JP7792852B2 - Fiber surface treatment agent, fiber surface treatment method, and surface-treated fiber - Google Patents

Description

The present invention relates to a fiber surface treatment agent, a fiber surface treatment method using the surface treatment agent, and surface-treated fibers having a coating obtained by the surface treatment method.

Various techniques for surface treatment of metal materials have been known. For example, International Publication No. 2010/070728 (Patent Document 1) describes a surface treatment agent for metal materials that has various properties such as corrosion resistance and topcoatability.
The surface treatment agent for metal materials contains a silicate compound (A), an organoalkoxysilane (B), a metal compound (C) containing at least one metal element selected from the group consisting of Zr, Ti, Co, Fe, V, Ce, Mo, Mn, Mg, Al, Ni, Ca, W, Nb, Cr, and Zn, at least one compound (D) selected from the group consisting of phosphoric acid compounds and fluorine compounds, water (E), and an alcohol (F) produced by hydrolysis of the organoalkoxysilane (B).

This document describes that the ratio (C F1 /C F2 ) of the molar concentration (mol/L) (C _F1 ) of the alcohol (F) in the surface treatment agent for metal materials to the molar concentration (mol/L) (C _F2 ) of the alcohol generated when all alkoxy groups contained in the organoalkoxysilane ( _B ) are hydrolyzed in the treatment agent is adjusted to a range of 0.05 to _0.9 . Furthermore, this document lists materials used in various fields such as construction, electricity, and automobiles as metal materials.

International Publication No. 2010/070728

Patent Document 1 describes how the use of the surface treatment agent for metal materials provides various properties such as corrosion resistance and topcoatability, and in particular, the formed film has excellent adhesion to the surface of the metal material, and how components that act as corrosion inhibitors for metal materials can be immobilized within the film.

However, Patent Document 1 does not mention surface treatment of fibers, nor does it discuss the effects of such treatment. Fibers are used in everyday items such as clothing, bedding, curtains, and sanitary products, and therefore require different performance characteristics from those required of metal materials. For example, there is currently an increasing need for fibers with excellent antibacterial properties.

In light of the above circumstances, one embodiment of the present invention aims to provide a fiber surface treatment agent that has excellent antibacterial properties and durability, has little effect on the water absorbency of fibers, is capable of forming a film that is resistant to fiber deterioration, and has high liquid stability. In another embodiment, the present invention aims to provide a fiber surface treatment method using the surface treatment agent. In yet another embodiment, the present invention aims to provide a surface-treated fiber having a film obtained by the surface treatment method.

As a result of extensive research to solve the above problems, the inventors discovered that blending a specific silane compound, a silver salt and/or a silver complex, an organic acid, and water under specific blending conditions is advantageous for obtaining a fiber surface treatment agent that has excellent antibacterial properties and durability, has little effect on the water absorbency of fibers, is capable of forming a coating that is resistant to fiber deterioration, and has high liquid stability, and thus completed the present invention.

The present invention is exemplarily specified as follows.
[1]
a silane compound (A) which is a hydrolyzate and/or condensation reaction product of a tetraalkoxysilane (A1) and a silane coupling agent (A2);
a silver salt and/or silver complex (B);
an organic acid (C) having two or more carboxyl groups;
and water (E),
A surface treatment agent for fibers prepared so as to satisfy the following compounding conditions 1) and 2).
1) The molar ratio {(A1+A2)/B} of the total (A1+A2) of the tetraalkoxysilane (A1) and the silane coupling agent (A2) to the silver salt and/or silver complex (B) is 100 to 500.
2) The molar ratio (C/B) of the carboxyl groups of the organic acid (C) to the silver salt and/or silver complex (B) is 5 to 25.
[2]
The silane compound (A) contains an alcohol (D) which is a hydrolyzate of at least one of the tetraalkoxysilane (A1) and the silane coupling agent (A2),
The fiber surface treatment agent according to [1], wherein the ratio (Dα/Dβ) of the actual molar concentration (mol/L) (Dα) of the alcohol (D) in the surface treatment agent to the molar concentration (mol/L) (Dβ) of the alcohol generated in the surface treatment agent when all alkoxy groups contained in the tetraalkoxysilane (A1) and the silane coupling agent (A2) are assumed to be hydrolyzed is 0.05 to 0.9.
[3]
A method for treating the surface of fibers, comprising contacting the fiber surface treatment agent according to [1] or [2] with part or all of the fibers to form a coating.
[4]
[3] A surface-treated fiber having a coating, obtained by the surface treatment method according to [3].

One embodiment of the present invention has the exceptional effect of providing a fiber surface treatment agent that is excellent in antibacterial properties and durability, has little effect on the water absorbency of fibers, is capable of forming a film that is resistant to fiber deterioration, and has high liquid stability. Therefore, the present invention can be suitably used for antibacterial applications of various fibers used in daily necessities such as clothing and hygiene products.

The following provides a detailed description of embodiments of the present invention, including a surface treatment agent, a surface treatment method, and surface-treated fibers. The present invention can be modified as desired without departing from the spirit of the present invention, and is not limited to the embodiments described below. In this specification, the term "to" indicating a numerical range includes both the upper and lower limits. For example, "X to Y" means that the range is from X to Y.

