Underwear comprising fiber containing metal

Abstract: This invention relates to underwear comprising the fiber containing metal, which comprises fiber materials mixed-spun with 2-50% 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, where in, 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 underwear is put on and thermal conductivity while it is worn, and enabling manifestation of an extremely excellent heat-retaining effect.

Description: This invention relates to underwear comprising fibre containing metal and the object of the present invention is to provide underwear comprising fibre containing metal which not only provides flexibility and excellent smooth touch when it is put on and agreeable wear comfort while it is worn but also manifests an extremely good heat-retaining effect. In general, for fibre materials forming men's underwear such as long-sleeved shirts, shirts with half-length sleeves, and drawers, and ladies' tee shirts, semi-long-sleeved shirts and panties, cotton, nylon, polyester, acrylic, and urethane fibre are popularly used, and these fibre materials are selected according to wearing seasons and are mixed-spun at an optimal ratio to form underwear. For example, underwear for summer is formed with fibre materials primarily comprising cotton in view of permeability and absorbency, while underwear for winter has, in addition to said fibre materials, wool frequently mixed-spun to improve the heat-retaining properties. Recently, in anticipation of heat-retaining property of far infrared radiation, underwear using fibre mixed with far infrared irradiating ceramics as a component material has become known. This underwear uses 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 materials containing this far infrared irradiating materials are further covered with a protection layer, as part of the component fibre, and are formed in anticipation of the heat-retaining effect on wearing. Underwear mixed-spun with wool gives sufficient heat-retaining effect if wool is mixed-spun at high ratio, but mixed-spinning wool at high ratio to increase the heat-retaining effect causes bulkiness of the underwear itself, generating a feeling that the underwear which is put directly on the skin does not fit well. This not only adversely affects wear comfort but also restricts movement of the wearer, producing a problem that the underwear can not be worn readily. On the other hand, underwear mixed with far infrared irradiating ceramics can eliminate the bulkiness as compared with underwear mixed-spun with wool but it has a problem that the intended effect is difficult to achieve unless a large area is covered with the fibre material containing the far infrared irradiating substance. In addition another problem is that in this underwear a covering layer is provided to protect the far infrared irradiating layer but this covering layer absorbs far infrared radiation, so that the far infrared radiation emitted from the ceramics is unable to be effectively used. Consequently, this underwear has a problem that the effect of the far infrared radiation is unable to work most effectively on the feeling of comfort when the underwear is put in contact with the skin, is unable to exhibit good thermal conductivity while it is worn, and skin temperature after it is worn, so that excellent heat-retaining effect cannot be expected. In JP-A-4 073 226 underwear is described which comprises fibres to which platinum and at least one of the metal oxides selected from alumina and silica are mixed. It is desirable to produce underwear which provides superb wear comfort to wearers, results in a good contact feeling when it is put on, good thermal conductivity while it is worn, is comfortable to wear, and manifests an excellent heat-retaining property. All of the above-mentioned desiderata can be met by underwear comprising fibre containing platinum and a metal oxide, characterised in that it comprises fibre materials mixed-spun with polyurethane elastic fibre in the range of 2-50%, to which platinum and at least one metal oxide selected from alumina, silica, titania are mixed. The construction of underwear comprising fibre containing metal relating to the present invention will be described in detail hereinafter. In this invention, the fibre material mixed-spun with 2-50% polyurethane elastic fibre mixed with at least one metal oxide selected from alumina (Al 2 O 3 ), silica (SiO 2 ), and titania (TiO 2 ) as well as platinum (Pt) as essential components is designated as component fibre. The alumina (Al 2 O 3 ), silica (SiO 2 ), or titania (TiO 2 ) used in the present invention is preferably in the powder form with grain size of 1µ or smaller, but there is no restriction. The platinum (Pt) preferably has a grain size as fine as 7-40Å and is preferably 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 preferably about 9-45% alumina (Al 2 O 3 ), 50-80% silica (SiO 2 ), 8-15% each titania (TiO 2 ) and/or platinum (Pt), but there is no restriction. To these metal oxides, oxides of calcium, zinc, and copper may be mixed by about 2-10%. The metal oxides comprised as above emit electromagnetic radiation (far infrared radiation) with a 5-12 micron wavelength range. This