JP2003003148A - Method for adhering synthetic resin plate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for butt-bonding synthetic resin plates each other, having an irregular surface of the resin plate or a secondarily processed face such as a printed or coated face, and for obscuring the bonded line without affecting to bonded part. SOLUTION: This method comprises injecting a polymerizable adhesive of a photocurable type into a butt-bonding part and irradiating the adhesive with ultraviolet rays to cure, wherein the adhesive contains a raw material monomer composing an adhered substrate resin plate.

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 a large display board, a screen sheet for images, a large signboard, etc. using various synthetic resin plates, and the surface of the synthetic resin plate is a finely uneven design. This is a processing technology used for expanding the area of products by butt-bonding resin plates that have undergone secondary processing such as patterns, lens shapes, printing or painting.

[0002]

2. Description of the Related Art Since an ordinary synthetic resin plate is manufactured in a shape and a size that are limited by a manufacturing method, end faces are butt-bonded to each other in a large-sized application. As the adhesive, a dope type in which a normal resin component is dissolved in a solvent or a polymerization adhesive type in which a reactive monomer and a polymerization initiator (curing agent) are mixed are used.

In the former case, there are drawbacks such as poor appearance and low strength due to the inclusion of air bubbles in the adhesive portion after solvent drying. In the latter case, these points can be improved, but the reaction time is long, so that there is a problem in workability, and Since the secondary processed uneven shape (design pattern etc.) of the resin plate and the printed part are soaked by the contact of the adhesive monomer liquid, the adhesive periphery becomes cloudy or the pattern or pattern is deformed to improve the quality of the product. It was a significant loss.

[0004]

Since it is used as a large panel, it has a good appearance in which the bonding line is hard to see without immersing the bonding part in the butt-bonding of the surface having an uneven shape and the printed or painted resin plates, and it is used as a large panel. Bonding method with high adhesive strength.

[0005]

A photo-curing type polymerizable material is used in butt-bonding of synthetic resin plates having a design pattern or a lens pattern or a secondary processed surface such as a printing surface on one side or both sides in contact with an end surface to be bonded. An adhesive method in which an adhesive is injected and the material is irradiated with ultraviolet rays to cure.

The synthetic resin plate to be bonded in the present invention may be any material that can be polymerized and bonded with a material used for a transparent or semitransparent large display panel or a large screen, and is usually a methacrylic resin, a polystyrene resin, or a monomer of both. Examples of the resin include MS resin obtained by copolymerization with, or polycarbonate resin.

There are cases where the synthetic resin plate is formed with a concavo-convex pattern for design purposes or a lens-type pattern for the purpose of obtaining a specific optical diffusion effect, such as a photographing screen.

These patterns are formed by a profile extrusion molding method in which a discharge die of a sheet extrusion molding machine is provided with a pattern shape, or after molding a flat plate with a similar molding machine, followed by an in-line method or an off-line method at a high temperature. There is a method of die pressing.

As another method, a method of transferring the surface pattern of the mold at the time of casting and curing by a cast polymerization method to obtain a resin plate with a mold, a UV curable resin or the like on the flat plate surface obtained by the above extrusion molding or cast polymerization method And a method of forming a design or a pattern shape.

The photocurable adhesive used in the present invention may be one which exhibits adhesiveness between these materials by a method capable of being polymerized and cured by a high energy ray such as an ultraviolet ray in a very short time such as several minutes to several tens of minutes. Good. It is conceivable that the reaction curing does not affect the surface of the synthetic resin plate of the adherend because the effect of the contact of the adhesive at the butt-bonded portion is small when the reaction curing is short.

The polymerizable monomer is a vinyl-based, allyl-based, acryl-based or methacrylic-based monomer having at least one double bond in the molecule.

Specifically, as monofunctional monomers, in addition to acrylic acid and methacrylic acid, alkyl acrylates such as methyl acrylate and ethyl acrylate, methyl methacrylate, butyl methacrylate or their hydroxy compounds are included. Examples thereof include alkyl methacrylic acid esters, styrene monomers, and acrylonitrile monomers.

The polyfunctional monomer is an acrylic type such as ethylene glycol dimethacrylate or an allyl type such as diallyl phthalate. These polyfunctional monomers have a crosslinked structure obtained in the course of polymerization and curing, and can improve the durability and heat resistance stability of the adhesive part.

