Fiber product including sizing agent, sizing agent, method for producing fiber product including sizing agent, and method for producing fiber product

Abstract

Provided is a fiber product including a sizing agent, the sizing agent containing at least one cellulose ether (A) selected from the group consisting of alkyl cellulose, hydroxyalkyl cellulose, and hydroxyalkyl alkyl cellulose.

Description

Sized textile product, sizing agent, method for manufacturing sized textile product, and method for manufacturing textile product

[0001] The present invention relates to a sized textile product, a sizing agent, a method for producing a sized textile product, and a method for producing a textile product.

[0002] Generally, woven fabrics, such as cotton products, are made by interlacing warp and weft threads. Therefore, the process of making a woven fabric begins with separating the raw yarns into warp and weft threads. The separated raw yarns are then put through various processes. Among these processes, the warp sizing process has a significant impact on the efficiency of the loom and the quality of the finished product. The sizing agent used in the sizing process is required to perform various functions, such as increasing the fiber convergence, suppressing fiber fuzz, and imparting physical properties such as tensile strength and abrasion resistance to the fibers.

[0003] Starch-containing sizing agents have traditionally been used in sizing processes. However, starch-containing sizing agents require the addition of ingredients other than the main ingredient starch (e.g., corn starch) such as wax, propylene glycol, and polyvinyl alcohol (PVA) to improve fiber convergence, smoothness, and flexibility, leading to complex formulations and increased costs. Furthermore, as shown in Comparative Example 1 below, the inventors have conducted extensive research and found that even when starch paste containing ingredients other than the starch is used as a sizing agent, there is still room for improvement in fiber convergence. As described above, there is a demand for sizing textile products with excellent fiber convergence.

[0004] An object of the present invention is to provide a sizing-coated textile product that has excellent fiber bundling properties.

[0005] As a result of intensive research aimed at solving the above problems, the present inventors have discovered that the above problems can be solved by using a sizing agent containing a specific cellulose ether, and have thus completed the present invention. Specific aspects of the present invention are as follows.

[0006] [1] A sizing textile, wherein the sizing agent comprises at least one cellulose ether (A) selected from the group consisting of alkyl cellulose, hydroxyalkyl cellulose, and hydroxyalkyl alkyl cellulose. [2] The sizing textile according to [1], wherein the cellulose ether (A) comprises at least one selected from the group consisting of methyl cellulose, hydroxypropyl methyl cellulose, and hydroxyethyl methyl cellulose. [3] The sizing textile according to [1] or [2], wherein the alkyl cellulose or the hydroxyalkyl alkyl cellulose has an alkoxy group substitution degree of 1 to 3. [4] The sizing textile according to any one of [1] to [3], wherein the viscosity of the cellulose ether (A) when prepared as a 1 wt % or 5 wt % aqueous solution is 3 to 300 mPa·s. [5] The sizing textile according to any one of [1] to [4], wherein the textile comprises cotton yarn or cotton fabric. [6] The sizing textile according to any one of [1] to [5], wherein the adhesion rate of the sizing agent to the sizing textile is 0.1 to 10% by weight. [7] A sizing agent for producing the sizing textile according to any one of [1] to [6], comprising at least one cellulose ether (A) selected from the group consisting of alkyl cellulose, hydroxyalkyl cellulose, and hydroxyalkyl alkyl cellulose. [8] A method for producing the sizing textile according to any one of [1] to [6], comprising a step of bringing a textile into contact with a fluid containing the sizing agent to size the textile. [9] A method for producing a textile from the sizing textile according to any one of [1] to [6], comprising a step of bringing the sizing textile into contact with a fluid containing supercritical carbon dioxide to desize the sizing textile.

[10] The method according to [9], wherein the desizing step is performed by batch processing or continuous processing.

[0007] The sizing-coated textile product according to one aspect of the present invention has excellent fiber bundling properties.

[0008] FIG. 1 is a temperature-pressure phase diagram of carbon dioxide. FIG. 2 is an SEM image of cotton yarn without adhesive. FIG. 3 is an SEM image of cotton yarn with starch adhesive. FIG. 4 is an SEM image of cotton yarn with cellulose ether (1) (methylcellulose) attached. FIG. 5 is a diagram showing an outline of an apparatus used for treatment with a fluid containing supercritical carbon dioxide. FIG. 6(a) is a diagram showing a jig with fabric wrapped around it. FIG. 6(b) is a diagram showing an outer cylinder with a paper wiper wrapped around it. FIG. 7 is a diagram showing a jig with cotton yarn wrapped around it. FIG. 8 is an SEM image of fabric with adhesive attached to cellulose ether (3) (hydroxypropyl methylcellulose) before desizing. FIG. 9 is an SEM image of fabric with adhesive attached to cellulose ether (3) (hydroxypropyl methylcellulose) after desizing. FIG. 10 is a photograph of the fabric after evaluation of water wettability.

[0009] In this specification, when a numerical range is expressed using "X to Y," the range is intended to include both end values.

[0010] The sizing textile product, the sizing agent, the method for producing the sizing textile product, and the method for producing the textile product of the present invention will be described below.

[0011] 1. Sized Textiles One aspect of the present invention provides a sized textile, wherein the sizing agent contains at least one cellulose ether (A) selected from the group consisting of alkyl cellulose, hydroxyalkyl cellulose, and hydroxyalkyl alkyl cellulose. The sized textile according to one aspect of the present invention has excellent fiber convergence. In some cases, the sized textile can enhance fiber convergence without excessively increasing the amount of sizing agent applied, or the sized textile can exhibit high tensile strength, or the sized textile has high durability against friction, making it less likely to experience a decrease in tensile strength even after a friction test.

[0012] (Sizing Agent) The sizing agent may further contain components other than the cellulose ether (A), or may contain no components other than the cellulose ether (A) (the sizing agent may consist of the cellulose ether (A)). In this specification, "not containing" a specific component means that the component is not intentionally added, and does not exclude the presence of the component as an impurity. The components other than the cellulose ether (A) are not particularly limited, but may include or consist of, for example, corn starch, wax, propylene glycol, polyvinyl alcohol (PVA), or a combination of two or more of these. On the other hand, in the sizing agent of this embodiment, fiber convergence can be improved even when the sizing agent consists of the cellulose ether (A) without adding any other components other than the cellulose ether (A). As described above, conventional starch-containing sizing agents require the addition of components other than starch to improve fiber convergence, smoothness, flexibility, etc., whereas the cellulose ether (A) possesses properties not found in conventional starch pastes. Since it is not necessary to add any components other than the cellulose ether (A), the sizing agent-containing fiber product of this embodiment does not require complicated blending, improving production efficiency and reducing costs.

[0013] The adhesion rate (amount of adhesion) of sizing agent to a sizing-coated textile product is not particularly limited, but is preferably 0.1 to 10% by weight, more preferably 1 to 8% by weight, and most preferably 3 to 7% by weight. When the adhesion rate of sizing agent is within the above numerical range, pilling due to friction between threads or between threads and metal is less likely to occur, and thread breakage is reduced, thereby improving weaving efficiency. The adhesion amount of sizing agent to a sizing-coated textile product can be calculated based on the method and procedure described in (4-2) of 1. [Examples] below.

[0014] The sizing agent (or a fluid containing a sizing agent) is not particularly limited, but for example, it may not contain a pigment. Examples of such pigments include dyes, pigments, and mixtures thereof. The sizing agent is not particularly limited, but for example, it may be a sizing agent other than a printing paste (a printing paste). Examples of such a sizing agent other than a printing paste include a warp sizing agent for textiles.