range is effective for human bodies and is stably and sufficiently emitted even at the temperature range of around 30°C , as clear from the following tests. Preferably the polyurethane elastic fibre used is SPANDEX (SPANDEX is a Registered Trade Mark) which comprises a noncrystalline segments including either polyester or polyether portions and crystalline segments with urethane bonds and is popularly used in regular textile products. However other polyurethane elastic fibre may alternatively be used. A method of mixing metal oxides and platinum to the polyurethane elastic fibre is not particularly specified but any of known method can be adopted as required, such as the method of mixing the polymerised fibre material solution dispersedly in the solution before dry spinning or mix into the dry-spun yarns. The blending ratio of metal oxides mixed in polyurethane elastic fibre is not particularly specified but any blending ratio can be used if it results in the emission of electromagnetic radiation (far infrared radiation) with a wavelength range of about 5-12 microns to be effective for human bodies at the temperature around 30°C, as well as successfully effecting contact feeling and thermal conductivity during wearing and manifesting satisfactory heat-retaining effect and is within the range that enables spinning and does not impair wear comfort as a component fibre material of underwear. 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 underwear 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 underwear closely in contact with the body of the wearer, 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 on the contact feeling when the underwear is put on. The thermal conductivity and thereby the temperature variation in the body increase after the underwear is worn, and the blood flow rate at the wearing portion is easy to increase, so that a superior heat-retaining effect can be manifested. The polyurethane elastic fibre mixed with at least one of metal oxides selected from the above-mentioned alumina (Al 2 O 3 ), silica (SiO 2 ), and titania (TiO 2 ) as well as platinum (Pt) as essential components is mixed-spun with other regular fibre materials into underwear through a conventional method. In this event, polyurethane elastic fibre must be mixed-spun with metal oxides in the range of 2-50%. If the mixed-spinning ratio of polyurethane elastic fibre containing metal oxides is less than 2%, emission of electromagnetic radiation from metal oxides using the expandability of the above-mentioned polyurethane elastic fibre does not take place effectively and the superior heat-retaining property is not manifested. If the ratio exceeds 50%, a disagreeable touch is provided for the wearer and certain people may develop allergic symptoms, indicating that either of the cases is not desirable. As other fibre materials to be mixed-spun with polyurethane elastic fibre, ordinary natural and artificial fibre materials such as cotton, hemp, wool, acrylic, polyester, and nylon are favourably used and these fibre materials may be optimally mixed-spun to make underwear at an optional ratio, and are not particularly specified. Regular men's underwear such as undershirts, athletic shirts, briefs, shorts, and drawers and regular ladies' underwear such as panties, tanks, panty hoses, semi-long sleeve and tee shirts are given as examples of underwear included in the present invention, but the invention is not limited to items in this list. The underwear comprising fibre containing metal, which is characterised in comprising fibre material mixed-spun with 2-50% polyurethane elastic fibre, to which at least one metal oxide selected from alumina, silica, and titania as well as platinum are mixed as essential components, has hardly any bulkiness and has agreeable wear comfort such as flexibility and expandability which is ensured when the underwear is put on. At the same time because electromagnetic radiation (far infrared radiation) by metal oxides is emitted nearly in close contact with the wearer by making use of expandability of polyurethane elastic fibre, as clear from the results of said tests, electromagnetic radiation (far infrared radiation) is permitted to work effectively on contact feeling of the wearing portion both when the underwear is put on and thermal conductivity while it is worn, enabling manifestation of an excellent heat-retaining effect. 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 properties of underwear comprising fibre containing metal according to the present invention will become more apparent from the following examples. Example 1 15% polyurethane elastic fibre mixed with metal oxides comprising alumina (Al 2 O 3 ), silica (SiO 2 ), titania (TiO 2 ), and platinum (Pt) in the ratio 10:82:3:5 was mixed-spun with 85% cotton and made into ladies' tee shirts by an ordinary method. Comparison 1 Ladies' tee shirts were made in the same manner as in Example 1 except using polyurethane elastic fibre not mixed with metal oxides. Comparison 2 1.7% polyurethane elastic fibre mixed with metal oxides comprising alumina (Al 2 O 3 ), silica (SiO 2 ), titania (TiO 2 ), and platinum (Pt) in the ratio 10:82:3:5 was mixed-spun with 98.3% cotton