DE69302865T2 - Socks and stockings made of fibers containing metal - Google Patents

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

The invention relates to socks and stockings comprising metal-containing fibers, and the object of the invention is to provide socks and stockings comprising metal-containing fibers which not only provide comfortable wear while being worn, but also emit electromagnetic rays released from the metal oxides close to the wearer's body, affecting the contact feeling when they are put on and providing good thermal conductivity during wear, resulting in an extremely good heat retention effect.

Generally, fiber materials constituting socks and stockings are well known as cotton, nylon, polyester, acrylic and urethane fibers, and these fiber materials are appropriately selected according to the season such as summer or winter and blend-spun in an optional ratio to form socks and stockings.

For example, socks and stockings for summer are made of fiber materials mainly comprising cotton in terms of permeability and absorbability, while for winter socks and stockings, wool is mixed in addition to these fiber materials to improve heat retention properties.

Recently, considering the heat retention properties of far-infrared radiation, socks and stockings using fibers with far-infrared emitting ceramics as a component material have been reported.

These socks and stockings use fibers containing far-infrared emitting materials such as aluminum oxide, zirconium oxide or magnesium oxide contained in polyethylene and polyamide-based fiber materials, which exhibit high permeability to far-infrared radiation. The fiber material containing this far-infrared emitting material is further coated with a protective layer as part of the component fiber, which is formed in anticipation of the heat retention effect when worn.

Socks and stockings incorporating metal-containing polyurethane fibers are also disclosed in JP-A-63 112 701 (Derwent Publications WPI Database, Week 8825, AN 88-173138).

It is difficult for socks and stockings blended with wool to achieve sufficient heat-retaining effects on the soles of the wearer's feet. Blended wool in a large proportion to increase the heat-retaining effect causes the socks and stockings themselves to be thick, so that the socks and stockings are not comfortable to wear.

On the other hand, socks and stockings blended with far-infrared-emitting ceramics can reduce the thickness compared with wool blended socks and stockings, but they present a problem in that the intended effect is difficult to achieve unless a large area of the socks and stockings is covered with the fiber material containing far-infrared-emitting substances.

In addition, such socks and stockings present another problem in that the coating layer is provided to protect the far-infrared emitting layer. However, this protective layer absorbs far-infrared radiation. As a result, the far-infrared radiation emitted from the ceramics cannot be effectively utilized.

Accordingly, these socks and stockings have a problem that the effect of far infrared radiation cannot be most effectively utilized for producing a good feeling of contact when the socks and stockings are put on, and for the thermal conductivity during wearing and the skin temperature after wearing, so that excellent heat retention effects cannot be achieved.

It would be desirable to produce socks and stockings that provide a good contact feeling when donning, good thermal conductivity when worn and a comfortable wearing temperature with excellent heat retention properties.

According to the invention, the socks or stockings comprise metal-mixed fiber materials, characterized in that the fiber materials are mixed-spun with at least 2% elastic polyurethane fiber, to which platinum and at least one metal oxide selected from aluminum oxide, silicon oxide and titanium oxide are mixed.

The structure of socks and stockings comprising the metal-containing fiber material according to the invention is described in detail below.

In this invention, the fiber material mixed spun with at least 2% elastic polyurethane fiber mixed with at least one metal oxide selected from aluminum oxide (Al₂O₃), silicon oxide (SiO₂) and titanium oxide (TiO₂) as well as platinum (Pt) as essential components is referred to as component fiber.

The components used in the invention, aluminum oxide (Al₂O₃), silicon oxide (SiO₂) and titanium oxide (TiO₂), are preferably in powder form with a grain size of 1 µ or smaller. However, there is no restriction on the form. The platinum (Pt) preferably has a grain size of 7-40 Å and is in colloidal form.

This is based on the inventor's experimental findings that the use of platinum in colloidal form gives satisfactory heat retention properties.

