Water-repellent treatment agent for fibers, water-repellent fiber product, and method for producing water-repellent fiber product

Abstract

The purpose of the present invention is to provide: a water-repellent treatment agent for fibers capable of performing, in supercritical carbon dioxide, water-repellent finishing that realizes less pot stain and sufficient water-repellent performance and washing durability (therefore, durable water repellency), even though a silicone-based compound is used therein; a water-repellent fiber product treated with said water-repellent treatment agent for fibers; and a method for producing said water-repellent fiber product. One embodiment of the present invention provides a water-repellent treatment agent for fibers, in which a silicone resin including M units is contained in supercritical carbon dioxide.

Description

Water-repellent treatment agent for textiles, water-repellent textile product, and method for manufacturing water-repellent textile product

[0001] The present invention relates to a water-repellent treating agent for fibers, a water-repellent textile product, and a method for producing a water-repellent textile product.

[0002] Conventionally, it is known that fluorine-based water repellents and silicone-based water repellents are used as water repellents for fibers in processing treatments to improve the water repellency of fibers in supercritical carbon dioxide.

[0003] Fluorine-based water repellents are generally produced by polymerizing or copolymerizing monomers having a fluoroalkyl group. Although textile products treated with fluorine-based water repellents exhibit excellent water repellency, the monomers having a fluoroalkyl group are difficult to decompose, which poses environmental problems. In recent years, research has been progressing on non-fluorine-based water repellents that do not contain fluorine.

[0004] Patent Document 1 describes a fiber treatment agent characterized by containing a fluorine-based compound and / or a silicone-based compound in a supercritical fluid or a similar fluid, and also describes that the supercritical fluid or a similar fluid may use carbon dioxide as a medium.

[0005] Patent Document 2 describes a method for imparting functionality to a fiber structure, characterized in that when a functionality-imparting agent is attached to the fiber structure in a supercritical fluid, the functionality-imparting agent is attached while the supercritical fluid is circulated.

[0006] JP 2000-220074 A JP 2002-212884 A

[0007] In the technology described in Patent Document 1, a water-repellent treatment is carried out using a silicone compound, methylhydrogenpolysiloxane, having a molecular weight of 10,000. However, this silicone compound can cause staining of the vessel in which the water-repellent treatment is carried out. This technology is not practical when producing water-repellent textile products using a large water-repellent treatment device, as it is difficult to clean the inside of the vessel.

[0008] In the technology described in Patent Document 2, dimethylpolysiloxane with a molecular weight of 10,000 is used as a function-imparting agent, and the dimethylpolysiloxane is attached to a fiber structure in supercritical carbon dioxide. However, this method can also cause pot fouling, making it impractical for producing water-repellent fiber products using large water-repellent processing equipment.

[0009] The present invention has been made in view of the above technical problems, and aims to provide a water-repellent treating agent for fibers that enables a water-repellent treatment to be carried out in supercritical carbon dioxide, which, despite the use of a silicone-based compound, results in little pot fouling and achieves sufficient water-repellent performance and washing durability (hence durable water repellency); a water-repellent textile product treated with the water-repellent treating agent for fibers; and a method for producing the water-repellent textile product.

[0010] As a result of extensive research by the inventors to achieve the above object, the present inventors have completed the invention described below.

[0011] One aspect of the present invention provides a water repellent treatment agent for fibers, which comprises a silicone resin containing M units contained in supercritical carbon dioxide.

[0012] Another aspect of the present invention provides a water-repellent textile product treated with the water-repellent treating agent for textiles.

[0013] Another aspect of the present invention provides a method for producing a water-repellent textile product, comprising treating a substrate with the water repellency treating agent for fibers to obtain a water-repellent textile product, wherein the treatment is carried out under conditions where the temperature of the supercritical carbon dioxide is in the range of 40°C to 130°C.

[0014] According to the present invention, it is possible to provide a water-repellent treating agent for fibers that enables a water-repellent treatment to be carried out in supercritical carbon dioxide, which, despite the use of a silicone-based compound, results in little pot fouling and achieves sufficient water-repellent performance and washing durability (hence durable water repellency); a water-repellent textile product treated with the water-repellent treating agent for fibers; and a method for producing the water-repellent textile product.

[0015] Hereinafter, exemplary embodiments of the present invention will be described in detail, but the present invention is not limited to the following embodiments.

[0016] <Water-repellent treatment agent for fibers> The water-repellent treatment agent for fibers of this embodiment contains a silicone resin containing M units.

[0017] [[Silicone Resin Containing M Units]] A silicone resin containing M units is a silicone that contains M units and is a resin. In this disclosure, "silicone resin" means a silicone that has a three-dimensional network structure and is solid at 25°C (i.e., has a melting point above 25°C).

[0018] Silicone resins containing M units preferably contain MQ, MDQ, MT, MTQ, MDT, or MDTQ as structural units. That is, MQ resins, MT resins, and MDT resins are generally known as silicone resins containing M units. Silicone resins containing M units may also have a moiety represented as MDQ, MTQ, or MDTQ. Here, M, D, T, and Q are each (R'')SiO 0.5 unit, (R'')2SiO unit, R''SiO 1.5 units and SiO2 units (wherein R" is a monovalent organic group). In one embodiment, R" is a monovalent hydrocarbon group, and is preferably a monovalent aliphatic hydrocarbon group having 1 to 10 carbon atoms or a monovalent aromatic hydrocarbon group having 6 to 15 carbon atoms. Suitable examples of the (R") group include a methyl group, an ethyl group, a benzyl group, and a phenyl group. The (R") group present in the silicone resin containing M units may be of one type or two or more types.

