JP7501694B2 - Stain-resistant textile structure - Google Patents

Description

The present invention relates to a fiber structure with high stain resistance.

There has been a strong demand for improving the stain resistance of textile structures such as woven and knitted fabrics, and various methods for improving the stain resistance have been proposed. Generally, methods for imparting stain resistance to textile structures include processing methods that impart hydrophilic resins to textile structures to increase their affinity with cleaning fluids and make it easier to remove stains, and processing techniques that impart water- and oil-repellent resins to textile structures to suppress adhesion of stains to the fibers.

However, when a hydrophilic resin is applied to a textile structure, there is an issue that once water-based dirt adheres to the textile structure, the dirt tends to spread widely. Furthermore, when a water- and oil-repellent resin is applied to a textile structure, the affinity between the cleaning solution and water-based dirt decreases due to the water repellency, so once dirt adheres to the textile structure, it is difficult to remove it by washing, and re-contamination is likely to occur.

To address these issues, consideration is being given to adding water- and oil-repellent resins containing hydrophilic groups to fibers in order to satisfy both the requirements of stain resistance and ease of cleaning.

Patent Documents 1 and 2 propose a water-, oil-, and stain-resistant processing method that forms a coating of a fluorine-based water repellent agent that contains a hydrophilic component.

Patent Document 3 proposes a water-, oil-, and stain-resistant processing method in which a fluorine-based water repellent is applied to a fiber fabric using a non-blocking water-dispersible isocyanate crosslinking agent.

Patent Document 4 proposes a water-, oil-, and stain-resistant processing method in which a coating made of a mixture of a polymer made of a triazine ring-containing polymerizable monomer and a fluorine-based water repellent agent having a hydrophilic component is formed on the surface of a single fiber.

Patent Document 5 proposes a weakly water-repellent, oil-repellent, and stain-resistant processing method in which a coating of a fluorine-based water-repellent agent containing a hydrophilic component with an adjusted mass concentration ratio of oxygen atoms and fluorine atoms is formed.

JP 2006-152508 A JP 2014-163030 A JP 2013-36136 A Patent No. 5114946 International Publication No. 2017/006849

However, the processing methods proposed in Patent Documents 1 and 2 have a problem in that, because the material is highly hydrophilic, once water-based dirt adheres to the material, the dirt tends to diffuse.

The processing method proposed in Patent Document 3 exhibits high water repellency, which tends to reduce the affinity between the washing liquid and water-based stains during washing, reducing the ability to remove stains by washing, and there is a problem in particular with low stain removal after processing.

The processing method proposed in Patent Document 4 uses a large amount of a polymer made of a triazine ring-containing polymerizable monomer, which causes the fluororesin and hydrophilic components to become buried, resulting in the problem that sufficient stain resistance cannot be achieved.

The processing method proposed in Patent Document 5 has high washing durability, but there is a problem in that the stain resistance of the processed product may be low.

In view of the problems with the conventional technology described above, the object of the present invention is to provide a fiber structure that simultaneously has high adhesion inhibition properties and stain removal properties for both aqueous and oily stains, even after repeated washing after processing.

The present invention adopts the following measures to solve the above problems.

(1) A stain-resistant fiber structure having a coating containing a fluorine-based oil-repellent resin having a hydrophilic component and polyvinyl alcohol on at least a portion of the fiber surface, the water repellency measured by the JIS L-1092 spray test being grade 2 or less, and the oil repellency measured by the AATCC 118 method being grade 2 or more.

(2) The stain-resistant fiber structure according to (1), in which the fluorine-based oil-repellent resin having a hydrophilic component is a fluorine-based oil-repellent resin containing a polyoxyalkylene group.

(3) A stain-resistant fiber structure according to (1) or (2), in which the average degree of polymerization of the polyvinyl alcohol is from 200 to 1500.

(4) The stain-resistant fiber structure according to any one of (1) to (3), wherein the fluorine-based oil-repellent resin contains a repeating unit derived from a vinyl fluoride monomer represented by the following general formula (I), and the content of perfluorooctanoic acid and perfluorooctanesulfonic acid is less than the detection limit:
_CH2 =C( _{CH3 )} C(=O) _OCH2CH2 ( _CF2 ) _5CF3 ( _I )

(5) A stain-resistant fiber structure according to any one of (1) to (4), characterized in that the fluorine-based oil-repellent resin, polyvinyl alcohol, and a triazine ring-containing resin are applied to the surface of the fiber structure.

(6) A stain-resistant fiber structure according to any one of (1) to (5), in which the stain removability of the fiber structure in a stain removal test for a pressed-in stain is grade 3-4 or higher even after 50 industrial washes.

(7) Clothing made using the fiber structure described in any one of (1) to (6).

(8) A method for producing a stain-resistant fiber structure, comprising treating the fiber structure with a treatment liquid containing a fluorine-based oil-repellent resin having a hydrophilic component and polyvinyl alcohol (hereinafter sometimes referred to as a "treatment liquid containing a stain-resistant resin").

