JP7736969B1 - Treatment agent for long fiber nonwoven fabric and its use - Google Patents

Abstract

The present invention provides a treatment agent for long-fiber nonwoven fabrics that has both low foaming properties and excellent wettability, and a long-fiber nonwoven fabric to which the treatment agent for long-fiber nonwoven fabrics is attached.
A treatment agent for a long-fiber nonwoven fabric, comprising the following components (A), (B), and (C): component (A): a fatty acid having a melting point of 30 to 80°C; component (B): a nonionic surfactant having an HLB of 6 to 12; and component (C): a polyhydric alcohol having 2 to 8 carbon atoms. It is preferable that component (B) contains a polyhydric alcohol fatty acid ester. It is preferable that the polyhydric alcohol constituting the polyhydric alcohol fatty acid ester is at least one selected from sorbitan, castor oil, and hydrogenated castor oil.

Description

The present invention relates to a treatment agent for long-fiber nonwoven fabrics and its use.

Polyolefin-based synthetic fibers are generally used as the raw material fibers for nonwoven fabrics. For example, nonwoven fabrics are manufactured using long fibers made from polyolefin-based synthetic fibers. Nonwoven fabrics manufactured using long fibers are called long-fiber nonwoven fabrics. Durable hydrophilicity and other properties are imparted to nonwoven fabrics by applying a treatment agent that functions as a nonwoven fabric treatment agent. Nonwoven fabrics imparted with durable hydrophilicity and other properties are used in a wide range of fields, including hygiene, medical, and civil engineering.

Patent document 1 discloses a treatment agent for nonwoven fabrics containing an ether ester compound.

International Publication No. 2022/065261

However, the nonwoven fabric treatment agent of Patent Document 1 sometimes lacks hydrophilicity. As a result of investigating the cause, it was found that foaming and insufficient wettability when the treatment agent is diluted and applied to the nonwoven fabric result in insufficient uniform adhesion of the treatment agent to the nonwoven fabric.
The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a treatment agent for long-fiber nonwoven fabrics that exhibits both low foaming and excellent wettability, and to provide a long-fiber nonwoven fabric to which the treatment agent for long-fiber nonwoven fabrics is adhered.

As a result of extensive research into solving the above problems, the present inventors have found that a treatment agent for long-fiber nonwoven fabrics containing three specific components can solve the problems.
That is, the treatment agent for long-fiber nonwoven fabrics of the present invention is a treatment agent for long-fiber nonwoven fabrics containing the following components (A), (B), and (C), and the weight ratio of component (B) to the nonvolatile content of the treatment agent for long-fiber nonwoven fabrics is 62 to 99 wt % .

The component (B) preferably contains a polyhydric alcohol fatty acid ester.
The polyhydric alcohol constituting the polyhydric alcohol fatty acid ester is preferably at least one selected from sorbitan, castor oil, and hydrogenated castor oil.
It is preferable that the composition further contains an anionic surfactant (D).
The proportion of the component (B) relative to the total amount of the components (B) and (D) is preferably 50 to 99% by weight.

The long fiber nonwoven fabric of the present invention is treated with the above-mentioned long fiber nonwoven fabric treatment agent.

The treatment agent for long-fiber nonwoven fabrics of the present invention provides long-fiber nonwoven fabrics with excellent hydrophilicity. The long-fiber nonwoven fabrics of the present invention have excellent hydrophilicity.

The treatment agent for long-fiber nonwoven fabrics of the present invention contains components (A), (B), and (C). Each component is described in detail below.

[Component (A)]
Component (A) is a component that is essential for the treatment agent for long-fiber nonwoven fabrics, and is a component that is primarily excellent in defoaming effect.
Component (A) is a fatty acid having a melting point of 30 to 80°C, and specific examples include lauric acid (melting point 44°C), tridecylic acid (melting point 52°C), myristic acid (59°C), pentadecylic acid (melting point 61°C), palmitic acid (melting point 63°C), stearic acid (melting point 70°C), icosenoic acid (melting point 79°C), and behenic acid (melting point 75°C). Among these, palmitic acid (melting point 63°C) and stearic acid (melting point 70°C) are more preferred from the viewpoint of exerting the effects of the present invention, and palmitic acid (melting point 63°C) is particularly preferred. Fatty acids with melting points below 30°C are liquid at room temperature and therefore lack defoaming effect, while fatty acids with melting points above 80°C result in poor appearance of the treatment agent. Component (A) may be a mixture, or one or more types may be used.
The melting point in the present invention was measured as follows: A measurement sample was collected to a height of approximately 10 mm in a capillary tube (inner diameter 1 mm, outer diameter 2 mm or less, length 50 to 80 mm) with both ends open. This was then set in a BUCHI M-565 melting point measuring apparatus, and the temperature was raised at a rate of 1°C/min from a temperature below the melting point. The temperature at which the measurement sample melted and became transparent was taken as the melting point.

