Water-repellent fiber structure and production method for same

Abstract

The present invention relates to: a water-repellent fiber structure that has excellent water repellence and wash durability; and a production method for the water-repellent fiber structure.　A water-repellent fiber structure according to the present invention comprises: a fiber base material that includes synthetic fibers; and a resin coating film that is adhered to the surface of the synthetic fibers. The resin coating film is formed using (a) an acrylic acid compound, (b) an aromatic isocyanate compound, (c) an alicyclic isocyanate compound, and (d) a polyol compound. The (a) acrylic acid compound includes a unit represented by structural formula (1) and a unit represented by structural formula (2). The fluorine content as measured by combustion ion chromatography is no more than 25 ng / g, and the air permeability is at least 0.1 cm3 / cm2 / sec but no more than 15 cm3 / cm2 / sec. (In the formula, R1 represents an alkyl group that has at least 16 carbon atoms.)

Description

Water-repellent fiber structure and method for producing the same

[0001] The present invention relates to a water-repellent fiber structure and a method for producing the same.

[0002] Conventionally, in order to obtain a fiber structure having improved water repellency and durability, a fluorine-based water repellent agent has been fixed to the fiber surface, and various techniques have been proposed.

[0003] On the other hand, since it was discovered that conventionally used fluorine-based water repellents contain compounds that may have an impact on the living environment and living organisms, such as perfluorooctanoic acid (hereinafter referred to as "PFOA") and perfluorooctanesulfonic acid (hereinafter referred to as "PFOS"), many technologies have been proposed that use water repellents having a fluoroalkyl group with six or fewer carbon atoms as fluorine-based water repellents that do not contain these substances or contain as little of them as possible.

[0004] Recently, there has been a growing demand for water-repellent fiber structures that do not use fluorine-based compounds and that provide high water repellency and durability equivalent to that achieved by conventional fluorine-based water-repellent treatments, as well as for techniques for producing such water-repellent fiber structures.

[0005] As an environmentally friendly non-fluorine-containing water-repellent fiber structure that aims to achieve performance equivalent to that of such fluorine-containing water-repellent treatment, a method has been proposed in which water and oil repellency are imparted using a hydrocarbon compound and a blocked isocyanate (Patent Document 1).

[0006] Furthermore, as methods for imparting water repellency and washing durability through a non-fluorine-containing water repellent treatment, there have been proposed a method in which a resin coating containing a hydrocarbon compound, a silicone compound, and a melamine compound is fixed to the surface of a fiber (Patent Document 2), and a method in which a water repellent agent containing a hydrogen group-containing organopolysiloxane, a polymer having an aliphatic hydrocarbon group with 16 or more carbon atoms as a side chain, and an antistatic agent is applied to a fabric (Patent Document 3).

[0007] Also known is a method of improving the washing durability of a fluorine-based water-repellent finish by using a polyisocyanate containing an alicyclic diisocyanate monomer unit (Patent Document 4).

[0008] Japanese Patent Application Laid-Open No. 2021-155896 International Publication No. 2015-083627 Japanese Patent Application Laid-Open No. 2015-165056 Japanese Patent Application Laid-Open No. 2014-65833

[0009] However, the methods described in Patent Documents 1 to 3 result in a low water repellency after washing, and are unable to achieve both high water repellency and washing durability comparable to those of fluorine water repellent treatment.

[0010] Furthermore, the method described in Patent Document 4 can improve washing durability by using a fluorine-containing water-repellent finish, but the water repellency of non-fluorine-containing water-repellent finishes is inherently lower than that of fluorine-containing water-repellent finishes from the viewpoint of surface tension, and even if the technology described in this document is adapted to non-fluorine-containing water-repellent finishes, it is not possible to maintain high water repellency after washing, which is not sufficient.

[0011] The present invention has been made in view of the above-mentioned conventional inventions, and relates to a water-repellent fiber structure having excellent water repellency and washing durability, and a method for producing the same.

[0012] To solve the above problems, the present invention employs the following configuration: [1] A water-repellent fiber structure comprising a fiber substrate containing synthetic fibers and a resin coating attached to the surface of the synthetic fibers, the resin coating being formed using (a) an acrylic acid compound, (b) an aromatic isocyanate compound, (c) an alicyclic isocyanate compound, and (d) a polyol compound, the (a) acrylic acid compound containing a unit represented by the following structural formula (1) and a unit represented by the following structural formula (2), and the water-repellent fiber structure has a fluorine content of 25 ng / g or less and an air permeability of 0.1 cm as measured by combustion ion chromatography. ３ / cm ２ / sec~15cm ３ / cm ２ / sec. A water-repellent fiber structure represented by structural formula (1):

[0013]

[0014] Structural formula (2)

[0015]

[0016] (In the formula R １ indicates an alkyl group having 16 or more carbon atoms.１ [3] The water-repellent fiber structure according to [1] or [2], wherein the (d) polyol compound contains a triol compound represented by the following structural formula (3):

