JP7836880B2 - Deodorizing fiber structure - Google Patents

Description

This invention relates to a deodorizing fiber structure with high deodorizing performance and high washability.

Deodorizing fibers are used in carpets, curtains, bedding, underwear, diapers, and sanitary products. Clothing that comes into direct contact with the skin can cause discomfort due to odors such as sweat and age-related body odor, so there is a high demand for textile products with deodorizing properties.
Patent Document 1 proposes knitting using elastic fibers and crosslinked acrylate yarn containing carboxyl groups and crosslinked bonds due to hydrazine treatment as deodorizing fibers. Patent Document 2 proposes elastic fibers containing zinc oxide and zirconium phosphate. Patent Document 3 proposes synthetic fibers containing α-zirconium phosphate and/or α-titanium phosphate.

Japanese Patent Publication No. 2002-000659 Japanese Patent Publication No. 2006-028453 Japanese Patent Publication No. 2018-178313

However, cross-linked acrylate yarns like those described in Patent Document 1 have the problem of high hygroscopicity, meaning that their deodorizing function is lost when they absorb moisture. Furthermore, the fibers described in Patent Documents 2 and 3 have the problem of losing their deodorizing function when subjected to alkaline treatment. Alkaline treatment is used in the case of polyester fibers for alkaline weight reduction, and in the case of cotton fibers, linen fibers, etc., for scouring, bleaching, and mercerizing. The loss of deodorizing function is problematic in these cases.

This invention solves the problems of the conventional technology described above and provides a deodorizing fiber structure that is bleached yet highly washable.

The odor-eliminating fiber structure of the present invention comprises a first fiber which is at least one selected from synthetic fibers and regenerated fibers, and a second fiber which is a natural fiber, and is in a bleached state .
The first fiber is a deodorizing fiber obtained by mixing a polymer with an inorganic layered deodorant, which is α-zirconium phosphate , and the second fiber contains cotton.
The inorganic layered deodorant has an interlayer distance of 0.1 nm or more and 0.9 nm or less, and a crystallite size of 1 nm or more and 30 nm or less.
The aforementioned deodorizing fiber structure is characterized by a reduction rate of 70% or more in ammonia gas after 0 and 10 washes at home.

This invention provides a deodorizing fiber structure containing deodorizing fibers in which an inorganic layered deodorant is mixed with a polymer. The inorganic layered deodorant has an interlayer distance of 0.1 nm to 0.9 nm and a crystallite size of 1 nm to 30 nm. The deodorizing fiber structure exhibits a 70% or higher reduction in ammonia gas after 0 and 10 washes, thus providing a deodorizing fiber structure with high deodorizing performance and high washability. Specifically, while the deodorizing fiber structure containing the inorganic layered deodorant, before bleaching, shows a significant decrease in deodorizing function when treated with alkali, as the interlayer distance exceeds 0.9 nm, organic acid treatment reduces the interlayer distance of the deodorant to 0.9 nm or less, resulting in a bleached deodorizing fiber structure with restored deodorizing function. This deodorizing fiber structure also exhibits good washability.

Figure 1 is a wide-angle X-ray diffraction pattern multiplexing graph of an inorganic layered deodorant used in one embodiment of the present invention, and is an enlarged view of the area around 2θ = 10°.

The inventors encountered a problem in which elastic fibers containing inorganic layered deodorants such as α-zirconium phosphate initially have deodorizing properties, but lose their deodorizing function upon alkaline treatment. They investigated the cause of this problem. The layered structure of α-zirconium phosphate is shown below (Chemical Formula 1), and the interlayer distance is approximately 7.55 Å (angstroms, 0.755 nm) (Hasegawa et al., "On the Ion Exchange Properties of Layered Phosphate M( _IV )(HPO₄) _₂ · _H₂O (M=Zr,Hf)", IONICS, October 1985).

The interlayer distance of the α-zirconium phosphate is sufficient to accommodate substances smaller than ammonia molecules, and it is presumed that the absorbed gases are neutralized and deodorized by ionic bonding with the functional groups of the α-zirconium phosphate crystals.
However, it was found that when the fibrous structure is subjected to strongly alkaline conditions such as alkali treatment, it expands to a distance exceeding 0.9 nm due to ion exchange with alkali metals, etc., incorporating substances other than ammonia, reducing the active functional groups, and causing the deodorizing function to be deactivated. Therefore, various studies were conducted to restore the deodorizing function, and it was found that treating with an organic acid after alkali treatment can return the interlayer distance of the inorganic layered deodorant to its original state, and the deodorizing function is restored. The experimental conditions and results will be explained later, but the important points are as shown in Table 1 below.

As is clear from Table 1, the interlayer distance and crystallite size of α-zirconium phosphate increase after scouring and bleaching, but the interlayer distance returns to its original state and the crystallite size becomes smaller than the original state after organic acid treatment. This is a novel finding.
This invention was completed based on the above ideas and problems.