<1. Surface treatment agent>
According to one embodiment of the present invention,
a silane compound (A) which is a hydrolyzate and/or condensation reaction product of a tetraalkoxysilane (A1) and a silane coupling agent (A2);
a silver salt and/or silver complex (B);
an organic acid (C) having two or more carboxyl groups;
Water (E),
A surface treatment agent for fibers containing the compound is provided.

[1-1. Silane compound (A)]
The surface treatment agent contains a hydrolysate and/or a condensation reaction product derived from both a tetraalkoxysilane (A1) and a silane coupling agent (A2) as the silane compound (A). The tetraalkoxysilane (A1) and the silane coupling agent (A2) may each be used alone or in combination of two or more.

Tetraalkoxysilane (A1) is represented by the general formula Si(OR) ₄ (wherein R represents an alkyl group), and R is preferably an alkyl group having 1 to 4 carbon atoms, more preferably an alkyl group having 1 to 3 carbon atoms, and even more preferably an alkyl group having 1 to 2 carbon atoms. Specific examples of tetraalkoxysilane (A1) include tetraethoxysilane, tetramethoxysilane, and tetra-normal-propoxysilane, with tetraethoxysilane being preferred.

The silane coupling agent (A2) is an organosilicon compound having a hydrolyzable group and an organic functional group. Examples of the hydrolyzable group include alkoxy groups having 1 to 4 carbon atoms (especially 1 or 2 carbon atoms), such as methoxy, ethoxy, propoxy, butoxy, and 2-methoxyethoxy. Examples of the organic functional group include vinyl, epoxy (especially glycidoxy), styryl, methacrylic, acrylic, amino, isocyanate, isocyanurate, ureido, mercapto, and acid anhydride groups. Among these, silane coupling agents having an alkoxy group as the hydrolyzable group and an epoxy and/or amino group as the organic functional group are preferred. Glycidoxy and/or amino groups are more preferred as the organic functional group. It is even more preferred to use a silane coupling agent having a glycidoxy group in combination with a silane coupling agent having an amino group. When a silane coupling agent having a glycidoxy group and a silane coupling agent having an amino group are used in combination, the molar ratio of glycidoxy group-containing silane coupling agent to amino group-containing silane coupling agent is preferably 10:1 to 1:1, and more preferably 5:1 to 2:1. Furthermore, it is more preferable to use a trialkoxysilane compound having three alkoxy groups and one organic functional group in the molecule as the silane coupling agent (A2).

One preferred embodiment of the silane coupling agent (A2) is a compound represented by the general formula (I): (Y) ₃ --Si--L--X.

In general formula (I), X represents a functional group selected from an epoxy group, an amino group, a mercapto group, a vinyl group, and an isocyanate group, with an epoxy group or an amino group being preferred.

In general formula (I), L represents a divalent linking group or a simple bond. Examples of the linking group represented by L include an alkylene group (preferably having 1 to 20 carbon atoms), -O-, -S-, an arylene group, -CO-, -NH-, _-SO2- , -COO-, -CONH-, or a group combining two or more of these. In the case of a simple bond, this means that X in general formula (I) is directly linked to Si (silicon atom).

In general formula (I), each Y independently represents an alkoxy group. Of these, alkoxy groups having 1 to 3 carbon atoms are preferred.

Specific examples of silane coupling agents (A2) include epoxy silanes such as 3-glycidoxypropyltrimethoxysilane and 3-glycidoxypropylmethyldimethoxysilane; amino silanes such as N-(2-aminoethyl)3-aminopropylmethyldimethoxysilane, N-(aminoethyl)3-aminopropyltrimethoxysilane, and 3-aminopropyltriethoxysilane; mercapto silanes such as 3-mercaptopropyltrimethoxysilane and 3-mercaptopropyltriethoxysilane; isocyanate silanes such as 3-isocyanatepropyltrimethoxysilane and 3-isocyanatepropyltriethoxysilane; and vinyl group-containing silanes such as vinyltriethoxysilane and p-styryltrimethoxysilane.

When tetraalkoxysilane (A1) is hydrolyzed, silanol (Si(OR) _4-n (OH) _n ) and alcohol (ROH) hydrolyzates are produced according to the reaction formula represented by formula A.
Formula A: Si(OR) ₄ + nH ₂ O → Si(OR) _4-n (OH) _n + nROH (where n is an integer from 1 to 4)
When the silane coupling agent (A2) is hydrolyzed, a hydrolyzate corresponding to the hydrolyzable group contained in the silane coupling agent is produced. When the hydrolyzable group is an alkoxy group, hydrolyzates of silanol and alcohol are produced.
In the surface treatment agent, silanols and/or alcohols produced by hydrolysis may be hydrogen-bonded to each other, and in this specification, such substances are also treated as hydrolysates.

