Socks and stockings comprising fiber containing metal

Abstract: This invention relates to socks and stockings comprising the fiber containing metal which comprises fiber materials mixed-spun with at least 2% polyurethane elastic fiber to which at least one of metal oxides selected from alumina, silica, and titania, as well as platinum are mixed as essential components, wherein, because metal oxides are mixed in the polyurethane elastic fiber with expandability, electromagnetic radiation (far infrared radiation) liberated from the metal oxides are emitted nearly in close contact with the human body, permitting electromagnetic radiation (far infrared radiation) to work effectively on the contact feeling at the wearing portion as well as when the socks and stockings are put on and thermal conductivity while they are worn, and enabling manifestation of an extremely excellent heat-retaining effect.

Description: This invention relates to socks and stockings comprising fibre containing metal and the object of the present invention is to provide socks and stockings comprising fibre containing metal which not only provide agreeable wear comfort while they are worn but which also emit electromagnetic radiation liberated from the metal oxides close to the body of wearer to work effectively on contact feeling when they are put on and providing good thermal conductivity while they are worn, resulting in an extremely good heat-retaining effect. In general, for fibre materials forming socks and stockings, cotton, nylon, polyester, acrylic, and urethane fibre are well-known, and these fibre materials are properly selected according to the season, such as for summer or for winter and mixed-spun at an optional ratio to form socks and stockings. For example, socks and stockings for summer are formed with fibre materials primarily comprising cotton in view of permeability and absorbency, while for winter socks and stockings, in addition to said fibre materials, wool is frequently mixed to improve heat-retaining properties. Recently, in anticipation of heat-retaining property of far infrared radiation, socks and stockings using fibre mixed with far infrared irradiating ceramics as a component material have been known. These socks and stockings use fibre having far infrared irradiating materials like alumina, zirconia, or magnesia contained in polyethylene- and polyamide-based fibre materials which show high permeability to far infrared radiation. The fibre material containing this far infrared irradiating material is further covered with a protection layer as part of the component fibre, formed in anticipation of the heat-retaining effect on wearing. Socks and stocking are also disclosed in JP-A-63 112 701 (Derwent Publications WPI Database, Week 8825, AN 88-173138) which include polyurethane fibres containing metal. It is difficult for socks and stockings mixed-spun with wool to give sufficient heat-retaining effect at the soles of the wearer's feet. Mixed-spinning wool at high ratio to increase the heat-retaining effect causes bulkiness of the socks and stockings themselves, so that the socks and stockings are not comfortable to wear. On the other hand, socks and stockings mixed with far infrared irradiating ceramics can eliminate the bulkiness as compared with socks and stockings mixed-spun with wool but they have a problem that the intended effect is difficult to achieve unless a large area of the socks and stockings is covered with the fibre material containing far infrared irradiating substance. In addition, such socks and stockings have another problem in that a covering layer is provided to protect the far infrared irradiating layer. This covering layer absorbs far infrared radiation. As a result, the far infrared radiation emitted from the ceramics is unable to be effectively used. Consequently, these socks and stockings have a problem that the effect of the far infrared radiation is unable to work most effectively to give on contact feeling when the socks and stockings are put on, on thermal conductivity while they are worn, and on skin temperature after they are worn, so that the excellent heat-retaining effects cannot be achieved. It would be desirable to produce socks and stockings which give a good contact feeling when they are put on, good thermal conductivity while they are worn, and comfortable wearing temperature, with an excellent heat retaining property. According to the invention, the socks or stockings comprise fibre materials mixed with metal, characterised in that the fibre materials are mixed-spun with at least 2% polyurethane elastic fibre, to which platinum and at least one metal oxide selected from alumina, silica