[0017]

[0018] (wherein n is an integer from 1 to 4.) [4] The water-repellent fiber structure according to any one of [1] to [3], wherein the amount of the (b) aromatic isocyanate compound added is 0.16% by mass to 1.2% by mass relative to the synthetic fiber. [5] The water-repellent fiber structure according to any one of [1] to [4], wherein the synthetic fiber is a polyamide fiber or a polyester fiber. [6] The water-repellent fiber structure according to any one of [1] to [5], wherein the amount of the (a) acrylic acid compound added is 0.6% by mass to 2.0% by mass relative to the synthetic fiber. [7] The water-repellent fiber structure according to any one of [1] to [6], wherein the amount of the (c) alicyclic isocyanate compound added is 0.02% by mass to 0.2% by mass relative to the synthetic fiber. [8] The water-repellent fiber structure according to any one of [1] to [7], wherein the amount of the (d) polyol compound added is 0.04% by mass to 0.20% by mass relative to the synthetic fiber. [9] A method for producing a water-repellent fiber structure according to any one of [1] to [8], comprising a step of impregnating a fiber substrate containing synthetic fibers with a treatment liquid containing (a) an acrylic acid compound, (b) an aromatic isocyanate compound, (c) an alicyclic isocyanate compound, and (d) a polyol compound, followed by a step of dry-heat treating the fiber substrate impregnated with the treatment liquid obtained in the step.

[0019] According to the present invention, it is possible to provide a water-repellent fiber structure that combines high water repellency and its washing durability. In particular, it is noteworthy that the present invention makes it possible to obtain a water-repellent fiber structure that combines high water repellency and its durability comparable to that achieved by fluorine water-repellent treatment, without using substantially any fluorine compound.

[0020] The present invention will be described in detail below.

[0021] The water-repellent fiber structure of the present invention is a water-repellent fiber structure comprising a fiber substrate containing synthetic fibers and a resin coating attached to the surface of the synthetic fibers, wherein the resin coating is formed using (a) an acrylic acid compound, (b) an aromatic isocyanate compound, (c) an alicyclic isocyanate compound, and (d) a polyol compound, and the (a) acrylic acid compound contains a unit represented by the following structural formula (1) and a unit represented by the following structural formula (2): Structural formula (1):

[0022]

[0023] Structural formula (2)

[0024]

[0025] (In the formula R １ (In this invention, the term "adhesion" is defined as a state of being physically or chemically bonded. In this state, resin coatings and the like do not easily come off by washing, etc.)

[0026] The (a) acrylic acid compound used in the present invention is an acrylic acid ester, and includes those having an alkyl group via an ester bond and those having an ethylene group and a hydroxy group. Specifically, an acrylic acid ester having an alkyl group via an ester bond and an acrylic acid ester having an ethylene group and a hydroxy group may be used in combination. The alkyl group in the acrylic acid ester is, for example, an acrylic acid ester represented by R １ and R １ is an alkyl group having 16 or more carbon atoms. １ is preferably an alkyl group having 16 to 28 carbon atoms, more preferably an alkyl group having 18 to 22 carbon atoms, and most preferably an alkyl group having 18 carbon atoms. １ If the carbon number is 15 or less, sufficient water repellency cannot be obtained, and conversely, if the carbon number is 29 or more, the washing durability of the water repellent coating film decreases. １The most preferred is an acrylic acid compound having 18 carbon atoms. (a) When the acrylic acid compound has an alkyl group having 18 carbon atoms, it may also contain an acrylic acid compound having an alkyl group having 18 carbon atoms within the range of 18±2. For example, in structural formula (1), R １ An example of a commercially available agent containing an acrylic acid compound containing a unit in which is an alkyl group having 18 carbon atoms is "RUCO" (registered trademark)-DRY-DHC (manufactured by Rudolph).

[0027] The (a) acrylic acid compound contains 2-hydroxyethyl acrylate, which has an ethylene group and a hydroxy group via an ester bond. The presence of a hydroxy group improves reactivity with isocyanate, which tends to improve washing durability. An example of a commercially available agent containing 2-hydroxyethyl acrylate is "RUCO" (registered trademark)-DRY-DHC (manufactured by Rudolph).

[0028] In the (a) acrylic acid-based compound, from the viewpoint of water repellency, it is preferable that the acrylic acid-based compound having a unit represented by the structural formula (1) accounts for 80% by mass to 99% by mass of the total amount of the (a) acrylic acid-based compound.

[0029] In a preferred embodiment of the water-repellent fiber structure of the present invention, the amount of (a) acrylic acid-based compound added is preferably in the range of 0.6% by mass to 2.0% by mass relative to the fiber mass, and from the viewpoint of water repellency and its washing durability, is more preferably in the range of 1.0% by mass to 2.0% by mass, and even more preferably in the range of 1.2% by mass to 2.0% by mass. If the amount of (a) acrylic acid-based compound added is 0.6% by mass or more relative to the fiber mass, the proportion of the fiber surface coated is increased, resulting in good water repellency. However, even if the amount of (a) acrylic acid-based compound added is too large relative to the fiber mass, the water repellency does not necessarily improve accordingly.