This invention relates to a deodorizing fiber structure containing deodorizing fibers in which an inorganic layered deodorizing agent is mixed with a polymer. As an example, fibers obtained by adding and mixing an inorganic layered deodorizing agent to a spinning solution are used. Spinning may be performed by melt spinning or wet spinning. The deodorizing fiber structure is alkali-treated. In the case of polyester fibers, alkali treatment is used in alkali weight reduction processing. In the case of cotton fibers, linen fibers, etc., it is used in scouring, bleaching, mercerizing, and other processes. The amount of inorganic layered deodorizing agent added to the deodorizing fibers is preferably 0.5 to 10% by mass, and more preferably 1 to 7% by mass, when the deodorizing fibers are considered as the base amount. Within this range, high deodorizing performance can be maintained.

The aforementioned fiber structure is subjected to alkali treatment followed by organic acid treatment, and the interlayer distance of the deodorant is 0.9 nm or less, and the ammonia deodorization performance is 70% or more after 0 and 10 washes. The preferred interlayer distance of the deodorant is 0.70 to 0.85 nm, and more preferably 0.72 to 0.80 nm. This results in a deodorizing fiber structure with high deodorizing performance and high washability. Furthermore, the organic acid treatment removes the alkali metal bonds such as sodium and potassium from the deodorant, and the deodorizing function of the deodorant is restored.
The deodorant is preferably at least one selected from α-zirconium phosphate, α-hafnium phosphate, and α-titanium phosphate. α-zirconium phosphate and α-titanium phosphate have been shown to have deodorizing effects in Patent Document 3. The source document for (Chemical Formula 1) states that the interlayer distance of α-hafnium phosphate is equivalent to that of α-zirconium phosphate. Among these, α-zirconium phosphate is preferred.

The deodorizing fiber is preferably at least one selected from synthetic fibers and regenerated fibers. The polymer constituting the deodorizing fiber may be a thermoplastic resin such as polyester, polyamide, polyolefin, or polyurethane, or a thermosetting resin such as regenerated cellulose or acrylic polymer. These resins can be mixed with the inorganic layered deodorant in the spinning solution. Regenerated fibers include rayon, cupro, polynosic, and lyocell (registered trademark). Any spinning solution capable of mixing with the inorganic layered deodorant can be used.

The aforementioned fiber structure contains 100% by mass of the deodorizing fibers or the deodorizing fibers and other fibers. When other fibers are included, the deodorizing fibers are preferably 1 to 99% by mass when the fiber structure is considered as the base. More preferably, the deodorizing fibers are 2 to 50% by mass, and even more preferably 5 to 30% by mass. Within these ranges, deodorizing properties can be achieved. The other fibers are preferably at least one selected from natural fibers, synthetic fibers, and regenerated fibers. Natural fibers include cotton, linen, wool, silk, etc.

The organic acid is preferably an organic acid having 2 to 6 carbon atoms and containing a carboxyl group. The organic acid is effective in reviving the deodorant. It can also be dissolved in an aqueous solution, making it convenient for processing. The organic acid having 2 to 6 carbon atoms and containing a carboxyl group is preferably at least one selected from citric acid, maleic acid, malic acid, acetic acid, and succinic acid. Optical isomers are also included if they exist.
Citric acid has the structure shown in (Chemical Formula 2) below.
Maleic acid has the structure shown in (Chemical Formula 3) below.
Malic acid has the structure shown in (Chemical Formula 4) below.
Acetic acid has the structure shown in (Chemical Formula 5) below.
Succinic acid has the structure shown in (Chemical Formula 6) below.

The pH of the aforementioned fiber structure is preferably 4.0 to 5.8, and more preferably 4.1 to 5.5. Having a slightly acidic pH like this is gentle on the skin and does not cause adverse effects. The pH of the fabric is measured according to the "Test Methods for Woven and Knitted Fabrics" specified in JIS L1096:2010 8.37.

The ammonia deodorization performance of the aforementioned fiber structure after 10 washes at home is preferably 70% or higher, more preferably 80% or higher, and even more preferably 90% or higher. This allows for a deodorizing fiber structure with high deodorizing performance and high washability. The home washing method and ammonia deodorization test will be described later.

In this invention, the fibrous structure may have any structure or shape, such as a fabric, strip, cord, or thread. Preferably, a fabric containing a woven or knitted fabric or a nonwoven fabric is used, and a composite material containing such a fibrous structure may also be used.

The fibrous structure of one embodiment of the present invention contains elastic fibers and at least cotton, and may also contain other fibers such as synthetic fibers, regenerated fibers, semi-synthetic fibers, and natural fibers other than cotton. When the fibrous structure is used as the base, the ratio of elastic fibers to cotton is preferably 1 to 30% by mass for elastic fibers and 70 to 99% by mass for cotton. Furthermore, when cotton is used as the base, it is preferable that the ratio be 10 to 90% by mass for cotton and 10 to 90% by mass for other fibers.

