Vanadiumized cotton yarn and its manufacturing method

Abstract

This invention provides a cotton fabric material that is almost uniformly colored and possesses the functions of absorbing light to generate heat and retaining heat, as well as a functional cotton yarn that possesses the functions of absorbing light to generate heat and retaining heat. [Solution] A method for producing vanadium-dyed cotton yarn having the function of absorbing light and generating heat and retaining heat comprises a yarn immersion step and a dyeing step. In the yarn immersion step, cationized cotton yarn, whose surface is cationized, is immersed in a liquid containing vanadium-containing ions, and vanadium-containing ions are attached to the surface of the cationized cotton yarn to obtain vanadium-dyed cotton yarn having the function of absorbing light and generating heat and retaining heat. In the dyeing step, the vanadium-dyed cotton yarn is dyed with a dye to obtain vanadium-dyed cotton yarn having the function of absorbing light and generating heat and retaining heat.

Description

Technical Field

[0001] This application relates to cotton yarn having a function of absorbing light and generating heat and a heat preservation function with a vanadium component adhering to its surface, and a method for manufacturing this cotton yarn.

Background Art

[0002] There is known a technique of attaching a vanadium component and a chemical dye to a wool fabric to impart a function of absorbing light and exhibiting heat generation and heat retention properties to the wool fabric (Patent Document 1). The heat generation and heat retention properties of the functional wool fabric described in Patent Document 1 are very excellent. However, it has been difficult to attach a vanadium component to a cotton fabric and to uniformly attach a dye to the cotton fabric, that is, to produce a cotton fabric that is uniformly colored and to which a vanadium component is attached. Since the surface properties of wool and cotton are different, it is considered that the reason is that the vanadium component and the dye are less likely to adhere to the cotton fabric than to the wool fabric. If a cotton fabric that is uniformly colored also has a function of absorbing light and generating heat and a heat preservation function, the options for materials such as clothing will be expanded.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] This application has been made in view of such circumstances, and aims to provide a material for cotton fabric that is colored almost uniformly and has the functions of absorbing light and generating heat and heat retention, as well as functional cotton fibers and functional cotton yarns having the functions of absorbing light and generating heat and heat retention. In this application, to avoid confusion, the Chinese character "绵" (mén) is used to represent cotton, and the katakana "ワタ" is used to represent a mass formed by entangled fibers. Therefore, a mass formed by entangled cotton fibers may be referred to as "ワタ状の綿".

Means for Solving the Problems

[0005] The method for manufacturing vanadiumized cotton fibers of this application comprises a fiber immersion step of immersing cationized cotton fibers with cationized surfaces of cotton fibers in a liquid containing vanadium-containing ions, attaching the vanadium-containing ions to the surfaces of the cationized cotton fibers, and obtaining vanadiumized cotton fibers having the functions of absorbing light and generating heat and heat retention.

[0006] The method for manufacturing vanadiumized cotton yarns in one aspect of this application comprises a fiber immersion step of immersing cationized cotton fibers with cationized surfaces of cotton fibers in a liquid containing vanadium-containing ions, attaching the vanadium-containing ions to the surfaces of the cationized cotton fibers, and obtaining vanadiumized cotton fibers having the functions of absorbing light and generating heat and heat retention, and a vanadiumized spinning step of spinning the vanadiumized cotton fibers to obtain vanadiumized cotton yarns.

[0007] The method for manufacturing vanadiumized cotton yarns in another aspect of this application comprises a cationized spinning step of spinning cationized cotton fibers with cationized surfaces of cotton fibers to obtain cationized cotton yarns, and a yarn immersion step of immersing the cationized cotton yarns in a liquid containing vanadium-containing ions, attaching the vanadium-containing ions to the surfaces of the cationized cotton yarns, and obtaining vanadiumized cotton yarns having the functions of absorbing light and generating heat and heat retention.

[0008] A further embodiment of the present invention relates to a method for producing vanadium-treated cotton yarn, which comprises a yarn immersion step in a liquid containing vanadium-containing ions, in which cationized cotton yarn is cationized on the surface of the cotton yarn by cationizing the cotton yarn, thereby depositing vanadium-containing ions on the surface of the cationized cotton yarn to obtain vanadium-treated cotton yarn that has the function of absorbing light and generating heat, and the function of retaining heat.