[Component (B)]
Component (B) is a component that is essential for the treatment agent for long-fiber nonwoven fabrics, and is a component that is primarily excellent in wettability and hydrophilicity.
Component (B) is a nonionic surfactant. Component (B) preferably contains a polyhydric alcohol fatty acid ester.
The HLB value of component (B) is from 6 to 12, preferably from 7 to 11.5, and more preferably from 8 to 11, from the viewpoint of exerting the effects of the present invention.
The HLB value of component (B) is an index showing the balance between hydrophilicity and lipophilicity, and can be calculated from the ratio of the organic value to the inorganic value of an organic compound, for example, by the Oda method described on page 212 of "Introduction to Surfactants" (published by Sanyo Chemical Industries, Ltd. in 2007, written by Takehiko Fujimoto).
HLB = 10 x inorganic/organic The organic and inorganic values for deriving the HLB can be calculated using the values in the table on page 213 of the aforementioned "Introduction to Surfactants."

When two or more compounds are used as component (B), the HLB value of component (B) can be calculated by a weighted average. For example, when component (B) is a combination of M1 parts by weight of compound (Ax) having an HLB value of h1 and M2 parts by weight of compound (Ay) having an HLB value of h2, the HLB value of surfactant (A) can be calculated by the following formula:
HLB value of surfactant (A) = (h1 × M1 + h2 × M2) / (M1 + M2)

Examples of component (B) include alkylene oxide adducts of esters of polyhydric alcohols and fatty acids (B1), esters of alkylene oxide adducts of polyhydric alcohols and fatty acids (B2), esters of polyoxyalkylene glycols and fatty acids (B3), and monoesters of polyhydric alcohols and fatty acids (B4).
The component (B) may be used alone or in combination of two or more.

Specific examples of the polyhydric alcohol constituting the alkylene oxide adduct (B1) of an ester of a polyhydric alcohol and a fatty acid include aliphatic polyhydric (tri- to hexahydric) alcohols having 3 to 6 carbon atoms (glycerin, trimethylolpropane, pentaerythritol, sorbitol, sorbitan, etc.).
Specific examples of the fatty acid constituting the alkylene oxide adduct (B1) of an ester of a polyhydric alcohol and a fatty acid include aliphatic carboxylic acids having 8 to 24 carbon atoms [aliphatic saturated carboxylic acids (caprylic acid, 2-ethylhexanoic acid, pelargonic acid, capric acid, lauric acid, tridecanoic acid, isotridecanoic acid, myristic acid, palmitic acid, stearic acid, isostearic acid, etc.), and aliphatic unsaturated carboxylic acids (oleic acid, linoleic acid, linolenic acid, ricinoleic acid, beef tallow fatty acid, hydrogenated beef tallow fatty acid, castor oil fatty acid, hydrogenated castor oil fatty acid, etc.)].
Examples of the alkylene oxide constituting the alkylene oxide adduct (B1) of an ester of a polyhydric alcohol and a fatty acid include alkylene oxides having 2 to 4 carbon atoms (hereinafter abbreviated as AO). Examples of AOs having 2 to 4 carbon atoms include ethylene oxide (hereinafter abbreviated as EO), 1,2- or 1,3-propylene oxide (hereinafter abbreviated as PO), and 1,2-, 1,3-, 1,4-, or 2,3-butylene oxide (hereinafter abbreviated as BO). One type of AO may be used, or two or more types may be used in combination. When two or more types of AOs are used in combination, they may be added in block or random addition.
The alkylene oxide adduct (B1) of an ester of a polyhydric alcohol and a fatty acid includes an AO adduct of an ester of an aliphatic polyhydric alcohol having 3 to 6 carbon atoms and an aliphatic carboxylic acid having 8 to 24 carbon atoms.
Specific examples include an EO 20 mole adduct of glycerin di-rapeseed oil fatty acid ester, an EO 20 mole adduct of trimethylolpropane dioleate, an EO 20 mole adduct of sorbitan trioleate, an EO 10 mole adduct of castor oil (ester of glycerin and aliphatic carboxylic acid), and an EO 20 mole adduct of hydrogenated castor oil.
Among these, from the viewpoint of exerting the effects of the present invention, sorbitan trioleate adduct with 20 moles of EO, castor oil adduct with 10 moles of EO, and hydrogenated castor oil with 20 moles of EO are preferred.