Examples of synthetic fibers include polyester fibers, polyamide fibers, polyethylene fibers, polypropylene fibers, polyvinyl alcohol fibers, polyvinyl chloride fibers, and polyacrylonitrile fibers. Polyester fibers include polyethylene terephthalate, polybutylene terephthalate, and polytrimethylene terephthalate, as well as copolymers of these with a third component such as isophthalic acid. Examples of regenerated and semi-synthetic fibers include rayon and acetate, while examples of natural fibers include hemp, wool, and silk. These fibers can be either short or long fibers and can be used individually or in blends of two or more types as composite yarns. Furthermore, these synthetic or natural fibers can be used as composite yarns such as covering, air entanglement, twisting, composite false twist, and core-spun yarns with elastic fibers made of polyurethane.

The aforementioned fibrous structure is preferably a knitted fabric, woven fabric, or clothing sewn from these. In particular, knitted fabrics are suitable for stretchy clothing such as legwear, innerwear, sportswear, and socks. It can also be applied to diapers, sanitary products, etc. These materials are required to have high deodorizing properties and high washability.

The present invention provides a method for producing a deodorizing fiber structure, comprising an alkaline treatment step of treating the fiber structure with an aqueous solution containing an alkaline substance, and an organic acid treatment step of immersing and heating the fiber structure in an aqueous solution containing an organic acid. The alkaline treatment step is preferably at least one selected from bleaching and alkaline weight reduction. Bleaching can be done using conventional methods, and treatment with an oxygen-based bleach such as an aqueous hydrogen peroxide solution is preferred. Chlorine-based bleaches such as aqueous solutions containing sodium hypochlorite are undesirable because they damage polyurethane elastic fibers. The organic acid treatment is preferably performed before or after dyeing. Particularly preferable is dyeing after the organic acid treatment. This allows for vivid dyeing.

If the deodorizing fiber structure includes natural fibers such as cotton or hemp, it is preferable to include the following steps.
(1) Scouring process (2) Bleaching process (3) Dyeing process (4) Softening process (5) Processing process involving immersion and heating in an aqueous solution containing organic acid Of the above processes, (1) to (4) can be carried out using conventional methods. The scouring process and the bleaching process may be carried out in the same process. In the dyeing process, various shades of color can be achieved. In the processing process of (5), in addition to immersion and heating, padding treatment is also possible, but batch immersion and heating is preferred from the viewpoint of deodorizing performance. The concentration of organic acid in the aqueous solution containing organic acid is preferably 0.5 to 10 g/L.
As mentioned above, it is preferable to perform the dyeing after the organic acid treatment.

Next, we will describe the case where the deodorizing fiber containing the inorganic layered deodorizer is an elastic fiber. Examples of such elastic fibers include polyester-based elastic fibers, polyamide-based elastic fibers, polyolefin-based elastic fibers, and polyurethane-based elastic fibers, with polyurethane-based elastic fibers being particularly preferred. The aforementioned deodorizer is mixed into the elastic fiber.

In this invention, the polyurethane used in the elastic fiber is not particularly limited, as long as it contains a structure in which the starting materials are a polymer diol and a diisocyanate. Furthermore, the synthesis method is not particularly limited. That is, for example, it may be a polyurethane urea derived from a polymer diol, a diisocyanate, and a low molecular weight diamine, or it may be a polyurethane urethane derived from a polymer diol, a diisocyanate, and a low molecular weight diol.

In this invention, a polymer diol compound refers to a diol compound with a number-average molecular weight (hereinafter sometimes abbreviated as molecular weight) of 200 or more, while a compound with a molecular weight of less than 200 is called a low-molecular-weight diol compound. Furthermore, the molecular weight of the polymer diol is preferably between 1000 and 8000, and more preferably between 1500 and 6000. A polyurethane urea containing a compound with hydroxyl and amino groups in its molecule as a chain extender may also be used. It is also preferable to use trifunctional or polyfunctional glycols or isocyanates, etc., within a range that does not hinder the effects of this invention.

Preferred polymer diols include polyether glycols, polyester glycols, and polycarbonate diols. Polyether glycols are particularly preferred from the viewpoint of imparting flexibility and elongation to the yarn.
Examples of polyether glycols include polyethylene glycol, modified polyethylene glycol, polypropylene glycol, polytrimethylene ether glycol, polytetramethylene ether glycol (hereinafter abbreviated as PTMG), modified PTMG which is a copolymer of tetrahydrofuran (hereinafter abbreviated as THF) and 3-methyl-THF, modified PTMG which is a copolymer of THF and 2,3-dimethyl-THF, modified PTMG which is a copolymer of THF and neopentyl glycol, and random copolymers in which THF and ethylene oxide and/or propylene oxide are irregularly arranged. One of these polyether glycols may be used, or two or more may be used. Among these, PTMG or modified PTMG is preferred.
Next, as diisocyanates, aromatic diisocyanates such as diphenylmethane diisocyanate (hereinafter abbreviated as MDI), tolylene diisocyanate, 1,4-diisocyanatebenzene, xylylene diisocyanate, and 2,6-naphthalene diisocyanate are particularly suitable because they can be used to obtain elastic yarns made of polyurethane with high heat resistance and strength. Furthermore, as alicyclic diisocyanates, for example, methylenebis(cyclohexyl isocyanate), isophorone diisocyanate, methylcyclohexane-2,4-diisocyanate, methylcyclohexane-2,6-diisocyanate, cyclohexane-1,4-diisocyanate, hexahydroxylylene diisocyanate, hexahydrotolylene diisocyanate, and octahydro-1,5-naphthalene diisocyanate are preferred. Aliphatic diisocyanates can be used particularly effectively to suppress yellowing of elastic yarns made of polyurethane. These diisocyanates may be used individually or in combination of two or more.