[0009] The present invention relates to a method for producing vanadium-dyed cotton yarn, which includes a dyeing step of dyeing the vanadium-dyed cotton yarn obtained by the present invention relates to a method for producing vanadium-dyed cotton yarn with a dye to obtain vanadium-dyed cotton yarn that has the function of absorbing light and generating heat and the function of retaining heat.

[0010] The vanadium-containing cotton fiber of the present invention comprises cotton fibers, cations provided on the surface of the cotton fibers, and vanadium-containing ions attached to the cations, and possesses the function of absorbing light to generate heat and the function of retaining heat.

[0011] The vanadium-treated cotton yarn of the present invention comprises a cotton yarn, a cation provided on the surface of the cotton yarn, and vanadium-containing ions attached to the cation, and possesses the function of absorbing light to generate heat and the function of retaining heat.

[0012] The vanadium-colored cotton yarn of the present invention comprises a cotton yarn, a cation provided on the surface of the cotton yarn, vanadium-containing ions and a dye attached to the cation, and possesses the functions of absorbing light to generate heat and retaining heat. [Effects of the Invention]

[0013] According to the method for producing vanadium-treated cotton fibers of the present invention, vanadium-treated cotton fibers can be obtained that are almost uniformly colored and have the functions of absorbing light to generate heat and retaining heat, making them suitable as a material for cotton fabrics. Furthermore, according to the method for producing vanadium-treated cotton yarn of the present invention, vanadium-treated cotton yarn can be obtained that are almost uniformly colored and have the functions of absorbing light to generate heat and retaining heat, making them suitable as a material for cotton fabrics. [Modes for carrying out the invention]

[0014] The following describes the method for producing vanadium-treated cotton fibers, vanadium-treated cotton yarn, vanadium-treated colored cotton yarn, vanadium-treated cotton fibers, vanadium-treated cotton yarn, and vanadium-treated colored cotton yarn of this application, based on embodiments and examples. Repetitive explanations will be omitted as appropriate. Note that in this application, "having the function of absorbing light to generate heat and the function of retaining heat" means possessing both the function of absorbing light to generate heat and the function of absorbing light to retain heat.

[0015] Vanadium-dyed cotton yarn, which has the function of absorbing light and generating heat, refers to vanadium-dyed cotton yarn whose temperature after 10 minutes of light irradiation is 3°C or more higher than the temperature of cationized cotton yarn after 10 minutes of light irradiation. Preferably, the temperature of vanadium-dyed cotton yarn after 10 minutes of light irradiation is 5°C or more higher than the temperature of cationized cotton yarn after 10 minutes of light irradiation. Similarly, vanadium-dyed cotton yarn, which has the function of absorbing light and generating heat, refers to vanadium-dyed cotton yarn whose temperature after 10 minutes of light irradiation is 3°C or more higher than the temperature of cationized cotton yarn after 10 minutes of light irradiation, and vanadium-dyed cotton fiber, which has the function of absorbing light and generating heat, refers to vanadium-dyed cotton fiber whose temperature after 10 minutes of light irradiation is 3°C or more higher than the temperature of cationized cotton fiber after 10 minutes of light irradiation. Preferably, the temperature of vanadium-dyed cotton yarn and vanadium-dyed cotton fiber after 10 minutes of light irradiation is 5°C or more higher than the temperature of cationized cotton yarn and cationized cotton fiber after 10 minutes of light irradiation.

[0016] Vanadium-dyed cotton yarn, which has the function of absorbing light and retaining heat, is defined as vanadium-dyed cotton yarn whose temperature 1 minute after stopping light irradiation after 10 minutes of light irradiation is 1°C or higher than the temperature of cationized cotton yarn 1 minute after stopping light irradiation after 10 minutes of light irradiation. Similarly, vanadium-dyed cotton yarn, which has the function of absorbing light and retaining heat, is defined as vanadium-dyed cotton yarn whose temperature 1 minute after stopping light irradiation after 10 minutes of light irradiation is 1°C or higher than the temperature of cationized cotton yarn 1 minute after stopping light irradiation after 10 minutes of light irradiation. Vanadium-dyed cotton fiber, which has the function of absorbing light and retaining heat, is defined as vanadium-dyed cotton fiber whose temperature 1 minute after stopping light irradiation after 10 minutes of light irradiation is 1°C or higher than the temperature of cationized cotton fiber 1 minute after stopping light irradiation after 10 minutes of light irradiation.