Specific examples of the polyhydric alcohol constituting the ester (B2) of an alkylene oxide adduct of a polyhydric alcohol and a fatty acid include aliphatic polyhydric (tri- to hexahydric) alcohols having 3 to 6 carbon atoms such as glycerin, trimethylolpropane, pentaerythritol, sorbitol, and sorbitan, alkylene oxide adducts of castor oil, alkylene oxide adducts of hydrogenated castor oil, maleic acid condensates of alkylene oxide adducts of castor oil, and maleic acid condensates of alkylene oxide adducts of hydrogenated castor oil.
Specific examples of alkylene oxides constituting the ester (B2) of an alkylene oxide adduct of a polyhydric alcohol and a fatty acid include AOs having 2 to 4 carbon atoms (EO, PO, BO, etc.). One type of AO may be used alone, or two or more types may be used in combination. When two or more types of AOs are used in combination, they may be added in block or random order.
Examples of the fatty acid constituting the ester (B2) of an alkylene oxide adduct of a polyhydric alcohol and a fatty acid include aliphatic carboxylic acids having 8 to 24 carbon atoms [aliphatic saturated carboxylic acids (caprylic acid, 2-ethylhexanoic acid, pelargonic acid, capric acid, lauric acid, tridecanoic acid, isotridecanoic acid, myristic acid, palmitic acid, stearic acid, isostearic acid, etc.), aliphatic unsaturated carboxylic acids (oleic acid, linoleic acid, linolenic acid, ricinoleic acid, beef tallow fatty acid, hydrogenated beef tallow fatty acid, castor oil fatty acid, hydrogenated castor oil fatty acid, etc.)].
Examples of the ester (B2) of an alkylene oxide adduct of a polyhydric alcohol and a fatty acid include an ester of an AO adduct of an aliphatic polyhydric alcohol having 3 to 6 carbon atoms and an aliphatic carboxylic acid having 8 to 24 carbon atoms. Specific examples include a dirapeseed oil fatty acid ester of a glycerin adduct with 20 moles of EO, a dioleate ester of a trimethylolpropane adduct with 20 moles of EO, a trioleate ester of a sorbitan adduct with 20 moles of EO, and a blocked stearic acid ester of a 20 moles of EO-added hydrogenated castor oil maleic acid condensate.

Examples of the polyoxyalkylene glycol ester (B3) include mono- or diesters (B3-1) of polyoxyalkylene glycol and fatty acid.
Specific examples of the oxyalkylene group constituting the mono- or diester (B3-1) of polyoxyalkylene glycol and fatty acid include oxyalkylene groups having 2 to 4 carbon atoms (oxyethylene group, 1,2- or 1,3-oxypropylene group, 1,2-, 1,3-, 1,4- or 2,3-oxybutylene group, etc.). The oxyalkylene group may be one type or two or more types in combination. When two or more types of oxyalkylene groups are used in combination, they may be added in block or random manner.
Specific examples of fatty acids constituting the mono- or diester (B3-1) of polyoxyalkylene glycol and fatty acid include aliphatic carboxylic acids having 8 to 24 carbon atoms [aliphatic saturated carboxylic acids (caprylic acid, 2-ethylhexanoic acid, pelargonic acid, capric acid, lauric acid, tridecanoic acid, isotridecanoic acid, myristic acid, palmitic acid, stearic acid, isostearic acid, etc.), aliphatic unsaturated carboxylic acids (oleic acid, linoleic acid, linolenic acid, etc.), and fatty acids of animal and vegetable oils (coconut oil, palm oil, castor oil, hydrogenated castor oil, beef tallow, hydrogenated beef tallow, lard, etc.)].
Examples of the mono- or diester (B3-1) of polyoxyalkylene glycol and fatty acid include (mono- or di-)esters of polyoxyalkylene glycol and aliphatic carboxylic acid having 8 to 24 carbon atoms. Among these, preferred from the viewpoint of exerting the effects of the present invention is oleic acid monoester of polyoxyethylene glycol (having 5 to 10 repeating oxyethylene groups).