[0030] (b) Examples of aromatic isocyanate compounds include diphenylmethane diisocyanate, 1,4-phenylene diisocyanate, tolylene diisocyanate, and 1,5-naphthylene diisocyanate, with tolylene diisocyanate being preferred. Aromatic isocyanate compounds have a highly planar molecular structure and, compared to copolymers derived from aliphatic / alicyclic isocyanates, have excellent mechanical and thermal properties and contribute to water repellency and washing durability, but are prone to yellowing when exposed to ultraviolet rays or the like. For example, commercially available agents containing tolylene diisocyanate include "RIKEN RESIN" (trademark) MBX-31 (manufactured by Miki Riken Kogyo Co., Ltd.) and "MEIKANATE" (registered trademark) TP-10 (manufactured by Meisei Chemical Industry Co., Ltd.).

[0031] (c) Examples of alicyclic polyisocyanates include 1,3-bis(isocyanatomethyl)cyclohexane, 1,4-bis(isocyanatomethyl)cyclohexane, 3-isocyanatomethyl-3,5,5-trimethylcyclohexyl isocyanate (also known as isophorone diisocyanate), bis-(4-isocyanatocyclohexyl)methane (also known as hydrogenated MDI), and norbornane diisocyanate, which are characterized by resistance to yellowing. Among these, isophorone diisocyanate, which has a high isocyanate group concentration, is preferred. For example, a commercially available agent containing isophorone diisocyanate is "RUCO" (registered trademark)-DRY-DHC (manufactured by Rudolph).

[0032] The isocyanate compounds referred to as (b) aromatic isocyanate compounds and (c) alicyclic isocyanate compounds used in the present invention are preferably compounds having a structure in which the isocyanate group is blocked and which can regenerate the isocyanate group by heating at 70° C. to 200° C., and such so-called blocked isocyanate compounds are also included in the isocyanate compounds. Examples of such compounds include polyfunctional blocked isocyanate group-containing compounds obtained by reacting an isocyanate compound with, for example, phenol, malonic acid diethyl ester, methyl ethyl ketoxime, methyl butyl ketoxime, sodium bisulfite, and ε-caprolactam.

[0033] A dissociation catalyst may be used to promote an increase in the thermal dissociation rate of the blocked isocyanate and a decrease in the thermal dissociation temperature. Preferred examples of the catalyst include dibutyltin diolate, dibutyltin stearate, stearyl zinc, and organic amine compounds.

[0034] From the viewpoint of imparting sufficient washing durability, the amount of the (b) aromatic isocyanate compound added is preferably in the range of 0.16% to 1.2% by mass, more preferably 0.16% to 1.20% by mass, and even more preferably 0.30% to 0.98% by mass, relative to the synthetic fiber, based on the synthetic fiber. Similarly, the amount of the (c) alicyclic isocyanate compound added is preferably 0.02% to 0.2% by mass, more preferably 0.10% to 0.20% by mass, relative to the synthetic fiber. When the amount of the (b) aromatic isocyanate compound added is in the range of 0.16% to 1.2% by mass, and the amount of the (c) alicyclic isocyanate compound added is in the range of 0.02% to 0.2% by mass, sufficient washing durability can be obtained without impairing the texture of the fiber structure or the stability of the treatment solution when used as a treatment solution. The more preferable the range, the greater the effect.

[0035] In the present invention, the total amount of the (b) aromatic isocyanate compound and the (c) alicyclic isocyanate compound is preferably in the range of 0.18% to 1.4% by mass, more preferably 0.18% to 1.40% by mass, based on the mass of the fiber. From the viewpoint of water repellency and washing durability, the total amount is even more preferably 0.4% to 1.0% by mass, and particularly preferably 0.40% to 0.80% by mass. When the total amount of the (b) aromatic isocyanate compound and the (c) alicyclic isocyanate compound is 0.18% by mass or more based on the mass of the fiber, crosslinking of the resin coating proceeds and sufficient washing durability is obtained. Furthermore, when the total amount of the (b) aromatic isocyanate compound and the (c) alicyclic isocyanate compound is 1.4% by mass or less based on the mass of the fiber, sufficient washing durability is obtained without impairing the texture of the fiber structure or the stability of the treatment solution.

[0036] Furthermore, from the viewpoint of washing durability, the total amount of the (b) aromatic isocyanate compound and the (c) alicyclic isocyanate compound is preferably in the range of 30% by mass to 70% by mass, more preferably 50% by mass to 70% by mass, relative to the (a) acrylic acid compound. If the total amount of the (b) aromatic isocyanate compound and the (c) alicyclic isocyanate compound is in the range of 30% by mass to 70% by mass, relative to the (a) acrylic acid compound, sufficient washing durability can be obtained without impairing texture or water repellency, and the more preferable the range, the greater the effect.