[0015] (Cellulose Ether (A)) Alkyl cellulose is a type of cellulose ether and can be produced by reacting cellulose with an etherifying agent. Alkyl cellulose is a compound in which some or all of the hydrogen atoms of hydroxyl groups (—OH) of cellulose are substituted with alkyl groups (—R) to convert them into alkoxyl groups (—OR). Unalkylated cellulose is insoluble in water, but when the hydroxyl groups are reduced by alkylation, the hydrogen bonds between the hydroxyl groups are weakened, making the cellulose water-soluble. The alkyl cellulose is not particularly limited, but can include or consist of, for example, methyl cellulose, ethyl cellulose, or a combination thereof. Of these, methyl cellulose is preferred. The use of methyl cellulose enables sizing in an aqueous system, reduces costs, and also facilitates desizing using supercritical carbon dioxide, as described below.

[0016] Hydroxyalkyl cellulose is a compound in which some or all of the hydrogen atoms of hydroxy groups (-OH) of cellulose are substituted with hydroxyalkyl groups to convert them into hydroxyalkoxy groups. The hydroxyalkyl cellulose is not particularly limited, but may include or consist of, for example, hydroxymethyl cellulose, hydroxyethyl cellulose, hydroxypropyl cellulose, or a combination thereof.

[0017] Hydroxyalkyl alkyl cellulose is a compound in which some or all of the hydrogen atoms of cellulose's hydroxy groups (—OH) are substituted with alkyl groups and hydroxyalkyl groups, converting them into alkoxy groups and hydroxyalkoxy groups. The hydroxyalkyl alkyl cellulose is not particularly limited, but can include or consist of, for example, hydroxypropyl methylcellulose, hydroxyethyl methylcellulose, or a combination thereof. Among these, hydroxypropyl methylcellulose is preferred. Use of hydroxypropyl methylcellulose enables sizing in an aqueous system, reduces costs, and also facilitates desizing using supercritical carbon dioxide, as described below.

[0018] The cellulose ether (A) is not particularly limited, and may comprise or consist of at least one selected from the group consisting of methyl cellulose, hydroxypropyl methyl cellulose, and hydroxyethyl methyl cellulose. One or a combination of two or more of these compounds can be used as the cellulose ether (A).

[0019] The degree of substitution of alkoxy groups in alkyl cellulose and / or hydroxyalkyl alkyl cellulose (the average number of alkoxy groups present per glucose ring unit of cellulose) is not particularly limited, but is preferably 1 to 3, more preferably 1.2 to 2.5, and most preferably 1.4 to 1.9. When the degree of substitution of alkoxy groups is within the above numerical range, the concentration and deposition amount of sizing agent are minimized, while the permeability into the yarn is good, leading to improved weaving efficiency. The degree of substitution of the alkoxy groups can be the degree of substitution of methoxy groups. In the case of methyl cellulose, the degree of substitution of methoxy groups is most preferably 1.64 to 1.92. In the case of hydroxypropyl methyl cellulose, the degree of substitution of methoxy groups is most preferably 1.79 to 2.04.

[0020] The molar substitution number of hydroxyalkoxy groups in hydroxyalkyl cellulose and / or hydroxyalkyl alkyl cellulose is not particularly limited, but is preferably 0.1 to 0.5, more preferably 0.15 to 0.4, and most preferably 0.2 to 0.35. When the molar substitution number of hydroxyalkoxy groups is within the above numerical range, the sizing agent concentration and deposition amount are minimized, while providing good penetration into the yarn, leading to improved weaving efficiency. The molar substitution number of hydroxypropoxy groups is most preferably 0.18 to 0.34. In this specification, the molar substitution number of hydroxyalkoxy groups refers to the average number of moles of hydroxyalkoxy groups added per glucose ring unit of cellulose. The above-mentioned numerical ranges for the degree of substitution of methoxy groups and the above-mentioned numerical ranges for the molar substitution number of hydroxyalkoxy groups can be combined in any manner.

[0021] The weight-average molecular weight of the cellulose ether (A) is not particularly limited, but is preferably 20,000 to 100,000, more preferably 30,000 to 90,000, and most preferably 50,000 to 80,000. When the weight-average molecular weight of the cellulose ether (A) is within the above numerical range, the concentration and adhesion amount of the sizing agent are minimized, while the permeability into the yarn is good, leading to improved weaving efficiency. The weight-average molecular weight of the cellulose ether (A) was measured using a GPC apparatus (integrated apparatus, manufactured by Tosoh Corporation, HLC (registered trademark)-8420GPC) (column: SB-806MHQ 40°C, guard column: SB-G6B, both manufactured by Resonac Corporation) in a solvent, eluent: 0.1 M NaNO . ３ Measurement can be performed by GPC under conditions of 1.0 mL / min and injection volume of 100 μl.

[0022] The viscosity of the cellulose ether (A) is not particularly limited, but for example, when prepared as a 1 wt% aqueous solution, it is preferably 3 to 300 mPa·s, more preferably 30 to 200 mPa·s, and most preferably 50 to 150 mPa·s. When the viscosity of methylcellulose is within the above numerical range, it can minimize both the concentration and amount of sizing agent applied, while providing good penetration into the yarn, leading to improved weaving efficiency. Furthermore, the viscosity of the cellulose ether (A) is not particularly limited, but for example, when prepared as a 5 wt% aqueous solution, it is preferably 3 to 300 mPa·s, more preferably 30 to 200 mPa·s, and most preferably 50 to 150 mPa·s. When the viscosity of methylcellulose is within the above numerical range, it can minimize both the concentration and amount of sizing agent applied, while providing good penetration into the yarn, leading to improved weaving efficiency. The above-mentioned range of viscosity in a 1 wt% aqueous solution is applicable to, for example, methyl cellulose, and the above-mentioned range of viscosity in a 5 wt% aqueous solution is applicable to, for example, hydroxypropyl methyl cellulose. The viscosity of the cellulose ether (A) can be calculated based on the method described in (4-1) of Section 1 of [Examples] below.

[0023] The content of cellulose ether (A) in the paste can be 100% by weight (the paste consists of cellulose ether (A)). In this case, as described above, the blending can be simplified, costs can be reduced, and fiber bundling can be improved. The content of cellulose ether (A) in the paste can be 80% by weight or more, 90% by weight or more, or 95% by weight or more. The content of cellulose ether (A) in the paste can be 100% by weight or less. The above numerical ranges can be combined arbitrarily.

[0024] (Textile Products) Examples of textile products include, but are not limited to, fibers, yarns, fabrics, etc. Examples of fibers include tow before being made into yarn. Examples of yarns include, but are not limited to, spun yarns, filament yarns, and mixed twisted yarns and blended yarns obtained by mixing and twisting these. Examples of fabrics include woven fabrics and knitted fabrics using yarns, as well as nonwoven fabrics and felts. In this embodiment, it is preferable to use yarns as the textile product, and in this case, the yarns to which the sizing agent has been applied obtained by this method can be subjected to a subsequent weaving process. The textile product can also include or consist of cotton yarns or cotton fabrics.

[0025] The type of yarn is not particularly limited, but examples include natural fibers such as plant fibers like cotton and hemp, animal fibers like silk and wool, synthetic fibers like polyester and acrylic, semi-synthetic fibers like acetate, triacetate, and promix, regenerated fibers like rayon, polynosic, cupra, and lyocell, and inorganic fibers like glass fiber, metal fiber, and carbon fiber. Two or more of these yarns may be blended or twisted together. These yarns may also be single yarns, two-ply yarns, triple-ply yarns, or four or more twisted yarns. In this embodiment, cotton yarn is preferred from the perspective of the feel of the towel. The type of fabric is not particularly limited, but may be the same as the above-mentioned yarn types.

[0026] The sizing textile product is not particularly limited, but can be, for example, a sizing yarn or a sizing fabric. The sizing yarn is not particularly limited, but can be, for example, the warp yarn of a woven fabric. The sizing fabric is not particularly limited, but can be, for example, a woven fabric including a sizing warp yarn (having a sizing agent attached) containing the cellulose ether (A) and a weft yarn not having a sizing agent containing the cellulose ether (A) attached. Here, the weft yarn not having a sizing agent containing the cellulose ether (A) attached means a weft yarn to which the sizing agent has not been actively attached. Therefore, the weft yarn not having a sizing agent containing the cellulose ether (A) attached can also include a state in which the sizing warp yarn containing the cellulose ether (A) comes into contact with the weft yarn, and the sizing agent of the warp yarn is transferred to the weft yarn.