In order to enhance the adhesive strength of the synthetic resin plate to be adhered in the present invention, it is effective to include a monomer component constituting the synthetic resin, and if it is 20% by weight or more based on the total amount of the photocurable adhesive. However, if the amount of the monomer component is too large, the shape pattern formed on the surface of the resin plate is likely to be dipped, so that it is preferably within 50% by weight at the maximum.

Further, in order to improve the practical strength in the cutting process and finishing process of the adhesive portion, it is preferable to make it soft, and if a copolymerizable reactive softening agent is added to the photocurable adhesive of the present invention. good. As the polymerizable softening agent, the lower the glass transition point (Tg) of the polymerized and cured product alone, the better, and practically 2
Effective below 0 ° C.

Examples of the polymerizable monomer having a Tg of 20 ° C. or less include n-hexyl methacrylate, methyl acrylate, ethyl acrylate, n-propyl acrylate, i-butyl acrylate, n-butyl acrylate,
2 Ethylhexyl acrylate and the like. (From "Functional Acrylic Resin" published by 1985 Techno System)

The addition amount of these is more than 20% by weight of the photocurable adhesive, but if too much, the heat resistance of the bonded portion will be lowered, so that it is practically preferable to be 30 to 50% by weight.

As another softening method, an elastomer material such as acrylic rubber or butadiene rubber may be added to and dispersed in the photocurable adhesive of the present invention to be adhesively cured.

The photopolymerization initiator to be added to the photocurable adhesive used in the present invention may be any photopolymerization initiator that can be radically polymerized by ordinary ultraviolet rays, such as acetophenone-based, benzophenone-based, benzoin-based, thioxanthone-based, acylphosphine. It is a variety of fin oxide compounds.

The addition amount of these photopolymerization initiators is usually 1.0 to 5.0 parts by weight based on the whole photocurable adhesive.
Particularly in the butt-bonding of a plate-shaped material having a wall thickness as in the present invention, since the deep-part curability is lowered, by combining with an initiator having a light absorbing property in the long wavelength side of the ultraviolet region or in the visible light region, the meat A more uniform polymerization and curing can be obtained even in the thick interior.

In order to make the butt adhesive lines inconspicuous in the photocurable adhesive used in the present invention, a coloring pigment, inorganic silica, barium sulfate, or oxidation is added so as to match the color and light diffusivity of the adhered synthetic resin plate. Light diffusion is added such as titanium or organic based crosslinked polyester beads.

The adhesive curing method of the present invention is an ordinary apparatus capable of irradiating ultraviolet rays, for example, a high pressure mercury lamp or an ultraviolet light emitting type chemical lamp, which can be easily polymerized and cured by irradiating a butt-bonded portion at a constant speed. it can.

[0023]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be specifically described below with reference to Examples.

Example 1. A synthetic resin plate containing a methyl methacrylate resin as a main component and having a lenticular lens pattern on one surface was preliminarily polymerized with a 1.1 mm thick screen sheet as a photo-curing adhesive in butt bonding as shown in FIG. , 30% by weight of ethyl acrylate as a softening agent in a polymerizable syrup made of a methylmethacrylate monomer containing 30% by weight of polymethylmethacrylate (Tg
-22 ° C.), and further 2.0 parts by weight of hydroxycyclohexyl phenyl ketone (IRGACURE 184 manufactured by CHIBA) as a photopolymerization initiator was added for adjustment.

As shown in FIG. 1, the periphery of the adhesive was protected with a tape, and after the adhesive was injected, it was exposed under a high pressure mercury lamp (12
0 m / m) with an irradiation distance of about 10 cm
The butt-bonded portion was repeatedly irradiated twice at an in-speed to be polymerized and cured. Except for the protective tape, the protruding cured product was finished and the transmission image was observed with a slide projector. As a result, as shown in Table 1, a good appearance was obtained without invading the periphery of the adhesive part, and the adhesive strength was also practical. It was recognized that it was high enough to endure.

[0025]

Example 2. The synthetic resin plate of the adherend, the photo-curing initiator, and the butt-bonding method were the same as in Example 1, and the softening agent ethyl acrylate was increased to 50% by weight as the photo-curing adhesive. It was good and the finish workability could be further improved.

[0026]

Example 3. The synthetic resin plate of the adherend, the butt bonding method and the photopolymerization initiator were the same as in Example 1, and methyl acrylate (T) was added as a softening agent to be added to the photocurable adhesive.
g 8 ° C.) was set to 30% by weight and evaluated by irradiation with ultraviolet rays. As a result, the appearance and finish workability were maintained and the strength was sufficiently good.