[0017] The method for producing vanadium-treated cotton fibers according to the embodiment of the present invention includes a fiber immersion step. In the fiber immersion step, cationized cotton fibers, whose surface has been cationized, are immersed in a liquid containing vanadium-containing ions to deposit vanadium-containing ions on the surface of the cationized cotton fibers. Note that the surface of the cotton fibers does not have to be entirely cationized; it may be partially or partially cationized. The same applies to the cationization of the surface of cotton yarn, which will be described later. Cotton fibers are cotton in fibrous form. Examples of cotton fibers include cotton in the form of cotton balls. Cotton fibers may be natural cotton fibers, or they may be regenerated fibers made from natural cotton fibers, such as cupro.

[0018] Cationic cotton fibers, in which the surface of cotton fibers is cationized, can be obtained, for example, by mixing a commercially available cationizing agent with an alkaline aqueous solution, immersing cotton fibers in this solution, stirring for several tens of minutes while heating at 50°C to 90°C, and then washing with running water. Examples of cationizing agents include those containing quaternary ammonium salts. After such a cationization treatment of the surface of cotton fibers, cationized cotton fibers are obtained in which cations, i.e., cationic functional groups, are imparted to the surface of the cotton fibers.

[0019] Examples of vanadium-containing ions include vanadium ions, vanadyl ions, pervanadyl ions, metavanadate ions, and orthovanadate ions. When cationized cotton fibers are immersed in a liquid containing vanadium-containing ions, it is thought that the vanadium-containing ions adhere to the cationized cotton fibers by coordinating with coordination groups present on the surface of the cationized cotton fibers, such as quaternary ammonium groups. Furthermore, if the vanadium-containing ions themselves are anionic, they adhere to the cationized cotton fibers by binding with cations on the surface of the cationized cotton fibers.

[0020] When an appropriate amount of vanadium-containing ions adhere to cationized cotton fibers, vanadized cotton fibers are obtained that possess the functions of absorbing light and generating heat, as well as heat retention. If too few vanadium-containing ions adhere to the cationized cotton fibers, these functions will not be exhibited. For this reason, it is preferable that the concentration of vanadium-containing ions in the liquid containing vanadium-containing ions be high, for example, 10 mM or higher.

[0021] There are no particular restrictions on the wavelength of light irradiated onto vanadium-treated cotton fibers, vanadium-treated cotton yarn, and vanadium-treated colored cotton yarn, as described later. However, vanadium-treated cotton fibers, vanadium-treated cotton yarn, and vanadium-treated colored cotton yarn particularly absorb light on the short-wavelength side in the near-infrared region, exhibiting high heat generation and heat retention performance. Sunlight has high energy intensity on the short-wavelength side even in the near-infrared region. Therefore, vanadium-treated cotton fibers, vanadium-treated cotton yarn, and vanadium-treated colored cotton yarn are advantageous for exhibiting heat generation and heat retention performance using sunlight.

[0022] The manufacturing method of the vanadiumized cotton yarn of the first embodiment of the present application includes a fiber dipping step and a vanadiumized spinning step. The fiber dipping step is the same as the fiber dipping step in the manufacturing method of the vanadiumized cotton fiber of the embodiment. In the vanadiumized spinning step, the vanadiumized cotton fiber is spun to obtain a vanadiumized cotton yarn. For the spinning of the vanadiumized cotton fiber, the spinning of general fibers can be adopted. When the vanadiumized cotton fiber having the functions of absorbing light and generating heat and the function of heat preservation is spun, these functions are maintained, and a vanadiumized cotton yarn having the functions of absorbing light and generating heat and the function of heat preservation is obtained.

[0023] The manufacturing method of the vanadiumized cotton yarn of the second embodiment of the present application includes a cationized spinning step and a yarn dipping step. In the manufacturing method of the vanadiumized cotton yarn of the first embodiment, vanadium-containing ions are attached to cotton fibers, while in the manufacturing method of the vanadiumized cotton yarn of the second embodiment, vanadium-containing ions are attached to cotton yarns. In the cationized spinning step, the cationized cotton fiber with the surface of the cotton fiber cationized is spun to obtain a cationized cotton yarn. The obtained cationized cotton yarn includes a cotton yarn and cations provided on the surface of the cotton yarn. That is, the cations on the surface of the fiber remain even after passing through the spinning process of the fiber to become yarn.