Therefore, in one embodiment, the surface treatment agent contains, as the silane compound (A), an alcohol (D) that is a hydrolyzate of at least one of a tetraalkoxysilane (A1) and a silane coupling agent (A2), typically an alcohol (D) that is a hydrolyzate of both. In a preferred embodiment, the surface treatment agent has a ratio (Dα/Dβ) of the actual molar concentration (mol/L) of the alcohol (D) in the surface treatment agent (Dα) to the molar concentration (mol/L) (Dβ) of the alcohol generated in the surface treatment agent when all alkoxy groups contained in the tetraalkoxysilane (A1) and the silane coupling agent (A2) are assumed to be hydrolyzed, of 0.05 to 0.9. The lower limit of Dα/Dβ is more preferably 0.3 or greater, and even more preferably 0.5 or greater. The upper limit of Dα/Dβ is more preferably 0.85 or less, and even more preferably 0.8 or less.

Assuming that all alkoxy groups contained in the tetraalkoxysilane (A1) and silane coupling agent (A2) are hydrolyzed, the molar concentration (Dβ) of the alcohol produced in the surface treatment agent is calculated by multiplying the total molar concentration of A1 by 4 + (total molar concentration of A2) x (number of alkoxy groups contained in one molecule of A2).

The molar concentration (Dα) of alcohol (D) in the surface treatment agent is measured using the following method. Using an NMR device (e.g., JNM-FCX400, manufactured by JEOL Ltd.), the integral value of the protons belonging to alcohol (D) in the surface treatment agent is calculated by comparing it with the integral value of protons of known molar concentrations. The internal standard method is used for quantification.

The surface treatment agent may also contain a condensation reaction product (organosiloxane) having a siloxane bond (Si-O-Si) formed by a dehydration condensation reaction of some of the silanols produced by hydrolysis. Examples of condensation reaction products include: (1) a condensation reaction product formed by a dehydration condensation reaction between silanols produced by the hydrolysis of tetraalkoxysilane (A1); (2) a condensation reaction product formed by a dehydration condensation reaction between silanols produced by the hydrolysis of silane coupling agent (A2); and (3) a condensation reaction product formed by a dehydration condensation reaction between silanols produced by the hydrolysis of tetraalkoxysilane (A1) and silanols produced by the hydrolysis of silane coupling agent (A2). These products may be polycondensed alone or in combination of two or more.

Since the surface treatment agent is provided in a liquid state, it is considered desirable not to allow dehydration condensation to proceed to such an extent that a solid phase is formed, but it is preferable to allow dehydration condensation to occur to a certain extent. For example, when the weight average molecular weight of the condensation reaction product in the surface treatment agent is measured by the following GPC method, it is preferably in the range of 100 to 5,000, and more preferably in the range of 150 to 3,000.
<Method for measuring weight average molecular weight>
The weight average molecular weight is determined using a high-speed GPC device (HLC-8320GPC: manufactured by Tosoh Corporation) in combination with a SEC column and a guard column under the following measurement conditions:
SEC column: TSKgel SuperAWM-H (manufactured by Tosoh Corporation)
Guard column: TSK guard column Super AW-H (manufactured by Tosoh Corporation)
Detector: RI (HLC-8320GPC built-in detector)
Standard sample: polystyrene Sample injection volume: 30 μL of 0.06% DMF solution
Flow rate: 0.5mL/min
Eluent _: DMF/100mM LiBr/60mM _H3PO4

[1-2. Silver salt and/or silver complex (B)]
The silver salt and/or silver complex (B) is a component that exhibits antibacterial properties. Examples of silver salts and/or silver complexes (B) include silver carboxylate, silver nitrate, silver carbonate, silver sulfate, silver perchlorate, silver fluoride, silver chloride, silver chlorate, silver chromate, silver cyanide, silver bromide, silver bromate, silver iodide, and silver iodate. A silver salt or silver complex of a carboxylic acid is preferred. Other examples of silver salts and/or silver complexes (B) include compounds of silver with substances having active sites such as amino acids and their derivatives, carboxylic acid or phosphonic acid chelating agents, activated sulfur such as thiols, amines, nitrogen-containing heterocycles, guanidine, sulfonic acid, and phosphoric acid. These compounds also include hydrates. These compounds may be used alone or in combination.

[1-3. Organic acid (C) having two or more carboxyl groups]
Although the present invention is not intended to be limited by theory, it is believed that an organic acid (C) having two or more carboxyl groups has the effect of improving the stability of silver ions in the surface treatment agent. Among them, hydroxy acids having two or more carboxyl groups are preferred, hydroxy acids having an even number of carboxyl groups are more preferred, and hydroxy acids having two carboxyl groups are even more preferred. Examples of organic acids (C) include tartaric acid, malic acid, citric acid, succinic acid, malonic acid, oxalic acid, adipic acid, phthalic acid, isophthalic acid, maleic acid, fumaric acid, aspartic acid, glutamic acid, polyacrylic acid, and polymaleic acid. Among these, hydroxy acids such as tartaric acid, malic acid, and citric acid are preferred, and hydroxy acids having two carboxyl groups such as tartaric acid and malic acid are more preferred. The organic acids (C) may be used alone or in combination of two or more.

[1-4. Water (E)]
The surface treatment agent contains water as a solvent. From the viewpoint of avoiding the influence of unintentionally mixed substances, it is preferable to use deionized water as the water. The content of water is preferably 70 to 99.9 mass % and more preferably 95 to 99.5 mass % based on the total amount of the surface treatment agent.