The mixing ratio of these metal oxides and platinum is about 9 to 45% of aluminum oxide (Al₂O₃), 50 to 80% of silicon oxide (SiO₂), 8 to 15% of each of titanium oxide (TiO₂) and/or platinum (Pt), but there is no limitation.

Oxides of calcium, zinc and copper can be added to these metal oxides up to about 2 to 10%.

From the above metal oxides, electromagnetic radiation (far infrared radiation) with a wavelength of 5 to 12 micrometers is emitted stably and sufficiently in an effective manner for human bodies, even at a temperature of about 30ºC, as is clear from the following tests.

The invention is not limited to, but is preferably used for, a specific elastic polyurethane fiber, SPANDEX (SPANDEX is a registered trademark), which comprises a non-crystalline component including either polyester or polyether moieties and a crystalline component containing urethane bonds and is widely used in conventional textile products.

The invention is not limited to a specific method of mixing metal oxides and platinum with the elastic polyurethane fiber. Any conventional method may be used as needed, such as mixing the polymerized fiber material dispersed in the solution before dry spinning or mixing into the dry spun yarns.

No specific mixing ratio of metal oxides to elastic polyurethane fibre is specified, but any mixing ratio can be assumed if it results in emission of electromagnetic radiation (far infrared radiation) in a wavelength range of about 5 to 12 microns, which is effective for human body at a temperature of about 30 ºC. The blending ratio should also provide a good feeling when in contact with the skin and good thermal conductivity when worn. In addition, a satisfactory heat retention effect should be exerted, and the blending ratio should be in a range that allows spinning and does not deteriorate the wearing comfort as a component fiber material of socks and stockings.

Furthermore, the reason for using elastic polyurethane fiber in the present invention is that blended elastic polyurethane fiber with high expandability results in improved wearing comfort of socks and stockings, and at the same time, blending the above-mentioned metal oxides and platinum into this elastic polyurethane fiber enables the emission of electromagnetic radiation (far infrared radiation) of metal oxides into the body when socks and stockings are in close contact with the wearer's body. They also most effectively utilize the effect of the emitted electromagnetic radiation (far infrared radiation) and enable the action of the electromagnetic radiation (far infrared radiation) to bring about a good feeling in contact with the skin when the socks and stockings are put on. They result in an appropriate level of thermal conductivity, where the temperature in the body rises after the socks and stockings are worn, and the blood flow rate in the wearing area is simply increased, as a result showing a superior heat retention effect.

Elastic polyurethane fiber mixed with at least one of metal oxides selected from the above-mentioned aluminum oxide (Al₂O₃), silicon oxide (SiO₂) and titanium oxide (TiO₂) as well as platinum (Pt) as essential components is blend-spun with other usual fiber materials by a common method into socks and stockings. In this case, the elastic polyurethane fiber must be blend-spun with metal oxides of at least 2%.

When the blend spinning ratio of elastic polyurethane fiber containing metal oxides is less than 2%, the emission of electromagnetic radiation from metal oxides does not take place effectively using the expandability of the above-mentioned elastic polyurethane fibers, and the superior heat retaining property is not exerted.

Other fiber materials that can be blended with the elastic polyurethane fiber are common natural and man-made fiber materials such as cotton, hemp, wool, acrylic, polyester and nylon, and these fiber materials can be optimally blended to produce socks and stockings in an optional ratio and are not specified.

The socks and stockings of the present invention are characterized in that the thickness of the socks and stockings themselves is hardly present and that a comfortable wearing experience is ensured when the socks and stockings are put on. At the same time, because electromagnetic radiation (far infrared radiation) is emitted from metal oxides in close contact with the wearer and the expandability of the elastic polyurethane fiber is utilized, electromagnetic radiation (far infrared radiation) can effectively act on contact during wearing as well as on putting on the socks and stockings and on thermal conductivity during wearing, thereby showing a very excellent heat retention effect as is apparent from the results of the following tests.

