JPS5878102A - Retroreflecting sheetlike material with superior weather resistance - Google Patents

Abstract

PURPOSE:To obtain a durable retroreflecting sheetlike material provided with weather resistance by laying a transparent surface resin layer and an adhesive layer each contg. an ultraviolet absorber, many transparent fine spheres, a focusing resin layer, a light reflecting layer and strippable paper. CONSTITUTION:A retroreflecting sheetlike material is composed of a transparent surface resin layer 1 maintaining certain optical relation, many transparent fine spheres 2, a focusing resin layer 3, a light reflecting layer 4 behind the layer 3, an adhesive layer 5 and strippable paper 6, and an ultraviolet absorber is added to the layers 1, 5. By forming micropores or fine slits through which the absorber passes actively in the layer 4, the amount of the absorber to be diffused or shifted can be controlled. The preferred absorber is 2, 4-dihydroxy-benzophenone or 2(2'-hydroxy-5'-methylphenyl) benzotriazole.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides durable, weather resistant, and highly recursive properties.
It is related to things like this.

Optical retroreflection (V-) is not only a physical quantity, but also has the characteristic that even at night, light incident at a normal or -night angle is strongly retroreflected.

Various transportation-related information, instructions, regulations, 51" gold markings, etc.

It is widely used as a sign for automobiles, advertising media, and decoration.

In some cases, insufficient resin is used. For this reason, the tree 11c is made of weather-resistant china clay with an ultraviolet absorber added thereto.

However, these ultraviolet absorbers are subject to large amounts of wear due to sunlight, and some resins have poor phase compatibility.
It has the disadvantage that it diffuses through the resin and flies off the surface, gradually reducing the concentration of the ultraviolet absorber in the resin.
It is said that it is female that gives durable weather resistance,
It had some problems. Depending on the contrast, determine the amount of UV absorber added.

There is also a method of predicting scattering and adding more than the specified amount, but if too much is added, the transparency of the resin may deteriorate (or the UV absorber may become discolored), and the ultraviolet absorber migrates and diffuses to the resin surface. This increases the amount of powder, causing problems such as dusting on one surface.

It was also difficult to increase the content.

The present invention improves the above-mentioned problems and provides a retroreflective material F-) which has durable weather resistance.

In other words, the present invention provides a recursive material that is composed of a transparent surface resin layer that maintains a certain optical relationship, a large number of transparent microspheres, a focusing resin layer, a light reflecting layer provided behind it, an adhesive layer, and a release paper. The reflective &-) shaped product C relates to a retroreflective V-shaped product with excellent weather resistance, which is formed by blending an ultraviolet absorber into a transparent surface resin layer and an adhesive layer, and further includes:
By providing the light reflective layer with a large number of microscopic pores or thin linear transmission grooves that more effectively transfer the ultraviolet absorber to the transparent surface resin layer side, the effect can be made even more effective.

The present invention will be explained below with reference to the drawings. FIG. 1 is a diagram of a sphere to which the method of the present invention is applied.

(1) is transparent surface - fat layer, (2) is transparent microspheres, (
S) is the back of the transparent microspheres (as a lens). The incident light is focused by the transparent microspheres to form a focal point. C) is the focal resin layer with the required thickness. It is a metal vapor deposited film provided as a light reflective layer on the back side, and these (
1), (ri, (萄), (4) is configured to maintain the optical relationship of the helmet and retroreflect the incident light. (5) is to attach the retroreflective V-) to the substrate. Adhesive layer for
(6) is release paper.

The transparent surface resin layer (1) is made of a thermosetting or thermowarmable transparent colorless resin, and these resins include Ak1y resin, Bori ester resin, 1μ Kid resin, and Metsushin resin. Resin, /l filled vinyl resin.

1*? Although resins such as resins and resins are used, generally resins such as resins, which have particularly good weather resistance, are used.

However, in the case of a flexible retroreflective oil (V-) as a special use oil, the above-mentioned ac-1y-based resin has poor softness, and the main ψ-urene-based resin or A flexible resin such as vinyl chloride resin is used as the transparent surface resin layer. However, these resins generally have poor weather resistance, and as mentioned above, ultraviolet absorbers are added to the resins to improve their weather resistance, but the UV absorbers are consumed by the sun's rays. , Also, the compatibility with the resin is poor (,
It diffused through the 11 m and was scattered from the surface of 5 mg 1 t.The problem of poor sustainability of weather resistance emerged.
6. The present invention aims to improve the above-mentioned problems by incorporating an ultraviolet absorber into the transparent surface resin layer.

By bonding the adhesive layer IC4ffi, it is intended to provide durable weather resistance.

In general, it has a light-reflecting layer that may also be a metal vapor (F-)
In autumn products, the light-reflecting layer acts as a light-shielding plate, so it is pointless to add a LiC ultraviolet absorber to the back of the layer. It was discovered that the absorbent passes through the light reflective layer and diffuses onto the surface, and the present invention C11 was achieved. In other words, the ultraviolet absorber combined with the adhesive layer has *recursive radiation V-)
When used outside the layer of a material, it permeates and moves through the metal vapor deposited film or focal resin layer, which is a resistance layer, and gradually continues to diffuse in the fat layer, imparting durable weather resistance. It is. A further advantage of the present invention is that problems such as decreased transparency and coloring of the resin layer due to the inclusion of a large amount of external ray absorbing lI4 are not a problem because the adhesive layer is not related to the optical path. Furthermore, since sunlight is blocked by the light-reflecting layer, the ultraviolet absorber is not consumed by sunlight (it is extremely stable and can maintain its weather resistance for a long period of time).