The present invention makes it possible to stably supply textile structures with high stain resistance.

The stain-resistant fiber structure of the present invention has a resin coating containing a fluorine-based oil-repellent resin having a hydrophilic component and polyvinyl alcohol on at least a portion of the fiber surface, which inhibits adhesion of oily stains that are difficult to remove by washing to the fiber and increases the affinity with the washing liquid during washing, thereby providing a fiber structure that simultaneously has high adhesion inhibition properties against aqueous and oily stains and stain removal properties even after repeated washing after processing.

The stain-resistant fiber structure of the present invention has a coating containing a fluorine-based oil-repellent resin having a hydrophilic component and polyvinyl alcohol on at least a portion of the fiber surface, and has a water repellency of grade 2 or less as measured by the JIS L-1092 spray test and an oil repellency of grade 2 or more as measured by the AATCC 118 method.

With oil repellency of grade 2 or higher, the fiber has sufficient oil repellency and dirt is less likely to adhere to the fiber. Grade 5 or higher is preferable. With water repellency of grade 2 or lower, the fiber has sufficient hydrophilicity and can maintain affinity between the fiber and the cleaning solution, allowing the cleaning solution to penetrate into the fiber structure during washing without being repelled, come into contact with the dirt, and remove the dirt.

In other words, in the present invention, by producing a fiber structure that has low water repellency and oil repellency, it is possible to achieve high stain resistance, and by controlling the water repellency to a more appropriate weak water repellency range, it is possible to improve washing durability.

The oil repellency of the above textile structures is measured according to AATCC 118 (2013), and the water repellency is measured according to the spray method specified in JIS L 1092 "Test method for waterproofing of textile products" (2009).

As the fluorine-based oil-repellent resin and polyvinyl alcohol having hydrophilic components of the present invention, those that, when a coating containing these is formed on the fiber surface, have an oil repellency of grade 2 or higher and a water repellency of grade 2 or lower are preferably used.

The fluorine-based oil-repellent resin having a hydrophilic component is preferably a fluorine-containing copolymer having a repeating unit derived from a vinyl monomer having a perfluoroalkyl group and a vinyl monomer having a hydrophilic functional group (hydrophilic vinyl monomer).

As the vinyl monomer having a perfluoroalkyl group, a vinyl monomer having a perfluoro group having 6 or less carbon atoms is preferably used, and more preferably, one containing a repeating unit derived from CH ₂ ═C(CH ₃ )C(═O)OCH ₂ CH ₂ (CF ₂ ) ₅ CF ₃ is used.

Examples of the hydrophilic vinyl monomer include vinyl monomers containing a hydrophilic functional group such as a sulfonyl group, a sulfonyl base, a carboxyl group, a carboxyl base, an ammonium group, an oxyalkylene group, or a polyoxyalkylene group. Among these, vinyl monomers represented by the following general formula (II) are preferred.
CH ₂ ═CR ₁ C(═O)O—(R ₂ O) _n —R ₃ (II)
In the formula, R ₁ is usually H or an alkyl group having 1 to 4 carbon atoms, and preferably H or CH _3. -(R ₂ O) _n - represents an oxyalkylene group or a polyoxyalkylene group. R ₂ is usually preferably an alkylene group having 2 to 5 carbon atoms, and is more preferably CH ₂ CH _2, CH ₂ CH ₂ CH ₂ or CH ₂ (CH ₃ ) CH ₂ in that the hydrophilicity can be controlled to a more preferred range. R ₃ usually represents H or CH _3. n represents the degree of polymerization, which is 1 to 20.

The fluorine-based oil-repellent resin preferably used in the present invention is one that has a water absorption of 40 seconds or more, a water repellency of grade 2 or less, and an oil repellency of grade 2 or more, as measured by the JIS L 1907-Dropping Method (2010). Weak water repellency, such as a water absorption of 60 seconds or more, is more preferable in terms of improving the washing durability of the dirt removal properties for pressed-in dirt. In addition, an oil repellency of grade 7 or less is more preferable in terms of the balance between dirt resistance and affinity with cleaning water.

The ratio of the vinyl monomer having a perfluoroalkyl group to the hydrophilic vinyl monomer in the fluorine-containing copolymer preferably used above is not limited as long as it satisfies the range specified in the present invention, but it is preferable to control it by the following method so that it has weak water and oil repellency and water and oil absorption repellency. This control can be performed by the following method. In other words, water repellency can be suppressed by increasing the ratio of the vinyl monomer containing a hydrophilic functional group, and oil repellency can be increased by increasing the ratio of the vinyl monomer having a perfluoroalkyl group.

Also, for vinyl monomers containing hydrophilic functional groups, even if the ratio is the same, the hydrophilicity can be increased. This can be achieved by increasing the ratio of hydrophilic functional groups or by selecting a more hydrophilic functional group as the hydrophilic functional group, thereby decreasing the water repellency. The hydrophilic functional group is preferably an oxyalkylene group (more preferably an oxyethylene group) or a polyoxyalkylene group (more preferably a polyoxyethylene group). When using a polyoxyalkylene group, the higher the degree of polymerization, the greater the hydrophilicity can be.

