JPS59177168A - Formation of surface protective layer - Google Patents

Abstract

PURPOSE:To easily form a layer capable of protecting the surface of a body to be coated from before to after processing, by processing the body to be coated to which a sheet coated with a photocuring vinyl chloride adhesive composition comprising specified components has been laminated, curing said composition, and then peeling off the sheet. CONSTITUTION:A photocuring adhesive composition comprising a) a photopolymerizable vinyl compound having one or more vinyl groups and one or more aromatic or N-contg. heterocyclic rings in its molecule but not having a (meth) acryloyl group in its molecule, b) a substrate polymer and a photosensitizer is applied onto the surface of a self-supporting sheet (or film). After the composite sheet on which said adhesive layer onto the surface of a body to be coated, e.g. a plate body, said adhesive layer is cured by light irradiation. Then, said self-supporting sheet only is peeled off to form a protective layer comprising a polymerizedly cured product on the surface of the body to be coated. According to this method, the damage of the surface of the body to be coated before and during processing can be inhibited by the application of the composite sheet, and the surface after being processed can be protected by the surface protective layer.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for forming a surface protective layer on the surface of an adherend, and more specifically to a method for forming a surface protective layer on an adherend, and more specifically to plate-shaped articles such as metal plates, glass plates, wooden plates, decorative plates, and plastic plates. The present invention provides a method for forming a surface protective layer that semi-permanently prevents damage to the surface of an adherend made of .

Conventionally, the surface protection of adherends, such as plate-shaped articles, is generally done by temporarily attaching a surface protection adhesive film before processing, and then applying paint after processing. It is true.

These series of steps start with attaching the film to a plate-shaped article 9, and then undergo processing such as bending, drawing, and punching, and then peeling off the film, surface cleaning, painting, and so on.
It consists of a drying process, which is not only complicated, but also
Since cleaning solutions and paints contain large amounts of organic solvents, they pose various safety and hygiene problems.

Therefore, the first object of the present invention is to provide a method for forming a surface protective layer that can be easily performed from surface protection of a plate-shaped article before processing to surface protection after processing.

A second object of the present invention is to provide a method for forming a surface protective layer by a simple operation without using an organic solvent during construction.

That is, this invention provides: a) at least one vinyl group and at least one vinyl group in the molecule;
A photopolymerizable vinyl compound (
1) Base polymer (hereinafter referred to as component a), 1)) Base polymer (hereinafter referred to as component b)
A composite sheet (or film) formed by coating a photocurable adhesive composition on a self-supporting sheet (or film) surface to form a photocurable adhesive layer. ) is laminated onto the surface of the adherend via the light-curing adhesive layer and irradiated with a backlight to harden the light-curing (thermal adhesive layer), and then the self-supporting sheet ( The present invention relates to a method for forming a surface protective layer, which is characterized in that the surface protective layer (or film) alone is peeled off, and a surface protective layer made of a polymerized hardener is formed on the surface of the adherend.

According to the method of the present invention, damage to the surface of an adherend consisting of a plate-like article before and during processing is prevented by pasting it on a composite sheet for 9N, and after processing, it is irradiated with light. Since the surface of the adherend is protected by the surface protective layer formed by polymerizing and curing the photocurable adhesive layer, the surface of the adherend is not damaged.

Component a used in the practice of this invention is a photopolymerizable vinyl 11 compound (hereinafter referred to as , 21 aromatic components),
or a photopolymerizable vinyl compound having at least one a:nyl group and a nitrogen-containing heterocycle in the molecule and no (meth)acryloyl group (hereinafter referred to as heterocyclic component a); be.

Examples of the aromatic component a include styrene, divinylbenzene, α-methylstyrene, paramethylstyrene, parachlorostyrene, and 9-vinylanthracene.

The chopped heterocyclic a component includes vinylpyridine, N-
Monomers such as vinylcarbazole, phenylmaleimide 1, alkylmaleimide, and N-vinylimidazole, oligomers made of these monomers, or low molecular weight copolymers of these monomers and unsaturated f-polymers such as imprene and butadiene. Examples include combination, and two or more of these may be used in combination if necessary.

Component b used in the practice of this invention includes those that have adhesive properties themselves, and those that exhibit the necessary adhesive properties when combined with component a.

Examples of the former include rubbers mainly composed of rubbers such as natural rubber, imprene rubber, styrene-isoprene-styrene block [combined rubber, styrene-butadiene-styrene block 1-1 rubber, styrene-butadiene rubber, butadiene rubber] Examples include adhesive substances.