[0027]

Comparative Example 1. A synthetic resin plate and a butt-bonding method are the same as those in Example 1, and a softening agent ethyl acrylate is used as an adhesive in a main component monomer of a commercially available two-component polymerization adhesive for acrylics Akribomed (manufactured by Mitsubishi Rayon Co., Ltd.).
As a result of adding 4.0% by weight of the curing agent and injecting it, the adhesive could be cured after about 1 hour at room temperature, but as a result of observation after finishing processing, the adhesive line was noticeably white in the projector projection and became conspicuous.

[0028]

Comparative Example 2. Fig. 1 shows a butt-bonding method for synthetic resin plates.
As a photo-curing adhesive, a prepolymer containing only a methylmethacrylate monomer as a photo-curing adhesive was used to carry out adhesive curing in the same manner as in Example 1 as a method for curing the adhesion of a photopolymerization initiator and ultraviolet rays. This product is liable to be chipped during finishing, and it is difficult to obtain a good product.

[0029]

Comparative Example 3. The synthetic resin plate and the butt-bonding method are as in Example 1, and t-butyl acrylate (Tg 41) is used as a softening agent added to the photo-curing adhesive.
As a result of ultraviolet curing at (.degree. C.) of 30% by weight, the appearance of the bonded portion was good, but it was easy to chip in the finishing process and it took time to process it.

[0030]

Example 4. As a synthetic resin plate for an adherend, two 5.0 mm-thick acrylic display plate materials printed on one side with a room temperature dry type ink were used to protect the periphery of the bond with a tape to prepare a dam for bonding. The softening agent added, ethyl acrylate, should be 40% by weight or less. Outside, a photocurable adhesive was prepared in the same manner as in Example 1, and the surface and the back surface were repeatedly irradiated twice under a high pressure mercury lamp at a speed of 1.0 m / min to polymerize and cure. As a result of finishing after curing, a good large-sized display panel was obtained in which adhesive lines were not noticeable.

[0031]

Comparative Example 3. Prepared in the same manner as in Example 4 for butt-adhesion of synthetic resin plates (5.0 mm thick single-sided printing product) and used a commercially available two-component polymerization adhesive for acrylics Akrabido (above) as an adhesive in the same manner as in Comparative Example 1. As a result of adjusting and bonding, the printed pattern was disturbed along the bonding line, resulting in poor appearance.

[0032]

According to the present invention, the following effects can be obtained by butt-bonding synthetic resin plates by the method described above.

A fine uneven pattern sheet on one or both sides of a synthetic resin plate or a sheet having a printed or painted secondary processed surface does not impair the transparency of the adhesive layer required as a display board, and can be used as an adhesive agent. Since it is not soaked, a product having a conspicuous adhesive line is obtained.

In addition, since the photopolymerization method using high-energy light is used, the adhesive curing can be accelerated and the working process can be remarkably shortened as compared with the conventional butt-bonding method.

[0035]

[Brief description of drawings]

FIG. 1 is a cross-sectional view of a butt bonding method using synthetic resin plates having a lens pattern on one surface.

[Explanation of symbols]

1. Synthetic resin plate 2. Camellia-shaped lens pattern (lens pitch: about 0.1 mm) 3. Adhesive peripheral protection tape 4. Adhesive dam tape 5. Light curable adhesive

   ─────────────────────────────────────────────────── ─── Continued front page    F-term (reference) 4F211 AA21 AB04 AR06 TA03 TC01                       TC13 TD07 TN44 TN53 TN58                       TN63                 4J040 FA041 FA091 FA111 FA141                       FA181 JB08 KA13 LA02                       MA10 MB09 MB15 NA13 NA18                       PA28 PA32

Claims (3)

[Claims] 1. A photocurable polymerizable adhesive is injected into a butt joint of a synthetic resin plate having a design pattern, a lens pattern, or a secondary processed surface such as a printing surface on one or both sides in contact with an end surface to be adhered. ,
An adhesive method that cures by irradiation with ultraviolet rays. 2. The bonding method according to claim 1, wherein the photocurable adhesive has a composition containing 20 to 50% by weight of a polymerizable monomer constituting the synthetic resin plate of the adherend substrate. 3. A photo-curable adhesive containing 3 polymerizable monomers whose glass transition point is 20 ° C. or lower as a single polymerized cured product.
The bonding method according to claim 1, comprising a composition containing 0 to 50% by weight.