It is also possible to improve oil repellency by increasing the number of carbon atoms in the perfluoroalkyl group in a vinyl monomer having a perfluoroalkyl group.

The fluorine-based oil-repellent resin having a hydrophilic component that satisfies the above-mentioned requirements is preferably one that exhibits performance classified as a water-repellent type having a water repellency of grade 2 or less (preferably grade 1), oil repellency of grade 2 or more, and water absorption of less than 40 seconds, or a weak water-repellent type having a water repellency of grade 2 or less, oil repellency of grade 2 or more, and water absorption of 40 seconds or more, when applied to a fiber structure, and is preferably one classified as a weak water-repellent type. Commercially available products include "Palazine" KFS-100 (manufactured by Keihin Chemical Industry Co., Ltd.), which is a weak water-repellent and oil-repellent type, and "Palazine" KFS-150 (manufactured by Keihin Chemical Industry Co., Ltd.), which is a water-absorption and oil-repellent type. Note that even a strongly water-repellent and oil-repellent type fluorine-based water-repellent resin may be used as long as it satisfies the range specified in the present invention, but care must be taken because if the water repellency or oil repellency is too strong, it will be difficult to control it to the range specified in the present invention.

The fluorine-based oil-repellent resin preferably has a perfluorooctanoic acid and perfluorooctanesulfonic acid content below the detection limit, which means that the concentrations of perfluorooctanoic acid, perfluorooctanesulfonic acid, their precursors, and their salts measured by a high performance liquid chromatograph-mass spectrometer (LC-MS) shown below are all less than 5 ng/g.
Apparatus: LC-MS/MS tandem mass spectrometer TSQ-7000 (Thermo Electron)
High-performance liquid chromatograph LC-10Avp (Shimadzu Corporation)
Column: Capcellpak C8 100 mm x 2 mm i.d. (5 μm)
Mobile phase: A; 0.5 mmol/L ammonium acetate B; acetonitrile Flow rate: 0.2 mL/min
Sample injection volume: 3 μL
CP temperature: 220°C
Ionization voltage: 4.5 kV
Ion Multi: 1300v
Ionization method: ESI-Negative
The average degree of polymerization of polyvinyl alcohol is usually from 100 to 3,500, preferably from 200 to 1,500.

Polyvinyl alcohol may be produced by saponifying polyvinyl acetate. The degree of saponification of polyvinyl alcohol is preferably 70 to 99%, and more preferably 80 to 95%.

The average degree of polymerization and the degree of saponification are values obtained by measuring in accordance with JIS K 6726 (1994), items 3.7 and 3.5, respectively.

The ratio of the fluorine-based oil-repellent resin and polyvinyl alcohol used in the present invention is usually 5 to 60 parts by weight, preferably 10 to 40 parts by weight, of polyvinyl alcohol per 100 parts by weight of solid content of the fluorine-based oil-repellent resin.

The polyvinyl alcohol used in the present invention may contain functional groups other than hydroxyl groups and/or acetate groups, such as acetoacetyl groups, sulfonyl groups, sulfonyl bases, carboxyl groups, carboxyl bases, quaternary ammonium bases, oxyalkylene groups, polyoxyalkylene groups, alkyl groups, alkenyl groups, alkynyl groups, and phenyl groups.

The amount of the fluororesin and polyvinyl alcohol adhering to the fibers as solids is 0.2 to 1.0% by mass, preferably 0.4 to 0.8% by mass. This preferred range allows sufficient dirt removal performance and a soft feel, which is preferable.

In the present invention, in addition to the fluorine-based oil-repellent resin and polyvinyl alcohol having the above hydrophilic components, it is also possible to use other resins, compounds, and other agents in combination.

The use of a triazine ring-containing resin as the above resin is particularly preferred in terms of the washing durability of the stain-resistant properties. Examples of triazine ring-containing resins include melamine resins, guanamine resins, and bismaleimide triazine resins, with melamine resins being particularly preferred.

The term "triazine ring-containing resin" refers to a resin that contains a triazine ring-containing compound as a polymerization component. The triazine ring-containing compound is a compound that contains a triazine ring and has at least two polymerizable functional groups, and examples of such compounds include the triazine ring-containing compounds represented by the following structural formula:

(wherein R ₄ to R ₆ represent H, OH, C ₆ H ₅ , C _n0 H _2n0+1 (n0=1 to 2), COOC _n1 H _2n1+1 (n1=1 to 20), CONR ₇ R ₈ , and NR ₇ R ₈ , where R ₇ and R ₈ represent H, OC _n3 H _2n3+1 (n3=1 to 20), CH ₂ COOC _n3 H _2n3+1 (n3=1 to 20), CH ₂ OH, CH ₂ CH ₂ OH, CONH ₂ , CONHCH ₂ -O-(X-O) _n4 -R ₉ (X=C ₂ H ₄ , C ₃ H ₆ , C ₄ H ₈ ; n4=1 to 1500; R ₉ =H, _{CH3 , C3H7} )

In addition to the triazine ring-containing compounds represented by the above general formula, ethylene urea copolymer compounds, dimethylol urea copolymer compounds, dimethylol thiourea copolymer compounds, and acid colloid compounds of the above compounds can also be used.