[0024] In the yarn dipping step, the cationized cotton yarn is immersed in a liquid containing vanadium-containing ions to attach the vanadium-containing ions to the surface of the cationized cotton yarn. In the yarn dipping step, similar to the fiber dipping step, when the cationized cotton yarn is immersed in a liquid containing vanadium-containing ions, it is considered that the vanadium-containing ions attach to the cationized cotton yarn due to the coordination of the vanadium-containing ions to the ligand groups present on the surface of the cationized cotton yarn. When an appropriate amount of vanadium-containing ions attach to the cationized cotton yarn, a vanadiumized cotton yarn having the functions of absorbing light and generating heat and the function of heat preservation is obtained.

[0025] The manufacturing method of the vanadiumized cotton yarn of the third embodiment of the present application includes a yarn immersion step. In the yarn immersion step, a cationized cotton yarn with a cationized surface is immersed in a liquid containing vanadium-containing ions by cationizing the cotton yarn, and vanadium-containing ions are attached to the surface of the cationized cotton yarn to obtain a vanadiumized cotton yarn having a function of absorbing light and generating heat and a heat retaining function. In the manufacturing methods of the vanadiumized cotton yarn of the first and second embodiments, cationized cotton fibers with a cationized surface of cotton fibers are used, but in the manufacturing method of the vanadiumized cotton yarn of the third embodiment, a cationized cotton yarn obtained by cationizing the surface of the cotton yarn is used.

[0026] The cationized cotton yarn obtained by cationizing the surface of the cotton yarn can be obtained, for example, by mixing a commercially available cationizing agent and an alkaline aqueous solution as a yarn treatment agent, immersing the cotton yarn therein, stirring for several minutes while heating to 50°C to 90°C, and then washing with running water. Examples of the cationizing agent include those containing a quaternary ammonium salt. Through such cationization treatment of the surface of the cotton yarn, a cationized cotton yarn with cations, that is, cationic functional groups, imparted to the surface of the cotton yarn can be obtained.

[0027] The manufacturing method of the vanadiumized colored cotton yarn of the embodiment of the present application includes a dyeing step. In the dyeing step, the vanadiumized cotton yarn obtained by the manufacturing method of the vanadiumized cotton yarn from the first embodiment to the third embodiment is dyed with a dye to obtain a vanadiumized colored cotton yarn having a function of absorbing light and generating heat and a heat retaining function. Even when the vanadiumized cotton yarn having the function of absorbing light and generating heat and the heat retaining function is dyed, these functions remain. It is considered that even when an appropriate amount of vanadium-containing ions adhere to the cationized cotton yarn, cations remain sufficiently, and the dye can adhere to the remaining cations.

[0028] The dye is not particularly limited as long as it can dye cotton. It is preferable that the dye be anionic, as it readily adheres to cations. Furthermore, if the surface of the vanadium-treated cotton yarn has cations containing quaternary ammonium salts, it is preferable that the dye be a direct dye or reactive dye that readily adheres to quaternary ammonium salts. In addition, from the viewpoint of quality stability, it is preferable that the dye be a chemical dye.

[0029] On the other hand, when attempting to attach vanadium-containing ions to cationized cotton yarn after dyeing it with dye, very few vanadium-containing ions adhered. This lack of attachment was confirmed by experimental results showing that no heat was generated even when irradiated with light. Possible reasons for this include the fact that when cationized cotton yarn is dyed with dye, the dye adheres to most of the cations, leaving almost no room for vanadium-containing ions to adhere, and even if vanadium-containing ions do adhere to the cationized cotton yarn through the dye, they are easily removed by subsequent washing.

[0030] The vanadium-treated cotton fibers of the embodiment of the present application have the function of absorbing light and generating heat, and the function of retaining heat. The vanadium-treated cotton fibers of the embodiment comprise cotton fibers, cations provided on the surface of the cotton fibers, and vanadium-containing ions attached to the cations. The vanadium-treated cotton yarn of the embodiment of the present application has the function of absorbing light and generating heat, and the function of retaining heat. The vanadium-treated cotton yarn of the embodiment comprises cotton yarn, cations provided on the surface of the cotton yarn, and vanadium-containing ions attached to the cations. The vanadium-treated colored cotton yarn of the embodiment of the present application has the function of absorbing light and generating heat, and the function of retaining heat. The vanadium-treated colored cotton yarn of the embodiment comprises cotton yarn, cations provided on the surface of the cotton yarn, vanadium-containing ions attached to the cations, and a dye. [Examples]

[0031] Example 1: Vanadium-containing cotton fibers • Manufacturing of vanadium-treated cotton fibers Vanadium-containing ions were attached to the surface of cationized cotton fibers (Asahi Kasei Corporation, Bemberg), which are cotton-like regenerated cotton fibers, in the following manner. Vanadyl sulfate VOSO4 (Kanto Chemical Co., Ltd.) was dissolved in distilled water to prepare a vanadium-containing aqueous solution with a vanadyl ion concentration of 10 mM.