[0019] Silicone resins have a three-dimensional network structure, which is thought to have low fluidity. This is thought to provide the advantage that the attached drug is less likely to fall off the substrate. In addition, when silicone resins contain M units, it is thought that the organic groups, which are hydrophobic groups, are more likely to be oriented on the outermost surface of the particles, which is thought to provide the advantage of exhibiting better water repellency than silicone resins that do not contain M units.

[0020] For example, the silicone compounds described in Patent Documents 1 and 2 are thought to have weak adhesion to fabric. That is, even if the agent adheres to the fabric in supercritical carbon dioxide, it is thought that the agent is likely to detach and adhere to the inside of the kettle (and therefore, the kettle is likely to become soiled). On the other hand, the silicone resin of the present embodiment is thought to have strong adhesion to fabric. That is, it is thought that the agent is unlikely to detach from the fabric, and therefore, the agent is unlikely to remain in the kettle (and therefore, the kettle is unlikely to become soiled).

[0021] In a silicone resin containing M units, the monovalent groups bonded to silicon atoms in one embodiment contain a hydrocarbon group and optionally further contain any of hydrogen, amino groups, halogens (e.g., chlorine and bromine), alkoxy groups, etc. From the viewpoint of affinity with supercritical carbon dioxide, the proportion of hydrocarbon groups in the total number (100%) of monovalent groups bonded to silicon atoms is preferably 50% or more, 70% or more, or 90% or more, or may be 100%.

[0022] In a silicone resin containing M units, the ratio of M units to 100 mol% of all constituent units is preferably 10 mol% or more, or 20 mol% or more, or 30 mol% or more, and preferably 90 mol% or less, or 80 mol% or less, or 70 mol% or less, from the viewpoint of water repellency. The molecular structure of the silicone resin can be confirmed by methods such as nuclear magnetic resonance (NMR) and X-ray photoelectron spectroscopy (XPS).

[0023] The silicone resin containing M units contained in the water repellent treatment agent for fibers may be one type or two or more types. For example, a combination of MQ resin and MT resin may be used. From the viewpoint of water repellency, MQ resin is more preferred among silicone resins containing M units. In one embodiment, the MQ resin may have M units at the molecular terminals and Q units at sites other than the molecular terminals.

[0024] The silicone resin containing M units can be obtained alone or as a solution in alkylpolysiloxane and / or a suitable solvent other than alkylpolysiloxane, such as n-hexane, isopropyl alcohol, methylene chloride, 1,1,1-trichloroethane, and mixtures thereof.

[0025] Examples of solutions in which a silicone resin containing M units is dissolved in an alkylpolysiloxane include KF7312J (a mixture of trimethylsilyl group-containing polysiloxane and decamethylcyclopentasiloxane in a mass ratio of 50:50), KF7312F (a mixture of trimethylsilyl group-containing polysiloxane and octamethylcyclotetrasiloxane in a mass ratio of 50:50), KF9021L (a mixture of trimethylsilyl group-containing polysiloxane and low-viscosity methylpolysiloxane in a mass ratio of 50:50), and KF7312L (a mixture of trimethylsilyl group-containing polysiloxane and low-viscosity methylpolysiloxane in a mass ratio of 50:50) commercially available from Shin-Etsu Chemical Co., Ltd.

[0026] Examples of silicone resins containing M units include MQ-1600 solid resin (trimethylsilyl group-containing polysiloxane) and MQ-1640 flake resin (a mixture of trimethylsilyl group-containing polysiloxane and polypropylsilsesquioxane), both of which are commercially available from Dow Corning Toray Co., Ltd. The above commercially available products contain trimethylsilyl group-containing polysiloxane and include MQ, MDQ, MT, MTQ, MDT, or MDTQ.

[0027] The hardness of the silicone resin containing M units, as measured with a Type A durometer in accordance with JIS K 6249:200313. Hardness Test, is preferably 20 or more, more preferably 60 or more, from the viewpoint of water repellency. In one aspect, the hardness may be 80 or less, or 70 or less, from the viewpoint of affinity with supercritical carbon dioxide.

[0028] The weight-average molecular weight of the silicone resin containing M units is preferably 1,000 or more, or 2,000 or more, or 3,000 or more, or 4,000 or more from the viewpoint of water repellency, and preferably 50,000 or less, or 45,000 or less, or 40,000 or less from the viewpoint of affinity with supercritical carbon dioxide. The weight-average molecular weight is a polystyrene-equivalent molecular weight calculated from a GPC curve (elution curve) obtained by gel permeation chromatography (GPC). The solvent used in GPC measurement may be any solvent capable of dissolving the sample, such as tetrahydrofuran. The mobile phase solvent may be any solvent capable of dissolving the sample, such as tetrahydrofuran. A column packed with gel particles such as styrene-divinylbenzene is used. The size of the gel particles packed in the column may be selected to match the molecular weight range to be measured.