[0027] 2. Sizing Agent One aspect of the present invention is a sizing agent containing at least one cellulose ether (A) selected from the group consisting of alkyl cellulose, hydroxyalkyl cellulose, and hydroxyalkyl alkyl cellulose, for producing the sizing agent-coated textile product described in 1. above. The sizing agent of this embodiment can reduce the BOD and / or COD values ​​when made into a solution compared to conventional starch pastes, thereby suppressing water pollution. In the sizing agent of this embodiment, the types, contents, etc. of the sizing agent, cellulose ether (A), textile product, etc. can be similarly configured to those described in 1. above.

[0028] As described in 1. above, the size (or the fluid containing the size) may not contain a pigment. The size may be a size other than a printing paste (a printing paste). Such a size other than a printing paste may include a size for warp threads of a textile.

[0029] 3. Method for Producing a Sized Textile Product A method for producing a sized textile product according to one aspect of the present invention is the method for producing a sized textile product described in 1 above, and includes a step of bringing a fluid containing the sizing agent into contact with a textile product to size the textile product.

[0030] In the method of this embodiment, the types and contents of the sizing agent, cellulose ether (A), and textiles can be the same as those described in 1 above.

[0031] In this embodiment, the treatment conditions when the fluid containing the sizing agent is brought into contact with the textile product are not particularly limited. For example, from the viewpoint of improving sizing properties, the temperature can be in the range of 0 to 100°C, preferably in the range of 0 to 75°C, and most preferably in the range of 0 to 55°C. Furthermore, from the viewpoint of improving sizing properties, the pressure is preferably 0.01 to 0.2 MPa. Furthermore, from the viewpoint of improving sizing properties, the treatment time is preferably about 60 minutes per 450 kg of textile product. The process of bringing the fluid containing the sizing agent into contact with the textile product can be performed by batch processing.

[0032] The amount of sizing agent used is not particularly limited, but for example, when cotton yarn is used as the textile product, it is preferable to use 0.03 to 0.07 g of sizing agent per 1 g of cotton yarn in order to improve sizing properties.

[0033] The content of the cellulose ether (A) in the fluid containing the sizing agent is not particularly limited, but is, for example, preferably 0.1 to 10% by weight, more preferably 0.5 to 7% by weight, and most preferably 1 to 5% by weight. When the content of the cellulose ether (A) in the fluid is within the above range, the sizing agent has good penetration into the yarn, leading to improved weaving efficiency, while minimizing both the concentration and adhesion amount of the sizing agent.

[0034] In this embodiment, the fluid containing the adhesive agent may further contain, for example, a solvent, but is not particularly limited thereto. The solvent may include, but is not particularly limited to, for example, water, a glycol ether-based solvent, an aqueous solvent such as a lower alcohol, glycerin, polyethylene glycol, polypropylene glycol, DMSO, DMF, benzyl alcohol, N-methyl-2-pyrrolidone, or a combination of two or more of these. Among these, water is preferred. By including water in the fluid, excellent solubility and appropriate viscosity can be achieved. The glycol ether-based solvent may include, but is not particularly limited to, for example, ethylene glycol monobutyl ether (2-butoxyethanol) (EGME), diethylene glycol mono-2-ethylhexyl ether, ethylene glycol monophenyl ether, 2-methylpentane-2,4-diol, diethylene glycol monohexyl ether, diethylene glycol dibutyl ether, triethylene glycol monobutyl ether, or a combination of two or more of these. Among these, EGME is preferred. The lower alcohol may include, but is not particularly limited to, for example, methanol, ethanol, or a combination of these. The content of the solvent in the fluid containing the adhesive is not particularly limited, but is preferably 50 to 99 wt %, more preferably 65 to 95 wt %, and most preferably 80 to 95 wt %. When the content of the solvent in the fluid containing the adhesive is within the above range, the solubility of the solid content is improved.

[0035] In this embodiment, when a solvent is used, the solvent can be sent into the processing vessel.

[0036] When a solvent is used, the ratio (mol) of the solvent to 1 to 5 g of the adhesive is not particularly limited, but from the viewpoint of improving the sizing property, for example, 1 to 6 mol is preferable.

[0037] The method of this embodiment can be used as a sizing process, which is one of the fiber processing steps, and can also be used in combination with other fiber processing steps such as spinning, weaving, desizing / refining / bleaching, dyeing, and finishing. Furthermore, the method for producing a sizing-applied fiber product of this embodiment can be combined with a method for producing a fiber product from a sizing-applied fiber product, which will be described later, to form a single method or production method.

[0038] In the method of this embodiment, the step of sizing the textile product may include or consist of a step of contacting a fluid containing the sizing agent with a yarn to size the yarn. In this case, the method of this embodiment may further include a step of forming a fabric using the sized yarn to form a sized fabric. In this case, the method of this embodiment may further include or consist of a step of forming a woven fabric using the sized yarn as a warp yarn to form a sized woven fabric.

[0039] 4. Method for Producing Textiles from Sized Textiles A method for producing textiles from sized textiles according to one aspect of the present invention is a method for producing textiles from sized textiles as described in 1 above, and includes a step of desizing the sized textiles by contacting the sized textiles with a fluid containing supercritical carbon dioxide. The method for producing textiles from sized textiles of this embodiment can efficiently remove the sizing agent, and can produce textiles with excellent water wettability.

[0040] In the method of this embodiment, the types, contents, etc. of the starch, cellulose ether (A), and fiber products can be similar to those described in 1. In this embodiment, it is preferable to use cotton yarn as the fiber from the viewpoint of the feel of the towel.

[0041] In this embodiment, the sizing agent-coated textile product is not particularly limited, but for example, a product obtained by the method for producing a sizing agent-coated textile product described in 3 above can be used.

[0042] Here, we will explain supercritical carbon dioxide. It is known that supercritical carbon dioxide is used for textile processing. The supercritical state occurs when a compound exceeds its specific critical temperature (Tc) and critical pressure (Tp). This state is called a supercritical fluid and has properties intermediate between those of a gas and a liquid. As shown in Figure 1, carbon dioxide can reach a supercritical state under relatively mild conditions: Tc is 31.1°C and Tp is 7.38 MPa. It has the advantages of being non-explosive, non-toxic, highly safe, inexpensive, and readily available. Furthermore, supercritical carbon dioxide has the following characteristics: (1) its density fluctuates significantly with slight changes in pressure near its critical temperature; (2) its low viscosity and high diffusivity result in excellent transport properties and high penetration into materials; (3) its high thermal conductivity results in rapid heat transfer; (4) its solvation effect results in a fast reaction rate; (5) its dielectric constant is smaller than that of water, making it comparable to that of conventional nonpolar organic solvents, making it a good solvent for nonpolar organic substances; and (6) the carbon dioxide can be recovered and reused.

[0043] In this embodiment, the treatment conditions when the fluid containing supercritical carbon dioxide is brought into contact with the sizing-applied textile product are not particularly limited, but from the viewpoint of improving desizing properties, for example, the temperature can be 31 to 150°C or 40 to 120°C, the pressure can be 8 to 25 MPa or 10 to 25 MPa, and the time can be 30 to 800 minutes or 120 to 180 minutes. In this embodiment, the desizing step can be a batch process or a continuous process.