In the monoester (B4) of a polyhydric alcohol and a fatty acid, specific examples of the polyhydric alcohol constituting (B4) include aliphatic polyhydric (tri- to hexahydric) alcohols having 3 to 6 carbon atoms (glycerin, trimethylolpropane, pentaerythritol, sorbitol, sorbitan, etc.).
Specific examples of the fatty acid constituting the monoester (B4) of a polyhydric alcohol and a fatty acid include aliphatic carboxylic acids having 8 to 24 carbon atoms [aliphatic saturated carboxylic acids (caprylic acid, 2-ethylhexanoic acid, pelargonic acid, capric acid, lauric acid, tridecanoic acid, isotridecanoic acid, myristic acid, palmitic acid, stearic acid, isostearic acid, etc.), aliphatic unsaturated carboxylic acids (oleic acid, linoleic acid, linolenic acid, ricinoleic acid, beef tallow fatty acid, hydrogenated beef tallow fatty acid, castor oil fatty acid, hydrogenated castor oil fatty acid, etc.)].
Examples of the monoester (B4) of a polyhydric alcohol and a fatty acid include a monoester of an aliphatic polyhydric alcohol having 3 to 6 carbon atoms and an aliphatic carboxylic acid having 8 to 24 carbon atoms. Among these, the monolaurate of sorbitan (sorbitan laurate) is preferred from the viewpoint of exerting the effects of the present invention.

The chemical formula weight or number average molecular weight (Mn) of the nonionic surfactant in the present invention is preferably 200 to 2,000, more preferably 250 to 1,000, from the viewpoint of exerting the effects of the present invention.
In the present invention, the number average molecular weight (Mn) and the weight average molecular weight in the present invention were calculated from the peaks measured with a differential refractive index detector using a high performance gel permeation chromatography apparatus HLC-8220GPC manufactured by Tosoh Corporation, by injecting a sample at a sample concentration of 3 mg/cc into a separation column KF-402HQ or KF-403HQ manufactured by Showa Denko K.K.

[Component (C)]
Component (C) is a component that is essential for the treatment agent for long-fiber nonwoven fabrics, and it mainly serves to enhance the defoaming effect of component A.
Component (C) is a polyhydric alcohol having 2 to 8 carbon atoms. Component (C) may be a mixture, and one or more types may be used.
The polyhydric alcohol is not particularly limited as long as it has two or more hydroxyl groups, and examples thereof include ethylene glycol, propylene glycol, 1,3-propanediol, 1,2-butanediol, 1,3-butanediol, 1,4-butanediol, 2-methyl-1,2-propanediol, 1,2-pentanediol, 1,5-pentanediol, 1,2-hexanediol, 1,6-hexanediol, 2,5-hexanediol, 2-methyl-2,4-pentanediol, 2,3-dimethyl-2,3-butanediol, 1,2-octanediol, glycerin, 2-methyl-2-hydroxymethyl-1,3-propanediol, trimethylolpropane, sorbitan, pentaerythritol, and sorbitol. Among these, from the viewpoint of exerting the effects of the present invention, 1,2-propanediol, 1,3-propanediol, 1,4-butanediol, and 1,6-hexanediol are more preferred, and 1,4-butanediol is even more preferred.

[Treatment agent for long fiber nonwoven fabric]
The treating agent for long-fiber nonwoven fabrics of the present invention preferably further contains an anionic surfactant (D) in addition to the components (A) to (C) from the viewpoint of exerting the effects of the present invention.
[Anionic surfactant (D)]
The anionic surfactant (D) is a component that, when contained in the treatment agent for a long-fiber nonwoven fabric of the present invention, exhibits the effect of improving wettability and water permeability.
The anionic surfactant is at least one selected from the group consisting of sulfonic acid type anionic surfactants (D1), sulfate ester type anionic surfactants (D2), and phosphate ester type anionic surfactants (D3). From the viewpoint of exerting the effects of the present invention, at least one selected from the group consisting of sulfonic acid type anionic surfactants (D1) and phosphate ester type anionic surfactants (D3) is preferred.
In addition, from the viewpoint of exerting the effects of the present invention, it is more preferable to contain a sulfonic acid type anionic surfactant (D1). One type of component (D) may be used alone, or two or more types may be used in combination.

