JPS6236480A - Adhesion method using adhesive - Google Patents

Abstract

PURPOSE:To conduct bonding through a simple step under excellent working atmosphere without a risk of damaging an adherend, by applying a nonsolvent soln., which forms an adhesive through radiation of an electromagnetic wave, on the bonding surface of at least one adherend and bonding the bonding surfaces. CONSTITUTION:A nonsolvent soln. (e.g., liquid acryl/rubber/photosensitizer compsn.), which forms an adhesive upon exposure to an electromagnetic wave, is applied on the bonding surface of at least one of adherends. The soln. may be applied on the bonding surface of one adherend or on the bonding surface of each adherend. Examples of the electromagnetic wave include light rays, particularly radiation such as ultraviolet rays and gamma rays, alpha rays, beta rays, X rays and electron rays. The ultraviolet rays can be obtd., e.g., from a high- pressure mercury lamp, ultrahigh pressure mercury lamp, xenon mercury lamp, etc. Radiation of the electromagnetic wave for several sec to several min leads to formation of an adhesive on the bonding surface. In the final step, the bonding surfaces of the adherends are bonded to each other. In this step, the adherends can be firmly bonded, e.g., by simply passing through between pressing rolls or press tightening the adherends at a predetermined pressure.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to an adhesion method using an adhesive, and more particularly to an adhesion method using a solvent-free solution that forms an adhesive by irradiation with electromagnetic waves.

<Prior Art and Problems> Conventionally, pressure-sensitive adhesives and adhesives have been widely used to bond adherends together. Double-sided tape with release paper attached to both sides is known as an adhesive, but it can be used to bond adherends together.

First, cut the double-sided tape to the length to be pasted, then peel off the release paper on one side and apply it to one adherend, then peel off the release paper on the other side and apply the other adherend. It is extremely difficult to automate the process because it requires a large number of steps and is complex.

In addition, hot-melt adhesives and solvent-volatile adhesives are known as adhesives, and since both can be applied directly onto the adherend, it is relatively easy to incorporate them into automated processes, but the former Since it has to be melted, if the melting temperature is high, the adherend may be damaged by heat, and if the melting temperature is low, the viscosity increases, making it difficult to coat, and the coating layer becomes thick. On the other hand, in the latter case, it takes time for the solvent to volatilize, and the adherend may be eroded by the solvent.
In addition, it is necessary to be careful of fire caused by volatilization of the solvent, and it is necessary to install an explosion-proof device, which increases equipment costs and also causes problems in the working environment due to the solvent.

Light-curing adhesives and two-component poxy adhesives are known as adhesives, but the former cures by irradiation with light and cannot be applied unless the adherend is light-transmissive. The latter requires weighing and mixing the two liquids, resulting in a complicated process, and has disadvantages such as pot life problems and the need for a pressing jig for curing after bonding.

In the case of manufacturing optical discs, conventional adhesives include two-component poxy adhesives, double-sided tape adhesives, and solvent-based adhesives.

Hot-melt adhesives have been used, but in addition to the problems mentioned above, hot-melt adhesives have poor heat resistance because they are true melts, and they tend to peel off when the temperature rises. This can lead to quality and product problems. In addition, hot melt coating requires thick coating, which deteriorates the flatness of the disk, and requires higher pick-up performance. Furthermore, in order to avoid affecting the disc material when heating and melting it at high temperatures and applying it, the applicator is of an upper tank type so that the heat from the tank does not affect the disc, but due to the structure of the tank, the applicator There are disadvantages such as defects such as sagging, sagging, falling on the disk and forming a pile, and bulging in that area after lamination, resulting in a defective disk.

<Problems to be Solved by the Invention> According to the present invention, an adherend can be attached through a simple process, there is no fear of damage to the adherend, and special jigs and equipment other than the irradiator are required. It is an object of the present invention to provide a bonding method that can perform bonding in a good working environment without the need for , and can also be automated.

Means for Solving Problems> According to the present invention, in an adhesive method using an adhesive, a solvent-free solution is used to form an adhesive on one or both adhesive surfaces of adherends to be adhered by irradiating electromagnetic waves. a step of applying electromagnetic waves to the adhesive surface coated with the solution to form an adhesive; and a step of bonding both adhesive surfaces and attaching an adherend. An adhesion method is provided which is characterized in that:

The present invention will be explained in more detail below.

In the present invention, first, a solvent-free solution that forms an adhesive is applied to one or both adhesive surfaces of adherends to be adhered by irradiation with electromagnetic waves. Such solvent-free solutions are liquid acrylic/
There are rubber/photosensitizer-based compositions, and permanent adhesive types are commercially available (trade names: "CEMEDINE CTl0IJ" and "CEMEDINE CTl0IJ").
Cemedine CT103J (manufactured by Cemedine ■) and adhesive-disappearing type (trade name "Cemedine CT 102" manufactured by Cemedine ■) can be used. The solvent-free solution used in the present invention does not contain volatile solvents (b, those below 9180°C) and does not have the above-mentioned problems associated with solvent volatilization, and since it is in a solution form, applicators etc. Since it can be easily applied to the adhesive surface of an adherend, it can be easily incorporated into an automated process. In the bonding step of the present invention, the solution may be applied to the bonding surface of one adherend, or may be applied to the bonding surfaces of both adherends, respectively.

