JPH04355134A - Preparation of anti-glare sheet - Google Patents

Abstract

PURPOSE:To easily prepare an anti-glare sheet free from residual air bubbles or adhesion inferiority and having good transmissivity within a short time by bonding and laminating a transparent film to a stripe pattern sheet. CONSTITUTION:In the manufacture of an anti-glare sheet, a laminate is formed by alternately laminating transparent films or sheets and opaque films or sheets through adhesive layers in a multiple form and sliced so as to traverse the laminated surface thereof to obtain a stripe pattern sheet and a transparent sheet is laminated to the stripe pattern sheet through an uncured adhesive layer and the whole is deaerated under reduced pressure in a vacuum box and heated to cure the uncured adhesive layer.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing an anti-glare sheet.

0002

[Prior Art] Conventionally, when producing an anti-glare sheet, unvulcanized silicone rubber is dispensed onto a primer-treated transparent plastic film at a constant thickness, and then a transparent film or sheet and an opaque film are used. Alternatively, the striped sheet obtained by slicing across the laminated surface of a laminate in which sheets and sheets are alternately laminated with adhesive layers interposed therebetween is laminated with an unvulcanized silicone rubber layer inside, and then pressed. to remove air bubbles (about 16 hours),
Thereafter, the adhesive was cured by heating in an oven (100° C., approximately 1 hour).

0003

[Problems to be Solved by the Invention] However, with conventional methods, there is a limit to dispensing unvulcanized silicone rubber to a constant thickness, and it is difficult to reduce the dispensing thickness to 50 μm or less due to equipment and precision issues. It was extremely difficult. Furthermore, the long time it takes to remove air bubbles using a press has been an obstacle to automating the equipment. Furthermore, it was difficult to manufacture the plastic film with a thickness exceeding 0.6 mm. The present invention
This was done in an attempt to provide a new method that does not have the above-mentioned drawbacks and can easily produce an anti-glare sheet.

0004

[Means for Solving the Problems] The present invention has solved the above problems, and is a laminate in which transparent films or sheets and opaque films or sheets are alternately laminated with adhesive layers interposed therebetween. A striped sheet (hereinafter abbreviated as striped sheet) obtained by slicing across the laminated surface,
The gist of the present invention is a method for producing an anti-glare sheet, which comprises bonding transparent films together via an uncured adhesive layer, degassing under reduced pressure in a vacuum box, and then heating and curing the uncured adhesive layer. It is something.

[0005] The present invention will be explained in detail below. Known striped sheets and transparent films can be used as materials in the present invention, and RTV
Examples include silicone adhesives and acrylic adhesives, but liquid, transparent, solvent-free adhesives that cure at room temperature or by heating are preferred. In addition, adhesive application methods include roll coating, spraying, brushing, etc.
Screen printing is most suitable in terms of uniformity and precision. The coating thickness of the adhesive is preferably 10 to 40 μm.

[0006] For example, the following procedure may be used to apply the adhesive and bond the parts together. First, adhesive is repeatedly screen-printed in a predetermined area on one side of a roll of transparent film, and then the film is separated to create adhesive-coated film pieces. A sheet of film may be used for screen printing. Next, place the striped pattern sheet on top of the adhesive-coated film piece with the adhesive layer facing upwards, place the adhesive-coated film piece with the adhesive layer facing downwards, and sandwich the striped pattern sheet. Paste it together.

[0007] However, if the obtained bonded product is heated immediately, it will harden with air bubbles remaining, and the air bubbles may cause poor adhesion, so a vacuum degassing treatment is performed before heating. . During the vacuum degassing treatment, it is preferable to maintain a constant load at 0.1 Torr or less while applying a constant load to the bonded product of the striped pattern sheet and the transparent film. The load may be about 10 g/cm2, and for this, for example, as shown in FIG. A vacuum box can be used. In this way, the process can be performed regardless of the thickness of the bonded product 7. In this case, as shown in FIG. 2(b), the open-cell sponge sheet 10 is in a suspended state when no pressure is applied, and as it descends, it gradually touches the side edges of the bonded product 7. It is designed to be in contact with each other. For this reason, the striped sheet 5 and the film piece 3
, 4, the air bubbles will be pushed out from the bonded surfaces.

