JPS63150330A - Production of polyolefin-coated metallic sheet - Google Patents

Abstract

PURPOSE:To facilitate the formation of the title stable metallic sheet by bonding both members with an excellent adhesive strength, by laminating a polyolefin film having a metallic surface through acrylic acid or its mixture with a radiation-curable monomer and irradiating the assemblage with a radiation. CONSTITUTION:A monomer (B) comprising acrylic acid (a) or a mixture of component (a) with at least one monomer (b) selected from among a monomer containing an acryloyl group, a monomer of mol.wt. >=500, having at least two methacryloyl groups, and a monomer having at least three methacryloyl groups is applied to a metallic sheet (A) (e.g., stainless steel sheet or Al sheet) which is optionally pretreated, and a polyolefin film (C) of PE, PP or the like is laminated with this film. This laminate is irradiated with a radiation such as electron beams, gamma-rays or the like from the side of component C to bond components A and C together by graft polymerization of component B.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to a method for producing a polyolefin-coated metal plate using a radiation-curable monomer for adhesion between gold and polyolefin.

(Prior art) Conventionally, when polyolefin-coated metal sheets are continuously manufactured, polyolefins and modified polyolefins obtained by grafting unsaturated carboxylic acids or their anhydrides are mainly melted into polyolefins and lIt preheated to a temperature of vÅ or higher. This is carried out by a heat fusion method in which the metal sheet is extruded and coated on the surface of the metal plate and heat fused, and then further heated to increase the adhesive strength.

(Problem to be solved by the invention, α) However, with this method, the adhesive strength will fluctuate during manufacturing unless the preheating temperature of the metal plate, the grease temperature, the post-coating heating temperature, etc. are strictly controlled. This required advanced technology.

(Means for Solving the Problem) As a result of intensive studies to solve this problem, the inventors of the present invention used a film as the polyolefin and laminated this film on the surface of a metal plate via a radiation-curable monomer. By polymerizing monomers by irradiation with radiation, it became possible to easily produce polyolefin-coated metal plates with constant adhesive strength.

That is, the present invention produces a polyolefin-coated metal plate by laminating a polyolefin film on the surface of a metal plate via acrylic acid or a mixture of acrylic acid and a radiation-curable moamer, and then irradiating the polyolefin film with radiation to bond the polyolefin film to the metal plate. is manufactured.

In the present invention, acrylic acid or a mixture of acrylic acid and a radiation-curable monomer is used to bond a metal plate and a polyolefin film because the carboxyl groups of acrylic acid are oriented toward the top surface of the metal when curing with radiation. This is because the radiation-reactive groups of acrylic acid and radiation-curable moamers frequently graft polymerize to the film, making it difficult to obtain a certain high adhesive strength.

Furthermore, the reason why at least acrylic acid is used as the 7-mer is that among the polar groups, carboxyl groups have the greatest adhesion to the metal plate surface. Even if a monomer having a polar group such as a hydroxyl group, an amide group, or a glycityl group is used instead of acrylic acid, sufficient adhesive strength cannot be obtained.

Further, as the radiation-curable heptamer to be mixed with this acrylic acid, for example, (a) heptamer having a 7-acrylic group;
Those having an acryloyl group as a radiation-reactive group are preferred, such as (b) a monomer having a molecular weight of 500 or more and having two tsutacryloyl groups, and (c) a monomer having three or more tsutacryloyl groups. Since all monomers other than these have low radiation curability, the cohesive force between the monomers is insufficient, the strength of the adhesive layer itself is weak, and the adhesive force is generally weak. In the case of (a), monomers belonging to these (a) to (c) include methyl acrylate, ethyl acrylate, propyl acrylate, butyl acrylate, 2-ethyl hequinyl acrylate, 2-hydroxyethyl acrylate, 2- Hydroxypropyl acrylate, glycinol acrylate, tetrahydrofurfuryl 7 acrylate, acrylamide, etc. are also (b)
In the case of (c), there are polyethylene glycol noacrylate, polyethylene glycol dimethacrylate (n>7), etc., and in the case of (c), there is trimenalol propane trinotacrylate.