[0044] In this embodiment, the fluid containing supercritical carbon dioxide may further contain a co-solvent. By including a co-solvent in the fluid, the solubility of the glue in the solvent (including supercritical carbon dioxide and the co-solvent) can be improved, thereby improving removability. The co-solvent is not particularly limited, and the solvents described in 3. above can be used, but it is preferable to use a glycol ether solvent, particularly EGME. By using the solvent described in 3. above as the co-solvent, the solubility of the glue in the solvent (including supercritical carbon dioxide and the co-solvent) can be improved, thereby improving removability. The above effect is particularly noticeable when EGME is used as the co-solvent.

[0045] In this embodiment, when a co-solvent is used, the co-solvent can be fed into the processing vessel separately from the supercritical carbon dioxide.

[0046] In this embodiment, when the desizing step is performed by batch processing and a co-solvent is used, the ratio (mol %) of the co-solvent to the supercritical carbon dioxide is not particularly limited, but is preferably 0.1 to 2 mol % from the viewpoint of improving the solubility of the sizing agent in the solvent and thereby improving resizing. The volume ratio of the supercritical carbon dioxide to the co-solvent is not particularly limited, but is preferably 400:1 to 10:1, more preferably 300:1 to 25:1, and most preferably 200:1 to 40:1. The volume ratio of the supercritical carbon dioxide to the co-solvent can also be 150:1 to 50:1, 100:1 to 60:1, or 90:1 to 70:1.

[0047] In the present embodiment, when the desizing step is a continuous process, the flow rate of supercritical carbon dioxide into the processing vessel is not particularly limited. However, from the viewpoint of improving the solubility of the sizing agent in the solvent and thereby improving the desizing properties, the flow rate is preferably 50 mL to 2000 mL, and more preferably 100 mL to 1500 mL, per 1 g of fiber.

[0048] In this embodiment, when the desizing step is a continuous process and a co-solvent is used, the flow rate of the co-solvent into the processing vessel is not particularly limited, but is preferably 1 mL to 500 mL, and more preferably 10 mL to 400 mL, per 1 g of fiber.

[0049] The removal rate (%) of the sizing agent after desizing by the method of this embodiment is not particularly limited, but can be, for example, 1 to 99%, etc. The removal rate (%) of the sizing agent can be calculated based on the procedure and method described in (4-1) of 5. of [Examples] below. In the method of this embodiment, the solubility of the sizing agent in the fluid containing supercritical carbon dioxide (amount of dissolved sizing agent (g) / volume of fluid containing supercritical carbon dioxide (mL)) is not particularly limited, but is, for example, preferably 0.0001 to 0.01 g / mL, more preferably 0.001 to 0.008 g / mL, and most preferably 0.002 to 0.006 g / mL. The solubility of the sizing agent in the fluid containing supercritical carbon dioxide is not particularly limited, but can be, for example, 1 x 10 －５ g / mL or more, 1×10 －４ g / mL or more, or 1 x 10 －３ The solubility of the adhesive in the fluid containing supercritical carbon dioxide is not particularly limited, but can be, for example, 1 g / mL or less, 1×10 －１ g / mL or less, or 1 x 10 －２ The above numerical ranges can be combined in any manner.

[0050] In this embodiment, the desizing step can include moving the sizing-coated textile product using power. By moving the sizing-coated textile product using power, the entire sizing-coated textile product (fabric) can be kneaded, thereby improving desizing properties. The power source is not particularly limited, but can be, for example, wind power, electricity, etc., and among these, wind power is preferred.

[0051] The method of this embodiment can be used as a desizing process, which is one of the fiber processing steps, and can also be used in combination with other fiber processing steps such as spinning, weaving, sizing, scouring / bleaching, dyeing, and finishing. Furthermore, the method of producing a fiber product from a sized fiber product of this embodiment can be combined with the above-mentioned method of producing a sized fiber product to form a single method or production method.

[0052] The present invention will be specifically described below with reference to examples, but the present invention is not limited to the contents described in the examples.

[0053] 1. Measurement of physical properties or observation of surface condition of sizing agent or sizing-coated textile product (1) Preparation of aqueous solution containing sizing agent The sizing agents used are as follows: Cellulose ether (1): Metolose (registered trademark) SM-1500 (methylcellulose, weight average molecular weight: 90,000, degree of substitution of methoxy group: 1.8, manufactured by Shin-Etsu Chemical Co., Ltd.) Cellulose ether (2): Metolose (registered trademark) 60SH-06 (hydroxypropyl methylcellulose, weight average molecular weight: 80,000, degree of substitution of methoxy group: 1.9, number of moles of hydroxypropoxy group substituted: 0.25, manufactured by Shin-Etsu Chemical Co., Ltd.) Starch paste: A paste containing corn starch (weight average molecular weight: 500,000 to 1,000,000) as the main starch component and additives (content of each component relative to the total paste: wax 2% by weight, glycerin 1% by weight, small amount of PVA added).

[0054] [Example 1] Boiling water was added to the cellulose ether (1) to give a dilution ratio of 40 times based on the weight of the cellulose ether, and the resulting diluted solution was stirred for a certain period of time. Room temperature water was added to the diluted solution after stirring to give a dilution ratio of 60 times based on the weight of the cellulose ether, and the resulting diluted solution was stirred for a certain period of time to prepare an aqueous solution having a solids concentration of 1.0 wt% of cellulose ether (1). [Example 2] An aqueous solution having a solids concentration of 1.0 wt% of cellulose ether (2) was prepared in the same manner as in Example 1, except that the cellulose ether (2) was used instead of the cellulose ether (1). [Example 3] Boiling water was added to the cellulose ether (2) to give a dilution ratio of 8 times based on the weight of the cellulose ether, and the resulting diluted solution was stirred for a certain period of time. Room temperature water was added to the diluted solution after stirring to give a dilution ratio of 12 times based on the weight of the cellulose ether, and the resulting diluted solution was stirred for a certain period of time to prepare an aqueous solution having a solids concentration of 5.0 wt% of cellulose ether (2). Comparative Example 1 After adding water to the above starch paste, the mixture was heated to 90° C. or higher to dissolve and gelatinize the starch paste, thereby preparing an aqueous solution of starch paste with a solids concentration of 2.0% by weight.

[0055] (2) Apparatus and Reagents As a sizing machine, a Minisizer DCI001P (manufactured by Kaji Seisakusho Co., Ltd.) and an HGA-357 type sizing machine (manufactured in China, glue tank capacity approximately 47 L) were prepared.

[0056] (3) Operating Procedure [Example 1] 2500 mL of the cellulose ether aqueous solution of Example 1 obtained in (1) above was placed in the above-mentioned sizing machine: Minisizer DC1001P. Furthermore, cotton yarn (1) (raw silk (unbleached yarn, spun yarn, etc.), 100% cotton, 20 count, single yarn, twist coefficient 4.5, average fiber length approximately 25 mm) manufactured by Izawa Towel Co., Ltd., fed from a cheese bobbin was placed in the cellulose ether aqueous solution in the sizing machine. At this time, the weight of the cotton yarn (1) per unit length fed from the cheese bobbin was measured. Thereafter, the cotton yarn with the adhered size solution (aqueous solution) was passed through a squeezing roll (first pass roll) under a pressure load of 0.04 MPa and an immersion roll (second pass roll) under a pressure load of 0.06 MPa, and further passed through a hot air drying section with a temperature of 110°C and a drying chamber length of approximately 3.8 m, and a cylinder roll drying section with a temperature of 110°C and seven cylinder rolls of 100 mm diameter at a speed of 10 m / min, thereby carrying out a sizing treatment. The weight of the obtained dried (sizing) cotton yarn (1) per unit length was measured.