Next, the chain extender used in polyurethane is preferably at least one of low molecular weight diamines and low molecular weight diols. It may also be a substance having both a hydroxyl group and an amino group in its molecule, such as ethanolamine.
Examples of low molecular weight diamines include ethylenediamine, 1,2-propanediamine, 1,3-propanediamine, hexamethylenediamine, p-phenylenediamine, p-xylylenediamine, m-xylylenediamine, p,p'-methylenedianiline, 1,3-cyclohexyldiamine, hexahydrometaphenylenediamine, 2-methylpentamethylenediamine, and bis(4-aminophenyl)phosphine oxide. It is preferable to use one or more of these. Ethylenediamine is particularly preferred. By using ethylenediamine, yarns with excellent elongation, elastic recovery, and heat resistance can be easily obtained. Triamine compounds capable of forming crosslinked structures, such as diethylenetriamine, may be added to these chain elongators in an amount that does not diminish their effectiveness. Typical examples of low molecular weight diols include ethylene glycol, 1,3-propanediol, 1,4-butanediol, bishydroxyethoxybenzene, bishydroxyethylene terephthalate, and 1-methyl-1,2-ethanediol. It is preferable that one or more of these be used. Particularly preferred are ethylene glycol, 1,3-propanediol, and 1,4-butanediol. Using these results in a polyurethane with higher heat resistance and a higher strength, making it possible to obtain an elastic yarn made of polyurethane.

It is also preferable that one or more end-capping agents be used in combination with the polyurethane. Preferred end-capping agents include monoamines such as dimethylamine, diisopropylamine, ethylmethylamine, diethylamine, methylpropylamine, isopropylmethylamine, diisopropylamine, butylmethylamine, isobutylmethylamine, isopentylmethylamine, dibutylamine, and diamylamine; monools such as ethanol, propanol, butanol, isopropanol, allyl alcohol, and cyclopentanol; and monoisocyanates such as phenyl isocyanates.

The content of the deodorant is preferably in the range of 0.5% by mass or more and 10% by mass or less relative to the total mass of the elastic fibers made of polyurethane. A content of 0.5% by mass or more of the deodorant is preferable because it provides even higher ammonia gas deodorizing properties when the fabric is made. More preferably, it is 1.0% by mass or more. On the other hand, a content exceeding 10% by mass is undesirable due to deterioration of stretchability and cost. More preferably, it is 7.0% by mass or less. Considering the balance between deodorizing properties, physical properties, and cost, a range of 1.5% by mass or more and 5.0% by mass or less is particularly preferred.

From the viewpoint of suppressing clogging of the spinneret with the spinning solution, the deodorant is preferably one with an average primary particle diameter of 3.0 μm or less. More preferably, it is 1.5 μm or less. Furthermore, from the viewpoint of dispersibility, if the average primary particle diameter is smaller than 0.05 μm, the cohesive force increases, making uniform mixing in the spinning solution difficult. Therefore, an average primary particle diameter of 0.05 μm or more is preferred. More preferably, it is 0.15 μm or more.

Furthermore, the elastic fibers made of polyurethane may contain various stabilizers and pigments. For example, it is preferable that these contain lightfasteners and antioxidants such as BHT and hindered phenol-based agents such as "Sumilyzer" (registered trademark) GA-80 manufactured by Sumitomo Chemical Co., Ltd., various benzotriazole-based and benzophenone-based agents such as "Tinuvin" (registered trademark) manufactured by Ciba-Geigy, phosphorus-based agents such as "Sumilyzer" (registered trademark) P-16 manufactured by Sumitomo Chemical Co., Ltd., various hindered amine-based agents, various pigments such as iron oxide and titanium dioxide, inorganic substances such as zinc oxide, cerium oxide, magnesium oxide, calcium carbonate, and carbon black, fluorine-based or silicone-based resin powders, metal soaps such as magnesium stearate, lubricants such as silicone and mineral oil, and various antistatic agents such as cerium oxide, betaine, and phosphoric acid-based agents, and that these also bond with the polyurethane. Furthermore, to further enhance durability against light and various nitrogen oxides, it is preferable to include, for example, a nitrogen oxide scavenger such as HN-150 manufactured by Nippon Hydrazine Co., Ltd., a thermal oxidation stabilizer such as "SumiLizer" (registered trademark) GA-80 manufactured by Sumitomo Chemical Co., Ltd., and a light stabilizer such as "SumiSorb" (registered trademark) 300#622 manufactured by Sumitomo Chemical Co., Ltd. The concentration of the resulting polyurethane spinning solution is usually preferably in the range of 30% by mass to 80% by mass. The deodorant is then mixed into this spinning solution.