[1-5. Blending conditions of silane compound (A), silver salt and/or silver complex (B), and organic acid (C)]
The surface treatment agent is preferably prepared so as to satisfy the following blending conditions 1) and 2).
1) The molar ratio of the total (A1+A2) of the tetraalkoxysilane (A1) and the silane coupling agent (A2) to the silver salt and/or silver complex (B) {(A1+A2)/B} is 100 to 500.
2) The molar ratio (C/B) of the carboxyl group of the organic acid (C) to the silver salt and/or silver complex (B) is 5 to 25.

The lower limit of (A1+A2)/B is preferably 100 or more, more preferably 200 or more, and even more preferably 250 or more. The upper limit of (A1+A2)/B is preferably 500 or less, more preferably 400 or less, and even more preferably 300 or less.

The lower limit of C/B is preferably 5 or more, more preferably 7 or more, and even more preferably 10 or more. The upper limit of C/B is preferably 25 or less, more preferably 20 or less, and even more preferably 15 or less.

Also, A1 and A2 are preferably blended so that the molar ratio of A1 to A2 (A1/A2) is 0.30 to 3.00, more preferably 0.50 to 2.00, and even more preferably 0.70 to 1.50.

The above blending conditions are the conditions under which each component is blended to prepare the surface treatment agent, and are thought to differ from the ratios actually present in the surface treatment agent. In particular, the tetraalkoxysilane (A1) and silane coupling agent (A2) are largely hydrolyzed in the surface treatment agent, and some of the hydrolyzate undergoes dehydration condensation. Since it is difficult to accurately analyze the components in the surface treatment agent, the surface treatment agent is specified by the blending conditions of the raw materials.

The surface treatment agent may contain various additives as needed, such as lubricants, surfactants, pigments, dyes, inhibitors for imparting corrosion resistance, film-forming aids, conductivity improvers, thickeners, and aqueous resins (water-soluble resins, water-dispersible resins, or emulsion-type resins). However, from the perspective of achieving the desired effects of the present invention, the total mass of these various additives is preferably 20% by mass or less, more preferably 10% by mass or less, and even more preferably, for example, 0 to 5% by mass, based on the total mass of A1, A2, B, and C blended to prepare the surface treatment agent.

The surface treatment agent may contain a water-miscible solvent. There are no particular limitations on the water-miscible solvent, as long as it does not undergo phase separation after mixing with water.

[1-6. Manufacturing method]
The surface treatment agent can be prepared, for example, by blending and stirring a silane compound (A), a silver salt and/or a silver complex (B), an organic acid (C), water (E), and, if necessary, other components in the desired ratio. Furthermore, in order to control the weight-average molecular weight of the condensation reaction product contained in the silane compound (A) within a suitable range, it is preferable to allow the dehydration condensation reaction between the tetraalkoxysilane (A1) and the silane coupling agent (A2) to proceed to a certain extent in advance. Heating is effective for promoting the dehydration condensation reaction. The liquid temperature during heating is preferably 60 to 90°C, more preferably 70 to 80°C. The heating time is preferably 30 to 120 minutes, more preferably 60 to 90 minutes.

2. Surface treatment method and surface-treated fiber
According to one embodiment of the present invention, there is provided a method for surface treating fibers, comprising contacting the surface treatment agent with part or all of the fibers to form a coating. Also, according to one embodiment of the present invention, there is provided a surface-treated fiber having a coating obtained by the surface treatment method. The coating has excellent antibacterial properties and durability, has little effect on the water absorption of the fiber, and is resistant to fiber deterioration. Therefore, the surface-treated fiber having the coating is suitable for use as a variety of fibers used in textile products such as clothing, ties, aprons, swimwear, sportswear, gloves, hats, shoes, work clothes, office wear, textiles, bedding, mattresses, curtains, sanitary products, wallpaper, rugs, carpets, floor coverings, shoji screens, paper, wood, sofas, chairs, handkerchiefs, towels, cushions, bags, filters, rush grass, leather, furoshiki wrapping cloths, and diapers.

[2-1. Fiber]
Typical fibers include, but are not limited to, organic fibers obtained by spinning acrylic, rayon, polyester, polypropylene, polyethylene, polyamide (nylon), vinylon, polyurethane, polyvinylidene chloride, polyacrylonitrile, acetate, cupra, polyvinyl chloride, fluororesin, liquid crystal polymer, aramid, cellulose, wool, silk, hemp, cotton, etc. Inorganic fibers such as glass fiber, artificial mineral fiber, mineral fiber, carbon fiber, and ceramic fiber can also be used. However, metal fibers are not considered to be "fibers" in this invention.

[2-2. Surface treatment]
The method for contacting the surface treatment agent with part or all of the fibers is not particularly limited, and examples thereof include immersion, spraying, roll coating, brush coating, etc. The temperature of the surface treatment agent at this time is preferably 10 to 60° C., more preferably 15 to 50° C., and even more preferably 25 to 40° C. The contact time is preferably 1 second to 5 minutes, and more preferably 30 seconds to 2 minutes.