[0029] The amount of silicone resin containing M units in the water repellent treatment agent for fibers relative to the total of 100% by mass of components other than supercritical carbon dioxide is, from the viewpoint of obtaining good water repellency, preferably 50% by mass or more, or 70% by mass or more, or 80% by mass or more, or may be 100% by mass.

[0030] The amount of silicone resin containing M units relative to 100% by mass of the total amount of the water repellent treatment agent for fibers is preferably 0.0006% by mass or more, or 0.006% by mass or more, or 0.03% by mass or more, from the viewpoint of obtaining good water repellency, and is preferably 3.0% by mass or less, or 2.5% by mass or less, or 2.0% by mass or less, from the viewpoint of suppressing pot fouling by allowing a desired amount of supercritical carbon dioxide to be present.

[0031] In the water repellent treatment agent for fibers, the amount of silicone resin containing M units per 100 ml of supercritical carbon dioxide is preferably 0.00035 g or more, or 0.0035 g or more, or 0.0175 g or more from the viewpoint of obtaining good water repellency, and is preferably 0.7 g or less, or 0.525 g or less, or 0.35 g or less from the viewpoint of suppressing pot staining. Note that the above amounts are values ​​at the temperature and pressure when the water repellent treatment agent for fibers is applied to the fibers.

[0032] [Supercritical Carbon Dioxide] The water-repellent treatment agent for fibers of this embodiment contains a silicone resin containing M units in supercritical carbon dioxide. Supercritical carbon dioxide is carbon dioxide in a supercritical state, i.e., as a supercritical fluid possessing both gas and liquid properties. Silicone resins containing M units may be difficult to dissolve and / or disperse in liquid media due to their three-dimensional network structure, but they dissolve and / or disperse well in supercritical carbon dioxide. That is, by using supercritical carbon dioxide as a medium when applying a silicone resin containing M units to a water-repellent textile product, a desired amount, e.g., a relatively large amount, of the silicone resin containing M units can be present in the medium. In addition, using supercritical carbon dioxide as a medium can simplify the solvent removal process required when using a liquid medium, for example. That is, supercritical carbon dioxide is easily vaporized by pressure reduction, allowing for easy removal in a short, simple process. Although various molecules other than carbon dioxide are known to constitute supercritical fluids, carbon dioxide is particularly suitable as a medium for silicone resins containing M units because it is non-polar and can dissolve many drugs, has a lower critical point than other substances and can be brought into a supercritical fluid state relatively easily, and is non-toxic. Methods for generating supercritical carbon dioxide and methods for incorporating silicone resins containing M units into supercritical carbon dioxide will be explained in the section <Method for producing water-repellent textile products> below.

[0033] [Other Components] In addition to the silicone resin containing M units and supercritical carbon dioxide described above, the water repellent treatment agent for fibers of this embodiment may further contain silicone resins not containing M units, various organic solvents, antibacterial and antiviral agents, antifungal agents, dyes, pigments, deodorizers, antistatic agents, texture improvers, light resistance improvers, flame retardants, flame retardants, etc. In the water repellent treatment agent for fibers, the total amount of other components relative to 100% by mass of the total of components other than supercritical carbon dioxide may in one aspect be 1% by mass or more, or 5% by mass or more, and in one aspect may be 50% by mass or less.

[0034] An organic solvent may be added to increase the solubility of the water repellent treatment agent for fibers in supercritical carbon dioxide. Examples of the organic solvent include monohydric alcohols such as methanol, ethanol, normal propanol, isopropanol, normal butanol, isobutanol, secondary butanol, tertiary butanol, pentanol, 2-ethylhexanol, benzyl alcohol, and metaethoxybenzyl alcohol; polyhydric alcohols such as ethylene glycol, diethylene glycol, glycerin, triethylene glycol, and propylene glycol; glycol ethers such as propylene glycol monomethyl ether, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol butyl ether, butyl diglycol, and diisopropyl ether; tetrahydrofuran, ... ethers such as furan; esters such as ethyl acetate, n-butyl acetate, isobutyl acetate, sec-butyl acetate, methoxybutyl acetate, ethyl lactate, methyl lactate, and butyl lactate; ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone, diisobutyl ketone, methyl isopropyl ketone, and cyclohexanone; hydrocarbons such as toluene, xylene, normal pentane, normal hexane, isohexane, normal heptane, isoheptane, isooctane, normal nonane, cyclohexane, cyclohexene, ethylcyclohexane, methylcyclohexane, naphtha, mineral spirits, and paraffin; and nitrogen-containing compounds such as pyridine, N-methylpyrrolidone, and N-vinylpyrrolidone.

[0035] It is preferable to use an antibacterial / antiviral agent that does not easily inhibit water-repellent performance. Examples of antibacterial agents include quaternary ammonium salts such as dimethyloctadecylammonium chloride, lauryldimethylhydroxyethylammonium-butyl phosphate, hexadecylethyldimethylammonium-ethyl sulfate, and didecyldimethylammonium methyl sulfate; phosphate esters such as alkyl-group-containing phosphate monoesters and alkyl-group-containing phosphate diesters; phosphate ester salts such as alkyl-group-containing phosphate monoesters and alkyl-group-containing phosphate diesters; metal ions such as silver ions, copper ions, and zinc ions; selenium disulfide, zinc pyrithione, sodium pyrithione, 2-(4-thiazolyl)-benzimidazole, 10,10'-oxybisphenoxanodine, pyridine-2-thiol-oxide, salicylic acid, and oxazoline. The antibacterial / antiviral agents can be used alone or in combination of two or more.