The polyurethane elastic fiber of the present invention can be obtained by, for example, dry spinning, wet spinning, or melt spinning the spinning solution configured as described above and then winding it up. Among these methods, dry spinning is preferred from the viewpoint of being able to stably spin fibers of all finenesses, from thin to thick.

The fineness, cross-sectional shape, etc., of the polyurethane elastic fiber of the present invention are not particularly limited. For example, the cross-sectional shape of the yarn may be circular or flat.
Furthermore, there are no particular restrictions on the dry spinning method; spinning should be performed by appropriately selecting spinning conditions that match the desired characteristics and spinning equipment.
For example, the permanent strain rate and stress relaxation of the polyurethane elastic fiber of the present invention are particularly susceptible to the influence of the speed ratio between the Godet roller and the winding machine, so it is preferable to determine them appropriately according to the intended use of the yarn.
In other words, from the viewpoint of obtaining polyurethane elastic fibers having a desired permanent strain and stress relaxation, it is preferable to wind the Gode roller with a speed ratio of 1.10 or more and 1.65 or less. Furthermore, when obtaining polyurethane elastic fibers with a particularly low permanent strain and low stress relaxation, it is more preferable for the speed ratio of the Gode roller with the winding machine to be in the range of 1.15 or more and 1.4 or less, and even more preferable for the range of 1.15 or more and 1.35 or less. On the other hand, when obtaining polyurethane elastic fibers with a high permanent strain and high stress relaxation, it is preferable to wind the Gode roller with a speed ratio of 1.25 or more and 1.65 or less, and more preferably for the range of 1.35 or more and 1.65 or less.

Furthermore, from the viewpoint of improving the strength of the resulting polyurethane elastic fibers, the spinning speed is preferably 300 m/min or higher.

To apply the oil to the elastic fibers, it is preferable to use so-called neat lubrication, where the oil is applied directly without dilution with a solvent or other means. This application process can take place during the process between spinning and winding into a package, the process of rewinding the package, or the warping process using a warping machine; any of these processes is acceptable. Furthermore, known methods such as roller lubrication, guide lubrication, and spray lubrication can be applied. The amount of oil applied is preferably 0.1 to 5% by mass relative to the elastic fibers.

The present invention will be described in more detail using examples, but the present invention is not limited to these embodiments. First, the methods for evaluating various characteristics in the present invention will be described below.
[Method for evaluating deodorizing properties]
In accordance with the deodorizing test described in the SEK Mark Textile Product Certification Standards (established by the Product Certification Department of the Textile Evaluation Technology Council, revised on April 1, 2015), the deodorizing properties of odor components were evaluated using the detector tube method. Ammonia was used as the odor component.
The initial concentration of the odor component was set at 100 ppm ammonia. As a blank test, 5L sample bags (film) were filled with only the odor components, sealed, and left for 2 hours. The remaining gas concentration was measured using gas detection tubes corresponding to each component, and this was taken as the blank concentration. Next, the sample to be used for measurement (10 cm x 10 cm) was placed in a sample bag (film), filled with the odor components at the predetermined concentrations mentioned above, sealed, and the remaining gas concentration after 2 hours was measured using a gas detection tube. This was taken as the measured concentration. Three measurements were taken, and the average value was used to calculate the rate of decrease in the remaining gas concentration using the following formula, and this was expressed as the rate of decrease.
Deodorizing component reduction rate (%) = ((Blank test concentration - Measured concentration of each sample) / Blank test concentration)) × 100
The evaluation criteria for the reduction rate were as follows: ammonia 70% or more, acetic acid 70% or more, isovaleric acid 85% or more, and nonenal 75% or more.
[Washing Instructions]
In accordance with the standard washing method described in the SEK Mark Textile Product Washing Instructions (established by the Product Certification Department of the Textile Evaluation Technology Council, revised on April 1, 2014), a household electric washing machine as specified in Washing Instruction 103 of JIS L 0217: 1995, "Symbols and Methods of Displaying Textile Products for Handling," was used. A washing solution was prepared by adding 40 mL of JAFET standard blended detergent (containing polyoxyethylene alkyl ether and sodium alpha-olefin sulfonate) to 30 L of 40°C water. The sample and, if necessary, the load fabric were added to the bath to a bath ratio of 1:30. The process of washing for 5 minutes, spinning, rinsing for 2 minutes, spinning, rinsing for 2 minutes, and spinning was repeated 10 times, after which the samples were dried by hanging.
[Dough pH]
The measurements were performed according to the "Test Method for Woven and Knitted Fabrics" specified in JIS L1096:2010 8.37. 50 ml of distilled water was placed in a glass flask and boiled for 2 minutes. 5.0 g of finely chopped fabric test pieces were then added, the flask was sealed, and left for 30 minutes. After 30 minutes, the extract was adjusted to 25°C ± 2°C, and the pH of the extract was measured using a pH meter.