Examples of the sulfonic acid type anionic surfactant (D1) include alkylbenzenesulfonates such as linear sodium dodecylbenzenesulfonate and branched sodium dodecylbenzenesulfonate; α-olefinsulfonates such as sodium α-tetradecenesulfonate, sodium α-hexadecenesulfonate and potassium α-hexadecenesulfonate; alkanesulfonates such as sodium dodecylsulfonate and sodium tetradecylsulfonate; α-sulfofatty acid ester salts such as sodium methyl α-sulfolaurate and sodium methyl methoxyhexaethylene glycol-α-sulfolaurate; acyl isethionates such as sodium cocoyl isethionate and ammonium cocoyl isethionate; N-acyl-N-methyl taurates such as sodium cocoyl methyl taurate; dialkyl sulfosuccinates such as sodium dioctyl sulfosuccinate; and alkyl naphthalenesulfonates such as sodium propyl naphthalenesulfonate.
As the sulfonic acid type anionic surfactant, alkylbenzenesulfonate, α-olefinsulfonate, alkane sulfonate, dialkyl sulfosuccinate, etc. are preferred, and dialkyl sulfosuccinate, etc. are more preferred. These sulfonic acid type anionic surfactants may be used alone or in combination of two or more.

Examples of sulfate ester-type anionic surfactants (D2) include alkyl sulfates such as sodium dodecyl sulfate, potassium dodecyl sulfate, triethanolamine dodecyl sulfate, sodium stearyl sulfate, and sodium oleyl sulfate; polyoxyethylene alkyl ether sulfates such as polyoxyethylene (3) sodium dodecyl sulfate, polyoxyethylene (3) sodium cetyl sulfate, and polyoxyethylene (3) cetyl sulfate triethanolamine; sulfated oils such as turmeric oil; and sulfated fatty acid esters such as sulfated butyl oleate. In the above, polyoxyethylene (3) refers to a polyoxyethylene group containing three repeating oxyethylene units. Preferred sulfate ester-type anionic surfactants include alkyl sulfates, polyoxyethylene alkyl ether sulfates, and sulfated fatty acid ester salts, with alkyl sulfates and polyoxyethylene alkyl ether sulfates being more preferred. These sulfate ester-type anionic surfactants may be used alone or in combination.

Examples of phosphate ester-type anionic surfactants (D3) include alkyl phosphates such as sodium dodecyl phosphate, potassium dodecyl phosphate, sodium stearyl phosphate, and potassium stearyl phosphate; polyoxyethylene alkyl ether phosphates such as polyoxyethylene (3) lauryl ether sodium phosphate and polyoxyethylene (3) lauryl ether potassium phosphate; and polyoxyethylene alkyl phenyl ether phosphates such as polyoxyethylene (3) lauryl phenyl ether sodium phosphate and polyoxyethylene (3) lauryl phenyl ether potassium phosphate. Preferred phosphate ester-type anionic surfactants include alkyl phosphate esters and polyoxyethylene alkyl ether phosphate esters, with alkyl phosphate esters being more preferred. These phosphate ester-type anionic surfactants may be used alone or in combination.

From the viewpoint of achieving the effects of the present invention, the weight proportion of the component (A) in the nonvolatile content of the treatment agent for long-fiber nonwoven fabrics is preferably 0.01 to 30% by weight, more preferably 0.05 to 25% by weight, even more preferably 0.11 to 20% by weight, and particularly preferably 1 to 15% by weight.
The weight proportion of the component (B) in the nonvolatile content of the treatment agent for long-fiber nonwoven fabrics is preferably 10 to 99.9% by weight, more preferably 20 to 99.5% by weight, even more preferably 30 to 99% by weight, and particularly preferably 40 to 95% by weight, from the viewpoint of achieving the effects of the present application.
From the viewpoint of achieving the effects of the present invention, the weight proportion of the component (C) in the non-volatile content of the treatment agent for long-fiber nonwoven fabrics is preferably 0.1 to 80% by weight, more preferably 0.3 to 70% by weight, even more preferably 0.5 to 60% by weight, and particularly preferably 1 to 50% by weight.
In the present invention, the non-volatile content refers to the bone-dry component when the treatment agent for long-fiber nonwoven fabrics is heat-treated at 105°C to remove the solvent and the like, and the weight reaches a constant. The active ingredient in the present invention refers to the non-volatile content.