After contacting the surface treatment agent with the fiber, the surface treatment agent is dried, evaporating the solvent and forming a coating. The drying method is not particularly limited as long as it evaporates the solvent in the surface treatment agent. Examples include drying methods using known drying equipment, such as ovens, batch-type drying ovens, continuous hot air circulation drying ovens, conveyor-type hot air drying ovens, and electromagnetic induction heating ovens using induction heaters. The drying temperature can be 40 to 200°C, preferably 60 to 150°C, and more preferably 80 to 120°C. To promote the dehydration condensation reaction between (A1) and (A2), a drying temperature of 100°C or higher is most preferable, but the drying temperature is determined taking into account the heat resistance of the fiber. The drying time can be 1 to 120 minutes, preferably 2 to 60 minutes.

During the drying process, the silane compound (A) in the surface treatment agent undergoes a dehydration condensation reaction, and the silicon atoms in the coating are thought to primarily form condensation products (organosiloxanes) with siloxane bonds (Si-O-Si). Typically, the silicon atoms in the coating are thought to form organopolysiloxanes through polycondensation. Furthermore, the condensation products with siloxane bonds (Si-O-Si) in the coating are thought to play an important role (binder effect) in stably holding together the silver salt and/or silver complex (B) and the organic acid (C) with two or more carboxyl groups.

[2-3. Mass of the coating]
The mass (adhesion amount) of the coating on the surface-treated fiber having a coating is not particularly limited as long as the effect of the present invention can be exhibited. However, the mass of Si is preferably within the range of 1.0 to 50.0 mg, more preferably 1.5 to 35 mg, and particularly preferably 2.0 to 20.0 mg per 1 ^m2 of fiber before the coating is formed.

The present invention will be explained in more detail below based on examples, but the present invention is not limited to these examples.

[1. Preparation of surface treatment agent]
<Treatment liquid type S1>
The raw materials used in preparing the surface treatment agent of treatment liquid type S1 are shown below.
<Tetraalkoxysilane (A1)>
Tetraethoxysilane (TEOS)
<Silane Coupling Agent (A2)>
3-Glycidoxypropyltrimethoxysilane 3-Aminopropyltriethoxysilane <Silver salt and/or silver complex (B)>
A silver nitrate aqueous solution adjusted to a silver concentration of 0.5% by mass (4.64 mmol/100 g) was used. As a chelating agent, HEDP (Hydroxyethylidene Diphosphonic Acid) (trade name: Chelest-PH210) manufactured by Chelest Co., Ltd. was used in an amount of 1 molar equivalent relative to Ag, and PBTC (Phosphonobutane Tricarboxylic Acid) (trade name: Chelest-PH430) was used in an amount of 2 molar equivalents relative to Ag.
<Organic Acid (C) Having Two or More Carboxyl Groups>
Malic acid

The above components (A1, A2, and C) were blended in deionized water at 75°C as shown in Table 1 and stirred for 70 minutes. After cooling to room temperature, B was further added as shown in Table 1 and dissolved. The weight loss due to evaporation was replenished with deionized water to obtain various surface treatment agents of treatment liquid type S1 (Examples 1, 9 to 28, 31 to 33, Comparative Examples 1 to 8). Note that the "mol %" of A, B, and C in Table 1 is the value when the sum of A (= A1 + A2), B, and C is taken as 100 mol %.
The above components (A1, A2, and C) were blended in deionized water at 85°C as shown in Table 1 and stirred for 120 minutes. After cooling to room temperature, B was further added and dissolved as shown in Table 1. The weight loss due to evaporation was replenished with deionized water to obtain a surface treatment agent of treatment liquid type S1 (Example 29).
The above components (A1, A2, and C) were blended in deionized water at 65°C as shown in Table 1 and stirred for 30 minutes. After cooling to room temperature, B was further added and dissolved as shown in Table 1. The weight loss due to evaporation was replenished with deionized water to obtain a surface treatment agent of treatment liquid type S1 (Example 30).
The above components (A1, A2, and C) were blended in deionized water at 90°C as shown in Table 1 and stirred for 120 minutes. After cooling to room temperature, B was further added and dissolved as shown in Table 1. The weight loss due to evaporation was replenished with deionized water to obtain a surface treatment agent of treatment liquid type S1 (Comparative Example 9).
The above components (A1, A2, and C) were blended in deionized water at 25°C as shown in Table 1 and stirred for 30 minutes. After cooling to room temperature, B was further added and dissolved as shown in Table 1. The weight loss due to evaporation was replenished with deionized water to obtain a surface treatment agent of treatment liquid type S1 (Comparative Example 10).
In all examples, A2 was blended into the treatment liquid type S1 so that the molar ratio of 3-glycidoxypropyltrimethoxysilane:3-aminopropyltriethoxysilane was 3:1. The molar concentration of A2 listed in Table 1 is the total value of both.
The water content in the surface treatment agent of treatment liquid type S1 was 95 mass % in all cases.

<Treatment liquid type S2>
The raw materials used in preparing the surface treatment agent of treatment liquid type S2 are shown below.
<Tetraalkoxysilane (A1)>
Tetraethoxysilane (TEOS)
<Silane Coupling Agent (A2)>
3-glycidoxypropyltrimethoxysilane <silver salt and/or silver complex (B)>
Same as treatment liquid type S1.
<Organic Acid (C) Having Two or More Carboxyl Groups>
Malic acid

The above components (A1, A2, and C) were blended in deionized water at 75°C as shown in Table 1 and stirred for 70 minutes. After cooling to room temperature, B was added as shown in Table 1 and dissolved. The weight loss due to evaporation was replenished with deionized water to obtain a surface treatment agent of treatment liquid type S2 (Example 2). The water content in this surface treatment agent was 95% by mass.

