Fiber, fabric, wearing article, and method for producing fiber

Abstract

The objective of the present invention is to provide a fiber that enables warming in a shorter time, a fabric, a wearing article, and a method for producing a fiber. In the present invention, a fiber (F) is obtained by kneading a powder (P) containing iron oxide in a blending ratio within a predetermined specific range, that is, preferably in a blending ratio of 1-20% by weight (inclusive) of the powder (P), into a material (M) of the fiber. Such a fiber (F) enables warming in a shorter time. The particle size of the powder (P) is preferably 0.1 μm or more and less than 1 μm, and the blending ratio of the powder (P) to the material (M) is less than 10% by weight of the material (M).

Description

Fibers, fabrics, accessories, and fiber manufacturing methods

[0001] The present invention relates to fibers, fabrics, garments, and methods for making fibers.

[0002] Among textile products (wearable articles worn on the human body) worn in winter, there are some that use moisture-absorbing heat-generating fibers to increase warmth (see, for example, Patent Document 1).

[0003] JP 2013-129947 A

[0004] However, with conventional wearable devices, including the technology described in Patent Document 1, it takes a long time for the body to warm up.

[0005] The present invention has been made in consideration of the above circumstances, and aims to provide a fiber, fabric, wearable item, and method for manufacturing the fiber that can shorten the time it takes to warm up.

[0006] The fiber of one embodiment of the present invention is obtained by kneading a powder containing iron oxide at a blending ratio within a predetermined range into a fiber material.

[0007] In addition, a fabric according to one embodiment of the present invention is composed of fibers obtained by kneading a powder containing iron oxide at a blending ratio within a predetermined range into a fiber material, and other fibers different from the fibers.

[0008] Furthermore, an article of wear according to one aspect of the present invention is one that is worn on the human body using the above-mentioned fabric.

[0009] A method for producing a fiber according to an embodiment of the present invention corresponds to the above-described fiber according to an embodiment of the present invention.

[0010] According to the present invention, the time required for heating can be shortened.

[0011] 5 is a diagram showing an example of the configuration of a fiber according to one embodiment of the present invention, based on image analysis of a cross section. It is a tabular diagram showing an example of test results when a light absorption heat generation test was conducted on the fiber of FIG. 1 and a fiber as a comparative example. It is a graph corresponding to the test results of FIG. 2. It is a thermography image corresponding to the test results of FIG. 2. It is a tabular diagram showing an example of test results when a moisture absorption heat generation test was conducted on the fiber of FIG. 1 and a fiber as a comparative example. It is a graph corresponding to the test results of FIG. 5. It is a diagram for explaining the sample used in the moisture absorption heat generation test of FIG. 5. It is a thermography image corresponding to the test results of FIG. 5. It is a diagram showing an example of test results when a thermal effect experiment was conducted on underwear using the fiber of FIG. 1 and underwear using a fiber as a comparative example. It is a tabular diagram showing an example of lava suitable for powder to be kneaded into the fiber of FIG. 1, and the component ratio when this lava powder is kneaded into the fiber. It is a diagram showing an example of far-infrared radiation characteristics of lava suitable for powder to be kneaded into the fiber of FIG. 1 and a mineral as a comparative example. It is a tabular diagram showing an example of test results when a light absorption heat generation test was conducted using a reagent on iron oxide contained in the fiber of FIG. 1. 13 is a graph showing the test results of FIG. 12 . FIG. 14 is a thermography image corresponding to the test results of FIG. 12 . FIG. 14 is a diagram relating to verification of effective formulation conditions for iron oxide using a reagent. FIG. 15 is a tabular diagram showing an example of test results when a light absorption exothermic test was performed on a formulated reagent (iron oxide, etc.). FIG. 16 is a tabular diagram showing an example of test results when a light absorption exothermic test was performed on a formulated reagent (iron oxide, etc.). FIG. 17 is a thermography image corresponding to the test results of FIG. 17 . FIG. 18 is a thermography image corresponding to the test results of FIG. 18 . FIG. 18 is a graph showing an example of test results when a light absorption exothermic test was performed on 16 formulated reagents (iron oxide, etc.).

[0012] Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

[0013] FIG. 1 is a diagram showing an example of the structure of a fiber according to one embodiment of the present invention, based on image analysis of a cross section.

[0014] The fiber F of one embodiment of the present invention is obtained by using a powder P containing iron oxide, which will be described later, at a blending ratio within a predetermined range, and kneading this powder P into the material M of the fiber F. Note that the following description will be given on the premise that the powder P is kneaded, but this does not exclude the adhesion of the powder P.

[0015] As shown in Figure 1, there are multiple fibers F. Rayon is used as the material M here, but there is no particular limitation. Preferably, the material M functions as a moisture-absorbing and heat-generating fiber when made into a fiber. Examples of the material M include cotton, silk, wool, cupra, hemp, linen, and synthetic fibers, which have a high standard moisture regain.

[0016] The powder P is kneaded into the material M of the fiber F at a weight ratio of less than 10%. If the weight ratio is 10% or more, the fiber F may break, and the fiber may not be able to function properly. As a lower limit, if the powder P is kneaded into the material M of the fiber F at a weight ratio of 1% or less, the effect of the fiber F of this embodiment, i.e., the effect of shortening the time it takes to heat up, may not be fully obtained.

[0017] In this embodiment, the powder P has a particle size of less than 1 μm. Specifically, the particle size is 0.1 μm or more and less than 1 μm. By reducing the particle size, a sufficient surface area can be secured within the material M of the fibers F. By securing a sufficient surface area, the power to absorb heat and generate heat can be increased.

[0018] Powder P is obtained from basalt. Preferably, it is obtained from lava of Mt. Fuji. In the following, the lava of Mt. Fuji will be referred to as "Mt. Fuji lava" or "lava" to distinguish it from basalt itself. Powder P may be obtained from basalt or Mt. Fuji lava, or may be made of the components described below, or may be a combination of these components with materials obtained from basalt or Mt. Fuji lava.

[0019] The iron oxide blended into powder P includes at least ferrous oxide. Ferrous oxide is generally called iron oxide 2 (the 2 is actually a Roman numeral) and is an iron oxide with the composition formula FeO. When powder P is obtained from the lava of Mount Fuji, for example, the iron oxide contained therein is ferric oxide and ferrous oxide with a higher blending ratio than ferric oxide. Ferric oxide is generally called iron oxide 3 (the 3 is actually a Roman numeral) and is an iron oxide with the composition formula FeO.

[0020] As will be described later, when comparing ferrous oxide (FeO) and ferric oxide (Fe2O3), ferrous oxide (FeO) has a higher far-infrared heat generation, and therefore in this embodiment, the blending ratio of ferrous oxide (FeO) is higher than that of ferric oxide (Fe2O3). In addition, in this embodiment, the blending ratio of ferrous oxide (FeO) is also higher in consideration of the color appearance of the Mount Fuji lava. The reason for increasing the blending ratio of ferrous oxide (FeO) is that, for example, if there is a large amount of ferric oxide (Fe2O3), there are concerns about rust formation, weight increase, and strength reduction.

[0021] The ferrous oxide (FeO) is blended in the powder P at a weight ratio of 1% to 20% (preferably 5% to 20%, and more preferably 11% to 20%). Blending ratios of 1% to 20% and 5% to 20% will be described later with reference to FIG. 16 and other figures. As will be described later, the blending ratio of ferrous oxide (FeO) has a strong correlation with temperature, and thus has the advantage of providing sufficient heat-generating effects. In other words, adjusting the blending ratio of ferrous oxide (FeO) allows temperature control according to the intended use and environment, for example, for underwear, bedding, rugs, socks, etc.

[0022] In addition to iron oxide, the powder P preferably contains silicon dioxide and aluminum oxide. The blending of silicon dioxide and aluminum oxide will be described later with reference to FIG. 16 etc. When ceramic components such as silicon dioxide and aluminum oxide are blended appropriately, the heat absorbed and generated by the iron oxide can be thermally conducted to the entire fiber F. Silicon dioxide can contribute to increasing the hygroscopic heat generation properties of the fiber F. The blending of silicon dioxide will be described later with reference to FIG. 16 etc.

[0023] The left image in image analysis IA of Figure 1 is an SEM image of fiber F. Powder P is kneaded into material M of fiber F, and its presence can be confirmed from Figure 1. Of the multiple fibers F in the left image, the gray-looking portion of fiber F in the center is material M itself, and the multiple white objects scattered within it are particles of powder P (which appear shiny white in the image).

[0024] The right-hand image in Image Analysis IA shows the left-hand image after image processing and conversion to RGB. In the right-hand image, points are plotted and connected with lines to grasp the outline of the fiber F. The area inside the lines (cross-sectional area of ​​the fiber F) was calculated, and the amount of powder P particles contained was measured. In this example, it was found to be approximately 2% to 4%. From Figure 1, it can be seen that the powder P is kneaded into the fiber F material M at a weight ratio of 10% or less.

[0025] Here, we will explain the manufacturing methods of the powder P and the fiber F. In the explanation, the source of the powder P is assumed to be lava from Mt. Fuji, and the material M of the fiber F is assumed to be rayon (although there is no particular limitation as long as it is basalt other than the lava from Mt. Fuji, or a material (raw material) that functions as a moisture-absorbing and heat-generating fiber).