[0057] Comparative Example 1 35 L of the starch sizing solution of Comparative Example 1 obtained in (1) above was placed into the above-mentioned sizing machine: Model HGA-357 sizing machine. Furthermore, cotton yarn (1) (raw silk (e.g., raw yarn, spun yarn, etc.), 100% cotton, 20 count, single yarn, twist coefficient 4.5, average fiber length approximately 25 mm) manufactured by Izawa Towel Co., Ltd., fed from a cheese bobbin was placed into the starch sizing solution in the sizing machine. The weight of the cotton yarn (1) per unit length fed from the cheese bobbin was measured. The cotton yarn with the attached sizing solution (aqueous solution) was then passed through a drying chamber of approximately 20 m and dried at 300°C. The excess sizing solution was then removed using a cylinder roll at approximately 120°C, and the resulting sized cotton yarn (1) was wound onto a weaving beam. The cotton yarn passed through the drying chamber and the cylinder roll at a speed of 30 m / min. The weight of the resulting dried (sized) cotton thread (1) per unit length was measured.

[0058] [Examples 2 and 3] 2500 mL of each aqueous solution of cellulose ether of Examples 2 and 3 obtained in (1) above was placed into the above-mentioned sizing machine: Minisizer DC1001P. Furthermore, cotton yarn (2) (raw silk, 20 count, single yarn, long staple cotton, combed, containing fewer short fibers and less fuzz than the cotton yarn (1)) manufactured by Izawa Towel Co., Ltd., fed from a cheese bobbin was placed into each of the above-mentioned aqueous solutions of cellulose ether in the sizing machine. The weight of the cotton yarn (2) fed from the cheese bobbin per unit length was measured. Thereafter, a sizing treatment was carried out in the same manner as the sizing treatment of the cotton yarn in Example 1 above. The weight of the resulting dried (sized) cotton yarn (2) per unit length was measured.

[0059] (4) Evaluation (4-1) Viscosity of aqueous solution containing sizing agent The viscosity (mPa·s) of the aqueous solutions of cellulose ether in Examples 1 and 3 obtained in (1) above and the aqueous solution of starch paste in Comparative Example 1 was measured using a BL-type viscometer (manufactured by Tokimec Co., Ltd.) at 20°C. (4-2) Adhesion rate (amount of adhesion) of sizing agent For each of the sized yarns in Examples 1 to 3 and Comparative Example 1, the adhesion rate (amount of adhesion) of the sizing agent (Sizing rate S) was calculated based on the following formula (1) using the weight (g) of the cotton yarn before sizing (weight before treatment) and the weight (g) of the cotton yarn after sizing (weight after treatment) in (3) above.

[0060]

[0061] (4-3) Abrasion Resistance (Number of Frictions) For each of the sized yarns in Examples 1 to 3 and Comparative Example 1, the abrasion resistance was measured using an incorporation tester (1065, manufactured by Maeda Seisakusho) in accordance with JIS L 1095:2010 (9.10 Abrasion Resistance, Method B). Specifically, an abrasion test was conducted under the following test conditions, and the number of frictions until two out of 20 samples broke was measured. <Test Conditions> - Friction speed: 120 times / min - Friction angle: 110 degrees - Reciprocating distance: 2.5 cm - Test length: 20 cm - Friction element: hard steel wire with a diameter of 0.6 mm

[0062] (4-4) Single Yarn Tensile Strength and Elongation For each of the sized yarns of Examples 1 to 3 and Comparative Example 1, the single yarn tensile strength and elongation were measured using a tensile tester (Autograph AG-Xplus, manufactured by Shimadzu Corporation) based on JIS L 1095:2010 (9.5 Single Yarn Tensile Strength and Elongation) under the conditions of a gripping distance of 20 cm and a pulling speed of 20 cm / min.

[0063] (4-5) Observation by Scanning Electron Microscope Using a tabletop microscope (Miniscope (registered trademark) TM4000Plus, manufactured by Hitachi High-Technologies Corporation), the surfaces of the cotton yarn before sizing and the cotton yarn after sizing in Example 1 were observed at an accelerating voltage of 15 kV. In addition, using an ultra-deep multi-angle lens VHX-D510 (SEM 200x, manufactured by Keyence Corporation), the surface of the cotton yarn after sizing in Comparative Example 1 was observed at an accelerating voltage of 0.9 kV.

[0064] The evaluation results of Example 1 and Comparative Example 1 in the above items (4-1) to (4-4) are shown in Table 1, and the evaluation results of Examples 2 and 3 in the above items (4-1) to (4-4) are shown in Table 2. The SEM observation results of Example 1 and Comparative Example 1 in the above item (4-5) are shown in Figures 2 to 4. Figure 2 is an SEM image (magnification: 150x) of cotton yarn to which no sizing agent was attached, Figure 3 is an SEM image (magnification: 200x) of cotton yarn to which starch sizing agent was attached (Comparative Example 1), and Figure 4 is an SEM image (magnification: 150x) of cotton yarn to which cellulose ether (1) was attached (Example 1).

[0065]

[0066]

[0067] The results in Table 1 show that the aqueous solution containing cellulose ether (1) in Example 1 had a higher viscosity and a more appropriate viscosity than the aqueous solution containing starch paste in Comparative Example 1. A more appropriate viscosity results in good penetration, reduced fuzzing, and convergence. Therefore, the above results demonstrate that the aqueous solution containing cellulose ether (1) is optimal as a paste from the viewpoint of weaving efficiency.

[0068] Furthermore, the results in Table 1 indicate that the cotton yarn with cellulose ether (1) of Example 1 had approximately 120% more friction cycles than the cotton yarn with starch sizing of Comparative Example 1, demonstrating superior abrasion resistance. Although the single-yarn tensile strength of the cotton yarn of Example 1 was approximately 3% lower than that of the cotton yarn of Comparative Example 1, it could be considered equivalent and was at a practically acceptable level for a sizing-applied cotton yarn. Furthermore, the cotton yarn of Example 1 had approximately 20% higher elongation than the cotton yarn of Comparative Example 1, demonstrating superior elongation. As shown in Table 1, the adhesion rate of the sizing agent (cellulose ether (1)) to the cotton yarn of Example 1 was approximately half that of the adhesion rate of the sizing agent (starch sizing) to the cotton yarn of Comparative Example 1. Despite this lower adhesion rate of the sizing agent, the cotton yarn of Example 1 exhibited physical properties equivalent to or superior to those of the cotton yarn of Comparative Example 1, as described above. These results demonstrate that by using the cellulose ether of the present invention as a sizing agent, it is possible to impart excellent physical properties to cotton yarn while reducing the amount of sizing agent used and suppressing costs and environmental load.

[0069] Furthermore, as mentioned above, the starch paste used in Comparative Example 1 requires the addition of components other than corn starch, which is the main starch component, such as wax, propylene glycol, polyvinyl alcohol (PVA), to improve fiber convergence, smoothness, flexibility, etc., which leads to complex formulation and increased costs. On the other hand, the results in Table 1 show that the cellulose ether (1) of Example 1 can improve fiber convergence, smoothness, flexibility, etc., even when the sizing agent is composed of cellulose ether (1) without adding any components other than cellulose ether (1), and thus has performance not found in conventional starch pastes.

[0070] Furthermore, the SEM photograph in Figure 4 shows that when cellulose ether (1) was used as the sizing agent, fuzzing was suppressed and the entire surface was fixed by the sizing agent. On the other hand, the SEM photograph in Figure 3 shows that when starch paste was used as the sizing agent, fuzzing was not completely suppressed and the convergence was inferior to that of cellulose ether (1). The results in Table 1 and Figures 2 to 4 above show that the cellulose ether of the present invention has low viscosity and good impregnation properties, and has excellent convergence properties even when the adhesion rate of the sizing agent is low.

[0071] Furthermore, the results in Table 2 show that an aqueous solution containing cellulose ether (2) can be used as a sizing agent. The results in Tables 1 and 2 show that the cellulose ether (A) of the present invention is useful as a sizing agent regardless of its type.

