JPS6263902A - Ultraviolet reflection sheet for camouflage - Google Patents

Abstract

PURPOSE:To obtain a reflection sheet having extremely high UV reflectivity at about 300nm by using white lead as a white pigment. CONSTITUTION:This reflection sheet contains the white lead as a white UV reflecting agent. The while lead to be used refers to lead hydroxycarbonate 2PbCO3.Pb(OH)2. The white lead to be used for the UV reflection sheet for camouflage is used at 20-200wt%, more preferably 50-180wt% by the weight of the base material for the sheet. The UV reflectivity of the resulted UV reflection sheet for camouflage is not enough and a hiding characteristic is not satisfactory if the content of the white lead is less than 20wt%. Such is, therefore, undesirable. The flexural flexibility of the resulted sheet decreases and the sheet is hard if the content exceeds 200wt%. Then the sheet has an easier tendency to cracking at a low temp. and the UV reflectivity is not so much improved and therefore, such is undesirable.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an ultraviolet reflective sheet for camouflage that is effective for concealing objects existing in environments such as snow fields.

(Prior Art) For a long time, military bases, military equipment, etc. have been covered with camouflage to disguise the appearance of field battles and create the illusion that they are objects in the environment.

For example, camouflage in the Arctic Circle is based on white, dark lines, yellow, etc. are used to hide certain objects in forested environments, and dark brown is used in areas where the soil is predominant. Tenasu is a common camouflage color tone.

A commonly used method to hide military objects in areas with a lot of snow is to treat woven fabrics, plastic sheets, etc. with white pigments such as titanium dioxide, and use the white cloth or white sheet to hide them. Methods of coating objects are known.

(The problem that the invention is trying to solve) However,
Snow reflects 70 to 90% of the ultraviolet rays irradiated with it, whereas conventional white pigments such as titanium dioxide have the property of absorbing most of the irradiated ultraviolet rays and hardly reflecting them.

For this reason, there was a drawback that the areas covered in the snow could be easily seen by measuring instruments such as remote sensitive computers equipped with ultraviolet-transparent filters.

In order to eliminate such drawbacks, technologies such as white reflective sheets using powders such as magnesium oxide, magnesium carbonate, barium sulfate, and zirconium oxide in place of titanium dioxide are already known (for example, Japanese Patent Publication No. 57-1771).
Publication No. 1, Special Publication No. 57-17712, Special Publication No. 17712, Special Publication No. 58
-36108).

The white reflective sheet using magnesium oxide etc. has a higher UV reflection effect than the one using -1 titanium oxide, but the UV reflectance in the wavelength range of 300 rv or more is about 50%, compared to snow. It was not satisfactory to be able to discriminate within 1 minute.

(Means for Solving the Problem) As a result of intensive research in order to solve the above-mentioned drawbacks of the conventional technology, the present inventor has found that by using lead white as a white pigment, the ultraviolet reflectance near 30 Onm is extremely excellent. The present invention was completed after discovering that a reflective sheet can be obtained.

That is, the present invention is a camouflage ultraviolet reflecting sheet characterized by containing lead white as a white ultraviolet reflecting agent.

Hereinafter, to explain the present invention in detail, the white lead used in the present invention is hydroxylead carbonate 2PbC03.Pb
(OH), throat.

In the present invention, the reflective sheet is colored with lead white (for example, the material of the reflective sheet is polyamide, polyester, polyacrylic, acetate, polyvinyl chloride, polypropylene). Woven fabrics, non-woven fabrics, synthetic leather, synthetic wood-impregnated fabrics, polyethylene films, polypropylene films, polyamide films, etc.
Polyvinyl chloride film, polyvinylidene chloride film, polyethylene terephthalate film, etc., including flexible or hard sheet plates.

In the method of coloring woven fabrics, non-woven fabrics, plastic films, etc. with lead white according to the present invention and 1-, in the case of woven fabrics and non-woven fabrics, lead white is used as a binder, such as an acrylic resin,
A method of blending with polyurethane resin etc.17 to make an oil-based or water-based paint, and impregnating or coating woven or non-woven fabrics with this paint.In the case of synthetic fibers, lead white is blended during melt spinning without post-coating etc. It is also effective to produce colored fibers using the five-color fibers, and then to make woven or non-woven fabrics using the five-colored fibers.

Furthermore, methods for coloring plastic film materials with lead white include: (1) A method in which lead white is blended into the plastic at the time of film production, that is, lead white is blended, and if necessary, stabilizers and stabilizers are added.
A method in which plasticizers, antioxidants, etc. are blended, and the product is formed into a film or sheet using a conventional method such as extrusion using a T-die method, an inflation method, or film formation using a calendar method; There is a method of applying UV reflective coloring to the surface of a plastic film by applying a polymer solution or dispersion containing lead white.

In the method (2), the binder used in the coating solution is one that has excellent adhesiveness to the base film. Useful polymers for this purpose include acrylic resins and polyurethane resins.

The lead white used in the camouflage ultraviolet reflective sheet of the present invention is used in an amount of 20 to 200% by weight, preferably 50 to 180% by weight, based on the sheet base material.