The method for forming the triazine ring-containing resin is as follows: After applying an aqueous solution containing the above-mentioned triazine ring-containing compound and a catalyst onto the fibers, heat treatment is performed to polymerize the compound.

Catalysts that can be used include acids such as acetic acid, formic acid, acrylic acid, malic acid, tartaric acid, maleic acid, phthalic acid, sulfuric acid, persulfuric acid, hydrochloric acid, and phosphoric acid, as well as their ammonium salts, sodium salts, potassium salts, and magnesium salts, and one or more of these can be used. Among these, ammonium persulfate and potassium persulfate are preferably used as catalysts. The amount of catalyst used is preferably 0.1 to 20% by mass based on the amount of monomer used.

The heat treatment for such polymerization is preferably a dry heat treatment and a steam treatment at a temperature of 50 to 200°C, preferably 80 to 150°C, for 0.1 to 30 minutes. The amount of the triazine ring-containing resin attached is preferably 10 to 100% by mass, more preferably 20 to 60% by mass, based on the total weight of the fluorine-based oil-repellent resin having a hydrophilic component and the polyvinyl alcohol.

The stain-resistant fiber structure of the present invention preferably has a stain removability of grade 3-4 or higher, and more preferably grade 4 or higher, after 50 industrial washes from the end of processing, when tested in a "stain removability test for intrusion stains" conforming to Method C using a component of lipophilic contaminant-3 as specified in JIS L 1919 (2006) "stain removability test."

Examples of fiber materials used in the stain-resistant fiber structure of the present invention include fibers made of polyalkylene terephthalates such as polyethylene terephthalate, polypropylene terephthalate, and polybutylene terephthalate, aromatic polyester fibers obtained by copolymerizing these with a third component, aliphatic polyester fibers made of aliphatic polyesters such as polylactic acid, which is represented by fibers mainly made of L-lactic acid, polyamide fibers made of polyamides such as nylon 6 and nylon 66, acrylic fibers mainly made of polyacrylonitrile, polyolefin fibers made of polyolefins such as polyethylene and polypropylene, synthetic fibers such as polyvinyl chloride fibers, semi-synthetic fibers such as acetate and rayon, and natural fibers such as cotton, silk, and wool. In the present invention, these fibers can be used alone or as a mixture of two or more types. Among them, fibers mainly made of polyester fibers or polyamide fibers, or mixtures of fibers mainly made of polyester fibers or polyamide fibers and natural fibers such as cotton, silk, and wool are preferably used. Here, the main component refers to the fiber with the highest content among the components contained, and it is preferable that it is contained in an amount of 50 mass% or more.

The fibers used in the stain-resistant fiber structure of the present invention may be ordinary flat yarns, or filament yarns such as false twisted yarns, twisted yarns, taslan-textured yarns, nanofibers, thick and thin yarns, and blended yarns, and various forms of fibers such as staple fibers, tows, and spun yarns can be used. Filament yarns are preferably used.

The cross-sectional shape of the single fiber of the fiber used in the stain-resistant fiber structure of the present invention is not particularly limited, and fibers of various shapes such as round, triangular, flat, and multi-lobed can be used. A round cross-sectional shape is preferably used.

The stain-resistant fiber structure of the present invention includes fabric-like materials, such as knitted fabrics, woven fabrics, and nonwoven fabrics, and string-like materials, which are made using the above-mentioned fibers. Knitted fabrics, woven fabrics, and nonwoven fabrics are preferably used.

The fabric-like or string-like material may be treated with general processing agents such as fluorescent dyes and fabric softeners. Fibers internally modified with antibacterial or bacteriostatic agents may also be used as materials for stain-resistant fiber structures. Examples of the processing agents that can be used include pyridine-based compounds such as 2-chloro-6-trichloromethylpyridine, 2-chloro-4-trichloromethyl-6-methoxypyridine, 2-chloro-4-trichloromethyl-6-(2-furylmethoxy)pyridine, di(4-chlorophenyl)pyridylmethanol, 2,3,5-trichloro-4-(n-propylsulfonyl)pyridine, zinc 2-pyridylthiol-1-oxide, and di(2-pyridylthiol-1-oxide).

The fabric-like or string-like material may be made of fibers to which a resin other than a fluorine-based oil-repellent resin having a hydrophilic component and polyvinyl alcohol (hereinafter collectively referred to as "stain-resistant resin", and a film containing the same may be referred to as "stain-resistant resin layer") is attached. In this case, a resin layer other than the stain-resistant resin is formed on the fiber, and the stain-resistant resin layer formed thereafter and two other resin layers are present on the fiber. Examples of such resins other than the stain-resistant resin include silicone resins, polyester resins, isocyanate compounds, epoxy resins, melamine resins, guanamine resins, and bismaleimide triazine resins.