[0072] 2. Evaluation of Weavability of Sized Textile Products Furthermore, as shown in Section 1 above, the cotton yarn of Example 1 exhibits physical properties equivalent to or superior to those of the cotton yarn of Comparative Example 1. Therefore, it can be estimated that the cotton yarn of Example 1 and the cotton yarn of Comparative Example 1 can be woven at the same speed on an air jet loom (approximately 350-400 rpm). Consequently, it can be estimated that the cotton yarn of Example 1 and the cotton yarn of Comparative Example 1 also produce the same amount of woven towels per day (8 hours) (approximately 30-50 kg). As noted in the SEM photograph analysis results above, the cotton yarn of Example 1, which has almost no fuzz, is less likely to pill during weaving and there is less risk of thread breakage compared to the cotton yarn of Comparative Example 1, which has fuzz. From the above, it was found that using the cellulose ether of the present invention as a sizing agent can reduce the amount of sizing agent used, thereby suppressing costs and environmental impact, while maintaining woven fabric production efficiency.

[0073] 3. Environmental evaluation of sizing treatment When starch paste is used with a deposition rate of 3% by weight as in Comparative Example 1 and sizing is performed on 450 kg of cotton yarn (20 count, single yarn), it is assumed that the sizing machine must be operated under the following conditions: water consumption: 675 L, treatment time: 1 hour, treatment temperature: 95 to 120°C. In this case, the output of the motor that drives the sizing machine is 8 kW, the electricity cost is 23 yen / kWh, and CO ２Assuming an emission coefficient of 0.47 kg / kWh, the power consumption can be calculated as 8 (kW) x 1 (hour) = 8 (kWh). As a result, the electricity cost required to operate the gluing machine is 23 (yen / kWh) x 8 (kWh) = 184 (yen), and the CO2 emissions during operation of the gluing machine are 23 (yen / kWh) x 8 (kWh) = 184 (yen). ２ The amount of emissions can be calculated as 0.47 (kg / kWh) x 8 (kWh) = 4 (kg). It is also estimated that 608 kg of steam must be used to raise the temperature to a processing temperature of 95-120°C. Since the amount of heat required to pressurize 20°C water to turn it into steam is estimated to be 2607 kJ / kg, the amount of heat required to raise the temperature can be calculated as 608 (kg) x 2607 (kg / kg) x 1 / 1000 = 1584 (MJ). When city gas is used to raise the temperature of the steam, the lower heating value of the city gas is 40.3 MJ / m ３ , CO ２ Emission coefficient: 2.23 kg / m ３ Fuel cost: 100 yen / m ３ , boiler efficiency: 0.9, city gas consumption: 1584 (MJ) ÷ 0.9 ÷ 40.3 (MJ / m ３ ) = 44 (m ３ As a result, the cost of city gas required to raise the temperature is 44 (m ３ ) x 100 (yen / m ３ ) = 4,400 (yen), CO ２ The discharge amount is 44 (m ３ )×2.23(kg / m ３ ) = 97 (kg).

[0074] Starch paste such as that in Comparative Example 1 is insoluble in water at room temperature (20°C) and must be heated to about 90°C for dissolution and gelatinization, necessitating the above-mentioned heating process using steam. On the other hand, the cellulose ether of the present invention has the property of being difficult to dissolve in high-temperature liquids such as hot water, but easily soluble in low-temperature liquids such as cold water and water at room temperature. Therefore, when methylcellulose is used as the sizing agent as in Example 1, sizing at room temperature (20°C) is preferred, and the above-mentioned heating process using steam is not necessary. Therefore, in the case of Example 1, the above-mentioned city gas costs of 4,400 yen and CO are incurred in the heating process. ２ Emissions: 97 kg is no longer needed, reducing energy consumption and CO２ This will reduce emissions and reduce the burden on the environment.

[0075] 4. Measurement of BOD and COD of Aqueous Solutions Containing Sizing Agents Using the cellulose ether (1) described in 1.(1) above, an aqueous solution containing cellulose ether (1) with a solids concentration of 1.0 wt% was prepared according to the same procedure as in 1.(1) above. Also, using the starch paste described in 1.(1) above, water was added to the starch paste, and the mixture was heated to 90°C or higher to dissolve and gelatinize the starch paste, thereby preparing an aqueous solution containing the starch paste with a solids concentration of 1.0 wt%. The BOD (biochemical oxygen consumption) and COD (chemical oxygen consumption) of each aqueous solution of methylcellulose or starch paste were measured according to JIS K 0102:2016 (21. Biochemical oxygen consumption (BOD)) and (17. Oxygen consumption (COD) by potassium permanganate at 100°C). The results are shown in Table 3. BOD is a value that indicates how much oxygen is required for microbial decomposition. COD is a value that indicates how much oxygen is required when an oxidizing agent (potassium permanganate) is added to cause oxidation. Both BOD and COD are used as indicators of water pollution, and the higher the value, the more polluting substances there are in the water.

[0076]

[0077] The results in Table 3 show that the BOD and COD of the aqueous solution of cellulose ether (1) were significantly lower than those of the aqueous solution of starch paste, demonstrating that the cellulose ether of the present invention as a sizing agent can suppress water pollution. As shown in Example 1 and Comparative Example 1 above, the use of cellulose ether (1) as a sizing agent can impart excellent physical properties to cotton yarn even when used in a reduced amount compared to conventional starch paste. In the tests shown in Table 3 above, the solids concentrations of cellulose ether (1) and starch paste were the same, but in actual sizing, the amount of cellulose ether (1) used can be reduced to perform sizing while further suppressing water pollution.

[0078] 5. Desizing using supercritical carbon dioxide (1) Fabric with sizing agent and cotton yarn with sizing agent (1-1) Fabric with cellulose ether (2) Boiling water was added to the cellulose ether (2) to a dilution ratio of approximately 14 times based on the weight of the cellulose ether, and the resulting diluted solution was stirred for a certain period of time. Room temperature water was added to the diluted solution after stirring to a dilution ratio of approximately 34 times based on the weight of the cellulose ether, and the resulting diluted solution was stirred for a certain period of time to prepare an aqueous solution with a solids concentration of cellulose ether (2) of 3.0 wt%. A 100% cotton fabric woven with raw silk manufactured by Izawa Towel Co., Ltd. was immersed in the aqueous solution with a solids concentration of cellulose ether (2) of 3.0 wt% obtained as above. The immersed fabric was subjected to the same procedure as in 1. The fabric was passed through a squeezing roll (first passing roll) and an immersion roll (second passing roll) of a sizing machine: Minisizer DCI001P shown in (2) of the above under a pressure load of 0.2 MPa to remove excess sizing agent, and then dried in a dryer at 100 to 110°C for 30 minutes to prepare a fabric to which cellulose ether (2) was attached (the adhesive rate of adhesive agent calculated based on the formula (1) in (4-2) of 1 above: 3.24%).

[0079] (1-2) Fabric with Cellulose Ether (3) Adhered Cellulose ether (3): Metolose (registered trademark) 60SH-50 (hydroxypropyl methylcellulose, weight average molecular weight: 80,000, degree of substitution of methoxy groups: 1.9, molar substitution of hydroxypropoxy groups: 0.25, manufactured by Shin-Etsu Chemical Co., Ltd.) was prepared, and boiling water was added to the cellulose ether (3) to a dilution ratio of approximately 20 times based on the weight of the cellulose ether, and the resulting diluted solution was stirred for a certain period of time. Room temperature water was added to the diluted solution after stirring to a dilution ratio of approximately 30 times based on the weight of the cellulose ether, and the resulting diluted solution was stirred for a certain period of time to prepare an aqueous solution with a solids concentration of cellulose ether (3) of 2.0 wt%. A 100% cotton fabric woven with raw silk manufactured by Izawa Towel Co., Ltd. was immersed in the aqueous solution with a solids concentration of cellulose ether (3) of 2.0 wt% obtained as described above. The immersed fabric was then subjected to the same procedure as described in 1. The fabric was passed through a squeezing roll (first passing roll) and an immersion roll (second passing roll) of a sizing machine: Minisizer DCI001P shown in (2) of the above under a pressure load of 0.2 MPa to remove excess sizing agent, and then dried in a dryer at 100 to 110°C for 30 minutes to prepare a fabric to which cellulose ether (3) was attached (the adhesive rate of adhesive agent calculated based on the formula (1) in (4-2) of 1 above: 1.69%).