Examples of radiation for polymerizing and curing monomers include electron beams and γ
Use a material such as a wire that can pass through the polyolefin film and cause monomers to be graft-polymerized frequently.

According to this bonding method using monomer, 4tJA board can be cooled!
! ! It can be bonded to steel plates such as steel plates, various plated steel plates, and stainless steel plates, as well as non-ferrous metal plates such as aluminum plates and D4 roots. Types of Saranipolyolefin film are limited.

For example, polyethylene, polypropylene, polybutene,
・Even if it is a single substance such as t-methylpentene-1 polymer, ethylene-vinyl acetate copolymer, ethylene-dityl acrylate 4 copolymer, ethylene-propylene copolymer, EPDM, etc., or a blend of two or more of these Even if it's a body, you can get +1. In addition, it contains conventional antioxidants, heat stabilizers, ultraviolet absorbers, and colorants for auxiliary machining.
) Even #: Can be worn.

Note that it is preferable to pre-treat the metal plate before bonding it. Depending on the IIM, mechanical polishing, phosphate treatment, chromate treatment, pickling, alkali treatment, etc. may be performed as appropriate.

(Example) 5IIS304 stainless steel plate with a plate thickness of 0.4no+, hot-dip galvanized steel plate (coating amount 609/m2)
, hot-dip aluminized steel sheet (coating weight 609/
A sandblasted aluminum plate with a thickness of 0.111 mm was degreased under reflux with trichlorethylene for 1 hour, and then coated with 777- or the monomer mixture shown in Table 1 using a #5 bar coater. A low density polyethylene film (film 1'7100 μm) or a high density polyethylene film (film thickness 50 μm) was laminated thereon.

Subsequently, an electron beam is applied to this 82-layer body at an accelerating voltage of 2()OKe.
V, electron current 20III^, Iil amount 5 An electron beam was irradiated from the film side with an irradiation flux 6F of Mrad to polymerize and harden the monomer or monomer mixture and bond it.

Table 1 shows the peel strength depending on the type of metal plate, monomer or monomer inclusion, and film. The peel strength of the metal foil is determined by cutting open one end of a sample with a width of 20 mm and peeling each cut-out metal foil to the opposite side in the horizontal direction at a rate of 50111 m/wi.
The force required to peel off the film was measured by pulling at a speed of n.

Table 1 shows that the adhesives using acrylic acid or a mixture of acrylic acid and a radiation-curable moamer as a monomer (Examples 1 to 8) have a high adhesive strength. On the other hand, examples containing no acrylic acid (Comparative Example 1.2) and monomers that are difficult to cure by radiation (methacrylic acid, methacrylic acid-2-
hydroxyethyl) (Comparative Example 3.4) has extremely weak adhesive strength or does not harden, making it impossible to obtain practical adhesive strength.

(Effects) As described above, since the present invention uses a monomer that cures the metal plate and the polyolefin film by irradiation with radiation, the adhesive strength is always constant during manufacturing, and a stable polyolefin-coated metal plate can be manufactured. be able to.

Claims (2)

[Claims] (1) A polyolefin coating characterized by laminating a polyolefin film on the surface of a metal plate via acrylic acid or a mixture of acrylic acid and a radiation-curable monomer, and then irradiating the polyolefin film with radiation to adhere the polyolefin film to the metal plate. Method of manufacturing metal plates. (2) The radiation-curable monomer is (a) a monomer having an acryloyl group, (b) a monomer having a molecular weight of 500 or more and having two methacryloyl groups, or (c) a monomer having three or more methacryloyl groups. The method for producing a polyolefin-coated metal sheet according to claim 1, wherein the polyolefin-coated metal sheet is a polyolefin-coated metal sheet or a mixture of two or more types.