Crosslinked and modified fibers may also be used. The crosslinking agent used for crosslinking and modification is preferably a compound that reacts with hydroxyl groups in the cellulose molecules that make up cellulosic fibers, particularly with hydroxyl groups in the amorphous regions that cause wrinkles, deformation, and shrinkage during washing, to form crosslinked structures between and within cellulose molecules. Specific examples include formaldehyde, dimethylolethyleneurea, dimethyloltriazone, dimethyloluron, dimethylolglyoxalmonourein, dimethylolpropyleneurea, cellulose-reactive resins such as those in which some or all of the methylol groups have been methoxylated or ethoxylated, polycarboxylic acids, isocyanates, etc.

In the present invention, the fixation of the resin to the fiber structure can be achieved by treating the fiber structure with a treatment liquid containing a stain-resistant resin, a triazine ring-containing resin as an optional component, or raw materials for obtaining the resin, such as a polymerizable monomer and a catalyst. Specific treatment methods include the pad dry cure method in which the fiber structure is immersed in a treatment liquid containing a stain-resistant resin, squeezed at a constant pressure in a spread-out state, and then heat-treated, the pad cure method in which the fiber structure is immersed in a treatment liquid containing a stain-resistant resin, squeezed at a constant pressure in a spread-out state, and then heat-treated, or the pad steam method in which the fiber structure is immersed in the above method and then steam-treated, or the bath method in which the fiber structure is immersed in the treatment liquid containing the above stain-resistant resin and heated. Among these, the pad dry cure method, in which the fiber structure is immersed in a treatment liquid containing an antifouling resin, squeezed at a constant pressure in a spread-out state, dried at a temperature of preferably 80 to 170°C, and then heat-treated at a temperature of preferably 170 to 200°C, the pad cure method, in which the fiber structure is dried all at once at a temperature of 170 to 200°C, the pad steam method, in which steaming is performed at a temperature of 80 to 110°C, or the bath method, in which the fiber structure is immersed in the treatment liquid containing the above-mentioned antifouling resin and the temperature is raised to preferably 50 to 130°C, are preferably used. Furthermore, the pad dry cure method, in which the fiber structure is dried at a temperature of 120°C to 170°C, and then heat-treated at a temperature of 170 to 200°C, is most preferably used.

The thus obtained stain-resistant fiber structure has a resin coating containing polyvinyl alcohol, which inhibits adhesion of oily stains that are difficult to remove by washing to the fiber, and also increases its affinity with the washing liquid during washing. Therefore, even after repeated washing after processing, it has high adhesion inhibition properties against water-based and oily stains, and stain removal properties at the same time, making it suitable for use in general clothing, work uniforms, bedding, medical clothing, interior goods, industrial materials, etc.

Next, the stain-resistant fiber structure of the present invention will be described based on examples. Various measurements and evaluations in the examples are as follows.

(Water repellency)
The water repellency was evaluated by spraying in accordance with the method specified in JIS L 1092 "Testing method for waterproofing of textile products" (2009), and the water repellency was graded. The grade was evaluated three times (n = 3). The water repellency is graded from grade 1 to grade 5, and the higher the value, the higher the water repellency. The judging criteria are determined by the judgment photograph attached to JIS L 1092.

(oil repellency)
The oil repellency was measured according to the method specified in AATCC 118, and the oil repellency was graded. The oil repellency is graded from grade 1 to grade 8, and the higher the value, the higher the oil repellency. The judging criteria are determined by the judgment photograph attached to the AATCC 118 method. The grade was determined by the average value of n = 3 evaluations.

(Industrial washing conditions for stain removal testing)
The washing durability and stain removability of the stain removability test were carried out once in an industrial washing process under the following conditions and in the following order.
1. Washing (water temperature 60°C, bath ratio 1:10, time 15 minutes)
Detergent: Murindash (manufactured by Lion Corporation) 2.0 g/L
Sodium metasilicate 2.0g/L
Crewat N (Nagase Chemtex Corporation) 1.0 g/L
2. Dehydration (1 minute)
3. Rinse 1 (water temperature 50°C, bath ratio 1:10, time 3 minutes)
4. Dehydration (1 minute)
5. Rinse 2 (water temperature 35°C, bath ratio 1:10, time 3 minutes)
6. Dehydration (1 minute)
7. Rinse 3 (normal water temperature, bath ratio 1:10, time 3 minutes)
8. Dehydration (1 minute)
9. Tumble dry

