JPS5938061A - Method of forming surface protective layer - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for forming a surface retention layer on an adherend surface.
This invention provides a method for forming a surface protective layer that semi-permanently prevents damage to the surface of adherends made of plate-shaped articles such as woodblocks, decorative boards, and plastic plates. The surface of adherends, such as articles, can be protected by temporarily attaching a surface protection adhesive film before processing, and then applying paint after processing.
This is commonly done.

These series of steps start with pasting the film on the plate-shaped article, then perform processing such as bending, drawing, and punching, and then peeling off the film, cleaning the surface, painting, and drying. Na.

In addition to being complicated and complicated, cleaning solutions and paints contain a large amount of organic solvents, which poses various safety and hygiene problems.Therefore, the first object of the present invention is to Another object of the present invention is to provide a method for forming a surface protective layer that can easily perform operations ranging from maintaining the flatness of a plate-shaped article before processing to protecting the surface after processing.

A second object of the present invention is to provide a method for forming a surface protective layer by simple operations without using heavy solvents during construction.

The object of the present invention is to provide a photopolymerizable compound having at least one (meth)acryloino group in the molecule, a photosensitizer, and a base polymer on the surface of a self-supporting sheet (or film). A composite sheet (or film) formed with a photocurable adhesive layer containing the adhesive layer is laminated onto the surface of an adherend via the adhesive layer, the adhesive layer is cured by backlight irradiation, and then the self-supporting adhesive layer is cured. Peel off only the sheet (or film) and
According to the method of the present invention, which is achieved by forming a surface protective layer made of a polymerized cured product on the surface of the adherend, damage to the surface of the adherend, such as a plate-shaped article, before and during processing can be prevented. 1. Paste the composite sheet. After processing, it is protected by a surface protection layer formed by polymerizing and curing a photocurable adhesive layer after irradiation with light, so the surface of the adherend will not be damaged. be.

The photopolymerizable compound having at least one (meth)acryloyl group in the molecule used in carrying out the present invention refers to a methacryloyl group, IJ, or acryloyl group as a double bond polymerized in the molecule. For example, 1.4-butylene glycol di(meth)acrylate, 1.6--, xangri:1-di(meth)acrylate, etc. , neobentyl glycol di(meth)°r acrylate, polyethylene glycol di(meth)acrylate, trimethylolpropane tri(meth)acrylate,
Examples include monomers such as tetramethylolmethanetetra(meth)acrylate, and oligomers such as epoxy acrylate, urethane-modified acrylate (-), and oligoester acrylate, and two or more of these may be used in combination as necessary. It's okay.

Base polymers can be divided into those that have adhesive properties themselves and those that exhibit the necessary adhesive properties by incorporating the photopolymerizable compound. Examples of the former include alkyl (meth)acrylic acid alkyl ester polymers having 1 to 12 carbon atoms, (meth)acrylic acid alkyl esters and (meth)acrylic acid, 2-hydroxyethyl (meth)acrylate, dimethylaminoethyl (meth)acrylate , a binary or tertiary copolymer formed by copolymerizing with an unsaturated compound such as vinyl acetate, vinyl acetate, (meth)acrylonitrile (including a polymer formed by crosslinking using a crosslinking agent), or Examples include rubber-based sticky substances based on rubbers such as styrene-isoprene-styrene block copolymer rubber, □styrene-butadiene rubber, and nitrile-butadiene rubber. Examples of the latter include saturated or unsaturated polyesters. Examples include resin, polybutyral resin, and the like.

The blending ratio of the photopolymerizable compound and the base polymer is 8
0:20 to 10:90 preferably 70:3 (J
~30:70 (each ratio by weight) If the content of the above compound exceeds 80%, the cohesiveness of the photocurable adhesive layer before light irradiation will be poor, and the adhesive will ooze out to the sides. If it is less than 10%, sufficient curing cannot be obtained, so it is undesirable. As a photosensitizer,
Examples include benzoins such as Eva, benzoin, benzoin methyl ether, benzoin methyl ether, penzoin isoglobyl ether, and α-methylbenzoin; -Chloroanthraquinone, 2-n.