[0080] (1-3) Cotton yarn with cellulose ether (3) attached Furthermore, 2500 mL of the aqueous solution of cellulose ether (3) obtained in (1-2) above, having a solids concentration of 0% by weight, was placed in the sizing machine: Minisizer DC1001P shown in (2) above 1. Then, in the same manner as the sizing method described in [Example 1] in (3) above 1., cotton yarn (1) (raw silk (unbleached yarn, spun yarn, etc.), 100% cotton, 20 count, single yarn, twist coefficient 4.5, average fiber length approximately 25 mm) manufactured by Izawa Towel Co., Ltd. was treated to prepare cotton yarn with cellulose ether (3) attached (size attachment rate: 1.6%, calculated based on formula (1) in (4-2) above 1.).

[0081] (2) Apparatus and Reagents The overall apparatus used in the treatment with a fluid containing supercritical carbon dioxide is shown in Figure 5. The reference numerals in Figure 5 represent: 1: chiller unit; 2: CO ２ Supply pump, 3: Air vent valve, 4: Check valve, 5: Pressure transmitter, 6: Safety valve, 7: Dyeing vessel, 8: Vessel drain valve, 9: Vessel temperature sensor, 10: Magnetic induction type agitator, 11: Exhaust flow rate adjustment valve, 12: Vessel exhaust valve, 13: Control panel, 14: CO ２ Outlet for supply pump, 15: Outlet for dyeing vessel heater, A: CO ２ The chiller unit 1 is a cooling water circulation device LTC-450α (manufactured by AS ONE Corporation), CO ２ A double plunger pump NP-KX-500 (manufactured by Nippon Seimitsu Kagaku Co., Ltd.) was used as the supply pump 2, and a high-pressure vessel (manufactured by ITEC Co., Ltd., model: C-04-M-FU, capacity: 400 mL) was used as the dyeing vessel 7. A liquefied carbon dioxide cylinder (Kind Gas Co., Ltd., purity 99.5% or higher) was used as the carbon dioxide supply source.

[0082] (3) Operating Procedure (3-1) Fabric with Cellulose Ether (2) Adhered A jig (110 cm long x 15 mm outer diameter, hollow cylindrical, mesh structure, made of metal) was prepared, and the fabric (approximately 10 cm x approximately 10 cm, approximately 2 g) with the cellulose ether (2) described in (1-1) above attached was wrapped around the jig. A cotton string was further wrapped around the jig to secure the wrapped fabric in place. Figure 6(a) shows the jig with the fabric wrapped around it. An outer cylinder (110 cm long, 36 mm inner diameter, 41 mm outer diameter, hollow cylindrical) was also prepared, and a paper wiper (Kimwipe (registered trademark), 120 mm x 210 mm) soaked evenly with 1 mL of water as a co-solvent was wrapped around the outer cylinder. A cotton string was further wrapped around the wrapped paper wiper to secure it in place. Figure 6(b) shows the outer cylinder with the paper wiper wrapped around it. The jig around which the fabric was wrapped was placed and fixed inside an outer cylinder around which a paper wiper was wrapped, to obtain a measurement sample. The obtained measurement sample was placed in the dyeing container 7. Next, CO ２Using the supply pump 2, 200 mL of carbon dioxide was sent to the dyeing vessel 7 at a liquid delivery rate of 20 to 300 mL / min, pressurizing the dyeing vessel 7. The conditions for treating the measurement sample with supercritical carbon dioxide fluid were 40°C, 10 MPa, 120 minutes, batchwise. Agitation was performed using a propeller, with one set consisting of 60 seconds of forward rotation and 60 seconds of reverse rotation, and this set was repeated at 900 rpm for 120 minutes. The water soaked into the paper wiper was mixed with supercritical carbon dioxide, resulting in a supercritical carbon dioxide:water volume ratio of 200:1. After treatment with supercritical carbon dioxide fluid, the valve for the dyeing vessel 7 was opened and the pressure was released to atmospheric pressure. After releasing the pressure in the dyeing vessel 7, the fabric was removed from the jig and dried at 105°C for 2 hours. The dried fabric was weighed.

[0083] (3-2) Fabric with Cellulose Ether (3) Adhered A jig similar to that used in the treatment (3-1) above was prepared, and the fabric (approximately 10 cm x approximately 10 cm, approximately 8 g) with cellulose ether (3) adhering thereto as shown in (1-2) above was wrapped around the jig. A cotton string was further wrapped around the jig to secure the wrapped fabric in place. The jig with the fabric wrapped around it was in the same state as in (a) of Figure 6. In addition, an outer cylinder similar to that used in the treatment (3-1) above was prepared, and a paper wiper (Kimwipe (registered trademark), 120 mm x 210 mm) that had been evenly impregnated with 5 mL of EGME (ethylene glycol monobutyl ether), a co-solvent, was wrapped around the outside of the outer cylinder. A cotton string was further wrapped around the wrapped paper wiper to secure it in place in order to prevent it from coming off. The outer cylinder with the paper wiper wrapped around it was in the same state as in (b) of Figure 6. The jig wrapped around the fabric was placed and fixed inside an outer cylinder wrapped with paper wipers to obtain a measurement sample. The obtained measurement sample was placed in a dyeing vessel 7, and the measurement sample was treated with supercritical carbon dioxide fluid in the same manner as in the treatment described above in (3-1), except that the conditions for treating the measurement sample with supercritical carbon dioxide fluid were changed from 40°C, 10 MPa, 120 minutes, and batchwise treatment to 120°C, 25 MPa, 180 minutes, and batchwise treatment. The EGME impregnated into the paper wipers was mixed with supercritical carbon dioxide, resulting in a supercritical carbon dioxide:fabric volume ratio of 45:1 and a supercritical carbon dioxide:EGME volume ratio of 80:1. After treatment with supercritical carbon dioxide fluid, the valve of the dyeing vessel 7 was opened and the pressure was released to atmospheric pressure. After releasing the pressure in the dyeing vessel 7, the fabric was removed from the jig and dried at 100°C for 1 hour, and the dried fabric was weighed.

[0084] (3-3) Cotton thread with cellulose ether (3) attached A jig similar to that used in the treatment (3-1) above was prepared, and cotton thread (length: approximately 400 m, approximately 10 g) with cellulose ether (3) attached as shown in (1-3) above was wound around the jig. A cotton string was further wrapped around the wound cotton thread to secure it in place. Figure 7 shows the jig with the cotton string wrapped around it. In addition, an outer cylinder similar to that used in the treatment (3-1) above was prepared, and a paper wiper (Kimwipe (registered trademark), 120 mm x 210 mm) that had been evenly impregnated with 5 mL of EGME (ethylene glycol monobutyl ether), a co-solvent, was wrapped around the outside of the outer cylinder. A cotton string was further wrapped around the wound paper wiper to secure it in place. The outer cylinder with the paper wiper wrapped around it was in the same state as in Figure 6(b). The jig wrapped around the cotton yarn was placed and fixed inside an outer cylinder wrapped around a paper wiper to obtain a measurement sample. The obtained measurement sample was placed in a dyeing vessel 7, and the measurement sample was treated with supercritical carbon dioxide fluid in the same manner as in the treatment described in (3-2) above. The EGME impregnated into the paper wiper became mixed with supercritical carbon dioxide, resulting in a supercritical carbon dioxide:cotton yarn volume ratio of 40:1 and a supercritical carbon dioxide:EGME volume ratio of 80:1. After treatment with supercritical carbon dioxide fluid, the valve of the dyeing vessel 7 was opened and the pressure was released to atmospheric pressure. After releasing the pressure in the dyeing vessel 7, the cotton yarn was removed from the jig and dried at 110°C for 1 hour, and the dried cotton yarn was weighed.