[0008] Next, the bonded product of the striped pattern sheet and transparent film that has undergone the above treatment is heated to harden the adhesive layer. The heating temperature may be usually 100 to 130°C, and the heating time may be usually 2 to 4 hours. In addition, in the present invention, it is also possible to adhere a transparent film to only one side of the striped pattern sheet, if necessary.

[0009]

[Example] Next, an example of the present invention will be given. A uniform mixture of liquid silicone KE1935A/B [manufactured by Shin-Etsu Chemical Co., Ltd., trade name, viscosity 400-800P] and primer was printed on a semi-automatic screen printing machine, Minomat 600, using a 150# mesh screen.
W [manufactured by Mino Group Co., Ltd., product name] is used to
), an adhesive layer 2 was provided on one side of a polycarbonate film 1 having a thickness of 0.3 mm to have an average thickness of 30 μm (maximum thickness 40 μm, minimum thickness 10 μm).

Next, as shown in FIG. 1(b), the polycarbonate film 1 having the adhesive layer 2 is cut, and a 0-thick film is placed on the adhesive-coated polycarbonate film piece 4 with the adhesive layer 2 facing upward. A 24 mm striped pattern sheet 5 was placed thereon, and then an adhesive-coated polycarbonate film piece 3 with the adhesive layer 2 facing downward was placed thereon, and the three were bonded together.

The laminated product 7 of the striped pattern sheet obtained above and the polycarbonate film piece is shown in FIG. 1(c).
As shown in FIG. 2, degassing was carried out in a vacuum box 6, but this was done in a vacuum box as shown in FIG. For degassing, use a vacuum pump to suck air from the exhaust port 11 at 0.1To
The test was carried out by holding the temperature below rr for 70 seconds. At the same time, in order to apply a uniform load to the bonded product 7, the load plate 9 whose weight has been adjusted is lowered from the state shown in FIG. 2(b) to the state shown in FIG. I applied a load. This brought the striped pattern sheet and polycarbonate film into close contact.

[0012] Furthermore, this closely bonded product is
The liquid silicone adhesive was cured by heating at 20° C. for 3 hours, and the striped pattern sheet and polycarbonate film were bonded together. Through the above steps, it was possible to easily produce an anti-glare sheet with no residual bubbles or poor adhesion with good reproducibility.

[0013]

[Effects of the Invention] According to the present invention, each process of applying adhesive to a transparent film, supplying a striped sheet, pasting, and degassing under reduced pressure in a vacuum box can be performed using a series of devices. , an excellent anti-glare sheet can be easily obtained without any bubbles remaining during adhesion or poor adhesion. Furthermore, since the thickness of the adhesive can be reduced, the light transmittance is improved compared to the case of bonding with conventional silicone rubber. Furthermore, if an adhesive that does not contain fillers such as silica is used, it is possible to reduce scattered light and improve functionality.

[Brief explanation of drawings]

FIG. 1 (a), (b), and (c) are explanatory diagrams of the method of the present invention.

FIGS. 2(a) and 2(b) are explanatory diagrams of a vacuum box used in the method of the present invention.

[Explanation of symbols]

1 Polycarbonate film 2 Adhesive layer 3, 4 Polycarbonate film piece 5 with adhesive
Striped pattern sheet 6 Vacuum box 7 Laminated product 8 Table 9 Load plate 10 Sponge sheet 11 Exhaust port

Claims (1)

[Claims] Claim 1: A striped sheet obtained by slicing across the laminated surface of a laminate in which transparent films or sheets and opaque films or sheets are alternately laminated with adhesive layers interposed therebetween, and an uncured transparent film. A method for producing an anti-glare sheet, which comprises bonding the sheets together via an adhesive layer, degassing under reduced pressure in a vacuum box, and then curing the uncured adhesive layer by heating.