Anthraquinones such as loanthraquinone, benzophenones such as benzophenone, p-chlorobenzophene/p-dimethylnaminobenzophenone, sulfur-containing compounds such as diphenyl disulfide, tetramethylthiuram disulfide, etc. The amount of the photosensitizer is 0.05 based on the total amount of the compound and polymer.
IAI is added in a range of 20% by weight, preferably 0.5 to 10% by weight.

In this way, the photocurable adhesive composition composed of the photopolymerizable compound, the original image sensitizer, and the base polymer is a colored or colorless transparent self-supporting sheet (or film) that transmits light.
, for example, polyvinyl chloride sheets or films, polyolefin sheets or films (including sheets or films made of ethylene-vinyl acetate copolymers and saponified products thereof), polyester sheets or films (thickness: 10
~300 μm is preferred), thickness of approximately 1 ~
100μ? It is coated or transferred in a range of n to form a photocurable adhesive layer, but appropriate amounts of other compounding agents can be added to the composition depending on the purpose.

Examples of compounding agents include polymerization inhibitors that prevent heat build-up during production and reactions during storage, such as hydroquinone, hydroquinone monomethyl nitrate, t, θrt-butylcatechol, p-benzoquinone, 2.5 -tert-butylhydroquinone, fuzunothiazine, pigments such as zinc white, yellow lead, and red iron for coloring or decoration purposes, toluidine red, phthalodianiline blue,
Dyes such as phthalodianiline green, other metal powders,
Examples include glass beads, glass powder, glass flakes, and adhesion-imparting resins such as xylene resin and coumaron resin for the purpose of improving adhesive strength to the surface of the adherend.

A composite sheet (or film) consisting of a self-supporting notebook (or film) and a photocurable adhesive layer configured in this way can be used in the form of a plate made of a metal plate, glass plate, wood board, decorative board, plastic board, etc. High-pressure mercury lamps, ultra-high-pressure mercury lamps, and generally self-supporting sheets (or films) that are attached to the surface of adherends such as articles through one adhesive layer.

Using a light source such as a metal halide lamp, a carbon arc lamp, or a xenon lamp, the adhesive layer is photopolymerized and cured by irradiating it with light for 0.3 seconds or more at a 1-1 angle of 1° for 3 seconds or more. Then, by peeling off only the support sheet (or film), a surface protective layer made of a polymerized cured product is formed on the surface of the adherend.

Peeling of the support sheet (or film) after curing is difficult because the adhesive strength of the sheet (or film) is largely due to the plastic flow of the adhesive layer at the time of peeling.
This can be easily done from an adhesive layer that has lost its plastic fluidity.

It will be understood that the timing of the light irradiation may be after the composite 7-t is affixed to an adherend such as a plate-shaped article, before or after the adherend is processed.

As described above, according to the method of the present invention, the composite sheet used for surface protection of the adherend surface is irradiated with light and the self-supporting sheet is peeled off, thereby providing a surface that can be semi-permanently protected. It has the feature of being able to form a protective layer. Of course, the method of the present invention can be used simply to form a surface protection layer on the surface of an article, regardless of the processing of the adherend.

Next, examples of the present invention will be shown. The text middle part means the weight part.

Example 1 2-Ethylhexyl acrylate 50 parts Methyl methacrylate 5o Methacrylic acid 21 Pensoyl perkioside o, 2 Ethyl acetate
100 The above blended composition was mixed in a conventional manner to obtain an acrylic copolymer.