<Interlayer distance, crystallite size, and ammonia gas reduction rate of the deodorant at each processing stage of the fiber structure>
α-zirconium phosphate powder (elementary) was subjected to scouring and bleaching, dyeing with reactive dyes, and organic acid treatment using citric acid, and the interlayer distance, crystallite size, and ammonia gas reduction rate were investigated at each treatment stage. In addition, the interlayer distance and deodorizing function of α-zirconium phosphate powder (elementary) at each treatment stage of the fiber structure were also analyzed. Specifically, α-zirconium phosphate powder (elementary) was extracted from the fiber structure at each treatment stage (scouring and bleaching, dyeing with reactive dyes, organic acid treatment using citric acid), and the interlayer distance, crystallite size, and ammonia gas reduction rate were investigated.
The method for extracting the organic components from the fibrous structure involved using the treated fabrics of Example 1 and Example 3, dissolving the organic components completely with a solvent capable of dissolving the fibers constituting the fibrous structure, and then separating the residue by centrifugation.
<Inorganic layered deodorant>
α-Zirconium phosphate powder (average particle size 0.8 μm, volume-based particle size distribution measured by laser diffraction scattering method, cumulative particle size distribution D50 median diameter) (single element) was used.
<Scouring and bleaching of powders>
In a flask, 2.5 g/L of sodium hydroxide aqueous solution, 3.0 g/L of "WX-HC" (manufactured by Nikka Chemical Co., Ltd.) as a scouring agent, 0.5 g/L of a chelating agent, and 5 g/L of a 35% hydrogen peroxide aqueous solution as a bleaching agent were measured out to make a total volume of 1000 mL of aqueous solution. 10 g of α-zirconium phosphate powder was added to this solution and mixed while raising the temperature from 20°C to 95°C for 30 minutes to perform the scouring and bleaching treatment. Next, the treated water was centrifuged in a centrifuge to remove the scouring and bleaching treatment of α-zirconium phosphate powder.
<Dyeing treatment of powders>
Fluorescent whitening was performed using reactive dyes under the following components and conditions.
• Fluorescent whitening agent: 2 g/L of "UVITEX BHT LIQ" manufactured by Huntsman Japan.
・Buffer: Glauber's salt (sodium sulfate) 10g/L
- Dyeing agent: 0.5 g/L of "Newbon" manufactured by Nikka Chemical Co., Ltd. was measured out and the whole was mixed into a 1000 mL aqueous solution. The scouring and bleaching-treated α-zirconium phosphate was then added to this aqueous solution and mixed.
Conditions: After staining at 80°C for 60 minutes, the stained α-zirconium phosphate powder was extracted by centrifugation.
<Organic acid treatment of powder with citric acid>
A 1000 mL aqueous solution of citric acid at a concentration of 10 g/L was mixed with the stained α-zirconium phosphate, treated at 70°C for 20 minutes, and then centrifuged to obtain the organic acid-treated α-zirconium phosphate powder.
In addition to untreated α-zirconium phosphate powder, the deodorizing properties of α-zirconium phosphate powder obtained as described above (after scouring and bleaching), dyed α-zirconium phosphate powder (after dyeing), and organic acid treated α-zirconium phosphate powder (after organic acid treatment) were evaluated.
<Interlayer distance, crystallite size>
Interlayer distance and crystallite size were measured using Cu-Kα radiation, and powder X-ray diffraction analysis was performed using a Ni plate as a filter. The crystal structure was identified by comparing the obtained diffraction patterns with ASTM cards or existing literature.
Interlayer distances were analyzed by wide-angle X-ray diffraction. The results are summarized in Figure 1 and Tables 2-4. The horizontal axis of Figure 1 is a multi-plot (overlay) of the wide-angle X-ray diffraction patterns for each sample, and is an enlarged view around 2θ = 10°. In Figure 1, 2θ = 9° corresponds to 1.0 nm, and 2θ = 11.7° corresponds to 0.75 nm.
Table 2 shows the analysis results of the powder treatment, Table 3 shows the analysis results of the deodorant extracted from the treated cloth of Example 1, and Table 4 shows the analysis results of the deodorant extracted from the treated cloth of Example 3.

As is clear from Tables 2-4, the deodorizing function of the α-zirconium phosphate powder used as a deodorant was significantly reduced after scouring and bleaching, but it was confirmed that it could be restored by organic acid treatment. Furthermore, the interlayer distance, which was approximately 1.0 nm after scouring and bleaching, was confirmed to return to 0.75 nm after organic acid treatment.
Next, the deodorants were identified after staining and organic acid treatment using standard data from wide-angle X-ray diffraction. The results are shown in Table 5.