It is also possible to control the amount of diffusion and transfer of the ultraviolet absorber by providing micropores or narrow linear transmission grooves through which the ultraviolet absorber actively passes through in the armpit light resistance layer. Ta Jshi.

When pores or linear-super pores are provided in the light reflecting layer.

The area of the light-reflecting part decreases, causing a drop in the reflected brightness, so the UV absorber can pass through.

It is desirable to make the pores as small as possible.

The ultraviolet absorber used in the present invention includes 2.4-s
Ft Doro etc. V benzophenone, 2-hand W Ki V-4-n
-Ota) Kirebenzophenone, 2.2'-Dinido w
F-4.4'-sr) IIPv benzophenone.

2-t**F-4-fi＞*V-5-x#ds 612 (2'-OtoriQV-5'-MethipFue#)bensitoψazo-Ne
t(2'-*do wav-3', 5'-II-V palm-
Ami ~ Hue N) Benzo such as Pensito 1 Azo-p)! Azole compounds? Preferred are 9-thi-acid ester compounds such as 9-thi-acid ester compounds such as 9-thi-acid ester compounds such as 9-thi-acid ester compounds such as 9-thi-acid ester compounds, and Pahu t-butyl al-A/f so-thi-acid ester compounds.

Other UV absorbers 1 e.g. 2-ethy~-hex5tx
t-2-Va/-s, s'-yyx=sty relay)
etc. can also be used. These ultraviolet absorbers may be used alone or in combination of two or more. Further, an antioxidant, an IR fixative, etc. may be appropriately added together with the ultraviolet absorber.

Next, the complete WI4vt will be further explained using an example.

Example 1 One-component hardening type soft melt? 2 (2'-human F, S', St-Nl) as an ultraviolet absorber in Lane resin.
-s””rw-y Flies sp Feni k) Benzo) Hibiki Azo-A
/ to form a transparent surface resin layer by adding 2 weights of If a light reflecting layer is installed from the top surface of A71/@Nium**C, it will reflect the light y->*? IIF Isu・ru.

Furthermore, UV absorber 2 (2I-Hidoki $
/, 3', S'-8'JI-r'r! -71#7!
Wlkl) Adhesive t-made of modified urethane tea tree A containing 4% by weight of benzo) azo azo A/directly applied, +
A desired retroreflective F-) was obtained by pasting w+sy paper. The reflective V-) shaped object configured in this way is JI8
- A weather resistance test was conducted by irradiating for 200 hours and 400 hours using a V-yain carbon type accelerated weather resistance test according to Z-9117. Weather resistance rating is from J to Z
According to the reflection performance test of Reflection F-) described in -91171c, observation angle 0.2@, incident angle -4", 50°, 50@
The reflected brightness was measured and compared using the average value of the retention rate (excellent) of the reflected brightness of the unirradiated reflective V-tab material for each incident angle C*t. The results are shown in Table 1.

Example 2 The reflective S/-) created in Example 1 before applying the adhesive was heated and pressed from the light-reflecting layer side on the back side with an embossed field with a tortoise-shell pattern of a polytechnic square with a side length of 2 squares. and approximately 0 on the light reflective layer.
．． The zero-order reflection F- is carved with a tortoiseshell-like linear groove of 21 widths.
A pressure-sensitive adhesive tm containing 4% by weight of Oka's ultraviolet absorber and WnW-resistant layer WnW-Example 1 was applied to the light of No. 1, and a release paper was attached to obtain a retroreflective material. The retention rate of reflection brightness of the reflective V-) product after the weather resistance test was as shown in Table 1.

Comparative Example 1 To Example 1 and Okaji (F-) containing 2 weights of ultraviolet absorber GS?V methane fat as a transparent surface resin layer,
An adhesive containing no ultraviolet absorber was applied, and a release paper was pasted on top of the adhesive to create a retroreflective V-) shaped article. *
The retention rate of reflection brightness after the weather resistance test of the reflective F-1 type product was as shown in Table 1.

Comparative Example 2 A retroreflective V-F-shaped product was produced in exactly the same manner as in Example 1, except that no ultraviolet absorber was added to the surface resin layer and adhesive layer. The reflection brightness retention rate of the reflection F- shaped product after the weather resistance test was as shown in Table 1.

Table 1 As is clear from Table 1, the retention rate of the reflective brightness of the retroreflective r-H shaped material of Example 1.2 was 400/hour in the V-yain carbon accelerated weathering test cm. Even in the case of irradiation C, the results were extremely good. Remarriage reflex V- of Comparative Example 1
)-like material, the reflection brightness decreases sharply from 200 hours to 400 hours (it can be seen that the durability of the weather resistance effect of the UV absorber is poor.In addition, the product of Comparative Example 2 without the UV absorber) The brightness of the summer material of the retroreflective V-) type material is 0 or more, which shows a significant decrease even with irradiation during closed and closed hours. It is clear that it is in possession.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal cross-sectional view of the retroreflective F-) product according to the present invention. (1) - Transparent surface resin layer, (2) - Transparent microspheres, (
1) - Non-dot resin layer, (4) - Light reflective layer, (Xun - Adhesive layer, (Ou - Release paper patent applicant Unitika Co., Ltd.)

Claims (1)

[Claims] (1) A transparent surface with a certain optical relationship
In the recursive #v-t-like article, it consists of a layer, a large number of transparent microspheres, a focusing resin layer, a light reflecting layer on the back thereof, an adhesive layer and a release paper. #v-Tote-shaped material with excellent recursive properties as described in Item 1, which is made by blending a transparent surface resin layer and an adhesive layer C* with an external ray absorber.