and titania are mixed. The construction of socks and stockings comprising fibre containing metal relating to the present invention will be described in detail hereinafter. In this invention, the fibre material mixed-spun with at least 2% polyurethane elastic fibre mixed with at least one metal oxide selected from alumina (Al₂O₃), silica (SiO₂), and titania (TiO₂) as well as platinum (Pt) as essential components will be referred to as component fibre. The alumina (Al₂O₃), silica (SiO₂), and titania (TiO₂) used in the present invention are preferably in the powder form with a grain size of 1µ or smaller. However there is no restriction to this form. The platinum (Pt) preferably has a grain size as fine as 7-40Å and is in a colloidal form. This is based on the experimental knowledge of the inventor that the use of colloidal-form platinum can yield satisfactory heat-retaining properties. The mix ratio of these metal oxides and platinum is about 9-45% alumina (Al₂O₃), 50-80% silica (SiO₂), 8-15% each titania (TiO₂) and/or platinum (Pt), but there is no restriction. To these metal oxides, oxides of calcium, zinc, and copper may be mixed to about 2-10%. From the metal oxides above, electromagnetic radiation (far infrared radiation) with a 5-12 micron wavelength range to be effective for human bodies are stably and sufficiently emitted even at a temperature of around 30°C, as will be clear from the following tests. The invention is not restricted to any particular polyurethane elastic fibre, but SPANDEX (SPANDEX is a Registered Trade Mark) which comprises a noncrystalline component including either polyester or polyether portions and a crystalline component with urethane bonds and is popularly used in regular textile products is preferably used. The invention is not restricted to any particular method of mixing metal oxides and platinum to polyurethane elastic fibre. Any conventional method can be adopted as required, such as the mixing of the polymerized fibre material dispersedly in the solution before dry spinning or mixing into the dry-spun yarns. No particular blending ratio of metal oxides to polyurethane elastic fibre is specified, but any blending ratio can be adopted if it results in emission of electromagnetic radiation (far infrared radiation) with a wavelength range of about 5-12 microns which is effective for human bodies at the temperature around 30°C. The blending ratio should also successfully produce a good feeling in contact with the skin and good thermal conductivity during wearing. Furthermore a satisfactory heat-retaining effect should be exhibited and the blending ratio should be within the range that enables spinning to be carried out and that does not impair wear comfort as component fibre material of socks and stockings. Furthermore, in the present invention, the reason why polyurethane elastic fibre is particularly used is that mixed-spinning polyurethane elastic fibre with generous expandability results in improved wear comfort of socks and stockings and at the same time mixing the above-mentioned metal oxides and platinum to this polyurethane elastic fibre enables emission of electromagnetic radiation (far infrared radiation) from the metal oxides into the body with the socks and stockings closely in contact with the body of the wearer. It also makes the best use of the effect of emitted electromagnetic radiation (far infrared radiation), and allows the electromagnetic radiation (far infrared radiation) to work effectively to produce a good feeling in contact with the skin when the socks and stockings are put on. It results in an appropriate level of thermal conductivity, whereby temperature in the body increases after the socks and stockings are worn and the blood flow rate at the wearing portion is easy to increase, as a result, a superior heat-retaining effect can be manifested. Polyurethane elastic fibre mixed with at least one of the metal oxides selected from the above-mentioned alumina (Al₂O₃), silica (SiO₂), and titania (TiO₂) as well as platinum (Pt) as essential components is mixed-spun with other regular fibre materials into socks and stockings through a conventional method. In this event, polyurethane elastic fibre must be mixed-spun with metal oxides by at least 2%. When the mixed-spinning ratio of polyurethane elastic fibre containing metal oxides is less than 2%, emission of electromagnetic radiation from metal oxides using expandability of the above-mentioned polyurethane elastic fibre does not take place effectively and the superior heat-retaining property is not manifested. Other fibre materials which may be mixed-spun with polyurethane elastic fibre are ordinary natural and artificial