When the treatment agent for long-fiber nonwoven fabrics contains an anionic surfactant (D), the weight proportion of the anionic surfactant (D) in the nonvolatile components of the treatment agent for long-fiber nonwoven fabrics is, from the viewpoint of achieving the effects of the present application, preferably 0 to 80% by weight, more preferably 1 to 70% by weight, even more preferably 3 to 60% by weight, and particularly preferably 5 to 50% by weight.
The ratio of the component (B) to the total amount of the component (B) and the component (D) is preferably 50 to 99% by weight, more preferably 55 to 95% by weight, and even more preferably 60 to 90% by weight, from the viewpoint of achieving the effects of the present invention.

In the treatment agent for long-fiber nonwoven fabrics of the present invention, from the viewpoint of achieving the effects of the present invention, the weight proportion of the silicone compound in the nonvolatile content of the treatment agent for long-fiber nonwoven fabrics is preferably 5% by weight or less, more preferably 1% by weight or less, even more preferably 0.1% by weight or less, particularly preferably 100 ppm or less, and most preferably 0 ppm.
The silicone compound referred to here refers to various modified silicones such as dimethyl silicone, amino-modified silicone, amide polyether-modified silicone, epoxy-modified silicone, alkylene oxide-modified silicone (polyether-modified silicone), carboxy-modified silicone, carbinol-modified silicone, alkyl-modified silicone, amino polyether-modified silicone, epoxy polyether-modified silicone, phenol-modified silicone, methacrylate-modified silicone, alkoxy-modified silicone, and fluorine-modified silicone, and also includes silicone compounds used as antifoaming agents.

[Long-fiber nonwoven fabric]
The long-fiber nonwoven fabric of the present invention has the above-mentioned treatment agent for long-fiber nonwoven fabrics adhered thereto.
The long fiber nonwoven fabric of the present invention is preferably a spunbond nonwoven fabric.
Spunbond nonwoven fabrics are nonwoven fabrics obtained by heating and melting a raw material resin (high molecular weight polymer) in an extruder, extruding it through a spinneret with many fine holes, and stretching it into long fibers by roll take-up or air sucker take-up. These long fibers are then accumulated on a net conveyor to obtain a web, which is then entangled by a method using means such as needle punching, water jetting, or ultrasonic waves, or by partially bonding the web by thermocompression bonding using an embossing roll, or by partially heat-sealing the web using air-through.
The long-fiber nonwoven fabric of the present invention includes not only a single-layer spunbond nonwoven fabric but also a composite sheet (for example, SM, SMS, SMMS, etc.) of a spunbond nonwoven fabric (S) and a meltblown nonwoven fabric (M).

Spunbond nonwoven fabrics have long fibers made from thermoplastic resins. Examples of thermoplastic resins include polyolefin resins, polyester resins, polyamide resins, acrylonitrile resins, vinyl resins, and vinylidene resins. Examples of polyolefin resins include polyethylene, polypropylene, and polybutene. Examples of polyester resins include polyethylene terephthalate and polybutylene terephthalate. Examples of polyamide resins include nylon. Examples of vinyl resins include polyvinyl chloride. Examples of vinylidene resins include polyvinylidene chloride. These resins can be used alone or in combination, or modified versions of these resins can be used.

Spunbond nonwoven fabrics are preferably formed from polypropylene resin, a polyolefin-based resin, from the standpoint of spinnability. From the standpoints of smoothness, improved feel when in contact with the skin, and ease of breakage, polypropylene resins containing 5% to 100% by weight, more preferably 25% to 80% by weight, of one or more random copolymers, homopolymers, or block copolymers are preferred. These copolymers and homopolymers may be mixed, or other resins may be mixed. However, a mixture of polypropylene homopolymers and random copolymers is preferred because they are less susceptible to thread breakage during molding. Furthermore, random copolymers based on propylene components copolymerized with ethylene or α-olefins are preferred, with ethylene-propylene copolymer resins being particularly preferred. From the same standpoint, polypropylene resins containing 5% or more by weight, and even more preferably 25% or more by weight, of ethylene-propylene copolymer resins are preferred. The ethylene-propylene copolymer resin preferably contains 1 to 20% by weight of ethylene.