[0026] The first step involves preparing the Mount Fuji lava itself. The amount of Mount Fuji lava to be used is optional. In the first step, black Mount Fuji lava is prepared (black Mount Fuji lava contains a lot of ferrous oxide (FeO), while reddish Mount Fuji lava contains a lot of ferric oxide (Fe2O3)). This lava is also sorted in the first step. In the second step, the prepared Mount Fuji lava is cut into plates of a specified size. A large diamond cutter, for example, is used for cutting.

[0027] In the third step, the Mt. Fuji lava cut into plates is cut into pieces the size of a fist. A large diamond belt cutter is used for this cutting. In the fourth step, the fist-sized pieces are crushed into pieces the size of pebbles. A drum crusher is used for this step.

[0028] In the fifth step, the pebbled Mt. Fuji lava is ground into a fine powder of, for example, 5 μm or less. This step uses, for example, a dry grinder. In the sixth step, the 5 μm or less fine powder is sieved to a fine powder of, for example, less than 1 μm, i.e., powder P.

[0029] In the seventh step, the powder P, which has been made into a fine powder of less than 1 μm, is kneaded into rayon (material M) to produce fiber F. The fiber F is produced, for example, in the form of cotton (rayon cotton is produced). One example of the kneading of the powder P is to knead it in such a manner that the ratio of powder P is about 10 g per 100 g of rayon cotton. An example of the kneaded state of the powder P is as shown in FIG. 1.

[0030] In the eighth step, the produced rayon is mixed with, for example, cotton or acrylic to spin a yarn. Note that the cotton or acrylic used in the mixture is only an example.

[0031] Next, a light absorption heat generation test of the above-mentioned rayon batting (hereinafter sometimes referred to as powder-incorporated rayon batting or powder-incorporated rayon batting) will be described with reference to Figures 2 to 4. Figure 2 is a table showing an example of the test results when a light absorption heat generation test was conducted on the fiber of Figure 1 and a comparative fiber. Figure 3 is a graph corresponding to the test results of Figure 2. Figure 4 is a thermography image corresponding to the test results of Figure 2.

[0032] In Figure 2, the light absorption heat generation test is a test to measure the temperature change when irradiated with light, and the test subjects here are (1) powder-mixed rayon cotton and (2) unmixed rayon cotton. The powder-mixed rayon cotton (1) shown in Figure 2 is a "wadding" made of fiber F mixed with powder P, and the comparison product is (2) unmixed rayon cotton, that is, a "wadding" made of ordinary rayon fiber without powder P mixed in.

[0033] The measurement environment was 20°C and 65% RH. In preparation for the light absorption heat generation test, 0.3 g of samples (1) and (2) were loosened under temperature and humidity control in the measurement environment and packed into plastic petri dishes with a diameter of 8.5 cm. As a test method, the samples were placed under a solar light (500 W) and irradiated with light under the following conditions. During light irradiation, the irradiated surface of the sample was photographed using a thermograph. The irradiation time was 60 minutes, with the first 30 minutes being the irradiation time and the last 30 minutes being the time when the light was off. The irradiance was approximately 800 W / m ２ The type of light source is an artificial solar lamp.

[0034] As shown in Figure 2, the test items and results TC1, the initial (before irradiation) sample temperatures (°C) were 21.8 for (1) powder-mixed rayon cotton and 21.2 for (2) unmixed rayon cotton. Five minutes after the start of irradiation (5 minutes after the start of irradiation), the sample temperatures (°C) were 38.8 for (1) powder-mixed rayon cotton and 26.6 for (2) unmixed rayon cotton. Ten minutes after the start of irradiation (10 minutes after the start of irradiation), the sample temperatures (°C) were 40.9 for (1) powder-mixed rayon cotton and 27.7 for (2) unmixed rayon cotton. Fifteen minutes after the start of irradiation (15 minutes after the start of irradiation), the sample temperatures (°C) were 41.6 for (1) powder-mixed rayon cotton and 28.2 for (2) unmixed rayon cotton. The temperature (°C) of the sample 20 minutes after the start (20 minutes after the start of irradiation) was 41.4 for (1) powder-kneaded rayon cotton and 28.2 for (2) unprocessed rayon cotton. The temperature (°C) of the sample 25 minutes after the start (25 minutes after the start of irradiation) was 42.0 for (1) powder-kneaded rayon cotton and 28.4 for (2) unprocessed rayon cotton. The temperature (°C) of the sample 30 minutes after the start (30 minutes after the start of irradiation) was 41.4 for (1) powder-kneaded rayon cotton and 28.4 for (2) unprocessed rayon cotton.

[0035] The temperature (°C) of the sample 35 minutes after the start (5 minutes after lights out) was 24.1 for (1) powder-mixed rayon cotton and 22.6 for (2) unmixed rayon cotton. The temperature (°C) of the sample 40 minutes after the start (10 minutes after lights out) was 22.4 for (1) powder-mixed rayon cotton and 21.8 for (2) unmixed rayon cotton. The temperature (°C) of the sample 45 minutes after the start (15 minutes after lights out) was 21.8 for (1) powder-mixed rayon cotton and 21.5 for (2) unmixed rayon cotton. The temperature (°C) of the sample 50 minutes after the start (20 minutes after lights out) was 21.5 for (1) powder-mixed rayon cotton and 21.3 for (2) unmixed rayon cotton. The temperature (°C) of the sample 55 minutes after the start (25 minutes after the lights were turned off) was 21.3 for (1) the powder-processed rayon cotton and 21.2 for (2) the unprocessed rayon cotton. The temperature (°C) of the sample 60 minutes after the start (30 minutes after the lights were turned off) was 21.1 for (1) the powder-processed rayon cotton and 21.0 for (2) the unprocessed rayon cotton.

[0036] The maximum heat generation temperature (°C) of (1) powder-mixed rayon cotton was 41.6, and that of (2) unprocessed rayon cotton was 28.4. Therefore, it was found that (1) powder-mixed rayon cotton was 13.2°C higher than (2) unprocessed rayon cotton.

[0037] The above test results are shown graphically in Figure 3 (Test Results TR1-1) and Figure 4 (Test Results TR1-2). Figure 3 shows that 5 minutes after the start of irradiation, the temperature rose rapidly to 38.8°C, approximately 93% of the maximum heat release temperature (°C). This demonstrates the superiority of the rapid radiative reaction after heat absorption. The rapid radiative reaction is due to the iron oxide contained in Powder P. Figure 4 shows that (1) powder-incorporated rayon cotton maintained a high temperature until 30 minutes after the start of irradiation. In the thermography image taken 30 minutes after the start of irradiation, (1) powder-incorporated rayon cotton showed a temperature of 41.4°C, while (2) unprocessed rayon cotton showed a temperature of 28.4°C, clearly demonstrating that it maintained a high temperature.

[0038] Next, a moisture absorption and heat generation test of powder-mixed rayon and regular rayon will be described with reference to Figures 5 to 8. Figure 5 is a table showing an example of test results when a moisture absorption and heat generation test was conducted on the fiber of Figure 1 and a fiber serving as a comparative example. Figure 6 is a graph corresponding to the test results of Figure 5. Figure 7 is a diagram for explaining the sample used in the moisture absorption and heat generation test of Figure 5. Figure 8 is a thermography image corresponding to the test results of Figure 5.

[0039] In Figure 5, the moisture absorption heat generation test involves leaving a test specimen in a low-humidity environment for more than four hours, then transferring it to a high-humidity environment, and measuring the sample surface temperature every minute for 30 minutes using a thermograph. The test specimen corresponds to a 10 cm x 10 cm cushion-shaped sample with sides of approximately 10 cm, as shown in sample SP in Figure 7. The measurement surface is the surface of the test specimen. Specifically, it is a circular area with a diameter of approximately 5 cm in the center of the test specimen. The test results are the average of two measurements taken at the approximately 5 cm circular area. The low-humidity environment is a humidity of 20 ± 2°C and a humidity of 40 ± 5% RH, and the high-humidity environment is a humidity of 20 ± 2°C and a humidity of 90 ± 5% RH. The powder-incorporated rayon in the test specimen is made of fiber F kneaded with powder P, and the regular rayon is made of ordinary rayon fiber.

[0040] As shown in the test results (Test Items / Results TC2 in Figure 5 and Test Results TR2-1 in Figure 6, the measured temperatures (°C) at the start (0 minutes) were 20.6 for the powder-mixed rayon and 20.5 for the regular rayon (see Test Results TR2-2 in Figure 8 for thermography images). The measured temperatures (°C) after one minute were 22.4 for the powder-mixed rayon and 22.4 for the regular rayon (see Test Results TR2-2 in Figure 8 for thermography images after one minute). The measured temperatures (°C) after two minutes were 22.4 for the powder-mixed rayon and 22.5 for the regular rayon (see Test Results TR2-2 in Figure 8 for thermography images after two minutes). The measured temperatures (°C) after three minutes were 22.4 for the powder-mixed rayon and 22.4 for the regular rayon (see Test Results TR2-2 in Figure 8 for thermography images after three minutes). The measured temperatures (°C) after 4 minutes were 22.4 for the powder-kneaded rayon and 22.4 for the regular rayon. The measured temperatures (°C) after 5 minutes were 22.5 for the powder-kneaded rayon and 22.4 for the regular rayon. The measured temperatures (°C) after 6 minutes were 22.3 for the powder-kneaded rayon and 22.3 for the regular rayon. The measured temperatures (°C) after 7 minutes were 22.4 for the powder-kneaded rayon and 22.4 for the regular rayon. The measured temperatures (°C) after 8 minutes were 22.4 for the powder-kneaded rayon and 22.3 for the regular rayon. The measured temperatures (°C) after 9 minutes were 22.3 for the powder-kneaded rayon and 22.2 for the regular rayon.