[0037] (d) Examples of polyol compounds include compounds derived from ethylene glycol, diethylene glycol, and trimethylolpropane. From the viewpoint of washing durability, triol compounds (n is an integer of 1 to 4) shown in structural formula (3) are preferred in order to impart a network-like crosslinked structure to the resin coating, and more preferably trimethylolpropane (n = 2) is suitable for use. An example of a commercially available agent containing trimethylolpropane is "RIKEN RESIN" (trademark) MBX-31 (manufactured by Miki Riken Kogyo Co., Ltd.).

[0038] In the water-repellent fiber structure of the present invention, the amount of the (d) polyol compound added is preferably in the range of 0.04% by mass to 0.20% by mass relative to the fiber mass, and more preferably in the range of 0.09% by mass to 0.20% by mass from the viewpoint of water repellency and its washing durability. If the amount of the (d) polyol compound added is 0.04% by mass or more relative to the fiber mass, crosslinking of the resin coating proceeds, and sufficient washing durability is obtained. Furthermore, if the amount of the (d) polyol compound added is 0.20% by mass or less relative to the fiber mass, the non-crosslinked hydroxyl groups do not act as hydrophilic groups and inhibit water repellency, and good water repellency is obtained.

[0039] The resin coating of the water-repellent fiber structure of the present invention may contain an antistatic agent. It is preferable to use an antistatic agent that does not impair water repellency. Examples of antistatic agents that can be used include anionic surfactants such as higher alcohol sulfates, sulfated oils, sulfonates, and phosphate salts; cationic surfactants such as amine salts, quaternary ammonium salts, and imidaline quaternary salts; nonionic surfactants such as polyethylene glycols and polyhydric alcohol esters; amphoteric surfactants such as imidaline quaternary salts, alanine salts, and betaine salts; and polymeric compounds such as the antistatic polymers and polyalkylamines described above. However, the inclusion of an antistatic agent can increase slippage between yarns. Therefore, an antistatic agent composed of an organic salt of guanidine hydrochloride is preferred because it suppresses slippage and does not impair water repellency.

[0040] The antistatic agent is effective when it is contained in an amount of 0.02 to 0.10% by mass relative to the fiber structure, and there is little interference with water repellency.

[0041] In the present invention, the resin coating may contain a silicone compound. The silicone-based compound is a polysiloxane, and is usually a compound having a dimethylsiloxane structural unit. Compounds in which the methyl group of the dimethylsiloxane structural unit is substituted with an ethyl group or a compound in which the methyl group is substituted with a hydrogen group, such as compounds having a methylhydrosiloxane structural unit or an ethylmethylsiloxane structural unit, can also be used. When the resin coating contains a silicone compound, the texture of the fiber structure can be made soft.

[0042] In the present invention, the resin coating may contain fine particles. The fine particles may be either inorganic or organic, or a mixture thereof may be used. Examples of inorganic fine particles include aluminum oxide, silicon dioxide, titanium oxide, kaolin, bentonite, talc, calcium carbonate, calcium silicate, and magnesium oxide. These may be used alone or in combination of two or more, and are preferably used as an aqueous dispersion. Of these, silicon dioxide is preferably used.

[0043] The particle diameter of such inorganic fine particles is preferably 10,000 nm or less, more preferably 5 nm to 500 nm, and even more preferably 10 nm to 100 nm.

[0044] Examples of organic fine particles include particles made of acrylic resin, olefin resin, melamine resin, etc. Furthermore, composite particles in which the surface of organic particles is coated with silica or alumina can also be used.

[0045] The particle size of the organic fine particles is preferably 0.01 μm to 10.00 μm, and more preferably 0.10 μm to 6.00 μm.

[0046] The particle size referred to in the present invention is determined by observing the fiber structure with a scanning electron microscope (SEM) and measuring the particle size.

[0047] The resin coating containing particles has the effect of suppressing slippage between the threads. In addition, the inclusion of particles creates minute irregularities on the fiber surface, resulting in a lotus leaf effect.

[0048] A method for producing a water-repellent fiber structure of the present invention includes a step of impregnating a fiber substrate containing synthetic fibers with a treatment liquid containing (a) an acrylic acid compound, (b) an aromatic isocyanate compound, (c) an alicyclic isocyanate compound, and (d) a polyol compound, followed by a step of dry-heat treating the fiber substrate impregnated with the treatment liquid obtained in the above step. That is, a fiber substrate containing synthetic fibers is impregnated with a treatment liquid containing (a) an acrylic acid compound, (b) an aromatic isocyanate compound, (c) an alicyclic isocyanate compound, and (d) a polyol compound, and then dry-heat treated. The drying treatment preferably involves drying at 100°C to 140°C, followed by curing at a temperature of 160°C to 200°C, although the drying at 100°C to 140°C can be omitted.