fibre materials such as cotton, hemp, wool, acrylic, polyester and nylon, and these fibre materials may be optimally mixed-spun to make socks and stockings at an optional ratio, and are not particularly specified. The socks and stockings of the present invention are characterized in that bulkiness of the socks and stockings themselves hardly exists and agreeable wear comfort is ensured when the socks and stockings are put on. At the same time because electromagnetic radiation (far infrared radiation) by metal oxides is emitted in close contact with the wearer by making use of expandability of polyurethane elastic fibre, electromagnetic radiation (far infrared radiation) is permitted to work effectively on contact during wearing as well as when the socks and stockings are put on and on thermal conductivity while they are worn, enabling manifestation of an extremely excellent heat retaining effect, as will be clear from the results of the following tests. The invention will now be further described, by way of example, with reference to the accompanying drawings, in which: Figure 1 is a spectral emissivity chart for the fibre obtained in Example 2; Figure 2 is a spectral emissivity chart for the fibre obtained in Example 3; Figure 3 is a spectral emissivity chart for the fibre obtained in Example 4; Figure 4 is a spectral emissivity chart for the fibre obtained in Example 5; and Figure 5 is a spectral emissivity chart for the fibre obtained in Example 6. Examples The effects of socks and stockings comprising fibre containing metal relating to the present invention will become more apparent from the following examples. Example 1 6.4% polyurethane elastic fibre mixed with metal oxides comprising alumina (Al₂O₃), silica (SiO₂), titania (TiO₂), and platinum (Pt) in the ratio 10:82:3:5 was mixed-spun with 56% cotton, 24.1% acrylic, and 13.5% nylon, and made into ladies' socks by a conventional method. Comparison 1 Ladies' socks were made in the same manner as in Example 1, but using polyurethane elastic fibre not mixed with metal oxides Comparison 2 1.7% polyurethane elastic fibre mixed with metal oxides comprising alumina (Al₂O₃), silica (SiO₂), titania (TiO₂), and platinum (Pt) in the ratio 10:82:3:5 was mixed-spun with 64.7% cotton, 27.6% acrylic, and 5.2% nylon, and made into men's socks by a conventional method. Comparison 3 Men's socks were made in the same manner as in Comparison 2 but using polyurethane elastic fibre not mixed with metal oxides. Test 1 The ladies' and men's socks obtained in Example 1 and in Comparisons 1 to 3 were measured for various properties including density (g/m²), thickness (cm), contact feeling (Q max), steady thermal conductivity (W/cm °C x 10⁻⁴), and heat-retaining ratio (%) with THERMOLABO 2-KES7 (KATOHTEC: heat property measuring equipment). Table 1 shows the results. [A] [B] [C] [D] [E] EXAMPLE 1 286 0.102 0.083 3.525 42.3 COMPARISON 1 287 0.111 0.089 4.719 35.2 COMPARISON 2 438 0.221 0.064 8.495 39.7 COMPARISON 3 438 0.236 0.068 8.873 45.4 [A] DENSITY (g/m2) [B] THICKNESS (cm) [C] CONTACT FEELING (Q max) [D] STEADY THERMAL CONDUCTIVITY (W/cm°C x 10⁻⁴) [E] HEAT-RETAINING RATIO (%) Test 2 Using the ladies' and men's socks obtained in Example 1 and in Comparisons 1, 2 and 3, tests were carried out on the living body. First of all, the skin temperature of the right and left soles of a paneler were measured before putting on socks, after adjusting the skin temperature of the left and right soles on the living body for a specified period to harmonize the skin temperature of the right and left soles. After the measurement, the sock of Example 1 was put on the left foot, the sock of Comparison 1 was put on the right foot, and skin temperature (average, maximum) of the soles were measured in after putting on and retaining heat for 900 seconds. Then, the right and left socks were taken off, the skin temperature (average, maximum) of the right and left soles were measured immediately after and about 61 seconds after the socks was taken off. The overall temperature variation in skin temperature at the right and left soles while wearing the socks was calculated. Next, using the same paneler, the skin temperature of the right and left soles was adjusted on the living body for a specified period in the same manner, then the sock of Comparison 2 was put on the left foot, the sock of Comparison 3 was put on the right foot, and skin temperature (average, maximum) of the soles and the overall temperature variation in skin temperature were measured in the same manner. The measured skin temperatures in this test were calculated from average and maximum values of the picture analysis temperature distribution