[0036] It is preferable to use an antifungal agent that does not easily impair water repellency. Examples of antifungal agents include sodium hypochlorite, hydroxybenzoic acid esters, benzoates, phenylphenols, alcohols such as phenoxyethanol, benzalkonium chloride, triazole compounds, etc. Antifungal agents can be used alone or in combination of two or more.

[0037] It is preferable to use a dye that does not easily inhibit water-repellent performance. Examples of dyes include anthraquinone compounds, azo compounds, monochlorotriazine compounds, vinyl sulfone compounds, acid dyes such as Kayanol Milling Blue BW and Lanaset Blue 2R, and metal-containing dyes such as Irgaran Blue 3GL and Isolan Navy Blue S-RL. The dyes can be used alone or in combination of two or more.

[0038] It is preferable to use a pigment that does not easily impair the water repellency. Examples of pigments include inorganic pigments such as carbon black, titanium oxide, zinc oxide, lithopone, iron oxide, kaolinite, montmorillonite, talc, barium sulfate, calcium carbonate, silica, alumina, cadmium red, red iron oxide, molybdenum red, chrome vermilion, molybdate orange, chrome yellow, cadmium yellow, yellow iron oxide, titanium yellow, chromium oxide, viridian, cobalt green, titanium cobalt green, cobalt chrome green, ultramarine blue, Prussian blue, cobalt blue, cerulean blue, manganese violet, cobalt violet, and mica; and organic pigments such as azo compounds, azomethine compounds, polyazo compounds, phthalocyanine compounds, quinacridone compounds, anthraquinone compounds, indigo compounds, thioindigo compounds, quinophthalone compounds, benzimidazolone compounds, isoindoline compounds, and isoindolinone compounds. The pigments can be used alone or in combination of two or more.

[0039] It is preferable to use a deodorant that does not easily impair water repellency. Examples of deodorants include hydroxy acids such as citric acid, malic acid, tartaric acid, and lactic acid; inorganic compounds such as silicon dioxide or a reaction product of silicon dioxide and zinc oxide; sugars such as cyclodextrin; and alcohols such as ethanol. One type of deodorant can be used alone, or two or more types can be used in combination.

[0040] It is preferable to use an antistatic agent that does not easily impair water-repellent performance. Examples of antistatic agents include anionic surfactants such as higher alcohol sulfates, sulfated oils, and sulfonates; cationic surfactants such as quaternary ammonium salts and imidazoline-type quaternary salts; nonionic surfactants such as polyethylene glycols and polyhydric alcohol esters; and amphoteric surfactants such as alanine and betaine types. Examples of polymeric compound types include polyalkylamines. Antistatic agents can be used alone or in combination of two or more.

[0041] It is preferable to use a texture improver that does not easily impair water repellency. Examples of texture improvers include amino-modified silicone, epoxy-modified silicone, organo-modified silicone, dimethyl silicone, aliphatic amide compounds, and aliphatic ester compounds. However, the above silicones are not included in the silicone resin containing M units of this embodiment. The texture improver can be used alone or in combination of two or more.

[0042] It is preferable to use a light resistance improver that does not easily impair water repellency. Examples of light resistance improvers include benzotriazole derivatives, triazine derivatives, and hindered amine derivatives. The light resistance improvers can be used alone or in combination of two or more.

[0043] It is preferable to use a flame retardant that does not easily impair water repellency. Examples of flame retardants include phosphorus compounds such as triphenylphosphine compounds, phosphaphenanthrene compounds, halogen-containing phosphate esters, and aromatic phosphate esters; bromine compounds, etc. Flame retardants can be used alone or in combination of two or more.

[0044] It is preferable to use a flame retardant that does not easily impair water repellency. Examples of flame retardants include phosphorus compounds such as phosphate ester amide compounds, phosphorus nitrogen compounds, and phosphorus carbamates; bromine compounds, etc. Flame retardants can be used alone or in combination of two or more.

[0045] <Water-repellent textile product> One aspect of the present invention provides a water-repellent textile product treated with the water-repellent treatment agent for fibers described above. The water-repellent textile product treated with the water-repellent treatment agent for fibers comprises or consists of a substrate and a silicone resin containing M units. Because the silicone resin containing M units uses supercritical carbon dioxide, which is a fluid, as a medium, it can be absorbed into the substrate (i.e., introduced from the outside to the inside of the substrate) and / or adhered to the surface of the substrate.

[0046] The substrate includes a fiber. The substrate is not particularly limited, but examples thereof include substrates whose main material is a polymer compound. The polymer compound may be either a synthetic polymer compound or a natural polymer compound. Specific examples of the substrate include textile products, leather, etc.