[0049] Alternatively, a pad steam method can be used in which the acrylic acid compound or the like is attached to the fiber substrate by immersing the fiber substrate in the treatment solution, steaming the fiber substrate in saturated steam at 100°C to 200°C, and then performing a dry heat treatment.

[0050] Through the above treatment, (a) acrylic acid compound, (b) aromatic isocyanate compound, (c) alicyclic isocyanate compound, and (d) polyol compound react with each other, or at least one of (a) to (d) reacts physically or chemically with the surface of the synthetic fiber and adheres to the surface of the synthetic fiber, forming a resin film. Although the details of each agent after the reaction have not been clarified, it is presumed that the isocyanate compound crosslinks the synthetic fiber and the acrylic acid compound, and the polyol compound contributes to the formation of a network-like crosslinked structure.

[0051] From the viewpoints of fiber penetration and mechanical stability, the treatment solution may contain at least one of diethylene glycol monobutyl ether and ethylene glycol monobutyl ether. These are water-soluble organic solvents that contribute to a significant improvement in the aggregation suppression effect of the water-repellent resin. These organic solvents may be used alone or in combination of two kinds in any ratio. The content of at least one of the diethylene glycol monobutyl ether and ethylene glycol monobutyl ether in the formulation solution is preferably 0.5% by mass to 1.5% by mass, more preferably 0.5% by mass to 1.2% by mass.

[0052] Furthermore, in producing the water-repellent fiber structure of the present invention, a fiber structure may be subjected to calendering after a resin coating has been attached to the fiber surface. Alternatively, a cold calendering process without applying any temperature or a calendering process at a temperature of 130°C to 200°C may be used. In these processes, a linear pressure of 250 N / cm to 20,000 N / cm is preferably used. Calendering can further improve the slippage between fibers and the texture.

[0053] When the synthetic fiber used in the fiber structure of the present invention is a polyamide fiber, it is preferable from the viewpoint of water repellency and washing durability to attach a resin coating formed using (a) an acrylic acid compound, (b) an aromatic isocyanate compound, (c) an alicyclic isocyanate compound, and (d) a polyol compound to the fiber surface via at least one of a sulfone group-containing compound and a polyhydric phenol compound.

[0054] Examples of the sulfonic acid group-containing compound include salts of α-olefin sulfonates, sulfonates of phenol-formalin resins, and sodium isophthalate dimethylsulfonate. Salts of α-olefin sulfonates having an average carbon number of 12 to 30 are more preferred. Examples of polyhydric phenol compounds include natural tannins and synthetic tannins such as novolak-type and resol-type sulfonates of phenol-formalin resins.

[0055] These have an affinity for amino groups, and therefore adhere to the fiber surface not only physically but also chemically. Therefore, they are particularly preferred for use with polyamide fibers. However, they can also adhere to the surface of other synthetic fibers such as polyester fibers and polypropylene fibers chemically and physically depending on their chemical affinity, forming a film. This film improves the adhesion of the resin coating, and furthermore, the resin coating adheres uniformly to the fiber surface, improving water repellency.

[0056] The method for attaching the sulfonic acid-containing compound or polyhydric phenol compound to the fiber is not particularly limited, but is preferably immersed in an aqueous solution containing the sulfonic acid-containing compound or polyhydric phenol compound (hereinafter referred to as "pretreatment"). The solid content is preferably 1% to 10% by mass, more preferably 2% to 5% by mass, based on the mass of the fiber substrate before treatment. If the solid content is less than 1% by mass, the effect is not fully exerted, and if it exceeds 10% by mass, the texture tends to become hard. To achieve this effect, it is preferable to adjust the pH of the pretreatment liquid to 2 to 6. Acids such as acetic acid, maleic acid, hydrochloric acid, and sulfuric acid can be used to adjust the pH, and are not particularly limited. The bath ratio (mass ratio) of the fiber substrate to the pretreatment liquid is not particularly limited, but a ratio of 10 to 50 masses of pretreatment liquid to 1 mass of fiber substrate is preferred. The pretreatment temperature is preferably 40° C. to 100° C., more preferably 50° C. to 90° C., and the treatment time is preferably 10 to 60 minutes.

[0057] Synthetic fibers used in the present invention include polyamide fibers, polyester fibers, acrylic fibers, polyolefin fibers, polyvinyl chloride fibers, and polyurethane elastic fibers. Among these, polyamide fibers and polyester fibers are preferred. Examples of polyester fibers include aromatic polyester fibers such as polyethylene terephthalate, polypropylene terephthalate, and polybutylene terephthalate; aromatic polyester fibers copolymerized with aromatic polyesters and a third component such as isophthalic acid, isophthalic acid sulfonate, adipic acid, and polyethylene glycol; aliphatic polyester fibers such as polylactic acid; and polyester fibers composed of a mixture of multiple types of the above polyesters. Examples of polyamide fibers include polyamide fibers such as nylon 6 and nylon 66. Examples of acrylic fibers include acrylic fibers such as polyacrylonitrile; and examples of polyolefin fibers include polyolefin fibers such as polyethylene and polypropylene, and polyvinyl chloride fibers. These fibers may also be combined with polyurethane elastic fibers.