Next, electromagnetic waves are irradiated onto the adhesive surface coated with the above solution. Electromagnetic waves include light, mainly ultraviolet rays, gamma rays, alpha rays,
Radiation such as β-rays, X-rays, and electron beams can be used. When using the aforementioned commercial product, it is irradiated with ultraviolet rays. Ultraviolet rays can be obtained from, for example, high-pressure mercury lamps, ultra-high pressure mercury lamps, xenon mercury lamps, carbon arc lamps, metal halide lamps, and the like. In the case of an automated process, the material may be passed through the irradiation of such a device at a predetermined speed. An adhesive is formed on the adhesive surface simply by irradiating it with electromagnetic waves for a few seconds to several tens of seconds. In this irradiation step, since the adhesive surface is exposed and irradiated, the adhesive can be formed without depending on the electromagnetic wave permeability of the adherend.

As the final step, the adhesive surfaces of the adherends are joined and pasted. In this process, for example, the adherend is passed between pressure rolls,
It is possible to firmly bond adherends simply by tightening with a predetermined pressure.

For example, when the bonding method of the present invention is applied to the production of optical disk plates, the above-mentioned solution is applied to the signal back side of one or both of the optical disk plates, and the two optical disk plates are bonded together in the above-mentioned process. Accordingly, it is possible to automatically manufacture an optical disc plate that can be used in both cases.

The types of optical discs mentioned here include read-only (ROM), write-once type (DRAW), and erase/rewrite type (R/WM).Specifically, read-only types include optical video discs and compact discs. (CD) etc.
Write-once types include color image files, document files, code information files, etc., and erase/write types include document files, image files, code information files, etc.

<Effects of the Invention> Since the present invention uses an adhesive, it is possible to adhere even if the adherend is made of a material that is difficult to adhere to, such as polyethylene or polypropylene. Further, the bonding method of the present invention can be applied not only to permanent bonding but also to temporary bonding.

When the method of the present invention is applied to the production of optical discs, the above-mentioned problems are solved, and the problems of Hot Null 1 to Adhesives are solved. Regarding the issue of heat resistance, since liquid acrylic is used, a certain degree of crosslinking is possible.
Heat resistance can be improved, and the flatness achieved by thick coating can be applied with low viscosity, so there is no burden on the pickup and performance is stable. In addition, since no heat is used, there are no equipment defects and variations in quality are reduced.

In addition, in the production of this optical disk, both the permanent adhesive type and the non-adhesive type can be used without any practical problem, as mentioned previously, but the permanent adhesive type is more preferable because it causes less stress distortion due to curing.

Example 1 Adhesive solution that forms an adhesive by light irradiation on a metal operation panel for an electrical control box, "CEMEDINE CTl0IJ"
(Acrylic permanent adhesive type, Cemedine ■Crack) was applied uniformly to a thickness of 25μ using a Baker applicator.
Irradiate the inside of the ultraviolet irradiation device (manufactured by Aikurafiku ■, metal halide lamp 120W/■, 15 fish height, cold mirror parallel light reflector) at a speed of 1.4 m/ll1 inch to form an adhesive on the metal panel. On top of this adhesive layer, a polyester operation sheet panel was pasted and adhered from the edges using a hand roll to avoid air bubbles. The control box joined in this way could be used without any practical problems.

Example 2 To bond a polyethylene sheet onto an aluminum plate for masking purposes, Cemedine CTl0I (same as in Example 1) was uniformly applied to the area where the polyethylene was bonded, and UV rays were irradiated in the same manner as in Example 1. , after forming an adhesive and pasting polyethylene on top of it for masking.

Water-based paint (rLaticote 7728X5J (P
(manufactured by KS): 95 parts, p-toluenesulfonic acid: 0
．． Part 5, “EM Color Yellow FG J (
5 parts) manufactured by Toyo Ink) was applied by spray, and after drying, the polyethylene sheet was peeled off, the coating was baked at 130° C. for 10 minutes, and the adhesive was removed by washing with trichlene. The painted surface was very clear.

Example 3 Cemedine CT 102J (acrylic adhesive disappearing type, manufactured by Cemedine ■) was applied to the signal surface (acrylic surface protection coat) of an acrylic board for optical discs with a diameter of 120 mm and a thickness of 1.2 mm. An adhesive was formed in the same manner as above.The other optical disc was also coated in the same manner to form an adhesive, and the adhesive surfaces were bonded together to give 2 iCg/a.
They were joined by applying a clamping force of 1. Both sides of the optical disc plate thus produced could be used, and there were no practical problems.

Example 4 Cemedine CTl0IJ (acrylic permanent adhesive type, manufactured by Cemedine ■) was applied to the signal surface (acrylic surface protection coat) of an acrylic plate for optical discs with a diameter of 300 mm and a thickness of 1.2 m, and the same procedure as in Example 1 was applied. An adhesive was applied to the other optical disc.The other optical disc was coated in the same manner to form an adhesive, the adhesive surfaces were pasted together, and a pressure of 2 kg/cJ was applied to join them.The optical disc made in this way Both sides of the board could be used, and there were no practical problems.

Example 5 “CEMEDINE CT 1” was placed on the same optical disk board as in Example 4.
Even if 03J (acrylic permanent adhesive type, manufactured by Cemedine ■) was applied in the same manner as in Example 1, there was no practical problem.

Patent applicant: Cemedine Co., Ltd. Pioneer Co., Ltd.

Claims (1)

[Scope of Claims] 1) In an adhesive method using an adhesive, a step of applying a solvent-free solution that forms an adhesive by irradiating electromagnetic waves to the adhesive surface of one or both of the adherends to be adhered; An adhesion method characterized by comprising the steps of irradiating electromagnetic waves to the adhesive surface coated with the solution to form an adhesive, and joining both adhesive surfaces and attaching an adherend. . 2) The bonding method according to claim 1, wherein the adherend is an optical disk plate.