The long-fiber nonwoven fabric of the present invention may have a structure of a single fiber or a composite fiber with two or more thermoplastic resin components. It may also be composed of a blend of single fibers made from different thermoplastic resins, or a blend of single fibers and composite fibers. The composite fiber structure may be any of sheath-core, side-by-side, or sea-island, and among these, sheath-core composite fibers, which use a low-melting-point resin as the sheath component and a high-melting-point resin as the core component, are particularly preferred because they have good thermal adhesion and maintain a stable thermally bonded state. Other composite fibers that can be used include those with a modified cross-section structure, a split structure, and a hollow structure.

The treatment agent for long-fiber nonwoven fabrics can be applied using known methods such as dipping, spraying, or coating (kiss coater or gravure coater) using a diluted treatment agent. It is preferable to premix the agent and dilute it with a solvent such as water before applying. When applying the agent, the amount of application may differ between the front and back of the nonwoven fabric, if necessary.

When a treatment agent for long-fiber nonwoven fabrics is diluted with a solvent such as water and applied, a drying process may be required. The drying method can be any known method that utilizes convective heat transfer, conductive heat transfer, or radiative heat transfer, such as drying with hot air or infrared rays, or drying by thermal contact.

The long-fiber nonwoven fabric preferably has a basis weight of 8 g/m ² to 30 g/m ² , and more preferably 10 g/m ² to 25 g/m ^2. When the basis weight is within the above range, the balance between strength and flexibility tends to be excellent. Furthermore, the nonwoven fabric of the present disclosure preferably has a thickness of 0.05 mm to 2.00 mm, and more preferably 0.10 mm to 1.00 mm.
The amount of the treatment agent for long fiber nonwoven fabrics to be applied must be in the range of 0.1 to 3% by weight based on the nonwoven fabric, and since the fabric comes into direct contact with the human body, it is preferable to set the amount to the minimum necessary.

<Application>
The long-fiber nonwoven fabric having the treatment agent for long-fiber nonwoven fabric of the present invention adhered thereto has excellent hydrophilicity and can therefore be suitably used in applications for conventionally known nonwoven fabrics, such as absorbent articles (disposable diapers, disposable pants, sanitary products, urine absorption pads, pet sheets, etc.), cosmetic materials (face masks, etc.), sanitary materials (poultices, sheets, towels, industrial masks, sanitary masks, hair caps, etc.), and packaging materials (oxygen absorbers, body warmers, hot compresses, food packaging materials).

The present invention will be described below with reference to examples, but is not limited thereto. The evaluation items and evaluation methods for each example and comparative example are as follows. The details of the treatment agents and the evaluation results for each example and comparative example are summarized in Tables 1 to 3. In the details of the treatment agents, the blending ratios are all expressed in weight percent. However, Examples 3, 5, 8, and 9 are also referred to as Reference Examples 3, 5, 8, and 9.

The nonvolatile content of the treatment agent for long-fiber nonwoven fabric of each Example and Comparative Example was prepared using the following components (A-1 to D-4).
A-1: Lauric acid A-2: Palmitic acid A-3: Stearic acid A-4: Behenic acid B-1: Sorbitan monolaurate (HLB: 10.8)
B-2: Ester of polyoxyethylene (20 moles) castor wax condensate with maleic acid, blocked with 1 mole equivalent of stearic acid per mole equivalent of hydroxyl groups (HLB: 8.3)
(B'-1): Polyoxyethylene (50) castor oil ether (HLB: 12.9)
(B'-2): Sorbitan trioleate (HLB: 2.6)
C-1: 1,2-propanediol C-2: 1,3-propanediol C-3: 1,4-butanediol C-4: 1,6-hexanediol D-1: Dioctyl sulfosuccinate sodium salt D-2: Octyl phosphate potassium salt D-3: Lauryl phosphate potassium salt D-4: Lauryl sulfate sodium salt The ingredients were mixed and stirred in the ratios shown in Tables 1 to 3 to prepare the non-volatile content of the treatment agent for long-fiber nonwoven fabrics of each Example and Comparative Example, and the following evaluations were performed.