<Treatment liquid type S3>
The raw materials used in preparing the surface treatment agent of treatment liquid type S3 are shown below.
<Tetraalkoxysilane (A1)>
Tetraethoxysilane (TEOS)
<Silane Coupling Agent (A2)>
3-Aminopropyltriethoxysilane <Silver salt and/or silver complex (B)>
Same as treatment liquid type S1.
<Organic Acid (C) Having Two or More Carboxyl Groups>
Malic acid

The above components (A1, A2, and C) were blended in deionized water at 75°C according to the test number as shown in Table 1 and stirred for 70 minutes. After cooling to room temperature, B was added as shown in Table 1 and dissolved. The weight loss due to evaporation was replenished with deionized water to obtain a surface treatment agent of treatment liquid type S3 (Example 3). The water content in this surface treatment agent was 95% by mass.

<Treatment liquid type S4>
The raw materials used in preparing the surface treatment agent of treatment liquid type S4 are shown below.
<Tetraalkoxysilane (A1)>
Tetraethoxysilane (TEOS)
<Silane Coupling Agent (A2)>
3-mercaptopropyltriethoxysilane <silver salt and/or silver complex (B)>
Same as treatment liquid type S1.
<Organic Acid (C) Having Two or More Carboxyl Groups>
Malic acid

The above components (A1, A2, and C) were blended in deionized water at 75°C according to the test number as shown in Table 1 and stirred for 70 minutes. After cooling to room temperature, B was added as shown in Table 1 and dissolved. The weight loss due to evaporation was replenished with deionized water to obtain a surface treatment agent of treatment liquid type S4 (Example 4). The water content in this surface treatment agent was 95% by mass.

<Treatment liquid type S5>
The raw materials used in preparing the surface treatment agent of treatment liquid type S5 are shown below.
<Tetraalkoxysilane (A1)>
Tetraethoxysilane (TEOS)
<Silane Coupling Agent (A2)>
3-Glycidoxypropyltrimethoxysilane 3-Aminopropyltriethoxysilane <Silver salt and/or silver complex (B)>
Same as treatment liquid type S1.
<Organic Acid (C) Having Two or More Carboxyl Groups>
・Tartaric acid

The above components (A1, A2, and C) were blended in deionized water at 75°C according to the test number as listed in Table 1 and stirred for 70 minutes. After cooling to room temperature, B was added as listed in Table 1 and dissolved. The weight loss due to evaporation was replenished with deionized water to obtain treatment liquid type S5 surface treatment agent (Example 5). In treatment liquid type S5, A2 was blended so that the molar ratio of 3-glycidoxypropyltrimethoxysilane:3-aminopropyltriethoxysilane was 3:1. The molar concentration of A2 listed in Table 1 is the total value of both. The water content in this surface treatment agent was 95% by mass.

<Treatment liquid type S6>
The raw materials used in preparing the surface treatment agent of treatment liquid type S6 are shown below.
<Tetraalkoxysilane (A1)>
Tetraethoxysilane (TEOS)
<Silane Coupling Agent (A2)>
3-Isocyanatepropyltrimethoxysilane <Silver salt and/or silver complex (B)>
Same as treatment liquid type S1.
<Organic Acid (C) Having Two or More Carboxyl Groups>
・Tartaric acid

The above components (A1, A2, and C) were blended in deionized water at 75°C according to the test number as shown in Table 1 and stirred for 70 minutes. After cooling to room temperature, B was added as shown in Table 1 and dissolved. The weight loss due to evaporation was replenished with deionized water to obtain a surface treatment agent of treatment liquid type S6 (Example 6). The water content in this surface treatment agent was 95% by mass.

<Treatment liquid type S7>
The raw materials used in preparing the surface treatment agent of treatment liquid type S7 are shown below.
<Tetraalkoxysilane (A1)>
Tetraethoxysilane (TEOS)
<Silane Coupling Agent (A2)>
Vinyltriethoxysilane 3-aminopropyltriethoxysilane <Silver salt and/or silver complex (B)>
Same as treatment liquid type S1.
<Organic Acid (C) Having Two or More Carboxyl Groups>
・Tartaric acid

The above components (A1, A2, and C) were blended in deionized water at 75°C according to the test number as listed in Table 1 and stirred for 70 minutes. After cooling to room temperature, B was added as listed in Table 1 and dissolved. The weight loss due to evaporation was replenished with deionized water to obtain treatment liquid type S7 surface treatment agent (Example 7). In treatment liquid type S7, A2 was blended so that the molar ratio of vinyltriethoxysilane:3-aminopropyltriethoxysilane was 3:1. The molar concentration of A2 listed in Table 1 is the total value of both. The water content in this surface treatment agent was 95% by mass.

