JPH0921067A - Production of radiation shielding fiber or its product - Google Patents

Abstract

PROBLEM TO BE SOLVED: To produce a radiation shielding fiber, excellent in shielding properties for radiations and good in touch feeling and whiteness degree by applying fine powder of zinc oxide or a zinc oxide-based ceramic to fibers such as a polyester, a polyamide, a polyolefin or cellulose acetate. SOLUTION: A fine powder, prepared by finely pulverizing or classifying zinc oxide or a ceramic consisting essentially of the zinc oxide and having<=3μm particle diameter is converted into an aqueous suspension containing an acryllc ester-based binder. The resultant suspension in an amount of 1-40wt.%, preferably 2-30wt.% is then applied to polyester, polyamide, polyolefin or cellulose acetate fibers or a textile product formed by using the respective fibers such as a nonwoven fabric and the fibers or textile product is predrled and heat- treated to uniformly bond and fix the fine powder to the fiber surfaces thereof.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a polyester fiber, a polyamide fiber, which has an excellent ability to block radiation rays such as sunlight, ultraviolet rays, visible rays, infrared rays, and heat rays, and which has good whiteness and texture.
The present invention relates to a method for producing a polyolefin fiber or a cellulose acetate fiber or a product thereof.

[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 have been 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.

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

[0005]

SUMMARY OF THE INVENTION
Excellent shielding against radiation such as ultraviolet rays and heat rays, feeling,
The whiteness is good, and the purpose is to obtain a cool textile product by preventing sunburn for clothing and the like.

[0006]

In order to achieve the above object, the present invention uses finely pulverized or classified fine particles of zinc oxide or an inorganic compound powder mainly composed of zinc oxide as a polyester fiber. , 1 to 40% by weight with respect to polyamide fiber, polyolefin fiber or cellulose acetate 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 directly block the heat caused by the irradiation of radiation such as sunlight and the like from the outside, and it is possible to obtain a cool textile product by wearing it.

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, dry 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. 1,
Zinc oxide absorbs near-ultraviolet rays, but shows a reflectance of 100% or higher in a wavelength range from 0.7 μ to long wavelengths, that is, near-, middle-, and far-infrared rays, 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 emissivity (%) and the horizontal axis is 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 a very 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, a mixture of titanium oxide, zirconium oxide, aluminum oxide and the like ( Collectively referred to as zinc oxide ceramics).

The above zinc oxide ceramics are used in the form of suspension in padding, coating, printing, spraying, etc., on fiber products such as polyester, polyamide, polyolefin or cellulose acetate fibers, yarns, woven fabrics, knitted fabrics and non-woven fabrics. It is applied by processing means.

To apply the above zinc oxide ceramics to the above fiber product, the particle size is 3 μm or less, preferably 1 μm.
It is preferable to finely pulverize to the following or to use a classified one because the suspension becomes stable.

The fibers used in the present invention are polyester,
Fibers such as polyamide, polyolefin and cellulose acetate can be mentioned.

The blending ratio of the zinc oxide type ceramics to 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.

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

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

【Example】

Example 1 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 binder agent,
Approximately 15% by weight was mixed and stirred in a binder emulsion liquid to which auxiliary agents such as stabilizers and softeners were added to prepare a suspension.

This suspension was applied to a long-fiber non-woven fabric made of polypropylene fibers by doctor coating to give the suspension (weight per unit area of 40 g / m ² ), pre-dried at 110 ° C., and then heat-treated at 155 ° C. Zinc oxide was uniformly adhered and fixed on the fiber surface.

The temperature rise when the obtained polypropylene fiber cloth was irradiated with light was measured.

For comparison, a temperature rise is similarly caused in the case where only the binder emulsion mainly containing an acrylic acid ester-based polymer containing no zinc oxide is applied to the above-mentioned non-woven fabric, and also in the case of an ordinary untreated polypropylene non-woven fabric. It was measured. Table 1 shows the results.

The temperature rise was measured by stretching this non-woven fabric on a box surface having a depth of 3 cm, irradiating light with a 300 W reflex lamp (Matsushita Electric Industrial Co., Ltd.) from a distance of 25 cm from the knitted fabric, and then the bottom surface of the box. The temperature was gradually measured immediately after irradiation.

[0025]

[Table 1]

As is clear from the results shown in Table 1, the zinc oxide-added polypropylene non-woven fabric of the present invention showed a small and slow increase in the air temperature on the side opposite to the light irradiation surface, and this polypropylene non-woven fabric was used as a tent. In this case, there is little temperature rise inside the tent even in the summer sunlight.

Example 2 The zinc oxide suspension prepared in Example 1 was mixed with polyamide taffeta (50 denier, 24 filament yarn 110).
Book, weft 75 denier, 36 filament yarn 80 pieces)
Was subjected to a padding method (100% mangle drawing), pre-dried at 110 ° C., and then heat-treated at 155 ° C. for 1.5 minutes to uniformly bond and fix zinc oxide to the fiber surface.

The temperature rise of the obtained polyamide taffeta upon light irradiation was measured by the same method as in Example 1. For comparison, the temperature rise was measured in the same manner when 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 polyamide taffeta. Table 2 shows the results.

[0029]

[Table 2]

As is clear from Table 2, the zinc oxide-added polyamide taffeta of the present invention shows little and slow increase in the air temperature on the side opposite to the light irradiation surface. Underneath you can understand that it is cool.

[0031]

[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.

[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 (%).

Claims (1)

[Claims] 1. Finely pulverized or classified finely divided particles of zinc oxide having a particle diameter of 3 μm or less, or a finely divided ceramic powder mainly composed of zinc oxide as an aqueous suspension into polyester fibers,
A method for producing a radiation-shielding fiber or a product thereof, which comprises adding 1 to 40% by weight to polyamide fiber, polyolefin fiber and / or cellulose acetate fiber.