[Wettability]
This is a substitute evaluation for judging uniform adhesion to nonwoven fabric. A 1% aqueous solution of the prepared long-fiber nonwoven fabric treatment agent of each example was prepared, and felt was floated in this 1% aqueous solution. The time until the felt sank was measured and evaluated according to the following criteria. 5 is the best rating, and 4 or higher is suitable for practical use.
5...less than 10 seconds, 4...10 seconds or more but less than 20 seconds, 3...20 seconds or more but less than 30 seconds, 2...30 seconds or more but less than 60 seconds, 1...60 seconds or more

[Low foaming]
A 1% aqueous solution of the long-fiber nonwoven fabric treatment agent of each example was prepared, and 20 mL of this 1% aqueous solution was placed in a 100 mL stoppered measuring cylinder (manufactured by Miyahara Keiryoki Seisakusho Co., Ltd.) and the temperature was adjusted to 25°C. Since the amount of foam generated varies depending on the height of the measuring cylinder, it is preferable to measure using a stoppered measuring cylinder with a height of 26.5±0.1 cm excluding the stopper. The stoppered measuring cylinder's lid was closed and the cylinder was vigorously shaken up and down 30 times per 15 seconds. After shaking, the cylinder was allowed to stand, and the foam height H1 [ml] 10 seconds after the start of standing and the foam height H2 [ml] 5 minutes after standing were measured. In the above test, H1 indicates foam inhibition and H2 indicates foam breaking, and each was evaluated according to the following criteria.
(foam control)
◎: H1≦30ml, ○: 30ml<H1≦60ml, ×: H1>60ml
(foam-breaking property)
◎: H2≦20ml, ○: 20ml<H2≦40ml, ×: H2>40ml
Based on the above-mentioned foam suppression property and foam remaining property, the low foaming property was evaluated according to the following criteria.
The results are shown in the "Low Foaming" column of Tables 1 to 3.
5 is the best rating, and 3 or higher is suitable for practical use.
(Low foaming)
5: When both foam suppression and foam breaking are rated as ⊚ 4: When foam suppression is ◯ and foam breaking is ⊚ 3: When both foam suppression and foam breaking are ◯ 2: When either foam suppression or foam breaking is x 1: When both foam suppression and foam breaking are x

[Repeated permeability]
Measurement was performed in accordance with EDANA (European Disposables and Nonwovens Manufacturers Association) standard NWSP070.7.RO(15), and the obtained time (number of seconds) was evaluated according to the following criteria: 5 is the best rating, and 3 or higher is suitable for practical use.
5: Less than 2 seconds 4: 2 seconds or more but less than 3.5 seconds 3: 3.5 seconds or more but less than 5 seconds 2: 5 seconds or more but less than 10 seconds 1: 10 seconds or more

As is clear from Tables 1 to 3, the treatment agents for long-fiber nonwoven fabrics of Examples 1 to 11 contain component (A): a fatty acid with a melting point of 30 to 80°C, component (B): a nonionic surfactant with an HLB of 6 to 12, and component (C): a polyhydric alcohol with 2 to 8 carbon atoms, and therefore have good appearance, low foaming after long-term storage, and excellent wettability, thereby solving the problems of the present application. It was also confirmed that the effects of the present application were also exhibited in diapers and sanitary products in which the nonwoven fabrics produced in the examples were used as topsheets.
On the other hand, when component (A) was not present (Comparative Examples 1 and 3), when component (B) was not present (Comparative Example 4), when component (C) was not present (Comparative Examples 1 and 2), or when the HLB of the nonionic surfactant was not 6 to 12 (Comparative Examples 5 and 6), at least one of the problems of the present application could not be solved.

Claims (6)

A treatment agent for a long-fiber nonwoven fabric, comprising the following components (A), (B), and (C) , wherein the weight ratio of component (B) to the nonvolatile content of the treatment agent for a long-fiber nonwoven fabric is 62 to 99 wt %.
Component (A): a fatty acid having a melting point of 30 to 80°C; Component (B): a nonionic surfactant having an HLB of 6 to 12; Component (C): a polyhydric alcohol having 2 to 8 carbon atoms; The treatment agent for long-fiber nonwoven fabrics according to claim 1, wherein component (B) contains a polyhydric alcohol fatty acid ester. The treatment agent for long-fiber nonwoven fabrics according to claim 2, wherein the polyhydric alcohol constituting the polyhydric alcohol fatty acid ester is at least one selected from sorbitan, castor oil, and hydrogenated castor oil. The treatment agent for long-fiber nonwoven fabrics according to claim 1, further comprising an anionic surfactant (D). The treatment agent for long-fiber nonwoven fabrics according to claim 4, wherein the proportion of component (B) relative to the total amount of component (B) and component (D) is 50 to 99% by weight. A long-fiber nonwoven fabric to which the treatment agent for long-fiber nonwoven fabric described in claims 1 to 5 has been applied.