[0032] Using a small rotary pot dyeing test machine (Texam Giken Co., Ltd., MINI COLOUR) (hereinafter sometimes simply referred to as "rotary pot"), cationized cotton fibers were immersed in this vanadium-containing aqueous solution at a bath ratio of 1:20 and rotated at 60°C for 1 hour. Next, using the rotary pot, the treated cationized cotton fibers were immersed in a 2.0 g / L Marcel soap solution at a bath ratio of 1:20 and rotated soaping was performed at 50°C for 20 minutes. After soaping, the cationized cotton fibers were washed with running water for 5 minutes and dried to obtain vanadium-treated cotton fibers.

[0033] • Light absorption heat generation and heat retention performance test Cationic cotton fibers and vanadium-treated cotton fibers were placed side-by-side on a polystyrene foam sample stage and irradiated with light for 10 minutes from a distance of 30 cm using a photographic reflector lamp (PRF-500WB / D, Panasonic Corporation). The temperatures of the cationic cotton fibers and vanadium-treated cotton fibers after 10 minutes of light irradiation were measured using an infrared camera (NEC Avio Infrared Technology Co., Ltd., InfReC Thermo GEAR G100) (the same applies hereafter). The temperatures of the cationic cotton fibers and vanadium-treated cotton fibers were also measured 1 minute after the reflector lamp was turned off.

[0034] After 10 minutes of light irradiation, the temperature of the cationized cotton fiber was 44.4°C, and the temperature of the vanadiumized cotton fiber was 53.7°C, a difference of 9.3°C. Therefore, this vanadiumized cotton fiber has the function of absorbing light and generating heat. Furthermore, one minute after the lights were turned off, the temperature of the cationized cotton fiber was 33.5°C, and the temperature of the vanadiumized cotton fiber one minute after the lights were turned off was 38.3°C, a difference of 4.8°C. Therefore, this vanadiumized cotton fiber also has the function of absorbing light and retaining heat.

[0035] Example 2: Vanadium-treated cotton yarn • Manufacturing of vanadium-treated cotton yarn Vanadium-containing ions were attached to the surface of cationized cotton yarn (Asahi Kasei Corporation, Bemberg), which is made from recycled cotton fibers, in the same manner as the procedure for attaching vanadium-containing ions in Example 1, by cationizing the surface of the yarn.

[0036] • Light absorption heat generation and heat retention performance test The temperatures of cationized cotton yarn and vanadiumized cotton yarn were measured in the same manner as in Example 1. After 10 minutes of light irradiation, the temperature of the cationized cotton yarn was 38.3°C, and the temperature of the vanadiumized cotton yarn after 10 minutes of light irradiation was 46.9°C, a difference of 8.6°C. Therefore, this vanadiumized cotton yarn has the function of absorbing light and generating heat. Furthermore, after 1 minute of light being turned off, the temperature of the cationized cotton yarn was 30.1°C, and the temperature of the vanadiumized cotton yarn after 1 minute of light being turned off was 34.8°C, a difference of 4.7°C. Therefore, this vanadiumized cotton yarn also has the function of absorbing light and retaining heat.

[0037] Example 3: Vanadium-dyed cotton yarn • Manufacturing of vanadium-dyed cotton yarn The vanadium-treated cotton yarn of Example 2 was dyed using the following three types of dyes to obtain vanadium-treated colored cotton yarn. Dye A: 0.2% by mass aqueous solution of Kayarus Light Red F5G Dye B: 5.8% by mass aqueous solution of Kayarus Light Red F5G Dye C: 3.0% by mass aqueous solution of Kayarus Light Yellow F8G

[0038] Using a rotary pot, vanadium-dyed cotton yarn was immersed in dyes A, B, and C in a bath ratio of 1:20, and rotary dyeing was performed at 60°C for 1 hour. Next, using a rotary pot, the dyed vanadium-dyed cotton yarn was immersed in a 2.0 g / L Marcel soap solution in a bath ratio of 1:20, and rotary soaping was performed at 50°C for 20 minutes. After soaping, the vanadium-dyed cotton yarn was washed with running water for 5 minutes and dried to obtain three types of vanadium-dyed cotton yarn. These vanadium-dyed cotton yarns were almost uniformly colored. Therefore, even if cotton fabric is made from vanadium-dyed cotton yarn, the color of the resulting cotton fabric will also be almost uniform. Furthermore, even if the uniformity of coloring of the vanadium-dyed cotton yarn is slightly low, the resulting cotton fabric will have a harmonious texture.

