JPS6024587Y2 - White UV reflective sheet - Google Patents

Description

[Detailed description of the invention] The present invention relates to a white reflective sheet.
This relates to a white reflective sheet.

2. Description of the Related Art When objects, personnel, etc. are to be hidden from visual inspection in areas covered with snow, it is generally well known to cover them with a white sheet.

In this case, as the white pigment, conventionally known pigments such as
Titanium dioxide or the like can be used.

However, snow accounts for 70-90% of the UV irradiation.
In contrast, conventional white pigments have the property of absorbing most of the UV rays and not reflecting much of it.

For this reason, when observed using an ultraviolet observation means such as a camera equipped with an ultraviolet-transparent filter or a special measuring instrument such as a spectrophotometer, a conventional white sheet can be clearly distinguished from snow.

An object of the present invention is to provide a white reflective sheet that is difficult to distinguish from snow not only with the naked eye but also when observed using ultraviolet light.

The white ultraviolet reflective sheet of the present invention includes a sheet-like base material made of polyvinyl alcohol fibers made water-insoluble or hardly soluble, and a matrix made of thermoplastic polyvinyl chloride resin formed on one or both sides of this base material. dispersed in this matrix and relative to this matrix 20~
It is characterized by having a white ultraviolet reflection layer containing 200% by weight of zircon oxide powder.

In the white reflective layer of the white reflective sheet of the present invention, the thermoplastic polymer material constituting the matrix is polyvinyl chloride resin.

This polyvinyl chloride resin may contain a plasticizer, various stabilizers, and other additives as long as they do not impede the purpose of the present invention.

In the white reflective sheet of the present invention, the specific combination of the polyvinyl chloride resin matrix and zircon oxide is important.

For example, if a polyolefin resin such as polyethylene or polypropylene is used instead of polyvinyl chloride resin, its UV resistance is low and it deteriorates quickly when exposed to UV rays. It is completely unusable as a reflective sheet.

Furthermore, if another white oxide, such as titanium oxide, is used in place of zirconium oxide, the resulting sheet will not be able to remotely meet the purpose of the present invention (ultraviolet reflection) because it absorbs ultraviolet rays.

In the white reflective layer of the white reflective sheet of the present invention, the amount of zircon oxide is 20% relative to the weight of the polymer matrix.
It is used in an amount of from 70 to 200%, preferably from 70 to 150%.

If the amount of zirconium oxide is less than 20%, the resulting white sheet will not only have insufficient ultraviolet reflectance but also insufficient light shielding properties, resulting in insufficient concealment of articles and personnel.

In addition, if the amount of zircon oxide exceeds 200%, the resulting white sheet will have disadvantages such as a decrease in bending flexibility and hardness, making it more likely to break at low temperatures, and moreover, the reflectance of ultraviolet rays will not improve much. do not.

White reflection of this invention? - The zirconium oxide (zrO2) used in this process is a white fine powder,
The particle size is preferably finer than 100 mesh, and more preferably about 350 mesh.

To disperse the zircon oxide in the polymer matrix, conventional kneading methods such as calender kneading, Banbury kneading, or screw kneading can be used.

In the white reflective sheet of the present invention, a white reflective layer is formed on one or both sides of a sheet-like base material.

The base material used for the white reflective sheet with this structure is
It may be a fabric such as a knitted fabric, a woven fabric, a non-woven fabric, or a sheet or a film, and the fabric may be composed of any fibers such as long fibers, short fibers, split yarns, tape yarns, etc. You can.

The material forming the above-mentioned base material is a knitted fabric or woven fabric made of long fibers or short fibers of polyvinyl alcohol that is rendered insoluble or hardly soluble in water.

In particular, a base material composed of polyvinyl alcohol fibers made water-insoluble or hardly soluble, such as vinylon, has a wavelength of 300 nm.
Even for ultraviolet rays of 0 to 400 millimicrons, 60 to 7
It has the characteristic of exhibiting a good reflectance of 0%, and is most suitable as a base material for the white reflective sheet of the present invention.

Therefore, by using such a UV-reflective sheet base material, the amount of UV-reflecting agent used in the white reflective layer can be reduced, and the reflective performance will drop sharply even if it is repeatedly washed and used. gives particularly favorable results in use without any

In order to form a white reflective layer on a base material, a white reflective sheet or film may be prepared from the above-mentioned kneaded material and this may be attached onto the base material, or a solution or The dispersion may be applied onto a substrate and the liquid may be removed by evaporation.