[0047] There are no particular limitations on the fibers contained in the substrate, and examples thereof include natural fibers such as cotton, linen, silk, and wool, semi-synthetic fibers such as rayon and acetate, synthetic fibers such as nylon, polyester, polyurethane, and polypropylene, composite fibers thereof, and blended fibers thereof. The substrate may be in the form of a textile product such as yarn, cloth (nonwoven fabric, woven fabric, knitted fabric, etc.), or paper.

[0048] An example of a method for confirming the exhaustion of silicone resins containing M units into the substrate and / or their adhesion to the substrate surface is to treat the substrate with a water-repellent treatment agent for fibers containing silicone resins containing M units in supercritical carbon dioxide to obtain a water-repellent textile product, then prepare a cross-sectional section of the water-repellent textile product and analyze it using an electron microscope. For example, elemental mapping analysis using a scanning electron microscope (SEM-EDX) can be used to confirm whether silicon atoms are detected within the cross section of a single fiber or on the fiber surface. If the substrate contains silicon, this can be confirmed or inferred from the distribution of silicon atoms in elemental mapping analysis. Other methods include X-ray photoelectron spectroscopy (XPS) to confirm the bonding state of silicon atoms, or nuclear magnetic resonance analysis (NMR) to confirm the silicon atoms derived from the silicone resin and the polysiloxane. These methods may also be combined.

[0049] <Method for producing a water-repellent textile product> One aspect of the present invention provides a method for producing a water-repellent textile product. The method includes treating a substrate with the water-repellent treating agent for fibers described above to obtain a water-repellent textile product. That is, in the method for producing a water-repellent textile product of this embodiment, the substrate is treated to have water repellency in supercritical carbon dioxide. The steps for producing a water-repellent textile product are described below.

[0050] In this embodiment, a silicone resin containing M units is absorbed into a substrate and / or adhered to the substrate surface in supercritical carbon dioxide. For example, the substrate and the water repellent treatment agent for fibers are allowed to coexist in a supercritical carbon dioxide treatment device. The supercritical carbon dioxide treatment device is a pressure-resistant kettle, which may be made of, for example, thick stainless steel.

[0051] The supercritical carbon dioxide treatment device has an openable door or lid, which is opened to place the substrate in the device under atmospheric pressure. The device preferably has a mechanism for holding the substrate, such as a cylindrical tube, inside. The device preferably also has a mechanism for stirring the fluid within the device. This can reduce unevenness in the absorption and / or adhesion of the silicone resin containing M units to the substrate.

[0052] The water repellent treatment agent for fibers may be formed in a supercritical carbon dioxide treatment device. First, carbon dioxide is introduced into the supercritical carbon dioxide treatment device and a pressurization operation is performed. For example, a valve on a carbon dioxide supply line fluidly connected to the supercritical carbon dioxide treatment device may be opened to introduce carbon dioxide into the supercritical carbon dioxide treatment device and pressurize the inside of the supercritical carbon dioxide treatment device. At this time, the carbon dioxide in the supercritical carbon dioxide treatment device may be made into a supercritical fluid by adjusting the temperature and pressure inside the device to predetermined values. The critical points of carbon dioxide are a temperature of 31.1°C and a pressure of 7.4 MPa, and carbon dioxide becomes a supercritical fluid when these are exceeded. Note that, before introducing carbon dioxide into the supercritical carbon dioxide treatment device, it is preferable to degas the air in the supercritical carbon dioxide treatment device under reduced pressure.

[0053] The silicone resin containing M units and any other components may be introduced into the supercritical carbon dioxide treatment device at any time before the carbon dioxide in the device becomes a supercritical fluid, or they may be introduced into the device after it has been filled with supercritical carbon dioxide. In the latter case, a preparation tank for dissolving and / or dispersing the silicone resin containing M units and any other components in supercritical carbon dioxide may be provided separately from the supercritical carbon dioxide treatment device. This allows a fluid in which the silicone resin containing M units and any other components are dissolved and / or dispersed in supercritical carbon dioxide to be produced as a water repellent treatment agent for fibers, and the fluid may be introduced from the preparation tank into the supercritical carbon dioxide treatment device via a pipe. In one embodiment, a pipe for injecting the water repellent treatment agent for fibers into the supercritical carbon dioxide treatment device and a pipe for discharging the water repellent treatment agent for fibers from the supercritical carbon dioxide treatment device may be installed between the supercritical carbon dioxide treatment device and the preparation tank, and a pump may be installed and driven between these pipes. In this case, the silicone resin containing M units can be efficiently exhausted and / or adhered to the substrate by circulating the water repellent treatment agent for fibers within the supercritical carbon dioxide treatment device. Alternatively, by attaching a stirrer inside the supercritical carbon dioxide treatment device at a position that does not contact the mechanism (e.g., a cylindrical tube) that holds the substrate, and stirring the water repellent treatment agent for fibers within the supercritical carbon dioxide treatment device, the silicone resin containing M units can be efficiently exhausted and / or adhered to the substrate.

[0054] When the water repellent treatment agent for fibers contains one or more other components in addition to the silicone resin containing M units and supercritical carbon dioxide, the other components may be introduced into the device in a mixed form with the silicone resin containing M units or separately from the silicone resin containing M units. For example, when an organic solvent is introduced, the organic solvent may be introduced from a location in the supercritical carbon dioxide treatment device that does not come into contact with the substrate and the silicone resin containing M units at any timing before the supercritical carbon dioxide becomes a supercritical fluid, or any other component other than the silicone resin containing M units and the organic solvent may be dissolved in the organic solvent and introduced into the supercritical carbon dioxide treatment device from a location that does not come into contact with the substrate.