The invention will now be described by way of example with reference to the accompanying drawings, in which:

Figure 1 is a spectral emission curve for the fibre obtained in Example 2;

Figure 2 is a spectral emission curve for the fibre obtained in Example 3;

Figure 3 is a spectral emission curve for the fibre obtained in Example 4;

Figure 4 is a spectral emission curve for the fiber obtained in Example 5; and

Figure 5 is a spectral emission curve for the fiber obtained in Example 6.

Examples

The effects of socks and stockings containing metal-containing fibers in connection with the present invention will become clearer from the following examples.

example 1

6.4% elastic polyurethane fibre mixed with aluminium oxide (Al₂O₃), silicon oxide (SiO₂), titanium oxide (TiO₂) and platinum (Pt) in the ratio The yarn, which contains 10:82:3:5 metal oxides, was blended with 56% cotton, 24.1% acrylic and 13.5% nylon and then processed into women's socks using a conventional method.

Comparison example 1

Women’s socks were prepared in the same manner as in Example 1, but using elastic polyurethane fiber without any mixed metal oxides.

Comparison example 2

1.7% elastic polyurethane fiber mixed with metal oxides comprising aluminum oxide (Al₂O₃), silicon oxide (SiO₂), titanium oxide (TiO₂) and platinum (Pt) in a ratio of 10:82:3:5 was blend-spun with 64.7% cotton, 27.6% acrylic and 5.2% nylon and processed into men's socks using a conventional method.

Comparison example 3

Men's socks were prepared in the same manner as in Comparative Example 2, but using elastic polyurethane fiber without any metal oxides mixed in.

Testing 1

The women's and men's socks obtained in Example 1 and Comparative Examples 1 to 3 were measured for various properties including density (g/m²), thickness (cm), contact feeling (Qmax), uniform thermal conductivity (W/cmºC x 10⁻⁴) and heat retention ratio (%) using THERMOLABO 2-KES7 (KATOHTEC: thermal property measuring equipment).

Table 1 shows the results. Table 1 [A] [B] [C] [D] Example Compare Example

[A] Density (g/m²)

[B] Thickness (cm)

[C] Contact feeling (Q max) *1

[D] uniform thermal conductivity (W/cm ºC x 10⊃min;⊃4;) *2

[E] Heat retention ratio *3

*1: Coldness felt by the wearer when putting on; higher values mean more coldness.

*2: Ease of thermal conduction of fabric; higher value means higher lightness.

*3: Heat retention ability of fabric; higher values mean better ability.

Testing 2

Using women's and men's socks obtained in Example 1 and Comparative Examples 1, 2 and 3, living body tests were conducted.

First, the skin temperature of the right and left soles of a tester was measured before putting on socks, after the skin temperature of the left and right soles was adjusted on the living body for a specified time to harmonize the skin temperature of the right and left soles.

After the measurement, the sock from example 1 was worn on the left foot and the sock from Comparative Example 1 was put on the right foot, and the skin temperature (mean, maximum) of the soles was measured after putting on and heat retention for 900 seconds.

Then the right and left socks were removed, and the skin temperature (average, maximum) of the right and left soles was measured immediately afterwards and after about 61 seconds after the socks were removed.

The total temperature variation of the skin temperature on the right and left soles while wearing the socks was calculated.

Next, with the same test subject, the skin temperature of the right and left soles on the living body was adjusted in the same way for a specified time, then the sock of Comparative Example 2 was put on the left foot and the sock of Comparative Example 3 was put on the right foot, and the skin temperature (average, maximum) of the soles and the total temperature deviation of the skin temperature were measured in the same way.

The measured skin temperatures in this test were calculated from the mean and maximum values of the image analysis temperature distribution of a specific region of the thermogram obtained from thermal analysis with a thermograph (NEC San-Ei 6T/62 type (HgCdTe sensor, 8 to 13 µm): infrared radiation thermometer -50 to 2000ºC).