[0041] The measured temperatures (°C) after 10 minutes were 22.4 for the powder-mixed rayon and 22.3 for the regular rayon (see test result TR2-2 in Figure 8 for the thermography image after 10 minutes). The measured temperatures (°C) after 11 minutes were 22.2 for the powder-mixed rayon and 22.2 for the regular rayon. The measured temperatures (°C) after 12 minutes were 22.2 for the powder-mixed rayon and 22.2 for the regular rayon. The measured temperatures (°C) after 13 minutes were 22.2 for the powder-mixed rayon and 22.1 for the regular rayon. The measured temperatures (°C) after 14 minutes were 22.1 for the powder-mixed rayon and 22.0 for the regular rayon. The measured temperatures (°C) after 15 minutes were 22.1 for the powder-mixed rayon and 22.0 for the regular rayon. The measured temperatures (°C) after 16 minutes were 22.2 for powder-kneaded rayon and 22.1 for regular rayon. The measured temperatures (°C) after 17 minutes were 22.1 for powder-kneaded rayon and 22.0 for regular rayon. The measured temperatures (°C) after 18 minutes were 22.1 for powder-kneaded rayon and 22.0 for regular rayon. The measured temperatures (°C) after 19 minutes were 22.1 for powder-kneaded rayon and 22.0 for regular rayon.

[0042] The measured temperatures (°C) after 20 minutes were 22.0 for the powder-kneaded rayon and 21.9 for the regular rayon. The measured temperatures (°C) after 21 minutes were 22.0 for the powder-kneaded rayon and 21.9 for the regular rayon. The measured temperatures (°C) after 22 minutes were 22.0 for the powder-kneaded rayon and 21.9 for the regular rayon. The measured temperatures (°C) after 23 minutes were 22.0 for the powder-kneaded rayon and 21.9 for the regular rayon. The measured temperatures (°C) after 24 minutes were 22.1 for the powder-kneaded rayon and 22.0 for the regular rayon. The measured temperatures (°C) after 25 minutes were 22.0 for the powder-kneaded rayon and 21.9 for the regular rayon. The measured temperatures (°C) after 26 minutes were 21.9 for the powder-kneaded rayon and 21.9 for the regular rayon. The measured temperatures (°C) after 27 minutes were 21.9 for powder-mixed rayon and 21.8 for regular rayon. The measured temperatures (°C) after 28 minutes were 22.0 for powder-mixed rayon and 21.9 for regular rayon. The measured temperatures (°C) after 29 minutes were 22.0 for powder-mixed rayon and 21.9 for regular rayon. The measured temperatures (°C) after 30 minutes were 21.9 for powder-mixed rayon and 21.8 for regular rayon (see test results TR2-2 in Figure 8 for the thermography image after 30 minutes).

[0043] 5 and 6 show that both the powder-mixed rayon and regular rayon showed a temperature rise of approximately 2°C. It was found that the powder-mixed rayon continued to generate heat that was approximately 0.1°C higher than regular rayon even after 5 minutes. Therefore, it was found that by mixing powder P into rayon, the heat retention ability of rayon, that is, the ability to retain the heat generated by rayon, was improved by approximately 5% compared to regular rayon. One factor that contributed to this improvement in retention ability is the inclusion of silicon dioxide in powder P. It can be said that silicon dioxide increases moisture absorption ability and increases the effect of heat adsorption.

[0044] Next, a thermal effect experiment will be described with reference to Fig. 9. Fig. 9 is a diagram showing an example of test results when a thermal effect experiment was conducted on underwear using the fiber of Fig. 1 and underwear using a fiber as a comparative example.

[0045] In the test result TR3 shown in Figure 9, the powder-infused rayon blended underwear contains fiber F kneaded with powder P, and the unprocessed rayon blended underwear contains the above-mentioned regular rayon (general rayon fiber). Note that for reference, underwear not containing iron oxide, i.e., mineral-infused underwear without iron oxide, is also included.

[0046] The powder-infused rayon blended underwear is made with 56% of the above-mentioned powder-infused rayon, 29% cotton, 10% nylon, and 5% polyurethane. The unprocessed rayon blended underwear is made with 39% polyester, 31% acrylic, 20% of the above-mentioned regular rayon, and 10% polyurethane. The iron oxide-free mineral-infused underwear is made with 64% cotton and 36% of the mineral-infused polyester.

[0047] Test result TR3 in Figure 9 shows the results when these three types of underwear were worn by a 32-year-old female subject, 153 cm tall and weighing 49 kg, indoors at an ambient temperature of 27°C and humidity of 40%. The skin surface temperature was measured by thermography before wearing the underwear, 10 minutes after wearing it, and 30 minutes after wearing it (the thermography image was taken 10 minutes after wearing it).

[0048] For the powder-incorporated rayon blended underwear, the skin surface temperature was 32°C before wearing, 34.0°C after 10 minutes of wearing (a temperature increase of 2°C), and 34.7°C after 30 minutes of wearing (a temperature increase of 2.7°C). In contrast, for the unprocessed rayon blended underwear, the skin surface temperature was 32.2°C before wearing, 33.8°C after 10 minutes of wearing (a temperature increase of 1.6°C), and 34.3°C after 30 minutes of wearing (a temperature increase of 2.1°C). For the iron oxide-free mineral-incorporated underwear, the skin surface temperature was 32.1°C before wearing, 33.5°C after 10 minutes of wearing (a temperature increase of 1.4°C), and 34.4°C after 30 minutes of wearing (a temperature increase of 2.3°C).

[0049] 9, it can be seen that the powder-incorporated rayon blended underwear had a higher skin surface temperature 10 minutes and 30 minutes after wearing, demonstrating its superiority over unprocessed rayon blended underwear and mineral-incorporated underwear without iron oxide. This superiority can be attributed to two effects: the far-infrared heat-generating effect of the iron oxide contained in the powder P, and the enhanced moisture-absorbing heat-generating effect of the silicon dioxide also contained in the powder P.

[0050] In the thermal effect experiment, it was found that powder-mixed rayon blended underwear can achieve the two effects mentioned above by generating heat through both far-infrared radiation and moisture absorption (unprocessed rayon blended underwear can only obtain the effect of moisture absorption and heat generation, and iron oxide-free mineral-mixed underwear can only obtain the effect of far-infrared radiation, so it was found that powder-mixed rayon blended underwear has a great advantage).

[0051] Here, with reference to Fig. 10, lava suitable for processing into powder P and the component ratio when the powder P made from this lava is kneaded into fiber F will be described. Fig. 10 is a table showing an example of lava suitable for the powder to be kneaded into the fiber of Fig. 1 and the component ratio when the powder made from this lava is kneaded into fiber. Note that the lava is not limited to lava, and any basalt with the components described below will suffice.

[0052] The Aokigahara lava from Narusawa Village, Yamanashi Prefecture, Japan, is listed as a suitable lava for powder P, based on the component ratio CR1 shown in Figure 10. This lava contains 51.34% silicon dioxide (SiO2), 17.17% aluminum oxide (Al2O3), and 10.99% iron oxide (FeO) as its main components. Other components include 9.81% calcium oxide (CaO), 5.27% magnesium oxide (MgO), 2.71% sodium oxide (Na2O), 1.44% titanium oxide (TiO2), 0.79% potassium oxide (KO), 0.30% diphosphorus pentoxide (PO5), and 0.18% manganese oxide (MnO).

[0053] The lava components in Fiber F were 44.65% silicon dioxide (SiO2), 13.03% aluminum oxide (Al2O3), and 7.40% iron oxide (FeO). It also contained 6.53% calcium oxide (CaO), 4.30% magnesium oxide (MgO), 17.17% sodium oxide (Na2O), 0.00% titanium oxide (TiO2), 6.92% potassium oxide (K2O), 0.00% diphosphorus pentoxide (P2O5), and 0.00% manganese oxide (MnO).

[0054] The component ratios differ from those of the Aokigahara lava because the amount of sodium oxide (Na2O) and potassium oxide (KO2O) derived from the chemicals used in the rayon manufacturing process (corresponding to the seventh step mentioned above) has increased, resulting in a relative decrease.