[0055] The amount of silicone resin containing M units contained in supercritical carbon dioxide is preferably 0.01% o.w.f. or more. If the amount of silicone resin containing M units is too small, sufficient water repellency may not be obtained. On the other hand, if the amount of silicone resin containing M units is too large, the silicone resin containing M units dissolved and / or dispersed in supercritical carbon dioxide may become saturated, and the silicone resin may remain in the device, causing problems such as pot staining. From these points of view, the amount is preferably 0.01% o.w.f. or more, or 0.1% o.w.f. or more, or 0.5% o.w.f. or more, or 0.7% o.w.f. or more, and preferably 20% o.w.f. or less, or 15% o.w.f. or less, or 10% o.w.f. or less. Note that % o.w.f. represents the weight percent of the silicone resin containing M units when the weight of the substrate is taken as 100 weight percent.

[0056] When treating a substrate in supercritical carbon dioxide, the pressure within the supercritical carbon dioxide treatment device may be within a range in which the carbon dioxide within the device is in a supercritical state, but may be adjusted appropriately depending on the type and amount of the silicone resin containing M units, the substrate, etc. As the pressure increases, the energy required to generate supercritical carbon dioxide increases. On the other hand, the higher the pressure, the more easily the silicone resin containing M units dissolves and / or disperses in supercritical carbon dioxide. From these perspectives, the pressure is preferably 13 to 50 MPa, more preferably 15 to 40 MPa, and even more preferably 17 to 30 MPa.

[0057] When treating a substrate in supercritical carbon dioxide, the temperature inside the supercritical carbon dioxide treatment device may be within a range in which the carbon dioxide inside the device is in a supercritical state. However, this may be adjusted appropriately depending on the type and amount of the silicone resin containing M units, the substrate, etc. Higher temperatures increase the energy required to generate supercritical carbon dioxide, and the silicone resin containing M units becomes more difficult to dissolve and / or disperse in supercritical carbon dioxide. On the other hand, if the temperature is too low, the diffusion movement of the water repellent treatment agent for fibers in supercritical carbon dioxide decreases, making it difficult for the silicone resin containing M units to adhere to the substrate surface or to be absorbed into the substrate. From these perspectives, the preferred temperature is 40°C to 130°C, more preferably 40°C to 110°C, and even more preferably 40°C to 100°C.

[0058] In one embodiment, the time for treating the substrate in supercritical carbon dioxide is 10 minutes or longer. Longer times require more energy to generate supercritical carbon dioxide. On the other hand, shorter times may result in the silicone resin containing M units not adhering sufficiently to the substrate surface or not being sufficiently absorbed into the substrate, resulting in uneven exhaustion and / or adhesion of the silicone resin containing M units. From these perspectives, the preferred time is 20 to 240 minutes, more preferably 20 to 210 minutes, and even more preferably 20 to 180 minutes.

[0059] After the treatment with the water-repellent treatment agent for textiles is completed, the discharge valve is opened to discharge the fluid from the inside of the supercritical carbon dioxide treatment device. To avoid problems such as deterioration of the substrate, it is preferable to discharge the fluid as slowly as possible. For example, if the substrate contains polyethylene terephthalate (PET), a slow discharge rate is desirable because an excessively high discharge rate can easily cause PET oligomers to be generated due to a sudden drop in pressure. After the fluid is discharged, the substrate to which the silicone resin containing M units has been absorbed and / or adhered is removed as the desired water-repellent textile product.

[0060] In addition, when the carbon dioxide discharged from the supercritical carbon dioxide treatment device is recovered and reused, it is preferable to introduce the fluid discharged from the supercritical carbon dioxide treatment device into a gas separation tank. In the gas separation tank, the carbon dioxide gas may be separated and recovered from the remaining components of the water repellent treatment agent for fibers (i.e., silicone resin containing M units, etc.) by reducing the pressure or other means. The recovered carbon dioxide may be introduced into the carbon dioxide supply line as a gas or liquefied.

[0061] The present invention will be described in detail below with reference to examples, but the content of the present invention is not limited to these examples in any way.

[0062] Materials and substrates for producing water-repellent textile products were prepared as follows.

[0063] [Silicone resin containing M units] MQ resin (trimethylsilyl group-containing polysiloxane, manufactured by Dow Corning Toray Co., Ltd., trade name: MQ-1600, hardness: 60, weight average molecular weight: 10,000, solid at 25°C) [Dimethyl silicone] (non-resin silicone compound) Dimethyl silicone (manufactured by Dow Corning Toray Co., Ltd., trade name: SH-200, 100 cst (value at 25°C), weight average molecular weight: 12,000, liquid at 25°C) [Methyl hydrogen silicone] (non-resin silicone compound) Methyl hydrogen silicone (manufactured by Shin-Etsu Chemical Co., Ltd., trade name: KF-99, functional group equivalent: 60 g / mol, weight average molecular weight: 1,000, liquid at 25°C)

[0064] [Silicone Resin Containing No M Units] (DT Resin) A sample was prepared as follows. 88 g of a hydrolysis condensate of tetramethoxysilane (an oligomer with an average tetramer), 110 g of octamethyltetracyclosiloxane, and 0.2 g of trifluoromethanesulfonic acid were added to a 500 ml four-neck separable flask equipped with a thermometer and a stirrer, and the mixture was stirred. 0.2 g of water was then added. The resulting mixture was stirred at 80°C for 4 hours and then neutralized by adding ammonia gas. The mixture was filtered, and the filtrate was stripped under reduced pressure at 100°C to obtain the target compound. GPC analysis revealed a weight-average molecular weight of 2,000.

