JPS583830B2 - Saikisei Handshashi - Tojiyoubutsunoseizouhou - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for manufacturing a retroreflective sheet, and its purpose is to have excellent flexibility, a matte effect on the surface of the reflective material, and good air circulation. Our goal is to provide innovative suede-like retroreflective leather that also serves as a combination of materials.

Conventionally, efforts have been made to make the surface structure of reflective sheets as smooth as possible to improve reflective brightness, but when used as clothing, the smoothness reduces the value as clothing.

In the present invention, the foamed surface resin layer is physically or chemically post-treated during the manufacturing process of the retroreflective sheet to give the surface a suede-like appearance with a raised or fluffy structure, thereby significantly reducing the reflective brightness. This is a manufacturing method for obtaining retroreflective leather that is suitable for clothing without causing deterioration, and when the retroreflective leather of the present invention is used as outer clothing, it can be used even at night when visibility is poor, such as by car headlights, etc. It shines brightly when illuminated by lights, making it possible to accurately notify drivers of its presence even from a distance, and playing a major role in preventing traffic accidents.

To explain the present invention with reference to the drawings, FIG. 1 shows that a transparent foaming surface resin 2 is applied onto a temporary base 1 such as a release paper or a polyester film, and in a pre-drying process, a part or all of it is chemically or Physically foam.

Here, the preferable surface resin 2 is soft polyvinyl chloride,
These materials include soft polyurethane, polyamide, and soft acrylic resin, to which plasticizers, stabilizers, pigments, and the like may be added as appropriate.

Surface resin 20 foaming methods include a physical foaming method in which gas is mechanically mixed into the resin, a method in which gas is dissolved in the resin at high pressure and the gas is expanded at normal pressure, and a volatile liquid is used as a foaming agent. Examples of the chemical foaming method include a method in which a chemical foaming agent is thermally decomposed in a resin at an arbitrary temperature to form foam.

What is important in the pre-drying process of the surface resin 2 is the next step of dispersing and fixing the glass microspheres 3. In order to fix the glass microspheres 3 into a single layer with as uniform a height as possible, the foaming should be as small as possible. The surface should be finished as smooth as possible.

Next, a transparent fixing resin 4 for fixing the glass microspheres 3 is applied, and after semi-drying, a large number of glass microspheres 3 are scattered, and the lower hemispherical part is buried and fixed.

Here, a transparent focusing resin layer 5 with a concentric hemispherical shell approximately corresponding to the upper hemisphere of the glass microsphere is provided at a position corresponding to the focal point of the glass microsphere 3 as a lens, and the temperature is raised to a temperature that completes foaming of the two surface resin layers. After the heat treatment, the reflective layer 6 is provided.

The most suitable size of the bubbles in the two surface resin layers thus formed is 10 to 100 microns, which is about the same as the glass microspheres 3, and it is important that they have an open cell structure. This causes diffused reflection after the surface is post-treated, which significantly impedes the original retroreflection performance, which is not preferable.

Next, when the retroreflective sheet obtained by the above method is used as retroreflective leather or cloth, a step of joining it to a base fabric 7 such as a knitted fabric or a nonwoven fabric is included, but in this case, the retroreflective sheet finally obtained A sealing resin 8 is applied to the base fabric side so that the surface of the object becomes substantially flat regardless of the weave or knitting structure of the base fabric, and after semi-drying, it is adhered to the back surface of the reflective layer 6. is desirable.

In this case, a reflective material such as metal aluminum powder may be dispersed in the sealing resin 8.

Figure 2 shows a cross section after the temporary base 1, such as release paper or polyester film, has been finally peeled off, a part of the physically or chemically foamed surface resin layer has been removed, and it has been post-processed to create resin fuzz 9. It is a diagram.

The length of this suede-like fuzz 9 can be freely adjusted to a length that does not impair the retroreflective angular characteristics.In addition, it can of course be used as a foamed surface, in which case it will have a different texture and an iridescent appearance. do.

Although the present invention will be described in detail with reference to specific examples below, the present invention is not limited to the present invention.