(Stain removal test for indentation stains)
The fiber structure after 50 industrial washes under the above conditions and the fiber structure before washing were evaluated for the push-in stain removal performance in accordance with JIS L 1919 "Testing methods for stain resistance of textile products" (2006), Method C. A stain (oil red fraction 0.1%) was prepared using the components of lipophilic stain-3 specified in JIS L 1919 "Testing methods for stain resistance of textile products" (2006), Method C, and the test was carried out according to the following procedure.
1. A PET film was placed on a rectangular filter paper, and a piece of fabric cut to 8 cm x 8 cm was placed on top of the PET film. 0.1 mL of oily soil was dropped from a height of 10 cm and left for 30 seconds.
2. A PET film cut to the same size as the fabric was placed on the contaminated fabric, and a load of 4 g/ ^cm2 was applied for 30 seconds. After removing the load and the film, a circular filter paper was placed on top and the dirt was absorbed by the weight of the filter paper. Furthermore, the position of the filter paper was shifted and the dirt was absorbed again by the part of the filter paper that was not contaminated. This operation was repeated until the filter paper could no longer absorb the dirt. If the filter paper did not touch the contaminated part, both ends of the filter paper were held, and the filter paper was brought into contact with the dirt and absorbed with as little weight as possible. Then, it was left for 24 hours under conditions of a temperature of 20°C and a relative humidity of 65%. After leaving it, the contaminated fabric was sewn together to a size of about 40 cm x 40 cm, and washed. If there was not enough contaminated fabric, a discarded cloth was sewn together.
3. The SR grade was judged by naked eye using the JIS L 0805 (2005) staining color gray scale. There are five grades, from grade 1 to grade 5, and the higher the number, the higher the stain resistance. The equipment used in the above tests is shown in Table 1.

(Evaluation of how dirt spreads after being pressed in)
In the above-mentioned test for the ability to remove indented stains, the spread of the stain 24 hours after its deposition was visually evaluated and rated on a scale of 1 to 5.

Grade 1: The dirt has penetrated more than 80% of the surface area of the test fabric, excluding the area where the dirt has been pressed in.

Grade 2: The dirt has penetrated approximately 50% of the surface area of the test fabric, excluding the area where the dirt was pressed in.

Grade 3: The dirt has penetrated approximately 30% of the surface area of the test fabric, excluding the area where the dirt was pressed in.

Grade 4: A condition in which dirt has penetrated slightly into areas other than the dirt-pressed area.

Grade 5: No dirt has penetrated anywhere except the dirt-pressed area.

The following Examples 9 and 10, including those in the tables, should be read as Comparative Examples 6 and 7, respectively.
Example 1
A twill fabric was woven using warp and weft yarns of 14-count single yarns consisting of 65% polyethylene terephthalate and 35% cotton. The resulting twill fabric was scoured in a continuous scourer at 95°C in a conventional manner, washed in hot water, and then dried at 130°C. It was then dyed fluorescent white at 130°C using a jet dyeing machine, washed in a conventional manner, washed in hot water, and dried.
Heating was performed at a temperature of 170°C, and the vertical density was 86 threads/2.54 cm and the horizontal density was 55 threads/2.5
A 4 cm white fabric was obtained.

Next, 90 g/L of (A), 18 g/L of (B), 4.5 g/L of (H), and 0.75 g/L of (I) described below were dissolved to prepare a treatment solution, and the white fabric produced above was immersed in this in an open-weave state and squeezed to a wringing rate of 60% using a mangle, dried at a temperature of 130°C, and then heat-treated at a temperature of 170°C to obtain a stain-resistant fiber structure. The resulting stain-resistant fiber structure had a push-in stain removability of grade 4 after processing on the stain gray scale, and the push-in stain removability after 50 industrial washes was grade 4 on the stain gray scale.

Example 2
A stain-resistant fiber structure was obtained in the same manner as in Example 1, except that (B) was changed to 36 g/L in Example 1. The resulting stain-resistant fiber structure had a push-in stain removability after processing of grade 4 on the stain gray scale, and the push-in stain removability after 50 industrial washes was grade 3-4 on the stain gray scale.

Example 3
A stain-resistant fiber structure was obtained in the same manner as in Example 1, except that 18 g/L of (C) was used as the polyvinyl alcohol in Example 1. The resulting stain-resistant fiber structure had a push-in stain removability after processing that was graded 3-4 on the staining gray scale, and the push-in stain removability after 50 industrial washes was graded 3-4 on the staining gray scale.

Example 4
A stain-resistant fiber structure was obtained in the same manner as in Example 1, except that 18 g/L of (D) was used as polyvinyl alcohol in Example 1. The push-in stain removability of the obtained stain-resistant fiber structure after processing was graded 3-4 on the stain gray scale, and the push-in stain removability after 50 industrial washes was graded 3 on the stain gray scale.

Example 5
A plain weave fabric was woven using 48-count single yarns consisting of 65% polyethylene terephthalate and 35% cotton as warp and weft yarns. The obtained plain weave fabric was refined in a continuous refining machine at a temperature of 95°C according to a conventional method, washed with hot water, and then dried at a temperature of 130°C. Next, using a liquid jet dyeing machine, it was dyed in fluorescent white at a temperature of 130°C, washed in a conventional manner, washed with hot water, dried, and heated at a temperature of 170°C to obtain a white fabric with a warp density of 138 threads/2.54 cm and a weft density of 72 threads/2.54 cm.