[0085] (4) Evaluation (4-1) Size Removal Rate First, the weight (g) of the fabric or cotton yarn before sizing and desizing and the weight (g) of the fabric or cotton yarn after desizing were used to calculate the adhesion rate of cellulose ether (2) or cellulose ether (3) (size) on the fabric or cotton yarn after desizing based on the above-mentioned formula (1) described in (4-2) of 1. Then, the size removal rate (Desizing rate D) was calculated based on the following formula (2) using the size adhesion rate (%) of the sizing fabric or cotton yarn (fabric or cotton yarn after sizing and before desizing) (the above-mentioned 3.24%, 1.69%, or 1.6%) and the size adhesion rate (%) of the fabric or cotton yarn after desizing.

[0086]

[0087] The calculated removal rate of cellulose ether (2) (sizing agent) obtained for the fabric was approximately 12%. This result demonstrates that cellulose ether (2) can be removed by desizing treatment using supercritical carbon dioxide. It is presumed that it is possible to further increase the removal rate of the sizing agent through improvements such as improving the stirring efficiency and increasing the number of batches. In addition, the solubility of cellulose ether (2) (sizing agent) in supercritical carbon dioxide fluid (total of supercritical carbon dioxide and water) (amount of dissolved cellulose ether (2) (sizing agent) (g) / volume of supercritical carbon dioxide fluid (mL)) was calculated to be 3.7 × 10 －５ g / mL.

[0088] The calculated removal rate of cellulose ether (3) (sizing agent) obtained for the fabric was approximately 98%. This result shows that desizing treatment with supercritical carbon dioxide using EGME as a co-solvent can remove cellulose ether (3) at an extremely high removal rate. Furthermore, when the same desizing treatment was performed with an increased amount of EGME, it was found that the removal rate of cellulose ether (3) (sizing agent) improved even when the ratio of the volume of supercritical carbon dioxide to the volume of EGME (volume of supercritical carbon dioxide / volume of EGME) was lowered. Furthermore, the solubility of cellulose ether (3) (sizing agent) in supercritical carbon dioxide fluid (total of supercritical carbon dioxide and EGME) (amount of dissolved cellulose ether (3) (sizing agent) (g) / volume of supercritical carbon dioxide fluid (mL)) was calculated to be 3.1 × 10 －３ g / mL.

[0089] The calculated removal rate of cellulose ether (3) (sizing agent) obtained for cotton yarn was about 96%. The solubility of cellulose ether (3) (sizing agent) in supercritical carbon dioxide fluid (total of supercritical carbon dioxide and EGME) (amount of dissolved cellulose ether (3) (sizing agent) (g) / volume of supercritical carbon dioxide fluid (mL)) was calculated to be 3.5 × 10 －３By comparing the results for these cotton yarns with the results for cellulose ether (3) (sizing agent) on the fabric described above, it was found that the removal rate and solubility of cellulose ether (3) (sizing agent) did not change regardless of whether fabric or cotton yarn was used as the target for desizing, and that cellulose ether (3) could be removed extremely efficiently.

[0090] (4-2) Observation by Scanning Electron Microscope Using a tabletop microscope (Miniscope (registered trademark) TM4000Plus, manufactured by Hitachi High-Technologies Corporation) at an accelerating voltage of 15 kV, the surfaces of the fabric with the cellulose ether (3) described in (3-2) attached thereto were observed, both before and after the desizing treatment. The results of the SEM observation are shown in Figures 8 and 9. Figure 8 is an SEM image (magnification: 200x) of the fabric with the sizing agent attached thereto before the desizing treatment, and Figure 9 is an SEM image (magnification: 200x) of the fabric after the desizing treatment. Comparing Figures 8 and 9 reveals that the threads converging due to the sizing agent before the desizing treatment (Figure 8) but after the desizing treatment (Figure 9) the threads converging and becoming less convergent.

[0091] (4-3) Water Wettability (Water Absorbency) For the fabrics to which the cellulose ether (3) described in (3-2) above had been applied, the water wettability (water absorbency) of the fabrics with the adhesive agent applied before desizing and the fabrics after desizing was evaluated. The water wettability of the fabrics was measured according to the drop method of "JIS L 1907 Testing Method for Water Absorbency of Textile Products." Figure 10 shows photographs of the fabrics after water wettability evaluation. The fabric on the left side of Figure 10 is the fabric with the adhesive agent applied before desizing, and the fabric on the right side is the fabric after desizing. As can be seen from Figure 10, in the fabric with the adhesive agent applied before desizing, water droplets remained on the surface of the fabric, and almost no water absorbency was observed. On the other hand, in the fabric after desizing, water was absorbed from the surface of the fabric, and no water droplets were present on the surface. These results demonstrate that the cellulose ether adhesive agent was sufficiently removed by the desizing process using supercritical carbon dioxide, allowing the fabric to exhibit its water absorbency.

[0092] From the above, it was found that the sizing textile product according to one embodiment of the present invention has excellent fiber convergence properties. Furthermore, from the above results, the following points were also confirmed: The sizing textile product of this embodiment can improve fiber convergence without excessively increasing the amount of sizing agent attached, or the sizing textile product of this embodiment can exhibit high tensile strength, or the sizing textile product of this embodiment has high durability against friction and is less likely to lose tensile strength even after a friction test. The sizing agent of this embodiment can reduce the BOD and / or COD values ​​when made into a solution compared to conventional starch pastes, thereby suppressing water pollution. The method for producing a textile product from the sizing textile product of this embodiment can efficiently remove the sizing agent and obtain a textile product with excellent water wettability.

[0093] 1: Chiller unit 2: CO ２ Supply pump 3: Air vent valve 4: Check valve 5: Pressure transmitter 6: Safety valve 7: Dyeing vessel 8: Vessel drain valve 9: Vessel temperature sensor 10: Magnetic induction stirrer 11: Exhaust flow rate adjustment valve 12: Vessel exhaust valve 13: Control panel 14: CO ２ Outlet for supply pump 15: Outlet for dyeing vessel heater A: CO ２ cylinder

Claims

1. A sizing textile product, wherein the sizing agent contains at least one cellulose ether (A) selected from the group consisting of alkyl cellulose, hydroxyalkyl cellulose, and hydroxyalkyl alkyl cellulose.

2. The sized textile product according to claim 1, wherein the cellulose ether (A) comprises at least one member selected from the group consisting of methyl cellulose, hydroxypropyl methyl cellulose, and hydroxyethyl methyl cellulose.

3. The sizing fiber product according to claim 1 or 2, wherein the degree of substitution of the alkoxy group in the alkyl cellulose or the hydroxyalkyl alkyl cellulose is 1 to 3.

4. A sizing textile product according to claim 1 or 2, wherein the viscosity of the cellulose ether (A) when made into a 1% by weight or 5% by weight aqueous solution is 3 to 300 mPa·s.

5. The sized textile product according to claim 1 or 2, wherein the textile product comprises cotton yarn or cotton fabric.

6. The sized textile product according to claim 1 or 2, wherein the adhesion rate of the sizing agent to the sized textile product is 0.1 to 10% by weight.

7. A sizing agent for producing the sizing textile product according to claim 1 or 2, comprising at least one cellulose ether (A) selected from the group consisting of alkyl cellulose, hydroxyalkyl cellulose, and hydroxyalkyl alkyl cellulose.

8. A method for producing a sizing agent-coated textile product according to claim 1 or 2, comprising the step of bringing a fluid containing the sizing agent into contact with the textile product to size the textile product.

9. A method for producing textile products from sized textile products according to claim 1 or 2, comprising the step of contacting the sized textile product with a fluid containing supercritical carbon dioxide to desize the sized textile product.

10. The method of claim 9, wherein the desizing step is a batch or continuous process.

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