As is clear from Table 5, sodium and potassium compounds were identified in the inorganic layered deodorant after dyeing treatment. Furthermore, in the inorganic layered deodorant after organic acid treatment, the sodium and potassium were eliminated, and the original zirconium phosphate was identified.
From the above, it was found that inorganic layered deodorants without sodium and potassium bonded to them have high ammonia deodorizing function, while inorganic layered deodorants with sodium and potassium bonded to them have reduced ammonia deodorizing function.
From the experiments using the inorganic layered deodorant powder described above, it can be seen that any spinning solution that can be mixed with the inorganic layered deodorant can be used.

(Example 1)
<Textile materials>
- Cotton yarn: Commercially available spun cotton yarn (40 count per meter, single yarn) was used.
- For the polyurethane elastic fiber, we used 33decitex, an elastic yarn made of polyurethane containing 4% by mass of α-zirconium phosphate as an inorganic layered deodorant.
<Knitting Patterns>
Using the cotton yarn and elastic yarn described above, a knitted fabric was produced on a circular knitting machine with a gauge of 28. The resulting fabric had a weight of 165 g/ ^m² , with a mass ratio of 91.1% cotton yarn and 8.9% elastic yarn. The resulting fabric is called raw material.
<Scouring and bleaching process>
In a dyeing machine, 2.5 g/L of sodium hydroxide aqueous solution, 3.0 g/L of "WX-HC" (manufactured by Nikka Chemical Co., Ltd.) as a scouring agent, 0.5 g/L of a chelating agent, and 5 g/L of 35% hydrogen peroxide aqueous solution as a bleaching agent were added to a total volume of 20 L. 1000 g of knitted fabric was immersed in this solution, and the liquid temperature was raised from 20°C to 95°C for 30 minutes for scouring and bleaching treatment. Next, the treated water was drained, clean water was added, and the temperature was raised to 50°C for 5 minutes for hot water washing. Then the hot water was drained, 0.25 g/L of 90% acetic acid water was added, the temperature was raised to 40°C for 5 minutes for mixing, the acetic acid water was drained, clean water was added again, the temperature was raised to 50°C for 5 minutes for hot water washing, and then dewatered and dried.
<Dyeing process>
Fluorescent whitening was performed using reactive dyes under the following components and conditions.
• Fluorescent whitening agent: Huntsman Japan Co., Ltd. product name "UVITEX BHT LIQ" 0.15% owf
・Buffer: Glauber's salt (sodium sulfate) 10g/L
- Dyeing agent: "Newbon" product name manufactured by Nikka Chemical Co., Ltd., 0.5 g/L
Conditions: After dyeing at 80°C for 60 minutes, the material was neutralized at 60°C for 10 minutes, soaped at 60°C for 10 minutes, washed with hot water at 60°C for 10 minutes, and then dehydrated and dried.
<Softening treatment>
The fabric was treated with a softening agent by adding 1.5 owf% of "Softex A-1017S" manufactured by Kitahiro Chemical Co., Ltd. to an aqueous solution at 40°C for 20 minutes, then rinsed with water at 20°C for 5 minutes, and finally dehydrated and dried.
<Organic acid treatment with citric acid>
The dyed knitted garment was immersed in a 10 g/L aqueous solution of citric acid in a dyeing machine, treated at 70°C for 20 minutes, then washed, dehydrated, and dried.
The knitted fabrics obtained after treatment with citric acid as described above were evaluated.

(Example 2)
The procedure was carried out in the same manner as in Example 1, except that a 5 g/L aqueous solution of citric acid was used.

(Comparative Example 1)
The above raw materials were evaluated.

(Comparative Example 2)
The knitted fabrics were evaluated after the scouring and bleaching treatments described above.

(Comparative Example 3)
The knitted fabric after the dyeing treatment described above was evaluated.

(Comparative Example 4)
The knitted fabric after the softening treatment described above was evaluated.

The above conditions and results are summarized in Tables 6 and 7.

Table 6, Comparative Examples 1 and 2, shows that when knitted fabrics made of elastic fibers and cotton yarn are scoured and bleached, the deodorizing performance of the elastic fibers decreases, and this decreases further with fluorescent whitening treatment and softening treatment. However, it was confirmed that fabrics treated with citric acid immersion and heat treatment exhibit high deodorizing performance and high wash durability.