Table 2 shows the results. Table 2 [A] [B] [C] [D] Example Compare Example

[A] ... Before dressing

[B] ... Wearing and heat retention/heat retention for 900 seconds

[C] ... Immediately after undressing

[D] ... thermal radiation/radiation after 60 seconds

[E] ... total temperature variation

top row: average temperature (ºC)

bottom row: maximum temperature (ºC)

( ) means temperature of heat retention effect.

Testing 3

The women's socks of Example 1 and Comparative Example 1 were each worn on the hand of the same test subject, and the blood flow rate (ml/minute/100g) was measured by the laser double method using the laser double rheometer (ADVANST: ALF-21) (Journal of the Laser Medical Society of Japan Vol. 12, No. 1, July 1988) in both cases of heat retention and heating by radiation with a lamp.

Table 3 shows the results. Table 3 Finger blood flow (ml/minute/100g) Example 1 Comparative example 1

* bottom row ... irradiation with lamp

It is clear from Table 1 that when using a spinning blend ratio of elastic polyurethane fiber of 6.4%, when comparing women's socks blended with metal oxide (Example 1) with women's socks not blended with metal oxide (Comparative Example 1), the density and thickness are small, but a small contact feeling results in little coldness when they are put on, and a small uniform thermal conductivity results in little temperature deviation by coldness of the air, thereby showing a high heat retention ratio.

When the elastic polyurethane fiber is mixed spun with as little as 1.7% (Comparative Example 2), the effect is equal to that of using elastic polyurethane fiber without metal oxides (Comparative Example 3), showing that the heat retention effect does not sufficiently occur. It can be seen from Table 2 that in the case of a mixed spinning ratio of polyurethane elastic fiber of 6.4%, in the balance of heat retention and heat radiation after putting on the socks, the socks containing metal oxide (Example 1) show total temperature deviation differences of 0.2 ºC more on average and 1.1 ºC more on maximum than those of the socks not containing metal oxide (Comparative Example 1), showing a higher heat retention effect.

On the other hand, when the blending ratio of elastic polyurethane fiber is low (Comparative Examples 2 and 3), a heat retention effect is not exerted by wearing the socks.

Table 3 shows that the socks of Example 1 increase the blood flow rate by heat retention compared to the socks of Comparative Example 1.

Example 2

15% elastic polyurethane fiber containing metal oxides comprising aluminum oxide (Al₂O₃), silicon oxide (SiO₂), titanium oxide (TiO₂) and platinum (Pt) in a ratio of 10:82:3:5 is mixed-spun with 85% cotton to produce fibers.

Example 3

18% elastic polyurethane fiber, identical to Example 2, is mixed spun with 82% cotton to produce fibers.

Example 4

28% of the same elastic polyurethane fiber as in Example 2 are mixed spun with 72% cotton to form fibers.

Example 5

50% identical elastic polyurethane fiber as in Example 2 are mixed spun with 50% staple fibers to produce fibers.

Example 6

17% identical elastic polyurethane fiber as in Example 2 are mixed spun with 83% nylon to produce fibers.

Testing 4

The spectral emissivity was measured for the fibers obtained in Examples 2 to 6.

Measurement conditions are wavelength range 4.5 to 20.0 µm; Resolution: 16 cm⊃min;¹; Detector: broadband MCT; Measurement temperature: 33 ºC for surface temperature of the texture; Measurement position and time: 4 times in total, each at 2 different positions and 2 times at the same position.

Figures 1 to 5 show the relevant spectral emissivities obtained.

It can be seen from the obtained spectral emissivity that the fiber obtained in Examples 2 to 6 emits electromagnetic radiation (far infrared radiation) having wavelengths of about 5 to 12 micrometers, which is effective for human bodies, even at a comparatively low temperature of 33 ºC.

Claims (1)

1. Socks or stockings comprising fiber materials mixed with metal, characterized in that the fiber materials are mixed-spun with at least 2% elastic polyurethane fiber, with which platinum and at least one metal oxide selected from aluminum oxide, silicon oxide and titanium oxide are mixed.