[0058] The fiber substrate used in the present invention may be in the form of a fabric such as a woven fabric, knitted fabric or nonwoven fabric made from the above synthetic fibers, but from the viewpoint of water repellency, a woven fabric is preferred.

[0059] The water-repellent fiber structure of the present invention has an air permeability of 0.1 cm ３ / cm ２ / sec~15cm ３ / cm ２ / sec. ３ / cm ２ If it is smaller than / sec, it will get stuffy, ３ / cm ２ If the air permeability is greater than 0.1 cm / sec, the voids become large and sufficient water repellency cannot be obtained. ３ / cm ２ / sec ~ 15.0 cm ３ / cm ２ / sec, and more preferably 0.2 cm ３ / cm ２ / sec ~ 10.0cm ３ / cm ２ These air permeabilities can be achieved by controlling not only the total fineness and density (number of threads per unit length) of the fibers used, but also the amount of acrylic acid compounds and isocyanate compounds added.

[0060] A fiber structure having a resin coating attached to the surface of a fiber substrate containing synthetic fibers must be substantially free of elemental fluorine. "Substantially free of elemental fluorine" as used herein means that the fluorine content is 25 ng / g or less as measured by combustion ion chromatography. Note that a fluorine content of 25 ng / g or less means that the fluorine content is below the detection limit of the AQF-100 and GA-100 (manufactured by Mitsubishi Chemical Corporation) systems used in the combustion ion chromatography measurement method described below.

[0061] The water-repellent fiber structure of the present invention has excellent water repellency and durability, and therefore can be suitably used for general clothing, work uniforms, industrial materials, etc. In particular, it is suitably used for textile product applications such as outerwear and bedding, specifically, down jackets, coats, blousons, windbreakers, blouses, dress shirts, skirts, slacks, gloves, hats, curtains, and tents, as well as non-clothing applications.

[0062] Among these, applications requiring high water repellency include down jacket linings and windbreakers, and for these applications, high-density fabrics using fine fibers are suitable because they require down shedding and wind resistance. When using high-density fabrics using fine fibers, it is preferable that the total fineness is 5 dtex to 55 dtex and the single fiber fineness is 0.4 dtex to 2.2 dtex.

[0063] The present invention is not limited to the following examples. The measurement and evaluation methods in the examples of the present invention were as follows.

[0064] (Water repellency) Evaluation was performed using a spray test specified in JIS L 1092:2020 "Test method for waterproofness of textile products" and a grade was determined. Grades were determined on a total of 9 levels between grades 1 to 5, with grades 4 and 5 being grade 4-5, grades 3 and 4 being grade 3-4, grades 2 and 3 being grade 2-3, and grades 1 and 2 being grade 1-2.

[0065] (Air permeability) Measured by JIS L 1096:2010 Method A "Fragile method".

[0066] (Combustion ion chromatography) (1) Sample preparation: After cutting the test fabric into small pieces, the sample was freeze-pulverized and dried under reduced pressure (at room temperature for 2 hours). (2) Preparation of standard solution: A fluorine ion standard solution (1005 μg / mL, manufactured by Wako Pure Chemical Industries, Ltd., Lot. KPP6061) was sequentially diluted with a bromine internal standard solution to prepare a standard solution. Of these, a calibration curve was created using the analytical data of the standard solution appropriate for analyzing the concentration in the sample. (3) Combustion ion chromatography of the sample: The sample was weighed and burned in the combustion tube of the following analyzer. The generated gas was absorbed into a solution, and a portion of the absorbed solution was analyzed by ion chromatography. The sample was measured with n=2 after weighing, and the average of the measured values ​​was calculated. <Combustion and absorption conditions> System: AQF-100, GA-100 (manufactured by Mitsubishi Chemical Corporation) Electric furnace temperature: Inlet 900°C, Outlet 1000°C Gas: Ar / O ２ 200mL / min O ２ 400 mL / min Absorption liquid: H ２ O ２ 90 μg / mL, internal standard solution: Br 2 μg / mL Absorption solution volume: 10 mL

[0067] (Washing Method) The laundry was performed according to the method specified in Appendix F, Table F.1-C, C4M of JIS L 1930:2014, "Test Methods for Home Laundry of Textile Products." Specifically, the laundry was performed in a washing machine specified in Appendix E of JIS L 1930:2014, "Test Methods for Home Laundry of Textile Products." The laundry was adjusted to a mass of 2.0±0.1 kg, 40 L of water at 40±3°C was added to a bath ratio (mass ratio) of 1:20, and a weak alkaline synthetic detergent was added and dissolved. The laundry was then washed for 6 minutes. The laundry was then drained and spun for 3 minutes. New water was added to a bath ratio of 1:20, and the laundry was rinsed for 2 minutes. After draining and spinning again, new water was added to a bath ratio of 1:20, and the laundry was rinsed for 2 minutes. This cycle was repeated 100 times, which constituted 100 home washes. After washing, the laundry was hung to dry indoors at 20°C and 65% RH.