Examples of the latter include saturated or unsaturated polyester resins, polybutyral resins, and the like.

One or more types of commercially available petroleum-based, terpene-based, and phenol-based tackifiers may be added to component b for the purpose of enhancing tackiness.

The blending ratio of component a and component 1 in mJ is 9 by weight.
The ratio is preferably from 5:5 to 5:95, and if the amount of component a is too large, the cohesiveness of the photocurable adhesive layer before irradiation with light will be poor, and adhesive extrusion to the side surfaces will occur, which is not preferable. On the other hand, if the amount is too small, sufficient curing cannot be obtained after irradiation with light, which is not preferable.

The photosensitizer is not particularly limited as long as it promotes the photopolymerization reaction of the above-mentioned components, but examples include benzoin, benzoin methyl ether, henzine ethyl ether, and benzoin isopropyl ether-1α-methylbenzoinato. 1-taloloanthraquinone, anthraquinones such as 2-10roan-1-laquinone, benzophenone, p-talolobenzophenone,
Examples include benzophenone bodies such as P-dimethylaminobenzophenone, and sulfur-containing polymers such as diphenyl disulfide and tetramethylthiuram disulfide.

1) 1J photosensitizer has a total amount of +1 component and 1) component 10
005 to 20 parts by weight, preferably 08 to 0 parts by weight
It is mixed in a range of 5 to 10 parts by weight.

Appropriate amounts of other compounding agents can be added to the photocurable pressure-sensitive adhesive composition constructed in this way depending on the purpose. Examples of compounding agents include thermal polymerization during manufacturing and reactions during storage. Polymerization inhibitors to prevent such as hydroquinone, hydroquinone monomethyl ether, tert-butylcatechol,
■]-benzoquinone, 2,5-tert-butylhydroquinone, phenothiazine, etc.; pigments such as zinc white, yellow lead, and red iron oxide for the purpose of coloring or decoration;
Dyes such as toluidine red, phthalocyanine blue, and fucrocyanine green, other metal powders, glass beads, glass powder, glass flakes, etc., and tackifying resins such as quinolene resin for the purpose of improving adhesion to adherend surfaces. etc.

In the method of the present invention, the photocurable adhesive composition is a colored or colorless transparent self-supporting sheet (or film) that transmits light, such as a polyvinyl chloride sheet or film, a polyolefin sheet or film (ethylene- (including sheets or films made of vinyl acetate copolymers and their derivatives), polyester sheets or films (thickness is preferably 10 to 300 μI11), etc., coated with a thickness in the range of about 1 to 100 μI11, or It is transferred and used as an arsenic adhesive layer.

The composite sheet (or film) composed of the self-supporting sheet (or film) and the adhesive layer configured in this way can be used for metal plates, glass plates, wood plates, decorative plates, plastic plates, etc. It is attached to the surface of an adherend, such as a plate-shaped article, through an adhesive layer.

[) To polymerize and harden the IJ adhesive layer, use a light source such as a high-pressure mercury lamp, ultra-high-pressure mercury lamp, metal halide lamp, carbon arc lamp, or xenon lamp for 0° or more for 3 seconds or more.
Preferably, the light irradiation is performed for 3 seconds or more. Incidentally, the timing of the light irradiation may be before or after the processing of the deposit (2) depending on the purpose.

After irradiation with light, by peeling off only the self-supporting sheet (or film), a surface protective layer made of a polymerized hard material is formed on the surface of the adherend. The sheet (or film) has lost its plastic fluidity.
can be easily peeled off.

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 creating a surface protective layer that can semi-permanently protect the surface. can be formed. In fact, the method of the present invention can be used simply to form a surface protective layer on the surface of an article, regardless of the processing of the adherend.

Next, examples of this invention will be shown. Parts below mean parts by weight.

Example 1 Raw natural rubber wire zI/(gap approximately 1r)
nm) for about 30 minutes, and the Mouni viscosity ML (1+
4) 40 strands of natural rubber were obtained.

The above-mentioned wire-stripped natural rubber 20 parts Divinylbenzene 30 parts Nuthylene oligomer (degree of polymerization 20) 40 parts Benzophenone 7 parts Hexane 40 parts 2 parts of the reaction product with 1 mole of methylolpropane and 0.0 parts of hydroquinone.
01 parts were blended and mixed uniformly to prepare a photocurable pressure-sensitive adhesive composition.