If the amount of lead white is less than 20%, the UV reflectance of the resulting camouflage UV reflective sheet will not be sufficient, and the concealing property will also be insufficient, which is not preferred. If the amount is more than 200% by weight, the resulting sheet will have lower bending flexibility and become hard, and will be more likely to break at low temperatures, and its ultraviolet reflectance will not be so good, which is not preferable.

Further, in the camouflage ultraviolet reflecting sheet of the present invention, in addition to the lead white described above, flame retardants such as chlorinated paraffin and antimony trioxide, and various other additives can be used in combination.

Hereinafter, the present invention will be specifically explained with reference to Examples.

Example 1, Comparative Examples 1 to 4 A vinyl chloride resin sol was prepared by kneading the formulations shown in Table 1 using a roll mill, and this was applied to a Tetoron e cotton blend fabric to a thickness of 0.3 mm. Apply it smoothly, 2
The camouflage ultraviolet reflective sheet of the present invention was obtained by heating and curing at 00° C. for 10 minutes.

The ultraviolet reflectance of the obtained sheet was measured using a Hitachi Model 330 self-recording spectrophotometer (measurement, reflection integrating sphere). The results are shown in Table 2 and FIG.

-Book list-U L1! ! Uj le 1 yu
Yu Dan 4I
100 100 100 100 100I
I 70 70 70 70
70m 3 3 3 3
3IV 85 V 85 ■85 ■ 85■
85 (Note) Values are parts by weight.

Engineering; Vinyl chloride emulsion polymer resin II; DOA III; Na-Zn soap ■
; Lead white V; Zirconium oxide ■; Barium sulfate ■; Magnesium carbonate ■; Magnesium oxide, 2- One wave - J [■ 1st instar - Anti-11 group voice Part seal υnaka ... ... ... Hainsetsu 98 H98978797 Example 1 98 95 95 95 95
95 Comparative Example 1 38 59 83 91 9
3 93 Comparative Example 2 5El 5B 71
8892 113 Comparative Example 3 51 56
B7 8El 1111 92 Comparative Example 4 4
8 49 49 58 78 89 (note)
The numerical value is the reflectance (%).

Examples 2-3, Comparative Examples 5-12 The formulations in Table 3 were calendered to a thickness of 0.1 mm.
A UV reflective sheet for camouflage according to the present invention was obtained.

The ultraviolet reflectance of the obtained sheet was measured using a Hitachi Model 330 self-recording spectrophotometer (measurement, reflection integrating sphere). The results are shown in Table 4 and Figures 2 and 3 □.

Branch JIIU! tJJ name
100
100 100 100II 1
00 m 50 50 IV 50 V 50Vl
50th day
dan 1dan, dan 12go 1
00 Ding T 100
100 100 100■ IV 50V
50■
50■ 50
5゜(Note)
Values are parts by weight.

I; Low-density polyethylene T; Thermoplastic polyurethane; Lead white; Zirconium oxide V; Barium sulfate; Magnesium carbonate; Upper I… World……” Snow H11811887979?Example 2
88 98 96 9fli 95
95 Example 3 94 95 95 9696
H Comparative Example 5 43 82 85 82
93 93 Comparative Example 6 59 59 73 9
0 92 92 Comparative Example 7 54 57 70
B7 91 91 Comparative example 8 49 52
59 83 90 91 Comparative example 9 34
57 83 91 83 93 Comparative example +0
54 55 70 89 92 93 Comparative example 11 48 54 83 85 90
92 Comparative Example 12 43 45 57 80
89 91 (Note) Values are reflectance (%).

(Function/Effect) The camouflage ultraviolet reflective sheet of the present invention has such whiteness that it cannot be distinguished from snow with the naked eye when placed on a snow surface.
In addition, zirconium oxide, barium sulfate,
Sheets using magnesium carbonate and magnesium oxide have a reflectance of 60% or more, whereas the reflectance of the purple line reflective sheet for camouflage of the present invention is 95% or more, which is very effective against snow; Calculate the reflectance.

Therefore, when the camouflage ultraviolet reflective sheet of the present invention is placed on a snow surface, it is difficult to distinguish it from snow not only with the naked eye but also with high-performance glue. It is very effective as a material for hiding objects that exist in snowfield environments.

[Brief explanation of the drawing]

Figure 1 shows the spectral reflectance curves in the ultraviolet and visible ranges of the sheets of Example 1 and Comparative Examples 1 to 4, and Figure 2 shows the ultraviolet and +il viewing ranges of the sheets of Example 2 and Comparative Examples 5 to 8. FIG. 3 shows the spectral reflectance curves of Example 3, Comparative Examples 9 to 12 in the violet range, and the visible range. Note that the vertical axis represents the reflectance (%), and the horizontal axis represents the wavelength of light (nl). 4ff Applicant Dai II Seika Nigyo Co., Ltd. Figure 1 Figure 2

Claims (1)

[Claims] A camouflage ultraviolet reflective sheet characterized by containing white lead as a white ultraviolet reflector.