[0068] (Amount of Compound Added) When the amount of chemical containing the compound used is A (g / kg), the active ingredient of the compound in the chemical is B (%), and the mangle squeezing rate is C (%), the amount of compound added relative to the fiber mass, X (mass%), is calculated as the value expressed by the following formula: X (mass%) = (A / 1000) x (B / 100) x (C / 100) x 100. When a compound is contained in multiple chemicals, the amount of compound added in each chemical is added together. The mangle squeezing rate, C (%), can be calculated by the following formula: C (%) = [(weight of fabric after one dip and one nip in processing solution) / (weight of fabric in dry state)] x 100

[0069] (Base Fabric 1) A polyester fabric was prepared using 50 decitex, 72 filament polyethylene terephthalate yarn as the warp and 50 decitex, 72 filament polyethylene terephthalate yarn as the weft, and was then subjected to the usual scouring and dyeing to produce a fabric with a warp density of 152 threads / 2.54 cm and a weft density of 119 threads / 2.54 cm, which was designated as base fabric 1.

[0070] (Base Fabric 2) A nylon fabric was prepared using 20 decitex, 24 filament nylon 66 processed yarn as the warp and 30 decitex, 68 filament nylon 66 processed yarn as the weft, and was then refined and dyed as usual to produce a fabric with a warp density of 186 threads / 2.54 cm and a weft density of 160 threads / 2.54 cm, which was designated as base fabric 2.

[0071] (Base Fabric 3) A nylon fabric was prepared using 70 decitex, 48 filament nylon 66 raw silk as the warp and 160 decitex, 96 filament nylon 66 processed yarn as the weft. This was then subjected to the usual scouring and dyeing to produce a fabric with a warp density of 143 threads / 2.54 cm and a weft density of 50 threads / 2.54 cm, which was designated as base fabric 3.

[0072] The obtained base fabrics 1 to 3 were scoured (90°C) with an open soaper, then intermediately set with a pin tenter, and dyed black with a jet dyeing machine at 170°C for 30 seconds.

[0073] For Examples 1 to 4, dried fabrics were used, while for Examples 5 to 8 and Comparative Example 3, after dyeing, the same jet dyeing machine was used to adjust the bath ratio to 1:20 with a processing solution containing 5% owf of Nylonfix 501 (a polyhydric phenol condensate manufactured by Senka Corporation). The temperature was raised from room temperature to 80°C at a rate of 2°C / min, and the fabric was fixed in the bath for 30 minutes. After the temperature was lowered to 50°C, the solution was discharged in order, and the fabric was washed with water, dehydrated, and then dried at 140°C using a pin tenter. The resulting base fabrics 1 to 3 were designated test base fabrics 1 to 3, respectively.

[0074] (Emulsion) Each of the drugs shown in Tables 1 to 5 was mixed and diluted with water to prepare emulsions having the formulations shown in Tables 1 to 5.

[0075] (Examples 1 to 4) Test fabric 1 was immersed in the emulsion liquid shown in Table 1, squeezed with a mangle, dried at 140°C for 40 seconds using a pin tenter, and cured at 170°C for 60 seconds. The squeezing rate of the mangle was 66%. Then, the fabric was calendered at 170°C for 50 seconds.

[0076] The water repellency, fluorine compound content, and air permeability of the resulting treated fabric were measured before and after washing, and the results are shown in Table 1. The resulting treated fabric exhibited high water repellency before and after washing, and was a fiber structure that exhibited excellent water repellency and washing durability.

[0077] (Examples 5 and 6) Test fabric 2 was immersed in the emulsion liquid shown in Table 2, squeezed with a mangle, dried at 140°C for 40 seconds using a pin tenter, and cured at 170°C for 60 seconds. The squeezing rate of the mangle was 75%. Then, the fabric was calendered at 170°C for 50 seconds.

[0078] The water repellency, fluorine compound content, and air permeability of the resulting treated fabric were measured before and after washing, and the results are shown in Table 2. The resulting treated fabric exhibited high water repellency before and after washing, and was a fiber structure that exhibited excellent water repellency and washing durability.

[0079] (Examples 7 and 8) Test fabric 3 was immersed in the emulsion liquid shown in Table 2, squeezed with a mangle, dried at 140°C for 40 seconds using a pin tenter, and cured at 170°C for 60 seconds. The squeezing rate of the mangle was 75%.

[0080] The water repellency, fluorine compound content, and air permeability of the resulting treated fabric were measured before and after washing, and the results are shown in Table 2. The resulting treated fabric exhibited high water repellency before and after washing, and was a fiber structure that exhibited excellent water repellency and washing durability.

[0081] Examples 9 to 13 Test fabric 1 was immersed in the emulsion liquid shown in Table 3, and then processed in the same manner as in Example 1.

