JPH05117910A - Radiation shielding fiber or its production - Google Patents

Abstract

PURPOSE:To provide the subject fiber containing zinc oxide, etc., in a specific amount based on the fiber, having an excellent radiation shielding property, and having good whiteness and touch. CONSTITUTION:The objective fiber is obtained by mixing kneading zinc oxide powder and ceramic powder consisting mainly of zinc oxide (e.g. a ceramic mixture comprising >=50wt.% of zinc oxide and the balance of titanium oxide, zirconium oxide, etc.) with fiber in an amount of 1-40wt.% based on the fiber.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fiber or a product thereof which has an excellent property of blocking radiant rays such as sun rays, ultraviolet rays, visible rays, infrared rays and heat rays and has a good whiteness and texture.

[0002]

2. Description of the Related Art It is already known that by incorporating an ultraviolet absorber or an inorganic compound powder that cuts off ultraviolet rays and visible rays into fibers, it has an effect of shielding radiation rays such as sunlight rays.

Titanium oxide-based powders and the like are known and used as such inorganic compound powders, but these inorganic compound powders absorb radiation in the so-called far infrared region having a wavelength longer than 4 μ. In addition, since it emits radiation, it has a drawback that the heat ray shielding property is poor.

Further, when a large amount of the above-mentioned inorganic compound powder is contained in a fiber or the like, the titanium oxide-based compound powder has a high hardness, so that there is a drawback that troubles such as abrasion damage of the device frequently occur in the fiber manufacturing process.

[0005]

SUMMARY OF THE INVENTION
Excellent shielding against radiation such as ultraviolet rays and heat rays, feeling,
The whiteness is good, and it is intended for clothing to prevent sunburn and to obtain a cool fiber product.

[0006]

In order to achieve the above object, the present invention comprises zinc oxide or an inorganic compound powder mainly containing zinc oxide in an amount of 1 to 40% by weight based on the fiber.

Zinc oxide absorbs near-ultraviolet rays, but exhibits extremely high reflectance from the visible light region to the near, middle, far, and infrared regions. Therefore, it is possible to block heat due to radiation from the outside, such as direct sunlight, and it is possible to obtain a textile product that is cool to wear.

Zinc oxide has a good whiteness, a low powder hardness, and a particle size of 5 μm or less by the Microtrac method.
Very fine particles of 0% or more can be easily produced, and it is easy to knead into synthetic fibers in the melt spinning method, the wet spinning method and the like, and to easily post-process fiber products. Excellent product can be obtained.

The spectral reflectance curve of zinc oxide used in the present invention at room temperature is shown in FIG. In addition, this FIG.
The vertical axis represents the reflectance (%) and the horizontal axis represents the wavelength (μm), which are values when the reflectance of barium sulfate is 100%.

As shown in the spectral reflectance curve of FIG.
Zinc oxide absorbs near-ultraviolet light, but exhibits a reflectance of 100% or higher in a wavelength range from 0.7μ to a long wavelength range, that is, near-, middle-, and far-infrared light regions, and thus has low heat absorption. ..

This radiation reflecting property is far superior to that of titanium oxide, and it is possible to obtain a fiber product which blocks radiation.

From the viewpoint of emissivity characteristics of zinc oxide, FIG. 2 is an emissivity curve of zinc oxide and titanium oxide, where the vertical axis is the emissivity (%) and the horizontal axis is the wavelength (μm). ..

As can be seen from FIG. 2, titanium oxide emits a considerable amount of energy in the near or far infrared region, whereas zinc oxide has an extremely low energy emission, which also has a radiation blocking property. I understand.

The zinc oxide used in the present invention may be ceramics alone or containing 50% by weight or more of zinc oxide, and other than this, titanium oxide, zirconium oxide, aluminum oxide and the like may be mixed ( Collectively referred to as zinc oxide ceramics).

The above zinc oxide ceramics are preferably kneaded into the fiber in a powder state from the viewpoint of durability, but the fiber products such as fiber, yarn, woven fabric and knitted fabric are padded and coated in a suspension state. Alternatively, it may be applied by post-processing means such as printing, spraying or the like.

When the above zinc oxide ceramics are kneaded into the fibers, it is preferable to use finely pulverized or classified particles having a particle size of 3 μm or less, preferably 1 μm or less.

When the post-processing means is used, the particles need not be as fine particles as in the case of kneading, but it is preferable to make the particles in the same state because the suspension becomes stable.

The fibers used in the present invention include melt-spun fibers such as polyester, polyamide and polyolefin, wet spun fibers such as polyacrylonitrile-based and rayon-based fibers,
Examples include dry spun fibers such as acetate.