<Treatment liquid type S8>
The raw materials used in preparing the surface treatment agent of treatment liquid type S8 are shown below.
<Tetraalkoxysilane (A1)>
Tetraethoxysilane (TEOS)
<Silane Coupling Agent (A2)>
Vinyltriethoxysilane 3-glycidoxypropyltrimethoxysilane <Silver salt and/or silver complex (B)>
Same as treatment liquid type S1.
<Organic Acid (C) Having Two or More Carboxyl Groups>
・Tartaric acid

The above components (A1, A2, and C) were blended in deionized water at 75°C according to the test number as listed in Table 1 and stirred for 70 minutes. After cooling to room temperature, B was added as listed in Table 1 and dissolved. The weight loss due to evaporation was replenished with deionized water to obtain treatment liquid type S8 surface treatment agent (Example 8). In treatment liquid type S8, A2 was blended so that the molar ratio of vinyltriethoxysilane:3-glycidoxypropyltrimethoxysilane was 3:1. The molar concentration of A2 listed in Table 1 is the total value of both. The water content in the surface treatment agent was 95% by mass.

<Condition 1: (A1+A2)/B>
The molar ratio ((A1+A2)/B) of the total (A1+A2) of the tetraalkoxysilane (A1) and the silane coupling agent (A2) to the silver salt and/or silver complex (B) was calculated from the raw material blending conditions. The results are shown in Table 1.

<Condition 2: C/B>
The molar ratio (C/B) of the carboxyl group of the organic acid (C) to the silver salt and/or silver complex (B) was calculated from the raw material blending conditions. The results are shown in Table 1.

<Condition 3: Dα/Dβ>
For each surface treatment agent prepared by the above method, the molar concentration (mol/L) (Dα) of the alcohol was measured using an NMR device (e.g., JNM-FCX400, manufactured by JEOL Ltd.). This gave the ratio (Dα/Dβ) of Dα to the molar concentration (mol/L) (Dβ) of the alcohol in the surface treatment agent that would result if all alkoxy groups contained in A1 and A2 were hydrolyzed. The results are shown in Table 1.

<Weight average molecular weight>
The weight average molecular weight of each of the surface treatment agents prepared by the above method was measured by the GPC method described above. The results are shown in Table 2.

[2. Fiber surface treatment]
Type I (100% cotton woven fabric) and Type III (100% polyester knitted fabric) washing test load fabrics specified in JIS L1930:2014, Appendix H were prepared. The load fabrics were immersed in each surface treatment agent prepared by the above method at 25°C, and after 1 minute, squeezed to adjust the amount of surface treatment agent adhered to 1 g of fiber. The load fabrics were then placed in an oven and dried for 2 minutes at the maximum drying temperature listed in Table 2. This resulted in surface-treated fibers with a coating. The number of surface-treated fibers required for the following property evaluations was prepared. Of the following evaluation tests, "fiber deterioration" was performed on both the surface-treated fibers using the type I (cotton) load fabric and the surface-treated fibers using the type III (polyester) load fabric, while the other evaluation tests were performed only on the surface-treated fibers using the type I (cotton) load fabric.

[3. Coating Amount]
The amount of Si was measured as an index of the amount of coating attached to the surface-treated fiber. Specifically, a wavelength dispersive X-ray fluorescence analyzer (Rigaku Corporation, Model: ZSX-Primus III) was used to quantitatively analyze the amount of Si (mg) attached per 1 ^m2 of the surface-treated fiber under the following analytical conditions:
Tube: Rh
Spectroscopic crystal: PET
Analysis diameter: 30mmφ
Voltage-current: 50kV 50mA
Specifically, the mass of _SiO2 was first determined by a calibration curve method from the Si intensity measured with a wavelength dispersive X-ray fluorescence analyzer. A coated plate was prepared by coating it with a urethane resin (HYDRAN SP-510, manufactured by DIC Corporation) to which a predetermined amount of _SiO2 had been added, and a calibration curve was created using the amount of _SiO2 attached per ^m2 of the coated plate. The determined mass of _SiO2 was converted into Si and the mass of Si was calculated as [ _SiO2 mass × Si atomic weight / _SiO2 molecular weight (28.1 / 60.1)]. The results are shown in Table 2.

4. Characterization
<Antibacterial performance (before washing)>
The antibacterial performance of each surface-treated fiber obtained using the above surface treatment method was evaluated in accordance with JIS L1902:2015. Specifically, Escherichia coli and Staphylococcus aureus were separately inoculated onto the surface-treated fibers and cultured at 37°C for 18 hours. After culture, the surface-treated fibers were placed in a vial, a washout solution was added to wash away the bacteria, and the viable cell count was measured. The same method was also used to inoculate, culture, and measure the viable cell count for the above-mentioned unsurface-treated loaded fabric (control). The antibacterial activity value was calculated by comparing the surface-treated fibers with the control. The antibacterial performance was evaluated according to the following criteria. The results are shown in Table 2.
◎: Antibacterial activity values of 3.0 or more for both bacterial species. ○: Antibacterial activity values of bacterial species with low antibacterial activity values are less than 3.0, 2.0 or more. △: Antibacterial activity values of bacterial species with high antibacterial activity values are 2.0 or more, but antibacterial activity values of bacterial species with low antibacterial activity values are less than 2.0. ×: Antibacterial activity values of both bacterial species are less than 2.0.