[0065] (DQ Resin) A sample was prepared as follows. 147 g of methyltrimethoxysilane, 14 g of octamethyltetracyclosiloxane, 5 g of methanol, and 0.1 g of trifluoromethanesulfonic acid were added to a 500 ml four-neck separable flask equipped with a thermometer, a stirrer, and a dropping funnel, and the mixture was stirred and heated to 60°C. 24 g of water was added dropwise to the mixture over 1 hour. The resulting mixture was stirred at 60°C for 4 hours and then neutralized by adding ammonia gas. The mixture was filtered, and the filtrate was concentrated at 115°C to obtain a liquid residue. GPC analysis revealed that the weight-average molecular weight was 6,500.

[0066] [Hardness] The hardness was measured in accordance with JIS K 6249:200313. Hardness test using a Type A durometer (manufactured by Major Co., Ltd., model number: GSD-719J).

[0067] [Weight-average molecular weight] The weight-average molecular weight was measured using gel permeation chromatography (GPC) according to the following procedure. 20 mg of a measurement sample was dissolved in 5 ml of a THF / toluene mixed solution (250 ml / 0.1 ml), and the solution was filtered through 5C filter paper to prepare a measurement sample. Next, the molecular weight was measured using a GPC apparatus (Tosoh Technosystems Corporation, model number: HLC-8320), a semi-micro SEC column (TSKgel Super Multipore Hz) as the column, and THF as the mobile phase.

[0068] [Base material] Polyethylene terephthalate knit piece (10.5 cm x 50 cm, 14 g)

[0069] (Preparation of Water-Repellent Textile Product) (Example 1) The substrate was wrapped around a cylindrical tube, secured to the tube with silk thread, and placed in a 400 mL supercritical carbon dioxide treatment device. 0.14 g (1% owf) of silicone resin containing M units was wrapped in wrapping paper and placed in the supercritical carbon dioxide treatment device so as not to come into contact with the substrate. After closing the lid of the supercritical carbon dioxide treatment device, the temperature inside the treatment device was heated to 40°C. Then, while cooling the carbon dioxide injection pump to below 10°C, the carbon dioxide injection valve was opened, and carbon dioxide was injected into the tank while rotating the agitator attached to the top of the device until the pressure inside the tank reached 25 MPa. After carbon dioxide injection, the carbon dioxide injection valve was closed. 30 minutes after the carbon dioxide injection, the carbon dioxide exhaust valve was opened, and the treated fabric was removed after the pressure inside the supercritical carbon dioxide treatment device reached 0 MPa. Through the above operations, water-repellent textile product 1 was prepared.

[0070] Example 2 Water-repellent textile product 2 was produced in the same manner as in Example 1, except that the temperature inside the treatment device was changed to 60°C.

[0071] Example 3 Water-repellent textile product 3 was produced in the same manner as in Example 1, except that the temperature inside the treatment device was changed to 80°C.

[0072] Example 4 Water-repellent textile product 4 was produced in the same manner as in Example 1, except that the temperature inside the treatment device in Example 1 was changed to 110°C.

[0073] Example 5 Water-repellent textile product 5 was produced in the same manner as in Example 3, except that the pressure inside the treatment device was changed to 15 MPa.

[0074] Example 6 Water-repellent textile product 6 was produced in the same manner as in Example 3, except that the pressure inside the treatment device was changed to 20 MPa.

[0075] Example 7 Water-repellent textile product 7 was produced in the same manner as in Example 3, except that the amount of silicone resin containing M units was changed to 0.070 g (0.5% owf).

[0076] Example 8 Water-repellent textile product 8 was produced in the same manner as in Example 3, except that the amount of silicone resin containing M units was changed to 0.105 g (0.75% owf).

[0077] Comparative Example 1 Water-repellent textile product 9 was produced in the same manner as in Example 3, except that the silicone resin containing M units was changed to dimethyl silicone.

[0078] Comparative Example 2 A water-repellent textile product 10 was produced in the same manner as in Example 3, except that the silicone resin containing M units was changed to methyl hydrogen silicone.

[0079] Comparative Example 3 A water-repellent textile product 11 was produced in the same manner as in Comparative Example 2, except that the temperature inside the treatment device was changed to 120°C.

[0080] Comparative Example 4 A water-repellent textile product 12 was produced in the same manner as in Example 3, except that the silicone resin containing M units was changed to DT resin.

[0081] Comparative Example 5 A water-repellent textile product 13 was produced in the same manner as in Example 3, except that the silicone resin containing M units was changed to a DQ resin.

[0082] Comparative Example 6 A water-repellent textile product 14 was produced in the same manner as in Example 3, except that the pressure inside the treatment device was changed to 7 MPa and a non-supercritical state was established.