[0039] • Light absorption heat generation and heat retention performance test The temperatures of three types of vanadium-dyed cotton yarns were measured in the same manner as in Example 1. The temperatures of the cationized cotton yarns were the same as those used in Example 2. The temperatures of the vanadium-dyed cotton yarns dyed with dyes A to C after 10 minutes of light irradiation were 44.8°C, 47.4°C, and 41.5°C, respectively. The temperature of the cationized cotton yarn after 10 minutes of light irradiation was 38.3°C, so the temperature differences between the cationized cotton yarn and the vanadium-dyed cotton yarns were 6.5°C, 9.1°C, and 3.2°C, respectively. Therefore, these vanadium-dyed cotton yarns possess the function of absorbing light and generating heat.

[0040] Furthermore, the temperatures of the vanadium-dyed cotton yarns dyed with dyes A to C one minute after the lights were turned off were 36.0°C, 37.3°C, and 34.1°C, respectively. The temperature of the cationized cotton yarn one minute after the lights were turned off was 30.1°C, so the temperature difference between the cationized cotton yarn and the vanadium-dyed cotton yarn was 5.9°C, 7.2°C, and 4.0°C, respectively. Therefore, these vanadium-dyed cotton yarns also possess the function of absorbing light and retaining heat.

Claims

1. A method for producing vanadium-treated cotton fibers, comprising a fiber immersion step of immersing cationized cotton fibers, whose surface has been cationized, in a liquid containing vanadium-containing ions, thereby adhering the vanadium-containing ions to the surface of the cationized cotton fibers, and obtaining vanadium-treated cotton fibers that have the function of absorbing light and generating heat, and the function of retaining heat.

2. A fiber immersion step involves immersing cationized cotton fibers, whose surface is cationized, in a liquid containing vanadium-containing ions, thereby depositing the vanadium-containing ions onto the surface of the cationized cotton fibers, and obtaining vanadized cotton fibers that have the function of absorbing light and generating heat, and the function of retaining heat. A vanadium spinning process to obtain vanadium cotton yarn by spinning the vanadium cotton fibers, A method for producing vanadium-treated cotton yarn.

3. A cationization spinning process to obtain cationized cotton yarn by spinning cationized cotton fibers, in which the surface of cotton fibers is cationized, A yarn immersion step involves immersing the cationized cotton yarn in a liquid containing vanadium-containing ions, thereby depositing the vanadium-containing ions onto the surface of the cationized cotton yarn, and obtaining a vanadized cotton yarn that has the function of absorbing light and generating heat, and the function of retaining heat. A method for producing vanadium-treated cotton yarn.

4. A method for producing vanadium-treated cotton yarn, comprising a yarn immersion step, in which cationized cotton yarn, whose surface has been cationized by cationizing cotton yarn, is immersed in a liquid containing vanadium-containing ions, and the vanadium-containing ions are attached to the surface of the cationized cotton yarn to obtain vanadium-treated cotton yarn having the function of absorbing light and generating heat and the function of retaining heat.

5. A method for producing vanadium-dyed cotton yarn, comprising a dyeing step of dyeing vanadium-dyed cotton yarn obtained by any one of claims 2 to 4 with a dye to obtain vanadium-dyed colored cotton yarn having the function of absorbing light and generating heat and the function of retaining heat.

6. The material comprises cotton fibers, cations provided on the surface of the cotton fibers, and vanadium-containing ions attached to the cations. Vanadium-treated cotton fiber possesses the function of absorbing light to generate heat and retaining heat.

7. The material comprises cotton yarn, a cation provided on the surface of the cotton yarn, and vanadium-containing ions attached to the cation, Vanadium-treated cotton yarn that has the function of absorbing light to generate heat and retaining heat.

8. The material comprises cotton yarn, a cation provided on the surface of the cotton yarn, vanadium-containing ions and a dye attached to the cation, Vanadium-dyed cotton yarn that has the function of absorbing light to generate heat and retaining heat.