Next, a stain-resistant finish was performed in the same manner as in Example 1 to obtain a stain-resistant fiber structure. The resulting stain-resistant fiber structure had a push-in stain removability of grade 4 on the stain gray scale after processing, and the push-in stain removability after 50 industrial washes was graded 4-5 on the stain gray scale.

Example 6
A soil-resistant fiber structure was obtained in the same manner as in Example 5, except that (B) was 36 g/L in Example 5. The resulting soil-resistant fiber structure had a push-in stain removability of grade 4-5 after processing in the soiling gray scale, and a push-in stain removability after 50 industrial washes was grade 4 in the soiling gray scale.

(Example 7)
A plain weave fabric was woven using 48-count single yarns consisting of 55% polyethylene terephthalate and 45% cotton as warp and weft yarns. The obtained plain weave fabric was refined in a continuous refining machine at a temperature of 95°C according to a conventional method, washed with hot water, and then dried at a temperature of 130°C. Next, using a liquid jet dyeing machine, it was dyed in fluorescent white at a temperature of 130°C, washed in a conventional manner, washed with hot water, dried, and heated at a temperature of 170°C to obtain a white fabric with a warp density of 115 threads/2.54 cm and a weft density of 72 threads/2.54 cm.

Next, a stain-resistant finish was performed in the same manner as in Example 1 to obtain a stain-resistant fiber structure. The resulting stain-resistant fiber structure had a push-in stain removability of grade 4 on the stain gray scale after processing, and the push-in stain removability after 50 industrial washes was graded 4-5 on the stain gray scale.

(Example 8)
A soil-resistant fiber structure was obtained in the same manner as in Example 7, except that (B) was 36 g/L. The resulting soil-resistant fiber structure had a push-in stain removability after processing of grade 4 on the soiling gray scale, and a push-in stain removability after 50 industrial washes of grade 4-5 on the soiling gray scale.

Example 9
A stain-resistant fiber structure was obtained in the same manner as in Example 1, except that the amount of (B) was 54 g/L. The resulting stain-resistant fiber structure had a push-in stain removability of grade 4-5 after processing in the stain gray scale, and a push-in stain removability after 50 industrial washes was grade 2-3 in the stain gray scale.

Example 10
A stain-resistant fiber structure was obtained in the same manner as in Example 1, except that 90 g/L of (E) was used as the fluorine-based oil-repellent resin in Example 1. The resulting stain-resistant fiber structure had a push-in stain removability after processing of grade 3-4 on the stain gray scale, and a push-in stain removability after 50 industrial washes of grade 2-3 on the stain gray scale.

(Comparative Example 1)
A weakly water- and oil-repellent stain-resistant fiber structure was obtained in the same manner as in Example 1, except that (B) was not used. The resulting stain-resistant fiber structure had a push-in stain removability after processing of grade 2-3 on the staining gray scale, and the push-in stain removability after 50 industrial washes was grade 3-4 on the staining gray scale.

(Comparative Example 2)
A fiber structure was obtained in the same manner as in Example 1, except that (A) was not used. The resulting soil-resistant fiber structure had a push-in stain removability after processing of grade 1-2 on the staining gray scale, and the push-in stain removability after 50 industrial washes was grade 2 on the staining gray scale.

(Comparative Example 3)
A water-absorbent, oil-repellent, stain-resistant fiber structure was obtained in the same manner as in Comparative Example 1, except that 90 g/L of (E) was used as the fluorine-based oil-repellent resin in Comparative Example 1. The resulting stain-resistant fiber structure had a push-in stain removability of grade 3-4 after processing in the stain gray scale, and a push-in stain removability after 50 industrial washes in the stain gray scale was grade 2-3. Compared with Example 8, the range of spread of stain after pushing was larger.

(Comparative Example 4)
The white fabric obtained in Example 1 was immersed in a treatment solution prepared by dissolving 45 g/L of (F), 15 g/L of (H), and 3.0 g/L of (J), squeezed using a mangle to a squeeze rate of 60%, and treated for 5 minutes in a saturated steam atmosphere at 105° C. Then, the fabric was washed for 1 minute in an aqueous solution of 1 g/L of sodium carbonate at 60° C., rinsed with water, dried at a temperature of 130° C., and then heat-treated at a temperature of 170° C. to obtain a water- and oil-repellent stain-resistant fiber structure. The resulting stain-resistant fiber structure had a push-in stain removability of grade 3 on the staining gray scale after processing, and had a push-in stain removability of grade 3 after 50 industrial washes on the staining gray scale.