[0083] In the examples and comparative examples, the drug adhesion rate and the exhaustion rate were measured by the following methods.

[0084] <Measurement of Chemical Adhesion Rate> The bone-dry weights of the treated fabric samples before and after treatment were measured and calculated using the following formula. Chemical Adhesion Rate (%) = 100 × (W2 - W1) / W0 W0: Weight (g) of the silicone compound charged W1: Bone-dry weight (g) of the treated fabric sample before treatment W2: Bone-dry weight (g) of the treated fabric sample after treatment The treated fabric was brought to an bone-dry state in accordance with 5.3.2 of JIS L0105 (2020), and the bone-dry weight was measured. Specifically, the following procedure was used. The treated fabric sample was dried at 105°C for 2 hours in a constant-temperature blower dryer (model: DRM420DD, manufactured by Advantec Toyo Co., Ltd.), and the bone-dry weight was measured after it was brought to an bone-dry state.

[0085] <Measurement of Exhaustion Rate> The bone dry weight of the treated fabric sample before treatment and after 30 washes was measured and calculated using the following formula. The washing was carried out in accordance with Method 103 of JIS L 0217 (1995). Exhaustion rate (%) = 100 × (W3 - W1) / W0 W0: weight (g) of the silicone compound charged W1: bone dry weight (g) of the treated fabric sample before treatment W3: bone dry weight (g) of the treated fabric sample after 30 washes

[0086] The water repellency of the water-repellent textile product obtained above was measured by the following method before washing (HL-0) and after 30 washings (HL-30). The results are shown in Table 1.

[0087] (Evaluation of water repellency of water-repellent textile products) The test was conducted in accordance with the spray method of JIS L 1092 (2009) with shower water at a temperature of 20°C (HL-0). The results were visually evaluated using the following grades. If the characteristics were slightly good, a "+" was added to the grade, and if the characteristics were between grades 4 and 5, the grade was rated as "4-5". An HL-0 water repellency of 3 or higher was considered to be acceptable. Water repellency: Condition 5: No adhesion or wetting of the surface 4: Slight adhesion or wetting of the surface 3: Partial wetting of the surface 2: Wetting of the surface 1: Wetting of the entire surface 0: Complete wetting of both the front and back surfaces

[0088] (Evaluation of durable water repellency of water-repellent textile products) The water-repellent textile products were washed 30 times (HL-30) according to method 103 of JIS L 0217 (1995), and the water repellency after air drying was evaluated in the same manner as the water repellency evaluation method described above. A water repellency score of 3 or more after HL-30 was considered to be acceptable.

[0089] (Evaluation of Pot Staining) After the processing was completed and the water-repellent textile product and chemicals were removed from the apparatus, another substrate was wrapped around a cylindrical tube, and the substrate was then secured to the tube with silk thread and placed in a 400 mL supercritical carbon dioxide treatment device. After closing the lid of the supercritical carbon dioxide treatment device, the temperature inside the treatment device was heated to 40°C. Then, while cooling the carbon dioxide injection pump to below 10°C, the carbon dioxide injection valve was opened, and while rotating the agitator attached to the top of the device, carbon dioxide was injected until the pressure inside the tank reached 25 MPa. After carbon dioxide injection, the carbon dioxide injection valve was closed. Thirty minutes after carbon dioxide injection, the carbon dioxide exhaust valve was opened, and after the pressure inside the supercritical carbon dioxide treatment device reached 0 MPa, the treated fabric was removed. Following this procedure, a basin-dyed fabric was obtained. Five randomly selected locations on the basin-dyed fabric were subjected to X-ray fluorescence analysis (XRF), and the average Si content (by mass) of the five measurement locations was calculated. Evaluation was performed according to the following criteria, with a rating of 3 or higher being considered a pass. 5: Si content is less than 100 ppm 4: Si content is 100 ppm or more and less than 300 ppm 3: Si content is 300 ppm or more and less than 1,000 ppm 2: Si content is 1,000 ppm or more and less than 5,000 ppm 1: Si content is 5,000 ppm or more

[0090]

[0091] It was confirmed that the water-repellent textile products treated with the water-repellent treatment agents for textiles of Examples 1 to 8 had sufficient water repellency and excellent washing durability even after HL-30.

[0092] According to the present invention, it is possible to provide a water-repellent treating agent for fibers that enables a water-repellent treatment to be carried out in supercritical carbon dioxide, which, despite the use of a silicone-based compound, results in little pot fouling and achieves sufficient water-repellent performance and washing durability (hence durable water repellency); a water-repellent textile product treated with the water-repellent treating agent for fibers; and a method for producing the water-repellent textile product.

Claims

1. A water-repellent treatment agent for fibers, comprising a silicone resin containing M units and contained in supercritical carbon dioxide.

2. A water-repellent fiber product treated with the water-repellent treatment agent for fibers according to claim 1.

3. A method for manufacturing a water-repellent fiber product, comprising treating a substrate with the water-repellent treatment agent for fibers according to claim 1 to obtain a water-repellent fiber product, wherein the treatment is carried out under conditions where the temperature of supercritical carbon dioxide is in the range of 40°C to 130°C.

Images