(Example 3)
<Textile materials>
The procedure was the same as in Example 1, except that a blended spun yarn (meter count 40, single yarn) consisting of 30% by mass of acrylic fiber and 70% by mass of cotton fiber was used instead of cotton yarn. The mass ratio of the knitted fabric was 27% by mass of acrylic fiber, 62% by mass of cotton fiber, and 11% by mass of elastic fiber.
<Dyeing process>
In addition to the method described in Example 1, fluorescent whitening was performed using a cationic dye.
• Fluorescent whitening agent: Huntsman Japan Co., Ltd. product name "UVITEX AC LIQ" 0.3% owf
- Leveling agent: Nichilon Salt C-25, manufactured by Nissei Kasei Co., Ltd., 0.5% owf
Acid: 0.5 g/L aqueous acetic acid solution
Conditions: After dyeing at 40°C for 10 minutes, 75°C for 15 minutes, and 100°C for 45 minutes, the material was soaped at 60°C for 10 minutes, washed with hot water at 60°C for 10 minutes, and then dehydrated and dried.
- After treating the acrylic with fluorescent whitening treatment, the cotton was treated with fluorescent whitening treatment in the same manner as in Example 1. All other treatments were carried out in the same manner as in Example 1.

(Example 4)
The procedure was carried out in the same manner as in Example 3, except that a 5 g/L aqueous solution of citric acid was used.

(Comparative Example 5)
The knitted fabrics after the above scouring and bleaching treatments were evaluated.

(Comparative Example 6)
The knitted fabric after the softening treatment described above was evaluated.
The above conditions and results are summarized in Table 8.

As is clear from Table 8, knitted fabrics made from elastic fibers and acrylic/cotton fiber blended yarns, bleached and treated with citric acid, exhibited high deodorizing performance and high wash durability.

(Examples 5-8)
(1) The raw materials used were as follows:
- Cotton yarn: Commercially available spun cotton yarn (40 count per meter, single yarn) was used.
- For the polyurethane elastic fiber, we used elastic yarn 22decitex, which is made of polyurethane containing 4% by mass of α-zirconium phosphate as an inorganic layered deodorant.
(2) The dough was as follows:
- Using the cotton yarn and elastic yarn mentioned above, a knitted fabric was produced on a circular knitting machine with a gauge of 28. - The resulting knitted fabric had a weight of 160 g/ ^m² , with a mass ratio of 94.4% cotton yarn and 5.6% elastic yarn.
(3) Post-processing The procedure was carried out in the same manner as in Example 1, except as shown in Table 9. The conditions and results are summarized in Table 9.

As is clear from Table 9, acetic acid, malic acid, citric acid, and maleic acid were also used as organic acids to achieve washable deodorizing treatment.

(Example 9)
(1) The raw materials used were as follows:
- Cotton yarn: Commercially available spun cotton yarn (40 count per meter, single yarn) was used.
- For the polyurethane elastic fiber, we used elastic yarn 22decitex, which is made of polyurethane containing 4% by mass of α-zirconium phosphate as an inorganic layered deodorant.
(2) The dough was as follows:
- Using the cotton yarn and elastic yarn mentioned above, a knitted fabric was produced on a circular knitting machine with a gauge of 28. - The resulting knitted fabric had a weight of 160 g/ ^m² , with a mass ratio of 93.1% cotton yarn and 6.9% elastic yarn.
(3) Post-treatment The procedure was carried out in the same manner as in Example 1, except as shown in Table 10. The conditions and results are summarized in Table 10. The whiteness was determined by measuring X, Y, Z, x, y on the dyed fabric using a spectrophotometer (KONICA MINOLTA, model: CM-3700d, D65 light source) and determining the whiteness according to JIS Z 8715-1999. A higher value indicates a whiter fabric.

(Example 10)
The procedure was carried out in the same manner as in Example 9, except that the order of staining and organic acid treatment was changed, with the organic acid treatment performed first and the staining second. The conditions and results are summarized in Tables 10 and 11.

As is clear from Examples 9 and 10, it was confirmed that whiteness is higher when organic acid treatment is performed first and dyeing is performed afterward.
Furthermore, Table 12 shows that the deodorizing function of the α-zirconium phosphate powder deodorant is significantly reduced after scouring and bleaching, but the deodorizing function is restored even if the organic acid treatment is performed first and the dyeing is done afterward.

The odor-eliminating fiber structure of the present invention is excellent at eliminating sweat odor and age-related odor, and is suitable for carpets, curtains, bedding, underwear, diapers, sanitary products, etc. It is particularly suitable for stretchy clothing such as legwear, innerwear, sportswear, and socks.

Claims (3)

A deodorizing fiber structure in a bleached state , comprising a first fiber which is at least one selected from synthetic fibers and regenerated fibers, and a second fiber which is a natural fiber,
The first fiber is a deodorizing fiber obtained by mixing a polymer with an inorganic layered deodorant, which is α-zirconium phosphate , and the second fiber contains cotton.
The inorganic layered deodorant has an interlayer distance of 0.1 nm or more and 0.9 nm or less, and a crystallite size of 1 nm or more and 30 nm or less.
The aforementioned deodorizing fiber structure is characterized in that the ammonia gas reduction rate after 0 and 10 washes at home is 70% or more. The odor-eliminating fiber structure according to claim 1, wherein the odor-eliminating fibers make up 1 to 99% by mass of the fiber structure as the base quantity. The odor-eliminating fiber structure according to claim 1 or 2, wherein the fiber structure is a knitted fabric, a woven fabric, or a garment sewn from the same.