The proportion of the zinc oxide ceramic compounded in these fibers is 1 to 40% by weight, preferably 2 to 30% by weight, based on the fibers. If the blending ratio is further increased, the spinnability is deteriorated, and if the blending ratio is further decreased, the reflection of radiation having a wavelength of 0.7 to 6 μ is deteriorated.

The kneading into the fiber is usually carried out by kneading a zinc oxide ceramic powder into a raw material resin to produce a master chip, mixing the raw material resin with a predetermined concentration, and spinning. Further, this ceramics kneading polymer may be subjected to composite spinning with another fiber-forming polymer. This composite spinning may be either a core-sheath type or a bimetal type.

When the zinc oxide-based ceramic powder is applied as a post-treatment to a textile product, fine particles of the powder are applied as an aqueous suspension by a conventional method such as dipping, padding, spraying, etc. according to a conventional method. To do.

Next, the present invention will be described in more detail with reference to Examples.

[0023]

【Example】

Example 1 Fine powder having a particle size of 1 μm or less obtained by finely pulverizing zinc oxide was melt-mixed with a low molecular weight polyester composed of butylene glycol and adipic acid at a weight ratio of 4: 1 and extruded to form pellets. These pellets were melt-mixed with polyethylene terephthalate (intrinsic viscosity 0.7) in an amount of 5% by weight, melt-extruded and spun, and stretched according to a conventional method to obtain 3d × 50 filament fibers.

This zinc oxide-containing fiber was knitted with a circular knitting machine to form a 10 cm × 10 cm knitted fabric. The obtained knitted fabric had a good whiteness, a smooth texture, and a good feel to the touch.

This knitted fabric was stretched on a box surface having a depth of 3 cm, and light was irradiated from a distance of 25 cm from the knitted material with a 300 W reflex lamp (manufactured by Matsushita Electric Industrial Co., Ltd.), and the temperature of the bottom surface of the box was gradually measured immediately after the irradiation. did.

For comparison, 3 containing no zinc oxide was used.
The temperature rise was measured by the same method for a normal polyester fiber knitted fabric having d × 50 filaments and a polyester fiber knitted fabric containing 5% by weight of zirconium oxide. The results are shown in Table 1.

[0027]

[Table 1]

As is clear from Table 1, the knitted fabric of the fiber of the present invention has a small and slow increase in air temperature on the side opposite to the light irradiation surface. That is, it can be seen that wearing this knitted fabric makes it cool even in the summer sunlight.

Example 2 A fine powder having a particle size of 20 μm or less obtained by finely pulverizing zinc oxide was mainly composed of an acrylic ester-based binder agent.
Approximately 15% by weight was mixed with a binder emulsion liquid to which auxiliary agents such as stabilizers and softeners were added, and the mixture was stirred to prepare a suspension.

[0030] This suspension was mixed with cotton poplin (160 pieces /
70 lines), padding method (100% mangle diaphragm)
After predrying at 110 ° C., heat treatment was performed at 155 ° C. to uniformly adhere and fix zinc oxide to the fiber surface.

The temperature rise of the obtained cotton poplin fabric was measured in the same manner as in Example 1 during light irradiation.

For comparison, the temperature rise was similarly measured in the case where only the binder emulsion mainly containing an acrylic acid ester-based polymer containing no zinc oxide was applied to the above cloth, and also in the case of ordinary cotton poplin cloth. .. The results are shown in Table 2.

[0033]

[Table 2]

As is clear from Table 2, the zinc oxide-added cotton cloth of the present invention has a small and slow increase in the air temperature on the side opposite to the light-irradiated surface. Underneath you can see that it's cool.

[0035]

[Effect] As can be understood from the examples, the fiber of the present invention and the product thereof have a small and slow increase in the air temperature on the side opposite to the light irradiation surface. Therefore, if the product of the present invention is worn,
In summer, it has the excellent property of being cool even under outdoor sunlight.

[0036]

[Brief description of drawings]

FIG. 1 is a spectral reflectance curve of zinc oxide, where the horizontal axis represents wavelength (μm) and the vertical axis represents reflectance (%). However, this reflectance is a comparison value when the reflectance of barium sulfate is 100%.

FIG. 2 is a spectral emissivity curve of zinc oxide and titanium oxide, where the horizontal axis represents wavelength (μm) and the vertical axis represents reflectance (%).

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Claims (1)

[Claims] 1. A radiation-shielding fiber or a product thereof, which comprises 1 to 40% by weight of zinc oxide or a ceramic powder mainly composed of zinc oxide with respect to the fiber.