This composition was applied to a polyethylene sheet with a thickness of 60 μrrl.
Coat it on one side of the film so that the thickness after drying is 5μIn,
The composite sheet was dried by heating at 85° C. for 5 minutes to obtain a composite sheet formed with an arsenic adhesive layer.

This composite sheet is made of BA finished stainless steel plate 5O8304.
After pasting it on the adhesive layer D″lJ, it was affixed with a high-pressure mercury lamp (80W/cm/1 lamp) from a distance of about 5 locm.
The adhesive layer 2 was hardened by irradiation with ultraviolet rays for a minute, and then only the polyethylene sheet was peeled off to form a surface protective layer made of a polymerized hard material on the Mi stainless steel plate.

EXAMPLE 1 An oligomer of para-methylstyrene of approximately 5°C was prepared using benzoyl peroxide as a catalyst.

The above paramethylnutylene oligomer 40 parts Divinylbenzene 30 parts SIS block copolymer rubber 30 parts Benzoin methyl ethyl ether 3 parts Hydroquinone 0.01 part The above compounded composition was uniformly mixed to form a photocurable adhesive composition. did. Note that SIS Glock copolymer rubber refers to styrene-isoprene-Styrek floc copolymer rubber.

This composition was applied to one side of a polyvinyl chloride sheet with a thickness of 60 μm so that the thickness after drying was 5 μm.
A composite sheet was obtained by heating and drying at °C for 5 minutes.

Using this composite sheeter, a surface protective layer was formed in the same manner as in Example 1.

Example 3 Kraton 1107) 60 parts Divinylbenzene 10 parts N-vinylimidazo-/L' 80 parts Benzophenone 7 parts Hydroquinone 0.01 part The above blended composition was dissolved in 7 parts rhene to prepare a 30 part toluene solution. It was made into a sticky adhesive composition.

This composition was coated on one side of a 60 μm thick polysalt “hivinyl” sheet so that the thickness after drying was 5 μnl, and
A composite sheet was obtained by heating and drying at 00°C for 5 minutes.

A surface protective layer was formed using this composite sheet in the same manner as in Example 1.

The results of measuring the pencil hardness and adhesion of the surface protective layers obtained in Examples 1 to 3 above are shown in the following table.

In addition, regarding the adhesion strength, the values when the surface protective layer was formed in the same manner as in Examples 1 to 3 using a copper plate and an acrylic plate as adherends are also shown.

In addition, the adhesive strength of the composite sheet before light irradiation (initial adhesive strength) and the adhesive strength when peeling off the self-supporting sheet after light irradiation (
The results of the self-supporting sheet peeling force are also listed in the table below.

Incidentally, the above measurements were carried out using the following method.

Initial tenacity: The composite sheet was cut into a 25W width, pasted on a BA finished stainless steel plate SUS 304, left for 30 minutes, and then peeled off at 180 degrees to measure the adhesive strength (peel speed 8 Q O#/mjn, 20”CX65
Sorry, ).

Self-supporting sheet peeling force; composite sheet)'fr: 25
Cut into mm width, BA finished stainless steel plate SO8'3
After pasting it on 04 and getting the No.
After irradiating ultraviolet light for about 5 seconds from a distance of 10 cm with 1 lamp),
The 180 degree peel adhesion of the self-supporting sheet was measured (peeling speed 800+a+/min, 20°CX65%
几. ■. ).

Pencil hardness: The hardness of the surface protective layer was measured according to JIS K 5400.

Adhesion: 1 to 00 cuts with 1 μm intervals were made in the shape of a base grid on the surface protective layer, a commercially available cellophane adhesive tape was pasted thereon, and the tape was then peeled off to indicate the residual strength of the base grid.

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

Patent applicant: Hizuka Tunki Industry Co., Ltd.

Claims (1)

[Claims] (1) FL> A photopolymerizable vinyl compound having at least one vinyl group and at least one aromatic ring or nitrogen-containing heterocycle in the molecule and no (meth)acryloyl group in the molecule, b) A composite sheet (or film) is prepared by applying a photocurable adhesive composition containing a base polymer and a photosensitizer to a self-supporting sheet (or film) surface to form a photocurable adhesive layer. The self-supporting sheet (or film) is laminated onto the surface of the adherend via the photocurable adhesive layer, irradiated with backlight to cure the photocurable adhesive layer, and then the self-supporting sheet (or film)
1. A method for forming a surface protective layer, which comprises peeling off only the adherend, and forming a surface protective layer made of a polymeric hard material on the adhered surface.