[0055] FIG. 11 shows an example of the far-infrared radiation characteristics of lava suitable for the powder P to be kneaded into the fiber F of FIG. 1 and a comparative mineral. The horizontal axis of the graph in FIG. 11 represents wavelength (μm). The vertical axis represents far-infrared emissivity (the top 1 corresponds to 100%). It is known that the thermal energy of far-infrared rays increases as the wavelength decreases. Therefore, high emissivity in the low-wavelength range indicates the ability to absorb thermal energy and generate heat. In the test results TR4 (far-infrared emissivity measurement results) shown in FIG. 11, for example, ceramics C (e.g., the mineral used in FIG. 9) exhibits a decrease in far-infrared emissivity in the low-wavelength range of 5 μm or less. However, Mount Fuji lava L exhibits a high far-infrared emissivity of 80% to 90% or more even in the low-wavelength range of 5 μm or less. Because the far-infrared emissivity is high even in the low-wavelength range of 5 μm or less, the heat absorption and heat generation speed are rapid (see, for example, FIGS. 2 to 4).

[0056] To explain in more detail, approximately 70% of the human body is water. Therefore, far-infrared rays are easily absorbed, reaching a depth of approximately 0.2 mm from the surface of the body and converted into thermal energy. This converted heat is transmitted throughout the body via the blood flowing through the capillaries, causing a sensation of warmth from the core. Far-infrared rays refer to the wavelength range of 2 μm to 20 μm, but the thermal energy is particularly strong in the low wavelength range of 3 μm to 5 μm or less. While the emissivity of ordinary minerals drops to approximately 50% in the 3 μm to 5 μm range, the far-infrared emissivity of Mount Fuji Lava L remains above 80% even in the 3 μm to 5 μm range, showing no decrease, as shown in Figure 11. This is due to the presence of iron oxide.

[0057] Next, with reference to Figures 12 to 15, test results when a light absorption heat generation test was conducted using a reagent on the iron oxide contained in fiber F will be described. Figure 12 is a table showing an example of test results when a light absorption heat generation test was conducted using a reagent on the iron oxide contained in the fiber of Figure 1. Figure 13 is a graph corresponding to the test results of Figure 12. Figure 14 is a thermography image corresponding to the test results of Figure 12. Figure 15 is a thermography image corresponding to the test results of Figure 12.

[0058] Here, the purpose of the light absorption heat generation test is to identify the component with the highest far-infrared heat generation among the above-mentioned main components, iron oxide (FeO), silicon dioxide (SiO2), and aluminum oxide (Al2O3). In the light absorption heat generation test shown in Figures 12 to 15, the samples used were four types: (1) ferrous oxide (FeO), (2) ferric oxide (Fe2O3), (3) silicon dioxide (quartz type), and (4) aluminum oxide α type. The measurement environment was 20°C and 65% RH. Prior to the light absorption heat generation test, approximately 15 g of each of the four samples was flattened and crushed with a medicine spoon in a round petri dish under the measurement environment. The test method involved placing the samples under a solar light (500 W) and irradiating them with light under the following conditions. During the light irradiation, the irradiated surface of the sample was photographed using a thermograph. The irradiation time was 60 minutes, with the first 30 minutes being irradiated and the last 30 minutes being turned off. The irradiance was approximately 800 W / m ２ The type of light source is an artificial solar lamp.

[0059] As shown in Test Items / Results TC3 in Figure 12, the initial (before irradiation) sample temperatures (°C) were (1) ferrous oxide 21.1, (2) ferric oxide 21.1, (3) silicon dioxide 21.0, and (4) α-aluminum oxide 20.9. Five minutes after the start of irradiation (5 minutes after the start of irradiation), the sample temperatures (°C) were (1) ferrous oxide 58.6, (2) ferric oxide 43.0, (3) silicon dioxide 23.8, and (4) α-aluminum oxide 24.4. Ten minutes after the start of irradiation (10 minutes after the start of irradiation), the sample temperatures (°C) were (1) ferrous oxide 63.5, (2) ferric oxide 46.9, (3) silicon dioxide 24.4, and (4) α-aluminum oxide 25.2. The temperatures (°C) of the samples 15 minutes after the start of irradiation (15 minutes after the start of irradiation) were (1) ferrous oxide 64.7, (2) ferric oxide 48.0, (3) silicon dioxide 24.7, and (4) α-aluminum oxide 25.6. The temperatures (°C) of the samples 20 minutes after the start of irradiation (20 minutes after the start of irradiation) were (1) ferrous oxide 65.0, (2) ferric oxide 48.2, (3) silicon dioxide 24.8, and (4) α-aluminum oxide 25.7. The temperatures (°C) of the samples 25 minutes after the start of irradiation (25 minutes after the start of irradiation) were (1) ferrous oxide 64.9, (2) ferric oxide 48.5, (3) silicon dioxide 24.8, and (4) α-aluminum oxide 25.7. The temperatures (°C) of the samples 30 minutes after the start (30 minutes after the start of irradiation) were: (1) ferrous oxide 65.8, (2) ferric oxide 48.8, (3) silicon dioxide 25.1, and (4) α-aluminum oxide 25.7.

[0060] The temperatures (°C) of the samples 35 minutes after the start (5 minutes after lights out) were (1) ferrous oxide 30.5, (2) ferric oxide 28.3, (3) silicon dioxide 22.2, and (4) α-aluminum oxide 22.6. The temperatures (°C) of the samples 40 minutes after the start (10 minutes after lights out) were (1) ferrous oxide 23.9, (2) ferric oxide 23.6, (3) silicon dioxide 21.4, and (4) α-aluminum oxide 21.5. The temperatures (°C) of the samples 45 minutes after the start (15 minutes after lights out) were (1) ferrous oxide 22.0, (2) ferric oxide 22.1, (3) silicon dioxide 21.1, and (4) α-aluminum oxide 21.3. The temperatures (°C) of the samples 50 minutes after the start (20 minutes after lights out) were: (1) ferrous oxide 21.5, (2) ferric oxide 21.4, (3) silicon dioxide 21.0, and (4) α-aluminum oxide 21.1. The temperatures (°C) of the samples 55 minutes after the start (25 minutes after lights out) were: (1) ferrous oxide 21.2, (2) ferric oxide 21.2, (3) silicon dioxide 21.0, and (4) α-aluminum oxide 20.9. The temperatures (°C) of the samples 60 minutes after the start (30 minutes after lights out) were: (1) ferrous oxide 21.2, (2) ferric oxide 21.0, (3) silicon dioxide 20.9, and (4) α-aluminum oxide 20.9.

[0061] The calorific value (heat increase (°C)) was 4.1 for (3) silicon dioxide and 4.8 for (4) α-type aluminum oxide, while it was 44.7 for (1) ferrous oxide and 27.7 for (2) ferric oxide. Therefore, it was found that iron oxide has higher heat generation property (far-infrared heat generation property). Furthermore, it was found that among iron oxides, (1) ferrous oxide has higher heat generation property than (2) ferric oxide. Therefore, it was found that it is preferable for the iron oxide contained in powder P to be only (1) ferrous oxide, or to contain more (1) ferrous oxide than (2) ferric oxide.

[0062] The above test results can be represented graphically as test result TR5-1 in Figure 13, test result TR5-2 in Figure 14, and test result TR5-3 in Figure 15. Figure 13 shows that the temperature rose suddenly after 5 minutes from the start of irradiation. Figure 14 shows that (1) ferrous oxide and (2) ferric oxide maintained high temperatures 30 minutes from the start of irradiation (because the samples were placed in round petri dishes, the areas where the temperature rose appear round in the thermography image 30 minutes from the start of irradiation).

[0063] Next, effective blending conditions for iron oxide (ferrous oxide (FeO)) using a reagent will be described with reference to Fig. 16. Fig. 16 is a diagram relating to verification of effective blending conditions for iron oxide using a reagent.

[0064] The measurement conditions were as follows: 15 g of each of 14 types of reagents (see (1) to (14) in Figure 16) with different blending ratios were placed in a petri dish, and then irradiated with a 500 W solar light for 30 minutes, and then the temperature was measured with a thermal camera. Under these conditions, the temperatures of the 14 types of reagents after 30 minutes of irradiation were as shown in blending ratio temperature result CR2 in Figure 16.

[0065] That is, when the compounding ratio of (1) was 74.3% silicon dioxide (SiO2), 24.8% aluminum oxide (Al2O3), and 1.00% iron oxide (FeO), the temperature (°C) after 30 minutes of irradiation was 39.4. When the compounding ratio of (2) was 73.5% silicon dioxide (SiO2), 24.5% aluminum oxide (Al2O3), and 2.00% iron oxide (FeO), the temperature (°C) after 30 minutes of irradiation was 41.5. When the compounding ratio of (3) was 72.75% silicon dioxide (SiO2), 24.25% aluminum oxide (Al2O3), and 3.00% iron oxide (FeO), the temperature (°C) after 30 minutes of irradiation was 44.4. When the blending ratio of (4) was 70.58% silicon dioxide (SiO2), 23.53% aluminum oxide (Al2O3), and 5.90% iron oxide (FeO), the temperature (°C) after 30 minutes of irradiation was 47.6. When the blending ratio of (5) was 69.23% silicon dioxide (SiO2), 23.08% aluminum oxide (Al2O3), and 7.70% iron oxide (FeO), the temperature (°C) after 30 minutes of irradiation was 49.4. When the blending ratio of (6) was 67.50% silicon dioxide (SiO2), 22.50% aluminum oxide (Al2O3), and 10.00% iron oxide (FeO), the temperature (°C) after 30 minutes of irradiation was 51.8.