In this case, the thickness of the white reflective layer on the substrate is 0.05 to 0.
．． It is preferably about 5TrrIrL, and 0.1 to
More preferably, it is about 0.3 m.

The white ultraviolet reflection sheet of the present invention shown in FIG. 1 includes a base fabric 1 and a white ultraviolet reflection layer 1a formed on one surface thereof.

Further, the white ultraviolet reflection sheet of the present invention shown in FIG. 2 consists of a base fabric 1 and white ultraviolet reflection layers 1a and 1b formed on both surfaces thereof.

A white reflective layer is formed on a sheet-like substrate made of polyvinyl alcohol fibers made insoluble or hardly soluble in water,
Since this sheet-like base material has a hiding property, the amount of zirconium oxide contained in the white reflective layer may be 20 to 70% based on the weight of the polyvinyl chloride resin.

The hiding property of the sheet-like base material is JIS-6828, 4.
10.2, it is possible to judge based on the legibility of 8-point type.

Further, it is preferable that the sheet-like base material has as high a white discoloration as possible.

The white reflective sheet of the present invention not only has good whiteness and light blocking properties, but also has a UV resistance of 300 to 400 millimicrons, for example, 350 millimicrons, by 70% or more, generally 80% or more. Since it shows a reflectance of ~85%, when these white reflective sheets are placed on the snow surface, they can be observed with the naked eye or by observation means using ultraviolet light.
It is difficult to tell from the snow.

In addition to zirconium oxide, the white reflective sheet of the present invention preferably contains 2 to 1
It may contain 0%, more preferably 4-7% antimony trioxide powder.

Antimony trioxide powder can improve the flame retardancy of the white reflective sheet without significantly reducing the ultraviolet reflection performance of the white reflective sheet.

Reference examples 1 and 2 A mixture having the following composition (unit double placement part) was prepared.

(Stabilizer: Zinc Stearate) Each of the above mixtures was kneaded using a calendar to create a sheet with a thickness of 0.1 mm.

These sheets had the following properties.

Flame retardancy was determined by the method of JIS-Z-2150-B.
Measured with a heating time of 2 minutes.

Comparison reference example 1 The operation of Reference Example 1 was repeated.

However, zircon oxide was not used.

The obtained sheet was transparent and hardly reflected ultraviolet rays with a wavelength of 350 mμ.

Comparison reference example 2 The operation of Reference Example 1 was repeated.

However, titanium dioxide was used instead of zirconium oxide.

A white sheet was obtained, and the wavelength of this sheet was 350 m,
The UV reflectance of μ was only about 20% and the sheet was easily distinguishable from the snow.

Examples 1 and 2 In Example 1, composite sheets were prepared by heat-adhering the white reflective sheet obtained in Reference Example 1 to both sides of a base material made of polyvinyl acetal filament fabric having the following fabric structure.

The thickness of this composite sheet is 0.22 mm, and its thickness is 35 mm.
The reflectance for ultraviolet light of 0771μ was 85%.

Moreover, the flame retardant property of this composite sheet was 2nd class flame retardant.

In Example 2, the same operations as above were repeated.

However, the white reflective sheet obtained in Reference Example 2 was used.

The thickness of this composite sheet is 0.22rrrm, 350mmμ
The reflectance against ultraviolet rays was 83%, and the flame retardant property was grade 1 flame retardant.

The composite sheets obtained in Examples 1 and 2 had excellent strength and durability.

The white reflective sheet of the present invention can be cut, punched, sewn, trimmed, etc. into desired dimensions and shapes to produce various uses, such as camouflage tools.

[Brief explanation of the drawing]

FIGS. 1 and 2 are explanatory cross-sectional views of the white ultraviolet reflective sheet of the present invention, respectively. 1...Base fabric, 2a, 2b...White ultraviolet reflective layer.

Claims (1)

[Scope of utility model registration request] A sheet-like base material made of polyvinyl alcohol fibers made water-insoluble or hardly soluble; a matrix made of thermoplastic polyvinyl chloride resin formed on one or both sides of this base material; and dispersed in this matrix; A white ultraviolet reflection sheet comprising a white ultraviolet reflection layer containing zirconium oxide powder in an amount of 20 to 200% by weight based on the matrix.