(Comparative Example 5)
A water/oil absorbing, stain resistant fiber structure was obtained in the same manner as in Comparative Example 1, except that 90 g/L of (G) was used instead of the fluorine-based oil repellent resin (A) in Comparative Example 1. The push-in stain removability of the obtained stain resistant fiber structure after processing was graded 2-3 on the staining gray scale, and the push-in stain removability after 50 industrial washes was graded 2-3 on the staining gray scale.
(A) "Palladin" KFS-100 (manufactured by Keihin Chemical Industry Co., Ltd., weakly water- and oil-repellent fluorine-based oil-repellent resin, solid content 10%, polyoxyethylene group-containing, water repellency grade 2, oil repellency grade 6, water absorption 60 seconds or more)
(B) Polyvinyl alcohol (solid content 10%, average polymerization degree 500, saponification degree 90%)
(C) Polyvinyl alcohol (solid content 10%, average polymerization degree 1500, saponification degree 90%)
(D) Polyvinyl alcohol (solid content 10%, average polymerization degree 2000, saponification degree 90%)
(E) "Palladin" KFS-150 (manufactured by Keihin Chemical Industry Co., Ltd., water-absorbing and oil-repellent fluororesin, solid content 10%, polyoxyethylene group-containing, water repellency grade 1, oil repellency grade 6, water absorption 30 seconds)
(F) "Asahi Guard" AG-1100 (manufactured by Asahi Glass Co., Ltd., highly water- and oil-repellent fluorine-based resin, solid content 20%, polyoxyethylene group-containing, water repellency grade 3, oil repellency grade 6, water absorption 60 seconds or more)
(G) "Brillant" SR2100 (manufactured by Matsumoto Yushi Seiyaku Co., Ltd., solid content 10%, hydrophilic polyester resin, water repellency grade 1, oil repellency 0, water absorption 1 second or less)
(H) "Amidea" M-3 (triazine ring-containing compound manufactured by DIC Corporation: solid content 80%)
(I) "Catalyst" ACX (DIC Corporation, catalyst, solid content 35%)
(J) Ammonium persulfate The treatment solution compositions (A) to (J) of Examples 1 to 8 and Comparative Examples 1 to 5 above, and the performance and other results of the obtained fiber structures are shown in Table 2.

As is clear from Table 2, in Examples 1 to 10, which are the fiber structures of the present invention, all of them easily repelled dirt after pressing, and the area over which the dirt spread was small, making it difficult for dirt to adhere. In addition, the fiber structures also had excellent dirt removal properties against pressed-in dirt, whereas Comparative Examples 1 to 5, which are different from the stain-resistant fiber structures of the present invention, had inferior dirt removal properties against pressed-in dirt compared to the Examples. Alternatively, in the example of Example 9, in which the amount of polyvinyl alcohol was increased, the amount of polyvinyl alcohol added was optimized, and the washing durability of the stain-resistant properties could be improved. By improving washing durability, functionality can be maintained even after repeated washing, and the life of the clothing can be extended.

The stain-resistant fiber structure of the present invention has high adhesion inhibition properties against aqueous and oily stains and stain removal properties by washing at the same time, and is therefore suitable for use in general clothing, work uniforms, bedding, medical clothing, interior goods, industrial materials, etc. In particular, it is suitable for use in work uniforms, which are prone to adhesion of oily stains that are difficult to remove by washing and therefore require stain-resistant properties.

Claims (7)

A stain-resistant fiber structure having a resin coating containing a fluorine-based oil-repellent resin having a hydrophilic component and polyvinyl alcohol on at least a part of a fiber surface, the water repellency measured by a JIS L-1092 spray test being grade 2 and the oil repellency measured by an AATCC 118 method being grade 2 or higher, the fluorine-based oil-repellent resin containing a repeating unit derived from a fluorinated vinyl monomer represented by the following general formula (I), the perfluorooctanoic acid and perfluorooctane sulfonic acid contents being below the detection limit, and the fluorine-based oil-repellent resin and polyvinyl alcohol being used in a ratio of 20 to 40 by mass of polyvinyl alcohol per 100 by mass of solid content of the fluorine-based oil- repellent resin:
CH2 =C(CH3 _{) C (} =O ) _OCH2CH2 ( CF2 _{) 5CF3} ( _I ) The stain-resistant fiber structure according to claim 1, wherein the fluorine-based oil-repellent resin is a fluorine-based oil-repellent resin containing a polyoxyalkylene group. The stain-resistant fiber structure according to claim 1 or 2, wherein the average degree of polymerization of the polyvinyl alcohol is 200 to 1500. 4. The stain-resistant fiber structure according to claim 1 , wherein the fluorine-based oil-repellent resin, polyvinyl alcohol, and a triazine ring-containing resin are applied to the surface of the fiber structure. 5. The stain-resistant fiber structure according to claim 1, wherein the stain removability of said fiber structure in a stain removability test for indentation stains is grade 3-4 or higher even after 50 industrial washings. A garment comprising the stain-resistant fiber structure according to any one of claims 1 to 5 . The method for producing a stain-resistant fiber structure according to any one of claims 1 to 5, characterized in that the fiber structure is treated with a treatment liquid containing a fluorine-based oil-repellent resin having a hydrophilic component and polyvinyl alcohol.