[0066] When the blending ratio of (7) was 66.75% silicon dioxide (SiO2), 22.25% aluminum oxide (Al2O3), and 11.00% iron oxide (FeO), the temperature (°C) after 30 minutes of irradiation was 54.2. When the blending ratio of (8) was 65.63% silicon dioxide (SiO2), 21.88% aluminum oxide (Al2O3), and 12.50% iron oxide (FeO), the temperature (°C) after 30 minutes of irradiation was 53.7. When the blending ratio of (9) was 64.71% silicon dioxide (SiO2), 21.57% aluminum oxide (Al2O3), and 13.72% iron oxide (FeO), the temperature (°C) after 30 minutes of irradiation was 55.1. When the compounding ratio of (10) was 62.55% silicon dioxide (SiO2), 20.85% aluminum oxide (Al2O3), and 16.60% iron oxide (FeO), the temperature (°C) after 30 minutes of irradiation was 56.7. When the compounding ratio of (11) was 60.00% silicon dioxide (SiO2), 20.00% aluminum oxide (Al2O3), and 20.00% iron oxide (FeO), the temperature (°C) after 30 minutes of irradiation was 58.3.

[0067] When the blending ratio of (12) was 56.25% silicon dioxide (SiO2), 18.75% aluminum oxide (Al2O3), and 25.00% iron oxide (FeO), the temperature (°C) after 30 minutes of irradiation was 58.6. When the blending ratio of (13) was 37.5% silicon dioxide (SiO2), 12.5% ​​aluminum oxide (Al2O3), and 50.00% iron oxide (FeO), the temperature (°C) after 30 minutes of irradiation was 59.3. When the blending ratio of (14) was 0.0% silicon dioxide (SiO2), 0.0% aluminum oxide (Al2O3), and 100.0% iron oxide (FeO), the temperature (°C) after 30 minutes of irradiation was 65.8.

[0068] Next, the test results when a light absorption exothermic test was performed on a compounded reagent (iron oxide, etc.) will be described with reference to Figures 17 to 22. Figures 17 and 18 are tabular diagrams showing an example of the test results when a light absorption exothermic test was performed on a compounded reagent (iron oxide, etc.). Figures 19 and 20 are diagrams of thermography images corresponding to the test results in Figure 17. Figures 21 and 22 are diagrams of thermography images corresponding to the test results in Figure 18.

[0069] The purpose of this experiment is to observe the temperature changes of the compounded reagents, Powders A to J and Powders X to Z, described below, by conducting a light absorption exothermic test. In the light absorption exothermic test shown in Figures 17 to 22, the sample Powders A to J and Powders X to Z each have a different ferrous oxide (FeO) content. The correlation with Figure 16 will be described later. The measurement environment was 20°C and 65% RH. In preparation for the light absorption exothermic test, approximately 15 g of sample was flattened in a round dish using a medicine spoon. The test method involved placing the sample under a solar light (500 W) and irradiating it under the following conditions. During the light irradiation, the irradiated surface of the sample was photographed using a thermograph. The irradiation time was 60 minutes, with the first 30 minutes irradiated and the second 30 minutes off. The irradiance was approximately 800 W / m. ２ The type of light source is an artificial solar lamp.

[0070] As shown in Test Items / Results TC4-1 in Figure 17, (1) for Powder A, the initial (before irradiation) sample temperature (°C) was 21.2 (see Test Results TR6-1 in Figure 19 for a thermographic image). The sample temperature (°C) 5 minutes after the start (5 minutes after the start of irradiation) was 40.7. The sample temperature (°C) 10 minutes after the start (10 minutes after the start of irradiation) was 43.9. The sample temperature (°C) 15 minutes after the start (15 minutes after the start of irradiation) was 44.2. The sample temperature (°C) 20 minutes after the start (20 minutes after the start of irradiation) was 44.2. The sample temperature (°C) 25 minutes after the start (25 minutes after the start of irradiation) was 44.6. The sample temperature (°C) 30 minutes after the start (30 minutes after the start of irradiation) was 44.4 (see Test Results TR6-1 in Figure 19 for a thermographic image). The temperature (°C) of the sample 35 minutes after the start (5 minutes after lights off) was 26.1. The temperature (°C) of the sample 40 minutes after the start (10 minutes after lights off) was 22.8. The temperature (°C) of the sample 45 minutes after the start (15 minutes after lights off) was 22.3. The temperature (°C) of the sample 50 minutes after the start (20 minutes after lights off) was 22.2. The temperature (°C) of the sample 55 minutes after the start (25 minutes after lights off) was 22.1. The temperature (°C) of the sample 60 minutes after the start (30 minutes after lights off) was 21.9 (see test result TR6-1 in Figure 19 for the thermography image).

[0071] (2) For Powder B, the initial (before irradiation) sample temperature (°C) was 21.3. The sample temperature (°C) 5 minutes after the start (5 minutes after the start of irradiation) was 43.6 (see Test Results TR6-1 in Figure 19 for thermography images). The sample temperature (°C) 10 minutes after the start (10 minutes after the start of irradiation) was 46.8. The sample temperature (°C) 15 minutes after the start (15 minutes after the start of irradiation) was 47.1. The sample temperature (°C) 20 minutes after the start (20 minutes after the start of irradiation) was 47.7. The sample temperature (°C) 25 minutes after the start (25 minutes after the start of irradiation) was 48.0. The sample temperature (°C) 30 minutes after the start (30 minutes after the start of irradiation) was 47.6 (see Test Results TR6-1 in Figure 19 for thermography images). The temperature (°C) of the sample 35 minutes after the start (5 minutes after lights off) was 26.6. The temperature (°C) of the sample 40 minutes after the start (10 minutes after lights off) was 23.2. The temperature (°C) of the sample 45 minutes after the start (15 minutes after lights off) was 22.3. The temperature (°C) of the sample 50 minutes after the start (20 minutes after lights off) was 22.1. The temperature (°C) of the sample 55 minutes after the start (25 minutes after lights off) was 22.0. The temperature (°C) of the sample 60 minutes after the start (30 minutes after lights off) was 21.9 (see test result TR6-1 in Figure 19 for thermography images).

[0072] (3) For Powder C, the initial (before irradiation) sample temperature (°C) was 21.3. The sample temperature (°C) 5 minutes after the start (5 minutes after the start of irradiation) was 45.8 (see Test Results TR6-1 in Figure 19 for thermography images). The sample temperature (°C) 10 minutes after the start (10 minutes after the start of irradiation) was 48.3. The sample temperature (°C) 15 minutes after the start (15 minutes after the start of irradiation) was 49.1. The sample temperature (°C) 20 minutes after the start (20 minutes after the start of irradiation) was 49.0. The sample temperature (°C) 25 minutes after the start (25 minutes after the start of irradiation) was 49.5. The sample temperature (°C) 30 minutes after the start (30 minutes after the start of irradiation) was 49.4 (see Test Results TR6-1 in Figure 19 for thermography images). The temperature (°C) of the sample 35 minutes after the start (5 minutes after lights off) was 26.8. The temperature (°C) of the sample 40 minutes after the start (10 minutes after lights off) was 23.1. The temperature (°C) of the sample 45 minutes after the start (15 minutes after lights off) was 22.2. The temperature (°C) of the sample 50 minutes after the start (20 minutes after lights off) was 22.0. The temperature (°C) of the sample 55 minutes after the start (25 minutes after lights off) was 21.9. The temperature (°C) of the sample 60 minutes after the start (30 minutes after lights off) was 21.9 (see test result TR6-1 in Figure 19 for the thermography image).

[0073] (4) For Powder D, the initial (before irradiation) sample temperature (°C) was 21.2. The sample temperature (°C) 5 minutes after the start of irradiation (5 minutes after the start of irradiation) was 47.6 (see Test Results TR6-1 in Figure 19 for thermography images). The sample temperature (°C) 10 minutes after the start of irradiation (10 minutes after the start of irradiation) was 51.2. The sample temperature (°C) 15 minutes after the start of irradiation (15 minutes after the start of irradiation) was 51.1. The sample temperature (°C) 20 minutes after the start of irradiation (20 minutes after the start of irradiation) was 52.0. The sample temperature (°C) 25 minutes after the start of irradiation (25 minutes after the start of irradiation) was 51.9. The sample temperature (°C) 30 minutes after the start of irradiation (30 minutes after the start of irradiation) was 51.8 (see Test Results TR6-1 in Figure 19 for thermography images). The temperature (°C) of the sample 35 minutes after the start (5 minutes after lights off) was 27.3. The temperature (°C) of the sample 40 minutes after the start (10 minutes after lights off) was 23.2. The temperature (°C) of the sample 45 minutes after the start (15 minutes after lights off) was 22.3. The temperature (°C) of the sample 50 minutes after the start (20 minutes after lights off) was 22.1. The temperature (°C) of the sample 55 minutes after the start (25 minutes after lights off) was 22.0. The temperature (°C) of the sample 60 minutes after the start (30 minutes after lights off) was 21.9 (see test result TR6-1 in Figure 19 for the thermography image).