Example: On a polyester film with a thickness of 75 microns as temporary base 1, foamed vinyl chloride plastisol of the following formulation was applied to a thickness of 0.5 mm using a top-feed reverse roll coater, and the coated glastisol was heated to 120°C. After gelation, a resin solution for fixing the glass microspheres is applied.

Composition of expanded vinyl chloride plastisol Diversion type vinyl chloride resin 100 parts Dioctyl phthalate 70 parts Tricresyl phosphate 50 parts Barium-cadmium stabilizer 5 parts Azodicarbonamide blowing agent
The composition of the resin solution for fixing the 15-part glass microspheres is a one-component flexible polyurethane mixed solvent resin solution of toluene and ingropanol with a solid content of 25% (weight concentration), which is applied to a constant thickness.

After drying the fixing resin at 80°C for 2 to 3 and a half minutes, the refractive index was 2.2.
Glass microspheres having an average diameter of 53 to 63 microns are uniformly scattered, the lower hemispherical surface of the glass microspheres is buried 70 to 80%, and the glass microspheres are dried at 120° C. for 5 minutes to fix the glass microspheres.

Next, a toluene-butanol solution of a soft acrylic resin with a solid content of 30% is applied as a focal resin to a constant thickness that provides the highest reflection brightness, and is dried at 150° C. for 5 minutes, at the same time completing foaming of the surface resin layer.

The formed focal resin layer forms a concentric hemispherical shell along the upper hemispherical surface of the glass microsphere.

Subsequently, aluminum is vacuum-deposited on the surface of the focal resin layer to form a reflective layer, and the film is then wound up.

Next, 100% polyester woven taffeta was used as the base fabric, and two-component flexible polyurethane with a solid content of 6 was used as the sealing resin.
A 0% ethyl acetate solution is applied so that the surface of the base fabric is substantially flat, and then semi-dried at 60° C. for 1 minute until tack remains.

In this case, the step of sealing the base fabric may be applied two or more times depending on the type and structure of the base fabric.

Next, the aluminum vapor-deposited surface of the retroreflective sheet previously obtained is laminated and pressure-bonded to the surface of the adhesive base fabric, and heat-treated at 130.degree. C. for 3 minutes to ensure complete adhesion.

Finally, the temporary paste of the polyester film is peeled off, and the foamed surface resin layer is used to form a fluff with a length of about 20 microns using a high-speed rotating abrasive machine to form a suede-like retroreflective sheet with good retroreflectivity. I got something.

Note that it is also possible to perform post-processing such as needling in order to impart air permeability and moisture permeability to the retroreflective sheet material as clothing.

The retroreflective sheet material obtained by the method of the present invention can be used by traffic police officers at night, school children driving motorcycles, etc., regardless of rain or shine.
It is effective in various uses, including safety clothing for preventing traffic accidents such as when working on railroad tracks, as well as fashion clothing, reflective fabric products for indoor equipment, and decorative items because of its special brightness.

[Brief Description of the Drawings] Fig. 1 is a sectional view of a retroreflective sheet showing one implementation step of the method of the present invention, and Fig. 2 is a final sectional view of the retroreflective sheet of the present invention. . 1 is a temporary base, 2 is a surface resin, 3 is a glass microsphere, 4 is a fixing resin, 5 is a focal resin, 6 is a reflective layer, 7 is a base fabric, 8
9 is a sealing resin, and 9 is a fluff.

Claims (1)

[Claims] 1. A transparent surface resin layer is applied on a temporary base, the resin layer is foamed by a chemical or physical method, a fixing resin layer is applied on top of the resin layer, and after semi-drying, a large number of microlens spheres are scattered. The lower hemispherical portion is buried and fixed therein, and a transparent focusing resin layer having a concentric hemispherical shell approximately corresponding to the upper hemispherical surface of the microlens sphere is formed, a light reflecting layer is provided on the surface of the focusing resin layer, and a base fabric is formed. A method for producing a retroreflective sheet-like article, which comprises peeling off the temporary base and removing a portion of the foamed surface resin layer by a physical or chemical method.