and made into ladies' tee shirts by an ordinary method. Comparison 3 Ladies' tee shirts were made in the same manner as in Comparison 2 except using polyurethane elastic fibre not mixed with metal oxides. Test 1 The ladies' underwear obtained in Example 1 and in Comparisons 1 through 3 were measured for various properties including density (g/m 2 ), 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] [D] EXAMPLE 1 154 0.065 0.091 4.906 28.6 COMPARISON 1 149 0.068 0.102 3.855 25.3 COMPARISON 2 235 0.137 0.073 8.913 26.3 COMPARISON 3 233 0.140 0.078 9.020 26.9 [A] DENSITY (g/m 2 ) [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' underwear obtained in Example 1 and in Comparisons 1 through 3, tests were carried out on the living body. First of all, for ladies' underwear of Example 1 and Comparison 1, skin temperature (minimum, average, maximum) of the back of the same paneler before and after putting on the underwear was measured. The measurement was carried out on temperature retained by the underwear about 1200 seconds after it was put on and skin temperature of the back immediately after and about 66 seconds after the underwear was taken off. The overall temperature variation in skin temperature at the back was calculated. Next, using the same paneler, the measurement was carried out on the ladies' underwear of Comparisons 2 and 3 in the same manner. The measured skin temperatures in this test were calculated from minimum, average, and maximum values of the picture analysis temperature distribution of a specific region of the thermogram obtained from thermo analysis 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] EXAMPLE 1 AVE. 34.25 34.63 (0.38) 34.38 0.13 ↑ MIN. 33.00 33.50 (0.50) 33.25 0.25 ↑ MAX. 35.13 35.63 (0.47) 35.38 0.25 ↑ COMPARISON 1 AVE. 34.13 33.88 (-0.25) 33.63 -0.50 ↓ MIN. 32.88 32.50 (0.38) 32.25 -0.63 ↓ MAX. 35.13 35.00 (-0.13) 34.75 -0.38 ↓ COMPARISON 2 AVE. 34.01 34.11 (0.10) 33.94 -0.07 ↓ MIN. 32.88 32.22 (0.01) 32.10 -0.11 ↓ MAX. 35.01 35.23 (0.22) 35.10 0.09 ↑ COMPARISON 3 AVE. 34.52 34.70 (0.18) 34.55 0.03 ↑ MIN. 32.91 32.85 (-0.06) 32.84 -0.07 ↓ MAX. 35.21 35.51 (0.30) 35.30 0.09 ↑ [A] BEFORE PUTTING ON / HEAT-RETAINING FOR 1,200 SEC. [B] RIGHT AFTER TAKING OFF [C] RADIATION OF HEAT / RADIATION FOR 66 SEC. [D] OVERALL TEMPERATURE VARIATION THE UPPER ROW : AVERAGE TEMPERATURE (°C ) THE MIDDLE ROW : MINIMUM TEMPERATURE (°C ) THE LOWER ROW : MAXIMUM TEMPERATURE (°C ) ( ) indicates temperature of heat-retaining effect. Test 3 The ladies' underwear of Example 1 and Comparison 1 was respectively worn by two panelers, 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) when the underwear was worn for a specified period. Table 3 shows the results. BLOOD FLOW OF FINGER (ml/min/100g) PANELER A PANELER B EXAMPLE 1 30 31 11:40∼10:50 11:00∼11:06 COMPARISON 1 22 14 10:40∼10:50 11:50∼12:00 THE LOWER ROW ... TIME OF MEASURE As clear from TABLE 1, when the mixed-spinning ratio of polyurethane elastic fibre is 15%, comparing ladies' underwear mixed with metal oxide (Example 1) with that not mixed with metal oxide (Comparison 1) shows that small contact feeling results in some coldness when it is 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. If 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 a heat-retaining effect is not sufficiently manifested. As clear from TABLE 2, when the mixed-spinning ratio of polyurethane elastic fibre is 15%, in the balance of heat-retaining and heat-radiation after putting on the underwear, the ladies' underwear containing metal oxides (Example 1) provides overall temperature variation difference 0.6°C higher on average than that of ladies' underwear 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 underwear is not manifested. As clear from TABLE 3, the ladies' underwear of Example 1 tends to increase the blood flow rate by heat-retaining as compared with the ladies' underwear of Comparison 1. Example 2 15% polyurethane elastic fibre containing metal oxides comprising alumina (Al 2 O 3 ), silica (SiO 2 ), titania (TiO 2 ), 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 is mixed-spun with 82% cotton to make fibre. Example 4 28% polyurethane elastic fibre the same as Example 2 is mixed-spun with 72% cotton into fibre. Example 5 50% polyurethane elastic fibre the same as Example 2 is mixed-spun with 50% staple fibre to make fibre. Example 6 17% polyurethane elastic fibre the same as Example 2 is 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: 4.5-20.0µm; 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. As is clear from the obtained spectral emissivity, 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 are emitted even at the comparatively low temperature range of 33°C.

Claims: Underwear comprising fibre containing platinum and a metal oxide, characterised in that it comprises fibre materials mixed-spun with polyurethane elastic fibre in the range of 2-50%, to which platinum and at least one metal oxide selected from alumina, silica, titania are mixed.

Inventors: MAGATA KATSUMI, MAGATA, KATSUMI,, MAGATA, KATSUMI, C/O SWANEE CO LTD.
Applicants: SWANEE CO LTD
Application year: 1993
Main classification: A41B17
IPC codes: A41B9, A41B17, D01F1, D01F6, A61N5