[0074] (5) For Powder E, the initial (before irradiation) sample temperature (°C) was 21.3. The sample temperature (°C) 5 minutes after the start of irradiation (5 minutes after the start of irradiation) was 49.3 (see Test Results TR6-2 in Figure 20 for a thermographic image). The sample temperature (°C) 10 minutes after the start of irradiation (10 minutes after the start of irradiation) was 52.9. The sample temperature (°C) 15 minutes after the start of irradiation (15 minutes after the start of irradiation) was 53.5. The sample temperature (°C) 20 minutes after the start of irradiation (20 minutes after the start of irradiation) was 53.7. The sample temperature (°C) 25 minutes after the start of irradiation (25 minutes after the start of irradiation) was 53.7. The sample temperature (°C) 30 minutes after the start of irradiation (30 minutes after the start of irradiation) was 54.2 (see Test Results TR6-2 in Figure 20 for a thermographic image). The temperature (°C) of the sample 35 minutes after the start (5 minutes after lights off) was 27.6. The temperature (°C) of the sample 40 minutes after the start (10 minutes after lights off) was 23.3. The temperature (°C) of the sample 45 minutes after the start (15 minutes after lights off) was 22.4. The temperature (°C) of the sample 50 minutes after the start (20 minutes after lights off) was 22.1. The temperature (°C) of the sample 55 minutes after the start (25 minutes after lights off) was 22.1. The temperature (°C) of the sample 60 minutes after the start (30 minutes after lights off) was 22.1 (see test result TR6-2 in Figure 20 for the thermography image).

[0075] (6) For Powder F, the initial (before irradiation) sample temperature (°C) was 21.3. The sample temperature (°C) 5 minutes after the start of irradiation (5 minutes after the start of irradiation) was 49.4 (see Test Results TR6-2 in Figure 20 for thermography images). The sample temperature (°C) 10 minutes after the start of irradiation (10 minutes after the start of irradiation) was 52.7. The sample temperature (°C) 15 minutes after the start of irradiation (15 minutes after the start of irradiation) was 53.4. The sample temperature (°C) 20 minutes after the start of irradiation (20 minutes after the start of irradiation) was 53.2. The sample temperature (°C) 25 minutes after the start of irradiation (25 minutes after the start of irradiation) was 52.9. The sample temperature (°C) 30 minutes after the start of irradiation (30 minutes after the start of irradiation) was 53.7 (see Test Results TR6-2 in Figure 20 for thermography images). The temperature (°C) of the sample 35 minutes after the start (5 minutes after lights off) was 27.5. The temperature (°C) of the sample 40 minutes after the start (10 minutes after lights off) was 23.0. The temperature (°C) of the sample 45 minutes after the start (15 minutes after lights off) was 22.1. The temperature (°C) of the sample 50 minutes after the start (20 minutes after lights off) was 21.9. The temperature (°C) of the sample 55 minutes after the start (25 minutes after lights off) was 21.8. The temperature (°C) of the sample 60 minutes after the start (30 minutes after lights off) was 21.8 (see test result TR6-2 in Figure 20 for the thermography image).

[0076] (7) For Powder G, the initial (before irradiation) sample temperature (°C) was 21.3. The sample temperature (°C) 5 minutes after the start of irradiation (5 minutes after the start of irradiation) was 50.5 (see Test Results TR6-2 in Figure 20 for a thermographic image). The sample temperature (°C) 10 minutes after the start of irradiation (10 minutes after the start of irradiation) was 54.1. The sample temperature (°C) 15 minutes after the start of irradiation (15 minutes after the start of irradiation) was 54.3. The sample temperature (°C) 20 minutes after the start of irradiation (20 minutes after the start of irradiation) was 54.8. The sample temperature (°C) 25 minutes after the start of irradiation (25 minutes after the start of irradiation) was 55.1. The sample temperature (°C) 30 minutes after the start of irradiation (30 minutes after the start of irradiation) was 55.1 (see Test Results TR6-2 in Figure 20 for a thermographic image). The temperature (°C) of the sample 35 minutes after the start (5 minutes after lights off) was 27.5. The temperature (°C) of the sample 40 minutes after the start (10 minutes after lights off) was 23.1. The temperature (°C) of the sample 45 minutes after the start (15 minutes after lights off) was 22.3. The temperature (°C) of the sample 50 minutes after the start (20 minutes after lights off) was 22.1. The temperature (°C) of the sample 55 minutes after the start (25 minutes after lights off) was 21.8. The temperature (°C) of the sample 60 minutes after the start (30 minutes after lights off) was 21.8 (see test result TR6-2 in Figure 20 for the thermography image).

[0077] (8) For Powder H, the initial (before irradiation) sample temperature (°C) was 21.3. The sample temperature (°C) 5 minutes after the start of irradiation (5 minutes after the start of irradiation) was 52.2 (see Test Results TR6-2 in Figure 20 for a thermographic image). The sample temperature (°C) 10 minutes after the start of irradiation (10 minutes after the start of irradiation) was 55.9. The sample temperature (°C) 15 minutes after the start of irradiation (15 minutes after the start of irradiation) was 56.4. The sample temperature (°C) 20 minutes after the start of irradiation (20 minutes after the start of irradiation) was 56.5. The sample temperature (°C) 25 minutes after the start of irradiation (25 minutes after the start of irradiation) was 56.5. The sample temperature (°C) 30 minutes after the start of irradiation (30 minutes after the start of irradiation) was 56.7 (see Test Results TR6-2 in Figure 20 for a thermographic image). The temperature (°C) of the sample 35 minutes after the start (5 minutes after lights off) was 27.8. The temperature (°C) of the sample 40 minutes after the start (10 minutes after lights off) was 23.3. The temperature (°C) of the sample 45 minutes after the start (15 minutes after lights off) was 22.4. The temperature (°C) of the sample 50 minutes after the start (20 minutes after lights off) was 22.1. The temperature (°C) of the sample 55 minutes after the start (25 minutes after lights off) was 21.9. The temperature (°C) of the sample 60 minutes after the start (30 minutes after lights off) was 21.9 (see test result TR6-2 in Figure 20 for the thermography image).

[0078] As shown in Test Items / Results TC4-2 in Figure 18, for (9) Powder I, the initial (before irradiation) sample temperature (°C) was 21.4 (see Test Results TR6-3 in Figure 21 for a thermographic image). The sample temperature (°C) 5 minutes after the start (5 minutes after the start of irradiation) was 53.4. The sample temperature (°C) 10 minutes after the start (10 minutes after the start of irradiation) was 57.3. The sample temperature (°C) 15 minutes after the start (15 minutes after the start of irradiation) was 57.8. The sample temperature (°C) 20 minutes after the start (20 minutes after the start of irradiation) was 58.0. The sample temperature (°C) 25 minutes after the start (25 minutes after the start of irradiation) was 58.0. The sample temperature (°C) 30 minutes after the start (30 minutes after the start of irradiation) was 58.3 (see Test Results TR6-3 in Figure 21 for a thermographic image). The temperature (°C) of the sample 35 minutes after the start (5 minutes after lights off) was 28.4. The temperature (°C) of the sample 40 minutes after the start (10 minutes after lights off) was 23.4. The temperature (°C) of the sample 45 minutes after the start (15 minutes after lights off) was 22.3. The temperature (°C) of the sample 50 minutes after the start (20 minutes after lights off) was 22.1. The temperature (°C) of the sample 55 minutes after the start (25 minutes after lights off) was 22.0. The temperature (°C) of the sample 60 minutes after the start (30 minutes after lights off) was 22.0 (see test result TR6-3 in Figure 21 for the thermography image).

[0079] (10) For Powder J, the initial (before irradiation) sample temperature (°C) was 21.2 (see Test Results TR6-3 in Figure 21 for thermography images). The sample temperature (°C) 5 minutes after the start (5 minutes after the start of irradiation) was 53.5. The sample temperature (°C) 10 minutes after the start (10 minutes after the start of irradiation) was 57.4. The sample temperature (°C) 15 minutes after the start (15 minutes after the start of irradiation) was 58.4. The sample temperature (°C) 20 minutes after the start (20 minutes after the start of irradiation) was 58.4. The sample temperature (°C) 25 minutes after the start (25 minutes after the start of irradiation) was 58.6. The sample temperature (°C) 30 minutes after the start (30 minutes after the start of irradiation) was 58.6 (see Test Results TR6-3 in Figure 21 for thermography images). The temperature (°C) of the sample 35 minutes after the start (5 minutes after lights off) was 28.2. The temperature (°C) of the sample 40 minutes after the start (10 minutes after lights off) was 23.3. The temperature (°C) of the sample 45 minutes after the start (15 minutes after lights off) was 22.3. The temperature (°C) of the sample 50 minutes after the start (20 minutes after lights off) was 21.9. The temperature (°C) of the sample 55 minutes after the start (25 minutes after lights off) was 21.9. The temperature (°C) of the sample 60 minutes after the start (30 minutes after lights off) was 21.9 (see test result TR6-3 in Figure 21 for the thermography image).