<Antibacterial performance (after 30 washes)>
Each surface-treated fiber obtained using the above surface treatment method was washed 30 times using the washing method No. C4G in accordance with Appendix F of JIS L1930:2014. The same method was also used for the untreated loaded fabric (control), which was also washed 30 times. Subsequently, bacteria were inoculated, cultured, and viable cell counts were measured using the same method as described above in "Antibacterial Performance (Before Washing)," and the antibacterial activity value was calculated. Antibacterial performance was evaluated according to the following criteria. The results are shown in Table 2.
◎: Antibacterial activity values of 3.0 or more for both bacterial species. ○: Antibacterial activity values of bacterial species with low antibacterial activity values are less than 3.0, 2.0 or more. △: Antibacterial activity values of bacterial species with high antibacterial activity values are 2.0 or more, but antibacterial activity values of bacterial species with low antibacterial activity values are less than 2.0. ×: Antibacterial activity values of both bacterial species are less than 2.0.

<Water absorption>
The water absorbency of each surface-treated fiber obtained by the above surface treatment method was evaluated. According to JIS L 1907:2010 (dropping method), a drop of water was dropped onto the surface-treated fiber, and the time (seconds) until the water drop was absorbed was measured. The same measurement was also performed on the above-mentioned unsurface-treated loaded fabric (control). The values for both were compared, and the time difference was evaluated according to the following criteria. The results are shown in Table 2.
◎: Less than 1 second compared to the control. ○: 1 second or more but less than 2 seconds compared to the control. △: 2 seconds or more but less than 3 seconds compared to the control. ×: 3 seconds or more compared to the control.

<Liquid stability>
For each of the surface treatment agents according to the above Examples and Comparative Examples, a 50-fold concentrated solution of each surface treatment agent was prepared by carrying out the same preparation method, except that the amount of deionized water added was changed. The resulting concentrated solution was placed in a JP bottle (a wide-mouth PP bottle), sealed, and stored in a dark room at room temperature for 6 months. The appearance of the concentrated solution was then measured for transmitted light turbidity using a formazin standard solution and chromaticity using platinum and cobalt in accordance with JIS K 0101:1998 "Testing Methods for Industrial Water," and evaluated according to the following criteria. The results are shown in Table 2.
◎: Turbidity 2 degrees or less and chromaticity 5 degrees or less ○: Turbidity more than 2 degrees and chromaticity more than 5 degrees and 50 degrees or less △: Turbidity more than 2 degrees and chromaticity more than 5 degrees and 50 degrees or less ×: Turbidity more than 100 degrees and chromaticity more than 50 degrees

<Deterioration of fiber>
Each surface-treated fiber obtained by the above surface treatment method was subjected to a weather resistance test under the following conditions.
Weather resistance tester: Super Xenon Weather Meter SX75 manufactured by Suga Test Instruments Co., Ltd.
Light source: Xenon arc lamp 7.5 kW
Irradiation intensity: 180W/m ²
Inner filter: Quartz Outer filter: #275
Black Panel Temperature (BPT): 63°C
Test mode: (Rainfall mode, 18 minutes during a 2-hour irradiation cycle) x 60 cycles. After the weather resistance test, the surface-treated fibers were visually inspected for appearance and evaluated for deterioration by touch. The evaluation was based on the following criteria. The results are shown in Table 2.
⊚: No change in texture or discoloration was observed before and after the weather resistance test.
○: There is no change in texture before and after the weather resistance test, but discoloration is observed.
△: No discoloration was observed before and after the weathering test, but a change in texture was observed.
×: Change in texture and discoloration was observed before and after the weather resistance test.

Claims (3)

a silane compound (A) which is a hydrolysis product and a condensation reaction product of a tetraalkoxysilane (A1) and a silane coupling agent (A2);
a silver salt and/or silver complex (B);
an organic acid (C) having two or more carboxyl groups;
Water (E),
The silane compound (A) includes an alcohol (D) which is a hydrolyzate of at least one of the tetraalkoxysilane (A1) and the silane coupling agent (A2);
A surface treatment agent comprising
a ratio (Dα/Dβ) of the actual molar concentration (mol/L) (Dα) of the alcohol (D) in the surface treatment agent to the molar concentration (mol/L) (Dβ) of the alcohol in the surface treatment agent that would be produced if all alkoxy groups contained in the tetraalkoxysilane (A1) and the silane coupling agent (A2) were hydrolyzed is 0.05 to 0.9,
A surface treatment agent for fibers prepared so as to satisfy the following compounding conditions 1) and 2).
1) The molar ratio {(A1+A2)/B} of the total (A1+A2) of the tetraalkoxysilane (A1) and the silane coupling agent (A2) to the silver salt and/or silver complex (B) is 100 to 500.
2) The molar ratio (C/B) of the carboxyl groups of the organic acid (C) to the silver salt and/or silver complex (B) is 5 to 25. A method for treating the surface of fibers, comprising contacting the fiber surface treating agent according to claim 1 with part or all of the fibers to form a film. A surface-treated fiber having a coating, obtained by the surface treatment method according to claim 2 .