of a specific region of the thermogram obtained from thermoanalysis by thermograph (NEC San-Ei 6T/62 type (HgCdTe sensor, 8-13 µm): infrared radiation thermometer - 50- 2000°C). Table 2 shows the results. [A] [B] [C] [D] [E] EXAMPLE 1 29.3 29.1 31.1 (1.0) 31.1 1.8 ↑ 31.5 31.5 33.8 (2.3) 33.8 2.3 ↑ COMPARISON 1 31.2 30.2 32.8 (0.5) 32.8 1.6 ↑ 33.5 32.3 34.7 (1.2) 34.7 1.2 ↑ COMPARISON 2 32.6 32.1 33.1 (0.5) 32.8 0.2 ↑ 34.3 34.0 35.2 (0.9) 34.6 0.3 ↑ COMPARISON 3 31.6 32.0 32.6 (1.0) 32.6 1.0 ↑ 33.7 34.0 34.2 (0.5) 34.2 0.5 ↑ [A] ... BEFORE PUTTING ON [B] ... WEARING AND HEAT-RETAINING / HEAT-RETAINING FOR 900 SEC. [C] ... RIGHT AFTER TAKING OFF [D] ... RADIATION OF HEAT / RADIATION FOR 66 SEC. [E] ... OVERALL TEMPERATURE VARIATION THE UPPER ROW : AVERAGE TEMPERATURE (°C) THE LOWER ROW : MAXIMUM TEMPERATURE (°C) ( ) indicates temperature of heat-retaining effect. Test 3 The ladies' socks of Example 1 and Comparison 1 were respectively worn by the same paneler on the hand, and the blood flow rate (ml/min/100g) was measured by the laser Doppler method (Journal of the Laser Medical Society of Japan Vol. 12, No. 1, 7. 1988) using the laser Doppler rheometer (ADVANST: ALF-21) in both cases of retaining heat and heating by irradiation from a lamp. Table 3 shows the results. BLOOD FLOW OF FINGER (ml/min/100g) EXAMPLE 1 23.5 24.0 COMPARISON 1 22.0 24.0 It is clear from TABLE 1 that, using a mixed-spinning ratio of polyurethane elastic fibre of 6.4%, comparing ladies' socks mixed with metal oxide (Example 1) with those not mixed with metal oxide (Comparison 1) shows that the density and thickness are small, however small contact feeling results in small coldness when they are put on and small steady thermal conductivity results in small temperature variation due to the coldness of open-air, proving a high heat-retaining ratio. When the polyurethane elastic fibre is mixed-spun as low as 1.7% (Comparison 2), the effect is similar to that using polyurethane elastic fibre not containing metal oxides (Comparison 3), showing that heat-retaining effect is not sufficiently manifested. It can be seen form TABLE 2 that in the case of a mixed-spinning ratio of polyurethane elastic fibre of 6.4%, in the balance of heat-retaining and heat-radiation after putting on the socks, the socks containing metal oxides (Example 1) provided overall temperature variation differences 0.2°C higher on average and 1.1°C higher on maximum than those of socks not containing metal oxides (Comparison 1), showing higher heat-retaining effect. On the other hand, when the mixed-spinning ratio of polyurethane elastic fibre is low (Comparisons 2 and 3), heat-retaining effect by wearing socks is not manifested. TABLE 3 shows that the socks of Example 1 tend to increase the blood flow rate by heat-retaining as compared to the socks of Comparison 1. Example 2 15% polyurethane elastic fibre containing metal oxides comprising alumina (Al₂O₃), silica (SiO₂), titania (TiO₂), and platinum (Pt) in the ratio 10:82:3:5 is mixed-spun with 85% cotton to make fibre. Example 3 18% polyurethane elastic fibre the same as Example 2 are mixed-spun with 82% cotton to make fibre. Example 4 28% polyurethane elastic fibre the same as Example 2 are mixed-spun with 72% cotton into fibre. Example 5 50% polyurethane elastic fibre the same as Example 2 are mixed-spun with 50% staple fibre to make fibre. Example 6 17% polyurethane elastic fibre the same as Example 2 are mixed-spun with 83% nylon to make fibre. Test 4 For the fibre obtained by Examples 2 through 6, spectral emissivity was measured. Measuring conditions are the wavelength range: 4.5-20.0 µm; resolution: 16cm⁻¹; detector: wide-range MCT; measuring temperature: 33°C for surface temperature of texture; measuring position and time: four times in total, each once at two different positions and twice at the same position. Figures 1 through 5 show the obtained relevant spectral emissivity. It can be seen from the obtained spectral emissivity that in the fibre obtained in Examples 2 through 6, electromagnetic radiation (far infrared radiation) with wavelengths about 5-12 microns to be effective for human bodies is emitted even at the comparatively low temperature of 33°C.

Claims: Socks or stockings comprising fibre materials mixed with metal, characterised in that the fibre materials are mixed-spun with at least 2% polyurethane elastic fibre, to which platinum and at least one metal oxide selected from alumina, silica and titania are mixed.

Inventors: MAGATA KATSUMI, MAGATA, KATSUMI, MAGATA, KATSUMI, C/O SWANEE CO LTD.
Applicants: SWANEE CO LTD
Application year: 1993
Main classification: A41B11
IPC codes: A41B11, A61N5, A41B17, D01F6, D01F1