[0080] (11) For Powder X, the initial (before irradiation) sample temperature (°C) was 21.5. The sample temperature (°C) 5 minutes after the start of irradiation (5 minutes after the start of irradiation) was 55.8 (see Test Results TR6-3 in Figure 21 for a thermographic image). The sample temperature (°C) 10 minutes after the start of irradiation (10 minutes after the start of irradiation) was 59.0. The sample temperature (°C) 15 minutes after the start of irradiation (15 minutes after the start of irradiation) was 59.5. The sample temperature (°C) 20 minutes after the start of irradiation (20 minutes after the start of irradiation) was 59.5. The sample temperature (°C) 25 minutes after the start of irradiation (25 minutes after the start of irradiation) was 59.3. The sample temperature (°C) 30 minutes after the start of irradiation (30 minutes after the start of irradiation) was 59.3 (see Test Results TR6-3 in Figure 21 for a thermographic image). The temperature (°C) of the sample 35 minutes after the start (5 minutes after lights off) was 28.1. The temperature (°C) of the sample 40 minutes after the start (10 minutes after lights off) was 23.3. The temperature (°C) of the sample 45 minutes after the start (15 minutes after lights off) was 22.2. The temperature (°C) of the sample 50 minutes after the start (20 minutes after lights off) was 21.8. The temperature (°C) of the sample 55 minutes after the start (25 minutes after lights off) was 21.7. The temperature (°C) of the sample 60 minutes after the start (30 minutes after lights off) was 21.8 (see test result TR6-3 in Figure 21 for the thermography image).

[0081] (12) For Powder Y, the initial (before irradiation) sample temperature (°C) was 21.6 (see Test Results TR6-3 in Figure 21 for thermography images). The sample temperature (°C) 5 minutes after the start (5 minutes after the start of irradiation) was 36.3. The sample temperature (°C) 10 minutes after the start (10 minutes after the start of irradiation) was 38.8. The sample temperature (°C) 15 minutes after the start (15 minutes after the start of irradiation) was 39.2. The sample temperature (°C) 20 minutes after the start (20 minutes after the start of irradiation) was 39.1. The sample temperature (°C) 25 minutes after the start (25 minutes after the start of irradiation) was 39.3. The sample temperature (°C) 30 minutes after the start (30 minutes after the start of irradiation) was 39.4 (see Test Results TR6-3 in Figure 21 for thermography images). The temperature (°C) of the sample 35 minutes after the start (5 minutes after lights off) was 25.3. The temperature (°C) of the sample 40 minutes after the start (10 minutes after lights off) was 22.5. The temperature (°C) of the sample 45 minutes after the start (15 minutes after lights off) was 21.8. The temperature (°C) of the sample 50 minutes after the start (20 minutes after lights off) was 21.6. The temperature (°C) of the sample 55 minutes after the start (25 minutes after lights off) was 21.6. The temperature (°C) of the sample 60 minutes after the start (30 minutes after lights off) was 21.5 (see test result TR6-3 in Figure 21 for the thermography image).

[0082] (13) For Powder Z, the initial (before irradiation) sample temperature (°C) was 21.3 (see Test Results TR6-4 in Figure 22 for thermography images). The sample temperature (°C) 5 minutes after the start (5 minutes after the start of irradiation) was 38.7. The sample temperature (°C) 10 minutes after the start (10 minutes after the start of irradiation) was 41.1. The sample temperature (°C) 15 minutes after the start (15 minutes after the start of irradiation) was 41.7. The sample temperature (°C) 20 minutes after the start (20 minutes after the start of irradiation) was 41.5. The sample temperature (°C) 25 minutes after the start (25 minutes after the start of irradiation) was 41.4. The sample temperature (°C) 30 minutes after the start (30 minutes after the start of irradiation) was 41.5 (see Test Results TR6-4 in Figure 22 for thermography images). The temperature (°C) of the sample 35 minutes after the start (5 minutes after lights off) was 25.6. The temperature (°C) of the sample 40 minutes after the start (10 minutes after lights off) was 22.7. The temperature (°C) of the sample 45 minutes after the start (15 minutes after lights off) was 21.9. The temperature (°C) of the sample 50 minutes after the start (20 minutes after lights off) was 21.8. The temperature (°C) of the sample 55 minutes after the start (25 minutes after lights off) was 21.7. The temperature (°C) of the sample 60 minutes after the start (30 minutes after lights off) was 21.7 (see test result TR6-4 in Figure 22 for the thermography image).

[0083] The temperature changes of the above (1) Powder A to (10) Powder J and (11) Powder X to (13) Powder Z correspond to (1) to (14) in FIG. 16, respectively.

[0084] That is, Powder A in Figure 17 (1) corresponds to Powder 3 in Figure 16 (3) (sample temperature (°C) 30 minutes after the start of irradiation was 44.4°C). Powder B in Figure 17 (2) corresponds to Powder 4 in Figure 16 (sample temperature (°C) 30 minutes after the start of irradiation was 47.6°C). Powder C in Figure 17 (3) corresponds to Powder 5 in Figure 16 (sample temperature (°C) 30 minutes after the start of irradiation was 49.4°C). Powder D in Figure 17 (4) corresponds to Powder 6 in Figure 16 (sample temperature (°C) 30 minutes after the start of irradiation was 51.8°C). Powder E in Figure 17 (5) corresponds to Powder 7 in Figure 16 (sample temperature (°C) 30 minutes after the start of irradiation was 54.2°C). Powder F in Figure 17 (6) corresponds to Powder 8 in Figure 16 (sample temperature (°C) 30 minutes after the start of irradiation was 53.7°C). Powder G in Figure 17 (7) corresponds to Powder G in Figure 16 (9) (sample temperature (°C) 30 minutes after the start of irradiation was 55.1°C). Powder H in Figure 17 (8) corresponds to Powder H in Figure 16 (10) (sample temperature (°C) 30 minutes after the start of irradiation was 56.7°C).

[0085] Powder I in Figure 18 (9) corresponds to Powder I in Figure 16 (11) (sample temperature (°C) 30 minutes after the start of irradiation was 58.3). Powder J in Figure 18 (10) corresponds to Powder J in Figure 16 (12) (sample temperature (°C) 30 minutes after the start of irradiation was 58.6). Powder X in Figure 18 (11) corresponds to Powder X in Figure 16 (13) (sample temperature (°C) 30 minutes after the start of irradiation was 59.3). Powder Y in Figure 18 (12) corresponds to Powder Y in Figure 16 (1) (sample temperature (°C) 30 minutes after the start of irradiation was 39.4). Powder Z in Figure 18 (13) corresponds to Powder Z in Figure 16 (2) (sample temperature (°C) 30 minutes after the start of irradiation was 41.5).

[0086] As can be seen from FIGS. 16 to 22, there is a strong correlation between the blending ratio of ferrous oxide (FeO) and temperature, and it was found that a high far-infrared heat generating effect can be obtained even when ferrous oxide (FeO) is blended at only 1%.

[0087] 23 is a graph showing an example of the test results when a light absorption exothermic reaction test was conducted on 16 types of compounded reagents (iron oxide, etc.). Note that the light absorption exothermic reaction test was the same as that described above, so a description of the test conditions, etc. will be omitted here.

[0088] In FIG. 23, (1) is a graph showing the temperature change of a prepared reagent containing 1% iron oxide (ferrous oxide (FeO)). (2) is a graph showing the temperature change of a prepared reagent containing 2% iron oxide (ferrous oxide (FeO)). (3) is a graph showing the temperature change of a prepared reagent containing 3% iron oxide (ferrous oxide (FeO)). (4) is a graph showing the temperature change of a prepared reagent containing 6% iron oxide (ferrous oxide (FeO)). (5) is a graph showing the temperature change of a prepared reagent containing 8% iron oxide (ferrous oxide (FeO)). (6) is a graph showing the temperature change of a prepared reagent containing 10% iron oxide (ferrous oxide (FeO)). (7) is a graph showing the temperature change of a prepared reagent containing 11% iron oxide (ferrous oxide (FeO)). (8) is a graph showing the temperature change of a compounded reagent containing 13% iron oxide (ferrous oxide (FeO)). (9) is a graph showing the temperature change of a compounded reagent containing 14% iron oxide (ferrous oxide (FeO)). (10) is a graph showing the temperature change of a compounded reagent containing 17% iron oxide (ferrous oxide (FeO)). (11) is a graph showing the temperature change of a compounded reagent containing 20% ​​iron oxide (ferrous oxide (FeO)). (12) is a graph showing the temperature change of a compounded reagent containing 25% iron oxide (ferrous oxide (FeO)). (13) is a graph showing the temperature change of a compounded reagent containing 50% iron oxide (ferrous oxide (FeO)). (14) is a graph showing the temperature change of a compounded reagent containing 100% iron oxide (ferrous oxide (FeO)). (15) is a graph showing the temperature change of a compounded reagent containing 100% silicon dioxide (SiO2) instead of iron oxide (ferrous oxide (FeO)). (16) is a graph showing the temperature change of a compounded reagent containing 100% aluminum oxide (Al2O3) instead of iron oxide (ferrous oxide (FeO)).