[0082] The water repellency, fluorine compound content, and breathability of the resulting treated fabric were measured before and after washing, and the results are shown in Table 3. The resulting treated fabric was a fiber structure exhibiting excellent water repellency.

[0083] (Example 14) Test fabric 1 was immersed in the emulsion liquid shown in Table 3, squeezed with a mangle, dried at 140°C for 40 seconds using a pin tenter, and cured at 170°C for 60 seconds. The mangle squeezing rate was 66%. Then, the fabric was calendered at 170°C for 50 seconds.

[0084] The water repellency, fluorine compound content, and air permeability of the resulting treated fabric were measured before and after washing, and the results are shown in Table 3. The resulting treated fabric exhibited high water repellency before and after washing, and was a fiber structure that exhibited excellent water repellency and washing durability.

[0085] (Comparative Examples 1 and 2) Test fabric 1 was immersed in the emulsion liquid shown in Table 4, squeezed with a mangle, dried at 140°C for 40 seconds using a pin tenter, and cured at 170°C for 60 seconds. The mangle squeezing rate was 66%. Then, the fabric was calendered at 170°C for 50 seconds.

[0086] The water repellency, fluorine compound content, and breathability of the resulting treated fabric were measured before and after washing, and the results are shown in Table 4. The water repellency of the resulting treated fabric decreased after washing, and the fiber structure did not exhibit sufficient washing durability.

[0087] (Comparative Example 3) Test fabric 2 was immersed in the emulsion liquid shown in Table 4, squeezed with a mangle, dried at 140°C for 40 seconds using a pin tenter, and cured at 170°C for 60 seconds. The squeezing rate of the mangle was 75%. Then, the fabric was calendered at 170°C for 50 seconds.

[0088] The water repellency, fluorine compound content, and breathability of the resulting treated fabric were measured before and after washing, and the results are shown in Table 4. The water repellency of the resulting treated fabric decreased after washing, and the fiber structure did not exhibit sufficient washing durability.

[0089] (Comparative Examples 4 to 8) Test fabric 1 was immersed in the emulsion liquid shown in Table 5, squeezed with a mangle, dried at 140°C for 40 seconds using a pin tenter, and cured at 170°C for 60 seconds. The mangle squeezing rate was 66%. Then, the fabric was calendered at 170°C for 50 seconds.

[0090] The water repellency, fluorine compound content, and air permeability of the resulting treated fabric were measured before and after washing, and the results are shown in Table 5. The water repellency of the resulting treated fabric decreased before and after washing, and the fiber structure did not exhibit sufficient washing durability.

[0091]

[0092]

[0093]

[0094]

[0095]

Claims

1. A water-repellent fiber structure comprising a fiber base material containing synthetic fibers and a resin coating attached to the surface of the synthetic fibers, the resin coating being formed using (a) an acrylic acid compound, (b) an aromatic isocyanate compound, (c) an alicyclic isocyanate compound, and (d) a polyol compound, the (a) acrylic acid compound containing a unit represented by the following structural formula (1) and a unit represented by the following structural formula (2), the fluorine content measured by combustion ion chromatography being 25 ng / g or less, and the air permeability being 0.1 cm ３ / cm ２ / sec~15cm ３ / cm ２ / sec. A water-repellent fiber structure represented by structural formula (1): Structural formula (2) (In the formula R １ indicates an alkyl group having 16 or more carbon atoms.) 2. The above R １ 2. The water-repellent fiber structure according to claim 1, wherein: is an alkyl group having 18 carbon atoms.

3. The water-repellent fiber structure according to claim 1 or 2, wherein the polyol compound (d) includes a triol compound represented by the following structural formula (3): (In the formula, n is an integer from 1 to 4.) 4. The water-repellent fiber structure according to claim 1 or 2, wherein the amount of the aromatic isocyanate compound (b) added is 0.16% by mass to 1.2% by mass relative to the synthetic fiber.

5. The water-repellent fiber structure according to claim 1 or 2, wherein the synthetic fiber is a polyamide fiber or a polyester fiber.

6. The water-repellent fiber structure according to claim 1 or 2, wherein the amount of the acrylic acid compound (a) added is 0.6% by mass to 2.0% by mass relative to the synthetic fiber.

7. The water-repellent fiber structure according to claim 1 or 2, wherein the amount of the alicyclic isocyanate compound (c) added is 0.02% by mass to 0.2% by mass based on the synthetic fiber.

8. The water-repellent fiber structure according to claim 1 or 2, wherein the amount of the polyol compound (d) added is 0.04% by mass to 0.20% by mass relative to the synthetic fiber.

9. A method for producing a water-repellent fiber structure as described in claim 1 or 2, comprising a step of impregnating a fiber substrate containing synthetic fibers with a treatment liquid containing (a) an acrylic acid compound, (b) an aromatic isocyanate compound, (c) an alicyclic isocyanate compound, and (d) a polyol compound, followed by a step of dry heat treating the fiber substrate impregnated with the treatment liquid obtained in the step.

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