 represented by the following formula (3), a phosphate ester P4 represented by the following formula (4), a phosphate ester P5 represented by the following formula (5), and orthophosphoric acid, and optionally further containing at least one selected from a phosphate ester P1 represented by the following formula (1) and a phosphate ester P2 represented by the following formula (2). (In Chemical Formula 1, M １ , M ２ , M ３ : hydrogen atom, alkali metal, alkaline earth metal (1 / 2), organic amine, ammonium, or phosphonium. (In Chemical Formula 2, R １ M: an alkyl or alkenyl group having 8 to 12 carbon atoms. ４ , M ５ : hydrogen atom, alkali metal, alkaline earth metal (1 / 2), organic amine, ammonium, or phosphonium. (In Chemical Formula 3, R ２ , R ３ M: an alkyl or alkenyl group having 8 to 12 carbon atoms. ６ : hydrogen atom, alkali metal, alkaline earth metal (1 / 2), organic amine, ammonium, or phosphonium. (In Chemical Formula 4, R ４ M: an alkyl or alkenyl group having 8 to 12 carbon atoms. ７ , M ８ : hydrogen atom, alkali metal, alkaline earth metal (1 / 2), organic amine, ammonium, or phosphonium. (In Chemical Formula 5, R ５ , R ６ M: an alkyl or alkenyl group having 8 to 12 carbon atoms. ９ : hydrogen atom, alkali metal, alkaline earth metal (1 / 2), organic amine, ammonium, or phosphonium. Alcohol (B): an aliphatic alcohol having 8 to 18 carbon atoms.

2. The fiber treatment agent for nonwoven fabrics according to claim 1, wherein the value obtained by the formula (1) is 3.5 or less.

3. The fiber treatment agent for nonwoven fabrics according to claim 1, wherein the P NMR integral ratio attributable to the phosphate ester P3 is 6.5% or more and 40% or less.

4. The fiber treatment agent for nonwoven fabrics according to claim 1, wherein the sum of the P nucleus NMR integral ratios attributable to the phosphate ester P2 and the phosphate ester P3 is more than 0% and less than 20%.

5. A fiber treatment agent for nonwoven fabrics according to claim 1, which contains the phosphoric acid compound (A) in an amount of 85% by mass or more and 99.9% by mass or less, and the alcohol (B) in an amount of 0.1% by mass or more and 15% by mass or less, assuming that the total content of the phosphoric acid compound (A) and the alcohol (B) is 100% by mass.

6. The fiber treatment agent for nonwoven fabrics according to claim 1, which satisfies at least one of the following two conditions: Condition 1: It contains two or more types of alcohol (B) having different carbon numbers, and Condition 2: It contains a fatty acid (C) having 12 to 20 carbon atoms.

7. The fiber treatment agent for nonwoven fabrics according to claim 1, further comprising the following nonionic surfactant (D): Nonionic surfactant (D): at least one selected from a compound in which a total of 5 to 100 moles of alkylene oxide having 2 to 4 carbon atoms are added to 1 mole of a monohydric aliphatic alcohol having 22 to 50 carbon atoms, and an ester compound of a polyglycerol having a condensation degree of 3 to 12 and a saturated fatty acid having 12 to 18 carbon atoms.

8. A fiber treatment agent for nonwoven fabrics as described in claim 7, containing the phosphoric acid compound (A) in an amount of 20% by mass or more and 80% by mass or less, the alcohol (B) in an amount of 0.1% by mass or more and 10% by mass or less, and the nonionic surfactant (D) in an amount of 10% by mass or more and 75% by mass or less, when the total content of the phosphoric acid compound (A), the alcohol (B), and the nonionic surfactant (D) is taken as 100% by mass.

9. An aqueous solution of a fiber treatment agent for nonwoven fabrics according to any one of claims 1 to 8, characterized in that the nonvolatile content of the fiber treatment agent for nonwoven fabrics is 0.1% by mass or more and 10% by mass or less.

10. Fibers having the fiber treatment agent for nonwoven fabrics according to any one of claims 1 to 8 attached thereto.

11. The fiber according to claim 10, wherein said fiber is a polyolefin-based synthetic fiber.

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