[0089] As described above with reference to FIGS. 1 to 23 , when comparing ferrous oxide (FeO) and ferric oxide (FeO), ferrous oxide (FeO) exhibits higher far-infrared heat generation, so it is preferable to use a higher blending ratio of ferrous oxide (FeO) than ferric oxide (FeO). For example, a large amount of ferric oxide (FeO) can cause concerns about rusting, weight gain, and strength loss, so a higher blending ratio of ferrous oxide (FeO) is preferable. The blending ratio of ferrous oxide (FeO) with respect to powder P is preferably 1% to 20% by weight (preferably 5% to 20%). To achieve a far-infrared heat generation effect comparable to that of Mount Fuji lava, a blending ratio of 11% to 20% by weight with respect to powder P is preferable. While the above test results indicate that effects can be achieved even at a blending ratio greater than 20% but less than 50%, the blending ratio is set to 20% or less in consideration of factors such as rusting and weight gain. As described above, ferrous oxide (FeO) has a strong correlation between its blending ratio and temperature, and therefore can provide a sufficient heat generation effect. In other words, by adjusting the blending ratio of ferrous oxide (FeO), it is possible to control the temperature of, for example, underwear, bedding, rugs, shoes, etc., depending on the purpose and environment of use.

[0090] In addition to iron oxide, the powder P preferably contains silicon dioxide and aluminum oxide. The ceramic components, such as silicon dioxide and aluminum oxide, are appropriately blended together to conduct the heat absorbed and generated by the iron oxide throughout the fibers F. Silicon dioxide contributes to enhancing the moisture absorption and heat generation properties of the fibers F. Based on the results of Figures 5 to 10, the silicon dioxide blending ratio is preferably 40% to 50%. Based on the results of Figures 16 to 22, the silicon dioxide blending ratio is preferably 40% to 70%. Therefore, although the silicon dioxide blending ratio depends on the iron oxide blending ratio, a blending ratio of 40% or more is preferred.

[0091] Powder P containing iron oxide at a blending ratio within a predetermined range is used, and the resulting fiber F obtained by kneading this powder P into material M can warm up much faster than conventional products. For example, underwear (powder-kneaded rayon blended underwear (belly warmer, etc.)) shown in Figure 9, which uses such fiber F, can obtain advantages from two effects: the far-infrared heat generating effect of the iron oxide contained in the powder P, and the enhanced moisture-absorbing heat generating effect of the silicon dioxide also contained in the powder P.

[0092] Below, we will explain the powder-infused rayon blended underwear (belly warmer) shown in Figure 9, although not specifically illustrated. This belly warmer is an ultra-thin belly warmer, only 1 mm thick. Warmth is ensured even at this thickness thanks to the use of fiber F, which contains approximately 10 g of powder P and 100 g of rayon batting. The fiber F is spun into yarn, and this yarn is then knitted with, for example, a cotton-blend silk yarn into a gauze-like knit fabric. Two layers of this knitted fabric are layered and knitted together with stretch yarn, creating an uneven air layer. The uneven air layer is formed by terry knitting on the skin side. By constructing this air layer so that warm air generated by the fiber F is trapped in it, a belly warmer that can ensure warmth despite its thinness can be provided. A shorts section can be integrated into the underside of this belly warmer, continuing from the bottom. A belly warmer / shorts combination can provide a garment that wraps from the stomach to the base of the thighs. Since veins and lymph nodes are located at the base of the thighs, covering and warming this area can further stimulate blood flow. Examples of wearable items (items worn on the human body) other than the above-mentioned belly warmer and belly warmer / shorts combination include socks, leg warmers, spats, and inner shirts, and these may also be provided.

[0093] In this embodiment, the powder P is kneaded into the fibers F, but the powder P may be attached to the surface of the material M. For example, a manufacturing device may be used that attaches about 10 g of powder P to 100 g of rayon cotton.

[0094] In summary, the fibers, fabrics, worn articles, and fiber manufacturing methods to which the present invention is applicable each need only have the following configurations, and can take on a variety of different embodiments. That is, the fibers to which the present invention is applicable (e.g., fiber F in FIG. 1) are sufficient as long as they are obtained by kneading a powder (e.g., powder P in FIG. 1) containing iron oxide (e.g., iron oxides shown in FIGS. 10, 16, 23, etc.) at a blending ratio within a predetermined range (e.g., a blending ratio of 1% to 20% by weight of powder P) into a fiber material (e.g., material M in FIG. 1 or the material (raw material) of the moisture-absorbing and heat-generating fiber described above). Such fibers can shorten the time it takes to warm up.

[0095] Furthermore, in the above-mentioned fiber (e.g., fiber F in FIG. 1), the predetermined range for the blending ratio of the iron oxide (e.g., iron oxides shown in FIGS. 10, 16, 23, etc.) can be set to a range in which the weight ratio of the powder (e.g., powder P in FIG. 1) is 1% or more and 20% or less.

[0096] Furthermore, in the above-mentioned fiber (for example, fiber F in FIG. 1 ), the particle size of the powder (for example, powder P in FIG. 1 ) can be set to 0.1 μm or more and less than 1 μm, and the blending ratio of the powder to the material can be set to less than 10% by weight of the material.

[0097] Furthermore, in the above-described fiber (for example, fiber F in FIG. 1 ), the iron oxide (for example, iron oxides shown in FIGS. 10 , 16 , 23 , etc.) may contain at least ferrous oxide (for example, ferrous oxide (FeO) shown in FIGS. 12 to 15 , 23 , etc.).

[0098] Furthermore, in the above-described fiber (for example, fiber F in FIG. 1), the iron oxide (for example, the iron oxide shown in FIG. 10, FIG. 16, FIG. 23, etc.) may contain ferric oxide (for example, ferric oxide (Fe2O3) shown in FIG. 12 to FIG. 15, etc.) and ferrous oxide (for example, ferrous oxide (FeO) shown in FIG. 12 to FIG. 15, FIG. 23, etc.) having a higher blending ratio than the ferric oxide.

[0099] In addition, in the above-mentioned fiber (for example, fiber F in FIG. 1), the powder (for example, powder P in FIG. 1) may be obtained from basalt (for example, basalt including the above-mentioned Mount Fuji lava).

[0100] Furthermore, in the above-mentioned fiber (for example, fiber F in FIG. 1), the powder (for example, powder P in FIG. 1) may further contain silicon dioxide (for example, silicon dioxide (SiO2) shown in FIGS. 12 to 15, 23, etc.).

[0101] The fabric to which the present invention is applicable (e.g., the gauze-like knit fabric used in the manufacture of the above-mentioned belly warmer) is sufficient as long as it is composed of a fiber (e.g., fiber F in FIG. 1) obtained by kneading a powder (e.g., powder P in FIG. 1) containing iron oxide (e.g., the iron oxides shown in FIGS. 10, 16, 23, etc.) at a blending ratio within a predetermined range (e.g., a blending ratio of 1% to 20% by weight of powder P) into a fiber material (e.g., material M in FIG. 1 or the material (raw material) of the above-mentioned moisture-absorbing and heat-generating fiber), and another fiber different from the powder (e.g., fiber F in FIG. 1). Such a fabric can shorten the time it takes to warm up.

[0102] The wearable article to which the present invention is applicable (for example, the belly warmer described above) is sufficient as long as it is made of the above-mentioned fabric (for example, the gauze-like knit fabric used in the manufacture of the belly warmer described above) and worn on a human body (for example, the above-mentioned 32-year-old female subject, 153 cm tall and weighing 49 kg). Such a wearable article can shorten the time it takes to warm up.

[0103] The method for producing a fiber (e.g., fiber F in FIG. 1 ) to which the present invention is applicable is sufficient as long as it includes a step (e.g., the seventh step described above) of producing a fiber (e.g., fiber F in FIG. 1 ) by kneading a powder (e.g., powder P in FIG. 1 ) containing iron oxide (e.g., iron oxides shown in FIGS. 10 , 16 , 23 , etc.) at a blending ratio within a predetermined range (e.g., a blending ratio of 1% to 20% by weight of powder P) into a fiber material (e.g., material M in FIG. 1 or the material (raw material) of the moisture-absorbing and heat-generating fiber described above). Such a manufacturing method can produce a fiber that shortens the warm-up time.

[0104] F: Fiber M: Material P: Powder

Claims

1. A fiber obtained by kneading a powder containing iron oxide at a blending ratio within a predetermined range into a fiber material.

2. The fiber according to claim 1, wherein the predetermined range for the blending ratio of the iron oxide is in the range of 1% or more and 20% or less by weight ratio of the powder.

3. The fiber according to claim 1, wherein the particle size of the powder is 0.1 μm or more and less than 1 μm, and the blending ratio of the powder with respect to the material is less than 10% by weight of the material.

4. The fiber according to claim 1, wherein the iron oxide contains at least ferrous oxide.

5. The fiber according to claim 1, wherein the iron oxide contains ferric oxide and ferrous oxide having a higher blending ratio than the ferric oxide.

6. The fiber according to claim 1, wherein the powder is obtained from basalt.

7. The fiber according to claim 1, wherein the powder further contains silicon dioxide.

8. A fabric composed of a fiber obtained by kneading a powder containing iron oxide at a blending ratio within a predetermined range into a fiber material, and a different fiber different from the fiber.

9. An article of clothing worn on a human body using the fabric according to claim 8.

10. A method for manufacturing a fiber, comprising the step of manufacturing a fiber by kneading a powder containing iron oxide at a blending ratio within a predetermined range into a fiber material.

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