Next, to 50 parts (solid content) of the copolymer, 50 parts of tetraethylene glycol dimethacrylate, 7 parts of benzophenone, and 3 moles of tri-1/diisocyanate were added.
1.1- To! 1 mol of J Menarol and 2 parts of the reactant and 1.01 parts of hydroquinone were blended and mixed uniformly,
It was coated on one side of a polyethylene sheet having a thickness of 60 μtI+ so that the thickness after drying would be 5 μm, and dried at 100° C. for 5 minutes to obtain a composite sheet.

Example 2 Vinyl acetate 60 parts Methyl methacrylate 20 Ethyl acrylate 20II Azobisisobutyronitrile 0.05//Ethyl acetate
lo'0 The above blended composition was polymerized by a conventional method to obtain an acrylic copolymer.

Next, 30 parts of tetramethyltetraacrylate, 3 parts of benzoin methyl ether, and 0.01 part of hydroquinone were added to 70 parts (solid content) of the copolymer, and mixed uniformly to form a 60% thick copolymer. It was coated on one side of a polyvinyl chloride sheet of FITll so that the thickness after drying was 5 μm, and dried at 100° C. for 5 minutes to obtain a composite sheet.

Example 3 Styrene-isoprene-styrene pro-yellow copolymer rubber (manufactured by Shell Kagaku Co., Ltd., trade name FRE・F TONO 101F)
60 parts acrylated butadiene oligomer at both ends (manufactured by Idemitsu Petrochemical Co., Ltd., trade name Poly B,
o->4spcR-Lc) 40 〃 Benzophenone 7〃Hydroquinoy O,01// The above blended composition was dissolved in toluene to create a 30% toene solution, and this was applied to the surface of a 60 μm thick polyethylene sheet after drying. It was coated to a thickness of 5 μm and dried at 100°C for 5 minutes to obtain the entire composite sheet. Product name Lipoxy 5P-15
07) 60s benzophenone
7.Hydroquinone
0. (Dissolve the blended composition in toluene to create a 30% toluene solution, and apply this to a thickness of 6
0μm polyvinyl chloride 7-sheet with a dry thickness of 5μm
A composite sheet was obtained by drying at 100°C for 5 minutes. The results are shown below.

Test method in Table 1 The initial adhesion crab composite sheet was cut to a width of 25 mm, pasted with BA finish stainless steel plate SU 304K, left for 30 minutes, and then peeled off at 180 degrees to measure the adhesive strength. Conditions ( Peeling speed 300 fights/min, 20℃ x 65%R,
H) After pasting the self-supporting notebook and peeling crab composite notebook on a BA finish stainless steel 1/stain plate 5US304 + I, irradiate it with ultraviolet rays for about 5 seconds from a distance of 10 cm with a high-pressure mercury lamp (80 W/cm/1 lamp), The peel force of the self-supporting sheet was measured. φ (pulling 1kIJ L speed 300v, W/
min, 20'Cx65%R,H,) Lead unhardened hardness: The hardness of the 15-go cured product (surface-retaining tJM layer) was measured according to TIS K 5400K.

Insert JW and spaced cuts in the shape of base grains into the adhesive crab polymerized cured product (surface protective layer), apply commercially available Hirohan adhesive tape to this, then peel off the tape and check the remaining percentage of base grains. It was displayed in

As is clear from the above examples, it is remarkable that according to the method of the present invention, a good surface protective layer can be easily formed on an adherend.

``Sectioned edition ^1) T person Nitto Kamekikogyo Co., Ltd. Representative Sanbe Hijikata

Claims (1)

[Claims] Forming a photocurable adhesive layer on the surface of a self-supporting sheet (or film) containing a photo-synthesizing compound having at least one (meth)acryloyl group in the molecule, a photosensitizer, and a base polymer. A composite sheet (or film) made of
The adhesive layer is bonded onto the surface of the adherend through the adhesive layer, the adhesive layer is cured by backlight irradiation, and then only the self-supporting sheet (or film) is peeled off, and the cured polymer is applied to the surface of the adherend. 4. A method for forming a surface protective layer, comprising: forming a surface protective layer comprising: